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Sample records for cell colony formation

  1. Study of budding yeast colony formation and its characterizations by using circular granular cell

    Science.gov (United States)

    Aprianti, D.; Haryanto, F.; Purqon, A.; Khotimah, S. N.; Viridi, S.

    2016-03-01

    Budding yeast can exhibit colony formation in solid substrate. The colony of pathogenic budding yeast can colonize various surfaces of the human body and medical devices. Furthermore, it can form biofilm that resists drug effective therapy. The formation of the colony is affected by the interaction between cells and with its growth media. The cell budding pattern holds an important role in colony expansion. To study this colony growth, the molecular dynamic method was chosen to simulate the interaction between budding yeast cells. Every cell was modelled by circular granular cells, which can grow and produce buds. Cohesion force, contact force, and Stokes force govern this model to mimic the interaction between cells and with the growth substrate. Characterization was determined by the maximum (L max) and minimum (L min) distances between two cells within the colony and whether two lines that connect the two cells in the maximum and minimum distances intersect each other. Therefore, it can be recognized the colony shape in circular, oval, and irregular shapes. Simulation resulted that colony formation are mostly in oval shape with little branch. It also shows that greater cohesion strength obtains more compact colony formation.

  2. Impaired T-lymphocyte colony formation by cord blood mononuclear cells

    International Nuclear Information System (INIS)

    Herrod, H.G.; Valenski, W.R.

    1982-01-01

    When compared to adult mononuclear cells, cord blood mononuclear cells demonstrated significantly decreased T-lymphocyte colony formation (1351 +/- 643 vs 592 +/- 862, P less than 0.01). This diminished colony-forming activity did not appear to be associated with impaired responsiveness to the stimulant phytohemagglutinin or with excessive suppressor-cell activity. Irradiation reduced the colony-forming capacity of cord blood mononuclear cells more than it did that of adult mononuclear cells. Depletion of adherent cells reduced cord blood mononuclear-cell colony-forming capacity by 40%, while similar treatment reduced adult colony formation by 10%. Lymphocyte proliferation in liquid culture of cord and adult cells was minimally affected by these procedures. The colony-forming capacity of cord blood could be enhanced by the addition of irradiated adult cells (284 +/- 72 vs 752 +/- 78, P less than 0.01). This enhancement was demonstrated to be due to a soluble factor produced by a population of irradiated adult cells depleted of the OKT8+ subpopulation of lymphocytes. These results indicate that the progenitor cells of T-lymphocyte colonies in cord blood have distinct biologic characteristics when compared to colony progenitors present in adult blood. This assay may prove to be useful in our efforts to understand the differentiation of T-cell function in man

  3. Human T cell colony formation in microculture: analysis of growth requirements and functional activities.

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    Gelfand, E W; Lee, J W; Dosch, H M; Price, G B

    1981-03-01

    A microculture method in methylcellulose has been developed for the study of human T cell colony formation. The technique is simple, reliable, does not require preincubation with lectin and requires small numbers of cells. Colony formation was dependent on the presence of phytohemagglutin-conditioned medium, a T colony precursor cell (TCPC), and a "helper" or accessory T cell. Plating efficiency was increased 10-fold in the presence of irradiated feeder cells. Progenitors of the T colony cells were identified in peripheral blood, tonsil, and spleen but not in thymus or thoracic duct. They were isolated in the E-rosetting, theophylline-resistant, Fc-IgG-negative cell populations. In peripheral blood the frequency of TCPC and accessory cells, the T colony forming unit, was estimated to be 8 X 10(-3). Colony cells proliferated in response to lectins and allogeneic cells. Forty to 80% of the cells were Ia-positive and stimulated both autologous and allogeneic mixed lymphocyte responses. They were incapable of mediating antibody-dependent cytotoxicity. In contrast, they were effective in assays of spontaneous cytotoxicity but only against certain target cells. This method for the analysis of T colony formation should prove valuable in the functional analysis of T cell subsets in immunodeficiency states or the transplant recipient.

  4. Effect of aspirin on tumour cell colony formation and evolution.

    Science.gov (United States)

    Wodarz, Dominik; Goel, Ajay; Boland, C Richard; Komarova, Natalia L

    2017-09-01

    Aspirin is known to reduce the risk of colorectal cancer (CRC) incidence, but the underlying mechanisms are not fully understood. In a previous study, we quantified the in vitro growth kinetics of different CRC tumour cell lines treated with varying doses of aspirin, measuring the rate of cell division and cell death. Here, we use these measured parameters to calculate the chances of successful clonal expansion and to determine the evolutionary potential of the tumour cell lines in the presence and absence of aspirin. The calculations indicate that aspirin increases the probability that a single tumour cell fails to clonally expand. Further, calculations suggest that aspirin increases the evolutionary potential of an expanding tumour cell colony. An aspirin-treated tumour cell population is predicted to result in the accumulation of more mutations (and is thus more virulent and more difficult to treat) than a cell population of the same size that grew without aspirin. This indicates a potential trade-off between delaying the onset of cancer and increasing its evolutionary potential through chemoprevention. Further work needs to investigate to what extent these findings apply to in vivo settings, and to what degree they contribute to the epidemiologically documented aspirin-mediated protection. © 2017 The Author(s).

  5. Arsenic promotes centrosome abnormalities and cell colony formation in p53 compromised human lung cells

    International Nuclear Information System (INIS)

    Liao Weiting; Lin Pinpin; Cheng, T.-S.; Yu, H.-S.; Chang, Louis W.

    2007-01-01

    Epidemiological evidence indicated that residents, especially cigarette smokers, in arseniasis areas had significantly higher lung cancer risk than those living in non-arseniasis areas. Thus, an interaction between arsenic and cigarette smoking in lung carcinogenesis was suspected. p53 dysfunction or mutation in lung epithelial cells was frequently observed in cigarette smokers. Our present study was to explore the differential effects by arsenic on H1355 cells (human lung adenocarcinoma cell line with mutation in p53), BEAS-2B (immortalized lung epithelial cell with functional p53) and pifithrin-α-treated BEAS-2B cells (p53-inhibited cells). These cells were treated with different doses of sodium arsenite (0, 0.1, 1, 5 and 10 μM) for 48 h. A greater reduction in cell viability was observed in the BEAS-2B cells vs. p53 compromised cells (H1355 or p53-inhibited BEAS-2B). Similar observation was also made on 7-day cell survival (growth) study. TUNEL analysis confirmed that there was indeed a significantly reduced arsenite-induced apoptosis found in p53-compromised cells. Centrosomal abnormality has been attributed to eventual chromosomal missegregation, aneuploidy and tumorigenesis. In our present study, reduced p21 and Gadd45a expressions and increased centrosomal abnormality (atopic and multiple centrosomes) were observed in both arsenite-treated H1355 and p53-inhibited BEAS-2B cells as compared with similarly treated BEAS-2B cells. Increased anchorage-independent growth (colony formation) of BEAS-2B cells co-treated with pifithrin-α and 5 μM sodium arsenite was also observed in soft agar. Our present investigation demonstrated that arsenic would act specifically on p53 compromised cells (either with p53 dysfunction or inhibited) to induce centrosomal abnormality and colony formation. These findings provided strong evidence on the carcinogenic promotional role of arsenic, especially under the condition of p53 dysfunction

  6. Cell colony formation induced by Xenopus egg extract as a marker for improvement of cloned blastocyst formation in pig

    DEFF Research Database (Denmark)

    Liu, Ying; Østrup, Olga; Li, Juan

    2011-01-01

    method based on the colony formation of cells after extract treatment, and subsequent in vitro cloning efficiency using treated cells as chromatin donors. Porcine fetal fibroblasts were treated with each batch of extract, and cultured in embryonic stem cell (ES) medium for 12 days. The number of forming...

  7. Extrapulmonary colony formation after intravenous injection of tumour cells into heparin treated animals

    NARCIS (Netherlands)

    Maat, B.

    1978-01-01

    Recent data on extrapulmonary colony formation after heparin administration are inconclusive. A systemic study of this topic was undertaken with 4 experimental tumour systems and 2 distinct periods of reduced clotting capacity in rats and mice. I.v. injection of various numbers of tumour cells into

  8. Impedimetric quantification of the formation process and the chemosensitivity of cancer cell colonies suspended in 3D environment.

    Science.gov (United States)

    Lei, Kin Fong; Wu, Zong-Ming; Huang, Chia-Hao

    2015-12-15

    In cancer research, colony formation assay is a gold standard for the investigation of the development of early tumors and the effects of cytotoxic agents on tumors in vitro. Quantification of cancer cell colonies suspended in hydrogel is currently achieved by manual counting under microscope. It is challenging to microscopically quantify the colony number and size without subjective bias. In this work, impedimetric quantification of cancer cell colonies suspended in hydrogel was successfully developed and provides a quantitative and objective method to describe the colony formation process and the development of colony size during the culture course. A biosensor embedded with a pair of parallel plate electrodes was fabricated for the impedimetric quantification. Cancer cell (cell line: Huh-7) were encapsulated in methyl cellulose hydrogel and cultured to gradually form cancer cell colonies suspended in 3D environment. At pre-set schedule during the culture course, small volume (50 μL) of colonies/MC hydrogel was collected, mixed with measurement hydrogel, and loaded to the biosensor for measurement. Hence, the colony formation process could be quantitatively represented by a colony index and a colony size index calculated from electrical impedance. Based on these developments, chemosensitivity of cancer cell colonies under different concentrations of anti-cancer drug, i.e., doxorubicin, was quantitatively investigated to study the efficacy of anti-cancer drug. Also, dose-response curve was constructed to calculate the IC50 value, which is an important indicator for chemosensitivity assay. These results showed the impedimetric quantification is a promising technique for the colony formation assay. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Binucleate cell formation correlates to loss of colony-forming ability in X-irradiated cultured mammalian cells

    International Nuclear Information System (INIS)

    Sasaki, H.; Yoshinaga, H.; Kura, S.

    1986-01-01

    The relationship between binucleate cell formation and the loss of colony-forming ability was examined in several cultured mammalian cell lines irradiated with X rays. The maximum fraction of binucleate cells after X irradiation increased dose-dependently within the range in which reproductive cell death might predominate over interphase cell death. When the logarithm of percentage survival was plotted against the percentage binucleate cells, a similar correlation was found for all cell lines tested, with the exception of mouse leukemia L5178Y cells, the most radiosensitive cells used. These observations suggest that the fraction of binucleate cells in the cell population can serve as a measure of cellular radiation damage

  10. Leukemic blast cell colony formation in semisolid culture with erythropoietin: a case report of acute poorly differentiated erythroid leukemia.

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    Tomonaga, M; Jinnai, I; Tagawa, M; Amenomori, T; Nishino, K; Yao, E; Nonaka, H; Kuriyama, K; Yoshida, Y; Matsuo, T

    1987-02-01

    The bone marrow of a patient with acute undifferentiated leukemia developed unique colonies after a 14-day culture in erythropoietin (EPO)-containing methylcellulose. The colonies consisted of 20 to 200 nonhemoglobinized large blast cells. Cytogenetic analysis of single colonies revealed hypotetraploid karyotypes with several marker chromosomes that were identical to those found in directly sampled bone marrow. The concurrently formed erythroid bursts showed only normal karyotypes. No leukemic colony formation was observed in other culture systems with either colony-stimulating activity (CSA) or phytohemagglutinin-stimulated leukocyte-conditioned medium (PHA-LCM). The leukemic colonies exhibited a complete EPO-dose dependency similar to that of the patient's normal BFU-E. Although cytochemical and immunologic marker studies of the bone marrow cells failed to clarify the cell lineage of the leukemic cells with extraordinarily large cell size, ultrastructural study revealed erythroid differentiation such as siderosome formation in the cytoplasm and ferritin particles in the rhophecytosis invaginations. These findings indicate that the patient had poorly differentiated erythroid leukemia and that some of the clonogenic cells might respond to EPO in vitro. Corresponding to this biological feature, the leukemic cells were markedly decreased in number in response to repeated RBC transfusions, and partial remission was obtained. These observations suggest that erythroid leukemia distinct from erythroleukemia (M6) with a myeloblastic component, can develop as a minor entity of human acute leukemia.

  11. Enhancement of committed hematopoietic stem cell colony formation by nandrolone decanoate after sublethal whole body irradiation

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    Gallicchio, V.S.; Chen, M.G.; Watts, T.D.

    1984-11-01

    The ability of an anabolic steroid, nandrolone decanoate, to increase committed topoietic stem cell (CFU-gm, CFU-e, and BFU-e) colony formation after sublethal irradiation was evaluated. Immediately after receiving whole body irradiation and on the next two days, each mouse was injected intraperitoneally with nandrolone decanoate (1.25 mg) in propylene glycol. Irradiated control mice received only propylene glycol. Compared to controls, drug-treated mice showed marked peripheral blood leukocytosis and more stable packed red cell volume. Drug-treated mice also demonstrated increased erythropoiesis, as CFU-e/BFU-e concentrations from both marrow (9% to 581%) and spleen (15% to 797%) were elevated. Granulopoiesis was increased similarly, as CFU-gm concentrations from marrow (38% to 685%) and spleen (9% to 373%) were elevated. These results demonstrate that nandrolone decanoate enhances hematopoietic stem cell recovery after sublethal whole body irradiation. This suggests that following hematopoietic suppression, nandrolone decanoate may stimulate the recovery of hematopoiesis at the stem cell level and in peripheral blood.

  12. Enhancement of committed hematopoietic stem cell colony formation by nandrolone decanoate after sublethal whole body irradiation

    International Nuclear Information System (INIS)

    Gallicchio, V.S.; Chen, M.G.; Watts, T.D.

    1984-01-01

    The ability of an anabolic steroid, nandrolone decanoate, to increase committed topoietic stem cell (CFU-gm, CFU-e, and BFU-e) colony formation after sublethal irradiation was evaluated. Immediately after receiving whole body irradiation and on the next two days, each mouse was injected intraperitoneally with nandrolone decanoate (1.25 mg) in propylene glycol. Irradiated control mice received only propylene glycol. Compared to controls, drug-treated mice showed marked peripheral blood leukocytosis and more stable packed red cell volume. Drug-treated mice also demonstrated increased erythropoiesis, as CFU-e/BFU-e concentrations from both marrow (9% to 581%) and spleen (15% to 797%) were elevated. Granulopoiesis was increased similarly, as CFU-gm concentrations from marrow (38% to 685%) and spleen (9% to 373%) were elevated. These results demonstrate that nandrolone decanoate enhances hematopoietic stem cell recovery after sublethal whole body irradiation. This suggests that following hematopoietic suppression, nandrolone decanoate may stimulate the recovery of hematopoiesis at the stem cell level and in peripheral blood

  13. Abiotic factors in colony formation: effects of nutrition and light on extracellular polysaccharide production and cell aggregates of Microcystis aeruginosa

    Science.gov (United States)

    Yang, Zhen; Kong, Fanxiang

    2013-07-01

    Colony morphology is important for Microcystis to sustain a competitive advantage in eutrophic lakes. The mechanism of colony formation in Microcystis is currently unclear. Extracellular polysaccharide (EPS) has been reported to play an important role in cell aggregate formation of some phytoplankton. Microcystis aeruginosa was cultivated under varied abiotic conditions, including different nutrient, light, and temperature conditions, to investigate their effects on EPS production and morphological change. The results show that nutrient concentration and light intensity have great effects on EPS productionin M. aeruginosa. There was a considerable increase in EPS production after M. aeruginosa was cultivated in adjusted culture conditions similar to those present in the field (28.9 mg C/L, 1.98 mg N/L, 0.65 mg P/L, light intensity: 100 μmol/(m2 · s)). These results indicate that abiotic factors might be one of the triggers for colony formation in Microcystis.

  14. Convergence of bone morphogenetic protein and laminin-1 signaling pathways promotes proliferation and colony formation by fetal mouse pancreatic cells

    International Nuclear Information System (INIS)

    Jiang Fangxu; Harrison, Leonard C.

    2005-01-01

    We previously reported that bone morphogenetic proteins (BMPs), members of the transforming growth factor superfamily, together with the basement membrane glycoprotein laminin-1 (Ln-1), promote proliferation of fetal pancreatic cells and formation of colonies containing peripheral insulin-positive cells. Here, we further investigate the cross-talk between BMP and Ln-1 signals. By RT-PCR, receptors for BMP (BMPR) (excepting BMPR-1B) and Ln-1 were expressed in the fetal pancreas between E13.5 and E17.5. Specific blocking antibodies to BMP-4 and -6 and selective BMP antagonists partially inhibited colony formation by fetal pancreas cells. Colony formation induced by BMP-6 and Ln-1 was completely abolished in a dose-dependent manner by blocking Ln-1 binding to its α 6 integrin and α-dystroglycan receptors or by blocking the Ln-1 signaling molecules, phosphatidyl-inositol-3-kinase (P13K) and MAP kinase kinase-1. These results demonstrate a convergence of BMP and Ln-1 signaling through P13K and MAP kinase pathways to induce proliferation and colony formation in E15.5 fetal mouse pancreatic cells

  15. RECOMBINANT HUMAN MAST-CELL GROWTH-FACTOR SUPPORTS ERYTHROID COLONY FORMATION IN POLYCYTHEMIA-VERA IN THE PRESENCE AND ABSENCE OF ERYTHROPOIETIN AND SERUM

    NARCIS (Netherlands)

    MULLER, EW; DEWOLF, JTM; HENDRIKS, DW; ESSELINK, MT; HALIE, MR; VELLENGA, E

    The effect of mast cell growth factor (MGF) was studied on erythropoietin (Epo)-dependent and Epo-independent (''spontaneous'') erythroid colony formation in patients with polycythemia vera (PV). MGF stimulated both Epo-dependent and Epo-independent erythroid colony formation from PV peripheral

  16. Freeze-drying of mononuclear cells derived from umbilical cord blood followed by colony formation.

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    Dity Natan

    Full Text Available BACKGROUND: We recently showed that freeze-dried cells stored for 3 years at room temperature can direct embryonic development following cloning. However, viability, as evaluated by membrane integrity of the cells after freeze-drying, was very low; and it was mainly the DNA integrity that was preserved. In the present study, we improved the cells' viability and functionality after freeze-drying. METHODOLOGY/PRINCIPAL FINDINGS: We optimized the conditions of directional freezing, i.e. interface velocity and cell concentration, and we added the antioxidant EGCG to the freezing solution. The study was performed on mononuclear cells (MNCs derived from human umbilical cord blood. After freeze-drying, we tested the viability, number of CD34(+-presenting cells and ability of the rehydrated hematopoietic stem cells to differentiate into different blood cells in culture. The viability of the MNCs after freeze-drying and rehydration with pure water was 88%-91%. The total number of CD34(+-presenting cells and the number of colonies did not change significantly when evaluated before freezing, after freeze-thawing, and after freeze-drying (5.4 x 10(4+/-4.7, 3.49 x 10(4+/-6 and 6.31 x 10(4+/-12.27 cells, respectively, and 31+/-25.15, 47+/-45.8 and 23.44+/-13.3 colonies, respectively. CONCLUSIONS: This is the first report of nucleated cells which have been dried and then rehydrated with double-distilled water remaining viable, and of hematopoietic stem cells retaining their ability to differentiate into different blood cells.

  17. Colony formation in the cyanobacterium Microcystis.

    Science.gov (United States)

    Xiao, Man; Li, Ming; Reynolds, Colin S

    2018-02-22

    Morphological evolution from a unicellular to multicellular state provides greater opportunities for organisms to attain larger and more complex living forms. As the most common freshwater cyanobacterial genus, Microcystis is a unicellular microorganism, with high phenotypic plasticity, which forms colonies and blooms in lakes and reservoirs worldwide. We conducted a systematic review of field studies from the 1990s to 2017 where Microcystis was dominant. Microcystis was detected as the dominant genus in waterbodies from temperate to subtropical and tropical zones. Unicellular Microcystis spp. can be induced to form colonies by adjusting biotic and abiotic factors in laboratory. Colony formation by cell division has been induced by zooplankton filtrate, high Pb 2+ concentration, the presence of another cyanobacterium (Cylindrospermopsis raciborskii), heterotrophic bacteria, and by low temperature and light intensity. Colony formation by cell adhesion can be induced by zooplankton grazing, high Ca 2+ concentration, and microcystins. We hypothesise that single cells of all Microcystis morphospecies initially form colonies with a similar morphology to those found in the early spring. These colonies gradually change their morphology to that of M. ichthyoblabe, M. wesenbergii and M. aeruginosa with changing environmental conditions. Colony formation provides Microcystis with many ecological advantages, including adaption to varying light, sustained growth under poor nutrient supply, protection from chemical stressors and protection from grazing. These benefits represent passive tactics responding to environmental stress. Microcystis colonies form at the cost of decreased specific growth rates compared with a unicellular habit. Large colony size allows Microcystis to attain rapid floating velocities (maximum recorded for a single colony, ∼ 10.08 m h -1 ) that enable them to develop and maintain a large biomass near the surface of eutrophic lakes, where they may shade

  18. Effect of fluid motion on colony formation in Microcystis aeruginosa

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    Lin Li

    2013-01-01

    Full Text Available Microcystis aeruginosa, generally occurring in large colonies under natural conditions, mainly exists as single cells in laboratory cultures. The mechanisms involved in colony formation in Microcystis aeruginosa and their roles in algal blooms remain unknown. In this study, based on previous research findings that fluid motion may stimulate the colony formation in green algae, culture experiments were conducted under axenic conditions in a circular water chamber where the flow rate, temperature, light, and nutrients were controlled. The number of cells of Microcystis aeruginosa, the number of cells per colony, and the colonial characteristics in various growth phases were observed and measured. The results indicated that the colony formation in Microcystis aeruginosa, which was not observed under stagnant conditions, was evident when there was fluid motion, with the number of cells per largest colony reaching 120 and the proportion of the number of cells in colonial form to the total number of cells and the mean number of cells per colony reaching their peak values at a flow rate of 35 cm/s. Based on the analysis of colony formation process, fluid motion stimulates the colony formation in Microcystis aeruginosa in the lag growth phase, while flushes and disaggregates the colonies in the exponential growth phase. The stimulation effect in the lag growth phase may be attributable to the involvement of fluid motion in a series of physiological processes, including the uptake of trace elements and the synthesis and secretion of polysaccharides. In addition, the experimental groups exhibiting typical colonial characteristics in the lag growth phase were found to have higher cell biomass in the later phase.

  19. Colony formation in agar: in vitro assay for haemopoietic stem cells

    NARCIS (Netherlands)

    Dicke, K.A.; Platenburg, M.G.C.; Bekkum, D.W. van

    1971-01-01

    Using a method in which embryo fibroblasts were used as feeder layers, the colony forming capacity in agar of a variety of mouse haemopoietic suspensions was compared with their CFUs content. A striking parallelism between the results of the two assays was found. In addition, under certain

  20. Single cell time-lapse analysis reveals that podoplanin enhances cell survival and colony formation capacity of squamous cell carcinoma cells.

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    Miyashita, Tomoyuki; Higuchi, Youichi; Kojima, Motohiro; Ochiai, Atsushi; Ishii, Genichiro

    2017-01-06

    Tumor initiating cells (TICs) are characterized by high clonal expansion capacity. We previously reported that podoplanin is a TIC-specific marker for the human squamous cell carcinoma cell line A431. The aim of this study is to explore the molecular mechanism underlying the high clonal expansion potential of podoplanin-positive A431cells using Fucci imaging. Single podoplanin-positive cells created large colonies at a significantly higher frequency than single podoplanin-negative cells, whereas no difference was observed between the two types of cells with respect to cell cycle status. Conversely, the cell death ratio of progenies derived from podoplanin-positive single cell was significantly lower than that of cells derived from podoplanin-negative cells. Single A431 cells, whose podoplanin expression was suppressed by RNA interference, exhibited increased cell death ratios and decreased frequency of large colony forming. Moreover, the frequency of large colony forming decreased significantly when podoplanin-positive single cells was treated with a ROCK (Rho-associated coiled-coil kinase) inhibitor, whereas no difference was observed in single podoplanin-negative cells. Our current study cleared that high clonal expansion capacity of podoplanin-positive TICs populations was the result of reduced cell death by podoplanin-mediated signaling. Therefore, podoplanin activity may be a therapeutic target in the treatment of squamous cell carcinomas.

  1. Thymidine kinase deficient human cells have increased UV sensitivity in their capacity to support herpes simplex virus but normal UV sensitivity for colony formation

    International Nuclear Information System (INIS)

    Rainbow, A.J.

    1989-01-01

    A thymidine kinase deficient (tk - ) and two thymidine kinase proficient (tk + ) human cell lines were compared for UV sensitivity using colony-forming ability as well as their capacity to support the plaque formation of herpes simplex type 1 (HSV-1).The tk - line (143 cells) was a derivative of one of the tk + lines (R970-5), whereas the other tk + line (AC4 cells) was a derivative of the 143 cells obtained by transfection with purified sheared HSV-2 DNA encoding the viral tk gene. 143, R970-5 and AC4 cells showed a similar UV sensitivity for colony-forming ability. In contrast, the capacity to support HSV-1 plaque formation immediately (within 1 h) afte UV-irradiation was reduced to a greater extent in the 143 cells compared to the R970-5 and AC4 cells. Capacity curves for plaque formation of the HSV-1: KOS wild-type (tk + ) strain were similar to those for the HSV-1: PTK3B mutant (tk - ) strain were similar to those for the HSV-1: PTK3B mutant (tk - ) strain in the 3 cell strains, indicating that the viral tk gene does not influence the ability of HSV-1 to form plaques in UV-irradiated compared to unirradiated human cells. Cellular capacity for HSV-1 plaque formation was found to recover in both tk - and tk + cells for cultures infected 24 h after UV-irradiation. These results suggest that repair of UV-damaged DNA takes place to a similar extent in both tk - and tk + human cells, but the kinetics of repair are initially slower in tk - compared to tk + human cells. (author). 33 refs.; 3 figs.; 1 tab

  2. Maintenance and induction of murine embryonic stem cell differentiation using E-cadherin-Fc substrata without colony formation

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    Meng, Qing-Yuan; Akaike, Toshihiro

    2013-03-01

    Induced embryonic stem (ES) cells are expected to be promising cell resources for the observation of the cell behaviors in developmental biology as well as the implantation in cell treatments in human diseases. A recombinant E-cadherin substratum was developed as a cell recognizable substratum to maintain the ES cells' self-renewal and pluripotency at single cell level. Furthermore, the generation of various cell lineages in different germ layers, including hepatic or neural cells, was achieved on the chimeric protein layer precisely and effectively. The induction and isolation of specific cell population was carried out with the enhancing effect of other artificial extracellular matrices (ECMs) in enzyme-free process. The murine ES cell-derived cells showed highly morphological similarities and functional expressions to matured hepatocytes or neural progenitor cells.

  3. Intermittent feeding as a factor enhancing hemopoietic stem cell proliferation and spleen colony formation in irradiated mice

    International Nuclear Information System (INIS)

    Kozubik, A.; Pospisil, M.

    1985-01-01

    The influence of metabolic stimulation induced by a 3 weeks' adaption of the animals to intermittent food intake on hemopoietic stem cells was investigated in mice. The methods used included transplantation of bone marrow to lethally irradiated recipients, assay of CFUs number, seeding efficiency, and incorporation of 125 iodode oxyuridine into the DNA of spleen cells. A stimulatory effect of the metabolically influenced hemopoietic environment on the proliferative activity in stem cell compartments and on the recovery of hemopoietic organs was demonstrated. These stimulatory effects were most marked when the bone marrow of metabolically influenced donors was transplanted to similarly influenced recipients. (orig.)

  4. Low temperature and Daphnia-associated infochemicals promote colony formation of Scenedesmus obliquus and its harvesting.

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    Zhu, Xuexia; Yang, Jingwen; Zhang, Xingxing; Zhang, Lu; Wang, Xiaojun; Huang, Yuan; Yang, Zhou

    2017-01-01

    To explore the combined effects of temperature and Daphnia-associated infochemicals on colony formation of Scenedesmus obliquus to faciliate harvesting the algal biomass. A three-parameter modified Gaussian model fitted the changes of the number of cells per particle in S. obliquus induced by Daphnia culture filtrate well under any temperature. Decreases in temperature enhanced the induced-colony formation of Scenedesmus. The maximum colony size at 15-25 °C was significantly larger than those at 30-35 °C. An additional 1 or 2 days at low temperature was needed to reach the maximum colony size, which indicates the best harvest time for algal biomass. Induced-colony formation of Scenedesmus by Daphnia culture filtrate at 15-25 °C is recommended to settle algal cells. This condition facilitates harvesting the biomass.

  5. Granulocyte macrophage colony-stimulating factor enhances the modulatory effect of cytokines on monocyte-derived multinucleated giant cell formation and fungicidal activity against Paracoccidioides brasiliensis

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    Magda Paula Pereira do Nascimento

    2011-09-01

    Full Text Available Multinucleated giant cells (MGC are cells present in characteristic granulomatous inflammation induced by intracellular infectious agents or foreign materials. The present study evaluated the modulatory effect of granulocyte macrophage colony-stimulating factor (GM-CSF in association with other cytokines such as interferon-gamma (IFN-γ, tumour necrosis factor-alpha, interleukin (IL-10 or transforming growth factor beta (TGF-β1 on the formation of MGC from human peripheral blood monocytes stimulated with Paracoccidioides brasiliensis antigen (PbAg. The generation of MGC was determined by fusion index (FI and the fungicidal activity of these cells was evaluated after 4 h of MGC co-cultured with viable yeast cells of P. brasiliensis strain 18 (Pb18. The results showed that monocytes incubated with PbAg and GM-CSF plus IFN-γ had a significantly higher FI than in all the other cultures, while the addition of IL-10 or TGF-β1 had a suppressive effect on MGC generation. Monocytes incubated with both pro and anti-inflammatory cytokines had a higher induction of foreign body-type MGC rather than Langhans-type MGC. MGC stimulated with PbAg and GM-CSF in association with the other cytokines had increased fungicidal activity and the presence of GM-CSF also partially inhibited the suppressive effects of IL-10 and TGF-β1. Together, these results suggest that GM-CSF is a positive modulator of PbAg-stimulated MGC generation and on the fungicidal activity against Pb18.

  6. Formation of large colonies: a defense mechanism of Microcystis aeruginosa under continuous grazing pressure by flagellate Ochromonas sp.

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    Fanxiang Kong

    2012-01-01

    Full Text Available Induced colony formation under grazing pressure has been reported in our previous results. However, the colonies induced in these studies comprised only tens of cells which are far smaller than the naturally occurring colonies. In this work, unicellular Microcystis aeruginosa Kützing were co-cultivated with flagellate Ochromonas sp. for 50 d to investigate colony formation in M. aeruginosa under continuous grazing pressure. Results revealed that colonial M. aeruginosa formed on the 10th d under the grazing pressure of flagellate. These algal colonies resulted from the daughter cells of freshly dividing cells that failed to separate during the reproductive process. The diameters and cell numbers of the colonies increased slowly with time. Under continuous grazing pressure by Ochromonas sp. for 50 d, the diameter of some colonies reached over 180 μm. Analysis showed that the extracellular polysaccharide (EPS content and relative gas vesicle (RGV of each cell increased significantly after colony formation. However, there was no significant difference on the monosaccharide composition between unicellular and colonial M. aeruginosa. The loose aggregation of cells in the floating colonies suggests that a correlation probably exists between cell compactness and colony buoyancy.

  7. Relationship of colony-stimulating activity to apparent kill of human colony-forming cells by irradiation and hydroxyurea

    International Nuclear Information System (INIS)

    Broxmeyer, H.E.; Galbraith, P.R.; Baker, F.L.

    1976-01-01

    Suspensions of human bone marrow cells were subjected to 137 Cs irradiation in vitro and then cultured in semisolid agar medium. Cultures of irradiated cells were stimulated with colony-stimulating activity (CSA) of different potencies, and it was found that the amount of stimulation applied to cultures influenced the apparent kill of colony-forming cells (CFC). It was also found that the effects of irradiation on colony formation were not confined to CFC kill since medium conditioned by cells during irradiation exhibited stimulatory and inhibitory properties after treatment by 600 and 1000 rads, respectively. Studies in which irradiated cells were pretreated with hydroxyurea indicated that CFC in the DNA synthetic phase of the cell cycle were particularly sensitive to low doses of irradiation. The proliferative capacity of CFC surviving 1000 rads was undiminished as judged by their ability to form large colonies. Estimates of CFC kill by hydroxyurea were also affected by the level of CSA

  8. CFAssay: statistical analysis of the colony formation assay

    International Nuclear Information System (INIS)

    Braselmann, Herbert; Michna, Agata; Heß, Julia; Unger, Kristian

    2015-01-01

    Colony formation assay is the gold standard to determine cell reproductive death after treatment with ionizing radiation, applied for different cell lines or in combination with other treatment modalities. Associated linear-quadratic cell survival curves can be calculated with different methods. For easy code exchange and methodological standardisation among collaborating laboratories a software package CFAssay for R (R Core Team, R: A Language and Environment for Statistical Computing, 2014) was established to perform thorough statistical analysis of linear-quadratic cell survival curves after treatment with ionizing radiation and of two-way designs of experiments with chemical treatments only. CFAssay offers maximum likelihood and related methods by default and the least squares or weighted least squares method can be optionally chosen. A test for comparision of cell survival curves and an ANOVA test for experimental two-way designs are provided. For the two presented examples estimated parameters do not differ much between maximum-likelihood and least squares. However the dispersion parameter of the quasi-likelihood method is much more sensitive for statistical variation in the data than the multiple R 2 coefficient of determination from the least squares method. The dispersion parameter for goodness of fit and different plot functions in CFAssay help to evaluate experimental data quality. As open source software interlaboratory code sharing between users is facilitated

  9. Combined effects of nitrogen content in media and Ochromonas sp. grazing on colony formation of cultured Microcystis aeruginosa

    Directory of Open Access Journals (Sweden)

    Zhou YANG

    2010-08-01

    Full Text Available To gain insight into the combined effects of nitrogen content in media and flagellate grazing on colony formation of Microcystis aeruginosa, we added Ochromonas sp. to M. aeruginosa cultured in different nitrogen content media for 7 days. Results showed that M. aeruginosa could be efficiently ingested by Ochromonas sp., no matter what nitrogen content media M. aeruginosa was cultured in. Colony formation was observed in M. aeruginosa in all Ochromonas sp. grazing treatments during the experiment. In contrast, M. aeruginosa populations in the controls were strongly dominated by unicellular and paired cell forms, and no colonies were observed. Among all Ochromonas sp. grazing treatments, the mean numbers of cells per particle of M. aeruginosa increased with decreased nitrogen concentration (except 0% N, therefore colony formation of M. aeruginosa can be enhanced under lower nitrogen conditions. This suggests that both nitrogen content and Ochromonas sp. grazing combine to affect M. aeruginosa colony formation. Three-way ANOVA showed a statistically significant interaction between time (day 1, 3, 5, and 7, treatment (with and without Ochromonas sp. grazing and N content (0%, 10%, 25%, and 100% N on the mean numbers of cells per particle, i.e. the extent of colony formation. At the end of the experiment, the influence of nitrogen content (except 0% N on the numbers of cells per particle followed a rectangular hyperbolic response. The experiments demonstrated that there exists a combined effect of nitrogen concentration and flagellate grazing on colony formation of M. aeruginosa under laboratory conditions.

  10. Increased numbers of spleen colony forming units in B cell deficient CBA/N mice

    International Nuclear Information System (INIS)

    Wiktor-Jedrzejczak, W.; Krupienicz, A.; Scher, I.

    1986-01-01

    The formation of exogenous and endogenous spleen colonies was studied in immune-defective mice expressing the CBA/N X-linked xid gene. Bone marrow and spleen cells of immune deficient mice formed increased numbers of eight-day exogenous spleen colonies when transferred to either normal or B cell deficient lethally irradiated recipients. Moreover, defective mice showed increased formation of five-day endogenous spleen colonies (derived from transient endogenous colony forming units; T-CFU) and of ten-day endogenous spleen colonies (derived from CFU-S). Among the possible mechanisms responsible for the observed effects, the most probable appears the one in which decreased numbers of B cell precursors stimulate stem cell pools through a feedback mechanism. (orig.) [de

  11. An HTS-compatible 3D colony formation assay to identify tumor-specific chemotherapeutics.

    Science.gov (United States)

    Horman, Shane R; To, Jeremy; Orth, Anthony P

    2013-12-01

    There has been increasing interest in the development of cellular behavior models that take advantage of three-dimensional (3D) cell culture. To enable assessment of differential perturbagen impacts on cell growth in 2D and 3D, we have miniaturized and adapted for high-throughput screening (HTS) the soft agar colony formation assay, employing a laser-scanning cytometer to image and quantify multiple cell types simultaneously. The assay is HTS compatible, providing high-quality, image-based, replicable data for multiple, co-cultured cell types. As proof of concept, we subjected colorectal carcinoma colonies in 3D soft agar to a mini screen of 1528 natural product compounds. Hit compounds from the primary screen were rescreened in an HTS 3D co-culture matrix containing colon stromal cells and cancer cells. By combining tumor cells and normal, nontransformed colon epithelial cells in one primary screening assay, we were able to obtain differential IC50 data, thereby distinguishing tumor-specific compounds from general cytotoxic compounds. Moreover, we were able to identify compounds that antagonized tumor colony formation in 3D only, highlighting the importance of this assay in identifying agents that interfere with 3D tumor structural growth. This screening platform provides a fast, simple, and robust method for identification of tumor-specific agents in a biologically relevant microenvironment.

  12. Colony, hanging drop, and methylcellulose three dimensional hypoxic growth optimization of renal cell carcinoma cell lines.

    Science.gov (United States)

    Matak, Damian; Brodaczewska, Klaudia K; Lipiec, Monika; Szymanski, Łukasz; Szczylik, Cezary; Czarnecka, Anna M

    2017-08-01

    Renal cell carcinoma (RCC) is the most lethal of the common urologic malignancies, comprising 3% of all human neoplasms, and the incidence of kidney cancer is rising annually. We need new approaches to target tumor cells that are resistant to current therapies and that give rise to recurrence and treatment failure. In this study, we focused on low oxygen tension and three-dimensional (3D) cell culture incorporation to develop a new RCC growth model. We used the hanging drop and colony formation methods, which are common in 3D culture, as well as a unique methylcellulose (MC) method. For the experiments, we used human primary RCC cell lines, metastatic RCC cell lines, human kidney cancer stem cells, and human healthy epithelial cells. In the hanging drop assay, we verified the potential of various cell lines to create solid aggregates in hypoxic and normoxic conditions. With the semi-soft agar method, we also determined the ability of various cell lines to create colonies under different oxygen conditions. Different cell behavior observed in the MC method versus the hanging drop and colony formation assays suggests that these three assays may be useful to test various cell properties. However, MC seems to be a particularly valuable alternative for 3D cell culture, as its higher efficiency of aggregate formation and serum independency are of interest in different areas of cancer biology.

  13. Sequestration and Distribution Characteristics of Cd(II by Microcystis aeruginosa and Its Role in Colony Formation

    Directory of Open Access Journals (Sweden)

    Xiangdong Bi

    2016-01-01

    Full Text Available To investigate the sequestration and distribution characteristics of Cd(II by Microcystis aeruginosa and its role in Microcystis colony formation, M. aeruginosa was exposed to six different Cd(II concentrations for 10 days. Cd(II exposure caused hormesis in the growth of M. aeruginosa. Low concentrations of Cd(II significantly induced formation of small Microcystis colonies (P93% of Cd(II was sequestrated in the groups with lower added concentrations of Cd(II. More than 80% of the sequestrated Cd(II was bioadsorbed by bEPS. The Pearson correlation coefficients of exterior and interior factors related to colony formation of M. aeruginosa revealed that Cd(II could stimulate the production of IPS and bEPS via increasing Cd(II bioaccumulation and bioadsorption. Increased levels of cross-linking between Cd(II and bEPS stimulated algal cell aggregation, which eventually promoted the formation of Microcystis colonies.

  14. An improved method for staining cell colonies in clonogenic assays

    OpenAIRE

    Guda, Kishore; Natale, Leanna; Markowitz, Sanford D.

    2007-01-01

    Clonogenic assay is a widely used experimental approach to test for the effects of drugs/genes on the growth and proliferative characteristics of cells in vitro. Accurate quantitation of treatment effects in clonogeneic assays depends on the ability to visualize and count cell colonies precisely. We report a novel method (referred as ETeB) for staining cell colonies grown on plastic and specially coated substrates like collagen. Using colon cancer cell lines grown on plastic and collagen, we ...

  15. An improved method for staining cell colonies in clonogenic assays.

    Science.gov (United States)

    Guda, Kishore; Natale, Leanna; Markowitz, Sanford D

    2007-06-01

    Clonogenic assay is a widely used experimental approach to test for the effects of drugs/genes on the growth and proliferative characteristics of cells in vitro. Accurate quantitation of treatment effects in clonogeneic assays depends on the ability to visualize and count cell colonies precisely. We report a novel method (referred as ETeB) for staining cell colonies grown on plastic and specially coated substrates like collagen. Using colon cancer cell lines grown on plastic and collagen, we compared the colony staining efficiencies of the widely used methylene blue, and Ethidium bromide (ETeB) stains. Results show that the ETeB protocol works well on plastic and is extremely effective for staining colonies on collagen when compared to methylene blue. The key features and advantages of ETeB technique are; (a) reduction in background for colonies grown on collagen and possibly other substrates, (b) the whole procedure takes less than a minute, (c) no post-stain washing step is required which eliminates colony losses for cell lines that are loosely adherent, (d) colony visualization and counting can be done immediately following the staining procedure using a standard UV illuminator and software, and (e) the method works across a wide variety of cell lines. The simplicity and robustness of this procedure should warrant its usage in both small and large-scale clonogenic experiments.

  16. Colonial Army Formats in Africa and Post-Colonial Military Coups:

    African Journals Online (AJOL)

    BSOS USER

    The centralised and autocratic features of Caliphate rule were .... latter's participation in the affairs of their respective societies, and leadership ..... deployment of the army by the NPC for internal colonial-style repression duties in the Middle Belt ...

  17. Colony formation in Scenedesmus: no contribution of urea in induction by a lipophilic Daphnia exudate

    NARCIS (Netherlands)

    Lürling, M.; Von Elert, E.

    2001-01-01

    The common green alga Scenedesmus may respond morphologically to numerous environmental factors. The formation of colonies in Scenedesmus resulting from exposure to grazer (Daphnia) excreta is of particular interest since the induced colony formation may be an induced defense. Recent studies

  18. Effect of serum from rats with destructed nuclei of the posterior hypothalamus on the formation of hemopoietic colonies in the spleen of lethally irradiated mice after bone marrow cell transplantation

    International Nuclear Information System (INIS)

    Fedorov, N.A.; Likhovetskaya, Z.M.; Kurbanova, G.N.; Prigozhina, T.A.; L'vovich, A.I.

    1982-01-01

    Colony formation capability of serum from animals with destructed nuclei of the posterior hypothalamus was studied in lethally irradiated mice. Male-rats of Wistar line and hybrid mice (CBA x C57 BL) were used in the experiments. The serum from rats with destructed nuclei of the posterior hypothalamus was injected simultaneously with bone marrow transplantation into lethally irradiated mice. The number of macrocolonies in the spleen was counted on the 9th day. It was ascertained that the serum from rats with destructed nuclei of the posterior hypothalamus caused an increase of the number of macroscopically visible colonies in the spleen of lethally irradiated mice. The determination of hemopoetic types of colonies showed that the effect of the serum from those animals caused an increase of the number of granulocytic-type colonies. The initiation of colony stimulating and leukopoetic activity in the blood of animals after the destruction of mammillary body nuclei and posterior hypothalamic nucleus attested, according to the authors point of view, that humoral mediators (humoral mediator) could participated in the mechanism of hypothalamus effect on leulopoiesis

  19. Video Bioinformatics Analysis of Human Embryonic Stem Cell Colony Growth

    Science.gov (United States)

    Lin, Sabrina; Fonteno, Shawn; Satish, Shruthi; Bhanu, Bir; Talbot, Prue

    2010-01-01

    Because video data are complex and are comprised of many images, mining information from video material is difficult to do without the aid of computer software. Video bioinformatics is a powerful quantitative approach for extracting spatio-temporal data from video images using computer software to perform dating mining and analysis. In this article, we introduce a video bioinformatics method for quantifying the growth of human embryonic stem cells (hESC) by analyzing time-lapse videos collected in a Nikon BioStation CT incubator equipped with a camera for video imaging. In our experiments, hESC colonies that were attached to Matrigel were filmed for 48 hours in the BioStation CT. To determine the rate of growth of these colonies, recipes were developed using CL-Quant software which enables users to extract various types of data from video images. To accurately evaluate colony growth, three recipes were created. The first segmented the image into the colony and background, the second enhanced the image to define colonies throughout the video sequence accurately, and the third measured the number of pixels in the colony over time. The three recipes were run in sequence on video data collected in a BioStation CT to analyze the rate of growth of individual hESC colonies over 48 hours. To verify the truthfulness of the CL-Quant recipes, the same data were analyzed manually using Adobe Photoshop software. When the data obtained using the CL-Quant recipes and Photoshop were compared, results were virtually identical, indicating the CL-Quant recipes were truthful. The method described here could be applied to any video data to measure growth rates of hESC or other cells that grow in colonies. In addition, other video bioinformatics recipes can be developed in the future for other cell processes such as migration, apoptosis, and cell adhesion. PMID:20495527

  20. The effect of dimethyl sulfoxide on the induction of DNA strand breaks in plasmid DNA and colony formation of PC Cl3 mammalian cells by alpha-, beta-, and Auger electron emitters (223)Ra, (188)Re, and (99m)Tc.

    Science.gov (United States)

    Runge, Roswitha; Oehme, Liane; Kotzerke, Jörg; Freudenberg, Robert

    2016-12-01

    DNA damage occurs as a consequence of both direct and indirect effects of ionizing radiation. The severity of DNA damage depends on the physical characteristics of the radiation quality, e.g., the linear energy transfer (LET). There are still contrary findings regarding direct or indirect interactions of high-LET emitters with DNA. Our aim is to determine DNA damage and the effect on cellular survival induced by (223)Ra compared to (188)Re and (99m)Tc modulated by the radical scavenger dimethyl sulfoxide (DMSO). Radioactive solutions of (223)Ra, (188)Re, or (99m)Tc were added to either plasmid DNA or to PC Cl3 cells in the absence or presence of DMSO. Following irradiation, single strand breaks (SSB) and double strand breaks (DSB) in plasmid DNA were analyzed by gel electrophoresis. To determine the radiosensitivity of the rat thyroid cell line (PC Cl3), survival curves were performed using the colony formation assay. Exposure to 120 Gy of (223)Ra, (188)Re, or (99m)Tc leads to maximal yields of SSB (80 %) in plasmid DNA. Irradiation with 540 Gy (223)Ra and 500 Gy (188)Re or (99m)Tc induced 40, 28, and 64 % linear plasmid conformations, respectively. DMSO prevented the SSB and DSB in a similar way for all radionuclides. However, with the α-emitter (223)Ra, a low level of DSB could not be prevented by DMSO. Irradiation of PC Cl3 cells with (223)Ra, (188)Re, and (99m)Tc pre-incubated with DMSO revealed enhanced survival fractions (SF) in comparison to treatment without DMSO. Protection factors (PF) were calculated using the fitted survival curves. These factors are 1.23 ± 0.04, 1.20 ± 0.19, and 1.34 ± 0.05 for (223)Ra, (188)Re, and (99m)Tc, respectively. For (223)Ra, as well as for (188)Re and (99m)Tc, dose-dependent radiation effects were found applicable for plasmid DNA and PC Cl3 cells. The radioprotection by DMSO was in the same range for high- and low-LET emitter. Overall, the results indicate the contribution of mainly indirect radiation

  1. The time-course relationship between endogenous spleen colony formation and marrow cellularity after midlethal irradiation of mice

    International Nuclear Information System (INIS)

    Koch, I.; Wiktor-Jedrzejczak, W.; Wojskowa Akademia Medyczna, Warsaw

    1981-01-01

    The kinetics of appearance and disappearance of endogenous spleen colonies following 4 and 6 Gy of X-irradiation was compared with the kinetics of changes of cellular contents of femur cavities. Additionally, the effect of postirradiation bleeding and this way of the subsequent increase in the level of endogenous erythropoietin was studied. It was found that the kinetics of endogenous haemopoietic recovery in the marrow follows the same characteristic biphasic pattern as in the spleen although it is slightly delayed in time. First wave of regeneration corresponded in time with the formation of transient endogenous spleen colonies 4-7 days postirradiation, and the 2nd wave corresponded in time witn the formation of classical haemopoietic stem-cell derived endogenous spleen colonies 9-12 days following irradiation. Postirradiation bleeding markedly stimulated particularly the first wave of regeneration both in the marrow and in the spleen. (orig.) [de

  2. Sequestration and Distribution Characteristics of Cd(II) by Microcystis aeruginosa and Its Role in Colony Formation.

    Science.gov (United States)

    Bi, Xiangdong; Yan, Ran; Li, Fenxiang; Dai, Wei; Jiao, Kewei; Zhou, Qixing; Liu, Qi

    2016-01-01

    To investigate the sequestration and distribution characteristics of Cd(II) by Microcystis aeruginosa and its role in Microcystis colony formation, M. aeruginosa was exposed to six different Cd(II) concentrations for 10 days. Cd(II) exposure caused hormesis in the growth of M. aeruginosa . Low concentrations of Cd(II) significantly induced formation of small Microcystis colonies ( P bEPS) contents of M. aeruginosa significantly ( P 93% of Cd(II) was sequestrated in the groups with lower added concentrations of Cd(II). More than 80% of the sequestrated Cd(II) was bioadsorbed by bEPS. The Pearson correlation coefficients of exterior and interior factors related to colony formation of M. aeruginosa revealed that Cd(II) could stimulate the production of IPS and bEPS via increasing Cd(II) bioaccumulation and bioadsorption. Increased levels of cross-linking between Cd(II) and bEPS stimulated algal cell aggregation, which eventually promoted the formation of Microcystis colonies.

  3. Longevity of U cells of differentiated yeast colonies grown on respiratory medium depends on active glycolysis.

    Science.gov (United States)

    Čáp, Michal; Váchová, Libuše; Palková, Zdena

    2015-01-01

    Colonies of Saccharomyces cerevisiae laboratory strains pass through specific developmental phases when growing on solid respiratory medium. During entry into the so-called alkali phase, in which ammonia signaling is initiated, 2 prominent cell types are formed within the colonies: U cells in upper colony regions, which have a longevity phenotype and activate the expression of a large number of metabolic genes, and L cells in lower regions, which die more quickly and exhibit a starvation phenotype. Here, we performed a detailed analysis of the activities of enzymes of central carbon metabolism in lysates of both cell types and determined several fermentation end products, showing that previously reported expression differences are reflected in the different enzymatic capabilities of each cell type. Hence, U cells, despite being grown on respiratory medium, behave as fermenting cells, whereas L cells rely on respiratory metabolism and possess active gluconeogenesis. Using a spectrum of different inhibitors, we showed that glycolysis is essential for the formation, and particularly, the survival of U cells. We also showed that β-1,3-glucans that are released from the cell walls of L cells are the most likely source of carbohydrates for U cells.

  4. In vitro radiosensitivity of human fresh T-lymphocytes by colony formation assay using PHA and recombinant Interleukin-2

    International Nuclear Information System (INIS)

    Tatsugawa, Kaori; Nakamura, Nori; Hakoda, Masayuki; Akiyama, Mitoshi.

    1988-05-01

    In vitro culture conditions for colony formation of human fresh peripheral T-cells using phytohemagglutinin (PHA) and recombinant Interleukin-2 are defined. Peripheral lymphocytes, from six individuals, were exposed to X or gamma rays in vitro, and dose-survival curves were obtained. The results showed typical sigmoid curves similar to those observed when other mammalian cells are exposed to radiation. The D 10 (dose required to kill 90 % of the cells) was found to be 3.0 to 3.5 Gy. (author)

  5. Multiscale modeling of bacterial colonies: how pili mediate the dynamics of single cells and cellular aggregates

    Science.gov (United States)

    Pönisch, Wolfram; Weber, Christoph A.; Juckeland, Guido; Biais, Nicolas; Zaburdaev, Vasily

    2017-01-01

    Neisseria gonorrhoeae is the causative agent of one of the most common sexually transmitted diseases, gonorrhea. Over the past two decades there has been an alarming increase of reported gonorrhea cases where the bacteria were resistant to the most commonly used antibiotics thus prompting for alternative antimicrobial treatment strategies. The crucial step in this and many other bacterial infections is the formation of microcolonies, agglomerates consisting of up to several thousands of cells. The attachment and motility of cells on solid substrates as well as the cell-cell interactions are primarily mediated by type IV pili, long polymeric filaments protruding from the surface of cells. While the crucial role of pili in the assembly of microcolonies has been well recognized, the exact mechanisms of how they govern the formation and dynamics of microcolonies are still poorly understood. Here, we present a computational model of individual cells with explicit pili dynamics, force generation and pili-pili interactions. We employ the model to study a wide range of biological processes, such as the motility of individual cells on a surface, the heterogeneous cell motility within the large cell aggregates, and the merging dynamics and the self-assembly of microcolonies. The results of numerical simulations highlight the central role of pili generated forces in the formation of bacterial colonies and are in agreement with the available experimental observations. The model can quantify the behavior of multicellular bacterial colonies on biologically relevant temporal and spatial scales and can be easily adjusted to include the geometry and pili characteristics of various bacterial species. Ultimately, the combination of the microbiological experimental approach with the in silico model of bacterial colonies might provide new qualitative and quantitative insights on the development of bacterial infections and thus pave the way to new antimicrobial treatments.

  6. Characterization of the integrated filamentous phage Pf5 and its involvement in small-colony formation

    NARCIS (Netherlands)

    Mooij, Marlies J.; Drenkard, Eliana; Llamas, María A.; Vandenbroucke-Grauls, Christina M. J. E.; Savelkoul, Paul H. M.; Ausubel, Frederick M.; Bitter, Wilbert

    2007-01-01

    Bacteriophages play an important role in bacterial virulence and phenotypic variation. It has been shown that filamentous bacteriophage Pf4 of Pseudomonas aeruginosa strain PAO1 mediates the formation of small-colony variants (SCVs) in biofilms. This morphology type is associated with parameters of

  7. Contact enhancement of locomotion in spreading cell colonies

    Science.gov (United States)

    D'Alessandro, Joseph; Solon, Alexandre P.; Hayakawa, Yoshinori; Anjard, Christophe; Detcheverry, François; Rieu, Jean-Paul; Rivière, Charlotte

    2017-10-01

    The dispersal of cells from an initially constrained location is a crucial aspect of many physiological phenomena, ranging from morphogenesis to tumour spreading. In such processes, cell-cell interactions may deeply alter the motion of single cells, and in turn the collective dynamics. While contact phenomena like contact inhibition of locomotion are known to come into play at high densities, here we focus on the little explored case of non-cohesive cells at moderate densities. We fully characterize the spreading of micropatterned colonies of Dictyostelium discoideum cells from the complete set of individual trajectories. From data analysis and simulation of an elementary model, we demonstrate that contact interactions act to speed up the early population spreading by promoting individual cells to a state of higher persistence, which constitutes an as-yet unreported contact enhancement of locomotion. Our findings also suggest that the current modelling paradigm of memoryless active particles may need to be extended to account for the history-dependent internal state of motile cells.

  8. Morphology and dynamics of tumor cell colonies propagating in epidermal growth factor supplemented media

    Science.gov (United States)

    Muzzio, N. E.; Carballido, M.; Pasquale, M. A.; González, P. H.; Azzaroni, O.; Arvia, A. J.

