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Large scale production of monoclonal antibodies has been accomplished using bioreactors with different length to diameter ratios, and diverse impeller and sparger designs. The differences in these physical attributes often result in dissimilar mass transfer, mechanical stresses due to turbulence and mixing inside the bioreactor that may lead to disparities in cell growth and antibody production. A rational analysis of impeller design parameters on cell growth, protein expression levels and subsequent antibody production is needed to understand such differences. The purpose of this study was to examine the impact of Rushton turbine and marine impeller designs on Chinese hamster ovary (CHO) cell growth and metabolism, and antibody production and quality. Experiments to evaluate mass transfer...

British Library Electronic Table of Contents (United Kingdom)

Abstract The glycosylation profile of therapeutic antibodies is routinely analyzed throughout development to monitor the impact of process parameters and to ensure consistency, efficacy, and safety for clinical and commercial batches of therapeutic products. In this study, unusually high levels of the mannose-5 (Man5) glycoform were observed during the early development of a therapeutic antibody produced from a Chinese hamster ovary (CHO) cell line, model cell line A. Follow up studies indicated that the antibody Man5 level was increased throughout the course of cell culture production as a result of increasing cell culture medium osmolality levels and extending culture duration. With model cell line A, Man5 glycosylation increased more than twofold from 12% to 28% in the fed-batch process...

International Nuclear Information System (INIS)

Ionizing radiations that differ in number, size, and distribution of energy deposition events might be expected to cause different effects for the same absorbed dose. Furthermore, microdosimetry calculations suggest that large variations in biological effectiveness might be expected for internally deposited alpha-emitting radionuclides for the same absorbed dose, depending upon the specific activity and spatial distribution of the sources in tissue. The study described in this article was designed to demonstrate these phenomena in vitro. Cultured Chinese hamster ovary (CHO-K1 BH4) cells were exposed in vitro to inert, insoluble ceramic microspheres in zirconium dioxide labeled with "2"3"9Pu. The average exit energy of the 5.15 MeV alpha particle was calculated to be 4.3 MeV. Exposure times varied from four to seven hours to achieve the desired dose level.

International Nuclear Information System (INIS)

Macrophage differentiation antigen associated with complement three receptor function (Mac-1) belongs to #beta#_2 subfamily of integrins that mediate important cell-cell and cell-extracellular matrix interactions. Biochemical studies have indicated that Mac-1 is a constitutive heterodimer in vitro. Here, we detected the heterodimerization of Mac-1 subunits in living cells by means of two fluorescence resonance energy transfer (FRET) techniques (fluorescence microscopy and fluorescence spectroscopy) and our results demonstrated that there is constitutive heterodimerization of the Mac-1 subunits and this constitutive heterodimerization of the Mac-1 subunits is cell-type independent. Through FRET imaging, we found that heterodimers of Mac-1 mainly localized in plasma membrane, perinuclear, and Golgi area in living cells. Furthermore, through analysis of the estimated physical distances ...

International Nuclear Information System (INIS)

Under certain growth conditions, the human colon adenocarcinoma cell line HT-29 exhibits intestinal enterocyte-like properties. The differentiated cells possess a brush border with the enzyme markers (aminopeptidase and sucrase) normally associated with the intestine. To aid in the characterization of the transport properties of these cells, the uptake of a non-metabolizable amino acid analog, "1"4C-#alpha#-methylaminoisobutyric acid (MeAIB) as examined in the HT-29-Al subclone which possesses a brush border. The cells exhibited a time-dependent uptake of MeAIB which was concentrative and sodium-dependent. The pH optimum for uptake was about 7.8. Uptake was inhibited by low temperature, 1 mM ouabain, or 0.5 mM dinitrophenol. A 1 hr-preincubation of the cells in an isotonic KCl solution resulted in a decreased uptake rate, suggesting that a negative membrane potential is important ...

Science.gov (United States)

Flow cytometric techniques were used to measure the cytological and biochemical damage to respiratory tract cells in animals exposed to particulates. Hamsters were exposed to raw and spent oil shale particulates and silica by intratracheal instillation. Exfoliated lung cells were obtained by sacrificing the animals and lavaging the respiratory tract posterior to the trachea with saline. Cell samples were fixed in ethanol and stained with mithramycin for fluorescence analysis of DNA content. DNA content distributions from hamsters exposed to spent oil shale and silica particulates showed atypical changes 28 to 35 days later. Cell counts and total numbers of macrophages, leukocytes, and epithelial cells in the lavage fluid also showed marked changes related to time after exposure.

International Nuclear Information System (INIS)

In recent years it has become evident from epidemiological and experimental data that a large number of environmental factors, including diet, play a role in modifying the incidence of cancer. Cell culture systems in which oncogenic transformation serves as an end point are powerful tools for evaluating these questions. Using such systems it has been shown recently that pyrolysis products from charred surfaces of broiled meat and fish can transform hamster embryo cells in vitro as well as produce tumors in the animal. Our studies in vitro have demonstrated the oncogenic potential of ionizing radiation in both hamster and human cells and have established in hamster cells the dose response relationship at doses ranging from 1 to 600 rad for x-rays and 0.1 to 150 rad for neutrons. The present work was aimed at evaluating whether there exists a ...

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This study was carried out to evaluate the biochemical and morphological effects of ionizing radiation on ovary. Immature mice (ICR, 3 week-old) were irradiated at a dose of LD{sub 80(30)} at KAERI. The ovaries were collected after 6 hours, 12 hours, 1 day, and 2 days post irradiation. To analyze the morphological changes, histological staining with hematoxylin-eosin, immuno- histochemical preparation using in situ 3'-end labeling was performed. DNA fragmentation analysis and flowcytometric evaluation of DNA extracted from whole ovary were performed. As a result of DNA fragmentation analysis, DNA fragments with 185, 370, and 555 base pairs were clearly shown at 6 hours post irradiation. The percentage of A{sub 0} cell cycle was significantly increased in the irradiated group than control. In situ 3'-end labeled follicles were increased at 6 hours post irradiation. The radiation-induced ...

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The distribution of /sup 35/S-sulfate and /sup 3/H-glucosamine in the angular region of the hamster was studied by light and electron microscopic autoradiography following intraperitoneal injection of these compounds to hamsters. Exposed silver grains of /sup 35/S-sulfate were concentrated in the trabecular meshwork, sclera, and cornea, and grains of /sup 3/H-glucosamine were localized in the trabecular region. The radioactivity of both isotopes was observed in the Golgi apparatuses of the endothelial cells of the angular aqueous plexus and the trabecular meshwork. The grains were noted over the entire cytoplasm, except for the nucleus, and then were incorporated into the amorphous substance and collagen fibers in the region adjacent to the angular aqueous sinus. These results suggest that endothelial cells in the angular region synthesize and secrete the sulfated glycosaminoglycans and hyaluronic acid.

UK PubMed Central (United Kingdom)

The cellular receptor for murine coronavirus mouse hepatitis virus (MHV)-A59 is a member of the carcinoembryonic antigen (CEA) family of glycoproteins in the immunoglobulin superfamily. We isolated...Full Text Available

International Nuclear Information System (INIS)

the cotton leaf worm, Spodoptera littoralis (boisd.) were irradiated with 100,150 and 200 Gy to induce inherited sterility. the effects of the tested doses applied to these pupae through three consequent fillial generations and the retarded influence on their F_1,F_2 and F_3 generations progeny were examined . irradiation of parental male induced damage to their daughter females ovaries. the overioles of females among P_1 ,F_1 and F_2 generations showed that the follicular epithelial cells appeared abnormal beside their limited separation from developing oocytes which became shrinked, semi absorbed or completely absorbed leaving vacuoles. the nurse cells were reduced or absent in some parts. damage was obvious through the first and second generations especially at 150 and 200 Gy. in the third generation, ovaries were not greatly affected

Science.gov (United States)

This paper summarizes results of preliminary experiments to develop cytological and biochemical indicators for estimating damage to respiratory cells in test animals exposed by inhalation to toxic agents associated with nonnuclear energy production, the specific goal being the application of advanced multiparameter flow-systems technologies to the detection of early atypical cellular changes in lung epithelium. Normal Syrian hamster lung cell samples composed of histiocytes, leukocytes, macrophages, ciliated columnar cells, and epithelial cells were stained with fluorescent dyes specific for different biochemical parameters and were analyzed in liquid suspension as they flowed through a chamber intersecting a laser beam of exciting light. Multiple sensors measured the total or two-color fluorescence and light scatter on a cell-by-cell basis. Cellular parameters ...

