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Population-level associations between preschool vulnerability and grade-four basic skills.

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Amedeo D'Angiulli

2009-11-01

Full Text Available This is a predictive validity study examining the extent to which developmental vulnerability at kindergarten entry (as measured by the Early Development Instrument, EDI is associated with children's basic skills in 4th grade (as measured by the Foundation Skills Assessment, FSA.Relative risk analysis was performed on a large database linking individual-level EDI ratings to the scores the same children obtained on a provincial assessment of academic skills (FSA--Foundation Skills Assessment four years later. We found that early vulnerability in kindergarten is associated with the basic skills that underlie populations of children's academic achievement in reading, writing and math, indicating that the Early Development Instrument permits to predict achievement-related skills four years in advance.The EDI can be used to predict children's educational trends at the population level and can help select early prevention and intervention programs targeting pre-school populations at minimum cost.
Tumor-Volume Simulation During Radiotherapy for Head-and-Neck Cancer Using a Four-Level Cell Population Model

International Nuclear Information System (INIS)

Chvetsov, Alexei V.; Dong Lei; Palta, Jantinder R.; Amdur, Robert J.

2009-01-01

Purpose: To develop a fast computational radiobiologic model for quantitative analysis of tumor volume during fractionated radiotherapy. The tumor-volume model can be useful for optimizing image-guidance protocols and four-dimensional treatment simulations in proton therapy that is highly sensitive to physiologic changes. Methods: The analysis is performed using two approximations: (1) tumor volume is a linear function of total cell number and (2) tumor-cell population is separated into four subpopulations: oxygenated viable cells, oxygenated lethally damaged cells, hypoxic viable cells, and hypoxic lethally damaged cells. An exponential decay model is used for disintegration and removal of oxygenated lethally damaged cells from the tumor. Results: We tested our model on daily volumetric imaging data available for 14 head-and-neck cancer patients treated with an integrated computed tomography/linear accelerator system. A simulation based on the averaged values of radiobiologic parameters was able to describe eight cases during the entire treatment and four cases partially (50% of treatment time) with a maximum 20% error. The largest discrepancies between the model and clinical data were obtained for small tumors, which may be explained by larger errors in the manual tumor volume delineation procedure. Conclusions: Our results indicate that the change in gross tumor volume for head-and-neck cancer can be adequately described by a relatively simple radiobiologic model. In future research, we propose to study the variation of model parameters by fitting to clinical data for a cohort of patients with head-and-neck cancer and other tumors. The potential impact of other processes, like concurrent chemotherapy, on tumor volume should be evaluated.
Emergence of cytotoxic resistance in cancer cell populations: Single-cell mechanisms and population-level consequences

International Nuclear Information System (INIS)

Lorenzi, Tommaso; Chisholm, Rebecca H.; Lorz, Alexander; Neves de Almeida, Luís; Clairambault, Jean; Larsen, Annette K.; Escargueil, Alexandre

2016-01-01

We formulate an individual-based model and a population model of phenotypic evolution, under cytotoxic drugs, in a cancer cell population structured by the expression levels of survival-potential and proliferation-potential. We apply these models to a recently studied experimental system. Our results suggest that mechanisms based on fundamental laws of biology can reversibly push an actively-proliferating, and drug-sensitive, cell population to transition into a weakly-proliferative and drug-tolerant state, which will eventually facilitate the emergence of more potent, proliferating and drug-tolerant cells.
Emergence of cytotoxic resistance in cancer cell populations: Single-cell mechanisms and population-level consequences

Energy Technology Data Exchange (ETDEWEB)

Lorenzi, Tommaso [Centre de Mathématiques et de Leurs Applications, ENS Cachan, CNRS, Cachan 94230 Cedex, France & INRIA-Paris-Rocquencourt, MAMBA Team, Domaine de Voluceau, BP105, 78153 Le Chesnay Cedex (France); Chisholm, Rebecca H. [School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney NSW 2052 (Australia); Lorz, Alexander; Neves de Almeida, Luís; Clairambault, Jean [Sorbonne Universités, UPMC Univ Paris 06, UMR 7598, Laboratoire Jacques-Louis Lions, F-75005, Paris (France); CNRS, UMR 7598, Laboratoire Jacques-Louis Lions, F-75005, Paris (France); INRIA-Paris-Rocquencourt, MAMBA Team, Domaine de Voluceau, BP105, 78153 Le Chesnay Cedex (France); Larsen, Annette K.; Escargueil, Alexandre [Sorbonne Universités, UPMC Univ Paris 06, F-75005, Paris (France); INSERM, UMR-S 938, Laboratory of “Cancer Biology and Therapeutics”, F-75012, Paris (France)

2016-06-08

We formulate an individual-based model and a population model of phenotypic evolution, under cytotoxic drugs, in a cancer cell population structured by the expression levels of survival-potential and proliferation-potential. We apply these models to a recently studied experimental system. Our results suggest that mechanisms based on fundamental laws of biology can reversibly push an actively-proliferating, and drug-sensitive, cell population to transition into a weakly-proliferative and drug-tolerant state, which will eventually facilitate the emergence of more potent, proliferating and drug-tolerant cells.
Age-dependent transition from cell-level to population-level control in murine intestinal homeostasis revealed by coalescence analysis.

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Zheng Hu

Full Text Available In multi-cellular organisms, tissue homeostasis is maintained by an exquisite balance between stem cell proliferation and differentiation. This equilibrium can be achieved either at the single cell level (a.k.a. cell asymmetry, where stem cells follow strict asymmetric divisions, or the population level (a.k.a. population asymmetry, where gains and losses in individual stem cell lineages are randomly distributed, but the net effect is homeostasis. In the mature mouse intestinal crypt, previous evidence has revealed a pattern of population asymmetry through predominantly symmetric divisions of stem cells. In this work, using population genetic theory together with previously published crypt single-cell data obtained at different mouse life stages, we reveal a strikingly dynamic pattern of stem cell homeostatic control. We find that single-cell asymmetric divisions are gradually replaced by stochastic population-level asymmetry as the mouse matures to adulthood. This lifelong process has important developmental and evolutionary implications in understanding how adult tissues maintain their homeostasis integrating the trade-off between intrinsic and extrinsic regulations.
Nonlinear Absorption-Gain Response and Population Dynamics in a Laser-Driven Four-Level Dense Atomic System

International Nuclear Information System (INIS)

Li Jiahua; Liu Jibing; Luo Jinming; Xie Xiaotao

2006-01-01

We theoretically investigate the response of nonlinear absorption and population dynamics in optically dense media of four-level atoms driven by a single-mode probe laser, via taking the density-dependent near dipole-dipole (NDD) interactions into consideration. The influence of the NDD effects on the absorption of the probe field and population dynamics is predicted via numerical calculations. It is shown that the NDD effects can reduce gradually to transient absorption with the increase of the strengths of the NDD interactions, and transient amplification can be achieved. In the steady-state limit, the probe field exhibits transparency for strong NDD interactions. Alternatively, the population entirely remains at the ground state due to the NDD effects.
Observation of coherent population transfer in a four-level tripod system with a rare-earth-metal-ion-doped crystal

International Nuclear Information System (INIS)

Goto, Hayato; Ichimura, Kouichi

2007-01-01

Coherent population transfer in a laser-driven four-level system in a tripod configuration is experimentally investigated with a rare-earth-metal-ion-doped crystal (Pr 3+ :Y 2 SiO 5 ). The population transfers observed here indicate that a main process inducing them is not optical pumping, which is an incoherent process inducing population transfer. Moreover, numerical simulation, which well reproduces the experimental results, also shows that the process inducing the observed population transfers is similar to stimulated Raman adiabatic passage (STIRAP) in the sense that this process possesses characteristic features of STIRAP
Nonadiabatic population transfer in a driven four-level system

International Nuclear Information System (INIS)

Prants, S.V.

1994-01-01

The coherent dynamics of a four-level quantum system with an arbitrary level configuration is described analytically in the modulated polychromatic laser field. The method of dynamical symmetries is invoked to develop the formalism for explicit calculation of the evolution matrix of the system in the resonance fields. The method is free of the usual adiabatic-passage, weak-field approximations, and approximation of the slowly varying amplitudes. The conditions for occurrence of the coherent effects of the total inversion and the total depletion of the initial level of a system driven simultaneously driven simultaneously at several transitions by the laser pulses of arbitrary shape are derived analytically. The obtained results can be applied to problems of the control of quantum processes in multilevel atoms and molecules. 14 refs
Levels and predictors of persistent organic pollutants in an adult population from four Spanish regions

International Nuclear Information System (INIS)

Fernández-Rodríguez, M.; Arrebola, J.P.; Artacho-Cordón, F.; Amaya, E.; Aragones, N.; Llorca, J.; Perez-Gomez, B.

2015-01-01

This research aimed to assess serum concentrations of a group of persistent organic pollutants (POPs) in a sample of adults recruited in four different regions from Spain and to assess socio-demographic, dietary, and lifestyle predictors of the exposure. The study population comprised 312 healthy adults selected from among controls recruited in the MCC-Spain multicase-control study. Study variables were collected using standardized questionnaires, and pollutants were analyzed by means of gas chromatography with electron capture detection. Multivariable analyses were performed to identify predictors of log-transformed pollutant concentrations, using combined backward and forward stepwise multiple linear regression models. Detection rates ranged from 89.1% (hexachlorobenzene, HCB) to 93.6% (Polychlorinated biphenyl-153 [PCB-153]); p,p′-dichlorodiphenyldichloroethylene (p,p′-DDE) showed the highest median concentrations (1.04 ng/ml), while HCB showed the lowest (0.24 ng/ml). In the multivariable models, age was positively associated with HCB, p,p′-DDE, and PCB-180. BMI was associated positively with p,p′-DDE but negatively with PCB-138. Total accumulated time residing in an urban area was positively associated with PCB-153 concentrations. The women showed higher HCB and lower p,p′-DDE concentrations versus the men. Notably, POP exposure in our study population was inversely associated with the breastfeeding received by participants and with the number of pregnancies of their mothers but was not related to the participants' history of breastfeeding their children or parity. Smoking was negatively associated with HCB and PCB-153 concentrations. Consumption of fatty foods, including blue fish, was in general positively associated with POP levels. Although POP environmental levels are declining worldwide, there is a need for the continuous monitoring of human exposure in the general population. The results of the present study confirm previous findings and point
Levels and predictors of persistent organic pollutants in an adult population from four Spanish regions

Energy Technology Data Exchange (ETDEWEB)

Fernández-Rodríguez, M., E-mail: mafero@ugr.es [Instituto de Investigación Biosanitaria ibs.Granada, University of Granada, San Cecilio University Hospital, Granada (Spain); Arrebola, J.P., E-mail: jparrebola@ugr.es [Instituto de Investigación Biosanitaria ibs.Granada, University of Granada, San Cecilio University Hospital, Granada (Spain); Oncology Unit, Virgen de las Nieves University Hospital, Granada (Spain); Consortium for Biomedical Research in Epidemiology & Public Health (CIBERESP), Instituto de Salud Carlos III, Madrid (Spain); Artacho-Cordón, F.; Amaya, E. [Instituto de Investigación Biosanitaria ibs.Granada, University of Granada, San Cecilio University Hospital, Granada (Spain); Aragones, N. [Consortium for Biomedical Research in Epidemiology & Public Health (CIBERESP), Instituto de Salud Carlos III, Madrid (Spain); Cancer Epidemiology Unit, National Center for Epidemiology, Instituto de Salud Carlos III, Madrid (Spain); Cancer Epidemiology Research Group, Oncology and Hematology Area, IIS Puerta de Hierro (IDIPHIM), Majadahonda, Madrid (Spain); Llorca, J. [Consortium for Biomedical Research in Epidemiology & Public Health (CIBERESP), Instituto de Salud Carlos III, Madrid (Spain); Universidad de Cantabria-IDIVAL, Santander (Spain); Perez-Gomez, B. [Consortium for Biomedical Research in Epidemiology & Public Health (CIBERESP), Instituto de Salud Carlos III, Madrid (Spain); Cancer Epidemiology Unit, National Center for Epidemiology, Instituto de Salud Carlos III, Madrid (Spain); Cancer Epidemiology Research Group, Oncology and Hematology Area, IIS Puerta de Hierro (IDIPHIM), Majadahonda, Madrid (Spain); and others

2015-12-15

This research aimed to assess serum concentrations of a group of persistent organic pollutants (POPs) in a sample of adults recruited in four different regions from Spain and to assess socio-demographic, dietary, and lifestyle predictors of the exposure. The study population comprised 312 healthy adults selected from among controls recruited in the MCC-Spain multicase-control study. Study variables were collected using standardized questionnaires, and pollutants were analyzed by means of gas chromatography with electron capture detection. Multivariable analyses were performed to identify predictors of log-transformed pollutant concentrations, using combined backward and forward stepwise multiple linear regression models. Detection rates ranged from 89.1% (hexachlorobenzene, HCB) to 93.6% (Polychlorinated biphenyl-153 [PCB-153]); p,p′-dichlorodiphenyldichloroethylene (p,p′-DDE) showed the highest median concentrations (1.04 ng/ml), while HCB showed the lowest (0.24 ng/ml). In the multivariable models, age was positively associated with HCB, p,p′-DDE, and PCB-180. BMI was associated positively with p,p′-DDE but negatively with PCB-138. Total accumulated time residing in an urban area was positively associated with PCB-153 concentrations. The women showed higher HCB and lower p,p′-DDE concentrations versus the men. Notably, POP exposure in our study population was inversely associated with the breastfeeding received by participants and with the number of pregnancies of their mothers but was not related to the participants' history of breastfeeding their children or parity. Smoking was negatively associated with HCB and PCB-153 concentrations. Consumption of fatty foods, including blue fish, was in general positively associated with POP levels. Although POP environmental levels are declining worldwide, there is a need for the continuous monitoring of human exposure in the general population. The results of the present study confirm previous findings and
Human skin is protected by four functionally and phenotypically discrete populations of resident and recirculating memory T cells

Science.gov (United States)

Watanabe, Rei; Gehad, Ahmed; Yang, Chao; Campbell, Laura; Teague, Jessica E.; Schlapbach, Christoph; Elco, Christopher; Huang, Victor; Matos, Tiago R.; Kupper, Thomas S.; Clark, Rachael A.

2015-01-01

The skin of an adult human contains approximately 20 billion memory T cells. Epithelial barrier tissues are infiltrated by a combination of resident and recirculating T cells in mice but the relative proportions and functional activities of resident versus recirculating T cells have not been evaluated in human skin. We discriminated resident from recirculating T cells in human engrafted mice and lymphoma patients using alemtuzumab, a medication that depletes recirculating T cells from skin, and then analyzed these T cell populations in healthy human skin. All non-recirculating resident memory T cells (TRM) expressed CD69, but the majority were CD4+, CD103− and located in the dermis, in contrast to studies in mice. Both CD4+ and CD8+ CD103+ TRM were enriched in the epidermis, had potent effector functions and had a limited proliferative capacity compared to CD103− TRM. TRM of both types had more potent effector functions than recirculating T cells. Induction of CD103 on human T cells was enhanced by keratinocyte contact, depended on TGFβ and was independent of T cell keratinocyte adhesive interactions. We observed two distinct populations of recirculating T cells, CCR7+/L-selectin+ central memory T cells (TCM) and CCR7+/L-selectin− T cells, which we term migratory memory T cells (TMM). Circulating skin-tropic TMM were intermediate in cytokine production between TCM and effector memory T cells. In patients with cutaneous T cell lymphoma, malignant TCM and TMM induced distinct inflammatory skin lesions and TMM were depleted more slowly from skin after alemtuzumab, suggesting TMM may recirculate more slowly. In summary, human skin is protected by four functionally distinct populations of T cells, two resident and two recirculating, with differing territories of migration and distinct functional activities. PMID:25787765
Response of single bacterial cells to stress gives rise to complex history dependence at the population level

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Mathis, Roland; Ackermann, Martin

2016-01-01

Most bacteria live in ever-changing environments where periods of stress are common. One fundamental question is whether individual bacterial cells have an increased tolerance to stress if they recently have been exposed to lower levels of the same stressor. To address this question, we worked with the bacterium Caulobacter crescentus and asked whether exposure to a moderate concentration of sodium chloride would affect survival during later exposure to a higher concentration. We found that the effects measured at the population level depended in a surprising and complex way on the time interval between the two exposure events: The effect of the first exposure on survival of the second exposure was positive for some time intervals but negative for others. We hypothesized that the complex pattern of history dependence at the population level was a consequence of the responses of individual cells to sodium chloride that we observed: (i) exposure to moderate concentrations of sodium chloride caused delays in cell division and led to cell-cycle synchronization, and (ii) whether a bacterium would survive subsequent exposure to higher concentrations was dependent on the cell-cycle state. Using computational modeling, we demonstrated that indeed the combination of these two effects could explain the complex patterns of history dependence observed at the population level. Our insight into how the behavior of single cells scales up to processes at the population level provides a perspective on how organisms operate in dynamic environments with fluctuating stress exposure. PMID:26960998
Coherent population transfer and superposition of atomic states via stimulated Raman adiabatic passage using an excited-doublet four-level atom

International Nuclear Information System (INIS)

Jin Shiqi; Gong Shangqing; Li Ruxin; Xu Zhizhan

2004-01-01

Coherent population transfer and superposition of atomic states via a technique of stimulated Raman adiabatic passage in an excited-doublet four-level atomic system have been analyzed. It is shown that the behavior of adiabatic passage in this system depends crucially on the detunings between the laser frequencies and the corresponding atomic transition frequencies. Particularly, if both the fields are tuned to the center of the two upper levels, the four-level system has two degenerate dark states, although one of them contains the contribution from the excited atomic states. The nonadiabatic coupling of the two degenerate dark states is intrinsic, it originates from the energy difference of the two upper levels. An arbitrary superposition of atomic states can be prepared due to such nonadiabatic coupling effect
TWO-DIMENSIONAL LOCALIZATION OF ATOMIC POPULATIONS IN FOUR-LEVEL QUANTUM SYSTEMS

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E. A. Efremova

2014-07-01

Full Text Available The paper deals with investigation of one aspect of fundamental problem of laser radiation interaction with the matter. This problem is spatial localization of atomic populations due to fields impact of few running waves. We are the first to propose in our work two–dimensional spatial localization of atomic populations in medium with tripod–like configuration of levels under the field influence of running waves only. Three running waves, propagating along one plane 120o angle-wise to each other, form the system of standing waves in this plane. Atomic populations can be localized in the field of these standing waves. Moreover, the degree of such localization can make up hundredth parts of the wavelength of the incident optical radiation. It is shown that an excitation of the central transition of the tripod-like system using a field of multidirectional linearly polarized running waves is the necessary condition of the population dependence from spatial coordinates in the XY – plane. The two–dimensional shapes that appear in this system can have very complicated structure such as “double – craters”.
Plasmodium vivax Diversity and Population Structure across Four Continents.

Science.gov (United States)

Koepfli, Cristian; Rodrigues, Priscila T; Antao, Tiago; Orjuela-Sánchez, Pamela; Van den Eede, Peter; Gamboa, Dionicia; van Hong, Nguyen; Bendezu, Jorge; Erhart, Annette; Barnadas, Céline; Ratsimbasoa, Arsène; Menard, Didier; Severini, Carlo; Menegon, Michela; Nour, Bakri Y M; Karunaweera, Nadira; Mueller, Ivo; Ferreira, Marcelo U; Felger, Ingrid

2015-01-01

Plasmodium vivax is the geographically most widespread human malaria parasite. To analyze patterns of microsatellite diversity and population structure across countries of different transmission intensity, genotyping data from 11 microsatellite markers was either generated or compiled from 841 isolates from four continents collected in 1999-2008. Diversity was highest in South-East Asia (mean allelic richness 10.0-12.8), intermediate in the South Pacific (8.1-9.9) Madagascar and Sudan (7.9-8.4), and lowest in South America and Central Asia (5.5-7.2). A reduced panel of only 3 markers was sufficient to identify approx. 90% of all haplotypes in South Pacific, African and SE-Asian populations, but only 60-80% in Latin American populations, suggesting that typing of 2-6 markers, depending on the level of endemicity, is sufficient for epidemiological studies. Clustering analysis showed distinct clusters in Peru and Brazil, but little sub-structuring was observed within Africa, SE-Asia or the South Pacific. Isolates from Uzbekistan were exceptional, as a near-clonal parasite population was observed that was clearly separated from all other populations (FST>0.2). Outside Central Asia FST values were highest (0.11-0.16) between South American and all other populations, and lowest (0.04-0.07) between populations from South-East Asia and the South Pacific. These comparisons between P. vivax populations from four continents indicated that not only transmission intensity, but also geographical isolation affect diversity and population structure. However, the high effective population size results in slow changes of these parameters. This persistency must be taken into account when assessing the impact of control programs on the genetic structure of parasite populations.
Heteroresistance at the single-cell level: adapting to antibiotic stress through a population-based strategy and growth-controlled interphenotypic coordination.

Science.gov (United States)

Wang, Xiaorong; Kang, Yu; Luo, Chunxiong; Zhao, Tong; Liu, Lin; Jiang, Xiangdan; Fu, Rongrong; An, Shuchang; Chen, Jichao; Jiang, Ning; Ren, Lufeng; Wang, Qi; Baillie, J Kenneth; Gao, Zhancheng; Yu, Jun

2014-02-11

Heteroresistance refers to phenotypic heterogeneity of microbial clonal populations under antibiotic stress, and it has been thought to be an allocation of a subset of "resistant" cells for surviving in higher concentrations of antibiotic. The assumption fits the so-called bet-hedging strategy, where a bacterial population "hedges" its "bet" on different phenotypes to be selected by unpredicted environment stresses. To test this hypothesis, we constructed a heteroresistance model by introducing a blaCTX-M-14 gene (coding for a cephalosporin hydrolase) into a sensitive Escherichia coli strain. We confirmed heteroresistance in this clone and that a subset of the cells expressed more hydrolase and formed more colonies in the presence of ceftriaxone (exhibited stronger "resistance"). However, subsequent single-cell-level investigation by using a microfluidic device showed that a subset of cells with a distinguishable phenotype of slowed growth and intensified hydrolase expression emerged, and they were not positively selected but increased their proportion in the population with ascending antibiotic concentrations. Therefore, heteroresistance--the gradually decreased colony-forming capability in the presence of antibiotic--was a result of a decreased growth rate rather than of selection for resistant cells. Using a mock strain without the resistance gene, we further demonstrated the existence of two nested growth-centric feedback loops that control the expression of the hydrolase and maximize population growth in various antibiotic concentrations. In conclusion, phenotypic heterogeneity is a population-based strategy beneficial for bacterial survival and propagation through task allocation and interphenotypic collaboration, and the growth rate provides a critical control for the expression of stress-related genes and an essential mechanism in responding to environmental stresses. Heteroresistance is essentially phenotypic heterogeneity, where a population
Sorting of cells of the same size, shape, and cell cycle stage for a single cell level assay without staining

Directory of Open Access Journals (Sweden)

Yomo Tetsuya

2006-06-01

Full Text Available Abstract Background Single-cell level studies are being used increasingly to measure cell properties not directly observable in a cell population. High-performance data acquisition systems for such studies have, by necessity, developed in synchrony. However, improvements in sample purification techniques are also required to reveal new phenomena. Here we assessed a cell sorter as a sample-pretreatment tool for a single-cell level assay. A cell sorter is routinely used for selecting one type of cells from a heterogeneous mixture of cells using specific fluorescence labels. In this case, we wanted to select cells of exactly the same size, shape, and cell-cycle stage from a population, without using a specific fluorescence label. Results We used four light scatter parameters: the peak height and area of the forward scatter (FSheight and FSarea and side scatter (SSheight and SSarea. The rat pheochromocytoma PC12 cell line, a neuronal cell line, was used for all experiments. The living cells concentrated in the high FSarea and middle SSheight/SSarea fractions. Single cells without cell clumps were concentrated in the low SS and middle FS fractions, and in the higher FSheight/FSarea and SSheight/SSarea fractions. The cell populations from these viable, single-cell-rich fractions were divided into twelve subfractions based on their FSarea-SSarea profiles, for more detailed analysis. We found that SSarea was proportional to the cell volume and the FSarea correlated with cell roundness and elongation, as well as with the level of DNA in the cell. To test the method and to characterize the basic properties of the isolated single cells, sorted cells were cultured in separate wells. The cells in all subfractions survived, proliferated and differentiated normally, suggesting that there was no serious damage. The smallest, roundest, and smoothest cells had the highest viability. There was no correlation between proliferation and differentiation. NGF increases
Population-level assessments should be emphasized over community/ecosystem-level assessments. Environmental Sciences Division Publication No. 1535

International Nuclear Information System (INIS)

Van Winkle, W.

1980-01-01

Arguments are presented in favor of emphasizing population-level assessments over community/ecosystem-level assessments. The two approaches are compared on each of four issues: (1) the nature of entrainment/impingement impacts; (2) the ability to forecast reliably for a single fish population as contrasted to the ability to forecast for an aquatic community or ecosystem; (3) practical considerations involving money, manpower, time, and the need to make decisions; and (4) the nature of societal and economic concerns. The conclusion on each of these four issues is that population-level assessments provide the optimal approach for evaluating the effects of entrainment and impingement mortality
Identification of the Rare, Four Repeat Allele of IL-4 Intron-3 VNTR Polymorphism in Indian Populations.

Science.gov (United States)

Verma, Henu Kumar; Jha, Aditya Nath; Khodiar, Prafulla Kumar; Patra, Pradeep Kumar; Bhaskar, Lakkakula Venkata Kameswara Subrahmanya

2016-06-01

Cytokines are cell signaling molecules which upon release by cells facilitate the recruitment of immune-modulatory cells towards the sites of inflammation. Genetic variations in cytokine genes are shown to regulate their production and affect the risk of infectious as well as autoimmune diseases. Intron-3 of interleukin-4 gene (IL-4) harbors 70-bp variable number of tandem repeats (VNTR) that may alter the expression level of IL-4 gene. To determine the distribution of IL-4 70-bp VNTR polymorphism in seven genetically heterogeneous populations of Chhattisgarh, India and their comparison with the finding of other Indian and world populations. A total of 371 healthy unrelated individuals from 5 caste and 2 tribal populations were included in the present study. The IL-4 70-bp VNTR genotyping was carried out using PCR and electrophoresis. Overall, 3 alleles of IL-4 70-bp VNTR (a2, a3 and a4) were detected. The results demonstrated the variability of the IL-4 70-bp VNTR polymorphism in Chhattisgarh populations. Allele a3 was the most common allele at the 70-bp VNTR locus in all populations followed by a2 allele. This study reports the presence four repeat allele a4 at a low frequency in the majority of the Chhattisgarh populations studied. Further, the frequency of the minor allele (a2) in Chhattisgarh populations showed similarity with the frequencies of European populations but not with the East Asian populations where the a2 allele is a major allele. Our study provides a baseline for future research into the role of the IL-4 locus in diseases linked to inflammation in Indian populations.
Use of Multicolor Flow Cytometry for Isolation of Specific Cell Populations Deriving from Differentiated Human Embryonic Stem Cells

NARCIS (Netherlands)

Mengarelli, Isabella; Fryga, Andrew; Barberi, Tiziano

2016-01-01

Flow Cytometry-Sorting (FCM-Sorting) is a technique commonly used to identify and isolate specific types of cells from a heterogeneous population of live cells. Here we describe a multicolor flow cytometry technique that uses five distinct cell surface antigens to isolate four live populations with

Response of Listeria monocytogenes to disinfection stress at the single-cell and population levels as monitored by intracellular pH measurements and viable-cell counts

DEFF Research Database (Denmark)

Kastbjerg, Vicky Gaedt; Nielsen, Dennis S.; Arneborg, Nils

2009-01-01

of the bacterium. In situ analyses of Listeria monocytogenes single cells were performed during exposure to different concentrations of the disinfectant Incimaxx DES to study a possible population subdivision. Bacterial survival was quantified with plate counting and disinfection stress at the single-cell level...... by measuring intracellular pH (pHi) over time by fluorescence ratio imaging microscopy. pHi values were initially 7 to 7.5 and decreased in both attached and planktonic L. monocytogenes cells during exposure to sublethal and lethal concentrations of Incimaxx DES. The response of the bacterial population...... was homogenous; hence, subpopulations were not detected. However, pregrowth with NaCl protected the planktonic bacterial cells during disinfection with Incimaxx (0.0015%) since pHi was higher (6 to 6.5) for the bacterial population pregrown with NaCl than for cells grown without NaCl (pHi 5 to 5.5) (P
Four-cell solar tracker

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Berdahl, C. M.

1981-01-01

Forty cm Sun tracker, consisting of optical telescope and four solar cells, stays pointed at Sun throughout day for maximum energy collection. Each solar cell generates voltage proportional to part of solar image it receives; voltages drive servomotors that keep image centered. Mirrored portion of cylinder extends acquisition angle of device by reflecting Sun image back onto solar cells.
Phenotype heterogeneity in cancer cell populations

International Nuclear Information System (INIS)

Almeida, Luis; Chisholm, Rebecca; Clairambault, Jean; Escargueil, Alexandre; Lorenzi, Tommaso; Lorz, Alexander; Trélat, Emmanuel

2016-01-01

Phenotype heterogeneity in cancer cell populations, be it of genetic, epigenetic or stochastic origin, has been identified as a main source of resistance to drug treatments and a major source of therapeutic failures in cancers. The molecular mechanisms of drug resistance are partly understood at the single cell level (e.g., overexpression of ABC transporters or of detoxication enzymes), but poorly predictable in tumours, where they are hypothesised to rely on heterogeneity at the cell population scale, which is thus the right level to describe cancer growth and optimise its control by therapeutic strategies in the clinic. We review a few results from the biological literature on the subject, and from mathematical models that have been published to predict and control evolution towards drug resistance in cancer cell populations. We propose, based on the latter, optimisation strategies of combined treatments to limit emergence of drug resistance to cytotoxic drugs in cancer cell populations, in the monoclonal situation, which limited as it is still retains consistent features of cell population heterogeneity. The polyclonal situation, that may be understood as “bet hedging” of the tumour, thus protecting itself from different sources of drug insults, may lie beyond such strategies and will need further developments. In the monoclonal situation, we have designed an optimised therapeutic strategy relying on a scheduled combination of cytotoxic and cytostatic treatments that can be adapted to different situations of cancer treatments. Finally, we review arguments for biological theoretical frameworks proposed at different time and development scales, the so-called atavistic model (diachronic view relying on Darwinian genotype selection in the coursof billions of years) and the Waddington-like epigenetic landscape endowed with evolutionary quasi-potential (synchronic view relying on Lamarckian phenotype instruction of a given genome by reversible mechanisms), to
Phenotype heterogeneity in cancer cell populations

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Almeida, Luis [CNRS UMR 7598, LJLL, & INRIA MAMBA team, Sorbonne Universités, UPMC Univ Paris 06, Boîte courrier 187, 4 Pl. Jussieu, 75252 Paris cedex 05, France, luis@ann.jussieu.fr (France); Chisholm, Rebecca [School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia, rebecca.chisholm@gmail.com (Australia); Clairambault, Jean [INRIA MAMBA team & LJLL, UMR 7598, Sorbonne Universités, UPMC Univ Paris 06, Boîte courrier 187, 4 Pl. Jussieu, 75252 Paris cedex 05, France, jean.clairambault@inria.fr, Corresponding author (France); Escargueil, Alexandre [INSERM “Cancer Biology and Therapeutics”, Sorbonne Universités, UPMC Univ Paris 06, UMR-S 938, CDR St Antoine, Hôpital St Antoine, 184 Fbg. St Antoine, 75571 Paris cedex 12, France, alexandre.escargueil@upmc.fr (France); Lorenzi, Tommaso [CMLA, ENS Cachan, 61, Av. du Président Wilson, 94230 Cachan cedex & INRIA MAMBA team, & LJLL, UMR 7598, UPMC Univ Paris 06, Boîte courrier 187, 4 Pl. Jussieu, 75252 Paris cedex 05, France, tommaso.lorenzi@gmail.com (France); Lorz, Alexander [Sorbonne Universités, UPMC Univ Paris 06, LJLL, UMR 7598 & INRIA Boîte courrier 187, 4 Pl. Jussieu, 75252 Paris cedex 05, France, alex.lorz@ann.jussieu.fr (France); Trélat, Emmanuel [Institut Universitaire de France, Sorbonne Universités, UPMC Univ Paris 06, LJLL, UMR 7598, Boîte courrier 187, UPMC Univ Paris 06, 4 Pl. Jussieu, 75252 Paris cedex 05, France, emmanuel.trelat@upmc.fr (France)

2016-06-08

Phenotype heterogeneity in cancer cell populations, be it of genetic, epigenetic or stochastic origin, has been identified as a main source of resistance to drug treatments and a major source of therapeutic failures in cancers. The molecular mechanisms of drug resistance are partly understood at the single cell level (e.g., overexpression of ABC transporters or of detoxication enzymes), but poorly predictable in tumours, where they are hypothesised to rely on heterogeneity at the cell population scale, which is thus the right level to describe cancer growth and optimise its control by therapeutic strategies in the clinic. We review a few results from the biological literature on the subject, and from mathematical models that have been published to predict and control evolution towards drug resistance in cancer cell populations. We propose, based on the latter, optimisation strategies of combined treatments to limit emergence of drug resistance to cytotoxic drugs in cancer cell populations, in the monoclonal situation, which limited as it is still retains consistent features of cell population heterogeneity. The polyclonal situation, that may be understood as “bet hedging” of the tumour, thus protecting itself from different sources of drug insults, may lie beyond such strategies and will need further developments. In the monoclonal situation, we have designed an optimised therapeutic strategy relying on a scheduled combination of cytotoxic and cytostatic treatments that can be adapted to different situations of cancer treatments. Finally, we review arguments for biological theoretical frameworks proposed at different time and development scales, the so-called atavistic model (diachronic view relying on Darwinian genotype selection in the coursof billions of years) and the Waddington-like epigenetic landscape endowed with evolutionary quasi-potential (synchronic view relying on Lamarckian phenotype instruction of a given genome by reversible mechanisms), to
Phenotype heterogeneity in cancer cell populations

Science.gov (United States)

Almeida, Luis; Chisholm, Rebecca; Clairambault, Jean; Escargueil, Alexandre; Lorenzi, Tommaso; Lorz, Alexander; Trélat, Emmanuel

2016-06-01

Phenotype heterogeneity in cancer cell populations, be it of genetic, epigenetic or stochastic origin, has been identified as a main source of resistance to drug treatments and a major source of therapeutic failures in cancers. The molecular mechanisms of drug resistance are partly understood at the single cell level (e.g., overexpression of ABC transporters or of detoxication enzymes), but poorly predictable in tumours, where they are hypothesised to rely on heterogeneity at the cell population scale, which is thus the right level to describe cancer growth and optimise its control by therapeutic strategies in the clinic. We review a few results from the biological literature on the subject, and from mathematical models that have been published to predict and control evolution towards drug resistance in cancer cell populations. We propose, based on the latter, optimisation strategies of combined treatments to limit emergence of drug resistance to cytotoxic drugs in cancer cell populations, in the monoclonal situation, which limited as it is still retains consistent features of cell population heterogeneity. The polyclonal situation, that may be understood as "bet hedging" of the tumour, thus protecting itself from different sources of drug insults, may lie beyond such strategies and will need further developments. In the monoclonal situation, we have designed an optimised therapeutic strategy relying on a scheduled combination of cytotoxic and cytostatic treatments that can be adapted to different situations of cancer treatments. Finally, we review arguments for biological theoretical frameworks proposed at different time and development scales, the so-called atavistic model (diachronic view relying on Darwinian genotype selection in the coursof billions of years) and the Waddington-like epigenetic landscape endowed with evolutionary quasi-potential (synchronic view relying on Lamarckian phenotype instruction of a given genome by reversible mechanisms), to
Recovery of the Erythropoietin-Sensitive Stem-Cell Population following Total-Body X-Irradiation

Energy Technology Data Exchange (ETDEWEB)

Byron, J. W. [Paterson Laboratories, Christie Hospital and Holt Radium Institute, Manchester (United Kingdom)

1968-08-15

Erythropoietin acts upon haemopoietic stem cells to initiate their differentiation into the erythroid series. This effect may be used in polycythaemic mice to estimate changes in the erythropoietin-sensitive stem-cell population following total-body irradiation (TBR). Generally, single doses of erythropoietin, less than that needed for maximum stem-cell response, are used to estimate changes in the stem-cell population. The validity of results using this test is based upon accepting several assumptions regarding erythropoietin kinetics. These are: (a) the contribution of endogenous erythropoietin is always negligible; (b) the origin of the dose-response curve to erythropoietin alters only because of changes in stem-cell numbers; (c) the proportion of stem cells responding to a given concentration of erythropoietin is independent of stem-cell numbers; (d) the slope of the dose-response curve does not alter; and (e) competition between erythropoietin and other factors for the stem cells remains unchanged. The studies to be reported indicate that some of these assumptions m a y not always be valid. Following 150 rad TBR, changes in erythropoietin dose-response curves were not always due to changes in the size of the stem-cell population, but also due to changes in erythropoietin kinetics. Changes in erythropoietin kinetics could be corrected for by using doses of erythropoietin which at any particular time after TBR gave maximum stem-cell response; through full dose-response studies, the nature of changes in erythropoietin kinetics following TBR could be established. These studies appear to explain discrepancies in results obtained in different laboratories using the erythropoietin test. The effect of 150 rad TBR on the erythropoietin-sensitive stem-cell population is an initial depression within 30 min to 20% of normal followed by a second depression (post-irradiation dip) at about 12 h. Twenty-four hours after TBR there is a recovery to the initial depression. This
Trichromatic π-Pulse for Ultrafast Total Inversion of a Four-Level Ladder System

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Carles Serrat

2015-11-01

Full Text Available We present a numerical solution for complete population inversion in a four-level ladder system obtained by using a full π-pulse illumination scheme with resonant ultrashort phase-locked Gaussian laser pulses. We find that a set of pulse areas such as √3π , √2π , and √3π completely inverts the four-level system considering identical effective dipole coupling coefficients. The solution is consistent provided the involved electric fields are not too strong and it is amply accurate also in the case of diverse transition dipole moments. We study the effect of detuning and chirp of the laser pulses on the complete population inversion using the level structure of atomic sodium interacting with ps and fs pulses as an example. Our result opens the door for multiple applications such as efficient ultrashort pulse lasing in the UV or the engineering of quantum states for quantum computing.
Targeting population heterogeneity for optimal cell factories

DEFF Research Database (Denmark)

Heins, Anna-Lena; Carlqvist, Magnus; Helmark, S.

the heterogeneity level of the population. To further investigate these phenomena and gain a deeper understanding of population heterogeneity, Saccharomyces cerevisiae growth reporter strains based on the expression of green fluorescent protein (GFP) were constructed which enabled us to perform single cell level...... analysis, and thereby created the possibility to map population heterogeneity. A factorial design with pH, glucose concentration and oxygen level was performed in batch cultivations using the growth reporter strains to evaluate the effect of those environmental factors on heterogeneity level and amount......To achieve an efficient production process, it is essential to optimize both the strain and the cultivation conditions. Traditionally, a microbial population has been considered homogeneous in optimization studies of fermentation processes. However, research has shown that a typical microbial...
Development of genetic diversity, differentiation and structure over 500 years in four ponderosa pine populations.

Science.gov (United States)

Lesser, M R; Parchman, T L; Jackson, S T

2013-05-01

Population history plays an important role in shaping contemporary levels of genetic variation and geographic structure. This is especially true in small, isolated range-margin populations, where effects of inbreeding, genetic drift and gene flow may be more pronounced than in large continuous populations. Effects of landscape fragmentation and isolation distance may have implications for persistence of range-margin populations if they are demographic sinks. We studied four small, disjunct populations of ponderosa pine over a 500-year period. We coupled demographic data obtained through dendroecological methods with microsatellite data to discern how and when contemporary levels of allelic diversity, among and within-population levels of differentiation, and geographic structure, arose. Alleles accumulated rapidly following initial colonization, demonstrating proportionally high levels of gene flow into the populations. At population sizes of approximately 100 individuals, allele accumulation saturated. Levels of genetic differentiation among populations (F(ST) and Jost's D(est)) and diversity within populations (F(IS)) remained stable through time. There was no evidence of geographic genetic structure at any time in the populations' history. Proportionally, high gene flow in the early stages of population growth resulted in rapid accumulation of alleles and quickly created relatively homogenous genetic patterns among populations. Our study demonstrates that contemporary levels of genetic diversity were formed quickly and early in population development. How contemporary genetic diversity accumulates over time is a key facet of understanding population growth and development. This is especially relevant given the extent and speed at which species ranges are predicted to shift in the coming century. © 2013 Blackwell Publishing Ltd.
Population dynamics in vasopressin cells.

Science.gov (United States)

Leng, Gareth; Brown, Colin; Sabatier, Nancy; Scott, Victoria

2008-01-01

Most neurons sense and code change, and when presented with a constant stimulus they adapt, so as to be able to detect a fresh change. However, for some things it is important to know their absolute level; to encode such information, neurons must sustain their response to an unchanging stimulus while remaining able to respond to a change in that stimulus. One system that encodes the absolute level of a stimulus is the vasopressin system, which generates a hormonal signal that is proportional to plasma osmolality. Vasopressin cells sense plasma osmolality and secrete appropriate levels of vasopressin from the neurohypophysis as needed to control water excretion; this requires sustained secretion under basal conditions and the ability to increase (or decrease) secretion should plasma osmolality change. Here we explore the mechanisms that enable vasopressin cells to fulfill this function, and consider how coordination between the cells might distribute the secretory load across the population of vasopressin cells. 2008 S. Karger AG, Basel.
Shaping bacterial population behavior through computer-interfaced control of individual cells.

Science.gov (United States)

Chait, Remy; Ruess, Jakob; Bergmiller, Tobias; Tkačik, Gašper; Guet, Călin C

2017-11-16

Bacteria in groups vary individually, and interact with other bacteria and the environment to produce population-level patterns of gene expression. Investigating such behavior in detail requires measuring and controlling populations at the single-cell level alongside precisely specified interactions and environmental characteristics. Here we present an automated, programmable platform that combines image-based gene expression and growth measurements with on-line optogenetic expression control for hundreds of individual Escherichia coli cells over days, in a dynamically adjustable environment. This integrated platform broadly enables experiments that bridge individual and population behaviors. We demonstrate: (i) population structuring by independent closed-loop control of gene expression in many individual cells, (ii) cell-cell variation control during antibiotic perturbation, (iii) hybrid bio-digital circuits in single cells, and freely specifiable digital communication between individual bacteria. These examples showcase the potential for real-time integration of theoretical models with measurement and control of many individual cells to investigate and engineer microbial population behavior.
A novel staining protocol for multiparameter assessment of cell heterogeneity in Phormidium populations (cyanobacteria employing fluorescent dyes.

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Daria Tashyreva

Full Text Available Bacterial populations display high heterogeneity in viability and physiological activity at the single-cell level, especially under stressful conditions. We demonstrate a novel staining protocol for multiparameter assessment of individual cells in physiologically heterogeneous populations of cyanobacteria. The protocol employs fluorescent probes, i.e., redox dye 5-cyano-2,3-ditolyl tetrazolium chloride, 'dead cell' nucleic acid stain SYTOX Green, and DNA-specific fluorochrome 4',6-diamidino-2-phenylindole, combined with microscopy image analysis. Our method allows simultaneous estimates of cellular respiration activity, membrane and nucleoid integrity, and allows the detection of photosynthetic pigments fluorescence along with morphological observations. The staining protocol has been adjusted for, both, laboratory and natural populations of the genus Phormidium (Oscillatoriales, and tested on 4 field-collected samples and 12 laboratory strains of cyanobacteria. Based on the mentioned cellular functions we suggest classification of cells in cyanobacterial populations into four categories: (i active and intact; (ii injured but active; (iii metabolically inactive but intact; (iv inactive and injured, or dead.
Ovarian cancer stem cells are enriched in side population and aldehyde dehydrogenase bright overlapping population.

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Kazuyo Yasuda

Full Text Available Cancer stem-like cells (CSCs/cancer-initiaiting cells (CICs are defined as a small population of cancer cells that have self-renewal capacity, differentiation potential and high tumor-initiating ability. CSCs/CICs of ovarian cancer have been isolated by side population (SP analysis, ALDEFLUOR assay and using cell surface markers. However, these approaches are not definitive markers for CSCs/CICs, and it is necessary to refine recent methods for identifying more highly purified CSCs/CICs. In this study, we analyzed SP cells and aldehyde dehydrogenese bright (ALDH(Br cells from ovarian cancer cells. Both SP cells and ALDH(Br cells exhibited higher tumor-initiating ability and higher expression level of a stem cell marker, sex determining region Y-box 2 (SOX2, than those of main population (MP cells and ALDH(Low cells, respectively. We analyzed an SP and ALDH(Br overlapping population (SP/ALDH(Br, and the SP/ALDH(Br population exhibited higher tumor-initiating ability than that of SP cells or ALDH(Br cells, enabling initiation of tumor with as few as 10(2 cells. Furthermore, SP/ADLH(Br population showed higher sphere-forming ability, cisplatin resistance, adipocyte differentiation ability and expression of SOX2 than those of SP/ALDH(Low, MP/ALDH(Br and MP/ALDH(Low cells. Gene knockdown of SOX2 suppressed the tumor-initiation of ovarian cancer cells. An SP/ALDH(Br population was detected in several gynecological cancer cells with ratios of 0.1% for HEC-1 endometrioid adenocarcinoma cells to 1% for MCAS ovary mucinous adenocarcinoma cells. Taken together, use of the SP and ALDH(Br overlapping population is a promising approach to isolate highly purified CSCs/CICs and SOX2 might be a novel functional marker for ovarian CSCs/CICs.
High epitope expression levels increase competition between T cells.

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Almut Scherer

2006-08-01

Full Text Available Both theoretical predictions and experimental findings suggest that T cell populations can compete with each other. There is some debate on whether T cells compete for aspecific stimuli, such as access to the surface on antigen-presenting cells (APCs or for specific stimuli, such as their cognate epitope ligand. We have developed an individual-based computer simulation model to study T cell competition. Our model shows that the expression level of foreign epitopes per APC determines whether T cell competition is mainly for specific or aspecific stimuli. Under low epitope expression, competition is mainly for the specific epitope stimuli, and, hence, different epitope-specific T cell populations coexist readily. However, if epitope expression levels are high, aspecific competition becomes more important. Such between-specificity competition can lead to competitive exclusion between different epitope-specific T cell populations. Our model allows us to delineate the circumstances that facilitate coexistence of T cells of different epitope specificity. Understanding mechanisms of T cell coexistence has important practical implications for immune therapies that require a broad immune response.
Emergence of cytotoxic resistance in cancer cell populations*

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Lorenzi Tommaso

2015-01-01

Full Text Available We formulate an individual-based model and an integro-differential model of phenotypic evolution, under cytotoxic drugs, in a cancer cell population structured by the expression levels of survival-potential and proliferation-potential. We apply these models to a recently studied experimental system. Our results suggest that mechanisms based on fundamental laws of biology can reversibly push an actively-proliferating, and drug-sensitive, cell population to transition into a weakly-proliferative and drug-tolerant state, which will eventually facilitate the emergence of more potent, proliferating and drug-tolerant cells.
A microarray analysis of two distinct lymphatic endothelial cell populations

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Bernhard Schweighofer

2015-06-01

Full Text Available We have recently identified lymphatic endothelial cells (LECs to form two morphologically different populations, exhibiting significantly different surface protein expression levels of podoplanin, a major surface marker for this cell type. In vitro shockwave treatment (IVSWT of LECs resulted in enrichment of the podoplaninhigh cell population and was accompanied by markedly increased cell proliferation, as well as 2D and 3D migration. Gene expression profiles of these distinct populations were established using Affymetrix microarray analyses. Here we provide additional details about our dataset (NCBI GEO accession number GSE62510 and describe how we analyzed the data to identify differently expressed genes in these two LEC populations.
The effects of nongenetic memory on population level sensitivity to stress

Science.gov (United States)

Adams, Rhys; Nevozhay, Dmitry; van Itallie, Elizabeth; Bennett, Matthew; Balazsi, Gabor

2011-03-01

While gene expression is often thought of as a unidirectional determinant of cellular fitness, recent studies have shown how growth retardation due to protein expression can affect gene expression levels in single cells. We developed two yeast strains carrying a drug resistance protein under the control of different synthetic gene constructs, one of which was monostable, while the other was bistable. The gene expression of these cell populations was tuned using a molecular inducer so that their respective means and noises were identical, while their nongenetic memory properties were different. We tested the sensitivity of these two cell population distributions to the antibiotic zeocin. We found that the gene expression distributions of bistable cell populations were sensitive to stressful environments, while the gene expression distribution of monostable cells were nearly unchanged by stress. We conclude that cell populations with high nongenetic memory are more adaptable to their environment. This work was funded by the National Institutes of Health through the NIH Director's New Innovator Award Program, 1-DP2- OD006481-01.
Deconstructing stem cell population heterogeneity: Single-cell analysis and modeling approaches

Science.gov (United States)

Wu, Jincheng; Tzanakakis, Emmanuel S.

2014-01-01

Isogenic stem cell populations display cell-to-cell variations in a multitude of attributes including gene or protein expression, epigenetic state, morphology, proliferation and proclivity for differentiation. The origins of the observed heterogeneity and its roles in the maintenance of pluripotency and the lineage specification of stem cells remain unclear. Addressing pertinent questions will require the employment of single-cell analysis methods as traditional cell biochemical and biomolecular assays yield mostly population-average data. In addition to time-lapse microscopy and flow cytometry, recent advances in single-cell genomic, transcriptomic and proteomic profiling are reviewed. The application of multiple displacement amplification, next generation sequencing, mass cytometry and spectrometry to stem cell systems is expected to provide a wealth of information affording unprecedented levels of multiparametric characterization of cell ensembles under defined conditions promoting pluripotency or commitment. Establishing connections between single-cell analysis information and the observed phenotypes will also require suitable mathematical models. Stem cell self-renewal and differentiation are orchestrated by the coordinated regulation of subcellular, intercellular and niche-wide processes spanning multiple time scales. Here, we discuss different modeling approaches and challenges arising from their application to stem cell populations. Integrating single-cell analysis with computational methods will fill gaps in our knowledge about the functions of heterogeneity in stem cell physiology. This combination will also aid the rational design of efficient differentiation and reprogramming strategies as well as bioprocesses for the production of clinically valuable stem cell derivatives. PMID:24035899
Making sense of snapshot data: ergodic principle for clonal cell populations.

Science.gov (United States)

Thomas, Philipp

2017-11-01

Population growth is often ignored when quantifying gene expression levels across clonal cell populations. We develop a framework for obtaining the molecule number distributions in an exponentially growing cell population taking into account its age structure. In the presence of generation time variability, the average acquired across a population snapshot does not obey the average of a dividing cell over time, apparently contradicting ergodicity between single cells and the population. Instead, we show that the variation observed across snapshots with known cell age is captured by cell histories, a single-cell measure obtained from tracking an arbitrary cell of the population back to the ancestor from which it originated. The correspondence between cells of known age in a population with their histories represents an ergodic principle that provides a new interpretation of population snapshot data. We illustrate the principle using analytical solutions of stochastic gene expression models in cell populations with arbitrary generation time distributions. We further elucidate that the principle breaks down for biochemical reactions that are under selection, such as the expression of genes conveying antibiotic resistance, which gives rise to an experimental criterion with which to probe selection on gene expression fluctuations. © 2017 The Author(s).
SCA-1 Expression Level Identifies Quiescent Hematopoietic Stem and Progenitor Cells

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Mina N.F. Morcos

2017-06-01

Full Text Available Blood cell generation depends on continuous cellular output by the sequential hierarchy of hematopoietic stem cell (HSC and progenitor populations that all contain quiescent and actively cycling cells. Hematopoietic stem and progenitor cells (HSPCs express the surface molecule Stem cell antigen 1 (SCA-1/LY6A. Using histone 2B-red fluorescent fusion protein label retention and cell-cycle reporter mice, we demonstrate that high SCA-1 expression (SCA-1hi identifies not only quiescent HSCs but quiescent cells on all hierarchical levels within the lineage−SCA-1+KIT+ (LSK population. Each transplanted SCA-1hi HSPC population also displayed self-renewal potential superior to that of the respective SCA-1lo population. SCA-1 expression is inducible by type I interferon (IFN. We show, however, that quiescence and high self-renewal capacity of cells with brighter SCA-1 expression at steady state were independent of type I IFN signaling. We conclude that SCA-1 expression levels can be used to prospectively isolate functionally heterogeneous HSPC subpopulations.

Immunohistochemical study on gastrointestinal endocrine cells of four reptiles

Science.gov (United States)

Huang, Xu-Gen; Wu, Xiao-Bing

2005-01-01

AIM: To clarify the types, regional distributions and distribution densities as well as morphological features of gastrointestinal (GI) endocrine cells in various parts of the gastrointestinal track (GIT) of four reptiles, Gekko japonicus, Eumeces chinensis, Sphenomorphus indicus and Eumeces elegans. METHODS: Paraffin-embedded sections (5 μm) of seven parts (cardia, fundus, pylorus, duodenum, jejunum, ileum, rectum) of GIT dissected from the four reptiles were prepared. GI endocrine cells were revealed by using immunohistochemical techniques of streptavidin-peroxidase (S-P) method. Seven types of antisera against 5-hydroxy-tryptamine (5-HT), somatostatin (SS), gastrin (GAS), glucagon (GLU), substance P (SP), insulin and pancreatic polypeptide were identified and then GI endocrine cells were photomicrographed and counted. RESULTS: The GI endocrine system of four reptiles was a complex structure containing many endocrine cell types similar in morphology to those found in higher vertebrates. Five types of GI endocrine cells, namely 5-HT, SS, GAS, SP and GLU immunoreactive (IR) cells were identified in the GIT of G. japonicus, E. chinensis and S. indicus; while in the GIT of E. elegans only the former three types of endocrine cells were observed. No PP- and INS- IR cells were found in all four reptiles. 5-HT-IR cells, which were most commonly found in the pylorus or duodenum, distributed throughout the whole GIT of four reptiles. However, their distribution patterns varied from each other. SS-IR cells, which were mainly found in the stomach especially in the pylorus and/or fundus, were demonstrated in the whole GIT of E. chinensis, only showed restricted distribution in the other three species. GAS-IR cells, with a much restricted distribution, were mainly demonstrated in the pylorus and/or the proximal small intestine of four reptiles. GLU-IR cells exhibited a limited and species-dependent variant distribution in the GIT of four reptiles. SP-IR cells were found
Rate of inbreeding and effective population size in four major South ...

African Journals Online (AJOL)

huis

Keywords: Dairy cattle, genetic diversity, pedigree analysis ... inbreeding and effective population sizes for the four major South African ... breeding programs and therefore L was computed as an average of generation intervals for the four.
Influence of Cell-Cell Interactions on the Population Growth Rate in a Tumor

Science.gov (United States)

Chen, Yong

2017-12-01

The understanding of the macroscopic phenomenological models of the population growth at a microscopic level is important to predict the population behaviors emerged from the interactions between the individuals. In this work, we consider the influence of the population growth rate R on the cell-cell interaction in a tumor system and show that, in most cases especially small proliferative probabilities, the regulative role of the interaction will be strengthened with the decline of the intrinsic proliferative probabilities. For the high replication rates of an individual and the cooperative interactions, the proliferative probability almost has no effect. We compute the dependences of R on the interactions between the cells under the approximation of the nearest neighbor in the rim of an avascular tumor. Our results are helpful to qualitatively understand the influence of the interactions between the individuals on the growth rate in population systems. Supported by the National Natural Science Foundation of China under Grant Nos. 11675008 and 21434001
Imbalance of placental regulatory T cell and Th17 cell population dynamics in the FIV-infected pregnant cat

Directory of Open Access Journals (Sweden)

Boudreaux Crystal E

2012-05-01

Full Text Available Abstract Background An appropriate balance in placental regulatory T cells (Tregs, an immunosuppressive cell population, and Th17 cells, a pro-inflammatory cell population, is essential in allowing tolerance of the semi-allogeneic fetus. TGF-β and IL-6 are cytokines that promote differentiation of Tregs and Th17 cells from a common progenitor; aberrant expression of the cytokines may perturb the balance in the two cell populations. We previously reported a pro-inflammatory placental environment with decreased levels of FoxP3, a Treg marker, and increased levels of IL-6 in the placentas of FIV-infected cats at early pregnancy. Thus, we hypothesized that FIV infection in the pregnant cat causes altered placental Treg and Th17 cell populations, possibly resulting in placental inflammation. Methods We examined the effect of FIV infection on Treg and Th17 populations in placentas at early pregnancy using quantitative confocal microscopy to measure FoxP3 or RORγ, a Th17 marker, and qPCR to quantify expression of the key cytokines TGF-β and IL-6. Results FoxP3 and RORγ were positively correlated in FIV-infected placentas at early pregnancy, but not placentas from normal cats, indicating virus-induced alteration in the balance of these cell populations. In control cats the expression of IL-6 and RORγ was positively correlated as predicted, but this relationship was disrupted in infected animals. TGF-β was reduced in infected queens, an occurrence that could dysregulate both Treg and Th17 cell populations. Co-expression analyses revealed a highly significant positive correlation between IL-6 and TGF-β expression in control animals that did not occur in infected animals. Conclusion Collectively, these data point toward potential disruption in the balance of Treg and Th17 cell populations that may contribute to FIV-induced inflammation in the feline placenta.
Passive synchronized Q-switching between a quasi-three-level and a four-level laser

DEFF Research Database (Denmark)

Cheng, Haynes Pak Hay; Tidemand-Lichtenberg, Peter; Jensen, Ole Bjarlin

2011-01-01

Synchronized Q-switching between quasi-three-level and four-level lasers is interesting for sum-frequency generation into the blue and ultraviolet. We report, for the first time, stable synchronized Q-switching between a quasi-three-level laser at 946 nm and a four-level laser at 1064 nm in an all...
High-level 13C-enrichment of random and synchronous populations of Chlamydomonas reinhardii

International Nuclear Information System (INIS)

Price, R.L.; Crissman, H.A.; Martin, J.C.; Kollman, V.H.

1975-01-01

The alga Chlamydomonas reinhardii was grown in suspension culture at high levels of 13 C-enrichment (98 mol percent) both in synchronous and random populations for the purpose of investigating possible macro- and ultrastructural changes in the cell as induced by essentially total carbon replacement. The algae, grown in spinner flasks, were analyzed using a newly developed multiparameter flow-system technique applied to characterizing various algal genera. The versatility of this technique provides for measuring and processing several cell characteristics simultaneously and separating cells according to selected combinations of parameters. In these studies, cell volume (by Coulter aperture) and DNA and chlorophyll content were determined simultaneously. Cell ultrastructure was examined at various levels of isotope enrichment and time periods by electron microscopy. The data presented for synchronous growth of this organism demonstrate the absence of biological effects (considering the parameters measured) due to the almost total replacement of cellular 12 C with 13 C. Interpretational problems encountered when looking for biological effects on random populations are discussed
Four-wave mixing and six-wave mixing in a four-level confined atomic system

International Nuclear Information System (INIS)

Chang-Biao, Li; Yan-Peng, Zhang; Zhi-Qiang, Nie; Huai-Bin, Zheng; Mei-Zhen, Shi; Dong-Ning, Liu; Jian-Ping, Song; Ke-Qing, Lu

2009-01-01

We have investigated coexisting four-wave mixing and six-wave mixing (SWM) in ultra-thin, micrometre and long vapour cells. There exists competition between Dicke-narrowing features and polarization interference in the micrometre cell. The oscillation behaviour of SWM signal intensities and linewidths results from destructive interference. With a larger destructive interference, the SWM signal in ultra-thin cells shows a narrow spectrum, in contrast to the long cell case. Due to the Dicke-narrowing features, a narrow spectrum can be obtained, and such spectra can be used for high precision measurements and metrological standards. (classical areas of phenomenology)
Distinct gene expression signatures in human embryonic stem cells differentiated towards definitive endoderm at single-cell level

DEFF Research Database (Denmark)

Norrman, Karin; Strömbeck, Anna; Semb, Henrik

2013-01-01

for the three activin A based protocols applied. Our data provide novel insights in DE gene expression at the cellular level of in vitro differentiated human embryonic stem cells, and illustrate the power of using single-cell gene expression profiling to study differentiation heterogeneity and to characterize...... of anterior definitive endoderm (DE). Here, we differentiated human embryonic stem cells towards DE using three different activin A based treatments. Differentiation efficiencies were evaluated by gene expression profiling over time at cell population level. A panel of key markers was used to study DE...... formation. Final DE differentiation was also analyzed with immunocytochemistry and single-cell gene expression profiling. We found that cells treated with activin A in combination with sodium butyrate and B27 serum-free supplement medium generated the most mature DE cells. Cell population studies were...
Mixed-valence molecular four-dot unit for quantum cellular automata: Vibronic self-trapping and cell-cell response.

Science.gov (United States)

Tsukerblat, Boris; Palii, Andrew; Clemente-Juan, Juan Modesto; Coronado, Eugenio

2015-10-07

Our interest in this article is prompted by the vibronic problem of charge polarized states in the four-dot molecular quantum cellular automata (mQCA), a paradigm for nanoelectronics, in which binary information is encoded in charge configuration of the mQCA cell. Here, we report the evaluation of the electronic levels and adiabatic potentials of mixed-valence (MV) tetra-ruthenium (2Ru(ii) + 2Ru(iii)) derivatives (assembled as two coupled Creutz-Taube complexes) for which molecular implementations of quantum cellular automata (QCA) was proposed. The cell based on this molecule includes two holes shared among four spinless sites and correspondingly we employ the model which takes into account the two relevant electron transfer processes (through the side and through the diagonal of the square) as well as the difference in Coulomb energies for different instant positions of localization of the hole pair. The combined Jahn-Teller (JT) and pseudo JT vibronic coupling is treated within the conventional Piepho-Krauzs-Schatz model adapted to a bi-electronic MV species with the square-planar topology. The adiabatic potentials are evaluated for the low lying Coulomb levels in which the antipodal sites are occupied, the case just actual for utilization in mQCA. The conditions for the vibronic self-trapping in spin-singlet and spin-triplet states are revealed in terms of the two actual transfer pathways parameters and the strength of the vibronic coupling. Spin related effects in degrees of the localization which are found for spin-singlet and spin-triplet states are discussed. The polarization of the cell is evaluated and we demonstrate how the partial delocalization caused by the joint action of the vibronic coupling and electron transfer processes influences polarization of a four-dot cell. The results obtained within the adiabatic approach are compared with those based on the numerical solution of the dynamic vibronic problem. Finally, the Coulomb interaction between
The regrowth kinetic of the surviving population is independent of acute and chronic responses to temozolomide in glioblastoma cell lines

International Nuclear Information System (INIS)

Silva, Andrew Oliveira; Dalsin, Eloisa; Onzi, Giovana Ravizzoni; Filippi-Chiela, Eduardo Cremonese; Lenz, Guido

2016-01-01

Chemotherapy acts on cancer cells by producing multiple effects on a cell population including cell cycle arrest, necrosis, apoptosis and senescence. However, often a subpopulation of cells survives and the behavior of this subpopulation, which is responsible for cancer recurrence, remains obscure. Here we investigated the in vitro short- and long-term responses of six glioblastoma cell lines to clinically relevant doses of temozolomide for 5 days followed by 23 days of recovery, mimicking the standard schedule used in glioblastoma patient for this drug. These cells presented different profiles of sensitivity to temozolomide with varying levels of cell cycle arrest, autophagy and senescence, followed by a regrowth of the surviving cells. The initial reduction in cell number and the subsequent regrowth was analyzed with four new parameters applied to Cumulative Population Doubling (CPD) curves that describe the overall sensitivity of the population and the characteristic of the regrowth: the relative end point CPD (RendCPD); the relative Area Under Curve (rAUC); the Relative Time to Cross a Threshold (RTCT); and the Relative Proliferation Rate (RPR). Surprisingly, the kinetics of regrowth were not predicted by the mechanisms activated after treatment nor by the acute or overall sensitivity. With this study we added new parameters that describe key responses of glioblastoma cell populations to temozolomide treatment. These parameters can also be applied to other cell types and treatments and will help to understand the behavior of the surviving cancer cells after treatment and shed light on studies of cancer resistance and recurrence. - Highlights: • Little is known about the behavior of the glioma cells surviving to TMZ. • The short- and long-term response of six glioma cells lines to TMZ varies considerably. • These glioma cells lines recovered proliferation after therapeutic levels of TMZ. • The growth velocity of the surviving cells was different from the
The regrowth kinetic of the surviving population is independent of acute and chronic responses to temozolomide in glioblastoma cell lines

Energy Technology Data Exchange (ETDEWEB)

Silva, Andrew Oliveira, E-mail: andrewbiomed@gmail.com [Department of Biophysics, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil); Dalsin, Eloisa, E-mail: dalsineloisa@gmail.com [Department of Biophysics, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil); Onzi, Giovana Ravizzoni, E-mail: gioonzi@gmail.com [Department of Biophysics, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil); Center of Biotechnology, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil); Filippi-Chiela, Eduardo Cremonese, E-mail: eduardochiela@gmail.com [Department of Biophysics, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil); Lenz, Guido, E-mail: lenz@ufrgs.br [Department of Biophysics, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil); Center of Biotechnology, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil)

2016-11-01

Chemotherapy acts on cancer cells by producing multiple effects on a cell population including cell cycle arrest, necrosis, apoptosis and senescence. However, often a subpopulation of cells survives and the behavior of this subpopulation, which is responsible for cancer recurrence, remains obscure. Here we investigated the in vitro short- and long-term responses of six glioblastoma cell lines to clinically relevant doses of temozolomide for 5 days followed by 23 days of recovery, mimicking the standard schedule used in glioblastoma patient for this drug. These cells presented different profiles of sensitivity to temozolomide with varying levels of cell cycle arrest, autophagy and senescence, followed by a regrowth of the surviving cells. The initial reduction in cell number and the subsequent regrowth was analyzed with four new parameters applied to Cumulative Population Doubling (CPD) curves that describe the overall sensitivity of the population and the characteristic of the regrowth: the relative end point CPD (RendCPD); the relative Area Under Curve (rAUC); the Relative Time to Cross a Threshold (RTCT); and the Relative Proliferation Rate (RPR). Surprisingly, the kinetics of regrowth were not predicted by the mechanisms activated after treatment nor by the acute or overall sensitivity. With this study we added new parameters that describe key responses of glioblastoma cell populations to temozolomide treatment. These parameters can also be applied to other cell types and treatments and will help to understand the behavior of the surviving cancer cells after treatment and shed light on studies of cancer resistance and recurrence. - Highlights: • Little is known about the behavior of the glioma cells surviving to TMZ. • The short- and long-term response of six glioma cells lines to TMZ varies considerably. • These glioma cells lines recovered proliferation after therapeutic levels of TMZ. • The growth velocity of the surviving cells was different from the
Temporal and Spatial Variation in, and Population Exposure to, Summertime Ground-Level Ozone in Beijing.

Science.gov (United States)

Zhao, Hui; Zheng, Youfei; Li, Ting; Wei, Li; Guan, Qing

2018-03-29

Ground-level ozone pollution in Beijing has been causing concern among the public due to the risks posed to human health. This study analyzed the temporal and spatial distribution of, and investigated population exposure to, ground-level ozone. We analyzed hourly ground-level ozone data from 35 ambient air quality monitoring sites, including urban, suburban, background, and traffic monitoring sites, during the summer in Beijing from 2014 to 2017. The results showed that the four-year mean ozone concentrations for urban, suburban, background, and traffic monitoring sites were 95.1, 99.8, 95.9, and 74.2 μg/m³, respectively. A total of 44, 43, 45, and 43 days exceeded the Chinese National Ambient Air Quality Standards (NAAQS) threshold for ground-level ozone in 2014, 2015, 2016, and 2017, respectively. The mean ozone concentration was higher in suburban sites than in urban sites, and the traffic monitoring sites had the lowest concentration. The diurnal variation in ground-level ozone concentration at the four types of monitoring sites displayed a single-peak curve. The peak and valley values occurred at 3:00-4:00 p.m. and 7:00 a.m., respectively. Spatially, ground-level ozone concentrations decreased in gradient from the north to the south. Population exposure levels were calculated based on ground-level ozone concentrations and population data. Approximately 50.38%, 44.85%, and 48.49% of the total population of Beijing were exposed to ground-level ozone concentrations exceeding the Chinese NAAQS threshold in 2014, 2015, and 2016, respectively.
Temporal and Spatial Variation in, and Population Exposure to, Summertime Ground-Level Ozone in Beijing

Science.gov (United States)

Zheng, Youfei; Li, Ting; Wei, Li; Guan, Qing

2018-01-01

Ground-level ozone pollution in Beijing has been causing concern among the public due to the risks posed to human health. This study analyzed the temporal and spatial distribution of, and investigated population exposure to, ground-level ozone. We analyzed hourly ground-level ozone data from 35 ambient air quality monitoring sites, including urban, suburban, background, and traffic monitoring sites, during the summer in Beijing from 2014 to 2017. The results showed that the four-year mean ozone concentrations for urban, suburban, background, and traffic monitoring sites were 95.1, 99.8, 95.9, and 74.2 μg/m3, respectively. A total of 44, 43, 45, and 43 days exceeded the Chinese National Ambient Air Quality Standards (NAAQS) threshold for ground-level ozone in 2014, 2015, 2016, and 2017, respectively. The mean ozone concentration was higher in suburban sites than in urban sites, and the traffic monitoring sites had the lowest concentration. The diurnal variation in ground-level ozone concentration at the four types of monitoring sites displayed a single-peak curve. The peak and valley values occurred at 3:00–4:00 p.m. and 7:00 a.m., respectively. Spatially, ground-level ozone concentrations decreased in gradient from the north to the south. Population exposure levels were calculated based on ground-level ozone concentrations and population data. Approximately 50.38%, 44.85%, and 48.49% of the total population of Beijing were exposed to ground-level ozone concentrations exceeding the Chinese NAAQS threshold in 2014, 2015, and 2016, respectively. PMID:29596366
Temporal and Spatial Variation in, and Population Exposure to, Summertime Ground-Level Ozone in Beijing

Directory of Open Access Journals (Sweden)

Hui Zhao

2018-03-01

Full Text Available Ground-level ozone pollution in Beijing has been causing concern among the public due to the risks posed to human health. This study analyzed the temporal and spatial distribution of, and investigated population exposure to, ground-level ozone. We analyzed hourly ground-level ozone data from 35 ambient air quality monitoring sites, including urban, suburban, background, and traffic monitoring sites, during the summer in Beijing from 2014 to 2017. The results showed that the four-year mean ozone concentrations for urban, suburban, background, and traffic monitoring sites were 95.1, 99.8, 95.9, and 74.2 μg/m3, respectively. A total of 44, 43, 45, and 43 days exceeded the Chinese National Ambient Air Quality Standards (NAAQS threshold for ground-level ozone in 2014, 2015, 2016, and 2017, respectively. The mean ozone concentration was higher in suburban sites than in urban sites, and the traffic monitoring sites had the lowest concentration. The diurnal variation in ground-level ozone concentration at the four types of monitoring sites displayed a single-peak curve. The peak and valley values occurred at 3:00–4:00 p.m. and 7:00 a.m., respectively. Spatially, ground-level ozone concentrations decreased in gradient from the north to the south. Population exposure levels were calculated based on ground-level ozone concentrations and population data. Approximately 50.38%, 44.85%, and 48.49% of the total population of Beijing were exposed to ground-level ozone concentrations exceeding the Chinese NAAQS threshold in 2014, 2015, and 2016, respectively.
HOX and TALE signatures specify human stromal stem cell populations from different sources.

Science.gov (United States)

Picchi, Jacopo; Trombi, Luisa; Spugnesi, Laura; Barachini, Serena; Maroni, Giorgia; Brodano, Giovanni Barbanti; Boriani, Stefano; Valtieri, Mauro; Petrini, Mario; Magli, Maria Cristina

2013-04-01

Human stromal stem cell populations reside in different tissues and anatomical sites, however a critical question related to their efficient use in regenerative medicine is whether they exhibit equivalent biological properties. Here, we compared cellular and molecular characteristics of stromal stem cells derived from the bone marrow, at different body sites (iliac crest, sternum, and vertebrae) and other tissues (dental pulp and colon). In particular, we investigated whether homeobox genes of the HOX and TALE subfamilies might provide suitable markers to identify distinct stromal cell populations, as HOX proteins control cell positional identity and, together with their co-factors TALE, are involved in orchestrating differentiation of adult tissues. Our results show that stromal populations from different sources, although immunophenotypically similar, display distinct HOX and TALE signatures, as well as different growth and differentiation abilities. Stromal stem cells from different tissues are characterized by specific HOX profiles, differing in the number and type of active genes, as well as in their level of expression. Conversely, bone marrow-derived cell populations can be essentially distinguished for the expression levels of specific HOX members, strongly suggesting that quantitative differences in HOX activity may be crucial. Taken together, our data indicate that the HOX and TALE profiles provide positional, embryological and hierarchical identity of human stromal stem cells. Furthermore, our data suggest that cell populations derived from different body sites may not represent equivalent cell sources for cell-based therapeutical strategies for regeneration and repair of specific tissues. Copyright © 2012 Wiley Periodicals, Inc.
Population of vibrational levels of carbon dioxide by cylindrical fast ionization wave

KAUST Repository

Levko, Dmitry; Pachuilo, Michael; Raja, Laxminarayan L.

2017-01-01

The population of vibrational levels of carbon dioxide (CO2) by a cylindrical fast ionization wave is analyzed using a one-dimensional Particle-in-Cell Monte Carlo collisions model. The model takes into account the inelastic electron
Tools for Genomic and Transcriptomic Analysis of Microbes at Single-Cell Level

Directory of Open Access Journals (Sweden)

Zixi Chen

2017-09-01

Full Text Available Microbiologists traditionally study population rather than individual cells, as it is generally assumed that the status of individual cells will be similar to that observed in the population. However, the recent studies have shown that the individual behavior of each single cell could be quite different from that of the whole population, suggesting the importance of extending traditional microbiology studies to single-cell level. With recent technological advances, such as flow cytometry, next-generation sequencing (NGS, and microspectroscopy, single-cell microbiology has greatly enhanced the understanding of individuality and heterogeneity of microbes in many biological systems. Notably, the application of multiple ‘omics’ in single-cell analysis has shed light on how individual cells perceive, respond, and adapt to the environment, how heterogeneity arises under external stress and finally determines the fate of the whole population, and how microbes survive under natural conditions. As single-cell analysis involves no axenic cultivation of target microorganism, it has also been demonstrated as a valuable tool for dissecting the microbial ‘dark matter.’ In this review, current state-of-the-art tools and methods for genomic and transcriptomic analysis of microbes at single-cell level were critically summarized, including single-cell isolation methods and experimental strategies of single-cell analysis with NGS. In addition, perspectives on the future trends of technology development in the field of single-cell analysis was also presented.
2D atom localization in a four-level tripod system in laser fields

OpenAIRE

Ivanov, Vladimir; Rozhdestvensky, Yuri

2012-01-01

We propose a scheme for two-dimensional (2D) atom localization in a four-level tripod system under an influence of two orthogonal standing-wave fields. Position information of the atom is retained in the atomic internal states by an additional probe field either of a standing or of a running wave. It is shown that the localization factors depend crucially on the atom-field coupling that results in such spatial structures of populations as spikes, craters and waves. We demonstrate a high-preci...
Modeling population dynamics of mitochondria in mammalian cells

Science.gov (United States)

Kornick, Kellianne; Das, Moumita

Mitochondria are organelles located inside eukaryotic cells and are essential for several key cellular processes such as energy (ATP) production, cell signaling, differentiation, and apoptosis. All organisms are believed to have low levels of variation in mitochondrial DNA (mtDNA), and alterations in mtDNA are connected to a range of human health conditions, including epilepsy, heart failure, Parkinsons disease, diabetes, and multiple sclerosis. Therefore, understanding how changes in mtDNA accumulate over time and are correlated to changes in mitochondrial function and cell properties can have a profound impact on our understanding of cell physiology and the origins of some diseases. Motivated by this, we develop and study a mathematical model to determine which cellular parameters have the largest impact on mtDNA population dynamics. The model consists of coupled ODEs to describe subpopulations of healthy and dysfunctional mitochondria subject to mitochondrial fission, fusion, autophagy, and mutation. We study the time evolution and stability of each sub-population under specific selection biases and pressures by tuning specific terms in our model. Our results may provide insights into how sub-populations of mitochondria survive and evolve under different selection pressures. This work was supported by a Grant from the Moore Foundation.
Comparison of Four Protocols to Generate Chondrocyte-Like Cells from Human Induced Pluripotent Stem Cells (hiPSCs).

Science.gov (United States)

Suchorska, Wiktoria Maria; Augustyniak, Ewelina; Richter, Magdalena; Trzeciak, Tomasz

2017-04-01

Stem cells (SCs) are a promising approach to regenerative medicine, with the potential to treat numerous orthopedic disorders, including osteo-degenerative diseases. The development of human-induced pluripotent stem cells (hiPSCs) has increased the potential of SCs for new treatments. However, current methods of differentiating hiPSCs into chondrocyte-like cells are suboptimal and better methods are needed. The aim of the present study was to assess four different chondrogenic differentiation protocols to identify the most efficient method of generating hiPSC-derived chondrocytes. For this study, hiPSCs were obtained from primary human dermal fibroblasts (PHDFs) and differentiated into chondrocyte-like cells using four different protocols: 1) monolayer culture with defined growth factors (GF); 2) embryoid bodies (EBs) in a chondrogenic medium with TGF-β3 cells; 3) EBs in chondrogenic medium conditioned with human chondrocytes (HC-402-05a cell line) and 4) EBs in chondrogenic medium conditioned with human chondrocytes and supplemented with TGF-β3. The cells obtained through these four protocols were evaluated and compared at the mRNA and protein levels. Although chondrogenic differentiation of hiPSCs was successfully achieved with all of these protocols, the two fastest and most cost-effective methods were the monolayer culture with GFs and the medium conditioned with human chondrocytes. Both of these methods are superior to other available techniques. The main advantage of the conditioned medium is that the technique is relatively simple and inexpensive while the directed method (i.e., monolayer culture with GFs) is faster than any protocol described to date because it is does not require additional steps such as EB formation.

Levels of circulating CD45dimCD34+VEGFR2+ progenitor cells correlate with outcome in metastatic renal cell carcinoma patients treated with tyrosine kinase inhibitors

Science.gov (United States)

Farace, F; Gross-Goupil, M; Tournay, E; Taylor, M; Vimond, N; Jacques, N; Billiot, F; Mauguen, A; Hill, C; Escudier, B

2011-01-01

Background: Predicting the efficacy of antiangiogenic therapy would be of clinical value in patients (pts) with metastatic renal cell carcinoma (mRCC). We tested the hypothesis that circulating endothelial cell (CEC), bone marrow-derived CD45dimCD34+VEGFR2+ progenitor cell or plasma angiogenic factor levels are associated with clinical outcome in mRCC pts undergoing treatment with tyrosine kinase inhibitors (TKI). Methods: Fifty-five mRCC pts were prospectively monitored at baseline (day 1) and day 14 during treatment (46 pts received sunitinib and 9 pts received sorafenib). Circulating endothelial cells (CD45−CD31+CD146+7-amino-actinomycin (7AAD)− cells) were measured in 1 ml whole blood using four-color flow cytometry (FCM). Circulating CD45dimCD34+VEGFR2+7AAD− progenitor cells were measured in progenitor-enriched fractions by four-color FCM. Plasma VEGF, sVEGFR2, SDF-1α and sVCAM-1 levels were determined by ELISA. Correlations between baseline CEC, CD45dimCD34+VEGFR2+7AAD− progenitor cells, plasma factors, as well as day 1–day 14 changes in CEC, CD45dimCD34+VEGFR2+7AAD− progenitor, plasma factor levels, and response to TKI, progression-free survival (PFS) and overall survival (OS) were examined. Results: No significant correlation between markers and response to TKI was observed. No association between baseline CEC, plasma VEGF, sVEGFR-2, SDF-1α, sVCAM-1 levels with PFS and OS was observed. However, baseline CD45dimCD34+VEGFR2+7AAD− progenitor cell levels were associated with PFS (P=0.01) and OS (P=0.006). Changes in this population and in SDF-1α levels between day 1 and day 14 were associated with PFS (P=0.03, P=0.002). Changes in VEGF and SDF-1α levels were associated with OS (P=0.02, P=0.007). Conclusion: Monitoring CD45dimCD34+VEGFR2+ progenitor cells, plasma VEGF and SDF-1α levels could be of clinical interest in TKI-treated mRCC pts to predict outcome. PMID:21386843
RESULTS REGARDING THE REPRODUCTION PERFORMANCES OF FOUR GOATS POPULATIONS IN THE SOUTHERN

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Horia PRISECEANU

2015-04-01

Full Text Available The researches in the present paper were carried out upon four goat populations in the southern Romania, on 718 adult goats, in two breeds, reared in different production systems, with different mating season and activity. There were recorded primary data about the reproduction activity and there were calculated the reproduction indices, by the classic formulas in the special literature. The results were compared by breed and reproductive category, and there were calculated the main statistically parameters. The main conclusion reveals the fact that the reproduction activity in Carpathian breed farms is placed on an acceptable to good level; this breed could be continuously improved by a more careful monitoring of the factors affecting the reproduction function.
Population genetics inside a cell: Mutations and mitochondrial genome maintenance

Science.gov (United States)

Goyal, Sidhartha; Shraiman, Boris; Gottschling, Dan

2012-02-01

In realistic ecological and evolutionary systems natural selection acts on multiple levels, i.e. it acts on individuals as well as on collection of individuals. An understanding of evolutionary dynamics of such systems is limited in large part due to the lack of experimental systems that can challenge theoretical models. Mitochondrial genomes (mtDNA) are subjected to selection acting on cellular as well as organelle levels. It is well accepted that mtDNA in yeast Saccharomyces cerevisiae is unstable and can degrade over time scales comparable to yeast cell division time. We utilize a recent technology designed in Gottschling lab to extract DNA from populations of aged yeast cells and deep sequencing to characterize mtDNA variation in a population of young and old cells. In tandem, we developed a stochastic model that includes the essential features of mitochondrial biology that provides a null model for expected mtDNA variation. Overall, we find approximately 2% of the polymorphic loci that show significant increase in frequency as cells age providing direct evidence for organelle level selection. Such quantitative study of mtDNA dynamics is absolutely essential to understand the propagation of mtDNA mutations linked to a spectrum of age-related diseases in humans.
Novel microchip-based tools facilitating live cell imaging and assessment of functional heterogeneity within NK cell populations

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Elin eForslund

2012-10-01

Full Text Available Each individual has a heterogeneous pool of NK cells consisting of cells that may be specialized towards specific functional responses such as secretion of cytokines or killing of tumor cells. Many conventional methods are not fit to characterize heterogeneous populations as they measure the average response of all cells. Thus, there is a need for experimental platforms that provide single cell resolution. In addition, there are also transient and stochastic variations in functional responses at the single cell level, calling for methods that allow studies of many events over extended times. This paper presents a versatile microchip platform enabling long-term microscopic studies of individual NK cells interacting with target cells. Each microchip contains an array of microwells, optimized for medium or high-resolution time-lapse imaging of single or multiple NK and target cells, or for screening of thousands of isolated NK-target cell interactions. Individual NK cells confined with target cells in small microwells is a suitable setup for high-content screening and rapid assessment of heterogeneity within populations, while microwells of larger dimensions are appropriate for studies of NK cell migration and sequential interactions with multiple target cells. By combining the chip technology with ultrasonic manipulation, NK and target cells can be forced to interact and positioned with high spatial accuracy within individual microwells. This setup effectively and synchronously creates NK-target conjugates at hundreds of parallel positions in the microchip. Thus, this facilitates assessment of temporal aspects of NK-target cell interactions, e.g. conjugation, immune synapse formation and cytotoxic events. The microchip platform presented here can be used to effectively address questions related to fundamental functions of NK cells that can lead to better understanding of how the behavior of individual cells add up to give a functional response at
Targeting population heterogeneity in Saccharomyces cerevisiae batch fermentation for optimal cell factories

DEFF Research Database (Denmark)

Heins, Anna-Lena; Lencastre Fernandes, Rita; Lundin, L.