    2018-07-01

    The epidermal growth factor (EGF) plays a key role in physiological and pathological processes. This work reports on the influence of EGF concentration (c EGF) on the modulation of individual cell phenotype and cell colony kinetics with the aim of perturbing the colony front roughness fluctuations. For this purpose, HeLa cell colonies that remain confluent along the whole expansion process with initial quasi-radial geometry and different initial cell populations, as well as colonies with initial quasi-linear geometry and large cell population, are employed. Cell size and morphology as well as its adhesive characteristics depend on c EGF. Quasi-radial colonies (QRC) expansion kinetics in EGF-containing medium exhibits a complex behavior. Namely, at the first stages of growth, the average QRC radius evolution can be described by a t 1/2 diffusion term coupled with exponential growth kinetics up to a critical time, and afterwards a growth regime approaching constant velocity. The extension of each regime depends on c EGF and colony history. In the presence of EGF, the initial expansion of quasi-linear colonies (QLCs) also exhibits morphological changes at both the cell and the colony levels. In these cases, the cell density at the colony border region becomes smaller than in the absence of EGF and consequently, the extension of the effective rim where cell duplication and motility contribute to the colony expansion increases. QLC front displacement velocity increases with c EGF up to a maximum value in the 2–10 ng ml‑1 range. Individual cell velocity is increased by EGF, and an enhancement in both the persistence and the ballistic characteristics of cell trajectories can be distinguished. For an intermediate c EGF, collective cell displacements contribute to the roughening of the colony contours. This global dynamics becomes compatible with the standard Kardar–Parisi–Zhang growth model, although a faster colony roughness saturation in EGF-containing medium

  9. High nutrient concentration and temperature alleviated formation of large colonies of Microcystis: Evidence from field investigations and laboratory experiments.

    Science.gov (United States)

    Zhu, Wei; Zhou, Xiaohua; Chen, Huaimin; Gao, Li; Xiao, Man; Li, Ming

    2016-09-15

    Correlations between Microcystis colony size and environmental factors were investigated in Meiliang Bay and Gonghu Bay of Lake Taihu (China) from 2011 to 2013. Compared with Gonghu Bay, both nutrient concentrations and Microcystis colony sizes were greater in Meiliang Bay. The median colony size (D50: 50% of the total mass of particles smaller than this size) increased from April to August and then decreased until November. In both bays, the average D50 of Microcystis colonies were 500 μm) dominated in summer. The differences in colony size in Meiliang Bay and Gonghu Bay were probably due to horizontal drift driven by the prevailing south wind in summer. Redundancy analysis (RDA) of field data indicated that colony size was negatively related to nutrient concentrations but positively related to air temperature, suggesting that low nutrient concentrations and high air temperature promoted formation of large colonies. To validate the field survey, Microcystis colonies collected from Lake Taihu were cultured at different temperatures (15, 20, 25 and 30 °C) under high and low nutrient concentrations for 9 days. The size of Microcystis colonies significantly decreased when temperature was above 20 °C but had no significant change at 15 °C. The differences in temperature effects on colony formation shown from field and laboratory suggested that the larger colonies in summer were probably due to the longer growth period rather than the higher air temperature and light intensity. In addition, colony size decreased more significantly at high nutrient levels. Therefore, it could be concluded that high nutrient concentration and temperature may alleviate formation of large colonies of Microcystis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Accumulation of neutral mutations in growing cell colonies with competition.

    Science.gov (United States)

    Sorace, Ron; Komarova, Natalia L

    2012-12-07

    Neutral mutations play an important role in many biological processes including cancer initiation and progression, the generation of drug resistance in bacterial and viral diseases as well as cancers, and the development of organs in multicellular organisms. In this paper we study how neutral mutants are accumulated in nonlinearly growing colonies of cells subject to growth constraints such as crowding or lack of resources. We investigate different types of growth control which range from "division-controlled" to "death-controlled" growth (and various mixtures of both). In division-controlled growth, the burden of handling overcrowding lies with the process of cell-divisions, the divisions slow down as the carrying capacity is approached. In death-controlled growth, it is death rate that increases to slow down expansion. We show that division-controlled growth minimizes the number of accumulated mutations, and death-controlled growth corresponds to the maximum number of mutants. We check that these results hold in both deterministic and stochastic settings. We further develop a general (deterministic) theory of neutral mutations and achieve an analytical understanding of the mutant accumulation in colonies of a given size in the absence of back-mutations. The long-term dynamics of mutants in the presence of back-mutations is also addressed. In particular, with equal forward- and back-mutation rates, if division-controlled and a death-controlled types are competing for space and nutrients, cells obeying division-controlled growth will dominate the population. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Barrier cell sheath formation

    International Nuclear Information System (INIS)

    Kesner, J.

    1980-04-01

    The solution for electrostatic potential within a simply modeled tandem mirror thermal barrier is seen to exhibit a sheath at each edge of the cell. The formation of the sheath requires ion collisionality and the analysis assmes that the collisional trapping rate into the barrier is considerably slower than the barrier pump rate

  12. Radiosensitivity of mice and its modifiers based on the endogeneous spleen colony formation

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Jindo; Wagatuma, Kaoru

    1987-02-01

    In irradiated mouse hematopoietic tissue, there is a group of cells which can proliferate and form macroscopic colonies. In the spleen, the colonies formed in this manner are discrete and easy to count. In order to look into a difference of radiosensitivity between male and female and the mechanisms of the modification, such as protective agent and hormones on radiosensitivity, the spleen colony forming (SCF) is used as an indicator of reactions in the x-rays irradiated mice. A linear decrease was found in SCF depended on x-rays dose. From the colony forming after irradiation the male was more radiosensitive than female. AET protected from the injury depended on the radiation dose in male mice, but in female mice, protection effects were not observed. Gonatropin showed protective effects for radiation injury on high dose irradiation both in male and female mice. Adrenaline showed similar effects as Gonatropin. Insuline showed a negative effects of protection on 400 R irradiation, while on 600 R irradiation, protective effects were observed.

  13. Are self-ligating brackets related to less formation of Streptococcus mutans colonies? A systematic review

    Directory of Open Access Journals (Sweden)

    Leonard Euler Andrade Gomes do Nascimento

    2014-01-01

    Full Text Available OBJECTIVE: To verify, by means of a systematic review, whether the design of brackets (conventional or self-ligating influences adhesion and formation of Streptococcus mutans colonies. METHODS: Search strategy: four databases (Cochrane Central Register of Controlled Trials, Ovid ALL EMB Reviews, PubMed and BIREME were selected to search relevant articles covering the period from January 1965 to December 2012. Selection Criteria: in first consensus by reading the title and abstract. The full text was obtained from publications that met the inclusion criteria. Data collection and analysis: Two reviewers independently extracted data using the keywords: conventional, self-ligating, biofilm, Streptococcus mutans, and systematic review; and independently evaluated the quality of the studies. In case of divergence, the technique of consensus was adopted. RESULTS: The search strategy resulted in 1,401 articles. The classification of scientific relevance revealed the high quality of the 6 eligible articles of which outcomes were not unanimous in reporting not only the influence of the design of the brackets (conventional or self-ligating over adhesion and formation of colonies of Streptococcus mutans, but also that other factors such as the quality of the bracket type, the level of individual oral hygiene, bonding and age may have greater influence. Statistical analysis was not feasible because of the heterogeneous methodological design. CONCLUSIONS: Within the limitations of this study, it was concluded that there is no evidence for a possible influence of the design of the brackets (conventional or self-ligating over colony formation and adhesion of Streptococcus mutans.

  14. Responses of the Murine Myeloid Colony-Forming Cell to Ansamycin Antibiotics

    Science.gov (United States)

    Horoszewicz, Julius S.; Carter, William A.

    1974-01-01

    The in vitro susceptibility of murine myeloid colony-forming cells to the antiproliferative activities of three ansamycin antibiotics was determined. These cells were found to be 10- to 40-fold more susceptible than the corresponding human ones. PMID:4151701

  15. Colony formation by sublethally heat-injured Zygosaccharomyces rouxii as affected by solutes in the recovery medium and procedure for sterilizing medium.

    Science.gov (United States)

    Golden, D A; Beuchat, L R

    1990-01-01

    Recovery and colony formation by healthy and sublethally heat-injured cells of Zygosaccharomyces rouxii as influenced by the procedure for sterilizing recovery media (YM agar [YMA], wort agar, cornmeal agar, and oatmeal agar) were investigated. Media were supplemented with various concentrations of glucose, sucrose, glycerol, or sorbitol and sterilized by autoclaving (110 degrees C, 15 min) and by repeated treatment with steam (100 degrees C). An increase in sensitivity was observed when heat-injured cells were plated on glucose-supplemented YMA at an aw of 0.880 compared with aws of 0.933 and 0.998. Colonies which developed from unheated and heated cells on YMA at aws of 0.998 and 0.933 generally exceeded 0.5 mm in diameter within 3.5 to 4 days of incubation at 25 degrees C, whereas colonies formed on YMA at an aw of 0.880 typically did not exceed 0.5 mm in diameter until after 5.5 to 6.5 days of incubation. The number of colonies exceeding 0.5 mm in diameter which were formed by heat-injured cells on YMA at an aw of 0.880 was 2 to 3 logs less than the total number of colonies detected, i.e., on YMA at an aw of 0.933 and using no limits of exclusion based on colony diameter. A substantial portion of cells which survived heat treatment were sublethally injured as evidenced by increased sensitivity to a suboptimum aw (0.880). In no instance was recovery of Z. rouxii significantly affected by medium sterilization procedure when glucose or sorbitol was used as the aw-suppressing solute.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2403251

  16. Colony formation by sublethally heat-injured Zygosaccharomyces rouxii as affected by solutes in the recovery medium and procedure for sterilizing medium.

    Science.gov (United States)

    Golden, D A; Beuchat, L R

    1990-08-01

    Recovery and colony formation by healthy and sublethally heat-injured cells of Zygosaccharomyces rouxii as influenced by the procedure for sterilizing recovery media (YM agar [YMA], wort agar, cornmeal agar, and oatmeal agar) were investigated. Media were supplemented with various concentrations of glucose, sucrose, glycerol, or sorbitol and sterilized by autoclaving (110 degrees C, 15 min) and by repeated treatment with steam (100 degrees C). An increase in sensitivity was observed when heat-injured cells were plated on glucose-supplemented YMA at an aw of 0.880 compared with aws of 0.933 and 0.998. Colonies which developed from unheated and heated cells on YMA at aws of 0.998 and 0.933 generally exceeded 0.5 mm in diameter within 3.5 to 4 days of incubation at 25 degrees C, whereas colonies formed on YMA at an aw of 0.880 typically did not exceed 0.5 mm in diameter until after 5.5 to 6.5 days of incubation. The number of colonies exceeding 0.5 mm in diameter which were formed by heat-injured cells on YMA at an aw of 0.880 was 2 to 3 logs less than the total number of colonies detected, i.e., on YMA at an aw of 0.933 and using no limits of exclusion based on colony diameter. A substantial portion of cells which survived heat treatment were sublethally injured as evidenced by increased sensitivity to a suboptimum aw (0.880). In no instance was recovery of Z. rouxii significantly affected by medium sterilization procedure when glucose or sorbitol was used as the aw-suppressing solute.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. The effects of electrospun substrate-mediated cell colony morphology on the self-renewal of human induced pluripotent stem cells.

    Science.gov (United States)

    Maldonado, Maricela; Wong, Lauren Y; Echeverria, Cristina; Ico, Gerardo; Low, Karen; Fujimoto, Taylor; Johnson, Jed K; Nam, Jin

    2015-05-01

    The development of xeno-free, chemically defined stem cell culture systems has been a primary focus in the field of regenerative medicine to enhance the clinical application of pluripotent stem cells (PSCs). In this regard, various electrospun substrates with diverse physiochemical properties were synthesized utilizing various polymer precursors and surface treatments. Human induced pluripotent stem cells (IPSCs) cultured on these substrates were characterized by their gene and protein expression to determine the effects of the substrate physiochemical properties on the cells' self-renewal, i.e., proliferation and the maintenance of pluripotency. The results showed that surface chemistry significantly affected cell colony formation via governing the colony edge propagation. More importantly, when surface chemistry of the substrates was uniformly controlled by collagen conjugation, the stiffness of substrate was inversely related to the sphericity, a degree of three dimensionality in colony morphology. The differences in sphericity subsequently affected spontaneous differentiation of IPSCs during a long-term culture, implicating that the colony morphology is a deciding factor in the lineage commitment of PSCs. Overall, we show that the capability of controlling IPSC colony morphology by electrospun substrates provides a means to modulate IPSC self-renewal. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Endogenous Sheet-Averaged Tension Within a Large Epithelial Cell Colony.

    Science.gov (United States)

    Dumbali, Sandeep P; Mei, Lanju; Qian, Shizhi; Maruthamuthu, Venkat

    2017-10-01

    Epithelial cells form quasi-two-dimensional sheets that function as contractile media to effect tissue shape changes during development and homeostasis. Endogenously generated intrasheet tension is a driver of such changes, but has predominantly been measured in the presence of directional migration. The nature of epithelial cell-generated forces transmitted over supracellular distances, in the absence of directional migration, is thus largely unclear. In this report, we consider large epithelial cell colonies which are archetypical multicell collectives with extensive cell-cell contacts but with a symmetric (circular) boundary. Using the traction force imbalance method (TFIM) (traction force microscopy combined with physical force balance), we first show that one can determine the colony-level endogenous sheet forces exerted at the midline by one half of the colony on the other half with no prior assumptions on the uniformity of the mechanical properties of the cell sheet. Importantly, we find that this colony-level sheet force exhibits large variations with orientation-the difference between the maximum and minimum sheet force is comparable to the average sheet force itself. Furthermore, the sheet force at the colony midline is largely tensile but the shear component exhibits significantly more variation with orientation. We thus show that even an unperturbed epithelial colony with a symmetric boundary shows significant directional variation in the endogenous sheet tension and shear forces that subsist at the colony level.

  19. Application of Artificial Bee Colony in Model Parameter Identification of Solar Cells

    Directory of Open Access Journals (Sweden)

    Rongjie Wang

    2015-07-01

    Full Text Available The identification of values of solar cell parameters is of great interest for evaluating solar cell performances. The algorithm of an artificial bee colony was used to extract model parameters of solar cells from current-voltage characteristics. Firstly, the best-so-for mechanism was introduced to the original artificial bee colony. Then, a method was proposed to identify parameters for a single diode model and double diode model using this improved artificial bee colony. Experimental results clearly demonstrate the effectiveness of the proposed method and its superior performance compared to other competing methods.

  20. Isolation and characterization of human umbilical cord-derived endothelial colony-forming cells

    Science.gov (United States)

    Zhang, Hao; Tao, Yanling; Ren, Saisai; Liu, Haihui; Zhou, Hui; Hu, Jiangwei; Tang, Yongyong; Zhang, Bin; Chen, Hu

    2017-01-01

    Endothelial colony-forming cells (ECFCs) are a population of endothelial progenitor cells (EPCs) that display robust proliferative potential and vessel-forming capability. Previous studies have demonstrated that a limited number of ECFCs may be obtained from adult bone marrow, peripheral blood and umbilical cord (UC) blood. The present study describes an effective method for isolating ECFCs from human UC. The ECFCs derived from human UC displayed the full properties of EPCs. Analysis of the growth kinetics, cell cycle and colony-forming ability of the isolated human UC-ECFCs indicated that the cells demonstrated properties of stem cells, including relative stability and rapid proliferation in vitro. Gene expression of Fms related tyrosine kinase 1, kinase insert domain receptor, vascular endothelial cadherin, cluster of differentiation (CD)31, CD34, epidermal growth factor homology domains-2, von Willebrand factor and endothelial nitric oxide synthase was assessed by reverse transcription-polymerase chain reaction. The cells were positive for CD34, CD31, CD73, CD105 and vascular endothelial growth factor receptor-2, and negative for CD45, CD90 and human leukocyte antigen-antigen D related protein according to flow cytometry. 1,1′-dioctadecyl-3,3,3′,3′-tetra-methyl-indocarbocyanine perchlorate-labeled acetylated low-density lipoprotein and fluorescein isothiocyanate-Ulex europaeus-l were used to verify the identity of the UC-ECFCs. Matrigel was used to investigate tube formation capability. The results demonstrated that the reported technique is a valuable method for isolating human UC-ECFCs, which have potential for use in vascular regeneration. PMID:29067104

  1. Functional Differences Between Placental Micro- and Macrovascular Endothelial Colony-Forming Cells

    Science.gov (United States)

    Solomon, Ioana; O’Reilly, Megan; Ionescu, Lavinia; Alphonse, Rajesh S.; Rajabali, Saima; Zhong, Shumei; Vadivel, Arul; Shelley, W. Chris; Yoder, Mervin C.

    2016-01-01

    Alterations in the development of the placental vasculature can lead to pregnancy complications, such as preeclampsia. Currently, the cause of preeclampsia is unknown, and there are no specific prevention or treatment strategies. Further insight into the placental vasculature may aid in identifying causal factors. Endothelial colony-forming cells (ECFCs) are a subset of endothelial progenitor cells capable of self-renewal and de novo vessel formation in vitro. We hypothesized that ECFCs exist in the micro- and macrovasculature of the normal, term human placenta. Human placentas were collected from term pregnancies delivered by cesarean section (n = 16). Placental micro- and macrovasculature was collected from the maternal and fetal side of the placenta, respectively, and ECFCs were isolated and characterized. ECFCs were CD31+, CD105+, CD144+, CD146+, CD14−, and CD45−, took up 1,1′-dioctadecyl-3,3,3′,3′-tetramethyl-indocarbocyanine perchlorate-labeled acetylated low-density lipoprotein, and bound Ulex europaeus agglutinin 1. In vitro, macrovascular ECFCs had a greater potential to generate high-proliferative colonies and formed more complex capillary-like networks on Matrigel compared with microvascular ECFCs. In contrast, in vivo assessment demonstrated that microvascular ECFCs had a greater potential to form vessels. Macrovascular ECFCs were of fetal origin, whereas microvascular ECFCs were of maternal origin. ECFCs exist in the micro- and macrovasculature of the normal, term human placenta. Although macrovascular ECFCs demonstrated greater vessel and colony-forming potency in vitro, this did not translate in vivo, where microvascular ECFCs exhibited a greater vessel-forming ability. These important findings contribute to the current understanding of normal placental vascular development and may aid in identifying factors involved in preeclampsia and other pregnancy complications. Significance This research confirms that resident endothelial colony

  2. Stimulation and support of haemopoietic stem cell proliferation by irradiated stroma cell colonies in bone marrow cell culture in vitro

    International Nuclear Information System (INIS)

    Mori, K.J.; Izumi, Hiroko; Seto, Akira

    1981-01-01

    A culture system was established in which haemopoietic stem cells can undergo a recovery proliferation after a depletion of the stem cells, completely in vitro. To elucidate the source of the stimulatory factors, normal bone marrow cells were overlayed on top of the irradiated adherent 'stromal' cell colonies in the bone marrow cell culture. This stimulated the proliferation of haemopoietic stem cells in the cultured cells in suspension. The present results indicate that the stromal cells produce factors which stimulate stem cell proliferation. Whether the stimulation is evoked by direct cell-cell interactions or by humoral factors is as yet to be studied. (author)

  3. Matrix production and organization by endothelial colony forming cells in mechanically strained engineered tissue constructs.

    Directory of Open Access Journals (Sweden)

    Nicky de Jonge

    Full Text Available AIMS: Tissue engineering is an innovative method to restore cardiovascular tissue function by implanting either an in vitro cultured tissue or a degradable, mechanically functional scaffold that gradually transforms into a living neo-tissue by recruiting tissue forming cells at the site of implantation. Circulating endothelial colony forming cells (ECFCs are capable of differentiating into endothelial cells as well as a mesenchymal ECM-producing phenotype, undergoing Endothelial-to-Mesenchymal-transition (EndoMT. We investigated the potential of ECFCs to produce and organize ECM under the influence of static and cyclic mechanical strain, as well as stimulation with transforming growth factor β1 (TGFβ1. METHODS AND RESULTS: A fibrin-based 3D tissue model was used to simulate neo-tissue formation. Extracellular matrix organization was monitored using confocal laser-scanning microscopy. ECFCs produced collagen and also elastin, but did not form an organized matrix, except when cultured with TGFβ1 under static strain. Here, collagen was aligned more parallel to the strain direction, similar to Human Vena Saphena Cell-seeded controls. Priming ECFC with TGFβ1 before exposing them to strain led to more homogenous matrix production. CONCLUSIONS: Biochemical and mechanical cues can induce extracellular matrix formation by ECFCs in tissue models that mimic early tissue formation. Our findings suggest that priming with bioactives may be required to optimize neo-tissue development with ECFCs and has important consequences for the timing of stimuli applied to scaffold designs for both in vitro and in situ cardiovascular tissue engineering. The results obtained with ECFCs differ from those obtained with other cell sources, such as vena saphena-derived myofibroblasts, underlining the need for experimental models like ours to test novel cell sources for cardiovascular tissue engineering.

  4. Stem cells in Nanomia bijuga (Siphonophora), a colonial animal with localized growth zones.

    Science.gov (United States)

    Siebert, Stefan; Goetz, Freya E; Church, Samuel H; Bhattacharyya, Pathikrit; Zapata, Felipe; Haddock, Steven H D; Dunn, Casey W

    2015-01-01

    Siphonophores (Hydrozoa) have unparalleled colony-level complexity, precision of colony organization, and functional specialization between zooids (i.e., the units that make up colonies). Previous work has shown that, unlike other colonial animals, most growth in siphonophores is restricted to one or two well-defined growth zones that are the sites of both elongation and zooid budding. It remained unknown, however, how this unique colony growth and development is realized at the cellular level. To understand the colony-level growth and development of siphonophores at the cellular level, we characterize the distribution of proliferating cells and interstitial stem cells (i-cells) in the siphonophore Nanomia bijuga. Within the colony, we find evidence that i-cells are present at the tip of the horn, the structure within the growth zone that gives rise to new zooids. Co-localized gene expression of vasa-1, pl10, piwi, nanos-1, and nanos-2 suggests that i-cells persist in the youngest zooid buds and that i-cells become progressively restricted to specific regions within the zooids until they are mostly absent from the oldest zooids. The examined genes remain expressed in gametogenic regions. No evidence for i-cells is found in the stem between maturing zooids. Domains of high cell proliferation include regions where the examined genes are expressed, but also include some areas in which the examined genes were not expressed such as the stem within the growth zones. Cell proliferation in regions devoid of vasa-1, pl10, piwi, nanos-1, and nanos-2 expression indicates the presence of mitotically active epithelial cell lineages and, potentially, progenitor cell populations. We provide the first evidence for i-cells in a siphonophore. Our findings suggest maintenance of i-cell populations at the sites of growth zones and that these sites are the main source of i-cells. This restriction of stem cells to particular regions in the colony, in combination with localized budding

  5. Peripheral blood cells from children with RASopathies show enhanced spontaneous colonies growth in vitro and hyperactive RAS signaling

    International Nuclear Information System (INIS)

    Gaipa, G; Bugarin, C; Cianci, P; Sarno, J; Bonaccorso, P; Biondi, A; Selicorni, A

    2015-01-01

    Germline mutations in genes coding for molecules involved in the RAS/RAF/MEK/ERK pathway are the hallmarks of a newly classified family of autosomal dominant syndromes termed RASopathies. Myeloproliferative disorders (MPDs), in particular, juvenile myelomonocytic leukemia, can lead to potentially severe complications in children with Noonan syndrome (NS). We studied 27 children with NS or other RASopathies and 35 age-matched children as control subjects. Peripheral blood (PB) cells from these patients were studied for in vitro colony-forming units (CFUs) activity, as well as for intracellular phosphosignaling. Higher spontaneous growth of both burst-forming units-erythroid (BFU-E) and CFU-granulocyte/macrophage (CFU-GM) colonies from RAS-mutated patients were observed as compared with control subjects. We also observed a significantly higher amount of GM-colony-stimulating factor-induced p-ERK in children with RASopathies. Our findings demonstrate for the first time that PB cells isolated from children suffering from NS or other RASopathies without MPD display enhanced BFU-E and CFU-GM colony formation in vitro. The biological significance of these findings clearly awaits further studies. Collectively, our data provide a basis for further investigating of only partially characterized hematological alterations present in children suffering from RASopathies, and may provide new markers for progression toward malignant MPD in these patients

  6. Formation of Ramified Colony of Fungus Aspergillus Oryzae on Agar Media

    Science.gov (United States)

    Matsuura, Shu; Miyazima, Sasuke

    Ramified colonies of fungus Aspergillus oryzae have been found to grow at a low growth rate on "liquid-like" agar media with low concentrations of agar and glucose. Box-counting fractal dimensions of the individual colony branches have been found to decrease with the time of incubation. Addition of glucose solution in the interior of branched colonies has brought about the production of the hyphal filaments almost only at the apical region of the colony branches. Active growth of the ramified colonies is localized in the peripheral zone, and this growth manner implies that the fungus is exhibiting a positive exploitation.

  7. Early Developmental Program Shapes Colony Morphology in Bacteria

    Directory of Open Access Journals (Sweden)

    Gideon Mamou

    2016-03-01

    Full Text Available When grown on a solid surface, bacteria form highly organized colonies, yet little is known about the earliest stages of colony establishment. Following Bacillus subtilis colony development from a single progenitor cell, a sequence of highly ordered spatiotemporal events was revealed. Colony was initiated by the formation of leading-cell chains, deriving from the colony center and extending in multiple directions, typically in a “Y-shaped” structure. By eradicating particular cells during these early stages, we could influence the shape of the resulting colony and demonstrate that Y-arm extension defines colony size. A mutant in ymdB encoding a phosphodiesterase displayed unordered developmental patterns, indicating a role in guiding these initial events. Finally, we provide evidence that intercellular nanotubes contribute to proper colony formation. In summary, we reveal a “construction plan” for building a colony and provide the initial molecular basis for this process.

  8. Metabolic diversification of cells during the development of yeast colonies

    Czech Academy of Sciences Publication Activity Database

    Váchová, Libuše; Kučerová, Helena; Devaux, F.; Úlehlová, M.; Palková, Z.

    2009-01-01

    Roč. 11, č. 2 (2009), s. 494-504 ISSN 1462-2912 R&D Projects: GA ČR GA204/05/0294; GA ČR GA204/08/0718; GA MŠk(CZ) LC531 Grant - others:GB(GB) Howard Hughes Medical Institute International Research Award Institutional research plan: CEZ:AV0Z50200510 Keywords : yeast * yeast colonies * saccharomyces cerevisiae Subject RIV: EE - Microbiology, Virology Impact factor: 4.909, year: 2009

  9. Small-cell comb does not control Varroa mites in colonies of honeybees of European origin

    OpenAIRE

    Seeley , Thomas; Griffin , Sean

    2011-01-01

    International audience; We tested the idea that Varroa destructor can be controlled in colonies of the European subspecies of Apis mellifera by providing them with combs built of small cells, in which immature mites might have difficulty developing for lack of space. We established seven pairs of equal-size colonies that started out equally infested with mites. In each pair, one hive contained only standard-cell (5.4 mm) comb, and the other contained only small-cell (4.8 mm) comb. We measured...

  10. The hematopoietic chemokine CXCL12 promotes integration of human endothelial colony forming cell-derived cells into immature vessel networks.

    Science.gov (United States)

    Newey, Sarah E; Tsaknakis, Grigorios; Khoo, Cheen P; Athanassopoulos, Thanassi; Camicia, Rosalba; Zhang, Youyi; Grabowska, Rita; Harris, Adrian L; Roubelakis, Maria G; Watt, Suzanne M

    2014-11-15

    Proangiogenic factors, vascular endothelial growth factor (VEGF), and fibroblast growth factor-2 (FGF-2) prime endothelial cells to respond to "hematopoietic" chemokines and cytokines by inducing/upregulating expression of the respective chemokine/cytokine receptors. Coculture of human endothelial colony forming cell (ECFC)-derived cells with human stromal cells in the presence of VEGF and FGF-2 for 14 days resulted in upregulation of the "hematopoietic" chemokine CXCL12 and its CXCR4 receptor by day 3 of coculture. Chronic exposure to the CXCR4 antagonist AMD3100 in this vasculo/angiogenesis assay significantly reduced vascular tubule formation, an observation recapitulated by delayed AMD3100 addition. While AMD3100 did not affect ECFC-derived cell proliferation, it did demonstrate a dual action. First, over the later stages of the 14-day cocultures, AMD3100 delayed tubule organization into maturing vessel networks, resulting in enhanced endothelial cell retraction and loss of complexity as defined by live cell imaging. Second, at earlier stages of cocultures, we observed that AMD3100 significantly inhibited the integration of exogenous ECFC-derived cells into established, but immature, vascular networks. Comparative proteome profiler array analyses of ECFC-derived cells treated with AMD3100 identified changes in expression of potential candidate molecules involved in adhesion and/or migration. Blocking antibodies to CD31, but not CD146 or CD166, reduced the ECFC-derived cell integration into these extant vascular networks. Thus, CXCL12 plays a key role not only in endothelial cell sensing and guidance, but also in promoting the integration of ECFC-derived cells into developing vascular networks.

  11. Fabrication of corneal epithelial cell sheets maintaining colony-forming cells without feeder cells by oxygen-controlled method.

    Science.gov (United States)

    Nakajima, Ryota; Takeda, Shizu

    2014-01-01

    The use of murine 3T3 feeder cells needs to be avoided when fabricating corneal epithelial cell sheets for use in treating ocular surface diseases. However, the expression level of the epithelial stem/progenitor cell marker, p63, is down-regulated in feeder-free culture systems. In this study, in order to fabricate corneal epithelial cell sheets that maintain colony-forming cells without using any feeder cells, we investigated the use of an oxygen-controlled method that was developed previously to fabricate cell sheets efficiently. Rabbit limbal epithelial cells were cultured under hypoxia (1-10% O2) and under normoxia during stratification after reaching confluence. Multilayered corneal epithelial cell sheets were fabricated using an oxygen-controlled method, and immunofluorescence analysis showed that cytokeratin 3 and p63 was expressed in appropriate localization in the cell sheets. The colony-forming efficiency of the cell sheets fabricated by the oxygen-controlled method without feeder cells was significantly higher than that of cell sheets fabricated under 20% O2 without feeder cells. These results indicate that the oxygen-controlled method has the potential to achieve a feeder-free culture system for fabricating corneal epithelial cell sheets for corneal regeneration. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Lysophosphatidic Acid Upregulates Laminin-332 Expression during A431 Cell Colony Dispersal

    Directory of Open Access Journals (Sweden)

    Hironobu Yamashita

    2010-01-01

    Full Text Available Lysophosphatidic acid (LPA is a bioactive phospholipid that affects various biological functions, such as cell proliferation, migration, survival, wound healing, and tumor invasion through LPA receptors. Previously, we reported that LPA induces A431 colony dispersal, accompanied by disruption of cell-cell contacts and cell migration. However, it remains unclear how LPA affects cell migration and gene expression during A431 colony dispersal. In this paper, we performed cDNA microarray analysis to investigate this question by comparing gene expression between untreated and LPA-treated A431 cells. Interestingly, these results revealed that LPA treatment upregulates several TGF-β1 target genes, including laminin-332 (Ln-332 components (α3, β3, and γ2 chains. Western blot analysis also showed that LPA increased phosphorylation of Smad2, an event that is carried out by TGF-β1 interactions. Among the genes upregulated, we further addressed the role of Ln-332. Real-time PCR analysis confirmed the transcriptional upregulation of all α3, β3, and γ2 chains of Ln-332 by LPA, corresponding to the protein level increases revealed by western blot. Further, the addition of anti-Ln-332 antibody prevented LPA-treated A431 colonies from dispersing. Taken together, our results suggest that LPA-induced Ln-332 plays a significant role in migration of individual cells from A431 colonies.

  13. Colony variation of Helicobacter pylori: pathogenic potential is correlated to cell wall lipid composition.

    Science.gov (United States)

    Bukholm, G; Tannaes, T; Nedenskov, P; Esbensen, Y; Grav, H J; Hovig, T; Ariansen, S; Guldvog, I

    1997-05-01

    Differences in expression of disease after infection with Helicobacter pylori have so far been connected with host factors and bacterial interstrain variation. In this study, spontaneous and ecology-mediated intrastrain variation was examined. Four clinical isolates of H. pylori were shown to give rise to two colony forms. Bacterial morphology was examined by electron microscopy. Bacterial fractions were examined for proteins using ion exchange chromatography and SDS-PAGE; for lipids using thin-layer chromatography, lipid anion-exchange chromatography, column chromatography on silica gel, 31P-NMR, gas chromatography and mass spectrometry. Bacterial in vitro invasiveness and adhesiveness were examined in two different systems, and urease and VacA toxin were assayed by Western blot analysis. H. pylori was shown to give rise to two colony forms: at normal pH the population was dominated by L colonies. One strain was chosen for further studies. Bacteria from L colonies retained VacA toxin and urease, did not invade or adhere to epithelial cells, and contained normal quantities of phosphatidylethanolamine. In a small frequency, spontaneous S colonies were formed. Bacteria from these colonies released VacA and urease, adhered to and invaded epithelial cells and contained increased amounts of lysophosphatidyl ethanolamine and phosphatidyl serine. After addition of HCl to the culture medium (pH6), almost only S colonies were formed. The results demonstrate that environmental factors, such as HCl, can change the bacterial cell wall, and thereby enhance expression of virulence factors of H. pylori in vitro. A similar in vivo variation would have implications for our understanding of the interaction between HCl secretion in the gastric mucosa and H. pylori in the development of peptic ulcer disease.

  14. Identification and enrichment of colony-forming cells from the adult murine pituitary

    International Nuclear Information System (INIS)

    Lepore, D.A.; Roeszler, K.; Wagner, J.; Ross, S.A.; Bauer, K.; Thomas, P.Q.

    2005-01-01

    Stem and progenitor cells have been identified in many adult tissues including bone marrow, the central nervous system, and skin. While there is direct evidence to indicate the activity of a progenitor cell population in the pituitary gland, this putative subpopulation has not yet been identified. Herein we describe the isolation and characterization of a novel clonogenic cell type in the adult murine pituitary, which we have termed Pituitary Colony-Forming Cells (PCFCs). PCFCs constitute 0.2% of pituitary cells, and generate heterogeneous colonies from single cells. PCFCs exhibit variable proliferative potential, and may exceed 11 population doublings in 14 days. Enrichment of PCFCs to 61.5-fold with 100% recovery can be obtained through the active uptake of the fluorescent dipeptide, β-Ala-Lys-Nε-AMCA. PCFCs are mostly contained within the large, agranular subpopulation of AMCA + cells, and constitute 28% of this fraction, corresponding to 140.5-fold enrichment. Interestingly, the AMCA + population contains rare cells that are GH + or PRL + . GH + cells were also identified in PCFC single cell colonies, suggesting that PCFCs have the potential to differentiate into GH + cells. Together, these data show that the pituitary contains a rare clonogenic population which may correspond to the somatotrope/lactotrope progenitors suggested by previous experiments

  15. Isolation of endothelial colony-forming cells from blood samples collected from the jugular and cephalic veins of healthy adult horses.

    Science.gov (United States)

    Sharpe, Ashley N; Seeto, Wen J; Winter, Randolph L; Zhong, Qiao; Lipke, Elizabeth A; Wooldridge, Anne A

    2016-10-01

    OBJECTIVE To evaluate optimal isolation of endothelial colony-forming cells (ECFCs) from peripheral blood of horses. SAMPLE Jugular and cephalic venous blood samples from 17 adult horses. PROCEDURES Each blood sample was divided; isolation was performed with whole blood adherence (WBA) and density gradient centrifugation (DGC). Isolated cells were characterized by uptake of 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate-labeled acetylated low-density lipoprotein (DiI-Ac-LDL), vascular tubule formation, and expression of endothelial (CD34, CD105, vascular endothelial growth factor receptor-2, and von Willebrand factor) and hematopoietic (CD14) cell markers by use of indirect immunofluorescence assay (IFA) and flow cytometry. RESULTS Colonies with cobblestone morphology were isolated from 15 of 17 horses. Blood collected from the cephalic vein yielded colonies significantly more often (14/17 horses) than did blood collected from the jugular vein (8/17 horses). Of 14 cephalic blood samples with colonies, 13 were obtained with DGC and 8 with WBA. Of 8 jugular blood samples with colonies, 8 were obtained with DGC and 4 with WBA. Colony frequency (colonies per milliliter of blood) was significantly higher for cephalic blood samples and samples isolated with DGC. Cells formed vascular tubules, had uptake of DiI-Ac-LDL, and expressed endothelial markers by use of IFA and flow cytometry, which confirmed their identity as ECFCs. CONCLUSIONS AND CLINICAL RELEVANCE Maximum yield of ECFCs was obtained for blood samples collected from both the jugular and cephalic veins and use of DGC to isolate cells. Consistent yield of ECFCs from peripheral blood of horses will enable studies to evaluate diagnostic and therapeutic uses.

  16. Colony Dimorphism in Bradyrhizobium Strains

    Science.gov (United States)

    Sylvester-Bradley, Rosemary; Thornton, Philip; Jones, Peter

    1988-01-01

    Ten isolates of Bradyrhizobium spp. which form two colony types were studied; the isolates originated from a range of legume species. The two colony types differed in the amount of gum formed or size or both, depending on the strain. Whole 7-day-old colonies of each type were subcultured to determine the proportion of cells which had changed to the other type. An iterative computerized procedure was used to determine the rate of switching per generation between the two types and to predict proportions reached at equilibrium for each strain. The predicted proportions of the wetter (more gummy) or larger colony type at equilibrium differed significantly between strains, ranging from 0.9999 (strain CIAT 2383) to 0.0216 (strain CIAT 2469), because some strains switched faster from dry to wet (or small to large) and others switched faster from wet to dry (or large to small). Predicted equilibrium was reached after about 140 generations in strain USDA 76. In all but one strain (CIAT 3030) the growth rate of the wetter colony type was greater than or similar to that of the drier type. The mean difference in generation time between the two colony types was 0.37 h. Doubling times calculated for either colony type after 7 days of growth on the agar surface ranged from 6.0 to 7.3 h. The formation of two persistent colony types by one strain (clonal or colony dimorphism) may be a common phenomenon among Bradyrhizobium strains. Images PMID:16347599

  17. Patterns of proliferation and differentiation of irradiated haemopoietic stem cells cultured on normal 'stromal' cell colonies in vitro

    International Nuclear Information System (INIS)

    Mori, K.J.

    1981-01-01

    Experiments were designed to elucidate whether or not the irradiated bone marrow cells receive any stimulation for the self-replication and differentiation from normal 'stromal' cell colonies in the bone marrow cell culture in vitro. When irradiated or unirradiated bone marrow cells were overlaid on the normal adherent cell colonies, the proliferation of haemopoietic stem cells was supported, the degree of the stimulation depending on the starting cellular concentration. There was, however, no significant changes in the concentration of either CFUs or CFUc regardless of the dose of irradiation on the bone marrow cells overlaid. This was a great contrast to the dose-dependent decrease of CFUs or CFUc within the culture in which both the stem cells and stromal cells were simultaneously irradiated. These results suggest that the balance of self-replication and differentiation of the haemopoietic stem cells is affected only when haemopoietic microenvironment is perturbed. (author)

  18. Heterogeneity within the spleen colony-forming cell population in rat bone marrow

    International Nuclear Information System (INIS)

    Martens, A.C.; van Bekkum, D.W.; Hagenbeek, A.

    1986-01-01

    The pluripotent hemopoietic stem cell (HSC) of the rat can be enumerated in a spleen colony assay (SCA) in rats as well as mice. After injection of rat bone marrow into lethally irradiated mice, macroscopically visible spleen colonies (CFU-S) are found from day 6 through 14, but the number varies on consecutive days. In normal bone marrow a constant ratio of day-8 to day-12 colony numbers is observed. However, this ratio is changed after in vivo treatment of rats with cyclophosphamide, as well as after in vitro treatment of rat bone marrow with cyclophosphamide derivatives. This indicates that the CFU-S that form colonies on day 8 react differently to this treatment than the CFU-S that form colonies on day 12, and suggests heterogeneity among the CFU-S population. Posttreatment regrowth of day-8 and day-12 CFU-S is characterized by differences in population-doubling times (Td = 0.85 days vs 1.65 days). Another argument in support of the postulate of heterogeneity within the rat CFU-S population is derived from the fact that (in contrast to normal rat spleen) the spleen of leukemic rats contains high numbers of CFU-S that show a ratio of day-8 to day-12 CFU-S of 4.5, which is different than that observed for a CFU-S population in normal bone marrow (a ratio of 2.4). It is concluded that, in rat hemopoiesis, two populations of spleen colony-forming cells can be distinguished using the rat-to-mouse SCA. This indicates that mouse and rat hemopoiesis are comparable in this respect and that heterogeneity in the stem cell compartment is a general phenomenon

  19. Chinua Achebe and the Post-colonial Esthetic: Writing, Identity, and National Formation

    Directory of Open Access Journals (Sweden)

    Simon Gikandi

    1991-01-01

    Full Text Available Chinua Achebe is recognized as one of Africa's most important and influential writers, and his novels have focused on the ways in which the European tradition of the novel and African modes of expression relate to each other in both complementary and contesting ways. Achebe's novels are informed by an important theory of writing which tries to mediate the politics of the novel as a form of commentary on the emergence and transformation of nationalism which constitutes the African writer's epistemological context. Achebe's esthetic has been overdetermined by the changing discourse on representation and national identity in colonial and post-colonial Africa. His anxious quest for a post-colonial esthetic is predicated on the belief that narrative can enable the writer to express an alternative order of things opposed to realities imprisoned by imperialism and Western domination.

  20. Automated autoradiographic analysis of tumor cell colonies in vitro

    International Nuclear Information System (INIS)

    Kallman, R.F.

    1984-01-01

    The studies reported are basic to the design of therapeutic strategies against cancer and to the understanding of therapeutic effects. It is unlikely that clinical therapy could employ the same methodology, however, so this approach could not be incorporated into 'kinetics-directe' therapy. As defined and implemented successfully by Barranco et al. therapy is kinetics-directed when the kinetic properties of cell populations under treatment are actually determined and used to schedule the timing of multiple treatments. Thus, the substance of this paper is of potential importance to kinetic-based cancer therapy, i.e. using historical or empirical data to formulate models. (orig./AJ)

  1. Colony Expansion of Socially Motile Myxococcus xanthus Cells Is Driven by Growth, Motility, and Exopolysaccharide Production.

    Directory of Open Access Journals (Sweden)

    Pintu Patra

    2016-06-01

    Full Text Available Myxococcus xanthus, a model organism for studies of multicellular behavior in bacteria, moves exclusively on solid surfaces using two distinct but coordinated motility mechanisms. One of these, social (S motility is powered by the extension and retraction of type IV pili and requires the presence of exopolysaccharides (EPS produced by neighboring cells. As a result, S motility requires close cell-to-cell proximity and isolated cells do not translocate. Previous studies measuring S motility by observing the colony expansion of cells deposited on agar have shown that the expansion rate increases with initial cell density, but the biophysical mechanisms involved remain largely unknown. To understand the dynamics of S motility-driven colony expansion, we developed a reaction-diffusion model describing the effects of cell density, EPS deposition and nutrient exposure on the expansion rate. Our results show that at steady state the population expands as a traveling wave with a speed determined by the interplay of cell motility and growth, a well-known characteristic of Fisher's equation. The model explains the density-dependence of the colony expansion by demonstrating the presence of a lag phase-a transient period of very slow expansion with a duration dependent on the initial cell density. We propose that at a low initial density, more time is required for the cells to accumulate enough EPS to activate S-motility resulting in a longer lag period. Furthermore, our model makes the novel prediction that following the lag phase the population expands at a constant rate independent of the cell density. These predictions were confirmed by S motility experiments capturing long-term expansion dynamics.

  2. Colony Expansion of Socially Motile Myxococcus xanthus Cells Is Driven by Growth, Motility, and Exopolysaccharide Production.

    Science.gov (United States)

    Patra, Pintu; Kissoon, Kimberley; Cornejo, Isabel; Kaplan, Heidi B; Igoshin, Oleg A

    2016-06-01

    Myxococcus xanthus, a model organism for studies of multicellular behavior in bacteria, moves exclusively on solid surfaces using two distinct but coordinated motility mechanisms. One of these, social (S) motility is powered by the extension and retraction of type IV pili and requires the presence of exopolysaccharides (EPS) produced by neighboring cells. As a result, S motility requires close cell-to-cell proximity and isolated cells do not translocate. Previous studies measuring S motility by observing the colony expansion of cells deposited on agar have shown that the expansion rate increases with initial cell density, but the biophysical mechanisms involved remain largely unknown. To understand the dynamics of S motility-driven colony expansion, we developed a reaction-diffusion model describing the effects of cell density, EPS deposition and nutrient exposure on the expansion rate. Our results show that at steady state the population expands as a traveling wave with a speed determined by the interplay of cell motility and growth, a well-known characteristic of Fisher's equation. The model explains the density-dependence of the colony expansion by demonstrating the presence of a lag phase-a transient period of very slow expansion with a duration dependent on the initial cell density. We propose that at a low initial density, more time is required for the cells to accumulate enough EPS to activate S-motility resulting in a longer lag period. Furthermore, our model makes the novel prediction that following the lag phase the population expands at a constant rate independent of the cell density. These predictions were confirmed by S motility experiments capturing long-term expansion dynamics.

  3. Simulating biological processes: stochastic physics from whole cells to colonies

    Science.gov (United States)

    Earnest, Tyler M.; Cole, John A.; Luthey-Schulten, Zaida

    2018-05-01

    The last few decades have revealed the living cell to be a crowded spatially heterogeneous space teeming with biomolecules whose concentrations and activities are governed by intrinsically random forces. It is from this randomness, however, that a vast array of precisely timed and intricately coordinated biological functions emerge that give rise to the complex forms and behaviors we see in the biosphere around us. This seemingly paradoxical nature of life has drawn the interest of an increasing number of physicists, and recent years have seen stochastic modeling grow into a major subdiscipline within biological physics. Here we review some of the major advances that have shaped our understanding of stochasticity in biology. We begin with some historical context, outlining a string of important experimental results that motivated the development of stochastic modeling. We then embark upon a fairly rigorous treatment of the simulation methods that are currently available for the treatment of stochastic biological models, with an eye toward comparing and contrasting their realms of applicability, and the care that must be taken when parameterizing them. Following that, we describe how stochasticity impacts several key biological functions, including transcription, translation, ribosome biogenesis, chromosome replication, and metabolism, before considering how the functions may be coupled into a comprehensive model of a ‘minimal cell’. Finally, we close with our expectation for the future of the field, focusing on how mesoscopic stochastic methods may be augmented with atomic-scale molecular modeling approaches in order to understand life across a range of length and time scales.

  4. Radiosensitivity of CD4 and CD8 positive human T lymphocytes by an in vitro colony formation assay

    International Nuclear Information System (INIS)

    Nakamura, Nori; Kusunoki, Yoichiro; Akiyama, Mitoshi.

    1989-12-01

    The recent development of an in vitro lymphocyte colony assay provides a new opportunity to examine possible variations in human radiosensitivity using peripheral blood lymphocytes (PBL) in place of the hitherto used skin fibroblast assay. Our recent study showed that most of the colonies consisted of lymphocytes bearing CD4 or CD8 antigens. Since the fraction of CD4 + and CD8 + cells in PBL differs among individuals, it was suspected that individual radiosensitivity might be biased by the different subset frequencies if the dose-survival curves of the CD4 + and CD8 + cells differed. In the present study, CD4 + lymphocytes (helper/inducer T cells) and CD8 + lymphocytes (suppressor/cytotoxic T cells) were isolated from PBL and their dose-survival curves were determined. The results showed that the D 10 (the dose required to reduce the surviving fraction to 10 %) was quite similar for these two types of cells (3.13 ± 0.10 Gy [mean ±SD] for CD4 + , 3.34 ± 0.50 Gy for CD8 + and 3.07 ± 0.05 Gy for the unsorted cells), supporting the use of a whole PBL population for screening of individuals with altered radiosensitivity. (author)

  5. Heterogeneity of the radiosensitivity and origins of tissue macrophage colony-forming cells

    Energy Technology Data Exchange (ETDEWEB)

    Oghiso, Yoichi; Yamada, Yutaka (National Inst. of Radiological Sciences, Chiba (Japan))

    1992-12-01

    Previous studies suggest that the radiosensitivity and origin of tissue macrophage precursors differ from those of hemopoietic macrophage colony-forming units (CFU-Ms) committed to macrophage-lineage cells. We assessed the origins of tissue macrophage colony-forming cells (M-CFCs) in mice by comparing their kinetics and radiosensitivities in the normal steady state and under the conditions of bone marrow depletion by [sup 89]Sr-administration and/or splenectomy. The results indicate that the radiosensitive peritoneal M-CFCs elicited by thioglycollate are derived from bone marrow macrophage precursors; where as alveolar M-CFCs, which are radioresistant, are self-sustained locally and independent of hemopoietic macrophage precursors. In contrast, highly radiosensitive liver M-CFCs are probably derived from CFU-Ms that appear to be propagated in the spleen in association with hemopoietic responses. (author).

  6. Metabolic differentiation of surface and invasive cells of yeast colony biofilms revealed by gene expression profiling

    Czech Academy of Sciences Publication Activity Database

    Maršíková, J.; Wilkinson, D.; Hlaváček, Otakar; Gilfillan, G.D.; Mizeranschi, A.; Hughes, T.; Begany, Markéta; Rešetárová, Stanislava; Váchová, Libuše; Palková, Z.

    2017-01-01

    Roč. 18, OCT 23 (2017), s. 814 ISSN 1471-2164 R&D Projects: GA MŠk(CZ) 7F14083; GA MŠk(CZ) LQ1604; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:61388971 Keywords : Saccharomyces cerevisiae * Colony biofilms * Cell differentiation Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 3.729, year: 2016

  7. Hemopoiesis in mouse heterozygous for the W trait. Difference in postirradiation recovery related to the defect in formation of transient endogenous spleen colonies

    International Nuclear Information System (INIS)

    Wiktor-Jedrzejczak, W.; Urbanowska, E.; Szczylik, C.; Siekierzynski, M.; Pojda, Z.

    1985-01-01

    The hemopoietic regeneration following midlethal irradiation in Wsup(v)/+ mice had similarly biphasic kinetics as in their hematologically normal +/+ littermates. The first abortive phase of regeneration was either severly reduced (formation of transient endogenous spleen colonies, reticulocyte count, granulocyte count) or absent (spleen and femur cellularity, platelet count, PCV) in Wsup(v)/+ mice, when compared to +/+ mice. The second phase leading to permanent recovery of hemopoiesis was in Wsup(v)/+ mice delayed in time. Moreover, although to a lesser extent the values of spleen and femur cellularity, PCV and platelet count were decreased in Wsup(v)/+ mice. Postirradiation bleeding, which stimulated particularly the 1st phase of regeneration both in Wsup(v)/+ and +/+ mice did not lead to the minimization of differences between above two genotypes. It is suggested that the observed differences in the abortive regeneration between Wsup(v)/+ and +/+ mice are primarily dependent on the presence in Wsup(v)/+ mice of selective defect of transient endogeneous colony forming units (TE-CFUs). Moreover, it is possible that the differences in the second phase of regeneration leading to permanent recovery are secondarily dependent on the TE-CFUs defect, as most probably the TE-CFU is the step in stem cell differentiation to mature cells. (orig.) [de

  8. Genetic factors affecting radiosensitivity and cancer predisposition: application of a continuous low dose-rate irradiation colony formation assay to select radiosensitive retinoblastoma family members for correction with a cDNA library

    International Nuclear Information System (INIS)

    Wilson, P.F.; Nagasawa, H.; Bedford, J.S.; Little, J.B.

    2003-01-01

    Full text: The aim of this study is to identify new or undescribed functions of radiosensitivity and genomic instability genes using a continuous low dose-rate colony formation assay. This assay expands on the standard colony formation assay, whereby colony formation ability (retention of proliferative capacity) is measured during continuous low dose-rate irradiation rather than 10-14 days following the completion of such exposures. This approach has previously employed by the Bedford laboratory to identify a Prkdc (DNA-PKcs) mutant of CHO cells, irs-20. In this study we examine the growth response of fibroblasts derived from recently identified radiosensitive retinoblastoma family members, both affected probands and their unaffected parents, and various apparently normal fibroblast lines obtained from the NIGMS Human Genetic Cell Repository (Coriell Medical Institute, Camden, NJ). Colony formation was assayed by plating single cells, exposing them at 37 deg C to continuous Cs-137 gamma irradiation at dose rates of 0.5-8.5 cGy/h, and scoring survivors as colonies with >100 viable cells. The retinoblastoma family members display severely limited growth (survival less than 10E-3) at dose rates greater than 2-2.5 cGy/h, while the apparently normal cell lines do not display such inhibited growth until 6-7 cGy/h. Two of the retinoblastoma family cell lines, MF-6F and MF-15F (both unaffected but radiosensitive parents), were selected as targets of transfection with a viral cDNA library (ViraPort human cDNA library, Stratagene Cloning Systems, La Jolla, CA) and subjected to a ∼3 cGy/h selection dose rate, where uncorrected survival relative to normal cells is lower by a factor of 50-150. Colonies recovered will provide valuable information regarding the genetic nature of their radiosensitivity (possibly involving chromosome stability, DNA repair, and/or cell cycle regulatory pathways), that may influence risks for cancer and heritable effects for a previously

  9. Effects of lead(II) on the extracellular polysaccharide (EPS) production and colony formation of cultured Microcystis aeruginosa.

    Science.gov (United States)

    Bi, Xiang-dong; Zhang, Shu-lin; Dai, Wei; Xing, Ke-zhing; Yang, Fan

    2013-01-01

    To investigate the effects of lead(II) on the production of extracellular polysaccharides (EPS), including bound extracellular polysaccharides (bEPS) and soluble extracellular polysaccharides (sEPS), and the colony formation of Microcystis aeruginosa, cultures of M. aeruginosa were exposed to four concentrations (5.0, 10.0, 20.0 and 40.0 mg/L) of lead(II) for 10 d under controlled laboratory conditions. The results showed that 5.0 and 10.0 mg/L lead(II) stimulated M. aeruginosa growth throughout the experiment while 20.0 and 40.0 mg/L lead(II) inhibited M. aeruginosa growth in the first 2 d exposure and then stimulated it. As compared to the control group, significant increases in the bEPS and sEPS production were observed in 20.0 and 40.0 mg/L lead(II) treatments (P bEPS production, which conversely promoted colony formation, suggesting that heavy metals might be contributing to the bloom-forming of M. aeruginosa in natural conditions.

  10. High-Throughput Quantification of Bacterial-Cell Interactions Using Virtual Colony Counts

    Directory of Open Access Journals (Sweden)

    Stefanie Hoffmann

    2018-02-01

    Full Text Available The quantification of bacteria in cell culture infection models is of paramount importance for the characterization of host-pathogen interactions and pathogenicity factors involved. The standard to enumerate bacteria in these assays is plating of a dilution series on solid agar and counting of the resulting colony forming units (CFU. In contrast, the virtual colony count (VCC method is a high-throughput compatible alternative with minimized manual input. Based on the recording of quantitative growth kinetics, VCC relates the time to reach a given absorbance threshold to the initial cell count using a series of calibration curves. Here, we adapted the VCC method using the model organism Salmonella enterica sv. Typhimurium (S. Typhimurium in combination with established cell culture-based infection models. For HeLa infections, a direct side-by-side comparison showed a good correlation of VCC with CFU counting after plating. For MDCK cells and RAW macrophages we found that VCC reproduced the expected phenotypes of different S. Typhimurium mutants. Furthermore, we demonstrated the use of VCC to test the inhibition of Salmonella invasion by the probiotic E. coli strain Nissle 1917. Taken together, VCC provides a flexible, label-free, automation-compatible methodology to quantify bacteria in in vitro infection assays.

  11. Manufacture of endothelial colony-forming progenitor cells from steady-state peripheral blood leukapheresis using pooled human platelet lysate.