UK PubMed Central (United Kingdom)

Chinese hamster lung fibroblasts V79 cells were treated with heat stress for 4 weeks with short duration (15 min) heat shock every alternate day in culture. It was observed that Hsp...Full Text Available

International Nuclear Information System (INIS)

The present study was designed to assess the radioprotective effects of amifostine on ovarian follicles. Three week-old female mice with or without pretreatment of amifostine were irradiated with 6.42 Gy of #gamma# -ray. Ovaries were collected 0 and 6h after irradiation. DNA fragmentation pattern and expression of genes and activity of proteins related with apoptosis were investigated by means of RT-PCR and Western blot. Proliferation of granulosa cells was reduced and incidence rate of follicular atresia was increased in ovarian follicles in #gamma# -ray irradiated mice compared to those in control or amifostine-treated group. DNA fragmentation was increased in time-dependent manner in granulosa cells of all irradiated groups. However, no difference between amifostine pre-treated group and irradiated groups was found and the expression of p53 as tumor suppressor gene and Bax as one of pro-apoptotic Bcl-2 family was ...

Energy Technology Data Exchange (ETDEWEB)

Marmesin was isolated from the medicinal plant, Afraegle paniculata. Its cytotoxicity and mutagenicity in Chinese hamster V79 cells when sensitized to near ultraviolet (NUV) and long wavelength ultraviolet light or black light (BL) were assayed. Marmesin was extremely cytotoxic in the dark. This cytotoxicity was photoenhanced in NUV and BL; the photoenhanced lethality being higher in NUV than in BL. The LD/sub 50/ of marmesin under NUV and BL photosensitization were 0.002 ..mu..M and (0.012 ..mu..M), respectively. In the absence of NUV and BL, marmesin's LD/sub 50/ was 0.013 ..mu..M.NUV and BL without marmesin were not significantly cytotoxic at the fluence rates of 0.29 W/m/sup 2/ and 4.2 W/m/sup 2/, respectively, for up to 20 min. In contrast to the observed high cytotoxicity of marmesin, its mutagenicity at the HGPRT locus (Asub(z)Gsup(r)) was weak. The implication of this result in the high incidence of skin cancer in Nigeria in ...

Energy Technology Data Exchange (ETDEWEB)

The usefulness of the mouse, rat, and Syrian golden hamster as experimental models for studies of the development of respiratory tract cancer is considered. Three different application methods for examining the effects of environmental chemicals on the respiratory tract in these species are discussed: implantation, intratracheal instillation, and inhalation. The results of various investigations are presented to demonstrate that each particular method has both advantages and disadvantages. The techniques are also considered in comparison with the human situation and in the light of obtaining the most valid data for extrapolation to man. Brief attention is paid to the relevance to respiratory tract carcinogenesis of more recently developed organ and cell culture systems.

International Nuclear Information System (INIS)

Effect of single and chronic irradiation on factors of hamsters natural immunity such as complement, lysozyme and antibodies in norm and in the cestode invasion has been investigated. Significant phase changes in the complement activity level, lysozyme content and specific antibodies tite have been shown to occur in hamster blood under the influence of ionizing radiation. Cestode invasion in irradiated host organism increases the negative effect of ionizing radiation on the hamster immyne system.

International Nuclear Information System (INIS)

Application of gamma radiation as a physical method of disinfestations against melon flies was recognized as a potential quarantine treatment. At 50 Gy, oocytes showed degeneration one day after treatment whereas seven-day-old oocytes did not differ greatly in appearance from control groups. Abnormal enlargement of trophocyte cells and vacuolization of oocytes occurred predominantly following the treatment with 100 and 150 Gy. One day after treatment with 150 Gy trophocytes underwent hypertrophy and hyperplasia. Irradiation at 100 and 150 Gy reduced the fertility to almost zero percent in the female melon flies.(authors)

British Library Electronic Table of Contents (United Kingdom)

In many species social behaviors are dependent on integration of chemosensory and hormonal cues. Many chemosensory stimuli are detected by the vomeronasal organ, which projects to many regions that contain steroid receptors, including the medial amygdala. In male hamsters, testosterone is known to acutely increase in response to chemosensory stimulation, and can facilitate sexual behavior by direct action within the medial amygdala. Conspecific stimuli activate the anterior (MeA) and posterior (MeP) medial amygdala, while heterospecific stimuli activate only MeA. Chemosensory stimuli with different social significance differentially activate the dorsal and ventral subdivisions of MeA and MeP. Therefore, it is likely that steroids differentially facilitate stimulation of the medial amygdala...

UK PubMed Central (United Kingdom)

In laboratory studies, hamsters (Mesocricetus spp.) exhibit intense male-male aggression, thus making them an excellent model system for studies of the functional and mechanistic...Full Text Available

Science.gov (United States)

A tick/rickettsial survey in various parts of Switzerland revealed the presence of a new, hitherto undescribed spotted fever group rickettsia ("Swiss agent") in up to 11.7% of I. ricinus collected off vegetation. Infection in ticks was found to be generalized with rickettsiae developing intracellularly and occasionally also intranuclearly. As a result of massive growth in ovarial tissues, including the germinative cells, the rate of transovarial and filial infection was 100%. The "Swiss agent" appears to be nonpathogenic for guinea pigs, domestic rabbits, and Swiss mice, but in male meadow voles (Microtus pennsylvanicus) it produces a microscopically detectable infection in the tunica vaginalis. The rickettsia grows well in tissue culture systems including chick embryo fibroblast, Vero, and vole tissue cells, when inoculated via yolk sac into 5-day-old hens' eggs, it kills 100% of the embryos after 5 to 7 days. Antigenic ...

Science.gov (United States)

The study was conducted to determine potential target organ toxicity and its reversibility in hamsters following twice daily oral doses of NSC-D629243 for 28 consecutive days. Male and female hamsters were administered NSC-D629243 dissolved in sesame oil ...

UK PubMed Central (United Kingdom)

The basic biology of the menstrual cycle is a complex, coordinated sequence of events involving the hypothalamus, anterior pituitary, ovary, and endometrium. The menstrual cycle with all its...Full Text Available

International Nuclear Information System (INIS)

A rat thyrotropin (thyroid-stimulating hormone, TSH) receptor cDNA was isolated that encoded a protein of 764 amino acids, M_r 86,528. Transfection of the cDNA caused COS-7 cells to develop a TSH-sensitive adenylate cyclase response and the ability to bind "1"2"5I-labeled TSH; both activities were similar to those of rat FRTL-5 thyroid cells and not duplicated by lutropin. The gene represented by the cDNA was assigned to mouse chromosome 12 and human chromosome 14. Northern analyses identified two species of mRNA, 5.6 and 3.3 kilobases, in FRTL-5 thyroid cells; the transcripts appeared to differ only in the extent of their 3' noncoding sequences. There were minimal amounts of the two mRNAs in rat ovary, and neither was detected in RNA preparations from rat testis, liver, lung, brain, spleen, and FRT thyroid cells, which do not have a functional TSH receptor. TSH decreased both mRNA ...

Energy Technology Data Exchange (ETDEWEB)

The human zinc finger protein genes (ZFX/Y) were identified as a result of a systematic search for the testis-determining factor gene on the human Y chromosome. Although they play no direct role in sex determination, they are of particular interest because they are highly conserved among mammals, birds, and amphibians and because, in eutherian mammals at least, they have active alleles on both the X and the Y chromosomes outside the pseudoautosomal region. We used in situ hybridization to localize the homologues of the zinc finger protein gene to chromosome 1 of the Australian echidna and to an equivalent position on chromosomes 1 and 2 of the playtpus. The localization to platypus chromosome 1 was confirmed by Southern analysis of a Chinese hamster [times] platypus cell hybrid retaining most of platypus chromosome 1. This localization is consistent with the cytological homology of chromosome 1 between the two species. The zinc finger protein ...

British Library Electronic Table of Contents (United Kingdom)

BACKGROUND AND PURPOSE Human K2P3.1 (TASK1) channels represent potential targets for pharmacological management of atrial fibrillation. K2P channels control excitability by stabilizing membrane potential and by expediting repolarization. In the heart, inhibition of K2P currents by class III antiarrhythmic drugs results in action potential prolongation and suppression of electrical automaticity. Carvedilol exerts antiarrhythmic activity and suppresses atrial fibrillation following cardiac surgery or cardioversion. The objective of this study was to investigate acute effects of carvedilol on human K2P3.1 (hK2P3.1) channels. EXPERIMENTAL APPROACH Two-electrode voltage clamp and whole-cell patch clamp electrophysiology was used to record hK2P3.1 currents from Xenopus oocytes, Chinese hamster o...