)). Significant gradients of e.g. dissolved oxygen, substrates, and pH are typically observed in many industrial scale fermentation processes. Consequently, the microbial cells experience rapid changes in environmental conditions as they circulate throughout the reactor, which might pose stress on the cells...... and affect their metabolism and consequently affect the heterogeneity level of the population. To further investigate these phenomena and gain a deeper understanding of population heterogeneity, Saccharomyces cerevisiae growth reporter strains based on the expression of green fluorescent protein (GFP) were...... environmental factors on heterogeneity level and amount of living cells. A highly dynamic behavior with regard to subpopulation distribution during the different growth stages was seen for the batch cultivations. Moreover, it could be demonstrated that the glucose concentration had a clear influence...
The association between systemic inflammatory cellular levels and lung function: a population-based study.

Directory of Open Access Journals (Sweden)

Tricia McKeever

Full Text Available BACKGROUND: Lower lung function is associated with an elevated systemic white cell count in men. However, these observations have not been demonstrated in a representative population that includes females and may be susceptible to confounding by recent airway infections or recent cigarette smoking. We tested the hypothesis that lung function is inversely associated with systemic white cell count in a population-based study. METHODS: The study population consisted adults aged 17-90+ years who participated in the Third National Health and Nutrition Examination Survey who did not report a recent cough, cold or acute illness in a non-smoking and smoking population. RESULTS: In non-smoking adults with the highest quintile of the total white cell count had a FEV(1 125.3 ml lower than those in the lowest quintile (95% confidence interval CI: -163.1 to -87.5. Adults with the highest quintile of the total white cell count had a FVC 151.1 ml lower than those in the lowest quintile (95% confidence interval CI: -195.0 to -107.2. Similar associations were observed for granulocytes, mononuclear cells and lymphocytes. In current smokers, similar smaller associations observed for total white cell count, granulocytes and mononuclear cells. CONCLUSIONS: Systemic cellular inflammation levels are inversely associated with lung function in a population of both non-smokers and smokers without acute illnesses. This may contribute to the increased mortality observed in individuals with a higher baseline white cell count.
Different level of population differentiation among human genes.

Science.gov (United States)

Wu, Dong-Dong; Zhang, Ya-Ping

2011-01-14

During the colonization of the world, after dispersal out of African, modern humans encountered changeable environments and substantial phenotypic variations that involve diverse behaviors, lifestyles and cultures, were generated among the different modern human populations. Here, we study the level of population differentiation among different populations of human genes. Intriguingly, genes involved in osteoblast development were identified as being enriched with higher FST SNPs, a result consistent with the proposed role of the skeletal system in accounting for variation among human populations. Genes involved in the development of hair follicles, where hair is produced, were also found to have higher levels of population differentiation, consistent with hair morphology being a distinctive trait among human populations. Other genes that showed higher levels of population differentiation include those involved in pigmentation, spermatid, nervous system and organ development, and some metabolic pathways, but few involved with the immune system. Disease-related genes demonstrate excessive SNPs with lower levels of population differentiation, probably due to purifying selection. Surprisingly, we find that Mendelian-disease genes appear to have a significant excessive of SNPs with high levels of population differentiation, possibly because the incidence and susceptibility of these diseases show differences among populations. As expected, microRNA regulated genes show lower levels of population differentiation due to purifying selection. Our analysis demonstrates different level of population differentiation among human populations for different gene groups.
Sex ratio and time to pregnancy: analysis of four large European population surveys

DEFF Research Database (Denmark)

Joffe, Mike; Bennett, James; Best, Nicky

2007-01-01

To test whether the secondary sex ratio (proportion of male births) is associated with time to pregnancy, a marker of fertility. Design Analysis of four large population surveys. Setting Denmark and the United Kingdom. Participants 49 506 pregnancies.......To test whether the secondary sex ratio (proportion of male births) is associated with time to pregnancy, a marker of fertility. Design Analysis of four large population surveys. Setting Denmark and the United Kingdom. Participants 49 506 pregnancies....
Squamous cell carcinoma of temporal bone: four case reports

Energy Technology Data Exchange (ETDEWEB)

Lee, Jun Ha; Sung, Ki Joon; Sim, Young; Shim, Sue Yoen; Yoon, Byoung Moon [Wonju College of Medicine, Yonsei University, Wonju (Korea, Republic of)

2000-04-01

We report the CT findings of four cases of squamous cell carcinoma, paying special attention to the epicenter of the lesion and the pattern of bony destruction. All four patients had a past history of chronic otitis media. Squamous cell carcinoma affected mainly the hypotympanum and inferior wall of the external auditory canal. and in all cases revealed an irregular pattern of bony destruction. Irregular destruction of the tegmen tympani occurred in two cases. In cases of squamous cell carcinoma, CT findings suggesting involvement of the promontory are usually noted. (author)
Squamous cell carcinoma of temporal bone: four case reports

International Nuclear Information System (INIS)

Lee, Jun Ha; Sung, Ki Joon; Sim, Young; Shim, Sue Yoen; Yoon, Byoung Moon

2000-01-01

We report the CT findings of four cases of squamous cell carcinoma, paying special attention to the epicenter of the lesion and the pattern of bony destruction. All four patients had a past history of chronic otitis media. Squamous cell carcinoma affected mainly the hypotympanum and inferior wall of the external auditory canal. and in all cases revealed an irregular pattern of bony destruction. Irregular destruction of the tegmen tympani occurred in two cases. In cases of squamous cell carcinoma, CT findings suggesting involvement of the promontory are usually noted. (author)
Cytotoxicity of four denture adhesives on human gingival fibroblast cells.

Science.gov (United States)

Lee, Yoon; Ahn, Jin-Soo; Yi, Young-Ah; Chung, Shin-Hye; Yoo, Yeon-Jee; Ju, Sung-Won; Hwang, Ji-Yun; Seo, Deog-Gyu

2015-02-01

The purpose of this study was to compare the cytotoxicity of four denture adhesives on human gingival fibroblast cells. Immortalized human gingival fibroblasts were cultured with one of four different denture adhesives, Polident, Protefix, Staydent or Denfix-A, which was placed in insert dishes (10% w/v concentration) for 48 h. The MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay and flow cytometric apoptosis assay were used to evaluate cell viability and apoptosis rates. The fibroblasts were also examined under a scanning electron microscope. The MTT assay showed that all denture adhesives resulted in a significantly lower cell viability compared to the control cells propagated in normal culture medium (p 0.05). Staydent showed the highest apoptosis rate. Scanning electron microscopy showed that the cells of the Staydent group underwent cytoplasmic membrane shrinkage, with cell free areas containing residual fragments of the membrane of dead cells. The four denture adhesives evaluated in this study imparted cytotoxic effects on human gingival fibroblast cells. Staydent showed the highest toxicity.
Prolactin suppresses a progestin-induced CK5-positive cell population in luminal breast cancer through inhibition of progestin-driven BCL6 expression

Science.gov (United States)

Sato, Takahiro; Tran, Thai H.; Peck, Amy R.; Girondo, Melanie A.; Liu, Chengbao; Goodman, Chelain R.; Neilson, Lynn M.; Freydin, Boris; Chervoneva, Inna; Hyslop, Terry; Kovatich, Albert J.; Hooke, Jeffrey A.; Shriver, Craig D.; Fuchs, Serge Y.; Rui, Hallgeir

2014-01-01

Prolactin controls the development and function of milk-producing breast epithelia but also supports growth and differentiation of breast cancer, especially luminal subtypes. A principal signaling mediator of prolactin, Stat5, promotes cellular differentiation of breast cancer cells in vitro, and loss of active Stat5 in tumors is associated with anti-estrogen therapy failure in patients. In luminal breast cancer progesterone induces a cytokeratin-5 (CK5)-positive basal cell-like population. This population possesses characteristics of tumor stem cells including quiescence, therapy-resistance, and tumor-initiating capacity. Here we report that prolactin counteracts induction of the CK5-positive population by the synthetic progestin R5020 in luminal breast cancer cells both in vitro and in vivo. CK5-positive cells were chemoresistant as determined by four-fold reduced rate of apoptosis following docetaxel exposure. Progestin-induction of CK5 was preceded by marked up-regulation of BCL6, an oncogene and transcriptional repressor critical for the maintenance of leukemia-initiating cells. Knockdown of BCL6 prevented induction of CK5-positive cell population by progestin. Prolactin suppressed progestin-induced BCL6 through Jak2-Stat5 but not Erk- or Akt-dependent pathways. In premenopausal but not postmenopausal patients with hormone receptor-positive breast cancer, tumor protein levels of CK5 correlated positively with BCL6, and high BCL6 or CK5 protein levels were associated with unfavorable clinical outcome. Suppression of progestin-induction of CK5-positive cells represents a novel pro-differentiation effect of prolactin in breast cancer. The present progress may have direct implications for breast cancer progression and therapy since loss of prolactin receptor-Stat5 signaling occurs frequently and BCL6 inhibitors currently being evaluated for lymphomas may have value for breast cancer. PMID:23708665
Controlling the diversity of cell populations in a stem cell culture

NARCIS (Netherlands)

Heo, Inha; Clevers, Hans

2015-01-01

Culturing intestinal stem cells into 3D organoids results in heterogeneous cell populations, reflecting the in vivo cell type diversity. In a recent paper published in Nature, Wang et al. established a culture condition for a highly homogeneous population of intestinal stem cells.
Baseline natural killer and T cell populations correlation with virologic outcome after regimen simplification to atazanavir/ritonavir alone (ACTG 5201.

Directory of Open Access Journals (Sweden)

John E McKinnon

Full Text Available Simplified maintenance therapy with ritonavir-boosted atazanavir (ATV/r provides an alternative treatment option for HIV-1 infection that spares nucleoside analogs (NRTI for future use and decreased toxicity. We hypothesized that the level of immune activation (IA and recovery of lymphocyte populations could influence virologic outcomes after regimen simplification.Thirty-four participants with virologic suppression ≥ 48 weeks on antiretroviral therapy (2 NRTI plus protease inhibitor were switched to ATV/r alone in the context of the ACTG 5201 clinical trial. Flow cytometric analyses were performed on PBMC isolated from 25 patients with available samples, of which 24 had lymphocyte recovery sufficient for this study. Assessments included enumeration of T-cells (CD4/CD8, natural killer (NK (CD3+CD56+CD16+ cells and cell-associated markers (HLA-DR, CD's 38/69/94/95/158/279.Eight of the 24 patients had at least one plasma HIV-1 RNA level (VL >50 copies/mL during the study. NK cell levels below the group median of 7.1% at study entry were associated with development of VL >50 copies/mL following simplification by regression and survival analyses (p = 0.043 and 0.023, with an odds ratio of 10.3 (95% CI: 1.92-55.3. Simplification was associated with transient increases in naïve and CD25+ CD4+ T-cells, and had no impact on IA levels.Lower NK cell levels prior to regimen simplification were predictive of virologic rebound after discontinuation of nucleoside analogs. Regimen simplification did not have a sustained impact on markers of IA or T lymphocyte populations in 48 weeks of clinical monitoring.ClinicalTrials.gov NCT00084019.
Logic as Marr's computational level: Four case studies

NARCIS (Netherlands)

Baggio, G.; Lambalgen, M. van; Hagoort, P.

2015-01-01

We sketch four applications of Marr's levels-of-analysis methodology to the relations between logic and experimental data in the cognitive neuroscience of language and reasoning. The first part of the paper illustrates the explanatory power of computational level theories based on logic. We show
A probabilistic model for cell population phenotyping using HCS data.

Directory of Open Access Journals (Sweden)

Edouard Pauwels

Full Text Available High Content Screening (HCS platforms allow screening living cells under a wide range of experimental conditions and give access to a whole panel of cellular responses to a specific treatment. The outcome is a series of cell population images. Within these images, the heterogeneity of cellular response to the same treatment leads to a whole range of observed values for the recorded cellular features. Consequently, it is difficult to compare and interpret experiments. Moreover, the definition of phenotypic classes at a cell population level remains an open question, although this would ease experiments analyses. In the present work, we tackle these two questions. The input of the method is a series of cell population images for which segmentation and cellular phenotype classification has already been performed. We propose a probabilistic model to represent and later compare cell populations. The model is able to fully exploit the HCS-specific information: "dependence structure of population descriptors" and "within-population variability". The experiments we carried out illustrate how our model accounts for this specific information, as well as the fact that the model benefits from considering them. We underline that these features allow richer HCS data analysis than simpler methods based on single cellular feature values averaged over each well. We validate an HCS data analysis method based on control experiments. It accounts for HCS specificities that were not taken into account by previous methods but have a sound biological meaning. Biological validation of previously unknown outputs of the method constitutes a future line of work.
Effect of four herbicides on microbial population, soil organic matter ...

African Journals Online (AJOL)

The effect of four herbicides (atrazine, primeextra, paraquat and glyphosate) on soil microbial population, soil organic matter and dehydrogenase activity was assessed over a period of six weeks. Soil samples from cassava farms were treated with herbicides at company recommended rates. Soil dehydrogenase activity was ...
Different level of population differentiation among human genes

Directory of Open Access Journals (Sweden)

Zhang Ya-Ping

2011-01-01

Full Text Available Abstract Background During the colonization of the world, after dispersal out of African, modern humans encountered changeable environments and substantial phenotypic variations that involve diverse behaviors, lifestyles and cultures, were generated among the different modern human populations. Results Here, we study the level of population differentiation among different populations of human genes. Intriguingly, genes involved in osteoblast development were identified as being enriched with higher FST SNPs, a result consistent with the proposed role of the skeletal system in accounting for variation among human populations. Genes involved in the development of hair follicles, where hair is produced, were also found to have higher levels of population differentiation, consistent with hair morphology being a distinctive trait among human populations. Other genes that showed higher levels of population differentiation include those involved in pigmentation, spermatid, nervous system and organ development, and some metabolic pathways, but few involved with the immune system. Disease-related genes demonstrate excessive SNPs with lower levels of population differentiation, probably due to purifying selection. Surprisingly, we find that Mendelian-disease genes appear to have a significant excessive of SNPs with high levels of population differentiation, possibly because the incidence and susceptibility of these diseases show differences among populations. As expected, microRNA regulated genes show lower levels of population differentiation due to purifying selection. Conclusion Our analysis demonstrates different level of population differentiation among human populations for different gene groups.
Inferring individual-level processes from population-level patterns in cultural evolution

Science.gov (United States)

Wilder, Bryan

2017-01-01

Our species is characterized by a great degree of cultural variation, both within and between populations. Understanding how group-level patterns of culture emerge from individual-level behaviour is a long-standing question in the biological and social sciences. We develop a simulation model capturing demographic and cultural dynamics relevant to human cultural evolution, focusing on the interface between population-level patterns and individual-level processes. The model tracks the distribution of variants of cultural traits across individuals in a population over time, conditioned on different pathways for the transmission of information between individuals. From these data, we obtain theoretical expectations for a range of statistics commonly used to capture population-level characteristics (e.g. the degree of cultural diversity). Consistent with previous theoretical work, our results show that the patterns observed at the level of groups are rooted in the interplay between the transmission pathways and the age structure of the population. We also explore whether, and under what conditions, the different pathways can be distinguished based on their group-level signatures, in an effort to establish theoretical limits to inference. Our results show that the temporal dynamic of cultural change over time retains a stronger signature than the cultural composition of the population at a specific point in time. Overall, the results suggest a shift in focus from identifying the one individual-level process that likely produced the observed data to excluding those that likely did not. We conclude by discussing the implications for empirical studies of human cultural evolution. PMID:28989786
Inferring individual-level processes from population-level patterns in cultural evolution.

Science.gov (United States)

Kandler, Anne; Wilder, Bryan; Fortunato, Laura

2017-09-01

Our species is characterized by a great degree of cultural variation, both within and between populations. Understanding how group-level patterns of culture emerge from individual-level behaviour is a long-standing question in the biological and social sciences. We develop a simulation model capturing demographic and cultural dynamics relevant to human cultural evolution, focusing on the interface between population-level patterns and individual-level processes. The model tracks the distribution of variants of cultural traits across individuals in a population over time, conditioned on different pathways for the transmission of information between individuals. From these data, we obtain theoretical expectations for a range of statistics commonly used to capture population-level characteristics (e.g. the degree of cultural diversity). Consistent with previous theoretical work, our results show that the patterns observed at the level of groups are rooted in the interplay between the transmission pathways and the age structure of the population. We also explore whether, and under what conditions, the different pathways can be distinguished based on their group-level signatures, in an effort to establish theoretical limits to inference. Our results show that the temporal dynamic of cultural change over time retains a stronger signature than the cultural composition of the population at a specific point in time. Overall, the results suggest a shift in focus from identifying the one individual-level process that likely produced the observed data to excluding those that likely did not. We conclude by discussing the implications for empirical studies of human cultural evolution.

Population of vibrational levels of carbon dioxide by cylindrical fast ionization wave

KAUST Repository

Levko, Dmitry

2017-09-08

The population of vibrational levels of carbon dioxide (CO2) by a cylindrical fast ionization wave is analyzed using a one-dimensional Particle-in-Cell Monte Carlo collisions model. The model takes into account the inelastic electron-neutral collisions as well as the super-elastic collisions between electrons and excited species. We observe an efficient population of only the first two levels of the symmetric and asymmetric vibrational modes of CO2 by means of a fast ionization wave. The excitation of other higher vibrational modes by the fast ionization wave is inefficient. Additionally, we observe a strong influence of the secondary electron emission on the population of vibrational states of CO2. This effect is associated with the kinetics of high energy electrons generated in the cathode sheath.
Genetic architecture of fusarium head blight resistance in four winter triticale populations.

Science.gov (United States)

Kalih, R; Maurer, H P; Miedaner, T

2015-03-01

Fusarium head blight (FHB) is a devastating disease that causes significant reductions in yield and quality in wheat, rye, and triticale. In triticale, knowledge of the genetic architecture of FHB resistance is missing but essential due to modern breeding requirements. In our study, four doubled-haploid triticale populations (N=120 to 200) were evaluated for resistance to FHB caused by artificial inoculation with Fusarium culmorum in four environments. DArT markers were used to genotype triticale populations. Seventeen quantitative trait loci (QTL) for FHB resistance were detected across all populations; six of them were derived from rye genome and located on chromosomes 4R, 5R, and 7R, which are here reported for the first time. The total cross-validated ratio of the explained phenotypic variance for all detected QTL in each population was 41 to 68%. In all, 17 QTL for plant height and 18 QTL for heading stage were also detected across all populations; 3 and 5 of them, respectively, were overlapping with QTL for FHB. In conclusion, FHB resistance in triticale is caused by a multitude of QTL, and pyramiding them contributes to higher resistance.
Mitochondrial DNA deletion mutations in adult mouse cardiac side population cells

International Nuclear Information System (INIS)

Lushaj, Entela B.; Lozonschi, Lucian; Barnes, Maria; Anstadt, Emily; Kohmoto, Takushi

2012-01-01

We investigated the presence and potential role of mitochondrial DNA (mtDNA) deletion mutations in adult cardiac stem cells. Cardiac side population (SP) cells were isolated from 12-week-old mice. Standard polymerase chain reaction (PCR) was used to screen for the presence of mtDNA deletion mutations in (a) freshly isolated SP cells and (b) SP cells cultured to passage 10. When present, the abundance of mtDNA deletion mutation was analyzed in single cell colonies. The effect of different levels of deletion mutations on SP cell growth and differentiation was determined. MtDNA deletion mutations were found in both freshly isolated and cultured cells from 12-week-old mice. While there was no significant difference in the number of single cell colonies with mtDNA deletion mutations from any of the groups mentioned above, the abundance of mtDNA deletion mutations was significantly higher in the cultured cells, as determined by quantitative PCR. Within a single clonal cell population, the detectable mtDNA deletion mutations were the same in all cells and unique when compared to deletions of other colonies. We also found that cells harboring high levels of mtDNA deletion mutations (i.e. where deleted mtDNA comprised more than 60% of total mtDNA) had slower proliferation rates and decreased differentiation capacities. Screening cultured adult stem cells for mtDNA deletion mutations as a routine assessment will benefit the biomedical application of adult stem cells.
Coherence effects in three- and four-level laser-cooled rubidium systems

International Nuclear Information System (INIS)

De Echaniz, Sebastian R.

2002-01-01

This thesis presents developmental work on the existing magneto-optical trap (MOT) system and novel studies of coherence effects. The developmental work was carried out on the experimental apparatus used previously in this laboratory in order to perform experiments to study coherence effects in three- and four-level rubidium systems in the MOT. This developmental work includes the upgrading and installation of new laser systems, the improvement of the MOT, the installation of data acquisition hardware and software, and the commissioning of a new 'second generation' MOT. As part of our studies of coherence effects, we present a wide-ranging theoretical and experimental study of non-adiabatic transient phenomena in a Λ system which exhibits electromagnetically induced transparency when a strong coupling field is rapidly switched on or off using a Pockels cell. The theoretical treatment uses a Laplace transform approach as well as standard numerical methods to solve the time-dependent density matrix equation. The results show clear Rabi oscillations and transient gain without population inversion of a weak probe in parameter regions not previously studied, and provide insight into the transition dynamics between bare a dressed states. Experimental studies of a doubly driven V system are also reported, together with a theoretical dressed-state analysis of such systems. The expected three-peak spectrum is explored for various coupling field strengths and detunings. In all this work we have found good agreement between the theory and the experimental spectra once light shifts and uncoupled absorption in the rubidium system are taken into account. (author)
Variations in gene expression levels in four European zebra mussel, Dreissena polymorpha, populations in relation to metal bioaccumulation: A field study.

Science.gov (United States)

Kerambrun, E; Rioult, D; Delahaut, L; Evariste, L; Pain-Devin, S; Auffret, M; Geffard, A; David, E

2016-12-01

The present study was performed to validate the suitability of using gene expression in zebra mussels, Dreissena polymorpha, for biomonitoring of freshwater environment. Mussels were collected in four French rivers (Meuse, Moselle, Oise and Vilaine) in spring and autumn. Relative gene expression of 9 candidate genes involved in cellular metabolic activities (Cytochrome-c-oxidase - cox, and ATP synthase - atp), detoxification process (Metallothionein - mt and Glutathion-S-Transferase - gst), oxidative stress (Catalase - cat, Superoxyde Dismutase - sod and Glutathion peroxidase - gpx) and digestive functions (Amylase - amy and Cellulase - ghf) were measured in digestive gland. Metal bioaccumulation in tissues and morphometric parameters were also analyzed to interpret molecular responses. All our results are consistent with different physiological reactions to environmental condition between zebra mussel populations. In spring, the levels of mt, sod, gpx, cat, atp, amy and ghf relative expression were significantly higher in mussels with the lowest metal bioaccumulation (the Meuse) compared to at least one of the other sites. In autumn, this higher expression levels in Meuse River were still observed for gpx, cat, atp and amy. This study has also pointed out different sources of variability in gene expression (individual size, season, trophic resources and origin of mussels) which are inevitable in natural fluctuant environment. This underlines the importance to take them into account in field study to propose a correct interpretation of biomarker responses. Copyright © 2016 Elsevier Inc. All rights reserved.
Study on the gain media with four energy level model using two dimensional FDTD method

Energy Technology Data Exchange (ETDEWEB)

Wu, Bo; Sun, Bingbing; Xue, Hui; Xiao, Feng [Key Laboratory of Intelligent Computing and Signal Processing, Anhui University, Hefei 230039 (China); Huang, Zhixiang, E-mail: zxhuang@ahu.edu.cn [Key Laboratory of Intelligent Computing and Signal Processing, Anhui University, Hefei 230039 (China); Wu, Xianliang, E-mail: xlwu@ahu.edu.cn [Key Laboratory of Intelligent Computing and Signal Processing, Anhui University, Hefei 230039 (China); Department of Physics and Electronic Engineering, Hefei Normal University, Hefei 230061 (China)

2013-08-15

A four energy level model is applied to the gain media, which shows possible application to the complex metamaterials system due to its amplification effect. The coupled equations named polarization equation, rate equations of electronic population and Maxwell's equations are used to describe the coupling between the atoms and electromagnetic wave. Population inversion and lasing threshold are investigated using numerical simulations based on a novel finite-difference time-domain (FDTD) treatment of the optical field. The validations of the method are also tested. The numerical results show the good agreement with the classic lasing theory. Our numerical model can be used as an efficient design tool for investigating novel physical phenomena for new laser devices.
Autoradiographic research on cell proliferation of prenatal rat lung cells and their influence using the mitogen Kallikrein

International Nuclear Information System (INIS)

Bock-Lamberlin, P.R.

1980-01-01

In this work autoradiographic experiments were carried out on the kinetics of proliferation of four cell populations of the prenatal rat lung with the help of the determination of the 3 H-thymidine marker indices, with the following results: 1. The four studied cell populations exhibited variable proliferation rates on the twentieth or twenty-first day of development. 2. The strongest affect of the exogenously applied mitogen Kallikrein was demonstrated on the vessel wall cells, the next strongest on the bronchial epithelial cells, then the cartilage cells and finally the alveolar wall cells. 3. The mitogenic effect is dependent on dose. Higher doses significantly increased the 3 H-thymidine marker indices of the four cell populations tested in this work. 4. When the exposure time of the Kallikrein was extended by one hour this lead partially to stronger mitogenic effects than by the shorter exposure times at the same and higher dose levels of mitogen. 5. The 3 H-thymidine marker indices are dependent on the exposure time. 6. With increasing litter size, the 3 H indices as a rule decrease. (orig./MG) [de
Probing bacterial adhesion at the single-cell level

DEFF Research Database (Denmark)

Zeng, Guanghong; Müller, Torsten; Meyer, Rikke Louise

be considered. We have developed a simple and versatile method to make single-cell bacterial probes for measuring single cell adhesion by force spectroscopy using atomic force microscopy (AFM). A single-cell probe was readily made by picking up a bacterial cell from a glass surface by approaching a tipless AFM...... cantilever coated with the commercial cell adhesive CellTakTM. We applied the method to study adhesion of living cells to abiotic surfaces at the single-cell level. Immobilisation of single bacterial cells to the cantilever was stable for several hours, and viability was confirmed by Live/Dead staining...... on the adhesion force, we explored the bond formation and adhesive strength of four different bacterial strains towards three abiotic substrates with variable hydrophobicity and surface roughness. The adhesion force and final rupture length were dependent on bacterial strains, surfaces properties, and time...
Gene dosage compensation calibrates four regulatory RNAs to control Vibrio cholerae quorum sensing

DEFF Research Database (Denmark)

Svenningsen, Sine L; Tu, Kimberly C; Bassler, Bonnie L

2009-01-01

the quorum regulatory RNAs 1-4 (Qrr1-4). The four Qrr sRNAs are functionally redundant. That is, expression of any one of them is sufficient for wild-type quorum-sensing behaviour. Here, we show that the combined action of two feedback loops, one involving the sRNA-activator LuxO and one involving the sRNA......Quorum sensing is a mechanism of cell-to-cell communication that allows bacteria to coordinately regulate gene expression in response to changes in cell-population density. At the core of the Vibrio cholerae quorum-sensing signal transduction pathway reside four homologous small RNAs (sRNAs), named......-target HapR, promotes gene dosage compensation between the four qrr genes. Gene dosage compensation adjusts the total Qrr1-4 sRNA pool and provides the molecular mechanism underlying sRNA redundancy. The dosage compensation mechanism is exquisitely sensitive to small perturbations in Qrr levels. Precisely...
Identifying EGFR-Expressed Cells and Detecting EGFR Multi-Mutations at Single-Cell Level by Microfluidic Chip

Science.gov (United States)

Li, Ren; Zhou, Mingxing; Li, Jine; Wang, Zihua; Zhang, Weikai; Yue, Chunyan; Ma, Yan; Peng, Hailin; Wei, Zewen; Hu, Zhiyuan

2018-03-01

EGFR mutations companion diagnostics have been proved to be crucial for the efficacy of tyrosine kinase inhibitor targeted cancer therapies. To uncover multiple mutations occurred in minority of EGFR-mutated cells, which may be covered by the noises from majority of un-mutated cells, is currently becoming an urgent clinical requirement. Here we present the validation of a microfluidic-chip-based method for detecting EGFR multi-mutations at single-cell level. By trapping and immunofluorescently imaging single cells in specifically designed silicon microwells, the EGFR-expressed cells were easily identified. By in situ lysing single cells, the cell lysates of EGFR-expressed cells were retrieved without cross-contamination. Benefited from excluding the noise from cells without EGFR expression, the simple and cost-effective Sanger's sequencing, but not the expensive deep sequencing of the whole cell population, was used to discover multi-mutations. We verified the new method with precisely discovering three most important EGFR drug-related mutations from a sample in which EGFR-mutated cells only account for a small percentage of whole cell population. The microfluidic chip is capable of discovering not only the existence of specific EGFR multi-mutations, but also other valuable single-cell-level information: on which specific cells the mutations occurred, or whether different mutations coexist on the same cells. This microfluidic chip constitutes a promising method to promote simple and cost-effective Sanger's sequencing to be a routine test before performing targeted cancer therapy.[Figure not available: see fulltext.
Comparisons of metabolic syndrome definitions in four populations of the Asia-Pacific region

DEFF Research Database (Denmark)

Lee, C.M.; Huxley, R.R.; Woodward, M.

2008-01-01

BACKGROUND: To compare the prevalence of metabolic syndrome (MetS) by four MetS definitions in four Asia-Pacific populations, and to compare the prevalence of individual metabolic components. METHODS: Population-based cross-sectional studies from Australia, Japan, Korea, and Samoa were used...... for EGIR. There were marked differences in the prevalence of MetS between the sexes, with no systematic pattern, and between the prevalences of individual metabolic components. CONCLUSIONS: Differences in the prevalence of MetS and its components, using the various definitions, both within and between...
Population genetic implications from sequence variation in four Y chromosome genes.

Science.gov (United States)

Shen, P; Wang, F; Underhill, P A; Franco, C; Yang, W H; Roxas, A; Sung, R; Lin, A A; Hyman, R W; Vollrath, D; Davis, R W; Cavalli-Sforza, L L; Oefner, P J

2000-06-20

Some insight into human evolution has been gained from the sequencing of four Y chromosome genes. Primary genomic sequencing determined gene SMCY to be composed of 27 exons that comprise 4,620 bp of coding sequence. The unfinished sequencing of the 5' portion of gene UTY1 was completed by primer walking, and a total of 20 exons were found. By using denaturing HPLC, these two genes, as well as DBY and DFFRY, were screened for polymorphic sites in 53-72 representatives of the five continents. A total of 98 variants were found, yielding nucleotide diversity estimates of 2.45 x 10(-5), 5. 07 x 10(-5), and 8.54 x 10(-5) for the coding regions of SMCY, DFFRY, and UTY1, respectively, with no variant having been observed in DBY. In agreement with most autosomal genes, diversity estimates for the noncoding regions were about 2- to 3-fold higher and ranged from 9. 16 x 10(-5) to 14.2 x 10(-5) for the four genes. Analysis of the frequencies of derived alleles for all four genes showed that they more closely fit the expectation of a Luria-Delbrück distribution than a distribution expected under a constant population size model, providing evidence for exponential population growth. Pairwise nucleotide mismatch distributions date the occurrence of population expansion to approximately 28,000 years ago. This estimate is in accord with the spread of Aurignacian technology and the disappearance of the Neanderthals.
Understanding the sub-cellular dynamics of silicon transportation and synthesis in diatoms using population-level data and computational optimization.

Directory of Open Access Journals (Sweden)

Narjes Javaheri

2014-06-01

Full Text Available Controlled synthesis of silicon is a major challenge in nanotechnology and material science. Diatoms, the unicellular algae, are an inspiring example of silica biosynthesis, producing complex and delicate nano-structures. This happens in several cell compartments, including cytoplasm and silica deposition vesicle (SDV. Considering the low concentration of silicic acid in oceans, cells have developed silicon transporter proteins (SIT. Moreover, cells change the level of active SITs during one cell cycle, likely as a response to the level of external nutrients and internal deposition rates. Despite this topic being of fundamental interest, the intracellular dynamics of nutrients and cell regulation strategies remain poorly understood. One reason is the difficulties in measurements and manipulation of these mechanisms at such small scales, and even when possible, data often contain large errors. Therefore, using computational techniques seems inevitable. We have constructed a mathematical model for silicon dynamics in the diatom Thalassiosira pseudonana in four compartments: external environment, cytoplasm, SDV and deposited silica. The model builds on mass conservation and Michaelis-Menten kinetics as mass transport equations. In order to find the free parameters of the model from sparse, noisy experimental data, an optimization technique (global and local search, together with enzyme related penalty terms, has been applied. We have connected population-level data to individual-cell-level quantities including the effect of early division of non-synchronized cells. Our model is robust, proven by sensitivity and perturbation analysis, and predicts dynamics of intracellular nutrients and enzymes in different compartments. The model produces different uptake regimes, previously recognized as surge, externally-controlled and internally-controlled uptakes. Finally, we imposed a flux of SITs to the model and compared it with previous classical kinetics
Influence of neighbourhood purchasing power on breastfeeding at four months of age: a Swedish population-based cohort study.

Science.gov (United States)

Almquist-Tangen, Gerd; Strömberg, Ulf; Holmén, Anders; Alm, Bernt; Roswall, Josefine; Bergman, Stefan; Dahlgren, Jovanna

2013-11-15

Parental socioeconomic status (SES) is an important determinant in child health, influencing beneficial factors such as breastfeeding. A better understanding of the influence of neighbourhood-level SES measures, relating to spatial determinants, might lead to targeted actions to promote breastfeeding during infancy. A cross-sectional study analysis the association between breastfeeding at four months of age and neighbourhood purchasing power, taking account of individual-level variables including maternal age, smoking and parental level of education. Data were obtained from a prospective population- based cohort study recruited from birth in 2007-2008 in the Halland region, southwestern Sweden. Questionnaire data on the individual-level variables and the outcome variable of breastfeeding at four months (yes/no) were used (n=2,407). Each mother was geo-coded with respect to her residential parish (there are 61 parishes in the region) and then stratified by parish-level household purchasing power. It emerged that four neighbourhood characteristics were reasonable to use, viz. purchasing power. The proportion of mothers not breastfeeding at four months of age showed a highly significant trend across the neighbourhood strata (p=0.00004): from 16.3% (purchasing power) to 29.4% (≥ 30% with low purchasing power), yielding an OR of 2.24 (95% confidence interval: 1.45-3.16). After adjusting for the individual-level variables, the corresponding OR=1.63 (1.07-2.56) was significant and the trend across the strata was still evident (p=0.05). A multi-level analysis estimated that, in the neighbourhoods with ≥ 30% of the families with low purchasing power, 20% more mothers than expected, taking account of the individual-level factors, reported no breastfeeding at four months of age (≥ 95% posterior probability of an elevated observed-to-expected ratio). The neighbourhood purchasing power provided a spatial determinant of low numbers of mothers breastfeeding at four months
The Effects of Predator Evolution and Genetic Variation on Predator-Prey Population-Level Dynamics.

Science.gov (United States)

Cortez, Michael H; Patel, Swati

2017-07-01

This paper explores how predator evolution and the magnitude of predator genetic variation alter the population-level dynamics of predator-prey systems. We do this by analyzing a general eco-evolutionary predator-prey model using four methods: Method 1 identifies how eco-evolutionary feedbacks alter system stability in the fast and slow evolution limits; Method 2 identifies how the amount of standing predator genetic variation alters system stability; Method 3 identifies how the phase lags in predator-prey cycles depend on the amount of genetic variation; and Method 4 determines conditions for different cycle shapes in the fast and slow evolution limits using geometric singular perturbation theory. With these four methods, we identify the conditions under which predator evolution alters system stability and shapes of predator-prey cycles, and how those effect depend on the amount of genetic variation in the predator population. We discuss the advantages and disadvantages of each method and the relations between the four methods. This work shows how the four methods can be used in tandem to make general predictions about eco-evolutionary dynamics and feedbacks.
Antibiotic resistance shaping multi-level population biology of bacteria.

Science.gov (United States)

Baquero, Fernando; Tedim, Ana P; Coque, Teresa M

2013-01-01

Antibiotics have natural functions, mostly involving cell-to-cell signaling networks. The anthropogenic production of antibiotics, and its release in the microbiosphere results in a disturbance of these networks, antibiotic resistance tending to preserve its integrity. The cost of such adaptation is the emergence and dissemination of antibiotic resistance genes, and of all genetic and cellular vehicles in which these genes are located. Selection of the combinations of the different evolutionary units (genes, integrons, transposons, plasmids, cells, communities and microbiomes, hosts) is highly asymmetrical. Each unit of selection is a self-interested entity, exploiting the higher hierarchical unit for its own benefit, but in doing so the higher hierarchical unit might acquire critical traits for its spread because of the exploitation of the lower hierarchical unit. This interactive trade-off shapes the population biology of antibiotic resistance, a composed-complex array of the independent "population biologies." Antibiotics modify the abundance and the interactive field of each of these units. Antibiotics increase the number and evolvability of "clinical" antibiotic resistance genes, but probably also many other genes with different primary functions but with a resistance phenotype present in the environmental resistome. Antibiotics influence the abundance, modularity, and spread of integrons, transposons, and plasmids, mostly acting on structures present before the antibiotic era. Antibiotics enrich particular bacterial lineages and clones and contribute to local clonalization processes. Antibiotics amplify particular genetic exchange communities sharing antibiotic resistance genes and platforms within microbiomes. In particular human or animal hosts, the microbiomic composition might facilitate the interactions between evolutionary units involved in antibiotic resistance. The understanding of antibiotic resistance implies expanding our knowledge on multi-level
Modular Approach for Continuous Cell-Level Balancing to Improve Performance of Large Battery Packs: Preprint

Energy Technology Data Exchange (ETDEWEB)

Muneed ur Rehman, M.; Evzelman, M.; Hathaway, K.; Zane, R.; Plett, G. L.; Smith, K.; Wood, E.; Maksimovic, D.

2014-10-01

Energy storage systems require battery cell balancing circuits to avoid divergence of cell state of charge (SOC). A modular approach based on distributed continuous cell-level control is presented that extends the balancing function to higher level pack performance objectives such as improving power capability and increasing pack lifetime. This is achieved by adding DC-DC converters in parallel with cells and using state estimation and control to autonomously bias individual cell SOC and SOC range, forcing healthier cells to be cycled deeper than weaker cells. The result is a pack with improved degradation characteristics and extended lifetime. The modular architecture and control concepts are developed and hardware results are demonstrated for a 91.2-Wh battery pack consisting of four series Li-ion battery cells and four dual active bridge (DAB) bypass DC-DC converters.
Implementations of a four-level mechanical architecture for fault-tolerant robots

International Nuclear Information System (INIS)

Hooper, Richard; Sreevijayan, Dev; Tesar, Delbert; Geisinger, Joseph; Kapoor, Chelan

1996-01-01

This paper describes a fault tolerant mechanical architecture with four levels devised and implemented in concert with NASA (Tesar, D. and Sreevijayan, D., Four-level fault tolerance in manipulator design for space operations. In First Int. Symp. Measurement and Control in Robotics (ISMCR '90), Houston, Texas, 20-22 June 1990.) Subsequent work has clarified and revised the architecture. The four levels proceed from fault tolerance at the actuator level, to fault tolerance via in-parallel chains, to fault tolerance using serial kinematic redundancy, and finally to the fault tolerance multiple arm systems provide. This is a subsumptive architecture because each successive layer can incorporate the fault tolerance provided by all layers beneath. For instance a serially-redundant robot can incorporate dual fault-tolerant actuators. Redundant systems provide the fault tolerance, but the guiding principle of this architecture is that functional redundancies actively increase the performance of the system. Redundancies do not simply remain dormant until needed. This paper includes specific examples of hardware and/or software implementation at all four levels
Gene expression heterogeneities in embryonic stem cell populations

DEFF Research Database (Denmark)

Martinez Arias, Alfonso; Brickman, Joshua M

2011-01-01

Stem and progenitor cells are populations of cells that retain the capacity to populate specific lineages and to transit this capacity through cell division. However, attempts to define markers for stem cells have met with limited success. Here we consider whether this limited success reflects...... an intrinsic requirement for heterogeneity with stem cell populations. We focus on Embryonic Stem (ES) cells, in vitro derived cell lines from the early embryo that are considered both pluripotent (able to generate all the lineages of the future embryo) and indefinitely self renewing. We examine the relevance...... of recently reported heterogeneities in ES cells and whether these heterogeneities themselves are inherent requirements of functional potency and self renewal....
Investigating energy deposition within cell populations using Monte Carlo simulations.

Science.gov (United States)

Oliver, Patricia A K; Thomson, Rowan M

2018-06-27

In this work, we develop multicellular models of healthy and cancerous human soft tissues, which are used to investigate energy deposition in subcellular targets, quantify the microdosimetric spread in a population of cells, and determine how these results depend on model details. Monte Carlo (MC) tissue models combining varying levels of detail on different length scales are developed: microscopically-detailed regions of interest (>1500 explicitly-modelled cells) are embedded in bulk tissue phantoms irradiated by photons (20 keV to 1.25 MeV). Specific energy (z; energy imparted per unit mass) is scored in nuclei and cytoplasm compartments using the EGSnrc user-code egs_chamber; specific energy mean, <z>, standard deviation, σ_z, and distribution, f(z,D), are calculated for a variety of macroscopic doses, D. MC-calculated f(z,D) are compared with normal distributions having the same mean and standard deviation. For mGy doses, there is considerable variation in energy deposition (microdosimetric spread) throughout a cell population: e.g., for 30 keV photons irradiating melanoma with 7.5 μm cell radius and 3 μm nuclear radius, σ_z/<z> for nuclear targets is 170%, and the fraction of nuclei receiving no energy deposition, f_z=0, is 0.31 for a dose of 10 mGy. If cobalt-60 photons are considered instead, then σ_z/<z> decreases to 84%, and f_z=0 decreases to 0.036. These results correspond to randomly arranged cells with cell/nucleus sizes randomly sampled from a normal distribution with a standard deviation of 1 μm. If cells are arranged in a hexagonal lattice and cell/nucleus sizes are uniform throughout the population, then σ_z/<z> decreases to 106% and 68% for 30 keV and cobalt-60,respectively; f_z=0

Bridging the Timescales of Single-Cell and Population Dynamics

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Jafarpour, Farshid; Wright, Charles S.; Gudjonson, Herman; Riebling, Jedidiah; Dawson, Emma; Lo, Klevin; Fiebig, Aretha; Crosson, Sean; Dinner, Aaron R.; Iyer-Biswas, Srividya

2018-04-01

How are granular details of stochastic growth and division of individual cells reflected in smooth deterministic growth of population numbers? We provide an integrated, multiscale perspective of microbial growth dynamics by formulating a data-validated theoretical framework that accounts for observables at both single-cell and population scales. We derive exact analytical complete time-dependent solutions to cell-age distributions and population growth rates as functionals of the underlying interdivision time distributions, for symmetric and asymmetric cell division. These results provide insights into the surprising implications of stochastic single-cell dynamics for population growth. Using our results for asymmetric division, we deduce the time to transition from the reproductively quiescent (swarmer) to the replication-competent (stalked) stage of the Caulobacter crescentus life cycle. Remarkably, population numbers can spontaneously oscillate with time. We elucidate the physics leading to these population oscillations. For C. crescentus cells, we show that a simple measurement of the population growth rate, for a given growth condition, is sufficient to characterize the condition-specific cellular unit of time and, thus, yields the mean (single-cell) growth and division timescales, fluctuations in cell division times, the cell-age distribution, and the quiescence timescale.
Phase dependence of optical bistability and multistability in a four-level quantum system near a plasmonic nanostructure

International Nuclear Information System (INIS)

Asadpour, Seyyed Hossein; Rahimpour Soleimani, H.

2016-01-01

The optical bistability and multistability properties of a four-level quantum system near a plasmonic nanostructure embedded in a unidirectional ring cavity are studied theoretically. Two orthogonal circularly polarized laser fields with the same frequency, different phases and electric fields amplitude are interacted by four-level quantum system. It is found that in the presence of the plasmonic nanostructure, the bistable behaviors related to one of the laser fields propagating through the unidirectional ring cavity can be modified by relative phase and amplitude control of another laser fields. Our obtained results show that the optical bistability can be converted into the optical multistability by varying the value of distance between the quantum system and the surface of the plasmonic nanostructure. Moreover, it is shown that under specific condition related to the distance, the lasing without population inversion can be obtained
Phase dependence of optical bistability and multistability in a four-level quantum system near a plasmonic nanostructure

Energy Technology Data Exchange (ETDEWEB)

Asadpour, Seyyed Hossein; Rahimpour Soleimani, H., E-mail: Rahimpour@guilan.ac.ir [Computational Nanophysics Laboratory (CNL), Department of Physics, University of Guilan, Rasht (Iran, Islamic Republic of)

2016-01-14

The optical bistability and multistability properties of a four-level quantum system near a plasmonic nanostructure embedded in a unidirectional ring cavity are studied theoretically. Two orthogonal circularly polarized laser fields with the same frequency, different phases and electric fields amplitude are interacted by four-level quantum system. It is found that in the presence of the plasmonic nanostructure, the bistable behaviors related to one of the laser fields propagating through the unidirectional ring cavity can be modified by relative phase and amplitude control of another laser fields. Our obtained results show that the optical bistability can be converted into the optical multistability by varying the value of distance between the quantum system and the surface of the plasmonic nanostructure. Moreover, it is shown that under specific condition related to the distance, the lasing without population inversion can be obtained.
Reconstructing human pancreatic differentiation by mapping specific cell populations during development

DEFF Research Database (Denmark)

Ramond, Cyrille; Glaser, Nicolas; Berthault, Claire

2017-01-01

. Endocrine maturation progresses by up-regulating SUSD2 and lowering ECAD levels. Finally, in vitro differentiation of pancreatic endocrine cells derived from human pluripotent stem cells mimics key in vivo events. Our work paves the way to extend our understanding of the origin of mature human pancreatic......Information remains scarce on human development compared to animal models. Here, we reconstructed human fetal pancreatic differentiation using cell surface markers. We demonstrate that at 7weeks of development, the glycoprotein 2 (GP2) marks a multipotent cell population that will differentiate...... cell types and how such lineage decisions are regulated....
Genomic Dissection of Leaf Angle in Maize (Zea mays L. Using a Four-Way Cross Mapping Population.

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Junqiang Ding

Full Text Available Increasing grain yield by the selection for optimal plant architecture has been the key focus in modern maize breeding. As a result, leaf angle, an important determinant of plant architecture, has been significantly improved to adapt to the ever-increasing plant density in maize production over the past several decades. To extend our understanding on the genetic mechanisms of leaf angle in maize, we developed the first four-way cross mapping population, consisting of 277 lines derived from four maize inbred lines with varied leaf angles. The four-way cross mapping population together with the four parental lines were evaluated for leaf angle in two environments. In this study, we reported linkage maps built in the population and quantitative trait loci (QTL on leaf angle detected by inclusive composite interval mapping (ICIM. ICIM applies a two-step strategy to effectively separate the cofactor selection from the interval mapping, which controls the background additive and dominant effects at the same time. A total of 14 leaf angle QTL were identified, four of which were further validated in near-isogenic lines (NILs. Seven of the 14 leaf angle QTL were found to overlap with the published leaf angle QTL or genes, and the remaining QTL were unique to the four-way population. This study represents the first example of QTL mapping using a four-way cross population in maize, and demonstrates that the use of specially designed four-way cross is effective in uncovering the basis of complex and polygenetic trait like leaf angle in maize.
On interfaces between cell populations with different mobilities

KAUST Repository

Lorenzi, Tommaso

2016-11-18

Partial differential equations describing the dynamics of cell population densities from a fluid mechanical perspective can model the growth of avascular tumours. In this framework, we consider a system of equations that describes the interaction between a population of dividing cells and a population of non-dividing cells. The two cell populations are characterised by different mobilities. We present the results of numerical simulations displaying two-dimensional spherical waves with sharp interfaces between dividing and non-dividing cells. Furthermore, we numerically observe how different ratios between the mobilities change the morphology of the interfaces, and lead to the emergence of finger-like patterns of invasion above a threshold. Motivated by these simulations, we study the existence of one-dimensional travelling wave solutions.
Bet-hedging in bacteriocin producing Escherichia coli populations: the single cell perspective

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Bayramoglu, Bihter; Toubiana, David; van Vliet, Simon; Inglis, R. Fredrik; Shnerb, Nadav; Gillor, Osnat

2017-02-01

Production of public goods in biological systems is often a collaborative effort that may be detrimental to the producers. It is therefore sustainable only if a small fraction of the population shoulders the cost while the majority reap the benefits. We modelled this scenario using Escherichia coli populations producing colicins, an antibiotic that kills producer cells’ close relatives. Colicin expression is a costly trait, and it has been proposed that only a small fraction of the population actively expresses the antibiotic. Colicinogenic populations were followed at the single-cell level using time-lapse microscopy, and showed two distinct, albeit dynamic, subpopulations: the majority silenced colicin expression, while a small fraction of elongated, slow-growing cells formed colicin-expressing hotspots, placing a significant burden on expressers. Moreover, monitoring lineages of individual colicinogenic cells showed stochastic switching between expressers and non-expressers. Hence, colicin expressers may be engaged in risk-reducing strategies—or bet-hedging—as they balance the cost of colicin production with the need to repel competitors. To test the bet-hedging strategy in colicin-mediated interactions, competitions between colicin-sensitive and producer cells were simulated using a numerical model, demonstrating a finely balanced expression range that is essential to sustaining the colicinogenic population.
Heritability and genetic basis of protein level variation in an outbred population.

Science.gov (United States)

Parts, Leopold; Liu, Yi-Chun; Tekkedil, Manu M; Steinmetz, Lars M; Caudy, Amy A; Fraser, Andrew G; Boone, Charles; Andrews, Brenda J; Rosebrock, Adam P

2014-08-01

The genetic basis of heritable traits has been studied for decades. Although recent mapping efforts have elucidated genetic determinants of transcript levels, mapping of protein abundance has lagged. Here, we analyze levels of 4084 GFP-tagged yeast proteins in the progeny of a cross between a laboratory and a wild strain using flow cytometry and high-content microscopy. The genotype of trans variants contributed little to protein level variation between individual cells but explained >50% of the variance in the population's average protein abundance for half of the GFP fusions tested. To map trans-acting factors responsible, we performed flow sorting and bulk segregant analysis of 25 proteins, finding a median of five protein quantitative trait loci (pQTLs) per GFP fusion. Further, we find that cis-acting variants predominate; the genotype of a gene and its surrounding region had a large effect on protein level six times more frequently than the rest of the genome combined. We present evidence for both shared and independent genetic control of transcript and protein abundance: More than half of the expression QTLs (eQTLs) contribute to changes in protein levels of regulated genes, but several pQTLs do not affect their cognate transcript levels. Allele replacements of genes known to underlie trans eQTL hotspots confirmed the correlation of effects on mRNA and protein levels. This study represents the first genome-scale measurement of genetic contribution to protein levels in single cells and populations, identifies more than a hundred trans pQTLs, and validates the propagation of effects associated with transcript variation to protein abundance. © 2014 Parts et al.; Published by Cold Spring Harbor Laboratory Press.
Using Population Dose to Evaluate Community-level Health Initiatives.

Science.gov (United States)

Harner, Lisa T; Kuo, Elena S; Cheadle, Allen; Rauzon, Suzanne; Schwartz, Pamela M; Parnell, Barbara; Kelly, Cheryl; Solomon, Loel

2018-05-01

Successful community-level health initiatives require implementing an effective portfolio of strategies and understanding their impact on population health. These factors are complicated by the heterogeneity of overlapping multicomponent strategies and availability of population-level data that align with the initiatives. To address these complexities, the population dose methodology was developed for planning and evaluating multicomponent community initiatives. Building on the population dose methodology previously developed, this paper operationalizes dose estimates of one initiative targeting youth physical activity as part of the Kaiser Permanente Community Health Initiative, a multicomponent community-level obesity prevention initiative. The technical details needed to operationalize the population dose method are explained, and the use of population dose as an interim proxy for population-level survey data is introduced. The alignment of the estimated impact from strategy-level data analysis using the dose methodology and the data from the population-level survey suggest that dose is useful for conducting real-time evaluation of multiple heterogeneous strategies, and as a viable proxy for existing population-level surveys when robust strategy-level evaluation data are collected. This article is part of a supplement entitled Building Thriving Communities Through Comprehensive Community Health Initiatives, which is sponsored by Kaiser Permanente, Community Health. Copyright © 2018 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.
Crypt cell population kinetics in mouse jejunum under continuous beta irradiation from tritiated water

International Nuclear Information System (INIS)

Bhatia, A.L.; Gupta, M.L.; Saharan, B.R.

1979-01-01

The behaviour of crypt cell population in mouse jejunum under continuous beta irradiation from tritiated water (HTO) has been studied. Adult mice were maintained on tritiated drinking water of the activity of 1.25 μCi/ml, after priming injection. The crypts were studied at 1, 5, 7, 15 and 30 days after the initiation of treatment. It is observed that there is a partial recovery in proliferative activity after the first day of the treatment. Again there is a decrease in the crypt cells on the 7th day, after which this population appears to achieve a near-steady-state level at about 8% below normal at the last interval studied. Crypt cell population and mitotic figures showed a simultaneous dip and recovery, while dead cells showed inverse relationship. (orig.) [de
A Four-Level Hierarchy for Organizing Wildland Stream Resource Information

Science.gov (United States)

Harry Parrott; Daniel A. Marion; R. Douglas Perkinson

1989-01-01

An analysis of current USDA Forest Service methods of collecting and using wildland stream resource data indicates that required information can be organized into a four-level hierarchy. Information at each level is tiered with information at the preceding level. Level 1 is the ASSOCIATION, which is differentiated by stream size and flow regime. Level 2, STREAM TYPE,...
Cellular population dynamics control the robustness of the stem cell niche

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Adam L. MacLean

2015-11-01

Full Text Available Within populations of cells, fate decisions are controlled by an indeterminate combination of cell-intrinsic and cell-extrinsic factors. In the case of stem cells, the stem cell niche is believed to maintain ‘stemness’ through communication and interactions between the stem cells and one or more other cell-types that contribute to the niche conditions. To investigate the robustness of cell fate decisions in the stem cell hierarchy and the role that the niche plays, we introduce simple mathematical models of stem and progenitor cells, their progeny and their interplay in the niche. These models capture the fundamental processes of proliferation and differentiation and allow us to consider alternative possibilities regarding how niche-mediated signalling feedback regulates the niche dynamics. Generalised stability analysis of these stem cell niche systems enables us to describe the stability properties of each model. We find that although the number of feasible states depends on the model, their probabilities of stability in general do not: stem cell–niche models are stable across a wide range of parameters. We demonstrate that niche-mediated feedback increases the number of stable steady states, and show how distinct cell states have distinct branching characteristics. The ecological feedback and interactions mediated by the stem cell niche thus lend (surprisingly high levels of robustness to the stem and progenitor cell population dynamics. Furthermore, cell–cell interactions are sufficient for populations of stem cells and their progeny to achieve stability and maintain homeostasis. We show that the robustness of the niche – and hence of the stem cell pool in the niche – depends only weakly, if at all, on the complexity of the niche make-up: simple as well as complicated niche systems are capable of supporting robust and stable stem cell dynamics.
Reduced satellite cell population may lead to contractures in children with cerebral palsy.

Science.gov (United States)

Smith, Lucas R; Chambers, Henry G; Lieber, Richard L

2013-03-01

Satellite cells are the stem cells residing in muscle responsible for skeletal muscle growth and repair. Skeletal muscle in cerebral palsy (CP) has impaired longitudinal growth that results in muscle contractures. We hypothesized that the satellite cell population would be reduced in contractured muscle. We compared the satellite cell populations in hamstring muscles from participants with CP contracture (n=8; six males, two females; age range 6-15y; Gross Motor Function Classification System [GMFCS] levels II-V; 4 with hemiplegia, 4 with diplegia) and from typically developing participants (n=8; six males, two females, age range 15-18y). Muscle biopsies were extracted from the gracilis and semitendinosus muscles and mononuclear cells were isolated. Cell surface markers were stained with fluorescently conjugated antibodies to label satellite cells (neural cell adhesion molecule) and inflammatory and endothelial cells (CD34 and CD4 respectively). Cells were analyzed using flow cytometry to determine cell populations. After gating for intact cells a mean of 12.8% (SD 2.8%) were determined to be satellite cells in typically developing children, but only 5.3% (SD 2.3%; p0.05) suggesting the isolation procedure was valid. A reduced satellite cell population may account for the decreased longitudinal growth of muscles in CP that develop into fixed contractures or the decreased ability to strengthen muscle in CP. This suggests a unique musculoskeletal disease mechanism and provides a potential therapeutic target for debilitating muscle contractures. © The Authors. Developmental Medicine & Child Neurology © 2012 Mac Keith Press.
Preliminary assessment on exposure of four typical populations to potentially toxic metals by means of skin wipes under the influence of haze pollution.

Science.gov (United States)

Cao, Zhiguo; Wang, Mengmeng; Chen, Qiaoying; Zhang, Yajie; Dong, Wenjing; Yang, Tianfang; Yan, Guangxuan; Zhang, Xin; Pi, Yunqing; Xi, Benye; Bu, Qingwei

2018-02-01

To investigate the exposure risk of human beings to nine potentially toxic metals (PTMs), namely, Cu, Cr, Zn, As, Cd, Pb, Ni, Mn, and Co, skin wipe samples were collected from four types of populations, namely, children, undergraduates, security guards, and professional drivers, under different haze pollution levels in Xinxiang, China by using Ghost wipes. The Ghost wipes were quantitatively analyzed by inductively coupled plasma mass spectrometry (ICP-MS) after microwave digestion. Generally, Zn (ND-1350μg/m 2 for undergraduates, ND-2660μg/m 2 for security guards, ND-2460μg/m 2 for children, and ND-2530μg/m 2 for professional drivers) showed the highest concentration among the four populations, followed by Cu (0.02-83.4μg/m 2 for undergraduates, ND-70.2μg/m 2 for security guards, 23.2-487μg/m 2 for children, and ND-116μg/m 2 for professional drivers). As (ND-5.7μg/m 2 for undergraduates, ND-2.3μg/m 2 for security guards, ND-21.1μg/m 2 for children, and ND-11.0μg/m 2 for professional drivers) and Co (ND-6.0μg/m 2 for undergraduates, ND-7.9μg/m 2 for security guards, ND-13.4μg/m 2 for children, and ND-2.1μg/m 2 for professional drivers) showed the lowest concentrations in all populations. Remarkable differences were found among the four populations and PTM levels decreased in the following order: children, professional drivers, security guards, and undergraduates. Gender variation was discovered for undergraduates and children. Generally, PTM contamination in skin wipes collected during a light haze pollution level was generally higher than that during a heavy haze pollution level, but PTM contamination was comparable between the two haze pollution levels for children. Non-carcinogenic exposure risks to As, Cd, and Pb for all populations were higher than those for the other six elements but all of them were within the acceptable safety threshold, indicating no apparent non-carcinogenic risk. Copyright © 2017 Elsevier B.V. All rights reserved.
Mass Cytometry for Detection of Silver at the Bacterial Single Cell Level

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Yuting Guo

2017-07-01

Full Text Available Background: Mass cytometry (Cytometry by Time of Flight, CyTOF allows single-cell characterization on the basis of specific metal-based cell markers. In addition, other metals in the mass range such as silver can be detected per cell. Bacteria are known to be sensible to silver and a protocol was developed to measure both the number of affected cells per population and the quantities of silver per cell.Methods: For mass cytometry ruthenium red was used as a marker for all cells of a population while parallel application of cisplatin discriminated live from dead cells. Silver quantities per cell and frequencies of silver containing cells in a population were measured by mass cytometry. In addition, live/dead subpopulations were analyzed by flow cytometry and distinguished by cell sorting based on ruthenium red and propidium iodide double staining. Verification of the cells’ silver load was performed on the bulk level by using ICP-MS in combination with cell sorting. The protocol was developed by conveying both, fast and non-growing Pseudomonas putida cells as test organisms.Results: A workflow for labeling bacteria in order to be analyzed by mass cytometry was developed. Three different parameters were tested: ruthenium red provided counts for all bacterial cells in a population while consecutively applied cisplatin marked the frequency of dead cells. Apparent population heterogeneity was detected by different frequencies of silver containing cells. Silver quantities per cell were also well measurable. Generally, AgNP-10 treatment caused higher frequencies of dead cells, higher frequencies of silver containing cells and higher per-cell silver quantities. Due to an assumed chemical equilibrium of free and bound silver ions live and dead cells were associated with silver in equal quantities and this preferably during exponential growth. With ICP-MS up to 1.5 fg silver per bacterial cell were detected.Conclusion: An effective mass cytometry
Program-level and contextual-level determinants of low-median CD4+ cell count in cohorts of persons initiating ART in eight sub-Saharan African countries.

Science.gov (United States)

Nash, Denis; Wu, Yingfeng; Elul, Batya; Hoos, David; El Sadr, Wafaa

2011-07-31

In sub-Saharan Africa, many patients initiate antiretroviral therapy (ART) at CD4 cell counts much lower than those recommended in national guidelines. We examined program-level and contextual-level factors associated with low median CD4 cell count at ART initiation in populations initiating ART. Multilevel analysis of aggregate and program-level service delivery data. We examined data on 1690 cohorts of patients initiating ART during 2004-2008 in eight sub-Saharan African countries. Cohorts with median CD4 less than 111 cells/μl (the lowest quartile) were classified as having low median CD4 cell count at ART initiation. Cohort information was combined with time-updated program-level data and subnational contextual-level data, and analyzed using multilevel models. The 1690 cohorts had median CD4 cell count of 136 cells/μl and included 121,504 patients initiating ART at 267 clinics. Program-level factors associated with low cohort median CD4 cell count included urban setting [adjusted odds ratio (AOR) 2.1; 95% confidence interval (CI) 1.3-3.3], lower provider-to-patient ratio (AOR 2.2; 95% CI 1.3-4.0), no PMTCT program (AOR 3.6; 95% CI 1.0-12.8), outreach services for ART patients only vs. both pre-ART and ART patients (AOR 2.4; 95% CI 1.5-3.9), fewer vs. more adherence support services (AOR 1.6; 95% CI 1.0-2.5), and smaller cohort size (AOR 2.5; 95% CI 1.4-4.5). Contextual-level factors associated with low cohort median CD4 cell count included initiating ART in areas where a lower proportion of the population heard of AIDS, tested for HIV recently, and a higher proportion believed 'limiting themselves to one HIV-uninfected sexual partner reduces HIV risk'. Determinants of CD4 cell count at ART initiation in populations initiating ART operate at multiple levels. Structural interventions targeting points upstream from ART initiation along the continuum from infection to diagnosis to care engagement are needed.
Effects of profession on urinary PAH metabolite levels in the US population.

Science.gov (United States)

Liu, Bian; Jia, Chunrong

2016-01-01

Although exposure to polycyclic aromatic hydrocarbons (PAHs) is common in both environmental and occupational settings, few studies have compared PAH exposure among people with different professions. The purpose of this study was to investigate the variations in recent PAH exposure among different occupational groups over time using national representative samples. The study population consisted of 4162 participants from the 2001 to 2008 National Health and Nutrition Examination Survey, who had both urinary PAH metabolites and occupational information. Four corresponding monohydroxy-PAH urine metabolites: naphthalene (NAP), fluorene (FLUO), phenanthrene (PHEN), and pyrene (PYR) among seven broad occupational groups were analyzed using weighted linear regression models, adjusting for creatinine levels, sociodemographic factors, smoking status, and sampling season. The overall geometric mean concentrations of NAP, FLUO, PHEN, and PYR were 6927, 477, 335, and 87 ng/L, respectively. All four PAH metabolites were elevated in the "extractive, construction, and repair (ECR)" group, with 21-42 % higher concentrations than those in the reference group of "management." Similar trends were seen in the "operators, fabricators, and laborers (OFL)" group for FLUO, PHEN, and PYR. In addition, both "service" and "support" groups had elevated FLUO. Significant (p PAH exposure. Heterogeneous distributions of urinary PAH metabolites among people with different job categories exist at the population level. The upward temporal trends in NAP and PYR warrant reduction in PAH exposure, especially among those with OFL and ECR occupations.
Individual and population-level responses to ocean acidification.

Science.gov (United States)

Harvey, Ben P; McKeown, Niall J; Rastrick, Samuel P S; Bertolini, Camilla; Foggo, Andy; Graham, Helen; Hall-Spencer, Jason M; Milazzo, Marco; Shaw, Paul W; Small, Daniel P; Moore, Pippa J

2016-01-29

Ocean acidification is predicted to have detrimental effects on many marine organisms and ecological processes. Despite growing evidence for direct impacts on specific species, few studies have simultaneously considered the effects of ocean acidification on individuals (e.g. consequences for energy budgets and resource partitioning) and population level demographic processes. Here we show that ocean acidification increases energetic demands on gastropods resulting in altered energy allocation, i.e. reduced shell size but increased body mass. When scaled up to the population level, long-term exposure to ocean acidification altered population demography, with evidence of a reduction in the proportion of females in the population and genetic signatures of increased variance in reproductive success among individuals. Such increased variance enhances levels of short-term genetic drift which is predicted to inhibit adaptation. Our study indicates that even against a background of high gene flow, ocean acidification is driving individual- and population-level changes that will impact eco-evolutionary trajectories.
An efficient and reproducible process for transmission electron microscopy (TEM) of rare cell populations

Science.gov (United States)

Kumar, Sachin; Ciraolo, Georgianne; Hinge, Ashwini; Filippi, Marie-Dominique

2014-01-01

Transmission electron microscopy (TEM) provides ultra-structural details of cells at the sub-organelle level. However, details of the cellular ultrastructure, and the cellular organization and content of various organelles in rare populations, particularly in the suspension, like hematopoietic stem cells (HSCs) remained elusive. This is mainly due to the requirement of millions of cells for TEM studies. Thus, there is a vital requirement of a method that will allow TEM studies with low cell numbers of such rare populations. We describe an alternative and novel approach for TEM studies for rare cell populations. Here we performed TEM study from 10,000 HSC cells with quite ease. In particular, tiny cell pellets were identified by Evans blue staining after PFA-GA fixation. The cell pellet was pre-embedded in agarose in a small microcentrifuge tube and processed for dehydration, infiltration and embedding. Semi-thin and ultra-thin sections identified clusters of numerous cells per sections with well preserved morphology and ultrastructural details of golgi complex and mitochondria. Together, this method provides an efficient, easy and reproducible process to perform qualitative and quantitative TEM analysis from limited biological samples including cells in suspension. PMID:24291346
Taxonomic separation of hippocampal networks: principal cell populations and adult neurogenesis

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Roelof Maarten evan Dijk

2016-03-01

Full Text Available While many differences in hippocampal anatomy have been described between species, it is typically not clear if they are specific to a particular species and related to functional requirements or if they are shared by species of larger taxonomic units. Without such information, it is difficult to infer how anatomical differences may impact on hippocampal function, because multiple taxonomic levels need to be considered to associate behavioral and anatomical changes. To provide information on anatomical changes within and across taxonomic ranks, we present a quantitative assessment of hippocampal principal cell populations in 20 species or strain groups, with emphasis on rodents, the taxonomic group that provides most animals used in laboratory research. Of special interest is the importance of adult hippocampal neurogenesis in species-specific adaptations relative to other cell populations. Correspondence analysis of cell numbers shows that across taxonomic units, phylogenetically related species cluster together, sharing similar proportions of principal cell populations. CA3 and hilus are strong separators that place rodent species into a tight cluster based on their relatively large CA3 and small hilus while non-rodent species (including humans and non-human primates are placed on the opposite side of the spectrum. Hilus and CA3 are also separators within rodents, with a very large CA3 and rather small hilar cell populations separating mole-rats from other rodents that, in turn, are separated from each other by smaller changes in the proportions of CA1 and granule cells. When adult neurogenesis is included, the relatively small populations of young neurons, proliferating cells and hilar neurons become main drivers of taxonomic separation within rodents. The observations provide challenges to the computational modeling of hippocampal function, suggest differences in the organization of hippocampal information streams in rodent and non

Different levels of shade on population of grasshoppers and its oviposition preference on heliconias

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Ana Cristina Bittar

2018-02-01

Full Text Available ABSTRACT: Grasshoppers of the families Acrididae and Romaleidae (Orthoptera are among the insects that defoliate heliconias and have been gaining status as pests of commercial crops of these plants in Brazil. The objectives of the present study were to identify the grasshopper defoliating heliconias in the municipality of Santo Antônio de Pádua, RJ (Brazil, to evaluate the effect of different levels of shade on the population of this grasshopper and the production parameters of heliconias, and to determine if this grasshopper has an oviposition preference among the heliconias evaluated. The experiment was in a completely randomized block design, in subdivided plots (four levels of shade in the plot, 0%, 30%, 50% and 80%, and four species of Heliconia: H. psittacorum, H. stricta, H. wagneriana and H. psittacorum x H. spathocircinata ‘Golden Torch’ in the subplot, with four replications. The grasshopper was identified as Cornops frenatum frenatum (Acrididae. An increase in shade resulted in a decrease in the number of oviposition holes from the grasshopper and the number of lateral buds. Shade did not influence the number of C. f. frenatum nymphs and adults and the number of flower stems. H. wagneriana was the most preferred species for oviposition by C. f. frenatum. Results suggested using screens to shade heliconia plants can help control C. f. frenatum populations, however, the light requirements of the heliconias should be considered to guarantee productivity.
ARSENIC, CADMIUM, CHROMIUM, LEAD, MERCURY, AND SELENIUM LEVELS IN BLOOD OF FOUR SPECIES OF TURTLES FROM THE AMAZON IN BRAZIL

OpenAIRE

Burger, Joanna; Jeitner, Christian; Schneider, Larissa; Vogt, Richard; Gochfeld, Michael

2010-01-01

Using blood as a method of assessing metal levels in turtles may be useful for populations that are threatened or endangered or are decreasing. In this study the levels of arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg), and selenium (Se) in blood of four species of turtles from the tributaries of the Rio Negro in the Amazon of Brazil were examined. The turtles included the six-tubercled Amazon (river) turtle (Podocnemis sextuberculata), red-headed Amazon (river) turtle (Po...
Population modelling to compare chronic external radiotoxicity between individual and population endpoints in four taxonomic groups.

Science.gov (United States)

Alonzo, Frédéric; Hertel-Aas, Turid; Real, Almudena; Lance, Emilie; Garcia-Sanchez, Laurent; Bradshaw, Clare; Vives I Batlle, Jordi; Oughton, Deborah H; Garnier-Laplace, Jacqueline

2016-02-01

In this study, we modelled population responses to chronic external gamma radiation in 12 laboratory species (including aquatic and soil invertebrates, fish and terrestrial mammals). Our aim was to compare radiosensitivity between individual and population endpoints and to examine how internationally proposed benchmarks for environmental radioprotection protected species against various risks at the population level. To do so, we used population matrix models, combining life history and chronic radiotoxicity data (derived from laboratory experiments and described in the literature and the FREDERICA database) to simulate changes in population endpoints (net reproductive rate R0, asymptotic population growth rate λ, equilibrium population size Neq) for a range of dose rates. Elasticity analyses of models showed that population responses differed depending on the affected individual endpoint (juvenile or adult survival, delay in maturity or reduction in fecundity), the considered population endpoint (R0, λ or Neq) and the life history of the studied species. Among population endpoints, net reproductive rate R0 showed the lowest EDR10 (effective dose rate inducing 10% effect) in all species, with values ranging from 26 μGy h(-1) in the mouse Mus musculus to 38,000 μGy h(-1) in the fish Oryzias latipes. For several species, EDR10 for population endpoints were lower than the lowest EDR10 for individual endpoints. Various population level risks, differing in severity for the population, were investigated. Population extinction (predicted when radiation effects caused population growth rate λ to decrease below 1, indicating that no population growth in the long term) was predicted for dose rates ranging from 2700 μGy h(-1) in fish to 12,000 μGy h(-1) in soil invertebrates. A milder risk, that population growth rate λ will be reduced by 10% of the reduction causing extinction, was predicted for dose rates ranging from 24 μGy h(-1) in mammals to 1800 μGy h(-1) in
Cancer stem-like cells of ovarian clear cell carcinoma are enriched in the ALDH-high population associated with an accelerated scavenging system in reactive oxygen species.

Science.gov (United States)

Mizuno, T; Suzuki, N; Makino, H; Furui, T; Morii, E; Aoki, H; Kunisada, T; Yano, M; Kuji, S; Hirashima, Y; Arakawa, A; Nishio, S; Ushijima, K; Ito, K; Itani, Y; Morishige, K

2015-05-01

In ovarian cancer cases, recurrence after chemotherapy is frequently observed, suggesting the involvement of ovarian cancer stem-like cells (CSCs). The chemoresistance of ovarian clear cell carcinomas is particularly strong in comparison to other epithelial ovarian cancer subtypes. We investigated the relationship between a CSC marker, aldehyde dehydrogenase 1 (ALDH1), and clinical prognosis using ovarian clear cell carcinoma tissue samples. Furthermore, we investigated the antioxidant mechanism by which CSCs maintain a lower reactive oxygen species (ROS) level, which provides protection from chemotherapeutic agents. Immunohistochemical staining was performed to examine the CSC markers (CD133, CD44, ALDH1) using ovarian clear cell carcinoma tissue samples (n=81). Clear cell carcinoma cell lines (KOC-7C, OVTOKO) are separated into the ALDH-high and ALDH-low populations by ALDEFLUOR assay and fluorescence-activated cell sorting (FACS). We compared the intracellular ROS level, mRNA level of the antioxidant enzymes and Nrf2 expression of the two populations. High ALDH1 expression levels are related to advanced stage in clear cell carcinoma cases. ALDH1 expression significantly reduced progression free survival. Other markers are not related to clinical stage and prognosis. ALDH-high cells contained a lower ROS level than ALDH-low cells. Antioxidant enzymes were upregulated in ALDH-high cells. ALDH-high cells showed increased expression of Nrf2, a key transcriptional factor of the antioxidant system. ALDH-positive CSCs might have increased Nrf2-induced antioxidant scavengers, which lower ROS level relevant to chemoresistance in ovarian clear cell carcinoma. Copyright © 2014 Elsevier Inc. All rights reserved.
Population transcriptomics with single-cell resolution: a new field made possible by microfluidics: a technology for high throughput transcript counting and data-driven definition of cell types.

Science.gov (United States)

Plessy, Charles; Desbois, Linda; Fujii, Teruo; Carninci, Piero

2013-02-01

Tissues contain complex populations of cells. Like countries, which are comprised of mixed populations of people, tissues are not homogeneous. Gene expression studies that analyze entire populations of cells from tissues as a mixture are blind to this diversity. Thus, critical information is lost when studying samples rich in specialized but diverse cells such as tumors, iPS colonies, or brain tissue. High throughput methods are needed to address, model and understand the constitutive and stochastic differences between individual cells. Here, we describe microfluidics technologies that utilize a combination of molecular biology and miniaturized labs on chips to study gene expression at the single cell level. We discuss how the characterization of the transcriptome of each cell in a sample will open a new field in gene expression analysis, population transcriptomics, that will change the academic and biomedical analysis of complex samples by defining them as quantified populations of single cells. Copyright © 2013 WILEY Periodicals, Inc.
Four types of interference competition and their impacts on the ecology and evolution of size-structured populations and communities

DEFF Research Database (Denmark)

Zhang, Lai; Andersen, Ken Haste; Dieckmann, Ulf

2015-01-01

We investigate how four types of interference competition - which alternatively affect foraging, metabolism, survival, and reproduction - impact the ecology and evolution of size-structured populations. Even though all four types of interference competition reduce population biomass, interference...
Ecological feedbacks can reduce population-level efficacy of wildlife fertility control

Science.gov (United States)

Ransom, Jason I.; Powers, Jenny G.; Hobbs, N. Thompson; Baker, Dan L.

2014-01-01

1. Anthropogenic stress on natural systems, particularly the fragmentation of landscapes and the extirpation of predators from food webs, has intensified the need to regulate abundance of wildlife populations with management. Controlling population growth using fertility control has been considered for almost four decades, but nearly all research has focused on understanding effects of fertility control agents on individual animals. Questions about the efficacy of fertility control as a way to control populations remain largely unanswered. 2. Collateral consequences of contraception can produce unexpected changes in birth rates, survival, immigration and emigration that may reduce the effectiveness of regulating animal abundance. The magnitude and frequency of such effects vary with species-specific social and reproductive systems, as well as connectivity of populations. Developing models that incorporate static demographic parameters from populations not controlled by contraception may bias predictions of fertility control efficacy. 3. Many population-level studies demonstrate that changes in survival and immigration induced by fertility control can compensate for the reduction in births caused by contraception. The most successful cases of regulating populations using fertility control come from applications of contraceptives to small, closed populations of gregarious and easily accessed species. 4. Fertility control can result in artificial selection pressures on the population and may lead to long-term unintentional genetic consequences. The magnitude of such selection is dependent on individual heritability and behavioural traits, as well as environmental variation. 5. Synthesis and applications. Understanding species' life-history strategies, biology, behavioural ecology and ecological context is critical to developing realistic expectations of regulating populations using fertility control. Before time, effort and funding are invested in wildlife
Wortmannin efficiently suppresses the recovery from radiation-induced damage in pimonidazole-unlabeled quiescent tumor cell population

International Nuclear Information System (INIS)

Masunaga, Shin-ichiro; Suzuki, Minoru; Kondo, Natsuko; Narabayashi, Masaru; Ono, Koji; Sakurai, Yoshinori; Tanaka, Hiroki; Maruhashi, Akira

2013-01-01

Labeling of proliferating (P) cells in mice bearing EL4 tumors was achieved by continuous administration of 5-bromo-2'-deoxyuridine (BrdU). Tumors were irradiated with γ-rays at 1 h after pimonidazole administration followed by caffeine or wortmannin treatment. Twenty-four hours later, assessment of the responses of quiescent (Q) and total (=P+Q) cell populations were based on the frequencies of micronucleation and apoptosis using immunofluorescence staining for BrdU. The response of the pimonidazole-unlabeled tumor cell fractions was assessed by means of apoptosis frequency using immunofluorescence staining for pimonidazole. The pimonidazole-unlabeled cell fraction showed significantly enhanced radio-sensitivity compared with the whole cell fraction more remarkably in Q cells than total cells. However, a significantly greater decrease in radio-sensitivity in the pimonidazole-unlabeled than the whole cell fraction, evaluated using an assay performed 24 hours after irradiation, was more clearly observed in Q cells than total cells. In both the pimonidazole-unlabeled and the whole cell fractions, wortmannin efficiently suppressed the reduction in sensitivity due to delayed assay. Wortmannin combined with γ-ray irradiation is useful for suppressing the recovery from radiation-induced damage especially in the pimonidazole-unlabeled cell fraction within the total and Q tumor cell populations. (author)
Concise Review: Stem Cell Population Biology: Insights from Hematopoiesis.