    Science.gov (United States)

    Siegel, Georg; Fleck, Erika; Elser, Stefanie; Hermanutz-Klein, Ursula; Waidmann, Marc; Northoff, Hinnak; Seifried, Erhard; Schäfer, Richard

    2018-05-01

    Endothelial colony-forming progenitor cells (ECFCs) are promising candidates for cell therapies. However, ECFC translation to the clinic requires optimized isolation and manufacture technologies according to good manufacturing practice (GMP). ECFCs were manufactured from steady-state peripheral blood (PB) leukapheresis (11 donors), using GMP-compliant technologies including pooled human platelet (PLT) lysate, and compared to human umbilical cord endothelial cells, human aortic endothelial cells, and human cerebral microvascular endothelial cells. Specific variables assessed were growth kinetics, phenotype, trophic factors production, stimulation of tube formation, and Dil-AcLDL uptake. ECFCs could be isolated from PB leukapheresis units with mean processed volume of 5411 mL and mean white blood cell (WBC) concentration factor of 8.74. The mean frequency was 1.44 × 10 -8 ECFCs per WBC, corresponding to a mean of 177.8 ECFCs per apheresis unit. Expandable for up to 12 cumulative population doublings, calculated projection showed that approximately 730 × 10 3 ECFCs could be manufactured from 1 apheresis unit. ECFCs produced epidermal growth factor, hepatocyte growth factor, vascular endothelial growth factor (VEGF)-A, PLT-derived growth factor-B, interleukin-8, and monocyte chemoattractant protein-1, featured high potential for capillary-like tubes formation, and showed no telomerase activity. They were characterized by CD29, CD31, CD44, CD105, CD117, CD133, CD144, CD146, and VEGF-R2 expression, with the most common subpopulation CD34+CD117-CD133-. Compared to controls, ECFCs featured greater Dil-AcLDL uptake and higher expression of CD29, CD31, CD34, CD44, CD144, and VEGF-R2. Here we show that isolation of ECFCs with proangiogenic profile from steady-state PB leukapheresis is feasible, marking a first step toward ECFC product manufacture according to GMP. © 2018 AABB.

  12. Determination of the stem cell number by the amount of nondifferentiated cell colonies in the bone marrow of irradiated animals

    International Nuclear Information System (INIS)

    Shcherbova, E.N.; Gruzdev, G.P.

    1982-01-01

    A method is proposed for determination of the amout of haemopoietic stem cells in different mammalian species according to the number of nondifferentiated cell colonies (NCC) formed in the bone marrow on days 3 or 4 after irradiation. A quantitative similarity of NCC and haemopoietic stem cells, and also sameness of their reaction to irradiation were demonstated by determining the NCC number in histological preparations of the bone marrow and by the use of the Till and McCulloch method. A method is proposed for the deter-- mination and calculation of the number of NCC in the bone marrow

  13. Determination of the stem cell number by the amount of nondifferentiated cell colonies in the bone marrow of irradiated animals

    Energy Technology Data Exchange (ETDEWEB)

    Shcherbova, E.N.; Gruzdev, G.P.

    A method is proposed for determination of the amout of haemopoietic stem cells in different mammalian species according to the number of nondifferentiated cell colonies (NCC) formed in the bone marrow on days 3 or 4 after irradiation. A quantitative similarity of NCC and haemopoietic stem cells, and also sameness of their reaction to irradiation were demonstated by determining the NCC number in histological preparations of the bone marrow and by the use of the Till and McCulloch method. A method is proposed for the determination and calculation of the number of NCC in the bone marrow.

  14. Acute leukemia after radiotherapy in a patient with Turcot's syndrome. Impaired colony formation in skin fibroblast cultures after irradiation

    International Nuclear Information System (INIS)

    Li, F.P.; Little, J.B.; Bech-Hansen, N.T.; Paterson, M.C.; Arlett, C.; Garnick, M.B.; Mayer, R.J.

    1983-01-01

    Colonic polyposis and carcinoma developed in a woman with Turcot's syndrome at the age of 31 years; astrocytoma developed when she was 37. Her brother and sister had died of astrocytoma at the ages of 18 and 33 years, respectively. Progressive neutropenia developed in the patient three months after radiotherapy for her brain tumor and acute myelomonocytic leukemia 19 months after treatment. Three laboratories independently evaluated cultures of her skin fibroblasts for in vitro sensitivity to cell killing (loss of colony-forming ability) by x-rays. Survival assays consistently revealed slight but significant radiosensitivity in an early-passage (six to 10 doublings) fibroblast subculture. A later subculture (21 to 29 doublings) showed no abnormality, a possible effect of selective in vitro loss of radiosensitive cells

  15. Local behavioral rules sustain the cell allocation pattern in the combs of honey bee colonies (Apis mellifera).

    Science.gov (United States)

    Montovan, Kathryn J; Karst, Nathaniel; Jones, Laura E; Seeley, Thomas D

    2013-11-07

    In the beeswax combs of honey bees, the cells of brood, pollen, and honey have a consistent spatial pattern that is sustained throughout the life of a colony. This spatial pattern is believed to emerge from simple behavioral rules that specify how the queen moves, where foragers deposit honey/pollen and how honey/pollen is consumed from cells. Prior work has shown that a set of such rules can explain the formation of the allocation pattern starting from an empty comb. We show that these rules cannot maintain the pattern once the brood start to vacate their cells, and we propose new, biologically realistic rules that better sustain the observed allocation pattern. We analyze the three resulting models by performing hundreds of simulation runs over many gestational periods and a wide range of parameter values. We develop new metrics for pattern assessment and employ them in analyzing pattern retention over each simulation run. Applied to our simulation results, these metrics show alteration of an accepted model for honey/pollen consumption based on local information can stabilize the cell allocation pattern over time. We also show that adding global information, by biasing the queen's movements towards the center of the comb, expands the parameter regime over which pattern retention occurs. © 2013 Published by Elsevier Ltd. All rights reserved.

  16. Human papillomavirus 16 E5 induces bi-nucleated cell formation by cell-cell fusion

    International Nuclear Information System (INIS)

    Hu Lulin; Plafker, Kendra; Vorozhko, Valeriya; Zuna, Rosemary E.; Hanigan, Marie H.; Gorbsky, Gary J.; Plafker, Scott M.; Angeletti, Peter C.; Ceresa, Brian P.

    2009-01-01

    Human papillomaviruses (HPV) 16 is a DNA virus encoding three oncogenes - E5, E6, and E7. The E6 and E7 proteins have well-established roles as inhibitors of tumor suppression, but the contribution of E5 to malignant transformation is controversial. Using spontaneously immortalized human keratinocytes (HaCaT cells), we demonstrate that expression of HPV16 E5 is necessary and sufficient for the formation of bi-nucleated cells, a common characteristic of precancerous cervical lesions. Expression of E5 from non-carcinogenic HPV6b does not produce bi-nucleate cells. Video microscopy and biochemical analyses reveal that bi-nucleates arise through cell-cell fusion. Although most E5-induced bi-nucleates fail to propagate, co-expression of HPV16 E6/E7 enhances the proliferation of these cells. Expression of HPV16 E6/E7 also increases bi-nucleated cell colony formation. These findings identify a new role for HPV16 E5 and support a model in which complementary roles of the HPV16 oncogenes lead to the induction of carcinogenesis

  17. Live-cell imaging of conidial anastomosis tube fusion during colony initiation in Fusarium oxysporum.

    Directory of Open Access Journals (Sweden)

    Smija M Kurian

    Full Text Available Fusarium oxysporum exhibits conidial anastomosis tube (CAT fusion during colony initiation to form networks of conidial germlings. Here we determined the optimal culture conditions for this fungus to undergo CAT fusion between microconidia in liquid medium. Extensive high resolution, confocal live-cell imaging was performed to characterise the different stages of CAT fusion, using genetically encoded fluorescent labelling and vital fluorescent organelle stains. CAT homing and fusion were found to be dependent on adhesion to the surface, in contrast to germ tube development which occurs in the absence of adhesion. Staining with fluorescently labelled concanavalin A indicated that the cell wall composition of CATs differs from that of microconidia and germ tubes. The movement of nuclei, mitochondria, vacuoles and lipid droplets through fused germlings was observed by live-cell imaging.

  18. Effects of protozoan grazing on colony formation in Phaeocystis globosa (Prymnesiophyceae) and the potential costs and benefits

    DEFF Research Database (Denmark)

    Jakobsen, Hans Henrik; Tang, K.W.

    2002-01-01

    . scintillans increased the mean colony size by up to 50 % relative to the controls, whereas grazing by G. dominans enhanced the mean colony size by up to 3-fold. Microscopic observations confirmed that N. scintillans was also able to ingest small colonies. In contrast, G. dominans apparently did not ingest...

  19. Implementation of the Bee Colony Optimization method for the design of fuel cells; Implementacion del metodo Bee Colony Optimization para el diseno de celdas de combustible

    Energy Technology Data Exchange (ETDEWEB)

    Esquivel E, J.; Ortiz S, J. J., E-mail: jaime.esquivel@fi.uaemex.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2011-11-15

    The present work shows the results obtained after applying the Bee Colony Optimization algorithm in the design of fuel cells for a BWR. The algorithm that is implemented, works following the behavior that have the bees when pollinating a flowers field. The bees carry out an exhaustive analysis in the cell, so they leave generating diverse configurations where different fuel bars are placed with different uranium enrichments to reach a value mean, with a specific number of gadolinium bars. The behavior of the generated cell is evaluated by means of the use of the commercial code CASMO-4, which shows the variables that allow fixing if the cell fulfills the requirements. Such variables are the local potential peak factor and the neutrons multiplication factor in an infinite medium. (Author)

  20. Granulocyte colony-stimulating factor mobilizes functional endothelial progenitor cells in patients with coronary artery disease.

    Science.gov (United States)

    Powell, Tiffany M; Paul, Jonathan D; Hill, Jonathan M; Thompson, Michael; Benjamin, Moshe; Rodrigo, Maria; McCoy, J Philip; Read, Elizabeth J; Khuu, Hanh M; Leitman, Susan F; Finkel, Toren; Cannon, Richard O

    2005-02-01

    Endothelial progenitor cells (EPCs) that may repair vascular injury are reduced in patients with coronary artery disease (CAD). We reasoned that EPC number and function may be increased by granulocyte colony-stimulating factor (G-CSF) used to mobilize hematopoietic progenitor cells in healthy donors. Sixteen CAD patients had reduced CD34(+)/CD133(+) (0.0224+/-0.0063% versus 0.121+/-0.038% mononuclear cells [MNCs], P<0.01) and CD133(+)/VEGFR-2(+) cells, consistent with EPC phenotype (0.00033+/-0.00015% versus 0.0017+/-0.0006% MNCs, P<0.01), compared with 7 healthy controls. Patients also had fewer clusters of cells in culture, with out-growth consistent with mature endothelial phenotype (2+/-1/well) compared with 16 healthy subjects at high risk (13+/-4/well, P<0.05) or 14 at low risk (22+/-3/well, P<0.001) for CAD. G-CSF 10 microg/kg per day for 5 days increased CD34(+)/CD133(+) cells from 0.5+/-0.2/microL to 59.5+/-10.6/microL and CD133(+)/ VEGFR-2(+) cells from 0.007+/-0.004/microL to 1.9+/-0.6/microL (both P<0.001). Also increased were CD133(+) cells that coexpressed the homing receptor CXCR4 (30.4+/-8.3/microL, P<0.05). Endothelial cell-forming clusters in 10 patients increased to 27+/-9/well after treatment (P<0.05), with a decline to 9+/-4/well at 2 weeks (P=0.06). Despite reduced EPCs compared with healthy controls, patients with CAD respond to G-CSF with increases in EPC number and homing receptor expression in the circulation and endothelial out-growth in culture. Endothelial progenitor cells (EPCs) are reduced in coronary artery disease. Granulocyte colony-stimulating factor (CSF) administered to patients increased: (1) CD133+/VEGFR-2+ cells consistent with EPC phenotype; (2) CD133+ cells coexpressing the chemokine receptor CXCR4, important for homing of EPCs to ischemic tissue; and (3) endothelial cell-forming clusters in culture. Whether EPCs mobilized into the circulation will be useful for the purpose of initiating vascular growth and myocyte repair

  1. [Macrophage colony stimulating factor enhances non-small cell lung cancer invasion and metastasis by promoting macrophage M2 polarization].

    Science.gov (United States)

    Li, Y J; Yang, L; Wang, L P; Zhang, Y

    2017-06-23

    Objective: To investigate the key cytokine which polarizes M2 macrophages and promotes invasion and metastasis in non-small cell lung cancer (NSCLC). Methods: After co-culture with A549 cells in vitro, the proportion of CD14(+) CD163(+) M2 macrophages in monocytes and macrophage colony stimulating factor (M-CSF) levels in culture supernatant were detected by flow cytometry, ELISA assay and real-time qPCR, respectively. The effects of CD14(+) CD163(+) M2 macrophages on invasion of A549 cells and angiogenesis of HUVEC cells were measured by transwell assay and tubule formation assay, respectively. The clinical and prognostic significance of M-CSF expression in NSCLC was further analyzed. Results: The percentage of CD14(+) CD163(+) M2 macrophages in monocytes and the concentration of M-CSF in the supernatant followed by co-culture was (12.03±0.46)% and (299.80±73.76)pg/ml, respectively, which were significantly higher than those in control group [(2.80±1.04)% and (43.07±11.22)pg/ml, respectively, P macrophages in vitro . M2 macrophages enhanced the invasion of A549 cells (66 cells/field vs. 26 cells/field) and the angiogenesis of HUVEC cells (22 tubes/field vs. 8 tubes/field). The mRNA expression of M-CSF in stage Ⅰ-Ⅱ patients (16.23±4.83) was significantly lower than that in stage Ⅲ-Ⅳ (53.84±16.08; P macrophages, which can further promote the metastasis and angiogenesis of NSCLC. M-CSF could be used as a potential therapeutic target of NSCLC.

  2. Area-based cell colony surviving fraction evaluation: A novel fully automatic approach using general-purpose acquisition hardware.

    Science.gov (United States)

    Militello, Carmelo; Rundo, Leonardo; Conti, Vincenzo; Minafra, Luigi; Cammarata, Francesco Paolo; Mauri, Giancarlo; Gilardi, Maria Carla; Porcino, Nunziatina

    2017-10-01

    The current methodology for the Surviving Fraction (SF) measurement in clonogenic assay, which is a technique to study the anti-proliferative effect of treatments on cell cultures, involves manual counting of cell colony forming units. This procedure is operator-dependent and error-prone. Moreover, the identification of the exact colony number is often not feasible due to the high growth rate leading to the adjacent colony merging. As a matter of fact, conventional assessment does not deal with the colony size, which is generally correlated with the delivered radiation dose or the administered cytotoxic agent. Considering that the Area Covered by Colony (ACC) is proportional to the colony number and size as well as to the growth rate, we propose a novel fully automatic approach exploiting Circle Hough Transform, to automatically detect the wells in the plate, and local adaptive thresholding, which calculates the percentage of ACC for the SF quantification. This measurement relies just on this covering percentage and does not consider the colony number, preventing inconsistencies due to intra- and inter-operator variability. To evaluate the accuracy of the proposed approach, we compared the SFs obtained by our automatic ACC-based method against the conventional counting procedure. The achieved results (r = 0.9791 and r = 0.9682 on MCF7 and MCF10A cells, respectively) showed values highly correlated with the measurements using the traditional approach based on colony number alone. The proposed computer-assisted methodology could be integrated in laboratory practice as an expert system for the SF evaluation in clonogenic assays. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Agar Technique for the Cultivation In Vitro of Bone-Marrow Colonies

    Energy Technology Data Exchange (ETDEWEB)

    Metcalf, D. [Walter and Eliza Hall Institute, Royal Melbourne Hospital, Melbourne, VIC (Australia)

    1969-07-15

    In solid-state agar cultures certain haemopoietic cells proliferate and form discrete colonies of 200 - 4000 cells. Colony formation is dependent on stimulation by the colony-stimulating factor, and this is achieved by (1) the use of a cell feeder layer, (2) the addition of conditioned medium, or (3) the addition of human or mouse serum or urine containing the factor. All colonies initially contain granulocytic cells which differentiate from myeloblasts to polymorphs as colony growth proceeds. Later colonies develop a second population of phagocytic mononuclear cells (macrophages). The colony-forming-system is simple, readily quantitated and highly reproducible. Linear dose responses occur between the dose of colony-stimulating factor and the number and size of colonies developing from a standard number of bone-marrow cells. In-vitro colony formation has been achieved with haemopoietic cells of the following species: mouse, rat, hamster, guinea pig, rabbit and human. In the adult mouse, colony-forming cells are located in the bone marrow, spleen and blood and in the embryo, in the yolk sac, liver and spleen. The colony-forming cell appears to be an early member of the granulocytic series. The colony-forming system has been used as a quantitative assay system: (1) to assay levels of colony-stimulating factor in serum and urine and in the chemical- characterization and purification of the factor; and (2) to enumerate the number of colony-forming cells in haemopoietic tissues in response to a variety of experimental procedures and disease states. Since the system is applicable to human bone-marrow cells, it should prove of value in the quantitative assay of (1) survival of human bone marrow on storage, and (2) bone-marrow content of granulocytic precursor cells in various disease states and following various types of therapy. The system is not suitable for the mass production in vitro of haemopoietic cells for therapeutic use. (author)

  4. The influence of tethered epidermal growth factor on connective tissue progenitor colony formation

    OpenAIRE

    Marcantonio, Nicholas A.; Boehm, Cynthia A.; Rozic, Richard J.; Au, Ada; Wells, Alan; Muschler, George F.; Griffith, Linda G.

    2009-01-01

    Strategies to combine aspirated marrow cells with scaffolds to treat connective tissue defects are gaining increasing clinical attention and use. In situations such as large defects where initial survival and proliferation of transplanted connective tissue progenitors (CTPs) are limiting, therapeutic outcomes might be improved by using the scaffold to deliver growth factors that promote the early stages of cell function in the graft. Signaling by the epidermal growth factor receptor (EGFR) pl...

  5. Increase in Bacterial Colony Formation from a Permafrost Ice Wedge Dosed with a Tomitella biformata Recombinant Resuscitation-Promoting Factor Protein.

    Science.gov (United States)

    Puspita, Indun Dewi; Kitagawa, Wataru; Kamagata, Yoichi; Tanaka, Michiko; Nakatsu, Cindy H

    2015-01-01

    Resuscitation-promoting factor (Rpf) is a protein that has been found in a number of different Actinobacteria species and has been shown to promote the growth of active cells and resuscitate dormant (non-dividing) cells. We previously reported the biological activity of an Rpf protein in Tomitella biformata AHU 1821(T), an Actinobacteria isolated from a permafrost ice wedge. This protein is excreted outside the cell; however, few studies have investigated its contribution in environmental samples to the growth or resuscitation of bacteria other than the original host. Therefore, the aim of the present study was to determine whether Rpf from T. biformata impacted the cultivation of other bacteria from the permafrost ice wedge from which it was originally isolated. All experiments used recombinant Rpf proteins produced using a Rhodococcus erythropolis expression system. Dilutions of melted surface sterilized ice wedge samples mixed with different doses of the purified recombinant Rpf (rRpf) protein indicated that the highest concentration tested, 1250 pM, had a significantly (p permafrost sediments. The results of the present study demonstrated that rRpf not only promoted the growth of T. biformata from which it was isolated, but also enhanced colony formation by another Actinobacteria in an environmental sample.

  6. Ant Colony Optimization Algorithm for Centralized Dynamic Channel Allocation in Multi-Cell OFDMA Systems

    Science.gov (United States)

    Kim, Hyo-Su; Kim, Dong-Hoi

    The dynamic channel allocation (DCA) scheme in multi-cell systems causes serious inter-cell interference (ICI) problem to some existing calls when channels for new calls are allocated. Such a problem can be addressed by advanced centralized DCA design that is able to minimize ICI. Thus, in this paper, a centralized DCA is developed for the downlink of multi-cell orthogonal frequency division multiple access (OFDMA) systems with full spectral reuse. However, in practice, as the search space of channel assignment for centralized DCA scheme in multi-cell systems grows exponentially with the increase of the number of required calls, channels, and cells, it becomes an NP-hard problem and is currently too complicated to find an optimum channel allocation. In this paper, we propose an ant colony optimization (ACO) based DCA scheme using a low-complexity ACO algorithm which is a kind of heuristic algorithm in order to solve the aforementioned problem. Simulation results demonstrate significant performance improvements compared to the existing schemes in terms of the grade of service (GoS) performance and the forced termination probability of existing calls without degrading the system performance of the average throughput.

  7. Inductive potential of recombinant human granulocyte colony-stimulating factor to mature neutrophils from X-irradiated human peripheral blood hematopoietic progenitor cells

    International Nuclear Information System (INIS)

    Katsumori, Takeo; Yoshino, Hironori; Hayashi, Masako; Takahashi, Kenji; Kashiwakura, Ikuo

    2009-01-01

    Recombinant human granulocyte colony-stimulating factor (rhG-CSF) has been used for treatment of neutropenia. Filgrastim, Nartograstim, and Lenograstim are clinically available in Japan. However, the differences in potential benefit for radiation-induced disorder between these types of rhG-CSFs remain unknown. Therefore, the effects of three different types of rhG-CSFs on granulocyte progenitor cells and expansion of neutrophils from nonirradiated or 2 Gy X-irradiated human CD34 + hematopoietic progenitor cells were examined. For analysis of granulocyte colony-forming units (CFU-G) and a surviving fraction of CFU-G, nonirradiated or X-irradiated CD34 + cells were cultured in methylcellulose containing rhG-CSF. These cells were cultured in serum-free medium supplemented with rhG-CSF, and the expansion and characteristics of neutrophils were analyzed. All three types of rhG-CSFs increased the number of CFU-G in a dose-dependent manner; however, Lenograstim is superior to others because of CFU-G-derived colony formation at relatively low doses. The surviving fraction of CFU-G was independent of the types of rhG-CSFs. Expansion of neutrophils by rhG-CSF was largely attenuated by X-irradiation, though no significant difference in neutrophil number was observed between the three types of rhG-CSFs under both nonirradiation and X-irradiation conditions. In terms of functional characteristics of neutrophils, Lenograstim-induced neutrophils produced high levels of reactive oxygen species compared to Filgrastim, when rhG-CSF was applied to nonirradiated CD34 + cells. In conclusion, different types of rhG-CSFs lead to different effects when rhG-CSF is applied to nonirradiated CD34 + cells, though Filgrastim, Nartograstim, and Lenograstim show equal effects on X-irradiated CD34 + cells. (author)

  8. The Self-Identity Protein IdsD Is Communicated between Cells in Swarming Proteus mirabilis Colonies.

    Science.gov (United States)

    Saak, Christina C; Gibbs, Karine A

    2016-12-15

    Proteus mirabilis is a social bacterium that is capable of self (kin) versus nonself recognition. Swarming colonies of this bacterium expand outward on surfaces to centimeter-scale distances due to the collective motility of individual cells. Colonies of genetically distinct populations remain separate, while those of identical populations merge. Ids proteins are essential for this recognition behavior. Two of these proteins, IdsD and IdsE, encode identity information for each strain. These two proteins bind in vitro in an allele-restrictive manner. IdsD-IdsE binding is correlated with the merging of populations, whereas a lack of binding is correlated with the separation of populations. Key questions remained about the in vivo interactions of IdsD and IdsE, specifically, whether IdsD and IdsE bind within single cells or whether IdsD-IdsE interactions occur across neighboring cells and, if so, which of the two proteins is exchanged. Here we demonstrate that IdsD must originate from another cell to communicate identity and that this nonresident IdsD interacts with IdsE resident in the recipient cell. Furthermore, we show that unbound IdsD in recipient cells does not cause cell death and instead appears to contribute to a restriction in the expansion radius of the swarming colony. We conclude that P. mirabilis communicates IdsD between neighboring cells for nonlethal kin recognition, which suggests that the Ids proteins constitute a type of cell-cell communication. We demonstrate that self (kin) versus nonself recognition in P. mirabilis entails the cell-cell communication of an identity-encoding protein that is exported from one cell and received by another. We further show that this intercellular exchange affects swarm colony expansion in a nonlethal manner, which adds social communication to the list of potential swarm-related regulatory factors. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  9. Branch to colony trajectory in a modular organism: pattern formation in the Indo-Pacific coral Stylophora pistillata.

    Science.gov (United States)

    Shaish, Lee; Abelson, Avigdor; Rinkevich, Baruch

    2006-08-01

    The architecture of the colony in a branching coral is an iterative process in which new layers of calcium carbonate compile atop existing structures that remain unchanged. Colony growth and development, known as astogeny, is believed to be a continuous process, characterized by replication of lower rank unites, polyps, and branches. This study seeks to explore the genetic blueprint of branch-to-colony developmental trajectory in the branching coral Stylophora pistillata, within an astogeny period of 1 year. One hundred small branches (initially 2-4 cm long) were sampled from 10 colonies. A year later, 63 remaining colonies were analyzed for their architectural rules by using 15 morphometric parameters. Multivariate statistical tests were preformed. Cluster and two-dimensional nonmetric Multi-Dimensional Scaling analyses revealed that the 10 genotypes could be divided into two major morphometric groups and two intermediate groups, whereas SIMPER analyses (a similarity percentage test) on within-genet similarities showed high similarity between the ramets developed from each of the 10 genotypes. Although, at first, it seemed that different colonies exhibited variable and different architectural designs (each characterized by specific morphometric parameters), a comprehensive analysis revealed that all 10 coral genotypes exhibited a single common developmental plan that was characterized by a continuum of architectural design with several distinct stages. Each stage is marked by its own characteristic morphometric parameters. Changing of developmental rules during the trajectory from branch to coral colony may help the colony to cope better with environmental constraints.

  10. Exercise increases the frequency of circulating hematopoietic progenitor cells, but reduces hematopoietic colony-forming capacity.

    Science.gov (United States)

    Kroepfl, Julia Maria; Pekovits, Karin; Stelzer, Ingeborg; Fuchs, Robert; Zelzer, Sieglinde; Hofmann, Peter; Sedlmayr, Peter; Dohr, Gottfried; Wallner-Liebmann, Sandra; Domej, Wolfgang; Mueller, Wolfram

    2012-11-01

    Circulating hematopoietic progenitor cells (CPCs) may be triggered by physical exercise and/or normobaric hypoxia from the bone marrow. The aim of the study was to investigate the influence of physical exercise and normobaric hypoxia on CPC number and functionality in the peripheral blood as well as the involvement of oxidative stress parameters as possibly active agents. Ten healthy male subjects (25.3±4.4 years) underwent a standardized cycle incremental exercise test protocol (40 W+20 W/min) under either normoxic (FiO2 ∼0.21) or hypoxic conditions (FiO2exercise. The number of CPCs in the peripheral blood was analyzed by flow cytometry (CD34/CD45-positive cells). The functionality of cells present was addressed by secondary colony-forming unit-granulocyte macrophage (CFU-GM) assays. To determine a possible correlation between the mobilization of CPCs and reactive oxygen species, parameters for oxidative stress such as malondialdehyde (MDA) and myeloperoxidase (MPO) were obtained. Data showed a significant increase of CPC release under normoxic as well as hypoxic conditions after 10 min of recovery (Pexercise (Pexercise, possibly due to the influence of increased oxidative stress levels.

  11. Stem cell mobilization by granulocyte colony-stimulating factor for myocardial recovery after acute myocardial infarction: a meta-analysis

    DEFF Research Database (Denmark)

    Zohlnhofer, D.; Dibra, A.; Koppara, T.

    2008-01-01

    OBJECTIVES: The objective of this meta-analysis was to evaluate the effect of stem cell mobilization by granulocyte colony-stimulating factor (G-CSF) on myocardial regeneration on the basis of a synthesis of the data generated by randomized, controlled clinical trials of G-CSF after acute...

  12. [Endogenous pyrogen formation by bone marrow cells].

    Science.gov (United States)

    Efremov, O M; Sorokin, A V; El'kina, O A

    1978-01-01

    The cells of the rabbit bone marrow produced endogenous pyrogen in response to stimulation with bacterial lipopolysaccharide. Incubation of the cells in medium No 199 containing a 15% homologous serum is optimal for the release of pyrogen. It is supposed that the cells of the bone marrow take part in the formation of endgenous pyrogen and in the mechanism of pyrexia in the organism.

  13. Fusomorphogenesis: cell fusion in organ formation.

    Science.gov (United States)

    Shemer, G; Podbilewicz, B

    2000-05-01

    Cell fusion is a universal process that occurs during fertilization and in the formation of organs such as muscles, placenta, and bones. Very little is known about the molecular and cellular mechanisms of cell fusion during pattern formation. Here we review the dynamic anatomy of all cell fusions during embryonic and postembryonic development in an organism. Nearly all the cell fates and cell lineages are invariant in the nematode C. elegans and one third of the cells that are born fuse to form 44 syncytia in a reproducible and stereotyped way. To explain the function of cell fusion in organ formation we propose the fusomorphogenetic model as a simple cellular mechanism to efficiently redistribute membranes using a combination of cell fusion and polarized membrane recycling during morphogenesis. Thus, regulated intercellular and intracellular membrane fusion processes may drive elongation of the embryo as well as postembryonic organ formation in C. elegans. Finally, we use the fusomorphogenetic hypothesis to explain the role of cell fusion in the formation of organs like muscles, bones, and placenta in mammals and other species and to speculate on how the intracellular machinery that drive fusomorphogenesis may have evolved.

  14. YfiBNR mediates cyclic di-GMP dependent small colony variant formation and persistence in Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Jacob G Malone

    2010-03-01

    Full Text Available During long-term cystic fibrosis lung infections, Pseudomonas aeruginosa undergoes genetic adaptation resulting in progressively increased persistence and the generation of adaptive colony morphotypes. This includes small colony variants (SCVs, auto-aggregative, hyper-adherent cells whose appearance correlates with poor lung function and persistence of infection. The SCV morphotype is strongly linked to elevated levels of cyclic-di-GMP, a ubiquitous bacterial second messenger that regulates the transition between motile and sessile, cooperative lifestyles. A genetic screen in PA01 for SCV-related loci identified the yfiBNR operon, encoding a tripartite signaling module that regulates c-di-GMP levels in P. aeruginosa. Subsequent analysis determined that YfiN is a membrane-integral diguanylate cyclase whose activity is tightly controlled by YfiR, a small periplasmic protein, and the OmpA/Pal-like outer-membrane lipoprotein YfiB. Exopolysaccharide synthesis was identified as the principal downstream target for YfiBNR, with increased production of Pel and Psl exopolysaccharides responsible for many characteristic SCV behaviors. An yfi-dependent SCV was isolated from the sputum of a CF patient. Consequently, the effect of the SCV morphology on persistence of infection was analyzed in vitro and in vivo using the YfiN-mediated SCV as a representative strain. The SCV strain exhibited strong, exopolysaccharide-dependent resistance to nematode scavenging and macrophage phagocytosis. Furthermore, the SCV strain effectively persisted over many weeks in mouse infection models, despite exhibiting a marked fitness disadvantage in vitro. Exposure to sub-inhibitory concentrations of antibiotics significantly decreased both the number of suppressors arising, and the relative fitness disadvantage of the SCV mutant in vitro, suggesting that the SCV persistence phenotype may play a more important role during antimicrobial chemotherapy. This study establishes Yfi

  15. The Effects of Sertoli Cells Condition Medium and Retinoic Acid on the Number of Colonies of Bone Marrow Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    Maryam Salem

    2017-04-01

    Full Text Available Background & objectives: According to importance of bone marrow mesenchymal stem cells in production of different cell lines, transplantation of these cells are used for treatment of many different diseases during cell therapy. Viability and proliferation of these cells after transplantation are very important. Since infertility is as public health problem in men and women, the scientists attempt to produce germ cells from differentiation of stem cells. It is supposed to use these cells for treatment of different illnesses especially for men with lack of germ cells in testes in future. However, in using stem cells for cell therapy the culture medium should be designed to increase the number of cells and efficiency of transplantation and to guarantee the health of the cells in terms of DNA damage. This study designed a suitable culture medium in order to increase the number of colonies and decrease the cell injuries. Methods: In this study mesenchymal stem cells isolated from bone marrow of mice and exposed to retinoic acid (RA with concentration of 10-6 M and Sertoli cells condition medium. Since mesenchymal stem cells (MSCs produce fibroblastic colonies so the number of colonies was counted every 3 days after culture (days of 2, 5, 8, 11, and 15 under inverted microscope. The staining of ethidium bromide-acridine orange was also done for determination of apoptotic nucleus in days of 10 and 15 after culture. Results: The results showed that the effects of retinoic acid on grow and viability of MSCs is related to the time. It seems that RA increased the proliferation of the cells and the number of colonies increased in low time but the apoptotic cells elevated with increasing the time of culture. Condition medium of Sertoli cells also increased the proliferation of bone marrow stem cells. Conclusion: According to proliferative properties of condition medium, it seems that using condition medium together with RA is better than RA alone for

  16. Long-active granulocyte colony-stimulating factor for peripheral blood hematopoietic progenitor cell mobilization.

    Science.gov (United States)

    Martino, Massimo; Laszlo, Daniele; Lanza, Francesco

    2014-06-01

    Peg-filgrastim (PEG-FIL), a polyethylene glycol-conjugated form of granulocyte colony-stimulating factor (G-CSF), has been introduced in clinical practice and is effective in shortening the time of neutropenia after cytotoxic chemotherapy. G-CSF has emerged as the preferred cytokine for hematopoietic progenitor cells' (HPC) mobilization. Nevertheless, data on the ability of PEG-FIL in this field have been published. We review publications in the field with the goal of providing an overview of this approach. PEG-FIL may be able to mobilize CD34(+) cells in a more timely fashion than G-CSF, with the advantages of only a single-dose administration, an earlier start and a reduction in the number of apheresis procedures. The main controversies concern the dosage of the drug and the optimal dose. In the context of chemo-mobilization, a single dose of 6 mg PEG-FIL seems effective in terms of HPC's mobilization and there is no increase in this effect if the dose is doubled to 12 mg. Steady-state mobilization requires higher doses of PEG-FIL and this approach is not cost-effective when compared with G-CSF. The experiences with PEG-FIL in the healthy donor setting are very limited.

  17. Effect of adrenalectomy on recipients of allogeneic lymphocytes on inactivation of endogenous colony-forming cells in mice

    International Nuclear Information System (INIS)

    Semenkov, V.F.

    1985-01-01

    This paper presents a study of the killer functions of lymph node cells directed against endogenous colony-forming cells in adrenalectomized recipients in a genetic system with one-way incompatibility: parental line - F 1 hybrid. Mice were irradiated with Co 60 gamma rays on the EGO-2 apparatus with dose rate from 200 to 250 R/min. The results were subjected to statistical analysis by Student's test. It can be tentatively suggested that the killer action of T lymphocytes on endogenous colonies was intensified in adrenal-ectomized recipients with endogenous hypocorticism, as a result of cooperation with the cortisol-sensitive subpopulation of T helper cells, of a change in the properties of the antigen-recognizing receptors, or an increase in the sensitivity of target cells to the killer action of T lymphocytes

  18. Human endothelial colony-forming cells expanded with an improved protocol are a useful endothelial cell source for scaffold-based tissue engineering.

    Science.gov (United States)

    Denecke, Bernd; Horsch, Liska D; Radtke, Stefan; Fischer, Johannes C; Horn, Peter A; Giebel, Bernd

    2015-11-01

    One of the major challenges in tissue engineering is to supply larger three-dimensional (3D) bioengineered tissue transplants with sufficient amounts of nutrients and oxygen and to allow metabolite removal. Consequently, artificial vascularization strategies of such transplants are desired. One strategy focuses on endothelial cells capable of initiating new vessel formation, which are settled on scaffolds commonly used in tissue engineering. A bottleneck in this strategy is to obtain sufficient amounts of endothelial cells, as they can be harvested only in small quantities directly from human tissues. Thus, protocols are required to expand appropriate cells in sufficient amounts without interfering with their capability to settle on scaffold materials and to initiate vessel formation. Here, we analysed whether umbilical cord blood (CB)-derived endothelial colony-forming cells (ECFCs) fulfil these requirements. In a first set of experiments, we showed that marginally expanded ECFCs settle and survive on different scaffold biomaterials. Next, we improved ECFC culture conditions and developed a protocol for ECFC expansion compatible with 'Good Manufacturing Practice' (GMP) standards. We replaced animal sera with human platelet lysates and used a novel type of tissue-culture ware. ECFCs cultured under the new conditions revealed significantly lower apoptosis and increased proliferation rates. Simultaneously, their viability was increased. Since extensively expanded ECFCs could still settle on scaffold biomaterials and were able to form tubular structures in Matrigel assays, we conclude that these ex vivo-expanded ECFCs are a novel, very potent cell source for scaffold-based tissue engineering. Copyright © 2013 John Wiley & Sons, Ltd.

  19. High level of expression of recombinant human granulocyte-macrophage colony stimulating factor in transgenic rice cell suspension culture

    DEFF Research Database (Denmark)

    Shin, Yun-Ji; Hong, Shin-Young; Kwon, Tae-Ho

    2003-01-01

    Recombinant human granulocyte-macrophage colony stimulating factor (hGM-CSF) has been previously produced in tobacco cell suspension cultures. However, the amount of hGM-CSF accumulated in the culture medium dropped quickly from its maximum of 150 microg/L at 5 d after incubation. To overcome...... of recombinant hGM-CSF in transgenic rice cell suspension culture and protease activity of this culture medium was low compared to that of tobacco culture system....

  20. Deep vector-based convolutional neural network approach for automatic recognition of colonies of induced pluripotent stem cells.

    Directory of Open Access Journals (Sweden)

    Muthu Subash Kavitha

    Full Text Available Pluripotent stem cells can potentially be used in clinical applications as a model for studying disease progress. This tracking of disease-causing events in cells requires constant assessment of the quality of stem cells. Existing approaches are inadequate for robust and automated differentiation of stem cell colonies. In this study, we developed a new model of vector-based convolutional neural network (V-CNN with respect to extracted features of the induced pluripotent stem cell (iPSC colony for distinguishing colony characteristics. A transfer function from the feature vectors to the virtual image was generated at the front of the CNN in order for classification of feature vectors of healthy and unhealthy colonies. The robustness of the proposed V-CNN model in distinguishing colonies was compared with that of the competitive support vector machine (SVM classifier based on morphological, textural, and combined features. Additionally, five-fold cross-validation was used to investigate the performance of the V-CNN model. The precision, recall, and F-measure values of the V-CNN model were comparatively higher than those of the SVM classifier, with a range of 87-93%, indicating fewer false positives and false negative rates. Furthermore, for determining the quality of colonies, the V-CNN model showed higher accuracy values based on morphological (95.5%, textural (91.0%, and combined (93.2% features than those estimated with the SVM classifier (86.7, 83.3, and 83.4%, respectively. Similarly, the accuracy of the feature sets using five-fold cross-validation was above 90% for the V-CNN model, whereas that yielded by the SVM model was in the range of 75-77%. We thus concluded that the proposed V-CNN model outperforms the conventional SVM classifier, which strongly suggests that it as a reliable framework for robust colony classification of iPSCs. It can also serve as a cost-effective quality recognition tool during culture and other experimental

  1. Colony formation of C57BL/6J mice in visible burrow system: Identification of eusocial behaviors in a background strain for genetic animal models of autism

    OpenAIRE

    Arakawa, Hiroyuki; Blanchard, D. Caroline; Blanchard, Robert J.

    2006-01-01

    Deficits in social interaction are primary characteristics of autism, which has strong genetic components. Genetically-manipulated mouse models may provide a useful research tool to advance the investigation of genes associated with autism. To identify these genes using mouse models, behavioral assays for social relationships in the background strains must be developed. The present study examined colony formation in groups of one male and three female mice (Experiment 1) and, groups of three ...

  2. Swarming and complex pattern formation in Paenibacillus vortex studied by imaging and tracking cells

    Directory of Open Access Journals (Sweden)

    Jacob Eshel

    2008-02-01

    Full Text Available Abstract Background Swarming motility allows microorganisms to move rapidly over surfaces. The Gram-positive bacterium Paenibacillus vortex exhibits advanced cooperative motility on agar plates resulting in intricate colonial patterns with geometries that are highly sensitive to the environment. The cellular mechanisms that underpin the complex multicellular organization of such a simple organism are not well understood. Results Swarming by P. vortex was studied by real-time light microscopy, by in situ scanning electron microscopy and by tracking the spread of antibiotic-resistant cells within antibiotic-sensitive colonies. When swarming, P. vortex was found to be peritrichously flagellated. Swarming by the curved cells of P. vortex occurred on an extremely wide range of media and agar concentrations (0.3 to 2.2% w/v. At high agar concentrations (> 1% w/v rotating colonies formed that could be detached from the main mass of cells by withdrawal of cells into the latter. On lower percentage agars, cells moved in an extended network composed of interconnected "snakes" with short-term collision avoidance and sensitivity to extracts from swarming cells. P. vortex formed single Petri dish-wide "supercolonies" with a colony-wide exchange of motile cells. Swarming cells were coupled by rapidly forming, reversible and non-rigid connections to form a loose raft, apparently connected via flagella. Inhibitors of swarming (p-Nitrophenylglycerol and Congo Red were identified. Mitomycin C was used to trigger filamentation without inhibiting growth or swarming; this facilitated dissection of the detail of swarming. Mitomycin C treatment resulted in malcoordinated swarming and abortive side branch formation and a strong tendency by a subpopulation of the cells to form minimal rotating aggregates of only a few cells. Conclusion P. vortex creates complex macroscopic colonies within which there is considerable reflux and movement and interaction of cells. Cell

  3. Granulocyte colony-stimulating factor mobilizes dormant hematopoietic stem cells without proliferation in mice.

    Science.gov (United States)

    Bernitz, Jeffrey M; Daniel, Michael G; Fstkchyan, Yesai S; Moore, Kateri

    2017-04-06

    Granulocyte colony-stimulating factor (G-CSF) is used clinically to treat leukopenia and to enforce hematopoietic stem cell (HSC) mobilization to the peripheral blood (PB). However, G-CSF is also produced in response to infection, and excessive exposure reduces HSC repopulation capacity. Previous work has shown that dormant HSCs contain all the long-term repopulation potential in the bone marrow (BM), and that as HSCs accumulate a divisional history, they progressively lose regenerative potential. As G-CSF treatment also induces HSC proliferation, we sought to examine whether G-CSF-mediated repopulation defects are a result of increased proliferative history. To do so, we used an established H2BGFP label retaining system to track HSC divisions in response to G-CSF. Our results show that dormant HSCs are preferentially mobilized to the PB on G-CSF treatment. We find that this mobilization does not result in H2BGFP label dilution of dormant HSCs, suggesting that G-CSF does not stimulate dormant HSC proliferation. Instead, we find that proliferation within the HSC compartment is restricted to CD41-expressing cells that function with short-term, and primarily myeloid, regenerative potential. Finally, we show CD41 expression is up-regulated within the BM HSC compartment in response to G-CSF treatment. This emergent CD41 Hi HSC fraction demonstrates no observable engraftment potential, but directly matures into megakaryocytes when placed in culture. Together, our results demonstrate that dormant HSCs mobilize in response to G-CSF treatment without dividing, and that G-CSF-mediated proliferation is restricted to cells with limited regenerative potential found within the HSC compartment. © 2017 by The American Society of Hematology.

  4. Tritiated thymidine and deoxycytidine suicide of mouse hemopoietic colony forming cells (CFC)

    International Nuclear Information System (INIS)

    Uyeki, E.M.; Wierzba, K.; Bisel, T.U.

    1981-01-01

    Significant enhancement of tritiated dCyd suicide occurred when unlabelled dThd was added to cultures of mouse monocytic colony-forming cells. Incorporation experiments supported the suicide experiments in that incorporation of tritiated dCyd into DNA was significantly increased. One hundred micromolar dCyd significantly reduced the radiotoxicity of 0.3 μCi of tritiated dThd; incorporation experiments indicated a dose-related reduction in the incorporation of tritiated dThd into DNA with the addition of 1-100 μM unlabelled dCyd. The addition of 1 μM aminopterin reversed the effect of 100 μM deoxycytidine; viz., incorporation of dThd into DNA was 90% of controls. Aminopterin had a similar effect on deoxyuridine reversal of tritiated dThd incorporation into DNA. Aminopterin had no effect on the reduction of tritiated dThd incorporation into DNA due to the addition of 100 μM unlabelled thymidine. Unlabelled ribonucleosides, Urd and Cyd, did not significantly affect the suicide pattern of tritiated dThd or dCyd when they were added to CFC cultures. Unlabelled deoxyribonucleosides, dThd or dCyd, did not significantly affect the suicide pattern of either tritiated Cyd or Urd when they were added to cultures containing tritiated ribonucleosides. Unlabelled Urd or Cyd was effective in reversing the suicide due to tritiated Urd or Cyd. (author)

  5. Cell cycle of spermatogonial colony forming stem cells in the CBA mouse after neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Bootsma, A.L. (Rijksuniversiteit Utrecht (Netherlands). Academisch Ziekenhuis); Davids, J.A.G. (Netherlands Energy Research Foundation, Petten (Netherlands))

    1988-03-01

    In the CBA mouse testis, about 10% of the stem cell population is highly resistant to neutron irradiation (D/sub 0/, 0.75 Gy). Following a dose of 1.50 Gy these cells rapidly increase their sensitivity towards a second neutron dose and progress fairly synchronously through their first post-irradiation cell cycle. From experiments in which neutron irradiation was combined with hydroxyurea, it appeared that in this cycle the S-phase is less radiosensitive (D/sub 0/, 0.43 Gy) than the other phases of the cell cycle (D/sub 0/, 0.25 Gy). From experiments in which hydroxyurea was injected twice after irradiation, the speed of inflow of cells in S and the duration of S and the cell cycle could be calculated. Between 32 and 36 hr after irradiation cells start to enter the S-phase at a speed of 30% of the population every 12 hr. At 60 hr 50% of the population has already passed the S-phase while 30% is still in S. The data point to a cell cycle time of about 36 hr, while the S-phase lasts 12 hr at the most. (author).

  6. Mast cells mediate malignant pleural effusion formation.

    Science.gov (United States)

    Giannou, Anastasios D; Marazioti, Antonia; Spella, Magda; Kanellakis, Nikolaos I; Apostolopoulou, Hara; Psallidas, Ioannis; Prijovich, Zeljko M; Vreka, Malamati; Zazara, Dimitra E; Lilis, Ioannis; Papaleonidopoulos, Vassilios; Kairi, Chrysoula A; Patmanidi, Alexandra L; Giopanou, Ioanna; Spiropoulou, Nikolitsa; Harokopos, Vaggelis; Aidinis, Vassilis; Spyratos, Dionisios; Teliousi, Stamatia; Papadaki, Helen; Taraviras, Stavros; Snyder, Linda A; Eickelberg, Oliver; Kardamakis, Dimitrios; Iwakura, Yoichiro; Feyerabend, Thorsten B; Rodewald, Hans-Reimer; Kalomenidis, Ioannis; Blackwell, Timothy S; Agalioti, Theodora; Stathopoulos, Georgios T

    2015-06-01

    Mast cells (MCs) have been identified in various tumors; however, the role of these cells in tumorigenesis remains controversial. Here, we quantified MCs in human and murine malignant pleural effusions (MPEs) and evaluated the fate and function of these cells in MPE development. Evaluation of murine MPE-competent lung and colon adenocarcinomas revealed that these tumors actively attract and subsequently degranulate MCs in the pleural space by elaborating CCL2 and osteopontin. MCs were required for effusion development, as MPEs did not form in mice lacking MCs, and pleural infusion of MCs with MPE-incompetent cells promoted MPE formation. Once homed to the pleural space, MCs released tryptase AB1 and IL-1β, which in turn induced pleural vasculature leakiness and triggered NF-κB activation in pleural tumor cells, thereby fostering pleural fluid accumulation and tumor growth. Evaluation of human effusions revealed that MCs are elevated in MPEs compared with benign effusions. Moreover, MC abundance correlated with MPE formation in a human cancer cell-induced effusion model. Treatment of mice with the c-KIT inhibitor imatinib mesylate limited effusion precipitation by mouse and human adenocarcinoma cells. Together, the results of this study indicate that MCs are required for MPE formation and suggest that MC-dependent effusion formation is therapeutically addressable.

  7. Natural factors and antropics and their relationship with the density of colonies of Melipona beecheii in five vegetable formations of the valley San Andres

    Directory of Open Access Journals (Sweden)

    Katiuska Ravelo Pimentel

    2014-12-01

    Full Text Available It is evaluated the influence of natural factors and antropics on the density of colonies of Melipona beecheii in forest five vegetable formations of the solid one of the valley San Andrés, through surveys to residents and workers of the area, as well as the observations and samplings carried out in the studied vegetable formations. The following factors were studied: rocosity, vegetable covering, flourished plants, height of the entrance hole and the man's activity; being determined that the density of beehives has been affected fundamentally by factors antropics, having this its biggest incidence in the gallery forests, being this the most affected one. The pruning of trees, the naturalness of the forests and their access affect the population's conservation considerably under natural conditions, what demonstrates that this it is the main factor that locates in extirpation danger to the species in the study area. In turn the density of colonies keeps direct relationship with the other analyzed factors, since the same ones depend on the trees for the location of its nests, of the time in that the plants flourish for its feeding and of the holes found in the rocks, so much for the making of its colonies like it stops its establishment and reproduction.

  8. The influence of interleukin-2, feeder cells, and timing of irradiation on the radiosensitivity of human T lymphocytes assessed by the colony-forming assay

    International Nuclear Information System (INIS)

    Gerber, M.; Guichard, M.; Pioch, Y.; Dubois, J.B.

    1989-01-01

    The radiosensitivity of human lymphocytes was investigated by the method of colony formation in the absence of interleukin-2 (IL2) and feeder cells, both of which enhance growth of T-cell colonies. The shape of the survival curve and the radiosensitivity was shown to depend upon the ability of lymphocytes to produce IL2: the survival curve for lymphocytes that were the most competent producers of IL2 is the closest to linearity; the lymphocytes that were poor producers show biphasic survival curves. The radiosensitivity of the lymphocytes from the first group is less than that of the latter, when the comparison is based on the first part of the biphasic survival curve. This is more easily seen when cultures are irradiated 24 h after stimulation by phytohemagglutinin (the time of the peak IL2 production) than when cultures are irradiated 2 h before stimulation. This study demonstrates that growth conditions influence the response of lymphocytes to irradiation and that optimal growth conditions result in a linear survival curve

  9. Precursors (pre-CFCmulti) of multilineage hemopoietic colony-forming cells quantitated in vitro. Uniqueness of IL-1 requirement, partial separation from pluripotential colony-forming cells, and correlation with long term reconstituting cells in vivo

    International Nuclear Information System (INIS)

    Iscove, N.N.; Yan, X.Q.

    1990-01-01

    Pluripotential colony-forming cells (CFCmulti) from mouse marrow can expand significantly in number during 4 days of suspension culture with IL-1 and IL-3. In this study, the cells (pre-CFCmulti) which originate this response are characterized in terms of their frequency, progeny number, factor requirements, buoyant density, and extent of restoration following marrow transplantation. Parallel measurements of both CFCmulti and cells providing long term marrow reconstitution in vivo allowed direct comparisons to be made with pre-CFCmulti. The proliferative response of pre-CFCmulti was found to depend uniquely on the combination of IL-1 and IL-3, and neither of these regulators was replaceable by any of IL-4, IL-6, IL-7, GM-CSF, G-CSF, M-CSF or LIF. After separation on density gradients, pre-CFCmulti were recovered in fractions of lower density than most of the CFCmulti, but in the same fractions that contained most of the in vivo reconstituting cells. After irradiation and marrow transplantation, marrow CFCmulti were restored to near normal levels, while both pre-CFCmulti as well as reconstituting stem cells remained profoundly depressed. These results show pre-CFCmulti to be distinct from most CFCmulti and to represent the closest approach to quantitative detection of reconstituting stem cells so far achieved in vitro

  10. REVENUE FARMING AND IMPERIAL TRANSITION: AN ECONOMIC DIMENSION OF EARLY COLONIAL STATE FORMATION IN JAVA, C. 1800s-1820s

    Directory of Open Access Journals (Sweden)

    Abdul Wahid

    2012-11-01

    Full Text Available Revenue farming (pacht or verpachtingen in Dutch is a fiscal institution that existed in Java since the pre-colonial period. During the VOC period, the Dutch modified, institutionalized and &extended it as one of their fiscal institutions to solve human resource shortage and administrative barriers in collecting taxes from local population. For political and economic reasons the Dutch favored the Chinese as main partners in operating the system. The system was proven efficient to an extent that it collected substantial revenue contribution to the state exchequer. During the period of 'imperial'  transition from 1800s until 1820s, changing regimes in Java retained the system to finance their political agenda. This paper argues that revenue-farming system was the financial source for the Dutch in establishing a real colonial state in Java.

  11. A stimulator of proliferation of spleen colony-forming cells (CFU-S) in the bone marrow of irradiated rats

    Energy Technology Data Exchange (ETDEWEB)

    Ivanovic, Z.; Milenkovic, P.; Stojanovic, N.; Lukic, M.; Kataranovski, M.

    1993-07-01

    The presence and activity of a spleen colony - forming cell (CFU-S) proliferation stimulator was investigated in rat bone marrow after irradiation. The dose dependent increase in cytosine arabinoside induced cell dealth of normal mouse bone marrow. The results demonstrate the existence of a CFU-S proliferation stimulator in rat bone marrow similar to that originally found as a macrophage product in regenarating mouse bone marrow. The CFU-S proliferation stimulator activity was not associated with the presence of interleukin - 1,2, or 6 like activities in the material tested.

  12. Growth of human T lymphocyte colonies from whole blood: culture requirements and applications

    International Nuclear Information System (INIS)

    Knox, S.J.; Wilson, F.D.; Greenberg, B.R.; Shifrine, M.

    1982-01-01

    Growth of human lymphocyte colonies from whole blood following stimulation with PHA, Con A, or PPD is described. Individual colony cells were identified as T lymphocytes on the basis of surface marker and enzyme cytochemical characterizations. Colony formation increased as a power function over a wide range of cell concentrations above a critical minimal concentration. The whole blood culture system eliminates possible selective effects of lymphocyte colony techniques utilizing gradient-enriched lymphocyte fractions and more closely approximates the in vivo milieu. The whole blood colony method is more sensitive for the detection of low-level radiation effects on lymphocytes than widely used tests that measure 3 H-thymidine incorporation. In preliminary studies, researchers used the whole blood method to determine the relative radiosensitivity of lymphocytes from humans with various hematopoietic disorders, and observed abnormalities in mitogen responsiveness and colony formation in some of the patient groups. This method has wide application for studies in cellular and clinical immunology

  13. Colony size, cell number, carbon and nitrogen contents of Phaeocystis pouchetii from western Norway

    NARCIS (Netherlands)

    Verity, Peter G.; Whipple, S. J.; Nejstgaard, J. C.; Alderkamp, A.-C.