UK PubMed Central (United Kingdom)

In many rodent species, such as Syrian hamsters, reproductive behavior requires neural integration of chemosensory information and steroid hormone cues. The medial amygdala processes both of...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The nuclear lamina proteins, prelamin A, lamin B, and a 70-kD lamina-associated protein, are posttranslationally modified by a metabolite derived from mevalonate. This modification can be inhibited by treatment with (3-R,S)-3-fluoromevalonate, demonstrating that it is isoprenoid in nature. We have examined the association between isoprenoid metabolism and processing of the lamin A precursor in human and hamster cells. Inhibition of 3-hydroxy-3-methylglutaryl coenzyme A reductase by mevinolin (lovastatin) specifically depletes endogenous isoprenoid pools and inhibits the conversion of prelamin A to lamin A. Prelamin A processing is also blocked by mevalonate starvation of Mev-1, a CHO cell line auxotrophic for mevalonate. Moreover, inhibition of prelamin A processing by mevinolin treatment is rapidly reversed by the addition of exogenous mevalonate. Processing of prelamin A is, therefore, dependent on isoprenoid metabolism. ...

UK PubMed Central (United Kingdom)

BackgroundEarly exposure to ovarian hormones is considered to increase breast cancer incidence. The age at which the ovaries become functional is thus important.Full Text Available

UK PubMed Central (United Kingdom)

Experiments were conducted to investigate indole-3-acetic acid (IAA) and abscisic acid (ABA) metabolism associated with postanthesis senescence of ovaries from nonpollinated muskmelon (Cucumis...Full Text Available

International Nuclear Information System (INIS)

Simultaneous exposures of rats and hamsters to inhaled radon daughters, with and without uranium ore dust, were performed daily for five months. Pulmonary pathology developing in 6 to 13 mo after cessation of daily exposures included interstitial fibrosis, emphysema, epithelial hyperplasia, squamous metaplasia, and malignant neoplasia. Rats showed a greater variety and more severe response to these uranium mine inhalation exposures than did hamsters. Inhalation of radon daughters with uranium ore dust displayed the site of greatest damage, including squamous carcinoma, from the nasopharynx to the lungs. Sixty percent of the rats exposed to radon daughters with ore dust developed primary pulmonary carcinomas, providing an appropriate short-term experimental animal model for investigation of respiratory tract carcinogenesis in uranium miners.

UK PubMed Central (United Kingdom)

Sexual behavior is a natural reward for many rodent species, and it often includes chemosensory-directed components. Chemosensory stimuli themselves may also be rewarding. Conditioned place...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

BACKGROUNDLifestyle modifications are successfully employed to treat obese and overweight women with polycystic ovary syndrome (PCOS). The aims of the current pilot study were (i) to compare the efficacy on reproductive functions of a structured exercise training (SET) programme with a diet programme in obese PCOS patients and (ii) to study their clinical, hormonal and metabolic effects to elucidate potentially different mechanisms of action.METHODSForty obese PCOS patients with anovulatory infertility underwent a SET programme (SET group, n = 20) and a hypocaloric hyperproteic diet (diet group, n = 20). Clinical, hormonal and metabolic data were assessed at baseline, and at 12- and 24-week follow-ups. Primary endpoint was cumulative pregnancy rate.RESULTSThe two groups had similar demogra...

UK PubMed Central (United Kingdom)

Since April 2010, a severe outbreak of duck viral infection, with egg drop, feed uptake decline and ovary-oviduct disease, has spread around the major duck-producing regions in China. A new virus, named...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

The chemopreventive efficacy of turmeric has been established in experimental systems. However, its mechanism(s) of action are not fully elucidated in vivo. The present study investigates the mechanism of turmeric-mediated chemoprevention in 7,12-dimethylbenz(a)anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis at 2, 4, 6, 10 and 12?weeks. Dietary turmeric (1%) led to decrease in DMBA-induced tumor burden and multiplicity, and enhanced the latency period in parallel, to its modulatory effects on oncogene products and various cellular responses during HBP tumorigenesis. DMBA-induced expression of ras oncogene product, p21 and downstream target, the mitogen-activated protein kinases were significantly decreased by turmeric during HBP carcinogenesis. Turmeric also diminished ...

International Nuclear Information System (INIS)

PuO_2 particles behaved similarly in the lungs of rat and hamster. The relative concentrations of PuO_2 up to 1-yr postexposure were 1.0 for lung parenchyma, 1.3 for subpleural areas, 0.5 for peribronchiolar regions and 0.2 for perivascular regions in the lungs.

International Nuclear Information System (INIS)

Retention kinetics and tissue partition coefficients for "8"5Kr were determined in rats exposed to known concentrations of "8"5Kr gas. The tissue partition coefficients were used to calculate the relative tissue radiation dose, assuming exposure conditions equivalent to the maximum permissible concentration in air (MPC)a. The estimated radiation dose was highest in adrenals and body fat, about twice the dose estimated for the next highest tissue, ovaries. Saturation and desaturation curves show that the contents of the large intestines have a prolonged desaturation time compared to other samples analyzed.

J-STORE (Japan)

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International Nuclear Information System (INIS)

Background: In an effort to standardise radiological practices in the Republic of Ireland, current legislation states that 'written protocols for every type of standard radiological practice shall be established'. In order to fulfil this requirement the Irish Medical Council recommends the protocols issued by the Commission of European Communitees (CEC) for adoption in the country. Whilst this document does provide good guidance with regard to various radiographic factors, patient shielding instructions are notably ambiguous. The aim of this study was to remove some of this ambiguity by defining the optimal method of positioning patient shielding in antero-posterior (AP) and lateral lumbar spine radiographic examinations. These projections were chosen on the basis of their area of coverage being in close to and in some cases including the reproductive organs. They also represent the highest source of collective population dose of any conventional radiographic examination carried out in ...

International Nuclear Information System (INIS)

Full - grown pupae of the cotton leaf worm Spodoptera littorals (Boisd.) were gamma - irradiated with low doses of 25,50,75, or 100 Gy for male line and with 50 or 100 Gy for female line . The effects on reproduction, development and sex ratio were the biological aspects studied among P1,F1,F2 and F 3 generations . Also, the effects of dose accumulation applied grown male pupae through two or three filial generations and the retarded influence on their F1,F2,and F 3 progeny were examined. In another trial the histological examinations for ovaries and testes of irradiated parents and for their generation were made . The F1 males were more sterile than irradiated parental males while F1 females were more fertile than their irradiated parental females. Irradiation of P1 males did not clearly affect neither the percentage of mated females nor the average number of spermatophores per mated female among the individuals of P1,F1,F2 and F 3 generations. Irradiation of P1 ...

British Library Electronic Table of Contents (United Kingdom)

Abstract The term -stem cell- most commonly refers to embryonic stem cells, particularly in the lay media; however, it also describes other cell types. A stem cell represents a cell of multi-lineage potential with the ability for self-renewal. It is now clear that the plasticity and immortality of a given stem cell will depend on what type of stem cell it is, whether an embryonic stem cell, a fetal-placental stem cell or an adult stem cell. Stem cells offer great promise as cell-based therapies for the future. With evolving technology, much of the socio-political debate regarding stem cells can now be avoided.

DEFF Research Database (Denmark)

Udgivelsesdato: 2002-Mar

Science.gov (United States)

PMID:21290990

Energy Technology Data Exchange (ETDEWEB)

Abstract not provided

International Nuclear Information System (INIS)

... electric utilities electrochemistry energy storage fuel cells organizational models

UK PubMed Central (United Kingdom)

We studied telomeric DNA in leukemic cells as well as in normal T cells, B cells, monocytes, polymorphonuclear leukocytes, and bone marrow hematopoietic progenitor cells. No marked differences were...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

We have investigated the properties of nerve cell precursors in hydra by analyzing the differentiation and proliferation capacity of interstitial cells in the peduncle of Hydra oligactis, which is a region of active nerve cell differentiation. Our results indicate that about 50% of the interstitial cells in the peduncle can grow rapidly and also give rise to nematocyte precursors when transplanted into a gastric environment. If these cells were committed nerve cell precursors, one would not expect them to differentiate into nematocytes nor to proliferate apparently without limit. Therefore we conclude that cycling interstitial cells in peduncles are not intermediates in the nerve cell differentiation pathway but are stem cells. The remaining interstitial cells in the peduncle are ...