Science.gov (United States)

MacLean, Adam L; Lo Celso, Cristina; Stumpf, Michael P H

2017-01-01

Stem cells are fundamental to human life and offer great therapeutic potential, yet their biology remains incompletely-or in cases even poorly-understood. The field of stem cell biology has grown substantially in recent years due to a combination of experimental and theoretical contributions: the experimental branch of this work provides data in an ever-increasing number of dimensions, while the theoretical branch seeks to determine suitable models of the fundamental stem cell processes that these data describe. The application of population dynamics to biology is amongst the oldest applications of mathematics to biology, and the population dynamics perspective continues to offer much today. Here we describe the impact that such a perspective has made in the field of stem cell biology. Using hematopoietic stem cells as our model system, we discuss the approaches that have been used to study their key properties, such as capacity for self-renewal, differentiation, and cell fate lineage choice. We will also discuss the relevance of population dynamics in models of stem cells and cancer, where competition naturally emerges as an influential factor on the temporal evolution of cell populations. Stem Cells 2017;35:80-88. © 2016 AlphaMed Press.
Quantitative gene expression profiling of CD45+ and CD45- skeletal muscle-derived side population cells

DEFF Research Database (Denmark)

Ditte Caroline Andersen, Ditte Caroline; Kristiansen, Gitte Qvist; Jensen, Line

2012-01-01

The skeletal muscle-derived side population (mSP) which highly excludes Hoechst 33342 is composed of CD45(+) and CD45(-) subpopulations; yet, rareness of mSP cells in general has complicated extensive quantitative analysis of gene expression profiles in primarily isolated mSP cells. Here, we desc...... a satellite cell subpopulation) remain in the mSPCD45(-) fraction, and we show that these cells express high levels of many of the known myogenic precursor/stem cell related markers, including Pax7 and Myf5.......The skeletal muscle-derived side population (mSP) which highly excludes Hoechst 33342 is composed of CD45(+) and CD45(-) subpopulations; yet, rareness of mSP cells in general has complicated extensive quantitative analysis of gene expression profiles in primarily isolated mSP cells. Here, we...... describe the isolation of adult mouse normal skeletal muscle residing SPCD45(+) and SPCD45(-) cells from a parent mononuclear muscle-derived cell (MDC) population. Relative quantitative real time PCR (RT-PCR) of 64 genes revealed that mSPCD45(-) compared with mSPCD45(+) was enriched for cells expressing...
Achieving nonlinear optical modulation via four-wave mixing in a four-level atomic system

Science.gov (United States)

Li, Hai-Chao; Ge, Guo-Qin; Zubairy, M. Suhail

2018-05-01

We propose an accessible scheme for implementing tunable nonlinear optical amplification and attenuation via a synergetic mechanism of four-wave mixing (FWM) and optical interference in a four-level ladder-type atomic system. By constructing a cyclic atom-field interaction, we show that two reverse FWM processes can coexist via optical transitions in different branches. In the suitable input-field conditions, strong interference effects between the input fields and the generated FWM fields can be induced and result in large amplification and deep attenuation of the output fields. Moreover, such an optical modulation from enhancement to suppression can be controlled by tuning the relative phase. The quantum system can be served as a switchable optical modulator with potential applications in quantum nonlinear optics.
Chapter 22. Cell population kinetics

International Nuclear Information System (INIS)

Tubiana, M.

1975-01-01

The main contribution of radioisotopes to the development of a new discipline, cell population kinetics, was shown. The aim of this science is to establish, for each tissue of the organism, the life span of its component cells and the mechanisms governing its growth, its differentiation and its homeostasis with respect to outside attacks. Labelling techniques have been used to follow the cells during these various processes. The case of non-dividing cells was considered first, taking as example, the red blood cells of which the lifetime was studied, after which the case of proliferating cells was examined using 14 C- or tritium-labelled thymidine. The methods used to measure the cell cycle parameters were described: labelled-mitosis curve method, double-labelling and continuous labelling methods, proliferation coefficient measurement. Cell kinetics were shown to allow an interpretation of radiobiological data. Finally the practical value of cell kinetics research was shown [fr
An indication of major genes affecting hip and elbow dysplasia in four Finnish dog populations

NARCIS (Netherlands)

Maki, K.; Janss, L.L.G.; Groen, A.F.; Liinamo, A.E.; Ojala, M.

2004-01-01

The aim of the study was to assess the possible existence of major genes influencing hip and elbow dysplasia in four dog populations. A Bayesian segregation analysis was performed separately on each population. In total, 34 140 dogs were included in the data set. Data were analysed with both a
Radiosensitivity of four human tumor xenografts. Influence of hypoxia and cell-cell contact

International Nuclear Information System (INIS)

Guichard, M.; Dertinger, H.; Malaise, E.P.

1983-01-01

Contact effect (CE) and hypoxia have been studied in human tumor cell lines transplanted in athymic nude mice. Four cell lines - one melanoma (Bell) and three colorectal adenocarcinomas (HT29, HRT18, and HCT8) - were studied. Cell survival was determined with an in vivo in vitro colony-forming assay. Survival curves were obtained under three different conditions: (1) tumor cells irradiated in air-breathing mice, (2) tumor cells irradiated in animals asphyxiated for 10 min, and (3) tumor cells plated and irradiated either immediately or 5 hr later. For all cell lines, radiosensitivity appeared to be lower when cells were irradiated in vivo than when they were irradiated in vitro. Only in the case of the HCT8 tumor did the relative in vivo radioresistance seem to be linked to hypoxia; in the other cell lines, hypoxia alone could not account for the lower in vivo radiosensitivity. Our results suggest that a CE plays an important role in the response of human xenografts to irradiation
Multiple dendritic cell populations activate CD4+ T cells after viral stimulation.

Directory of Open Access Journals (Sweden)

Adele M Mount

2008-02-01

Full Text Available Dendritic cells (DC are a heterogeneous cell population that bridge the innate and adaptive immune systems. CD8alpha DC play a prominent, and sometimes exclusive, role in driving amplification of CD8(+ T cells during a viral infection. Whether this reliance on a single subset of DC also applies for CD4(+ T cell activation is unknown. We used a direct ex vivo antigen presentation assay to probe the capacity of flow cytometrically purified DC populations to drive amplification of CD4(+ and CD8(+ T cells following infection with influenza virus by different routes. This study examined the contributions of non-CD8alpha DC populations in the amplification of CD8(+ and CD4(+ T cells in cutaneous and systemic influenza viral infections. We confirmed that in vivo, effective immune responses for CD8(+ T cells are dominated by presentation of antigen by CD8alpha DC but can involve non-CD8alpha DC. In contrast, CD4(+ T cell responses relied more heavily on the contributions of dermal DC migrating from peripheral lymphoid tissues following cutaneous infection, and CD4 DC in the spleen after systemic infection. CD4(+ T cell priming by DC subsets that is dependent upon the route of administration raises the possibility that vaccination approaches could be tailored to prime helper T cell immunity.
Enhanced 2/3 four-ary modulation code using soft-decision Viterbi decoding for four-level holographic data storage systems

Science.gov (United States)

Kong, Gyuyeol; Choi, Sooyong

2017-09-01

An enhanced 2/3 four-ary modulation code using soft-decision Viterbi decoding is proposed for four-level holographic data storage systems. While the previous four-ary modulation codes focus on preventing maximum two-dimensional intersymbol interference patterns, the proposed four-ary modulation code aims at maximizing the coding gains for better bit error rate performances. For achieving significant coding gains from the four-ary modulation codes, we design a new 2/3 four-ary modulation code in order to enlarge the free distance on the trellis through extensive simulation. The free distance of the proposed four-ary modulation code is extended from 1.21 to 2.04 compared with that of the conventional four-ary modulation code. The simulation result shows that the proposed four-ary modulation code has more than 1 dB gains compared with the conventional four-ary modulation code.
Chromosomal imbalances in four new uterine cervix carcinoma derived cell lines

International Nuclear Information System (INIS)

Hidalgo, Alfredo; Monroy, Alberto; Arana, Rosa Ma; Taja, Lucía; Vázquez, Guelaguetza; Salcedo, Mauricio

2003-01-01

Uterine cervix carcinoma is the second most common female malignancy worldwide and a major health problem in Mexico, representing the primary cause of death among the Mexican female population. High risk human papillomavirus (HPV) infection is considered to be the most important risk factor for the development of this tumor and cervical carcinoma derived cell lines are very useful models for the study of viral carcinogenesis. Comparative Genomic Hybridization (CGH) experiments have detected a specific pattern of chromosomal imbalances during cervical cancer progression, indicating chromosomal regions that might contain genes that are important for cervical transformation. We performed HPV detection and CGH analysis in order to initiate the genomic characterization of four recently established cervical carcinoma derived cell lines from Mexican patients. All the cell lines were HPV18 positive. The most prevalent imbalances in the cell lines were gains in chromosomes 1q23-q32, 3q11.2-q13.1, 3q22-q26.1, 5p15.1-p11.2, this alteration present as a high copy number amplification in three of the cell lines, 7p15-p13, 7q21, 7q31, 11q21, and 12q12, and losses in 2q35-qter, 4p16, 6q26-qter, 9q34 and 19q13.2-qter. Analysis of our present findings and previously reported data suggest that gains at 1q31-q32 and 7p13-p14, as well as losses at 6q26-q27 are alterations that might be unique for HPV18 positive cases. These chromosomal regions, as well as regions with high copy number amplifications, coincide with known fragile sites and known HPV integration sites. The general pattern of chromosomal imbalances detected in the cells resembled that found in invasive cervical tumors, suggesting that the cells represent good models for the study of cervical carcinoma
Identification of XMRV infection-associated microRNAs in four cell types in culture.

Directory of Open Access Journals (Sweden)

Ketha V K Mohan

Full Text Available INTRODUCTION: XMRV is a gammaretrovirus that was thought to be associated with prostate cancer (PC and chronic fatigue syndrome (CFS in humans until recently. The virus is culturable in various cells of human origin like the lymphocytes, NK cells, neuronal cells, and prostate cell lines. MicroRNAs (miRNA, which regulate gene expression, were so far not identified in cells infected with XMRV in culture. METHODS: Two prostate cell lines (LNCaP and DU145 and two primary cells, Peripheral Blood Lymphocytes [PBL] and Monocyte-derived Macrophages [MDM] were infected with XMRV. Total mRNA was extracted from mock- and virus-infected cells at 6, 24 and 48 hours post infection and evaluated for microRNA profile in a microarray. RESULTS: MicroRNA expression profiles of XMRV-infected continuous prostate cancer cell lines differ from that of virus-infected primary cells (PBL and MDMs. miR-193a-3p and miRPlus-E1245 observed to be specific to XMRV infection in all 4 cell types. While miR-193a-3p levels were down regulated miRPlus-E1245 on the other hand exhibited varied expression profile between the 4 cell types. DISCUSSION: The present study clearly demonstrates that cellular microRNAs are expressed during XMRV infection of human cells and this is the first report demonstrating the regulation of miR193a-3p and miRPlus-E1245 during XMRV infection in four different human cell types.
Prevalence of problematic cell phone use in an adult population in Spain as assessed by the Mobile Phone Problem Use Scale (MPPUS)

Science.gov (United States)

de-Sola, José; Talledo, Hernán; Rubio, Gabriel

2017-01-01

Problematic cell phone use has alarmingly increased in industrialized countries in the past 10 years. For many perpetrators, it can turn into a behavioural addiction, although this is not a recognized medical condition. Although there are many tools for evaluating this use, one of the most widely used tools is the Mobile Phone Problematic Use Scale (MPPUS), which we test on a representative sample of the population in Spain to obtain an estimate of the prevalence of problematic cell phone use in our midst. The age range consists of 16–65 years, with 1,126 surveys conducted. In this population, we verify that the reliability and internal consistency of the MPPUS (α = 0.939) are maintained. Additionally, the construct validity, considering the derived factors (Abuse and Dependence, Craving and Loss of Control, and Dependence on the Social Environment) are aligned with other research and with diverse external criteria of addiction. We establish four categories of users (Casual, Regular, At Risk, and Problematic) and obtain a prevalence of 15.4% among At Risk Users and 5.1% among Problematic Users. This finding implies a total of 20.5% of Users with Problems. A binary logistic regression analysis shows that age, gender, level of education, and daily cell phone use predict problematic cell phone use. The results, based on multiple criteria, show that such problematic use shares features of recognized addictions, affecting large segments of the population and not only adolescents. PMID:28771626
Prevalence of problematic cell phone use in an adult population in Spain as assessed by the Mobile Phone Problem Use Scale (MPPUS).

Science.gov (United States)

de-Sola, José; Talledo, Hernán; Rodríguez de Fonseca, Fernando; Rubio, Gabriel

2017-01-01

Problematic cell phone use has alarmingly increased in industrialized countries in the past 10 years. For many perpetrators, it can turn into a behavioural addiction, although this is not a recognized medical condition. Although there are many tools for evaluating this use, one of the most widely used tools is the Mobile Phone Problematic Use Scale (MPPUS), which we test on a representative sample of the population in Spain to obtain an estimate of the prevalence of problematic cell phone use in our midst. The age range consists of 16-65 years, with 1,126 surveys conducted. In this population, we verify that the reliability and internal consistency of the MPPUS (α = 0.939) are maintained. Additionally, the construct validity, considering the derived factors (Abuse and Dependence, Craving and Loss of Control, and Dependence on the Social Environment) are aligned with other research and with diverse external criteria of addiction. We establish four categories of users (Casual, Regular, At Risk, and Problematic) and obtain a prevalence of 15.4% among At Risk Users and 5.1% among Problematic Users. This finding implies a total of 20.5% of Users with Problems. A binary logistic regression analysis shows that age, gender, level of education, and daily cell phone use predict problematic cell phone use. The results, based on multiple criteria, show that such problematic use shares features of recognized addictions, affecting large segments of the population and not only adolescents.

Prevalence of problematic cell phone use in an adult population in Spain as assessed by the Mobile Phone Problem Use Scale (MPPUS.

Directory of Open Access Journals (Sweden)

José de-Sola

Full Text Available Problematic cell phone use has alarmingly increased in industrialized countries in the past 10 years. For many perpetrators, it can turn into a behavioural addiction, although this is not a recognized medical condition. Although there are many tools for evaluating this use, one of the most widely used tools is the Mobile Phone Problematic Use Scale (MPPUS, which we test on a representative sample of the population in Spain to obtain an estimate of the prevalence of problematic cell phone use in our midst. The age range consists of 16-65 years, with 1,126 surveys conducted. In this population, we verify that the reliability and internal consistency of the MPPUS (α = 0.939 are maintained. Additionally, the construct validity, considering the derived factors (Abuse and Dependence, Craving and Loss of Control, and Dependence on the Social Environment are aligned with other research and with diverse external criteria of addiction. We establish four categories of users (Casual, Regular, At Risk, and Problematic and obtain a prevalence of 15.4% among At Risk Users and 5.1% among Problematic Users. This finding implies a total of 20.5% of Users with Problems. A binary logistic regression analysis shows that age, gender, level of education, and daily cell phone use predict problematic cell phone use. The results, based on multiple criteria, show that such problematic use shares features of recognized addictions, affecting large segments of the population and not only adolescents.
Population modelling to compare chronic external radiotoxicity between individual and population endpoints in four taxonomic groups

International Nuclear Information System (INIS)

Alonzo, Frédéric; Hertel-Aas, Turid; Real, Almudena; Lance, Emilie; Garcia-Sanchez, Laurent; Bradshaw, Clare; Vives i Batlle, Jordi; Oughton, Deborah H.; Garnier-Laplace, Jacqueline

2016-01-01

In this study, we modelled population responses to chronic external gamma radiation in 12 laboratory species (including aquatic and soil invertebrates, fish and terrestrial mammals). Our aim was to compare radiosensitivity between individual and population endpoints and to examine how internationally proposed benchmarks for environmental radioprotection protected species against various risks at the population level. To do so, we used population matrix models, combining life history and chronic radiotoxicity data (derived from laboratory experiments and described in the literature and the FREDERICA database) to simulate changes in population endpoints (net reproductive rate R_0, asymptotic population growth rate λ, equilibrium population size N_e_q) for a range of dose rates. Elasticity analyses of models showed that population responses differed depending on the affected individual endpoint (juvenile or adult survival, delay in maturity or reduction in fecundity), the considered population endpoint (R_0, λ or N_e_q) and the life history of the studied species. Among population endpoints, net reproductive rate R_0 showed the lowest EDR_1_0 (effective dose rate inducing 10% effect) in all species, with values ranging from 26 μGy h"−"1 in the mouse Mus musculus to 38,000 μGy h"−"1 in the fish Oryzias latipes. For several species, EDR_1_0 for population endpoints were lower than the lowest EDR_1_0 for individual endpoints. Various population level risks, differing in severity for the population, were investigated. Population extinction (predicted when radiation effects caused population growth rate λ to decrease below 1, indicating that no population growth in the long term) was predicted for dose rates ranging from 2700 μGy h"−"1 in fish to 12,000 μGy h"−"1 in soil invertebrates. A milder risk, that population growth rate λ will be reduced by 10% of the reduction causing extinction, was predicted for dose rates ranging from 24 μGy h"−"1
A millifluidic study of cell-to-cell heterogeneity in growth-rate and cell-division capability in populations of isogenic cells of Chlamydomonas reinhardtii.

Directory of Open Access Journals (Sweden)

Shima P Damodaran

Full Text Available To address possible cell-to-cell heterogeneity in growth dynamics of isogenic cell populations of Chlamydomonas reinhardtii, we developed a millifluidic drop-based device that not only allows the analysis of populations grown from single cells over periods of a week, but is also able to sort and collect drops of interest, containing viable and healthy cells, which can be used for further experimentation. In this study, we used isogenic algal cells that were first synchronized in mixotrophic growth conditions. We show that these synchronized cells, when placed in droplets and kept in mixotrophic growth conditions, exhibit mostly homogeneous growth statistics, but with two distinct subpopulations: a major population with a short doubling-time (fast-growers and a significant subpopulation of slowly dividing cells (slow-growers. These observations suggest that algal cells from an isogenic population may be present in either of two states, a state of restricted division and a state of active division. When isogenic cells were allowed to propagate for about 1000 generations on solid agar plates, they displayed an increased heterogeneity in their growth dynamics. Although we could still identify the original populations of slow- and fast-growers, drops inoculated with a single progenitor cell now displayed a wider diversity of doubling-times. Moreover, populations dividing with the same growth-rate often reached different cell numbers in stationary phase, suggesting that the progenitor cells differed in the number of cell divisions they could undertake. We discuss possible explanations for these cell-to-cell heterogeneities in growth dynamics, such as mutations, differential aging or stochastic variations in metabolites and macromolecules yielding molecular switches, in the light of single-cell heterogeneities that have been reported among isogenic populations of other eu- and prokaryotes.
Emergency concepts for the safety level four; Notfallkonzepte der Sicherheitsebene Vier

Energy Technology Data Exchange (ETDEWEB)

Richner, Martin [Axpo Power AG, Doettingen (Switzerland). Kernkraftwerk Beznau

2016-04-15

According to the IAEA Guidelines and the Swiss Safety Guidelines the defence-in depth safety concept for a nuclear power plant consists of four safety levels. Emergency measures for the limitation of beyond design basis accidents are of safety level four. They are referred to as incident management. After the Chernobyl accident in 1986, in Switzerland the former regulatory body HSK (today ENSI) requested several retrofit measures in the field of accident management. The importance of accident management was visible again in Fukushima and demands for preventive measures grew.
Genome of the Netherlands population-specific imputations identify an ABCA6 variant associated with cholesterol levels

Science.gov (United States)

van Leeuwen, Elisabeth M.; Karssen, Lennart C.; Deelen, Joris; Isaacs, Aaron; Medina-Gomez, Carolina; Mbarek, Hamdi; Kanterakis, Alexandros; Trompet, Stella; Postmus, Iris; Verweij, Niek; van Enckevort, David J.; Huffman, Jennifer E.; White, Charles C.; Feitosa, Mary F.; Bartz, Traci M.; Manichaikul, Ani; Joshi, Peter K.; Peloso, Gina M.; Deelen, Patrick; van Dijk, Freerk; Willemsen, Gonneke; de Geus, Eco J.; Milaneschi, Yuri; Penninx, Brenda W.J.H.; Francioli, Laurent C.; Menelaou, Androniki; Pulit, Sara L.; Rivadeneira, Fernando; Hofman, Albert; Oostra, Ben A.; Franco, Oscar H.; Leach, Irene Mateo; Beekman, Marian; de Craen, Anton J.M.; Uh, Hae-Won; Trochet, Holly; Hocking, Lynne J.; Porteous, David J.; Sattar, Naveed; Packard, Chris J.; Buckley, Brendan M.; Brody, Jennifer A.; Bis, Joshua C.; Rotter, Jerome I.; Mychaleckyj, Josyf C.; Campbell, Harry; Duan, Qing; Lange, Leslie A.; Wilson, James F.; Hayward, Caroline; Polasek, Ozren; Vitart, Veronique; Rudan, Igor; Wright, Alan F.; Rich, Stephen S.; Psaty, Bruce M.; Borecki, Ingrid B.; Kearney, Patricia M.; Stott, David J.; Adrienne Cupples, L.; Neerincx, Pieter B.T.; Elbers, Clara C.; Francesco Palamara, Pier; Pe'er, Itsik; Abdellaoui, Abdel; Kloosterman, Wigard P.; van Oven, Mannis; Vermaat, Martijn; Li, Mingkun; Laros, Jeroen F.J.; Stoneking, Mark; de Knijff, Peter; Kayser, Manfred; Veldink, Jan H.; van den Berg, Leonard H.; Byelas, Heorhiy; den Dunnen, Johan T.; Dijkstra, Martijn; Amin, Najaf; Joeri van der Velde, K.; van Setten, Jessica; Kattenberg, Mathijs; van Schaik, Barbera D.C.; Bot, Jan; Nijman, Isaäc J.; Mei, Hailiang; Koval, Vyacheslav; Ye, Kai; Lameijer, Eric-Wubbo; Moed, Matthijs H.; Hehir-Kwa, Jayne Y.; Handsaker, Robert E.; Sunyaev, Shamil R.; Sohail, Mashaal; Hormozdiari, Fereydoun; Marschall, Tobias; Schönhuth, Alexander; Guryev, Victor; Suchiman, H. Eka D.; Wolffenbuttel, Bruce H.; Platteel, Mathieu; Pitts, Steven J.; Potluri, Shobha; Cox, David R.; Li, Qibin; Li, Yingrui; Du, Yuanping; Chen, Ruoyan; Cao, Hongzhi; Li, Ning; Cao, Sujie; Wang, Jun; Bovenberg, Jasper A.; Jukema, J. Wouter; van der Harst, Pim; Sijbrands, Eric J.; Hottenga, Jouke-Jan; Uitterlinden, Andre G.; Swertz, Morris A.; van Ommen, Gert-Jan B.; de Bakker, Paul I.W.; Eline Slagboom, P.; Boomsma, Dorret I.; Wijmenga, Cisca; van Duijn, Cornelia M.

2015-01-01

Variants associated with blood lipid levels may be population-specific. To identify low-frequency variants associated with this phenotype, population-specific reference panels may be used. Here we impute nine large Dutch biobanks (~35,000 samples) with the population-specific reference panel created by the Genome of the Netherlands Project and perform association testing with blood lipid levels. We report the discovery of five novel associations at four loci (P value <6.61 × 10−4), including a rare missense variant in ABCA6 (rs77542162, p.Cys1359Arg, frequency 0.034), which is predicted to be deleterious. The frequency of this ABCA6 variant is 3.65-fold increased in the Dutch and its effect (βLDL-C=0.135, βTC=0.140) is estimated to be very similar to those observed for single variants in well-known lipid genes, such as LDLR. PMID:25751400
Development of a population of cancer cells: Observation and modeling by a Mixed Spatial Evolutionary Games approach.

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Świerniak, Andrzej; Krześlak, Michał; Student, Sebastian; Rzeszowska-Wolny, Joanna

2016-09-21

Living cells, like whole living organisms during evolution, communicate with their neighbors, interact with the environment, divide, change their phenotypes, and eventually die. The development of specific ways of communication (through signaling molecules and receptors) allows some cellular subpopulations to survive better, to coordinate their physiological status, and during embryonal development to create tissues and organs or in some conditions to become tumors. Populations of cells cultured in vitro interact similarly, also competing for space and nutrients and stimulating each other to better survive or to die. The results of these intercellular interactions of different types seem to be good examples of biological evolutionary games, and have been the subjects of simulations by the methods of evolutionary game theory where individual cells are treated as players. Here we present examples of intercellular contacts in a population of living human cancer HeLa cells cultured in vitro and propose an evolutionary game theory approach to model the development of such populations. We propose a new technique termed Mixed Spatial Evolutionary Games (MSEG) which are played on multiple lattices corresponding to the possible cellular phenotypes which gives the possibility of simulating and investigating the effects of heterogeneity at the cellular level in addition to the population level. Analyses performed with MSEG suggested different ways in which cellular populations develop in the case of cells communicating directly and through factors released to the environment. Copyright © 2016 Elsevier Ltd. All rights reserved.
Haplotype data for 23 Y-chromosome markers in four U.S. population groups.

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Coble, Michael D; Hill, Carolyn R; Butler, John M

2013-05-01

The PowerPlex Y23 kit contains 23 Y-chromosomal loci including all 17 of the markers in the Yfiler Y-STR kit plus six additional markers: DYS481, DYS533, DYS549, DYS570, DYS576, and DYS643. We have typed 1032 unrelated population samples from four self-declared US groups: African Americans, Asians, Hispanics, and Western European Caucasians. An analysis of the population genetic parameters and the improvement of adding additional Y-STR markers to the dataset are described. Published by Elsevier Ireland Ltd.
Trail networks formed by populations of immune cells

International Nuclear Information System (INIS)

Yang, Taeseok Daniel; Kwon, Tae Goo; Park, Jin-sung; Lee, Kyoung J

2014-01-01

Populations of biological cells that communicate with each other can organize themselves to generate large-scale patterns. Examples can be found in diverse systems, ranging from developing embryos, cardiac tissues, chemotaxing ameba and swirling bacteria. The similarity, often shared by the patterns, suggests the existence of some general governing principle. On the other hand, rich diversity and system-specific properties are exhibited, depending on the type of involved cells and the nature of their interactions. The study on the similarity and the diversity constitutes a rapidly growing field of research. Here, we introduce a new class of self-organized patterns of cell populations that we term as ‘cellular trail networks’. They were observed with populations of rat microglia, the immune cells of the brain and the experimental evidence suggested that haptotaxis is the key element responsible for them. The essential features of the observed patterns are well captured by the mathematical model cells that actively crawl and interact with each other through a decomposing but non-diffusing chemical attractant laid down by the cells. Our finding suggests an unusual mechanism of socially cooperative long-range signaling for the crawling immune cells. (paper)
Uptake of 3H-thymidine by the receptor cell populations after injury of the sensory nerve fibres

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Chuchkov, Ch.N.

1978-01-01

The material of the study was the skin from the beak of two-day ducklings. The investigation was carried out on the 2nd, 5th, 20th and 45th day after the crushing of the sensory nerve fibres entering the capsulated Herbst receptors. Twenty four hours before the biopsy, the ducklings were injected at 6 hours intervals with 3 H-thymidine. The number of labelled index in the three cell pupulations, participating in the receptor development was determined. The cells of the subcapsular space of all control animals (with intacted suborbital nerves) have shown the highest labelled index. The index of the capsular perineural cells is about 12 times lower, while the labelled index of the Schwann receptor cells is about 10 times lower. Following the denervation, the labelled index in increasing and reaches its maximum on the 5th postoperative day. The Schwann receptor cells in comparison to the two other cell populations show the most significant deviation during the regeneration (45th day after the intervention). The investigations show that all three cell populations pass through a miotic cycle of innovation. The low labelled index of the Schwann receptors (1-2 labelled cells in 1000) is an indication of a high differentiation. One can assume that their regeneration takes place at the expense of the proper proliferation activity as well as of the differentiation of the Schwann cells from the distal section of the regenerating sensory nerve fibres. Taking into consideration the high labelled index of the other populations, it seems most probable that their regeneration takes place for the expense of their own cell populations. (A.B.)
Endothelial Progenitor Cell Fraction Contained in Bone Marrow-Derived Mesenchymal Stem Cell Populations Impairs Osteogenic Differentiation

Directory of Open Access Journals (Sweden)

Fabian Duttenhoefer

2015-01-01

Full Text Available In bone tissue engineering (TE endothelial cell-osteoblast cocultures are known to induce synergies of cell differentiation and activity. Bone marrow mononucleated cells (BMCs are a rich source of mesenchymal stem cells (MSCs able to develop an osteogenic phenotype. Endothelial progenitor cells (EPCs are also present within BMC. In this study we investigate the effect of EPCs present in the BMC population on MSCs osteogenic differentiation. Human BMCs were isolated and separated into two populations. The MSC population was selected through plastic adhesion capacity. EPCs (CD34+ and CD133+ were removed from the BMC population and the resulting population was named depleted MSCs. Both populations were cultured over 28 days in osteogenic medium (Dex+ or medium containing platelet lysate (PL. MSC population grew faster than depleted MSCs in both media, and PL containing medium accelerated the proliferation for both populations. Cell differentiation was much higher in Dex+ medium in both cases. Real-time RT-PCR revealed upregulation of osteogenic marker genes in depleted MSCs. Higher values of ALP activity and matrix mineralization analyses confirmed these results. Our study advocates that absence of EPCs in the MSC population enables higher osteogenic gene expression and matrix mineralization and therefore may lead to advanced bone neoformation necessary for TE constructs.
Circulating levels of endothelin-1 in a homogenous Gulf Arab population with untreated essential hypertension.

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Obineche, Enyioma; Abdulle, Abdishakur M; Bokhari, Awais M; Yasin, Javed Y; Gillett, Michael P T

2006-01-01

Racial variations are reported in the natural history of hypertension. For example, hypertension is significantly more prevalent in blacks than whites. Endothelial cells are important regulators of vascular tone and homeostasis, in part through secretions of vasoactive substances including endothelin-1 (ET-1), a small peptide with potent vasopressor actions. In black hypertensives, ET-1 levels are higher than in normotensive blacks and in both hypertensive and normotensive whites. Since ET-1 might play a significant role in the development and severity of hypertension in the indigenous Arab population of the United Arab Emirates, we investigated the circulating levels of ET-1 in this homogenous population. ET-1 levels were measured in plasma samples from 60 untreated hypertensive Arabs and compared with 60 age- and sex-matched normotensive controls. ET-1 levels were significantly higher in hypertensives (mean 10.1 +/- 1 pmol/L) than normotensives (mean 2.2 +/- 0.5 pmol/L). Body mass index (BMI) was slightly higher among the hypertensives. For all subjects these levels significantly (P Arabs as compared with reported levels in white hypertensives and ET-1 could be a risk factor for cardiovascular diseases in this population. The endothelial system might be particularly important with respect to hypertension in this racial group and merits further study.
Performance of four ischemic stroke prognostic scores in a Brazilian population.

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Kuster, Gustavo W; Dutra, Lívia A; Brasil, Israel P; Pacheco, Evelyn P; Arruda, Márcio J C; Volcov, Cristiane; Domingues, Renan B

2016-02-01

Ischemic stroke (IS) prognostic scales may help clinicians in their clinical decisions. This study aimed to assess the performance of four IS prognostic scales in a Brazilian population. We evaluated data of IS patients admitted at Hospital Paulistano, a Joint Commission International certified primary stroke center. In-hospital mortality and modified Rankin score at discharge were defined as the outcome measures. The performance of National Institutes of Health Stroke Scale (NIHSS), Stroke Prognostication Using Age and NIHSS (SPAN-100), Acute Stroke Registry and Analysis of Lausanne (ASTRAL), and Totaled Health Risks in Vascular Events (THRIVE) were compared. Two hundred six patients with a mean ± SD age of 67.58 ± 15.5 years, being 55.3% male, were included. The four scales were significantly and independently associated functional outcome. Only THRIVE was associated with in-hospital mortality. With area under the curve THRIVE and NIHSS were the scales with better performance for functional outcome and THRIVE had the best performance for mortality. THRIVE showed the best performance among the four scales, being the only associated with in-hospital mortality.
Combined effects of gamma irradiation and cadmium on cellular and population-level endpoints of the micro-alga Pseudokirchneriella subcapitata

Energy Technology Data Exchange (ETDEWEB)

Bradshaw, C. [Stockholm University (Sweden); Abdul Meseh, D.; Alasawi, H.; Qiang, M.; Nascimento, F. [Dept of Ecology, Environment and Plant Sciences (Sweden)

2014-07-01

A major challenge in evaluating the risks of radiation to organisms is that radioactive substances often co-occur with other contaminants in the environment. The combined effects of multiple contaminants is poorly understood, particularly where radiation is involved, but mixture toxicity can give rise to synergistic, antagonistic or additive effects. The challenge of understanding mixture toxicity in a radiation context is the focus of one of the work packages of the STAR EU Network of Excellence in Radioecology, of which this study is a part. This paper presents results from an experiment where the green micro-alga Pseudokirchneriella subcapitata was exposed to both acute external gamma irradiation and the toxic metal cadmium (Cd) (over 72 hours); the experiment had a fully factorial design with 4 gamma doses and 4 Cd concentrations. The endpoints measured were chosen to reflect subcellular, cellular and population-level effects: antioxidant enzyme expression; membrane damage; protein, vitamin and pigment content of the cells; individual cell biomass and growth; population growth (biomass per ml and cells per ml). Preliminary results suggest effects of both Cd and gamma on some of the cellular and subcellular endpoints such as thiamine (vitamin B1) and chlorophyll concentrations in the cells, and individual cell biomass. In some cases interactive effects of the combined Cd and gamma treatments were seen, and these appeared to be dose level dependent. This lack of a consistent pattern of interactive mixture toxicity effects across the endpoints measured means that such effects would be very hard to predict in a risk assessment context. The lack of measurable effects at the population level was probably due to the short experimental duration (72 hours). Other experiments in our research group on the same micro-alga species that have looked at longer term effects (weeks) have shown that effects may not manifest themselves until at least a week after an acute gamma
Dignity and Distress towards the End of Life across Four Non-Cancer Populations

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Chochinov, Harvey Max

2016-01-01

Objective The purpose of this study was to identify four non-cancer populations that might benefit from a palliative approach; and describe and compare the prevalence and patterns of dignity related distress across these diverse clinical populations. Design A prospective, multi-site approach was used. Setting Outpatient clinics, inpatient facilities or personal care homes, located in Winnipeg, Manitoba and Edmonton, Alberta, Canada. Participants Patients with advanced Amyotrophic Lateral Sclerosis (ALS), Chronic Obstructive Pulmonary Disease (COPD), End Stage Renal Disease (ESRD); and the institutionalized alert frail elderly. Main Outcome Measure In addition to standardized measures of physical, psychological and spiritual aspects of patient experience, the Patient Dignity Inventory (PDI). Results Between February 2009 and December 2012, 404 participants were recruited (ALS, 101; COPD, 100; ESRD, 101; and frail elderly, 102). Depending on group designation, 35% to 58% died within one year of taking part in the study. While moderate to severe loss of sense of dignity did not differ significantly across the four study populations (4–11%), the number of PDI items reported as problematic was significantly different i.e. ALS 6.2 (5.2), COPD 5.6 (5.9), frail elderly 3.0 (4.4) and ESRD 2.3 (3.9) [p < .0001]. Each of the study populations also revealed unique and distinct patterns of physical, psychological and existential distress. Conclusion People with ALS, COPD, ESRD and the frail elderly face unique challenges as they move towards the end of life. Knowing the intricacies of distress and how they differ across these groups broadens our understanding of end-of-life experience within non-cancer populations and how best to meet their palliative care needs. PMID:26808530
Mercury levels in defined Italian population groups

International Nuclear Information System (INIS)

Ingrao, G.; Belloni, P.

1992-01-01

The consumption of fish and seafood usually is the main source of intake of methylmercury for members of the general population. Therefore subjects having a diet rich in these food items present a high risk of exceeding the tolerable recommended weekly intake of mercury set by FAO and WHO. The average consumption of fish at a national level is rather small in Italy, 12.5 kg per year, consequently the risk of exposure to elevated levels of mercury through the diet for members of the Italian general population is rather negligible. However, fish is one of the main components of the diet of some population groups. These groups are usually found in coastal towns close fishing ports and include subjects working as fishermen, fish dealers, restaurant workers and their families. The purpose of this research programme, carried our with the collaboration of the National Institute of Nutrition is to determine the levels of mercury and methylmercury in hair samples of subjects having a higher than average fish consumption and to evaluate the effects of elevated intakes of mercury. 1 ref., 13 figs
Transcriptional profiling at whole population and single cell levels reveals somatosensory neuron molecular diversity

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Chiu, Isaac M; Barrett, Lee B; Williams, Erika K; Strochlic, David E; Lee, Seungkyu; Weyer, Andy D; Lou, Shan; Bryman, Gregory S; Roberson, David P; Ghasemlou, Nader; Piccoli, Cara; Ahat, Ezgi; Wang, Victor; Cobos, Enrique J; Stucky, Cheryl L; Ma, Qiufu; Liberles, Stephen D; Woolf, Clifford J

2014-01-01

The somatosensory nervous system is critical for the organism's ability to respond to mechanical, thermal, and nociceptive stimuli. Somatosensory neurons are functionally and anatomically diverse but their molecular profiles are not well-defined. Here, we used transcriptional profiling to analyze the detailed molecular signatures of dorsal root ganglion (DRG) sensory neurons. We used two mouse reporter lines and surface IB4 labeling to purify three major non-overlapping classes of neurons: 1) IB4+SNS-Cre/TdTomato+, 2) IB4−SNS-Cre/TdTomato+, and 3) Parv-Cre/TdTomato+ cells, encompassing the majority of nociceptive, pruriceptive, and proprioceptive neurons. These neurons displayed distinct expression patterns of ion channels, transcription factors, and GPCRs. Highly parallel qRT-PCR analysis of 334 single neurons selected by membership of the three populations demonstrated further diversity, with unbiased clustering analysis identifying six distinct subgroups. These data significantly increase our knowledge of the molecular identities of known DRG populations and uncover potentially novel subsets, revealing the complexity and diversity of those neurons underlying somatosensation. DOI: http://dx.doi.org/10.7554/eLife.04660.001 PMID:25525749
Intracellular Drug Uptake-A Comparison of Single Cell Measurements Using ToF-SIMS Imaging and Quantification from Cell Populations with LC/MS/MS.

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Newman, Carla F; Havelund, Rasmus; Passarelli, Melissa K; Marshall, Peter S; Francis, Ian; West, Andy; Alexander, Morgan R; Gilmore, Ian S; Dollery, Colin T

2017-11-21

ToF-SIMS is a label-free imaging method that has been shown to enable imaging of amiodarone in single rat macrophage (NR8383) cells. In this study, we show that the method extends to three other cell lines relevant to drug discovery: human embryonic kidney (HEK293), cervical cancer (HeLa), and liver cancer (HepG2). There is significant interest in the variation of drug uptake at the single cell level, and we use ToF-SIMS to show that there is great diversity between individual cells and when comparing each of the cell types. These single cell measurements are compared to quantitative measurements of cell-associated amiodarone for the population using LC/MS/MS and cell counting with flow cytometry. NR8383 and HepG2 cells uptake the greatest amount of amiodarone with an average of 2.38 and 2.60 pg per cell, respectively, and HeLa and Hek 293 have a significantly lower amount of amiodarone at 0.43 and 0.36 pg per cell, respectively. The amount of cell-associated drug for the ensemble population measurement (LC/MS/MS) is compared with the ToF-SIMS single cell data: a similar amount of drug was detected per cell for the NR8383, and HepG2 cells at a greater level than that for the HEK293 cells. However, the two techniques did not agree for the HeLa cells, and we postulate potential reasons for this.
Four-point bending protocols to study the effects of dynamic strain in osteoblastic cells in vitro.

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Galea, Gabriel L; Price, Joanna S

2015-01-01

Strain engendered within bone tissue by mechanical loading of the skeleton is a major influence on the processes of bone modeling and remodeling and so a critical determinant of bone mass and architecture. The cells best placed to respond to strain in bone tissue are the resident osteocytes and osteoblasts. To address the mechanisms of strain-related responses in osteoblast-like cells, our group uses both in vivo and in vitro approaches, including a system of four-point bending of the substrate on which cells are cultured. A range of cell lines can be studied using this system but we routinely compare their responses to those in primary cultures of osteoblast-like cells derived from explants of mouse long bones. These cells show a range of well-characterized responses to physiological levels of strain, including increased proliferation, which in vivo is a feature of the osteogenic response.
Effects of Ambient Temperature on Growth Performance, Blood Metabolites, and Immune Cell Populations in Korean Cattle Steers.

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Kang, H J; Lee, I K; Piao, M Y; Gu, M J; Yun, C H; Kim, H J; Kim, K H; Baik, M

2016-03-01

Exposure to cold may affect growth performance in accordance with the metabolic and immunological activities of animals. We evaluated whether ambient temperature affects growth performance, blood metabolites, and immune cell populations in Korean cattle. Eighteen Korean cattle steers with a mean age of 10 months and a mean weight of 277 kg were used. All steers were fed a growing stage-concentrate diet at a rate of 1.5% of body weight and Timothy hay ad libitum for 8 weeks. Experimental period 1 (P1) was for four weeks from March 7 to April 3 and period 2 (P2) was four weeks from April 4 to May 1. Mean (8.7°C) and minimum (1.0°C) indoor ambient temperatures during P1 were lower (pambient temperature affects blood T cell populations. In conclusion, colder ambient temperature decreased growth and feed efficiency in Korean cattle steers. The higher circulating NEFA concentrations observed in March compared to April suggest that lipolysis may occur at colder ambient temperatures to generate heat and maintain body temperature, resulting in lower feed efficiency in March.
Reproductive characteristics and population decline of four species of skate (Rajidae) off the eastern coast of Canada.

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Mcphie, R P; Campana, S E

2009-07-01

Four of the most common species of skate (Rajidae) were studied off eastern Canada to determine if their reproductive characteristics were linked to their population trajectories. The fecundity of the winter skate Leucoraja ocellata, the little skate Leucoraja erinacea, the thorny skate Amblyraja radiata and the smooth skate Malacoraja senta averaged between 41 and 56 egg cases per year for each species. For all species but L. ocellata, males matured at larger sizes and at later ages than females. Theoretical rates of population increase for non-equilibrium populations of L. ocellata (c. 0.07), M. senta (c. 0.14) and L. erinacea and A. radiata (c. 0.20) were low compared to most fishes, indicating that north-west Atlantic skates are intrinsically unproductive, yet are theoretically capable of supporting low-level fisheries. Nevertheless, the results of 36 years of research surveys indicate that the abundance of mature L. ocellata, A. radiata and M. senta all decreased by >90% since 1970, indicating that past fishing mortality (both directed and undirected) has outstripped the net productivity of the skate populations on the eastern Scotian Shelf. The relationship between maximum age (t(max)) and age of maturity (t(mat)) was a better predictor of population growth rate than was body size, with the species exhibiting the highest ratios of t(mat) :t(max) (L. ocellata = 0.68, M. senta = 0.66) having the lowest predicted population growth rates. L. ocellata appears to have the lowest productivity and has experienced the greatest population decline, thus raising concerns over its future status.

Population levels of wellbeing and the association with social capital.

Science.gov (United States)

Taylor, A W; Kelly, G; Dal Grande, E; Kelly, D; Marin, T; Hey, N; Burke, K J; Licinio, J

2017-07-03

This research investigates wellbeing at the population level across demographic, social and health indicators and assesses the association between wellbeing and social capital. Data from a South Australian monthly chronic disease/risk factor surveillance system of randomly selected adults (mean age 48.7 years; range 16-99) from 2014/5 (n = 5551) were used. Univariable analyses compared wellbeing/social capital indicators, socio-demographic, risk factors and chronic conditions. Multi-nominal logistic regression modelling, adjusting for multiple covariates was used to simultaneously estimate odds ratios for good wellbeing (reference category) versus neither good nor poor, and good wellbeing versus poor wellbeing. 48.6% were male, mean age 48.7 (sd 18.3), 54.3% scored well on all four of the wellbeing indicators, and positive social capital indicators ranged from 93.1% for safety to 50.8% for control over decisions. The higher level of social capital corresponded with the good wellbeing category. Modeling showed higher odds ratios for all social capital variables for the lowest level of wellbeing. These higher odds ratios remained after adjusting for confounders. The relationship between wellbeing, resilience and social capital highlights areas for increased policy focus.
Expression of stanniocalcin 1 in thyroid side population cells and thyroid cancer cells.

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Hayase, Suguru; Sasaki, Yoshihito; Matsubara, Tsutomu; Seo, Daekwan; Miyakoshi, Masaaki; Murata, Tsubasa; Ozaki, Takashi; Kakudo, Kennichi; Kumamoto, Kensuke; Ylaya, Kris; Cheng, Sheue-yann; Thorgeirsson, Snorri S; Hewitt, Stephen M; Ward, Jerrold M; Kimura, Shioko

2015-04-01

Mouse thyroid side population (SP) cells consist of a minor population of mouse thyroid cells that may have multipotent thyroid stem cell characteristics. However the nature of thyroid SP cells remains elusive, particularly in relation to thyroid cancer. Stanniocalcin (STC) 1 and 2 are secreted glycoproteins known to regulate serum calcium and phosphate homeostasis. In recent years, the relationship of STC1/2 expression to cancer has been described in various tissues. Microarray analysis was carried out to determine genes up- and down-regulated in thyroid SP cells as compared with non-SP cells. Among genes up-regulated, stanniocalcin 1 (STC1) was chosen for study because of its expression in various thyroid cells by Western blotting and immunohistochemistry. Gene expression analysis revealed that genes known to be highly expressed in cancer cells and/or involved in cancer invasion/metastasis were markedly up-regulated in SP cells from both intact as well as partial thyroidectomized thyroids. Among these genes, expression of STC1 was found in five human thyroid carcinoma-derived cell lines as revealed by analysis of mRNA and protein, and its expression was inversely correlated with the differentiation status of the cells. Immunohistochemical analysis demonstrated higher expression of STC1 in the thyroid tumor cell line and thyroid tumor tissues from humans and mice. These results suggest that SP cells contain a population of cells that express genes also highly expressed in cancer cells including Stc1, which warrants further study on the role of SP cells and/or STC1 expression in thyroid cancer.
Dynamic Pedagogy for Effective Training of Youths in Cell Phone Maintenance

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Ogbuanya, T. C.; Jimoh, Bakare

2015-01-01

The study determined dynamic pedagogies for effective training of youths in cell phone maintenance. The study was conducted in Enugu State of Nigeria. Four research questions were developed while four null hypotheses formulated were tested at 0.05 level of significance. A survey research design was adopted for the study. The population for the…
Serum uric acid levels and mortality in the Japanese population: the Yamagata (Takahata) study.

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Kamei, Keita; Konta, Tsuneo; Ichikawa, Kazunobu; Sato, Hiroko; Suzuki, Natsuko; Kabasawa, Asami; Suzuki, Kazuko; Hirayama, Atsushi; Shibata, Yoko; Watanabe, Tetsu; Kato, Takeo; Ueno, Yoshiyuki; Kayama, Takamasa; Kubota, Isao

2016-12-01

Serum uric acid level is regulated by gender, dietary habit, genetic predisposition, and renal function, and is associated with the development of renal and cardiovascular diseases. This study prospectively investigated the association between serum uric acid levels and mortality in a community-based population. Three thousand four hundred and eighty-seven subjects regardless of the antihyperuricemic medication (45 % male; mean age 62 years old) from the Takahata town in Japan participated in this study and were followed up for 8 years (median 7.5 years). We examined the association between serum uric acid levels at baseline and the all-cause and cardiovascular mortality, respectively, in this population. One hundred seventy-nine subjects died during the follow-up period, with 49 deaths attributed to cardiovascular causes. Kaplan-Meier analysis revealed that the all-cause mortality was significantly higher along with the increase in serum uric acid levels at baseline among female (Log-rank P uric acid ≥7.0 mg/dL) was an independent risk factor for all-cause and cardiovascular mortality, respectively, in female [hazard ratio (HR) 5.92, 95 % confidence interval (CI) 2.10-14.6 for all-cause mortality, and HR 10.7, 95 % CI 1.76-50.2 for cardiovascular mortality], but not male subjects. Hyperuricemia was an independent risk for all-cause and cardiovascular mortality in female, but not among the male subjects in a community-based population.
Cell dualism: presence of cells with alternative membrane potentials in growing populations of bacteria and yeasts.

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Ivanov, Volodymyr; Rezaeinejad, Saeid; Chu, Jian

2013-10-01

It is considered that all growing cells, for exception of acidophilic bacteria, have negatively charged inside cytoplasmic membrane (Δψ⁻-cells). Here we show that growing populations of microbial cells contain a small portion of cells with positively charged inside cytoplasmic membrane (Δψ⁺-cells). These cells were detected after simultaneous application of the fluorescent probes for positive membrane potential (anionic dye DIBAC⁻) and membrane integrity (propidium iodide, PI). We found in exponentially growing cell populations of Escherichia coli and Saccharomyces cerevisiae that the content of live Δψ⁻-cells was 93.6 ± 1.8 % for bacteria and 90.4 ± 4.0 % for yeasts and the content of live Δψ⁺-cells was 0.9 ± 0.3 % for bacteria and 2.4 ± 0.7 % for yeasts. Hypothetically, existence of Δψ⁺-cells could be due to short-term, about 1 min for bacteria and 5 min for yeasts, change of membrane potential from negative to positive value during the cell cycle. This change has been shown by the reversions of K⁺, Na⁺, and Ca²⁺ ions fluxes across the cell membrane during synchronous yeast culture. The transformation of Δψ(⁻-cells to Δψ⁺-cells can be explained by slow influx of K⁺ ions into Δψ⁻-cell to the trigger level of K⁺ concentration ("compression of potassium spring"), which is forming "alternative" Δψ⁺-cell for a short period, following with fast efflux of K⁺ ions out of Δψ⁺-cell ("release of potassium spring") returning cell to normal Δψ⁻ state. We anticipate our results to be a starting point to reveal the biological role of cell dualism in form of Δψ⁻- and Δψ⁺- cells.
Cell mass and cell cycle dynamics of an asynchronous budding yeast population

DEFF Research Database (Denmark)

Lencastre Fernandes, Rita; Carlquist, Magnus; Lundin, Luisa

2013-01-01

of model predictions for cell property distributions against experimental data is scarce. This study focuses on the experimental and mathematical description of the dynamics of cell size and cell cycle position distributions, of a population of Saccharomyces cerevisiae, in response to the substrate...
Progenitor cell populations in the periodontal ligament of mice

International Nuclear Information System (INIS)

McCulloch, C.A.

1985-01-01

Stem cells in a variety of renewal tissues exhibit a slow rate of cell proliferation. The periodontal ligament of mouse molars was examined for the presence of slowly cycling progenitor cells to provide evidence for the existence of stem cells in this tissue. A pulse injection of 3 H-thymidine was administered and mice were sacrificed between 1 hour and 14 days after injection. Analysis of radioautographs using percentage of labeled cells and grain counts demonstrated that a population of label-retaining cells within 10 micron of blood vessels traversed the cell cycle more slowly than proliferating cells located greater than 10 micron from blood vessels. These data suggest that there is a slowly dividing population of progenitor cells in paravascular sites in mouse molar periodontal ligament which may be stem cells
Population genetics of four heavily exploited shark species around the Arabian Peninsula

KAUST Repository

Spaet, Julia L.Y.

2015-05-01

The northwestern Indian Ocean harbors a number of larger marine vertebrate taxa that warrant the investigation of genetic population structure given remarkable spatial heterogeneity in biological characteristics such as distribution, behavior, and morphology. Here, we investigate the genetic population structure of four commercially exploited shark species with different biological characteristics (Carcharhinus limbatus, Carcharhinus sorrah, Rhizoprionodon acutus, and Sphyrna lewini) between the Red Sea and all other water bodies surrounding the Arabian Peninsula. To assess intraspecific patterns of connectivity, we constructed statistical parsimony networks among haplotypes and estimated (1) population structure; and (2) time of most recent population expansion, based on mitochondrial control region DNA and a total of 20 microsatellites. Our analysis indicates that, even in smaller, less vagile shark species, there are no contemporary barriers to gene flow across the study region, while historical events, for example, Pleistocene glacial cycles, may have affected connectivity in C. sorrah and R. acutus. A parsimony network analysis provided evidence that Arabian S. lewini may represent a population segment that is distinct from other known stocks in the Indian Ocean, raising a new layer of conservation concern. Our results call for urgent regional cooperation to ensure the sustainable exploitation of sharks in the Arabian region.
Performance of four ischemic stroke prognostic scores in a Brazilian population

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Gustavo W. Kuster

2016-02-01

Full Text Available ABSTRACT Objective Ischemic stroke (IS prognostic scales may help clinicians in their clinical decisions. This study aimed to assess the performance of four IS prognostic scales in a Brazilian population. Method We evaluated data of IS patients admitted at Hospital Paulistano, a Joint Commission International certified primary stroke center. In-hospital mortality and modified Rankin score at discharge were defined as the outcome measures. The performance of National Institutes of Health Stroke Scale (NIHSS, Stroke Prognostication Using Age and NIHSS (SPAN-100, Acute Stroke Registry and Analysis of Lausanne (ASTRAL, and Totaled Health Risks in Vascular Events (THRIVE were compared. Results Two hundred six patients with a mean ± SD age of 67.58 ± 15.5 years, being 55.3% male, were included. The four scales were significantly and independently associated functional outcome. Only THRIVE was associated with in-hospital mortality. With area under the curve THRIVE and NIHSS were the scales with better performance for functional outcome and THRIVE had the best performance for mortality. Conclusion THRIVE showed the best performance among the four scales, being the only associated with in-hospital mortality.
DETERMINATION OF ORGANIZATIONAL STRESS AND ORGANIZATIONAL BURNOUT LEVELS OF MID LEVEL MANAGERS WORKING IN FOUR AND FIVE STAR HOTEL BUSINESSES

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Sevket Yirik

2015-04-01

Full Text Available The present study emphasizes the concepts of stress and organizational stress which are the main concepts constituting theoretical foundation of the research; evaluates influences of stress on organization; discusses the concept of organizational burnout as well as its sub-dimensions; and analyses organizational stress and burnout levels of mid level managers working in four and five star hotels. The purpose of this study is to analyze the relationship between organizational stress and organizational burnout levels of mid level managers of four and five star hotel businesses. Survey has been conducted on 318 employees of four and five star hotels operating in Alanya, Turkey. According to the analysis of data, it has been observed that ages of mid level managers have an influence on their organizational stress and burnout levels. Genders of mid level managers are influential on their organizational stress levels while they have no influence on their burnout levels. Education levels of managers influence their organizational stress levels while they have no influence on their burnout levels. The departments of managers are influential both on organizational stress and burnout. Positions of managers influence their burnout levels while they have no influence on their organizational stress levels.
Atomic four-level N systems

International Nuclear Information System (INIS)

Goren, C.; Rosenbluh, M.; Wilson-Gordon, A.D.; Friedmann, H.

2004-01-01

We investigate the atomic four-level N configuration both analytically and numerically, for various pump and probe intensities, with and without transfer of coherence (TOC) and Doppler broadening, and compare the results obtained to those of realistic atomic systems. We find that TOC affects the whole spectrum, in addition to producing an electromagnetically induced absorption (EIA) peak at line center. We show that the EIA peak splits as the pump intensity increases. These results are compared with those of realistic systems. When the pump is σ + polarized and the probe is π polarized, the results are similar to those of the N configuration. When the pump and probe polarizations are both linear with perpendicular polarizations, various N-like subsystems contribute to the spectrum. Consequently, the splitting of the EIA peak only occurs at very high pump intensities. We also discuss the influence of the probe on the pump absorption and refraction and find that both the pump and probe show EIA peaks when the pump intensity is low, and complementary behavior when the pump is intense. At both low and high pump intensity, the pump and probe dispersions are of opposite sign
Different culture conditions affect the growth of human tendon stem/progenitor cells (TSPCs) within a mixed tendon cells (TCs) population.

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Viganò, M; Perucca Orfei, C; Colombini, A; Stanco, D; Randelli, P; Sansone, V; de Girolamo, L

2017-12-01

Tendon resident cells (TCs) are a mixed population made of terminally differentiated tenocytes and tendon stem/progenitor cells (TSPCs). Since the enrichment of progenitors proportion could enhance the effectiveness of treatments based on these cell populations, the interest on the effect of culture conditions on the TSPCs is growing. In this study the clonal selection and the culture in presence or absence of basic fibroblast growth factor (bFGF) were used to assess their influences on the stemness properties and phenotype specific features of tendon cells. Cells cultured with the different methods were analyzed in terms of clonogenic and differentiation abilities, stem and tendon specific genes expression and immunophenotype at passage 2 and passage 4. The clonal selection allowed to isolate cells with a higher multi-differentiation potential, but at the same time a lower proliferation rate in comparison to the whole population. Moreover, the clones express a higher amounts of stemness marker OCT4 and tendon specific transcription factor Scleraxis (SCX) mRNA, but a lower level of decorin (DCN). On the other hand, the number of cells obtained by clonal selection was extremely low and most of the clones were unable to reach a high number of passages in cultures. The presence of bFGF influences TCs morphology, enhance their proliferation rate and reduce their clonogenic ability. Interestingly, the expression of CD54, a known mesenchymal stem cell marker, is reduced in presence of bFGF at early passages. Nevertheless, bFGF does not affect the chondrogenic and osteogenic potential of TCs and the expression of tendon specific markers, while it was able to downregulate the OCT4 expression. This study showed that clonal selection enhance progenitors content in TCs populations, but the extremely low number of cells produced with this method could represent an insurmountable obstacle to its application in clinical approaches. We observed that the addition of bFGF to the
Increasing cell culture population doublings for long-term growth of finite life span human cell cultures

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Stampfer, Martha R; Garbe, James C

2015-02-24

Cell culture media formulations for culturing human epithelial cells are herein described. Also described are methods of increasing population doublings in a cell culture of finite life span human epithelial cells and prolonging the life span of human cell cultures. Using the cell culture media disclosed alone and in combination with addition to the cell culture of a compound associated with anti-stress activity achieves extended growth of pre-stasis cells and increased population doublings and life span in human epithelial cell cultures.
Characterization of Fluorescent Proteins for Three- and Four-Color Live-Cell Imaging in S. cerevisiae.

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Higuchi-Sanabria, Ryo; Garcia, Enrique J; Tomoiaga, Delia; Munteanu, Emilia L; Feinstein, Paul; Pon, Liza A

2016-01-01

Saccharomyces cerevisiae are widely used for imaging fluorescently tagged protein fusions. Fluorescent proteins can easily be inserted into yeast genes at their chromosomal locus, by homologous recombination, for expression of tagged proteins at endogenous levels. This is especially useful for incorporation of multiple fluorescent protein fusions into a single strain, which can be challenging in organisms where genetic manipulation is more complex. However, the availability of optimal fluorescent protein combinations for 3-color imaging is limited. Here, we have characterized a combination of fluorescent proteins, mTFP1/mCitrine/mCherry for multicolor live cell imaging in S. cerevisiae. This combination can be used with conventional blue dyes, such as DAPI, for potential four-color live cell imaging.
Logic as Marr's Computational Level: Four Case Studies.

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Baggio, Giosuè; van Lambalgen, Michiel; Hagoort, Peter

2015-04-01

We sketch four applications of Marr's levels-of-analysis methodology to the relations between logic and experimental data in the cognitive neuroscience of language and reasoning. The first part of the paper illustrates the explanatory power of computational level theories based on logic. We show that a Bayesian treatment of the suppression task in reasoning with conditionals is ruled out by EEG data, supporting instead an analysis based on defeasible logic. Further, we describe how results from an EEG study on temporal prepositions can be reanalyzed using formal semantics, addressing a potential confound. The second part of the article demonstrates the predictive power of logical theories drawing on EEG data on processing progressive constructions and on behavioral data on conditional reasoning in people with autism. Logical theories can constrain processing hypotheses all the way down to neurophysiology, and conversely neuroscience data can guide the selection of alternative computational level models of cognition. Copyright © 2014 Cognitive Science Society, Inc.
Biocompatible micro-sized cell culture chamber for the detection of nanoparticle-induced IL8 promoter activity on a small cell population

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Oostingh Gertie

2011-01-01

Full Text Available Abstract In most conventional in vitro toxicological assays, the response of a complete cell population is averaged, and therefore, single-cell responses are not detectable. Such averaging might result in misinterpretations when only individual cells within a population respond to a certain stimulus. Therefore, there is a need for non-invasive in vitro systems to verify the toxicity of nanoscale materials. In the present study, a micro-sized cell culture chamber with a silicon nitride membrane (0.16 mm2 was produced for cell cultivation and the detection of specific cell responses. The biocompatibility of the microcavity chip (MCC was verified by studying adipogenic and neuronal differentiation. Thereafter, the suitability of the MCC to study the effects of nanoparticles on a small cell population was determined by using a green fluorescence protein-based reporter cell line. Interleukin-8 promoter (pIL8 induction, a marker of an inflammatory response, was used to monitor immune activation. The validation of the MCC-based method was performed using well-characterized gold and silver nanoparticles. The sensitivity of the new method was verified comparing the quantified pIL8 activation via MCC-based and standard techniques. The results proved the biocompatibility and the sensitivity of the microculture chamber, as well as a high optical quality due to the properties of Si3N4. The MCC-based method is suited for threshold- and time-dependent analysis of nanoparticle-induced IL8 promoter activity. This novel system can give dynamic information at the level of adherent single cells of a small cell population and presents a new non-invasive in vitro test method to assess the toxicity of nanomaterials and other compounds. PACS: 85.35.Be, 81.16.Nd, 87.18.Mp
Biocompatible micro-sized cell culture chamber for the detection of nanoparticle-induced IL8 promoter activity on a small cell population

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Kohl, Yvonne; Oostingh, Gertie J.; Sossalla, Adam; Duschl, Albert; von Briesen, Hagen; Thielecke, Hagen

2011-08-01

In most conventional in vitro toxicological assays, the response of a complete cell population is averaged, and therefore, single-cell responses are not detectable. Such averaging might result in misinterpretations when only individual cells within a population respond to a certain stimulus. Therefore, there is a need for non-invasive in vitro systems to verify the toxicity of nanoscale materials. In the present study, a micro-sized cell culture chamber with a silicon nitride membrane (0.16 mm2) was produced for cell cultivation and the detection of specific cell responses. The biocompatibility of the microcavity chip (MCC) was verified by studying adipogenic and neuronal differentiation. Thereafter, the suitability of the MCC to study the effects of nanoparticles on a small cell population was determined by using a green fluorescence protein-based reporter cell line. Interleukin-8 promoter (pIL8) induction, a marker of an inflammatory response, was used to monitor immune activation. The validation of the MCC-based method was performed using well-characterized gold and silver nanoparticles. The sensitivity of the new method was verified comparing the quantified pIL8 activation via MCC-based and standard techniques. The results proved the biocompatibility and the sensitivity of the microculture chamber, as well as a high optical quality due to the properties of Si3N4. The MCC-based method is suited for threshold- and time-dependent analysis of nanoparticle-induced IL8 promoter activity. This novel system can give dynamic information at the level of adherent single cells of a small cell population and presents a new non-invasive in vitro test method to assess the toxicity of nanomaterials and other compounds. PACS: 85.35.Be, 81.16.Nd, 87.18.Mp
Quantitation and renewal of alveolar and bronchiolar cell populations of rat lungs. Changes during some pathological processes

International Nuclear Information System (INIS)

Fritsch, Paul.

1979-02-01

The various cells of alveolar and bronchiolar tissues of rat lungs were studied qualitatively and quantitatively. In physiological conditions, the renewal rate of the cell populations is low and the frequency of the various cell types is constant. This stability, especially at the level of the alveolar tissue, was also found during the latency period and the development of radiation-induced lung cancers. A particular cellular population was demonstrated: marginated leukocyte pool at the level of the pulmonary circulation. This pool was different both qualitatively and quantitatively from the leukocytes of the systemic circulation and, in physiological conditions, behaved as a cellular reservoir of monocytes chiefly re-distributed according to the body needs. In pathological conditions, its fast migration contributed to the defence of the alveolar medium. A quantitative study of the renewal of alveolar macrophages showed that under 1 p. cent of the marginated leukocyte pool is used daily to keep up this population. This fraction undergoes a maturation stage by cellular division within the endoalveolar medium. In some pathological conditions, this division can be completely inhibited [fr
Phase-controlled all-optical switching based on coherent population oscillation in a two-level system

International Nuclear Information System (INIS)

Liao, Ping; Yu, Song; Luo, Bin; Shen, Jing; Gu, Wanyi; Guo, Hong

2011-01-01

We theoretically propose a scheme of phase-controlled all-optical switching due to the effect of degenerate four-wave mixing (FWM) and coherent population oscillation (CPO) in a two-level system driven by a strong coupling field and two weak symmetrically detuned fields. The results show that the phase of the FWM field can be utilized to switch between constructive and destructive interference, which can lead to the transmission or attenuation of the probe field and thus switch the field on or off. We also find the intensity of the coupling field and the propagation distance have great influence on the performance of the switching. In our scheme, due to the quick response in semiconductor systems, a fast all-optical switching can be realized at low light level. -- Highlights: ► We study a new all-optical switching based on coherent population oscillation. ► The phase of the FWM field can be utilized to switch the probe field on or off. ► A fast and low-light-level switching can be realized in semiconductors.
Organ-level quorum sensing directs regeneration in hair stem cell populations

Science.gov (United States)

Chen, Chih-Chiang; Wang, Lei; Plikus, Maksim V.; Jiang, Ting Xin; Murray, Philip J.; Ramos, Raul; Guerrero-Juarez, Christian F.; Hughes, Michael W; Lee, Oscar K.; Shi, Songtao; Widelitz, Randall B.; Lander, Arthur D.; Chuong, Cheng Ming

2015-01-01

SUMMARY Coordinated organ behavior is crucial for an effective response to environmental stimuli. By studying regeneration of hair follicles in response to patterned hair removal, we demonstrate that organ-level quorum sensing allows coordinated responses to skin injury. Removing hair at different densities leads to a regeneration of up to 5 times more neighboring, unplucked resting hairs, indicating activation of a collective decision-making process. Through data modeling, the range of the quorum signal was estimated to be on the order of 1 mm, greater than expected for a diffusible molecular cue. Molecular and genetic analysis uncovered a two-step mechanism, where release of CCL2 from injured hairs leads to recruitment of TNF-α secreting macrophages, which accumulate and signal to both plucked and unplucked follicles. By coupling immune response with regeneration, this mechanism allows skin to respond predictively to distress, disregarding mild injury, while meeting stronger injury with full-scale cooperative activation of stem cells. PMID:25860610

County-Level Population Economic Status and Medicare Imaging Resource Consumption.

Science.gov (United States)

Rosenkrantz, Andrew B; Hughes, Danny R; Prabhakar, Anand M; Duszak, Richard

2017-06-01

The aim of this study was to assess relationships between county-level variation in Medicare beneficiary imaging resource consumption and measures of population economic status. The 2013 CMS Geographic Variation Public Use File was used to identify county-level per capita Medicare fee-for-service imaging utilization and nationally standardized costs to the Medicare program. The County Health Rankings public data set was used to identify county-level measures of population economic status. Regional variation was assessed, and multivariate regressions were performed. Imaging events per 1,000 Medicare beneficiaries varied 1.8-fold (range, 2,723-4,843) at the state level and 5.3-fold (range, 1,228-6,455) at the county level. Per capita nationally standardized imaging costs to Medicare varied 4.2-fold (range, $84-$353) at the state level and 14.1-fold (range, $33-$471) at the county level. Within individual states, county-level utilization varied on average 2.0-fold (range, 1.1- to 3.1-fold), and costs varied 2.8-fold (range, 1.1- to 6.4-fold). For both large urban populations and small rural states, Medicare imaging resource consumption was heterogeneously variable at the county level. Adjusting for county-level gender, ethnicity, rural status, and population density, countywide unemployment rates showed strong independent positive associations with Medicare imaging events (β = 26.96) and costs (β = 4.37), whereas uninsured rates showed strong independent positive associations with Medicare imaging costs (β = 2.68). Medicare imaging utilization and costs both vary far more at the county than at the state level. Unfavorable measures of county-level population economic status in the non-Medicare population are independently associated with greater Medicare imaging resource consumption. Future efforts to optimize Medicare imaging use should consider the influence of local indigenous socioeconomic factors outside the scope of traditional beneficiary-focused policy
Fitness evaluation of two Brazilian Aedes aegypti field populations with distinct levels of resistance to the organophosphate temephos

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Thiago Affonso Belinato

2012-11-01

Full Text Available In Brazil, decades of dengue vector control using organophosphates and pyrethroids have led to dissemination of resistance. Although these insecticides have been employed for decades against Aedes aegypti in the country, knowledge of the impact of temephos resistance on vector viability is limited. We evaluated several fitness parameters in two Brazilian Ae. aegypti populations, both classified as deltamethrin resistant but with distinct resistant ratios (RR for temephos. The insecticide-susceptible Rockefeller strain was used as an experimental control. The population presenting the higher temephos resistance level, Aparecida de Goiânia, state of Goiás (RR95 of 19.2, exhibited deficiency in the following four parameters: blood meal acceptance, amount of ingested blood, number of eggs and frequency of inseminated females. Mosquitoes from Boa Vista, state of Roraima, the population with lower temephos resistance level (RR95 of 7.4, presented impairment in only two parameters, blood meal acceptance and frequency of inseminated females. These results indicate that the overall fitness handicap was proportional to temephos resistance levels. However, it is unlikely that these disabilities can be attributed solely to temephos resistance, since both populations are also resistant to deltamethrin and harbour the kdr allele, which indicates resistance to pyrethroids. The effects of reduced fitness in resistant populations are discussed.
Sickle cell disease in tribal populations in India.

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Colah, Roshan B; Mukherjee, Malay B; Martin, Snehal; Ghosh, Kanjaksha

2015-05-01

The sickle gene is widespread among many tribal population groups in India with prevalence of heterozygotes varying from 1-40 per cent. Co-inheritance of the sickle gene with β-thalassaemia, HbD Punjab and glucose-6-phosphate dehydrogenase (G6PD) deficiency has also been reported. Most of the screening programmes in India now use high performance liquid chromatography (HPLC) analysis although the solubility test is also sensitive and cheap. Sickle cell disease (SCD) among tribal populations is generally milder than among non-tribal groups with fewer episodes of painful crises, infections, acute chest syndrome and need for hospitalization. This has partly been attributed to the very high prevalence of α-thalassaemia among these tribes as well as higher foetal haemoglobin levels. However, the clinical presentation is variable with many cases having a severe presentation. There is not much information available on maternal and perinatal outcome in tribal women with sickle cell disease. Newborn screening programmes for SCD have recently been initiated in Maharashtra, Gujarat, Orissa and Chattisgarh and monitoring these birth cohorts will help to understand the natural history of SCD in India. Prenatal diagnosis is acceptable by tribal families in India. The Indian Council of Medical Research and the National Rural Health Mission in different States are undertaking outreach programmes for better management and control of the disease.
T Cell Epitope Immunotherapy Induces a CD4+ T Cell Population with Regulatory Activity

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Verhoef Adrienne

2005-01-01

Full Text Available Background Synthetic peptides, representing CD4+ T cell epitopes, derived from the primary sequence of allergen molecules have been used to down-regulate allergic inflammation in sensitised individuals. Treatment of allergic diseases with peptides may offer substantial advantages over treatment with native allergen molecules because of the reduced potential for cross-linking IgE bound to the surface of mast cells and basophils. Methods and Findings In this study we address the mechanism of action of peptide immunotherapy (PIT in cat-allergic, asthmatic patients. Cell-division-tracking dyes, cell-mixing experiments, surface phenotyping, and cytokine measurements were used to investigate immunomodulation in peripheral blood mononuclear cells (PBMCs after therapy. Proliferative responses of PBMCs to allergen extract were significantly reduced after PIT. This was associated with modified cytokine profiles generally characterised by an increase in interleukin-10 and a decrease in interleukin-5 production. CD4+ cells isolated after PIT were able to actively suppress allergen-specific proliferative responses of pretreatment CD4neg PBMCs in co-culture experiments. PIT was associated with a significant increase in surface expression of CD5 on both CD4+ and CD8+ PBMCs. Conclusion This study provides evidence for the induction of a population of CD4+ T cells with suppressor/regulatory activity following PIT. Furthermore, up-regulation of cell surface levels of CD5 may contribute to reduced reactivity to allergen.
Functional heterogeneity and heritability in CHO cell populations.

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Davies, Sarah L; Lovelady, Clare S; Grainger, Rhian K; Racher, Andrew J; Young, Robert J; James, David C

2013-01-01

In this study, we address the hypothesis that it is possible to exploit genetic/functional variation in parental Chinese hamster ovary (CHO) cell populations to isolate clonal derivatives that exhibit superior, heritable attributes for biomanufacturing--new parental cell lines which are inherently more "fit for purpose." One-hundred and ninety-nine CHOK1SV clones were isolated from a donor CHOK1SV parental population by limiting dilution cloning and microplate image analysis, followed by primary analysis of variation in cell-specific proliferation rate during extended deep-well microplate suspension culture of individual clones to accelerate genetic drift in isolated cultures. A subset of 100 clones were comparatively evaluated for transient production of a recombinant monoclonal antibody (Mab) and green fluorescent protein following transfection of a plasmid vector encoding both genes. The heritability of both cell-specific proliferation rate and Mab production was further assessed using a subset of 23 clones varying in functional capability that were subjected to cell culture regimes involving both cryopreservation and extended sub-culture. These data showed that whilst differences in transient Mab production capability were not heritable per se, clones exhibiting heritable variation in specific proliferation rate, endocytotic transfectability and N-glycan processing were identified. Finally, for clonal populations most "evolved" by extended sub-culture in vitro we investigated the relationship between cellular protein biomass content, specific proliferation rate and cell surface N-glycosylation. Rapid-specific proliferation rate was inversely correlated to CHO cell size and protein content, and positively correlated to cell surface glycan content, although substantial clone-specific variation in ability to accumulate cell biomass was evident. Taken together, our data reveal the dynamic nature of the CHO cell functional genome and the potential to evolve and
Dendritic cell populations in patients with self-reported food hypersensitivity

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Lied GA

2011-05-01

Full Text Available Gülen A Lied1,3,4,*, Petra Vogelsang2,*, Arnold Berstad1,4, Silke Appel2 1Institute of Medicine, 2Broegelmann Research Laboratory, The Gade Institute, University of Bergen, Norway; 3Division of Gastroenterology, Department of Medicine; 4Section of Clinical Allergology, Department of Occupational Medicine, Haukeland University Hospital, Bergen, Norway *These authors contributed equally to this workAbstract: Self-reported hypersensitivity to food is a common condition and many of these patients have indications of intestinal immune activation. Dendritic cells (DCs are recognized as the most potent antigen-presenting cells involved in both initiating immune responses and maintaining tolerance. The aims of this study were to evaluate the DC populations with their phenotype and T cell stimulatory capacity in patients with food hypersensitivity and to study its relationship with atopic disease. Blood samples from 10 patients with self-reported food hypersensitivity, divided into atopic and nonatopic subgroups, and 10 gender- and age-matched healthy controls were analyzed by flow cytometry using the Miltenyi Blood Dendritic cells kit. Monocyte-derived DCs (moDCs were evaluated concerning their phenotype and T cell stimulatory capacity. DC populations and cell surface markers were not significantly different between patients and healthy controls, but moDCs from atopic patients expressed significantly more CD38 compared to moDCs from nonatopic patients. Moreover, lipopolysaccharide stimulated moDCs from atopic patients produced significantly more interleukin-10 compared to nonatopic patients. CD38 expression was correlated to total serum immunoglobulin E levels. These findings support the notion of immune activation in some patients with self-reported food hypersensitivity. They need to be confirmed in a larger cohort.Keywords: food hypersensitivity, atopy, dendritic cells, CD38
Derivation and characterization of human embryonic stem cell lines from the Chinese population

Institute of Scientific and Technical Information of China (English)

Zhao Wu; Huimin Dai; Lei Qian; Qing Tian; Lei Xiao; Xiaojun Tan; Hui Li; Lingjun Rao; Lixiazi He; Lei Bao; Jing Liao; Chun Cui; Zhenyu Zuo; Qiao Li

2011-01-01

Human embryonic stem cells (hESCs) can self-renew indefinitely and differentiate into all cell types in the human body. Therefore, they are valuable in regenerative medicine, human developmental biology and drug discovery. A number of hESC lines have been derived from the Chinese population,but limited of them are available for research purposes. Here we report the derivation and characterization of two hESC lines derived from human blastocysts of Chinese origin. These hESCs express alkaline phosphatase and hESC-specific markers, including Oct4, Nanog, SSEA-3, SSEA-4,TRA-1-60 and TRA-1-81. They also have high levels of telomerase activity and normal karyotypes. These cells can form embryoid body in vitro and can be differentiated into all three germ layers in vivo by teratoma formation. The newly established hESCs will be distributed for research purposes.The availability of hESC lines from the Chinese population will facilitate studies on the differences in hESCs from different ethnic groups.
The prevalence of malnutrition according to the new ESPEN definition in four diverse populations.

Science.gov (United States)

Rojer, A G M; Kruizenga, H M; Trappenburg, M C; Reijnierse, E M; Sipilä, S; Narici, M V; Hogrel, J Y; Butler-Browne, G; McPhee, J S; Pääsuke, M; Meskers, C G M; Maier, A B; de van der Schueren, M A E

2016-06-01

Consensus on the definition of malnutrition has not yet been reached. Recently, The European Society for Clinical Nutrition and Metabolism (ESPEN) proposed a consensus definition of malnutrition. The aim of the present study was to describe the prevalence of malnutrition according to the ESPEN definition in four diverse populations. In total, 349 acutely ill middle-aged patients, 135 geriatric outpatients, 306 healthy old individuals and 179 healthy young individuals were included in the study. Subjects were screened for risk of malnutrition using the SNAQ. The ESPEN definition of malnutrition, i.e. low BMI (malnutrition. The prevalence of malnutrition ranged from 0% in the healthy young, 0.5% in healthy old individuals, 6% in the geriatric outpatients to 14% in the acutely ill middle-aged patients. Prevalence of low FFMI was observed in all four populations (14-33%), but concurred less frequently with weight loss (0-13%). Using the ESPEN definition, 0%-14% malnutrition was found in the diverse populations. Further work is needed to fully address the validity of a two-step approach, including risk assessment as an initial step in screening and defining malnutrition. Furthermore, assessing the predictive validity of the ESPEN definition is needed. Copyright © 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.
Discovery of Power-Law Growth in the Self-Renewal of Heterogeneous Glioma Stem Cell Populations.

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Michiya Sugimori

Full Text Available Accumulating evidence indicates that cancer stem cells (CSCs drive tumorigenesis. This suggests that CSCs should make ideal therapeutic targets. However, because CSC populations in tumors appear heterogeneous, it remains unclear how CSCs might be effectively targeted. To investigate the mechanisms by which CSC populations maintain heterogeneity during self-renewal, we established a glioma sphere (GS forming model, to generate a population in which glioma stem cells (GSCs become enriched. We hypothesized, based on the clonal evolution concept, that with each passage in culture, heterogeneous clonal sublines of GSs are generated that progressively show increased proliferative ability.To test this hypothesis, we determined whether, with each passage, glioma neurosphere culture generated from four different glioma cell lines become progressively proliferative (i.e., enriched in large spheres. Rather than monitoring self-renewal, we measured heterogeneity based on neurosphere clone sizes (#cells/clone. Log-log plots of distributions of clone sizes yielded a good fit (r>0.90 to a straight line (log(% total clones = k*log(#cells/clone indicating that the system follows a power-law (y = xk with a specific degree exponent (k = -1.42. Repeated passaging of the total GS population showed that the same power-law was maintained over six passages (CV = -1.01 to -1.17. Surprisingly, passage of either isolated small or large subclones generated fully heterogeneous populations that retained the original power-law-dependent heterogeneity. The anti-GSC agent Temozolomide, which is well known as a standard therapy for glioblastoma multiforme (GBM, suppressed the self-renewal of clones, but it never disrupted the power-law behavior of a GS population.Although the data above did not support the stated hypothesis, they did strongly suggest a novel mechanism that underlies CSC heterogeneity. They indicate that power-law growth governs the self-renewal of heterogeneous
Analysis of pharmacogenomic variants associated with population differentiation.

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Bora Yeon

Full Text Available In the present study, we systematically investigated population differentiation of drug-related (DR genes in order to identify common genetic features underlying population-specific responses to drugs. To do so, we used the International HapMap project release 27 Data and Pharmacogenomics Knowledge Base (PharmGKB database. First, we compared four measures for assessing population differentiation: the chi-square test, the analysis of variance (ANOVA F-test, Fst, and Nearest Shrunken Centroid Method (NSCM. Fst showed high sensitivity with stable specificity among varying sample sizes; thus, we selected Fst for determining population differentiation. Second, we divided DR genes from PharmGKB into two groups based on the degree of population differentiation as assessed by Fst: genes with a high level of differentiation (HD gene group and genes with a low level of differentiation (LD gene group. Last, we conducted a gene ontology (GO analysis and pathway analysis. Using all genes in the human genome as the background, the GO analysis and pathway analysis of the HD genes identified terms related to cell communication. "Cell communication" and "cell-cell signaling" had the lowest Benjamini-Hochberg's q-values (0.0002 and 0.0006, respectively, and "drug binding" was highly enriched (16.51 despite its relatively high q-value (0.0142. Among the 17 genes related to cell communication identified in the HD gene group, five genes (STX4, PPARD, DCK, GRIK4, and DRD3 contained single nucleotide polymorphisms with Fst values greater than 0.5. Specifically, the Fst values for rs10871454, rs6922548, rs3775289, rs1954787, and rs167771 were 0.682, 0.620, 0.573, 0.531, and 0.510, respectively. In the analysis using DR genes as the background, the HD gene group contained six significant terms. Five were related to reproduction, and one was "Wnt signaling pathway," which has been implicated in cancer. Our analysis suggests that the HD gene group from PharmGKB is
Analysis of pharmacogenomic variants associated with population differentiation.