    Phaeocystis pouchetii is an ecologically important colony-forming marine phytoplankton species in northern hemisphere cold waters. It plays a central role in the processing of biogeochemically important elements in the upper ocean during spring blooms. Here, we report highly significant quantitative

  14. Bacterial lipopolysaccharide induces osteoclast formation in RAW 264.7 macrophage cells

    International Nuclear Information System (INIS)

    Islam, Shamima; Hassan, Ferdaus; Tumurkhuu, Gantsetseg; Dagvadorj, Jargalsaikhan; Koide, Naoki; Naiki, Yoshikazu; Mori, Isamu; Yoshida, Tomoaki; Yokochi, Takashi

    2007-01-01

    Lipopolysaccharide (LPS) is a potent bone resorbing factor. The effect of LPS on osteoclast formation was examined by using murine RAW 264.7 macrophage cells. LPS-induced the formation of multinucleated giant cells (MGC) in RAW 264.7 cells 3 days after the exposure. MGCs were positive for tartrate-resistant acid phosphatase (TRAP) activity. Further, MGC formed resorption pits on calcium-phosphate thin film that is a substrate for osteoclasts. Therefore, LPS was suggested to induce osteoclast formation in RAW 264.7 cells. LPS-induced osteoclast formation was abolished by anti-tumor necrosis factor (TNF)-α antibody, but not antibodies to macrophage-colony stimulating factor (M-CSF) and receptor activator of nuclear factor (NF)-κB ligand (RANKL). TNF-α might play a critical role in LPS-induced osteoclast formation in RAW 264.7 cells. Inhibitors of NF-κB and stress activated protein kinase (SAPK/JNK) prevented the LPS-induced osteoclast formation. The detailed mechanism of LPS-induced osteoclast formation is discussed

  15. The Transcription Factor Nrf2 Protects Angiogenic Capacity of Endothelial Colony-Forming Cells in High-Oxygen Radical Stress Conditions

    Directory of Open Access Journals (Sweden)

    Hendrik Gremmels

    2017-01-01

    Full Text Available Background. Endothelial colony forming cells (ECFCs have shown a promise in tissue engineering of vascular constructs, where they act as endothelial progenitor cells. After implantation, ECFCs are likely to be subjected to elevated reactive oxygen species (ROS. The transcription factor Nrf2 regulates the expression of antioxidant enzymes in response to ROS. Methods. Stable knockdown of Nrf2 and Keap1 was achieved by transduction with lentiviral shRNAs; activation of Nrf2 was induced by incubation with sulforaphane (SFN. Expression of Nrf2 target genes was assessed by qPCR, oxidative stress was assessed using CM-DCFDA, and angiogenesis was quantified by scratch-wound and tubule-formation assays. Results. Nrf2 knockdown led to a reduction of antioxidant gene expression and increased ROS. Angiogenesis was disturbed after Nrf2 knockdown even in the absence of ROS. Conversely, angiogenesis was preserved in high ROS conditions after knockdown of Keap1. Preincubation of ECFCs with SFN reduced intracellular ROS in the presence of H2O2 and preserved scratch-wound closure and tubule-formation. Conclusion. The results of this study indicate that Nrf2 plays an important role in the angiogenic capacity of ECFCs, particularly under conditions of increased oxidative stress. Pretreatment of ECFCs with SFN prior to implantation may be a protective strategy for tissue-engineered constructs or cell therapies.

  16. Colony Size of Phaeocystis Antarctica (Prymnesiophyceae) as Influenced by Zooplankton Grazers

    Science.gov (United States)

    The haptophyte Phaeocystis antarctica is a dominant phytoplankton species in the Ross Sea, Antarctica, and exists as solitary cells and mucilaginous colonies that differ by several orders of magnitude in size. Recent studies with P. globosa suggested that colony formation and enl...

  17. Increase in colony-forming efficiency in soft agar of thymus cells from radiation-induced thymomas of NIH Swiss mice

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Nobuko; Takamori, Yasuhiko; Hori, Yasuharu [Radiation Center of Osaka Prefecture, Sakai (Japan)

    1982-03-01

    Colony-forming efficiency in soft agar of radiation-induced thymoma in NIH Swiss mice was determined in the presence of cultured medium of reticulo-epitherial cells from normal thymus of NIH Swiss mouse as conditioned medium. A similar experiment was done with thymomas spontaneously developed in AKR mice. Most of colonies developed in soft agar were not composed of thymic lymphoma cells, but of macrophage-like cells. The ratio of the number of colonies to that of the seeded cells significantly increased in thymomas comparing with that in normal thymus. This result corresponded with the increased number of macrophages in thymoma, as determined by counting phagocytic cells of adherent cells.

  18. OpenCFU, a new free and open-source software to count cell colonies and other circular objects.

    Science.gov (United States)

    Geissmann, Quentin

    2013-01-01

    Counting circular objects such as cell colonies is an important source of information for biologists. Although this task is often time-consuming and subjective, it is still predominantly performed manually. The aim of the present work is to provide a new tool to enumerate circular objects from digital pictures and video streams. Here, I demonstrate that the created program, OpenCFU, is very robust, accurate and fast. In addition, it provides control over the processing parameters and is implemented in an intuitive and modern interface. OpenCFU is a cross-platform and open-source software freely available at http://opencfu.sourceforge.net.

  19. Mechanisms of foam cell formation in atherosclerosis.

    Science.gov (United States)

    Chistiakov, Dimitry A; Melnichenko, Alexandra A; Myasoedova, Veronika A; Grechko, Andrey V; Orekhov, Alexander N

    2017-11-01

    Low-density lipoprotein (LDL) and cholesterol homeostasis in the peripheral blood is maintained by specialized cells, such as macrophages. Macrophages express a variety of scavenger receptors (SR) that interact with lipoproteins, including SR-A1, CD36, and lectin-like oxLDL receptor-1 (LOX-1). These cells also have several cholesterol transporters, including ATP-binding cassette transporter ABCA1, ABCG1, and SR-BI, that are involved in reverse cholesterol transport. Lipids internalized by phagocytosis are transported to late endosomes/lysosomes, where lysosomal acid lipase (LAL) digests cholesteryl esters releasing free cholesterol. Free cholesterol in turn is processed by acetyl-CoA acetyltransferase (ACAT1), an enzyme that transforms cholesterol to cholesteryl esters. The endoplasmic reticulum serves as a depot for maintaining newly synthesized cholesteryl esters that can be processed by neutral cholesterol ester hydrolase (NCEH), which generates free cholesterol that can exit via cholesterol transporters. In atherosclerosis, pro-inflammatory stimuli upregulate expression of scavenger receptors, especially LOX-1, and downregulate expression of cholesterol transporters. ACAT1 is also increased, while NCEH expression is reduced. This results in deposition of free and esterified cholesterol in macrophages and generation of foam cells. Moreover, other cell types, such as endothelial (ECs) and vascular smooth muscle cells (VSMCs), can also become foam cells. In this review, we discuss known pathways of foam cell formation in atherosclerosis.

  20. Effect of barbiturates on radiosensitivity of cells: a comparative study of electrophoretic mobility, colony forming ability and thymidine uptake on human amnion cells

    International Nuclear Information System (INIS)

    Lalwani, N.D.; Chaubal, K.A.

    1980-01-01

    Suspensions of human amnion cells were 60 Co γ-irradiated in the presence of phenobarbital or thiobarbital (50 μg/ml). The barbiturates protected the cells against the dose-dependent reduction in electrophoretic mobility (EPM) observed 4 hours after irradiation of untreated cells, although there was an initial decrease in the EPM of treated cells followed by recovery. Treated irradiated cells exhibited greater colony-forming ability than the untreated cells. Pentobarbital and phenobarbital had similar effects, but thiobarbital was not so effective. 3 H-TdR uptake increased within 4 hours of irradiation for the treated cells. The reproductive capacity of the cells was retained at doses as high as 500 rad. The results are discussed with reference to the effects of anaesthetics on cell membranes. (U.K.)

  1. Density of founder cells affects spatial pattern formation and cooperation in Bacillus subtilis biofilms.

    Science.gov (United States)

    van Gestel, Jordi; Weissing, Franz J; Kuipers, Oscar P; Kovács, Akos T

    2014-10-01

    In nature, most bacteria live in surface-attached sedentary communities known as biofilms. Biofilms are often studied with respect to bacterial interactions. Many cells inhabiting biofilms are assumed to express 'cooperative traits', like the secretion of extracellular polysaccharides (EPS). These traits can enhance biofilm-related properties, such as stress resilience or colony expansion, while being costly to the cells that express them. In well-mixed populations cooperation is difficult to achieve, because non-cooperative individuals can reap the benefits of cooperation without having to pay the costs. The physical process of biofilm growth can, however, result in the spatial segregation of cooperative from non-cooperative individuals. This segregation can prevent non-cooperative cells from exploiting cooperative neighbors. Here we examine the interaction between spatial pattern formation and cooperation in Bacillus subtilis biofilms. We show, experimentally and by mathematical modeling, that the density of cells at the onset of biofilm growth affects pattern formation during biofilm growth. At low initial cell densities, co-cultured strains strongly segregate in space, whereas spatial segregation does not occur at high initial cell densities. As a consequence, EPS-producing cells have a competitive advantage over non-cooperative mutants when biofilms are initiated at a low density of founder cells, whereas EPS-deficient cells have an advantage at high cell densities. These results underline the importance of spatial pattern formation for competition among bacterial strains and the evolution of microbial cooperation.

  2. Collagen-IV supported embryoid bodies formation and differentiation from buffalo (Bubalus bubalis) embryonic stem cells

    International Nuclear Information System (INIS)

    Taru Sharma, G.; Dubey, Pawan K.; Verma, Om Prakash; Pratheesh, M.D.; Nath, Amar; Sai Kumar, G.

    2012-01-01

    Graphical abstract: EBs formation, characterization and expression of germinal layers marker genes of in vivo developed teratoma using four different types of extracellular matrices. Highlights: ► Collagen-IV matrix is found cytocompatible for EBs formation and differentiation. ► Established 3D microenvironment for ES cells development and differentiation into three germ layers. ► Collagen-IV may be useful as promising candidate for ES cells based therapeutic applications. -- Abstract: Embryoid bodies (EBs) are used as in vitro model to study early extraembryonic tissue formation and differentiation. In this study, a novel method using three dimensional extracellular matrices for in vitro generation of EBs from buffalo embryonic stem (ES) cells and its differentiation potential by teratoma formation was successfully established. In vitro derived inner cell masses (ICMs) of hatched buffalo blastocyst were cultured on buffalo fetal fibroblast feeder layer for primary cell colony formation. For generation of EBs, pluripotent ES cells were seeded onto four different types of extracellular matrices viz; collagen-IV, laminin, fibronectin and matrigel using undifferentiating ES cell culture medium. After 5 days of culture, ESCs gradually grew into aggregates and formed simple EBs having circular structures. Twenty-six days later, they formed cystic EBs over collagen matrix with higher EBs formation and greater proliferation rate as compared to other extracellular matrices. Studies involving histological observations, fluorescence microscopy and RT-PCR analysis of the in vivo developed teratoma revealed that presence of all the three germ layer derivatives viz. ectoderm (NCAM), mesoderm (Flk-1) and endoderm (AFP). In conclusion, the method described here demonstrates a simple and cost-effective way of generating EBs from buffalo ES cells. Collagen-IV matrix was found cytocompatible as it supported buffalo EBs formation, their subsequent differentiation could prove to

  3. Collagen-IV supported embryoid bodies formation and differentiation from buffalo (Bubalus bubalis) embryonic stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Taru Sharma, G., E-mail: gts553@gmail.com [Reproductive Physiology Laboratory, Division of Physiology and Climatology, Indian Veterinary Research Institute, Izatnagar-243 122, Bareilly, U.P. (India); Dubey, Pawan K.; Verma, Om Prakash; Pratheesh, M.D.; Nath, Amar; Sai Kumar, G. [Reproductive Physiology Laboratory, Division of Physiology and Climatology, Indian Veterinary Research Institute, Izatnagar-243 122, Bareilly, U.P. (India)

    2012-08-03

    Graphical abstract: EBs formation, characterization and expression of germinal layers marker genes of in vivo developed teratoma using four different types of extracellular matrices. Highlights: Black-Right-Pointing-Pointer Collagen-IV matrix is found cytocompatible for EBs formation and differentiation. Black-Right-Pointing-Pointer Established 3D microenvironment for ES cells development and differentiation into three germ layers. Black-Right-Pointing-Pointer Collagen-IV may be useful as promising candidate for ES cells based therapeutic applications. -- Abstract: Embryoid bodies (EBs) are used as in vitro model to study early extraembryonic tissue formation and differentiation. In this study, a novel method using three dimensional extracellular matrices for in vitro generation of EBs from buffalo embryonic stem (ES) cells and its differentiation potential by teratoma formation was successfully established. In vitro derived inner cell masses (ICMs) of hatched buffalo blastocyst were cultured on buffalo fetal fibroblast feeder layer for primary cell colony formation. For generation of EBs, pluripotent ES cells were seeded onto four different types of extracellular matrices viz; collagen-IV, laminin, fibronectin and matrigel using undifferentiating ES cell culture medium. After 5 days of culture, ESCs gradually grew into aggregates and formed simple EBs having circular structures. Twenty-six days later, they formed cystic EBs over collagen matrix with higher EBs formation and greater proliferation rate as compared to other extracellular matrices. Studies involving histological observations, fluorescence microscopy and RT-PCR analysis of the in vivo developed teratoma revealed that presence of all the three germ layer derivatives viz. ectoderm (NCAM), mesoderm (Flk-1) and endoderm (AFP). In conclusion, the method described here demonstrates a simple and cost-effective way of generating EBs from buffalo ES cells. Collagen-IV matrix was found cytocompatible as it

  4. Colony stimulating factor 1 receptor inhibition delays recurrence of glioblastoma after radiation by altering myeloid cell recruitment and polarization

    Science.gov (United States)

    Stafford, Jason H.; Hirai, Takahisa; Deng, Lei; Chernikova, Sophia B.; Urata, Kimiko; West, Brian L.; Brown, J. Martin

    2016-01-01

    Background Glioblastoma (GBM) may initially respond to treatment with ionizing radiation (IR), but the prognosis remains extremely poor because the tumors invariably recur. Using animal models, we previously showed that inhibiting stromal cell–derived factor 1 signaling can prevent or delay GBM recurrence by blocking IR-induced recruitment of myeloid cells, specifically monocytes that give rise to tumor-associated macrophages. The present study was aimed at determining if inhibiting colony stimulating factor 1 (CSF-1) signaling could be used as an alternative strategy to target pro-tumorigenic myeloid cells recruited to irradiated GBM. Methods To inhibit CSF-1 signaling in myeloid cells, we used PLX3397, a small molecule that potently inhibits the tyrosine kinase activity of the CSF-1 receptor (CSF-1R). Combined IR and PLX3397 therapy was compared with IR alone using 2 different human GBM intracranial xenograft models. Results GBM xenografts treated with IR upregulated CSF-1R ligand expression and increased the number of CD11b+ myeloid-derived cells in the tumors. Treatment with PLX3397 both depleted CD11b+ cells and potentiated the response of the intracranial tumors to IR. Median survival was significantly longer for mice receiving combined therapy versus IR alone. Analysis of myeloid cell differentiation markers indicated that CSF-1R inhibition prevented IR-recruited monocyte cells from differentiating into immunosuppressive, pro-angiogenic tumor-associated macrophages. Conclusion CSF-1R inhibition may be a promising strategy to improve GBM response to radiotherapy. PMID:26538619

  5. The Transcription Factor Nrf2 Protects Angiogenic Capacity of Endothelial Colony-Forming Cells in High-Oxygen Radical Stress Conditions

    NARCIS (Netherlands)

    Gremmels, Hendrik; De Jong, Olivier G.; Hazenbrink, Diënty H.; Fledderus, Joost O.; Verhaar, Marianne C.

    2017-01-01

    Background. Endothelial colony forming cells (ECFCs) have shown a promise in tissue engineering of vascular constructs, where they act as endothelial progenitor cells. After implantation, ECFCs are likely to be subjected to elevated reactive oxygen species (ROS). The transcription factor Nrf2

  6. Optimization of the culturing conditions of human umbilical cord blood-derived endothelial colony-forming cells under xeno-free conditions applying a transcriptomic approach

    NARCIS (Netherlands)

    Zeisberger, Steffen M.; Zoller, Stefan; Riegel, Mariluce; Chen, Shuhua; Krenning, Guido; Harmsen, Martin C.; Sachinidis, Agapios; Zisch, Andreas H.

    Establishment of fetal bovine serum (FBS)-free cell culture conditions is essential for transplantation therapies. Blood-derived endothelial colony-forming cells (ECFCs) are potential candidates for regenerative medicine applications. ECFCs were isolated from term umbilical cord blood units and

  7. Culture on fibrin matrices maintains the colony-forming capacity and osteoblastic differentiation of mesenchymal stem cells

    International Nuclear Information System (INIS)

    Colley, Helen; McArthur, Sally L; Stolzing, Alexandra; Scutt, Andy

    2012-01-01

    Mesenchymal stem cells (MSC) are multipotent cells capable of differentiating into a number of mesenchymal tissues including bone, cartilage, and tendon. Low numbers in vivo means exponential growth is needed in culture to enable therapeutic applications. MSC can expand rapidly in culture but usually lose their extensive capacity for differentiation that makes them therapeutically attractive. To try and maintain their capacity for differentiation and expansion in vitro, we cultured MSC on fibrin gels of different concentrations to create more physiological growth conditions for the cells. The cells were then re-plated onto tissue culture plastic and analysed. The cells that had been pre-cultured for seven days on fibrin, proliferated and maintained their differential potential to the osteogenic lineage better than tissue culture plastic expanded MSC. A concentration relationship between colony number and fibrin concentration was seen with decreasing numbers as fibrin concentration increased. These data support the concept that substrate signals significantly influence MSC growth and differentiation and that growth on a fibrin matrix could be used to maintain a stem cell phenotype during MSC expansion. (paper)

  8. Acidic preconditioning of endothelial colony-forming cells (ECFC) promote vasculogenesis under proinflammatory and high glucose conditions in vitro and in vivo.

    Science.gov (United States)

    Mena, Hebe Agustina; Zubiry, Paula Romina; Dizier, Blandine; Schattner, Mirta; Boisson-Vidal, Catherine; Negrotto, Soledad

    2018-05-02

    We have previously demonstrated that acidic preconditioning of human endothelial colony-forming cells (ECFC) increased proliferation, migration, and tubulogenesis in vitro, and increased their regenerative potential in a murine model of hind limb ischemia without baseline disease. We now analyze whether this strategy is also effective under adverse conditions for vasculogenesis, such as the presence of ischemia-related toxic molecules or diabetes, one of the main target diseases for cell therapy due to their well-known healing impairments. Cord blood-derived CD34 + cells were seeded in endothelial growth culture medium (EGM2) and ECFC colonies were obtained after 14-21 days. ECFC were exposed at pH 6.6 (preconditioned) or pH 7.4 (nonpreconditioned) for 6 h, and then pH was restored at 7.4. A model of type 2 diabetes induced by a high-fat and high-sucrose diet was developed in nude mice and hind limb ischemia was induced in these animals by femoral artery ligation. A P value < 0.05 was considered statistically significant (by one-way analysis of variance). We found that acidic preconditioning increased ECFC adhesion and the release of pro-angiogenic molecules, and protected ECFC from the cytotoxic effects of monosodium urate crystals, histones, and tumor necrosis factor (TNF)α, which induced necrosis, pyroptosis, and apoptosis, respectively. Noncytotoxic concentrations of high glucose, TNFα, or their combination reduced ECFC proliferation, stromal cell-derived factor (SDF)1-driven migration, and tubule formation on a basement membrane matrix, whereas almost no inhibition was observed in preconditioned ECFC. In type 2 diabetic mice, intravenous administration of preconditioned ECFC significantly induced blood flow recovery at the ischemic limb as measured by Doppler, compared with the phosphate-buffered saline (PBS) and nonpreconditioned ECFC groups. Moreover, the histologic analysis of gastrocnemius muscles showed an increased vascular density and reduced

  9. Characterization and molecular features of the cell surface receptor for human granulocyte-macrophage colony-stimulating factor

    International Nuclear Information System (INIS)

    Chiba, S.; Tojo, A.; Kitamura, T.; Urabe, A.; Miyazono, K.; Takaku, F.

    1990-01-01

    The receptors for human granulocyte-macrophage colony-stimulating factor (GM-CSF) on the surfaces of normal and leukemic myeloid cells were characterized using 125I-labeled bacterially synthesized GM-CSF. The binding was rapid, specific, time dependent, and saturable. Scatchard analysis of the 125I-GM-CSF binding to peripheral blood neutrophils indicated the presence of a single class of binding site (Kd = 99 +/- 21 pM; 2,304 +/- 953 sites/cell). However, for peripheral blood monocytes and two GM-CSF-responsive myeloid cell lines (U-937 and TF-1), the Scatchard plots were biphasic curvilinear, which were best fit by curves derived from two binding site model: one with high affinity (Kd1 = 10-40 pM) and the other with low affinity (Kd2 = 0.9-2.0 nM). For U-937 cells, the number of high-affinity receptors was 1,058 +/- 402 sites/cell and that of low-affinity receptors was estimated to be 10,834 +/- 2,396 sites/cell. Cross-linking studies yielded three major bands with molecular masses of 150 kDa, 115 kDa, and 95 kDa, which were displaced by an excess amount of unlabeled GM-CSF, suggesting 135-kDa, 100-kDa, and 80-kDa species for the individual components of the human GM-CSF receptor. These bands comigrated for different cell types including peripheral blood neutrophils, U-937 cells and TF-1 cells. In experiments using U-937 cells, only the latter two bands appeared to be labeled in a dose-dependent manner in a low-affinity state. These results suggest that the human GM-CSF receptor possibly forms a multichain complex

  10. Cells, bilirubin and light: formation of bilirubin photoproducts and cellular damage at defined wavelengths

    International Nuclear Information System (INIS)

    Christensen, T.; Kinn, G.; Granli, T.; Amundsen, I.

    1994-01-01

    Cultured cells from one human and one murine cell line were treated with bilirubin and irradiated with visible light of different wavelengths, either from phototherapy lamps or from a Xenon/Mercury lamp equipped with a monochromator. Bilirubin bound to human serum albumin was also irradiated with light. After irradiation, the bilirubin and its photoisomers were extracted with High Pressure Liquid Chromatography. The formation of single strand breaks in the DNA of treated cells was studied using a fluorescence marker. Cytotoxicity in the mouse skin cell line was measured by loss of the ability to form visible colonies in vitro. Green light exposure favours the production of lumirubin, while blue light causes more DNA damage and cytotoxicity. Green light may be more efficient and safer than shorter wavelength exposure when treating jaundiced newborns with phototherapy. 27 refs., 6 figs

  11. Colonial Institutions

    DEFF Research Database (Denmark)

    McAtackney, Laura; Palmer, Russell

    2016-01-01

    and the USA which reveal that the study of colonial institutions should not be limited to the functional life of these institutions—or solely those that take the form of monumental architecture—but should include the long shadow of “imperial debris” (Stoler 2008) and immaterial institutions....

  12. Macrophage colony-stimulating factor receptor marks and regulates a fetal myeloid-primed B-cell progenitor in mice.

    Science.gov (United States)

    Zriwil, Alya; Böiers, Charlotta; Wittmann, Lilian; Green, Joanna C A; Woll, Petter S; Jacobsen, Sten Eirik W; Sitnicka, Ewa

    2016-07-14

    Although it is well established that unique B-cell lineages develop through distinct regulatory mechanisms during embryonic development, much less is understood about the differences between embryonic and adult B-cell progenitor cells, likely to underpin the genetics and biology of infant and childhood PreB acute lymphoblastic leukemia (PreB-ALL), initiated by distinct leukemia-initiating translocations during embryonic development. Herein, we establish that a distinct subset of the earliest CD19(+) B-cell progenitors emerging in the E13.5 mouse fetal liver express the colony-stimulating factor-1 receptor (CSF1R), previously thought to be expressed, and play a lineage-restricted role in development of myeloid lineages, and macrophages in particular. These early embryonic CSF1R(+)CD19(+) ProB cells also express multiple other myeloid genes and, in line with this, possess residual myeloid as well as B-cell, but not T-cell lineage potential. Notably, these CSF1R(+) myeloid-primed ProB cells are uniquely present in a narrow window of embryonic fetal liver hematopoiesis and do not persist in adult bone marrow. Moreover, analysis of CSF1R-deficient mice establishes a distinct role of CSF1R in fetal B-lymphopoiesis. CSF1R(+) myeloid-primed embryonic ProB cells are relevant for infant and childhood PreB-ALLs, which frequently have a bi-phenotypic B-myeloid phenotype, and in which CSF1R-rearrangements have recently been reported. © 2016 by The American Society of Hematology.

  13. Mural cell associated VEGF is required for organotypic vessel formation.

    Directory of Open Access Journals (Sweden)

    Lasse Evensen

    Full Text Available BACKGROUND: Blood vessels comprise endothelial cells, mural cells (pericytes/vascular smooth muscle cells and basement membrane. During angiogenesis, mural cells are recruited to sprouting endothelial cells and define a stabilizing context, comprising cell-cell contacts, secreted growth factors and extracellular matrix components, that drives vessel maturation and resistance to anti-angiogenic therapeutics. METHODS AND FINDINGS: To better understand the basis for mural cell regulation of angiogenesis, we conducted high content imaging analysis on a microtiter plate format in vitro organotypic blood vessel system comprising primary human endothelial cells co-cultured with primary human mural cells. We show that endothelial cells co-cultured with mural cells undergo an extensive series of phenotypic changes reflective of several facets of blood vessel formation and maturation: Loss of cell proliferation, pathfinding-like cell migration, branching morphogenesis, basement membrane extracellular matrix protein deposition, lumen formation, anastamosis and development of a stabilized capillary-like network. This phenotypic sequence required endothelial-mural cell-cell contact, mural cell-derived VEGF and endothelial VEGFR2 signaling. Inhibiting formation of adherens junctions or basement membrane structures abrogated network formation. Notably, inhibition of mural cell VEGF expression could not be rescued by exogenous VEGF. CONCLUSIONS: These results suggest a unique role for mural cell-associated VEGF in driving vessel formation and maturation.

  14. Growth Mechanism of Microbial Colonies

    Science.gov (United States)

    Zhu, Minhui; Martini, K. Michael; Kim, Neil H.; Sherer, Nicholas; Lee, Jia Gloria; Kuhlman, Thomas; Goldenfeld, Nigel

    Experiments on nutrient-limited E. coli colonies, growing on agar gel from single cells reveal a power-law distribution of sizes, both during the growth process and in the final stage when growth has ceased. We developed a Python simulation to study the growth mechanism of the bacterial population and thus understand the broad details of the experimental findings. The simulation takes into account nutrient uptake, metabolic function, growth and cell division. Bacteria are modeled in two dimensions as hard circle-capped cylinders with steric interactions and elastic stress dependent growth characteristics. Nutrient is able to diffuse within and between the colonies. The mechanism of microbial colony growth involves reproduction of cells within the colonies and the merging of different colonies. We report results on the dynamic scaling laws and final state size distribution, that capture in semi-quantitative detail the trends observed in experiment. Supported by NSF Grant 0822613.

  15. Radiation induced formation of giant cells (Saccharomyces uvarum). Pt. 1

    Energy Technology Data Exchange (ETDEWEB)

    Baumstark-Khan, C; Schnitzler, L; Rink, H

    1984-02-01

    X-irradiated yeast cells (Saccharomyces uvarum) grown in liquid media stop mitosis and form giant cells. Chitin ring formation, being a prerequisite for cell separation, was studied by fluorescence microscopy using Calcofluor White, a chitin specific dye. Experiments with inhibitors of DNA synthesis (hydroxyurea) and chitin synthesis (polyoxin D) demonstrate chitin ring formation to be dependent on DNA synthesis, whereas bud formation is independent of DNA synthesis and chitin ring formation respectively. Basing on these results the formation of X-ray induced giant cells implies one DNA replication which in turn induces the formation of only one chitin ring between mother cell and giant bud. Obviously no septum can be formed. Thus cell separation does not occur, but the bud already formed, produces another bud demonstrating that bud formation itself is independent of DNA synthesis.

  16. Radiation induced formation of giant cells (Saccharomyces uvarum). Pt. 1

    International Nuclear Information System (INIS)

    Baumstark-Khan, C.; Schnitzler, L.; Rink, H.

    1984-01-01

    X-irradiated yeast cells (Saccharomyces uvarum) grown in liquid media stop mitosis and form giant cells. Chitin ring formation, being a prerequisite for cell separation, was studied by fluorescence microscopy using Calcofluor White, a chitin specific dye. Experiments with inhibitors of DNA synthesis (hydroxyurea) and chitin synthesis (polyoxin D) demonstrate chitin ring formation to be dependent on DNA synthesis, whereas bud formation is independent of DNA synthesis and chitin ring formation respectively. Basing on these results the formation of X-ray induced giant cells implies one DNA replication which in turn induces the formation of only one chitin ring between mother cell and giant bud. Obviously no septum can be formed. Thus cell separation does not occur, but the bud already formed, produces another bud demonstrating that bud formation itself is independent of DNA synthesis. (orig.)

  17. Increased biological activity of deglycosylated recombinant human granulocyte/macrophage colony-stimulating factor produced by yeast or animal cells

    International Nuclear Information System (INIS)

    Moonen, P.; Mermod, J.J.; Ernst, J.F.; Hirschi, M.; DeLamarter, J.F.

    1987-01-01

    Human granulocyte/macrophage colony-stimulating factor (hGM-CSF) produced by several recombinant sources including Escherichia coli, yeast, and animal cells was studied. Recombinant animal cells produced hGM-CSF in low quantities and in multiple forms of varying size. Mammalian hGM-CSF was purified 200,000-fold using immunoaffinity and lectin chromatography. Partially purified proteins produced in yeast and mammalian cells were assayed for the effects of deglycosylation. Following enzymatic deglycosylation, immunoreactivity was measured by radioimmunoassay and biological activity was measured in vitro on responsive human primary cells. Removal of N-linked oligosaccharides from both proteins increased their immunoreactivities by 4- to 8-fold. Removal of these oligosaccharides also increased their specific biological activities about 20-fold, to reach approximately the specific activity of recombinant hGM-CSF from E. coli. The E. coli produced-protein-lacking any carbohydrate- had by far the highest specific activity observed for the recombinant hGM-CSFs

  18. vasa-related genes and their expression in stem cells of colonial parasitic rhizocephalan barnacle Polyascus polygenea (Arthropoda: Crustacea: Cirripedia: Rhizocephala).

    Science.gov (United States)

    Shukalyuk, Andrey I; Golovnina, Kseniya A; Baiborodin, Sergei I; Gunbin, Konstantin V; Blinov, Alexander G; Isaeva, Valeria V

    2007-02-01

    vasa (vas)-related genes are members of the DEAD-box protein family and are expressed in the germ cells of many Metazoa. We cloned vasa-related genes (PpVLG, CpVLG) and other DEAD-box family related genes (PpDRH1, PpDRH2, CpDRH, AtDRHr) from the colonial parasitic rhizocephalan barnacle Polyascus polygenea, the non-colonial Clistosaccus paguri (Crustacea: Cirripedia: Rhizocephala), and the parasitic isopodan Athelgis takanoshimensis (Crustacea: Isopoda). The colonial Polyascus polygenea, a parasite of the coastal crabs Hemigrapsus sanguineus and Hemigrapsus longitarsis was used as a model object for further detailed investigations. Phylogenetic analysis suggested that PpVLG and CpVLG are closely related to vasa-like genes of other Arthropoda. The rest of the studied genes form their own separate branch on the phylogenetic tree and have a common ancestry with the p68 and PL10 subfamilies. We suppose this group may be a new subfamily of the DEAD-box RNA helicases that is specific for parasitic Crustacea. We found PpVLG and PpDRH1 expression products in stem cells from stolons and buds of internae, during asexual reproduction of colonial P. polygenea, and in germ cells from sexually reproducing externae, including male spermatogenic cells and female oogenic cells.

  19. Reduced proliferation of endothelial colony-forming cells in unprovoked venous thromboembolic disease as a consequence of endothelial dysfunction

    Science.gov (United States)

    Hernandez-Lopez, Rubicel; Chavez-Gonzalez, Antonieta; Torres-Barrera, Patricia; Moreno-Lorenzana, Dafne; Lopez-DiazGuerrero, Norma; Santiago-German, David; Isordia-Salas, Irma; Smadja, David; C. Yoder, Mervin; Majluf-Cruz, Abraham

    2017-01-01

    Background Venous thromboembolic disease (VTD) is a public health problem. We recently reported that endothelial colony-forming cells (ECFCs) derived from endothelial cells (EC) (ECFC-ECs) from patients with VTD have a dysfunctional state. For this study, we proposed that a dysfunctional status of these cells generates a reduction of its proliferative ability, which is also associated with senescence and reactive oxygen species (ROS). Methods and results Human mononuclear cells (MNCs) were obtained from peripheral blood from 40 healthy human volunteers (controls) and 50 patients with VTD matched by age (20−50 years) and sex to obtain ECFCs. We assayed their proliferative ability with plasma of patients and controls and supernatants of cultures from ECFC-ECs, senescence-associated β-galactosidase (SA-β-gal), ROS, and expression of ephrin-B2/Eph-B4 receptor. Compared with cells from controls, cells from VTD patients showed an 8-fold increase of ECFCs that emerged 1 week earlier, reduced proliferation at long term (39%) and, in passages 4 and 10, a highly senescent rate (30±1.05% vs. 91.3±15.07%, respectively) with an increase of ROS and impaired expression of ephrin-B2/Eph-4 genes. Proliferation potential of cells from VTD patients was reduced in endothelial medium [1.4±0.22 doubling population (DP)], control plasma (1.18±0.31 DP), or plasma from VTD patients (1.65±0.27 DP). Conclusions As compared with controls, ECFC-ECs from individuals with VTD have higher oxidative stress, proliferation stress, cellular senescence, and low proliferative potential. These findings suggest that patients with a history of VTD are ECFC-ECs dysfunctional that could be associated to permanent risk for new thrombotic events. PMID:28910333

  20. Spontaneous emergence of large-scale cell cycle synchronization in amoeba colonies

    International Nuclear Information System (INIS)

    Segota, Igor; Boulet, Laurent; Franck, David; Franck, Carl

    2014-01-01

    Unicellular eukaryotic amoebae Dictyostelium discoideum are generally believed to grow in their vegetative state as single cells until starvation, when their collective aspect emerges and they differentiate to form a multicellular slime mold. While major efforts continue to be aimed at their starvation-induced social aspect, our understanding of population dynamics and cell cycle in the vegetative growth phase has remained incomplete. Here we show that cell populations grown on a substrate spontaneously synchronize their cell cycles within several hours. These collective population-wide cell cycle oscillations span millimeter length scales and can be completely suppressed by washing away putative cell-secreted signals, implying signaling by means of a diffusible growth factor or mitogen. These observations give strong evidence for collective proliferation behavior in the vegetative state. (paper)

  1. Lipid nanocarriers containing sorafenib inhibit colonies formation in human hepatocarcinoma cells.

    Science.gov (United States)

    Bondì, Maria Luisa; Botto, Chiara; Amore, Erika; Emma, Maria Rita; Augello, Giuseppa; Craparo, Emanuela Fabiola; Cervello, Melchiorre

    2015-09-30

    Here, the potential of two nanostructured lipid carriers (NLC) for controlled release of sorafenib was evaluated. The obtained systems showed characteristics suitable as drug delivery systems for the treatment of hepatocellular carcinoma (HCC) through parenteral administration. The use of a mixture between a solid lipid (tripalmitin) with a liquid lipid (Captex 355 EP/NF or Miglyol 812) to prepare NLC systems could give a higher drug loading capacity and a longer term stability during storage than that obtained by using only solid lipids. The obtained nanoparticles showed a nanometer size and high negative zeta potential values. Scansion electron microscopy (SEM) of the sorafenib loaded NLC revealed a spherical shape with a diameter <300 nm. In vitro biological studies demonstrated that sorafenib loaded into NLC had enhanced anti-tumor activity compared to that of free drug. This finding raises hope in terms of future drug delivery strategy of sorafenib loaded NLC, that can be useful for therapeutic application in HCC. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Effect of Supplementation of Branched Chain Fatty Acid on Colony of Ruminal Bacteria and Cell of Protozoa

    Directory of Open Access Journals (Sweden)

    W Suryapratama

    2009-05-01

    Full Text Available A study was conducted to evaluate the potential of branched-chain volatile fatty acids (isobutyric, α-methylbutyric and β-methylbutiric that supplemented into the diet on the colony of ruminal bacteria and the cell of protozoa population. Five progeny Friesian Holstein males with initial weight 348±29 kg were used in a 5x5 Latin square design (30-d periods. The basal diet composed of 55% forage and 45% concentrate containing 10.5 MJ ME/kg and 15% crude protein (CP. There were five dietary treatments where A: basal diet, B: A+139 mg urea/kg W0.75, C: B+28 mg CaSO4/kg W0.75, D: C+0.05 mM isobutyric acid+0.05 mM β-methylbutyric acid, and E: D+0.05 mM α-methylbutyric acid. Rearing period was 30 days, consists of feed adaptation period 20 days, then growth observation was done within the last 10 days. Collection of ruminal fluid was done within the last day of observation period, and took 3-4 h after the feeding. The results showed that supplementation branched chain volatile fatty acids did not significant affect on the number of colonies of bacteria and protozoa population, but the significant effect (P<0.05 on the concentration of branched chain volatile fatty acids in the rumen fluid. The supplementation of α-methylbutyric (P <0.05 decreased of concentration of isobutyric and isovaleric in rumen fluid than the other treatments. It is concluded that supplementation of branched chain volatile fatty acids not used by rumen bacteria for their growth but for the elongation of fatty acid synthesis. The supplementation of branched chain volatile fatty acids was 0.05 mM not enough strong influence on the growth of colony of rumen bacteria. (Animal Production 11(2: 129-134 (2009 Key Words: rumen fermentation, branched-chain fatty acid, ruminal bacteria, protozoa

  3. Mobilization and collection of CD34+ cells for autologous transplantation of peripheral blood hematopoietic progenitor cells in children: analysis of two different granulocyte-colony stimulating factor doses

    Directory of Open Access Journals (Sweden)

    Kátia Aparecida de Brito Eid

    2015-06-01

    Full Text Available Introduction: The use of peripheral hematopoietic progenitor cells (HPCs is the cell choice in autologous transplantation. The classic dose of granulocyte-colony stimulating factor (G- CSF for mobilization is a single daily dose of 10 µg/kg of patient body weight. There is a theory that higher doses of granulocyte-colony stimulating factor applied twice daily could increase the number of CD34+ cells collected in fewer leukapheresis procedures. Objective: The aim of this study was to compare a fractionated dose of 15 µg G-CSF/kg of body weight and the conventional dose of granulocyte-colony stimulating factor in respect to the number of leukapheresis procedures required to achieve a minimum collection of 3 × 106 CD34+ cells/kg body weight. Methods: Patients were divided into two groups: Group 10 - patients who received a single daily dose of 10 µg G-CSF/kg body weight and Group 15 - patients who received a fractioned dose of 15 µg G-CSF/kg body weight daily. The leukapheresis procedure was carried out in an automated cell separator. The autologous transplantation was carried out when a minimum number of 3 × 106 CD34+ cells/kg body weight was achieved. Results: Group 10 comprised 39 patients and Group 15 comprised 26 patients. A total of 146 apheresis procedures were performed: 110 (75.3% for Group 10 and 36 (24.7% for Group 15. For Group 10, a median of three (range: 1-7 leukapheresis procedures and a mean of 8.89 × 106 CD34+ cells/kg body weight (±9.59 were collected whereas for Group 15 the corresponding values were one (range: 1-3 and 5.29 × 106 cells/kg body weight (±4.95. A statistically significant difference was found in relation to the number of apheresis procedures (p-value <0.0001. Conclusions: To collect a minimum target of 3 × 106 CD34+ cells/kg body weight, the administration of a fractionated dose of 15 µg G-CSF/kg body weight significantly decreased the number of leukapheresis procedures performed.

  4. Stem cells are units of natural selection for tissue formation, for germline development, and in cancer development.

    Science.gov (United States)

    Weissman, Irving L

    2015-07-21

    It is obvious that natural selection operates at the level of individuals and collections of individuals. Nearly two decades ago we showed that in multi-individual colonies of protochordate colonial tunicates sharing a blood circulation, there exists an exchange of somatic stem cells and germline stem cells, resulting in somatic chimeras and stem cell competitions for gonadal niches. Stem cells are unlike other cells in the body in that they alone self-renew, so that they form clones that are perpetuated for the life of the organism. Stem cell competitions have allowed the emergence of competitive somatic and germline stem cell clones. Highly successful germline stem cells usually outcompete less successful competitors both in the gonads of the genotype partner from which they arise and in the gonads of the natural parabiotic partners. Therefore, natural selection also operates at the level of germline stem cell clones. In the colonial tunicate Botryllus schlosseri the formation of natural parabionts is prevented by a single-locus highly polymorphic histocompatibility gene called Botryllus histocompatibility factor. This limits germline stem cell predation to kin, as the locus has hundreds of alleles. We show that in mice germline stem cells compete for gonad niches, and in mice and humans, blood-forming stem cells also compete for bone marrow niches. We show that the clonal progression from blood-forming stem cells to acute leukemias by successive genetic and epigenetic events in blood stem cells also involves competition and selection between clones and propose that this is a general theme in cancer.

  5. Accumulated lipids rather than the rigid cell walls impede the extraction of genetic materials for effective colony PCRs in Chlorella vulgaris

    Science.gov (United States)

    2013-01-01

    Background Failure of colony PCRs in green microalga Chlorella vulgaris is typically attributed to the difficulty in disrupting its notoriously rigid cell walls for releasing the genetic materials and therefore the development of an effective colony PCR procedure in C. vulgaris presents a challenge. Results Here we identified that colony PCR results were significantly affected by the accumulated lipids rather than the rigid cell walls of C. vulgaris. The higher lipids accumulated in C. vulgaris negatively affects the effective amplification by DNA polymerase. Based on these findings, we established a simple and extremely effective colony PCR procedure in C. vulgaris. By simply pipetting/votexing the pellets of C. vulgaris in 10 ul of either TE (10 mM Tris/1 mM EDTA) or 0.2% SDS buffer at room temperature, followed by the addition of 10 ul of either hexane or Phenol:Chloroform:Isoamyl Alcohol in the same PCR tube for extraction. The resulting aqueous phase was readily PCR-amplified as genomic DNA templates as demonstrated by successful amplification of the nuclear 18S rRNA and the chloroplast rbcL gene. This colony PCR protocol is effective and robust in C. vulgaris and also demonstrates its effectiveness in other Chlorella species. Conclusions The accumulated lipids rather than the rigid cell walls of C. vulgaris significantly impede the extraction of genetic materials and subsequently the effective colony PCRs. The finding has the potential to aid the isolation of high-quality total RNAs and mRNAs for transcriptomic studies in addition to the genomic DNA isolation in Chlorella. PMID:24219401

  6. Spatio-temporal morphology changes in and quenching effects on the 2D spreading dynamics of cell colonies in both plain and methylcellulose-containing culture media.

    Science.gov (United States)

    Muzzio, N E; Pasquale, M A; Huergo, M A C; Bolzán, A E; González, P H; Arvia, A J

    2016-06-01

    To deal with complex systems, microscopic and global approaches become of particular interest. Our previous results from the dynamics of large cell colonies indicated that their 2D front roughness dynamics is compatible with the standard Kardar-Parisi-Zhang (KPZ) or the quenched KPZ equations either in plain or methylcellulose (MC)-containing gel culture media, respectively. In both cases, the influence of a non-uniform distribution of the colony constituents was significant. These results encouraged us to investigate the overall dynamics of those systems considering the morphology and size, the duplication rate, and the motility of single cells. For this purpose, colonies with different cell populations (N) exhibiting quasi-circular and quasi-linear growth fronts in plain and MC-containing culture media are investigated. For small N, the average radial front velocity and its change with time depend on MC concentration. MC in the medium interferes with cell mitosis, contributes to the local enlargement of cells, and increases the distribution of spatio-temporal cell density heterogeneities. Colony spreading in MC-containing media proceeds under two main quenching effects, I and II; the former mainly depending on the culture medium composition and structure and the latter caused by the distribution of enlarged local cell domains. For large N, colony spreading occurs at constant velocity. The characteristics of cell motility, assessed by measuring their trajectories and the corresponding velocity field, reflect the effect of enlarged, slow-moving cells and the structure of the medium. Local average cell size distribution and individual cell motility data from plain and MC-containing media are qualitatively consistent with the predictions of both the extended cellular Potts models and the observed transition of the front roughness dynamics from a standard KPZ to a quenched KPZ. In this case, quenching effects I and II cooperate and give rise to the quenched

  7. The formation and repair of cisplatin-DNA adducts in wild-type and cisplatin-resistant L1210 cells : comparison of immunocytochemical determination with detection in isolated DNA

    NARCIS (Netherlands)

    Blommaert, F.A.; Floot, B.G.J.; Dijk-Knijnenburg, H.C.M. van; Berends, F.; Baan, R.A.; Schornagel, J.H.; Engelse, L. den; Fichtinger-Schepman, A.M.J.

    1998-01-01

    We have studied the formation and repair of cisplatin-DNA adducts in wild-type mouse leukemia L1210/0 cells and in the sublines L1210/2 and L1210/5, which differ in cisplatin sensitivity. In a colony-formation assay these sublines were 9- and 22-fold more resistant compared to L1210/0, respectively.

  8. Colony stimulating factors and their clinical implication

    International Nuclear Information System (INIS)

    Asano, Shigetaka

    1989-01-01

    Granulocytes and macrophage are dependent for their production and/or functional activation in vitro on the presence of a family of glycoproteins. They are generally called colony-stimulating factors (CSFs) because of their capacity to stimulate colony formation in semi-solid cultures, and are currently classified into four distinct subtypes, that is, Multi-CSF, GM-CSF, G-CSF and M-CSF, according to the cell type of colonies formed under their stimulation or their target cell specificity. All of the murine and human CSF subtypes and the genes for them have become available in a purified form and in a large scale, and now allow us to investigate their interactions, the mechanisms for their actions, the cell-cell interactions leading to their production and secretion, and their actions in vivo. Furthermore, the preclinical and/or clinical studies which were carried out using the purified CSFs strongly indicate that human CSFs will be effective strategies for preventing and treating opportunistic bacterial and fungal infection as a major cause of death in granulocytopenic patients. (author)

  9. Micronucleus formation compared to the survival rate of human melanoma cells after X-ray and neutron irradiation and hyperthermia

    Energy Technology Data Exchange (ETDEWEB)

    van Beuningen, D.; Streffer, C.; Bertholdt, G.

    1981-09-01

    After neutron and X-ray irradiation and combined X-ray irradiation and hyperthermia (3 hours, 42/sup 0/C), the survival rate of human melanoma cells was measured by means of the colony formation test and compared to the formation of micronuclei. Neutrons had a stronger effect on the formation of micronuclei than the combination of X-rays and hyperthermia. X-rays had the lowest effect. The dose effect curve showed a break at that dose level at which a reduction of cells was observed in the cultures. A good relation between survival rate and formation of micronuclei was found for the X-ray irradiation, but not for the neutron irradiation and the combined treatment. These observations are discussed. At least for X-rays, the micronucleus test has turned out to be a good screening method for the radiosensitivity of a biologic system.

  10. OCT4 expression in outgrowth colonies derived from porcine inner cell masses and epiblasts

    DEFF Research Database (Denmark)

    Rasmussen, M A; Wolf, X A; Schauser, K

    2011-01-01

    on the relationship between OCT4 expression and embryonic stem cell (ESC)-like morphology. A total of 104 zona pellucida-enclosed and 101 hatched blastocysts were subjected to four different methods of ICM and epiblast isolation, respectively: Manual isolation, immunosurgery, immunosurgery with manual cleaning......, or whole blastocyst culture. OCs were established on mouse embryonic fibroblast (MEF) cells and categorized according to morphology and OCT4 staining. Although all isolation methods resulted in ESC-like OCs, immunosurgery with manual cleaning yielded significantly higher rates of ICM/epiblast attachment...

  11. Role of Granulocyte-Macrophage Colony-Stimulating Factor Production by T Cells during Mycobacterium tuberculosis Infection.

    Science.gov (United States)

    Rothchild, Alissa C; Stowell, Britni; Goyal, Girija; Nunes-Alves, Cláudio; Yang, Qianting; Papavinasasundaram, Kadamba; Sassetti, Christopher M; Dranoff, Glenn; Chen, Xinchun; Lee, Jinhee; Behar, Samuel M

    2017-10-24

    Mice deficient for granulocyte-macrophage colony-stimulating factor (GM-CSF -/- ) are highly susceptible to infection with Mycobacterium tuberculosis , and clinical data have shown that anti-GM-CSF neutralizing antibodies can lead to increased susceptibility to tuberculosis in otherwise healthy people. GM-CSF activates human and murine macrophages to inhibit intracellular M. tuberculosis growth. We have previously shown that GM-CSF produced by iNKT cells inhibits growth of M. tuberculosis However, the more general role of T cell-derived GM-CSF during infection has not been defined and how GM-CSF activates macrophages to inhibit bacterial growth is unknown. Here we demonstrate that, in addition to nonconventional T cells, conventional T cells also produce GM-CSF during M. tuberculosis infection. Early during infection, nonconventional iNKT cells and γδ T cells are the main source of GM-CSF, a role subsequently assumed by conventional CD4 + T cells as the infection progresses. M. tuberculosis -specific T cells producing GM-CSF are also detected in the peripheral blood of infected people. Under conditions where nonhematopoietic production of GM-CSF is deficient, T cell production of GM-CSF is protective and required for control of M. tuberculosis infection. However, GM-CSF is not required for T cell-mediated protection in settings where GM-CSF is produced by other cell types. Finally, using an in vitro macrophage infection model, we demonstrate that GM-CSF inhibition of M. tuberculosis growth requires the expression of peroxisome proliferator-activated receptor gamma (PPARγ). Thus, we identified GM-CSF production as a novel T cell effector function. These findings suggest that a strategy augmenting T cell production of GM-CSF could enhance host resistance against M. tuberculosis IMPORTANCE Mycobacterium tuberculosis is the bacterium that causes tuberculosis, the leading cause of death by any infection worldwide. T cells are critical components of the immune

  12. Granulocyte-colony stimulating factor and umbilical cord blood cell transplantation: Synergistic therapies for the treatment of traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Michael G Liska

    2017-01-01

    Full Text Available Traumatic brain injury (TBI is now characterized as a progressive, degenerative disease and continues to stand as a prevalent cause of death and disability. The pathophysiology of TBI is complex, with a variety of secondary cell death pathways occurring which may persist chronically following the initial cerebral insult. Current therapeutic options for TBI are minimal, with surgical intervention or rehabilitation therapy existing as the only viable treatments. Considering the success of stem-cell therapies in various other neurological diseases, their use has been proposed as a potential potent therapy for patients suffering TBI. Moreover, stem cells are highly amenable to adjunctive use with other therapies, providing an opportunity to overcome the inherent limitations of using a single therapeutic agent. Our research has verified this additive potential by demonstrating the efficacy of co-delivering human umbilical cord blood (hUCB cells with granulocyte-colony stimulating factor (G-CSF in a murine model of TBI, providing encouraging results which support the potential of this approach to treat patients suffering from TBI. These findings justify ongoing research toward uncovering the mechanisms which underlie the functional improvements exhibited by hUCB + G-CSF combination therapy, thereby facilitating its safe and effect transition into the clinic. This paper is a review article. Referred literature in this paper has been listed in the reference section. The datasets supporting the conclusions of this article are available online by searching various databases, including PubMed. Some original points in this article come from the laboratory practice in our research center and the authors' experiences.

  13. Self-Organization of Stem Cell Colonies and of Early Mammalian Embryos: Recent Experiments Shed New Light on the Role of Autonomy vs. External Instructions in Basic Body Plan Development

    Directory of Open Access Journals (Sweden)

    Hans-Werner Denker

    2016-10-01

    Full Text Available “Organoids”, i.e., complex structures that can develop when pluripotent or multipotent stem cells are maintained in three-dimensional cultures, have become a new area of interest in stem cell research. Hopes have grown that when focussing experimentally on the mechanisms behind this type of in vitro morphogenesis, research aiming at tissue and organ replacements can be boosted. Processes leading to the formation of organoids in vitro are now often addressed as self-organization, a term referring to the formation of complex tissue architecture in groups of cells without depending on specific instruction provided by other cells or tissues. The present article focuses on recent reports using the term self-organization in the context of studies on embryogenesis, specifically addressing pattern formation processes in human blastocysts attaching in vitro, or in colonies of pluripotent stem cells (“gastruloids”. These morphogenetic processes are of particular interest because, during development in vivo, they lead to basic body plan formation and individuation. Since improved methodologies like those employed by the cited authors became available, early embryonic pattern formation/self-organization appears to evolve now as a research topic of its own. This review discusses concepts concerning the involved mechanisms, focussing on autonomy of basic body plan development vs. dependence on external signals, as possibly provided by implantation in the uterus, and it addresses biological differences between an early mammalian embryo, e.g., a morula, and a cluster of pluripotent stem cells. It is concluded that, apart from being of considerable biological interest, the described type of research needs to be contemplated carefully with regard to ethical implications when performed with human cells.

  14. Formation of reactive oxygen species in rat epithelial cells upon ...

    Indian Academy of Sciences (India)

    In our study, we investigated the influence of fly ash on the promotion of early inflammatory reactions like the formation of reactive oxygen species (ROS) in rat lung epithelial cells (RLE-6TN). Furthermore, we determined the formation of nitric oxide (NO). The cells show a clear dose-response relationship concerning the ...

  15. The optimal use of granulocyte macrophage colony stimulating factor in radiation induced mucositis in head and neck squamous cell carcinoma.

    Directory of Open Access Journals (Sweden)

    Patni Nidhi

    2005-01-01

    Full Text Available Objective: Evaluation of response of granulocyte macrophage colony stimulating factor (GM-CSF on acute radiation toxicity profile in head and neck squamous cell carcinoma. Methods and Materials: Thirty three patients with proven stage I or II head & neck carcinoma received conventional external beam radiation therapy. Out of these, six patients received postoperative adjuvant therapy while remaining 27 received definitive RT. Patients were given 100 mcg GM-CSF subcutaneously per day along with radiation after they developed grade 2 mucositis and /or grade 2 dysphagia and / or complained of moderate pain. GM-CSF was administered till there was a subjective relief or objective response. Patients were evaluated for oral ulceration, swallowing status, pain and weight loss. Response to the treatment and patient outcome was assessed. Results: There was a decreased severity of mucositis and dysphagia in the evaluated patients. None of the patients suffered severe pain or required opioids. The mean weight loss was only 1.94%. Minimal side effects were experienced with GM-CSF. Conclusions: GM-CSF reduces the severity of acute side effects of radiation therapy thereby allowing completion of the treatment without interruption. Its remarkable response needs to be evaluated further in large randomized trials. The time of initiation and cessation of GM-CSF during radiation therapy and the required dose needs to be established.

  16. Mobilization of stem cell with granulocyte-colony stimulating factor promotes recovery after traumatic brain injury in rat

    Directory of Open Access Journals (Sweden)

    Mohsen Marzban

    2010-01-01

    Full Text Available Introduction: This study was designed to investigate the effects of granulocyte colony-stimulating factor (G-CSF administration in rats for 6 weeks after traumatic brain injury (TBI. Methods: Adult male Wistar rats (n = 30 were injured with controlled cortical impact device and divided into four groups. The treatment groups (n = 10 each were injected subcutaneously with recombinant human G-CSF. Vehicle group (n=10 received phosphate buffered saline (PBS and only Brdu intraperitoneally. Bromodeoxyuridine (BrdU was used for mitotic labeling. Experimental rats were injected intraperitoneally with BrdU. Rats were killed at 6th week after traumatic brain injury. Neurological functional evaluation of animals was performed before and after injury using neurological severity scores (NSS. Animals were sacrificed 42 days after TBI and brain sections were stained using Brdu immunohistochemistry. Results: Statistically significant improvement in functional outcome was observed in treatment groups when compared with control (p<0.01. This benefit was visible 7 days after TBI and persisted until 42 days (end of trial. Histological analysis showed that Brdu cell positive was more in the lesion boundary zone at treatment animal group than all injected animals. Discussion: We believe that G-CSF therapeutic protocol reported here represents an attractive strategy for the development of a clinically significant noninvasive traumatic brain injury therapy.