Science.gov (United States)

A silicon solar cell assembly comprising a large, thin silicon solar cell bonded to a metal mount for use when there exists a mismatch in the thermal expansivities of the device and the mount.

UK PubMed Central (United Kingdom)

Ethane oxidation was studied in ethane-grown resting cells (mycelia) of an Acremonium sp. and in cell-free preparations of such mycelia. From resting cell experiments evidence was found for a pathway...Full Text Available

Science.gov (United States)

... FLUENT PEM fuel cell toolbox is actually composed of many User Defined Functions that are incorporated into the fuel cell model developed by ...

DEFF Research Database (Denmark)

Udgivelsesdato: 2009-Jun

International Nuclear Information System (INIS)

Cell cultures were prepared from lung tumors occurring in beagles following exposure to inhaled plutonium. Morphologic and growth characteristics of two of these cell lines are described.

Science.gov (United States)

PMID:17103063

UK PubMed Central (United Kingdom)

SummaryIn vivo tumor cell migration through integrin-dependent pathways is key to the metastatic behavior of malignant cells. Using quantitative in vivo...Full Text Available

UK PubMed Central (United Kingdom)

For proper tissue morphogenesis, cell divisions and cell fate decisions must be tightly and coordinately regulated. One elegant way to accomplish this is to couple them with asymmetric cell divisions....Full Text Available

UK PubMed Central (United Kingdom)

We have established a cartilaginous fish cell line [Squalus acanthias embryo cell line (SAE)], a mesenchymal stem cell line derived from the embryo of an elasmobranch, the spiny dogfish...Full Text Available

UK PubMed Central (United Kingdom)

Interleukin 2 (IL-2) and B-cell growth factors I and II (BCGF I and BCGF II) are lymphokines produced by T cells that play a major role in T- and B-cell cooperation. Peripheral blood lymphocytes from...Full Text Available

UK PubMed Central (United Kingdom)

Normal cells, both in vivo and in vitro, become quiescent after serial cell proliferation. During this process, cells can develop immortality with genomic instability,...Full Text Available

UK PubMed Central (United Kingdom)

Endothelial cells and mural cells (smooth muscle cells, pericytes, or fibroblasts) are known to communicate with one another. Their interactions not only serve to support fully functional blood...Full Text Available

UK PubMed Central (United Kingdom)

Craniofacial injuries require a variety of different cell types to repopulate areas of bone, cartilage, tendon, and fat. Mesenchymal stem cells (MSCs) provide a multipotent cell source for tissue...Full Text Available

UK PubMed Central (United Kingdom)

Somatic cell nuclear transfer or therapeutic cloning has provided great hope for stem cell-based therapies. However therapeutic cloning has been experiencing both ethical and technical difficulties....Full Text Available

KoreaScience (Korea)

Full Text Available

UK PubMed Central (United Kingdom)

It has been postulated that thrombin binds to endothelial cells through, at least in part, cell surface glycosaminoglycans such as heparan sulfate, which could serve as antithrombin cofactor on the...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

KoreaScience (Korea)

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UK PubMed Central (United Kingdom)

In preimplantation mouse development, the first cell lineages to be established are the trophectoderm (TE) and inner cell mass. TE possesses epithelial features, including apical-basal cell polarity...Full Text Available

Wastenet

...Basic Information | Fuel Cells & Vehicles | US EPA This web page provides basic information on EPA's Fuel Cells & Vehicles web site ...including the chemical composition of fuel cell technology, how it works, descriptions of the various types of fuel cells , their availability and ... background,electrochemical,hydrogen,fuel cell,fuel cell vehicle,fuel reformer,performace,improved fuel economy,increased engine efficiency,lower emissions,zero emissions,availablity,fuel cell types,diagram,Proton ...Exchange Membrane,PEM Basic Information | Fuel Cells & Vehicles | US EPA background,electrochemical,hydrogen,fuel cell,fuel cell vehicle,fuel reformer,performace,improved fuel economy,...

Science.gov (United States)

Students get a background on Stem Cell technology and learn to write an effective opinion essay.

Energy Technology Data Exchange (ETDEWEB)

Laser-assisted processing techniques for producing high-quality solar cell metallization patterns are investigated, developed, and characterized. The tasks comprising these investigations are outlined. A new batch of solar cells was processed using the laser decomposition of spun-on silver neodecanoate to metallize cells. Decomposition of silver neodecanoate was carried out at different laser powers on different cells on a given wafer to determine whether this would have any effect on cell performance. Solar cells which were written with laser powers of 5 to 8 watts, gave excellent results with cell efficiencies in the range of 14 to 16%.

Science.gov (United States)

... nent to the design and construction of metal-semiconductor solar cells, in that both the photovoltage and the efficiency of metal-semiconductor cells ...

Energy Technology Data Exchange (ETDEWEB)

Ovarian function was evaluated in 11 women 16 to 43 years of age at treatment who received doxorubicin, cyclophosphamide, and high doses of methotrexate with or without radiotherapy in adjuvant therapy of soft tissue sarcoma. Five women (16-33 yr old) who received chemotherapy alone or combined with radiotherapy only at sites distant from the ovaries (chest wall, thigh, and leg) had minimal menstrual irregularities or temporary cessation of menses during therapy; cyclic menses returned promptly after therapy. Gonadotropin levels (expressed as means +/- SD) (follicle-stimulating hormone (FSH), 10 +/- 15 mlU/ml; luteinizing hormone (LH), 10 +/- 4 mlU/ml) and 17 ..beta..-estradiol (E/sub 2/) levels (means +/- SD, 208 +/- 147 pg/ml) were normal. By contrast, 4 older women (ages 36-43 yr) who received similar treatment developd persistent amenorrhea with postmenopausal levels of gonadotropin (FSH, 109 +/- 29 mlU/ml; LH, 72 +/- 19 mlU/ml) and E/sub 2/ (19 +/- 8 pg/ml). ...

International Nuclear Information System (INIS)

The accuracy is investigated of both lymphangiography and CT in detecting lymph nodes metastases in 59 patients evaluated preoperatively and subsequently submitted to surgery with selective/systemic pelvic and paraaortic lymphadenectomy. CT accuracy was also investigated in 46 patients with a clinically suspected relapse of ovarian cancer (verified by means of clinical and/or CT follow-up in 36 patients, by laparotomy in 7, by fine-needle biopsy in 1 and by necroscopy in the last 2). In the first group (previously untreated patients) the overall results in the pelvis were, respectively, for lymphangiography and CT: 94.9% vs 89.8% accuracy, 86.6% vs 60% sensitivity, 97.7% vs 100% specificity, and 92.8% vs 100%, 95.5% vs 88% positive and negative predictive values. In the paraaortic region the results were: 89.1% vs 86.5% accuracy, 73.3% vs 66.6% sensitivity, 100% specificity for both techniques, 100% positive predictive value, and 84.6% vs 81.5% negative predictive value. In the second ...

British Library Electronic Table of Contents (United Kingdom)

Abstract Epstein-Barr virus (EBV), which infects not only B cells, but also T cells and natural killer (NK) cells, is associated with multiple lymphoid malignancies. Recently, the proteasome inhibitor bortezomib was reported to induce apoptosis of EBV-transformed B cells. We evaluated the killing effect of this proteasome inhibitor on EBV-associated T lymphoma cells and NK lymphoma cells. First, we found that bortezomib treatment decreased the viability of multiple T and NK cell lines. No significant difference was observed between EBV-positive and EBV-negative cell lines. The decreased viability in response to bortezomib treatment was abrogated by a pan-caspase inhibitor. The induction of apoptosis was confirmed by flow cytometric assessment of annexin V staining. Additionally, cleavage o...

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An assay system for the stem cell that colonizes the thymus and differentiates into T cells was developed, and by using this assay system the existence of two subpopulations of stem cells for T cell lineage was clarified. Part-body-shielded and 900-R-irradiated C57BL/6 (H-2b, Thy-1.2) recipient mice, which do not require the transfer of pluripotent stem cells for their survival, were transferred with cells from B10 X Thy-1.1 (H-2b, Thy-1.1) donor mice. The reconstitution of the recipient's thymus lymphocytes was accomplished by stem cells in the donor cells and those spared in the shielded portion of the recipient that competitively colonize the thymus. Thus, the stem cell activity of donor cells can be evaluated by determining the proportion of donor-type (Thy-1.1+) ...