Science.gov (United States)

Yeon, Bora; Ahn, Eunyong; Kim, Kyung-Im; Kim, In-Wha; Oh, Jung Mi; Park, Taesung

2015-01-01

In the present study, we systematically investigated population differentiation of drug-related (DR) genes in order to identify common genetic features underlying population-specific responses to drugs. To do so, we used the International HapMap project release 27 Data and Pharmacogenomics Knowledge Base (PharmGKB) database. First, we compared four measures for assessing population differentiation: the chi-square test, the analysis of variance (ANOVA) F-test, Fst, and Nearest Shrunken Centroid Method (NSCM). Fst showed high sensitivity with stable specificity among varying sample sizes; thus, we selected Fst for determining population differentiation. Second, we divided DR genes from PharmGKB into two groups based on the degree of population differentiation as assessed by Fst: genes with a high level of differentiation (HD gene group) and genes with a low level of differentiation (LD gene group). Last, we conducted a gene ontology (GO) analysis and pathway analysis. Using all genes in the human genome as the background, the GO analysis and pathway analysis of the HD genes identified terms related to cell communication. "Cell communication" and "cell-cell signaling" had the lowest Benjamini-Hochberg's q-values (0.0002 and 0.0006, respectively), and "drug binding" was highly enriched (16.51) despite its relatively high q-value (0.0142). Among the 17 genes related to cell communication identified in the HD gene group, five genes (STX4, PPARD, DCK, GRIK4, and DRD3) contained single nucleotide polymorphisms with Fst values greater than 0.5. Specifically, the Fst values for rs10871454, rs6922548, rs3775289, rs1954787, and rs167771 were 0.682, 0.620, 0.573, 0.531, and 0.510, respectively. In the analysis using DR genes as the background, the HD gene group contained six significant terms. Five were related to reproduction, and one was "Wnt signaling pathway," which has been implicated in cancer. Our analysis suggests that the HD gene group from PharmGKB is associated with
The PSA−/lo prostate cancer cell population harbors self-renewing long-term tumor-propagating cells that resist castration

Science.gov (United States)

Qin, Jichao; Liu, Xin; Laffin, Brian; Chen, Xin; Choy, Grace; Jeter, Collene; Calhoun-Davis, Tammy; Li, Hangwen; Palapattu, Ganesh S.; Pang, Shen; Lin, Kevin; Huang, Jiaoti; Ivanov, Ivan; Li, Wei; Suraneni, Mahipal V.; Tang, Dean G.

2012-01-01

SUMMARY Prostate cancer (PCa) is heterogeneous and contains both differentiated and undifferentiated tumor cells, but the relative functional contribution of these two cell populations remains unclear. Here we report distinct molecular, cellular, and tumor-propagating properties of PCa cells that express high (PSA+) and low (PSA−/lo) levels of the differentiation marker PSA. PSA−/lo PCa cells are quiescent and refractory to stresses including androgen deprivation, exhibit high clonogenic potential, and possess long-term tumor-propagating capacity. They preferentially express stem cell genes and can undergo asymmetric cell division generating PSA+ cells. Importantly, PSA−/lo PCa cells can initiate robust tumor development and resist androgen ablation in castrated hosts, and harbor highly tumorigenic castration-resistant PCa cells that can be prospectively enriched using ALDH+CD44+α2β1+ phenotype. In contrast, PSA+ PCa cells possess more limited tumor-propagating capacity, undergo symmetric division and are sensitive to castration. Together, our study suggests PSA−/lo cells may represent a critical source of castration-resistant PCa cells. PMID:22560078
CD34 defines an osteoprogenitor cell population in mouse bone marrow stromal cells

DEFF Research Database (Denmark)

Abdallah, Basem M; Al-Shammary, Asma; Skagen, Peter

2015-01-01

Bone marrow stromal cells (BMSCs, also known as bone marrow-derived mesenchymal stem cells) and their progenitors have been identified based on retrospective functional criteria. CD markers are employed to define cell populations with distinct functional characteristics. However, defining and pro...
Association Study for 26 Candidate Loci in Idiopathic Pulmonary Fibrosis Patients from Four European Populations

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Amit Kishore

2016-07-01

Full Text Available Idiopathic pulmonary fibrosis (IPF affects lung parenchyma with progressing fibrosis. In this study, we aimed to replicate MUC5B rs35705950 variants and determine new plausible candidate variants for IPF among four different European populations. We genotyped 26 IPF candidate loci in 165 IPF patients from four European countries: Czech Republic (n = 41, Germany (n = 33, Greece (n = 40, France (n = 51 and performed association study comparing observed variant distribution with this obtained in a genetically similar Czech healthy control population (n = 96 described in our earlier data report. A highly significant association for a promoter variant (rs35705950 of mucin encoding MUC5B gene was observed in all IPF populations, individually and combined [OR (95% CI; p-value as 5.23 (8.94-3.06; 1.80x10-11. Another non-coding variant, rs7934606 in MUC2 was significant among German patients [2.85 (5.05-1.60; 4.03x10-4] and combined European IPF cases [2.18 (3.16-1.50; 3.73x10-5]. The network analysis for these variants indicated gene-gene and gene-phenotype interactions in IPF and lung biology. With replication of MUC5B rs35705950 previously reported in U.S. populations of European descent and indicating other plausible polymorphic variants relevant for IPF, we provide additional reference information for future extended functional and population studies aimed, ideally with inclusion of clinical parameters, at identification of IPF genetic markers.
Biologic characteristics of the side population of human small cell lung cancer cell line H446.

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Wang, Bo; Yang, Huan; Huang, Yu-Zheng; Yan, Ru-Hong; Liu, Fen-Ju; Zhang, Jun-Ning

2010-03-01

Recently, the theory of cancer stem cells (CSCs) has presented new targets and orientations for tumor therapy. The major difficulties in researching CSCs include their isolation and purification. The aim of this study is to identify and characterize the side population (SP) cells in small cell lung cancer (SCLC) cell line H446, which lays the foundation for the isolation and purification of CSCs. Fluorescence-activated cell sorting (FACS) was used to sort SP and non-SP (NSP) cells from H446. Both subgroups were cultivated to survey the capacity to form into suspended tumor cell spheres. Reverse transcription-polymerase chain reaction (RT-PCR) and real-time PCR were used to evaluate the expression levels of the mRNA of CD133, ABCG2, and nucleostemin in both subgroups. The capacity of proliferation and the differences in drug resistance of both subgroups and unsorted cells were tested by the MTT method. The differentiation ability of both subgroups was determined by FACS. Proliferation was determined by subcutaneous tumor formation in nude mice. The percent of Hoechst 33342 negative cells was about (5.1 +/- 0.2)% in H446 by fluorescence microscopy. The percent of SP cells was (6.3 +/- 0.1)% by flow cytometry. SP cells had a stronger capability of forming into tumor spheres than NSP cells. The mRNA expression levels of ABCG2, CD133, and nucleostemin in SP cells were 21.60 +/- 0.26, 7.10 +/- 0.14, and 1.02 +/- 0.08 folds higher than that in NSP cells (P 0.05, respectively). In vivo, SP cells showed better proliferative ability and tougher viability when treated with drugs. SP cells can differentiate into NSP cells, but NSP cells cannot differentiate into SP cells. SP cells had a greater ability to form tumors. The H446 cell line contained some SP cells with stem cell properties. CD133 and ABCG2 may be cancer stem cell markers of SCLC.
T cell responsiveness correlates differentially with antibody isotype levels in clinical and asymptomatic filariasis

NARCIS (Netherlands)

Yazdanbakhsh, M.; Paxton, W. A.; Kruize, Y. C.; Sartono, E.; Kurniawan, A.; van het Wout, A.; Selkirk, M. E.; Partono, F.; Maizels, R. M.

1993-01-01

To establish the relationships among T and B cell responses, active infection, and clinical manifestations in lymphatic filariasis, filarial-specific lymphocyte proliferation, IgG antibody isotypes, and IgE levels were determined in an exposed population: 31 asymptomatic amicrofilaremics, 43
Inverse associations between obesity indicators and thymic T-cell production levels in aging atomic-bomb survivors.

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Kengo Yoshida

Full Text Available Reduction of the naive T-cell population represents a deteriorating state in the immune system that occurs with advancing age. In animal model studies, obesity compromises the T-cell immune system as a result of enhanced adipogenesis in primary lymphoid organs and systemic inflammation. In this study, to test the hypothesis that obesity may contribute to the aging of human T-cell immunity, a thousand atomic-bomb survivors were examined for obesity status and ability to produce naive T cells, i.e., T-cell receptor excision circle (TREC numbers in CD4 and CD8 T cells. The number of TRECs showed a strong positive correlation with naive T cell numbers, and lower TREC numbers were associated with higher age. We found that the TREC number was inversely associated with levels of obesity indicators (BMI, hemoglobin A1c and serum CRP levels. Development of type-2 diabetes and fatty liver was also associated with lower TREC numbers. This population study suggests that obesity with enhanced inflammation is involved in aging of the human T-cell immune system. Given the fact that obesity increases the risk of numerous age-related diseases, attenuated immune competence is a possible mechanistic link between obesity and disease development among the elderly.
Inverse associations between obesity indicators and thymic T-cell production levels in aging atomic-bomb survivors.

Science.gov (United States)

Yoshida, Kengo; Nakashima, Eiji; Kubo, Yoshiko; Yamaoka, Mika; Kajimura, Junko; Kyoizumi, Seishi; Hayashi, Tomonori; Ohishi, Waka; Kusunoki, Yoichiro

2014-01-01

Reduction of the naive T-cell population represents a deteriorating state in the immune system that occurs with advancing age. In animal model studies, obesity compromises the T-cell immune system as a result of enhanced adipogenesis in primary lymphoid organs and systemic inflammation. In this study, to test the hypothesis that obesity may contribute to the aging of human T-cell immunity, a thousand atomic-bomb survivors were examined for obesity status and ability to produce naive T cells, i.e., T-cell receptor excision circle (TREC) numbers in CD4 and CD8 T cells. The number of TRECs showed a strong positive correlation with naive T cell numbers, and lower TREC numbers were associated with higher age. We found that the TREC number was inversely associated with levels of obesity indicators (BMI, hemoglobin A1c) and serum CRP levels. Development of type-2 diabetes and fatty liver was also associated with lower TREC numbers. This population study suggests that obesity with enhanced inflammation is involved in aging of the human T-cell immune system. Given the fact that obesity increases the risk of numerous age-related diseases, attenuated immune competence is a possible mechanistic link between obesity and disease development among the elderly.
What Population Reveals about Individual Cell Identity: Single-Cell Parameter Estimation of Models of Gene Expression in Yeast.

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Artémis Llamosi

2016-02-01

Full Text Available Significant cell-to-cell heterogeneity is ubiquitously observed in isogenic cell populations. Consequently, parameters of models of intracellular processes, usually fitted to population-averaged data, should rather be fitted to individual cells to obtain a population of models of similar but non-identical individuals. Here, we propose a quantitative modeling framework that attributes specific parameter values to single cells for a standard model of gene expression. We combine high quality single-cell measurements of the response of yeast cells to repeated hyperosmotic shocks and state-of-the-art statistical inference approaches for mixed-effects models to infer multidimensional parameter distributions describing the population, and then derive specific parameters for individual cells. The analysis of single-cell parameters shows that single-cell identity (e.g. gene expression dynamics, cell size, growth rate, mother-daughter relationships is, at least partially, captured by the parameter values of gene expression models (e.g. rates of transcription, translation and degradation. Our approach shows how to use the rich information contained into longitudinal single-cell data to infer parameters that can faithfully represent single-cell identity.
A computational model incorporating neural stem cell dynamics reproduces glioma incidence across the lifespan in the human population.

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Roman Bauer

Full Text Available Glioma is the most common form of primary brain tumor. Demographically, the risk of occurrence increases until old age. Here we present a novel computational model to reproduce the probability of glioma incidence across the lifespan. Previous mathematical models explaining glioma incidence are framed in a rather abstract way, and do not directly relate to empirical findings. To decrease this gap between theory and experimental observations, we incorporate recent data on cellular and molecular factors underlying gliomagenesis. Since evidence implicates the adult neural stem cell as the likely cell-of-origin of glioma, we have incorporated empirically-determined estimates of neural stem cell number, cell division rate, mutation rate and oncogenic potential into our model. We demonstrate that our model yields results which match actual demographic data in the human population. In particular, this model accounts for the observed peak incidence of glioma at approximately 80 years of age, without the need to assert differential susceptibility throughout the population. Overall, our model supports the hypothesis that glioma is caused by randomly-occurring oncogenic mutations within the neural stem cell population. Based on this model, we assess the influence of the (experimentally indicated decrease in the number of neural stem cells and increase of cell division rate during aging. Our model provides multiple testable predictions, and suggests that different temporal sequences of oncogenic mutations can lead to tumorigenesis. Finally, we conclude that four or five oncogenic mutations are sufficient for the formation of glioma.

Cell population structure prior to bifurcation predicts efficiency of directed differentiation in human induced pluripotent cells.

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Bargaje, Rhishikesh; Trachana, Kalliopi; Shelton, Martin N; McGinnis, Christopher S; Zhou, Joseph X; Chadick, Cora; Cook, Savannah; Cavanaugh, Christopher; Huang, Sui; Hood, Leroy

2017-02-28

Steering the differentiation of induced pluripotent stem cells (iPSCs) toward specific cell types is crucial for patient-specific disease modeling and drug testing. This effort requires the capacity to predict and control when and how multipotent progenitor cells commit to the desired cell fate. Cell fate commitment represents a critical state transition or "tipping point" at which complex systems undergo a sudden qualitative shift. To characterize such transitions during iPSC to cardiomyocyte differentiation, we analyzed the gene expression patterns of 96 developmental genes at single-cell resolution. We identified a bifurcation event early in the trajectory when a primitive streak-like cell population segregated into the mesodermal and endodermal lineages. Before this branching point, we could detect the signature of an imminent critical transition: increase in cell heterogeneity and coordination of gene expression. Correlation analysis of gene expression profiles at the tipping point indicates transcription factors that drive the state transition toward each alternative cell fate and their relationships with specific phenotypic readouts. The latter helps us to facilitate small molecule screening for differentiation efficiency. To this end, we set up an analysis of cell population structure at the tipping point after systematic variation of the protocol to bias the differentiation toward mesodermal or endodermal cell lineage. We were able to predict the proportion of cardiomyocytes many days before cells manifest the differentiated phenotype. The analysis of cell populations undergoing a critical state transition thus affords a tool to forecast cell fate outcomes and can be used to optimize differentiation protocols to obtain desired cell populations.
Modification of optical properties by adiabatic shifting of resonances in a four-level atom

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Dutta, Bibhas Kumar; Panchadhyayee, Pradipta

2018-04-01

We describe the linear and nonlinear optical properties of a four-level atomic system, after reducing it to an effective two-level atomic model under the condition of adiabatic shifting of resonances driven by two coherent off-resonant fields. The reduced form of the Hamiltonian corresponding to the two-level system is obtained by employing an adiabatic elimination procedure in the rate equations of the probability amplitudes for the proposed four-level model. For a weak probe field operating in the system, the nonlinear dependence of complex susceptibility on the Rabi frequencies and the detuning parameters of the off-resonant driving fields makes it possible to exhibit coherent control of single-photon and two-photon absorption and transparency, the evolution of enhanced Self-Kerr nonlinearity and noticeable dispersive switching. We have shown how the quantum interference results in the generic four-level model at the adiabatic limit. The present scheme describes the appearance of single-photon transparency without invoking any exact two-photon resonance.
Influence of Climate Change and Trophic Coupling across Four Trophic Levels in the Celtic Sea

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Lauria, Valentina; Attrill, Martin J.; Pinnegar, John K.; Brown, Andrew; Edwards, Martin; Votier, Stephen C.

2012-01-01

Climate change has had profound effects upon marine ecosystems, impacting across all trophic levels from plankton to apex predators. Determining the impacts of climate change on marine ecosystems requires understanding the direct effects on all trophic levels as well as indirect effects mediated by trophic coupling. The aim of this study was to investigate the effects of climate change on the pelagic food web in the Celtic Sea, a productive shelf region in the Northeast Atlantic. Using long-term data, we examined possible direct and indirect ‘bottom-up’ climate effects across four trophic levels: phytoplankton, zooplankton, mid-trophic level fish and seabirds. During the period 1986–2007, although there was no temporal trend in the North Atlantic Oscillation index (NAO), the decadal mean Sea Surface Temperature (SST) in the Celtic Sea increased by 0.66±0.02°C. Despite this, there was only a weak signal of climate change in the Celtic Sea food web. Changes in plankton community structure were found, however this was not related to SST or NAO. A negative relationship occurred between herring abundance (0- and 1-group) and spring SST (0-group: p = 0.02, slope = −0.305±0.125; 1-group: p = 0.04, slope = −0.410±0.193). Seabird demographics showed complex species–specific responses. There was evidence of direct effects of spring NAO (on black-legged kittiwake population growth rate: p = 0.03, slope = 0.0314±0.014) as well as indirect bottom-up effects of lagged spring SST (on razorbill breeding success: p = 0.01, slope = −0.144±0.05). Negative relationships between breeding success and population growth rate of razorbills and common guillemots may be explained by interactions between mid-trophic level fish. Our findings show that the impacts of climate change on the Celtic Sea ecosystem is not as marked as in nearby regions (e.g. the North Sea), emphasizing the need for more research at regional scales. PMID:23091621
Influence of climate change and trophic coupling across four trophic levels in the Celtic Sea.

Directory of Open Access Journals (Sweden)

Valentina Lauria

Full Text Available Climate change has had profound effects upon marine ecosystems, impacting across all trophic levels from plankton to apex predators. Determining the impacts of climate change on marine ecosystems requires understanding the direct effects on all trophic levels as well as indirect effects mediated by trophic coupling. The aim of this study was to investigate the effects of climate change on the pelagic food web in the Celtic Sea, a productive shelf region in the Northeast Atlantic. Using long-term data, we examined possible direct and indirect 'bottom-up' climate effects across four trophic levels: phytoplankton, zooplankton, mid-trophic level fish and seabirds. During the period 1986-2007, although there was no temporal trend in the North Atlantic Oscillation index (NAO, the decadal mean Sea Surface Temperature (SST in the Celtic Sea increased by 0.66 ± 0.02 °C. Despite this, there was only a weak signal of climate change in the Celtic Sea food web. Changes in plankton community structure were found, however this was not related to SST or NAO. A negative relationship occurred between herring abundance (0- and 1-group and spring SST (0-group: p = 0.02, slope = -0.305 ± 0.125; 1-group: p = 0.04, slope = -0.410 ± 0.193. Seabird demographics showed complex species-specific responses. There was evidence of direct effects of spring NAO (on black-legged kittiwake population growth rate: p = 0.03, slope = 0.0314 ± 0.014 as well as indirect bottom-up effects of lagged spring SST (on razorbill breeding success: p = 0.01, slope = -0.144 ± 0.05. Negative relationships between breeding success and population growth rate of razorbills and common guillemots may be explained by interactions between mid-trophic level fish. Our findings show that the impacts of climate change on the Celtic Sea ecosystem is not as marked as in nearby regions (e.g. the North Sea, emphasizing the need for more research at regional scales.
Distinct types of glial cells populate the Drosophila antenna

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Jhaveri Dhanisha

2005-11-01

Full Text Available Abstract Background The development of nervous systems involves reciprocal interactions between neurons and glia. In the Drosophila olfactory system, peripheral glial cells arise from sensory lineages specified by the basic helix-loop-helix transcription factor, Atonal. These glia wrap around the developing olfactory axons early during development and pattern the three distinct fascicles as they exit the antenna. In the moth Manduca sexta, an additional set of central glia migrate to the base of the antennal nerve where axons sort to their glomerular targets. In this work, we have investigated whether similar types of cells exist in the Drosophila antenna. Results We have used different P(Gal4 lines to drive Green Fluorescent Protein (GFP in distinct populations of cells within the Drosophila antenna. Mz317::GFP, a marker for cell body and perineural glia, labels the majority of peripheral glia. An additional ~30 glial cells detected by GH146::GFP do not derive from any of the sensory lineages and appear to migrate into the antenna from the brain. Their appearance in the third antennal segment is regulated by normal function of the Epidermal Growth Factor receptor and small GTPases. We denote these distinct populations of cells as Mz317-glia and GH146-glia respectively. In the adult, processes of GH146-glial cells ensheath the olfactory receptor neurons directly, while those of the Mz317-glia form a peripheral layer. Ablation of GH146-glia does not result in any significant effects on the patterning of the olfactory receptor axons. Conclusion We have demonstrated the presence of at least two distinct populations of glial cells within the Drosophila antenna. GH146-glial cells originate in the brain and migrate to the antenna along the newly formed olfactory axons. The number of cells populating the third segment of the antenna is regulated by signaling through the Epidermal Growth Factor receptor. These glia share several features of the sorting
[Levels of plasma cholinesterase in Colombian working-class populations].

Science.gov (United States)

Carmona-Fonseca, Jaime

2003-12-01

Levels of plasma cholinesterase in Colombian working-class populations Reference values for plasma cholinesterase (EC 3.1.1.8) are not available for Colombian populations. A representative sample of a working-class population was used to establish these values to provide reference data for use by the social security system. Two working-class populations were sampled from the Aburrá Valley (Aburrá) and eastern Antioquia (Oriente). Cholinesterase activity was measured in 827 workers, with ages spanning 18-49 years, 415 from Aburrá and 412 people from Oriente. Three methods were used to measure cholinesterase: Michel, EQM and Monotest The average values by Michel and EQM were not statistically different between regions (Michel: Aburrá, 1.11, and East, 1.13 deltas pH/hora; EQM: Aburrá, 2.55, and Oriente, 2.48 U/ml). By the Monotest, the enzyme average was statistically higher in Aburra than in Oriente (5,743 and 5,459 U/L respectively; p = 0 .012). By region and technique, men had significantly higher enzymatic levels than women. Within both regions and sexes, no statistically significant difference among the three aged groups was noted. Our obtained Colombian values differed significantly from foreign reference values: Michel and Monotest levels were higher and EQM levels were lower. For making clinical and epidemiologic decisions in Colombia related to these data, the values obtained for the Colombian populations are preferred over values derived from external sources.
A stem cell medium containing neural stimulating factor induces a pancreatic cancer stem-like cell-enriched population

Science.gov (United States)

WATANABE, YUSAKU; YOSHIMURA, KIYOSHI; YOSHIKAWA, KOICHI; TSUNEDOMI, RYOICHI; SHINDO, YOSHITARO; MATSUKUMA, SOU; MAEDA, NORIKO; KANEKIYO, SHINSUKE; SUZUKI, NOBUAKI; KURAMASU, ATSUO; SONODA, KOUHEI; TAMADA, KOJI; KOBAYASHI, SEI; SAYA, HIDEYUKI; HAZAMA, SHOICHI; OKA, MASAAKI

2014-01-01

Cancer stem cells (CSCs) have been studied for their self-renewal capacity and pluripotency, as well as their resistance to anticancer therapy and their ability to metastasize to distant organs. CSCs are difficult to study because their population is quite low in tumor specimens. To overcome this problem, we established a culture method to induce a pancreatic cancer stem-like cell (P-CSLC)-enriched population from human pancreatic cancer cell lines. Human pancreatic cancer cell lines established at our department were cultured in CSC-inducing media containing epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), leukemia inhibitory factor (LIF), neural cell survivor factor-1 (NSF-1), and N-acetylcysteine. Sphere cells were obtained and then transferred to a laminin-coated dish and cultured for approximately two months. The surface markers, gene expression, aldehyde dehydrogenase (ALDH) activity, cell cycle, and tumorigenicity of these induced cells were examined for their stem cell-like characteristics. The population of these induced cells expanded within a few months. The ratio of CD24high, CD44high, epithelial specific antigen (ESA) high, and CD44variant (CD44v) high cells in the induced cells was greatly enriched. The induced cells stayed in the G0/G1 phase and demonstrated mesenchymal and stemness properties. The induced cells had high tumorigenic potential. Thus, we established a culture method to induce a P-CSLCenriched population from human pancreatic cancer cell lines. The CSLC population was enriched approximately 100-fold with this method. Our culture method may contribute to the precise analysis of CSCs and thus support the establishment of CSC-targeting therapy. PMID:25118635
Three-dimensional technology for linear morphological studies: a re-examination of cranial variation in four southern African indigenous populations.

Science.gov (United States)

Franklin, D; Freedman, L; Milne, N

2005-01-01

In order to compare linear dimensions made by traditional anthropometric techniques, and those obtained from three-dimensional coordinates, samples of four indigenous southern African populations were analysed. Linear measurements were obtained using mathematically transformed, three-dimensional landmark data on 207 male crania of Cape Nguni, Natal Nguni, Sotho and Shangaan. Univariate comparisons for accuracy of the transformed linear data were made with those in a traditional linear study by de Villiers (The Skull of the South African Negro: A Biometrical and Morphological Study. Witwatersrand University Press, Johannesburg) on similar samples and equivalent landmarks. Comparisons were not made with her Penrose (Ann Eugenics 18 (1954) 337) analysis as an apparently anomalous 'shape'-'size' statistic was found. The univariate comparisons demonstrated that accurate linear measurements could be derived from three-dimensional data, showing that it is possible to simultaneously obtain data for three-dimensional geometric 'shape' and linear interlandmark analyses. Using Penrose and canonical variates analyses of the transformed three-dimensional interlandmark measurements, similar population distances were found for the four indigenous southern African populations. The inter-population distance relationships took the form of three separated pairs of distances, with the within-pair distances very similar in size. The cranial features of the four populations were found to be overall very similar morphometrically. However the populations were each shown by CVA to have population specific features, and using discriminant analyses 50% or more of the individual crania (with the exception of the Sotho) could be referred to their correct populations.
The effect of ultraviolet light on arrested human diploid cell populations

International Nuclear Information System (INIS)

Kantor, G.J.; Warner, C.; Hull, D.R.

1977-01-01

The results of the experiments to determine an effect of UV (254 nm) on human diploid fibroblasts (HDF) arrested with respect to division by using 0.5% fetal calf serum in the culture medium are reported. A fraction of cells from irradiated arrested populations, maintained in the arrested state post-irradiation, was lost from the populations. The extent of cell loss was fluence-dependent and cell strain specific. A Xeroderma pigmentosum cell strain was more sensitive to UV than were normal HDF. No difference in sensitivity were observed when arrested populations established from normal HDF populations of various in vitro ages were used. The length of the pre-irradiation arrested period affected the sensitivity of normal HDF, which appeared more resistant at longer arrested periods, but not the sensitivity of arrested Xeroderma populations. These results suggest that DNA repair processes play a role in maintaining irradiated cells in the arrested state. The suggestion is made that the lethal event caused by UV is an effect on transcription leading to an inhibition of required protein synthesis. (author)
Biochemical genetic variation between four populations of ...

African Journals Online (AJOL)

system) to 0.093 in the Spekboom River population (Limpopo River system). The genetic distance, FST and NEM values, as well as pair-wise contingency c2 analyses indicate a lack of gene flow between populations, as expected for isolated fish. Evidence of foreign genetic material in one population was also observed.
Circulating levels of endothelin-1 in a homogenous Gulf Arab population with untreated essential hypertension

International Nuclear Information System (INIS)

Obinache, C.N.; Abdullah, A.M.; Pathan, J.Y.; Bokahri, A.M.; Gillett, M.P.T.

2006-01-01

Rectal variations are reported in the natural history of high-tension. For example hypertension is significantly more prevalent in blacks than whites. Endothelial cells are important regulators of vasculars tone and homeostasis, in part through secretions of vasoactive substances including endothelin-I (ET-1), a small peptide with potent vaspressor actions in black hypertensive and normotensive whites. Since ET-I might play a significant role to the development and severity of hypertension in the indigenous Arab population of United Arab Emirates; we investigated the circulatory levels of ET-1 in the homogenous population. ET-I levels were measured in plasma samples from 60 unteated hypertensive Arabs and compared with 60 age and sex matched normotensive controls. ET-I levels were significantly higher in hypertensive (10.1+-pmol/L) than normtensives (mean 2.2+-0.5 pmol/L). Body mass index (BMI) was slightly higher among the hypertensive. For all subjects these levels significantly (P<0.001) correlated with systolic blood pressure and less significantly (P<0.05) with diastolic blood pressure and body weight. The correlation with ET-1 and both systolic and diastolic blood pressure with persistently significant after adjusting for BMI. Plasma concentration of ET-I are significantly higher in hypertensive Gulf Arabs as compared with reported levels in which hypertensives and ET-I could be a risk factor for cardiovascular diseases in this population. The endothelial sate might be particularly important with respect to hypertension in this racial group and merits further study. (author)
Ecological interactions affecting population-level responses to chemical stress in Mesocyclops leuckarti.

Science.gov (United States)

Kulkarni, Devdutt; Hommen, Udo; Schäffer, Andreas; Preuss, Thomas G

2014-10-01

Higher tiers of ecological risk assessment (ERA) consider population and community-level endpoints. At the population level, the phenomenon of density dependence is one of the most important ecological processes that influence population dynamics. In this study, we investigated how different mechanisms of density dependence would influence population-level ERA of the cyclopoid copepod Mesocyclops leuckarti under toxicant exposure. We used a combined approach of laboratory experiments and individual-based modelling. An individual-based model was developed for M. leuckarti to simulate population dynamics under triphenyltin exposure based on individual-level ecological and toxicological data from laboratory experiments. The study primarily aimed to-(1) determine which life-cycle processes, based on feeding strategies, are most significant in determining density dependence (2) explore how these mechanisms of density dependence affect extrapolation from individual-level effects to the population level under toxicant exposure. Model simulations showed that cannibalism of nauplii that were already stressed by TPT exposure contributed to synergistic effects of biotic and abiotic factors and led to a twofold stress being exerted on the nauplii, thereby resulting in a higher population vulnerability compared to the scenario without cannibalism. Our results suggest that in population-level risk assessment, it is easy to underestimate toxicity unless underlying ecological interactions including mechanisms of population-level density regulation are considered. This study is an example of how a combined approach of experiments and mechanistic modelling can lead to a thorough understanding of ecological processes in ecotoxicology and enable a more realistic ERA. Copyright © 2014 Elsevier Ltd. All rights reserved.
Radiosensitizing Effects of Ectopic miR-101 on Non–Small-Cell Lung Cancer Cells Depend on the Endogenous miR-101 Level

International Nuclear Information System (INIS)

Chen, Susie; Wang Hongyan; Ng, Wooi Loon; Curran, Walter J.; Wang Ya

2011-01-01

Purpose: Previously, we showed that ectopic miR-101 could sensitize human tumor cells to radiation by targeting ATM and DNA-PK catalytic subunit (DNA-PKcs) to inhibit DNA repair, as the endogenous miR-101 levels are low in tumors in general. However, the heterogeneity of human cancers may result in an exception. The purpose of this study was to test the hypothesis that a few tumor cell lines with a high level of endogenous miR-101 would prove less response to ectopic miR-101. Methods and Materials: Fourteeen non–small-cell lung cancer (NSCLC) cell lines and one immortalized non-malignant lung epithelial cell line (NL20) were used for comparing endogenous miR-101 levels by real-time reverse transcription–polymerase chain reaction. Based on the different miR-101 levels, four cell lines with different miR-101 levels were chosen for transfection with a green fluorescent protein–lentiviral plasmid encoding miR-101. The target protein levels were measured by using Western blotting. The radiosensitizing effects of ectopic miR-101 on these NSCLC cell lines were determined by a clonogenic assay and xenograft mouse model. Results: The endogenous miR-101 level was similar or lower in 13 NSCLC cell lines but was 11-fold higher in one cell line (H157) than in NL20 cells. Although ectopic miR-101 efficiently decreased the ATM and DNA-PKcs levels and increased the radiosensitization level in H1299, H1975, and A549 cells, it did not change the levels of the miR-101 targets or radiosensitivity in H157 cells. Similar results were observed in xenograft mice. Conclusions: A small number of NSCLC cell lines could have a high level of endogenous miR-101. The ectopic miR-101 was able to radiosensitize most NSCLC cells, except for the NSCLC cell lines that had a much higher endogenous miR-101 level. These results suggest that when we choose one miRNA as a therapeutic tool, the endogenous level of the miRNA in each tumor should be considered.
Radiosensitizing Effects of Ectopic miR-101 on Non-Small-Cell Lung Cancer Cells Depend on the Endogenous miR-101 Level

Energy Technology Data Exchange (ETDEWEB)

Chen, Susie; Wang Hongyan; Ng, Wooi Loon; Curran, Walter J. [Department of Radiation Oncology, School of Medicine and the Winship Cancer Institute, Emory University, Atlanta, GA (United States); Wang Ya, E-mail: ywang94@emory.edu [Department of Radiation Oncology, School of Medicine and the Winship Cancer Institute, Emory University, Atlanta, GA (United States)

2011-12-01

Purpose: Previously, we showed that ectopic miR-101 could sensitize human tumor cells to radiation by targeting ATM and DNA-PK catalytic subunit (DNA-PKcs) to inhibit DNA repair, as the endogenous miR-101 levels are low in tumors in general. However, the heterogeneity of human cancers may result in an exception. The purpose of this study was to test the hypothesis that a few tumor cell lines with a high level of endogenous miR-101 would prove less response to ectopic miR-101. Methods and Materials: Fourteeen non-small-cell lung cancer (NSCLC) cell lines and one immortalized non-malignant lung epithelial cell line (NL20) were used for comparing endogenous miR-101 levels by real-time reverse transcription-polymerase chain reaction. Based on the different miR-101 levels, four cell lines with different miR-101 levels were chosen for transfection with a green fluorescent protein-lentiviral plasmid encoding miR-101. The target protein levels were measured by using Western blotting. The radiosensitizing effects of ectopic miR-101 on these NSCLC cell lines were determined by a clonogenic assay and xenograft mouse model. Results: The endogenous miR-101 level was similar or lower in 13 NSCLC cell lines but was 11-fold higher in one cell line (H157) than in NL20 cells. Although ectopic miR-101 efficiently decreased the ATM and DNA-PKcs levels and increased the radiosensitization level in H1299, H1975, and A549 cells, it did not change the levels of the miR-101 targets or radiosensitivity in H157 cells. Similar results were observed in xenograft mice. Conclusions: A small number of NSCLC cell lines could have a high level of endogenous miR-101. The ectopic miR-101 was able to radiosensitize most NSCLC cells, except for the NSCLC cell lines that had a much higher endogenous miR-101 level. These results suggest that when we choose one miRNA as a therapeutic tool, the endogenous level of the miRNA in each tumor should be considered.
Atherosclerosis across 4000 years of human history: the Horus study of four ancient populations.

Science.gov (United States)

Thompson, Randall C; Allam, Adel H; Lombardi, Guido P; Wann, L Samuel; Sutherland, M Linda; Sutherland, James D; Soliman, Muhammad Al-Tohamy; Frohlich, Bruno; Mininberg, David T; Monge, Janet M; Vallodolid, Clide M; Cox, Samantha L; Abd el-Maksoud, Gomaa; Badr, Ibrahim; Miyamoto, Michael I; el-Halim Nur el-Din, Abd; Narula, Jagat; Finch, Caleb E; Thomas, Gregory S

2013-04-06

Atherosclerosis is thought to be a disease of modern human beings and related to contemporary lifestyles. However, its prevalence before the modern era is unknown. We aimed to evaluate preindustrial populations for atherosclerosis. We obtained whole body CT scans of 137 mummies from four different geographical regions or populations spanning more than 4000 years. Individuals from ancient Egypt, ancient Peru, the Ancestral Puebloans of southwest America, and the Unangan of the Aleutian Islands were imaged. Atherosclerosis was regarded as definite if a calcified plaque was seen in the wall of an artery and probable if calcifications were seen along the expected course of an artery. Probable or definite atherosclerosis was noted in 47 (34%) of 137 mummies and in all four geographical populations: 29 (38%) of 76 ancient Egyptians, 13 (25%) of 51 ancient Peruvians, two (40%) of five Ancestral Puebloans, and three (60%) of five Unangan hunter gatherers (p=NS). Atherosclerosis was present in the aorta in 28 (20%) mummies, iliac or femoral arteries in 25 (18%), popliteal or tibial arteries in 25 (18%), carotid arteries in 17 (12%), and coronary arteries in six (4%). Of the five vascular beds examined, atherosclerosis was present in one to two beds in 34 (25%) mummies, in three to four beds in 11 (8%), and in all five vascular beds in two (1%). Age at time of death was positively correlated with atherosclerosis (mean age at death was 43 [SD 10] years for mummies with atherosclerosis vs 32 [15] years for those without; phuman beings raises the possibility of a more basic predisposition to the disease. National Endowment for the Humanities, Paleocardiology Foundation, The National Bank of Egypt, Siemens, and St Luke's Hospital Foundation of Kansas City. Copyright © 2013 Elsevier Ltd. All rights reserved.
Future coastal population growth and exposure to sea-level rise and coastal flooding--a global assessment.

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Barbara Neumann

Full Text Available Coastal zones are exposed to a range of coastal hazards including sea-level rise with its related effects. At the same time, they are more densely populated than the hinterland and exhibit higher rates of population growth and urbanisation. As this trend is expected to continue into the future, we investigate how coastal populations will be affected by such impacts at global and regional scales by the years 2030 and 2060. Starting from baseline population estimates for the year 2000, we assess future population change in the low-elevation coastal zone and trends in exposure to 100-year coastal floods based on four different sea-level and socio-economic scenarios. Our method accounts for differential growth of coastal areas against the land-locked hinterland and for trends of urbanisation and expansive urban growth, as currently observed, but does not explicitly consider possible displacement or out-migration due to factors such as sea-level rise. We combine spatially explicit estimates of the baseline population with demographic data in order to derive scenario-driven projections of coastal population development. Our scenarios show that the number of people living in the low-elevation coastal zone, as well as the number of people exposed to flooding from 1-in-100 year storm surge events, is highest in Asia. China, India, Bangladesh, Indonesia and Viet Nam are estimated to have the highest total coastal population exposure in the baseline year and this ranking is expected to remain largely unchanged in the future. However, Africa is expected to experience the highest rates of population growth and urbanisation in the coastal zone, particularly in Egypt and sub-Saharan countries in Western and Eastern Africa. The results highlight countries and regions with a high degree of exposure to coastal flooding and help identifying regions where policies and adaptive planning for building resilient coastal communities are not only desirable but essential
Future coastal population growth and exposure to sea-level rise and coastal flooding--a global assessment.

Science.gov (United States)

Neumann, Barbara; Vafeidis, Athanasios T; Zimmermann, Juliane; Nicholls, Robert J

2015-01-01

Coastal zones are exposed to a range of coastal hazards including sea-level rise with its related effects. At the same time, they are more densely populated than the hinterland and exhibit higher rates of population growth and urbanisation. As this trend is expected to continue into the future, we investigate how coastal populations will be affected by such impacts at global and regional scales by the years 2030 and 2060. Starting from baseline population estimates for the year 2000, we assess future population change in the low-elevation coastal zone and trends in exposure to 100-year coastal floods based on four different sea-level and socio-economic scenarios. Our method accounts for differential growth of coastal areas against the land-locked hinterland and for trends of urbanisation and expansive urban growth, as currently observed, but does not explicitly consider possible displacement or out-migration due to factors such as sea-level rise. We combine spatially explicit estimates of the baseline population with demographic data in order to derive scenario-driven projections of coastal population development. Our scenarios show that the number of people living in the low-elevation coastal zone, as well as the number of people exposed to flooding from 1-in-100 year storm surge events, is highest in Asia. China, India, Bangladesh, Indonesia and Viet Nam are estimated to have the highest total coastal population exposure in the baseline year and this ranking is expected to remain largely unchanged in the future. However, Africa is expected to experience the highest rates of population growth and urbanisation in the coastal zone, particularly in Egypt and sub-Saharan countries in Western and Eastern Africa. The results highlight countries and regions with a high degree of exposure to coastal flooding and help identifying regions where policies and adaptive planning for building resilient coastal communities are not only desirable but essential. Furthermore, we
Future Coastal Population Growth and Exposure to Sea-Level Rise and Coastal Flooding - A Global Assessment

Science.gov (United States)

Neumann, Barbara; Vafeidis, Athanasios T.; Zimmermann, Juliane; Nicholls, Robert J.

2015-01-01

Coastal zones are exposed to a range of coastal hazards including sea-level rise with its related effects. At the same time, they are more densely populated than the hinterland and exhibit higher rates of population growth and urbanisation. As this trend is expected to continue into the future, we investigate how coastal populations will be affected by such impacts at global and regional scales by the years 2030 and 2060. Starting from baseline population estimates for the year 2000, we assess future population change in the low-elevation coastal zone and trends in exposure to 100-year coastal floods based on four different sea-level and socio-economic scenarios. Our method accounts for differential growth of coastal areas against the land-locked hinterland and for trends of urbanisation and expansive urban growth, as currently observed, but does not explicitly consider possible displacement or out-migration due to factors such as sea-level rise. We combine spatially explicit estimates of the baseline population with demographic data in order to derive scenario-driven projections of coastal population development. Our scenarios show that the number of people living in the low-elevation coastal zone, as well as the number of people exposed to flooding from 1-in-100 year storm surge events, is highest in Asia. China, India, Bangladesh, Indonesia and Viet Nam are estimated to have the highest total coastal population exposure in the baseline year and this ranking is expected to remain largely unchanged in the future. However, Africa is expected to experience the highest rates of population growth and urbanisation in the coastal zone, particularly in Egypt and sub-Saharan countries in Western and Eastern Africa. The results highlight countries and regions with a high degree of exposure to coastal flooding and help identifying regions where policies and adaptive planning for building resilient coastal communities are not only desirable but essential. Furthermore, we
Late post-irradiation phenomena in mammalain cell populations. Pt. 2. Intraclonal recovery in sublines isolated from X-irradiated L5178Y-S cell populations

International Nuclear Information System (INIS)

Beer, J.Z.

1975-01-01

Clonal analysis of L5178Y-S cell populations irradiated with 300 rads of X-rays indicates occurence of cell sublines with considerably prolonged mean doubling times up to 22 h as compared to 10-11 h for control. Subsequent observations of growth of the handicapped sublines derived from single cells showed capability of all more than 100 studied sublines to recover normal proliferative activity. This process of intraclonal recovery required in many cases longer periods of time, corresponding to many tens, sometimes more than 200, generations. Late intraclonal recovery was further analysed by subcloning. It was found that although cytochemically assayed viability of the handicapped sublines was normal, cloning efficiency strongly depended on the stage of the recovery process. The recovery processes occuring in clones isolated from irradiated cell populations were compared with analogous processes occuring in slowly growing sublines isolated from non-irradiated cell cultures. Marked differences in kinetics of these processes show that either they are different in sublines derived from irradiated and non-irradiated cell populations or that the mechanisms of the late intraclonal recovery are affected by radiation. The results presented allow to conclude that gradual post-irradiation recovery of growth depends primarily on formation, in the developing populations, of cells with higher proliferative activities. Possible nature of the recovery processes is discussed in the light of available information on mammalian somatic cell variants with altered drug or temperature sensitivity, or with nutritional requirements. A sequence is proposed of changes leading from radiation-induced disturbance of the normably existing equilibrium between three basic cell subpopulations to ultimate restoration of this equilibrium. (author)
In vitro development of cloned bovine embryos produced by handmade cloning using somatic cells from distinct levels of cell culture confluence.

Science.gov (United States)

Gerger, R P C; Ribeiro, E S; Forell, F; Bertolini, L R; Rodrigues, J L; Ambrósio, C E; Miglino, M A; Mezzalira, A; Bertolini, M

2010-02-18

The relationship between the level of cell confluence near the plateau phase of growth and blastocyst yield following somatic cell cloning is not well understood. We examined the effect of distinct cell culture confluence levels on in vitro development of cloned bovine embryos. In vitro-matured bovine oocytes were manually bisected and selected by DNA staining. One or two enucleated hemi-cytoplasts were paired and fused with an adult skin somatic cell. Cultured skin cells from an adult Nellore cow harvested at three distinct culture confluence levels (70-80, 80-90, and >95%) were used for construction of embryos and hemi-embryos. After activation, structures were cultured in vitro as one embryo (1 x 100%) or as aggregates of two hemi-embryos (2 x 50%) per microwell. Fusion, cleavage and blastocyst rates were compared using the chi(2) test. The fusion rate for hemi-embryos (51.4%) was lower than for embryos (67.6%), with no influence of degree of cell confluence. However, blastocyst rates improved linearly (7.0, 17.5, and 29.4%) with increases in cell confluence. We conclude that degree of cell culture confluence significantly influences subsequent embryo development; use of a cell population in high confluence (>90%) for nuclear transfer significantly improved blastocyst yield after cloning.

Canine Distemper Viral Inclusions in Blood Cells of Four Vaccinated Dogs

OpenAIRE

McLaughlin, Bruce G.; Adams, Pamela S.; Cornell, William D.; Elkins, A. Darrel

1985-01-01

Four cases of canine distemper were detected by the presence of numerous cytoplasmic inclusions in various circulating blood cells. Fluorescent antibody techniques and electron microscopy confirmed the identity of the viral inclusions. The cases occurred in the same geographic area and within a short time span. All four dogs had been vaccinated against canine distemper, but stress or other factors may have compromised their immune status. The possibility of an unusually virulent virus strain ...
A stochastic step model of replicative senescence explains ROS production rate in ageing cell populations.

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Conor Lawless

Full Text Available Increases in cellular Reactive Oxygen Species (ROS concentration with age have been observed repeatedly in mammalian tissues. Concomitant increases in the proportion of replicatively senescent cells in ageing mammalian tissues have also been observed. Populations of mitotic human fibroblasts cultured in vitro, undergoing transition from proliferation competence to replicative senescence are useful models of ageing human tissues. Similar exponential increases in ROS with age have been observed in this model system. Tracking individual cells in dividing populations is difficult, and so the vast majority of observations have been cross-sectional, at the population level, rather than longitudinal observations of individual cells.One possible explanation for these observations is an exponential increase in ROS in individual fibroblasts with time (e.g. resulting from a vicious cycle between cellular ROS and damage. However, we demonstrate an alternative, simple hypothesis, equally consistent with these observations which does not depend on any gradual increase in ROS concentration: the Stochastic Step Model of Replicative Senescence (SSMRS. We also demonstrate that, consistent with the SSMRS, neither proliferation-competent human fibroblasts of any age, nor populations of hTERT overexpressing human fibroblasts passaged beyond the Hayflick limit, display high ROS concentrations. We conclude that longitudinal studies of single cells and their lineages are now required for testing hypotheses about roles and mechanisms of ROS increase during replicative senescence.
A stochastic step model of replicative senescence explains ROS production rate in ageing cell populations.

Science.gov (United States)

Lawless, Conor; Jurk, Diana; Gillespie, Colin S; Shanley, Daryl; Saretzki, Gabriele; von Zglinicki, Thomas; Passos, João F

2012-01-01

Increases in cellular Reactive Oxygen Species (ROS) concentration with age have been observed repeatedly in mammalian tissues. Concomitant increases in the proportion of replicatively senescent cells in ageing mammalian tissues have also been observed. Populations of mitotic human fibroblasts cultured in vitro, undergoing transition from proliferation competence to replicative senescence are useful models of ageing human tissues. Similar exponential increases in ROS with age have been observed in this model system. Tracking individual cells in dividing populations is difficult, and so the vast majority of observations have been cross-sectional, at the population level, rather than longitudinal observations of individual cells.One possible explanation for these observations is an exponential increase in ROS in individual fibroblasts with time (e.g. resulting from a vicious cycle between cellular ROS and damage). However, we demonstrate an alternative, simple hypothesis, equally consistent with these observations which does not depend on any gradual increase in ROS concentration: the Stochastic Step Model of Replicative Senescence (SSMRS). We also demonstrate that, consistent with the SSMRS, neither proliferation-competent human fibroblasts of any age, nor populations of hTERT overexpressing human fibroblasts passaged beyond the Hayflick limit, display high ROS concentrations. We conclude that longitudinal studies of single cells and their lineages are now required for testing hypotheses about roles and mechanisms of ROS increase during replicative senescence.
Experimental depletion of different renal interstitial cell populations

International Nuclear Information System (INIS)

Bohman, S.O.; Sundelin, B.; Forsum, U.; Tribukait, B.

1988-01-01

To define different populations of renal interstitial cells and investigate some aspects of their function, we studied the kidneys of normal rats and rats with hereditary diabetes insipidus (DI, Brattleboro) after experimental manipulations expected to alter the number of interstitial cells. DI rats showed an almost complete loss of interstitial cells in their renal papillae after treatment with a high dose of vasopressin. In spite of the lack of interstitial cells, the animals concentrated their urine to the same extent as vasopressin-treated normal rats, indicating that the renomedullary interstitial cells do not have an important function in concentrating the urine. The interstitial cells returned nearly to normal within 1 week off vasopressin treatment, suggesting a rapid turnover rate of these cells. To further distinguish different populations of interstitial cells, we studied the distribution of class II MHC antigen expression in the kidneys of normal and bone-marrow depleted Wistar rats. Normal rats had abundant class II antigen-positive interstitial cells in the renal cortex and outer medulla, but not in the inner medulla (papilla). Six days after 1000 rad whole body irradiation, the stainable cells were almost completely lost, but electron microscopic morphometry showed a virtually unchanged volume density of interstitial cells in the cortex and outer medulla, as well as the inner medulla. Thus, irradiation abolished the expression of the class II antigen but caused no significant depletion of interstitial cells
Nonequilibrium population dynamics of phenotype conversion of cancer cells.

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Joseph Xu Zhou

Full Text Available Tumorigenesis is a dynamic biological process that involves distinct cancer cell subpopulations proliferating at different rates and interconverting between them. In this paper we proposed a mathematical framework of population dynamics that considers both distinctive growth rates and intercellular transitions between cancer cell populations. Our mathematical framework showed that both growth and transition influence the ratio of cancer cell subpopulations but the latter is more significant. We derived the condition that different cancer cell types can maintain distinctive subpopulations and we also explain why there always exists a stable fixed ratio after cell sorting based on putative surface markers. The cell fraction ratio can be shifted by changing either the growth rates of the subpopulations (Darwinism selection or by environment-instructed transitions (Lamarckism induction. This insight can help us to understand the dynamics of the heterogeneity of cancer cells and lead us to new strategies to overcome cancer drug resistance.
Nonclassical Effects of a Four-Level Excited-Doublet Atom Model

International Nuclear Information System (INIS)

Zhang Jiansong; Xu Jingbo

2006-01-01

We adopt a dynamical algebraic method to study a four-level excited-doublet atom model and obtain the explicit expressions of the time-evolution operator and the density operator for the system. The nonclassical effects of the system, such as collapses and revivals of the atomic inversion and squeezing of the radiation field, are also discussed.
Census and vaccination coverage of owned dog populations in four resource-limited rural communities, Mpumalanga province, South Africa.

Science.gov (United States)

Conan, Anne; Geerdes, Joy A C; Akerele, Oluyemisi A; Reininghaus, Bjorn; Simpson, Gregory J G; Knobel, Darryn

2017-09-22

Dogs (Canis familiaris) are often free-roaming in sub-Saharan African countries. Rabies virus circulates in many of these populations and presents a public health issue. Mass vaccination of dog populations is the recommended method to decrease the number of dog and human rabies cases. We describe and compare four populations of dogs and their vaccination coverage in four different villages (Hluvukani, Athol, Utah and Dixie) in Bushbuckridge Municipality, Mpumalanga province, South Africa. Cross-sectional surveys were conducted in the villages of Athol, Utah and Dixie, while data from a Health and Demographic Surveillance System were used to describe the dog population in Hluvukani village. All households of the villages were visited to obtain information on the number, sex, age and rabies vaccination status of dogs. From May to October 2013, 2969 households were visited in the four villages and 942 owned dogs were reported. The populations were all young and skewed towards males. No differences were observed in the sex and age distributions (puppies 0-3 months excluded) among the villages. Athol had a higher proportion of dog-owning households than Hluvukani and Utah. Vaccination coverages were all above the 20% - 40% threshold required for herd immunity to rabies (38% in Hluvukani, 51% in Athol, 65% in Dixie and 74% in Utah). For the preparation of vaccination campaigns, we recommend the use of the relatively stable dog:human ratio (between 1:12 and 1:16) to estimate the number of dogs per village in Bushbuckridge Municipality.
Genetic polymorphisms of nine X-STR loci in four population groups from Inner Mongolia, China.

Science.gov (United States)

Hou, Qiao-Fang; Yu, Bin; Li, Sheng-Bin

2007-02-01

Nine short tandem repeat (STR) markers on the X chromosome (DXS101, DXS6789, DXS6799, DXS6804, DXS7132, DXS7133, DXS7423, DXS8378, and HPRTB) were analyzed in four population groups (Mongol, Ewenki, Oroqen, and Daur) from Inner Mongolia, China, in order to learn about the genetic diversity, forensic suitability, and possible genetic affinities of the populations. Frequency estimates, Hardy-Weinberg equilibrium, and other parameters of forensic interest were computed. The results revealed that the nine markers have a moderate degree of variability in the population groups. Most heterozygosity values for the nine loci range from 0.480 to 0.891, and there are evident differences of genetic variability among the populations. A UPGMA tree constructed on the basis of the generated data shows very low genetic distance between Mongol and Han (Xi'an) populations. Our results based on genetic distance analysis are consistent with the results of earlier studies based on linguistics and the immigration history and origin of these populations. The minisatellite loci on the X chromosome studied here are not only useful in showing significant genetic variation between the populations, but also are suitable for human identity testing among Inner Mongolian populations.
Morphology and ecology of Daphnia middendorffiana, Fisher 1851 (Crustacea, Daphniidae from four new populations in the Alps

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Rocco TIBERTI

2011-08-01

Full Text Available Daphnia middendorffiana has an arctic, circumpolar distribution, with some isolated southerly populations restricted to mountainous areas, including the Alps. In this paper, new records of Daphnia middendorffiana on the Alps are reported. The species was regularly recorded in several samples collected from 2006 to 2009 in four high altitude lakes in the Gran Paradiso National Park (GPNP during the ice free period. This is the third finding for the Alps and the described populations are the largest. Chemical and morphometric features of the lakes are provided, the morphology of the Daphnia middendorffiana from GPNP is described as well as some aspects concerning its ecology. The studied lakes are small, oligotrophic (total phosphorus ranged from 0 to 7 μg L-1 and well preserved from acidification risk (pH ranged from 6.45 to 8.14. D. middendorffiana is the largest zooplanktonic crustacean inhabiting the Alpine lakes in GPNP reaching 3.43 mm in length; the morphological analysis noted some differences within the studied populations; however there is a clear resemblance to the only Alpine population previously described (from Central Alps, Bognanco Valley, Lake Campo IV and to the arctic populations. D. middendorffiana in GPNP lives at low density levels, reaching higher densities in late August and early September. No males have been found during the sample campaign confirming its ability to produce asexual viable diapauses eggs. This study confirms the attitude of this species for cold and oligotrophic waters and increases the current knowledge on the geographical distribution, morphology and ecology of this species in Alpine environments. The finding of D. middendordorffiana in the GPNP poses interesting issues concerning the phylogeography of Alpine Daphnia middendorffiana, as well as raising need for conservation efforts aimed at keeping the populations safe from several global and local threats, such as climate warming and the ecological
The effect of additives on red cell 2,3 diphosphoglycerate levels in CPDA preservatives.

Science.gov (United States)

Vora, S; West, C; Beutler, E

1989-01-01

Forty-two chemical substances, chosen because they might influence red cell metabolism, were screened for effect on red cell adenosine triphosphate and 2,3 diphosphoglycerate (2,3 DPG) levels during storage in CPD or CPDA-1 at 4 degrees C. Of these substances, six appeared on initial screening to increase 2,3 DPG levels during storage; on repeated examination, four compounds, i.e., oxalate, glyoxalate, ethyl oxaloacetate, and L-phenylalanyl-L-alanine, consistently increased 2,3 DPG levels during storage. It was shown that glyoxalate was converted rapidly to oxalate in blood, presumably through the lactate dehydrogenase reaction. Ethyl oxaloacetate is known to hydrolyze, giving rise to oxalate. Thus, the effect of both glyoxalate and ethyl oxaloacetate can be explained by the formation of oxalate, a compound already known to increase 2,3 DPG levels. The effect of L-phenylalanyl-L-alanine remains to be explained, but it may be hydrolyzed to L-alanine and L-phenylalanine, both of which are thought to have the capacity to increase red cell 2,3 DPG levels by inhibiting pyruvate kinase activity.
CD71(high) population represents primitive erythroblasts derived from mouse embryonic stem cells.

Science.gov (United States)

Chao, Ruihua; Gong, Xueping; Wang, Libo; Wang, Pengxiang; Wang, Yuan

2015-01-01

The CD71/Ter119 combination has been widely used to reflect dynamic maturation of erythrocytes in vivo. However, because CD71 is expressed on all proliferating cells, it is unclear whether it can be utilized as an erythrocyte-specific marker during differentiation of embryonic stem cells (ESCs). In this study, we revealed that a population expressing high level of CD71 (CD71(high)) during mouse ESC differentiation represented an in vitro counterpart of yolk sac-derived primitive erythroblasts (EryPs) isolated at 8.5days post coitum. In addition, these CD71(high) cells went through "maturational globin switching" and enucleated during terminal differentiation in vitro that were similar to the yolk sac-derived EryPs in vivo. We further demonstrated that the formation of CD71(high) population was regulated differentially by key factors including Scl, HoxB4, Eaf1, and Klf1. Taken together, our study provides a technical advance that allows efficient segregation of EryPs from differentiated ESCs in vitro for further understanding molecular regulation during primitive erythropoiesis. Copyright © 2014. Published by Elsevier B.V.
Integrating Traditional and Evolutionary Knowledge in Biodiversity Conservation: a Population Level Case Study

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Dylan J. Fraser

2006-12-01

Full Text Available Despite their dual importance in the assessment of endangered/threatened species, there have been few attempts to integrate traditional ecological knowledge (TEK and evolutionary biology knowledge (EBK at the population level. We contrasted long-term aboriginal TEK with previously obtained EBK in the context of seasonal migratory habits and population biology of a salmonid fish, brook charr, (Salvelinus fontinalis inhabiting a large, remote postglacial lake. Compilation of TEK spanning four decades involved analytical workshops, semidirective interviews, and collaborative fieldwork with local aboriginal informants and fishing guides. We found that TEK complemented EBK of brook charr by providing concordant and additional information about (1 population viability; (2 breeding areas and migration patterns of divergent populations; and (3 the behavioral ecology of populations within feeding areas; all of which may ultimately affect the maintenance of population diversity. Aboriginal concerns related to human pressures on this species, not revealed by EBK, also help to focus future conservation initiatives for divergent populations and to encourage restoration of traditional fishing practices. However, relative to EBK, the relevance of TEK to salmonid biodiversity conservation was evident mainly at a smaller spatial scale, for example, that of individual rivers occupied by populations or certain lake sectors. Nevertheless, EBK was only collected over a 4-yr period, so TEK provided an essential long-term temporal window to evaluate population differences and persistence. We concluded that, despite different conceptual underpinnings, spatially and temporally varying TEK and EBK both contribute to the knowledge base required to achieve sustainability and effective biodiversity conservation planning for a given species. Such integration may be particularly relevant in many isolated regions, where intraspecific diversity can go unrecognized due to sparse
Correlation of Cell Surface Biomarker Expression Levels with Adhesion Contact Angle Measured by Lateral Microscopy.

Science.gov (United States)

Walz, Jenna A; Mace, Charles R

2018-06-05

Immunophenotyping is typically achieved using flow cytometry, but any influence a biomarker may have on adhesion or surface recognition cannot be determined concurrently. In this manuscript, we demonstrate the utility of lateral microscopy for correlating cell surface biomarker expression levels with quantitative descriptions of cell morphology. With our imaging system, we observed single cells from two T cell lines and two B cell lines adhere to antibody-coated substrates and quantified this adhesion using contact angle measurements. We found that SUP-T1 and CEM CD4+ cells, both of which express similar levels of CD4, experienced average changes in contact angle that were not statistically different from one another on surfaces coated in anti-CD4. However, MAVER-1 and BJAB K20 cells, both of which express different levels of CD20, underwent average changes in contact angle that were significantly different from one another on surfaces coated in anti-CD20. Our results indicate that changes in cell contact angles on antibody-coated substrates reflect the expression levels of corresponding antigens on the surfaces of cells as determined by flow cytometry. Our lateral microscopy approach offers a more reproducible and quantitative alternative to evaluate adhesion compared to commonly used wash assays and can be extended to many additional immunophenotyping applications to identify cells of interest within heterogeneous populations.
Signaling profiling at the single-cell level identifies a distinct signaling signature in murine hematopoietic stem cells.

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Du, Juan; Wang, Jinyong; Kong, Guangyao; Jiang, Jing; Zhang, Jingfang; Liu, Yangang; Tong, Wei; Zhang, Jing

2012-07-01

Hematopoietic stem cell (HSC) function is tightly regulated by cytokine signaling. Although phospho-flow cytometry allows us to study signaling in defined populations of cells, there has been tremendous hurdle to carry out this study in rare HSCs due to unrecoverable critical HSC markers, low HSC number, and poor cell recovery rate. Here, we overcame these difficulties and developed a "HSC phospho-flow" method to analyze cytokine signaling in murine HSCs at the single-cell level and compare HSC signaling profile to that of multipotent progenitors (MPPs), a cell type immediately downstream of HSCs, and commonly used Lin(-) cKit(+) cells (LK cells, enriched for myeloid progenitors). We chose to study signaling evoked from three representative cytokines, stem cell factor (SCF) and thrombopoietin (TPO) that are essential for HSC function and granulocyte macrophage-colony-stimulating factor (GM-CSF) that is dispensable for HSCs. HSCs display a distinct TPO and GM-CSF signaling signature from MPPs and LK cells, which highly correlates with receptor surface expression. In contrast, although majority of LK cells express lower levels of cKit than HSCs and MPPs, SCF-evoked ERK1/2 activation in LK cells shows a significantly increased magnitude for a prolonged period. These results suggest that specific cellular context plays a more important role than receptor surface expression in SCF signaling. Our study of HSC signaling at the homeostasis stage paves the way to investigate signaling changes in HSCs under conditions of stress, aging, and hematopoietic diseases. Copyright © 2012 AlphaMed Press.
Age-related patterns in human myeloid dendritic cell populations in people exposed to Schistosoma haematobium infection.

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Norman Nausch

Full Text Available Urogenital schistosomiasis is caused by the helminth parasite Schistosoma haematobium. In high transmission areas, children acquire schistosome infection early in life with infection levels peaking in early childhood and subsequently declining in late childhood. This age-related infection profile is thought to result from the gradual development of protective acquired immunity. Age-related differences in schistosome-specific humoral and cellular responses have been reported from several field studies. However there has not yet been a systematic study of the age-related changes in human dendritic cells, the drivers of T cell polarisation.Peripheral blood mononuclear cells were obtained from a cohort of 61 Zimbabwean aged 5-45 years with a S. haematobium prevalence of 47.5%. Two subsets of dendritic cells, myeloid and plasmacytoid dendritic cells (mDCs and pDCs, were analyzed by flow cytometry.In this population, schistosome infection levels peaked in the youngest age group (5-9 years, and declined in late childhood and adulthood (10+ years. The proportions of both mDCs and pDCs varied with age. However, for mDCs the age profile depended on host infection status. In the youngest age group infected people had enhanced proportions of mDCs as well as lower levels of HLA-DR on mDCs than un-infected people. In the older age groups (10-13 and 14-45 years infected people had lower proportions of mDCs compared to un-infected individuals, but no infection status-related differences were observed in their levels of HLA-DR. Moreover mDC proportions correlated with levels of schistosome-specific IgG, which can be associated with protective immunity. In contrast proportions of pDCs varied with host age, but not with infection status.Our results show that dendritic cell proportions and activation in a human population living in schistosome-endemic areas vary with host age reflecting differences in cumulative history of exposure to schistosome infection.
In situ probing of cholesterol in astrocytes at the single-cell level using laser desorption ionization mass spectrometric imaging with colloidal silver.

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Perdian, D C; Cha, Sangwon; Oh, Jisun; Sakaguchi, Donald S; Yeung, Edward S; Lee, Young Jin

2010-04-30

Mass spectrometric imaging has been utilized to localize individual astrocytes and to obtain cholesterol populations at the single-cell level in laser desorption ionization (LDI) with colloidal silver. The silver ion adduct of membrane-bound cholesterol was monitored to detect individual cells. Good correlation between mass spectrometric and optical images at different cell densities indicates the ability to perform single-cell studies of cholesterol abundance. The feasibility of quantification is confirmed by the agreement between the LDI-MS ion signals and the results from a traditional enzymatic fluorometric assay. We propose that this approach could be an effective tool to study chemical populations at the cellular level. Published in 2010 by John Wiley & Sons, Ltd.
Nitrogen balance study in young Nigerian adult males using four levels of protein intake.

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Atinmo, T; Mbofung, C M; Egun, G; Osotimehin, B

1988-11-01

1. The present study was carried out to estimate precisely, via the nitrogen balance technique, the protein requirement of Nigerians (earlier estimated via the obligatory N method) using graded levels of protein intake. 2. Fifteen medical students of the University of Ibadan who volunteered to participate in the study were given graded levels of protein (0.3, 0.45, 0.6 and 0.75 g/kg body-weight per d) derived from foods similar to those usually consumed by the subjects. 3. Each subject was given each of the dietary protein levels for a period of 10 d. Subjects were divided into two groups and the feeding pattern followed a criss-cross design with one group starting with the highest level of protein intake (0.3 g). Mean energy intake during each of the eleven experimental periods was maintained at 0.2 MJ/kg per d. After an initial 5 d adaptation period in each experimental period, 24 h urine and faecal samples were collected in marked containers for five consecutive days for N determination. 4. Mean N balance during consumption of the four protein levels (0.30, 0.45, 0.6 and 0.75 g/kg) were -11.02 (SD 8.07), -9.90 (SD 6.64), +9.70 (SD 4.15) and +5.13 (SD 4.62) respectively. Using regression analysis, the mean daily N requirement was estimated at 110.25 mg N/kg body-weight (0.69 g protein/kg body-weight). Estimates of allowances for individual variations to cover 97.5% of the population adjusted this value to 0.75 g protein/kg body-weight. Net protein utilization for the diet at maintenance level was estimated at 57.5.
Census and vaccination coverage of owned dog populations in four resource-limited rural communities, Mpumalanga province, South Africa

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Anne Conan

2017-09-01

Full Text Available Dogs (Canis familiaris are often free-roaming in sub-Saharan African countries. Rabies virus circulates in many of these populations and presents a public health issue. Mass vaccination of dog populations is the recommended method to decrease the number of dog and human rabies cases. We describe and compare four populations of dogs and their vaccination coverage in four different villages (Hluvukani, Athol, Utah and Dixie in Bushbuckridge Municipality, Mpumalanga province, South Africa. Cross-sectional surveys were conducted in the villages of Athol, Utah and Dixie, while data from a Health and Demographic Surveillance System were used to describe the dog population in Hluvukani village. All households of the villages were visited to obtain information on the number, sex, age and rabies vaccination status of dogs. From May to October 2013, 2969 households were visited in the four villages and 942 owned dogs were reported. The populations were all young and skewed towards males. No differences were observed in the sex and age distributions (puppies 0–3 months excluded among the villages. Athol had a higher proportion of dog-owning households than Hluvukani and Utah. Vaccination coverages were all above the 20% – 40% threshold required for herd immunity to rabies (38% in Hluvukani, 51% in Athol, 65% in Dixie and 74% in Utah. For the preparation of vaccination campaigns, we recommend the use of the relatively stable dog:human ratio (between 1:12 and 1:16 to estimate the number of dogs per village in Bushbuckridge Municipality.
Population dynamics of Hawaiian seabird colonies vulnerable to sea-level rise

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Hatfield, Jeff S.; Reynolds, Michelle H.; Seavy, Nathaniel E.; Krause, Crystal M.

2012-01-01

Globally, seabirds are vulnerable to anthropogenic threats both at sea and on land. Seabirds typically nest colonially and show strong fidelity to natal colonies, and such colonies on low-lying islands may be threatened by sea-level rise. We used French Frigate Shoals, the largest atoll in the Hawaiian Archipelago, as a case study to explore the population dynamics of seabird colonies and the potential effects sea-level rise may have on these rookeries. We compiled historic observations, a 30-year time series of seabird population abundance, lidar-derived elevations, and aerial imagery of all the islands of French Frigate Shoals. To estimate the population dynamics of 8 species of breeding seabirds on Tern Island from 1980 to 2009, we used a Gompertz model with a Bayesian approach to infer population growth rates, density dependence, process variation, and observation error. All species increased in abundance, in a pattern that provided evidence of density dependence. Great Frigatebirds (Fregata minor), Masked Boobies (Sula dactylatra), Red-tailed Tropicbirds (Phaethon rubricauda), Spectacled Terns (Onychoprion lunatus), and White Terns (Gygis alba) are likely at carrying capacity. Density dependence may exacerbate the effects of sea-level rise on seabirds because populations near carrying capacity on an island will be more negatively affected than populations with room for growth. We projected 12% of French Frigate Shoals will be inundated if sea level rises 1 m and 28% if sea level rises 2 m. Spectacled Terns and shrub-nesting species are especially vulnerable to sea-level rise, but seawalls and habitat restoration may mitigate the effects of sea-level rise. Losses of seabird nesting habitat may be substantial in the Hawaiian Islands by 2100 if sea levels rise 2 m. Restoration of higher-elevation seabird colonies represent a more enduring conservation solution for Pacific seabirds.
Tumourigenic canine osteosarcoma cell lines associated with frizzled-6 up-regulation and enhanced side population cell frequency.

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de Sá Rodrigues, L C; Holmes, K E; Thompson, V; Newton, M A; Stein, T J

2017-03-01

An increased serum alkaline phosphatase concentration is known to be associated with a negative prognosis in canine and human osteosarcoma. To expand upon previous studies regarding the biological relevance of increased serum alkaline phosphatase as a negative prognostic factor, xenogeneic heterotopic transplants were performed using six canine primary osteosarcoma cell lines generated from patients with differing serum alkaline phosphatase concentrations (three normal and three increased). Three of the six cell lines were capable of generating tumours and tumour formation was independent of the serum alkaline phosphatase status of the cell line. Microarray analysis identified 379 genes as being differentially expressed between the tumourigenic and non-tumourigenic cell lines. Frizzled-6 was upregulated to the greatest extent (7.78-fold) in tumourigenic cell lines compared with non-tumourigenic cell lines. Frizzled-6, a co-receptor for Wnt ligands has been associated with enhanced tumour-initiating cells and poor prognosis for other tumours. The increased expression of frizzled-6 was confirmed by quantitative reverse transcription polymerase chain reaction (QPCR) and Western blot analysis. Additionally, the tumourigenic cell lines also had an increase in the percentage of side population cells compared with non-tumourigenic cell lines (5.89% versus 1.58%, respectively). There were no differences in tumourigenicity, frizzled-6 or percentage of side population cells noted between osteosarcoma cell lines generated from patients of differing serum alkaline phosphatase concentration. However, to our knowledge this is the first study to identified frizzled-6 as a possible marker of osteosarcoma cell populations with enhanced tumourigenicity and side population cells. Future work will focus on defining the role of frizzled-6 in osteosarcoma tumourigenesis and tumour-initiating cells. © 2015 John Wiley & Sons Ltd.

Genetic variability of CYP2B6 polymorphisms in four southern Chinese populations

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Xu, Bing-Ying; Guo, Li-Ping; Lee, Shui-Shan; Dong, Qing-Ming; Tan, Yi; Yao, Hong; Li, Li-Hua; Lin, Che-Kit; Kung, Hsiang-Fu; He, Ming-Liang

2007-01-01

AIM: To investigate the genotype and allelic frequencies of Cytochrome P450 2B6 polymorphisms in four southern Chinese populations. METHODS: DNA was obtained from blood samples from Han Chinese from Hong Kong and three minority groups, the Wa, Bulang and Lahu from Yunnan in southern China. Genotyping was performed using real-time PCR and confirmed by direct sequencing. RESULTS: A total of 507 subjects from southern China were studied. Results showed there is a high prevalence of 516G > T (34.5%) in ethnic Chinese compared to literature reports on other Asian populations and Caucasians. The frequency of the 516TT genotype is higher in the Han majority (23.1%) than in three other ethnic minority groups (i.e., 7.4%, 9.1% and 15.8%) in southern China. CONCLUSION: This was the first study to document the spectrum of CYP2B6 allelic variants and genotypes in a southern Chinese population. The 516G > T allele is associated with a defective metabolism of efavirenz (EFV), which therefore may predispose to drug toxicity. Treatment regimens for human immunodeficiency virus (HIV) and heroin addiction may need to be optimized in different populations because of the marked variability of the key metabolizing enzyme. PMID:17465455
Sodium arsenite alters cell cycle and MTHFR, MT1/2, and c-Myc protein levels in MCF-7 cells

International Nuclear Information System (INIS)

Ruiz-Ramos, Ruben; Lopez-Carrillo, Lizbeth; Albores, Arnulfo; Hernandez-Ramirez, Raul U.; Cebrian, Mariano E.

2009-01-01

There is limited available information on the effects of arsenic on enzymes participating in the folate cycle. Therefore, our aim was to evaluate the effects of sodium arsenite on the protein levels of methylenetetrahydrofolate reductase (MTHFR) and dihydrofolate reductase (DHFR) and its further relationship with the expression MT1/2 and c-myc in MCF-7 cells. Arsenite treatment (0-10 μM) for 4 h decreased MTHFR levels in a concentration-dependent fashion without significant effects on DHFR. The effects on MTHFR were observed at arsenite concentrations not significantly affecting cell viability. We also observed an increase in S-phase recruitment at all concentrations probed. Lower concentrations (< 5 μM) induced cell proliferation, showing a high proportion of BrdU-stained cells, indicating a higher DNA synthesis rate. However, higher concentrations (≥ 5 μM) or longer treatment periods induced apoptosis. Arsenite also induced dose-dependent increases in MT1/2 and c-Myc protein levels. The levels of MTHFR were inversely correlated to MT1/2 and c-Myc overexpression and increased S-phase recruitment. Our findings indicate that breast epithelial cells are responsive to arsenite and suggest that exposure may pose a risk for breast cancer. The reductions in MTHFR protein levels contribute to understand the mechanisms underlying the induction of genes influencing growth regulation, such as c-myc and MT1/2. However, further research is needed to ascertain if the effects here reported following short-time and high-dose exposure are relevant for human populations chronically exposed to low arsenic concentrations.
Analysis of antigen-specific B-cell memory directly ex vivo.

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McHeyzer-Williams, Louise J; McHeyzer-Williams, Michael G

2004-01-01

Helper T-cell-regulated B-cell memory develops in response to initial antigen priming as a cellular product of the germinal center (GC) reaction. On antigen recall, memory response precursors expand rapidly with exaggerated differentiation into plasma cells to produce the high-titer, high-affinity antibody(Ab) that typifies the memory B-cell response in vivo. We have devised a high-resolution flow cytometric strategy to quantify the emergence and maintenance of antigen-specific memory B cells directly ex vivo. Extended cell surface phenotype establishes a level of cellular diversity not previously appreciated for the memory B-cell compartment. Using an "exclusion transfer" strategy, we ascertain the capacity of two distinct memory B-cell populations to transfer antigen-specific memory into naive adoptive hosts. Finally, we sequence expressed messenger ribonucleic acid (mRNA) from single cells within the population to estimate the level of somatic hypermutation as the best molecular indicator of B-cell memory. In this chapter, we describe the methods used in each of these four sections that serve to provide high-resolution quantification of antigen-specific B-cell memory responses directly ex vivo.
Simulating spontaneously generated coherence in a four-level atomic system

International Nuclear Information System (INIS)

Li Aijun; Gao Jinyue; Wu Jinhui; Wang Lei

2005-01-01

We study the spontaneous emission property of a four-level atomic system driven by two coherent fields. By numerical calculations in the bare state picture, we show that such interesting phenomena as extremely narrow peaks and spontaneous emission quenching can be realized, which are well understood by qualitative explanations in the partially and fully dressed state pictures. Especially, this coherently driven atomic system has two close-lying levels in the partially dressed state picture so that spontaneously generated coherence arises. Using our considered scheme it is feasible to carry out experiments based on spontaneously generated coherence because all rigorous requirements have been avoided in the bare state picture
Analysing the Influence of the Spontaneous Aneuploidy Frequency on the Cell Population System Cultivation

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G. A. Nefedov

2015-01-01

Full Text Available The paper provides a qualitative analysis of M.S. Vinogradova's nonlinear model for dynamics of the cell population system. This system describes the stem cells cultivation in vitro under resource constraints. The system consists of two populations, namely: population of normal cells and population of abnormal cells. Resource constraints are considered as linear dependences of mitosis parameters on the normalized densities of each population.One of the key parameters that effects on the realization of the system evolution scenarios is a parameter that determines a share of the normal cells, which pass, when dividing, into population of the abnormal cells. The paper analyses both the existence conditions of the rest points and the changes of the evolution scenarios of population system with changing abovementioned parameter and other system parameters held fixed. It is shown that there is a saddle-node bifurcation in the system; the bifurcation value of the parameter is found. The paper shows the interval of parameter values in which the favorable scenarios of population system evolution are implemented. It also presents results of mathematical modeling.
A sub-population of circulating porcine gammadelta T cells can act as professional antigen presenting cells.

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Takamatsu, H-H; Denyer, M S; Wileman, T E

2002-09-10

A sub-population of circulating porcine gammadelta T cells express cell surface antigens associated with antigen presenting cells (APCs), and are able to take up soluble antigen very effectively. Functional antigen presentation by gammadelta T cells to memory helper T cells was studied by inbred pig lymphocytes immunised with ovalbumin (OVA). After removing all conventional APCs from the peripheral blood of immunised pigs, the remaining lymphocytes still proliferated when stimulated with OVA. When gammadelta T cells were further depleted, OVA specific proliferation was abolished, but reconstitution with gammadelta T cells restored proliferation. The proliferation was blocked by monoclonal antibodies (mAb) against MHC class II or CD4, and by pre-treatment of gammadelta T cells with chloroquine. These results indicate that a sub-population of circulating porcine gammadelta T cells act as APCs and present antigen via MHC class II.
Diversity and effective population size of four horse breeds from microsatellite DNA markers in South-Central Mexico

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J. F. Vázquez-Armijo

2017-06-01

Full Text Available The South-Central region of Mexico has experienced a sizeable introduction of purebred horses for recreational aims. A study was designed to assess effective population sizes and genetic diversity and to verify the genetic integrity of four horse breeds. Using a 12-microsatellite panel, Quarter Horse, Azteca, Thoroughbred and Creole (CRL horses were sampled and analysed for diversity and genetic structure. Genetic diversity parameters showed high numbers of heterozygous horses but small effective population sizes in all breeds. Population structure results suggested some degree of admixture of CRL with the other reference breeds. The highly informative microsatellite panel allowed the verification of diversity in introduced horse populations and the confirmation of small effective population sizes, which suggests a risk for future breed integrity.
Quantitation of DNA repair in brain cell cultures: implications for autoradiographic analysis of mixed cell populations

International Nuclear Information System (INIS)

Dambergs, R.; Kidson, C.

1979-01-01

Quantitation of DNA repair in the mixed cell population of mouse embryo brain cultures has been assessed by autoradiographic analysis of unscheduled DNA synthesis following UV-irradiation. The proportion of labelled neurons and the grain density over neuronal nuclei were both less than the corresponding values for glial cells. The nuclear geometries of these two classes of cell are very different. Partial correction for the different geometries by relating grain density to nuclear area brought estimates of neuronal and glial DNA repair synthesis more closely in line. These findings have general implications for autoradiographic measurement of DNA repair in mixed cell populations and in differentiated versus dividing cells. (author)
CCR6(+) Th cell populations distinguish ACPA positive from ACPA negative rheumatoid arthritis.