  17. Cholesterol inhibits entotic cell-in-cell formation and actomyosin contraction.

    Science.gov (United States)

    Ruan, Banzhan; Zhang, Bo; Chen, Ang; Yuan, Long; Liang, Jianqing; Wang, Manna; Zhang, Zhengrong; Fan, Jie; Yu, Xiaochen; Zhang, Xin; Niu, Zubiao; Zheng, You; Gu, Songzhi; Liu, Xiaoqing; Du, Hongli; Wang, Jufang; Hu, Xianwen; Gao, Lihua; Chen, Zhaolie; Huang, Hongyan; Wang, Xiaoning; Sun, Qiang

    2018-01-01

    Cell-in-cell structure is prevalent in human cancer, and associated with several specific pathophysiological phenomena. Although cell membrane adhesion molecules were found critical for cell-in-cell formation, the roles of other membrane components, such as lipids, remain to be explored. In this study, we attempted to investigate the effects of cholesterol and phospholipids on the formation of cell-in-cell structures by utilizing liposome as a vector. We found that Lipofectamine-2000, the reagent commonly used for routine transfection, could significantly reduce entotic cell-in-cell formation in a cell-specific manner, which is correlated with suppressed actomyosin contraction as indicated by reduced β-actin expression and myosin light chain phosphorylation. The influence on cell-in-cell formation was likely dictated by specific liposome components as some liposomes affected cell-in-cell formation while some others didn't. Screening on a limited number of lipids, the major components of liposome, identified phosphatidylethanolamine (PE), stearamide (SA), lysophosphatidic acid (LPA) and cholesterol (CHOL) as the inhibitors of cell-in-cell formation. Importantly, cholesterol treatment significantly inhibited myosin light chain phosphorylation, which resembles the effect of Lipofectamine-2000, suggesting cholesterol might be partially responsible for liposomes' effects on cell-in-cell formation. Together, our findings supporting a role of membrane lipids and cholesterol in cell-in-cell formation probably via regulating actomyosin contraction. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Genetic Interaction Mapping in Schizosaccharomyces pombe Using the Pombe Epistasis Mapper (PEM) System and a ROTOR HDA Colony Replicating Robot in a 1536 Array Format.

    Science.gov (United States)

    Roguev, Assen; Xu, Jiewei; Krogan, Nevan

    2018-02-01

    This protocol describes an optimized high-throughput procedure for generating double deletion mutants in Schizosaccharomyces pombe using the colony replicating robot ROTOR HDA and the PEM (pombe epistasis mapper) system. The method is based on generating high-density colony arrays (1536 colonies per agar plate) and passaging them through a series of antidiploid and mating-type selection (ADS-MTS) and double-mutant selection (DMS) steps. Detailed program parameters for each individual replication step are provided. Using this procedure, batches of 25 or more screens can be routinely performed. © 2018 Cold Spring Harbor Laboratory Press.

  19. Design of Recombinant Stem Cell Factor macrophage Colony Stimulating Factor Fusion Proteins and their Biological Activity In Vitro

    Science.gov (United States)

    Chen, Tao; Yang, Jie; Wang, Yuelang; Zhan, Chenyang; Zang, Yuhui; Qin, Junchuan

    2005-05-01

    Stem cell factor (SCF) and macrophage colony stimulating factor (M-CSF) can act in synergistic way to promote the growth of mononuclear phagocytes. SCF-M-CSF fusion proteins were designed on the computer using the Homology and Biopolymer modules of the software packages InsightII. Several existing crystal structures were used as templates to generate models of the complexes of receptor with fusion protein. The structure rationality of the fusion protein incorporated a series of flexible linker peptide was analyzed on InsightII system. Then, a suitable peptide GGGGSGGGGSGG was chosen for the fusion protein. Two recombinant SCF-M-CSF fusion proteins were generated by construction of a plasmid in which the coding regions of human SCF (1-165aa) and M-CSF (1-149aa) cDNA were connected by this linker peptide coding sequence followed by subsequent expression in insect cell. The results of Western blot and activity analysis showed that these two recombinant fusion proteins existed as a dimer with a molecular weight of 84 KD under non-reducing conditions and a monomer of 42 KD at reducing condition. The results of cell proliferation assays showed that each fusion protein induced a dose-dependent proliferative response. At equimolar concentration, SCF/M-CSF was about 20 times more potent than the standard monomeric SCF in stimulating TF-1 cell line growth, while M-CSF/SCF was 10 times of monomeric SCF. No activity difference of M-CSF/SCF or SCF/M-CSF to M-CSF (at same molar) was found in stimulating the HL-60 cell linear growth. The synergistic effect of SCF and M-CSF moieties in the fusion proteins was demonstrated by the result of clonogenic assay performed with human bone mononuclear, in which both SCF/M-CSF and M-CSF/SCF induced much higher number of CFU-M than equimolar amount of SCF or M-CSF or that of two cytokines mixture.

  20. Cell Growth Rate Dictates the Onset of Glass to Fluidlike Transition and Long Time Superdiffusion in an Evolving Cell Colony

    Science.gov (United States)

    Malmi-Kakkada, Abdul N.; Li, Xin; Samanta, Himadri S.; Sinha, Sumit; Thirumalai, D.

    2018-04-01

    Collective migration dominates many phenomena, from cell movement in living systems to abiotic self-propelling particles. Focusing on the early stages of tumor evolution, we enunciate the principles involved in cell dynamics and highlight their implications in understanding similar behavior in seemingly unrelated soft glassy materials and possibly chemokine-induced migration of CD 8+T cells. We performed simulations of tumor invasion using a minimal three-dimensional model, accounting for cell elasticity and adhesive cell-cell interactions, as well as cell birth and death, to establish that cell-growth-rate-dependent tumor expansion results in the emergence of distinct topological niches. Cells at the periphery move with higher velocity perpendicular to the tumor boundary, while the motion of interior cells is slower and isotropic. The mean-square displacement Δ (t ) of cells exhibits glassy behavior at times comparable to the cell cycle time, while exhibiting superdiffusive behavior, Δ (t )≈tα (α >1 ), at longer times. We derive the value of α ≈1.33 using a field theoretic approach based on stochastic quantization. In the process, we establish the universality of superdiffusion in a class of seemingly unrelated nonequilibrium systems. Superdiffusion at long times arises only if there is an imbalance between cell birth and death rates. Our findings for the collective migration, which also suggest that tumor evolution occurs in a polarized manner, are in quantitative agreement with in vitro experiments. Although set in the context of tumor invasion, the findings should also hold in describing the collective motion in growing cells and in active systems, where creation and annihilation of particles play a role.

  1. Biological role of granulocyte macrophage colony-stimulating factor (GM-CSF) and macrophage colony-stimulating factor (M-CSF) on cells of the myeloid lineage

    Science.gov (United States)

    Ushach, Irina; Zlotnik, Albert

    2016-01-01

    M-CSF and GM-CSF are 2 important cytokines that regulate macrophage numbers and function. Here, we review their known effects on cells of the macrophage-monocyte lineage. Important clues to their function come from their expression patterns. M-CSF exhibits a mostly homeostatic expression pattern, whereas GM-CSF is a product of cells activated during inflammatory or pathologic conditions. Accordingly, M-CSF regulates the numbers of various tissue macrophage and monocyte populations without altering their "activation" status. Conversely, GM-CSF induces activation of monocytes/macrophages and also mediates differentiation to other states that participate in immune responses [i.e., dendritic cells (DCs)]. Further insights into their function have come from analyses of mice deficient in either cytokine. M-CSF signals through its receptor (CSF-1R). Interestingly, mice deficient in CSF-1R expression exhibit a more significant phenotype than mice deficient in M-CSF. This observation was explained by the discovery of a novel cytokine (IL-34) that represents a second ligand of CSF-1R. Information about the function of these ligands/receptor system is still developing, but its complexity is intriguing and strongly suggests that more interesting biology remains to be elucidated. Based on our current knowledge, several therapeutic molecules targeting either the M-CSF or the GM-CSF pathways have been developed and are currently being tested in clinical trials targeting either autoimmune diseases or cancer. It is intriguing to consider how evolution has directed these pathways to develop; their complexity likely mirrors the multiple functions in which cells of the monocyte/macrophage system are involved. PMID:27354413

  2. Benefits of gene transduction of granulocyte macrophage colony-stimulating factor in cancer vaccine using genetically modified dendritic cells.

    Science.gov (United States)

    Ojima, Toshiyasu; Iwahashi, Makoto; Nakamura, Masaki; Matsuda, Kenji; Nakamori, Mikihito; Ueda, Kentaro; Naka, Teiji; Katsuda, Masahiro; Miyazawa, Motoki; Yamaue, Hiroki

    2007-10-01

    Granulocyte macrophage colony-stimulating factor (GM-CSF) is a key cytokine for the generation and stimulation of dendritic cells (DCs), and it may also play a pivotal role in promoting the survival of DCs. In this study, the feasibility of creating a cancer vaccine using DCs adenovirally transduced with the carcinoembryonic antigen (CEA) gene and the GM-CSF gene was examined. In addition, the effect of the co-transduction of GM-CSF gene on the lifespan of these genetically modified DCs was determined. A cytotoxic assay using peripheral blood mononuclear cell (PBMC)-derived cytotoxic T lymphocytes (CTLs) was performed in a 4-h 51Cr release assay. The apoptosis of DCs was examined by TdT-mediated dUTP-FITC nick end labeling (TUNEL) assay. CEA-specific CTLs were generated from PBMCs stimulated with genetically modified DCs expressing CEA. The cytotoxicity of these CTLs was augmented by co-transduction of DCs with the GM-CSF gene. Co-transduction of the GM-CSF gene into DCs inhibited apoptosis of these DCs themselves via up-regulation of Bcl-x(L) expression, leading to the extension of the lifespan of these DCs. Furthermore, the transduction of the GM-CSF gene into DCs also suppressed the incidence of apoptosis of DCs induced by transforming growth factor-beta1 (TGFbeta-1). Immunotherapy using these genetically modified DCs may therefore be useful with several advantages as follows: i) adenoviral toxicity to DCs can be reduced; ii) the lifespan of vaccinated DCs can be prolonged; and iii) GM-CSF may protect DCs from apoptosis induced by tumor-derived TGFbeta-1 in the regional lymph nodes.

  3. Cell Competition Drives the Formation of Metastatic Tumors in a Drosophila Model of Epithelial Tumor Formation

    DEFF Research Database (Denmark)

    Eichenlaub, Teresa; Cohen, Stephen M; Herranz, Héctor

    2016-01-01

    . The mechanisms that allow for ongoing cell competition during adult life could, in principle, contribute to tumorigenesis. However, direct evidence supporting this hypothesis has been lacking. Here, we provide evidence that cell competition drives tumor formation in a Drosophila model of epithelial cancer. Cells...

  4. Dysregulation of endothelial colony-forming cell function by a negative feedback loop of circulating miR-146a and -146b in cardiovascular disease patients.

    Directory of Open Access Journals (Sweden)

    Ting-Yu Chang

    Full Text Available Functional impairment of endothelial colony-forming cells (ECFCs, a specific cell lineage of endothelial progenitor cells (EPCs is highly associated with the severity of coronary artery disease (CAD, the most common type of cardiovascular disease (CVD. Emerging evidence show that circulating microRNAs (miRNAs in CAD patients' body fluid hold a great potential as biomarkers. However, our knowledge of the role of circulating miRNA in regulating the function of ECFCs and the progression of CAD is still in its infancy. We showed that when ECFCs from healthy volunteers were incubated with conditioned medium or purified exosomes of cultured CAD ECFCs, the secretory factors from CAD ECFCs dysregulated migration and tube formation ability of healthy ECFCs. It is known that exosomes influence the physiology of recipient cells by introducing RNAs including miRNAs. By using small RNA sequencing (smRNA-seq, we deciphered the circulating miRNome in the plasma of healthy individual and CAD patients, and found that the plasma miRNA spectrum from CAD patients was significantly different from that of healthy control. Interestingly, smRNA-seq of both healthy and CAD ECFCs showed that twelve miRNAs that had a higher expression in the plasma of CAD patients also showed higher expression in CAD ECFCs when compared with healthy control. This result suggests that these miRNAs may be involved in the regulation of ECFC functions. For identification of potential mRNA targets of the differentially expressed miRNA in CAD patients, cDNA microarray analysis was performed to identify the angiogenesis-related genes that were down-regulated in CAD ECFCs and Pearson's correlation were used to identify miRNAs that were negatively correlated with the identified angiogenesis-related genes. RT-qPCR analysis of the five miRNAs that negatively correlated with the down-regulated angiogenesis-related genes in plasma and ECFC of CAD patients showed miR-146a-5p and miR-146b-5p up

  5. Defibrotide in combination with granulocyte colony-stimulating factor significantly enhances the mobilization of primitive and committed peripheral blood progenitor cells in mice.

    Science.gov (United States)

    Carlo-Stella, Carmelo; Di Nicola, Massimo; Magni, Michele; Longoni, Paolo; Milanesi, Marco; Stucchi, Claudio; Cleris, Loredana; Formelli, Franca; Gianni, Massimo A

    2002-11-01

    Defibrotide is a polydeoxyribonucleotide, which significantly reduces the expression of adhesion molecules on endothelial cells. We investigated the activity of Defibrotide alone or in combination with recombinant human granulocyte colony-stimulating factor (rhG-CSF) to mobilize peripheral blood progenitor cells (PBPCs) in BALB/c mice. A 5-day treatment with Defibrotide alone (1-15 mg/mouse/day) had no effect on WBC counts, frequencies and absolute numbers of total circulating colony-forming cells (CFCs), i.e., granulocyte-macrophage colony-forming units, erythroid burst-forming units, and multilineage colony-forming units. As compared with mock-injected mice, administration of rhG-CSF alone (5 micro g/mouse/day) for 5 days significantly (P Defibrotide (15 mg/mouse/day) and rhG-CSF significantly (P Defibrotide plus rhG-CSF resulted in a significant increase (P Defibrotide/rhG-CSF-mobilized mononuclear cells rescued 43% and 71% of recipient mice, respectively. Experiments of CFC homing performed in lethally irradiated or nonirradiated recipients showed that marrow homing of transplanted PBPCs was reduced by 3-fold in Defibrotide-treated animals as compared with mock-injected mice (P Defibrotide might be because of an effect on PBPC trafficking. In conclusion, our data demonstrate that Defibrotide synergizes with rhG-CSF and significantly increases the mobilization of a broad spectrum of PBPCs, including primitive and committed progenitor cells. These data might have relevant implications for autologous and allogeneic anticancer therapy in humans.

  6. Manipulation of the response of human endothelial colony-forming cells by focal adhesion assembly using gradient nanopattern plates.

    Science.gov (United States)

    Cui, Long-Hui; Joo, Hyung Joon; Kim, Dae Hwan; Seo, Ha-Rim; Kim, Jung Suk; Choi, Seung-Cheol; Huang, Li-Hua; Na, Ji Eun; Lim, I-Rang; Kim, Jong-Ho; Rhyu, Im Joo; Hong, Soon Jun; Lee, Kyu Back; Lim, Do-Sun

    2018-01-01

    Nanotopography plays a pivotal role in the regulation of cellular responses. Nonetheless, little is known about how the gradient size of nanostructural stimuli alters the responses of endothelial progenitor cells without chemical factors. Herein, the fabrication of gradient nanopattern plates intended to mimic microenvironment nanotopography is described. The gradient nanopattern plates consist of nanopillars of increasing diameter ranges [120-200 nm (GP 120/200), 200-280 nm (GP 200/280), and 280-360 nm (GP 280/360)] that were used to screen the responses of human endothelial colony-forming cells (hECFCs). Nanopillars with a smaller nanopillar diameter caused the cell area and perimeter of hECFCs to decrease and their filopodial outgrowth to increase. The structure of vinculin (a focal adhesion marker in hECFCs) was also modulated by nanostructural stimuli of the gradient nanopattern plates. Moreover, Rho-associated protein kinase (ROCK) gene expression was significantly higher in hECFCs cultured on GP 120/200 than in those on flat plates (no nanopillars), and ROCK suppression impaired the nanostructural-stimuli-induced vinculin assembly. These results suggest that the gradient nanopattern plates generate size-specific nanostructural stimuli suitable for manipulation of the response of hECFCs, in a process dependent on ROCK signaling. This is the first evidence of size-specific nanostructure-sensing behavior of hECFCs. Nano feature surfaces are of growing interest as materials for a controlled response of various cells. In this study, we successfully fabricated gradient nanopattern plates to manipulate the response of blood-derived hECFCs without any chemical stimulation. Interestingly, we find that the sensitive nanopillar size for manipulation of hECFCs is range between 120 nm and 200 nm, which decreased the area and increased the filopodial outgrowth of hECFCs. Furthermore, we only modulate the nanopillar size to increase ROCK expression can be an

  7. Lipocalin-2 inhibits osteoclast formation by suppressing the proliferation and differentiation of osteoclast lineage cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun-Ju, E-mail: biohjk@knu.ac.kr [Department of Molecular Medicine, Cell and Matrix Research Institute, Clinical Trial Center, BK21 Plus KNU Biomedical Convergence Program, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Yoon, Hye-Jin [Department of Molecular Medicine, Cell and Matrix Research Institute, Clinical Trial Center, BK21 Plus KNU Biomedical Convergence Program, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Yoon, Kyung-Ae [Department of Orthopedic Surgery, Skeletal Diseases Genome Research Center, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Gwon, Mi-Ri; Jin Seong, Sook [Department of Molecular Medicine, Cell and Matrix Research Institute, Clinical Trial Center, BK21 Plus KNU Biomedical Convergence Program, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Suk, Kyoungho [Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Kim, Shin-Yoon [Department of Orthopedic Surgery, Skeletal Diseases Genome Research Center, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Yoon, Young-Ran, E-mail: yry@knu.ac.kr [Department of Molecular Medicine, Cell and Matrix Research Institute, Clinical Trial Center, BK21 Plus KNU Biomedical Convergence Program, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of)

    2015-06-10

    Lipocalin-2 (LCN2) is a member of the lipocalin superfamily and plays a critical role in the regulation of various physiological processes, such as inflammation and obesity. In this study, we report that LCN2 negatively modulates the proliferation and differentiation of osteoclast precursors, resulting in impaired osteoclast formation. The overexpression of LCN2 in bone marrow-derived macrophages or the addition of recombinant LCN2 protein inhibits the formation of multinuclear osteoclasts. LCN2 suppresses macrophage colony-stimulating factor (M-CSF)-induced proliferation of osteoclast precursor cells without affecting their apoptotic cell death. Interestingly, LCN2 decreases the expression of the M-CSF receptor, c-Fms, and subsequently blocks its downstream signaling cascades. In addition, LCN2 inhibits RANKL-induced osteoclast differentiation and attenuates the expression of c-Fos and nuclear factor of activated T cells c1 (NFATc1), which are important modulators in osteoclastogenesis. Mechanistically, LCN2 inhibits NF-κB signaling pathways, as demonstrated by the suppression of IκBα phosphorylation, nuclear translocation of p65, and NF-κB transcriptional activity. Thus, LCN2 is an anti-osteoclastogenic molecule that exerts its effects by retarding the proliferation and differentiation of osteoclast lineage cells. - Highlights: • LCN2 expression is regulated during osteoclast development. • LCN2 suppresses M-CSF-mediated osteoclast precursor proliferation. • LCN2 inhibits RANKL-induced osteoclast differentiation.

  8. Photoreactivation of ultraviolet light-induced damage in cultured fish cells as revealed by increased colony forming ability and decreased content of pyrimidine dimers

    International Nuclear Information System (INIS)

    Shima, A.; Ikenaga, M.; Egami, N.

    1981-01-01

    Cultured cells derived from a goldfish were irradiated with 254 nm ultraviolet light. Cell survival and splitting of pyrimidine dimers after photoreactivation treatment with white fluorescent lamps were examined by colony forming ability and by a direct dimer assay, respectively. When UV-irradiated (5 J/m 2 ) cells were illuminated by photoreactivating light, cell survival was enhanced up to a factor of 9(40 min) followed by a decline after prolonged exposures. Exposure of UV-irradiated (15 J/m 2 ) cells to radiation from white fluorescent lamps reduced the amounts of thymine-containing dimers in a photoreactivating fluence dependent manner, up to about 60% reduction at 120 min exposure. Keeping UV-irradiated cells in the dark for up to 120 min did not affect either cell survival or the amount of pyrimidine dimers in DNA, indicating that there were not detectable levels of a dark-repair system in the cells under our conditions. Correlation between photoreactivation of colony forming ability and photoreactivation of the pyrimidine dimers was demonstrated, at least at relatively low fluences of photoreactivating light. (author)

  9. Photoreactivation of ultraviolet light-induced damage in cultured fish cells as revealed by increased colony forming ability and decreased content of pyrimidine dimers

    Energy Technology Data Exchange (ETDEWEB)

    Shima, A. (Shiga University of Medical Science, Otsu (Japan)); Ikenaga, M. (Osaka Univ. (Japan). Faculty of Medicine); Nikaido, O.; Takebe, H. (Kyoto Univ. (Japan)); Egami, N. (Tokyo Univ. (Japan). Faculty of Science)

    1981-03-01

    Cultured cells derived from a goldfish were irradiated with 254 nm ultraviolet light. Cell survival and splitting of pyrimidine dimers after photoreactivation treatment with white fluorescent lamps were examined by colony forming ability and by a direct dimer assay, respectively. When UV-irradiated (5 J/m/sup 2/) cells were illuminated by photoreactivating light, cell survival was enhanced up to a factor of 9(40 min) followed by a decline after prolonged exposures. Exposure of UV-irradiated (15 J/m/sup 2/) cells to radiation from white fluorescent lamps reduced the amounts of thymine-containing dimers in a photoreactivating fluence dependent manner, up to about 60% reduction at 120 min exposure. Keeping UV-irradiated cells in the dark for up to 120 min did not affect either cell survival or the amount of pyrimidine dimers in DNA, indicating that there were not detectable levels of a dark-repair system in the cells under our conditions. Correlation between photoreactivation of colony forming ability and photoreactivation of the pyrimidine dimers was demonstrated, at least at relatively low fluences of photoreactivating light.

  10. Adrenaline administration promotes the efficiency of granulocyte colony stimulating factor-mediated hematopoietic stem and progenitor cell mobilization in mice.

    Science.gov (United States)

    Chen, Chong; Cao, Jiang; Song, Xuguang; Zeng, Lingyu; Li, Zhenyu; Li, Yong; Xu, Kailin

    2013-01-01

    A high dose of granulocyte colony stimulating factor (G-CSF) is widely used to mobilize hematopoietic stem and progenitor cells (HSPC), but G-CSF is relatively inefficient and may cause adverse effects. Recently, adrenaline has been found to play important roles in HSPC mobilization. In this study, we explored whether adrenaline combined with G-CSF could induce HSPC mobilization in a mouse model. Mice were treated with adrenaline and either a high or low dose of G-CSF alone or in combination. Peripheral blood HSPC counts were evaluated by flow cytometry. Levels of bone marrow SDF-1 were measured by ELISA, the transcription of CXCR4 and SDF-1 was measured by real-time RT-PCR, and CXCR4 protein was detected by Western blot. Our results showed that adrenaline alone fails to mobilize HSPCs into the peripheral blood; however, when G-CSF and adrenaline are combined, the WBC counts and percentages of HSPCs are significantly higher compared to those in mice that received G-CSF alone. The combined use of adrenaline and G-CSF not only accelerated HSPC mobilization, but also enabled the efficient mobilization of HSPCs into the peripheral blood at lower doses of G-CSF. Adrenaline/G-CSF treatment also extensively downregulated levels of SDF-1 and CXCR4 in mouse bone marrow. These results demonstrated that adrenaline combined with G-CSF can induce HSPC mobilization by down-regulating the CXCR4/SDF-1 axis, indicating that the use of adrenaline may enable the use of reduced dosages or durations of G-CSF treatment, minimizing G-CSF-associated complications.

  11. Predicting the distribution of spiral waves from cell properties in a developmental-path model of Dictyostelium pattern formation.

    Directory of Open Access Journals (Sweden)

    Daniel Geberth

    2009-07-01

    Full Text Available The slime mold Dictyostelium discoideum is one of the model systems of biological pattern formation. One of the most successful answers to the challenge of establishing a spiral wave pattern in a colony of homogeneously distributed D. discoideum cells has been the suggestion of a developmental path the cells follow (Lauzeral and coworkers. This is a well-defined change in properties each cell undergoes on a longer time scale than the typical dynamics of the cell. Here we show that this concept leads to an inhomogeneous and systematic spatial distribution of spiral waves, which can be predicted from the distribution of cells on the developmental path. We propose specific experiments for checking whether such systematics are also found in data and thus, indirectly, provide evidence of a developmental path.

  12. Enhancement of the grafting efficiency of transplanted marrow cells by preincubation with interleukin-3 and granulocyte-macrophage colony-stimulating factor

    Energy Technology Data Exchange (ETDEWEB)

    Tavassoli, M.; Konno, M.; Shiota, Y.; Omoto, E.; Minguell, J.J.; Zanjani, E.D.

    1991-04-01

    To improve the grafting efficiency of transplanted murine hematopoietic progenitors, we briefly preincubated mouse bone marrow cells with interleukin-3 (IL-3) or granulocyte-macrophage colony-stimulating factor (GM-CSF) ex vivo before their transplantation into irradiated recipients. This treatment was translated into an increase in the seeding efficiency of colony-forming unit-spleen (CFU-S) and CFU-GM after transplantation. Not only was the concentration of CFU-S in the tibia increased 2 and 24 hours after transplantation, but the total cell number and CFU-S and CFU-GM concentrations were persistently higher in IL-3- and GM-CSF-treated groups 1 to 3 weeks after transplantation. In addition, the survival of animals as a function of transplanted cell number was persistently higher in IL-3- and GM-CSF-treated groups compared with controls. The data indicate that the pretreatment of marrow cells with IL-3 and GM-CSF before transplantation increases the seeding efficiency of hematopoietic stem cells and probably other progenitor cells after transplantation. This increased efficiency may be mediated by upward modulation of homing receptors. Therefore, ex vivo preincubation of donor marrow cells with IL-3 and GM-CSF may be a useful tactic in bone marrow transplantation.

  13. Changes in numbers and types of mast cell colony-forming cells in the peritoneal cavity of mice after injection of distilled water: evidence that mast cells suppress differentiation of bone marrow-derived precursors

    International Nuclear Information System (INIS)

    Kanakura, Y.; Kuriu, A.; Waki, N.; Nakano, T.; Asai, H.; Yonezawa, T.; Kitamura, Y.

    1988-01-01

    Two different types of cells in the peritoneal cavity of mice produce mast cell colonies in methylcellulose. Large mast cell colonies are produced by bone marrow-derived precursors resembling lymphoid cells by light microscopy (L-CFU-Mast), whereas medium and small mast cell colonies are produced by morphologically identifiable mast cells (M-CFU-Mast and S-CFU-Mast, respectively). In the present study we eradicated peritoneal mast cells by intraperitoneal (IP) injection of distilled water. The regeneration process was investigated to clarify the relationship between L-CFU-Mast, M-CFU-Mast, and S-CFU-Mast. After injection of distilled water, M-CFU-Mast and S-CFU-Mast disappeared, but L-CFU-Mast increased, and then M-CFU-Mast and S-CFU-Mast appeared, suggesting the presence of a hierarchic relationship. When purified peritoneal mast cells were injected two days after the water injection, the L-CFU-Mast did not increase. In the peritoneal cavity of WBB6F1-+/+ mice that had been lethally irradiated and rescued by bone marrow cells of C57BL/6-bgJ/bgJ (beige, Chediak-Higashi syndrome) mice, L-CFU-Mast were of bgJ/bgJ type, but M-CFU-Mast and S-CFU-Mast were of +/+ type. The injection of distilled water to the radiation chimeras resulted in the development of bgJ/bgJ-type M-CFU-Mast and then S-CFU-Mast. The presence of mast cells appeared to suppress the recruitment of L-CFU-Mast from the bloodstream and to inhibit the differentiation of L-CFU-Mast to M-CFU-Mast

  14. Increased Frequency of Peripheral B and T Cells Expressing Granulocyte Monocyte Colony-Stimulating Factor in Rheumatoid Arthritis Patients

    Directory of Open Access Journals (Sweden)

    Anastasia Makris

    2018-01-01

    Full Text Available ObjectivesGranulocyte monocyte colony-stimulating factor (GM-CSF is currently considered a crucial inflammatory mediator and a novel therapeutic target in rheumatoid arthritis (RA, despite the fact that its precise cellular sources remain uncertain. We studied the expression of GM-CSF in peripheral lymphocytes from RA patients and its change with antirheumatic therapies.MethodsIntracellular GM-CSF expression was assessed by flow cytometry in stimulated peripheral B (CD19+ and T (CD3+ cells from RA patients (n = 40, disease (n = 31 including osteoarthritis n = 15, psoriatic arthritis n = 10, and systemic rheumatic diseases n = 6 and healthy (n = 16 controls. The phenotype of GM-CSF+ B cells was assessed as well as longitudinal changes in GM-CSF+ lymphocytes during methotrexate (MTX, n = 10 or anti-tumor necrosis factor (anti-TNF, n = 10 therapy.ResultsAmong untreated RA patients with active disease (Disease Activity Score 28-C-reactive protein = 5.6 ± 0.89 an expanded population of peripheral GM-CSF+ B (4.1 ± 2.2% and T (3.4 ± 1.6% cells was detected compared with both disease (1.7 ± 0.9%, p < 0.0001 and 1.7 ± 1.3%, p < 0.0001, respectively and healthy (0.3 ± 0.2%, p < 0.0001 and 0.6 ± 0.6%, p < 0.0001 controls. RA GM-CSF+ B cells displayed more commonly a plasmablast or transitional phenotype (37.12 ± 18.34% vs. 14.26 ± 9.46%, p = 0.001 and 30.49 ± 15.04% vs. 2.45 ± 1.84%, p < 0.0001, respectively and less a memory phenotype (21.46 ± 20.71% vs. 66.99 ± 16.63%, p < 0.0001 compared to GM-CSF− cells. GM-CSF expression in RA patients did not correlate to disease duration, activity or serological status. Anti-TNF treatment led to a statistically significant decrease in GM-CSF+ B and T cells while MTX had no significant effect.DiscussionThis is the first study showing an expanded population of GM-CSF+ B and T lymphocytes

  15. Suppression of T cell-induced osteoclast formation

    Energy Technology Data Exchange (ETDEWEB)

    Karieb, Sahar; Fox, Simon W., E-mail: Simon.fox@plymouth.ac.uk

    2013-07-12

    Highlights: •Genistein and coumestrol prevent activated T cell induced osteoclast formation. •Anti-TNF neutralising antibodies prevent the pro-osteoclastic effect of activated T cells. •Phytoestrogens inhibit T cell derived TNF alpha and inflammatory cytokine production. •Phytoestrogens have a broader range of anti-osteoclastic actions than other anti-resorptives. -- Abstract: Inhibition of T cell derived cytokine production could help suppress osteoclast differentiation in inflammatory skeletal disorders. Bisphosphonates are typically prescribed to prevent inflammatory bone loss but are not tolerated by all patients and are associated with an increased risk of osteonecrosis of the jaw. In light of this other anti-resorptives such as phytoestrogens are being considered. However the effect of phytoestrogens on T cell-induced osteoclast formation is unclear. The effect of genistein and coumestrol on activated T cell-induced osteoclastogenesis and cytokine production was therefore examined. Concentrations of genistein and coumestrol (10{sup −7} M) previously shown to directly inhibit osteoclast formation also suppressed the formation of TRAP positive osteoclast induced by con A activated T cells, which was dependent on inhibition of T cell derived TNF-α. While both reduced osteoclast formation their mechanism of action differed. The anti-osteoclastic effect of coumestrol was associated with a dual effect on con A induced T cell proliferation and activation; 10{sup −7} M coumestrol significantly reducing T cell number (0.36) and TNF-α (0.47), IL-1β (0.23) and IL-6 (0.35) expression, whereas genistein (10{sup −7} M) had no effect on T cell number but a more pronounced effect on T cell differentiation reducing expression of TNF-α (0.49), IL-1β (0.52), IL-6 (0.71) and RANKL (0.71). Phytoestrogens therefore prevent the pro-osteoclastic action of T cells suggesting they may have a role in the control of inflammatory bone loss.

  16. The role of donor characteristics and post-granulocyte colony-stimulating factor white blood cell counts in predicting the adverse events and yields of stem cell mobilization.

    Science.gov (United States)

    Chen, Shu-Huey; Yang, Shang-Hsien; Chu, Sung-Chao; Su, Yu-Chieh; Chang, Chu-Yu; Chiu, Ya-Wen; Kao, Ruey-Ho; Li, Dian-Kun; Yang, Kuo-Liang; Wang, Tso-Fu

    2011-05-01

    Granulocyte colony-stimulating factor (G-CSF) is now widely used for stem cell mobilization. We evaluated the role of post-G-CSF white blood cell (WBC) counts and donor factors in predicting adverse events and yields associated with mobilization. WBC counts were determined at baseline, after the third and the fifth dose of G-CSF in 476 healthy donors. Donors with WBC ≥ 50 × 10(3)/μL post the third dose of G-CSF experienced more fatigue, myalgia/arthralgia, and chills, but final post-G-CSF CD34(+) cell counts were similar. Although the final CD34(+) cell count was higher in donors with WBC ≥ 50 × 10(3)/μL post the fifth G-CSF, the incidence of side effects was similar. Females more frequently experienced headache, nausea/anorexia, vomiting, fever, and lower final CD34(+) cell count than did males. Donors with body mass index (BMI) ≥ 25 showed higher incidences of sweat and insomnia as well as higher final CD34(+) cell counts. Donor receiving G-CSF ≥ 10 μg/kg tended to experience bone pain, headache and chills more frequently. Multivariate analysis indicated that female gender is an independent factor predictive of the occurrence of most side effects, except for ECOG > 1 and chills. Higher BMI was also an independent predictor for fatigue, myalgia/arthralgia, and sweat. Higher G-CSF dose was associated with bone pain, while the WBC count post the third G-CSF was associated with fatigue only. In addition, one donor in the study period did not complete the mobilization due to suspected anaphylactoid reaction. Observation for 1 h after the first injection of G-CSF is required to prevent complications from unpredictable side effects.

  17. Cell Formation in Industrial Engineering : Theory, Algorithms and Experiments

    NARCIS (Netherlands)

    Goldengorin, B.; Krushynskyi, D.; Pardalos, P.M.

    2013-01-01

    This book focuses on a development of optimal, flexible, and efficient models and algorithms for cell formation in group technology. Its main aim is to provide a reliable tool that can be used by managers and engineers to design manufacturing cells based on their own preferences and constraints

  18. Sexual Biofilm Formation in Candida tropicalis Opaque Cells

    Science.gov (United States)

    Jones, Stephen K.; Hirakawa, Matthew P.; Bennett, Richard J.

    2014-01-01

    Summary Candida albicans and Candida tropicalis are opportunistic fungal pathogens that can transition between white and opaque phenotypic states. White and opaque cells differ both morphologically and in their responses to environmental signals. In C. albicans, opaque cells respond to sexual pheromones by undergoing conjugation, while white cells are induced by pheromones to form sexual biofilms. Here, we show that sexual biofilm formation also occurs in C. tropicalis but, unlike C. albicans, biofilms are formed exclusively by opaque cells. C. tropicalis biofilm formation was dependent on the pheromone receptors Ste2 and Ste3, confirming the role of pheromone signaling in sexual biofilm development. Structural analysis of C. tropicalis sexual biofilms revealed stratified communities consisting of a basal layer of yeast cells and an upper layer of filamentous cells, together with an extracellular matrix. Transcriptional profiling showed that genes involved in pheromone signaling and conjugation were upregulated in sexual biofilms. Furthermore, FGR23, which encodes an agglutinin-like protein, was found to enhance both mating and sexual biofilm formation. Together, these studies reveal that C. tropicalis opaque cells form sexual biofilms with a complex architecture, and suggest a conserved role for sexual agglutinins in mediating mating, cell cohesion and biofilm formation. PMID:24612417

  19. Cell-fusion method to visualize interphase nuclear pore formation.

    Science.gov (United States)

    Maeshima, Kazuhiro; Funakoshi, Tomoko; Imamoto, Naoko

    2014-01-01

    In eukaryotic cells, the nucleus is a complex and sophisticated organelle that organizes genomic DNA to support essential cellular functions. The nuclear surface contains many nuclear pore complexes (NPCs), channels for macromolecular transport between the cytoplasm and nucleus. It is well known that the number of NPCs almost doubles during interphase in cycling cells. However, the mechanism of NPC formation is poorly understood, presumably because a practical system for analysis does not exist. The most difficult obstacle in the visualization of interphase NPC formation is that NPCs already exist after nuclear envelope formation, and these existing NPCs interfere with the observation of nascent NPCs. To overcome this obstacle, we developed a novel system using the cell-fusion technique (heterokaryon method), previously also used to analyze the shuttling of macromolecules between the cytoplasm and the nucleus, to visualize the newly synthesized interphase NPCs. In addition, we used a photobleaching approach that validated the cell-fusion method. We recently used these methods to demonstrate the role of cyclin-dependent protein kinases and of Pom121 in interphase NPC formation in cycling human cells. Here, we describe the details of the cell-fusion approach and compare the system with other NPC formation visualization methods. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Granulocyte Colony-Stimulating Factor Use after Autologous Peripheral Blood Stem Cell Transplantation: Comparison of Two Practices.

    Science.gov (United States)

    Singh, Amrita D; Parmar, Sapna; Patel, Khilna; Shah, Shreya; Shore, Tsiporah; Gergis, Usama; Mayer, Sebastian; Phillips, Adrienne; Hsu, Jing-Mei; Niesvizky, Ruben; Mark, Tomer M; Pearse, Roger; Rossi, Adriana; van Besien, Koen

    2018-02-01

    Administration of granulocyte colony-stimulating factor (G-CSF) after autologous peripheral blood stem cell transplantation (PBSCT) is generally recommended to reduce the duration of severe neutropenia; however, data regarding the optimal timing of G-CSFs post-transplantation are limited and conflicting. This retrospective study was performed at NewYork-Presbyterian/Weill Cornell Medical Center between November 5, 2013, and August 9, 2016, of adult inpatient autologous PBSCT recipients who received G-CSF empirically starting on day +5 (early) versus on those who received G-CSF on day +12 only if absolute neutrophil count (ANC) was ANC-driven). G-CSF was dosed at 300 µg in patients weighing ANC-driven (n = 50) G-CSF regimen. Patient and transplantation characteristics were comparable in the 2 groups. In the ANC-driven group, 24% (n = 12) received G-CSF on day +12 and 60% (n = 30) started G-CSF earlier due to febrile neutropenia or at the physician's discretion, 6% (n = 3) started after day +12 at the physician's discretion, and 10% (n = 5) did not receive any G-CSF. The median start day of G-CSF therapy was day +10 in the ANC-driven group versus day +5 in the early group (P ANC-driven group (P = .07). There were no significant between-group differences in time to platelet engraftment, 1-year relapse rate, or 1-year overall survival. The incidence of febrile neutropenia was 74% in the early group versus 90% in the ANC-driven group (P = .04); however, there was no significant between-group difference in the incidence of positive bacterial cultures or transfer to the intensive care unit. The duration of G-CSF administration until neutrophil engraftment was 6 days in the early group versus 3 days in the ANC-driven group (P ANC-driven group (P = .28). Our data show that early initiation of G-CSF (on day +5) and ANC-driven initiation of G-CSF following autologous PBSCT were associated with a similar time to neutrophil engraftment

  1. Direct anti-inflammatory effects of granulocyte colony-stimulating factor (G-CSF) on activation and functional properties of human T cell subpopulations in vitro.

    Science.gov (United States)

    Malashchenko, Vladimir Vladimirovich; Meniailo, Maxsim Evgenievich; Shmarov, Viacheslav Anatolievich; Gazatova, Natalia Dinislamovna; Melashchenko, Olga Borisovna; Goncharov, Andrei Gennadievich; Seledtsova, Galina Victorovna; Seledtsov, Victor Ivanovich

    2018-03-01

    We investigated the direct effects of human granulocyte colony-stimulating factor (G-CSF) on functionality of human T-cell subsets. CD3 + T-lymphocytes were isolated from blood of healthy donors by positive magnetic separation. T cell activation with particles conjugated with antibodies (Abs) to human CD3, CD28 and CD2 molecules increased the proportion of cells expressing G-CSF receptor (G-CSFR, CD114) in all T cell subpopulations studied (CD45RA + /CD197 + naive T cells, CD45RA - /CD197 + central memory T cells, CD45RA - /CD197 - effector memory T cells and CD45RA + /CD197 - terminally differentiated effector T cells). Upon T-cell activation in vitro, G-CSF (10.0 ng/ml) significantly and specifically enhanced the proportion of CD114 + T cells in central memory CD4 + T cell compartment. A dilution series of G-CSF (range, 0.1-10.0 ng/ml) was tested, with no effect on the expression of CD25 (interleukin-2 receptor α-chain) on activated T cells. Meanwhile, G-CSF treatment enhanced the proportion of CD38 + T cells in CD4 + naïve T cell, effector memory T cell and terminally differentiated effector T cell subsets, as well as in CD4 - central memory T cells and terminally differentiated effector T cells. G-CSF did not affect IL-2 production by T cells; relatively low concentrations of G-CSF down-regulated INF-γ production, while high concentrations of this cytokine up-regulated IL-4 production in activated T cells. The data obtained suggests that G-CSF could play a significant role both in preventing the development of excessive and potentially damaging inflammatory reactivity, and in constraining the expansion of potentially cytodestructive T cells. Copyright © 2018 Elsevier Inc. All rights reserved.

  2. Inhibition of miR-155, a therapeutic target for breast cancer, prevented in cancer stem cell formation.

    Science.gov (United States)

    Zuo, Jiangcheng; Yu, Yalan; Zhu, Man; Jing, Wei; Yu, Mingxia; Chai, Hongyan; Liang, Chunzi; Tu, Jiancheng

    2018-02-06

    Breast cancer is a common cancer in women of worldwide. Cancer cells with stem-like properties played important roles in breast cancer, such as relapse, metastasis and treatment resistance. Micro-RNA-155 (miR-155) is a well-known oncogenic miRNA overexpressed in many human cancers. The expression levels of miR-155 in 38 pairs of cancer tissues and adjacent normal tissues from breast cancer patients were detected using quantitative real-time PCR. The invasive cell line MDA-MB-231 was used to quantify the expression of miR-155 by tumor-sphere forming experiment. Soft agar colony formation assay and tumor xenografts was used to explore whether the inhibition of miR-155 could reduce proliferation of cancer cells in vivo and vitro. In the study, we found miR-155 was upregulated in BC. Soft agar colony formation assay and tumor xenografts showed inhibition of miR-155 could significantly reduce proliferation of cancer cells in vivo and vitro, which confirmed that miR-155 is an effective therapeutic target of breast cancer. Sphere-forming experiment showed that overexpression of miR-155 significantly correlated with stem-like properties. Expressions of ABCG2, CD44 and CD90 were repressed by inhibition of miR-155, but CD24 was promoted. Interestingly, inhibition of miR-155 rendered MDA-MB-231 cells more sensitive to Doxorubicinol, which resulted in an increase of inhibition rate from 20.23% to 68.72%. Expression of miR-155 not only was a therapeutic target but also was associated with cancer stem cell formation and Doxorubicinol sensitivity. Our results underscore the importance of miR-155 as a therapeutic target and combination of Doxorubicinol and miR-155-silencing would be a potential way to cure breast cancer.

  3. Evaluation of drug-induced hematotoxicity using novel in vitro monkey CFU-GM and BFU-E colony assays.

    Science.gov (United States)

    Goto, Koichi; Goto, Mayumi; Ando-Imaoka, Masako; Kai, Kiyonori; Mori, Kazuhiko

    2017-01-01

    In order to evaluate drug-induced hematotoxicity in monkey cells in vitro, colony-forming unit-granulocyte, macrophage (CFU-GM), and burst-forming unit-erythroid (BFU-E) colony assays were established using mononuclear cells in the bone marrow collected from male cynomolgus monkeys. Furthermore, the effects of doxorubicin, chloramphenicol, and linezolid on CFU-GM and BFU-E colony formation were investigated using established monkey CFU-GM and BFU-E colony assays in comparison with those on human CFU-GM and BFU-E colonies acquired from human umbilical cord blood cells. Bone marrow mononuclear cells were collected from the ischial or iliac bone of male cynomolgus monkeys. The cells were subsequently processed by density gradient separation at 1.067, 1.070, or 1.077 g/mL for CFU-GM or 1.077 g/mL for BFU-E, and then cultured in methylcellulose medium for 9 or 13 days, respectively. A sufficient number of CFU-GM colonies were formed from mononuclear cells processed at a density of 1.070 g/mL. Moreover, the number of BFU-E colonies from the cells processed at a density of 1.077 g/mL was sufficient for the colony assay. The number of CFU-GM or BFU-E colonies decreased after treatment with the drugs of interest in a concentration-dependent manner. Compared with human CFU-GM, monkey CFU-GM were more sensitive to chloramphenicol and resistant to doxorubicin, whereas monkey BFU-E were more sensitive to all compounds in comparison to the sensitivity of human BFU-E. In conclusion, monkey CFU-GM and BFU-E colony assays were established and considered useful tools to evaluate the differences in drug-induced hematotoxicity between species.

  4. HONEY BEE COLONY PHEROMONES

    Directory of Open Access Journals (Sweden)

    M Dražić

    2001-09-01

    Full Text Available ABSTRACT Pheromones are chemicals produced as liquids by specialised cells or glands and transmitted into the environment as liquids or gases. In contrary to hormones, which are excreted in organism and have effect exclusively on organism that produced them, pheromones are excreted outside organism and effect on different individuals of the same species. Pheromones mediate nearly all aspects of honeybee colony life including social defence, brood care, mating, orientation, foraging and reproduction. Pheromone investigation has high economic importance. With use of pheromones it is possible to manipulate with pest insects on crops or to direct honeybees during pollination on target plants.

  5. Formation of photovoltaic modules based on polycrystalline solar cells

    OpenAIRE

    L. A. Dobrzański; A. Drygała; A. Januszka

    2009-01-01

    Purpose: The main aim of the paper is formation of photovoltaic modules and analysis of their main electric parameters.Design/methodology/approach: Photovoltaic modules were produced from four polycrystalline silicon solar cells, that were cut and next joined in series. Soft soldering technique and copper-tin strip were used for joining cells.Findings: In order to provide useful power for any application, the individual solar cells must be connected together to give the appropriate current an...

  6. The impact of donor characteristics on the immune cell composition of mixture allografts of granulocyte-colony-stimulating factor-mobilized marrow harvests and peripheral blood harvests.

    Science.gov (United States)

    Wang, Yu-Tong; Zhao, Xiang-Yu; Zhao, Xiao-Su; Xu, Lan-Ping; Zhang, Xiao-Hui; Wang, Yu; Liu, Kai-Yan; Chang, Ying-Jun; Huang, Xiao-Jun

    2015-12-01

    The association of donor characteristics with immune cell composition in allografts remains poorly understood. In this retrospective study, the effects of donor characteristics on immune cell composition in allografts were investigated. The correlations of donor characteristics with the immune cell composition in mixture allografts of granulocyte-colony-stimulating factor-mobilized marrow harvests and peripheral blood harvests of 390 healthy donors (male, 240; female, 150; median age, 40 years old) were analyzed. The median doses of CD3+ T cells, CD4+ T cells, CD8+ T cells, CD3+CD4-CD8- T cells, and monocytes in mixture allografts were 160.57 × 10(6), 89.29 × 10(6), 56.16 × 10(6), 10.87 × 10(6), and 137.94 × 10(6)/kg, respectively. Multivariate analysis showed that younger donor age was associated with a higher dose of CD3+ T cells (p = 0.006), CD3+CD8+ T cells (p donor weight with CD3+ T cells (p blood lymphocyte pre-peripheral blood apheresis was correlated with the yield of CD3+ T cells (p blood monocyte count before marrow harvest predicted the monocyte dose (p = 0.002). The results suggested that older and overweight donors should not be chosen. The monocyte and lymphocyte counts before harvest could predict the yield of immune cells in allografts. © 2015 AABB.

  7. solving the cell formation problem in group technology

    Directory of Open Access Journals (Sweden)

    Prafulla Joglekar

    2001-01-01

    Full Text Available Over the last three decades, numerous algorithms have been proposed to solve the work-cell formation problem. For practicing manufacturing managers it would be nice to know as to which algorithm would be most effective and efficient for their specific situation. While several studies have attempted to fulfill this need, most have not resulted in any definitive recommendations and a better methodology of evaluation of cell formation algorithms is urgently needed. Prima facie, the methodology underlying Miltenburg and Zhang's (M&Z (1991 evaluation of nine well-known cell formation algorithms seems very promising. The primary performance measure proposed by M&Z effectively captures the objectives of a good solution to a cell formation problem and is worthy of use in future studies. Unfortunately, a critical review of M&Z's methodology also reveals certain important flaws in M&Z's methodology. For example, M&Z may not have duplicated each algorithm precisely as the developer(s of that algorithm intended. Second, M&Z's misrepresent Chandrasekharan and Rajagopalan's [C&R's] (1986 grouping efficiency measure. Third, M&Z's secondary performance measures lead them to unnecessarily ambivalent results. Fourth, several of M&Z's empirical conclusions can be theoretically deduced. It is hoped that future evaluations of cell formation algorithms will benefit from both the strengths and weaknesses of M&Z's work.

  8. Pulp stem cells: implication in reparative dentin formation.

    Science.gov (United States)

    Dimitrova-Nakov, Sasha; Baudry, Anne; Harichane, Yassine; Kellermann, Odile; Goldberg, Michel

    2014-04-01

    Many dental pulp stem cells are neural crest derivatives essential for lifelong maintenance of tooth functions and homeostasis as well as tooth repair. These cells may be directly implicated in the healing process or indirectly involved in cell-to-cell diffusion of paracrine messages to resident (pulpoblasts) or nonresident cells (migrating mesenchymal cells). The identity of the pulp progenitors and the mechanisms sustaining their regenerative capacity remain largely unknown. Taking advantage of the A4 cell line, a multipotent stem cell derived from the molar pulp of mouse embryo, we investigated the capacity of these pulp-derived precursors to induce in vivo the formation of a reparative dentin-like structure upon implantation within the pulp of a rodent incisor or a first maxillary molar after surgical exposure. One month after the pulp injury alone, a nonmineralized fibrous matrix filled the mesial part of the coronal pulp chamber. Upon A4 cell implantation, a mineralized osteodentin was formed in the implantation site without affecting the structure and vitality of the residual pulp in the central and distal parts of the pulp chamber. These results show that dental pulp stem cells can induce the formation of reparative dentin and therefore constitute a useful tool for pulp therapies. Finally, reparative dentin was also built up when A4 progenitors were performed by alginate beads, suggesting that alginate is a suitable carrier for cell implantation in teeth. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  9. Human disc cells in monolayer vs 3D culture: cell shape, division and matrix formation

    Directory of Open Access Journals (Sweden)

    Hanley Edward N

    2000-10-01

    Full Text Available Abstract Background The relationship between cell shape, proliferation, and extracellular matrix (ECM production, important aspects of cell behavior, is examined in a little-studied cell type, the human annulus cell from the intervertebral disc, during monolayer vs three-dimensional (3D culture. Results Three experimental studies showed that cells respond specifically to culture microenvironments by changes in cell shape, mitosis and ECM production: 1 Cell passages showed extensive immunohistochemical evidence of Type I and II collagens only in 3D culture. Chondroitin sulfate and keratan sulfate were abundant in both monolayer and 3D cultures. 2 Cells showed significantly greater proliferation in monolayer in the presence of platelet-derived growth factor compared to cells in 3D. 3 Cells on Matrigel™-coated monolayer substrates became rounded and formed nodular colonies, a finding absent during monolayer growth. Conclusions The cell's in vivo interactions with the ECM can regulate shape, gene expression and other cell functions. The shape of the annulus cell changes markedly during life: the young, healthy disc contains spindle shaped cells and abundant collagen. With aging and degeneration, many cells assume a strikingly different appearance, become rounded and are surrounded by unusual accumulations of ECM products. In vitro manipulation of disc cells provides an experimental window for testing how disc cells from given individuals respond when they are grown in environments which direct cells to have either spindle- or rounded-shapes. In vitro assessment of the response of such cells to platelet-derived growth factor and to Matrigel™ showed a continued influence of cell shape even in the presence of a growth factor stimulus. These findings contribute new information to the important issue of the influence of cell shape on cell behavior.

  10. Apolipoprotein E Regulates Amyloid Formation within Endosomes of Pigment Cells

    Directory of Open Access Journals (Sweden)

    Guillaume van Niel

    2015-10-01

    Full Text Available Accumulation of toxic amyloid oligomers is a key feature in the pathogenesis of amyloid-related diseases. Formation of mature amyloid fibrils is one defense mechanism to neutralize toxic prefibrillar oligomers. This mechanism is notably influenced by apolipoprotein E variants. Cells that produce mature amyloid fibrils to serve physiological functions must exploit specific mechanisms to avoid potential accumulation of toxic species. Pigment cells have tuned their endosomes to maximize the formation of functional amyloid from the protein PMEL. Here, we show that ApoE is associated with intraluminal vesicles (ILV within endosomes and remain associated with ILVs when they are secreted as exosomes. ApoE functions in the ESCRT-independent sorting mechanism of PMEL onto ILVs and regulates the endosomal formation of PMEL amyloid fibrils in vitro and in vivo. This process secures the physiological formation of amyloid fibrils by exploiting ILVs as amyloid nucleating platforms.

  11. Effect of X-Rays on Growth Rate of Rose Shoot Cultures and the Ability of Isolated Protoplasts to Form Cell Colonies

    International Nuclear Information System (INIS)

    Moustafa, R. A. K.

    2004-01-01

    The popularity of rose as a garden plant, allied with its use in the production of cut flowers and also as a source of aromatic rose oils, make it one of the most important ornamental crops. Roses, however, have suffered from a narrow genetic base to which only few species have contributed significantly. In vitro culture of plants might facilitate the improvement of rose via the exploitation of somaclonal variation to generate new genetic variability and selection within the variation for desirable traits. The application of mutagens for in vitro cultures, in addition to the induced mutations, may lead to increase the somaclonal variation, thus providing additional variation for selection. On the other hand, plant protoplasts offer exciting possibilities to establish in vitro selection programs based on single cells. Induced variation in isolated protoplasts using mutagen agents may be one mean to select useful mutants. Thus the present experiments were conducted to determine the effect of X-rays on shoot cultures and the isolated protoplasts of rose (Rosa sp.). The materials consisted of the three rose varieties Rosa wichuriana, Paricer charm and Heckenzauber.The applied doses were 0, 10, 20, 30, 40, 50 and 60 Gy. Obtained results indicated that the genotypes differed in their sensitivity to X-rays. Rosa wichuriana seemed to be the most sensitive variety to radiation, where a dose of 20 Gy caused approximately 50% reduction in growth rate of shoot cultures, while the same dose decreased the growth rate of Paricer charm only by 25% and did not affect the growth of Heckenzauber. Results also revealed that the ability of irradiated protoplasts to form cell colonies increased when a dose of 10 Gy was performed. Doses higher than that level caused gradual decreasing in the forming of cell colonies, but however, the protoplasts could form colonies even when a dose of 60 Gy was applied. (Author)

  12. Formation of a cylindrical bridge in cell division

    Science.gov (United States)

    Citron, Daniel; Schmidt, Laura E.; Reichl, Elizabeth; Ren, Yixin; Robinson, Douglas; Zhang, Wendy W.

    2007-11-01

    In nature, the shape transition associated with the division of a mother cell into two daughter cells proceeds via a variety of routes. In the cylinder-thinning route, which has been observed in Dictyostelium and most animal cells, the mother cell first forms a broad bridge-like region, also known as a furrow, between two daughter cells. The furrow then rapidly evolves into a cylindrical bridge, which thins and eventually severs the mother cell into two. The fundamental mechanism underlying this division route is not understood. Recent experiments on Dictyostelium found that, while the cylinder-thinning route persists even when key actin cross-linking proteins are missing, it is disrupted by the removal of force-generating myosin-II proteins. Other measurements revealed that mutant cells lacking myosin-II have a much more uniform tension over the cell surface than wild-type cells. This suggests that tension variation may be important. Here we use a fluid model, previously shown to reproduce the thinning dynamics [Zhang & Robinson, PNAS 102, 7186 (2005)], to test this idea. Consistent with the experiments, the model shows that the cylinder formation process occurs regardless of the exact viscoelastic properties of the cell. In contrast to the experiments, a tension variation in the model hinders, rather then expedites, the cylinder formation.