British Library Electronic Table of Contents (United Kingdom)

The herbicide atrazine is a known immunotoxicant and an inhibitor of human natural killer (NK) cell lytic function. The precise changes in NK cell lytic function following atrazine exposure have not been fully elucidated. The current study identifies the point at which atrazine exerts its affect on the stepwise process of human NK cell-mediated lyses of the K562 target cell line. Using intracellular staining of human peripheral blood lymphocytes, it was determined that a 24-h in vitro exposure to atrazine did not decrease the level of NK cell lytic proteins granzyme A, granzyme B or perforin. Thus, it was hypothesized that atrazine exposure was inhibiting the ability of the NK cells to bind to the target cell and subsequently inhibit the release of lytic protein from the NK cell. To test t...

UK PubMed Central (United Kingdom)

The presence of a high number of activated T cells in the bloodstream and spontaneous proliferation of peripheral blood mononuclear cells in vitro are striking characteristics of human T-cell leukemia...Full Text Available

International Nuclear Information System (INIS)

The herbicide atrazine is a known immunotoxicant and an inhibitor of human natural killer (NK) cell lytic function. The precise changes in NK cell lytic function following atrazine exposure have not been fully elucidated. The current study identifies the point at which atrazine exerts its affect on the stepwise process of human NK cell-mediated lyses of the K562 target cell line. Using intracellular staining of human peripheral blood lymphocytes, it was determined that a 24-h in vitro exposure to atrazine did not decrease the level of NK cell lytic proteins granzyme A, granzyme B or perforin. Thus, it was hypothesized that atrazine exposure was inhibiting the ability of the NK cells to bind to the target cell and subsequently inhibit the release of lytic protein from the NK cell. To test this hypothesis, flow cytometry ...

UK PubMed Central (United Kingdom)

PCD (programmed cell death) in plants presents important morphological and biochemical differences compared with apoptosis in animal cells. This raises the question of whether PCD arose independently...Full Text Available

UK PubMed Central (United Kingdom)

Bovine leukemia virus (BLV), a retrovirus related to human T-cell leukemia virus types 1 and 2, can induce persistent nonneoplastic expansion of the CD5⁺ B-cell population, termed...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A comparison of the concentration-response effects of inhaled ozone (O/sub 3/) in different species of laboratory animals was made in order to better understand the influence of the choice of species in inhalation studies of this gas. The effect of 4-hour exposure to ozone (O/sub 3/) at concentrations of 0.0, 0.2, 0.5, 1.0, and 2.0 ppm was determined in rabbits, guinea pigs, rats, hamsters and mice. Lavage fluid protein (LFP) accumulation 18 hr after exposure was used as the indicator of O/sub 3/-induced pulmonary edema. All species had similar basal levels of LFP (250-350 ug/ml) when a volume of saline which approximated the total lung capacity was used for lavage of the collapsed lungs. Exponential dose-response curves were seen in all species except guinea pigs, which showed significant increases in LFP at low O/sub 3/ concentrations (0.2 ppm) and a leveling off of response at the higher O/sub 3/ levels. Other species usually showed significant elevations in LFP ...

Science.gov (United States)

The PVSCAN is an instrument designed to characterize silicon solar cell materials and devices. It performs a host of measurements that yield spatial maps of dislocation density, grain distribution, reflectance, and photoresponses from near-junction and the bulk of a solar cell.

UK PubMed Central (United Kingdom)

There is ample evidence suggesting that superantigens may act as a triggering factor in the pathogenesis of rheumatoid arthritis (RA). We investigated whether superantigen could activate T cells in...Full Text Available

UK PubMed Central (United Kingdom)

The proliferation of stem cell research, conflated with its ethical and moral implications, has led governments to attempt regulation of both the science and funding of stem cells. Due to a diversity...Full Text Available

UK PubMed Central (United Kingdom)

Background: In North America and Europe, 80% of invasive skin cancers are basal cell carcinoma while 20% are squamous cell carcinoma (SCC). In contrast, African studies reveal a preponderance...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

This paper describes a radiation shield verification survey of a large hot cell at the Fast Flux Test Facility (FFTF). The following aspects of the shield test are discussed: description of the FFTF; description of the hot cell; the test procedures; radiation protection, and the test results.

UK PubMed Central (United Kingdom)

Human myeloid-lineage cells are refractory to HIV-1 infection. The Vpx proteins from HIV-2 and sooty mangabey SIV render these cells permissive to HIV-1 infection through proteasomal degradation of...Full Text Available

UK PubMed Central (United Kingdom)

Most genetic changes that promote tumorigenesis involve dysregulation of G1 cell cycle progression. A key regulatory site in G1 is a growth factor–dependent restriction point (R) where cells...Full Text Available

Science.gov (United States)

... based, disease treatment remains promising, the emphasis for stem cell research from the biomedical research community is clear, and ... diagnosis as a novel source of embryos for stem cell research. Repr...

UK PubMed Central (United Kingdom)

Placental and placental-like alkaline phosphatase (PLAP) levels in the culture media of 87 cell lines of neoplastic and 'normal' origin were measured by a conventional immunosorbent enzymatic assay...Full Text Available

UK PubMed Central (United Kingdom)

A new method is described for continuously measuring cell turgor pressure (P), hydraulic conductivity (L_p), and volumetric elastic modulus (ε) in higher plant cells, using a pressure...Full Text Available

UK PubMed Central (United Kingdom)

Neutral endopeptidase 24.11 (NEP, CD10) is a cell-surface enzyme expressed by prostatic epithelial cells that cleaves and inactivates neuropeptides implicated in the growth of androgen-independent prostate...Full Text Available

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Amorphous silicon solar cells have been shown to have efficiencies which degrade as a result of long exposure to light. Annealing such cells in air at a temperature of about 200.degree. C. for at least 30 minutes restores their efficiency.

UK PubMed Central (United Kingdom)

Red cell transfusions are associated with the development of acute lung injury in the critically ill. Recent evidence suggests that storage induced alterations of the red blood cell (RBC) collectively...Full Text Available

UK PubMed Central (United Kingdom)

Many patients who undergo hematopoietic cell transplantation (HCT) present with anemia and have received red blood cell transfusions before HCT. As a result, iron overload is frequent and appears...Full Text Available

UK PubMed Central (United Kingdom)

Stem cells of the human prostate gland have not yet been identified utilizing a structural biomarker. We have discovered a new prostatic epithelial cell phenotype-expressing cytokeratin 6a (Ck6a+...Full Text Available

Science.gov (United States)

... is known as "reproductive cloning." The Link to Stem Cell Research Stem cell research and research cloning are closely linked. Scientists in ... to arrive at a position on cloning and stem cell research. Many nations, including the UK, China, and South ...

UK PubMed Central (United Kingdom)

The glycolipid content of human non-seminomatous germ cell tumour cell lines correlates with their differentiation lineage. To analyse whether this reflects the situation in primary tumours, we studied...Full Text Available

UK PubMed Central (United Kingdom)

DNA from the peripheral blood mononuclear cells of 17 different individuals infected with human T-cell lymphoma/leukemia virus type II (HTLV-II) was successfully amplified by the polymerase chain reaction...Full Text Available

UK PubMed Central (United Kingdom)

Metastatic testicular germ cell tumours are cured in approximately 85% of patients using cisplatin-based combination chemotherapy. Patients who fail to respond have a poor prognosis, and there is a...Full Text Available

UK PubMed Central (United Kingdom)

Zygotes of fucoid algae have long been studied as a paradigm for cell polarity. Polarity is established early in the first cell cycle and is then expressed as localized growth and invariant cell division....Full Text Available

UK PubMed Central (United Kingdom)

BackgroundClara cell protein (CC16), the main secretory product of bronchiolar Clara cells, plays an important protective role in the respiratory tract against oxidative stress and...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundPerfluorocarbons (PFC) are used to improve gas exchange in diseased lungs. PFC have been shown to affect various cell types. Thus, effects on alveolar type II (ATII) cells...Full Text Available

UK PubMed Central (United Kingdom)

Reaggregated cells from 6- to 8-day-old mouse cerebella have been used to raise antibodies in rabbits. The interaction of these antibodies with cerebellar cell surface components was assessed by cytotoxicity...Full Text Available

UK PubMed Central (United Kingdom)