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Paulissen, Sandra M J; van Hamburg, Jan Piet; Davelaar, Nadine; Vroman, Heleen; Hazes, Johanna M W; de Jong, Pascal H P; Lubberts, Erik

2015-11-30

Patients with rheumatoid arthritis (RA) can be separated into two major subpopulations based on the absence or presence of serum anti-citrullinated protein antibodies (ACPAs). The more severe disease course in ACPA(+) RA and differences in treatment outcome between these subpopulations suggest that ACPA(+) and ACPA(-) RA are different disease subsets. The identification of T-helper (Th) cells specifically recognizing citrullinated peptides, combined with the strong association between HLA-DRB1 and ACPA positivity, point toward a pathogenic role of Th cells in ACPA(+) RA. In this context we recently identified a potential pathogenic role for CCR6(+) Th cells in RA. Therefore, we examined whether Th cell population distributions differ by ACPA status. We performed a nested matched case-control study including 27 ACPA(+) and 27 ACPA(-) treatment-naive early RA patients matched for disease activity score in 44 joints, presence of rheumatoid factor, sex, age, duration of complaints and presence of erosions. CD4(+)CD45RO(+) (memory) Th cell distribution profiles from these patients were generated based on differential chemokine receptor expression and related with disease duration. ACPA status was not related to differences in total CD4(+) T cell or memory Th cell proportions. However, ACPA(+) patients had significantly higher proportions of Th cells expressing the chemokine receptors CCR6 and CXCR3. Similar proportions of CCR4(+) and CCR10(+) Th cells were found. Within the CCR6(+) cell population, four Th subpopulations were distinguished based on differential chemokine receptor expression: Th17 (CCR4(+)CCR10(-)), Th17.1 (CXCR3(+)), Th22 (CCR4(+)CCR10(+)) and CCR4/CXCR3 double-positive (DP) cells. In particular, higher proportions of Th22 (p = 0.02), Th17.1 (p = 0.03) and CCR4/CXCR3 DP (p = 0.01) cells were present in ACPA(+) patients. In contrast, ACPA status was not associated with differences in Th1 (CCR6(-)CXCR3(+); p = 0.90), Th2 (CCR6(-)CCR4(+); p = 0.27) and T
The impact of insecticide applications on the dynamics of resistance: The case of four Aedes aegypti populations from different Brazilian regions

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Martins, Ademir de Jesus; Maciel-de-Freitas, Rafael; Linss, Jutta Gerlinde Birggitt; Araújo, Simone Costa; Lima, José Bento Pereira; Valle, Denise

2018-01-01

Background In the tropics, the utilization of insecticides is still an important strategy for controlling Aedes aegypti, the principle vector of dengue, chikungunya and Zika viruses. However, increasing insecticide resistance in Ae. aegypti populations might hinder insecticide efficacy on a long-term basis. It will be important to understand the dynamics and evolution of insecticide resistance by assessing its frequency and the mechanisms by which it occurs. Methodology/Principal findings The insecticide resistance status of four Brazilian Ae. aegypti populations was monitored. Quantitative bioassays with the major insecticides employed in the country was performed: the adulticide deltamethrin (a pyrethroid—PY) and the larvicides, temephos (an organophosphate) and diflubenzuron (a chitin synthesis inhibitor). Temephos resistance was detected in all populations although exhibiting a slight decrease over time probably due to the interruption of field use. All vector populations were susceptible to diflubenzuron, recently introduced in the country to control Ae. aegypti. Resistance against deltamethrin was extremely high in three populations. Molecular assays investigated substitutions in the voltage gated sodium channel (NaV), the PY target site, at positions 1011, 1016 and 1534. Elevated frequencies of substitutions Val1016Ile and Phe1534Cys related to high PY resistance levels were identified. Biochemical assays detected alterations in the activities of two detoxifying enzyme classes related to metabolic resistance, glutathion-S-transferases and esterases. The results obtained were evaluated in the context of both recent insecticide use and the records of dengue incidence in each locality. Conclusions/Significance The four Ae. aegypti populations evaluated were resistant to the neurotoxic insecticides, temephos and deltamethrin. However, they were still susceptible to diflubenzuron. A probable correlation between adult insect resistance to PY and the domestic
Population-level interventions in government jurisdictions for dietary sodium reduction.

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McLaren, Lindsay; Sumar, Nureen; Barberio, Amanda M; Trieu, Kathy; Lorenzetti, Diane L; Tarasuk, Valerie; Webster, Jacqui; Campbell, Norman Rc

2016-09-16

Excess dietary sodium consumption is a risk factor for high blood pressure, stroke and cardiovascular disease. Currently, dietary sodium consumption in almost every country is too high. Excess sodium intake is associated with high blood pressure, which is common and costly and accounts for significant burden of disease. A large number of jurisdictions worldwide have implemented population-level dietary sodium reduction initiatives. No systematic review has examined the impact of these initiatives. • To assess the impact of population-level interventions for dietary sodium reduction in government jurisdictions worldwide.• To assess the differential impact of those initiatives by social and economic indicators. We searched the following electronic databases from their start date to 5 January 2015: the Cochrane Central Register of Controlled Trials (CENTRAL); Cochrane Public Health Group Specialised Register; MEDLINE; MEDLINE In Process & Other Non-Indexed Citations; EMBASE; Effective Public Health Practice Project Database; Web of Science; Trials Register of Promoting Health Interventions (TRoPHI) databases; and Latin American Caribbean Health Sciences Literature (LILACS). We also searched grey literature, other national sources and references of included studies.This review was conducted in parallel with a comprehensive review of national sodium reduction efforts under way worldwide (Trieu 2015), through which we gained additional information directly from country contacts.We imposed no restrictions on language or publication status. We included population-level initiatives (i.e. interventions that target whole populations, in this case, government jurisdictions, worldwide) for dietary sodium reduction, with at least one pre-intervention data point and at least one post-intervention data point of comparable jurisdiction. We included populations of all ages and the following types of study designs: cluster-randomised, controlled pre-post, interrupted time series
Estimation of Potential Population Level Effects of Contaminants on Wildlife; FINAL

International Nuclear Information System (INIS)

Loar, J.M.

2001-01-01

The objective of this project is to provide DOE with improved methods to assess risks from contaminants to wildlife populations. The current approach for wildlife risk assessment consists of comparison of contaminant exposure estimates for individual animals to literature-derived toxicity test endpoints. These test endpoints are assumed to estimate thresholds for population-level effects. Moreover, species sensitivities to contaminants is one of several criteria to be considered when selecting assessment endpoints (EPA 1997 and 1998), yet data on the sensitivities of many birds and mammals are lacking. The uncertainties associated with this approach are considerable. First, because toxicity data are not available for most potential wildlife endpoint species, extrapolation of toxicity data from test species to the species of interest is required. There is no consensus on the most appropriate extrapolation method. Second, toxicity data are represented as statistical measures (e.g., NOAEL s or LOAELs) that provide no information on the nature or magnitude of effects. The level of effect is an artifact of the replication and dosing regime employed, and does not indicate how effects might increase with increasing exposure. Consequently, slight exceedance of a LOAEL is not distinguished from greatly exceeding it. Third, the relationship of toxic effects on individuals to effects on populations is poorly estimated by existing methods. It is assumed that if the exposure of individuals exceeds levels associated with impaired reproduction, then population level effects are likely. Uncertainty associated with this assumption is large because depending on the reproductive strategy of a given species, comparable levels of reproductive impairment may result in dramatically different population-level responses. This project included several tasks to address these problems: (1) investigation of the validity of the current allometric scaling approach for interspecies extrapolation
Changes in B Cell Populations and Merozoite Surface Protein-1-Specific Memory B Cell Responses after Prolonged Absence of Detectable P. falciparum Infection.

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Cyrus Ayieko

Full Text Available Clinical immunity to malaria declines in the absence of repeated parasite exposure. However, little is known about how B cell populations and antigen-specific memory B cells change in the absence of P. falciparum infection. A successful indoor residual insecticide spraying campaign in a highland area of western Kenya, led to an absence of blood-stage P. falciparum infection between March 2007 and April 2008. We assessed memory B cell responses in 45 adults at the beginning (April 2008 and end (April 2009 of a subsequent 12-month period during which none of the adults had evidence of asymptomatic parasitemia or clinical disease. Antibodies and memory B cells to the 42-kDa portion of the merozoite surface protein-1 (MSP-142 were measured using ELISA and ELISPOT assays, respectively. B cell populations were characterized by flow cytometry. From 2008 to 2009, the prevalence of MSP-142-specific memory B cells (45% vs. 55%, respectively, P = 0.32 or antibodies (91% vs. 82%, respectively, P = 0.32 did not differ significantly, although specific individuals did change from positive to negative and vice versa, particularly for memory B cells, suggesting possible low-level undetected parasitemia may have occurred in some individuals. The magnitude of MSP-142-specific memory B cells and levels of antibodies to MSP-142 also did not differ from 2008 to 2009 (P>0.10 for both. However, from 2008 to 2009 the proportions of both class-switched atypical (CD19+IgD-CD27-CD21-IgM- and class-switched activated (CD19+IgD-CD27+CD21-IgM- memory B cells decreased (both P<0.001. In contrast, class-switched resting classical memory B cells (CD19+IgD-CD27+CD21+IgM- increased (P<0.001. In this area of seasonal malaria transmission, a one- year absence of detectable P. falciparum infection was not associated with changes in the prevalence or level of MSP-142 specific memory B cells, but was associated with major changes in overall memory B cell subsets.
Community-based population-level interventions for promoting child oral health.

OpenAIRE

de Silva, AM; Hegde, S; Akudo Nwagbara, B; Calache, H; Gussy, MG; Nasser, M; Morrice, HR; Riggs, E; Leong, PM; Meyenn, LK; Yousefi-Nooraie, R

2016-01-01

BACKGROUND: Dental caries and gingival and periodontal disease are commonly occurring, preventable chronic conditions. Even though much is known about how to treat oral disease, currently we do not know which community-based population-level interventions are most effective and equitable in preventing poor oral health. OBJECTIVES: Primary • To determine the effectiveness of community-based population-level oral health promotion interventions in preventing dental caries and gingival and period...
Stochastic adaptation and fold-change detection: from single-cell to population behavior

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Leier André

2011-02-01

Full Text Available Abstract Background In cell signaling terminology, adaptation refers to a system's capability of returning to its equilibrium upon a transient response. To achieve this, a network has to be both sensitive and precise. Namely, the system must display a significant output response upon stimulation, and later on return to pre-stimulation levels. If the system settles at the exact same equilibrium, adaptation is said to be 'perfect'. Examples of adaptation mechanisms include temperature regulation, calcium regulation and bacterial chemotaxis. Results We present models of the simplest adaptation architecture, a two-state protein system, in a stochastic setting. Furthermore, we consider differences between individual and collective adaptive behavior, and show how our system displays fold-change detection properties. Our analysis and simulations highlight why adaptation needs to be understood in terms of probability, and not in strict numbers of molecules. Most importantly, selection of appropriate parameters in this simple linear setting may yield populations of cells displaying adaptation, while single cells do not. Conclusions Single cell behavior cannot be inferred from population measurements and, sometimes, collective behavior cannot be determined from the individuals. By consequence, adaptation can many times be considered a purely emergent property of the collective system. This is a clear example where biological ergodicity cannot be assumed, just as is also the case when cell replication rates are not homogeneous, or depend on the cell state. Our analysis shows, for the first time, how ergodicity cannot be taken for granted in simple linear examples either. The latter holds even when cells are considered isolated and devoid of replication capabilities (cell-cycle arrested. We also show how a simple linear adaptation scheme displays fold-change detection properties, and how rupture of ergodicity prevails in scenarios where transitions between
Decoherence in yeast cell populations and its implications for genome-wide expression noise.

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Briones, M R S; Bosco, F

2009-01-20

Gene expression "noise" is commonly defined as the stochastic variation of gene expression levels in different cells of the same population under identical growth conditions. Here, we tested whether this "noise" is amplified with time, as a consequence of decoherence in global gene expression profiles (genome-wide microarrays) of synchronized cells. The stochastic component of transcription causes fluctuations that tend to be amplified as time progresses, leading to a decay of correlations of expression profiles, in perfect analogy with elementary relaxation processes. Measuring decoherence, defined here as a decay in the auto-correlation function of yeast genome-wide expression profiles, we found a slowdown in the decay of correlations, opposite to what would be expected if, as in mixing systems, correlations decay exponentially as the equilibrium state is reached. Our results indicate that the populational variation in gene expression (noise) is a consequence of temporal decoherence, in which the slow decay of correlations is a signature of strong interdependence of the transcription dynamics of different genes.
Building the Evidence Base for Population-Level Interventions: Barriers and Opportunities

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Lifsey, Sarah; Cash, Amanda; Anthony, Jodi; Mathis, Sheryl; Silva, Sandra

2015-01-01

Population-level interventions focused on policy, systems, and environmental change strategies are increasingly being used to affect and improve the health of populations. At the same time, emphasis on implementing evidence-based public health practices and programming is increasing, particularly at the federal level. Valuing strategies in the…
International migration patterns of Red-throated Loons (Gavia stellata) from four breeding populations in Alaska

Science.gov (United States)

McCloskey, Sarah E.; Uher-Koch, Brian D.; Schmutz, Joel A.; Fondell, Thomas F.

2018-01-01

Identifying post-breeding migration and wintering distributions of migratory birds is important for understanding factors that may drive population dynamics. Red-throated Loons (Gavia stellata) are widely distributed across Alaska and currently have varying population trends, including some populations with recent periods of decline. To investigate population differentiation and the location of migration pathways and wintering areas, which may inform population trend patterns, we used satellite transmitters (n = 32) to describe migration patterns of four geographically separate breeding populations of Red-throated Loons in Alaska. On average (± SD) Red-throated Loons underwent long (6,288 ± 1,825 km) fall and spring migrations predominantly along coastlines. The most northern population (Arctic Coastal Plain) migrated westward to East Asia and traveled approximately 2,000 km farther to wintering sites than the three more southerly populations (Seward Peninsula, Yukon-Kuskokwim Delta, and Copper River Delta) which migrated south along the Pacific coast of North America. These migration paths are consistent with the hypothesis that Red-throated Loons from the Arctic Coastal Plain are exposed to contaminants in East Asia. The three more southerly breeding populations demonstrated a chain migration pattern in which the more northerly breeding populations generally wintered in more northerly latitudes. Collectively, the migration paths observed in this study demonstrate that some geographically distinct breeding populations overlap in wintering distribution while others use highly different wintering areas. Red-throated Loon population trends in Alaska may therefore be driven by a wide range of effects throughout the annual cycle.
Responses of Four Rice Varieties to Elevated CO2 and Different Salinity Levels

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Sheidollah Kazemi

2018-05-01

Full Text Available Abstract:: This study was carried out in 2014 at Isfahan University of Technology, Iran, to evaluate the responses of four rice varieties (Neda, Deylamani, Shiroudi and Domsorkh to ambient (360 ± 50 μmol/mol and elevated (700 ± 50 μmol/mol air carbon dioxide (CO2 concentrations under four salinity levels (0, 30, 60 and 90 mmol/L NaCl. There was significant variation among rice varieties in response to elevated CO2 concentration under the four salinity levels. Under non-saline condition, elevated CO2 increased the dry weight of Neda, Deylamani and Domsorkh by 8%, 50% and 8%, respectively, but reversely decreased that of Shiroudi by 34%. Increasing CO2 concentration significantly reduced the negative effects of salinity on Shiroudi, but these effects were even increased in Deylamani and Domsorkh under all the salinity levels and in Neda only under 30 and 60 mmol/L NaCl. Significant correlations were established between plant dry weight, SPAD value and leaf area under both CO2 levels. However, this trend was observed only at ambient CO2 concentration in the presence of soluble carbohydrates. The results revealed the genotype and salinity dependence of the effects of CO2 concentrations on the rice traits investigated. Key words: CO2 concentration, genetic diversity, salt tolerance, water soluble carbohydrate
Transcriptomic profiling of pancreatic alpha, beta and delta cell populations identifies delta cells as a principal target for ghrelin in mouse islets

DEFF Research Database (Denmark)

Adriaenssens, Alice E; Svendsen, Berit; Lam, Brian Y H

2016-01-01

cytometry and analysed by RNA sequencing. The role of the ghrelin receptor was validated by imaging delta cell calcium concentrations using islets with delta cell restricted expression of the calcium reporter GCaMP3, and in perfused mouse pancreases. RESULTS: A database was constructed of all genes...... expressed in alpha, beta and delta cells. The gene encoding the ghrelin receptor, Ghsr, was highlighted as being highly expressed and enriched in delta cells. Activation of the ghrelin receptor raised cytosolic calcium levels in primary pancreatic delta cells and enhanced somatostatin secretion in perfused...... pancreases, correlating with a decrease in insulin and glucagon release. The inhibition of insulin secretion by ghrelin was prevented by somatostatin receptor antagonism. CONCLUSIONS/INTERPRETATION: Our transcriptomic database of genes expressed in the principal islet cell populations will facilitate...

Radiation level analysis for the port cell of the ITER electron cyclotron-heating upper launcher

Energy Technology Data Exchange (ETDEWEB)

Weinhorst, Bastian, E-mail: bastian.weinhorst@kit.edu [KIT, Institute for Neutron Physics and Reactor Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Fischer, Ulrich; Lu, Lei [KIT, Institute for Neutron Physics and Reactor Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Strauss, Dirk; Spaeh, Peter; Scherer, Theo [KIT, Institute for Applied Materials, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Leichtle, Dieter [F4E, Analysis & Codes/Technical Support Services, Josep Pla 2, Torres Diagonal Litoral B3, 08019 Barcelona (Spain)

2016-11-01

Highlights: • First detailed neutronic modelling of the ECHUL port cell with ECHUL equipment (including beam lines with diamond windows, the beam lines mounting box, conduit boxes and rails). • Three different bioshield port plug configurations and two different neutron source configurations are investigated. • Radiation Levels are calculated in the port cell, focusing on the position of the diamond window. • The dose rate in the port cell is below the limit for maintenance in the port cell. • The radiation level at the diamond window is very low and should not influence its performance. - Abstract: The electron cyclotron-heating upper launcher (ECHUL) will be installed in four upper ports of the ITER tokamak thermonuclear fusion reactor. Each ECHUL is able to deposit 8 MW power into the plasma for plasma mode stabilization via microwave beam lines. An essential part of these beam lines are the diamond windows. They are located in the upper port cell behind the bioshield to reduce the radiation levels to a minimum. The paper describes the first detailed neutronic modelling of the ECHUL port cell with ECHUL equipment. The bioshield plug is modelled including passageways for the microwave beam lines, piping and cables looms as well as rails and openings for ventilation. The port cell is equipped with the beam lines including the diamond windows, the beam lines mounting box, conduit boxes and rails. The neutrons are transported into the port cell starting from a surface source in front of the bioshield. Neutronic results are obtained for radiation levels in the port cell at different positions, mainly focusing on the diamond windows position. It is shown that the radiation level is below the limit for maintenance in the port cell. The radiation level at the diamond window is very low and should not influence its performance.
Analysis of in vitro secretion profiles from adipose-derived cell populations

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Blaber Sinead P

2012-08-01

Full Text Available Abstract Background Adipose tissue is an attractive source of cells for therapeutic purposes because of the ease of harvest and the high frequency of mesenchymal stem cells (MSCs. Whilst it is clear that MSCs have significant therapeutic potential via their ability to secrete immuno-modulatory and trophic cytokines, the therapeutic use of mixed cell populations from the adipose stromal vascular fraction (SVF is becoming increasingly common. Methods In this study we have measured a panel of 27 cytokines and growth factors secreted by various combinations of human adipose-derived cell populations. These were 1. co-culture of freshly isolated SVF with adipocytes, 2. freshly isolated SVF cultured alone, 3. freshly isolated adipocytes alone and 4. adherent adipose-derived mesenchymal stem cells (ADSCs at passage 2. In addition, we produced an ‘in silico’ dataset by combining the individual secretion profiles obtained from culturing the SVF with that of the adipocytes. This was compared to the secretion profile of co-cultured SVF and adipocytes. Two-tailed t-tests were performed on the secretion profiles obtained from the SVF, adipocytes, ADSCs and the ‘in silico’ dataset and compared to the secretion profiles obtained from the co-culture of the SVF with adipocytes. A p-value of Results A co-culture of SVF and adipocytes results in a distinct secretion profile when compared to all other adipose-derived cell populations studied. This illustrates that cellular crosstalk during co-culture of the SVF with adipocytes modulates the production of cytokines by one or more cell types. No biologically relevant differences were detected in the proteomes of SVF cultured alone or co-cultured with adipocytes. Conclusions The use of mixed adipose cell populations does not appear to induce cellular stress and results in enhanced secretion profiles. Given the importance of secreted cytokines in cell therapy, the use of a mixed cell population such as the
Population dynamics of Hawaiian seabird colonies vulnerable to sea-level rise.

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Hatfield, Jeff S; Reynolds, Michelle H; Seavy, Nathaniel E; Krause, Crystal M

2012-08-01

Globally, seabirds are vulnerable to anthropogenic threats both at sea and on land. Seabirds typically nest colonially and show strong fidelity to natal colonies, and such colonies on low-lying islands may be threatened by sea-level rise. We used French Frigate Shoals, the largest atoll in the Hawaiian Archipelago, as a case study to explore the population dynamics of seabird colonies and the potential effects sea-level rise may have on these rookeries. We compiled historic observations, a 30-year time series of seabird population abundance, lidar-derived elevations, and aerial imagery of all the islands of French Frigate Shoals. To estimate the population dynamics of 8 species of breeding seabirds on Tern Island from 1980 to 2009, we used a Gompertz model with a Bayesian approach to infer population growth rates, density dependence, process variation, and observation error. All species increased in abundance, in a pattern that provided evidence of density dependence. Great Frigatebirds (Fregata minor), Masked Boobies (Sula dactylatra), Red-tailed Tropicbirds (Phaethon rubricauda), Spectacled Terns (Onychoprion lunatus), and White Terns (Gygis alba) are likely at carrying capacity. Density dependence may exacerbate the effects of sea-level rise on seabirds because populations near carrying capacity on an island will be more negatively affected than populations with room for growth. We projected 12% of French Frigate Shoals will be inundated if sea level rises 1 m and 28% if sea level rises 2 m. Spectacled Terns and shrub-nesting species are especially vulnerable to sea-level rise, but seawalls and habitat restoration may mitigate the effects of sea-level rise. Losses of seabird nesting habitat may be substantial in the Hawaiian Islands by 2100 if sea levels rise 2 m. Restoration of higher-elevation seabird colonies represent a more enduring conservation solution for Pacific seabirds. Conservation Biology ©2012 Society for Conservation Biology. No claim to original
Cost-effectiveness of population-level physical activity interventions: a systematic review.

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Laine, Johanna; Kuvaja-Köllner, Virpi; Pietilä, Eija; Koivuneva, Mikko; Valtonen, Hannu; Kankaanpää, Eila

2014-01-01

This systematic review synthesizes the evidence on the cost-effectiveness of population-level interventions to promote physical activity. A systematic literature search was conducted between May and August 2013 in four databases: PubMed, Scopus, Web of Science, and SPORTDiscus. Only primary and preventive interventions aimed at promoting and maintaining physical activity in wide population groups were included. An economic evaluation of both effectiveness and cost was required. Secondary interventions and interventions targeting selected population groups or focusing on single individuals were excluded. Interventions were searched for in six different categories: (1) environment, (2) built environment, (3) sports clubs and enhanced access, (4) schools, (5) mass media and community-based, and (6) workplace. The systematic search yielded 2058 articles, of which 10 articles met the selection criteria. The costs of interventions were converted to costs per person per day in 2012 U.S. dollars. The physical activity results were calculated as metabolic equivalent of task hours (MET-hours, or MET-h) gained per person per day. Cost-effectiveness ratios were presented as dollars per MET-hours gained. The intervention scale and the budget impact of interventions were taken into account. The most efficient interventions to increase physical activity were community rail-trails ($.006/MET-h), pedometers ($.014/MET-h), and school health education programs ($.056/MET-h). Improving opportunities for walking and biking seems to increase physical activity cost-effectively. However, it is necessary to be careful in generalizing the results because of the small number of studies. This review provides important information for decision makers.
Vitamin B12 and folate levels in normal population of northern Pakistan

International Nuclear Information System (INIS)

Madood-ul-mannan; Anwar, M.; Saleem, M.; Waqar, A.; Ahmad, M.

1990-01-01

Diagnosis of vitamin B12 or folate deficiency can not be made unless reference ranges of these vitamins in a given population are known. These serum levels depend upon the dietary intake of these vitamins which in turn depends upon the availability of foods containing these vitamins and the methods of cooking/processing. The latter vary in different populations. Therefore serum level of these vitamins would vary in different populations. Serum levels of vitamin B12 and folate were estimated by radioimmunoassay technique in 30 normal subjects of different age groups. The levels of vitamin B12 were found to be 215.2 pg/ml and that of folate 3.9 ng/ml. These values are much lower than those described for European population. It is therefore concluded that the cut off point of the levels of these vitamins should be different than the European figures. (author)
Describing a multitrophic plant-herbivore-parasitoid system at four spatial scales

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Cuautle, M.; Parra-Tabla, V.

2014-02-01

Herbivore-parasitoid interactions must be studied using a multitrophic and multispecies approach. The strength and direction of multiple effects through trophic levels may change across spatial scales. In this work, we use the herbaceous plant Ruellia nudiflora, its moth herbivore Tripudia quadrifera, and several parasitoid morphospecies that feed on the herbivore to answer the following questions: Do herbivore and parasitoid attack levels vary depending on the spatial scale considered? With which plant characteristics are the parasitoid and the herbivore associated? Do parasitoid morphospecies vary in the magnitude of their positive indirect effect on plant reproduction? We evaluated three approximations of herbivore and parasitoid abundance (raw numbers, ratios, and attack rates) at four spatial scales: regional (three different regions which differ in terms of abiotic and biotic characteristics); population (i.e. four populations within each region); patch (four 1 m2 plots in each population); and plant level (using a number of plant characteristics). Finally, we determined whether parasitoids have a positive indirect effect on plant reproductive success (seed number). Herbivore and parasitoid numbers differed at three of the spatial scales considered. However, herbivore/fruit ratio and attack rates did not differ at the population level. Parasitoid/host ratio and attack rates did not differ at any scale, although there was a tendency of a higher attack in one region. At the plant level, herbivore and parasitoid abundances were related to different plant traits, varying the importance and the direction (positive or negative) of those traits. In addition, only one parasitoid species (Bracon sp.) had a positive effect on plant fitness saving up to 20% of the seeds in a fruit. These results underline the importance of knowing the scales that are relevant to organisms at different trophic levels and distinguish between the specific effects of species.
Effects of tritiated water ingestion on mice: II. Damage at cellular vis-a-vis subcellular level monitored up to four generations

International Nuclear Information System (INIS)

Srivastava, P.N.; Sharan, R.N.; Pozzi, L.

1983-01-01

Damage at cellular level is measured using colony forming units in spleen (CFU-S) technique while that at subcellular level by DNA unwinding technique. The damage is monitored up to four generations in Swiss albino mice. The results show drastically reduced colony forming ability in mice bone marrow cells (BMC). On plotting survival fractions (percent of control) for BMC against generations of mice, the plateau is found around 50% survival. The role of DNA in colony forming ability of BMC is tested. The results indicate that, at least, initial impairment of colony ability is not DNA dependent but related to some other factor(s)
Stem cell-like differentiation potentials of endometrial side population cells as revealed by a newly developed in vivo endometrial stem cell assay.

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Kaoru Miyazaki

Full Text Available Endometrial stem/progenitor cells contribute to the cyclical regeneration of human endometrium throughout a woman's reproductive life. Although the candidate cell populations have been extensively studied, no consensus exists regarding which endometrial population represents the stem/progenitor cell fraction in terms of in vivo stem cell activity. We have previously reported that human endometrial side population cells (ESP, but not endometrial main population cells (EMP, exhibit stem cell-like properties, including in vivo reconstitution of endometrium-like tissues when xenotransplanted into immunodeficient mice. The reconstitution efficiency, however, was low presumably because ESP cells alone could not provide a sufficient microenvironment (niche to support their stem cell activity. The objective of this study was to establish a novel in vivo endometrial stem cell assay employing cell tracking and tissue reconstitution systems and to examine the stem cell properties of ESP through use of this assay.ESP and EMP cells isolated from whole endometrial cells were infected with lentivirus to express tandem Tomato (TdTom, a red fluorescent protein. They were mixed with unlabeled whole endometrial cells and then transplanted under the kidney capsule of ovariectomized immunodeficient mice. These mice were treated with estradiol and progesterone for eight weeks and nephrectomized. All of the grafts reconstituted endometrium-like tissues under the kidney capsules. Immunofluorescence revealed that TdTom-positive cells were significantly more abundant in the glandular, stromal, and endothelial cells of the reconstituted endometrium in mice transplanted with TdTom-labeled ESP cells than those with TdTom-labeled EMP cells.We have established a novel in vivo endometrial stem cell assay in which multi-potential differentiation can be identified through cell tracking during in vivo endometrial tissue reconstitution. Using this assay, we demonstrated that ESP
Joint modeling and registration of cell populations in cohorts of high-dimensional flow cytometric data.

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Saumyadipta Pyne

Full Text Available In biomedical applications, an experimenter encounters different potential sources of variation in data such as individual samples, multiple experimental conditions, and multivariate responses of a panel of markers such as from a signaling network. In multiparametric cytometry, which is often used for analyzing patient samples, such issues are critical. While computational methods can identify cell populations in individual samples, without the ability to automatically match them across samples, it is difficult to compare and characterize the populations in typical experiments, such as those responding to various stimulations or distinctive of particular patients or time-points, especially when there are many samples. Joint Clustering and Matching (JCM is a multi-level framework for simultaneous modeling and registration of populations across a cohort. JCM models every population with a robust multivariate probability distribution. Simultaneously, JCM fits a random-effects model to construct an overall batch template--used for registering populations across samples, and classifying new samples. By tackling systems-level variation, JCM supports practical biomedical applications involving large cohorts. Software for fitting the JCM models have been implemented in an R package EMMIX-JCM, available from http://www.maths.uq.edu.au/~gjm/mix_soft/EMMIX-JCM/.
Programming strategy for efficient modeling of dynamics in a population of heterogeneous cells

DEFF Research Database (Denmark)

Hald, Bjørn Olav; Hendriksen, Morten; Sørensen, Preben Graae

2013-01-01

Heterogeneity is a ubiquitous property of biological systems. Even in a genetically identical population of a single cell type, cell-to-cell differences are observed. Although the functional behavior of a given population is generally robust, the consequences of heterogeneity are fairly unpredict...
Consumption of processed food dietary patterns in four African populations.

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Holmes, Michelle D; Dalal, Shona; Sewram, Vikash; Diamond, Megan B; Adebamowo, Sally N; Ajayi, Ikeoluwapo O; Adebamowo, Clement; Chiwanga, Faraja S; Njelekela, Marina; Laurence, Carien; Volmink, Jimmy; Bajunirwe, Francis; Nankya-Mutyoba, Joan; Guwatudde, David; Reid, Todd G; Willett, Walter C; Adami, Hans-Olov; Fung, Teresa T

2018-06-01

To identify predominant dietary patterns in four African populations and examine their association with obesity. Cross-sectional study.Setting/SubjectsWe used data from the Africa/Harvard School of Public Health Partnership for Cohort Research and Training (PaCT) pilot study established to investigate the feasibility of a multi-country longitudinal study of non-communicable chronic disease in sub-Saharan Africa. We applied principal component analysis to dietary intake data collected from an FFQ developed for PaCT to ascertain dietary patterns in Tanzania, South Africa, and peri-urban and rural Uganda. The sample consisted of 444 women and 294 men. We identified two dietary patterns: the Mixed Diet pattern characterized by high intakes of unprocessed foods such as vegetables and fresh fish, but also cold cuts and refined grains; and the Processed Diet pattern characterized by high intakes of salad dressing, cold cuts and sweets. Women in the highest tertile of the Processed Diet pattern score were 3·00 times more likely to be overweight (95 % CI 1·66, 5·45; prevalence=74 %) and 4·24 times more likely to be obese (95 % CI 2·23, 8·05; prevalence=44 %) than women in this pattern's lowest tertile (both Pobesity. We identified two major dietary patterns in several African populations, a Mixed Diet pattern and a Processed Diet pattern. The Processed Diet pattern was associated with obesity.
Individual and Population Level Impact of Key HIV Risk Factors on HIV Incidence Rates in Durban, South Africa.

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Gita Ramjee

Full Text Available We aimed to estimate the individual and joint impact of age, marital status and diagnosis with sexually transmitted infections (STIs on HIV acquisition among young women at a population level in Durban, KwaZulu-Natal, South Africa. A total of 3,978 HIV seronegative women were recruited for four biomedical intervention trials from 2002-2009. Point and interval estimates of partial population attributable risk (PAR were used to quantify the proportion of HIV seroconversions which can be prevented if a combination of risk factors is eliminated from a target population. More than 70% of the observed HIV acquisitions were collectively attributed to the three risk factors: younger age (<25 years old, unmarried and not cohabiting with a stable/regular partner and diagnosis with STIs. Addressing these risks requires targeted structural, behavioural, biomedical and cultural interventions in order to impact on unacceptably high HIV incidence rates among young women and the population as a whole.
Energy Efficient Four Level Cooperative Opportunistic Communication for Wireless Personal Area Networks (WPAN)

DEFF Research Database (Denmark)

Rohokale, Vandana M.; Inamdar, Sandeep; Prasad, Neeli R.

2013-01-01

For wireless sensor networks (WSN),energy is a scarce resource. Due to limited battery resources, the energy consumption is the critical issue for the transmission as well as reception of the signals in the wireless communication. WSNs are infrastructure-less shared network demanding more energy...... consumption due to collaborative transmissions. This paper proposes a new cooperative opportunistic four level model for IEEE 802.15.4 Wireless Personal Area Network (WPAN).The average per node energy consumption is observed merely about 0.17mJ for the cooperative wireless communication which proves...... the proposed mechanism to be energy efficient. This paper further proposes four levels of cooperative data transmission from source to destination to improve network coverage with energy efficiency....
Maturation of Cerebellar Purkinje Cell Population Activity during Postnatal Refinement of Climbing Fiber Network

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Jean-Marc Good

2017-11-01

Full Text Available Neural circuits undergo massive refinements during postnatal development. In the developing cerebellum, the climbing fiber (CF to Purkinje cell (PC network is drastically reshaped by eliminating early-formed redundant CF to PC synapses. To investigate the impact of CF network refinement on PC population activity during postnatal development, we monitored spontaneous CF responses in neighboring PCs and the activity of populations of nearby CF terminals using in vivo two-photon calcium imaging. Population activity is highly synchronized in newborn mice, and the degree of synchrony gradually declines during the first postnatal week in PCs and, to a lesser extent, in CF terminals. Knockout mice lacking P/Q-type voltage-gated calcium channel or glutamate receptor δ2, in which CF network refinement is severely impaired, exhibit an abnormally high level of synchrony in PC population activity. These results suggest that CF network refinement is a structural basis for developmental desynchronization and maturation of PC population activity.
Gene expression profiling and secretome analysis differentiate adult-derived human liver stem/progenitor cells and human hepatic stellate cells.

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Silvia Berardis

Full Text Available Adult-derived human liver stem/progenitor cells (ADHLSC are obtained after primary culture of the liver parenchymal fraction. The cells are of fibroblastic morphology and exhibit a hepato-mesenchymal phenotype. Hepatic stellate cells (HSC derived from the liver non-parenchymal fraction, present a comparable morphology as ADHLSC. Because both ADHLSC and HSC are described as liver stem/progenitor cells, we strived to extensively compare both cell populations at different levels and to propose tools demonstrating their singularity. ADHLSC and HSC were isolated from the liver of four different donors, expanded in vitro and followed from passage 5 until passage 11. Cell characterization was performed using immunocytochemistry, western blotting, flow cytometry, and gene microarray analyses. The secretion profile of the cells was evaluated using Elisa and multiplex Luminex assays. Both cell types expressed α-smooth muscle actin, vimentin, fibronectin, CD73 and CD90 in accordance with their mesenchymal origin. Microarray analysis revealed significant differences in gene expression profiles. HSC present high expression levels of neuronal markers as well as cytokeratins. Such differences were confirmed using immunocytochemistry and western blotting assays. Furthermore, both cell types displayed distinct secretion profiles as ADHLSC highly secreted cytokines of therapeutic and immuno-modulatory importance, like HGF, interferon-γ and IL-10. Our study demonstrates that ADHLSC and HSC are distinct liver fibroblastic cell populations exhibiting significant different expression and secretion profiles.
Effect of levels of urea and cassava chip on feed intake, rumen fermentation, blood metabolites and microbial populations in growing goats

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Metha Wanapat

2007-01-01

Full Text Available The study was conducted to assess effect of levels of urea and cassava chip (CC on feed intake, rumen ecology, blood metabolites and microbial populations. Four, Thai Native X Anglo Nubian crossbred growing male goats with an average liveweight 19.0+1 kg were randomly assigned according to a 4x4 Latin square design to receive one of four diets: T1=urea at 0 % (CC=30%, T2=urea at 1% (CC=40%, T3=urea at 2% (CC = 50% and T4=urea at 3%(CC=60%, of DM basis, respectively. Elephant grass (Pennisetum purpureum was offered on an ad lib basis. The results revealed that total DM intake (%BW and g/kg W0.75 and BW change were similar among treatments (p>0.05. Likewise, rumen pH, BUN, blood glucose, PCV and microbial populations were similar among treatments (p>0.05, while NH3-N increased as the urea level increased and were found highest (p<0.05 in T4 at 12.8 mg/dL. Based on this experiment, it can be concluded that a higher level of urea (3% could be used with a high level of CC in concentrate and it was good approach in exploiting the use of local feed resources for goat production.
Modelling cell population growth with applications to cancer therapy in human tumour cell lines.

Science.gov (United States)

Basse, Britta; Baguley, Bruce C; Marshall, Elaine S; Wake, Graeme C; Wall, David J N

2004-01-01

In this paper we present an overview of the work undertaken to model a population of cells and the effects of cancer therapy. We began with a theoretical one compartment size structured cell population model and investigated its asymptotic steady size distributions (SSDs) (On a cell growth model for plankton, MMB JIMA 21 (2004) 49). However these size distributions are not similar to the DNA (size) distributions obtained experimentally via the flow cytometric analysis of human tumour cell lines (data obtained from the Auckland Cancer Society Research Centre, New Zealand). In our one compartment model, size was a generic term, but in order to obtain realistic steady size distributions we chose size to be DNA content and devised a multi-compartment mathematical model for the cell division cycle where each compartment corresponds to a distinct phase of the cell cycle (J. Math. Biol. 47 (2003) 295). We then incorporated another compartment describing the possible induction of apoptosis (cell death) from mitosis phase (Modelling cell death in human tumour cell lines exposed to anticancer drug paclitaxel, J. Math. Biol. 2004, in press). This enabled us to compare our model to flow cytometric data of a melanoma cell line where the anticancer drug, paclitaxel, had been added. The model gives a dynamic picture of the effects of paclitaxel on the cell cycle. We hope to use the model to describe the effects of other cancer therapies on a number of different cell lines. Copyright 2004 Elsevier Ltd.
Genetic structure of different cat populations in Europe and South America at a microgeographic level: importance of the choice of an adequate sampling level in the accuracy of population genetics interpretations

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Manuel Ruiz-Garcia

1999-12-01

Full Text Available The phenotypic markers, coat color, pattern and hair length, of natural domestic cat populations observed in four cities (Barcelona, Catalonia; Palma Majorca, Balearic Islands; Rimini, Italy and Buenos Aires, Argentina were studied at a microgeographical level. Various population genetics techniques revealed that the degree of genetic differentiation between populations of Felis catus within these cities is relatively low, when compared with that found between populations of other mammals. Two different levels of sampling were used. One was that of "natural" colonies of cat families living together in specific points within the cities, and the other referred to "artificial" subpopulations, or groups of colonies, inhabiting the same district within a city. For the two sampling levels, some of the results were identical: 1 little genic heterogeneity, 2 existence of panmixia, 3 similar levels of expected heterozygosity in all populations analyzed, 4 no spatial autocorrelation, with certain differentiation in the Buenos Aires population compared to the others, and 5 very high correlations between colonies and subpopulations with the first factors from a Q factor analysis. Nevertheless, other population genetic statistics were greatly affected by the differential choice of sampling level. This was the case for: 1 the amount of heterogeneity of the FST and GST statistics between the cities, which was greater at the subpopulation level than at colony level, 2 the existence of correlations between genic differentiation statistics and size variables at subpopulation level, but not at the colony level, and 3 the relationships between the genetic variables and the principal factors of the R factorial analysis. This suggests that care should be taken in the choice of the sampling unit, for inferences on population genetics to be valid at the microgeographical level.Os marcadores fenotípicos cor da pelagem, padrão e comprimento dos pelos de popula
Cost effectiveness of tobacco control policies in Vietnam: the case of population-level interventions.

Science.gov (United States)

Higashi, Hideki; Truong, Khoa D; Barendregt, Jan J; Nguyen, Phuong K; Vuong, Mai L; Nguyen, Thuy T; Hoang, Phuong T; Wallace, Angela L; Tran, Tien V; Le, Cuong Q; Doran, Christopher M

2011-05-01

Tobacco smoking is one of the leading public health problems in the world. It is also possible to prevent and/or reduce the harm from tobacco use through the use of cost-effective tobacco control measures. However, most of this evidence comes from developed countries and little research has been conducted on this issue in developing countries. The objective of this study was to analyse the cost effectiveness of four population-level tobacco control interventions in Vietnam. Four tobacco control interventions were evaluated: excise tax increase; graphic warning labels on cigarette packs; mass media campaigns; and smoking bans (in public or in work places). A multi-state life table model was constructed in Microsoft® Excel to examine the cost effectiveness of the tobacco control intervention options. A government perspective was adopted, with costing conducted using a bottom-up approach. Health improvement was considered in terms of disability-adjusted life-years (DALYs) averted. All assumptions were subject to sensitivity and uncertainty analysis. All the interventions fell within the definition of being very cost effective according to the threshold level suggested by the WHO (i.e. place smoking bans. If the cost offset was included in the analysis, all interventions would provide cost savings to the government health sector. All four interventions to reduce the harm from tobacco use appear to be highly cost effective and should be considered as priorities in the context of Vietnam. The government may initially consider graphic warning labels and tax increase, followed by other interventions.
Relative and absolute level populations in beam-foil--excited neutral helium

International Nuclear Information System (INIS)

Davidson, J.

1975-01-01

Relative and absolute populations of 19 levels in beam-foil--excited neutral helium at 0.275 MeV have been measured. The singlet angular-momentum sequences show dependences on principal quantum number consistent with n -3 , but the triplet sequences do not. Singlet and triplet angular-momentum sequences show similar dependences on level excitation energy. Excitation functions for six representative levels were measured in the range 0.160 to 0.500 MeV. The absolute level populations increase with energy, whereas the neutral fraction of the beam decreases with energy. Further, the P angular-momentum levels are found to be overpopulated with respect to the S and D levels. The overpopulation decreases with increasing principal quantum number

Asymmetric Damage Segregation Constitutes an Emergent Population-Level Stress Response

DEFF Research Database (Denmark)

Vedel, Søren; Nunns, Harry; Košmrlj, Andrej

2016-01-01

Asymmetric damage segregation (ADS) is a mechanism for increasing population fitness through non-random, asymmetric partitioning of damaged macromolecules at cell division. ADS has been reported across multiple organisms, though the measured effects on fitness of individuals are often small. Here...
Medullospheres from DAOY, UW228 and ONS-76 cells: increased stem cell population and proteomic modifications.

Science.gov (United States)

Zanini, Cristina; Ercole, Elisabetta; Mandili, Giorgia; Salaroli, Roberta; Poli, Alice; Renna, Cristiano; Papa, Valentina; Cenacchi, Giovanna; Forni, Marco

2013-01-01

Medulloblastoma (MB) is an aggressive pediatric tumor of the Central Nervous System (CNS) usually treated according to a refined risk stratification. The study of cancer stem cells (CSC) in MB is a promising approach aimed at finding new treatment strategies. The CSC compartment was studied in three characterized MB cell lines (DAOY, UW228 and ONS-76) grown in standard adhesion as well as being grown as spheres, which enables expansion of the CSC population. MB cell lines, grown in adherence and as spheres, were subjected to morphologic analysis at the light and electron microscopic level, as well as cytofluorimetric determinations. Medullospheres (MBS) were shown to express increasingly immature features, along with the stem cells markers: CD133, Nestin and β-catenin. Proteomic analysis highlighted the differences between MB cell lines, demonstrating a unique protein profile for each cell line, and minor differences when grown as spheres. In MBS, MALDI-TOF also identified some proteins, that have been linked to tumor progression and resistance, such as Nucleophosmin (NPM). In addition, immunocytochemistry detected Sox-2 as a stemness marker of MBS, as well as confirming high NPM expression. Culture conditioning based on low attachment flasks and specialized medium may provide new data on the staminal compartment of CNS tumors, although a proteomic profile of CSC is still elusive for MB.
Medullospheres from DAOY, UW228 and ONS-76 cells: increased stem cell population and proteomic modifications.

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Cristina Zanini

Full Text Available BACKGROUND: Medulloblastoma (MB is an aggressive pediatric tumor of the Central Nervous System (CNS usually treated according to a refined risk stratification. The study of cancer stem cells (CSC in MB is a promising approach aimed at finding new treatment strategies. METHODOLOGY/PRINCIPAL FINDINGS: The CSC compartment was studied in three characterized MB cell lines (DAOY, UW228 and ONS-76 grown in standard adhesion as well as being grown as spheres, which enables expansion of the CSC population. MB cell lines, grown in adherence and as spheres, were subjected to morphologic analysis at the light and electron microscopic level, as well as cytofluorimetric determinations. Medullospheres (MBS were shown to express increasingly immature features, along with the stem cells markers: CD133, Nestin and β-catenin. Proteomic analysis highlighted the differences between MB cell lines, demonstrating a unique protein profile for each cell line, and minor differences when grown as spheres. In MBS, MALDI-TOF also identified some proteins, that have been linked to tumor progression and resistance, such as Nucleophosmin (NPM. In addition, immunocytochemistry detected Sox-2 as a stemness marker of MBS, as well as confirming high NPM expression. CONCLUSIONS/SIGNIFICANCE: Culture conditioning based on low attachment flasks and specialized medium may provide new data on the staminal compartment of CNS tumors, although a proteomic profile of CSC is still elusive for MB.
Niche-dependent development of functional neuronal networks from embryonic stem cell-derived neural populations

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Siebler Mario

2009-08-01

Full Text Available Abstract Background The present work was performed to investigate the ability of two different embryonic stem (ES cell-derived neural precursor populations to generate functional neuronal networks in vitro. The first ES cell-derived neural precursor population was cultivated as free-floating neural aggregates which are known to form a developmental niche comprising different types of neural cells, including neural precursor cells (NPCs, progenitor cells and even further matured cells. This niche provides by itself a variety of different growth factors and extracellular matrix proteins that influence the proliferation and differentiation of neural precursor and progenitor cells. The second population was cultivated adherently in monolayer cultures to control most stringently the extracellular environment. This population comprises highly homogeneous NPCs which are supposed to represent an attractive way to provide well-defined neuronal progeny. However, the ability of these different ES cell-derived immature neural cell populations to generate functional neuronal networks has not been assessed so far. Results While both precursor populations were shown to differentiate into sufficient quantities of mature NeuN+ neurons that also express GABA or vesicular-glutamate-transporter-2 (vGlut2, only aggregate-derived neuronal populations exhibited a synchronously oscillating network activity 24 weeks after initiating the differentiation as detected by the microelectrode array technology. Neurons derived from homogeneous NPCs within monolayer cultures did merely show uncorrelated spiking activity even when differentiated for up to 12 weeks. We demonstrated that these neurons exhibited sparsely ramified neurites and an embryonic vGlut2 distribution suggesting an inhibited terminal neuronal maturation. In comparison, neurons derived from heterogeneous populations within neural aggregates appeared as fully mature with a dense neurite network and punctuated
Identification of a sub-population of B cells that proliferates after infection with epstein-barr virus

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Ye Jianjiang

2011-02-01

Full Text Available Abstract Background Epstein-Barr virus (EBV-driven B cell proliferation is critical to its subsequent persistence in the host and is a key event in the development of EBV-associated B cell diseases. Thus, inquiry into early cellular events that precede EBV-driven proliferation of B cells is essential for understanding the processes that can lead to EBV-associated B cell diseases. Methods Infection with high titers of EBV of mixed, primary B cells in different stages of differentiation occurs during primary EBV infection and in the setting of T cell-immunocompromise that predisposes to development of EBV-lymphoproliferative diseases. Using an ex vivo system that recapitulates these conditions of infection, we correlated expression of selected B cell-surface markers and intracellular cytokines with expression of EBV latency genes and cell proliferation. Results We identified CD23, CD58, and IL6, as molecules expressed at early times after EBV-infection. EBV differentially infected B cells into two distinct sub-populations of latently infected CD23+ cells: one fraction, marked as CD23hiCD58+IL6- by day 3, subsequently proliferated; another fraction, marked as CD23loCD58+, expressed IL6, a B cell growth factor, but failed to proliferate. High levels of LMP1, a critical viral oncoprotein, were expressed in individual CD23hiCD58+ and CD23loCD58+ cells, demonstrating that reduced levels of LMP1 did not explain the lack of proliferation of CD23loCD58+ cells. Differentiation stage of B cells did not appear to govern this dichotomy in outcome either. Memory or naïve B cells did not exclusively give rise to either CD23hi or IL6-expressing cells; rather memory B cells gave rise to both sub-populations of cells. Conclusions B cells are differentially susceptible to EBV-mediated proliferation despite expression of viral gene products known to be critical for continuous B cell growth. Cellular events, in addition to viral gene expression, likely play a
Differential induction of four msx homeobox genes during fin development and regeneration in zebrafish.

Science.gov (United States)

Akimenko, M A; Johnson, S L; Westerfield, M; Ekker, M

1995-02-01

To study the genetic regulation of growth control and pattern formation during fin development and regeneration, we have analysed the expression of four homeobox genes, msxA, msxB, msxC and msxD in zebrafish fins. The median fin fold, which gives rise to the unpaired fins, expresses these four msx genes during development. Transcripts of the genes are also present in cells of the presumptive pectoral fin buds. The most distal cells, the apical ectodermal ridge of the paired fins and the cleft and flanking cells of the median fin fold express all these msx genes with the exception of msxC. Mesenchymal cells underlying the most distal cells express all four genes. Expression of the msx genes in the fin fold and fin buds is transient and, by 3 days after fertilization, msx expression in the median fin fold falls below levels detectable by in situ hybridization. Although the fins of adult zebrafish normally have levels of msx transcripts undetectable by in situ hybridization, expression of all four genes is strongly reinduced during regeneration of both paired and unpaired fins. Induction of msx gene expression in regenerating caudal fins occurs as early as 30 hours postamputation. As the blastema forms, the levels of expression increase and reach a maximum between the third and fifth days. Then, msx expression progressively declines and disappears by day 12 when the caudal fin has grown back to its normal size. In the regenerating fin, the blastema cells that develop at the tip of each fin ray express msxB and msxC. Cells of the overlying epithelium express msxA and msxD, but do not express msxB or msxC. Amputations at various levels along the proximodistal axis of the fin suggest that msxB expression depends upon the position of the blastema, with cells of the rapidly proliferating proximal blastema expressing higher levels than the cells of the less rapidly proliferating distal blastema. Expression of msxC and msxD is independent of the position of the blastema cell
Establishment of reference CD4+ T cell values for adult Indian population

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Ray Krishnangshu

2011-10-01

Full Text Available Abstract Background CD4+ T lymphocyte counts are the most important indicator of disease progression and success of antiretroviral treatment in HIV infection in resource limited settings. The nationwide reference range of CD4+ T lymphocytes was not available in India. This study was conducted to determine reference values of absolute CD4+ T cell counts and percentages for adult Indian population. Methods A multicentric study was conducted involving eight sites across the country. A total of 1206 (approximately 150 per/centre healthy participants were enrolled in the study. The ratio of male (N = 645 to female (N = 561 of 1.14:1. The healthy status of the participants was assessed by a pre-decided questionnaire. At all centers the CD4+ T cell count, percentages and absolute CD3+ T cell count and percentages were estimated using a single platform strategy and lyse no wash technique. The data was analyzed using the Statistical Package for the Social Scientist (SPSS, version 15 and Prism software version 5. Results The absolute CD4+ T cell counts and percentages in female participants were significantly higher than the values obtained in male participants indicating the true difference in the CD4+ T cell subsets. The reference range for absolute CD4 count for Indian male population was 381-1565 cells/μL and for female population was 447-1846 cells/μL. The reference range for CD4% was 25-49% for male and 27-54% for female population. The reference values for CD3 counts were 776-2785 cells/μL for Indian male population and 826-2997 cells/μL for female population. Conclusion The study used stringent procedures for controlling the technical variation in the CD4 counts across the sites and thus could establish the robust national reference ranges for CD4 counts and percentages. These ranges will be helpful in staging the disease progression and monitoring antiretroviral therapy in HIV infection in India.
Four-Parameter white blood cell differential counting based on light scattering measurements

NARCIS (Netherlands)

Terstappen, Leonardus Wendelinus Mathias Marie; de Grooth, B.G.; Visscher, K.; Kouterik, F.A.; Greve, Jan

1988-01-01

Measurement of the depolarized orthogonal light scattering in flow cytometry enables one to discriminate human eosinephilic granulocytes from neutrophilic granulocytes. We use this method to perform a four-parameter differential white blood cell analysis. A simple flow cytometer was built equipped
Lin28a is a putative factor in regulating cancer stem cell-like properties in side population cells of oral squamous cell carcinoma

Energy Technology Data Exchange (ETDEWEB)

Hayashi, S.; Tanaka, J.; Okada, S.; Isobe, T.; Yamamoto, G.; Yasuhara, R.; Irie, T.; Akiyama, C.; Kohno, Y.; Tachikawa, T.; Mishima, K., E-mail: mishima-k@dent.showa-u.ac.jp

2013-05-01

Cancer stem cells (CSCs) are among the target cells of cancer therapy because they are uniquely involved in both cancer progression and sensitivity to chemotherapeutic agents. We identified side population (SP) cells, which are known to be an enriched population of CSC, in five oral squamous cell carcinoma (OSCC) cells (SCC9, SCC25, TOSCC7, TOSCC17, and TOSCC23). The percentages of SP cells ranged from 0% to 3.3%, with TOSCC23 cells showing the highest percentages of SP cells (3.3% of the total cell population). The SP cells isolated from TOSCC23 cells also showed greater cell proliferation and invasion compared to non-SP (MP) cells. Therefore, our initial findings suggested that SP cells were enriched for CSC-like cells. Furthermore, DNA microarray analysis revealed that the expression of cell proliferation-related and anti-apoptotic genes was greater in SP cells compared to MP cells. We focused on Lin28a, which showed the highest expression (approximately 22-fold) among the upregulated genes. The overexpression of Lin28a in TOSCC23 cells increased their proliferation, colony formation, and invasion. These findings suggest that Lin28a is an appropriate CSC target molecule for OSCC treatment - Highlights: ► Lin28a is a SP cell-specific factor in oral squamous cell carcinoma (OSCC) cells. ► SP cells in OSCC cells show cancer stem cell-like properties. ► Lin28a regulates OSCC proliferative and invasive activities.
Lin28a is a putative factor in regulating cancer stem cell-like properties in side population cells of oral squamous cell carcinoma

International Nuclear Information System (INIS)

Hayashi, S.; Tanaka, J.; Okada, S.; Isobe, T.; Yamamoto, G.; Yasuhara, R.; Irie, T.; Akiyama, C.; Kohno, Y.; Tachikawa, T.; Mishima, K.

2013-01-01

Cancer stem cells (CSCs) are among the target cells of cancer therapy because they are uniquely involved in both cancer progression and sensitivity to chemotherapeutic agents. We identified side population (SP) cells, which are known to be an enriched population of CSC, in five oral squamous cell carcinoma (OSCC) cells (SCC9, SCC25, TOSCC7, TOSCC17, and TOSCC23). The percentages of SP cells ranged from 0% to 3.3%, with TOSCC23 cells showing the highest percentages of SP cells (3.3% of the total cell population). The SP cells isolated from TOSCC23 cells also showed greater cell proliferation and invasion compared to non-SP (MP) cells. Therefore, our initial findings suggested that SP cells were enriched for CSC-like cells. Furthermore, DNA microarray analysis revealed that the expression of cell proliferation-related and anti-apoptotic genes was greater in SP cells compared to MP cells. We focused on Lin28a, which showed the highest expression (approximately 22-fold) among the upregulated genes. The overexpression of Lin28a in TOSCC23 cells increased their proliferation, colony formation, and invasion. These findings suggest that Lin28a is an appropriate CSC target molecule for OSCC treatment - Highlights: ► Lin28a is a SP cell-specific factor in oral squamous cell carcinoma (OSCC) cells. ► SP cells in OSCC cells show cancer stem cell-like properties. ► Lin28a regulates OSCC proliferative and invasive activities
Population genetical investigation of the level of mutagenesis and teratological events frequency in ecologically different regions of Kazakhstan

International Nuclear Information System (INIS)

Kashaganova, Zh.A.; Zhapbasov, R.; Kadyrova, N.Zh.; Karimbaeva, K.S.; Mamyrbaeva, A.N.; Altaeva, N.Z.

2008-01-01

Full text: Kazakhstan territory is unique including regions with radioactive pollution of Semipalatinsk nuclear test territory and storage of radioactive waste of uranium mines and metallurgy enterprises, and regions of drying Aral sea. These technogenic factors may cause some types of chromosome aberrations and developmental anomalies in mammals. The level of mutagenesis was estimated basing on chromosome aberrations and genomic mutation frequencies in bone marrow cells of natural rodents populations (Allactaga major Kern, Allactaga saltator Eversman, Cytellus eritrogenus Br.) and domestic animals (sheep, cattle, horse), which inhabit these regions. Sheep populations which are bred in the regions with different climatic conditions were used for teratological investigations. Different generations are met in the populations of mice family rodents caught in the nature. So studying the animals of different ages separately we can estimate the frequency of mutations in the animals of different age inhabiting the same radiation polluted regions. The frequency of chromosome abe rations in mice family rodents from such territories was twice as high as from the clear territories. In some animals chromosome aberration types characteristic for radiation mutagenesis (dicentrics, double acentric fragments) were found. High level of cytogenetical instability in somatic cells of agricultural animals which were bred on the pastures within former nuclear test territories for several generations may be caused by chronic radiation in low doses. The analysis of the spectrum of recorder chromosome aberrations in somatic cells and their dynamics in different animal species inhabiting for several generations these territories being chronically irradiated, allows us to investigate the direction of genetical evolution of mammals genofond structure induced by ecological factors. Comparative analysis of the frequencies of spontaneous abortuses, deadborn and newborn animals with innate
Predicting glycated hemoglobin levels in the non-diabetic general population

DEFF Research Database (Denmark)

Rauh, Simone P; Heymans, Martijn W; Koopman, Anitra D M

2017-01-01

AIMS/HYPOTHESIS: To develop a prediction model that can predict HbA1c levels after six years in the non-diabetic general population, including previously used readily available predictors. METHODS: Data from 5,762 initially non-diabetic subjects from three population-based cohorts (Hoorn Study, I...
CD146/MCAM defines functionality of human bone marrow stromal stem cell populations

DEFF Research Database (Denmark)

Harkness, Linda; Zaher, Walid; Ditzel, Nicholas

2016-01-01

BACKGROUND: Identification of surface markers for prospective isolation of functionally homogenous populations of human skeletal (stromal, mesenchymal) stem cells (hMSCs) is highly relevant for cell therapy protocols. Thus, we examined the possible use of CD146 to subtype a heterogeneous hMSC...... population. METHODS: Using flow cytometry and cell sorting, we isolated two distinct hMSC-CD146(+) and hMSC-CD146(-) cell populations from the telomerized human bone marrow-derived stromal cell line (hMSC-TERT). Cells were examined for differences in their size, shape and texture by using high...... and adipocytes on the basis of gene expression and protein production of lineage-specific markers. In vivo, hMSC-CD146(+) and hMSC-CD146(-) cells formed bone and bone marrow organ when implanted subcutaneously in immune-deficient mice. Bone was enriched in hMSC-CD146(-) cells (12.6 % versus 8.1 %) and bone...
Relative and absolute level populations in beam-foil-excited neutral helium

Science.gov (United States)

Davidson, J.

1975-01-01

Relative and absolute populations of 19 levels in beam-foil-excited neutral helium at 0.275 MeV have been measured. The singlet angular-momentum sequences show dependences on principal quantum number consistent with n to the -3rd power, but the triplet sequences do not. Singlet and triplet angular-momentum sequences show similar dependences on level excitation energy. Excitation functions for six representative levels were measured in the range from 0.160 to 0.500 MeV. The absolute level populations increase with energy, whereas the neutral fraction of the beam decreases with energy. Further, the P angular-momentum levels are found to be overpopulated with respect to the S and D levels. The overpopulation decreases with increasing principal quantum number.
The Long Intron 1 of Growth Hormone Gene from Reeves’ Turtle (Chinemys reevesii Correlates with Negatively Regulated GH Expression in Four Cell Lines

Directory of Open Access Journals (Sweden)

Wen-Sheng Liu

2016-04-01

Full Text Available Turtles grow slowly and have a long lifespan. Ultrastructural studies of the pituitary gland in Reeves’ turtle (Chinemys reevesii have revealed that the species possesses a higher nucleoplasmic ratio and fewer secretory granules in growth hormone (GH cells than other animal species in summer and winter. C. reevesii GH gene was cloned and species-specific similarities and differences were investigated. The full GH gene sequence in C. reevesii contains 8517 base pairs (bp, comprising five exons and four introns. Intron 1 was found to be much longer in C. reevesii than in other species. The coding sequence (CDS of the turtle’s GH gene, with and without the inclusion of intron 1, was transfected into four cell lines, including DF-1 chicken embryo fibroblasts, Chinese hamster ovary (CHO cells, human embryonic kidney 293FT cells, and GH4C1 rat pituitary cells; the turtle growth hormone (tGH gene mRNA and protein expression levels decreased significantly in the intron-containing CDS in these cell lines, compared with that of the corresponding intronless CDS. Thus, the long intron 1 of GH gene in Reeves’ turtle might correlate with downregulated gene expression.
Single cell analysis of innate cytokine responses to pattern recognition receptor stimulation in children across four continents

Science.gov (United States)

Smolen, Kinga K; Cai, Bing; Fortuno, Edgardo S; Gelinas, Laura; Larsen, Martin; Speert, David P; Chamekh, Mustapha; Kollmann, Tobias R

2014-01-01

Innate immunity instructs adaptive immunity, and suppression of innate immunity is associated with increased risk for infection. We had previously shown that whole blood cellular components from a cohort of South African children secreted significantly lower levels of most cytokines following stimulation of pattern recognition receptors (PRR) as compared to whole blood from cohorts of Ecuadorian, Belgian, or Canadian children. To begin dissecting the responsible molecular mechanisms, we now set out to identify the relevant cellular source of these differences. Across the four cohorts represented in our study, we identified significant variation in the cellular composition of whole blood; however, significant reduction of the intracellular cytokine production on the single cell level was only detected in South African childrens’ monocytes, cDC, and pDC. We also uncovered a marked reduction in polyfunctionality for each of these cellular compartments in South African children as compared to children from other continents. Together our data identify differences in cell composition as well as profoundly lower functional responses of innate cells in our cohort of South African children. A possible link between altered innate immunity and increased risk for infection or lower response to vaccines in South African infants needs to be explored. PMID:25135829
Integrative demographic modeling reveals population level impacts of PCB toxicity to juvenile snapping turtles

International Nuclear Information System (INIS)

Salice, Christopher J.; Rowe, Christopher L.; Eisenreich, Karen M.

2014-01-01

A significant challenge in ecotoxicology and risk assessment lies in placing observed contaminant effects in a meaningful ecological context. Polychlorinated biphenyls (PCBs) have been shown to affect juvenile snapping turtle survival and growth but the ecological significance of these effects is difficult to discern without a formal, population-level assessment. We used a demographic matrix model to explore the potential population-level effects of PCBs on turtles. Our model showed that effects of PCBs on juvenile survival, growth and size at hatching could translate to negative effects at the population level despite the fact that these life cycle components do not typically contribute strongly to population level processes. This research points to the utility of using integrative demographic modeling approaches to better understand contaminant effects in wildlife. The results indicate that population-level effects are only evident after several years, suggesting that for long-lived species, detecting adverse contaminant effects could prove challenging. -- Highlights: • Previous studies have shown the PCBs can impact juvenile snapping turtles. • We used a demographic model of turtles to evaluate population-level PCB effects. • PCB effects on turtles may translate to negative population responses. • Long-term monitoring is needed to detect contaminant effects on natural turtle populations. • Demographic models can improve our understanding contaminant ecotoxicity. -- A demographic model was used to show that PCB induced effects on young snapping turtles can result in adverse effects at the population level
Serum Total Tryptase Level Confirms Itself as a More Reliable Marker of Mast Cells Burden in Mast Cell Leukaemia (Aleukaemic Variant

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P. Savini

2015-01-01

Full Text Available Mast cell leukemia (MCL is a very rare form of systemic mastocytosis (SM with a short median survival of 6 months. We describe a case of a 65-year-old woman with aleukaemic variant of MCL with a very high serum total tryptase level of 2255 μg/L at diagnosis, which occurred following an episode of hypotensive shock. She fulfilled the diagnostic criteria of SM, with a bone marrow smear infiltration of 50–60% of atypical mast cells (MCs. She tested negative for the KIT D816V mutation, without any sign of organ damage (no B- or C-findings and only few mediator-related symptoms. She was treated with antihistamine alone and then with imatinib for the appearance of anemia. She maintained stable tryptase level and a very indolent clinical course for twenty-two months; then, she suddenly progressed to acute MCL with a serum tryptase level up to 12960 μg/L. The patient died due to haemorrhagic diathesis twenty-four months after diagnosis. This clinical case maybe represents an example of the chronic form of mast cell leukemia, described as unpredictable disease, in which the serum total tryptase level has confirmed itself as a reliable marker of mast cells burden regardless of the presence of other signs or symptoms.
High-precision two-dimensional atom localization from four-wave mixing in a double-Λ four-level atomic system

Science.gov (United States)

Shui, Tao; Yang, Wen-Xing; Chen, Ai-Xi; Liu, Shaopeng; Li, Ling; Zhu, Zhonghu

2018-03-01

We propose a scheme for high-precision two-dimensional (2D) atom localization via the four-wave mixing (FWM) in a four-level double-Λ atomic system. Due to the position-dependent atom-field interaction, the 2D position information of the atoms can be directly determined by the measurement of the normalized light intensity of output FWM-generated field. We further show that, when the position-dependent generated FWM field has become sufficiently intense, efficient back-coupling to the FWM generating state becomes important. This back-coupling pathway leads to competitive multiphoton destructive interference of the FWM generating state by three supplied and one internally generated fields. We find that the precision of 2D atom localization can be improved significantly by the multiphoton destructive interference and depends sensitively on the frequency detunings and the pump field intensity. Interestingly enough, we show that adjusting the frequency detunings and the pump field intensity can modify significantly the FWM efficiency, and consequently lead to a redistribution of the atoms. As a result, the atom can be localized in one of four quadrants with holding the precision of atom localization.
HLA-DRB1 alleles in four Amerindian populations from Argentina and Paraguay

Science.gov (United States)

2009-01-01

The major histocompatibility complex (MHC) is one of the biological systems of major polymorphisms. The study of HLA class II variability has allowed the identification of several alleles that are characteristic to Amerindian populations, and it is an excellent tool to define the relations and biological affinities among them. In this work, we analyzed the allelic distribution of the HLA-DRB1 class II locus in four Amerindian populations: Mapuche (n = 34) and Tehuelche (n = 23) from the Patagonian region of Argentina, and Wichi SV (n = 24) and Lengua (n = 17) from the Argentinean and Paraguayan Chaco regions, respectively. In all of these groups, relatively high frequencies of Amerindian HLA-DRB1 alleles were observed (DRB1*0403, DRB1*0407, DRB1*0411, DRB1*0417, DRB1*0802, DRB1*0901, DRB1*1402, DRB1*1406 and DRB1*1602). However, we also detected the presence of non-Amerindian variants in Mapuche (35%) and Tehuelche (22%). We compared our data with those obtained in six indigenous groups of the Argentinean Chaco region and in a sample from Buenos Aires City. The genetic distance dendrogram showed a clear-cut division between the Patagonian and Chaco populations, which formed two different clusters. In spite of their linguistic differences, it can be inferred that the biological affinities observed are in concordance with the geographic distributions and interethnic relations established among the groups studied. PMID:21637670

Distinct populations of hepatic stellate cells in the mouse liver have different capacities for retinoid and lipid storage.

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Diana N D'Ambrosio

Full Text Available Hepatic stellate cell (HSC lipid droplets are specialized organelles for the storage of retinoid, accounting for 50-60% of all retinoid present in the body. When HSCs activate, retinyl ester levels progressively decrease and the lipid droplets are lost. The objective of this study was to determine if the HSC population in a healthy, uninjured liver demonstrates heterogeneity in its capacity for retinoid and lipid storage in lipid droplets. To this end, we utilized two methods of HSC isolation, which leverage distinct properties of these cells, including their vitamin A content and collagen expression. HSCs were isolated either from wild type (WT mice in the C57BL/6 genetic background by flotation in a Nycodenz density gradient, followed by fluorescence activated cell sorting (FACS based on vitamin A autofluorescence, or from collagen-green fluorescent protein (GFP mice by FACS based on GFP expression from a GFP transgene driven by the collagen I promoter. We show that GFP-HSCs have: (i increased expression of typical markers of HSC activation; (ii decreased retinyl ester levels, accompanied by reduced expression of the enzyme needed for hepatic retinyl ester synthesis (LRAT; (iii decreased triglyceride levels; (iv increased expression of genes associated with lipid catabolism; and (v an increase in expression of the retinoid-catabolizing cytochrome, CYP2S1.Our observations suggest that the HSC population in a healthy, uninjured liver is heterogeneous. One subset of the total HSC population, which expresses early markers of HSC activation, may be "primed" and ready for rapid response to acute liver injury.
Levels of perfluorooctanesulfonate and related fluorochemicals in human blood from the general population of Korea

Energy Technology Data Exchange (ETDEWEB)

Yang, Jae-Ho; Kim, Sun-Young; Shin, Im-Hee [Catholic Univ. of Daegu, School of Medicine, Dept. of Pharmacology/Toxicology, Daegu (Korea); Kannan, K. [Wardsworth Center, New York State Dept. of Health and Dept. of Env. Health and Tox., SUNY, Albany, NY (United States)

2004-09-15

Perfluorooctanesulfonate (PFOS) was found to be widespread in human populations and wildlife Major applications of these POSF-based products have included surfactants in: specialty paper and packaging products, carpet, upholstery, and textile products and in certain insecticide formulation. Depending on the specific functional derivatization or the degree of polymerization, such POSF based products may degrade or metabolize to PFOS, a stable and persistent end product that has the potential to bioaccumulate in the food chain. The mechanisms and pathways leading to the presence of PFOS in human blood are not well characterized but likely involve environmental and dietary exposure to PFOS or to precursor molecules of PFOS. PFOS and related perfluorinated compounds have recently been detected at low parts per billion (nanogram per milliliter) concentrations in the general population from 10 different countries including Korea. In the present report, the levels of perfluoroalkylated compounds in the general population from Korea were analyzed with respect to occupation, smoking status, sex, age and socio-economic status. The degree of association between the four target fluorochemicals measured in this study (PFOS, PFHxS, PFOA, and PFOSA) were also analyzed by linear regression to determine the potential association between their sources of exposure.
Frequency of Dental Caries in Four Historical Populations from the Chalcolithic to the Middle Ages

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A.-M. Grimoud

2011-01-01

Full Text Available The majority of dental carie studies over the course of historical period underline mainly the prevalence evolution, the role of carbohydrates consumption and the impact of access to dietary resources. The purpose of the present investigation was to compare population samples from two archaeological periods the Chacolithic and Middle Age taking into account the geographical and socio economical situation. The study concerned four archaelogical sites in south west France and population samples an inlander for the Chalcolithic Age, an inlander, an costal and urban for the Middle Age. The materials studied included a total of 127 maxillaries, 103 mandibles and 3316 teeth. Data recorded allowed us to display that the Chalcolithic population sample had the lowest carie percentage and the rural inlander population samples of Middle Age the highest; in all cases molars were teeth most often affected. These ones differences could be explained according to time period, carious lesions were usually less recorded in the Chalcolithic Age than the Middle because of a lesser cultivation of cereals like in les Treilles Chacolithic population sample. In the Middle Age population samples, the rural inland sample Marsan showed the highest frequency of caries and ate more cereal than the coastal Vilarnau and the poor urban St Michel population samples, the first one ate fish and Mediterranean vegetal and fruits and the second one met difficulties to food access, in both cases the consumption of carbohydrates was lesser than Marsan population sample who lived in a geographical land convice to cereals cultivation.
On interfaces between cell populations with different mobilities

KAUST Repository

Lorenzi, Tommaso; Lorz, Alexander; Perthame, Benoit

2016-01-01

Partial differential equations describing the dynamics of cell population densities from a fluid mechanical perspective can model the growth of avascular tumours. In this framework, we consider a system of equations that describes the interaction
A distinct hematopoietic stem cell population for rapid multilineage engraftment in nonhuman primates.

Science.gov (United States)

Radtke, Stefan; Adair, Jennifer E; Giese, Morgan A; Chan, Yan-Yi; Norgaard, Zachary K; Enstrom, Mark; Haworth, Kevin G; Schefter, Lauren E; Kiem, Hans-Peter

2017-11-01

Hematopoietic reconstitution after bone marrow transplantation is thought to be driven by committed multipotent progenitor cells followed by long-term engrafting hematopoietic stem cells (HSCs). We observed a population of early-engrafting cells displaying HSC-like behavior, which persisted long-term in vivo in an autologous myeloablative transplant model in nonhuman primates. To identify this population, we characterized the phenotype and function of defined nonhuman primate hematopoietic stem and progenitor cell (HSPC) subsets and compared these to human HSPCs. We demonstrated that the CD34 + CD45RA - CD90 + cell phenotype is highly enriched for HSCs. This population fully supported rapid short-term recovery and robust multilineage hematopoiesis in the nonhuman primate transplant model and quantitatively predicted transplant success and time to neutrophil and platelet recovery. Application of this cell population has potential in the setting of HSC transplantation and gene therapy/editing approaches. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.
How much can be learned from populations exposed to low levels of radiation

International Nuclear Information System (INIS)

Gilbert, E.S.

1984-05-01

The assessment of health effects from low-level exposure to radiation is a matter of considerable controversy. Many of the problems in analyzing and interpreting data on populations exposed to low levels of radiation are well illustrated by a current study of the effects on mortality of occupational exposure to radiation at the Hanford plant. The conclusion drawn is that the amount that can be learned from the Hanford population, and other populations exposed to low levels of radiation, is extremely limited. The data are not adequate to determine reliable estimates of risks, or to investigate the appropriateness of various models. Although there are problems in using data from populations exposed at high levels to estimate risks of low level exposure to radiation, the problems in obtaining such estimates directly are even more severe. Thus data from populations such as the Japanese A-bomb survivors and the British ankylosing spondylitis patients must continue to serve as our primary source of information on radiation effects. 27 references, 3 tables
ALDH1-high ovarian cancer stem-like cells can be isolated from serous and clear cell adenocarcinoma cells, and ALDH1 high expression is associated with poor prognosis.

Directory of Open Access Journals (Sweden)

Takafumi Kuroda

Full Text Available Cancer stem-like cells (CSCs/cancer-initiating cells (CICs are defined as a small population of cancer cells that have high tumorigenicity. Furthermore, CSCs/CICs are resistant to several cancer therapies, and CSCs/CICs are therefore thought to be responsible for cancer recurrence after treatment and distant metastasis. In epithelial ovarian cancer (EOC cases, disease recurrence after chemotherapy is frequently observed, suggesting ovarian CSCs/CICs are involved. There are four major histological subtypes in EOC, and serous adenocarcinoma and clear cell adenocarcinoma are high-grade malignancies. We therefore analyzed ovarian CSCs/CICs from ovarian carcinoma cell lines (serous adenocarcinoma and clear cell adenocarcinoma and primary ovarian cancer cells in this study. We isolated ovarian CSCs/CICs as an aldehyde dehydrogenase 1 high (ALDH1(high population from 6 EOC cell lines (3 serous adenocarcinomas and 3 clear cell adenocarcinomas by the ALDEFLUOR assay. ALDH1(high cells showed greater sphere-forming ability, higher tumorigenicity and greater invasive capability, indicating that ovarian CSCs/CICs are enriched in ALDH1(high cells. ALDH1(high cells could also be isolated from 8 of 11 primary ovarian carcinoma samples. Immunohistochemical staining revealed that higher ALDH1 expression levels in ovary cancer cases are related to poorer prognosis in both serous adenocarcinoma cases and clear cell adenocarcinoma cases. Taken together, the results indicate that ALDH1 is a marker for ovarian CSCs/CICs and that the expression level of ALDH1 might be a novel biomarker for prediction of poor prognosis.
Stimulation of angiogenesis, neurogenesis and regeneration by side population cells from dental pulp.

Science.gov (United States)

Ishizaka, Ryo; Hayashi, Yuki; Iohara, Koichiro; Sugiyama, Masahiko; Murakami, Masashi; Yamamoto, Tsubasa; Fukuta, Osamu; Nakashima, Misako

2013-03-01

Mesenchymal stem cells (MSCs) have been used for cell therapy in various experimental disease models. However, the regenerative potential of MSCs from different tissue sources and the influence of the tissue niche have not been investigated. In this study, we compared the regenerative potential of dental pulp, bone marrow and adipose tissue-derived CD31(-) side population (SP) cells isolated from an individual porcine source. Pulp CD31(-) SP cells expressed the highest levels of angiogenic/neurotrophic factors and had the highest migration activity. Conditioned medium from pulp CD31(-) SP cells produced potent anti-apoptotic activity and neurite outgrowth, compared to those from bone marrow and adipose CD31(-) SP cells. Transplantation of pulp CD31(-) SP cells in a mouse hindlimb ischemia model produced higher blood flow and capillary density than transplantation of bone marrow and adipose CD31(-) SP cells. Motor function recovery and infarct size reduction were greater with pulp CD31(-) SP cells. Pulp CD31(-) SP cells induced maximal angiogenesis, neurogenesis and pulp regeneration in ectopic transplantation models compared to other tissue sources. These results demonstrate that pulp stem cells have higher angiogenic, neurogenic and regenerative potential and may therefore be superior to bone marrow and adipose stem cells for cell therapy. Copyright © 2012 Elsevier Ltd. All rights reserved.
A comprehensive assessment of mercury exposure in penguin populations throughout the Southern Hemisphere: Using trophic calculations to identify sources of population-level variation

International Nuclear Information System (INIS)

Brasso, Rebecka L.; Chiaradia, André; Polito, Michael J.; Raya Rey, Andrea; Emslie, Steven D.

2015-01-01

Highlights: • Mercury concentrations documented for 10 species of penguins (26 breeding populations). • Mercury concentrations ⩽2.00 ppm in feathers from 18/26 penguin populations. • Trophic level calculations revealed source of population-level variation in mercury. • First documentation of geographic mercury ‘hotspots’ for penguin populations. - Abstract: The wide geographic distribution of penguins (Order Sphenisciformes) throughout the Southern Hemisphere provided a unique opportunity to use a single taxonomic group as biomonitors of mercury among geographically distinct marine ecosystems. Mercury concentrations were compared among ten species of penguins representing 26 geographically distinct breeding populations. Mercury concentrations were relatively low (⩽2.00 ppm) in feathers from 18/26 populations considered. Population-level differences in trophic level explained variation in mercury concentrations among Little, King, and Gentoo penguin populations. However, Southern Rockhopper and Magellanic penguins breeding on Staten Island, Tierra del Fuego, had the highest mercury concentrations relative to their conspecifics despite foraging at a lower trophic level. The concurrent use of stable isotope and mercury data allowed us to document penguin populations at the greatest risk of exposure to harmful concentrations of mercury as a result of foraging at a high trophic level or in geographic ‘hot spots’ of mercury availability
Population Stabilization in India: A Sub-State level Analysis

OpenAIRE

Purohit C, Dr Brijesh

2007-01-01

The study aims at analyzing economic and policy factors impinging upon population stabilization measures at the district (sub-state level) in India. It reflects upon popularly debated notions, namely, that development is the best contraceptive or whether contraceptive is the best development. In order to reflect upon this notion, we hypothesize that the factors determining the success of population stabilization measures are likely to be different across rich and poor states. It is more likel...
Level of emotional awareness in the general French population: effects of gender, age, and education level.

Science.gov (United States)

Nandrino, Jean-Louis; Baracca, Margaret; Antoine, Pascal; Paget, Virginie; Bydlowski, Sarah; Carton, Solange

2013-01-01

The Levels of Emotional Awareness Scale (LEAS) developed by Lane et al. (1990) measures the ability of a subject to discriminate his or her own emotional state and that of others. The scale is based on a cognitive-developmental model in which emotional awareness increases in a similar fashion to intellectual functions. Because studies performed using North American and German populations have demonstrated an effect of age, gender, and level of education on the ability to differentiate emotional states, our study attempts to evaluate whether these factors have the same effects in a general French population. 750 volunteers (506 female, 244 male), who were recruited from three regions of France (Lille, Montpellier, Paris), completed the LEAS. The sample was divided into five age groups and three education levels. The results of the LEAS scores for self and others and the total score showed a difference in the level of emotional awareness for different age groups, by gender and education level. A higher emotional level was observed for younger age groups, suggesting that emotional awareness depends on the cultural context and generational societal teachings. Additionally, the level of emotional awareness was higher in women than in men and lower in individuals with less education. This result might be explained by an educational bias linked to gender and higher education whereby expressive ability is reinforced. In addition, given the high degree of variability in previously observed scores in the French population, we propose a standard based on our French sample.
HIV-1 Adaptation to Antigen Processing Results in Population-Level Immune Evasion and Affects Subtype Diversification

DEFF Research Database (Denmark)

Tenzer, Stefan; Crawford, Hayley; Pymm, Phillip

2014-01-01

these regions encode epitopes presented by ~30 more common HLA variants. By combining epitope processing and computational analyses of the two HIV subtypes responsible for ~60% of worldwide infections, we identified a hitherto unrecognized adaptation to the antigen-processing machinery through substitutions...... of intrapatient adaptations, is predictable, facilitates viral subtype diversification, and increases global HIV diversity. Because low epitope abundance is associated with infrequent and weak T cell responses, this most likely results in both population-level immune evasion and inadequate responses in most...
Comparative toxicity of water soluble fractions of four oils on the growth of a Microalga

Digital Repository Service at National Institute of Oceanography (India)

Phatarpekar, P.V.; Ansari, Z.A.

Toxic effects of water soluble fractions (WSF) of four different fuel oils on a microalga. Tetraselmis gracilis, were examined and compared. On applying different concentrations of WSF, a decrease in cell population was observed. Depending...
Lin- CD34hi CD117int/hi FcεRI+ cells in human blood constitute a rare population of mast cell progenitors.