  13. Diversity of cultivable bacteria involved in the formation of macroscopic microbial colonies (Cave silver on the walls of a cave in Slovenia

    Directory of Open Access Journals (Sweden)

    Blagajana Herzog Velikonja

    2014-01-01

    Full Text Available Karstic caves often support white, yellow, grey or pink microbial colonies that are termed ‘cave silver’ by speleologists. Using various sample pre-treatments and culture media, a wide variety of bacteria associated with these colonies were recovered from a cave in Slovenia, Pajsarjeva jama. Decreasing the inoculum size resulted in significant increases in viable counts, while pre-treatments had the opposite effect with the exception of microwave irradiation. While all growth media yielded viable counts, the maximal counts were observed on a low-nutrient TWA medium. Based on the 16S rRNA gene sequence of OTU representatives, the majority of the 80 isolates examined belonged to Streptomyces (25%, Micrococcus (16% and Rhodococcus (10% Other abundant groups were Pseudomonas (9%, Agrobacterium (8%, Lysobacter (6% and Paenibacillus (5%, while members of genera Microbacterium, Agrococcus, Arthrobacter, Bacillus, Kocuria, Oerskovia, Sphingomonas, Aerococcus, and Bosea represented a minor portion of cultivable diversity encountered. Members of Streptomyces and Agrobacterium were common to all samples. Although these microorganisms readily form colonies under laboratory conditions, they were unrelated to abundant environmental phylotypes recovered from same samples in a previous study. However, the comparative 16S rRNA analysis showed that microorganisms highly related to the ones obtained in this study were cultivated from other subterranean environments indicating that they might represent true microbial cave dwellers.

  14. Interregional synaptic maps among engram cells underlie memory formation.

    Science.gov (United States)

    Choi, Jun-Hyeok; Sim, Su-Eon; Kim, Ji-Il; Choi, Dong Il; Oh, Jihae; Ye, Sanghyun; Lee, Jaehyun; Kim, TaeHyun; Ko, Hyoung-Gon; Lim, Chae-Seok; Kaang, Bong-Kiun

    2018-04-27

    Memory resides in engram cells distributed across the brain. However, the site-specific substrate within these engram cells remains theoretical, even though it is generally accepted that synaptic plasticity encodes memories. We developed the dual-eGRASP (green fluorescent protein reconstitution across synaptic partners) technique to examine synapses between engram cells to identify the specific neuronal site for memory storage. We found an increased number and size of spines on CA1 engram cells receiving input from CA3 engram cells. In contextual fear conditioning, this enhanced connectivity between engram cells encoded memory strength. CA3 engram to CA1 engram projections strongly occluded long-term potentiation. These results indicate that enhanced structural and functional connectivity between engram cells across two directly connected brain regions forms the synaptic correlate for memory formation. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  15. Neutrophil-induced transmigration of tumour cells treated with tumour-conditioned medium is facilitated by granulocyte-macrophage colony-stimulating factor.

    LENUS (Irish Health Repository)

    Wu, Q D

    2012-02-03

    OBJECTIVE: To investigate the effect of different cytokines that are present in tumour-conditioned medium on human neutrophil (PMN)-induced tumour cell transmigration. DESIGN: Laboratory study. SETTING: University hospital, Ireland. MATERIAL: Isolated human PMN and cultured human breast tumour cell line, MDA-MB-231. Interventions: Human PMN treated with either tumour-conditioned medium or different media neutralised with monoclonal antibodies (MoAb), and MDA-MB-231 cells were plated on macrovascular and microvascular endothelial monolayers in collagen-coated transwells to assess migration of tumour cells. MAIN OUTCOME MEASURES: Cytokines present in tumour-conditioned medium, PMN cytocidal function and receptor expression, and tumour cell transmigration. RESULTS: tumour-conditioned medium contained high concentrations of granulocyte-macrophage colony-stimulating factor (GM-CSF), vascular endothelial growth factor (VEGF), and interleukin 8 (IL-8), but not granulocyte colony-stimulating factor (G-CSF) and interleukin 3 (IL-3). Anti-GM-CSF MoAb significantly reduced PMN-induced transmigration of tumour cells treated with tumour-conditioned medium (p < 0.05), whereas anti-VEGF and anti-IL-8 MoAbs did not affect their migration. In addition, anti-GM-CSF MoAb, but not anti-VEGF or anti-IL-8 MoAb, reduced PMN CD11b and CD18 overexpression induced by tumour-conditioned medium (p < 0.05). CONCLUSION: These results indicate that the GM-CSF that is present in tumour-conditioned medium may be involved, at least in part, in alterations in PMN function mediated by the medium and subsequently PMN-induced transmigration of tumour cells.

  16. Persistence and dynamics of DNA damage signal amplification determined by microcolony formation and live-cell imaging

    International Nuclear Information System (INIS)

    Oka, Yasuyoshi; Yamauchi, Motohiro; Suzuki, Masatoshi; Yamashita, Shunichi; Suzuki, Keiji

    2011-01-01

    Cell cycle checkpoints are essential cellular process protecting the integrity of the genome from DNA damaging agents. In the present study, we developed a microcolony assay, in which normal human diploid fibroblast-like cells exposed to ionizing radiation, were plated onto coverslips at very low density (3 cells/cm 2 ). Cells were grown for up to 3 days, and phosphorylated ataxia-telangiectasia mutated (ATM) at Ser1981 and 53BP1 foci were analyzed as the markers for an amplified DNA damage signal. We observed a dose-dependent increase in the fraction of non-dividing cells, whose increase was compromised by knocking down p53 expression. While large persistent foci were predominantly formed in non-dividing cells, we observed some growing colonies that contained cells with large foci. As each microcolony was derived from a single cell, it appeared that some cells could proliferate with large foci. A live-imaging analysis using hTERT-immortalized normal human diploid cells transfected with the EGFP-tagged 53BP1 gene revealed that the formation of persistent large foci was highly dynamic. Delayed appearance and disappearance of large foci were frequently observed in exposed cells visualized 12-72 hours after X-irradiation. Thus, our results indicate that amplified DNA damage signal could be ignored, which may be explained in part by the dynamic nature of the amplification process. (author)

  17. Method of monolayer cultures of the guinea pig spleen used to evaluate the radioprotective action of mexamine on the survival of colony-forming cells. [Method of monolayer cultures, quantitative estimation of radioprotective action of drugs

    Energy Technology Data Exchange (ETDEWEB)

    Baisogolov, G D; Rudakova, S F; Rudakov, I A; Konoplyannikov, A G [Akademiya Meditsinskikh Nauk SSSR, Obninsk. Nauchno-Issledovatel' skij Inst. Meditsinskoj Radiologii

    1976-01-01

    Dose dependent survival of colony-forming splenic cells of guinea pigs has been studied after ..gamma..-irradiation in vitro. The average lethal dose (D/sub 0/) for colony-forming cells is 245 rads, the extrapolation number - 1.5. Radiosensitivity of the splenic cells is markedly lower than that of the bone marrow cells (128 rads). After intraperitoneal administration of mexamine (150 mg/kg) to guinea pigs 10-15 min before irradiation, D/sub 0/ increases up to 319 rads, extrapolation number is 1.4, and DRF is 1.3.

  18. X-ray-induced production of granulocyte-macrophage colony-stimulating factor (GM-CSF) by mouse spleen cells in culture

    International Nuclear Information System (INIS)

    Onoda, M.; Shinoda, M.; Tsuneoka, K.; Shikita, M.

    1980-01-01

    Spleen cells were collected from normal mice and cultured in a medium containing 20% calf serum. Addition of lipopolysaccharide (LPS) in the culture significantly increased the production of granulocyte-macrophage colony-stimulating factor (GM-CSF), and a maximum induction was attained in 5 days. Irradiation of the spleen cells with 300 to 3000 R x rays also enhanced the production of GM-CSF, but there was a latent period of about 5 days before the factor appeared in the culture medium. The observed difference between LPS and x rays in the timing of inducing GM-CSF production in the spleen cell culture was consistent with the difference observed in animals. These results suggest that different mechanisms of GM-CSF production operate in the spleen in response to either LPS or x rays

  19. High Expression of Colony-Stimulating Factor 1 Receptor Associates with Unfavorable Cancer-Specific Survival of Patients with Clear Cell Renal Cell Carcinoma.

    Science.gov (United States)

    Yang, Liu; Liu, Yidong; An, Huimin; Chang, Yuan; Zhang, Weijuan; Zhu, Yu; Xu, Le; Xu, Jiejie

    2016-03-01

    Colony-stimulating factor 1 receptor (CSF-1R), a single-pass type III transmembrane tyrosine-protein kinase, is mainly involved in inflammation and immune regulation to facilitate the progression of solid tumors. This study aimed to evaluate the impact of CSF-1R expression on clinical outcome of patients with clear cell renal cell carcinoma (ccRCC) after surgery. We retrospectively enrolled 268 patients with ccRCC undergoing nephrectomy between 2001 and 2004. Clinicopathologic features and cancer-specific survival (CSS) were collected. Western blot analysis was performed in the pairwise comparisons of CSF-1R expression in peritumor and tumor tissues of patients with ccRCC. Immunohistochemistry was conducted to determine CSF-1R expression level in tumor specimens. Survival analysis was performed by the Kaplan-Meier method. Cox regression models were used to evaluate the impact of prognostic factors on CSS. A concordance index was calculated to measure prognostic accuracy. A prognostic nomogram was constructed on the basis of the identified independent prognostic factors. CSF-1R expression in tumor tissues was higher than in peritumor tissues in 71.4% (5 of 7) patients. CSF-1R expression of tumor tissues was positively associated with metastasis, tumor, node, metastasis classification system (TNM) stage, Eastern Cooperative Oncology Group performance status score and poor CSS. CSF-1R expression was determined as an independent prognostic factor for CSS in patients with ccRCC. Furthermore, extension of the well-established prognostic models with CSF-1R expression presented significantly improved prognostic accuracy. An efficient prognostic nomogram was constructed on the basis of the independent prognostic factors. High CSF-1R expression is a potential independent adverse prognostic factor for CSS in patients with ccRCC.

  20. Just-in-time rescue plerixafor in combination with chemotherapy and granulocyte-colony stimulating factor for peripheral blood progenitor cell mobilization.

    Science.gov (United States)

    Smith, Veronica R; Popat, Uday; Ciurea, Stefan; Nieto, Yago; Anderlini, Paolo; Rondon, Gabriela; Alousi, Amin; Qazilbash, Muzaffar; Kebriaei, Partow; Khouri, Issa; de Lima, Marcos; Champlin, Richard; Hosing, Chitra

    2013-09-01

    Plerixafor, a recently approved peripheral blood progenitor cell mobilizing agent, is often added to granulocyte-colony stimulating factor (G-CSF) to mobilize peripheral blood progenitor cells in patients with lymphoma or myeloma who cannot mobilize enough CD34+ cells with G-CSF alone to undergo autologous stem cell transplantation. However, data are lacking regarding the feasibility and efficacy of just-in-time plerixafor in combination with chemotherapy and G-CSF. We reviewed the peripheral blood stem cell collection data of 38 consecutive patients with lymphoma (Hodgkin's and non-Hodgkin's) and multiple myeloma who underwent chemomobilization and high-dose G-CSF and just-in-time plerixafor to evaluate the efficacy of this treatment combination. All patients with multiple myeloma and all but one patient with lymphoma collected the minimum required number of CD34+ cells to proceed with autologous stem cell transplantation (>2 × 10(6) /kg of body weight). The median CD34+ cell dose collected in patients with non-Hodgkin lymphoma was 4.93 × 10(6) /kg of body weight. The median CD34+ cell dose collected for patients with multiple myeloma was 8.81 × 10(6) /kg of body weight. Plerixafor was well tolerated; no grade 2 or higher non-hematologic toxic effects were observed. Copyright © 2013 Wiley Periodicals, Inc.

  1. Pretransplant mobilization with granulocyte colony-stimulating factor improves B-cell reconstitution by lentiviral vector gene therapy in SCID-X1 mice.

    Science.gov (United States)

    Huston, Marshall W; Riegman, Adriaan R A; Yadak, Rana; van Helsdingen, Yvette; de Boer, Helen; van Til, Niek P; Wagemaker, Gerard

    2014-10-01

    Hematopoietic stem cell (HSC) gene therapy is a demonstrated effective treatment for X-linked severe combined immunodeficiency (SCID-X1), but B-cell reconstitution and function has been deficient in many of the gene therapy treated patients. Cytoreductive preconditioning is known to improve HSC engraftment, but in general it is not considered for SCID-X1 since the poor health of most of these patients at diagnosis and the risk of toxicity preclude the conditioning used in standard bone marrow stem cell transplantation. We hypothesized that mobilization of HSC by granulocyte colony-stimulating factor (G-CSF) should create temporary space in bone marrow niches to improve engraftment and thereby B-cell reconstitution. In the present pilot study supplementing our earlier preclinical evaluation (Huston et al., 2011), Il2rg(-/-) mice pretreated with G-CSF were transplanted with wild-type lineage negative (Lin(-)) cells or Il2rg(-/-) Lin(-) cells transduced with therapeutic IL2RG lentiviral vectors. Mice were monitored for reconstitution of lymphocyte populations, level of donor cell chimerism, and antibody responses as compared to 2 Gy total body irradiation (TBI), previously found effective in promoting B-cell reconstitution. The results demonstrate that G-CSF promotes B-cell reconstitution similar to low-dose TBI and provides proof of principle for an alternative approach to improve efficacy of gene therapy in SCID patients without adverse effects associated with cytoreductive conditioning.

  2. Notch1-Dll4 signaling and mechanical force regulate leader cell formation during collective cell migration

    OpenAIRE

    Riahi, Reza; Sun, Jian; Wang, Shue; Long, Min; Zhang, Donna D.; Wong, Pak Kin

    2015-01-01

    At the onset of collective cell migration, a subset of cells within an initially homogenous population acquires a distinct “leader” phenotype with characteristic morphology and motility. However, the factors driving leader cell formation as well as the mechanisms regulating leader cell density during the migration process remain to be determined. Here, we use single cell gene expression analysis and computational modeling to show that leader cell identity is dynamically regulated by Dll4 sign...

  3. Lysinibacillus fusiformis M5 induces increased complexity in Bacillus subtilis 168 colony biofilms via hypoxanthine

    DEFF Research Database (Denmark)

    Gallegos-Monterrosa, Ramses; Kankel, Stefanie; Götze, Sebastian

    2017-01-01

    to identify soil bacteria, which induce architectural changes in biofilm colonies when cocultured with B. subtilis. We identified the soil bacterium Lysinibacillus fusiformis M5 as inducer of wrinkle-formation in B. subtilis colonies mediated by a diffusible signaling molecule. This compound was isolated......O, but not PbuG, is necessary for hypoxanthine to induce an increase in wrinkle formation of B. subtilis biofilm colonies. Our results suggest that hypoxanthine-stimulated wrinkle development is not due to a direct induction of biofilm-related gene expression, but rather caused by the excess of hypoxanthine...... within B. subtilis cells, which may lead to cell stress and death. Importance Biofilms are a bacterial lifestyle with high relevance regarding diverse human activities. Biofilms can be favorable, for instance in crop protection. In nature, biofilms are commonly found as multispecies communities...

  4. Formation and Expansion of Leukemia-Specific Chromosome Aberrations in Hematopoietic Cells of X-ray Irradiated Mice

    International Nuclear Information System (INIS)

    Ban, N.; Kai, M.; Kusama, T.

    2004-01-01

    C3H/He mice develop acute myeloid leukemia (AML) after whole-body irradiation, and typical chromosome 2 deletions are found in the leukemia cells. To investigate a process of the formation and the expansion of the AML-specific deletions, we have examined its frequency in primitive hematopoietic cells that could be the target of the leukemogenesis. Male C3H/He mice were exposed to 3Gy x-rays and sacrificed after certain periods of time. Bone marrow cells were collected from the femora and a single-cell suspension from each animal was divided into two parts. One part of the cell suspension was cultured in methylcellulose medium and metaphase spreads were prepared from each growing colony. The other part was sorted to obtain Lin+ and Lin Scal cells and those cells were scored with FISH for the AML-specific deletions. Karyotyping of the cultured cells detected signs of the delayed chromosomal instability, but an aberration involving chromosome 2 has not been found so far. FISH to the sorted cells, however, revealed the ANL-specific deletions could be produced in the primitive hematopoietic cells as an early event of radiation exposure. (Author) 16 refs

  5. Clinical outcome after stem cell mobilization with granulocyte-colony-stimulating factor after acute ST-elevation myocardial infarction:

    DEFF Research Database (Denmark)

    Ripa, Rasmus S; Jørgensen, Erik; Kastrup, Jens

    2013-01-01

    Background. Granulocyte-colony-stimulating factor (G-CSF) has been investigated in trials aiming to promote recovery of myocardial function after myocardial infarction. Long-term safety-data have never been reported. A few studies indicated an increased risk of in-stent re-stenosis. We aimed to i.......8; 0.3). Conclusions. We found no indication of increased risk of adverse events up to 5 years after G-CSF treatment. These results support the continued investigation of G-CSF for cardiac therapy....

  6. Subtotal ablation of parietal epithelial cells induces crescent formation.

    NARCIS (Netherlands)

    Sicking, E.M.; Fuss, A.; Uhlig, S.; Jirak, P.; Dijkman, H.; Wetzels, J.; Engel, D.R.; Urzynicok, T.; Heidenreich, S.; Kriz, W.; Kurts, C.; Ostendorf, T.; Floege, J.; Smeets, B.; Moeller, M.J.

    2012-01-01

    Parietal epithelial cells (PECs) of the renal glomerulus contribute to the formation of both cellular crescents in rapidly progressive GN and sclerotic lesions in FSGS. Subtotal transgenic ablation of podocytes induces FSGS but the effect of specific ablation of PECs is unknown. Here, we established

  7. Enhanced heterologous expression of biologically active human granulocyte colony stimulating factor in transgenic tobacco BY-2 cells by localization to endoplasmic reticulum.

    Science.gov (United States)

    Nair, Nisha R; Chidambareswaren, M; Manjula, S

    2014-09-01

    Tobacco Bright Yellow-2 (BY-2) cells, one of the best characterized cell lines is an attractive expression system for heterologous protein expression. However, the expression of foreign proteins is currently hampered by their low yield, which is partially the result of proteolytic degradation. Human granulocyte colony stimulating factor (hG-CSF) is a hematopoietic cytokine. Recombinant hG-CSF is successfully being used for the treatment of chemotherapy-induced neutropenia in cancer patients. Here, we describe a simple strategy for producing biologically active hG-CSF in tobacco BY-2 cells, localized in the apoplast of BY-2 cells, as well as targeted to the endoplasmic reticulum (ER). ER targeting significantly enhanced recombinant production which scaled to 17.89 mg/l from 4.19 mg/l when expressed in the apoplasts. Southern blotting confirmed the stable integration of hG-CSF in the BY-2 nuclear genome, and the expression of hG-CSF was analysed by Western blotting. Total soluble protein containing hG-CSF isolated from positive calli showed proliferative potential when tested on HL-60 cell lines by MTT assay. We also report the potential of a Fluorescence-activated cell sorting approach for an efficient sorting of the hG-CSF-expressing cell lines, which will enable the generation of homogenous high-producing cell lines.

  8. On colonial grounds

    NARCIS (Netherlands)

    Dommelen, Peter Alexander René van

    1998-01-01

    As a study of the colonial situations of first millennium BC Sardinia, this book is as much an investigation into colonialism as a sociological category, as it explores the specific historical conditions of a particular region. Taking a fresh look at colonialism in Mediterranean archaeology from a

  9. Short-term exposure of umbilical cord blood CD34+ cells to granulocyte-macrophage colony-stimulating factor early in culture improves ex vivo expansion of neutrophils.

    Science.gov (United States)

    Marturana, Flavia; Timmins, Nicholas E; Nielsen, Lars K

    2011-03-01

    Despite the availability of modern antibiotics/antimycotics and cytokine support, neutropenic infection accounts for the majority of chemotherapy-associated deaths. While transfusion support with donor neutrophils is possible, cost and complicated logistics make such an option unrealistic on a routine basis. A manufactured neutrophil product could enable routine prophylactic administration of neutrophils, preventing the onset of neutropenia and substantially reducing the risk of infection. We examined the use of pre-culture strategies and various cytokine/modulator combinations to improve neutrophil expansion from umbilical cord blood (UCB) hematopoietic stem and progenitor cells (HPC). Enriched UCB HPC were cultured using either two-phase pre-culture strategies or a single phase using various cytokine/modulator combinations. Outcome was assessed with respect to numerical expansion, cell morphology, granulation and respiratory burst activity. Pre-culture in the absence of strong differentiation signals (e.g. granulocyte colony-stimulating factor; G-CSF) failed to provide any improvement to final neutrophil yields. Similarly, removal of differentiating cells during pre-culture failed to improve neutrophil yields to an appreciable extent. Of the cytokine/modulator combinations, the addition of granulocyte-macrophage (GM)-colony-stimulating factor (CSF) alone gave the greatest increase. In order to avoid production of monocytes, it was necessary to remove GM-CSF on day 5. Using this strategy, neutrophil expansion improved 2.7-fold. Although all cytokines and culture strategies employed have been reported previously to enhance HPC expansion, we found that the addition of GM-CSF alone was sufficient to improve total cell yields maximally. The need to remove GM-CSF on day 5 to avoid monocyte differentiation highlights the context and time-dependent complexity of exogenous signaling in hematopoietic cell differentiation and growth.

  10. Observations of radiation-induced chromosome fragment loss in live mammalian cells in culture, and its effect on colony-forming ability

    International Nuclear Information System (INIS)

    Grote, S.J.; Joshi, G.P.; Revell, S.H.; Shaw, C.A.

    1981-01-01

    A preceding paper (Grote, Joshi, Revell and Shaw 1981) describe a method for the direct scrutiny of live cultured mammalian cells with a microscope, and reported that all diploid Syrian hamster cells (BHK 21 C13) of a sample given 1.4 Gy of 220 kV X-rays in G1 reached post-radiation mitosis without discernible abnormality, but then diverged in observed behaviour: descendant cells from some first mitoses continued to proliferate normally while cells from other first mitoses behaved abnormally and produced either slow-growth or stop-growth colonies. This paper completes the study of the same irradiated cell sample, and shows that these post-mitotic differences in clonogenic ability were related to acentric chromosome fragment losses at post-radiation mitosis, which were detected in live daughter-cell pairs as micronuclei. The proportion of live daughter-cell pairs scored as deficient was at least 80 per cent of the proportion of comparable fixed-and-stained mitoses with detected acentric fragments. (author)

  11. Percutaneous implantation of peripheral blood mononuclear cells mobilized with granulocyte colony stimulating factor in osteoarthritis of the knee. First case reported in Cuba

    International Nuclear Information System (INIS)

    Baganet Cobas, Aymara Maria; Hernandez Ramirez, Porfirio; Fernandez Delgado, Norma

    2010-01-01

    The degenerative joint disease, also known as osteoarthrosis affects to 10% of elderlies aged 60. It is mainly characterized by pain in the involved joint, crepitation, morning stiff and a progressive limitation of movement of that joint leading to a partial or total wear of articular cartilage. The treatment of the knee osteoarthrosis is a great challenge. The recent advances in use of regenerative medicine suggest that adult stem cells could represent a promisor alternative in the treatment of this entity. In a female patient aged 61 presenting with knee osteoarthrosis authors placed a percutaneous implant of autologous mononuclear cells mobilized to peripheral blood by granulocyte colony-stimulating factor achieving a fast clinical and radiological improvement. This result suggests that the procedure used is a feasible, simple, safe and less expensive method for treatment of articular degenerative lesions

  12. Adenosine formation in contracting primary rat skeletal muscle cells and endothelial cells in culture

    DEFF Research Database (Denmark)

    Hellsten, Ylva; Frandsen, Ulrik

    1997-01-01

    1. The present study examined the capacity for adenosine formation, uptake and metabolism in contracting primary rat muscle cells and in microvascular endothelial cells in culture. 2. Strong and moderate electrical simulation of skeletal muscle cells led to a significantly greater increase....... 3. Addition of microvascular endothelial cells to the cultured skeletal muscle cells enhanced the contraction-induced accumulation of extracellular adenosine (P Skeletal muscle cells were...... in the extracellular adenosine concentration (421 +/- 91 and 235 +/- 30 nmol (g protein)-1, respectively; P muscle cells (161 +/- 20 nmol (g protein)-1). The ATP concentration was lower (18%; P contracted, but not in the moderately contracted muscle cells...

  13. Impact of glutathione peroxidase-1 deficiency on macrophage foam cell formation and proliferation: implications for atherogenesis.

    Directory of Open Access Journals (Sweden)

    Fei Cheng

    Full Text Available Clinical and experimental evidence suggests a protective role for the antioxidant enzyme glutathione peroxidase-1 (GPx-1 in the atherogenic process. GPx-1 deficiency accelerates atherosclerosis and increases lesion cellularity in ApoE(-/- mice. However, the distribution of GPx-1 within the atherosclerotic lesion as well as the mechanisms leading to increased macrophage numbers in lesions is still unknown. Accordingly, the aims of the present study were (1 to analyze which cells express GPx-1 within atherosclerotic lesions and (2 to determine whether a lack of GPx-1 affects macrophage foam cell formation and cellular proliferation. Both in situ-hybridization and immunohistochemistry of lesions of the aortic sinus of ApoE(-/- mice after 12 weeks on a Western type diet revealed that both macrophages and - even though to a less extent - smooth muscle cells contribute to GPx-1 expression within atherosclerotic lesions. In isolated mouse peritoneal macrophages differentiated for 3 days with macrophage-colony-stimulating factor (MCSF, GPx-1 deficiency increased oxidized low density-lipoprotein (oxLDL induced foam cell formation and led to increased proliferative activity of peritoneal macrophages. The MCSF- and oxLDL-induced proliferation of peritoneal macrophages from GPx-1(-/-ApoE(-/- mice was mediated by the p44/42 MAPK (p44/42 mitogen-activated protein kinase, namely ERK1/2 (extracellular-signal regulated kinase 1/2, signaling pathway as demonstrated by ERK1/2 signaling pathways inhibitors, Western blots on cell lysates with primary antibodies against total and phosphorylated ERK1/2, MEK1/2 (mitogen-activated protein kinase kinase 1/2, p90RSK (p90 ribosomal s6 kinase, p38 MAPK and SAPK/JNK (stress-activated protein kinase/c-Jun N-terminal kinase, and immunohistochemistry of mice atherosclerotic lesions with antibodies against phosphorylated ERK1/2, MEK1/2 and p90RSK. Representative effects of GPx-1 deficiency on both macrophage proliferation and

  14. Yeast cell wall chitin reduces wine haze formation.

    Science.gov (United States)

    Ndlovu, Thulile; Divol, Benoit; Bauer, Florian F

    2018-04-27

    Protein haze formation in bottled wines is a significant concern for the global wine industry and wine clarification before bottling is therefore a common but expensive practice. Previous studies have shown that wine yeast strains can reduce haze formation through the secretion of certain mannoproteins, but it has been suggested that other yeast-dependent haze protective mechanisms exist. On the other hand, addition of chitin has been shown to reduce haze formation, likely because grape chitinases have been shown to be the major contributors to haze. In this study, Chardonnay grape must fermented by various yeast strains resulted in wines with different protein haze levels indicating differences in haze protective capacities of the strains. The cell wall chitin levels of these strains were determined, and a strong correlation between cell wall chitin levels and haze protection capability was observed. To further evaluate the mechanism of haze protection, Escherichia coli -produced GFP-tagged grape chitinase was shown to bind efficiently to yeast cell walls in a cell wall chitin concentration-dependent manner, while commercial chitinase was removed from synthetic wine in quantities also correlated with the cell wall chitin levels of the strains. Our findings suggest a new mechanism of reducing wine haze, and propose a strategy for optimizing wine yeast strains to improve wine clarification. Importance In this study, we establish a new mechanism by which wine yeast strains can impact on the protein haze formation of wines, and demonstrate that yeast cell wall chitin binds grape chitinase in a chitin-concentration dependent manner. We also show that yeast can remove this haze-forming protein from wine. Chitin has in the past been shown to efficiently reduce wine haze formation when added to the wine in high concentration as a clarifying agent. Our data suggest that the selection of yeast strains with high levels of cell wall chitin can reduce protein haze. We also

  15. Ligand mobility modulates immunological synapse formation and T cell activation.

    Directory of Open Access Journals (Sweden)

    Chih-Jung Hsu

    Full Text Available T cell receptor (TCR engagement induces clustering and recruitment to the plasma membrane of many signaling molecules, including the protein tyrosine kinase zeta-chain associated protein of 70 kDa (ZAP70 and the adaptor SH2 domain-containing leukocyte protein of 76 kDa (SLP76. This molecular rearrangement results in formation of the immunological synapse (IS, a dynamic protein array that modulates T cell activation. The current study investigates the effects of apparent long-range ligand mobility on T cell signaling activity and IS formation. We formed stimulatory lipid bilayers on glass surfaces from binary lipid mixtures with varied composition, and characterized these surfaces with respect to diffusion coefficient and fluid connectivity. Stimulatory ligands coupled to these surfaces with similar density and orientation showed differences in their ability to activate T cells. On less mobile membranes, central supramolecular activation cluster (cSMAC formation was delayed and the overall accumulation of CD3ζ at the IS was reduced. Analysis of signaling microcluster (MC dynamics showed that ZAP70 MCs exhibited faster track velocity and longer trajectories as a function of increased ligand mobility, whereas movement of SLP76 MCs was relatively insensitive to this parameter. Actin retrograde flow was observed on all surfaces, but cell spreading and subsequent cytoskeletal contraction were more pronounced on mobile membranes. Finally, increased tyrosine phosphorylation and persistent elevation of intracellular Ca(2+ were observed in cells stimulated on fluid membranes. These results point to ligand mobility as an important parameter in modulating T cell responses.

  16. Effect of human granulocyte macrophage-colony stimulating factor on differentiation and apoptosis of the human osteosarcoma cell line SaOS-2

    Directory of Open Access Journals (Sweden)

    L Postiglione

    2009-06-01

    Full Text Available We investigated the effects of human granulocyte macrophage- colony stimulating factor (GM-CSF on the relation between differentiation and apoptosis in SaOS-2 cells, an osteoblast-like cell line. To determine the relationship between these cellular processes, SaOS-2 cells were treated in vitro for 1, 7 and 14 days with 200 ng/mL GM-CSF and compared with untreated cells. Five nM insulin-like growth factor (IGF-I and 30 nM okadaic acid were used as negative and positive controls of apoptosis, respectively. Effects on cell differentiation were determined by ECM (extracellular matrix mineralization, morphology of some typical mature osteoblast differentiation markers, such as osteopontin and sialoprotein II (BSP-II, and production of bone ECM components such as collagen I. The results showed that treatment with GM-CSF caused cell differentiation accompanied by increased production of osteopontin and BSP-II, together with increased ECM deposition and mineralization. Flow cytometric analysis of annexin V and propidium iodide incorporation showed that GM-CSF up-regulated apoptotic cell death of SaOS-2 cells after 14 days of culture in contrast to okadaic acid, which stimulated SaOS-2 apoptosis only during the early period of culture. Endonucleolytic cleavage of genomic DNA, detected by “laddering analysis”, confirmed these data. The results suggest that GM-CSF induces osteoblastic differentiation and long-term apoptotic cell death of the SaOS-2 human osteosarcoma cell line, which in turn suggests a possible in vivo physiological role for GM-CSF on human osteoblast cells.

  17. Stem cell mobilization induced by subcutaneous granulocyte-colony stimulating factor to improve cardiac regeneration after acute ST-elevation myocardial infarction: result of the double-blind, randomized, placebo-controlled stem cells in myocardial infarction (STEMMI) trial

    DEFF Research Database (Denmark)

    Ripa, RS; Jorgensen, E; Wang, Y

    2006-01-01

    BACKGROUND: Phase 1 clinical trials of granulocyte-colony stimulating factor (G-CSF) treatment after myocardial infarction have indicated that G-CSF treatment is safe and may improve left ventricular function. This randomized, double-blind, placebo-controlled trial aimed to assess the efficacy of......: Bone marrow stem cell mobilization with subcutaneous G-CSF is safe but did not lead to further improvement in ventricular function after acute myocardial infarction compared with the recovery observed in the placebo group...

  18. Comparison of Teratoma Formation between Embryonic Stem Cells and Parthenogenetic Embryonic Stem Cells by Molecular Imaging

    Directory of Open Access Journals (Sweden)

    Hongyan Tao

    2018-01-01

    Full Text Available With their properties of self-renewal and differentiation, embryonic stem (ES cells hold great promises for regenerative therapy. However, teratoma formation and ethical concerns of ES cells may restrict their potential clinical applications. Currently, parthenogenetic embryonic stem (pES cells have attracted the interest of researchers for its self-renewing and pluripotent differentiation while eliciting less ethic concerns. In this study, we established a model with ES and pES cells both stably transfected with a double-fusion reporter gene containing renilla luciferase (Rluc and red fluorescent protein (RFP to analyze the mechanisms of teratoma formation. Transgenic Vegfr2-luc mouse, which expresses firefly luciferase (Fluc under the promoter of vascular endothelial growth factor receptor 2 (Vegfr2-luc, was used to trace the growth of new blood vessel recruited by transplanted cells. Bioluminescence imaging (BLI of Rluc/Fluc provides an effective tool in estimating the growth and angiogenesis of teratoma in vivo. We found that the tumorigenesis and angiogenesis capacity of ES cells were higher than those of pES cells, in which VEGF/VEGFR2 signal pathway plays an important role. In conclusion, pES cells have the decreased potential of teratoma formation but meanwhile have similar differentiating capacity compared with ES cells. These data demonstrate that pES cells provide an alternative source for ES cells with the risk reduction of teratoma formation and without ethical controversy.

  19. Evaluation of Dutch guideline for just-in-time addition of plerixafor to stem cell mobilization in patients who fail with granulocyte-colony-stimulating factor.

    Science.gov (United States)

    Bilgin, Yavuz M; Visser, Otto; Beckers, Erik A M; te Boome, Liane C J; Huisman, Cynthia; Ypma, Paula F; Croockewit, Alexandra J; Netelenbos, Tanja; Kramer, Ellen P A; de Greef, Georgine E

    2015-05-01

    Plerixafor in combination with granulocyte-colony-stimulating factor (G-CSF) is approved for the use of stem cell collection in patients who fail to mobilize on G-CSF. In 2009 the Stem Cell Working Party of the Dutch-Belgian Cooperative Trial group for Hematology Oncology (HOVON) composed a guideline for the use of plerixafor. According to this guideline it is recommended to add plerixafor to G-CSF in patients with circulating CD34+ cell counts of fewer than 20 × 10(6) /L on 2 consecutive days accompanied by increasing white blood cells. In this analysis we evaluated retrospectively the outcome of the use of this guideline in the Netherlands. In total 111 patients received plerixafor with a median one administration (range, one to four administrations). Of these patients 55.8% had non-Hodgkin lymphoma, 31.5% multiple myeloma, 8.1% Hodgkin lymphoma, and 4.5% nonhematologic malignancies. In 63.9% patients sufficient numbers of CD34+ cells were collected. In patients with multiple myeloma more successful mobilizations with plerixafor were observed compared to patients with non-Hodgkin lymphoma (71.4% vs. 61.3%). In patients with circulating CD34+ cell counts of at least 2.0 × 10(6) /L before administration of plerixafor a successful mobilization was achieved in 76.5%, and in the patients with very low (0-1 × 10(6) /L) circulating CD34+ cell counts the success rate was 44.2%. Application of the HOVON guideline on the just-in-time administration of plerixafor is effective for mobilization of hematopoietic stem cells in the majority of patients. Stem cell yield in patients with non-Hodgkin lymphoma was lower compared to patients with multiple myeloma. Also patients with very low circulating CD34+ cells before addition of plerixafor might benefit from this approach. © 2014 AABB.

  20. Selective binding and oligomerization of the murine granulocyte colony-stimulating factor receptor by a low molecular weight, nonpeptidyl ligand.

    Science.gov (United States)

    Doyle, Michael L; Tian, Shin-Shay; Miller, Stephen G; Kessler, Linda; Baker, Audrey E; Brigham-Burke, Michael R; Dillon, Susan B; Duffy, Kevin J; Keenan, Richard M; Lehr, Ruth; Rosen, Jon; Schneeweis, Lumelle A; Trill, John; Young, Peter R; Luengo, Juan I; Lamb, Peter

    2003-03-14

    Granulocyte colony-stimulating factor regulates neutrophil production by binding to a specific receptor, the granulocyte colony-stimulating factor receptor, expressed on cells of the granulocytic lineage. Recombinant forms of granulocyte colony-stimulating factor are used clinically to treat neutropenias. As part of an effort to develop granulocyte colony-stimulating factor mimics with the potential for oral bioavailability, we previously identified a nonpeptidyl small molecule (SB-247464) that selectively activates murine granulocyte colony-stimulating factor signal transduction pathways and promotes neutrophil formation in vivo. To elucidate the mechanism of action of SB-247464, a series of cell-based and biochemical assays were performed. The activity of SB-247464 is strictly dependent on the presence of zinc ions. Titration microcalorimetry experiments using a soluble murine granulocyte colony-stimulating factor receptor construct show that SB-247464 binds to the extracellular domain of the receptor in a zinc ion-dependent manner. Analytical ultracentrifugation studies demonstrate that SB-247464 induces self-association of the N-terminal three-domain fragment in a manner that is consistent with dimerization. SB-247464 induces internalization of granulocyte colony-stimulating factor receptor on intact cells, consistent with a mechanism involving receptor oligomerization. These data show that small nonpeptidyl compounds are capable of selectively binding and inducing productive oligomerization of cytokine receptors.

  1. A hydrodynamic microchip for formation of continuous cell chains

    Science.gov (United States)

    Khoshmanesh, Khashayar; Zhang, Wei; Tang, Shi-Yang; Nasabi, Mahyar; Soffe, Rebecca; Tovar-Lopez, Francisco J.; Rajadas, Jayakumar; Mitchell, Arnan

    2014-05-01

    Here, we demonstrate the unique features of a hydrodynamic based microchip for creating continuous chains of model yeast cells. The system consists of a disk shaped microfluidic structure, containing narrow orifices that connect the main channel to an array of spoke channels. Negative pressure provided by a syringe pump draws fluid from the main channel through the narrow orifices. After cleaning process, a thin layer of water is left between the glass substrate and the polydimethylsiloxane microchip, enabling leakage beneath the channel walls. A mechanical clamp is used to adjust the operation of the microchip. Relaxing the clamp allows leakage of liquid beneath the walls in a controllable fashion, leading to formation of a long cell chain evenly distributed along the channel wall. The unique features of the microchip are demonstrated by creating long chains of yeast cells and model 15 μm polystyrene particles along the side wall and analysing the hydrogen peroxide induced death of patterned cells.

  2. Blockade of mast cell activation reduces cutaneous scar formation.

    Directory of Open Access Journals (Sweden)

    Lin Chen

    Full Text Available Damage to the skin initiates a cascade of well-orchestrated events that ultimately leads to repair of the wound. The inflammatory response is key to wound healing both through preventing infection and stimulating proliferation and remodeling of the skin. Mast cells within the tissue are one of the first immune cells to respond to trauma, and upon activation they release pro-inflammatory molecules to initiate recruitment of leukocytes and promote a vascular response in the tissue. Additionally, mast cells stimulate collagen synthesis by dermal fibroblasts, suggesting they may also influence scar formation. To examine the contribution of mast cells in tissue repair, we determined the effects the mast cell inhibitor, disodium cromoglycate (DSCG, on several parameters of dermal repair including, inflammation, re-epithelialization, collagen fiber organization, collagen ultrastructure, scar width and wound breaking strength. Mice treated with DSCG had significantly reduced levels of the inflammatory cytokines IL-1α, IL-1β, and CXCL1. Although DSCG treatment reduced the production of inflammatory mediators, the rate of re-epithelialization was not affected. Compared to control, inhibition of mast cell activity caused a significant decrease in scar width along with accelerated collagen re-organization. Despite the reduced scar width, DSCG treatment did not affect the breaking strength of the healed tissue. Tryptase β1 exclusively produced by mast cells was found to increase significantly in the course of wound healing. However, DSCG treatment did not change its level in the wounds. These results indicate that blockade of mast cell activation reduces scar formation and inflammation without further weakening the healed wound.

  3. Granulocyte Colony-stimulating Factor-primed Bone Marrow: An Excellent Stem-cell Source for Transplantation in Acute Myelocytic Leukemia and Chronic Myelocytic Leukemia

    Directory of Open Access Journals (Sweden)

    Yuhang Li

    2015-01-01

    Full Text Available Background: Steady-state bone marrow (SS-BM and granulocyte colony-stimulating growth factor-primed BM/peripheral blood stem-cell (G-BM/G-PBSC are the main stem-cell sources used in allogeneic hematopoietic stem-cell transplantation. Here, we evaluated the treatment effects of SS-BM and G-BM/G-PBSC in human leucocyte antigen (HLA-identical sibling transplantation. Methods: A total of 226 patients (acute myelogenous leukemia-complete remission 1, chronic myelogenous leukemia-chronic phase 1 received SS-BM, G-BM, or G-PBSC from an HLA-identical sibling. Clinical outcomes (graft-versus-host disease [GVHD], overall survival, transplant-related mortality [TRM], and leukemia-free survival [LFS] were analyzed. Results: When compared to SS-BM, G-BM gave faster recovery time to neutrophil or platelet (P 0.05. Conclusions: G-CSF-primed bone marrow shared the advantages of G-PBSC and SS-BM. We conclude that G-BM is an excellent stem-cell source that may be preferable to G-PBSC or SS-BM in patients receiving HLA-identical sibling hematopoietic stem-cell transplantation.

  4. Exocytosis of macrophage lysosomes leads to digestion of apoptotic adipocytes and foam cell formation[S

    Science.gov (United States)

    Haka, Abigail S.; Barbosa-Lorenzi, Valéria C.; Lee, Hyuek Jong; Falcone, Domenick J.; Hudis, Clifford A.; Dannenberg, Andrew J.

    2016-01-01

    Many types of apoptotic cells are phagocytosed and digested by macrophages. Adipocytes can be hundreds of times larger than macrophages, so they are too large to be digested by conventional phagocytic processes. The nature of the interaction between macrophages and apoptotic adipocytes has not been studied in detail. We describe a cellular process, termed exophagy, that is important for macrophage clearance of dead adipocytes and adipose tissue homeostasis. Using mouse models of obesity, human tissue, and a cell culture model, we show that macrophages form hydrolytic extracellular compartments at points of contact with dead adipocytes using local actin polymerization. These compartments are acidic and contain lysosomal enzymes delivered by exocytosis. Uptake and complete degradation of adipocyte fragments, which are released by extracellular hydrolysis, leads to macrophage foam cell formation. Exophagy-mediated foam cell formation is a highly efficient means by which macrophages internalize large amounts of lipid, which may ultimately overwhelm the metabolic capacity of the macrophage. This process provides a mechanism for degradation of objects, such as dead adipocytes, that are too large to be phagocytosed by macrophages. PMID:27044658

  5. Long-Term Expansion in Platelet Lysate Increases Growth of Peripheral Blood-Derived Endothelial-Colony Forming Cells and Their Growth Factor-Induced Sprouting Capacity.

    Science.gov (United States)

    Tasev, Dimitar; van Wijhe, Michiel H; Weijers, Ester M; van Hinsbergh, Victor W M; Koolwijk, Pieter

    2015-01-01

    Efficient implementation of peripheral blood-derived endothelial-colony cells (PB-ECFCs) as a therapeutical tool requires isolation and generation of a sufficient number of cells in ex vivo conditions devoid of animal-derived products. At present, little is known how the isolation and expansion procedure in xenogeneic-free conditions affects the therapeutical capacity of PB-ECFCs. The findings presented in this study indicate that human platelet lysate (PL) as a serum substitute yields twice more colonies per mL blood compared to the conventional isolation with fetal bovine serum (FBS). Isolated ECFCs displayed a higher proliferative ability in PL supplemented medium than cells in FBS medium during 30 days expansion. The cells at 18 cumulative population doubling levels (CPDL) retained their proliferative capacity, showed higher sprouting ability in fibrin matrices upon stimulation with FGF-2 and VEGF-A than the cells at 6 CPDL, and displayed low β-galactosidase activity. The increased sprouting of PB-ECFCs at 18 CPDL was accompanied by an intrinsic activation of the uPA/uPAR fibrinolytic system. Induced deficiency of uPA (urokinase-type plasminogen activator) or uPAR (uPA receptor) by siRNA technology completely abolished the angiogenic ability of PB-ECFCs in fibrin matrices. During the serial expansion, the gene induction of the markers associated with inflammatory activation such as VCAM-1 and ICAM-1 did not occur or only to limited extent. While further propagation up to 31 CPDL proceeded at a comparable rate, a marked upregulation of inflammatory markers occurred in all donors accompanied by a further increase of uPA/uPAR gene induction. The observed induction of inflammatory genes at later stages of long-term propagation of PB-ECFCs underpins the necessity to determine the right time-point for harvesting of sufficient number of cells with preserved therapeutical potential. The presented isolation method and subsequent cell expansion in platelet lysate

  6. Long-Term Expansion in Platelet Lysate Increases Growth of Peripheral Blood-Derived Endothelial-Colony Forming Cells and Their Growth Factor-Induced Sprouting Capacity.

    Directory of Open Access Journals (Sweden)

    Dimitar Tasev

    Full Text Available Efficient implementation of peripheral blood-derived endothelial-colony cells (PB-ECFCs as a therapeutical tool requires isolation and generation of a sufficient number of cells in ex vivo conditions devoid of animal-derived products. At present, little is known how the isolation and expansion procedure in xenogeneic-free conditions affects the therapeutical capacity of PB-ECFCs.The findings presented in this study indicate that human platelet lysate (PL as a serum substitute yields twice more colonies per mL blood compared to the conventional isolation with fetal bovine serum (FBS. Isolated ECFCs displayed a higher proliferative ability in PL supplemented medium than cells in FBS medium during 30 days expansion. The cells at 18 cumulative population doubling levels (CPDL retained their proliferative capacity, showed higher sprouting ability in fibrin matrices upon stimulation with FGF-2 and VEGF-A than the cells at 6 CPDL, and displayed low β-galactosidase activity. The increased sprouting of PB-ECFCs at 18 CPDL was accompanied by an intrinsic activation of the uPA/uPAR fibrinolytic system. Induced deficiency of uPA (urokinase-type plasminogen activator or uPAR (uPA receptor by siRNA technology completely abolished the angiogenic ability of PB-ECFCs in fibrin matrices. During the serial expansion, the gene induction of the markers associated with inflammatory activation such as VCAM-1 and ICAM-1 did not occur or only to limited extent. While further propagation up to 31 CPDL proceeded at a comparable rate, a marked upregulation of inflammatory markers occurred in all donors accompanied by a further increase of uPA/uPAR gene induction. The observed induction of inflammatory genes at later stages of long-term propagation of PB-ECFCs underpins the necessity to determine the right time-point for harvesting of sufficient number of cells with preserved therapeutical potential.The presented isolation method and subsequent cell expansion in platelet

  7. Inhibitory Effects of Salinomycin on Cell Survival, Colony Growth, Migration, and Invasion of Human Non-Small Cell Lung Cancer A549 and LNM35: Involvement of NAG-1.

    Directory of Open Access Journals (Sweden)

    Kholoud Arafat

    Full Text Available A major challenge for oncologists and pharmacologists is to develop more potent and less toxic drugs that will decrease the tumor growth and improve the survival of lung cancer patients. Salinomycin is a polyether antibiotic used to kill gram-positive bacteria including mycobacteria, protozoans such as plasmodium falciparum, and the parasites responsible for the poultry disease coccidiosis. This old agent is now a serious anti-cancer drug candidate that selectively inhibits the growth of cancer stem cells. We investigated the impact of salinomycin on survival, colony growth, migration and invasion of the differentiated human non-small cell lung cancer lines LNM35 and A549. Salinomycin caused concentration- and time-dependent reduction in viability of LNM35 and A549 cells through a caspase 3/7-associated cell death pathway. Similarly, salinomycin (2.5-5 µM for 7 days significantly decreased the growth of LNM35 and A549 colonies in soft agar. Metastasis is the main cause of death related to lung cancer. In this context, salinomycin induced a time- and concentration-dependent inhibition of cell migration and invasion. We also demonstrated for the first time that salinomycin induced a marked increase in the expression of the pro-apoptotic protein NAG-1 leading to the inhibition of lung cancer cell invasion but not cell survival. These findings identify salinomycin as a promising novel therapeutic agent for lung cancer.

  8. Effect of doxorubicin on cell survival and micronuclei formation in HeLa cells exposed to different doses of gamma-radiation

    International Nuclear Information System (INIS)

    Jagetia, G.C.; Nayak, V.

    2000-01-01

    Purpose: The present study was undertaken to obtain an insight into the combined effects of doxorubicin with radiation on the cell survival and micronuclei induction in HeLa cells. Material and Methods: HeLa S3 cells were allowed to grow till they reached plateau phase, inoculated with 10 μg/ml doxorubicin hydrochloride and then exposed to 0, 0.5, 1, 2 and 3 Gy γ-radiation. Clonogenicity of cell was measured using the colony forming assay, micronuclei formation using the micronucleus assay. Results: The treatment of HeLa cells with doxorubicin (adriamycin) for 2 hours before exposure to different doses of γ-radiation resulted in a significant and dose-dependent decline in the cell survival and cell proliferation when compared to the PBS+irradiation group. Conversely, the frequency of micronuclei increased in a dose-related manner in both the PBS+irradiation and doxorubicin+irradiation groups. The pretreatment of HeLa cells with doxorubicin before irradiation to various doses of γ-rays resulted in a significant elevation in the frequency of micronuclei when compared with the concurrent PBS+irradiation group. The dose-response relationship for both PBS+irradiation and doxorubicin+irradiation groups was linear. The correlation between cell survival and micronuclei induction was also determined for PBS or doxorubicin+irradiation group, where the clonogenicity of cells declined with the increase in micronuclei formation. The correlation between cell survical and micronuclei induction was linear quadratic for both PBS+irradiation and doxorubicin+irradiation groups. Conclusion: From our study it can be concluded that combination treatment with doxorubicin and radiation increased the genotoxic effect of the either treatment given alone. (orig.) [de

  9. Rayleigh-Benard Natural Convection Cell Formation and Nusselt number

    International Nuclear Information System (INIS)

    Moon, Je Young; Chung, Bum Jin

    2013-01-01

    The experimental results lie within the predictions of the existing heat transfer correlations for the Rayleigh-Benard natural convections even though the material properties were different. For shorter separation distances, the heat transfers enhance due to the active interaction between heated and cooled plumes. For a step temperature difference, the time dependent Nusselt number variations were investigated. Both experimental and numerical results showed that with time the Nusselt number decreases monotonically to a minimum point presenting the onset of convection. As the hot and cold plumes increase and convey the heat to the other plates, the Nusselt number increases to the local maximum point, presenting the vertical movements of the plumes. Then, the Nusselt number fluctuates with the formation of square cells and larger vortices. This also predicted by the mass transfer experiment. The experiments and calculations show similar trend but the timings were different. These discrepancies are caused by the disturbances inherent in both systems. The molten pool is formed in a hypothetical severe accident condition at the lower head of reactor vessel and is stratified into two layers by the density difference: an upper metallic layer and a lower oxide pool. Rayleigh-Benard natural convection occurs in the metallic layer of relocated molten pool. This study aimed at the investigation of the time-dependent cell formation and Nusselt number variation in Rayleigh-Benard natural convection. Time dependent variation of Nusselt number was also measured experimentally and analyzed numerically to investigate the relationship between the cell formation and Nusselt number. Based on the analogy, heat transfer experiments were replaced by mass transfer experiments using a sulfuric acid-copper sulfate (H 2 SO 4 -CuSO 4 ) electroplating system. Numerical analysis using the commercial CFD program FLUENT 6.3 were carried out with the same material properties and heating conditions

  10. Colletotrichum higginsianum Mitogen-Activated Protein Kinase ChMK1: Role in Growth, Cell Wall Integrity, Colony Melanization and Pathogenicity

    Directory of Open Access Journals (Sweden)

    Wei Wei

    2016-08-01

    Full Text Available Colletotrichum higginsianum is an economically important pathogen that causes anthracnose disease in a wide range of cruciferous crops. To facilitate the efficient control of anthracnose disease, it will be important to understand the mechanism by which the cruciferous crops and C. higginsianum interact. A key step in understanding this interaction is characterizing the mitogen-activated protein kinases (MAPK signaling pathway of C. higginsianum. MAPK plays important roles in diverse physiological processes of multiple pathogens. In this study, a Fus3/Kss1-related MAPK gene, ChMK1, from C. higginsianum was analyzed. The results showed that the Fus3/Kss1-related MAPK ChMK1 plays a significant role in cell wall integrity. Targeted deletion of ChMK1 resulted in a hypersensitivity to cell wall inhibitors, reduced conidiation and albinistic colonies. Further, the deletion mutant was also unable to form melanized appressorium, a specialized infection structure that is necessary for successful infection. Therefore, the deletion mutant loses pathogenicity on A. thaliana leaves, demonstrating that ChMK1 plays an essential role in the early infection step. In addition, the ChMK1 deletion mutant showed an attenuated growth rate that is different from that of its homologue in C. lagenarium, indicating the diverse roles that Fus3/Kss1-related MAPKs plays in phytopathogenic fungi. Furthermore, the expression level of three melanin synthesis associated genes were clearly decreased in the albinistic ChMK1 mutant compared to that of the wild type strain, suggesting that ChMK1 is also required for colony melanization in C. higginsianum.

  11. Disruption of the pdhB pyruvate dehydrogenase [corrected] gene affects colony morphology, in vitro growth and cell invasiveness of Mycoplasma agalactiae.

    Directory of Open Access Journals (Sweden)

    Shivanand Hegde

    Full Text Available The utilization of available substrates, the metabolic potential and the growth rates of bacteria can play significant roles in their pathogenicity. This study concentrates on Mycoplasma agalactiae, which causes significant economic losses through its contribution to contagious agalactia in small ruminants by as yet unknown mechanisms. This lack of knowledge is primarily due to its fastidious growth requirements and the scarcity of genetic tools available for its manipulation and analysis. Transposon mutagenesis of M. agalactiae type strain PG2 resulted in several disruptions throughout the genome. A mutant defective in growth in vitro was found to have a transposon insertion in the pdhB gene, which encodes a component of the pyruvate dehydrogenase complex. This growth difference was quite significant during the actively dividing logarithmic phase but a gradual recovery was observed as the cells approached stationary phase. The mutant also exhibited a different and smaller colony morphology compared to the wild type strain PG2. For complementation, pdhAB was cloned downstream of a strong vpma promoter and upstream of a lacZ reporter gene in a newly constructed complementation vector. When transformed with this vector the pdhB mutant recovered its normal growth and colony morphology. Interestingly, the pdhB mutant also had significantly reduced invasiveness in HeLa cells, as revealed by double immunofluorescence staining. This deficiency was recovered in the complemented strain, which had invasiveness comparable to that of PG2. Taken together, these data indicate that pyruvate dehydrogenase might be an important player in infection with and colonization by M. agalactiae.

  12. Real-time monitoring of non-viable airborne particles correlates with airborne colonies and represents an acceptable surrogate for daily assessment of cell-processing cleanroom performance.

    Science.gov (United States)

    Raval, Jay S; Koch, Eileen; Donnenberg, Albert D

    2012-10-01

    Airborne particulate monitoring is mandated as a component of good manufacturing practice. We present a procedure developed to monitor and interpret airborne particulates in an International Organization for Standardization (ISO) class 7 cleanroom used for the cell processing of Section 351 and Section 361 products. We collected paired viable and non-viable airborne particle data over a period of 1 year in locations chosen to provide a range of air quality. We used receiver operator characteristic (ROC) analysis to determine empirically the relationship between non-viable and viable airborne particle counts. Viable and non-viable particles were well-correlated (r(2) = 0.78), with outlier observations at the low end of the scale (non-viable particles without detectable airborne colonies). ROC analysis predicted viable counts ≥ 0.5/feet(3) (a limit set by the United States Pharmacopeia) at an action limit of ≥ 32 000 particles (≥ 0.5 µ)/feet(3), with 95.6% sensitivity and 50% specificity. This limit was exceeded 2.6 times during 18 months of retrospective daily cleanroom data (an expected false alarm rate of 1.3 times/year). After implementing this action limit, we were alerted in real time to an air-handling failure undetected by our hospital facilities management. A rational action limit for non-viable particles was determined based on the correlation with airborne colonies. Reaching or exceeding the action limit of 32 000 non-viable particles/feet(3) triggers suspension of cleanroom cell-processing activities, deep cleaning, investigation of air handling, and a deviation management process. Our full procedure for particle monitoring is available as an online supplement.