The cell types involved in the cellular immune response were studied with the GVH in vitro as a test system. Comparison of the activities of cells of different lymphoid organs in the...Full Text Available

UK PubMed Central (United Kingdom)

Stem cell therapies for neurodegenerative disorders require accurate delivery of the transplanted cells to the sites of damage. Numerous studies have established that fluid injections to the hippocampus...Full Text Available

UK PubMed Central (United Kingdom)

One of the main obstacles encountered when trying to culture human seminoma (SE) cells in vitro is massive degeneration of the tumour cells. We investigated whether dissociation of tumour tissue, to...Full Text Available

UK PubMed Central (United Kingdom)

BACKGROUND--Interstitial lung diseases are characterised by the recruitment of mononuclear cells to disease sites where maturation occurs and activation products, including lysozyme (LZM), are released....Full Text Available

UK PubMed Central (United Kingdom)

Cultured mouse or human embryonic stem (ES) cells provide access to all of the genes required to elaborate the fundamental components and physiological systems of a mammalian cell. Chemical or insertional...Full Text Available

UK PubMed Central (United Kingdom)

Fate maps are generated by marking and tracking cells in vivo to determine how progenitors contribute to specific structures and cell types in developing and adult tissue. An advance in this...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

In the last two years, rapid progress has been made in the energy conversion efficiencies of GaAs solar cells fabricated from molecular beam epitaxy (MBE) material. The efficiencies of cells fabricated from MBE material are now comparable with those fabricated from metal-organic chemical vapor deposition material, even for cells of dimension 2 cmx4 cm. This paper reviews the progress in MBE cell efficiencies. Also discussed is the role oval defects play in GaAs diode and solar cell performance. (orig.).

British Library Electronic Table of Contents (United Kingdom)

Transdifferentiation of an individual's own cells into functional differentiated cells to replace an organ's lost function would be a personalized approach to therapeutics. In this two part series, we will describe the progress toward establishing functional transdifferentiated adrenal cortical cells. In this article (Part 2), we describe the disorders of the adrenal cortex, therefore establishing why there is the need for personalized cell-based therapy for individuals with these disorders. We then present our pilot studies of cell transdifferentiation toward an adrenal cortical fate using genes described in the first article of this pair (Part 1).

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We report on multijunction GaInP/GaAs photovoltaic cells with total-area efficiencies of 29.5% at one-sun concentration and air mass (AM) 1.5 global and 25.7% one-sun, AM0. These values represent the highest efficiencies achieved by any solar cell under these illumination conditions. Three key areas in this technology are identified and discussed: the grid design, front surface passivation of the top cell, and bottom surface passivation of both cells. Aspects of cell design related to its operation under different solar spectra and under concentration are also discussed.

Science.gov (United States)

pletely new PW fuel cell model had to be developed for CINDA. Several ...... following linear equation, which is used in the SINDA fuel cell model: ...

UK PubMed Central (United Kingdom)

ObjectiveTo achieve osteochondral regeneration utilizing transplantation of cartilage-lineage cells and adequate scaffolds, it is essential to characterize the behavior of transplanted...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundThe evolution of eukaryotic cells is widely agreed to have proceeded through a series of endosymbiotic events between larger cells and proteobacteria or cyanobacteria,...Full Text Available

Science.gov (United States)

Ti-Ag and Ti-Pd-Ag solar cell contacts structure and degradation dependence on high temperature and humidity environmental exposure

UK PubMed Central (United Kingdom)

The molecular structure, chemical properties, and biological function of the xyloglucan polysaccharide isolated from cell walls of suspension-cultured sycamore (Acer pseudoplatanus)...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

The most advanced frontier of allogeneic hematopoietic stem cell transplantation (allo-HSCT) is represented by the use of an HLA-partially matched relative as donor. In this type of transplantation, donor-derived natural killer (NK) cells, which are alloreactive towardtoward recipient cells, significantly contribute to the eradication of leukemia blasts. Alloreactive NK cells may also kill host dendritic cells and T lymphocytes, thus preventing graft-versus-host disease and graft rejection, respectively. Sophisticated strategies of adoptive infusion of T-cell lines/clones specific for the most life-threatening pathogens (namely cytomegalovirus, Epstein-Barr virus, Aspergillus and Adenovirus) have been envisaged, and successfully tested in a few pilot trials, to protect the recipient in the...

UK PubMed Central (United Kingdom)

Conditions were found in which Chlamydomonas reinhardi exhibits a circadian alteration of its cell surface, measured as ability to stick to glass. Under these same conditions the cells...Full Text Available

Science.gov (United States)

... mast cell staining; ref. 16). The severity of structural radiation injury was assessed using a histopathological radiation injury score ... ...

UK PubMed Central (United Kingdom)

There is a requirement for a noninvasive technique to monitor stem cell differentiation. Several candidates based on optical spectroscopy are discussed in this review: Fourier transform infrared (FTIR)...Full Text Available

International Science & Technology Center (ISTC)

Morphological, Electrophysiological and Behavioral Investigations of the Nervous Tissue Developed from the Embryonic Matrix Zone Cells of the Dorsolateral Walls of Lateral Ventricles, Implanted into the Lesioned Regions of the Adult Rat's Brain

Energy Technology Data Exchange (ETDEWEB)

The present volume on modeling of batteries and fuel cells discusses the significance of the effectiveness factor for flooded porous electrodes, active pore distribution spectroscopy for characterizing porous battery electrodes, the agglomerate model for porous electrodes, and dynamic-performance measurements of battery cells for electric vehicles and other applications. Attention is given to mathematical modeling of a primary zinc/air battery, mathematical modeling of Grace Li-TiS2 cells, modeling of electrocrystallization processes in battery systems, and rotating disk electrode studies in molten Li/K carbonate eutectic. Topics addressed include the variability of nickel oxide cathode dissolution in molten carbonate fuel cells, water transport properties of fuel cell ionomers, modeling water content effects in polymer electrolyte fuel cells, and computer ...

Science.gov (United States)

Oct 15, 1985 ... Title: Laser-assisted solar cell metallization processing. No Digital Version Available: Go to Tips on Ordering ...

International Nuclear Information System (INIS)

Methods for improving the sensitivity of scintillation cells for radon concentration measurements were studied with emphasis on improving light collection efficiency. This allows the length and hence the volume of the cell to be increased. Variables studied were choice of scintillator material, its method of application and thickness, length of cell, cell material, type and configuration of reflectors, choice of photomultipliers, and factors affecting background. Response from various areas of the cell surface was studied with an alphy source and with radon filling. Coating the window with phosphor was found to be counter-productive. The optimum results obtained were with the inside of the cell (other than the window) covered with a thick layer of ZnS(Ag), or with a thick layer of reflective material coated with a thin layer of phosphor. With it, a 10 cm ...

UK PubMed Central (United Kingdom)

Proliferating cells have been immunophenotypically characterized in lymph node and bronchoalveolar lavage (BAL) samples obtained from patients with active and inactive sarcoidosis with the cell-cycle-related...Full Text Available

UK PubMed Central (United Kingdom)

PASTICCINO (PAS) genes are required for coordinated cell division and differentiation during plant development. In loss-of-function pas mutants,...Full Text Available

Science.gov (United States)

1 The Elemental Fuel Cell Model. The cell reactions are also illustrated in. Figure 1. Hydrogen is oxidized at the anode. Oxy- ...

Science.gov (United States)

Proton exchange membrane (PEM) fuel cells are energy sources that have the ... for H2 /02 PEM fuel cells because their catalysts have properties suitable for 0 ...

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Sputtering of glass coatings on cadmium sulfide thin film solar cells

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Substantially genetically stable continuous human cell lines derived from normal human mammary epithelial cells (HMEC) and processes for making and using the same. In a preferred embodiment, the cell lines are derived by treating normal human mammary epithelial tissue with a chemical carcinogen such as benzo(a)pyrene. The novel cell lines serve as useful substrates for elucidating the potential effects of a number of toxins, carcinogens and mutagens as well as of the addition of exogenous genetic material. The autogenic parent cells from which the cell lines are derived serve as convenient control samples for testing. The cell lines are not neoplastically transformed, although they have acquired several properties which distinguish them from their normal progenitors. 2 tabs.