Science.gov (United States)

Dahlin, Joakim S; Malinovschi, Andrei; Öhrvik, Helena; Sandelin, Martin; Janson, Christer; Alving, Kjell; Hallgren, Jenny

2016-01-28

Mast cells are rare tissue-resident immune cells that are involved in allergic reactions, and their numbers are increased in the lungs of asthmatics. Murine lung mast cells arise from committed bone marrow-derived progenitors that enter the blood circulation, migrate through the pulmonary endothelium, and mature in the tissue. In humans, mast cells can be cultured from multipotent CD34(+) progenitor cells. However, a population of distinct precursor cells that give rise to mast cells has remained undiscovered. To our knowledge, this is the first report of human lineage-negative (Lin(-)) CD34(hi) CD117(int/hi) FcεRI(+) progenitor cells, which represented only 0.0053% of the isolated blood cells in healthy individuals. These cells expressed integrin β7 and developed a mast cell-like phenotype, although with a slow cell division capacity in vitro. Isolated Lin(-) CD34(hi) CD117(int/hi) FcεRI(+) blood cells had an immature mast cell-like appearance and expressed high levels of many mast cell-related genes as compared with human blood basophils in whole-transcriptome microarray analyses. Furthermore, serglycin, tryptase, and carboxypeptidase A messenger RNA transcripts were detected by quantitative reverse transcription-polymerase chain reaction. Altogether, we propose that the Lin(-) CD34(hi) CD117(int/hi) FcεRI(+) blood cells are closely related to human tissue mast cells and likely constitute an immediate precursor population, which can give rise to predominantly mast cells. Furthermore, asthmatics with reduced lung function had a higher frequency of Lin(-) CD34(hi) CD117(int/hi) FcεRI(+) blood mast cell progenitors than asthmatics with normal lung function. © 2016 by The American Society of Hematology.
Four Categories of Viral Infection Describe the Health Status of Honey Bee Colonies.

Directory of Open Access Journals (Sweden)

Esmaeil Amiri

Full Text Available Honey bee virus prevalence data are an essential prerequisite for managing epidemic events in a population. A survey study was carried out for seven viruses in colonies representing a healthy Danish honey bee population. In addition, colonies from apiaries with high level Varroa infestation or high level of winter mortality were also surveyed. Results from RT-qPCR showed a considerable difference of virus levels between healthy and sick colonies. In the group of healthy colonies, no virus was detected in 36% of cases, while at least one virus was found in each of the sick colonies. Virus titers varied among the samples, and multiple virus infections were common in both groups with a high prevalence of Sacbrood virus (SBV, Black queen cell virus (BQCV and Deformed wing virus (DWV. Based on the distribution of virus titers, we established four categories of infection: samples free of virus (C = 0, samples with low virus titer (estimated number of virus copies 0 < C < 103, samples with medium virus titer (103 ≤ C < 107 and samples with high virus titer (C ≥ 107. This allowed us to statistically compare virus levels in healthy and sick colonies. Using categories to communicate virus diagnosis results to beekeepers may help them to reach an informed decision on management strategies to prevent further spread of viruses among colonies.
Four MicroRNAs Promote Prostate Cell Proliferation with Regulation of PTEN and Its Downstream Signals In Vitro

Science.gov (United States)

Xue, Jing-lun; Chen, Jin-zhong

2013-01-01

Background Phosphatase and tensin homologue (PTEN), as a tumor suppressor, plays vital roles in tumorigenesis and progression of prostate cancer. However, the mechanisms of PTEN regulation still need further investigation. We here report that a combination of four microRNAs (miR-19b, miR-23b, miR-26a and miR-92a) promotes prostate cell proliferation by regulating PTEN and its downstream signals in vitro. Methodology/Principal Findings We found that the four microRNAs (miRNAs) could effectively suppress PTEN expression by directly interacting with its 3’ UTR in prostate epithelial and cancer cells. Under-expression of the four miRNAs by antisense neutralization up-regulates PTEN expression, while overexpression of the four miRNAs accelerates epithelial and prostate cancer cell proliferation. Furthermore, the expression of the four miRNAs could, singly or jointly, alter the expression of the key components in the phosphoinositide 3-kinase (PI3K)/Akt pathway, including PIK3CA, PIK3CD, PIK3R1 and Akt, along with their downstream signal, cyclin D1. Conclusions These results suggested that the four miRNAs could promote prostate cancer cell proliferation by co-regulating the expression of PTEN, PI3K/Akt pathway and cyclin D1 in vitro. These findings increase understanding of the molecular mechanisms of prostate carcinogenesis and progression, even provide valuable insights into the diagnosis, prognosis, and rational design of novel therapeutics for prostate cancer. PMID:24098737
Dissecting stem cell differentiation using single cell expression profiling

OpenAIRE

Moignard, Victoria Rachel; Göttgens, Berthold

2016-01-01

Many assumptions about the way cells behave are based on analyses of populations. However, it is now widely recognized that even apparently pure populations can display a remarkable level of heterogeneity. This is particularly true in stem cell biology where it hinders our understanding of normal development and the development of strategies for regenerative medicine. Over the past decade technologies facilitating gene expression analysis at the single cell level have become widespread, provi...
Measurement of Heme Synthesis Levels in Mammalian Cells.

Science.gov (United States)

Hooda, Jagmohan; Alam, Maksudul; Zhang, Li

2015-07-09

Heme serves as the prosthetic group for a wide variety of proteins known as hemoproteins, such as hemoglobin, myoglobin and cytochromes. It is involved in various molecular and cellular processes such as gene transcription, translation, cell differentiation and cell proliferation. The biosynthesis levels of heme vary across different tissues and cell types and is altered in diseased conditions such as anemia, neuropathy and cancer. This technique uses [4-(14)C] 5-aminolevulinic acid ([(14)C] 5-ALA), one of the early precursors in the heme biosynthesis pathway to measure the levels of heme synthesis in mammalian cells. This assay involves incubation of cells with [(14)C] 5-ALA followed by extraction of heme and measurement of the radioactivity incorporated into heme. This procedure is accurate and quick. This method measures the relative levels of heme biosynthesis rather than the total heme content. To demonstrate the use of this technique the levels of heme biosynthesis were measured in several mammalian cell lines.
Four-level conservative finite-difference schemes for Boussinesq paradigm equation

Science.gov (United States)

Kolkovska, N.

2013-10-01

In this paper a two-parametric family of four level conservative finite difference schemes is constructed for the multidimensional Boussinesq paradigm equation. The schemes are explicit in the sense that no inner iterations are needed for evaluation of the numerical solution. The preservation of the discrete energy with this method is proved. The schemes have been numerically tested on one soliton propagation model and two solitons interaction model. The numerical experiments demonstrate that the proposed family of schemes has second order of convergence in space and time steps in the discrete maximal norm.
CD44+CD24+ subset of PANC-1 cells exhibits radiation resistance via decreased levels of reactive oxygen species.

Science.gov (United States)

Wang, Lei; Li, Pengping; Hu, Wei; Xia, Youyou; Hu, Chenxi; Liu, Liang; Jiang, Xiaodong

2017-08-01

Emerging evidence has suggested that pancreatic adenocarcinoma is sustained by pancreatic cancer stem cells. The present study aimed to investigate the expression patterns of the pancreatic cancer stem cell surface markers cluster of differentiation CD44 and CD24 in a pancreatic adenocarcinoma cell line, and to investigate the possible mechanisms for their radiation resistance. Flow cytometry was used to analyze the expression patterns of CD44 and CD24 in the pancreatic adenocarcinoma PANC-1 cell line. In addition, a multi-target click model was used to fit cell survival curves and determine the sensitizer enhancement ratio. The apoptosis and cycle distribution of the four cell subsets was determined using flow cytometry, and the level of reactive oxygen species (ROS) was determined using the 2',7'-dichlorofluorescin diacetate probe. The present results identified that the ratios of CD44 + and CD24 + in the sorted PANC-1 cell line were 92.0 and 4.7%, respectively. Prior to radiation, no statistically significant differences were observed among the four groups. Following treatment with 6 MV of X-rays, the rate of apoptosis was decreased in the CD44 + CD24 + group compared with other subsets. The percentage of G0/G1 cells was highest in the CD44 + CD24 + group compared with the three other groups, which exhibited increased radiosensitivity. In addition, the level of ROS in the CD44 + CD24 + group was reduced compared with the other groups. In summary, the results of the present study indicated that CD44 + CD24 + exhibited stem cell properties. The lower level of ROS and apoptosis in CD44 + CD24 + cells may contribute to their resistance to radiation in pancreatic adenocarcinoma.

Mechanism of derivation of radioresistance in HeLa cell population after repeated x-irradiation

International Nuclear Information System (INIS)

Kubo, Kihei; Koiwai, Soichiro; Morita, Kazuo

1982-01-01

The Radioresistant strain (X-8-5) was obtained from HeLa-SC population X-irradiated repeatedly for five times with 800 rad. The mean lethal dose (D 0 ) was 196 rad for X-8-5 cells, while it was 166 rad for control HeLa-SC cells. The fraction of cells containing an unusually long acrocentric chromosome (LA 2) exclusively increased with increasing number of irradiation of HeLa-SC population. A clonal strain with LA 2 marker was isolated from X-8-5 population and named RC-355. Since the RC-355 cells were more resistant (D 0 = 220 rad)than parental X-8-5 cells (D 0 = 196 rad), it was suggested that the cells with LA 2 were responsible for the radioresistance of X-8-5 population. The RC-355 cells were further subjected to the analysis of Q-banded karyotypes and it was observed that 18 types of specific markers (rm 1-17 and LA 2) were included in RC-355 cells in addition to 12 types of markers observed in most of HeLa-SC cells. Since the analysis of Q-banded karyotypes of RC-355 cells showed that RC-355 specific markers were not produced by radiation-induced rearrangements of HeLa-SC chromosomes, because twelve kinds of HeLa-SC markers were presented in RC-355 cells without any change, it was concluded that a small number of cells with LA 2 marker were originally presented in the control population and the relative fraction of them occupied increased after irradiation. (author)
Coherent Control of Four-Wave Mixing

CERN Document Server

Zhang, Yanpeng; Xiao, Min

2011-01-01

"Coherent Control of Four-Wave Mixing" discusses the frequency, temporal and spatial domain interplays of four-wave mixing (FWM) processes induced by atomic coherence in multi-level atomic systems. It covers topics in five major areas: the ultrafast FWM polarization beats due to interactions between multi-color laser beams and multi-level media; coexisting Raman-Rayleigh-Brillouin-enhanced polarization beats due to color-locking noisy field correlations; FWM processes with different kinds of dual-dressed schemes in ultra-thin, micrometer and long atomic cells; temporal and spatial interference between FWM and six-wave mixing (SWM) signals in multi-level electromagnetically induced transparency (EIT) media; spatial displacements and splitting of the probe and generated FWM beams, as well as the observations of gap soliton trains, vortex solitons, and stable multicomponent vector solitons in the FWM signals. The book is intended for scientists, researchers, advanced undergraduate and graduate students in Nonlin...
Heterogenous populations of cytotoxic cells in the peritoneal cavity of BALB/c mice immunized with allogeneic EL4 leukemia cells

International Nuclear Information System (INIS)

Zighelboim, J.; Bonavida, B.; Fahey, J.L.

1974-01-01

Adherent cells, presumably macrophages, obtained from the peritoneal cavity shortly after rejection of the allogeneic leukemia EL4, produced effective cell-mediated cytotoxicity (CMC) in vitro. These cytotoxic cells were sensitive to anti-macrophage serum and resistant to anti-thymocyte serum and 10,000 roentgen irradiation. In contrast, a second population of specifically cytotoxic cells were nonadherent, sensitive to x-rays and anti-thymocyte serum, but not to anti-macrophage serum. The two cell populations had a cooperative cytotoxic effect in vitro against allogeneic tumor cells
A population of human brain cells expressing phenotypic markers of more than one lineage can be induced in vitro to differentiate into mesenchymal cells

International Nuclear Information System (INIS)

Rieske, Piotr; Augelli, Brian J.; Stawski, Robert; Gaughan, John; Azizi, S. Ausim; Krynska, Barbara

2009-01-01

Proliferating astrocytic cells from germinal, as well as mature areas of brain parenchyma, have the characteristics of neural stem/progenitor cells and are capable of generating both neurons and glia. We previously reported that primary fetal human brain cells, designated as Normal Human Astrocytes (NHA), expressed, in addition to GFAP, Vimentin and Nestin, low levels of βIII-Tubulin, an early neuronal marker, and differentiated into neurons and astrocytes in vitro. Here, we showed that primary NHA cells co-express low levels of mesenchymal markers Fibronectin and Collagen-1 in culture. These cells transitioned into mesenchymal-like cells when cultured in adherent conditions in serum containing media. The mesenchymal-like derivatives of these cells were characterized based on their morphological changes, high expression of Vimentin and extracellular matrix (ECM) proteins, Collagen-1 and Fibronectin, and decline of neural markers. When incubated in osteogenic and adipogenic induction media, the mesenchymal-like cells differentiated into osteoblasts and adipocytes. Furthermore, NHA cells express markers of neural crest cells, SOX-10 and p75. These data support the idea of ectoderm-derived mesenchymal lineages. These findings suggest that a population of primitive fetal brain cells with neural/neural crest/mesenchymal phenotype, resembles the remarkable phenotypic plasticity of neural crest cells, and differentiates into adipocytes and osteocytes under the influence of environmental factors
Low baseline levels of NK cells may predict a positive response to ipilimumab in melanoma therapy.

Science.gov (United States)

Tietze, Julia K; Angelova, Daniela; Heppt, Markus V; Ruzicka, Thomas; Berking, Carola

2017-07-01

The introduction of immune checkpoint blockade (ICB) has been a breakthrough in the therapy of metastatic melanoma. The influence of ICB on T-cell populations has been studied extensively, but little is known about the effect on NK cells. In this study, we analysed the relative and absolute amounts of NK cells and of the subpopulations of CD56 dim and CD56 bright NK cells among the peripheral blood mononuclear cells (PBMCs) of 32 patients with metastatic melanoma before and under treatment with ipilimumab or pembrolizumab by flow cytometry. In 15 (47%) patients, an abnormal low amount of NK cells was found at baseline. Analysis of the subpopulations showed also low or normal baseline levels for CD56 dim NK cells, whereas the baseline levels of CD56 bright NK cells were either normal or abnormally high. The relative and absolute amounts of NK cells and of CD56 dim and CD56 bright NK cell subpopulations in patients with a normal baseline did not change under treatment. However, patients with a low baseline of NK cells and CD56 dim NK cells showed a significant increase in these immune cell subsets, but the amounts remained to be lower than the normal baseline. The amount of CD56 bright NK cells was unaffected by treatment. The baseline levels of NK cells were correlated with the number of metastatic organs. Their proportion increased, whereas the expression of NKG2D decreased significantly when more than one organ was affected by metastases. Low baseline levels of NK cells and CD56 dim NK cells as well as normal baseline levels of CD56 bright NK cells correlated significantly with a positive response to ipilimumab but not to pembrolizumab. Survival curves of patients with low amounts of CD56 dim NK cells treated with ipilimumab showed a trend to longer survival. Normal baseline levels of CD56 bright NK cells were significantly correlated with longer survival as compared to patients with high baseline levels. In conclusion, analysis of the amounts of total NK cells
Phenotypic and functional profiling of CD4 T cell compartment in distinct populations of healthy adults with different antigenic exposure.

Directory of Open Access Journals (Sweden)

Sophie Roetynck

Full Text Available Multiparameter flow cytometry has revealed extensive phenotypic and functional heterogeneity of CD4 T cell responses in mice and humans, emphasizing the importance of assessing multiple aspects of the immune response in correlation with infection or vaccination outcome. The aim of this study was to establish and validate reliable and feasible flow cytometry assays, which will allow us to characterize CD4 T cell population in humans in field studies more fully.We developed polychromatic flow cytometry antibody panels for immunophenotyping the major CD4 T cell subsets as well as broadly characterizing the functional profiles of the CD4 T cells in peripheral blood. We then validated these assays by conducting a pilot study comparing CD4 T cell responses in distinct populations of healthy adults living in either rural or urban Kenya. This study revealed that the expression profile of CD4 T cell activation and memory markers differed significantly between African and European donors but was similar amongst African individuals from either rural or urban areas. Adults from rural Kenya had, however, higher frequencies and greater polyfunctionality among cytokine producing CD4 T cells compared to both urban populations, particularly for "Th1" type of response. Finally, endemic exposure to malaria in rural Kenya may have influenced the expansion of few discrete CD4 T cell populations with specific functional signatures.These findings suggest that environmentally driven T cell activation does not drive the dysfunction of CD4 T cells but is rather associated with greater magnitude and quality of CD4 T cell response, indicating that the level or type of microbial exposure and antigenic experience may influence and shape the functionality of CD4 T cell compartment. Our data confirm that it is possible and mandatory to assess multiple functional attributes of CD4 T cell response in the context of infection.
Comparison of bioengineered human bone construct from four sources of osteogenic cells.

Science.gov (United States)

Ng, Angela Min-Hwei; Saim, Aminuddin Bin; Tan, Kok-Keong; Tan, G H; Mokhtar, Sabarul Afian; Rose, Isa Mohamed; Othman, Fauziah; Idrus, Ruszymah Binti Haji

2005-01-01

Osteoprogenitor cells have been reported to be present in periosteum, cancellous and cortical bone, and bone marrow; but no attempt to identify the best cell source for bone tissue engineering has yet been reported. In this study, we aimed to investigate the growth and differentiation pattern of cells derived from these four sources in terms of cell doubling time and expression of osteoblast-specific markers in both monolayer cells and three-dimensional cell constructs in vitro. In parallel, human plasma derived-fibrin was evaluated for use as biomaterial when forming three-dimensional bone constructs. Our findings showed osteoprogenitor cells derived from periosteum to be most proliferative followed by cortical bone, cancellous bone, and then bone marrow aspirate. Bone-forming activity was observed in constructs formed with cells derived from periosteum, whereas calcium deposition was seen throughout the constructs formed with cells derived from cancellous and cortical bones. Although no mineralization activity was seen in constructs formed with osteoprogenitor cells derived from bone marrow, well-organized lacunae as would appear in the early phase of bone reconstruction were noted. Scanning electron microscopy evaluation showed cell proliferation throughout the fibrin matrix, suggesting the possible application of human fibrin as the bioengineered tissue scaffold at non-load-bearing sites.
Analyzing the Relationship between Poverty and Child Maltreatment: Investigating the Relative Performance of Four Levels of Geographic Aggregation

Science.gov (United States)

Aron, Sarah B.; McCrowell, Jean; Moon, Alyson; Yamano, Ryoichi; Roark, Duston A.; Simmons, Monica; Tatanashvili, Zurab; Drake, Brett

2010-01-01

The purpose of this article is to compare four different levels of aggregation to assess their utility as areal units in child maltreatment research. The units examined are county, zip code, tract, and block group levels. Each of the four levels is analyzed to determine which show the strongest effects in modeling the correlation between poverty…
Bone lead levels in an environmentally exposed elderly population in shanghai, China.

Science.gov (United States)

Specht, Aaron J; Lin, Yanfen; Xu, Jian; Weisskopf, Marc; Nie, Linda H

2018-06-01

This study looked at measurements of lead (Pb) in a pilot population of environmentally exposed elderly residents of Shanghai, China and presented the first set of bone Pb data on an elderly Chinese population. We found that with environmental exposures in this population using K-shell x-ray fluorescence (KXRF) bone Pb measurements 40% of the individuals had bone Pb levels above the nominal detection limit with an average bone lead level of 4.9 ± 3.6 μg/g. This bone lead level is lower than comparable values from previous studies of community dwelling adults in US cities. This population had a slightly higher geometric mean blood Pb of 2.6 μg/dL than the adult US population. The main conclusion of this data is that in Shanghai there is environmental exposure to Pb, measured through blood and bone, which should be further investigated to assess the health impact of this exposure. Copyright © 2018. Published by Elsevier B.V.
System level modeling and component level control of fuel cells

Science.gov (United States)

Xue, Xingjian

This dissertation investigates the fuel cell systems and the related technologies in three aspects: (1) system-level dynamic modeling of both PEM fuel cell (PEMFC) and solid oxide fuel cell (SOFC); (2) condition monitoring scheme development of PEM fuel cell system using model-based statistical method; and (3) strategy and algorithm development of precision control with potential application in energy systems. The dissertation first presents a system level dynamic modeling strategy for PEM fuel cells. It is well known that water plays a critical role in PEM fuel cell operations. It makes the membrane function appropriately and improves the durability. The low temperature operating conditions, however, impose modeling difficulties in characterizing the liquid-vapor two phase change phenomenon, which becomes even more complex under dynamic operating conditions. This dissertation proposes an innovative method to characterize this phenomenon, and builds a comprehensive model for PEM fuel cell at the system level. The model features the complete characterization of multi-physics dynamic coupling effects with the inclusion of dynamic phase change. The model is validated using Ballard stack experimental result from open literature. The system behavior and the internal coupling effects are also investigated using this model under various operating conditions. Anode-supported tubular SOFC is also investigated in the dissertation. While the Nernst potential plays a central role in characterizing the electrochemical performance, the traditional Nernst equation may lead to incorrect analysis results under dynamic operating conditions due to the current reverse flow phenomenon. This dissertation presents a systematic study in this regard to incorporate a modified Nernst potential expression and the heat/mass transfer into the analysis. The model is used to investigate the limitations and optimal results of various operating conditions; it can also be utilized to perform the
Destruction of radiation-resistant cell populations by hyperthermia

International Nuclear Information System (INIS)

Roettinger, E.M.; Gerweck, L.E.

1979-01-01

Animal experiments with local hyperthermia have shown that the radiauion dose necessary for the local control of 50% of the tumours examined was essentially reduced by heating to 42,5 0 C. In-vitro experients indicated selective destruction of relatively radiation-resistent cell populations by the combination of hyperthermie and reduced hydrogen ion concentration. Experiments with glioblastoma cells confirmed these results qualitatively, but showed quantitatively considerably lower sensitivity towards hyperthermia. (orig.) 891 MG/orig. 892 RDG [de
Population characteristics may reduce the levels of individual call identity.

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María del Mar Delgado

Full Text Available Individual variability influences the demographic and evolutionary dynamics of spatially structured populations, and conversely ecological and evolutionary dynamics provide the context under which variations at the individual level occur. Therefore, it is essential to identify and characterize the importance of the different factors that may promote or hinder individual variability. Animal signaling is a prime example of a type of behavior that is largely dependent on both the features of individuals and the characteristics of the population to which they belong. After 10 years studying the dynamics of a population of a long-lived species, the eagle owl (Bubo bubo, we investigated the emergence and maintenance of traits that reveal individual identity by focusing on vocal features. We found that individuals inhabiting a high density population characterized by a relative lack of heterogeneity (in terms of prey availability and breeding success among breeding sites might be selected for reducing the levels of identity. Two non-mutually exclusive hypotheses may explain the structural call patterns we detected: (1 similarity in calls may be principally a consequence of the particular characteristics of the population; and (2 high density may encourage individuals to mimic each other's vocalizations in a cascade effect, leading to a widespread and unique communication network.
The finite state projection approach to analyze dynamics of heterogeneous populations

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Johnson, Rob; Munsky, Brian

2017-06-01

Population modeling aims to capture and predict the dynamics of cell populations in constant or fluctuating environments. At the elementary level, population growth proceeds through sequential divisions of individual cells. Due to stochastic effects, populations of cells are inherently heterogeneous in phenotype, and some phenotypic variables have an effect on division or survival rates, as can be seen in partial drug resistance. Therefore, when modeling population dynamics where the control of growth and division is phenotype dependent, the corresponding model must take account of the underlying cellular heterogeneity. The finite state projection (FSP) approach has often been used to analyze the statistics of independent cells. Here, we extend the FSP analysis to explore the coupling of cell dynamics and biomolecule dynamics within a population. This extension allows a general framework with which to model the state occupations of a heterogeneous, isogenic population of dividing and expiring cells. The method is demonstrated with a simple model of cell-cycle progression, which we use to explore possible dynamics of drug resistance phenotypes in dividing cells. We use this method to show how stochastic single-cell behaviors affect population level efficacy of drug treatments, and we illustrate how slight modifications to treatment regimens may have dramatic effects on drug efficacy.
Haematological parameters in different african populations: an experience from united nations level 3 hospital

International Nuclear Information System (INIS)

Iftikhar, R.; Khan, N.U.; Iqbal, Z.; Anwar, M.I.

2017-01-01

To evaluate hematological parameters in African population to estimate normal reference intervals for these tests. Study Design: Cross sectional observational study. Place and Duration of Study: Department of Pathology, United Nations level 3 hospital, Nyala, Darfur from 1st Mar to 30th Dec 2014. Material and Methods: There were 396 healthy African male and female volunteers selected between 18-65 years of age, belonging to different countries. Fresh whole blood was used to measure haemoglobin (Hb) concentration, haematocrit (Hct), total red blood cell (TRBC) count, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), platelet count, total leucocyte count (TLC) and differential white blood cells count. Data were analysed using SPSS version 19. Results: Mean Hb of study group was 13.81 +- 1.99 g/dl. Mean TLC was 5.50 +- 1.96 x 103/ul. Mean lymphocyte count was 2.58 +- 0.95. Mean platelet count was 234 +- 92 x103 /ul. Mean values for Hb Concentration, TRBC, Hct Ratio, MCV, MCH and MCHC were all higher for African Males than Females; this difference was statistically significant (p<0.05). Conclusion: This multi-national African population based study confirms the variations in haematological parameters previously described in single nation African studies. The commonly observed variations in normal adults are low RBC indices, relative neutropenia and lymphocytosis. (author)
Optical preparation of H2 rovibrational levels with almost complete population transfer

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Dong, Wenrui; Mukherjee, Nandini; Zare, Richard N.

2013-08-01

Using stimulated Raman adiabatic passage (SARP), it is possible, in principle, to transfer all the population in a rovibrational level of an isolated diatomic molecule to an excited rovibrational level. We use an overlapping sequence of pump (532 nm) and dump (683 nm) single-mode laser pulses of unequal fluence to prepare isolated H2 molecules in a molecular beam. In a first series of experiments we were able to transfer more than half the population to an excited rovibrational level [N. Mukherjee, W. R. Dong, J. A. Harrison, and R. N. Zare, J. Chem. Phys. 138(5), 051101-1051101-4 (2013)], 10.1063/1.4790402. Since then, we have achieved almost complete transfer (97% ± 7%) of population from the H2 (v = 0, J = 0) ground rovibrational level to the H2 (v = 1, J = 0) excited rovibrational level. An explanation is presented of the SARP process and how these results are obtained.
Evaluation of the thermodynamics of a four level system using canonical density matrix method

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Awoga Oladunjoye A.

2013-02-01

Full Text Available We consider a four-level system with two subsystems coupled by weak interaction. The system is in thermal equilibrium. The thermodynamics of the system, namely internal energy, free energy, entropy and heat capacity, are evaluated using the canonical density matrix by two methods. First by Kronecker product method and later by treating the subsystems separately and then adding the evaluated thermodynamic properties of each subsystem. It is discovered that both methods yield the same result, the results obey the laws of thermodynamics and are the same as earlier obtained results. The results also show that each level of the subsystems introduces a new degree of freedom and increases the entropy of the entire system. We also found that the four-level system predicts a linear relationship between heat capacity and temperature at very low temperatures just as in metals. Our numerical results show the same trend.
The negative effects of development megaprojects: Comparative study of four cases of population relocation related to dam projects

International Nuclear Information System (INIS)

D'Almeida, K.

1993-11-01

As with any other hydroelectric installation project around the world, the construction of large dams in Africa such as the Kariba in Zambia, the Aswan High Dam in Egypt, the Akossombo in Ghana, and the Kossou in Ivory Coast have caused massive displacements of populations. Parallel to the attendant positive effects, negative effects have been observed following the relocation of those populations. These negative effects are social, cultural, political, economic, sanitary, demographic, psychological, and ecological. A comparative study is conducted of the four cases of dam construction cited above in order to demonstrate that errors committed by planners were at the source of those negative effects of population displacement. The knowledge of those errors committed in the past should serve as lessons for future instances of population relocation. Such lessons are outlined in the areas of relocation planning, principles of indemnization, re-housing of populations on new sites, and adaptation of the populations to new agricultural techniques. 116 refs., 14 figs., 5 tabs
Diversity and Seasonal Dynamics of Actinobacteria Populations in Four Lakes in Northeastern Germany

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Allgaier, Martin; Grossart, Hans-Peter

2006-01-01

The phylogenetic diversity and seasonal dynamics of freshwater Actinobacteria populations in four limnologically different lakes of the Mecklenburg-Brandenburg Lake District (northeastern Germany) were investigated. Fluorescence in situ hybridization was used to determine the seasonal abundances and dynamics of total Actinobacteria (probe HGC69a) and the three actinobacterial subclusters acI, acI-A, and acI-B (probes AcI-852, AcI-840-1, and AcI-840-2). Seasonal means of total Actinobacteria abundances in the epilimnia of the lakes varied from 13 to 36%, with maximum values of 30 to 58%, of all DAPI (4′,6′-diamidino-2-phenylindole)-stained cells. Around 80% of total Actinobacteria belonged to the acI cluster. The two subclusters acI-A and acI-B accounted for 60 to 91% of the acI cluster and showed seasonal means of 49% (acI-B) and 23% (acI-A) in relation to the acI cluster. Total Actinobacteria and members of the clusters acI and acI-B showed distinct seasonal changes in their absolute abundances, with maxima in late spring and fall/winter. In eight clone libraries constructed from the lakes, a total of 76 actinobacterial 16S rRNA gene sequences were identified from a total of 177 clones. The majority of the Actinobacteria sequences belonged to the acI and acIV cluster. Several new clusters and subclusters were found (acSTL, scB1-4, and acIVA-D). The majority of all obtained 16S rRNA gene sequences are distinct from those of already-cultured freshwater Actinobacteria. PMID:16672495
Differences in Sleep Duration among Four Different Population Groups of Older Adults in South Africa.

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Peltzer, Karl

2017-05-09

The study aims to investigate sleep duration in four different population groups in a national probability sample of older South Africans who participated in the Study of Global Ageing and Adult Health (SAGE) Wave 1. A national population-based cross-sectional study with a sample of 3284 aged 50 years or older in South Africa was conducted in 2008. The questionnaire included socio-demographic characteristics, health variables, and self-reported sleep duration. Results indicate that White Africans compared to other population groups had the lowest mean sleep duration (7.88 h among men and 7.46 h among women). The prevalence of short sleep was the highest among both men and women among the White African (18.8% in men and 16.9% in women) and Indian or Asian African population groups (14.5% in men and 17.1% in women), and lowest among both men and women in the Black African (7.0% in men and 6.5% in women) and multi-ancestry population groups (15.6% in men and 12.7% in women). The prevalence of long sleep was among both men and women the highest in the Black African population group (56.2% in men and 58.5% in women), and the lowest in the White African population group (36.4% in men and 24.3% in women). In a Poisson regression model, adjusted for sociodemographics and chronic disease status, coming from the male and female White African population group was associated with short sleep. In addition, coming from the Indian or Asian African population group was associated with short sleep. No population group differences were found regarding long sleep prevalence. White Africans reported more short sleep duration than the other population groups, while there were no racial or ethnic differences in long sleep. White Africans are more likely to have sleep durations that are associated with negative health outcomes. An explanation of the high short sleep prevalence among White Africans may be related to their racial or ethnic minority status in South Africa.
Differences in Sleep Duration among Four Different Population Groups of Older Adults in South Africa

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Karl Peltzer

2017-05-01

Full Text Available The study aims to investigate sleep duration in four different population groups in a national probability sample of older South Africans who participated in the Study of Global Ageing and Adult Health (SAGE Wave 1. A national population-based cross-sectional study with a sample of 3284 aged 50 years or older in South Africa was conducted in 2008. The questionnaire included socio-demographic characteristics, health variables, and self-reported sleep duration. Results indicate that White Africans compared to other population groups had the lowest mean sleep duration (7.88 h among men and 7.46 h among women. The prevalence of short sleep was the highest among both men and women among the White African (18.8% in men and 16.9% in women and Indian or Asian African population groups (14.5% in men and 17.1% in women, and lowest among both men and women in the Black African (7.0% in men and 6.5% in women and multi-ancestry population groups (15.6% in men and 12.7% in women. The prevalence of long sleep was among both men and women the highest in the Black African population group (56.2% in men and 58.5% in women, and the lowest in the White African population group (36.4% in men and 24.3% in women. In a Poisson regression model, adjusted for sociodemographics and chronic disease status, coming from the male and female White African population group was associated with short sleep. In addition, coming from the Indian or Asian African population group was associated with short sleep. No population group differences were found regarding long sleep prevalence. White Africans reported more short sleep duration than the other population groups, while there were no racial or ethnic differences in long sleep. White Africans are more likely to have sleep durations that are associated with negative health outcomes. An explanation of the high short sleep prevalence among White Africans may be related to their racial or ethnic minority status in South Africa.

Phenotypic Diversities of Four Populations of Clarias Gariepinus (Siluriformes, Clariidae Obtained from Ogun and Ondo State Waterbodies in South-Western Nigeria

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Ola-Oladimeji F. A.

2017-08-01

Full Text Available The study determined the variation in the morphological and meristic features among four populations of Clarias gariepinus Burchell, 1822 obtained from Owena Dam and River Oluwa in Ondo State and Rivers Omo and Ogbere in Ogun State, both in Nigeria. A total of ninety five (95 and one hundred and twenty (120 fish specimens collected from Ondo and Ogun states respectively were measured using standard procedures and the results were analysed using Analysis of variance and multivariate analyses. The results obtained from the ANOVA and Principal Component Analyses of Clarias gariepinus from the four populations revealed heterogeneity for most of their characters. Therefore, the morphological differences between the wild African catfish found in Ondo and Ogun state populations could be linked to genetic differences or environmental factors or a combination of both factors. Hence, this study concluded that the populations are different which could imply high genetic diversity if molecular marker techniques are employed in further studies.
Haplotype diversity and linkage disequilibrium at DRD2 locus--a study on four population groups of Andhra Pradesh, India.

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Saraswathy, Kallur Nava; Mukhopadhyay, Rupak; Shukla, Deepti; Kaur, Harpreet; Sachdeva, Mohinder Pal; Rao, A P; Saksena, Deepti; Kalla, Aloke Kumar

2009-02-01

Dopamine receptor D2 (DRD2) is expressed in the central nervous system and has a high affinity for many antipsychotic drugs. Besides several epidemiological investigations on association of DRD2 locus polymorphism(s) with neuropsychiatric problems and addictive behavior, a few polymorphisms in this locus have also been used to understand genomic diversity and population migratory histories globally. The present study attempts to understand the genomic diversity/affinity among four endogamous groups of Andhra Pradesh (India) against the backdrop of diversity studies from other parts of India and the rest of the world, with special reference to DRD2 locus. The four population groups from Adilabad District of Andhra Pradesh, namely, Brahmin (n=50), Nayakpod (n=49), Thoti (n=52), and Kolam (n=53), were included in the study. The DRD2 markers typed for the present study are three biallelic restriction fragments, that is, TaqI A (rs1800497), TaqI B (rs1079597), and TaqI D (rs1800498). Scoring of DRD2 haplotypes with respect to the three TaqI sites shows that five out of eight possible haplotypes are shared by the four populations. Ancestral haplotype B2D2A1 is most frequent among Thotis (0.359). The results of the present study indicate a differential gene flow into South India followed by certain important demographic events resulting in diversified peopling of India.
Quantifying risks experienced by populations exposed to low levels of environmental contaminants

International Nuclear Information System (INIS)

Gilbert, E.S.

1985-05-01

The objective was to provide a direct assessment of risks associated with exposures at the actual levels of interest. There are several epidemiological studies of populations that have received occupational exposure to radiation including workers at the Hanford nuclear facility. This population was used as a typical example to illustrate methods of analyzing such data. The Hanford data appear to demonstrate directly that risk estimates obtained by linear extrapolation from data on populations exposed at high levels are unlikely to underestimate risks by a factor greater than three. 15 refs
Effects of Ambient Temperature on Growth Performance, Blood Metabolites, and Immune Cell Populations in Korean Cattle Steers

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H. J. Kang

2016-03-01

Full Text Available Exposure to cold may affect growth performance in accordance with the metabolic and immunological activities of animals. We evaluated whether ambient temperature affects growth performance, blood metabolites, and immune cell populations in Korean cattle. Eighteen Korean cattle steers with a mean age of 10 months and a mean weight of 277 kg were used. All steers were fed a growing stage-concentrate diet at a rate of 1.5% of body weight and Timothy hay ad libitum for 8 weeks. Experimental period 1 (P1 was for four weeks from March 7 to April 3 and period 2 (P2 was four weeks from April 4 to May 1. Mean (8.7°C and minimum (1.0°C indoor ambient temperatures during P1 were lower (p<0.001 than those (13.0°C and 6.2°C, respectively during P2. Daily dry matter feed intake in both the concentrate diet and forage groups was higher (p<0.001 during P2 than P1. Average daily weight gain was higher (p<0.001 during P2 (1.38 kg/d than P1 (1.13 kg/d. Feed efficiency during P2 was higher (p = 0.015 than P1. Blood was collected three times; on March 7, April 4, and May 2. Nonesterified fatty acids (NEFA were higher on March 7 than April 4 and May 2. Blood cortisol, glucose, and triglyceride concentrations did not differ among months. Blood CD4+, CD8+, and CD4+CD25+ T cell percentages were higher, while CD8+CD25+ T cell percentage was lower, during the colder month of March than during May, suggesting that ambient temperature affects blood T cell populations. In conclusion, colder ambient temperature decreased growth and feed efficiency in Korean cattle steers. The higher circulating NEFA concentrations observed in March compared to April suggest that lipolysis may occur at colder ambient temperatures to generate heat and maintain body temperature, resulting in lower feed efficiency in March.
A preliminary study measuring the number of T-cell receptor-rearrangement excision circles (TRECs) in peripheral blood T-cell populations of A-bomb survivors and control populations

International Nuclear Information System (INIS)

Kubo, Yoshiko; Yamaoka, Mika; Kusunoki, Yoichiro

2006-01-01

More than a half century after damage of the immune systems by the radiation from A-bomb, we can still observe significant decreases in the percentages of naieve CD4 and CD8 T cells among the survivors. To investigate whether the observed decreases in the naieve T-cell populations may have resulted from reduction in thymic T-cell production ability of survivors, we established a real-time polymerase chain reaction (PCR) method to examine the number of T-cell receptor-rearrangement excision circles (TRECs) in peripheral blood CD4 and CD8 T-cell populations. The real-time PCR quantitatively detected TREC sequences with a good reproducibility in human laboratory controls. In the 445 survivors so far been examined, multiple regression analysis indicated that the number of TRECs in the CD4 T-cell fraction was significantly higher in females than in males and decreased significantly with age in both males and females. This analysis also suggested a possible dose-dependent decrease in the number of TRECs in the CD4 T-cell fraction of the survivors who were less than 20 years of age at the time of bombing (p=0.09). A similar statistically significant trend for gender difference or age was observed in the CD8 T-cell fraction of the survivors. However, there was no effect of radiation exposure on the number of TRECs in the CD8-T cell fraction. The results indicate the possibility that A-bomb radiation exposure may have induced a long-term impairment in thymic CD4 T-cell production. Further investigations in a larger study population are necessary to test this hypothesis. (author)
Long-term in vivo imaging of multiple organs at the single cell level.

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Benny J Chen

Full Text Available Two-photon microscopy has enabled the study of individual cell behavior in live animals. Many organs and tissues cannot be studied, especially longitudinally, because they are located too deep, behind bony structures or too close to the lung and heart. Here we report a novel mouse model that allows long-term single cell imaging of many organs. A wide variety of live tissues were successfully engrafted in the pinna of the mouse ear. Many of these engrafted tissues maintained the normal tissue histology. Using the heart and thymus as models, we further demonstrated that the engrafted tissues functioned as would be expected. Combining two-photon microscopy with fluorescent tracers, we successfully visualized the engrafted tissues at the single cell level in live mice over several months. Four dimensional (three-dimensional (3D plus time information of individual cells was obtained from this imaging. This model makes long-term high resolution 4D imaging of multiple organs possible.
POPULATION STRUCTURES OF FOUR TREE SPECIES IN LOGGED-OVER TROPICAL FOREST IN SOUTH PAPUA, INDONESIA: AN INTEGRAL PROJECTION MODEL APPROACH

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Relawan kuswandi

2015-12-01

Full Text Available Selective logging has been taking place in Papua for several decades. In contrast, very little is known about the stand structure in post-logged forest. Hence, this paper investigates stand structures in logged-over area of tropical forest in South Papua. Four species were selected in three one-hectare permanent sample plots (PSPs: Vatica rassak, Syzygium sp, Litsea timoriana and Canarium asperum. PSPs were located in the forest concession area of PT. Tunas Sawaerma in Assiki, Boven Digul, in South Papua. Data sets comprised measurements made in 2005 and 2012 consisting of species, diameter at breast height (DBH, mortality and number of tree of each species. Integral Projection Models (IPMs were developed, taking into account mortality, growth, recruitment and fecundity. Results show the pattern of stand structures of the four species were more or less similar, i.e. more individual trees were present in the small diameter classes than in the larger diameter classes. The general pattern of the individual distribution of the four species is the typical reverse-J shape. Syzygium sp. has a greater number of individuals in the small diameter classes than the other three species. Population growth rates (λ are above one, indicating that the stand structures of the population dynamics of the four species are recuperating. Conclusively, these results suggest that species composition and population structure in these logged-over forests are recovering increasingly.
The CEA−/lo colorectal cancer cell population harbors cancer stem cells and metastatic cells

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Zhang, Bo; Mu, Lei; Huang, Kaiyu; Zhao, Hui; Ma, Chensen; Li, Xiaolan; Tao, Deding; Gong, Jianping; Qin, Jichao

2016-01-01

Serum carcinoembryonic antigen (CEA) is the most commonly used tumor marker in a variety of cancers including colorectal cancer (CRC) for tumor diagnosis and monitoring. Recent studies have shown that colonic crypt cells expressing little or no CEA may enrich for stem cells. Numerous studies have clearly shown that there exist CRC patients with normal serum CEA levels during tumor progression or even tumor relapse, although CEA itself is considered to promote metastasis and block cell differentiation. These seemingly contradictory observations prompted us to investigate, herein, the biological properties as well as tumorigenic and metastatic capacity of CRC cells that express high (CEA+) versus low CEA (CEA−/lo) levels of CEA. Our findings show that the abundance of CEA−/lo cells correlate with poor differentiation and poor prognosis, and moreover, CEA−/lo cells form more spheres in vitro, generate more tumors and exhibit a higher potential in developing liver and lung metastases than corresponding CEA+ cells. Applying RNAi-mediated approach, we found that IGF1R mediated tumorigenic and capacity of CEA−/lo cells but did not mediate those of CEA+ cells. Notably, our data demonstrated that CEA molecule was capable of protecting CEA−/lo cells from anoikis, implying that CEA+ cells, although themselves possessing less tumorigenic and metastatic capacity, may promote metastasis of CEA−/lo cells via secreting CEA molecule. Our observations suggest that, besides targeting CEA molecule, CEA−/lo cells may represent a critical source of tumor progression and metastasis, and should therefore be the target of future therapies. PMID:27813496
Comparison of Antidepressant Efficacy-related SNPs Among Taiwanese and Four Populations in the HapMap Database

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Mei-Hung Chi

2011-07-01

Full Text Available The genetic influence of single nucleotide polymorphisms (SNPs on antidepressant efficacy has been previously demonstrated. To evaluate whether there are ethnic differences, we compared the allele frequencies of antidepressant efficacy-related SNPs between the Taiwanese population and four other populations in the HapMap database. We recruited 198 Taiwanese major depression patients and 106 Taiwanese controls. A panel of possible relevant SNPs (in brain-derived neurotrophic factor, 5-hydroxytryptamine receptor 2A, interleukin 1 beta, and G-protein beta 3 subunit genes was selected for comparisons of allele frequencies using the χ2 test. Our results suggested no difference between Taiwanese patients and controls, but there were significant differences among Taiwanese controls and the other four ethnic groups in brain-derived neurotrophic factor, 5-hydroxytryptamine receptor 2A, interleukin 1 beta and G-protein beta 3 subunit genes. We conclude that there are ethnic differences in the allele frequencies of antidepressant efficacy-related SNPs, and that the degree of variations is consistent with geographic distances. Further investigation is required to verify the attribution of genetic differences to ethnic-specific antidepressant responses.
Single Cell Dynamics Causes Pareto-Like Effect in Stimulated T Cell Populations.

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Cosette, Jérémie; Moussy, Alice; Onodi, Fanny; Auffret-Cariou, Adrien; Neildez-Nguyen, Thi My Anh; Paldi, Andras; Stockholm, Daniel

2015-12-09

Cell fate choice during the process of differentiation may obey to deterministic or stochastic rules. In order to discriminate between these two strategies we used time-lapse microscopy of individual murine CD4 + T cells that allows investigating the dynamics of proliferation and fate commitment. We observed highly heterogeneous division and death rates between individual clones resulting in a Pareto-like dominance of a few clones at the end of the experiment. Commitment to the Treg fate was monitored using the expression of a GFP reporter gene under the control of the endogenous Foxp3 promoter. All possible combinations of proliferation and differentiation were observed and resulted in exclusively GFP-, GFP+ or mixed phenotype clones of very different population sizes. We simulated the process of proliferation and differentiation using a simple mathematical model of stochastic decision-making based on the experimentally observed parameters. The simulations show that a stochastic scenario is fully compatible with the observed Pareto-like imbalance in the final population.
Climate change and unequal phenological changes across four trophic levels: constraints or adaptations?

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Both, Christiaan; van Asch, Margriet; Bijlsma, Rob G; van den Burg, Arnold B; Visser, Marcel E

2009-01-01

1. Climate change has been shown to affect the phenology of many organisms, but interestingly these shifts are often unequal across trophic levels, causing a mismatch between the phenology of organisms and their food. 2. We consider two alternative hypotheses: consumers are constrained to adjust sufficiently to the lower trophic level, or prey species react more strongly than their predators to reduce predation. We discuss both hypotheses with our analyses of changes in phenology across four trophic levels: tree budburst, peak biomass of herbivorous caterpillars, breeding phenology of four insectivorous bird species and an avian predator. 3. In our long-term study, we show that between 1988 and 2005, budburst advanced (not significantly) with 0.17 d yr(-1), while between 1985 and 2005 both caterpillars (0.75 d year(-1)) and the hatching date of the passerine species (range for four species: 0.36-0.50 d year(-1)) have advanced, whereas raptor hatching dates showed no trend. 4. The caterpillar peak date was closely correlated with budburst date, as were the passerine hatching dates with the peak caterpillar biomass date. In all these cases, however, the slopes were significantly less than unity, showing that the response of the consumers is weaker than that of their food. This was also true for the avian predator, for which hatching dates were not correlated with the peak availability of fledgling passerines. As a result, the match between food demand and availability deteriorated over time for both the passerines and the avian predators. 5. These results could equally well be explained by consumers' insufficient responses as a consequence of constraints in adapting to climate change, or by them trying to escape predation from a higher trophic level, or both. Selection on phenology could thus be both from matches of phenology with higher and lower levels, and quantifying these can shed new light on why some organisms do adjust their phenology to climate change, while
Metabolic heterogeneity in clonal microbial populations.

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Takhaveev, Vakil; Heinemann, Matthias

2018-02-21

In the past decades, numerous instances of phenotypic diversity were observed in clonal microbial populations, particularly, on the gene expression level. Much less is, however, known about phenotypic differences that occur on the level of metabolism. This is likely explained by the fact that experimental tools probing metabolism of single cells are still at an early stage of development. Here, we review recent exciting discoveries that point out different causes for metabolic heterogeneity within clonal microbial populations. These causes range from ecological factors and cell-inherent dynamics in constant environments to molecular noise in gene expression that propagates into metabolism. Furthermore, we provide an overview of current methods to quantify the levels of metabolites and biomass components in single cells. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.
Microelectromechanical System-Based Sensing Arrays for Comparative in Vitro Nanotoxicity Assessment at Single Cell and Small Cell-Population Using Electrochemical Impedance Spectroscopy.

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Shah, Pratikkumar; Zhu, Xuena; Zhang, Xueji; He, Jin; Li, Chen-zhong

2016-03-09

The traditional in vitro nanotoxicity assessment approaches are conducted on a monolayer of cell culture. However, to study a cell response without interference from the neighbor cells, a single cell study is necessary; especially in cases of neuronal, cancerous, and stem cells, wherein an individual cell's fate is often not explained by the whole cell population. Nonetheless, a single cell does not mimic the actual in vivo environment and lacks important information regarding cell communication with its microenvironment. Both a single cell and a cell population provide important and complementary information about cells' behaviors. In this research, we explored nanotoxicity assessment on a single cell and a small cell population using electrochemical impedance spectroscopy and a microelectromechanical system (MEMS) device. We demonstrated a controlled capture of PC12 cells in different-sized microwells (to capture a different number of cells) using a combined method of surface functionalization and dielectrophoresis. The present approach provides a rapid nanotoxicity response as compared to other conventional approaches. This is the first study, to our knowledge, which demonstrates a comparative response of a single cell and small cell colonies on the same MEMS platform, when exposed to metaloxide nanoparticles. We demonstrated that the microenvironment of a cell is also accountable for cells' behaviors and their responses to nanomaterials. The results of this experimental study open up a new hypothesis to be tested for identifying the role of cell communication in spreading toxicity in a cell population.
Lipid droplet organelle distribution in populations of dividing cells studied by simulation

International Nuclear Information System (INIS)

Dalhaimer, Paul

2013-01-01

One of the key questions in cell biology is how organelles are passed from parent to daughter cells. To help address this question, I used Brownian dynamics to simulate lipid droplets as model organelles in populations of dividing cells. Lipid droplets are dynamic bodies that can form both de novo and by fission, they can also be depleted. The quantitative interplay among these three events is unknown but would seem crucial for controlling droplet distribution in populations of dividing cells. Surprisingly, of the three main events studied: biogenesis, fission, and depletion, the third played the key role in maintaining droplet organelle number—and to a lesser extent volume—in populations of dividing cells where formation events would have seemed paramount. In the case of lipid droplets, this provides computational evidence that they must be sustained, most likely through contacts with the endoplasmic reticulum. The findings also agree with video microscopy experiments over much shorter timescales where droplet depletion in fission yeast cells was not observed. In general, this work shows that organelle maintenance is invaluable and lack thereof cannot necessarily be compensated for by organelle formation. This study provides a time-accurate, physical-based template for long-term cell division studies. (paper)
Lipid droplet organelle distribution in populations of dividing cells studied by simulation

Science.gov (United States)

Dalhaimer, Paul

2013-06-01

One of the key questions in cell biology is how organelles are passed from parent to daughter cells. To help address this question, I used Brownian dynamics to simulate lipid droplets as model organelles in populations of dividing cells. Lipid droplets are dynamic bodies that can form both de novo and by fission, they can also be depleted. The quantitative interplay among these three events is unknown but would seem crucial for controlling droplet distribution in populations of dividing cells. Surprisingly, of the three main events studied: biogenesis, fission, and depletion, the third played the key role in maintaining droplet organelle number—and to a lesser extent volume—in populations of dividing cells where formation events would have seemed paramount. In the case of lipid droplets, this provides computational evidence that they must be sustained, most likely through contacts with the endoplasmic reticulum. The findings also agree with video microscopy experiments over much shorter timescales where droplet depletion in fission yeast cells was not observed. In general, this work shows that organelle maintenance is invaluable and lack thereof cannot necessarily be compensated for by organelle formation. This study provides a time-accurate, physical-based template for long-term cell division studies.
Background matching and camouflage efficiency predict population density in four-eyed turtle (Sacalia quadriocellata).

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Xiao, Fanrong; Yang, Canchao; Shi, Haitao; Wang, Jichao; Sun, Liang; Lin, Liu

2016-10-01

Background matching is an important way to camouflage and is widespread among animals. In the field, however, few studies have addressed background matching, and there has been no reported camouflage efficiency in freshwater turtles. Background matching and camouflage efficiency of the four-eyed turtle, Sacalia quadriocellata, among three microhabitat sections of Hezonggou stream were investigated by measuring carapace components of CIE L*a*b* (International Commission on Illumination; lightness, red/green and yellow/blue) color space, and scoring camouflage efficiency through the use of humans as predators. The results showed that the color difference (ΔE), lightness difference (ΔL(*)), and chroma difference (Δa(*)b(*)) between carapace and the substrate background in midstream were significantly lower than that upstream and downstream, indicating that the four-eyed turtle carapace color most closely matched the substrate of midstream. In line with these findings, the camouflage efficiency was the best for the turtles that inhabit midstream. These results suggest that the four-eyed turtles may enhance camouflage efficiency by selecting microhabitat that best match their carapace color. This finding may explain the high population density of the four-eyed turtle in the midstream section of Hezonggou stream. To the best of our knowledge, this study is among the first to quantify camouflage of freshwater turtles in the wild, laying the groundwork to further study the function and mechanisms of turtle camouflage. Copyright © 2016. Published by Elsevier B.V.
Host–virus dynamics and subcellular controls of cell fate in a natural coccolithophore population

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Vardi, Assaf; Haramaty, Liti; Van Mooy, Benjamin A. S.; Fredricks, Helen F.; Kimmance, Susan A.; Larsen, Aud; Bidle, Kay D.

2012-01-01

Marine viruses are major evolutionary and biogeochemical drivers in marine microbial foodwebs. However, an in-depth understanding of the cellular mechanisms and the signal transduction pathways mediating host–virus interactions during natural bloom dynamics has remained elusive. We used field-based mesocosms to examine the “arms race” between natural populations of the coccolithophore Emiliania huxleyi and its double-stranded DNA-containing coccolithoviruses (EhVs). Specifically, we examined the dynamics of EhV infection and its regulation of cell fate over the course of bloom development and demise using a diverse suite of molecular tools and in situ fluorescent staining to target different levels of subcellular resolution. We demonstrate the concomitant induction of reactive oxygen species, caspase-specific activity, metacaspase expression, and programmed cell death in response to the accumulation of virus-derived glycosphingolipids upon infection of natural E. huxleyi populations. These subcellular responses to viral infection simultaneously resulted in the enhanced production of transparent exopolymer particles, which can facilitate aggregation and stimulate carbon flux. Our results not only corroborate the critical role for glycosphingolipids and programmed cell death in regulating E. huxleyi–EhV interactions, but also elucidate promising molecular biomarkers and lipid-based proxies for phytoplankton host–virus interactions in natural systems. PMID:23134731
Kinetics of granulocytic and erythroid progenitor cells are affected differently by short-term, low-level benzene exposure

Energy Technology Data Exchange (ETDEWEB)

Dempster, A.M.; Snyder, C.A. (New York Univ. Medical Center, NY (United States). Inst. of Environmental Medicine)

1991-09-01

Mice were exposed to either air or 10 ppm benzene for 6 h/d X 5 d. Immediately after the last exposure, mice were injected, i.v., with either saline or hydroxyurea (HU). The dose of HU was sufficient to kill hematopoietic cells in or near S-phase of the cell cycle and sufficient to synchronize the surviving populations of hematopoietic cells. Three days after benzene exposure, CFU-E numbers had declined to 50% of control values while CFU-GM numbers were equal to control values at this time. The benzene exposures were sufficient to double the percentage of CFU-E in S-phase but produced no such increase among CFU-Gm. During 3 days of recovery from benzene exposure and HU treatment, the CFU-E population expanded 30-fold while the CFU-GM population expanded less than 3-fold. Following benzene exposure and HU treatment, both progenitor cells produced elevated numbers of their respective progeny. When CFU-E from benzene-exposed mice were cultured with varying concentrations of erythropoietin (EPO), the response at maximal EPO concentration was 66% of the response by control CFU-E. This strongly suggests that the CFU-E populations from benzene-exposed mice had been depleted of cells in or near S-phase. The results indicate that CFU-GM respond to low-level benzene exposure by increasing their rate of differentiation but not their rate of proliferation, while CFU-E respond by increasing both their rates of differentiation and proliferation. We speculate that it is the increase in CFU-E proliferation that renders these cells more susceptible to benzene than their granulocytic counterparts, especially those CFU-E at or near the S-phase of the cell cycle. (orig.).
Mandibulary dental arch form differences between level four polynomial method and pentamorphic pattern for normal occlusion sample

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Y. Yuliana

2011-07-01

Full Text Available The aim of an orthodontic treatment is to achieve aesthetic, dental health and the surrounding tissues, occlusal functional relationship, and stability. The success of an orthodontic treatment is influenced by many factors, such as diagnosis and treatment plan. In order to do a diagnosis and a treatment plan, medical record, clinical examination, radiographic examination, extra oral and intra oral photos, as well as study model analysis are needed. The purpose of this study was to evaluate the differences in dental arch form between level four polynomial and pentamorphic arch form and to determine which one is best suitable for normal occlusion sample. This analytic comparative study was conducted at Faculty of Dentistry Universitas Padjadjaran on 13 models by comparing the dental arch form using the level four polynomial method based on mathematical calculations, the pattern of the pentamorphic arch and mandibular normal occlusion as a control. The results obtained were tested using statistical analysis T student test. The results indicate a significant difference both in the form of level four polynomial method and pentamorphic arch form when compared with mandibular normal occlusion dental arch form. Level four polynomial fits better, compare to pentamorphic arch form.
Surface-water hydrology and quality, and macroinvertebrate and smallmouth bass populations in four stream basins in southwestern Wisconsin, 1987-90

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Graczyk, David J.; Lillie, Richard A.; Schlesser, Roger A.; Mason, John W.; Lyons, John D.; Kerr, Roger A.; Graczyk, David J.

1993-01-01

Data on streamflow, water quality, and macroinvertebrate and smallmouth bass (microptercus dolomieni) populations were collected from July 1987 through September 1990, in four streams in southwestern Wisconsin to determine the effect of surface-water hydrology and quality on populations of macroinvertebrates and smallmouth bass. The study was a joint project of the U.S. Geological Survey and the Wisconsin Department of Natural Resources.

Immune cell distribution and immunoglobulin levels change following sciatic nerve injury in a rat model

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Wei Yuan

2016-07-01

Full Text Available Objective(s: To investigate the systemic and local immune status of two surgical rat models of sciatic nerve injury, a crushed sciatic nerve, and a sciatic nerve transection Materials and Methods:Twenty-four adult male Sprague-Dawley rats were randomly divided into three groups: sham-operation (control group, sciatic nerve crush, and sciatic nerve transaction. Sciatic nerve surgery was performed. The percentage of CD4+ cells and the CD4+/CD8+ratio were determined by flow cytometry. Serum IgM and IgG levels were analyzed by ELISA. T-cells (CD3 and macrophages (CD68 in sciatic nerve tissue sections were identified through immunohistochemistry. Results: Compared to sham-operated controls, in rats that underwent nerve injury, the percentage of CD4+ cells and the CD4+/CD8+ ratio in the peripheral blood were significantly decreased 7 days after surgery, serum IgM levels were increased 14 days after surgery, and serum IgG levels were increased 21 days after surgery. There were a large number of CD3+ cells and a small number of CD68+ cells in sciatic nerve tissue sections 21 days after surgery, indicating T-cell and macrophage activation and infiltration. Local IgG deposition was also detected at the nerve injury site 21 days after surgery. Conclusion: Rat humoral and cellular immune status changed following sciatic nerve injury, particularly with regard to the cellular immune response at the nerve injury site.
TERRA Expression Levels Do Not Correlate With Telomere Length and Radiation Sensitivity in Human Cancer Cell Lines

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Alexandra eSmirnova

2013-05-01

Full Text Available Mammalian telomeres are transcribed into long non-coding telomeric RNA molecules (TERRA that seem to play a role in the maintenance of telomere stability. In human cells, CpG island promoters drive TERRA transcription and are regulated by methylation. It was suggested that the amount of TERRA may be related to telomere length. To test this hypothesis we measured telomere length and TERRA levels in single clones isolated from five human cell lines: HeLa (cervical carcinoma, BRC-230 (breast cancer, AKG and GK2 (gastric cancers and GM847 (SV40 immortalized skin fibroblasts. We observed great clonal heterogeneity both in TRF (Terminal Restriction Fragment length and in TERRA levels. However, these two parameters did not correlate with each other. Moreover, cell survival to γ-rays did not show a significant variation among the clones, suggesting that, in this cellular system, the intra-population variability in telomere length and TERRA levels does not influence sensitivity to ionizing radiation. This conclusion was supported by the observation that in a cell line in which telomeres were greatly elongated by the ectopic expression of telomerase, TERRA expression levels and radiation sensitivity were similar to the parental HeLa cell line.
Different cellular effects of four anti-inflammatory eye drops on human corneal epithelial cells: independent in active components.

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Qu, Mingli; Wang, Yao; Yang, Lingling; Zhou, Qingjun

2011-01-01

To evaluate and compare the cellular effects of four commercially available anti-inflammatory eye drops and their active components on human corneal epithelial cells (HCECs) in vitro. The cellular effects of four eye drops (Bromfenac Sodium Hydrate Eye Drops, Pranoprofen Eye Drops, Diclofenac Sodium Eye Drops, and Tobramycin & Dex Eye Drops) and their corresponding active components were evaluated in an HCEC line with five in vitro assays. Cell proliferation and migration were measured using 3-(4,5)-dimethylthiahiazo (-z-y1)-3 5-di-phenytetrazoliumromide (MTT) assay and transwell migration assay. Cell damage was determined with the lactate dehydrogenase (LDH) assay. Cell viability and median lethal time (LT₅₀) were measured by 7-amino-actinomycin D (7-AAD) staining and flow cytometry analysis. Cellular effects after exposure of HCECs to the four anti-inflammatory eye drops were concentration dependent. The differences of cellular toxicity on cell proliferation became significant at lower concentrations (Eye Drops showed significant increasing effects on cell damage and viability when compared with the other three solutions. Tobramycin & Dex Eye Drops inhibited the migration of HCECs significantly. Tobramycin & Dex Eye Drops showed the quickest effect on cell viability: the LT₅₀ was 3.28, 9.23, 10.38, and 23.80 min for Tobramycin & Dex Eye Drops, Diclofenac Sodium Eye Drops, Pranoprofen Eye Drops, and Bromfenac Sodium Hydrate Eye Drops, respectively. However, the comparisons of cellular toxicity revealed significant differences between the eye drops and their active components under the same concentration. The corneal epithelial toxicity differences among the active components of the four eye drops became significant as higher concentration (>0.020%). The four anti-inflammatory eye drops showed different cellular effects on HCECs, and the toxicity was not related with their active components, which provides new reference for the clinical application and drug
Generational distribution of a Candida glabrata population: Resilient old cells prevail, while younger cells dominate in the vulnerable host.

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Bouklas, Tejas; Alonso-Crisóstomo, Luz; Székely, Tamás; Diago-Navarro, Elizabeth; Orner, Erika P; Smith, Kalie; Munshi, Mansa A; Del Poeta, Maurizio; Balázsi, Gábor; Fries, Bettina C

2017-05-01

Similar to other yeasts, the human pathogen Candida glabrata ages when it undergoes asymmetric, finite cell divisions, which determines its replicative lifespan. We sought to investigate if and how aging changes resilience of C. glabrata populations in the host environment. Our data demonstrate that old C. glabrata are more resistant to hydrogen peroxide and neutrophil killing, whereas young cells adhere better to epithelial cell layers. Consequently, virulence of old compared to younger C. glabrata cells is enhanced in the Galleria mellonella infection model. Electron microscopy images of old C. glabrata cells indicate a marked increase in cell wall thickness. Comparison of transcriptomes of old and young C. glabrata cells reveals differential regulation of ergosterol and Hog pathway associated genes as well as adhesion proteins, and suggests that aging is accompanied by remodeling of the fungal cell wall. Biochemical analysis supports this conclusion as older cells exhibit a qualitatively different lipid composition, leading to the observed increased emergence of fluconazole resistance when grown in the presence of fluconazole selection pressure. Older C. glabrata cells accumulate during murine and human infection, which is statistically unlikely without very strong selection. Therefore, we tested the hypothesis that neutrophils constitute the predominant selection pressure in vivo. When we altered experimentally the selection pressure by antibody-mediated removal of neutrophils, we observed a significantly younger pathogen population in mice. Mathematical modeling confirmed that differential selection of older cells is sufficient to cause the observed demographic shift in the fungal population. Hence our data support the concept that pathogenesis is affected by the generational age distribution of the infecting C. glabrata population in a host. We conclude that replicative aging constitutes an emerging trait, which is selected by the host and may even play an
Dielectrophoretic capture of low abundance cell population using thick electrodes

OpenAIRE

Marchalot, Julien; Chateaux, Jean-François; Faivre, Magalie; Mertani, Hichem C.; Ferrigno, Rosaria; Deman, Anne-Laure

2015-01-01

Enrichment of rare cell populations such as Circulating Tumor Cells (CTCs) is a critical step before performing analysis. This paper presents a polymeric microfluidic device with integrated thick Carbon-PolyDimethylSiloxane composite (C-PDMS) electrodes designed to carry out dielectrophoretic (DEP) trapping of low abundance biological cells. Such conductive composite material presents advantages over metallic structures. Indeed, as it combines properties of both the matrix and doping particle...
Assessment of genetic variation among four populations of Small ...

African Journals Online (AJOL)

From the findings, it can be concluded that the SEA goats in this study showed high in population genetic variation, which implies that there is good scope for their further improvement through selection within populations. The Sukuma population, which has fairly high inbreeding, is moderately differentiated from Pare, Sonjo ...
Functional heterogeneity of side population cells in skeletal muscle

International Nuclear Information System (INIS)

Uezumi, Akiyoshi; Ojima, Koichi; Fukada, So-ichiro; Ikemoto, Madoka; Masuda, Satoru; Miyagoe-Suzuki, Yuko; Takeda, Shin'ichi

2006-01-01

Skeletal muscle regeneration has been exclusively attributed to myogenic precursors, satellite cells. A stem cell-rich fraction referred to as side population (SP) cells also resides in skeletal muscle, but its roles in muscle regeneration remain unclear. We found that muscle SP cells could be subdivided into three sub-fractions using CD31 and CD45 markers. The majority of SP cells in normal non-regenerating muscle expressed CD31 and had endothelial characteristics. However, CD31 - CD45 - SP cells, which are a minor subpopulation in normal muscle, actively proliferated upon muscle injury and expressed not only several regulatory genes for muscle regeneration but also some mesenchymal lineage markers. CD31 - CD45 - SP cells showed the greatest myogenic potential among three SP sub-fractions, but indeed revealed mesenchymal potentials in vitro. These SP cells preferentially differentiated into myofibers after intramuscular transplantation in vivo. Our results revealed the heterogeneity of muscle SP cells and suggest that CD31 - CD45 - SP cells participate in muscle regeneration
The osteo-inductive activity of bone-marrow-derived mononuclear cells resides within the CD14+ population and is independent of the CD34+ population.

Science.gov (United States)

Henrich, D; Seebach, C; Verboket, R; Schaible, A; Marzi, I; Bonig, H

2018-03-06

Bone marrow mononuclear cells (BMC) seeded on a scaffold of β-tricalcium phosphate (β-TCP) promote bone healing in a critical-size femur defect model. Being BMC a mixed population of predominantly mature haematopoietic cells, which cell type(s) is(are) instrumental for healing remains elusive. Although clinical therapies using BMC are often dubbed as stem cell therapies, whether stem cells are relevant for the therapeutic effects is unclear and, at least in the context of bone repair, seems dubious. Instead, in light of the critical contribution of monocytes and macrophages to tissue development, homeostasis and injury repair, in the current study it was hypothesised that BMC-mediated bone healing derived from the stem cell population. To test this hypothesis, bone remodelling studies were performed in an established athymic rats critical-size femoral defect model, with β-TCP scaffolds augmented with complete BMC or BMC immunomagnetically depleted of stem cells (CD34+) or monocytes/macrophages (CD14+). Bone healing was assessed 8 weeks after transplantation. Compared to BMC-augmented controls, when CD14- BMC, but not CD34- BMC were transplanted into the bone defect, femora possessed dramatically decreased biomechanical stability and new bone formation was markedly reduced, as measured by histology. The degree of vascularisation did not differ between the two groups. It was concluded that the monocyte fraction within the BMC provided critical osteo-inductive cues during fracture healing. Which factors were responsible at the molecular levels remained elusive. However, this study marked a significant progress towards elucidating the mechanisms by which BMC elicit their therapeutic effects, at least in bone regeneration.
Individual and population level effects of partner notification for Chlamydia trachomatis.

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Christian L Althaus

Full Text Available Partner notification (PN or contact tracing is an important aspect of treating bacterial sexually transmitted infections (STIs, such as Chlamydia trachomatis. It facilitates the identification of new infected cases that can be treated through individual case management. PN also acts indirectly by limiting onward transmission in the general population. However, the impact of PN, both at the level of individuals and the population, remains unclear. Since it is difficult to study the effects of PN empirically, mathematical and computational models are useful tools for investigating its potential as a public health intervention. To this end, we developed an individual-based modeling framework called Rstisim. It allows the implementation of different models of STI transmission with various levels of complexity and the reconstruction of the complete dynamic sexual partnership network over any time period. A key feature of this framework is that we can trace an individual's partnership history in detail and investigate the outcome of different PN strategies for C. trachomatis. For individual case management, the results suggest that notifying three or more partners from the preceding 18 months yields substantial numbers of new cases. In contrast, the successful treatment of current partners is most important for preventing re-infection of index cases and reducing further transmission of C. trachomatis at the population level. The findings of this study demonstrate the difference between individual and population level outcomes of public health interventions for STIs.
I Want More and Better Cells! - An Outreach Project about Stem Cells and Its Impact on the General Population.

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Varela Amaral, Sara; Forte, Teresa; Ramalho-Santos, João; Girão da Cruz, M Teresa

2015-01-01

Although science and technology impact every aspect of modern societies, there is still an extensive gap between science and society, which impairs the full exercise of citizenship. In the particular case of biomedical research increased investment should be accompanied by parallel efforts in terms of public information and engagement. We have carried out a project involving the production and evaluation of educational contents focused on stem cells - illustrated newspaper chronicles, radio interviews, a comic book, and animated videos - and monitored their impact on the Portuguese population. The study of the outreach materials in a heterogeneous sample of the population suggests that they are valuable tools to disseminate scientific messages, and that this is especially true for the comic-book format. Furthermore, the data showed that clear and stimulating outreach materials, that are able to teach new concepts and to promote critical thinking, increase engagement in science at different levels, depending on the depth of the concepts involved. Additionally, these materials can influence political, social and personal attitudes toward science. These results, together with the importance attributed to scientific research in stem cells by the population sampled, validates the diffusion of such materials as a significant contribution towards an overall public understanding and engagement in contemporary science, and this strategy should thus be considered in future projects. Regardless, stringent quality control must be implemented in order to efficiently communicate accurate scientific developments, and the public stimulated in terms of finding additional sources of reliable information.
Identification and clonal characterisation of a progenitor cell sub-population in normal human articular cartilage.

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Rebecca Williams

Full Text Available BACKGROUND: Articular cartilage displays a poor repair capacity. The aim of cell-based therapies for cartilage defects is to repair damaged joint surfaces with a functional replacement tissue. Currently, chondrocytes removed from a healthy region of the cartilage are used but they are unable to retain their phenotype in expanded culture. The resulting repair tissue is fibrocartilaginous rather than hyaline, potentially compromising long-term repair. Mesenchymal stem cells, particularly bone marrow stromal cells (BMSC, are of interest for cartilage repair due to their inherent replicative potential. However, chondrocyte differentiated BMSCs display an endochondral phenotype, that is, can terminally differentiate and form a calcified matrix, leading to failure in long-term defect repair. Here, we investigate the isolation and characterisation of a human cartilage progenitor population that is resident within permanent adult articular cartilage. METHODS AND FINDINGS: Human articular cartilage samples were digested and clonal populations isolated using a differential adhesion assay to fibronectin. Clonal cell lines were expanded in growth media to high population doublings and karyotype analysis performed. We present data to show that this cell population demonstrates a restricted differential potential during chondrogenic induction in a 3D pellet culture system. Furthermore, evidence of high telomerase activity and maintenance of telomere length, characteristic of a mesenchymal stem cell population, were observed in this clonal cell population. Lastly, as proof of principle, we carried out a pilot repair study in a goat in vivo model demonstrating the ability of goat cartilage progenitors to form a cartilage-like repair tissue in a chondral defect. CONCLUSIONS: In conclusion, we propose that we have identified and characterised a novel cartilage progenitor population resident in human articular cartilage which will greatly benefit future cell
Screening of Chlamydomonas reinhardtii Populations with Single-Cell Resolution by Using a High-Throughput Microscale Sample Preparation for Matrix-Assisted Laser Desorption Ionization Mass Spectrometry.

Science.gov (United States)

Krismer, Jasmin; Sobek, Jens; Steinhoff, Robert F; Fagerer, Stephan R; Pabst, Martin; Zenobi, Renato

2015-08-15

The consequences of cellular heterogeneity, such as biocide persistence, can only be tackled by studying each individual in a cell population. Fluorescent tags provide tools for the high-throughput analysis of genomes, RNA transcripts, or proteins on the single-cell level. However, the analysis of lower-molecular-weight compounds that elude tagging is still a great challenge. Here, we describe a novel high-throughput microscale sample preparation technique for single cells that allows a mass spectrum to be obtained for each individual cell within a microbial population. The approach presented includes spotting Chlamydomonas reinhardtii cells, using a noncontact microarrayer, onto a specialized slide and controlled lysis of cells separated on the slide. Throughout the sample preparation, analytes were traced and individual steps optimized using autofluorescence detection of chlorophyll. The lysates of isolated cells are subjected to a direct, label-free analysis using matrix-assisted laser desorption ionization mass spectrometry. Thus, we were able to differentiate individual cells of two Chlamydomonas reinhardtii strains based on single-cell mass spectra. Furthermore, we showed that only population profiles with real single-cell resolution render a nondistorted picture of the phenotypes contained in a population. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
Hair mercury levels in Amazonian populations: spatial distribution and trends

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Barbieri Flavia L

2009-12-01

Full Text Available Abstract Background Mercury is present in the Amazonian aquatic environments from both natural and anthropogenic sources. As a consequence, many riverside populations are exposed to methylmercury, a highly toxic organic form of mercury, because of their intense fish consumption. Many studies have analysed this exposure from different approaches since the early nineties. This review aims to systematize the information in spatial distribution, comparing hair mercury levels by studied population and Amazonian river basin, looking for exposure trends. Methods The reviewed papers were selected from scientific databases and online libraries. We included studies with a direct measure of hair mercury concentrations in a sample size larger than 10 people, without considering the objectives, approach of the study or mercury speciation. The results are presented in tables and maps by river basin, displaying hair mercury levels and specifying the studied population and health impact, if any. Results The majority of the studies have been carried out in communities from the central Amazonian regions, particularly on the Tapajós River basin. The results seem quite variable; hair mercury means range from 1.1 to 34.2 μg/g. Most studies did not show any significant difference in hair mercury levels by gender or age. Overall, authors emphasized fish consumption frequency as the main risk factor of exposure. The most studied adverse health effect is by far the neurological performance, especially motricity. However, it is not possible to conclude on the relation between hair mercury levels and health impact in the Amazonian situation because of the relatively small number of studies. Conclusions Hair mercury levels in the Amazonian regions seem to be very heterogenic, depending on several factors. There is no obvious spatial trend and there are many areas that have never been studied. Taking into account the low mercury levels currently handled as acceptable, the
Toxicity of selenite in the unicellular green alga Chlamydomonas reinhardtii: Comparison between effects at the population and sub-cellular level

International Nuclear Information System (INIS)

Morlon, Helene; Fortin, Claude; Floriani, Magali; Adam, Christelle; Garnier-Laplace, Jacqueline; Boudou, Alain

2005-01-01

The toxicity of selenium in aquatic ecosystems is mainly linked to its uptake and biotransformation by micro-organisms, and its subsequent transfer upwards into the food chain. Thus, organisms at low trophic level, such as algae, play a crucial role. The aim of our study was to investigate the biological effects of selenite on Chlamydomonas reinhardtii, both at the sub-cellular level (effect on ultrastructure) and at the population level (effect on growth). The cells were grown under batch culture conditions in well-defined media and exposed to waterborne selenite at concentrations up to 500 μM; i.e. up to lethal conditions. Based on the relationship between Se concentration and cell density achieved after a 96 h exposure period, an EC 50 of 80 μM with a 95% confidence interval ranging between 64 and 98 μM was derived. No adaptation mechanisms were observed: the same toxicity was quantified for algae pre-contaminated with Se. The inhibition of growth was linked to impairments observed at the sub-cellular level. The intensity of the ultrastructural damages caused by selenite exposure depended on the level and duration of exposure. Observations by TEM suggested chloroplasts as the first target of selenite cytotoxicity, with effects on the stroma, thylakoids and pyrenoids. At higher concentrations, we could observe an increase in the number and volume of starch grains. For cells collected at 96 h, electron-dense granules were observed. Energy-dispersive X-ray microanalysis revealed that these granules contained selenium and were also rich in calcium and phosphorus. This study confirms that the direct toxicity of selenite on the phytoplankton biomass is not likely to take place at concentrations found in the environment. At higher concentrations, the link between effects at the sub-cellular and population levels, the over-accumulation of starch, and the formation of dense granules containing selenium are reported for the first time in the literature for a
From invasion to latency: intracellular noise and cell motility as key controls of the competition between resource-limited cellular populations

KAUST Repository

Guerrero, Pilar; Byrne, Helen M.; Maini, Philip K.; Alarcó n, Tomá s

2015-01-01

© 2015, Springer-Verlag Berlin Heidelberg. In this paper we analyse stochastic models of the competition between two resource-limited cell populations which differ in their response to nutrient availability: the resident population exhibits a switch-like response behaviour while the invading population exhibits a bistable response. We investigate how noise in the intracellular regulatory pathways and cell motility influence the fate of the incumbent and invading populations. We focus initially on a spatially homogeneous system and study in detail the role of intracellular noise. We show that in such well-mixed systems, two distinct regimes exist: In the low (intracellular) noise limit, the invader has the ability to invade the resident population, whereas in the high noise regime competition between the two populations is found to be neutral and, in accordance with neutral evolution theory, invasion is a random event. Careful examination of the system dynamics leads us to conclude that (i) even if the invader is unable to invade, the distribution of survival times, PS(t), has a fat-tail behaviour (PS(t)∼t-1) which implies that small colonies of mutants can coexist with the resident population for arbitrarily long times, and (ii) the bistable structure of the invading population increases the stability of the latent population, thus increasing their long-term likelihood of survival, by decreasing the intensity of the noise at the population level. We also examine the effects of spatial inhomogeneity. In the low noise limit we find that cell motility is positively correlated with the aggressiveness of the invader as defined by the time the invader takes to invade the resident population: the faster the invasion, the more aggressive the invader.
From invasion to latency: intracellular noise and cell motility as key controls of the competition between resource-limited cellular populations

KAUST Repository

Guerrero, Pilar

2015-04-02

© 2015, Springer-Verlag Berlin Heidelberg. In this paper we analyse stochastic models of the competition between two resource-limited cell populations which differ in their response to nutrient availability: the resident population exhibits a switch-like response behaviour while the invading population exhibits a bistable response. We investigate how noise in the intracellular regulatory pathways and cell motility influence the fate of the incumbent and invading populations. We focus initially on a spatially homogeneous system and study in detail the role of intracellular noise. We show that in such well-mixed systems, two distinct regimes exist: In the low (intracellular) noise limit, the invader has the ability to invade the resident population, whereas in the high noise regime competition between the two populations is found to be neutral and, in accordance with neutral evolution theory, invasion is a random event. Careful examination of the system dynamics leads us to conclude that (i) even if the invader is unable to invade, the distribution of survival times, PS(t), has a fat-tail behaviour (PS(t)∼t-1) which implies that small colonies of mutants can coexist with the resident population for arbitrarily long times, and (ii) the bistable structure of the invading population increases the stability of the latent population, thus increasing their long-term likelihood of survival, by decreasing the intensity of the noise at the population level. We also examine the effects of spatial inhomogeneity. In the low noise limit we find that cell motility is positively correlated with the aggressiveness of the invader as defined by the time the invader takes to invade the resident population: the faster the invasion, the more aggressive the invader.
Genome-wide association study for levels of total serum IgE identifies HLA-C in a Japanese population.

Directory of Open Access Journals (Sweden)

Yohei Yatagai

Full Text Available Most of the previously reported loci for total immunoglobulin E (IgE levels are related to Th2 cell-dependent pathways. We undertook a genome-wide association study (GWAS to identify genetic loci responsible for IgE regulation. A total of 479,940 single nucleotide polymorphisms (SNPs were tested for association with total serum IgE levels in 1180 Japanese adults. Fine-mapping with SNP imputation demonstrated 6 candidate regions: the PYHIN1/IFI16, MHC classes I and II, LEMD2, GRAMD1B, and chr13∶60576338 regions. Replication of these candidate loci in each region was assessed in 2 independent Japanese cohorts (n = 1110 and 1364, respectively. SNP rs3130941 in the HLA-C region was consistently associated with total IgE levels in 3 independent populations, and the meta-analysis yielded genome-wide significance (P = 1.07×10(-10. Using our GWAS results, we also assessed the reproducibility of previously reported gene associations with total IgE levels. Nine of 32 candidate genes identified by a literature search were associated with total IgE levels after correction for multiple testing. Our findings demonstrate that SNPs in the HLA-C region are strongly associated with total serum IgE levels in the Japanese population and that some of the previously reported genetic associations are replicated across ethnic groups.
Observation of inverted population levels in the FM-1 Spherator

International Nuclear Information System (INIS)

Suckewer, S.; Hawryluk, R.J.; Okabayashi, M.; Schmidt, J.A.