  13. Both systemic and local application of Granulocyte-colony stimulating factor (G-CSF is neuroprotective after retinal ganglion cell axotomy

    Directory of Open Access Journals (Sweden)

    Dietz Gunnar PH

    2009-05-01

    Full Text Available Abstract Background The hematopoietic Granulocyte-Colony Stimulating Factor (G-CSF plays a crucial role in controlling the number of neutrophil progenitor cells. Its function is mediated via the G-CSF receptor, which was recently found to be expressed also in the central nervous system. In addition, G-CSF provided neuroprotection in models of neuronal cell death. Here we used the retinal ganglion cell (RGC axotomy model to compare effects of local and systemic application of neuroprotective molecules. Results We found that the G-CSF receptor is robustly expressed by RGCs in vivo and in vitro. We thus evaluated G-CSF as a neuroprotectant for RGCs and found a dose-dependent neuroprotective effect of G-CSF on axotomized RGCs when given subcutaneously. As stem stell mobilization had previously been discussed as a possible contributor to the neuroprotective effects of G-CSF, we compared the local treatment of RGCs by injection of G-CSF into the vitreous body with systemic delivery by subcutaneous application. Both routes of application reduced retinal ganglion cell death to a comparable extent. Moreover, G-CSF enhanced the survival of immunopurified RGCs in vitro. Conclusion We thus show that G-CSF neuroprotection is at least partially independent of potential systemic effects and provide further evidence that the clinically applicable G-CSF could become a treatment option for both neurodegenerative diseases and glaucoma.

  14. Transplanted Peripheral Blood Stem Cells Mobilized by Granulocyte Colony-Stimulating Factor Promoted Hindlimb Functional Recovery After Spinal Cord Injury in Mice.

    Science.gov (United States)

    Takahashi, Hiroshi; Koda, Masao; Hashimoto, Masayuki; Furuya, Takeo; Sakuma, Tsuyoshi; Kato, Kei; Okawa, Akihiko; Inada, Taigo; Kamiya, Koshiro; Ota, Mitsutoshi; Maki, Satoshi; Takahashi, Kazuhisa; Yamazaki, Masashi; Mannoji, Chikato

    2016-01-01

    Granulocyte colony-stimulating factor (G-CSF) mobilizes peripheral blood stem cells (PBSCs) derived from bone marrow. We hypothesized that intraspinal transplantation of PBSCs mobilized by G-CSF could promote functional recovery after spinal cord injury. Spinal cords of adult nonobese diabetes/severe immunodeficiency mice were injured using an Infinite Horizon impactor (60 kdyn). One week after the injury, 3.0 µl of G-CSF-mobilized human mononuclear cells (MNCs; 0.5 × 10(5)/µl), G-CSF-mobilized human CD34-positive PBSCs (CD34; 0.5 × 10(5)/µl), or normal saline was injected to the lesion epicenter. We performed immunohistochemistry. Locomotor recovery was assessed by Basso Mouse Scale. The number of transplanted human cells decreased according to the time course. The CD31-positive area was significantly larger in the MNC and CD34 groups compared with the vehicle group. The number of serotonin-positive fibers was significantly larger in the MNC and CD34 groups than in the vehicle group. Immunohistochemistry revealed that the number of apoptotic oligodendrocytes was significantly smaller in cell-transplanted groups, and the areas of demyelination in the MNC- and CD34-transplanted mice were smaller than that in the vehicle group, indicating that cell transplantation suppressed oligodendrocyte apoptosis and demyelination. Both the MNC and CD34 groups showed significantly better hindlimb functional recovery compared with the vehicle group. There was no significant difference between the two types of transplanted cells. Intraspinal transplantation of G-CSF-mobilized MNCs or CD34-positive cells promoted angiogenesis, serotonergic fiber regeneration/sparing, and preservation of myelin, resulting in improved hindlimb function after spinal cord injury in comparison with vehicle-treated control mice. Transplantation of G-CSF-mobilized PBSCs has advantages for treatment of spinal cord injury in the ethical and immunological viewpoints, although further exploration

  15. Granulocyte colony-stimulating factor decreases the Th1/Th2 ratio in peripheral blood mononuclear cells from patients with chronic immune thrombocytopenic purpura in vitro.

    Science.gov (United States)

    Ge, Fei; Zhang, Zhuo; Hou, Jinxiao; Cao, Fenglin; Zhang, Yingmei; Wang, Ping; Wei, Hong; Zhou, Jin

    2016-12-01

    Chronic immune thrombocytopenia purpura (ITP) is an autoimmune disease that exhibits an abnormally high Th1/Th2 ratio. Granulocyte colony-stimulating factor (G-CSF) has been shown to decrease the Th1/Th2 ratio in healthy donors. In this study, we investigated the effects of G-CSF treatment on the Th1/Th2 cells and the underlying mechanisms in patients with ITP in vitro. Peripheral blood mononuclear cells (PBMCs) isolated from patients with ITP and healthy controls were treated with G-CSF. Expression levels of interferon (IFN)-γ, interleukin (IL)-2, IL-4, and IL-13 in supernatants were measured by enzyme-linked immunosorbent assays. The expression of IFN-γ, IL-4, and G-CSF receptor (G-CSFR) on Th1 and Th2 cells were examined by flow cytometry and confocal microscopy. The mRNA expression of IFN-γ, IL-2, IL-4, IL-13, and T-box expressed in T cells (T-bet) and GATA-binding protein 3 (GATA-3) in PBMCs was evaluated by reverse transcription polymerase chain reaction. The results showed that G-CSF could significantly reduce the Th1/Th2 ratio in PBMCs from patients with ITP in vitro. As the concentration of G-CSF increased, Th1/Th2 ([IFN-γ+IL-2]/[IL-4+IL-13]) cytokine ratios and T-bet/GATA-3 mRNA ratios decreased in a concentration-dependent manner. Th1 cells and Th2 cells both expressed G-CSFR. These results suggest that G-CSF could decrease the Th1/Th2 ratio in the context of ITP, and elucidate the direct and indirect immunomodulatory mechanisms underlying G-CSF functions in Th1/Th2 cells, thus supporting the therapeutic potential of G-CSF in the treatment of patients with ITP. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. RNA-binding IMPs promote cell adhesion and invadopodia formation

    DEFF Research Database (Denmark)

    Vikesaa, Jonas; Hansen, Thomas V O; Jønson, Lars

    2006-01-01

    Oncofetal RNA-binding IMPs have been implicated in mRNA localization, nuclear export, turnover and translational control. To depict the cellular actions of IMPs, we performed a loss-of-function analysis, which showed that IMPs are necessary for proper cell adhesion, cytoplasmic spreading and inva......Oncofetal RNA-binding IMPs have been implicated in mRNA localization, nuclear export, turnover and translational control. To depict the cellular actions of IMPs, we performed a loss-of-function analysis, which showed that IMPs are necessary for proper cell adhesion, cytoplasmic spreading...... and invadopodia formation. Loss of IMPs was associated with a coordinate downregulation of mRNAs encoding extracellular matrix and adhesion proteins. The transcripts were present in IMP RNP granules, implying that IMPs were directly involved in the post-transcriptional control of the transcripts. In particular......-mediated invadopodia formation. Taken together, our results indicate that RNA-binding proteins exert profound effects on cellular adhesion and invasion during development and cancer formation....

  17. Schwann Cells in Neuromuscular Junction Formation and Maintenance.

    Science.gov (United States)

    Barik, Arnab; Li, Lei; Sathyamurthy, Anupama; Xiong, Wen-Cheng; Mei, Lin

    2016-09-21

    The neuromuscular junction (NMJ) is a tripartite synapse that is formed by motor nerve terminals, postjunctional muscle membranes, and terminal Schwann cells (TSCs) that cover the nerve-muscle contact. NMJ formation requires intimate communications among the three different components. Unlike nerve-muscle interaction, which has been well characterized, less is known about the role of SCs in NMJ formation and maintenance. We show that SCs in mice lead nerve terminals to prepatterned AChRs. Ablating SCs at E8.5 (i.e., prior nerve arrival at the clusters) had little effect on aneural AChR clusters at E13.5, suggesting that SCs may not be necessary for aneural clusters. SC ablation at E12.5, a time when phrenic nerves approach muscle fibers, resulted in smaller and fewer nerve-induced AChR clusters; however, SC ablation at E15.5 reduced AChR cluster size but had no effect on cluster density, suggesting that SCs are involved in AChR cluster maturation. Miniature endplate potential amplitude, but not frequency, was reduced when SCs were ablated at E15.5, suggesting that postsynaptic alterations may occur ahead of presynaptic deficits. Finally, ablation of SCs at P30, after NMJ maturation, led to NMJ fragmentation and neuromuscular transmission deficits. Miniature endplate potential amplitude was reduced 3 d after SC ablation, but both amplitude and frequency were reduced 6 d after. Together, these results indicate that SCs are not only required for NMJ formation, but also necessary for its maintenance; and postsynaptic function and structure appeared to be more sensitive to SC ablation. Neuromuscular junctions (NMJs) are critical for survival and daily functioning. Defects in NMJ formation during development or maintenance in adulthood result in debilitating neuromuscular disorders. The role of Schwann cells (SCs) in NMJ formation and maintenance was not well understood. We genetically ablated SCs during development and after NMJ formation to investigate the consequences

  18. The role of granulocyte macrophage colony stimulating factor (GM-CSF) in radiation-induced tumor cell migration.

    Science.gov (United States)

    Vilalta, Marta; Brune, Jourdan; Rafat, Marjan; Soto, Luis; Graves, Edward E

    2018-03-13

    Recently it has been observed in preclinical models that that radiation enhances the recruitment of circulating tumor cells to primary tumors, and results in tumor regrowth after treatment. This process may have implications for clinical radiotherapy, which improves control of a number of tumor types but which, despite continued dose escalation and aggressive fractionation, is unable to fully prevent local recurrences. By irradiating a single tumor within an animal bearing multiple lesions, we observed an increase in tumor cell migration to irradiated and unirradiated sites, suggesting a systemic component to this process. Previous work has identified the cytokine GM-CSF, produced by tumor cells following irradiation, as a key effector of this process. We evaluated the ability of systemic injections of a PEGylated form of GM-CSF to stimulate tumor cell migration. While increases in invasion and migration were observed for tumor cells in a transwell assay, we found that daily injections of PEG-GM-CSF to tumor-bearing animals did not increase migration of cells to tumors, despite the anticipated changes in circulating levels of granulocytes and monocytes produced by this treatment. Combination of PEG-GM-CSF treatment with radiation also did not increase tumor cell migration. These findings suggest that clinical use of GM-CSF to treat neutropenia in cancer patients will not have negative effects on the aggressiveness of residual cancer cells. However, further work is needed to characterize the mechanism by which GM-CSF facilitates systemic recruitment of trafficking tumor cells to tumors.

  19. A microfluidic direct formate fuel cell on paper.

    Science.gov (United States)

    Copenhaver, Thomas S; Purohit, Krutarth H; Domalaon, Kryls; Pham, Linda; Burgess, Brianna J; Manorothkul, Natalie; Galvan, Vicente; Sotez, Samantha; Gomez, Frank A; Haan, John L

    2015-08-01

    We describe the first direct formate fuel cell on a paper microfluidic platform. In traditional membrane-less microfluidic fuel cells (MFCs), external pumping consumes power produced by the fuel cell in order to maintain co-laminar flow of the anode stream and oxidant stream to prevent mixing. However, in paper microfluidics, capillary action drives flow while minimizing stream mixing. In this work, we demonstrate a paper MFC that uses formate and hydrogen peroxide as the anode fuel and cathode oxidant, respectively. Using these materials we achieve a maximum power density of nearly 2.5 mW/mg Pd. In a series configuration, our MFC achieves an open circuit voltage just over 1 V, and in a parallel configuration, short circuit of 20 mA absolute current. We also demonstrate that the MFC does not require continuous flow of fuel and oxidant to produce power. We found that we can pre-saturate the materials on the paper, stop the electrolyte flow, and still produce approximately 0.5 V for 15 min. This type of paper MFC has potential applications in point-of-care diagnostic devices and other electrochemical sensors. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Magnetization of individual yeast cells by in situ formation of iron oxide on cell surfaces

    Science.gov (United States)

    Choi, Jinsu; Lee, Hojae; Choi, Insung S.; Yang, Sung Ho

    2017-09-01

    Magnetic functionalization of living cells has intensively been investigated with the aim of various bioapplications such as selective separation, targeting, and localization of the cells by using an external magnetic field. However, the magnetism has not been introduced to individual living cells through the in situ chemical reactions because of harsh conditions required for synthesis of magnetic materials. In this work, magnetic iron oxide was formed on the surface of living cells by optimizing reactions conditions to be mild sufficiently enough to sustain cell viability. Specifically, the reactive LbL strategy led to formation of magnetically responsive yeast cells with iron oxide shells. This facile and direct post-magnetization method would be a useful tool for remote manipulation of living cells with magnetic interactions, which is an important technique for the integration of cell-based circuits and the isolation of cell in microfluidic devices.

  1. Adaptive T cell responses induced by oncolytic Herpes Simplex Virus-granulocyte macrophage-colony-stimulating factor therapy expanded by dendritic cell and cytokine-induced killer cell adoptive therapy.

    Science.gov (United States)

    Ren, Jun; Gwin, William R; Zhou, Xinna; Wang, Xiaoli; Huang, Hongyan; Jiang, Ni; Zhou, Lei; Agarwal, Pankaj; Hobeika, Amy; Crosby, Erika; Hartman, Zachary C; Morse, Michael A; H Eng, Kevin; Lyerly, H Kim

    2017-01-01

    Purpose : Although local oncolytic viral therapy (OVT) may enhance tumor lysis, antigen release, and adaptive immune responses, systemic antitumor responses post-therapy are limited. Adoptive immunotherapy with autologous dendritic cells (DC) and cytokine-induced killer cells (DC-CIK) synergizes with systemic therapies. We hypothesized that OVT with Herpes Simplex Virus-granulocyte macrophage-colony-stimulating factor (HSV-GM-CSF) would induce adaptive T cell responses that could be expanded systemically with sequential DC-CIK therapy. Patients and Methods : We performed a pilot study of intratumoral HSV-GM-CSF OVT followed by autologous DC-CIK cell therapy. In addition to safety and clinical endpoints, we monitored adaptive T cell responses by quantifying T cell receptor (TCR) populations in pre-oncolytic therapy, post-oncolytic therapy, and after DC-CIK therapy. Results : Nine patients with advanced malignancy were treated with OVT (OrienX010), of whom seven experienced stable disease (SD). Five of the OVT treated patients underwent leukapheresis, generation, and delivery of DC-CIKs, and two had SD, whereas three progressed. T cell receptor sequencing of TCR β sequences one month after OVT therapy demonstrates a dynamic TCR repertoire in response to OVT therapy in the majority of patients with the systematic expansion of multiple T cell clone populations following DC-CIK therapy. This treatment was well tolerated and long-term event free and overall survival was observed in six of the nine patients. Conclusions : Strategies inducing the local activation of tumor-specific immune responses can be combined with adoptive cellular therapies to expand the adaptive T cell responses systemically and further studies are warranted.

  2. Enhanced SCAP glycosylation by inflammation induces macrophage foam cell formation.

    Directory of Open Access Journals (Sweden)

    Chao Zhou

    Full Text Available Inflammatory stress promotes foam cell formation by disrupting LDL receptor feedback regulation in macrophages. Sterol Regulatory Element Binding Proteins (SREBPs Cleavage-Activating Protein (SCAP glycosylation plays crucial roles in regulating LDL receptor and 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGCoAR feedback regulation. The present study was to investigate if inflammatory stress disrupts LDL receptor and HMGCoAR feedback regulation by affecting SCAP glycosylation in THP-1 macrophages. Intracellular cholesterol content was assessed by Oil Red O staining and quantitative assay. The expression of molecules controlling cholesterol homeostasis was examined using real-time quantitative RT-PCR and Western blotting. The translocation of SCAP from the endoplasmic reticulum (ER to the Golgi was detected by confocal microscopy. We demonstrated that exposure to inflammatory cytokines increased lipid accumulation in THP-1 macrophages, accompanying with an increased SCAP expression even in the presence of a high concentration of LDL. These inflammatory cytokines also prolonged the half-life of SCAP by enhancing glycosylation of SCAP due to the elevated expression of the Golgi mannosidase II. This may enhance translocation and recycling of SCAP between the ER and the Golgi, escorting more SREBP2 from the ER to the Golgi for activation by proteolytic cleavages as evidenced by an increased N-terminal of SREBP2 (active form. As a consequence, the LDL receptor and HMGCoAR expression were up-regulated. Interestingly, these effects could be blocked by inhibitors of Golgi mannosidases. Our results indicated that inflammation increased native LDL uptake and endogenous cholesterol de novo synthesis, thereby causing foam cell formation via increasing transcription and protein glycosylation of SCAP in macrophages. These data imply that inhibitors of Golgi processing enzymes might have a potential vascular-protective role in prevention of atherosclerotic foam

  3. Synergy of cell-cell repulsion and vacuolation in a computational model of lumen formation.

    Science.gov (United States)

    Boas, Sonja E M; Merks, Roeland M H

    2014-03-06

    A key step in blood vessel development (angiogenesis) is lumen formation: the hollowing of vessels for blood perfusion. Two alternative lumen formation mechanisms are suggested to function in different types of blood vessels. The vacuolation mechanism is suggested for lumen formation in small vessels by coalescence of intracellular vacuoles, a view that was extended to extracellular lumen formation by exocytosis of vacuoles. The cell-cell repulsion mechanism is suggested to initiate extracellular lumen formation in large vessels by active repulsion of adjacent cells, and active cell shape changes extend the lumen. We used an agent-based computer model, based on the cellular Potts model, to compare and study both mechanisms separately and combined. An extensive sensitivity analysis shows that each of the mechanisms on its own can produce lumens in a narrow region of parameter space. However, combining both mechanisms makes lumen formation much more robust to the values of the parameters, suggesting that the mechanisms may work synergistically and operate in parallel, rather than in different vessel types.

  4. Mobilization of hematopoietic progenitor cells with granulocyte colony stimulating factors for autologous transplant in hematologic malignancies: a single center experience

    Science.gov (United States)

    Gabús, Raul; Borelli, Gabriel; Ferrando, Martín; Bódega, Enrique; Citrín, Estela; Jiménez, Constanza Olivera; Álvarez, Ramón

    2011-01-01

    Background In 2006 the Hematology Service of Hospital Maciel published its experience with peripheral blood progenitor cell harvesting for autologous stem cell transplantation using Filgen JP (Clausen Filgrastim). After mobilization with a mean filgrastim dose of 78 mcg/Kg, 4.7 x 106 CD34+ cells/Kg were obtained by apheresis. Age above 50, multiple myeloma as underlying disease and a malignancy that was not in remission were identified as frequent characteristics among patients showing complex mobilization. Objective The aim of this study was to compare stem cell mobilization using different brands of filgrastim. Methods One hundred and fifty-seven mobilizations performed between 1997 and 2006 were analyzed. This retrospective analysis comparative two groups of patients: those mobilized with different brands of filgrastim (Group A) and those who received Filgen JP (Clausen Filgrastim) as mobilizing agent (Group B). A cluster analysis technique was used to identify four clusters of individuals with different behaviors differentiated by age, total dose of filgrastim required, number of apheresis and harvested CD34+ cells. Results The mean total dose of filgrastim administered was 105 mcg/Kg, the median number of apheresis was 2 procedures and the mean number of harvested stem cells was 4.98 x 106 CD34+ cells/Kg. No significant differences were observed between Groups A and B regarding the number of apheresis, harvested CD34+ cells and number of mobilization failures, however the total dose of filgrastim was significantly lower in Group B. Conclusions Among other factors, the origin of the cytokine used as mobilizing agent is an element to be considered when evaluating CD34+ cell mobilization results. PMID:23049356

  5. Black Silicon formation using dry etching for solar cells applications

    International Nuclear Information System (INIS)

    Murias, D.; Reyes-Betanzo, C.; Moreno, M.; Torres, A.; Itzmoyotl, A.; Ambrosio, R.; Soriano, M.; Lucas, J.; Cabarrocas, P. Roca i

    2012-01-01

    A study on the formation of Black Silicon on crystalline silicon surface using SF 6 /O 2 and SF 6 /O 2 /CH 4 based plasmas in a reactive ion etching (RIE) system is presented. The effect of the RF power, chamber pressure, process time, gas flow rates, and gas mixtures on the texture of silicon surface has been analyzed. Completely Black Silicon surfaces containing pyramid like structures have been obtained, using an optimized mask-free plasma process. Moreover, the Black Silicon surfaces have demonstrated average values of 1% and 4% for specular and diffuse reflectance respectively, feature that is suitable for the fabrication of low cost solar cells.

  6. Characteristics of cells producing stimulator for the proliferation of colony forming unit-spleen (CFU-S)

    International Nuclear Information System (INIS)

    Abdul Manaf Ali; Wright, E.G.; Riches, A.C.

    1994-01-01

    The presence of stimulator for haemopoietic stem cell (CFU-S) proliferation in regenerating bone marrow was assayed by incubating the conditioned medium (CM) prepared from bone marrow with quiescent CFU-S from normal bone marrow. The percentage of CFU-S normal bone marrow in DNA synthesis increased more than 30 percent after incubating with CM of 4.5 Gy regenerating bone marrow. Stimulator was also present in bone marrow of mice at 9.0 Gy whole body X-irradiation. However the conditioned medium prepared from regenerating bone marrow without Fc and Ia-2k cells failed to increase the percentage of CFU-S in DNA synthesis. On the other hand, elimination of Thy 1.2 positive cells with complement cytolysis did not affect the ability of regenerating bone marrow to produce stimulator. These observations suggest that the stimulator producing cells are radio-resistant, Thy 1.2 negative, Fc and Ia-2k positive

  7. Detection and quantification of intracellular bacterial colonies by automated, high-throughput microscopy.

    Science.gov (United States)

    Ernstsen, Christina L; Login, Frédéric H; Jensen, Helene H; Nørregaard, Rikke; Møller-Jensen, Jakob; Nejsum, Lene N

    2017-08-01

    To target bacterial pathogens that invade and proliferate inside host cells, it is necessary to design intervention strategies directed against bacterial attachment, cellular invasion and intracellular proliferation. We present an automated microscopy-based, fast, high-throughput method for analyzing size and number of intracellular bacterial colonies in infected tissue culture cells. Cells are seeded in 48-well plates and infected with a GFP-expressing bacterial pathogen. Following gentamicin treatment to remove extracellular pathogens, cells are fixed and cell nuclei stained. This is followed by automated microscopy and subsequent semi-automated spot detection to determine the number of intracellular bacterial colonies, their size distribution, and the average number per host cell. Multiple 48-well plates can be processed sequentially and the procedure can be completed in one working day. As a model we quantified intracellular bacterial colonies formed by uropathogenic Escherichia coli (UPEC) during infection of human kidney cells (HKC-8). Urinary tract infections caused by UPEC are among the most common bacterial infectious diseases in humans. UPEC can colonize tissues of the urinary tract and is responsible for acute, chronic, and recurrent infections. In the bladder, UPEC can form intracellular quiescent reservoirs, thought to be responsible for recurrent infections. In the kidney, UPEC can colonize renal epithelial cells and pass to the blood stream, either via epithelial cell disruption or transcellular passage, to cause sepsis. Intracellular colonies are known to be clonal, originating from single invading UPEC. In our experimental setup, we found UPEC CFT073 intracellular bacterial colonies to be heterogeneous in size and present in nearly one third of the HKC-8 cells. This high-throughput experimental format substantially reduces experimental time and enables fast screening of the intracellular bacterial load and cellular distribution of multiple

  8. Effects of Granulocyte-Macrophage Colony-Stimulating (GM-CSF Factor on Corneal Epithelial Cells in Corneal Wound Healing Model.

    Directory of Open Access Journals (Sweden)

    Chang Rae Rho

    Full Text Available Granulocyte-macrophage colony-stimulating factor (GM-CSF is a pleiotropic cytokine that activates granulocyte and macrophage cell lineages. It is also known to have an important function in wound healing. This study investigated the effect of GM-CSF in wound healing of human corneal epithelial cells (HCECs. We used human GM-CSF derived from rice cells (rice cell-derived recombinant human GM-CSF; rhGM-CSF. An in vitro migration assay was performed to investigate the migration rate of HCECs treated with various concentrations of rhGM-CSF (0.1, 1.0, and 10.0 μg/ml. MTT assay and flow cytometric analysis were used to evaluate the proliferative effect of rhGM-CSF. The protein level of p38MAPK was analyzed by western blotting. For in vivo analysis, 100 golden Syrian hamsters were divided into four groups, and their corneas were de-epithelialized with alcohol and a blade. The experimental groups were treated with 10, 20, or 50 μg/ml rhGM-CSF four times daily, and the control group was treated with phosphate-buffered saline. The corneal wound-healing rate was evaluated by fluorescein staining at the initial wounding and 12, 24, 36, and 48 hours after epithelial debridement. rhGM-CSF accelerated corneal epithelial wound healing both in vitro and in vivo. MTT assay and flow cytometric analysis revealed that rhGM-CSF treatment had no effects on HCEC proliferation. Western blot analysis demonstrated that the expression level of phosphorylated p38MAPK increased with rhGM-CSF treatment. These findings indicate that rhGM-CSF enhances corneal wound healing by accelerating cell migration.

  9. Activation of human gingival epithelial cells by cell-surface components of black-pigmented bacteria: augmentation of production of interleukin-8, granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor and expression of intercellular adhesion molecule 1.

    Science.gov (United States)

    Sugiyama, A; Uehara, A; Iki, K; Matsushita, K; Nakamura, R; Ogawa, T; Sugawara, S; Takada, H

    2002-01-01

    Black-pigmented anaerobic bacteria, such as Porphyromonas gingivalis and Prevotella intermedia, are amongst the predominant bacteria in periodontal pockets and have been implicated in periodontal diseases. To elucidate the roles of gingival keratinocytes, which are the first cells encountered by oral bacteria in periodontal diseases, human gingival keratinocytes in primary culture were stimulated with cell-surface components of P gingivalis and Pr. intermedia. A glycoprotein fraction from Pr. intermedia (PGP) clearly augmented the release of interleukin-8, granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor, as determined by enzyme-linked immunosorbent assay. This PGP also induced expression of intercellular adhesion molecule-1 (ICAM-1), as determined by flow cytometry. The augmentation of mRNA expression for these molecules was also confirmed by reverse transcription PCR. In contrast, lipopolysaccharide (LPS) from Pr. intermedia and Escherichia coli was completely inactive in these assays. LPS fraction and purified fimbriae from P gingivalis exhibited weak activities. Cytokine production and ICAM-1 expression by gingival keratinocytes might cause accumulation and activation of neutrophils in the epithelium and, therefore, may be involved in the initiation and development of inflammation in periodontal tissues.

  10. Spontaneous lung metastasis formation of human Merkel cell carcinoma cell lines transplanted into scid mice.

    Science.gov (United States)

    Knips, Jill; Czech-Sioli, Manja; Spohn, Michael; Heiland, Max; Moll, Ingrid; Grundhoff, Adam; Schumacher, Udo; Fischer, Nicole

    2017-07-01

    Merkel cell carcinoma (MCC) is an aggressive skin cancer entity that frequently leads to rapid death due to its high propensity to metastasize. The etiology of most MCC cases is linked to Merkel cell polyomavirus (MCPyV), a virus which is monoclonally integrated in up to 95% of tumors. While there are presently no animal models to study the role of authentic MCPyV infection on transformation, tumorigenesis or metastasis formation, xenograft mouse models employing engrafted MCC-derived cell lines (MCCL) represent a promising approach to study certain aspects of MCC pathogenesis. Here, the two MCPyV-positive MCC cell lines WaGa and MKL-1 were subcutaneously engrafted in scid mice. Engraftment of both MCC cell lines resulted in the appearance of circulating tumor cells and metastasis formation, with WaGa-engrafted mice showing a significantly shorter survival time as well as increased numbers of spontaneous lung metastases compared to MKL-1 mice. Interestingly, explanted tumors compared to parental cell lines exhibit an upregulation of MCPyV sT-Antigen expression in all tumors, with WaGa tumors showing significantly higher sT-Antigen expression than MKL-1 tumors. RNA-Seq analysis of explanted tumors and parental cell lines furthermore revealed that in the more aggressive WaGa tumors, genes involved in inflammatory response, growth factor activity and Wnt signalling pathway are significantly upregulated, suggesting that sT-Antigen is the driver of the observed differences in metastasis formation. © 2017 UICC.

  11. Capillary network formation from dispersed endothelial cells: Influence of cell traction, cell adhesion, and extracellular matrix rigidity

    Science.gov (United States)

    Ramos, João R. D.; Travasso, Rui; Carvalho, João

    2018-01-01

    The formation of a functional vascular network depends on biological, chemical, and physical processes being extremely well coordinated. Among them, the mechanical properties of the extracellular matrix and cell adhesion are fundamental to achieve a functional network of endothelial cells, able to fully cover a required domain. By the use of a Cellular Potts Model and Finite Element Method it is shown that there exists a range of values of endothelial traction forces, cell-cell adhesion, and matrix rigidities where the network can spontaneously be formed, and its properties are characterized. We obtain the analytical relation that the minimum traction force required for cell network formation must obey. This minimum value for the traction force is approximately independent on the considered cell number and cell-cell adhesion. We quantify how these two parameters influence the morphology of the resulting networks (size and number of meshes).

  12. Protective layer formation on magnesium in cell culture medium

    Energy Technology Data Exchange (ETDEWEB)

    Wagener, V.; Virtanen, S., E-mail: virtanen@ww.uni-erlangen.de

    2016-06-01

    In the past, different studies showed that hydroxyapatite (HA) or similar calcium phosphates can be precipitated on Mg during immersion in simulated body fluids. However, at the same time, in most cases a dark grey or black layer is built under the white HA crystals. This layer seems to consist as well of calcium phosphates. Until now, neither the morphology nor its influence on Mg corrosion have been investigated in detail. In this work commercially pure magnesium (cp) was immersed in cell culture medium for one, three and five days at room temperature and in the incubator (37 °C, 5% CO{sub 2}). In addition, the influence of proteins on the formation of a corrosion layer was investigated by adding 20% of fetal calf serum (FCS) to the cell culture medium in the incubator. In order to analyze the formed layers, SEM images of cross sections, X-ray Photoelectron Spectroscopy (XPS), X-ray diffraction (XRD), Energy Dispersive X-ray Spectroscopy (EDX) and Fourier Transformed Infrared Spectroscopy (FTIR) measurements were carried out. Characterization of the corrosion behavior was achieved by electrochemical impedance spectroscopy (EIS) and by potentio-dynamic polarization in Dulbecco's Modified Eagle's Medium (DMEM) at 37 °C. Surface analysis showed that all formed layers consist mainly of amorphous calcium phosphate compounds. For the immersion at room temperature the Ca/P ratio indicates the formation of HA, while in the incubator probably pre-stages to HA are formed. The different immersion conditions lead to a variation in layer thicknesses. However, electrochemical characterization shows that the layer thickness does not influence the corrosion resistance of magnesium. The main influencing factor for the corrosion behavior is the layer morphology. Thus, immersion at room temperature leads to the highest corrosion protection due to the formation of a compact outer layer. Layers formed in the incubator show much worse performances due to completely porous

  13. Protective layer formation on magnesium in cell culture medium

    International Nuclear Information System (INIS)

    Wagener, V.; Virtanen, S.

    2016-01-01

    In the past, different studies showed that hydroxyapatite (HA) or similar calcium phosphates can be precipitated on Mg during immersion in simulated body fluids. However, at the same time, in most cases a dark grey or black layer is built under the white HA crystals. This layer seems to consist as well of calcium phosphates. Until now, neither the morphology nor its influence on Mg corrosion have been investigated in detail. In this work commercially pure magnesium (cp) was immersed in cell culture medium for one, three and five days at room temperature and in the incubator (37 °C, 5% CO_2). In addition, the influence of proteins on the formation of a corrosion layer was investigated by adding 20% of fetal calf serum (FCS) to the cell culture medium in the incubator. In order to analyze the formed layers, SEM images of cross sections, X-ray Photoelectron Spectroscopy (XPS), X-ray diffraction (XRD), Energy Dispersive X-ray Spectroscopy (EDX) and Fourier Transformed Infrared Spectroscopy (FTIR) measurements were carried out. Characterization of the corrosion behavior was achieved by electrochemical impedance spectroscopy (EIS) and by potentio-dynamic polarization in Dulbecco's Modified Eagle's Medium (DMEM) at 37 °C. Surface analysis showed that all formed layers consist mainly of amorphous calcium phosphate compounds. For the immersion at room temperature the Ca/P ratio indicates the formation of HA, while in the incubator probably pre-stages to HA are formed. The different immersion conditions lead to a variation in layer thicknesses. However, electrochemical characterization shows that the layer thickness does not influence the corrosion resistance of magnesium. The main influencing factor for the corrosion behavior is the layer morphology. Thus, immersion at room temperature leads to the highest corrosion protection due to the formation of a compact outer layer. Layers formed in the incubator show much worse performances due to completely porous structures. The

  14. S6Ks isoforms contribute to viability, migration, docetaxel resistance and tumor formation of prostate cancer cells

    International Nuclear Information System (INIS)

    Amaral, Camila L.; Freitas, Lidia B.; Tamura, Rodrigo E.; Tavares, Mariana R.; Pavan, Isadora C. B.; Bajgelman, Marcio C.; Simabuco, Fernando M.

    2016-01-01

    The S6 Kinase (S6K) proteins are some of the main downstream effectors of the mammalian Target Of Rapamycin (mTOR) and act as key regulators of protein synthesis and cell growth. S6K is overexpressed in a variety of human tumors and is correlated to poor prognosis in prostate cancer. Due to the current urgency to identify factors involved in prostate cancer progression, we aimed to reveal the cellular functions of three S6K isoforms–p70-S6K1, p85-S6K1 and p54-S6K2–in prostate cancer, as well as their potential as therapeutic targets. In this study we performed S6K knockdown and overexpression and investigated its role in prostate cancer cell proliferation, colony formation, viability, migration and resistance to docetaxel treatment. In addition, we measured tumor growth in Nude mice injected with PC3 cells overexpressing S6K isoforms and tested the efficacy of a new available S6K1 inhibitor in vitro. S6Ks overexpression enhanced PC3-luc cell line viability, migration, resistance to docetaxel and tumor formation in Nude mice. Only S6K2 knockdown rendered prostate cancer cells more sensitive to docetaxel. S6K1 inhibitor PF-4708671 was particularly effective for reducing migration and proliferation of PC3 cell line. These findings demonstrate that S6Ks play an important role in prostate cancer progression, enhancing cell viability, migration and chemotherapy resistance, and place both S6K1 and S6K2 as a potential targets in advanced prostate cancer. We also provide evidence that S6K1 inhibitor PF-4708671 may be considered as a potential drug for prostate cancer treatment. The online version of this article (doi:10.1186/s12885-016-2629-y) contains supplementary material, which is available to authorized users

  15. Germ Cell-less Promotes Centrosome Segregation to Induce Germ Cell Formation

    Directory of Open Access Journals (Sweden)

    Dorothy A. Lerit

    2017-01-01

    Full Text Available The primordial germ cells (PGCs specified during embryogenesis serve as progenitors to the adult germline stem cells. In Drosophila, the proper specification and formation of PGCs require both centrosomes and germ plasm, which contains the germline determinants. Centrosomes are microtubule (MT-organizing centers that ensure the faithful segregation of germ plasm into PGCs. To date, mechanisms that modulate centrosome behavior to engineer PGC development have remained elusive. Only one germ plasm component, Germ cell-less (Gcl, is known to play a role in PGC formation. Here, we show that Gcl engineers PGC formation by regulating centrosome dynamics. Loss of gcl leads to aberrant centrosome separation and elaboration of the astral MT network, resulting in inefficient germ plasm segregation and aborted PGC cellularization. Importantly, compromising centrosome separation alone is sufficient to mimic the gcl loss-of-function phenotypes. We conclude Gcl functions as a key regulator of centrosome separation required for proper PGC development.

  16. Enhanced interleukin-8 production in THP-1 human monocytic cells by lipopolysaccharide from oral microorganisms and granulocyte-macrophage colony-stimulating factor.

    Science.gov (United States)

    Baqui, A A; Meiller, T F; Falkler, W A

    1999-10-01

    Granulocyte-macrophage colony-stimulating factor (GM-CSF) has been used to assist in bone marrow recovery during cancer chemotherapy. Interleukin-8 (IL-8) plays an important role in macrophage mediated inflammatory processes including exacerbation of periodontal diseases, one of the most common complications in GM-CSF receiving cancer patients. The effect of GM-CSF supplementation on IL-8 production was investigated in a human monocyte cell line THP-1, stimulated with lipopolysaccharide extracted from two oral microorganisms, Porphyromonas gingivalis and Fusobacterium nucleatum. Resting THP-1 cells were treated with lipopolysaccharide (1 microgram/ml) of P. gingivalis or F. nucleatum and/or GM-CSF (50 IU/ml) for varying time periods. The production of IL-8 in THP-1 cells was measured by a solid-phase enzyme-linked immunosorbent assay (ELISA). A very low level of the cytokine IL-8 was produced constitutive in THP-1 cells. Starting from 8 h of treatment and afterwards GM-CSF alone significantly increased IL-8 production in THP-1 cells. Lipopolysaccharide (1 microgram/ml) extracts from either F. nucleatum or P. gingivalis amplified IL-8 production 500-800 times in comparison to resting THP-1 cells. When lipopolysaccharide of F. nucleatum or P. gingivalis was supplemented with 50 IU/ml of GM-CSF, there was a statistically significant enhanced production of IL-8 by THP-1 cells after 1 day to 7 days of treatment as compared with lipopolysaccharide treatment alone. GM-CSF (50 IU/ml) also significantly increased IL-8 production from 2-7 days of treatment of THP-1 cells when supplemented with a positive control, phorbol-12-myristate-13 acetate (PMA), as compared to PMA treatment alone. These investigations using the in vitro THP-1 human monocyte cell model indicate that there may be an increase in the response on a cellular level to oral endotoxin following GM-CSF therapy as evidenced by enhanced production of the tissue-reactive inflammatory cytokine, IL-8.

  17. Buckling instability in ordered bacterial colonies

    Science.gov (United States)

    Boyer, Denis; Mather, William; Mondragón-Palomino, Octavio; Orozco-Fuentes, Sirio; Danino, Tal; Hasty, Jeff; Tsimring, Lev S.

    2011-04-01

    Bacterial colonies often exhibit complex spatio-temporal organization. This collective behavior is affected by a multitude of factors ranging from the properties of individual cells (shape, motility, membrane structure) to chemotaxis and other means of cell-cell communication. One of the important but often overlooked mechanisms of spatio-temporal organization is direct mechanical contact among cells in dense colonies such as biofilms. While in natural habitats all these different mechanisms and factors act in concert, one can use laboratory cell cultures to study certain mechanisms in isolation. Recent work demonstrated that growth and ensuing expansion flow of rod-like bacteria Escherichia coli in confined environments leads to orientation of cells along the flow direction and thus to ordering of cells. However, the cell orientational ordering remained imperfect. In this paper we study one mechanism responsible for the persistence of disorder in growing cell populations. We demonstrate experimentally that a growing colony of nematically ordered cells is prone to the buckling instability. Our theoretical analysis and discrete-element simulations suggest that the nature of this instability is related to the anisotropy of the stress tensor in the ordered cell colony.

  18. Botryllus schlosseri (Tunicata) whole colony irradiation: Do senescent zooid resorption and immunological resorption involve similar recognition events

    International Nuclear Information System (INIS)

    Rinkevich, B.; Weissman, I.L.

    1990-01-01

    The colonial tunicate Botryllus schlosseri undergoes cyclic blastogenesis where feeding zooids are senescened and resorbed and a new generation of zooids takes over the colony. When non-identical colonies come into direct contact, they either reject each other or fuse. Fusion is usually followed by the resorption of one of the partners in the chimera (immunological resorption). The striking morphological similarities between the two resorption phenomena suggest that both may involve tissue destruction following self-nonself recognition events. Here we attempt to modify these two events by whole colony gamma irradiation assays. Three sets of experiments were performed: (1) different doses of whole colony irradiation for determination of irradiation effects (110 colonies); (2) pairs of irradiated-nonirradiated isografts of clonal replicates for the potential of reconstruction of the irradiated partners (23 pairs); (3) chimeras of irradiated-nonirradiated partners for analysis of resorption hierarchy. Mortality increased with the irradiation dose. All colonies exposed to more than 5,000 rads died within 19 days, while no colony died below 2,000 rads. The average mortality periods, in days, for doses of 6,000-8,000, 5,000, and 2,500-4,000 rads were 14.4 +/- 3.1 (n = 24), 19.8 +/- 6.0 (n = 15), and 19.6 + 5.1 (n = 22), respectively. Younger colonies (3-6 months old) may survive radiation better than older ones (more than 13 months). Many morphological alterations were recorded in irradiated colonies: ampullar contraction and/or dilation, accumulation of pigment cells within ampullae, abnormal bleeding from blood vessels, sluggish blood circulation, necrotic zones, reduction in bud number, and irregularities in zooid and system structures. With doses of 3,000-4,000 rads and above, irradiation arrested the formation of new buds and interrupted normal takeover

  19. High-Throughput Cancer Cell Sphere Formation for 3D Cell Culture.

    Science.gov (United States)

    Chen, Yu-Chih; Yoon, Euisik

    2017-01-01

    Three-dimensional (3D) cell culture is critical in studying cancer pathology and drug response. Though 3D cancer sphere culture can be performed in low-adherent dishes or well plates, the unregulated cell aggregation may skew the results. On contrary, microfluidic 3D culture can allow precise control of cell microenvironments, and provide higher throughput by orders of magnitude. In this chapter, we will look into engineering innovations in a microfluidic platform for high-throughput cancer cell sphere formation and review the implementation methods in detail.

  20. The contribution of cell-cell signaling and motility to bacterial biofilm formation

    DEFF Research Database (Denmark)

    Shrout, Joshua D; Tolker-Nielsen, Tim; Givskov, Michael

    2011-01-01

    Many bacteria grow attached to a surface as biofilms. Several factors dictate biofilm formation, including responses by the colonizing bacteria to their environment. Here we review how bacteria use cell-cell signaling (also called quorum sensing) and motility during biofilm formation. Specifically...... gene expression important to the production of polysaccharides, rhamnolipid, and other virulence factors. Surface motility affects the assembly and architecture of biofilms, and some aspects of motility are also influenced by quorum sensing. While some genes and their function are specific to P....... aeruginosa, many aspects of biofilm development can be used as a model system to understand how bacteria differentially colonize surfaces....

  1. Buckling instability in ordered bacterial colonies

    International Nuclear Information System (INIS)

    Boyer, Denis; Mather, William; Mondragón-Palomino, Octavio; Danino, Tal; Hasty, Jeff; Orozco-Fuentes, Sirio; Tsimring, Lev S

    2011-01-01

    Bacterial colonies often exhibit complex spatio-temporal organization. This collective behavior is affected by a multitude of factors ranging from the properties of individual cells (shape, motility, membrane structure) to chemotaxis and other means of cell–cell communication. One of the important but often overlooked mechanisms of spatio-temporal organization is direct mechanical contact among cells in dense colonies such as biofilms. While in natural habitats all these different mechanisms and factors act in concert, one can use laboratory cell cultures to study certain mechanisms in isolation. Recent work demonstrated that growth and ensuing expansion flow of rod-like bacteria Escherichia coli in confined environments leads to orientation of cells along the flow direction and thus to ordering of cells. However, the cell orientational ordering remained imperfect. In this paper we study one mechanism responsible for the persistence of disorder in growing cell populations. We demonstrate experimentally that a growing colony of nematically ordered cells is prone to the buckling instability. Our theoretical analysis and discrete-element simulations suggest that the nature of this instability is related to the anisotropy of the stress tensor in the ordered cell colony

  2. Post-UV colony-forming ability of normal fibroblast strains and of the xeroderma pigmentosum group G strain

    International Nuclear Information System (INIS)

    Barrett, S.F.; Tarone, R.E.; Moshell, A.N.; Ganges, M.B.; Robbins, J.H.

    1981-01-01

    In xeroderma pigmentosum, an inherited disorder of defective DNA repair, post-uv colony-forming ability of fibroblasts from patients in complementation groups A through F correlates with the patients' neurological status. The first xeroderma pigmentosum patient assigned to the recently discovered group G had the neurological abnormalities of XP. Researchers have determined the post-uv colony-forming ability of cultured fibroblasts from this patient and from 5 more control donors. Log-phase fibroblasts were irradiated with 254 nm uv light from a germicidal lamp, trypsinized, and replated at known densities. After 2 to 4 weeks' incubation the cells were fixed, stained and scored for colony formation. The strains' post-uv colony-forming ability curves were obtained by plotting the log of the percent remaining post-uv colony-forming ability as a function of the uv dose. The post-uv colony-forming ability of 2 of the 5 new normal strains was in the previously defined control donor zone, but that of the other 3 extended down to the level of the most resistant xeroderma pigmentosum strain. The post-uv colony-forming ability curve of the group G fibroblasts was not significantly different from the curves of the group D fibroblast strains from patients with clinical histories similar to that of the group G patient

  3. A Burkholderia pseudomallei colony variant necessary for gastric colonization.

    Science.gov (United States)

    Austin, C R; Goodyear, A W; Bartek, I L; Stewart, A; Sutherland, M D; Silva, E B; Zweifel, A; Vitko, N P; Tuanyok, A; Highnam, G; Mittelman, D; Keim, P; Schweizer, H P; Vázquez-Torres, A; Dow, S W C; Voskuil, M I

    2015-02-03

    Diverse colony morphologies are a hallmark of Burkholderia pseudomallei recovered from infected patients. We observed that stresses that inhibit aerobic respiration shifted populations of B. pseudomallei from the canonical white colony morphotype toward two distinct, reversible, yet relatively stable yellow colony variants (YA and YB). As accumulating evidence supports the importance of B. pseudomallei enteric infection and gastric colonization, we tested the response of yellow variants to hypoxia, acidity, and stomach colonization. Yellow variants exhibited a competitive advantage under hypoxic and acidic conditions and alkalized culture media. The YB variant, although highly attenuated in acute virulence, was the only form capable of colonization and persistence in the murine stomach. The accumulation of extracellular DNA (eDNA) was a characteristic of YB as observed by 4',6-diamidino-2-phenylindole (DAPI) staining of gastric tissues, as well as in an in vitro stomach model where large amounts of eDNA were produced without cell lysis. Transposon mutagenesis identified a transcriptional regulator (BPSL1887, designated YelR) that when overexpressed produced the yellow phenotype. Deletion of yelR blocked a shift from white to the yellow forms. These data demonstrate that YB is a unique B. pseudomallei pathovariant controlled by YelR that is specifically adapted to the harsh gastric environment and necessary for persistent stomach colonization. Seemingly uniform populations of bacteria often contain subpopulations that are genetically identical but display unique characteristics which offer advantages when the population is faced with infrequent but predictable stresses. The pathogen Burkholderia pseudomallei is capable of forming several reversible colony types, and it interconverted between one white type and two yellow types under certain environmental stresses. The two yellow forms exhibited distinct advantages in low-oxygen and acidic environments. One yellow

  4. Differentiation-independent fluctuation of pluripotency-related transcription factors and other epigenetic markers in embryonic stem cell colonies

    Czech Academy of Sciences Publication Activity Database

    Šustáčková, Gabriela; Legartová, Soňa; Kozubek, Stanislav; Stixová, Lenka; Pacherník, J.; Bártová, Eva

    2012-01-01

    Roč. 21, č. 5 (2012), s. 710-720 ISSN 1547-3287 R&D Projects: GA MŠk(CZ) LC535; GA MŠk(CZ) LC06027; GA MŠk(CZ) ME 919; GA ČR(CZ) GAP302/10/1022 Institutional research plan: CEZ:AV0Z50040507 Keywords : ES cells * epigenetics * Oct4 Subject RIV: BO - Biophysics Impact factor: 4.670, year: 2012

  5. Protective layer formation on magnesium in cell culture medium.

    Science.gov (United States)

    Wagener, V; Virtanen, S

    2016-06-01

    In the past, different studies showed that hydroxyapatite (HA) or similar calcium phosphates can be precipitated on Mg during immersion in simulated body fluids. However, at the same time, in most cases a dark grey or black layer is built under the white HA crystals. This layer seems to consist as well of calcium phosphates. Until now, neither the morphology nor its influence on Mg corrosion have been investigated in detail. In this work commercially pure magnesium (cp) was immersed in cell culture medium for one, three and five days at room temperature and in the incubator (37 °C, 5% CO2). In addition, the influence of proteins on the formation of a corrosion layer was investigated by adding 20% of fetal calf serum (FCS) to the cell culture medium in the incubator. In order to analyze the formed layers, SEM images of cross sections, X-ray Photoelectron Spectroscopy (XPS), X-ray diffraction (XRD), Energy Dispersive X-ray Spectroscopy (EDX) and Fourier Transformed Infrared Spectroscopy (FTIR) measurements were carried out. Characterization of the corrosion behavior was achieved by electrochemical impedance spectroscopy (EIS) and by potentio-dynamic polarization in Dulbecco's Modified Eagle's Medium (DMEM) at 37°C. Surface analysis showed that all formed layers consist mainly of amorphous calcium phosphate compounds. For the immersion at room temperature the Ca/P ratio indicates the formation of HA, while in the incubator probably pre-stages to HA are formed. The different immersion conditions lead to a variation in layer thicknesses. However, electrochemical characterization shows that the layer thickness does not influence the corrosion resistance of magnesium. The main influencing factor for the corrosion behavior is the layer morphology. Thus, immersion at room temperature leads to the highest corrosion protection due to the formation of a compact outer layer. Layers formed in the incubator show much worse performances due to completely porous structures. The

  6. Diurnal Periodicity in the Supply of Cell Wall Components during Wood Cell Wall Formation

    OpenAIRE

    細尾, 佳宏

    2012-01-01

    This review summarizes recent studies on the diurnal periodicity in wood cell wall formation, with a major focus on those that we have conducted. Differences in the innermost surface of developing secondary walls of differentiating conifer tracheids can be seen from day to night Cellulose microfibrils are clearly evident during the day, and amorphous material containing abundant hemicelluloses is prevalent at night. These findings suggest a diurnal periodicity in the supply of cell wall compo...

  7. Multimodal Approaches for Regenerative Stroke Therapies: Combination of Granulocyte Colony-Stimulating Factor with Bone Marrow Mesenchymal Stem Cells is Not Superior to G-CSF Alone

    Directory of Open Access Journals (Sweden)

    Adrian Tudor Balseanu

    2014-06-01

    Full Text Available Attractive therapeutic strategies to enhance post-stroke recovery of aged brains include methods of cellular therapy that can enhance the endogenous restorative mechanisms of the injured brain. Since stroke afflicts mostly the elderly, it is highly desirable to test the efficacy of cell therapy in the microenvironment of aged brains that is generally refractory to regeneration. In particular, stem cells from the bone marrow allow an autologous transplantation approach that can be translated in the near future to the clinical practice. Such a bone marrow-derived therapy includes the grafting of stem cells as well as the delayed induction of endogenous stem cell mobilization and homing by the stem cell mobilizer granulocyte colony-stimulating factor (G-CSF. We tested the hypothesis that grafting of bone marrow-derived pre-differentiated mesenchymal cells (BM-MSCs in G-CSF-treated animals improves the long-term functional outcome in aged rodents. To this end, G-CSF alone (50 μg/kg or in combination with a single dose (106 cells of rat BM MSCs was administered intravenously to Sprague-Dawley rats at 6 h after transient occlusion (90 min of the middle cerebral artery. Infarct volume was measured by magnetic resonance imaging at 3 and 48 days post-stroke and additionally by immunhistochemistry at day 56. Functional recovery was tested during the entire post-stroke survival period of 56 days. Daily treatment for post-stroke aged rats with G-CSF led to a robust and consistent improvement of neurological function after 28 days. The combination therapy also led to robust angiogenesis in the formerly infarct core and beyond in the “islet of regeneration.” However, G-CSF + BM MSCs may not impact at all on the spatial reference-memory task or infarct volume and therefore did not further improve the post-stroke recovery. We suggest that in a real clinical practice involving older post-stroke patients, successful regenerative therapies

  8. Relationship between lung colony and in situ assays

    International Nuclear Information System (INIS)

    Ando, K.; Koike, S.

    1985-01-01

    The relationship between different assays: tumor control, tumor growth delay and lung colony formation was examined after fast neutron and γ ray irradiations. Fibrosarcomas (NFSa) in syngeneic C3Hf mice were irradiated locally with 60 Co γ rays, fast neutrons or mixed beams (γ rays and fast neutrons). A comparison between the lung colony assay and the TRT 50 (50% tumor growth delay time) assay when cells were exposed to single doses of fast neutrons or γ rays, resulted in identical growth delay times. The fraction of cells surviving a single dose of fast neutrons, was 10 times higher than the surviving fraction of cells after a single dose of γ rays. Both doses resulted in the same tumor control probability (TCD 50 assay). Neither repair of potentially lethal damage nor tumor bed effect was sufficient to explain the difference between cell survival and tumor control probability. The surviving fraction of cells following fractionated irradiations of γ rays and fast neutrons were identical at 50% tumor control probabilities

  9. Formation of Cell-To-Cell Connection between Bone Marrow Cells and Isolated Rat Cardiomyocytes in a Cocultivation Model

    Czech Academy of Sciences Publication Activity Database

    Skopalík, J.; Pásek, Michal; Rychtárik, M.; Koristek, Z.; Gabrielová, E.; Sheer, P.; Matejovič, P.; Modrianský, M.; Klabusay, M.

    2014-01-01

    Roč. 5, č. 5 (2014), s. 1000185 ISSN 2157-7013 Institutional support: RVO:61388998 Keywords : bone marrow * mononuclear cells * isolated cardiomyocytes * cocultivation Subject RIV: BO - Biophysics http://omicsonline.org/ open - access /formation-of-celltocell-connection-between-bone-marrow-cells- and -isolated-rat-cardiomyocytes-2157-7013.1000185.php?aid=33364

  10. Donor body mass index is an important factor that affects peripheral blood progenitor cell yield in healthy donors after mobilization with granulocyte-colony-stimulating factor.

    Science.gov (United States)

    Chen, Jian; Burns, Kevin M; Babic, Aleksandar; Carrum, George; Kennedy, Martha; Segura, Francisco J; Garcia, Salvador; Potts, Sandra; Leveque, Christopher

    2014-01-01

    The use of hematopoietic progenitor cell (HPC) transplantation has rapidly expanded in recent years. Currently, several sources of HPCs are available for transplantation including peripheral blood HPCs (PBPCs), cord blood cells, and marrow cells. Of these, PBPC collection has become the major source of HPCs. An important variable in PBPC collection is the response to PBPC mobilization, which varies significantly and sometime causes mobilization failure. A retrospective study of 69 healthy donors who underwent PBPC donation by leukapheresis was performed. All of these donors received 10 μg/kg/day or more granulocyte-colony-stimulating factor (G-CSF) for 5 days before PBPC harvest. Donor factors were evaluated and correlated with mobilization responses, as indicated by the precollection CD34 count (pre-CD34). Donors with a pre-CD34 of more than 100 × 10(6) /L had higher body mass index (BMI) compared with donors whose pre-CD34 was 38 × 10(6) to 99 × 10(6) /L or less than 38 × 10(6) /L (32.0 ± 1.04 kg/m(2) vs. 28.7 ± 0.93 kg/m(2) vs. 25.9 ± 1.27 kg/m(2) , respectively; p donors with high BMIs had higher pre-CD34 on a per-kilogram-of-body-weight basis compared with donors with low BMIs. BMI is an important factor that affects donor's response to mobilization and consequently the HPC yield. This effect may be due to a relatively high dose of G-CSF administered to donors with higher BMI or due to the presence of unknown intrinsic factors affecting mobilization that correlate with the amount of adipose tissue in each donor. © 2013 American Association of Blood Banks.