UK PubMed Central (United Kingdom)

Cancer, by definition, is a proliferative disease. The fundamental scientific issue explored at the international symposium "Cell Proliferation and Chemical Carcinogenesis" was the impact of chemically...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Abstract: In many biological processes heterogeneity within clonal cell populations is an important issue. One of the most striking examples is a population of cancer cells in which after a common, identical death signal some cells die whereas others survive. The reason for this heterogeneity is intrinsic and extrinsic noise. In this paper we present a mechanistic multi-scale modeling framework for cell populations, in which the dynamics of every individual cell is captured by a parameter dependent stochastic differential equation (SDE). Heterogeneity among individual cells is accounted for by differences in parameter values, modeling extrinsic influences. Based on the statistical properties of the extrinsic noise and the SDE model for the individual cell, a partial differential equation (...

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Annual report of fuel cell projects sponsored by Department of Energy, National Energy Technology Laboratory.

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The existence of stem cells committed to the T lymphoid lineage was deduced from studying how rat T and B stem cells differ in their expression of membrane W3/13 antigen and in their susceptibility in vivo to gamma irradiation. Stem cell activity of rat bone marrow and fetal liver was measured in long-term radiation chimeras using B and T cell alloantigenic surface markers to identify the progeny of donor cells. Monoclonal mouse anti-rat thymocyte antibody W3/13 labeled approximately 40% of fetal liver cells and 60-70% of young rat bone marrow cells (40% brightly, 25% dimly). Bright, dim, and negative cells were separated on a fluorescence-activated cell sorter. All B and T lymphoid stem cells in fetal liver were W3/13 bright, as were B lymphoid stem cells in ...

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The purpose of this review is to consider the hypothesis that cancer frequently originates from stem cells. Using the spleen transplantation assay where stem cells were transplanted in the spleen of mice lethally irradiated by ionizing radiation, the author undertook a study aimed at defining the risk of radiogenic cancer per susceptible cells with use of rat radiogenic mammary and thyroid cancers because of the high incidences of these cancers in a-bomb survivors. Measured were the number of cancer-susceptible cells initially present in the tissue, the number of such cells that survived at a given dose and the number of cancers that developed per surviving cell. Thyroid cell differentiation and proliferation in rats transplanted with thyroid cells were enhanced by thyroidectomy and low iodine diet. Further, the ...

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Bone marrow is one of the most radiosensitive organs. Irradiation causes a marked decrease in the total number of hematopoietic cells in the bone marrow. The reticular meshwork structure of marrow stromal cells, however, is relatively resistant to irradiation. Unimpaired stromal cell structure has been thought to be a prerequisite for the repopulation of hematopoietic cells during recovery from the effects of irradiation. The reticular framework is maintained by cell adhesion apparatuses such as gap junctions. The in vitro radiobiologic survival values of a cloned stromal cell line, H-1/A, were studied (n = 1.8, D0 = 138 cGy). Radiation doses of up to 4000 cGy had no detectable effects on the production of colony-stimulating factor 1. H-1/A cells communicate with each other via gap junctions as determined by the sensitive dye-transfer ...

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The cell is modeled as an ellipsoid with shell and the surface stress distribution calculated by means of the Maxwell Stress Tensor. The cell membrane is treated as incompressible material having both bending and shear energies of deformation. Employing the principle of virtual work, cell volume (and hence shape) is computed as a function of the external field strength and orientation with respect to the field. The following results were obtained: (1) The surface stresses that develop or the cell membrane are distributed having both normal and tangential components that act together to produce a rounding of the cell. (2) If the tangential component of the stress is ignored, then higher field strengths are needed to produce similar deformation (shape change) of cells. (3) The threshold value of the applied field, i.e, the field strength at which the volume ...

Science.gov (United States)

In order to study the neurobiological basis of seasonal changes in hippocampal structure and function, the rate of cell proliferation was examined in male and female wild meadow voles captured during different seasons. We found that the number of [3H]thymidine-labeled cells varied across the seasons and across sex in the meadow vole. Non-breeding female meadow voles had a higher rate of cell proliferation and cell death than males captured during either season or breeding females. These seasonal changes in the female meadow vole were associated with both fluctuating levels of adrenal steroids and gonadal steroids. Estradiol level was highly correlated with both the number of [3H]thymidine-labeled cells and the number of pyknotic cells in female meadow voles, with high levels of estradiol being associated with low levels of cell proliferation ...

UK PubMed Central (United Kingdom)

Hyperosmotic stress is known to significantly enhance net uptake of inorganic ions into plant cells. Direct evidence for cell turgor recovery via such a mechanism, however, is still lacking. In the...Full Text Available

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No Abstract Available

International Nuclear Information System (INIS)

... cadmium sulfides communications electrons performance testing physical

Science.gov (United States)

... prominent example today, perhaps, is the issue of stem cell research, but there is a whole list of issues ... ...

UK PubMed Central (United Kingdom)

Epidermal gamma delta T cells (γδ T) and Langerhans cells (LC) are immune cells altered by exposure to ultraviolet radiation (UVB), a powerful stressor resulting in immune suppression....Full Text Available

KoreaScience (Korea)

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DEFF Research Database (Denmark)

Udgivelsesdato: 2002-May

KoreaScience (Korea)

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DEFF Research Database (Denmark)

Udgivelsesdato: MAR

KoreaScience (Korea)

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Science.gov (United States)

No abstract prepared.

J-STORE (Japan)

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KoreaScience (Korea)

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DEFF Research Database (Denmark)

Udgivelsesdato: 1988-Jul

Science.gov (United States)

NASA's Ames Research Center awarded Ciencia, Inc., a Small Business Innovation Research contract to

UK PubMed Central (United Kingdom)

IntroductionThe phenotypic and functional differences between cells that initiate human breast tumors (cancer stem cells) and those that comprise the tumor bulk are difficult to...Full Text Available

Norwegian Open Research Archives (NORA)

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KoreaScience (Korea)

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UK PubMed Central (United Kingdom)

Murine embryonic stem (ES) cells have unusually long telomeres, much longer than those in embryonic tissues. Here we address whether hyper-long telomeres are a natural property of pluripotent stem cells,...Full Text Available

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Not Available

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KoreaScience (Korea)

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International Nuclear Information System (INIS)

Published in summary form only.

KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

The zinc-air battery/fuel cell is an old technology invented one hundred years ago. However, there is renewed interest in this technology in response to the growing need for clean energy technology. The zinc-air battery/fuel cell is more attractive than similar technologies because its characteristics include high power density, safe operation and storage, and low cost. Zinc-air battery/fuel cells can be made in milliwatts to mega watts to accommodate different applications. The zinc-air battery/fuel cell has four major designs, namely primary, mechanically rechargeable, continuous feed and electrically rechargeable zinc-air battery/fuel cells. Among the different designs, the most common is the air cathode. There are 3 generations of catalysts used in the air cathodes. This paper discussed the different designs of the zinc-air battery/fuel cell, and more ...

British Library Electronic Table of Contents (United Kingdom)

Summary The effects of high-intensity pulsed electromagnetic stimulation (HIPEMS) on proliferation and differentiation of neonatal rat neural stem cells in vitro were investigated. Neural stem cells derived from neonatal rats were exposed to 0.1 Hz, 0.5-10 Tesla (T) [8 groups of B-I, respectively], 5 stimuli of HIPEMF. The sham exposure controls were correspondingly established. Inverted phase contrast microscope was used to observe the cultured cells, MTT assay to detect the viability of the cells as expressed by absorbance (A) value, and flow cytometry to measure differentiation of neural stem cells. The results showed that A values of neural stem cells in both 3.0 T and 4.0 T groups were significantly higher than the other groups 24 to 168 h post HPEMS, indicating a strong promotion of ...

British Library Electronic Table of Contents (United Kingdom)

Cyclooxygenase-2 (COX-2) content is increased in many types of tumor cells. We have investigated the mechanism by which resveratrol, a stilbene that is pro-apoptotic in many tumor cell lines, causes apoptosis in human head and neck squamous cell carcinoma UMSCC-22B cells by a mechanism involving cellular COX-2. UMSCC-22B cells treated with resveratrol for 24 h, with or without selected inhibitors, were examined: (1) for the presence of nuclear activated ERK1/2, p53 and COX-2, (2) for evidence of apoptosis, and (3) by chromatin immunoprecipitation to demonstrate p53 binding to the p21 promoter. Stilbene-induced apoptosis was concentration-dependent, and associated with ERK1/2 activation, serine-15 p53 phosphorylation and nuclear accumulation of these proteins. These effects were blocked by ...