1976-04-01

Inversions in the populations of excited levels in hydrogen and HeII were observed in the FM-1 Spherator. The inversion increases strongly as the ratio of the decay time of the electron temperature to the decay time of the electron density was decreased. Time dependent numerical calculations of the populations were in good agreement with the experimental measurements. More general calculations for high Z hydrogen-like ions are discussed
Interval scanning photomicrography of microbial cell populations.

Science.gov (United States)

Casida, L. E., Jr.

1972-01-01

A single reproducible area of the preparation in a fixed focal plane is photographically scanned at intervals during incubation. The procedure can be used for evaluating the aerobic or anaerobic growth of many microbial cells simultaneously within a population. In addition, the microscope is not restricted to the viewing of any one microculture preparation, since the slide cultures are incubated separately from the microscope.
A multicenter study to standardize reporting and analyses of fluorescence-activated cell-sorted murine intestinal epithelial cells

Science.gov (United States)

Magness, Scott T.; Puthoff, Brent J.; Crissey, Mary Ann; Dunn, James; Henning, Susan J.; Houchen, Courtney; Kaddis, John S.; Kuo, Calvin J.; Li, Linheng; Lynch, John; Martin, Martin G.; May, Randal; Niland, Joyce C.; Olack, Barbara; Qian, Dajun; Stelzner, Matthias; Swain, John R.; Wang, Fengchao; Wang, Jiafang; Wang, Xinwei; Yan, Kelley; Yu, Jian

2013-01-01

Fluorescence-activated cell sorting (FACS) is an essential tool for studies requiring isolation of distinct intestinal epithelial cell populations. Inconsistent or lack of reporting of the critical parameters associated with FACS methodologies has complicated interpretation, comparison, and reproduction of important findings. To address this problem a comprehensive multicenter study was designed to develop guidelines that limit experimental and data reporting variability and provide a foundation for accurate comparison of data between studies. Common methodologies and data reporting protocols for tissue dissociation, cell yield, cell viability, FACS, and postsort purity were established. Seven centers tested the standardized methods by FACS-isolating a specific crypt-based epithelial population (EpCAM+/CD44+) from murine small intestine. Genetic biomarkers for stem/progenitor (Lgr5 and Atoh 1) and differentiated cell lineages (lysozyme, mucin2, chromogranin A, and sucrase isomaltase) were interrogated in target and control populations to assess intra- and intercenter variability. Wilcoxon's rank sum test on gene expression levels showed limited intracenter variability between biological replicates. Principal component analysis demonstrated significant intercenter reproducibility among four centers. Analysis of data collected by standardized cell isolation methods and data reporting requirements readily identified methodological problems, indicating that standard reporting parameters facilitate post hoc error identification. These results indicate that the complexity of FACS isolation of target intestinal epithelial populations can be highly reproducible between biological replicates and different institutions by adherence to common cell isolation methods and FACS gating strategies. This study can be considered a foundation for continued method development and a starting point for investigators that are developing cell isolation expertise to study physiology and

Human Peripheral Blood Mononuclear Cells Exhibit Heterogeneous CD52 Expression Levels and Show Differential Sensitivity to Alemtuzumab Mediated Cytolysis

Science.gov (United States)

Rao, Sambasiva P.; Sancho, Jose; Campos-Rivera, Juanita; Boutin, Paula M.; Severy, Peter B.; Weeden, Timothy; Shankara, Srinivas; Roberts, Bruce L.; Kaplan, Johanne M.

2012-01-01

Alemtuzumab is a monoclonal antibody that targets cell surface CD52 and is effective in depleting lymphocytes by cytolytic effects in vivo. Although the cytolytic effects of alemtuzumab are dependent on the density of CD52 antigen on cells, there is scant information regarding the expression levels of CD52 on different cell types. In this study, CD52 expression was assessed on phenotypically distinct subsets of lymphoid and myeloid cells in peripheral blood mononuclear cells (PBMCs) from normal donors. Results demonstrate that subsets of PBMCs express differing levels of CD52. Quantitative analysis showed that memory B cells and myeloid dendritic cells (mDCs) display the highest number while natural killer (NK) cells, plasmacytoid dendritic cells (pDCs) and basophils have the lowest number of CD52 molecules per cell amongst lymphoid and myeloid cell populations respectively. Results of complement dependent cytolysis (CDC) studies indicated that alemtuzumab mediated profound cytolytic effects on B and T cells with minimal effect on NK cells, basophils and pDCs, correlating with the density of CD52 on these cells. Interestingly, despite high CD52 levels, mDCs and monocytes were less susceptible to alemtuzumab-mediated CDC indicating that antigen density alone does not define susceptibility. Additional studies indicated that higher expression levels of complement inhibitory proteins (CIPs) on these cells partially contributes to their resistance to alemtuzumab mediated CDC. These results indicate that alemtuzumab is most effective in depleting cells of the adaptive immune system while leaving innate immune cells relatively intact. PMID:22761788
Human peripheral blood mononuclear cells exhibit heterogeneous CD52 expression levels and show differential sensitivity to alemtuzumab mediated cytolysis.

Directory of Open Access Journals (Sweden)

Sambasiva P Rao

Full Text Available Alemtuzumab is a monoclonal antibody that targets cell surface CD52 and is effective in depleting lymphocytes by cytolytic effects in vivo. Although the cytolytic effects of alemtuzumab are dependent on the density of CD52 antigen on cells, there is scant information regarding the expression levels of CD52 on different cell types. In this study, CD52 expression was assessed on phenotypically distinct subsets of lymphoid and myeloid cells in peripheral blood mononuclear cells (PBMCs from normal donors. Results demonstrate that subsets of PBMCs express differing levels of CD52. Quantitative analysis showed that memory B cells and myeloid dendritic cells (mDCs display the highest number while natural killer (NK cells, plasmacytoid dendritic cells (pDCs and basophils have the lowest number of CD52 molecules per cell amongst lymphoid and myeloid cell populations respectively. Results of complement dependent cytolysis (CDC studies indicated that alemtuzumab mediated profound cytolytic effects on B and T cells with minimal effect on NK cells, basophils and pDCs, correlating with the density of CD52 on these cells. Interestingly, despite high CD52 levels, mDCs and monocytes were less susceptible to alemtuzumab-mediated CDC indicating that antigen density alone does not define susceptibility. Additional studies indicated that higher expression levels of complement inhibitory proteins (CIPs on these cells partially contributes to their resistance to alemtuzumab mediated CDC. These results indicate that alemtuzumab is most effective in depleting cells of the adaptive immune system while leaving innate immune cells relatively intact.
Efficient cooling of quantized vibrations using a four-level configuration

Science.gov (United States)

Yan, Lei-Lei; Zhang, Jian-Qi; Zhang, Shuo; Feng, Mang

2016-12-01

Cooling vibrational degrees of freedom down to ground states is essential to observation of quantum properties of systems with mechanical vibration. We propose two cooling schemes employing four internal levels of the systems, which achieve the ground-state cooling in an efficient fashion by completely deleting the carrier and first-order blue-sideband transitions. The schemes, based on quantum interference and Stark-shift gates, are robust to fluctuations of laser intensity and frequency. The feasibility of the schemes is justified using current laboratory technology. In practice, our proposal readily applies to a nanodiamond nitrogen-vacancy center levitated in an optical trap or attached to a cantilever.
The validity and reliability of the four square step test in different adult populations: a systematic review.

Science.gov (United States)

Moore, Martha; Barker, Karen

2017-09-11

The four square step test (FSST) was first validated in healthy older adults to provide a measure of dynamic standing balance and mobility. The FSST has since been used in a variety of patient populations. The purpose of this systematic review is to determine the validity and reliability of the FSST in these different adult patient populations. The literature search was conducted to highlight all the studies that measured validity and reliability of the FSST. Six electronic databases were searched including AMED, CINAHL, MEDLINE, PEDro, Web of Science and Google Scholar. Grey literature was also searched for any documents relevant to the review. Two independent reviewers carried out study selection and quality assessment. The methodological quality was assessed using the QUADAS-2 tool, which is a validated tool for the quality assessment of diagnostic accuracy studies, and the COSMIN four-point checklist, which contains standards for evaluating reliability studies on the measurement properties of health instruments. Fifteen studies were reviewed studying community-dwelling older adults, Parkinson's disease, Huntington's disease, multiple sclerosis, vestibular disorders, post stroke, post unilateral transtibial amputation, knee pain and hip osteoarthritis. Three of the studies were of moderate methodological quality scoring low in risk of bias and applicability for all domains in the QUADAS-2 tool. Three studies scored "fair" on the COSMIN four-point checklist for the reliability components. The concurrent validity of the FSST was measured in nine of the studies with moderate to strong correlations being found. Excellent Intraclass Correlation Coefficients were found between physiotherapists carrying out the tests (ICC = .99) with good to excellent test-retest reliability shown in nine of the studies (ICC = .73-.98). The FSST may be an effective and valid tool for measuring dynamic balance and a participants' falls risk. It has been shown to have strong
Extreme lipoprotein(a) levels and risk of myocardial infarction in the general population

DEFF Research Database (Denmark)

Kamstrup, Pia R; Benn, Marianne; Tybjaerg-Hansen, Anne

2008-01-01

Elevated lipoprotein(a) levels are associated with myocardial infarction (MI) in some but not all studies. Limitations of previous studies include lack of risk estimates for extreme lipoprotein(a) levels, measurements in long-term frozen samples, no correction for regression dilution bias, and lack...... of absolute risk estimates in the general population. We tested the hypothesis that extreme lipoprotein(a) levels predict MI in the general population, measuring levels shortly after sampling, correcting for regression dilution bias, and calculating hazard ratios and absolute risk estimates....
Simulation-based comparisons of four apparel cell production modes of one clothing production line

Directory of Open Access Journals (Sweden)

Guoqiang Pan

2014-10-01

Full Text Available Purpose: This research, by using the SIMIO simulation platform, provides a quantitative and comparative analysis of how the efficiency of four different cell production modes is affected. It is hoped that the outcomes will be of some help for garment factories to optimize their production lines. Design/methodology/approach: The SIMIO simulation platform was employed in the research and comparisons were made of the simulation test results about the four different production modes. Findings: The operation mode, number of operators, and number of buffer areas are key factors affecting the production line efficiency, and need to be reasonably set to achieve the highest efficiency. Originality/value: As most research literature so far is qualitative, this research provided a simulation-based quantitative analysis of the production efficiency under different cell production modes.
Molecular signature and in vivo behavior of bone marrow endosteal and subendosteal stromal cell populations and their relevance to hematopoiesis

Energy Technology Data Exchange (ETDEWEB)

Balduino, Alex, E-mail: balduino@uva.edu.br [School of Dentistry, Veiga de Almeida University, Rio de Janeiro, RJ (Brazil); Mello-Coelho, Valeria [Biomedical Science Institute, Federal University of Rio de Janeiro, Rio de Janeiro, RJ (Brazil); National Institute on Aging, National Institute of Health, Baltimore, MD (United States); Wang, Zhou; Taichman, Russell S.; Krebsbach, Paul H. [Department of Periodontics, Prevention and Geriatrics, University of Michigan School of Dentistry, Ann Arbor, MI (United States); Weeraratna, Ashani T.; Becker, Kevin G. [National Institute on Aging, National Institute of Health, Baltimore, MD (United States); Mello, Wallace de [Instituto Oswaldo Cruz, Rio de Janeiro, RJ (Brazil); Taub, Dennis D. [National Institute on Aging, National Institute of Health, Baltimore, MD (United States); Borojevic, Radovan [Biomedical Science Institute, Federal University of Rio de Janeiro, Rio de Janeiro, RJ (Brazil)

2012-11-15

In the bone marrow cavity, hematopoietic stem cells (HSC) have been shown to reside in the endosteal and subendosteal perivascular niches, which play specific roles on HSC maintenance. Although cells with long-term ability to reconstitute full hematopoietic system can be isolated from both niches, several data support a heterogenous distribution regarding the cycling behavior of HSC. Whether this distinct behavior depends upon the role played by the stromal populations which distinctly create these two niches is a question that remains open. In the present report, we used our previously described in vivo assay to demonstrate that endosteal and subendosteal stromal populations are very distinct regarding skeletal lineage differentiation potential. This was further supported by a microarray-based analysis, which also demonstrated that these two stromal populations play distinct, albeit complementary, roles in HSC niche. Both stromal populations were preferentially isolated from the trabecular region and behave distinctly in vitro, as previously reported. Even though these two niches are organized in a very close range, in vivo assays and molecular analyses allowed us to identify endosteal stroma (F-OST) cells as fully committed osteoblasts and subendosteal stroma (F-RET) cells as uncommitted mesenchymal cells mainly represented by perivascular reticular cells expressing high levels of chemokine ligand, CXCL12. Interestingly, a number of cytokines and growth factors including interleukin-6 (IL-6), IL-7, IL-15, Hepatocyte growth factor (HGF) and stem cell factor (SCF) matrix metalloproteases (MMPs) were also found to be differentially expressed by F-OST and F-RET cells. Further microarray analyses indicated important mechanisms used by the two stromal compartments in order to create and coordinate the 'quiescent' and 'proliferative' niches in which hematopoietic stem cells and progenitors reside.
Molecular signature and in vivo behavior of bone marrow endosteal and subendosteal stromal cell populations and their relevance to hematopoiesis

International Nuclear Information System (INIS)

Balduino, Alex; Mello-Coelho, Valeria; Wang, Zhou; Taichman, Russell S.; Krebsbach, Paul H.; Weeraratna, Ashani T.; Becker, Kevin G.; Mello, Wallace de; Taub, Dennis D.; Borojevic, Radovan

2012-01-01

In the bone marrow cavity, hematopoietic stem cells (HSC) have been shown to reside in the endosteal and subendosteal perivascular niches, which play specific roles on HSC maintenance. Although cells with long-term ability to reconstitute full hematopoietic system can be isolated from both niches, several data support a heterogenous distribution regarding the cycling behavior of HSC. Whether this distinct behavior depends upon the role played by the stromal populations which distinctly create these two niches is a question that remains open. In the present report, we used our previously described in vivo assay to demonstrate that endosteal and subendosteal stromal populations are very distinct regarding skeletal lineage differentiation potential. This was further supported by a microarray-based analysis, which also demonstrated that these two stromal populations play distinct, albeit complementary, roles in HSC niche. Both stromal populations were preferentially isolated from the trabecular region and behave distinctly in vitro, as previously reported. Even though these two niches are organized in a very close range, in vivo assays and molecular analyses allowed us to identify endosteal stroma (F-OST) cells as fully committed osteoblasts and subendosteal stroma (F-RET) cells as uncommitted mesenchymal cells mainly represented by perivascular reticular cells expressing high levels of chemokine ligand, CXCL12. Interestingly, a number of cytokines and growth factors including interleukin-6 (IL-6), IL-7, IL-15, Hepatocyte growth factor (HGF) and stem cell factor (SCF) matrix metalloproteases (MMPs) were also found to be differentially expressed by F-OST and F-RET cells. Further microarray analyses indicated important mechanisms used by the two stromal compartments in order to create and coordinate the “quiescent” and “proliferative” niches in which hematopoietic stem cells and progenitors reside.
Reprogramming of human fibroblasts to pluripotent stem cells using mRNA of four transcription factors

Energy Technology Data Exchange (ETDEWEB)

Yakubov, Eduard [Department of Molecular Cell Biology, Weizmann Institute of Science, 76100 Rehovot (Israel); Rechavi, Gidi [Cancer Research Center, Chaim Sheba Medical Center, Tel-Hashomer and Sackler School of Medicine, Tel-Aviv University, Tel-Aviv (Israel); Rozenblatt, Shmuel [Department of Molecular Microbiology and Biotechnology, Tel-Aviv University, Tel-Aviv (Israel); Givol, David, E-mail: david.givol@weizmann.ac.il [Department of Molecular Cell Biology, Weizmann Institute of Science, 76100 Rehovot (Israel)

2010-03-26

Reprogramming of differentiated cells into induced pluripotent cells (iPS) was accomplished in 2006 by expressing four, or less, embryonic stem cell (ESC)-specific transcription factors. Due to the possible danger of DNA damage and the potential tumorigenicity associated with such DNA damage, attempts were made to minimize DNA integration by the vectors involved in this process without complete success. Here we present a method of using RNA transfection as a tool for reprogramming human fibroblasts to iPS. We used RNA synthesized in vitro from cDNA of the same reprogramming four transcription factors. After transfection of the RNA, we show intracellular expression and nuclear localization of the respective proteins in at least 70% of the cells. We used five consecutive transfections to support continuous protein expression resulting in the formation of iPS colonies that express alkaline phosphatase and several ESC markers and that can be expanded. This method completely avoids DNA integration and may be developed to replace the use of DNA vectors in the formation of iPS.
Homeostasis of peripheral CD4+ T cells: IL-2R alpha and IL-2 shape a population of regulatory cells that controls CD4+ T cell numbers

NARCIS (Netherlands)

Almeida, Afonso R. M.; Legrand, Nicolas; Papiernik, Martine; Freitas, António A.

2002-01-01

We show that the lymphoid hyperplasia observed in IL-2Ralpha- and IL-2-deficient mice is due to the lack of a population of regulatory cells essential for CD4 T cell homeostasis. In chimeras reconstituted with bone marrow cells from IL-2Ralpha-deficient donors, restitution of a population of
Endogenous knowledge of four leafy vegetables used by rural populations in Benin.

Science.gov (United States)

Vihotogbe-Sossa, Carole N A; Akissoe, Noël H; Anihouvi, Victor B; Ahohuendo, Bonaventure C; Ahanchede, Adam; Sanni, Ambaliou; Hounhouigan, D Joseph

2012-01-01

Leafy vegetables are sources of diet diversification and could contribute to food and nutritional security in African rural areas. However, in some places, little is known about if, how, and why leafy vegetables are consumed. Processing and preservation methods, food forms, and consumption determinants of four leafy vegetables (Sesamum radiatum, Ceratotheca sesamoïdes, Acmella uliginosa and Justicia tenella), known to contribute to the diet of rural populations in the Center and Northern parts of Benin, were investigated. Three hundred randomly selected households were investigated, using rapid appraisal and quantitative survey methods, descriptive statistics and correspondence analysis. Processing methods to prepare sauces varied depending on sociocultural groups. Cooking of fresh leaves predominated, while sun drying was the usual practice of preserving these leafy vegetables. Consumption frequencies were associated with sociocultural groups, food habits, and availability in living areas.
A novel quantitative model of cell cycle progression based on cyclin-dependent kinases activity and population balances.

Science.gov (United States)

Pisu, Massimo; Concas, Alessandro; Cao, Giacomo

2015-04-01

Cell cycle regulates proliferative cell capacity under normal or pathologic conditions, and in general it governs all in vivo/in vitro cell growth and proliferation processes. Mathematical simulation by means of reliable and predictive models represents an important tool to interpret experiment results, to facilitate the definition of the optimal operating conditions for in vitro cultivation, or to predict the effect of a specific drug in normal/pathologic mammalian cells. Along these lines, a novel model of cell cycle progression is proposed in this work. Specifically, it is based on a population balance (PB) approach that allows one to quantitatively describe cell cycle progression through the different phases experienced by each cell of the entire population during its own life. The transition between two consecutive cell cycle phases is simulated by taking advantage of the biochemical kinetic model developed by Gérard and Goldbeter (2009) which involves cyclin-dependent kinases (CDKs) whose regulation is achieved through a variety of mechanisms that include association with cyclins and protein inhibitors, phosphorylation-dephosphorylation, and cyclin synthesis or degradation. This biochemical model properly describes the entire cell cycle of mammalian cells by maintaining a sufficient level of detail useful to identify check point for transition and to estimate phase duration required by PB. Specific examples are discussed to illustrate the ability of the proposed model to simulate the effect of drugs for in vitro trials of interest in oncology, regenerative medicine and tissue engineering. Copyright © 2015 Elsevier Ltd. All rights reserved.
Can Population-Level Laterality Stem from Social Pressures? Evidence from Cheek Kissing in Humans.

Science.gov (United States)

Chapelain, Amandine; Pimbert, Pauline; Aube, Lydiane; Perrocheau, Océane; Debunne, Gilles; Bellido, Alain; Blois-Heulin, Catherine

2015-01-01

Despite extensive research, the origins and functions of behavioural laterality remain largely unclear. One of the most striking unresolved issues is the fact that laterality generally occurs at the population-level. Why would the majority of the individuals of a population exhibit the same laterality, while individual-level laterality would yet provide the advantages in terms of improving behavioural efficiency? Are social pressures the key factor? Can social pressures induce alignment of laterality between the individuals of a population? Can the effect of social pressures overpass the effect of other possible determining factors (e.g. genes)? We tested this important new hypothesis in humans, for the first time. We asked whether population-level laterality could stem from social pressures. Namely, we assessed social pressures on laterality in an interactive social behaviour: kissing on the cheek as a greeting. We performed observations in 10 cities of France. The observations took place in spots where people of the city meet and greet each other. We showed that: a) there is a population-level laterality for cheek kissing, with the majority of individuals being aligned in each city, and b) there is a variation between populations, with a laterality that depends on the city. These results were confirmed by our complementary data from questionnaires and internet surveys. These findings show that social pressures are involved in determining laterality. They demonstrate that population-level laterality can stem from social pressures.
Can Population-Level Laterality Stem from Social Pressures? Evidence from Cheek Kissing in Humans.

Directory of Open Access Journals (Sweden)

Amandine Chapelain

Full Text Available Despite extensive research, the origins and functions of behavioural laterality remain largely unclear. One of the most striking unresolved issues is the fact that laterality generally occurs at the population-level. Why would the majority of the individuals of a population exhibit the same laterality, while individual-level laterality would yet provide the advantages in terms of improving behavioural efficiency? Are social pressures the key factor? Can social pressures induce alignment of laterality between the individuals of a population? Can the effect of social pressures overpass the effect of other possible determining factors (e.g. genes? We tested this important new hypothesis in humans, for the first time. We asked whether population-level laterality could stem from social pressures. Namely, we assessed social pressures on laterality in an interactive social behaviour: kissing on the cheek as a greeting. We performed observations in 10 cities of France. The observations took place in spots where people of the city meet and greet each other. We showed that: a there is a population-level laterality for cheek kissing, with the majority of individuals being aligned in each city, and b there is a variation between populations, with a laterality that depends on the city. These results were confirmed by our complementary data from questionnaires and internet surveys. These findings show that social pressures are involved in determining laterality. They demonstrate that population-level laterality can stem from social pressures.
Poverty levels and children's health status: study of risk factors in an urban population of low socioeconomic level

Directory of Open Access Journals (Sweden)

Issler Roberto M.S.

1996-01-01

Full Text Available To test the hypothesis that the low socioeconomic population living is shanty towns in Porto Alegre presents different levels of poverty which are reflected on its health status, a cross-sectional study was designed involving 477 families living in Vila Grande Cruzeiro, Porto Alegre, Brazil. The poverty level of the families was measured by using an instrument specifically designed for poor urban populations. Children from families living in extreme poverty (poorest quartile were found to have higher infant mortality rate, lower birth weights, more hospitalizations, and higher malnutrition rates, in addition to belonging to more numerous families. Thus, the shanty town population of Porto Alegre is not homogeneous, and priority should be given to the more vulnerable subgroups.
Poverty levels and children's health status: study of risk factors in an urban population of low socioeconomic level

Directory of Open Access Journals (Sweden)

Roberto M.S. Issler

1996-12-01

Full Text Available To test the hypothesis that the low socioeconomic population living is shanty towns in Porto Alegre presents different levels of poverty which are reflected on its health status, a cross-sectional study was designed involving 477 families living in Vila Grande Cruzeiro, Porto Alegre, Brazil. The poverty level of the families was measured by using an instrument specifically designed for poor urban populations. Children from families living in extreme poverty (poorest quartile were found to have higher infant mortality rate, lower birth weights, more hospitalizations, and higher malnutrition rates, in addition to belonging to more numerous families. Thus, the shanty town population of Porto Alegre is not homogeneous, and priority should be given to the more vulnerable subgroups.
Ethical issues in using Twitter for population-level depression monitoring: a qualitative study.

Science.gov (United States)

Mikal, Jude; Hurst, Samantha; Conway, Mike

2016-04-14

Recently, significant research effort has focused on using Twitter (and other social media) to investigate mental health at the population-level. While there has been influential work in developing ethical guidelines for Internet discussion forum-based research in public health, there is currently limited work focused on addressing ethical problems in Twitter-based public health research, and less still that considers these issues from users' own perspectives. In this work, we aim to investigate public attitudes towards utilizing public domain Twitter data for population-level mental health monitoring using a qualitative methodology. The study explores user perspectives in a series of five, 2-h focus group interviews. Following a semi-structured protocol, 26 Twitter users with and without a diagnosed history of depression discussed general Twitter use, along with privacy expectations, and ethical issues in using social media for health monitoring, with a particular focus on mental health monitoring. Transcripts were then transcribed, redacted, and coded using a constant comparative approach. While participants expressed a wide range of opinions, there was an overall trend towards a relatively positive view of using public domain Twitter data as a resource for population level mental health monitoring, provided that results are appropriately aggregated. Results are divided into five sections: (1) a profile of respondents' Twitter use patterns and use variability; (2) users' privacy expectations, including expectations regarding data reach and permanence; (3) attitudes towards social media based population-level health monitoring in general, and attitudes towards mental health monitoring in particular; (4) attitudes towards individual versus population-level health monitoring; and (5) users' own recommendations for the appropriate regulation of population-level mental health monitoring. Focus group data reveal a wide range of attitudes towards the use of public
Marginal bone level in two Danish cross-sectional population samples in 1997-1998 and 2007-2008.

Science.gov (United States)

Bahrami, Golnosh; Vaeth, Michael; Wenzel, Ann; Isidor, Flemming

2018-04-12

The aim of this study was to compare the marginal bone level of two randomly selected population samples from 1997/1998 and 2007/2008, with special emphasis on the role of smoking habits and gender. Two cross-sectional randomly selected population samples [1997/1998 (N = 616) and 2007/2008 (N = 396)] were analysed with respect to the marginal bone level. The marginal bone level was measured in full-mouth intraoral radiographs. Information on smoking was gathered using questionnaires. Multiple regression analysis was used in order to adjust for correlating factors (gender, age, smoking habits and number of teeth). After adjusting for confounding factors, the population sample from 2007/2008 had on average a slightly, but statistically significantly, more reduced average marginal bone level (0.15 mm) than the population sample from 1997/1998. Men had more reduced marginal bone level than women (0.12 mm). Smokers in both population samples had more reduced marginal bone level than non-smokers (0.39 mm and 0.12 mm for 1997/1998; 0.65 mm and 0.16 mm for 2007/2008). In these populations, sampled 10 years apart, the 2007/2008 population sample had a slightly more reduced marginal bone level than the 1997/1998 population sample. Men had more reduced marginal bone level than women, and smoking is considered a major risk factor for a reduced marginal bone level.
Identifying States along the Hematopoietic Stem Cell Differentiation Hierarchy with Single Cell Specificity via Raman Spectroscopy.

Science.gov (United States)

Ilin, Yelena; Choi, Ji Sun; Harley, Brendan A C; Kraft, Mary L

2015-11-17

A major challenge for expanding specific types of hematopoietic cells ex vivo for the treatment of blood cell pathologies is identifying the combinations of cellular and matrix cues that direct hematopoietic stem cells (HSC) to self-renew or differentiate into cell populations ex vivo. Microscale screening platforms enable minimizing the number of rare HSCs required to screen the effects of numerous cues on HSC fate decisions. These platforms create a strong demand for label-free methods that accurately identify the fate decisions of individual hematopoietic cells at specific locations on the platform. We demonstrate the capacity to identify discrete cells along the HSC differentiation hierarchy via multivariate analysis of Raman spectra. Notably, cell state identification is accurate for individual cells and independent of the biophysical properties of the functionalized polyacrylamide gels upon which these cells are cultured. We report partial least-squares discriminant analysis (PLS-DA) models of single cell Raman spectra enable identifying four dissimilar hematopoietic cell populations across the HSC lineage specification. Successful discrimination was obtained for a population enriched for long-term repopulating HSCs (LT-HSCs) versus their more differentiated progeny, including closely related short-term repopulating HSCs (ST-HSCs) and fully differentiated lymphoid (B cells) and myeloid (granulocytes) cells. The lineage-specific differentiation states of cells from these four subpopulations were accurately identified independent of the stiffness of the underlying biomaterial substrate, indicating subtle spectral variations that discriminated these populations were not masked by features from the culture substrate. This approach enables identifying the lineage-specific differentiation stages of hematopoietic cells on biomaterial substrates of differing composition and may facilitate correlating hematopoietic cell fate decisions with the extrinsic cues that
Detection and characterization of side population in Ewing's sarcoma SK-ES-1 cells in vitro

International Nuclear Information System (INIS)

Yang, Min; Zhang, Rui; Yan, Ming; Ye, Zhengxu; Liang, Wei; Luo, Zhuojing

2010-01-01

Dye exclusion is a valuable technique to isolate cancer stem cells (CSCs) based on an ability of stem cell to efflux fluorescent DNA-binding dye, especially for tumors without unique surface markers. It has been proven that side population (SP) cells that exclude Hoechst 33342 dye are enriched with stem-like cells in several cancer cell lines. In this study, we isolated and characterized SP cells from human Ewing's sarcoma cell line SK-ES-1 in vitro. SP cells were detected in SK-ES-1 and comprised 1.2% of total cell population. Only SP cells had the capacity to regenerate both SP and non-SP cells. The proliferation rates were similar between SP and non-SP cells. However, the clonogenicity and invasiveness of SP cells were significantly higher than that of non-SP cells. Further characterization of this SP phenotype presented other properties. SP cells exhibited increased multi-drug resistance and the ATP binding cassette protein (ABC) transporters were up-regulated in SP population. These findings suggest that SP cells derived from Ewing's sarcoma play the critical role in tumor metastasis and recurrence and might be an ideal target for clinical therapy.

Restoring the quantity and quality of elderly human mesenchymal stem cells for autologous cell-based therapies.

Science.gov (United States)

Block, Travis J; Marinkovic, Milos; Tran, Olivia N; Gonzalez, Aaron O; Marshall, Amanda; Dean, David D; Chen, Xiao-Dong

2017-10-27

Degenerative diseases are a major public health concern for the aging population and mesenchymal stem cells (MSCs) have great potential for treating many of these diseases. However, the quantity and quality of MSCs declines with aging, limiting the potential efficacy of autologous MSCs for treating the elderly population. Human bone marrow (BM)-derived MSCs from young and elderly donors were obtained and characterized using standard cell surface marker criteria (CD73, CD90, CD105) as recommended by the International Society for Cellular Therapy (ISCT). The elderly MSC population was isolated into four subpopulations based on size and stage-specific embryonic antigen-4 (SSEA-4) expression using fluorescence-activated cell sorting (FACS), and subpopulations were compared to the unfractionated young and elderly MSCs using assays that evaluate MSC proliferation, quality, morphology, intracellular reactive oxygen species, β-galactosidase expression, and adenosine triphosphate (ATP) content. The ISCT-recommended cell surface markers failed to detect any differences between young and elderly MSCs. Here, we report that elderly MSCs were larger in size and displayed substantially higher concentrations of intracellular reactive oxygen species and β-galactosidase expression and lower amounts of ATP and SSEA-4 expression. Based on these findings, cell size and SSEA-4 expression were used to separate the elderly MSCs into four subpopulations by FACS. The original populations (young and elderly MSCs), as well as the four subpopulations, were then characterized before and after culture on tissue culture plastic and BM-derived extracellular matrix (BM-ECM). The small SSEA-4-positive subpopulation representing ~ 8% of the original elderly MSC population exhibited a "youthful" phenotype that was similar to that of young MSCs. The biological activity of this elderly subpopulation was inhibited by senescence-associated factors produced by the unfractionated parent population
Four-level time decomposition quasi-static power flow and successive disturbances analysis. [Power system disturbances

Energy Technology Data Exchange (ETDEWEB)

Jovanovic, S M [Nikola Tesla Inst., Belgrade (YU)

1990-01-01

This paper presents a model and an appropriate numerical procedure for a four-level time decomposition quasi-static power flow and successive disturbances analysis of power systems. The analysis consists of the sequential computation of the zero, primary, secondary and tertiary quasi-static states and of the estimation of successive structural disturbances during the 1200 s dynamics after a structural disturbance. The model is developed by detailed inspection of the time decomposition characteristics of automatic protection and control devices. Adequate speed of the numerical procedure is attained by a specific application of the inversion matrix lemma and the decoupled model constant coefficient matrices. The four-level time decomposition quasi-static method is intended for security and emergency analysis. (author).
Influence of polygenic risk scores on lipid levels and dyslipidemia in a psychiatric population receiving weight gain-inducing psychotropic drugs.

Science.gov (United States)

Delacrétaz, Aurélie; Lagares Santos, Patricia; Saigi Morgui, Nuria; Vandenberghe, Frederik; Glatard, Anaïs; Gholam-Rezaee, Mehdi; von Gunten, Armin; Conus, Philippe; Eap, Chin B

2017-12-01

Dyslipidemia represents a major health issue in psychiatry. We determined whether weighted polygenic risk scores (wPRSs) combining multiple single-nucleotide polymorphisms (SNPs) associated with lipid levels in the general population are associated with lipid levels [high-density lipoprotein (HDL), low-density lipoprotein (LDL), total cholesterol (TC), and triglycerides] and/or dyslipidemia in patients receiving weight gain-inducing psychotropic drugs. We also determined whether genetics improve the predictive power of dyslipidemia. The influence of wPRS on lipid levels was firstly assessed in a discovery psychiatric sample (n=332) and was then tested for replication in an independent psychiatric sample (n=140). The contribution of genetic markers to predict dyslipidemia was evaluated in the combined psychiatric sample. wPRSs were significantly associated with the four lipid traits in the discovery (P≤0.02) and in the replication sample (P≤0.03). Patients whose wPRS was higher than the median wPRS had significantly higher LDL, TC, and triglyceride levels (0.20, 0.32 and 0.26 mmol/l, respectively; P≤0.004) and significantly lower HDL levels (0.13 mmol/l; Pdyslipidemia prediction of HDL (P=0.03) and a trend for improvement was observed for the prediction of TC dyslipidemia (P=0.08). Population-based wPRSs have thus significant effects on lipid levels in the psychiatric population. As genetics improved the predictive power of dyslipidemia development, only 24 patients need to be genotyped to prevent the development of one case of HDL hypocholesterolemia. If confirmed by further prospective investigations, the present results could be used for individualizing psychotropic treatment.
In vitro neuroprotective potential of four medicinal plants against rotenone-induced toxicity in SH-SY5Y neuroblastoma cells.

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Seoposengwe, Keabetswe; van Tonder, Jacob John; Steenkamp, Vanessa

2013-12-12

Lannea schweinfurthii, Zanthoxylum capense, Scadoxus puniceus and Crinum bulbispermum are used traditionally to treat neurological disorders. The aim of this study was to evaluate the cytoprotective potential of the four plants, after induction of toxicity using rotenone, in SH-SY5Y neuroblastoma cells. Cytotoxicity of the plant extracts and rotenone was assessed using the sulforhodamine B (SRB) assay. Fluorometry was used to measure intracellular redox state (reactive oxygen species (ROS) and intracellular glutathione content), mitochondrial membrane potential (MMP) and caspase-3 activity, as a marker of apoptotic cell death. Of the tested plants, the methanol extract of Z. capense was the least cytotoxic; LC50 121.3 ± 6.97 μg/ml, while S. puniceus methanol extract was the most cytotoxic; LC50 20.75 ± 1.47 μg/ml. Rotenone reduced intracellular ROS levels after 24 h exposure. Pre-treating cells with S. puniceus and C. bulbispermum extracts reversed the effects of rotenone on intracellular ROS levels. Rotenone exposure also decreased intracellular glutathione levels, which was counteracted by pre-treatment with any one of the extracts. MMP was reduced by rotenone, which was neutralized by pre-treatment with C. bulbispermum ethyl acetate extract. All extracts inhibited rotenone-induced activation of caspase-3. The studied plants demonstrated anti-apoptotic activity and restored intracellular glutathione content following rotenone treatment, suggesting that they may possess neuroprotective properties.
Human skin is protected by four functionally and phenotypically discrete populations of resident and recirculating memory T cells

NARCIS (Netherlands)

Watanabe, Rei; Gehad, Ahmed; Yang, Chao; Scott, Laura L.; Teague, Jessica E.; Schlapbach, Christoph; Elco, Christopher P.; Huang, Victor; Matos, Tiago R.; Kupper, Thomas S.; Clark, Rachael A.

2015-01-01

The skin of an adult human contains about 20 billion memory T cells. Epithelial barrier tissues are infiltrated by a combination of resident and recirculating T cells in mice, but the relative proportions and functional activities of resident versus recirculating T cells have not been evaluated in
High Levels of Genetic Diversity of Plasmodium falciparum Populations in Papua New Guinea despite Variable Infection Prevalence

Science.gov (United States)

Barry, Alyssa E.; Schultz, Lee; Senn, Nicholas; Nale, Joe; Kiniboro, Benson; Siba, Peter M.; Mueller, Ivo; Reeder, John C.

2013-01-01

High levels of genetic diversity in Plasmodium falciparum populations are an obstacle to malaria control. Here, we investigate the relationship between local variation in malaria epidemiology and parasite genetic diversity in Papua New Guinea (PNG). Cross-sectional malaria surveys were performed in 14 villages spanning four distinct malaria-endemic areas on the north coast, including one area that was sampled during the dry season. High-resolution msp2 genotyping of 2,147 blood samples identified 761 P. falciparum infections containing a total of 1,392 clones whose genotypes were used to measure genetic diversity. Considerable variability in infection prevalence and mean multiplicity of infection was observed at all of the study sites, with the area sampled during the dry season showing particularly striking local variability. Genetic diversity was strongly associated with multiplicity of infection but not with infection prevalence. In highly endemic areas, differences in infection prevalence may not translate into a decrease in parasite population diversity. PMID:23400571
A correlation between altered O-GlcNAcylation, migration and with changes in E-cadherin levels in ovarian cancer cells

International Nuclear Information System (INIS)

Jin, Feng-zhen; Yu, Chao; Zhao, De-zhang; Wu, Ming-jun; Yang, Zhu

2013-01-01

O-GlcNAcylation is a dynamic and reversible posttranslational modification of nuclear and cytoplasmic proteins. In recent years, the roles of O-GlcNAcylation in several human malignant tumors have been investigated, and O-GlcNAcylation was found to be linked to cellular features relevant to metastasis. In this study, we modeled four diverse ovarian cancer cells and investigated the effects of O-GlcNAcylation on ovarian cancer cell migration. We found that total O-GlcNAcylation level was elevated in HO-8910PM cells compared to OVCAR3 cells. Additionally, through altering the total O-GlcNAcylation level by OGT silencing or OGA inhibition, we found that the migration of OVCAR3 cells was dramatically enhanced by PUGNAc and Thiamet G treatment, and the migration ability of HO-8910PM cells was significantly inhibited by OGT silencing. Furthermore, we also found that the expression of E-cadherin, an O-GlcNAcylated protein in ovarian cancer cells, was reduced by OGA inhibition in OVCAR3 cells and elevated by OGT silencing in HO-8910PM cells. These results indicate that O-GlcNAcylation could enhance ovarian cancer cell migration and decrease the expression of E-cadherin. Our studies also suggest that O-GlcNAcylation might become another potential target for the therapy of ovarian cancer. -- Highlights: • We examine the migration potential of diverse ovarian cancer cells. • We examine the total O-GlcNAcylation level of diverse ovarian cancer cells. • Increasing O-GlcNAcylation level will enhance the migration of ovarian cancer cells. • Reducing O-GlcNAcylation level will inhibit the migration of ovarian cancer cells. • The mechanism explains O-GlcNAcylation enhance ovarian cancer cell migration
Heterogeneity within populations of recombinant Chinese hamster ovary cells expressing human interferon-gamma.

Science.gov (United States)

Coppen, S R; Newsam, R; Bull, A T; Baines, A J

1995-04-20

The Chinese hamster ovary (CHO) cell line has great commercial importance in the production of recombinant human proteins, especially those for therapeutic use. Much attention has been paid to CHO cell population physiology in order to define factors affecting product fidelity and yield. Such studies have revealed that recombinant proteins, including human interferon-gamma (IFN-gamma), can be heterogeneous both in glycosylation and in proteolytic processing. The type of heterogeneity observed depends on the growth physiology of the cell population, although the relationship between them is complex. In this article we report results of a cytological study of the CHO320 line which expresses recombinant human IFN-gamma. When grown in suspension culture, this cell line exhibited three types of heterogeneity: (1) heterogeneity of the production of IFN-gamma within the cell population, (2) heterogeneity of the number of nuclei and mitotic spindles in dividing cells, and (3) heterogeneity of cellular environment. The last of these arises from cell aggregates which form in suspension culture: Some cells are exposed to the culture medium; others are fully enclosed within the mass with little or no direct access to the medium. Thus, live cells producing IFN-gamma are heterogeneous in their environment, with variable access to O(2) and nutrients. Within the aggregates, it appears that live cells proliferate on a dead cell mass. The layer of live cells can be several cells deep. Specific cell-cell attachments are observed between the living cells in these aggregates. Two proteins, known to be required for the formation of certain types of intercellular junctions, spectrin and vinculin, have been localized to the regions of cell-cell contact. The aggregation of the cells appears to be an active process requiring protein synthesis. (c) 1995 John Wiley & Sons, Inc.
Cell-type specific four-component hydrogel.

Directory of Open Access Journals (Sweden)

Timo Aberle

Full Text Available In the field of regenerative medicine we aim to develop implant matrices for specific tissue needs. By combining two per se, cell-permissive gel systems with enzymatic crosslinkers (gelatin/transglutaminase and fibrinogen/thrombin to generate a blend (technical term: quattroGel, an unexpected cell-selectivity evolved. QuattroGels were porous and formed cavities in the cell diameter range, possessed gelation kinetics in the minute range, viscoelastic properties and a mechanical strength appropriate for general cell adhesion, and restricted diffusion. Cell proliferation of endothelial cells, chondrocytes and fibroblasts was essentially unaffected. In contrast, on quattroGels neither endothelial cells formed vascular tubes nor did primary neurons extend neurites in significant amounts. Only chondrocytes differentiated properly as judged by collagen isoform expression. The biophysical quattroGel characteristics appeared to leave distinct cell processes such as mitosis unaffected and favored differentiation of sessile cells, but hampered differentiation of migratory cells. This cell-type selectivity is of interest e.g. during articular cartilage or invertebral disc repair, where pathological innervation and angiogenesis represent adverse events in tissue engineering.
Immunohistochemical study of jejunal graft mucosa cell populations during the initial adaptation phase in the host body in rats.

Science.gov (United States)

Tóth, Stefan; Jonecová, Zuzana; Varga, Ján; Staško, Pavel; Kovalčinová, Barbora; Maretta, Milan; Leško, Dušan; Veselá, Jarmila

2013-10-01

The character of the changes in cell populations within the jejunal graft mucosa during the initial adaptation phase in the host body was investigated. 24 adult male Wistar rats underwent intestinal heterotopic allotransplantation. Aorto-aortal and porto-caval anastomoses were performed using the end-to-side microsurgery technique. Graft tissues were compared to the intestinal tissues of the recipients. This study demonstrates that: (1) Distinct injury to the graft mucosa 1h after transplantation was accompanied by significant reduction in numbers of epithelial secretory cell populations. The injury was more intense in the mesenteric portion. Six hours after transplantation the graft mucosa was covered by a continuous epithelium, but the number of goblet and Paneth cells was found to be less than 30% of that in the recipient epithelium. (2) In comparison with recipients, myeloperoxidase-positive cell numbers increased significantly in the graft mucosa 1 h after transplantation. In the epithelial layer, denudation and destruction of villi was associated with a significant reduction in intraepithelial lymphocyte numbers. A significant decrease in mucosal mast cell numbers was detected 6 h after transplantation. They attained only 10% of the number found in the recipients. (3) Time-dependent changes in the graft mucosa revealed that CD163-positive cells increased significantly in the graft mucosa during 6 h after transplantation and reached the level found in the recipients. In contrast, the myeloperoxidase-positive cell population significantly decreased in the graft mucosa within the initial 6 h. Copyright © 2013 Elsevier GmbH. All rights reserved.
Fueling our future: Four steps to a new, reliable, cleaner, decentralized energy supply based on hydrogen and fuel cells

Energy Technology Data Exchange (ETDEWEB)

Evers, A. A. [Arno A. Evers FAIR-PR, Starnberg (Germany)

2004-07-01

The necessary preconditions and the driving forces operating to move hydrogen and fuel cells to world-wide commercialization are examined, focusing on trends that impacted the progress of new technologies in the past. The consensus is that consumers have played a vital role in the past, and will continue to play an even more vital role in the future as drivers in the mass market evolution of technological progress. The automobile, aircraft and cell phone industries are examined as examples of consumer influence on technology development. One such scenario, specific to the hydrogen economy is the potential dual role played by fuel cell-powered personal automobiles which may not only provide transportation but also supply electricity and heat to residential and commercial buildings while in a stationary mode. It is suggested that given the size of the population and the current level of economic development in the Peoples' Republic of China, conditions there are most favourable to accelerate the development of a hydrogen and fuel cell-based economy. Details of developments in China and how the hydrogen-fuel cells scenario may develop there, are discussed. 11 figs.
In vitro expansion of the mammary stem/progenitor cell population by xanthosine treatment

Directory of Open Access Journals (Sweden)

Choudhary Ratan K

2012-06-01

Full Text Available Abstract Background Mammary stem cells are critical for growth and maintenance of the mammary gland and therefore are of considerable interest for improving productivity and efficiency of dairy animals. Xanthosine treatment has been demonstrated to promote expansion of putative mammary stem cells in vivo, and hepatic and hair follicle stem cells in vitro. In the latter, xanthosine promoted the symmetrical division of hepatic and hair follicle stem cells. The objective of this study was to determine if treating primary cultures of bovine mammary epithelial cells (MEC with xanthosine increases the stem/progenitor cell population by promoting symmetrical division of mammary stem cells. Results In vitro treatment with xanthosine increased the population of MEC during the exponential phase of cell growth, reducing the doubling time from 86 h in control cultures to 60 h in xanthosine-treated cultures. The bromodeoxyuridine (BrdU labeling index and the proportion of MEC in S-phase both were increased by xanthosine treatment, indicating that increased cell accretion was due to increased cell proliferation. Analysis of daughter-pairs indicated that xanthosine promoted a shift from asymmetric to symmetric cell division. Moreover, the 30 % increase in symmetric cell division was concomitant with an increase in the proportion of MEC that were positive for a putative stem cell marker (FNDC3B and a trend toward increased telomerase activity. These results suggest that xanthosine treatment in vitro can increase cell proliferation, promote symmetric cell division and enhance stem/progenitor cell activity. Conclusions Xanthosine treatment increased the proliferation rate of bovine MEC in vitro. This was likely to be mediated by an increase in the proportion of stem/progenitor cells in the MEC population due to promotion of symmetrical stem cell division by xanthosine.
Comparison of lung cancer cell lines representing four histopathological subtypes with gene expression profiling using quantitative real-time PCR

Directory of Open Access Journals (Sweden)

Kawaguchi Makoto

2010-01-01

Full Text Available Abstract Background Lung cancers are the most common type of human malignancy and are intractable. Lung cancers are generally classified into four histopathological subtypes: adenocarcinoma (AD, squamous cell carcinoma (SQ, large cell carcinoma (LC, and small cell carcinoma (SC. Molecular biological characterization of these subtypes has been performed mainly using DNA microarrays. In this study, we compared the gene expression profiles of these four subtypes using twelve human lung cancer cell lines and the more reliable quantitative real-time PCR (qPCR. Results We selected 100 genes from public DNA microarray data and examined them by DNA microarray analysis in eight test cell lines (A549, ABC-1, EBC-1, LK-2, LU65, LU99, STC 1, RERF-LC-MA and a normal control lung cell line (MRC-9. From this, we extracted 19 candidate genes. We quantified the expression of the 19 genes and a housekeeping gene, GAPDH, with qPCR, using the same eight cell lines plus four additional validation lung cancer cell lines (RERF-LC-MS, LC-1/sq, 86-2, and MS-1-L. Finally, we characterized the four subtypes of lung cancer cell lines using principal component analysis (PCA of gene expression profiling for 12 of the 19 genes (AMY2A, CDH1, FOXG1, IGSF3, ISL1, MALL, PLAU, RAB25, S100P, SLCO4A1, STMN1, and TGM2. The combined PCA and gene pathway analyses suggested that these genes were related to cell adhesion, growth, and invasion. S100P in AD cells and CDH1 in AD and SQ cells were identified as candidate markers of these lung cancer subtypes based on their upregulation and the results of PCA analysis. Immunohistochemistry for S100P and RAB25 was closely correlated to gene expression. Conclusions These results show that the four subtypes, represented by 12 lung cancer cell lines, were well characterized using qPCR and PCA for the 12 genes examined. Certain genes, in particular S100P and CDH1, may be especially important for distinguishing the different subtypes. Our results
I Want More and Better Cells! – An Outreach Project about Stem Cells and Its Impact on the General Population

Science.gov (United States)

Varela Amaral, Sara; Forte, Teresa; Ramalho-Santos, João; Girão da Cruz, M. Teresa

2015-01-01

Although science and technology impact every aspect of modern societies, there is still an extensive gap between science and society, which impairs the full exercise of citizenship. In the particular case of biomedical research increased investment should be accompanied by parallel efforts in terms of public information and engagement. We have carried out a project involving the production and evaluation of educational contents focused on stem cells - illustrated newspaper chronicles, radio interviews, a comic book, and animated videos - and monitored their impact on the Portuguese population. The study of the outreach materials in a heterogeneous sample of the population suggests that they are valuable tools to disseminate scientific messages, and that this is especially true for the comic-book format. Furthermore, the data showed that clear and stimulating outreach materials, that are able to teach new concepts and to promote critical thinking, increase engagement in science at different levels, depending on the depth of the concepts involved. Additionally, these materials can influence political, social and personal attitudes toward science. These results, together with the importance attributed to scientific research in stem cells by the population sampled, validates the diffusion of such materials as a significant contribution towards an overall public understanding and engagement in contemporary science, and this strategy should thus be considered in future projects. Regardless, stringent quality control must be implemented in order to efficiently communicate accurate scientific developments, and the public stimulated in terms of finding additional sources of reliable information. PMID:26222053
Four-level and two-qubit systems, subalgebras, and unitary integration

International Nuclear Information System (INIS)

Rau, A.R.P.; Selvaraj, G.; Uskov, D.

2005-01-01

Four-level systems in quantum optics, and for representing two qubits in quantum computing, are difficult to solve for general time-dependent Hamiltonians. A systematic procedure is presented which combines analytical handling of the algebraic operator aspects with simple solutions of classical, first-order differential equations. In particular, by exploiting su(2)+su(2) and su(2)+su(2)+u(1) subalgebras of the full SU(4) dynamical group of the system, the nontrivial part of the final calculation is reduced to a single Riccati (first-order, quadratically nonlinear) equation, itself simply solved. Examples are provided of two-qubit problems from the recent literature, including implementation of two-qubit gates with Josephson junctions
Maternal hormone levels and risk of cryptorchism among populations at high and low risk of testicular germ cell tumors.

Science.gov (United States)

McGlynn, Katherine A; Graubard, Barry I; Nam, Jun-Mo; Stanczyk, Frank Z; Longnecker, Matthew P; Klebanoff, Mark A

2005-07-01

Cryptorchism is one of the few well-described risk factors for testicular cancer. It has been suggested that both conditions are related to increased in utero estrogen exposure. The evidence supporting the "estrogen hypothesis" has been inconsistent, however. An alternative hypothesis suggests that higher in utero androgen exposure may protect against the development of cryptorchism and testicular cancer. In order to examine both hypotheses, we studied maternal hormone levels in two populations at diverse risks of testicular cancer; Black Americans (low-risk) and White Americans (high-risk). The study population of 200 mothers of cryptorchid sons and 200 mothers of noncryptorchid sons was nested within the Collaborative Perinatal Project, a cohort study of pregnant women and their children. Third trimester serum levels of estradiol (total, free, bioavailable), estriol, testosterone (total, free, bioavailable), sex hormone-binding globulin, alpha-fetoprotein, and the ratios of estradiols to testosterones were compared between the case and control mothers. The results found no significant differences in the levels of testosterone (total, free, bioavailable), alpha-fetoprotein, sex hormone-binding globulin, or in the ratios of estrogens to androgens. Total estradiol, however, was significantly lower in the cases versus the controls (P = 0.03) among all mothers and, separately, among White mothers (P = 0.05). Similarly, estriol was significantly lower among all cases (P = 0.05) and among White cases (P = 0.05). These results do not support either the estrogen or the androgen hypothesis. Rather, lower estrogens in case mothers may indicate that a placental defect increases the risk of cryptorchism and, possibly, testicular cancer.
Controlling the optical bistability and transmission coefficient in a four-level atomic medium

International Nuclear Information System (INIS)

Asadpour, Seyyed Hossein; Eslami-Majd, Abdullah

2012-01-01

A novel four level atomic configuration is proposed for controlling the optical bistability and transmission coefficient with application on all-optical switching. Two circularly polarized components from a weak linearly-polarized probe beam are interacted separately by two transitions of this medium. A coherent coupling field has derived another atomic transition. It is demonstrated that the transmission coefficient of two orthogonally polarized beams at different frequencies can be achieved by adjusting the magnitude of the external magnetic field. It is found that the threshold of the optical bistability can be controlled by magnitude of the external magnetic field. Also, it is shown that optical bistability can be converted to optical multistability by switching the two orthogonally polarized beams. - Highlights: ► An inverted Y-type four level atomic system is proposed. ► Transmission coefficient can be controlled by a novel interesting parameter. ► Optical bistability and multistability can be achieved via external magnetic field. ► It is shown that our proposed model is suitable for all optical switching application.
Spontaneous emission spectrum of a four-level atom coupled by three kinds of reservoirs

International Nuclear Information System (INIS)

Yang Dong; Wang Jian; Zhang, Hanzhuang; Yao Jinbo

2007-01-01

A model of a four-level atom embedded in a double-band photonic crystal (PC) is presented. The atomic transitions from the upper two levels to the lower two levels are coupled by the same reservoir which is assumed in turn to be isotropic PC modes, anisotropic PC modes and free vacuum modes. The effects of the fine structure of the atomic ground state levels and the quantum interference on the spontaneous emission spectrum of an atom are investigated in detail. Most interestingly, it is shown for the first time that new spontaneous emission lines are produced from the fine splitting of atomic ground state levels in the isotropic PC case. Quantum interference induces additional narrow spontaneous lines near the transition from the empty upper level to the lower levels
Arsenic, cadmium, chromium, lead, mercury, and selenium levels in blood of four species of turtles from the Amazon in Brazil.

Science.gov (United States)

Burger, Joanna; Jeitner, Christian; Schneider, Larissa; Vogt, Richard; Gochfeld, Michael

2010-01-01

Using blood as a method of assessing metal levels in turtles may be useful for populations that are threatened or endangered or are decreasing. In this study the levels of arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg), and selenium (Se) in blood of four species of turtles from the tributaries of the Rio Negro in the Amazon of Brazil were examined. The turtles included the six-tubercled Amazon (river) turtle (Podocnemis sextuberculata), red-headed Amazon (river) turtle (Podocnemis erythrocephala), big-headed Amazon (river) turtle (Peltocephalus dumerilianus), and matamata turtle (Chelus fimbriatus). Blood samples were taken from the vein in the left hind leg of each turtle. There were significant interspecific differences in the sizes of the turtles from the Rio Negro, and in concentrations of Pb, Hg, and Se; the smallest species (red-headed turtles) had the highest levels of Pb in their blood, while Se levels were highest in big-headed turtles and lowest in red-headed turtles. Hg in blood was highest in matamata, intermediate in big-headed, and lowest in the other two turtles. Even though females were significantly larger than males, there were no significant differences in metal levels as a function of gender, and the only relationship of metals to size was for Cd. Variations in metal levels among species suggest that blood may be a useful bioindicator. Metal levels were not high enough to pose a health risk to the turtles or to consumers, such as humans.
A comprehensive assessment of mercury exposure in penguin populations throughout the Southern Hemisphere: Using trophic calculations to identify sources of population-level variation.

Science.gov (United States)

Brasso, Rebecka L; Chiaradia, André; Polito, Michael J; Raya Rey, Andrea; Emslie, Steven D

2015-08-15

The wide geographic distribution of penguins (Order Sphenisciformes) throughout the Southern Hemisphere provided a unique opportunity to use a single taxonomic group as biomonitors of mercury among geographically distinct marine ecosystems. Mercury concentrations were compared among ten species of penguins representing 26 geographically distinct breeding populations. Mercury concentrations were relatively low (⩽2.00ppm) in feathers from 18/26 populations considered. Population-level differences in trophic level explained variation in mercury concentrations among Little, King, and Gentoo penguin populations. However, Southern Rockhopper and Magellanic penguins breeding on Staten Island, Tierra del Fuego, had the highest mercury concentrations relative to their conspecifics despite foraging at a lower trophic level. The concurrent use of stable isotope and mercury data allowed us to document penguin populations at the greatest risk of exposure to harmful concentrations of mercury as a result of foraging at a high trophic level or in geographic 'hot spots' of mercury availability. Copyright © 2015 Elsevier Ltd. All rights reserved.

Divide and conquer: intermediate levels of population fragmentation maximize cultural accumulation.

Science.gov (United States)

Derex, Maxime; Perreault, Charles; Boyd, Robert

2018-04-05

Identifying the determinants of cumulative cultural evolution is a key issue in the interdisciplinary field of cultural evolution. A widely held view is that large and well-connected social networks facilitate cumulative cultural evolution because they promote the spread of useful cultural traits and prevent the loss of cultural knowledge through factors such as drift. This view stems from models that focus on the transmission of cultural information, without considering how new cultural traits actually arise. In this paper, we review the literature from various fields that suggest that, under some circumstances, increased connectedness can decrease cultural diversity and reduce innovation rates. Incorporating this idea into an agent-based model, we explore the effect of population fragmentation on cumulative culture and show that, for a given population size, there exists an intermediate level of population fragmentation that maximizes the rate of cumulative cultural evolution. This result is explained by the fact that fully connected, non-fragmented populations are able to maintain complex cultural traits but produce insufficient variation and so lack the cultural diversity required to produce highly complex cultural traits. Conversely, highly fragmented populations produce a variety of cultural traits but cannot maintain complex ones. In populations with intermediate levels of fragmentation, cultural loss and cultural diversity are balanced in a way that maximizes cultural complexity. Our results suggest that population structure needs to be taken into account when investigating the relationship between demography and cumulative culture.This article is part of the theme issue 'Bridging cultural gaps: interdisciplinary studies in human cultural evolution'. © 2018 The Author(s).
Lattice Boltzmann method with the cell-population equilibrium

International Nuclear Information System (INIS)

Zhou Xiaoyang; Cheng Bing; Shi Baochang

2008-01-01

The central problem of the lattice Boltzmann method (LBM) is to construct a discrete equilibrium. In this paper, a multi-speed 1D cell-model of Boltzmann equation is proposed, in which the cell-population equilibrium, a direct non-negative approximation to the continuous Maxwellian distribution, plays an important part. By applying the explicit one-order Chapman–Enskog distribution, the model reduces the transportation and collision, two basic evolution steps in LBM, to the transportation of the non-equilibrium distribution. Furthermore, 1D dam-break problem is performed and the numerical results agree well with the analytic solutions
Mono-2-ethylhexyl phthalate associated with insulin resistance and lower testosterone levels in a young population.

Science.gov (United States)

Chen, Szu-Ying; Hwang, Jing-Shiang; Sung, Fung-Chang; Lin, Chien-Yu; Hsieh, Chia-Jung; Chen, Pau-Chung; Su, Ta-Chen

2017-06-01

Phthalates are commonly used as plasticizers and are reported to associate with testicular dysfunction or insulin resistance in different studies, but the concurrent relationship between phthalate exposure, testosterone levels, and insulin resistance in the young population is not well understood. We recruited 786 subjects aged 12-30 years from a population-based sample of Taiwanese adolescents and young adults from 2006 to 2008. Generalized additive models were used to evaluate glucose homeostasis and testicular function in relation to seven urinary phthalate metabolites among adolescents (aged 12-20) and young adults (aged 20-30) in Taiwan. We observed a trend toward a decrease in male testosterone and an increase in urinary mono-2-ethylhexyl phthalate (MEHP) levels across four quartiles of homeostasis model assessment of insulin resistance (HOMA-IR). After adjusting for potential covariates, generalized additive models further showed that log-transformed insulin and HOMA-IR were raised by 0.055 [95% confidence interval (CI), 0.027-0.082] and 0.056 (95% CI, 0.027-0.084), respectively, with a one-unit increase in log-transformed MEHP in young adults. In male adults (aged 22-30), the log-testosterone levels were reduced by 0.018 (95% CI, 0.001-0.036), with a one-unit of increase in log-transformed MEHP. Such relationships were not observed in adolescents. In conclusion, this study demonstrated age-related associations of urinary MEHP metabolites with impaired metabolic homeostasis of glucose that were only observed in young adults. In addition, MEHP exposure was concurrently associated with lower testosterone levels in young, male adults. Copyright © 2017 Elsevier Ltd. All rights reserved.
Exposure to DEHP decreased four fatty acid levels in plasma of prepartum mice

International Nuclear Information System (INIS)

Nakashima, Ryosuke; Hayashi, Yumi; Khalequzzaman, Md.; Jia, Xiaofang; Wang, Dong; Naito, Hisao; Ito, Yuki; Kamijima, Michihiro; Gonzalez, Frank J.; Nakajima, Tamie

2013-01-01

Maternal exposure to di(2-ethylhexyl) phthalate (DEHP) decreased the plasma triglyceride in prepartum mice. To identify the fatty acid (FA) species involved and to understand the underlying mechanisms, pregnant Sv/129 wild-type (mPPARα), peroxisome proliferator-activated receptor α-null (Pparα-null) and humanized PPARα (hPPARα) mice were treated with diets containing 0%, 0.01%, 0.05% or 0.1% DEHP. Dams were dissected on gestational day 18 together with fetuses, and on postnatal day 2 together with newborns. n-3/n-6 polyunsaturated, saturated, and monounsaturated FAs in maternal plasma and in liver of wild-type offspring, and representative enzymes for FA desaturation and elongation in maternal liver, were measured. The plasma levels of linoleic acid, α-linolenic acid, palmitic acid and oleic acid were higher in the pregnant control mPPARa mice than in Ppara-null and hPPARa mice. DEHP exposure significantly decreased the levels of these four FAs only in pregnant mPPARα mice. Plasma levels of many FAs were higher in pregnant mice than in postpartum ones in a genotype-independent manner, while it was lower in the livers of fetuses than pups. DEHP exposure slightly increased hepatic arachidonic acid, α-linolenic acid, palmitoleic acid and oleic acid in fetuses, but not in pups. However, DEHP exposure did not clearly influence FA desaturase 1 and 2 nor elongase 2 and 5 expressions in the liver of all maternal mice. Taken together, the levels of plasma four FAs with shorter carbon chains were higher in pregnant mPPARα mice than in other genotypes, and DEHP exposure decreased these specific FA concentrations only in mPPARα mice, similarly to triglyceride levels
Effects of collisions on level populations and dielectronic recombination rates of multiply charged ions

International Nuclear Information System (INIS)

Jacobs, V.L.; Davis, J.

1978-01-01

A generalization of previously reported statistical theories is developed for determining the excited-level populations and the ionization-recombination balance of multiply charged atomic ions in an optically thin high-temperature plasma. Account is taken of the most important collisional and radiative processes involving bound and autoionizing levels in three consecutive ionization stages. We obtain a set of rate equations for the population densities of the low-lying levels which contains effective excitation, ionization, and recombination rates describing indirect transitions through the more highly excited bound and autoionizing levels. The familiar corona-model equations for the ground-state populations are recovered by making the assumption that all excited states decay by only spontaneous radiative or autoionization processes. When collisional processes become efficient in depopulating the highly excited levels important in dielectronic recombination, the effective rate of recombination must be described by a collisional-dielectronic recombination coefficient. Results of calculations are presented for the collisional-dielectronic recombination rate coefficients for recombination of Fe +8 --Fe +13 ions. At an electron density of 10 16 cm -3 , dielectronic recombination is still the dominant recombination process. However, the collisional-dielectronic recombination rate coefficients are found to be reduced by about an order of magnitude from their corona-model values due to the effects of multiple-collisional excitations on the populations of the highly excited bound levels of the recombined ion. The dielectronic recombination rates into these highly excited levels are found to be enhanced by the effects of collisionally induced angular momentum redistribution on the populations of the autoionizing levels
Identification and characterisation of side population cells in the canine pituitary gland.

Science.gov (United States)

van Rijn, Sarah J; Gremeaux, Lies; Riemers, Frank M; Brinkhof, Bas; Vankelecom, Hugo; Penning, Louis C; Meij, Björn P

2012-06-01

To date, stem/progenitor cells have not been identified in the canine pituitary gland. Cells that efficiently exclude the vital dye Hoechst 33342 can be visualised and identified using fluorescence activated cell sorting (FACS) as a 'side population' (SP), distinct from the main population (MP). Such SPs have been identified in several tissues and display stem/progenitor cell characteristics. In this study, a small SP (1.3%, n=6) was detected in the anterior pituitary glands of healthy dogs. Quantitative PCR indicated significantly higher expression of CD34 and Thy1 in this SP, but no differences in the expression of CD133, Bmi-1, Axin2 or Shh. Pro-opiomelanocortin (POMC) and Lhx3 expression were significantly higher in the MP than in the SP, but no differences in the expression of Tpit, GH or PRL were found. The study demonstrated the existence of an SP of cells in the normal canine pituitary gland, encompassing cells with stem cell characteristics and without POMC expression. Copyright © 2011 Elsevier Ltd. All rights reserved.
Extent of linkage disequilibrium and effective population size in four South African Sanga cattle breeds

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Sithembile Olga Makina

2015-12-01

Full Text Available Knowledge on the extent of linkage disequilibrium (LD in livestock populations is essential to determine the minimum distance between markers required for effective coverage when conducting genome-wide association studies. This study evaluated the extent of LD, persistence of allelic phase and effective population size (Ne for four Sanga cattle breeds in South Africa including the Afrikaner (n=44, Nguni (n=54, Drakensberger (n=47 and Bonsmara breeds (n=46, using Angus (n=31 and Holstein (n=29 as reference populations. We found that moderate LD extends up to inter-marker distances of 40-60 kb in Angus (0.21 and Holstein (0.21 and up to 100 kb in Afrikaner (0.20. This suggests that genomic selection and association studies performed within these breeds using an average inter-marker r2 ≥ 0.20 would require about 30,000 -50,000 SNPs. However, r2 ≥ 0.20 extended only up to 10-20 kb in the Nguni and Drakensberger and 20-40 kb in the Bonsmara indicating that 75,000 to 150,000 SNPs would be necessary for genome-wide association studies in these breeds. Correlation between alleles at contiguous loci indicated that phase was not strongly preserved between breeds. This suggests the need for breed-specific reference populations in which a much greater density of markers should be scored to identify breed specific haplotypes which may then be imputed into multi-breed commercial populations. Analysis of effective population size based on the extent of LD, revealed Ne=95 (Nguni, Ne=87 (Drakensberger, Ne=77 (Bonsmara and Ne=41 (Afrikaner. Results of this study form the basis for implementation of genomic selection programs in the Sanga breeds of South Africa.
Therapeutic implications of an enriched cancer stem-like cell population in a human osteosarcoma cell line

International Nuclear Information System (INIS)

Martins-Neves, Sara R; Lopes, Áurio O; Carmo, Anália do; Paiva, Artur A; Simões, Paulo C; Abrunhosa, Antero J; Gomes, Célia MF

2012-01-01

Osteosarcoma is a bone-forming tumor of mesenchymal origin that presents a clinical pattern that is consistent with the cancer stem cell model. Cells with stem-like properties (CSCs) have been identified in several tumors and hypothesized as the responsible for the relative resistance to therapy and tumor relapses. In this study, we aimed to identify and characterize CSCs populations in a human osteosarcoma cell line and to explore their role in the responsiveness to conventional therapies. CSCs were isolated from the human MNNG/HOS cell line using the sphere formation assay and characterized in terms of self-renewal, mesenchymal stem cell properties, expression of pluripotency markers and ABC transporters, metabolic activity and tumorigenicity. Cell's sensitivity to conventional chemotherapeutic agents and to irradiation was analyzed and related with cell cycle-induced alterations and apoptosis. The isolated CSCs were found to possess self-renewal and multipotential differentiation capabilities, express markers of pluripotent embryonic stem cells Oct4 and Nanog and the ABC transporters P-glycoprotein and BCRP, exhibit low metabolic activity and induce tumors in athymic mice. Compared with parental MNNG/HOS cells, CSCs were relatively more resistant to both chemotherapy and irradiation. None of the treatments have induced significant cell-cycle alterations and apoptosis in CSCs. MNNG/HOS osteosarcoma cells contain a stem-like cell population relatively resistant to conventional chemotherapeutic agents and irradiation. This resistant phenotype appears to be related with some stem features, namely the high expression of the drug efflux transporters P-glycoprotein and BCRP and their quiescent nature, which may provide a biological basis for resistance to therapy and recurrence commonly observed in osteosarcoma
Therapeutic implications of an enriched cancer stem-like cell population in a human osteosarcoma cell line

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Martins-Neves Sara R

2012-04-01

Full Text Available Abstract Background Osteosarcoma is a bone-forming tumor of mesenchymal origin that presents a clinical pattern that is consistent with the cancer stem cell model. Cells with stem-like properties (CSCs have been identified in several tumors and hypothesized as the responsible for the relative resistance to therapy and tumor relapses. In this study, we aimed to identify and characterize CSCs populations in a human osteosarcoma cell line and to explore their role in the responsiveness to conventional therapies. Methods CSCs were isolated from the human MNNG/HOS cell line using the sphere formation assay and characterized in terms of self-renewal, mesenchymal stem cell properties, expression of pluripotency markers and ABC transporters, metabolic activity and tumorigenicity. Cell's sensitivity to conventional chemotherapeutic agents and to irradiation was analyzed and related with cell cycle-induced alterations and apoptosis. Results The isolated CSCs were found to possess self-renewal and multipotential differentiation capabilities, express markers of pluripotent embryonic stem cells Oct4 and Nanog and the ABC transporters P-glycoprotein and BCRP, exhibit low metabolic activity and induce tumors in athymic mice. Compared with parental MNNG/HOS cells, CSCs were relatively more resistant to both chemotherapy and irradiation. None of the treatments have induced significant cell-cycle alterations and apoptosis in CSCs. Conclusions MNNG/HOS osteosarcoma cells contain a stem-like cell population relatively resistant to conventional chemotherapeutic agents and irradiation. This resistant phenotype appears to be related with some stem features, namely the high expression of the drug efflux transporters P-glycoprotein and BCRP and their quiescent nature, which may provide a biological basis for resistance to therapy and recurrence commonly observed in osteosarcoma.
Influences of lamin A levels on induction of pluripotent stem cells

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Bingfeng Zuo

2012-09-01

Lamin A is an inner nuclear membrane protein that maintains nuclear structure integrity, is involved in transcription, DNA damage response and genomic stability, and also links to cell differentiation, senescence, premature aging and associated diseases. Induced pluripotent stem (iPS cells have been successfully generated from various types of cells and used to model human diseases. It remains unclear whether levels of lamin A influence reprogramming of somatic cells to pluripotent states during iPS induction. Consistently, lamin A is expressed more in differentiated than in relatively undifferentiated somatic cells, and increases in expression levels with age. Somatic cells with various expression levels of lamin A differ in their dynamics and efficiency during iPS cell induction. Cells with higher levels of lamin A show slower reprogramming and decreased efficiency to iPS cells. Furthermore, depletion of lamin A by transient shRNA accelerates iPS cell induction from fibroblasts. Reduced levels of lamin A are associated with increased expression of pluripotent genes Oct4 and Nanog, and telomerase genes Tert and Terc. On the contrary, overexpression of lamin A retards somatic cell reprogramming to iPS-like colony formation. Our data suggest that levels of lamin A influence reprogramming of somatic cells to pluripotent stem cells and that artificial silencing of lamin A facilitates iPS cell induction. These findings may have implications in enhancing rejuvenation of senescent or older cells by iPS technology and manipulating lamin A levels.
Different cellular effects of four anti-inflammatory eye drops on human corneal epithelial cells: independent in active components

OpenAIRE

Qu, Mingli; Wang, Yao; Yang, Lingling; Zhou, Qingjun

2011-01-01

Purpose To evaluate and compare the cellular effects of four commercially available anti-inflammatory eye drops and their active components on human corneal epithelial cells (HCECs) in vitro. Methods The cellular effects of four eye drops (Bromfenac Sodium Hydrate Eye Drops, Pranoprofen Eye Drops, Diclofenac Sodium Eye Drops, and Tobramycin & Dex Eye Drops) and their corresponding active components were evaluated in an HCEC line with five in vitro assays. Cell proliferation and migration were...
3-Bromopyruvate inhibits cell proliferation and induces apoptosis in CD133+ population in human glioma.

Science.gov (United States)

Xu, Dong-Qiang; Tan, Xiao-Yu; Zhang, Bao-Wei; Wu, Tao; Liu, Ping; Sun, Shao-Jun; Cao, Yin-Guang

2016-03-01

The study was aimed to investigate the role of 3-bromopyruvate in inhibition of CD133+ U87 human glioma cell population growth. The results demonstrated that 3-bromopyruvate inhibited the viability of both CD133+ and parental cells derived from U87 human glioma cell line. However, the 3-bromopyruvate-induced inhibition in viability was more prominent in CD133+ cells at 10 μM concentration after 48 h. Treatment of CD133+ cells with 3-bromopyruvate caused reduction in cell population and cell size, membrane bubbling, and degradation of cell membranes. Hoechst 33258 staining showed condensation of chromatin material and fragmentation of DNA in treated CD133+ cells after 48 h. 3-Bromopyruvate inhibited the migration rate of CD133+ cells significantly compared to the parental cells. Flow cytometry revealed that exposure of CD133+ cells to 3-bromopyruvate increased the cell population in S phase from 24.5 to 37.9 % with increase in time from 12 to 48 h. In addition, 3-bromopyruvate significantly enhanced the expression of Bax and cleaved caspase 3 in CD133+ cells compared to the parental cells. Therefore, 3-bromopyruvate is a potent chemotherapeutic agent for the treatment of glioma by targeting stem cells selectively.
Population profiles associated with severe functioning difficulties and disability among two to four years old children in Mexico

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Rosalba Rojas-Martínez

2017-07-01

Full Text Available Objective. To describe the prevalence and factors associated with severe child functioning difficulties and disability (CFD among two to four year old children in Mexico, and estimates the probability of presenting CFD based on specific population profiles. Materials and methods. The sample consists of 5 104 children who participated in the National Survey of Children and Women 2015 (ENIM. We used postestimation exploration by computing predicted values of CFD to interpret the logistic models for discrete combinations of the independent variables. Results. CFD prevalence is 2%,which means at least 130 000 two to four year-old children are at risk of experiencing severely limited participation in an unaccommodating environment. The probability of presenting CFD is dramatically higher in specific sub-groups of the population, in particular, male children of women with low education, who live in the poorest households. Conclusions. A significant proportion of Mexican children face important challenges due to functioning difficulties and disability. Public policies must be developed to accommodate the needs of these children and provide a proper environment for their development.
Cell lineage patterns in the shoot meristem of the sunflower embryo in the dry seed

International Nuclear Information System (INIS)

Jegla, D.E.; Sussex, I.M.

1989-01-01

We mapped the fate of cells in the shoot meristem of the dry-seed embryo of sunflower, Helianthus annuus L. cv. Peredovic, using irradiation-induced somatic sectors. We analyzed 249 chlorophyll-deficient or glabrous (hairless) sectors generated in 236 plants. Most sectors observed in the inflorescence extended into vegetative nodes. Thus cell lineages that ultimately gave rise to reproductive structures also contributed to vegetative structures. No single sector extended the entire length of the shoot. Thus the shoot is not derived from one or a few apical initials. Rather, the position, vertical extent, and width of the sectors at different levels of the shoot suggest that the shoot is derived from three to four circumferential populations of cells in each of three cell layers of the embryo meristem. Sectors had no common boundaries even in plants with two or three independent sectors, but varied in extent and overlapped along the length of the shoot. Thus individual cells in a single circumferential population behaved independently to contribute lineages of different vertical extents to the growing shoot. The predicted number of circumferential populations of cells as well as the apparent cell number in each population was consistent with the actual number of cells in the embryo meristem observed in histological sections
Experimental study of relative level populations in beam-foil excited Ar+7 and Kr+7

International Nuclear Information System (INIS)

Bashkin, S.; Oona, H.; Veje, E.

1981-01-01

The relative level populations in beam-foil excited sodium-like argon (Ar VIII) and copper-like krypton (Kr VIII) have been studied at 2 MeV projectile energy. In Ar VIII, the 3p and the 3d terms are strongly excited. The level population decreases rapidly with increasing value of the principal quantum number n, reaches a minimum for levels with n = 5 or 6, but increases then and reaches a strong maximum for levels with n approximately 11. Also the Kr VIII data show a population maximum for levels with n = 11. The strong 3p and 3d level excitations in Ar VIII are explained as selective inner-shell processes which can be understood in the molecular-orbital electron-promotion picture. The preferential population of high-flying Rydberg states is explained as resulting from a near-resonance electron transfer from the valence band of the carbon foil to the projectile. This process takes place when the projectile leaves the back of the foil. (Auth.)
Enthesis fibrocartilage cells originate from a population of Hedgehog-responsive cells modulated by the loading environment.

Science.gov (United States)

Schwartz, Andrea G; Long, Fanxin; Thomopoulos, Stavros

2015-01-01

Tendon attaches to bone across a specialized tissue called the enthesis. This tissue modulates the transfer of muscle forces between two materials, i.e. tendon and bone, with vastly different mechanical properties. The enthesis for many tendons consists of a mineralized graded fibrocartilage that develops postnatally, concurrent with epiphyseal mineralization. Although it is well described that the mineralization and development of functional maturity requires muscle loading, the biological factors that modulate enthesis development are poorly understood. By genetically demarcating cells expressing Gli1 in response to Hedgehog (Hh) signaling, we discovered a unique population of Hh-responsive cells in the developing murine enthesis that were distinct from tendon fibroblasts and epiphyseal chondrocytes. Lineage-tracing experiments revealed that the Gli1 lineage cells that originate in utero eventually populate the entire mature enthesis. Muscle paralysis increased the number of Hh-responsive cells in the enthesis, demonstrating that responsiveness to Hh is modulated in part by muscle loading. Ablation of the Hh-responsive cells during the first week of postnatal development resulted in a loss of mineralized fibrocartilage, with very little tissue remodeling 5 weeks after cell ablation. Conditional deletion of smoothened, a molecule necessary for responsiveness to Ihh, from the developing tendon and enthesis altered the differentiation of enthesis progenitor cells, resulting in significantly reduced fibrocartilage mineralization and decreased biomechanical function. Taken together, these results demonstrate that Hh signaling within developing enthesis fibrocartilage cells is required for enthesis formation. © 2015. Published by The Company of Biologists Ltd.
Area-level poverty and preterm birth risk: A population-based multilevel analysis

Science.gov (United States)

DeFranco, Emily A; Lian, Min; Muglia, Louis A; Schootman, Mario

2008-01-01

Background Preterm birth is a complex disease with etiologic influences from a variety of social, environmental, hormonal, genetic, and other factors. The purpose of this study was to utilize a large population-based birth registry to estimate the independent effect of county-level poverty on preterm birth risk. To accomplish this, we used a multilevel logistic regression approach to account for multiple co-existent individual-level variables and county-level poverty rate. Methods Population-based study utilizing Missouri's birth certificate database (1989–1997). We conducted a multilevel logistic regression analysis to estimate the effect of county-level poverty on PTB risk. Of 634,994 births nested within 115 counties in Missouri, two levels were considered. Individual-level variables included demographics factors, prenatal care, health-related behavioral risk factors, and medical risk factors. The area-level variable included the percentage of the population within each county living below the poverty line (US census data, 1990). Counties were divided into quartiles of poverty; the first quartile (lowest rate of poverty) was the reference group. Results PTB rate of PTB poverty and increased through the 4th quartile (4.9%), p poverty was significantly associated with PTB risk. PTB risk (poverty, adjusted odds ratio (adjOR) 1.18 (95% CI 1.03, 1.35), with a similar effect at earlier gestational ages (birth, above other underlying risk factors. Although the risk increase is modest, it affects a large number of pregnancies. PMID:18793437
Area-level poverty and preterm birth risk: A population-based multilevel analysis

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Muglia Louis A

2008-09-01

Full Text Available Abstract Background Preterm birth is a complex disease with etiologic influences from a variety of social, environmental, hormonal, genetic, and other factors. The purpose of this study was to utilize a large population-based birth registry to estimate the independent effect of county-level poverty on preterm birth risk. To accomplish this, we used a multilevel logistic regression approach to account for multiple co-existent individual-level variables and county-level poverty rate. Methods Population-based study utilizing Missouri's birth certificate database (1989–1997. We conducted a multilevel logistic regression analysis to estimate the effect of county-level poverty on PTB risk. Of 634,994 births nested within 115 counties in Missouri, two levels were considered. Individual-level variables included demographics factors, prenatal care, health-related behavioral risk factors, and medical risk factors. The area-level variable included the percentage of the population within each county living below the poverty line (US census data, 1990. Counties were divided into quartiles of poverty; the first quartile (lowest rate of poverty was the reference group. Results PTB th quartile (4.9%, p adjOR 1.18 (95% CI 1.03, 1.35, with a similar effect at earlier gestational ages (adjOR 1.27 (95% CI 1.06, 1.52. Conclusion Women residing in socioeconomically deprived areas are at increased risk of preterm birth, above other underlying risk factors. Although the risk increase is modest, it affects a large number of pregnancies.
Systematics and Population Level Analysis of Anopheles darlingi

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Conn JE

1998-01-01

Full Text Available A new phylogenetic analysis of the Nyssorhynchus subgenus (Danoff-Burg and Conn, unpub. data using six data sets {morphological (all life stages; scanning electron micrographs of eggs; nuclear ITS2 sequences; mitochondrial COII, ND2 and ND6 sequences} revealed different topologies when each data set was analyzed separately but no heterogeneity between the data sets using the arn test. Consequently, the most accurate estimate of the phylogeny was obtained when all the data were combined. This new phylogeny supports a monophyletic Nyssorhynchus subgenus but both previously recognized sections in the subgenus (Albimanus and Argyritarsis were demonstrated to be paraphyletic relative to each other and four of the seven clades included species previously placed in both sections. One of these clades includes both Anopheles darlingi and An. albimanus, suggesting that the ability to vector malaria effectively may have originated once in this subgenus. Both a conserved (315 bp and a variable (425 bp region of the mitochondrial COI gene from 15 populations of An. darlingi from Belize, Bolivia, Brazil, French Guiana, Peru and Venezuela were used to examine the evolutionary history of this species and to test several analytical assumptions. Results demonstrated (1 parsimony analysis is equally informative compared to distance analysis using NJ; (2 clades or clusters are more strongly supported when these two regions are combined compared to either region separately; (3 evidence (in the form of remnants of older haplotype lineages for two colonization events; and (4 significant genetic divergence within the population from Peixoto de Azevedo (State of Mato Grosso, Brazil. The oldest lineage includes populations from Peixoto, Boa Vista (State of Roraima and Dourado (State of São Paulo.
A Four-Level T-Type Neutral Point Piloted Inverter for Solar Energy Applications

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Saddam Shueai Alnamer

2018-06-01

Full Text Available Multilevel inverters provide an output signal with low harmonic distortion and superior output voltages. This work proposes a new four-level T-type neutral point piloted (T-NPP topology with higher efficiency and low total harmonic distortion (THD and with the ability to withstand high voltage stresses, especially for high-power applications. The proposed topology is designed in such manner that the direct current (DC-voltage stresses split over the components with strong possibilities to increase the load current and switching frequency. However, the operation of the proposed topology is based on two essential principles. The first principle is that each upper and lower switch of each leg consists of two insulated gate bipolar transistors (IGBTs connected in series in order to withstand high voltage stresses and make it split over the two IGBTs in each switch. The second principle is using the DC-link circuit (T1 & T2 to generate 2Vdc and 1Vdc by connecting the bidirectional switches of each leg to the DC-link’s mid-point. Furthermore, the proposed four-level T-NPP inverter outperforms other converters by the high number of output voltage level, low number of components, simple structure and higher efficiency. Finally, the proposed T-NPP topology concept was validated via simulation, experiments and theoretical analysis.

Calcium Imaging Reveals Coordinated Simple Spike Pauses in Populations of Cerebellar Purkinje Cells

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Jorge E. Ramirez

2016-12-01

Full Text Available The brain’s control of movement is thought to involve coordinated activity between cerebellar Purkinje cells. The results reported here demonstrate that somatic Ca2+ imaging is a faithful reporter of Na+-dependent “simple spike” pauses and enables us to optically record changes in firing rates in populations of Purkinje cells in brain slices and in vivo. This simultaneous calcium imaging of populations of Purkinje cells reveals a striking spatial organization of pauses in Purkinje cell activity between neighboring cells. The source of this organization is shown to be the presynaptic gamma-Aminobutyric acid producing (GABAergic network, and blocking ionotropic gamma-Aminobutyric acid receptor (GABAARs abolishes the synchrony. These data suggest that presynaptic interneurons synchronize (inactivity between neighboring Purkinje cells, and thereby maximize their effect on downstream targets in the deep cerebellar nuclei.
Genetic structure of four socio-culturally diversified caste populations of southwest India and their affinity with related Indian and global groups

Science.gov (United States)

Rajkumar, Revathi; Kashyap, VK

2004-01-01

Background A large number of microsatellites have been extensively used to comprehend the genetic diversity of different global groups. This paper entails polymorphism at 15 STR in four predominant and endogamous populations representing Karnataka, located on the southwest coast of India. The populations residing in this region are believed to have received gene flow from south Indian populations and world migrants, hence, we carried out a detailed study on populations inhabiting this region to understand their genetic structure, diversity related to geography and linguistic affiliation and relatedness to other Indian and global migrant populations. Results Various statistical analyses were performed on the microsatellite data to accomplish the objectives of the paper. The heretozygosity was moderately high and similar across the loci, with low average GST value. Iyengar and Lyngayat were placed above the regression line in the R-matrix analysis as opposed to the Gowda and Muslim. AMOVA indicated that majority of variation was confined to individuals within a population, with geographic grouping demonstrating lesser genetic differentiation as compared to linguistic clustering. DA distances show the genetic affinity among the southern populations, with Iyengar, Lyngayat and Vanniyar displaying some affinity with northern Brahmins and global migrant groups from East Asia and Europe. Conclusion The microsatellite study divulges a common ancestry for the four diverse populations of Karnataka, with the overall genetic differentiation among them being largely confined to intra-population variation. The practice of consanguineous marriages might have attributed to the relatively lower gene flow displayed by Gowda and Muslim as compared to Iyengar and Lyngayat. The various statistical analyses strongly suggest that the studied populations could not be differentiated on the basis of caste or spatial location, although, linguistic affinity was reflected among the southern
Genetic structure of four socio-culturally diversified caste populations of southwest India and their affinity with related Indian and global groups

Directory of Open Access Journals (Sweden)

Rajkumar Revathi

2004-08-01

Full Text Available Abstract Background A large number of microsatellites have been extensively used to comprehend the genetic diversity of different global groups. This paper entails polymorphism at 15 STR in four predominant and endogamous populations representing Karnataka, located on the southwest coast of India. The populations residing in this region are believed to have received gene flow from south Indian populations and world migrants, hence, we carried out a detailed study on populations inhabiting this region to understand their genetic structure, diversity related to geography and linguistic affiliation and relatedness to other Indian and global migrant populations. Results Various statistical analyses were performed on the microsatellite data to accomplish the objectives of the paper. The heretozygosity was moderately high and similar across the loci, with low average GST value. Iyengar and Lyngayat were placed above the regression line in the R-matrix analysis as opposed to the Gowda and Muslim. AMOVA indicated that majority of variation was confined to individuals within a population, with geographic grouping demonstrating lesser genetic differentiation as compared to linguistic clustering. DA distances show the genetic affinity among the southern populations, with Iyengar, Lyngayat and Vanniyar displaying some affinity with northern Brahmins and global migrant groups from East Asia and Europe. Conclusion The microsatellite study divulges a common ancestry for the four diverse populations of Karnataka, with the overall genetic differentiation among them being largely confined to intra-population variation. The practice of consanguineous marriages might have attributed to the relatively lower gene flow displayed by Gowda and Muslim as compared to Iyengar and Lyngayat. The various statistical analyses strongly suggest that the studied populations could not be differentiated on the basis of caste or spatial location, although, linguistic affinity was
Genetic structure of four socio-culturally diversified caste populations of southwest India and their affinity with related Indian and global groups.

Science.gov (United States)

Rajkumar, Revathi; Kashyap, V K

2004-08-19

A large number of microsatellites have been extensively used to comprehend the genetic diversity of different global groups. This paper entails polymorphism at 15 STR in four predominant and endogamous populations representing Karnataka, located on the southwest coast of India. The populations residing in this region are believed to have received gene flow from south Indian populations and world migrants, hence, we carried out a detailed study on populations inhabiting this region to understand their genetic structure, diversity related to geography and linguistic affiliation and relatedness to other Indian and global migrant populations. Various statistical analyses were performed on the microsatellite data to accomplish the objectives of the paper. The heretozygosity was moderately high and similar across the loci, with low average GST value. Iyengar and Lyngayat were placed above the regression line in the R-matrix analysis as opposed to the Gowda and Muslim. AMOVA indicated that majority of variation was confined to individuals within a population, with geographic grouping demonstrating lesser genetic differentiation as compared to linguistic clustering. DA distances show the genetic affinity among the southern populations, with Iyengar, Lyngayat and Vanniyar displaying some affinity with northern Brahmins and global migrant groups from East Asia and Europe. The microsatellite study divulges a common ancestry for the four diverse populations of Karnataka, with the overall genetic differentiation among them being largely confined to intra-population variation. The practice of consanguineous marriages might have attributed to the relatively lower gene flow displayed by Gowda and Muslim as compared to Iyengar and Lyngayat. The various statistical analyses strongly suggest that the studied populations could not be differentiated on the basis of caste or spatial location, although, linguistic affinity was reflected among the southern populations, distinguishing them
Similar levels of diversity and population Structure in superflock and ...

African Journals Online (AJOL)

superflock cichlid fishes from Lake Victoria, Africa. ... Tropical Freshwater Biology ... We use DNA microsatellite loci to estimate neutral genetic diversity and the level of gene flow among populations of two cichlid species from southern Lake Victoria, ...
Heterogeneity of breast cancer stem cells as evidenced with Notch-dependent and Notch-independent populations

International Nuclear Information System (INIS)

Wong, Nelson K Y; Fuller, Megan; Sung, Sandy; Wong, Fred; Karsan, Aly

2012-01-01

Studies have suggested the potential importance of Notch signaling to the cancer stem cell population in some tumors, but it is not known whether all cells in the cancer stem cell fraction require Notch activity. To address this issue, we blocked Notch activity in MCF-7 cells by expressing a dominant-negative MAML-GFP (dnMAML) construct, which inhibits signaling through all Notch receptors, and quantified the effect on tumor-initiating activity. Inhibition of Notch signaling reduced primary tumor sphere formation and side population. Functional quantification of tumor-initiating cell numbers in vivo showed a significant decrease, but not a complete abrogation, of these cells in dnMAML-expressing cells. Interestingly, when assessed in secondary assays in vitro or in vivo, there was no difference in tumor-initiating activity between the dnMAML-expressing cells and control cells. The fact that a subpopulation of dnMAML-expressing cells was capable of forming primary and secondary tumors indicates that there are Notch-independent tumor-initiating cells in the breast cancer cell line MCF-7. Our findings thus provide direct evidence for a heterogeneous cancer stem cell pool, which will require combination therapies against multiple oncogenic pathways to eliminate the tumor-initiating cell population
The epidermis comprises autonomous compartments maintained by distinct stem cell populations

DEFF Research Database (Denmark)

Page, Mahalia E; Lombard, Patrick; Ng, Felicia

2013-01-01

populations. In contrast, upon wounding, stem cell progeny from multiple compartments acquire lineage plasticity and make permanent contributions to regenerating tissue. We further show that oncogene activation in Lrig1(+ve) cells drives hyperplasia but requires auxiliary stimuli for tumor formation....... In summary, our data demonstrate that epidermal stem cells are lineage restricted during homeostasis and suggest that compartmentalization may constitute a conserved mechanism underlying epithelial tissue maintenance....
Effects of x irradiation on the postnatally-forming granule cell populations in the olfactory bulb, hippocampus, and cerebellum of the rat

International Nuclear Information System (INIS)

Bayer, S.A.; Altman, J.

1975-01-01

Beginning on the second postnatal day, either two (2X group), four (4X group) or six (6X group) daily or alternate daily exposures to low-level x irradiation (150 to 200 R) were used to interfere with the acquisition of granule cells in the olfactory bulb, hippocampus, and cerebellum of the rat. At 60 days of age, the relationship between post-irradiation recovery and permanent granule cell loss was assessed with two quantitative techniques. First, the total number of granule cells was determined to estimate the magnitude of permanent loss. Secondly, the number of labeled granule cells were counted on day 60 after a 3 H-thymidine injection given on either day 15 or on day 20 to estimate differential rates of cell proliferation during the recovery period. Permanent loss of granule cells was sustained in all regions by all schedules of irradiation. The time for the most effective exposures was earlier in the hippocampus and olfactory bulb than in the cerebellum. In all regions, both the irradiated groups and the controls showed a decrease in the level of cell proliferation between 15 and 20 days. The number of cells that could be labeled after either the 15 or 20 day injection was below control levels for all groups in the hippocampus, at control levels for all groups in the cerebellum, and either at (2X and 4X) or below (6X) control levels in the olfactory bulb. These results are discussed in the light of the formation time of the granule cells in each region
Effects of x-irradiation on the postnatally-forming granule cell populations in the olfactory bulb, hippocampus, and cerebellum of the rat

International Nuclear Information System (INIS)

Bayer, S.A.; Altman, J.

1975-01-01

Beginning on the second postnatal day, either two (2X group), four (4X group) or six (6X group) daily or alternate daily exposures to low-level x irradiation (150-200 r) were used to interfere with the acquisition of granule cells in the olfactory bulb, hippocampus, and cerebellum of the rat. At 60 days of age, the relationship between post-irradiation recovery and permanent granule cell loss was assessed with two quantitative techniques. First, the total number of granule cells was determined to estimate the magnitude of permanent loss. Secondly, the number of labeled granule cells were counted on day 60 after a 3 H-thymidine injection given on either day 15 or on day 20 to estimate differential rates of cell proliferation during the recovery period. Permanent loss of granule cells was sustained in all regions by all schedules of irradiation. The time for the most effective exposures was earlier in the hippocampus and olfactory bulb than in the cerebellum. In all regions, both the irradiated groups and the controls showed a decrease in the level of cell proliferation between 15 and 20 days. The number of cells that could be labeled after either the 15 or 20 day injection was below control levels for all groups in the hippocampus, at control levels for all groups in the cerebellum, and either at (2X and 4X) or below (6X) control levels in the olfactory bulb. These results are discussed in the light of the formation time of the granule cells in each region
Dengue viral RNA levels in peripheral blood mononuclear cells are associated with disease severity and preexisting dengue immune status.

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Anon Srikiatkhachorn

Full Text Available Infection with dengue viruses (DENV causes a wide range of manifestations from asymptomatic infection to a febrile illness called dengue fever (DF, to dengue hemorrhagic fever (DHF. The in vivo targets of DENV and the relation between the viral burden in these cells and disease severity are not known.The levels of positive and negative strand viral RNA in peripheral blood monocytes, T/NK cells, and B cells and in plasma of DF and DHF cases were measured by quantitative RT-PCR.Positive strand viral RNA was detected in monocytes, T/NK cells and B cells with the highest amounts found in B cells. Viral RNA levels in CD14+ cells and plasma were significantly higher in DHF compared to DF, and in cases with a secondary infection compared to those undergoing a primary infection. The distribution of viral RNA among cell subpopulations was similar in DF and DHF cases. Small amounts of negative strand RNA were found in a few cases only. The severity of plasma leakage correlated with viral RNA levels in plasma and in CD14+ cells.B cells were the principal cells containing DENV RNA in peripheral blood, but overall there was little active DENV RNA replication detectable in peripheral blood mononuclear cells (PBMC. Secondary infection and DHF were associated with higher viral burden in PBMC populations, especially CD14+ monocytes, suggesting that viral infection of these cells may be involved in disease pathogenesis.
Yeast cells contain a heterogeneous population of peroxisomes that segregate asymmetrically during cell division

NARCIS (Netherlands)

Kumar, Sanjeev; de Boer, Rinse; van der Klei, Ida J

2018-01-01

Here we used fluorescence microscopy and a peroxisome-targeted tandem fluorescent protein timer to determine the relative age of peroxisomes in yeast. Our data indicate that yeast cells contain a heterogeneous population of relatively old and younger peroxisomes. During budding the peroxisome
Coherent population dynamics of a three-level atom in spacetime

International Nuclear Information System (INIS)

Netz, R.; Sauerbrey, R.; Feurer, T.; Roberts, G.

2002-01-01

This work explores temporal and spatial aspects of coherent population transfer in a three-level atom through a synergic combination of experimental measurements and theoretical calculations. Experimental measurements exploit the broad bandwidth of a femtosecond laser pulse to initiate simultaneous excitation of the 5p 2 P 1/2 2 S 1/2 and 5p 2 P 3/2 2 S 1/2 components of the doublet line of atomic rubidium. By adjusting positive or negative frequency sweeps the pump pulse favors either one of the two transitions and eventually even decouples the two excited states. The population of the excited spin-orbit levels is monitored in real time by stimulated emission probing under conditions of different intensity, chirp, and pulse width of the driving field, giving detailed information on the coupling between the three levels and their interactions with the driving and probe fields at different points in spacetime. Both pump and probe pulses are carefully characterized after the interaction region by frequency-resolved optical gating. In order to interpret and understand the experimental results it is essential to consider the close relationship between pulse propagation and time evolution of the atomic system via the coupled Maxwell-Bloch equations. This analysis highlights the importance of spatial propagation of the light fields, as well as their temporal dependence, in understanding the dynamical population evolution, and quantitatively reproduces all aspects of the experimental measurements
Survey of studies of occupational populations exposed to low-level radiation

International Nuclear Information System (INIS)

Marks, S.

1980-04-01

Studies of occupational populations exposed to large doses of radiation, principally from the ingestion of radium by dial painters and inhalation of radon and its daughters by miners, have provided important information on the health effects of those radioisotopes. Studies of medical radiologists, military personnel exposed to nuclear tests, and factory workers exposed to thorium are in progress. Employees of DOE-contractor facilities and of naval shipyards are also under study. Personnel dosimetry data are generally available for the latter category of occupational populations. Reasons for conducting the studies include interest in exploring the verification at low exposure levels of results of studies of heavily exposed populations and the responsibility of the employer to maintain adequate surveillance of the health of his workers by conducting appropriate epidemiologic studies. The low level of exposure of workers in facilities where adequate personnel dosimetry records are available make it unlikely that the results of such studies can be used to provide health risk estimates in the near future
Monitoring serum PCB levels in the adult population of the Canary Islands (Spain

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Guillermo Burillo-Putze

2015-07-01

Full Text Available Polychlorinated biphenyls (PCBs are persistent organic chemicals that have been detected in human serum or tissues all over the world. These pollutants could exert a number of deleterious effects on humans and wildlife, including carcinogenic processes. The Spanish population of the Canary Islands was evaluated with respect to PCB levels more than ten years ago showing lower levels than other Western populations. The objective of our study was to assess the current level of contamination by PCBs showed by this population. We measured serum PCBs in a sample of healthy adult subjects (206 serum samples from subjects with an average age of 66 years old to evaluate the potential modification of PCB serum levels in this population during the last decade. PCB congeners (28, 52, 77, 81, 101, 105, 114, 118, 123, 126, 138, 153, 156, 157, 167, 169, 180, and 189 were measured by gas chromatography-mass spectrometry (GC/MS. Our results showed that PCB residues were found in 84% of serum samples analyzed, the congeners 28, 153 and 180 being the most frequently detected and at the highest median values (0.1 ng/mL. In addition, the median concentration of the sum of those PCBs considered as markers of environmental contamination by these chemicals (Marker-PCBs was 0.6 ng/mL, reaching values as high as as 2.6 ng/mL in the 95th percentile. Levels of the sum of PCBs with toxic effects similar to dioxins (dioxin-like PCBs reached median values of 0.4 ng/mL in the 95th percentile. The reported levels are similar to those described previously in this population more than ten years ago, in the sense that the inhabitants of the Canary Archipelago show levels of PCB contamination lower than the majority of populations from developed countries. These findings suggest that currently there is not any active source of these chemicals in this archipelago. Nevertheless, as foods seem to be a relevant source for these compounds, Public Health authorities should monitor the
Glutamic acid decarboxylase 67 expression by a distinct population of mouse vestibular supporting cells.

Science.gov (United States)

Tavazzani, Elisa; Tritto, Simona; Spaiardi, Paolo; Botta, Laura; Manca, Marco; Prigioni, Ivo; Masetto, Sergio; Russo, Giancarlo

2014-01-01

The function of the enzyme glutamate decarboxylase (GAD) is to convert glutamate in γ-aminobutyric acid (GABA). Glutamate decarboxylase exists as two major isoforms, termed GAD65 and GAD67, that are usually expressed in GABA-containing neurons in the central nervous system. GAD65 has been proposed to be associated with GABA exocytosis whereas GAD67 with GABA metabolism. In the present immunofluorescence study, we have investigated the presence of the two GAD isoforms in the semicircular canal cristae of wild type and GAD67-GFP knock-in mice. While no evidence for GAD65 expression was found, GAD67 was detected in a distinct population of peripherally-located supporting cells, but not in hair cells or in centrally-located supporting cells. GABA, on the other hand, was found in all supporting cells. The present result indicate that only a discrete population of supporting cells use GAD67 to synthesize GABA. This is the first report of a marker that allows to distinguish two populations of supporting cells in the vestibular epithelium. On the other hand, the lack of GABA and GAD enzymes in hair cells excludes its involvement in afferent transmission.
Glutamic acid decarboxylase 67 expression by a distinct population of mouse vestibular supporting cells

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Giancarlo eRusso

2014-12-01

Full Text Available The function of the enzyme glutamate decarboxylase (GAD is to convert glutamate in -aminobutyric acid (GABA.GAD exists as two major isoforms, termed GAD65 and GAD67,.that are usually expressed in GABA-containing neurons in the central nervous system. GAD65 has been proposed to be associated with GABA exocytosis whereas GAD67 with GABA metabolism. In the present immunofluorescence study, we have investigated the presence of the two GAD isoforms in the semicircular canal cristae of wild type and GAD67-GFP knock-in mice. While no evidence for GAD65 expression was found, GAD67 was detected in a distinct population of peripherally-located supporting cells, but not in hair cells or in centrally-located supporting cells. GABA, on the other hand, was found in all supporting cells. The present result indicate that only a discrete population of supporting cells use GAD67 to synthesize GABA. This is the first report of a marker that allows to distinguish two populations of supporting cells in the vestibular epithelium. On the other hand, the lack of GABA and GAD enzymes in hair cells excludes its involvement in afferent transmission.
A common reference population from four European Holstein populations increases reliability of genomic predictions

DEFF Research Database (Denmark)

Lund, Mogens Sandø; de Ross, Sander PW; de Vries, Alfred G

2011-01-01

Background Size of the reference population and reliability of phenotypes are crucial factors influencing the reliability of genomic predictions. It is therefore useful to combine closely related populations. Increased accuracies of genomic predictions depend on the number of individuals added to...
The CD4+CD26-T-cell population in classical Hodgkin's lymphoma displays a distinctive regulatory T-cell profile

NARCIS (Netherlands)

Ma, Yue; Visser, Lydia; Blokzijl, Tjasso; Harms, Geert; Atayar, Cigdem; Poppema, Sibrand; van den Berg, Anke

Little is known about the gene expression profile and significance of the rosetting CD4+CD26- T cells in classical Hodgkin's lymphoma (cHL). To characterize these T cells, CD4+CD26- and CD4+CD26+ T-cell populations were sorted from lymph node (LN) cell suspensions from nodular sclerosis HL (NSHL)
[Vitamin B12 levels in the patient population attending an urban health centre in Madrid].

Science.gov (United States)

Camarero-Shelly, M

2018-04-01

Vitamin B 12 levels are usually measured in Primary Care when the patients have symptoms or risk factors associated with its deficiency, mostly in the elderly. However, no evidence has been found to support the recommendation of screening in the general population. The aim of this study is to assess the relevance of having extended the screening of vitamin B 12 deficiency to a younger population, after observing an increase in the prescription of this injected vitamin in a population under 65 years, by analysing the vitamin B 12 values obtained. A descriptive, retrospective, observational study was conducted on a sample consisting of 5,531 patients from Barajas Health Primary Centre, Madrid, between 2008 and 2012, and on whom a blood test was performed for any reason, with values of vitamin B 12 . A deficiency was found in 9.1% (SD 2.3) of the patients, of whom 49.4% were less than 65 years. The deficiencies were associated (P<.001, 95% CI) with age, dementia, changes in blood red cell counts, memory, and with the taking of metformin and proton pump inhibitors (P=.007). The prevalence of vitamin B 12 deficiency in our served population is similar in patients older and younger than 65 years. The extended screening was relevant. Copyright © 2017 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España, S.L.U. All rights reserved.
Expression of genes encoding multi-transmembrane proteins in specific primate taste cell populations.

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Bryan D Moyer

Full Text Available BACKGROUND: Using fungiform (FG and circumvallate (CV taste buds isolated by laser capture microdissection and analyzed using gene arrays, we previously constructed a comprehensive database of gene expression in primates, which revealed over 2,300 taste bud-associated genes. Bioinformatics analyses identified hundreds of genes predicted to encode multi-transmembrane domain proteins with no previous association with taste function. A first step in elucidating the roles these gene products play in gustation is to identify the specific taste cell types in which they are expressed. METHODOLOGY/PRINCIPAL FINDINGS: Using double label in situ hybridization analyses, we identified seven new genes expressed in specific taste cell types, including sweet, bitter, and umami cells (TRPM5-positive, sour cells (PKD2L1-positive, as well as other taste cell populations. Transmembrane protein 44 (TMEM44, a protein with seven predicted transmembrane domains with no homology to GPCRs, is expressed in a TRPM5-negative and PKD2L1-negative population that is enriched in the bottom portion of taste buds and may represent developmentally immature taste cells. Calcium homeostasis modulator 1 (CALHM1, a component of a novel calcium channel, along with family members CALHM2 and CALHM3; multiple C2 domains; transmembrane 1 (MCTP1, a calcium-binding transmembrane protein; and anoctamin 7 (ANO7, a member of the recently identified calcium-gated chloride channel family, are all expressed in TRPM5 cells. These proteins may modulate and effect calcium signalling stemming from sweet, bitter, and umami receptor activation. Synaptic vesicle glycoprotein 2B (SV2B, a regulator of synaptic vesicle exocytosis, is expressed in PKD2L1 cells, suggesting that this taste cell population transmits tastant information to gustatory afferent nerve fibers via exocytic neurotransmitter release. CONCLUSIONS/SIGNIFICANCE: Identification of genes encoding multi-transmembrane domain proteins

Paclitaxel-resistant HeLa cells have up-regulated levels of reactive oxygen species and increased expression of taxol resistance gene 1.

Science.gov (United States)

Bi, Wenxiang; Wang, Yuxia; Sun, Gaoying; Zhang, Xiaojin; Wei, Yongqing; Li, Lu; Wang, Xiaoyuan

2014-07-01

This study is to establish a paclitaxel (PTX)-resistant human cervical carcinoma HeLa cell line (HeLa/PTX) and to investigate its redox characteristics and the expression of taxol resistance gene 1 (Txr1). HeLa cells were treated with PTX and effects of PTX on cell proliferation were detected through cell counting and the MTT assay. Levels of cellular reactive oxygen species (ROS), reduced glutathione (GSH), and oxidized glutathione (GSSG) as well as the ratio of GSH to GSSG were measured by the 2,7-difluorescein diacetate (DCFH-DA) method and the 5,5'dithiobis(2-nitrobenzoic acid) (DTNB) method. Activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were determined by the nitrite formation method, the molybdate colorimetric method, and the DTNB colorimetric method, respectively. The level of Txr1 mRNA was determined by real-time PCR. Compared with the regular HeLa cells, HeLa/PTX cells were larger in size and had more cytoplasmic granules. The population doubling time for HeLa/PTX cells was 1.32 times of that of HeLa cells (PHeLa/PTX cells showed stronger resistance to PTX than HeLa cells with a resistance index of 122.69. HeLa/PTX cells had higher levels of ROS (PHeLa cells. HeLa/PTX cells, with higher levels of ROS and Txr1 mRNA expression, are more resistant to PTX than HeLa cells.
Study of probiotic potential of four wild Lactobacillus rhamnosus strains.

Science.gov (United States)

Tuo, Yanfeng; Zhang, Weiqin; Zhang, Lanwei; Ai, Lianzhong; Zhang, Yingchun; Han, Xue; Yi, Huaxi

2013-06-01

The four wild Lactobacillus rhamnosus strains were examined in vitro for resistance to simulated gastro and intestinal juices, adhesion to HT-29 cells, antagonistic activity against enteric pathogens and immunomodulating activity. The strains L. rhamnosus SB5L, J5L and IN1L were able to survive in simulated gastro juice while the strain L. rhamnosus SB31L lost viability exposed to simulated gastro juice for 3 h. The four strains had high viability in simulated small intestinal juice with little loss (<1.0 cycle reduction). The strains SB5L, J5L and IN1L antagonized against Escherichia coli ATCC 25922, Salmonella enterica serovar Typhimurium ATCC 14028, Shigella sonnei ATCC 25931. The strain L. rhamnosus IN1L had the highest adhesive capability to HT-29 cells in vitro (251 bacteria cells per 100 HT-29 cells) compared to the other three L. rhamnosus strains. The live bacteria, cell wall and DNA of the four L. rhamnosus induced the secretion of pro-inflammatory cytokines IL-12 (p70), IFN-γ and TNF-α by human peripheral blood mononuclear cells (PBMCs). The levels of IL-12 (p70), IFN-γ and TNF-α produced by stimulated PBMCs were significantly higher (P < 0.05) than those of the control. Those data indicated that the four L. rhamnosus strains have the potential as the probiotic for human being use, although further studies are still needed. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.
Berberine diminishes side population and down-regulates stem cell-associated genes in the pancreatic cancer cell lines PANC-1 and MIA PaCa-2.

Science.gov (United States)

Park, S H; Sung, J H; Chung, N

2014-09-01

Cancer stem cells play an important role in metastasis and the relapse of drug resistant cancers. Side-population (SP) cells are capable of effluxing Hoechst 33342 dye and are referred to as cancer stem cells. We investigated the effect of berberine on pancreatic cancer stem cells of PANC-1 and MIA PaCa-2. For both cell lines, the proportions of SP cells in the presence of berberine were investigated and compared to the proportions in the presence of gemcitabine, a standard pancreatic anti-cancer drug. The proportions of SP cells in the PANC-1 and MIA PaCa-2 cell lines were about 9 and PANC-1 decreased to 5.7 ± 2.0 and 6.8 ± 0.8%, respectively, which compares to the control proportion of (9.7 ± 1.7). After berberine and gemcitabine treatment of PANC-1, of the four stem cell-associated genes (SOX2, POU5F1, NANOG, and NOTCH1), all but NOTCH1 were down-regulated. Unfortunately, the effect of berberine and gemcitabine treatments on MIA PaCa-2 SP cells could not be clearly observed because SP cells represented only a very small proportion of MIA PaCa-2 cells. However, SOX2, POU5F1, and NANOG genes were shown to be effectively down-regulated in the MIA PaCa-2 cell line as a whole. Taken together, these results indicate that berberine is as effective at targeting pancreatic cancer cell lines as gemcitabine. Therefore, we believe that POU5F1, SOX2, and NANOG can serve as potential markers, and berberine may be an effective anti-cancer agent when targeting human pancreatic cancer cells and/or their cancer stem cells.
A Fast-Processing Modulation Strategy for Three-Phase Four-Leg Neutral-Point-Clamped Inverter Based on the Circuit-Level Decoupling Concept

DEFF Research Database (Denmark)

Ghoreishy, Hoda; Zhang, Zhe; Thomsen, Ole Cornelius

2012-01-01

In this paper, a modulation strategy based on the circuit-level decoupling concept is proposed and investigated for the three-level four-leg neutral-point-clamped (NPC) inverter,with the aim of delivering power to all sorts of loads, linear/nonlinear and balanced/unbalanced. By applying the propo......In this paper, a modulation strategy based on the circuit-level decoupling concept is proposed and investigated for the three-level four-leg neutral-point-clamped (NPC) inverter,with the aim of delivering power to all sorts of loads, linear/nonlinear and balanced/unbalanced. By applying...... the proposed modulation strategy, the four-leg NPC inverter can be decoupled into three three-level Buck converters in each defined operating section. This makes the controller design much simpler compared to the conventional four-leg NPC inverter controllers. Also, this technique can be implemented...
Physiological heterogeneities in microbial populations and implications for physical stress tolerance

DEFF Research Database (Denmark)

Carlquist, Magnus; Fernandes, Rita Lencastre; Helmark, Søren

2012-01-01

Background: Traditionally average values of the whole population are considered when analysing microbial cell cultivations. However, a typical microbial population in a bioreactor is heterogeneous in most phenotypes measurable at a single-cell level. There are indications that such heterogeneity...
Cervical level IIb metastases in squamous cell carcinoma of the oral cavity: a systematic review and meta-analysis

Directory of Open Access Journals (Sweden)

Kou Y

2017-09-01

Full Text Available Yurong Kou,1,* Tengfei Zhao,2,* Shaohui Huang,2 Jie Liu,3 Weiyi Duan,2 Yunjing Wang,2 Zechen Wang,2 Delong Li,2 Chunliu Ning,2 Changfu Sun2 1Department of Oral Biology, School of Stomatology, China Medical University, Shenyang, Liaoning, People’s Republic of China; 2Department of Oral and Maxillofacial Surgery, School of Stomatology, China Medical University, Shenyang, Liaoning, People’s Republic of China; 3Centre of Science Experiment, China Medical University, Shenyang, Liaoning, People’s Republic of China *These authors contributed equally to this work Purpose: The aim of this study was to clarify whether level IIb dissection should be performed or avoided in the treatment of oral squamous cell carcinoma by meta-analysis.Materials and methods: Articles that were published before June 2017 were searched electronically in four databases (Web of Science, PubMed, Ovid and China National Knowledge Infrastructure without any date or language restrictions by two independent reviewers. Abstracts and full-text papers which investigated the cervical metastases to level IIb from primary head and neck cancers and were deemed potentially relevant were screened. Data were analyzed using RevMan 5.3.Results: Four hundred and fifty-five abstracts and 129 full-text papers were screened, and 22 studies were included in the analysis. Among the 2001 patients included, 112 patients had level IIb metastases, the pooled frequency of which was 6% (95% confidence interval [CI]: 4.0–7.0. Among the 400 patients with tongue squamous cell carcinoma from 12 studies, 37 patients had level IIb metastases, the pooled incidence of which was 7% (95% CI: 5.0–10.0. Metastases to level IIb always went together with level IIa, and only three patients were found to have isolated level IIb metastases without involving the other levels.Conclusion: Due to the low frequency of level IIb nodal metastases in oral squamous cell carcinoma patients and rare occurrence of isolated
CAMAC-controlled 4-level discriminator with four settable threshold levels

International Nuclear Information System (INIS)

Ujiie, N.; Ikeda, M.

1989-01-01

A CAMAC-controlled discriminator containing four input channels per module has been developed to provide a fast trigger signal for the TOPAZ barrel electromagnetic calorimeter. The calorimeter consists of 4300 lead-glass counters constructed and operated at the e + e - collider at KEK. The performance of the discriminator obtained in a test and in a real setup with cosmic ray is described. (orig.)
The effects of spatial and temporal heterogeneity on the population dynamics of four animal species in a Danish landscape

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Forchhammer Mads C

2009-06-01

Full Text Available Abstract Background Variation in carrying capacity and population return rates is generally ignored in traditional studies of population dynamics. Variation is hard to study in the field because of difficulties controlling the environment in order to obtain statistical replicates, and because of the scale and expense of experimenting on populations. There may also be ethical issues. To circumvent these problems we used detailed simulations of the simultaneous behaviours of interacting animals in an accurate facsimile of a real Danish landscape. The models incorporate as much as possible of the behaviour and ecology of skylarks Alauda arvensis, voles Microtus agrestis, a ground beetle Bembidion lampros and a linyphiid spider Erigone atra. This allows us to quantify and evaluate the importance of spatial and temporal heterogeneity on the population dynamics of the four species. Results Both spatial and temporal heterogeneity affected the relationship between population growth rate and population density in all four species. Spatial heterogeneity accounted for 23–30% of the variance in population growth rate after accounting for the effects of density, reflecting big differences in local carrying capacity associated with the landscape features important to individual species. Temporal heterogeneity accounted for 3–13% of the variance in vole, skylark and spider, but 43% in beetles. The associated temporal variation in carrying capacity would be problematic in traditional analyses of density dependence. Return rates were less than one in all species and essentially invariant in skylarks, spiders and beetles. Return rates varied over the landscape in voles, being slower where there were larger fluctuations in local population sizes. Conclusion Our analyses estimated the traditional parameters of carrying capacities and return rates, but these are now seen as varying continuously over the landscape depending on habitat quality and the mechanisms
Carrier population control and surface passivation in solar cells

KAUST Repository

Cuevas, Andres

2018-05-02

Controlling the concentration of charge carriers near the surface is essential for solar cells. It permits to form regions with selective conductivity for either electrons or holes and it also helps to reduce the rate at which they recombine. Chemical passivation of the surfaces is equally important, and it can be combined with population control to implement carrier-selective, passivating contacts for solar cells. This paper discusses different approaches to suppress surface recombination and to manipulate the concentration of carriers by means of doping, work function and charge. It also describes some of the many surface-passivating contacts that are being developed for silicon solar cells, restricted to experiments performed by the authors.
Population-level impacts of pesticide-induced chronic effects on individuals depend more on ecology than toxicology

DEFF Research Database (Denmark)

Dalkvist, Trine; Topping, Christopher John; Forbes, Valery, E.

2009-01-01

at the population-level. Here we demonstrate how, using ABM modelling, assessments at the population-level can be obtained even for a pesticide with complex long-term effects such as epigenetic transmission of reproductive depression. By objectively fitting nonlinear models to the simulation outputs it was possible...... to compare population depression and recovery rates for a range of scenarios in which toxicity and exposure factors were varied. The system was differentially sensitive to the various factors, but vole ecology and behaviour were at least as important predictors of population-level effects as toxicology...
Decay kinetics of Krsup(*) levels populated by ArF laser radiation

International Nuclear Information System (INIS)

Wren, D.J.; Setser, D.W.

1981-01-01

The Kr 6p [3/2] 2 (or 3p 6 ) level was pumped via a two-photon absorption using a focused ArF laser (193 nm). The time dependent fluorescence from excited Kr levels was observed using a monochromator and photomultiplier tube and transient digitizer. Fluorescence from the pumped level, observed via the 3p 6 → 1s 5 transition, has a lifetime of 8 +- 2 ns independent of the Kr pressure (2-30 Torr). Fluorescence from other levels of the Kr (4p 5 6p) manifold was either unobserved or weak. Strong fluorescence was observed from the Kr (4p 5 5p) levels via transitions to the Kr (4p 5 5s) levels, the highest populated levels being 2p 6 , 2p 8 and 2p 9 . All Kr (4p 5 5p) levels display effective lifetimes much longer than the radiative lifetimes; effective zero pressure lifetimes for Kr 2p 3 , 2p 6 and 2p 7 are 72 +- 15, 66 +- 15 and 90 +- 15 ns, respectively. The short lifetime of the Kr (3p 6 ) level is explained by very fast collisional depopulation by photoelectrons produced in three photon ionization of Kr by the ArF laser. The Kr (4p 5 5p) levels are populated indirectly from the Kr (3p 6 ) level and the long lifetimes of the Kr (4p 5 5p) levels represent the lifetime of the intermediate state (or states) which lead to the Kr (4p 5 5p) levels. Strong possibilities for the intermediate states are the Kr (4p 5 4d) levels. (orig.)
Electrochemical noise and impedance of Au electrode/electrolyte interfaces enabling extracellular detection of glioma cell populations.

Science.gov (United States)

Rocha, Paulo R F; Schlett, Paul; Kintzel, Ulrike; Mailänder, Volker; Vandamme, Lode K J; Zeck, Gunther; Gomes, Henrique L; Biscarini, Fabio; de Leeuw, Dago M

2016-10-06

Microelectrode arrays (MEA) record extracellular local field potentials of cells adhered to the electrodes. A disadvantage is the limited signal-to-noise ratio. The state-of-the-art background noise level is about 10 μVpp. Furthermore, in MEAs low frequency events are filtered out. Here, we quantitatively analyze Au electrode/electrolyte interfaces with impedance spectroscopy and noise measurements. The equivalent circuit is the charge transfer resistance in parallel with a constant phase element that describes the double layer capacitance, in series with a spreading resistance. This equivalent circuit leads to a Maxwell-Wagner relaxation frequency, the value of which is determined as a function of electrode area and molarity of an aqueous KCl electrolyte solution. The electrochemical voltage and current noise is measured as a function of electrode area and frequency and follow unambiguously from the measured impedance. By using large area electrodes the noise floor can be as low as 0.3 μVpp. The resulting high sensitivity is demonstrated by the extracellular detection of C6 glioma cell populations. Their minute electrical activity can be clearly detected at a frequency below about 10 Hz, which shows that the methodology can be used to monitor slow cooperative biological signals in cell populations.
Mesenchymal stem cells induce mature dendritic cells into a novel Jagged-2-dependent regulatory dendritic cell population.

Science.gov (United States)

Zhang, Bin; Liu, Rui; Shi, Dan; Liu, Xingxia; Chen, Yuan; Dou, Xiaowei; Zhu, Xishan; Lu, Chunhua; Liang, Wei; Liao, Lianming; Zenke, Martin; Zhao, Robert C H

2009-01-01

Mesenchymal stem cells (MSCs), in addition to their multilineage differentiation, exert immunomodulatory effects on immune cells, even dendritic cells (DCs). However, whether they influence the destiny of full mature DCs (maDCs) remains controversial. Here we report that MSCs vigorously promote proliferation of maDCs, significantly reduce their expression of Ia, CD11c, CD80, CD86, and CD40 while increasing CD11b expression. Interestingly, though these phenotypes clearly suggest their skew to immature status, bacterial lipopolysaccharide (LPS) stimulation could not reverse this trend. Moreover, high endocytosic capacity, low immunogenicity, and strong immunoregulatory function of MSC-treated maDCs (MSC-DCs) were also observed. Furthermore we found that MSCs, partly via cell-cell contact, drive maDCs to differentiate into a novel Jagged-2-dependent regulatory DC population and escape their apoptotic fate. These results further support the role of MSCs in preventing rejection in organ transplantation and treatment of autoimmune disease.
Differences in heat-related mortality across four ecological regions with diverse urban, rural, and remote populations in British Columbia, Canada.

Science.gov (United States)

Henderson, Sarah B; Wan, Victoria; Kosatsky, Tom

2013-09-01

Temperature-mortality analyses are challenging in rural and remote communities with small populations, but this information is needed for climate change and emergency planning. The geographic health areas of British Columbia, Canada were aggregated into four ecoregions delineated by microclimatic conditions. Time series models were used to estimate the effect of maximum apparent temperature on daily non-traumatic mortality. The population of the coldest ecoregion was most sensitive to hot weather, while the population of the hottest ecoregion was least sensitive. The effects were consistently strongest in decedents aged less than 75 years. A province-wide total of 815 deaths was attributed to hot weather over the 25-year study period, with 735 deaths in the most populous ecoregion. The framework described could be adapted to other climatically variable regions with urban, rural, and remote populations. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.
THE CENTRAL BLUE STRAGGLER POPULATION IN FOUR OUTER-HALO GLOBULAR CLUSTERS

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Beccari, Giacomo; Luetzgendorf, Nora [European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching bei Muenchen (Germany); Olczak, Christoph [Astronomisches Rechen-Institut (ARI), Zentrum fuer Astronomie Universitaet Heidelberg, Moenchhofstrasse 1214, 69120 Heidelberg (Germany); Ferraro, Francesco R.; Lanzoni, Barbara [Dipartimento di Astronomia, Universita degli Studi di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Carraro, Giovanni; Boffin, Henri M. J. [European Southern Observatory, Alonso de Cordova 3107, Santiago de Chile (Chile); Stetson, Peter B. [National Research Council of Canada, Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Sollima, Antonio [INAF-Osservatorio Astronomico di Padova, Vicolo dell' Osservatorio 5, 35122 Padova (Italy)

2012-08-01

Using Hubble Space Telescope/Wide Field Planetary Camera 2 data, we have performed a comparative study of the Blue Straggler Star (BSS) populations in the central regions of the globular clusters (GCs) AM 1, Eridanus, Palomar 3, and Palomar 4. Located at distances R{sub GC} > 50 kpc from the Galactic center, these are (together with Palomar 14 and NGC 2419) the most distant clusters in the halo. We determine their color-magnitude diagrams and centers of gravity. The four clusters turn out to have similar ages (10.5-11 Gyr), significantly smaller than those of the inner-halo globulars, and similar metallicities. By exploiting wide-field ground-based data, we build the most extended radial density profiles from resolved star counts ever published for these systems. These are well reproduced by isotropic King models of relatively low concentration. BSSs appear to be significantly more centrally segregated than red giants in all GCs, in agreement with the estimated core and half-mass relaxation times which are smaller than the cluster ages. Assuming that this is a signature of mass segregation, we conclude that AM 1 and Eridanus are slightly dynamically more evolved than Pal 3 and Pal 4.
Red blood cell populations and membrane levels of peroxiredoxin 2 as candidate biomarkers to reveal blood doping.

Science.gov (United States)

Marrocco, Cristina; Pallotta, Valeria; D'alessandro, Angelo; Alves, Gilda; Zolla, Lello

2012-05-01

Blood doping represents one main trend in doping strategies. Blood doping refers to the practice of boosting the number of red blood cells (RBCs) in the bloodstream in order to enhance athletic performance, by means of blood transfusions, administration of erythropoiesis-stimulating substances, blood substitutes, natural or artificial altitude facilities, and innovative gene therapies. While detection of recombinant EPO and homologous transfusion is already feasible through electrophoretic, mass spectrometry or flow cytometry-based approaches, no method is currently available to tackle doping strategies relying on autologous transfusions. We exploited an in vitro model of autologous transfusion through a 1:10 dilution of concentrated RBCs after 30 days of storage upon appropriate dilution in freshly withdrawn RBCs from the same donor. Western blot towards membrane Prdx2 and Percoll density gradients were exploited to assess their suitability as biomarkers of transfusion. Membrane Prdx2 was visible in day 30 samples albeit not in day 0, while it was still visible in the 1:10 dilution of day 30 in day 0 RBCs. Cell gradients also highlighted changes in the profile of the RBC subpopulations upon dilution of stored RBCs in the fresh ones. From this preliminary in vitro investigation it emerges that Prdx2 and RBC populations might be further tested as candidate biomarkers of blood doping through autologous transfusion, though it is yet to be assessed whether the kinetics in vivo of Prdx2 exposure in the membrane of transfused RBCs will endow a sufficient time-window to allow reliable anti-doping testing.
The level of health education in the Polish population.

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Olszanecka-Glinianowicz, Magdalena; Chudek, Jerzy

2013-01-01

The study assessed factors influencing awareness of Poles concerning lifestyle factors that affect development of obesity, type 2 diabetes and cardiovascular diseases (CVD). A questionnaire survey covering awareness of lifestyle factors performed by general practitioners in 37,557 unselected patients. 96.1% of respondents believed that lifestyle has an impact on the occurrence of CVDs, especially: tobacco smoking (91.4%), excessive intake of fat (81.3%), alcohol (67.5%), salt (64.9%), and stress (64.9%). 79.0% respondents believed the smoking cessation, 77.5% weight loss and 66.8% healthy diet are most important to prevent diseases. Additionally, the belief in the need for an early weight reduction decreased with increasing BMI (82.9% with normal weight vs. 77.5% overweight and 70.4% obese). The most common source of health education was a physician (75.8%), the mass media, such as television and the press (62.0% and 64.8%, respectively), less often were educational materials (37.8%) and books (20.3 %), the Internet (3.8%) and radio (0.8%). Younger respondents presented a higher level of awareness about all analysed aspects of healthy lifestyle. The multiple regression analysis revealed that low education level and rural residence are the most important factors decreasing awareness of the lifestyle effect on health. 1. The level of knowledge about non-pharmacological methods of preventing lifestyle diseases in the Polish population is high except of the role of physical activity and daily vegetables consumption. This, however, has no impact on reducing the percentage of overweight and obese people and on increasing the tendency to pursue lifestyle changes. 2. Frustrating is the fact that more than one fifth of the study population is unaware that excessive weight reduction prevents development of cardiovascular diseases. Moreover, the convince to early weight decreases with increasing BMI. 3. The highest level of the knowledge among younger subjects reflect
Granulosa cell tumor of ovary: A clinicopathological study of four cases with brief review of literature

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B R Vani

2014-01-01

Full Text Available Introduction: Adult granulosa cell tumor (GCT is a rare ovarian malignancy having good prognosis in comparison with other epithelial tumors. The study aims to collect data of all granulosa cell tumors diagnosed in ESIC Medical College & PGIMSR, Rajajinagar, Bangalore over the last 3 years and to describe the patient profile, ultrasonographic and various histopathological features.Materials and Methods: A total of 4 granulosa cell tumors were diagnosed in ESIC Medical College & PGIMSR, Rajajinagar, Bangalore during the period from June 2010 to June 2013. The patient′s age, clinical manifestations, radiological and histopathological findings were evaluated.Results: All 4 patients were diagnosed as adult granulosa cell tumor, three of four cases were in premenopausal age group and one case was in perimenopausal age. The clinical manifestations were menorrhagia and abdominal pain. Ultrasonographically, 2 cases of granulosa cell tumors were both solid and cystic and one case each was either solid or cystic. Histologically, variety of patterns like diffuse, trabecular, cords, spindle and clear cells were noted. Both Call-Exner bodies and nuclear grooves were observed in all cases. All four cases showed simple hyperplasia without atypia endometrial findings. Follow up on all patients revealed no evidence of recurrence.Conclusion: Granulosa cell tumor of the ovary is a rare ovarian entity. The important prognostic factor is staging of the tumor. Staging and histopathology helps in prediction of survival. Also diligent endometrial pathology has to be sorted to rule out endometrial carcinoma.
Preconception healthcare delivery at a population level: construction of public health models of preconception care.

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Shannon, Geordan D; Alberg, Corinna; Nacul, Luis; Pashayan, Nora

2014-08-01

A key challenge of preconception healthcare is identifying how it can best be delivered at a population level. To review current strategies of preconception healthcare, explore methods of preconception healthcare delivery, and develop public health models which reflect different preconception healthcare pathways. Preconception care strategies, programmes and evaluations were identified through a review of Medline and Embase databases. Search terms included: preconception, pre-pregnancy, intervention, primary care, healthcare, model, delivery, program, prevention, trial, effectiveness, congenital disorders OR abnormalities, evaluation, assessment, impact. Inclusion criteria for review articles were: (1) English, (2) human subjects, (3) women of childbearing age, (4) 1980–current data, (5) all countries, (6) both high risk and universal approaches, (7) guidelines or recommendations, (8) opinion articles, (9) experimental studies. Exclusion criteria were: (1) non-human subjects, (2) non-English, (3) outside of the specified timeframe, (4) articles on male healthcare. The results of the literature review were synthesised into public health models of care: (1) primary care; (2) hospital-based and inter-conception care; (3) specific preconception care clinics; and, (4) community outreach. Fifteen evaluations of preconception care were identified. Community programmes demonstrated a significant impact on substance use, folic acid supplementation, diabetes optimization, and hyperphenylalaninemia. An ideal preconception visits entail risk screening, education, and intervention if indicated. Subsequently, four public health models were developed synthesizing preconception care delivery at a population level. Heterogeneity of risk factors, health systems and strategies of care reflect the lack of consensus about the best way to deliver preconception care. The proposed models aim to reflect differing aspects of preconception healthcare delivery.
Individual, population and community level effects of subtle anthropogenic contamination in estuarine meiobenthos

International Nuclear Information System (INIS)

Rubal, Marcos; Guilhermino, Lucia M.; Medina, Matias H.

2009-01-01

The study presented here searched for the level of taxonomic resolution required to detect the effects of low-level chronic pollution on estuarine meiobenthic communities. Meiofauna from two sites, with special attention to harpacticoid copepods, was analysed at different taxonomic levels of aggregation using uni- and multivariate methods. Adaptation processes that could buffer biodiversity disruptions were also considered through the analysis of fitness-related and tolerance traits in the harpacticoid copepod Paronychocamptus nanus. Results showed that uni- and multivariate analyses could be inadequate when assessing subtle anthropogenic contamination. Instead, the assessment of inter-population differences in tolerance to the main source of stress rises as a required procedure if potential effects of this type of contamination are being investigated. Specifically, a 96 h acute toxicity test performed with populations from the affected site appears as a faster and reliable general tool to assess impacts of low-level chronic pollution in estuaries. - Tolerance of local populations as a reliable tool to assess impacts of subtle anthropogenic contamination in estuaries.

Individual, population and community level effects of subtle anthropogenic contamination in estuarine meiobenthos

Energy Technology Data Exchange (ETDEWEB)

Rubal, Marcos [CIIMAR/CIMAR-LA - Centro Interdisciplinar de Investigacao Marinha e Ambiental, Universidade do Porto, Laboratorio de Ecotoxicologia, Rua dos Bragas 289, 4050-123 Porto (Portugal); Guilhermino, Lucia M. [CIIMAR/CIMAR-LA - Centro Interdisciplinar de Investigacao Marinha e Ambiental, Universidade do Porto, Laboratorio de Ecotoxicologia, Rua dos Bragas 289, 4050-123 Porto (Portugal); ICBAS - Instituto de Ciencias Biomedicas de Abel Salazar, Departamento de Estudos de Populacoes, Laboratorio de Ecotoxicologia, Universidade do Porto, Lg. Prof. Abel Salazar 2, 4099-003 Porto (Portugal); Medina, Matias H., E-mail: matias.medina@avs-chile.c [AVS Chile SA, Imperial 0655, Off. 3A, Puerto Varas (Chile); Centro i-mar, Universidad de Los Lagos, Camino Chinquihue km 6, Puerto Montt (Chile)

2009-10-15

The study presented here searched for the level of taxonomic resolution required to detect the effects of low-level chronic pollution on estuarine meiobenthic communities. Meiofauna from two sites, with special attention to harpacticoid copepods, was analysed at different taxonomic levels of aggregation using uni- and multivariate methods. Adaptation processes that could buffer biodiversity disruptions were also considered through the analysis of fitness-related and tolerance traits in the harpacticoid copepod Paronychocamptus nanus. Results showed that uni- and multivariate analyses could be inadequate when assessing subtle anthropogenic contamination. Instead, the assessment of inter-population differences in tolerance to the main source of stress rises as a required procedure if potential effects of this type of contamination are being investigated. Specifically, a 96 h acute toxicity test performed with populations from the affected site appears as a faster and reliable general tool to assess impacts of low-level chronic pollution in estuaries. - Tolerance of local populations as a reliable tool to assess impacts of subtle anthropogenic contamination in estuaries.
Autoantibody levels in myositis patients correlate with clinical response during B cell depletion with rituximab.

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Aggarwal, Rohit; Oddis, Chester V; Goudeau, Danielle; Koontz, Diane; Qi, Zengbiao; Reed, Ann M; Ascherman, Dana P; Levesque, Marc C

2016-06-01

To determine the longitudinal trends in serum levels of four myositis-associated autoantibodies: anti-Jo-1, -transcription intermediary factor 1 γ (TIF1-γ), -signal recognition particle (SRP) and -Mi-2, after B cell depletion with rituximab, and to determine the longitudinal association of these autoantibody levels with disease activity as measured by myositis core-set measures (CSMs). Treatment-resistant adult and pediatric myositis subjects (n = 200) received rituximab in the 44-week Rituximab in Myositis Trial. CSMs [muscle enzymes, manual muscle testing (MMT), physician and patient global disease activity, HAQ, and extramuscular disease activity] were evaluated monthly and anti-Jo-1 (n = 28), -TIF1-γ (n = 23), -SRP (n = 25) and -Mi-2 (n = 26) serum levels were measured using validated quantitative ELISAs. Temporal trends and the longitudinal relationship between myositis-associated autoantibodies levels and CSM were estimated using linear mixed models. Following rituximab, anti-Jo-1 levels decreased over time (P myositis subjects decreased after B cell depletion and were correlated with changes in disease activity, whereas anti-SRP levels were only associated with longitudinal muscle enzyme levels. The strong association of anti-Jo-1 levels with clinical outcomes suggests that anti-Jo-1 autoantibodies may be a good biomarker for disease activity. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Characterization of the expanded T cell population in infectious mononucleosis: apoptosis, expression of apoptosis-related genes, and Epstein–Barr virus (EBV) status

Science.gov (United States)

Verbeke, C S; Wenthe, U; Bergler, W F; Zentgraf, H

2000-01-01

Infectious mononucleosis (IM), a manifestation of primary infection with EBV, is characterized by a massive expansion of the T cell population. In this study we examined this expanded T cell population regarding its EBV status, its proliferative and apoptotic activity, and its expression of apoptosis-related genes. Whereas previous studies were performed on ex vivo cultures or on peripheral blood, our investigations included in vivo analysis of IM tonsillectomy specimens (14 cases) by in situ hybridization for viral RNA (EBERs) combined with immunohistochemistry (IHC; CD3, CD45RO, CD20, CD79a, Ki-67, Bcl-2, Bax, Fas, FasL) and the TUNEL method. Of the EBER+ cells 50–70% showed expression of the B cell markers CD20/CD79a. The remainder of the EBER+ cells expressed neither B nor T cell antigens. No co-expression of EBERs and T cell antigens was detected in any of the specimens. In accordance with a high rate of apoptosis (up to 2·37%) within the expanded T cell population, Bcl-2 expression was drastically reduced and FasL expression remarkably increased. The levels of Bax and Fas expression showed no or moderate up-regulation. In conclusion, the massive expansion of IM T cells is not caused by EBV infection of these cells but merely represents an intense immune reaction. Through altered expression of Bcl-2/Bax and Fas/FasL, the activated T cells are subject to enhanced apoptosis while residing within the lymphoid tissue, which eventually allows the efficient silencing of this potentially damaging T cell response. PMID:10792379
Soluble endothelial cell-selective adhesion molecule and incident cardiovascular events in a multiethnic population.

Science.gov (United States)

Ren, Hao-Yu; Khera, Amit; de Lemos, James A; Ayers, Colby R; Rohatgi, Anand

2017-09-01

Cell adhesion molecules are key regulators of atherosclerotic plaque development, but circulating levels of soluble fragments, such as intercellular adhesion molecule (sICAM-1) and vascular cell adhesion molecule (sVCAM-1), have yielded conflicting associations with atherosclerotic cardiovascular disease (ASCVD). Endothelial cell-selective adhesion molecule (ESAM) is expressed exclusively in platelets and endothelial cells, and soluble ESAM (sESAM) levels have been associated with prevalent subclinical atherosclerosis. We therefore hypothesized that sESAM would be associated with incident ASCVD. sESAM, sICAM-1, and sVCAM-1 were measured in 2,442 participants without CVD in the Dallas Heart Study, a probability-based population sample aged 30-65 years enrolled between 2000 and 2002. ASCVD was defined as first myocardial infarction, stroke, coronary revascularization, or CV death. A total of 162 ASCVD events were analyzed over 10.4 years. Increasing sESAM was associated with ASCVD, independent of risk factors (HR Q4 vs Q1: 2.7, 95% CI 1.6-4.6). Serial adjustment for renal function, sICAM-1, VCAM-1, and prevalent coronary calcium did not attenuate these associations. Continuous ESAM demonstrated similar findings (HR 1.31, 95% CI 1.2-1.4). Addition of sESAM to traditional risk factors improved discrimination and reclassification (delta c-index: P = .009; integrated-discrimination-improvement index P = .001; net reclassification index = 0.42, 95% CI 0.15-0.68). Neither sICAM-1 nor sVCAM-1 was independently associated with ASCVD. sESAM but not sICAM-1 or sVCAM-1 levels are associated with incident ASCVD. Further studies are warranted to investigate the role of sESAM in ASCVD. Copyright © 2017 Elsevier Inc. All rights reserved.
Elevated red blood cell 2,3-diphosphoglycerate levels in black blood donors.

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Wallas, C H

1978-01-01

Mean levels of 2,3-diphosphoglycerate (DPG) were significantly increased in erythrocytes (RBC) from 43 nonanemic black blood donors (4.80 +/- 0.06 micromoles/l RBC) compared with 22 white donors 4.47 +/- 0.08 micromoles/l RBCs from eight of the 12 black donors with DPG levels greater than 5 micromoles/l RBC. Although a potentially hemolytic disorder could be defined in four (AS hemoglobin, beta-Thalassemia minor, G6PD deficiency), reticulocyte counts were normal. However, when RBCs from the subgroup were compared to RBCs from an additional 25 unselected white donors, the following suggested an abnormally large population of young RBCs in the subgroup: 1) normal or elevated RBC-ATP with normal serum phosphate level; 2) significantly increased activities of RBC age-dependent enzymes hexokinase (p less than 0.02), pyruvate kinase (p less than 0.05), and glutamicoxaloacetic transaminase (p less than 0.01), with normal activity of phosphoglycerate kinase, an age-independent enzyme; 3) decreased dense (older) RBCs as determined by sedimentation in phthalate esters. Since DPG is increased in young RBCs and falls as the RBC ages, loss of older relatively DPG depleted RBCs due to shortened survival could account for the elevated DPG levels seen in the subgroup.
The TSH levels and risk of hypothyroidism: Results from a population based prospective cohort study in an Iranian adult's population.

Science.gov (United States)

Aminorroaya, Ashraf; Meamar, Rokhsareh; Amini, Massoud; Feizi, Awat; Nasri, Maryam; Tabatabaei, Azamosadat; Faghihimani, Elham

2017-06-01

The aim of current study was to assess the relationship between serum TSH levels and hypothyroidism risk in the euthyroid population. In a population-based cohort study, a total of 615 individuals with a normal baseline TSH, from of total population (n=2254) in 2006, were followed up for 6years. TSH, total T4, thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TgAb) were measured. The relative risk (RR) and 95% confidence interval (95%CI) were calculated based on logistic regression. The Receiver Operating Characteristic (ROC) analysis along with area under the curve (AUC) was used to prediction of future hypothyroidism. TSH level in 2006 was a significant predictor for overt hypothyroidism, in the total population (RR=3.5) and female (RR=1.37) (all, P valuehypothyroidism from euthyroid. However, this cut off was not observed when we included only negative TPO and TgAbs people in 2006. The RR of hypothyroidism increased gradually when TSH level increased from 2.06-3.6mIU/L to >3.6mIU/L in the total population and both sexes. In women, the risk of overt hypothyroidism was significantly higher in subjects with TSH above 3.6 than those subject with THS levels≤2.05 [RR: (CI95 %), 20.57(2.-207.04), P valuehypothyroidism in future. However, it was not applicable for people with negative TPOAb and negative TgAb. Copyright © 2016 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.
Scaling the consequences of interactions between invaders from the individual to the population level.

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Griffen, Blaine D

2016-03-01

The impact of human-induced stressors, such as invasive species, is often measured at the organismal level, but is much less commonly scaled up to the population level. Interactions with invasive species represent an increasingly common source of stressor in many habitats. However, due to the increasing abundance of invasive species around the globe, invasive species now commonly cause stresses not only for native species in invaded areas, but also for other invasive species. I examine the European green crab Carcinus maenas, an invasive species along the northeast coast of North America, which is known to be negatively impacted in this invaded region by interactions with the invasive Asian shore crab Hemigrapsus sanguineus. Asian shore crabs are known to negatively impact green crabs via two mechanisms: by directly preying on green crab juveniles and by indirectly reducing green crab fecundity via interference (and potentially exploitative) competition that alters green crab diets. I used life-table analyses to scale these two mechanistic stressors up to the population level in order to examine their relative impacts on green crab populations. I demonstrate that lost fecundity has larger impacts on per capita population growth rates, but that both predation and lost fecundity are capable of reducing population growth sufficiently to produce the declines in green crab populations that have been observed in areas where these two species overlap. By scaling up the impacts of one invader on a second invader, I have demonstrated that multiple documented interactions between these species are capable of having population-level impacts and that both may be contributing to the decline of European green crabs in their invaded range on the east coast of North America.
Levels of 2,3-diphosphoglycerate in Friend leukaemic cells.

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Yeoh, G C

1980-05-08

Most cells are thought to contain trace amounts of 2,3-diphosphoglycerate (DPG), as it acts as a cofactor in the interconversion of 2-phosphoglycerate and 3-phosphoglycerate by the glycolytic enzyme phosphoglyceromutase. DPG is synthesized from 1,3-diphosphoglycerate by the action of diphosphoglycerate mutase. Lowry et al. reported levels of 29 mumol DPG per kg wet weight brain tissue which is approximately 3 pmol per 10(8) cells, assuming that 1 g of brain tissue contains 10(9) cells. In contrast, erythroid cells contain 50-100 nmol DPG per 10(8) cells, depending on the species and the stage of development. This is of the order of a 1,000-fold more DPG compared with non-erythroid cells. In red cells DPG concentration modulates the binding of oxygen to haemoglobin. I show here that erythroid precurser cells also contain markedly raised levels of DPG.
Insulin resistance and β-cell function in Colombian mestizo and Embera-Chamí populations and their relation with adiposity degree.

Science.gov (United States)

Caro-Gomez, María Antonieta; Naranjo-González, Andrés; Parra-Marín, María Victoria; Gallego-Lopera, Natalia; Valencia, Diana María; Rúa-Molina, Diana Carolina; Rosique-Gracia, Javier; García-Pineda, Andres Felipe; Gómez-Isaza, Luis Felipe; Pizano-Ramírez, Norman Diego; Arcos, Edgar Gerardo; Villegas-Perrasse, Alberto; Duque-Botero, Julieta; Bedoya-Berrío, Gabriel

2017-04-01

Insulin resistance (IR) is a condition favored by metabolic and endocrine changes experienced by adipose tissue in the context of obesity. The prevalence and the presentation of both IR and obesity vary among the populations, and may be affected by ancestral genetic composition among other factors. The aim of this study was to compare the presence of IR and obesity in Amerindians of the Embera-Chamí ethnicity and Colombian mestizo population. A sample of 630 individuals, 471 mestizos and 159 Amerindians of the Embera-Chamí ethnicity, from the general population of Colombia were studied. For each participant, anthropometric and biochemical measurements, as well as blood pressure and the Homeostatic Model Assessment (HOMA) of IR and β-cell function (%B) were recorded. These values were compared between the two populations. While prevalence of central obesity was similar in both populations (48.7% and 42.6% in the mestizo and Embera groups respectively; p=0.148), body mass index (BMI) values suggested a higher prevalence of overweight in the Embera than in mestizo population (43.4% Embera, 31.8% mestizo; p=0.027). Despite the similarities in the prevalence of HOMA-IR and HOMA-%B status between both populations, the Embera population had a significantly greater pancreatic β-cell function, higher insulin levels, and better glucose control, across BMI and central obesity categories, than the mestizo population. There are differences in aspects related to energy metabolism between the samples of the mestizo and Amerindian populations analyzed. Copyright © 2017 SEEN. Publicado por Elsevier España, S.L.U. All rights reserved.
Life-style habits and homocysteine levels in an elderly population.

Science.gov (United States)

Dankner, Rachel; Chetrit, Angela; Lubin, Flora; Sela, Ben-Ami

2004-12-01

Increased plasma total homocysteine (Hcy) is a known cardiovascular disease (CVD) risk factor, related to several components of the established CVD risk profile. Observational studies support the role of modifying life-style related risk factors such as diet, physical activity and alcohol consumption in CVD prevention. Regular physical activity protects against coronary artery disease, possibly through its role in controlling risk factors such as hypertension, diabetes mellitus and obesity, but also independently. The aim of our study was to test the hypothesis that there is an association between physical activity, life-style habits and plasma Hcy levels in an elderly population. In this cross-sectional study, 423 males and females aged 69.0 +/- 6.7 years completed an interview and laboratory examinations. Our main outcome measure was plasma levels of Hcy. Mean Hcy values were 10.5 +/- 5.5 micromol/L (11.4 +/- 6.1 for males and 9.3 +/- 4.5 for females; p sedentary life-style, 17% higher amongst males, 1% higher for each one-year increment in age, and 10% higher amongst participants who used no B vitamin supplements. Any level of physical activity was found to be an independent life-style habit associated with a lower Hcy level in an elderly population. This study supports existing recommendations for elderly persons to maintain a physically active life-style.
Level of knowledge among the population of radiation safety basic issues

Directory of Open Access Journals (Sweden)

S. A. Zelencova

2015-01-01

Full Text Available The goal of research was to determine the level of knowledge among the population on issues like sources of ionising radiation, methods of ionising radiation measurement, measures of self-protection in case of threating or actual radioactive pollution in the district, and to study self-estimation by the population of their knowledge of radiation safety issues. Research was carried out using the method of questioning of population groups in three regions close to the places of previous peaceful nuclear explosions (Arkhangelsk, Murmansk and Tyumen regions, and in five Far East regions of the Russian Federation (Kamchatka, Khabarovsk, Primorsky, Magadan and South-Sakhalin regions after radiation accident in Japan at "Fukushima-1" NPP. This research included processing of 243 questionnaires from the regions close to places of previous peaceful nuclear explosions and 216 questionnaires from the Far East regions.The analysis of obtained questioning results enabled to make the following conclusions: the level of knowledge among the population about the basic concepts of radiation safety appeared to be generally low among respondents of all eight territories. Considerable number of respondents in seven groups correctly mentioned the x-ray device as a source of ionising radiation (from 71 to 88 % of answers. In Murmansk region – only 52 % of the answers. Respondents of the same seven groups often correctly answered the question on how to detect ionising radiation (only with devices – from 68 to 98 % in different groups. The smallest number of correct answers to this question (42 % is also noted among respondents from the Murmansk region.Level of knowledge on self-protection measures at threating or actual radioactive pollution of the places of residence appeared a little higher among the Far East region population, who had actual concerns regarding the threat of radioactive pollution at the present time. However, in all eight investigated groups
Population-expression models of immune response

International Nuclear Information System (INIS)

Stromberg, Sean P; Antia, Rustom; Nemenman, Ilya

2013-01-01

The immune response to a pathogen has two basic features. The first is the expansion of a few pathogen-specific cells to form a population large enough to control the pathogen. The second is the process of differentiation of cells from an initial naive phenotype to an effector phenotype which controls the pathogen, and subsequently to a memory phenotype that is maintained and responsible for long-term protection. The expansion and the differentiation have been considered largely independently. Changes in cell populations are typically described using ecologically based ordinary differential equation models. In contrast, differentiation of single cells is studied within systems biology and is frequently modeled by considering changes in gene and protein expression in individual cells. Recent advances in experimental systems biology make available for the first time data to allow the coupling of population and high dimensional expression data of immune cells during infections. Here we describe and develop population-expression models which integrate these two processes into systems biology on the multicellular level. When translated into mathematical equations, these models result in non-conservative, non-local advection-diffusion equations. We describe situations where the population-expression approach can make correct inference from data while previous modeling approaches based on common simplifying assumptions would fail. We also explore how model reduction techniques can be used to build population-expression models, minimizing the complexity of the model while keeping the essential features of the system. While we consider problems in immunology in this paper, we expect population-expression models to be more broadly applicable. (paper)
Tensin3 is a negative regulator of cell migration and all four Tensin family members are downregulated in human kidney cancer.

Directory of Open Access Journals (Sweden)

Danuta Martuszewska

Full Text Available The Tensin family of intracellular proteins (Tensin1, -2, -3 and -4 are thought to act as links between the extracellular matrix and the cytoskeleton, and thereby mediate signaling for cell shape and motility. Dysregulation of Tensin expression has previously been implicated in human cancer. Here, we have for the first time evaluated the significance of all four Tensins in a study of human renal cell carcinoma (RCC, as well as probed the biological function of Tensin3.Expression of Tensin2 and Tensin3 at mRNA and protein levels was largely absent in a panel of diverse human cancer cell lines. Quantitative RT-PCR analysis revealed mRNA expression of all four Tensin genes to be significantly downregulated in human kidney tumors (50-100% reduction versus normal kidney cortex; P<0.001. Furthermore, the mRNA expressions of Tensins mostly correlated positively with each other and negatively with tumor grade, but not tumor size. Immunohistochemical analysis revealed Tensin3 to be present in the cytoplasm of tubular epithelium in normal human kidney sections, whilst expression was weaker or absent in 41% of kidney tumors. A subset of tumor sections showed a preferential plasma membrane expression of Tensin3, which in clear cell RCC patients was correlated with longer survival. Stable expression of Tensin3 in HEK 293 cells markedly inhibited both cell migration and matrix invasion, a function independent of putative phosphatase activity in Tensin3. Conversely, siRNA knockdown of endogenous Tensin3 in human cancer cells significantly increased their migration.Our findings indicate that the Tensins may represent a novel group of metastasis suppressors in the kidney, the loss of which leads to greater tumor cell motility and consequent metastasis. Moreover, tumorigenesis in the human kidney may be facilitated by a general downregulation of Tensins. Therefore, anti-metastatic therapies may benefit from restoring or preserving Tensin expression in primary
The phenotypic equilibrium of cancer cells: From average-level stability to path-wise convergence.

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Niu, Yuanling; Wang, Yue; Zhou, Da

2015-12-07

The phenotypic equilibrium, i.e. heterogeneous population of cancer cells tending to a fixed equilibrium of phenotypic proportions, has received much attention in cancer biology very recently. In the previous literature, some theoretical models were used to predict the experimental phenomena of the phenotypic equilibrium, which were often explained by different concepts of stabilities of the models. Here we present a stochastic multi-phenotype branching model by integrating conventional cellular hierarchy with phenotypic plasticity mechanisms of cancer cells. Based on our model, it is shown that: (i) our model can serve as a framework to unify the previous models for the phenotypic equilibrium, and then harmonizes the different kinds of average-level stabilities proposed in these models; and (ii) path-wise convergence of our model provides a deeper understanding to the phenotypic equilibrium from stochastic point of view. That is, the emergence of the phenotypic equilibrium is rooted in the stochastic nature of (almost) every sample path, the average-level stability just follows from it by averaging stochastic samples. Copyright © 2015 Elsevier Ltd. All rights reserved.
The costs, efects and cost-effetiveness of counteracting overweight on a population level.

NARCIS (Netherlands)

Bemelmans, W.; van Baal, P; Wendel-Vos, W.; Schuit, A.J.; Feskens, E.; Ament, A.; Hoogenveen, R.

2008-01-01

Objectives: To gain insight in realistic policy targets for overweight at a population level and the accompanying costs. Therefore, the effect on overweight prevalence was estimated of large scale implementation of a community intervention (applied to 90% of general population) and an intensive
Does the Health Impact of Exposure to Neighbourhood Green Space Differ between Population Groups? An Explorative Study in Four European Cities

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Ruijsbroek, Annemarie; Droomers, Mariël; Kruize, Hanneke; van Kempen, Elise; Gidlow, Christopher J.; Hurst, Gemma; Andrusaityte, Sandra; Nieuwenhuijsen, Mark J.; Maas, Jolanda; Hardyns, Wim; Stronks, Karien; Groenewegen, Peter P.

2017-01-01

It has been suggested that certain residents, such as those with a low socioeconomic status, the elderly, and women, may benefit more from the presence of neighbourhood green space than others. We tested this hypothesis for age, gender, educational level, and employment status in four European cities. Data were collected in Barcelona (Spain; n = 1002), Kaunas (Lithuania; n = 989), Doetinchem (The Netherlands; n = 847), and Stoke-on-Trent (UK; n = 933) as part of the EU-funded PHENOTYPE project. Surveys were used to measure mental and general health, individual characteristics, and perceived neighbourhood green space. Additionally, we used audit data about neighbourhood green space. In Barcelona, there were positive associations between neighbourhood green space and general health among low-educated residents. In the other cities and for the other population groups, there was little evidence that the association between health and neighbourhood green space differed between population groups. Overall, our study does not support the assumption that the elderly, women, and residents who are not employed full-time benefit more from neighbourhood green space than others. Only in the highly urbanised city of Barcelona did the low-educated group benefit from neighbourhood green spaces. Perhaps neighbourhood green spaces are more important for the health of low-educated residents in particularly highly urbanised areas. PMID:28594390
Does the Health Impact of Exposure to Neighbourhood Green Space Differ between Population Groups? An Explorative Study in Four European Cities.

Science.gov (United States)

Ruijsbroek, Annemarie; Droomers, Mariël; Kruize, Hanneke; van Kempen, Elise; Gidlow, Christopher J; Hurst, Gemma; Andrusaityte, Sandra; Nieuwenhuijsen, Mark J; Maas, Jolanda; Hardyns, Wim; Stronks, Karien; Groenewegen, Peter P

2017-06-08

It has been suggested that certain residents, such as those with a low socioeconomic status, the elderly, and women, may benefit more from the presence of neighbourhood green space than others. We tested this hypothesis for age, gender, educational level, and employment status in four European cities. Data were collected in Barcelona (Spain; n = 1002), Kaunas (Lithuania; n = 989), Doetinchem (The Netherlands; n = 847), and Stoke-on-Trent (UK; n = 933) as part of the EU-funded PHENOTYPE project. Surveys were used to measure mental and general health, individual characteristics, and perceived neighbourhood green space. Additionally, we used audit data about neighbourhood green space. In Barcelona, there were positive associations between neighbourhood green space and general health among low-educated residents. In the other cities and for the other population groups, there was little evidence that the association between health and neighbourhood green space differed between population groups. Overall, our study does not support the assumption that the elderly, women, and residents who are not employed full-time benefit more from neighbourhood green space than others. Only in the highly urbanised city of Barcelona did the low-educated group benefit from neighbourhood green spaces. Perhaps neighbourhood green spaces are more important for the health of low-educated residents in particularly highly urbanised areas.
Morphological and genetic evolution in eastern populations of the Macrhybopsis aestivalis complex (Cypriniformes: Cyprinidae), with the descriptions of four new species.

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Gilbert, Carter R; Mayden, Richard L; Powers, Steven L

2017-03-30

For many years the North American cyprinid fish Macrhybopsis aestivalis (common name: Speckled Chub) was regarded as a single widespread and morphologically variable species, occurring in rivers throughout much of the Mississippi Valley and geographically adjacent eastern Gulf slope drainages, west to the Rio Grande basin in Texas, New Mexico, and Mexico. Eisenhour (1997) completed a morphological study of western populations of the Speckled Chub, the results of which appeared thereafter in published form (Eisenhour 1999, 2004). He demonstrated the existence of five valid species west of the Mississippi River (aestivalis, marconis, australis, tetranema, hyostoma), of which the name aestivalis was shown to be restricted to the population occurring in the Rio Grande and the geographically adjacent Rio San Fernando system, in northeastern Mexico. Eisenhour (2004) considered populations throughout the middle Mississippi Valley and its major tributaries to be a single morphologically variable species (hyostoma), and he also indicated that populations of Macrhybopsis from eastern Gulf slope drainages may represent a complex of species. Genetic confirmation of Eisenhour's conclusions regarding western species appeared in the publication by Underwood et al. (2003), who also showed that western populations of M. hyostoma, as presently recognized, are genetically much more complex than previously considered. Meanwhile, the present authors were involved in a companion study of eastern populations of Macrhybopsis, for which a genetic summary of the eastern Gulf coast species was published by Mayden & Powers (2004). Based on their findings, four species were recognized from southeastern drainages (identified as species A-D), although no formal taxonomic descriptions were included. Their genetic data, in combination with meristic, morphometric and other morphological data presented herein, form the basis for a revised classification of eastern Macrhybopsis populations
Anti-IL-2 treatment impairs the expansion of T(reg cell population during acute malaria and enhances the Th1 cell response at the chronic disease.

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Cláudia A Zago

Full Text Available Plasmodium chabaudi infection induces a rapid and intense splenic CD4(+ T cell response that contributes to both disease pathogenesis and the control of acute parasitemia. The subsequent development of clinical immunity to disease occurs concomitantly with the persistence of low levels of chronic parasitemia. The suppressive activity of regulatory T (T(reg cells has been implicated in both development of clinical immunity and parasite persistence. To evaluate whether IL-2 is required to induce and to sustain the suppressive activity of T(reg cells in malaria, we examined in detail the effects of anti-IL-2 treatment with JES6-1 monoclonal antibody (mAb on the splenic CD4(+ T cell response during acute and chronic P. chabaudi AS infection in C57BL/6 mice. JES6-1 treatment on days 0, 2 and 4 of infection partially inhibits the expansion of the CD4(+CD25(+Foxp3(+ cell population during acute malaria. Despite the concomitant secretion of IL-2 and expression of high affinity IL-2 receptor by large CD4(+ T cells, JES6-1 treatment does not impair effector CD4(+ T cell activation and IFN-γ production. However, at the chronic phase of the disease, an enhancement of cellular and humoral responses occurs in JES6-1-treated mice, with increased production of TNF-α and parasite-specific IgG2a antibodies. Furthermore, JES6-1 mAb completely blocked the in vitro proliferation of CD4(+ T cells from non-treated chronic mice, while it further increased the response of CD4(+ T cells from JES6-1-treated chronic mice. We conclude that JES6-1 treatment impairs the expansion of T(reg cell population during early P. chabaudi malaria and enhances the Th1 cell response in the late phase of the disease.
Self-organization of bacterial communities against environmental pH variation: Controlled chemotactic motility arranges cell population structures in biofilms.

Science.gov (United States)

Tasaki, Sohei; Nakayama, Madoka; Shoji, Wataru

2017-01-01

As with many living organisms, bacteria often live on the surface of solids, such as foods, organisms, buildings and soil. Compared with dispersive behavior in liquid, bacteria on surface environment exhibit significantly restricted mobility. They have access to only limited resources and cannot be liberated from the changing environment. Accordingly, appropriate collective strategies are necessarily required for long-term growth and survival. However, in spite of our deepening knowledge of the structure and characteristics of individual cells, strategic self-organizing dynamics of their community is poorly understood and therefore not yet predictable. Here, we report a morphological change in Bacillus subtilis biofilms due to environmental pH variations, and present a mathematical model for the macroscopic spatio-temporal dynamics. We show that an environmental pH shift transforms colony morphology on hard agar media from notched 'volcano-like' to round and front-elevated 'crater-like'. We discover that a pH-dependent dose-response relationship between nutritional resource level and quantitative bacterial motility at the population level plays a central role in the mechanism of the spatio-temporal cell population structure design in biofilms.

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