British Library Electronic Table of Contents (United Kingdom)

To determine whether PKH26 labeling affects the morphologies, phenotypes, proliferation, and secretion abilities of human umbilical mesenchymal stromal cells (HUMSCs) were investigated. Isolated HUMSCs were labeled with PKH26, and cell morphology was observed under microscope. Cell cycle, apoptotic cell death, expression of PKH26, and the proliferation rate were evaluated. Additionally, fluorescence intensity of PKH26 labeling at different passage times was quantified. There were no detectable differences in cell morphology, cell growth, and proliferation rate after PKH26 labeling. In addition, fluorescence intensity of PKH26 labeling was gradually reduced with increase of the passage times. The PKH26 labeling disappeared after passage six times. In summary, PKH26 labeling is a safe and ef...

British Library Electronic Table of Contents (United Kingdom)

Epigenetic regulations of genes by reversible methylation of DNA (at the carbon-5 of cytosine) and numerous reversible modifications of histones play important roles in normal physiology and development, and epigenetic deregulations are associated with developmental disorders and various disease states, including cancer. Stem cells have the capacity to self-renew indefinitely. Similar to stem cells, some malignant cells have the capacity to divide indefinitely and are referred to as cancer stem cells. In recent times, direct correlation between epigenetic modifications and reprogramming of stem cell and cancer stem cell is emerging. Major discoveries were made with investigations on reprogramming gene products, also known as master regulators of totipotency and inducer of pluoripotency, na...

British Library Electronic Table of Contents (United Kingdom)

Ex vivo expanded peripheral blood progenitor cells (PBPC) have been shown to provide rapid neutrophil engraftment, and in some patients, to eliminate neutropenia after transplantation to support high-dose chemotherapy. However, the effect of expansion culture on stem cell content and potential loss of stem cells caused by induction of differentiation remains a concern. We have transplanted 21 patients with breast cancer with expanded autologous PBPC, with 11 patients receiving expanded PBPC as their sole hematopoietic cell source. In these studies, the CD34+ cells were selected and cultured for 10 days in defined media containing 100 ng/mL each of recombinant human stem cell factor (rhSCF), recombinant human granulocyte colony stimulating factor (rhG-CSF), and recombinant human megakaryocy...

Science.gov (United States)

We report for the first time a relationship between the Tpl-2/cot oncogene and Mouse Mammary Tumor Virus (MMTV) associated transformation of mammary gland cells. A sub-genomic library generated from a primary mammary gland tumor yielded a novel MMTV integration site which disrupted the Tpl-2/cot proto-oncogene between exons 7 and 8. Comparison of a cell line derived from normal mammary gland (comma-D) and a cell line established from an MMTV induced mammary tumor (GR) demonstrated similar rearrangements within Tpl-2/cot for the GR cells but not in the comma-D cells. These rearrangements in the cell line were accompanied by an increase in the level of Tpl-2/cot specific mRNA. This data suggests that Tpl-2/cot expression may be important in epithelial cell transformation or tumor progression. PMID:8934549

British Library Electronic Table of Contents (United Kingdom)

Heart cells from the clam Ruditapes decussatus were routinely cultured with a high level of reproducibility in sea water based medium. Three cell types attached to the plastic after 2?days and could be maintained in vitro for at least 1?month: epithelial-like cells, round cells and fibroblastic cells. Fibroblastic cells were identified as functional cardiomyocytes due to their spontaneous beating, their ultrastructural characteristics and their reactivity with antibodies against sarcomeric ?-actinin, sarcomeric tropomyosin, myosin and troponin T-C. Patch clamp measurements allowed the identification of ionic currents characteristic of cardiomyocytes: a delayed potassium current (I K?slow) strongly suppressed (95%) by tetraethylammonium (1?mM), a fast inactivating potassium current (I K?fas...

DEFF Research Database (Denmark)

Pro-inflammatory cytokines may directly influence the viability and metabolic function of colonic epithelial cells (CEC) as an early event in the development of inflammatory bowel disease. We report here that TNF-alpha+IFN-gamma induced a synergistic, concentration-dependent decline in butyrate oxidation, an essential energy supply, in HT-29 and DLD-1 cells. TNF-alpha+IFN-gamma induced a parallel profound decline in cell viability in HT-29 cells, but not in DLD-1 cells, where impairment of butyrate oxidation seemed to precede later occurrence of cell damage. TNF-alpha+INF-gamma induced CEC damage was independent on NO formation and involved the IFN-gamma signalling pathway as well as induction of apoptosis. If cytokines have similar effects in vivo, these may lead to energy deficiency and thus contribute to CEC damage and disturbance of the epithelial integrity.

British Library Electronic Table of Contents (United Kingdom)

Colorectal cancer is the second most common cause of cancer death in the world and about half of the patients with colorectal cancer require adjuvant therapy after surgical resection. Therefore, the eradication of cancer cells via chemotherapy constitutes a viable approach to treating patients with colorectal cancer. In this study, the effects of bufalin isolated from a traditional Chinese medicine were evaluated and characterized in HT-29 and Caco-2 human colon cancer cells. Contrary to its well-documented apoptosis-promoting activity in other cancer cells, bufalin did not cause caspase-dependent cell death in colon cancer cells, as indicated by the absence of significant early apoptosis as well as poly(ADP-ribose) polymerase and caspase-3 cleavage. Instead, bufalin activated an autophagy...

Energy Technology Data Exchange (ETDEWEB)

The Interim Examination and Maintenance (IEM) Cell is located within the Fast Flux Test Facility (FFTF) Reactor Containment Building. This cell is a complex vertical hot cell whose purpose is to process reactor experiments and to perform maintenance on reactor and refueling components. Because access to this very complex cell is limited, a mock-up called the IEM Training Facility (IEMTF) has been developed. The IEMTF provides the IEM cell with many valuable benefits. Four of these benefits are: (1) development of alternate processing methods; (2) hands-on evaluation of equipment problems; (3) a ready source of verified parts, and (4) training facilities for IEM Cell technicians.

Energy Technology Data Exchange (ETDEWEB)

High-quality solar cells have been fabricated by utilizing localized argon-ion laser decomposition of silver neodecanoate spun onto diffused silicon substrates and subsequent electroplating. Early adhesion problems during electroplating have been carefully studied and finally solved using a novel coating procedure. The laser-metallized solar cells have been characterized using lighted and dark current-voltage measurements and compared with baseline cells metallized using standard photolithographic procedures. Non-AR-coated cell efficiencies ranging from 10 to over 11% have been obtained for the laser-metallized cells, comparable with the best baseline cells. The laser-metallized cells have 30 to 40% lower series resistance than the unsintered baseline cells, indicating that in-situ sintering takes place during laser ...

CERN Document Server

In culture migrating and interacting amoeboid cells can form nematic liquid crystal phases. A polar nematic liquid crystal is formed if the interaction has a polar symmetry. One type of white blood cells (granulocytes) form clusters where the cells are oriented towards the center. The core of such an orientational defect (disclination) is either a granulocyte forced to be in an isotropic state or another cell type like a monocyte. An apolar nematic liquid crystal is formed if the interaction has an apolar symmetry. Different cell types like human melanocytes (=pigment cells of the skin), human fibroblasts (=connective tissue cells), human osteoblasts (=bone cells), human adipocytes (= fat cells) etc., form an apolar nematic liquid crystal. The orientational elastic energy is derived and the ...

Energy Technology Data Exchange (ETDEWEB)

A conceptual design of an advanced sodium/sulfur cell for US electric-van applications has been completed. The important design factors included specific physical and electrical requirements, service life, manufacturability, thermal management, and safety. The capacity of this cell is approximately the same as that for the ``PB`` cell being developed by Silent Power Limited (10 Ah). The new cell offers a 50% improvement in energy capacity and nearly a 100% improvement in peak power over the existing PB cells. A battery constructed with such cells would significantly exceed the USABC`s mid-term performance specifications. In addition, a similar cell and battery design effort was completed for an advanced passenger car application. A battery using the van cell would have nearly 3 times the energy compared to lead-acid ...

Science.gov (United States)

The possibility of using lead and lead-bismuth mixed oxides as positive active materials in organic electrolyte lithium cells with a working voltage similar to those of silver zinc cells has been considered. Button cells of SR 44 size have been developed as a test vehicle and studied under various conditions of discharge rate and storage. This paper describes the performance characteristics obtained under these conditions and suggests in conclusion the possible replacement of silver zinc cells by such systems for a large range of low-rate applications on the basis of cost effectiveness.