  11. High frequency of endothelial colony forming cells marks a non-active myeloproliferative neoplasm with high risk of splanchnic vein thrombosis.

    Directory of Open Access Journals (Sweden)

    Vittorio Rosti

    Full Text Available Increased mobilization of circulating endothelial progenitor cells may represent a new biological hallmark of myeloproliferative neoplasms. We measured circulating endothelial colony forming cells (ECFCs in 106 patients with primary myelofibrosis, fibrotic stage, 49 with prefibrotic myelofibrosis, 59 with essential thrombocythemia or polycythemia vera, and 43 normal controls. Levels of ECFC frequency for patient's characteristics were estimated by using logistic regression in univariate and multivariate setting. The sensitivity, specificity, likelihood ratios, and positive predictive value of increased ECFC frequency were calculated for the significantly associated characteristics. Increased frequency of ECFCs resulted independently associated with history of splanchnic vein thrombosis (adjusted odds ratio = 6.61, 95% CI = 2.54-17.16, and a summary measure of non-active disease, i.e. hemoglobin of 13.8 g/dL or lower, white blood cells count of 7.8×10(9/L or lower, and platelet count of 400×10(9/L or lower (adjusted odds ratio = 4.43, 95% CI = 1.45-13.49 Thirteen patients with splanchnic vein thrombosis non associated with myeloproliferative neoplasms were recruited as controls. We excluded a causal role of splanchnic vein thrombosis in ECFCs increase, since no control had elevated ECFCs. We concluded that increased frequency of ECFCs represents the biological hallmark of a non-active myeloproliferative neoplasm with high risk of splanchnic vein thrombosis. The recognition of this disease category copes with the phenotypic mimicry of myeloproliferative neoplasms. Due to inherent performance limitations of ECFCs assay, there is an urgent need to arrive to an acceptable standardization of ECFC assessment.

  12. Subtotal Ablation of Parietal Epithelial Cells Induces Crescent Formation

    Science.gov (United States)

    Sicking, Eva-Maria; Fuss, Astrid; Uhlig, Sandra; Jirak, Peggy; Dijkman, Henry; Wetzels, Jack; Engel, Daniel R.; Urzynicok, Torsten; Heidenreich, Stefan; Kriz, Wilhelm; Kurts, Christian; Ostendorf, Tammo; Floege, Jürgen; Smeets, Bart

    2012-01-01

    Parietal epithelial cells (PECs) of the renal glomerulus contribute to the formation of both cellular crescents in rapidly progressive GN and sclerotic lesions in FSGS. Subtotal transgenic ablation of podocytes induces FSGS but the effect of specific ablation of PECs is unknown. Here, we established an inducible transgenic mouse to allow subtotal ablation of PECs. Proteinuria developed during doxycycline-induced cellular ablation but fully reversed 26 days after termination of doxycycline administration. The ablation of PECs was focal, with only 30% of glomeruli exhibiting histologic changes; however, the number of PECs was reduced up to 90% within affected glomeruli. Ultrastructural analysis revealed disruption of PEC plasma membranes with cytoplasm shedding into Bowman’s space. Podocytes showed focal foot process effacement, which was the most likely cause for transient proteinuria. After >9 days of cellular ablation, the remaining PECs formed cellular extensions to cover the denuded Bowman’s capsule and expressed the activation marker CD44 de novo. The induced proliferation of PECs persisted throughout the observation period, resulting in the formation of typical cellular crescents with periglomerular infiltrate, albeit without accompanying proteinuria. In summary, subtotal ablation of PECs leads the remaining PECs to react with cellular activation and proliferation, which ultimately forms cellular crescents. PMID:22282596

  13. Granulocyte-colony stimulating factor for hematopoietic stem cell donation from healthy female donors during pregnancy and lactation: what do we know?

    Science.gov (United States)

    Pessach, Ilias; Shimoni, Avichai; Nagler, Arnon

    2013-01-01

    BACKGROUND Hematopoietic growth factors (HGFs) are mostly used as supportive measures to reduce infectious complications associated with neutropenia. Over the past decade, the use of HGFs became a common method for mobilizing human CD34+ stem cells, either for autologous or allogeneic transplantation. However, since their introduction the long-term safety of the procedure has become a major focus of discussion and research. Most information refers to healthy normal donors and data concerning pregnant and lactating women are scarce. The clinical question, which is the core of this review, is whether stem cell donation, preceded by administration of granulocyte-colony stimulating factor (G-CSF) for mobilization, is a safe procedure for pregnant donors. METHODS Literature searches were performed in Pubmed for English language articles published before the end of May 2012, focusing on G-CSF administration during pregnancy, lactation and hematopoietic stem cell donation. Searches included animal and human studies. RESULTS Data from animals (n = 15 studies) and women (n = 46 studies) indicate that G-CSF crosses the placenta, stimulates fetal granulopoiesis, improves neonatal survival mostly for very immature infants, promotes trophoblast growth and placental metabolism and has an anti-abortive role. Granulocyte macrophage-CSF is a key cytokine in the maternal immune tolerance towards the implanted embryo and exerts protective long-term programming effects to preimplantation embryos. The available data suggest that probably CSFs should not be administered during the time of most active organogenesis (first trimester), except perhaps for the first week during which implantation takes place. Provided CSF is administered during the second and third trimesters, it appears to be safe, and pregnant women receiving the CSF treatment can become hematopoietic stem cell donors. There are also risks related to the anesthesia, which is required for the bone marrow aspiration. During

  14. Stem cell collection in unmanipulated HLA-haploidentical/mismatched related transplantation with combined granulocyte-colony stimulating factor-mobilised blood and bone marrow for patients with haematologic malignancies: the impact of donor characteristics and procedural settings.

    Science.gov (United States)

    Zhang, C; Chen, X-H; Zhang, X; Gao, L; Gao, L; Kong, P-Y; Peng, X-G; Sun, A-H; Gong, Y; Zeng, D-F; Wang, Q-Y

    2010-06-01

    Unmanipulated haploidentical/mismatched related transplantation with combined granulocyte-colony stimulating factor-mobilised peripheral blood stem cells (G-PBSCs) and granulocyte-colony stimulating factor-mobilised bone marrow (G-BM) has been developed as an alternative transplantation strategy for patients with haematologic malignancies. However, little information is available about the factors predicting the outcome of peripheral blood stem cell (PBSC) collection and bone marrow (BM) harvest in this transplantation. The effects of donor characteristics and procedure factors on CD34(+) cell yield were investigated. A total of 104 related healthy donors received granulocyte-colony stimulating factor (G-CSF) followed by PBSC collection and BM harvest. Male donors had significantly higher yields compared with female donors. In multiple regression analysis for peripheral blood collection, age and flow rate were negatively correlated with cell yield, whereas body mass index, pre-aphaeresis white blood cell (WBC) and circulating immature cell (CIC) counts were positively correlated with cell yields. For BM harvest, age was negatively correlated with cell yields, whereas pre-BM collection CIC counts were positively correlated with cell yield. All donors achieved the final product of >or=6 x10(6) kg(-1) recipient body weight. This transplantation strategy has been shown to be a feasible approach with acceptable outcomes in stem cell collection for patients who received HLA-haploidentical/mismatched transplantation with combined G-PBSCs and G-BM. In donors with multiple high-risk characteristics for poor aphaeresis CD34(+) cell yield, BM was an alternative source.

  15. A full genomic characterization of the development of a stable Small Colony Variant cell-type by a clinical Staphylococcus aureus strain.

    Science.gov (United States)

    Bui, Long M G; Kidd, Stephen P

    2015-12-01

    A key to persistent and recurrent Staphylococcus aureus infections is its ability to adapt to diverse and toxic conditions. This ability includes a switch into a biofilm or to the quasi-dormant Small Colony Variant (SCV). The development and molecular attributes of SCVs have been difficult to study due to their rapid reversion to their parental cell-type. We recently described the unique induction of a matrix-embedded and stable SCV cell-type in a clinical S. aureus strain (WCH-SK2) by growing the cells with limiting conditions for a prolonged timeframe. Here we further study their characteristics. They possessed an increased viability in the presence of antibiotics compared to their non-SCV form. Their stability implied that there had been genetic changes; we therefore determined both the genome sequence of WCH-SK2 and its stable SCV form at a single base resolution, employing Single Molecular Real-Time (SMRT) sequencing that enabled the methylome to also be determined. The genetic features of WCH-SK2 have been identified; the SCCmec type, the pathogenicity and genetic islands and virulence factors. The genetic changes that had occurred in the stable SCV form were identified; most notably being in MgrA, a global regulator, and RsbU, a phosphoserine phosphatase within the regulatory pathway of the sigma factor SigB. There was a shift in the methylomes of the non-SCV and stable SCV forms. We have also shown a similar induction of this cell-type in other S. aureus strains and performed a genetic comparison to these and other S. aureus genomes. We additionally map RNAseq data to the WCH-SK2 genome in a transcriptomic analysis of the parental, SCV and stable SCV cells. The results from this study represent the unique identification of a suite of epigenetic, genetic and transcriptional factors that are implicated in the switch in S. aureus to its persistent SCV form. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Diclofenac in Arabidopsis cells: Rapid formation of conjugates.

    Science.gov (United States)

    Fu, Qiuguo; Ye, Qingfu; Zhang, Jianbo; Richards, Jaben; Borchardt, Dan; Gan, Jay

    2017-03-01

    Pharmaceutical and personal care products (PPCPs) are continuously introduced into the soil-plant system, through practices such as agronomic use of reclaimed water and biosolids containing these trace contaminants. Plants may accumulate PPCPs from soil, serving as a conduit for human exposure. Metabolism likely controls the final accumulation of PPCPs in plants, but is in general poorly understood for emerging contaminants. In this study, we used diclofenac as a model compound, and employed 14 C tracing, and time-of-flight (TOF) and triple quadruple (QqQ) mass spectrometers to unravel its metabolism pathways in Arabidopsis thaliana cells. We further validated the primary metabolites in Arabidopsis seedlings. Diclofenac was quickly taken up into A. thaliana cells. Phase I metabolism involved hydroxylation and successive oxidation and cyclization reactions. However, Phase I metabolites did not accumulate appreciably; they were instead rapidly conjugated with sulfate, glucose, and glutamic acid through Phase II metabolism. In particular, diclofenac parent was directly conjugated with glutamic acid, with acyl-glutamatyl-diclofenac accounting for >70% of the extractable metabolites after 120-h incubation. In addition, at the end of incubation, >40% of the spiked diclofenac was in the non-extractable form, suggesting extensive sequestration into cell matter. The rapid formation of non-extractable residue and dominance of diclofenac-glutamate conjugate uncover previously unknown metabolism pathways for diclofenac. In particular, the rapid conjugation of parent highlights the need to consider conjugates of emerging contaminants in higher plants, and their biological activity and human health implications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. In vivo differentiation of induced pluripotent stem cells into neural stem cells by chimera formation.

    Science.gov (United States)

    Choi, Hyun Woo; Hong, Yean Ju; Kim, Jong Soo; Song, Hyuk; Cho, Ssang Gu; Bae, Hojae; Kim, Changsung; Byun, Sung June; Do, Jeong Tae

    2017-01-01

    Like embryonic stem cells, induced pluripotent stem cells (iPSCs) can differentiate into all three germ layers in an in vitro system. Here, we developed a new technology for obtaining neural stem cells (NSCs) from iPSCs through chimera formation, in an in vivo environment. iPSCs contributed to the neural lineage in the chimera, which could be efficiently purified and directly cultured as NSCs in vitro. The iPSC-derived, in vivo-differentiated NSCs expressed NSC markers, and their gene-expression pattern more closely resembled that of fetal brain-derived NSCs than in vitro-differentiated NSCs. This system could be applied for differentiating pluripotent stem cells into specialized cell types whose differentiation protocols are not well established.

  18. Mind bomb 1 is required for pancreatic ß-cell formation

    DEFF Research Database (Denmark)

    Horn, Signe; Kobberup, Sune; Jørgensen, Mette C

    2012-01-01

    the insulin producing ß-cells. However, signals that regulate proximodistal (P-D) patterning and thus formation of ß-cell progenitors are unknown. Here we show that Mind bomb 1 (Mib1) is required for correct P-D patterning of the developing pancreas and ß-cell formation. We found that endoderm...

  19. Enhancement of erythroid colony growth in culture by hemin

    International Nuclear Information System (INIS)

    Porter, P.N.; Meints, R.H.; Mesner, K.

    1979-01-01

    Hemin was found to enhance the growth of murine erythroid colonies in culture. In the presence of 100 mU/ml erythropoietin (EPO), the addition of hemin (0.05-0.2 mM) resulted in the growth of twice as many colonies as were obtained with EPO alone. Hemin also significantly increased erythroid colony formation in culture in the absence of added EPO. Hemoblobin synthesis as measured by the incorporation of 59 Fe into cyclohexanone extractable heme was augmented in culture by hemin. Neither Δ-aminolevulinic acid, a hemin precursor, nor FeCl 3 increased colony number. (author)

  20. The hypoxic microenvironment upgrades stem-like properties of ovarian cancer cells

    OpenAIRE

    Liang Dongming; Ma Yuanyuan; Liu Jian; Trope Claes; Holm Ruth; Nesland Jahn M; Suo Zhenhe

    2012-01-01

    Background To study whether hypoxia influences the stem-like properties of ovarian cancer cells and their biological behavior under hypoxia. Method Ovarian cancer cell lines ES-2 and OVCAR-3 were cultivated in different oxygen tensions for proliferation, cell cycling and invasion analyses. The clonogenic potential of cells was examined by colony formation and sphere formation assays. Stem cell surface...

  1. Colchicine affects cell motility, pattern formation and stalk cell differentiation in Dictyostelium by altering calcium signaling.

    Science.gov (United States)

    Poloz, Yekaterina; O'Day, Danton H

    2012-04-01

    Previous work, verified here, showed that colchicine affects Dictyostelium pattern formation, disrupts morphogenesis, inhibits spore differentiation and induces terminal stalk cell differentiation. Here we show that colchicine specifically induces ecmB expression and enhances accumulation of ecmB-expressing cells at the posterior end of multicellular structures. Colchicine did not induce a nuclear translocation of DimB, a DIF-1 responsive transcription factor in vitro. It also induced terminal stalk cell differentiation in a mutant strain that does not produce DIF-1 (dmtA-) and after the treatment of cells with DIF-1 synthesis inhibitor cerulenin (100 μM). This suggests that colchicine induces the differentiation of ecmB-expressing cells independent of DIF-1 production and likely through a signaling pathway that is distinct from the one that is utilized by DIF-1. Depending on concentration, colchicine enhanced random cell motility, but not chemotaxis, by 3-5 fold (10-50 mM colchicine, respectively) through a Ca(2+)-mediated signaling pathway involving phospholipase C, calmodulin and heterotrimeric G proteins. Colchicine's effects were not due to microtubule depolymerization as other microtubule-depolymerizing agents did not have these effects. Finally normal morphogenesis and stalk and spore cell differentiation of cells treated with 10 mM colchicine were rescued through chelation of Ca2+ by BAPTA-AM and EDTA and calmodulin antagonism by W-7 but not PLC inhibition by U-73122. Morphogenesis or spore cell differentiation of cells treated with 50 mM colchicine could not be rescued by the above treatments but terminal stalk cell differentiation was inhibited by BAPTA-AM, EDTA and W-7, but not U-73122. Thus colchicine disrupts morphogenesis and induces stalk cell differentiation through a Ca(2+)-mediated signaling pathway involving specific changes in gene expression and cell motility. Copyright © 2011 International Society of Differentiation. Published by Elsevier B

  2. Interordinal chimera formation between medaka and zebrafish for analyzing stem cell differentiation.

    Science.gov (United States)

    Hong, Ni; Chen, Songlin; Ge, Ruowen; Song, Jianxing; Yi, Meisheng; Hong, Yunhan

    2012-08-10

    Chimera formation is a standard test for pluripotency of stem cells in vivo. Interspecific chimera formation between distantly related organisms offers also an attractive approach for propagating endangered species. Parameters influencing interspecies chimera formation have remained poorly elucidated. Here, we report interordinal chimera formation between medaka and zebrafish, which separated ∼320 million years ago and exhibit a more than 2-fold difference in developmental speed. We show that, on transplantation into zebrafish blastulae, both noncultivated blastomeres and long-term cultivated embryonic stem (ES) cells of medaka adopted the zebrafish developmental program and differentiated into physiologically functional cell types including pigment cells, blood cells, and cardiomyocytes. We also show that medaka ES cells express differentiation gene markers during chimeric embryogenesis. Therefore, the evolutionary distance and different embryogenesis speeds do not produce donor-host incompatibility to compromise chimera formation between medaka and zebrafish, and molecular markers are valuable for analyzing lineage commitment and cell differentiation in interspecific chimeric embryos.

  3. Basal CD34+ Cell Count Predicts Peripheral Blood Stem Cell Mobilization in Healthy Donors after Administration of Granulocyte Colony-Stimulating Factor: A Longitudinal, Prospective, Observational, Single-Center, Cohort Study.

    Science.gov (United States)

    Martino, Massimo; Gori, Mercedes; Pitino, Annalisa; Gentile, Massimo; Dattola, Antonia; Pontari, Antonella; Vigna, Ernesto; Moscato, Tiziana; Recchia, Anna Grazia; Barilla', Santina; Tripepi, Giovanni; Morabito, Fortunato

    2017-07-01

    A longitudinal, prospective, observational, single-center, cohort study on healthy donors (HDs) was designed to identify predictors of CD34 + cells on day 5 with emphasis on the predictive value of the basal CD34 + cell count. As potential predictors of mobilization, age, sex, body weight, height, blood volume as well as white blood cell count, peripheral blood (PB) mononuclear cells, platelet count, hematocrit, and hemoglobin levels were considered. Two different evaluations of CD34 + cell counts were determined for each donor: baseline (before granulocyte colony-stimulating factor [G-CSF] administration) and in PB after G-CSF administration on the morning of the fifth day (day 5). A total of 128 consecutive HDs (66 males) with a median age of 43 years were enrolled. CD34 + levels on day 5 displayed a non-normal distribution, with a median value of 75.5 cells/µL. To account for the non-normal distribution of the dependent variable, a quantile regression analysis to predict CD34 + on day 5 using the baseline value of CD34 + as the key predictor was performed. On crude analysis, a baseline value of CD34 + ranging from .5 cells/µL to 1 cells/µL predicts a median value of 50 cells/µL on day 5; a value of 2 cells/µL predicts a median value of 70.7 cells/µL; a value of 3 cells/µL to 4 cells/µL predicts a median value of 91.3 cells/µL, and a value ≥ 5 predicts a median value of 112 cells/µL. In conclusion, the baseline PB CD34 + cell count correlates with the effectiveness of allogeneic PB stem cell mobilization and could be useful to plan the collection. Copyright © 2017 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  4. Specters of Colonialism

    DEFF Research Database (Denmark)

    Muhr, Sara Louise; Azad, Salam

    2013-01-01

    at the same time they always are bound to fail to become ‘Swedish’ because of the same foreign origins. Although Swedish culture – partly by distancing itself from having a colonial past – has successfully built up an image of openness, we argue that without acknowledging and confronting the role...

  5. Salidroside protects against foam cell formation and apoptosis, possibly via the MAPK and AKT signaling pathways.

    Science.gov (United States)

    Ni, Jing; Li, Yuanmin; Li, Weiming; Guo, Rong

    2017-10-10

    Foam cell formation and apoptosis are closely associated with atherosclerosis pathogenesis. We determined the effect of salidroside on oxidized low-density lipoprotein (ox-LDL)-induced foam cell formation and apoptosis in THP1 human acute monocytic leukemia cells and investigated the associated molecular mechanisms. THP1-derived macrophages were incubated with salidroside for 5 h and then exposed to ox-LDL for 24 h to induce foam cell formation. Cytotoxicity, lipid deposition, apoptosis, and the expression of various proteins were tested using the CCK8 kit, Oil Red O staining, flow cytometry, and western blotting, respectively. Ox-LDL treatment alone promoted macrophage-derived foam cell formation, while salidroside treatment alone inhibited it (p foam cell formation and apoptosis, partly by regulating the MAPK and Akt signaling pathways.

  6. [Advances in the research of function of Merkel cells in tactile formation of skin].

    Science.gov (United States)

    You, X; Wei, Z R

    2018-01-20

    Skin is the largest sense organ of human, with many mechanoreceptor cells under epidermis or dermis of skin and Merkel cell is one of them. It has been confirmed that Merkel cells play an important role in the process of mechanical transmission of mammalian soft tactile stimulation. Researches showed that Merkel cells had close relation to tactile formation and functioned by Merkel cell-neurite complexes and ion channels Piezo2. This article reviews Merkel cells and the function, problem and prospect of Merkel cells in tactile formation.

  7. Different tolerances to chemical contaminants between unicellular and colonial morph of Microcystis aeruginosa: excluding the differences among different strains.

    Science.gov (United States)

    Li, Ming; Nkrumah, Philip Nti; Peng, Qiang

    2015-03-21

    In order to ascertain the different tolerances to chemical contaminants in one strain of Microcystis with different morphology, unicellular and colonial Microcystis in one strain was obtained from different conditions of light intensity and temperature. The samples were divided into 8 groups including control (no chemical addition), CuSO4, chloromycetin, and linear alkylbenzene sulfonatelas (LAS) treatments. The cell density, cell viability, superoxide dismutase (SOD), and malonaldehyde of Microcystis were analyzed. It was observed that cell density of both unicellular and colonial Microcystis increased from the beginning to day-5 in the control and the CuSO4 treatments. However, the growth of Microcystis was significantly inhibited in the culture with chloromycetin and LAS treatments. Notably, the inhibition rate was significantly high in unicellular Microcystis relative to the colonial Microcystis. The esterase activity in all the treatments decreased dramatically relating to the control. In addition, the esterase activity in colonial Microcystis was significantly higher than that of the unicellular Microcystis in all the treatments. Although there were no significant differences in activities of SOD between the two morphologies in the control treatments, in all the other treatments, significant differences were observed. The results proved that colony formation of Microcystis could be considered as a strategy in response to chemical stress. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Myotube formation is affected by adipogenic lineage cells in a cell-to-cell contact-independent manner

    International Nuclear Information System (INIS)

    Takegahara, Yuki; Yamanouchi, Keitaro; Nakamura, Katsuyuki; Nakano, Shin-ichi; Nishihara, Masugi

    2014-01-01

    Intramuscular adipose tissue (IMAT) formation is observed in some pathological conditions such as Duchenne muscular dystrophy (DMD) and sarcopenia. Several studies have suggested that IMAT formation is not only negatively correlated with skeletal muscle mass but also causes decreased muscle contraction in sarcopenia. In the present study, we examined w hether adipocytes affect myogenesis. For this purpose, skeletal muscle progenitor cells were transfected with siRNA of PPARγ (siPPARγ) in an attempt to inhibit adipogenesis. Myosin heavy chain (MHC)-positive myotube formation was promoted in cells transfected with siPPARγ compared to that of cells transfected with control siRNA. To determine whether direct cell-to-cell contact between adipocytes and myoblasts is a prerequisite for adipocytes to affect myogenesis, skeletal muscle progenitor cells were cocultured with pre- or mature adipocytes in a Transwell coculture system. MHC-positive myotube formation was inhibited when skeletal muscle progenitor cells were cocultured with mature adipocytes, but was promoted when they were cocultured with preadipocytes. Similar effects were observed when pre- or mature adipocyte-conditioned medium was used. These results indicate that preadipocytes play an important role in maintaining skeletal muscle mass by promoting myogenesis; once differentiated, the resulting mature adipocytes negatively affect myogenesis, leading to the muscle deterioration observed in skeletal muscle pathologies. - Highlights: • We examined the effects of pre- and mature adipocytes on myogenesis in vitro. • Preadipocytes and mature adipocytes affect myoblast fusion. • Preadipocytes play an important role in maintaining skeletal muscle mass. • Mature adipocytes lead to muscle deterioration observed in skeletal muscle pathologies

  9. Myotube formation is affected by adipogenic lineage cells in a cell-to-cell contact-independent manner

    Energy Technology Data Exchange (ETDEWEB)

    Takegahara, Yuki; Yamanouchi, Keitaro, E-mail: akeita@mail.ecc.u-tokyo.ac.jp; Nakamura, Katsuyuki; Nakano, Shin-ichi; Nishihara, Masugi

    2014-05-15

    Intramuscular adipose tissue (IMAT) formation is observed in some pathological conditions such as Duchenne muscular dystrophy (DMD) and sarcopenia. Several studies have suggested that IMAT formation is not only negatively correlated with skeletal muscle mass but also causes decreased muscle contraction in sarcopenia. In the present study, we examined w hether adipocytes affect myogenesis. For this purpose, skeletal muscle progenitor cells were transfected with siRNA of PPARγ (siPPARγ) in an attempt to inhibit adipogenesis. Myosin heavy chain (MHC)-positive myotube formation was promoted in cells transfected with siPPARγ compared to that of cells transfected with control siRNA. To determine whether direct cell-to-cell contact between adipocytes and myoblasts is a prerequisite for adipocytes to affect myogenesis, skeletal muscle progenitor cells were cocultured with pre- or mature adipocytes in a Transwell coculture system. MHC-positive myotube formation was inhibited when skeletal muscle progenitor cells were cocultured with mature adipocytes, but was promoted when they were cocultured with preadipocytes. Similar effects were observed when pre- or mature adipocyte-conditioned medium was used. These results indicate that preadipocytes play an important role in maintaining skeletal muscle mass by promoting myogenesis; once differentiated, the resulting mature adipocytes negatively affect myogenesis, leading to the muscle deterioration observed in skeletal muscle pathologies. - Highlights: • We examined the effects of pre- and mature adipocytes on myogenesis in vitro. • Preadipocytes and mature adipocytes affect myoblast fusion. • Preadipocytes play an important role in maintaining skeletal muscle mass. • Mature adipocytes lead to muscle deterioration observed in skeletal muscle pathologies.

  10. Mobilization of peripheral blood progenitor cells by chemotherapy and granulocyte-macrophage colony-stimulating factor for hematologic support after high-dose intensification for breast cancer.

    Science.gov (United States)

    Elias, A D; Ayash, L; Anderson, K C; Hunt, M; Wheeler, C; Schwartz, G; Tepler, I; Mazanet, R; Lynch, C; Pap, S

    1992-06-01

    High-dose therapy with autologous marrow support results in durable complete remissions in selected patients with relapsed lymphoma and leukemia who cannot be cured with conventional dose therapy. However, substantial morbidity and mortality result from the 3- to 6-week period of marrow aplasia until the reinfused marrow recovers adequate hematopoietic function. Hematopoietic growth factors, particularly used after chemotherapy, can increase the number of peripheral blood progenitor cells (PBPCs) present in systemic circulation. The reinfusion of PBPCs with marrow has recently been reported to reduce the time to recovery of adequate marrow function. This study was designed to determine whether granulocyte-macrophage colony-stimulating factor (GM-CSF)-mobilized PBPCs alone (without marrow) would result in rapid and reliable hematopoietic reconstitution. Sixteen patients with metastatic breast cancer were treated with four cycles of doxorubicin, 5-fluorouracil, and methotrexate (AFM induction). Patients responding after the first two cycles were administered GM-CSF after the third and fourth cycles to recruit PBPCs for collection by two leukapheresis per cycle. These PBPCs were reinfused as the sole source of hematopoietic support after high doses of cyclophosphamide, thiotepa, and carboplatin. No marrow or hematopoietic cytokines were used after progenitor cell reinfusion. Granulocytes greater than or equal to 500/microL was observed on a median of day 14 (range, 8 to 57). Transfusion independence of platelets greater than or equal to 20,000/microL occurred on a median day of 12 (range, 8 to 134). However, three patients required the use of a reserve marrow for slow platelet engraftment. In retrospect, these patients were characterized by poor baseline bone marrow cellularity and poor platelet recovery after AFM induction therapy. When compared with 29 historical control patients who had received the same high-dose intensification chemotherapy using autologous

  11. Critical role of mast cell chymase in mouse abdominal aortic aneurysm formation

    DEFF Research Database (Denmark)

    Sun, J; Zhang, J; Lindholt, Jes S.

    2009-01-01

    Mast cell chymase may participate in the pathogenesis of human abdominal aortic aneurysm (AAA), yet a direct contribution of this serine protease to AAA formation remains unknown.......Mast cell chymase may participate in the pathogenesis of human abdominal aortic aneurysm (AAA), yet a direct contribution of this serine protease to AAA formation remains unknown....

  12. Effect of granulocyte colony-stimulating factor (G-CSF) in human immunodeficiency virus-infected patients: increase in numbers of naive CD4 cells and CD34 cells makes G-CSF a candidate for use in gene therapy or to support antiretroviral therapy

    DEFF Research Database (Denmark)

    Nielsen, S D; Afzelius, P; Dam-Larsen, S

    1998-01-01

    The potential of granulocyte colony-stimulating factor (G-CSF) to mobilize CD4 cells and/or CD34 cells for use in gene therapy or to support antiretroviral therapy was examined. Ten human immunodeficiency virus-infected patients were treated with G-CSF (300 microg/day) for 5 days. Numbers of CD4.......01/microL (P CSF induced increases in numbers of CD34 cells and CD4 cells in HIV-infected patients...

  13. Macrophage conditioned medium induced cellular network formation in MCF-7 cells through enhanced tunneling nanotube formation and tunneling nanotube mediated release of viable cytoplasmic fragments

    International Nuclear Information System (INIS)

    Patheja, Pooja; Sahu, Khageswar

    2017-01-01

    Infiltrating macrophages in tumor microenvironment, through their secreted cytokines and growth factors, regulate several processes of cancer progression such as cancer cell survival, proliferation, invasion, metastasis and angiogenesis. Recently, intercellular cytoplasmic bridges between cancer cells referred as tunneling nanotubes (TNTs) have been recognized as novel mode of intercellular communication between cancer cells. In this study, we investigated the effect of inflammatory mediators present in conditioned medium derived from macrophages on the formation of TNTs in breast adenocarcinoma cells MCF-7. Results show that treatment with macrophage conditioned medium (MφCM) not only enhanced TNT formation between cells but also stimulated the release of independently migrating viable cytoplasmic fragments, referred to as microplasts, from MCF-7 cells. Time lapse microscopy revealed that microplasts were released from parent cancer cells in extracellular space through formation of TNT-like structures. Mitochondria, vesicles and cytoplasm could be transferred from parent cell body to microplasts through connecting TNTs. The microplasts could also be resorbed into the parent cell body by retraction of the connecting TNTs. Microplast formation inhibited in presence cell migration inhibitor, cytochalasin-B. Notably by utilizing migratory machinery within microplasts, distantly located MCF-7 cells formed several TNT based intercellular connections, leading to formation of physically connected network of cells. Together, these results demonstrate novel role of TNTs in microplast formation, novel modes of TNT formation mediated by microplasts and stimulatory effect of MφCM on cellular network formation in MCF-7 cells mediated through enhanced TNT and microplast formation.

  14. Macrophage conditioned medium induced cellular network formation in MCF-7 cells through enhanced tunneling nanotube formation and tunneling nanotube mediated release of viable cytoplasmic fragments

    Energy Technology Data Exchange (ETDEWEB)

    Patheja, Pooja, E-mail: pooja.patheja8@gmail.com [Laser Biomedical Applications Section, Raja Ramanna Centre for Advanced Technology, Indore 452013, Madhya Pradesh (India); Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, Maharashtra (India); Sahu, Khageswar [Laser Biomedical Applications Section, Raja Ramanna Centre for Advanced Technology, Indore 452013, Madhya Pradesh (India)

    2017-06-15

    Infiltrating macrophages in tumor microenvironment, through their secreted cytokines and growth factors, regulate several processes of cancer progression such as cancer cell survival, proliferation, invasion, metastasis and angiogenesis. Recently, intercellular cytoplasmic bridges between cancer cells referred as tunneling nanotubes (TNTs) have been recognized as novel mode of intercellular communication between cancer cells. In this study, we investigated the effect of inflammatory mediators present in conditioned medium derived from macrophages on the formation of TNTs in breast adenocarcinoma cells MCF-7. Results show that treatment with macrophage conditioned medium (MφCM) not only enhanced TNT formation between cells but also stimulated the release of independently migrating viable cytoplasmic fragments, referred to as microplasts, from MCF-7 cells. Time lapse microscopy revealed that microplasts were released from parent cancer cells in extracellular space through formation of TNT-like structures. Mitochondria, vesicles and cytoplasm could be transferred from parent cell body to microplasts through connecting TNTs. The microplasts could also be resorbed into the parent cell body by retraction of the connecting TNTs. Microplast formation inhibited in presence cell migration inhibitor, cytochalasin-B. Notably by utilizing migratory machinery within microplasts, distantly located MCF-7 cells formed several TNT based intercellular connections, leading to formation of physically connected network of cells. Together, these results demonstrate novel role of TNTs in microplast formation, novel modes of TNT formation mediated by microplasts and stimulatory effect of MφCM on cellular network formation in MCF-7 cells mediated through enhanced TNT and microplast formation.

  15. A dynamical model for plant cell wall architecture formation.

    NARCIS (Netherlands)

    Mulder, B.M.; Emons, A.M.C.

    2001-01-01

    We discuss a dynamical mathematical model to explain cell wall architecture in plant cells. The highly regular textures observed in cell walls reflect the spatial organisation of the cellulose microfibrils (CMFs), the most important structural component of cell walls. Based on a geometrical theory

  16. Multinuclear giant cell formation is enhanced by down-regulation of Wnt signaling in gastric cancer cell line, AGS

    International Nuclear Information System (INIS)

    Kim, Shi-Mun; Kim, Rockki; Ryu, Jae-Hyun; Jho, Eek-Hoon; Song, Ki-Joon; Jang, Shyh-Ing; Kee, Sun-Ho

    2005-01-01

    AGS cells, which were derived from malignant gastric adenocarcinoma tissue, lack E-cadherin-mediated cell adhesion but have a high level of nuclear β-catenin, which suggests altered Wnt signal. In addition, approximately 5% of AGS cells form multinuclear giant cells in the routine culture conditions, while taxol treatment causes most AGS cells to become giant cells. The observation of reduced nuclear β-catenin levels in giant cells induced by taxol treatment prompted us to investigate the relationship between Wnt signaling and giant cell formation. After overnight serum starvation, the shape of AGS cells became flattened, and this morphological change was accompanied by decrease in Myc expression and an increase in the giant cell population. Lithium chloride treatment, which inhibits GSK3β activity, reversed these serum starvation effects, which suggests an inverse relationship between Wnt signaling and giant cell formation. Furthermore, the down-regulation of Wnt signaling caused by the over-expression of ICAT, E-cadherin, and Axin enhanced giant cell formation. Therefore, down-regulation of Wnt signaling may be related to giant cell formation, which is considered to be a survival mechanism against induced cell death

  17. Laser-induced speckle scatter patterns in Bacillus colonies

    Directory of Open Access Journals (Sweden)

    Huisung eKim

    2014-10-01

    Full Text Available Label-free bacterial colony phenotyping technology called BARDOT (BActerial Rapid Detection using Optical scattering Technology provided successful classification of several different bacteria at the genus, species, and serovar level. Recent experiments with colonies of Bacillus species provided strikingly different characteristics of elastic light scatter (ELS patterns, which were comprised of random speckles compared to other bacteria, which are dominated by concentric rings and spokes. Since this laser-based optical sensor interrogates the whole volume of the colony, 3-D information of micro- and macro-structures are all encoded in the far-field scatter patterns. Here, we present a theoretical model explaining the underlying mechanism of the speckle formation by the colonies from Bacillus species. Except for Bacillus polymyxa, all Bacillus spp. produced random bright spots on the imaging plane, which presumably dependent on the cellular and molecular organization and content within the colony. Our scatter model-based analysis revealed that colony spread resulting in variable surface roughness can modify the wavefront of the scatter field. As the center diameter of the Bacillus spp. colony grew from 500 μm to 900 μm, average speckles area decreased 2-fold and the number of small speckles increased 7-fold. In conclusion, as Bacillus colony grows, the average speckle size in the scatter pattern decreases and the number of smaller speckle increases due to the swarming growth characteristics of bacteria within the colony.

  18. Kant's Second Thoughts on Colonialism

    NARCIS (Netherlands)

    Kleingeld, Pauline; Flikschuh, Katrin; Ypi, Lea

    2014-01-01

    Kant is widely regarded as a fierce critic of colonialism. In Toward Perpetual Peace and the Metaphysics of Morals, for example, he forcefully condemns European conduct in the colonies as a flagrant violation of the principles of right. His earlier views on colonialism have not yet received much

  19. Merkel Cell Polyomavirus Small T Antigen Drives Cell Motility via Rho-GTPase-Induced Filopodium Formation.

    Science.gov (United States)

    Stakaitytė, Gabrielė; Nwogu, Nnenna; Dobson, Samuel J; Knight, Laura M; Wasson, Christopher W; Salguero, Francisco J; Blackbourn, David J; Blair, G Eric; Mankouri, Jamel; Macdonald, Andrew; Whitehouse, Adrian

    2018-01-15

    Cell motility and migration is a complex, multistep, and multicomponent process intrinsic to progression and metastasis. Motility is dependent on the activities of integrin receptors and Rho family GTPases, resulting in the remodeling of the actin cytoskeleton and formation of various motile actin-based protrusions. Merkel cell carcinoma (MCC) is an aggressive skin cancer with a high likelihood of recurrence and metastasis. Merkel cell polyomavirus (MCPyV) is associated with the majority of MCC cases, and MCPyV-induced tumorigenesis largely depends on the expression of the small tumor antigen (ST). Since the discovery of MCPyV, a number of mechanisms have been suggested to account for replication and tumorigenesis, but to date, little is known about potential links between MCPyV T antigen expression and the metastatic nature of MCC. Previously, we described the action of MCPyV ST on the microtubule network and how it impacts cell motility and migration. Here, we demonstrate that MCPyV ST affects the actin cytoskeleton to promote the formation of filopodia through a mechanism involving the catalytic subunit of protein phosphatase 4 (PP4C). We also show that MCPyV ST-induced cell motility is dependent upon the activities of the Rho family GTPases Cdc42 and RhoA. In addition, our results indicate that the MCPyV ST-PP4C interaction results in the dephosphorylation of β 1 integrin, likely driving the cell motility pathway. These findings describe a novel mechanism by which a tumor virus induces cell motility, which may ultimately lead to cancer metastasis, and provides opportunities and strategies for targeted interventions for disseminated MCC. IMPORTANCE Merkel cell polyomavirus (MCPyV) is the most recently discovered human tumor virus. It causes the majority of cases of Merkel cell carcinoma (MCC), an aggressive skin cancer. However, the molecular mechanisms implicating MCPyV-encoded proteins in cancer development are yet to be fully elucidated. This study builds

  20. All you can eat: is food supply unlimited in a colonially breeding bird?

    OpenAIRE

    Hoi, Herbert; Kri?tof?k, J?n; Darolov?, Al?beta

    2015-01-01

    Food availability is generally considered to determine breeding site selection and therefore plays an important role in hypotheses explaining the evolution of colony formation. Hypotheses trying to explain why birds join a colony usually assume that food is not limited, whereas those explaining variation in colony size suggest that food is under constraint. In this study, we investigate the composition and amount of food items not eaten by the nestlings and found in nest burrows of colonially...

  1. Granulocyte colony-stimulating factor induces in vitro lymphangiogenesis

    International Nuclear Information System (INIS)

    Lee, Ae Sin; Kim, Dal; Wagle, Susbin Raj; Lee, Jung Eun; Jung, Yu Jin; Kang, Kyung Pyo; Lee, Sik; Park, Sung Kwang; Kim, Won

    2013-01-01

    Highlights: •G-CSF induces tube formation, migration and proliferation of lymphatic cells. •G-CSF increases phosphorylation of MAPK and Akt in lymphatic endothelial cells. •MAPK and Akt pathways are linked to G-CSF-induced in vitro lymphangiogenesis. •G-CSF increases sprouting of a lymphatic ring. •G-CSF produces peritoneal lymphangiogenesis. -- Abstract: Granulocyte-colony stimulating factor (G-CSF) is reported to induce differentiation in cells of the monocyte lineage and angiogenesis in vascular endothelial cells, but its effects on lymphangiogenesis is uncertain. Here we examined the effects and the mechanisms of G-CSF-induced lymphangiogenesis using human lymphatic endothelial cells (hLECs). Our results showed that G-CSF induced capillary-like tube formation, migration and proliferation of hLECs in a dose- and time-dependent manner and enhanced sprouting of thoracic duct. G-CSF increased phosphorylation of Akt and ERK1/2 in hLECs. Supporting the observations, specific inhibitors of phosphatidylinositol 3′-kinase and MAPK suppressed the G-CSF-induced in vitro lymphangiogenesis and sprouting. Intraperitoneal administration of G-CSF to mice also stimulated peritoneal lymphangiogenesis. These findings suggest that G-CSF is a lymphangiogenic factor

  2. Control of cell fate by the formation of an architecturally complex bacterial community.

    Science.gov (United States)

    Vlamakis, Hera; Aguilar, Claudio; Losick, Richard; Kolter, Roberto

    2008-04-01

    Bacteria form architecturally complex communities known as biofilms in which cells are held together by an extracellular matrix. Biofilms harbor multiple cell types, and it has been proposed that within biofilms individual cells follow different developmental pathways, resulting in heterogeneous populations. Here we demonstrate cellular differentiation within biofilms of the spore-forming bacterium Bacillus subtilis, and present evidence that formation of the biofilm governs differentiation. We show that motile, matrix-producing, and sporulating cells localize to distinct regions within the biofilm, and that the localization and percentage of each cell type is dynamic throughout development of the community. Importantly, mutants that do not produce extracellular matrix form unstructured biofilms that are deficient in sporulation. We propose that sporulation is a culminating feature of biofilm formation, and that spore formation is coupled to the formation of an architecturally complex community of cells.

  3. Synthetic quorum sensing in model microcapsule colonies

    Science.gov (United States)

    Shum, Henry; Balazs, Anna C.

    2017-08-01

    Biological quorum sensing refers to the ability of cells to gauge their population density and collectively initiate a new behavior once a critical density is reached. Designing synthetic materials systems that exhibit quorum sensing-like behavior could enable the fabrication of devices with both self-recognition and self-regulating functionality. Herein, we develop models for a colony of synthetic microcapsules that communicate by producing and releasing signaling molecules. Production of the chemicals is regulated by a biomimetic negative feedback loop, the “repressilator” network. Through theory and simulation, we show that the chemical behavior of such capsules is sensitive to both the density and number of capsules in the colony. For example, decreasing the spacing between a fixed number of capsules can trigger a transition in chemical activity from the steady, repressed state to large-amplitude oscillations in chemical production. Alternatively, for a fixed density, an increase in the number of capsules in the colony can also promote a transition into the oscillatory state. This configuration-dependent behavior of the capsule colony exemplifies quorum-sensing behavior. Using our theoretical model, we predict the transitions from the steady state to oscillatory behavior as a function of the colony size and capsule density.

  4. Mathematical Modeling the Geometric Regularity in Proteus Mirabilis Colonies

    Science.gov (United States)

    Zhang, Bin; Jiang, Yi; Minsu Kim Collaboration

    Proteus Mirabilis colony exhibits striking spatiotemporal regularity, with concentric ring patterns with alternative high and low bacteria density in space, and periodicity for repetition process of growth and swarm in time. We present a simple mathematical model to explain the spatiotemporal regularity of P. Mirabilis colonies. We study a one-dimensional system. Using a reaction-diffusion model with thresholds in cell density and nutrient concentration, we recreated periodic growth and spread patterns, suggesting that the nutrient constraint and cell density regulation might be sufficient to explain the spatiotemporal periodicity in P. Mirabilis colonies. We further verify this result using a cell based model.

  5. [Influence of granulocyte colony stimulating factor on distribution of bone marrow stem cells and its role in protecting brain in rats with cerebral ischemia].

    Science.gov (United States)

    Li, Jian-sheng; Liu, Jing-xia; Liu, Ke; Wang, Ding-chao; Ren, Wei-hong; Zhang, Xin-feng; Tian, Yu-shou

    2011-06-01

    To explore the influence of recombination granulocyte colony stimulating factor (rG-CSF) on mobilization and distribution of bone marrow stem cells (BMSCs) in blood and brain tissue, and its role in protecting brain in rats with cerebral ischemia. One hundred and six Sprague-Dawley (SD) rats were divided into sham-operated group (n=10),model group (n=48), rG-CSF group (n=48) according to the method of random digital table, and rats in model and rG-CSF groups were divided into four subgroups: i.e. 2, 3, 7 and 14 days subgroups, with 12 rats in each subgroup. Middle cerebral artery occlusion (MCAO) model was reproduced with nylon thread. In rats of rG-CSF group rG-CSF (10 μg/kg) was administered by subcutaneous injection 3 days before and 2 days after operation respectively, once a day. Rats in sham-operated and model groups were administered with normal saline in the same volume, once a day. At the corresponding time after operation, general neural function score (GNFS) of rats was measured. Blood was collected through abdominal aorta, then white blood cell (WBC) and CD34+ cells in peripheral blood were counted. Brain pathologic changes were observed, and expression of CD34+ cells in rats brain tissue was determined by using immunohistochemical method. (1) GNFS was lower obviously in 2-day model group compared with that in sham-operated group, and then increased gradually. At 7 days and 14 days after operation, GNFS in rG-CSF group was higher significantly than that in model group (7 days: 11.86±0.69 vs. 10.53±0.76, 14 days: 13.38±0.52 vs. 12.38±0.52, both P<0.01). (2) WBC and CD34+ cells in peripheral blood in model group increased obviously, with the highest level appeared at 3 days and lowered at 7 days and 14 days. Increase of WBC and CD34+ cells in rats of rG-CSF group was more obvious than that of model group at each time point except CD34+ in 14 days group [WBC (×10(9)/L) 2 days: 11.75±1.76 vs. 8.07±1.27, 3 days: 13.07±1.70 vs. 10.88±1.78, 7 days: 8

  6. Hematopoietic stem cell mobilizing agents G-CSF, cyclophosphamide or AMD3100 have distinct mechanisms of action on bone marrow HSC niches and bone formation.

    Science.gov (United States)

    Winkler, I G; Pettit, A R; Raggatt, L J; Jacobsen, R N; Forristal, C E; Barbier, V; Nowlan, B; Cisterne, A; Bendall, L J; Sims, N A; Lévesque, J-P

    2012-07-01

    The CXCR4 antagonist AMD3100 is progressively replacing cyclophosphamide (CYP) as adjuvant to granulocyte colony-stimulating factor (G-CSF) to mobilize hematopoietic stem cells (HSC) for autologous transplants in patients who failed prior mobilization with G-CSF alone. It has recently emerged that G-CSF mediates HSC mobilization and inhibits bone formation via specific bone marrow (BM) macrophages. We compared the effect of these three mobilizing agents on BM macrophages, bone formation, osteoblasts, HSC niches and HSC reconstitution potential. Both G-CSF and CYP suppressed niche-supportive macrophages and osteoblasts, and inhibited expression of endosteal cytokines resulting in major impairment of HSC reconstitution potential remaining in the mobilized BM. In sharp contrast, although AMD3100 was effective at mobilizing HSC, it did not suppress osteoblasts, endosteal cytokine expression or reconstitution potential of HSC remaining in the mobilized BM. In conclusion, although G-CSF, CYP and AMD3100 efficiently mobilize HSC into the blood, their effects on HSC niches and bone formation are distinct with both G-CSF and CYP targeting HSC niche function and bone formation, whereas AMD3100 directly targets HSC without altering niche function or bone formation.

  7. Formation of reactive oxygen species in rat epithelial cells upon ...

    Indian Academy of Sciences (India)

    Unknown

    clear dose-response relationship concerning the formation of ROS with regard to the .... allowed to attach over night and subsequently washed .... days?; Environ. Res. 64 6–35. Simon R H and Paine R 1995 Participation of pulmonary alveo-.

  8. Cell-size distribution in epithelial tissue formation and homeostasis.

    Science.gov (United States)

    Puliafito, Alberto; Primo, Luca; Celani, Antonio

    2017-03-01

    How cell growth and proliferation are orchestrated in living tissues to achieve a given biological function is a central problem in biology. During development, tissue regeneration and homeostasis, cell proliferation must be coordinated by spatial cues in order for cells to attain the correct size and shape. Biological tissues also feature a notable homogeneity of cell size, which, in specific cases, represents a physiological need. Here, we study the temporal evolution of the cell-size distribution by applying the theory of kinetic fragmentation to tissue development and homeostasis. Our theory predicts self-similar probability density function (PDF) of cell size and explains how division times and redistribution ensure cell size homogeneity across the tissue. Theoretical predictions and numerical simulations of confluent non-homeostatic tissue cultures show that cell size distribution is self-similar. Our experimental data confirm predictions and reveal that, as assumed in the theory, cell division times scale like a power-law of the cell size. We find that in homeostatic conditions there is a stationary distribution with lognormal tails, consistently with our experimental data. Our theoretical predictions and numerical simulations show that the shape of the PDF depends on how the space inherited by apoptotic cells is redistributed and that apoptotic cell rates might also depend on size. © 2017 The Author(s).

  9. Aggregate formation affects ultrasonic disruption of microalgal cells.

    Science.gov (United States)

    Wang, Wei; Lee, Duu-Jong; Lai, Juin-Yih

    2015-12-01

    Ultrasonication is a cell disruption process of low energy efficiency. This study dosed K(+), Ca(2+) and Al(3+) to Chlorella vulgaris cultured in Bold's Basal Medium at 25°C and measured the degree of cell disruption under ultrasonication. Adding these metal ions yielded less negatively charged surfaces of cells, while with the latter two ions large and compact cell aggregates were formed. The degree of cell disruption followed: control=K(+)>Ca(2+)>Al(3+) samples. Surface charges of cells and microbubbles have minimal effects on the microbubble number in the proximity of the microalgal cells. Conversely, cell aggregates with large size and compact interior resist cell disruption under ultrasonication. Staining tests revealed high diffusional resistance of stains over the aggregate interior. Microbubbles may not be effective generated and collapsed inside the compact aggregates, hence leading to low cell disruption efficiencies. Effective coagulation/flocculation in cell harvesting may lead to adverse effect on subsequent cell disruption efficiency. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Lysophosphatidic acid directly induces macrophage-derived foam cell formation by blocking the expression of SRBI.

    Science.gov (United States)

    Chen, Linmu; Zhang, Jun; Deng, Xiao; Liu, Yan; Yang, Xi; Wu, Qiong; Yu, Chao

    2017-09-23

    The leading cause of morbidity and mortality is the result of cardiovascular disease, mainly atherosclerosis. The formation of macrophage foam cells by ingesting ox-LDL and focal retention in the subendothelial space are the hallmarks of the early atherosclerotic lesion. Lysophosphatidic acid (LPA), which is a low-molecular weight lysophospholipid enriched in oxidized LDL, exerts a range of effects on the cardiovascular system. Previous reports show that LPA increases the uptake of ox-LDL to promote the formation of foam cells. However, as the most active component of ox-LDL, there is no report showing whether LPA directly affects foam cell formation. The aim of this study was to investigate the effects of LPA on foam cell formation, as well as to elucidate the underlying mechanism. Oil red O staining and a Cholesterol/cholesteryl ester quantitation assay were used to evaluate foam cell formation in Raw264.7 macrophage cells. We utilized a Western blot and RT-PCR to investigate the relationship between LPA receptors and lipid transport related proteins. We found that LPA promoted foam cell formation, using 200 μM for 24 h. Meanwhile, the expression of the Scavenger receptor BI (SRBI), which promotes the efflux of free cholesterol, was decreased. Furthermore, the LPA 1/3 receptor antagonist Ki16425 significantly abolished the LPA effects, indicating that LPA 1/3 was involved in the foam cell formation and SRBI expression induced by LPA. Additionally, the LPA-induced foam cell formation was blocked with an AKT inhibitor. Our results suggest that LPA-enhanced foam cell formation is mediated by LPA 1/3 -AKT activation and subsequent SRBI expression. Copyright © 2017. Published by Elsevier Inc.

  11. Insulin resistance in vascular endothelial cells promotes intestinal tumour formation

    DEFF Research Database (Denmark)

    Wang, X; Häring, M-F; Rathjen, Thomas

    2017-01-01

    in vascular endothelial cells. Strikingly, these mice had 42% more intestinal tumours than controls, no change in tumour angiogenesis, but increased expression of vascular cell adhesion molecule-1 (VCAM-1) in primary culture of tumour endothelial cells. Insulin decreased VCAM-1 expression and leukocyte...... adhesion in quiescent tumour endothelial cells with intact insulin receptors and partly prevented increases in VCAM-1 and leukocyte adhesion after treatment with tumour necrosis factor-α. Knockout of insulin receptors in endothelial cells also increased leukocyte adhesion in mesenteric venules...

  12. Consistent bone marrow-derived cell mobilization following repeated short courses of granulocyte-colony-stimulating factor in patients with amyotrophic lateral sclerosis: results from a multicenter prospective trial.

    Science.gov (United States)

    Tarella, Corrado; Rutella, Sergio; Gualandi, Francesca; Melazzini, Mario; Scimè, Rosanna; Petrini, Mario; Moglia, Cristina; Ulla, Marco; Omedé, Paola; Bella, Vincenzo La; Corbo, Massimo; Silani, Vincenzo; Siciliano, Gabriele; Mora, Gabriele; Caponnetto, Claudia; Sabatelli, Mario; Chiò, Adriano

    2010-01-01

    The aim of this study was to evaluate and characterize the feasibility and safety of bone marrow-derived cell (BMC) mobilization following repeated courses of granulocyte-colony stimulating factor (G-CSF) in patients with amyotrophic lateral sclerosis (ALS). Between January 2006 and March 2007, 26 ALS patients entered a multicenter trial that included four courses of BMC mobilization at 3-month intervals. In each course, G-CSF (5 microg/kg b.i.d.) was administered for four consecutive days; 18% mannitol was also given. Mobilization was monitored by flow cytometry analysis of circulating CD34(+) cells and by in vitro colony assay for clonogenic progenitors. Co-expression by CD34(+) cells of CD133, CD90, CD184, CD117 and CD31 was also assessed. Twenty patients completed the four-course schedule. One patient died and one refused to continue the program before starting the mobilization courses; four discontinued the study protocol because of disease progression. Overall, 89 G-CSF courses were delivered. There were two severe adverse events: one prolactinoma and one deep vein thrombosis. There were no discontinuations as a result of toxic complications. Circulating CD34(+) cells were monitored during 85 G-CSF courses and were always markedly increased; the range of median peak values was 41-57/microL, with no significant differences among the four G-CSF courses. Circulating clonogenic progenitor levels paralleled CD34(+) cell levels. Most mobilized CD34(+) cells co-expressed stem cell markers, with a significant increase in CD133 co-expression. It is feasible to deliver repeated courses of G-CSF to mobilize a substantial number of CD34(+) cells in patients with ALS; mobilized BMC include immature cells with potential clinical usefulness.

  13. Effects of irradiated biodegradable polymer in endothelial cell monolayer formation

    Energy Technology Data Exchange (ETDEWEB)

    Arbeitman, Claudia R.; Grosso, Mariela F. del [CONICET – Consejo Nacional de Investigaciones Científicas y Técnicas (Argentina); Gerencia de Investigación y Aplicaciones, TANDAR-CNEA (Argentina); Behar, Moni [Instituto de Física, UFRGS, Porto Alegre, RS (Brazil); García Bermúdez, Gerardo, E-mail: ggb@tandar.cnea.gov.ar [CONICET – Consejo Nacional de Investigaciones Científicas y Técnicas (Argentina); Gerencia de Investigación y Aplicaciones, TANDAR-CNEA (Argentina); Escuela de Ciencia y Tecnología, UNSAM (Argentina)

    2013-11-01

    In this work we study cell adhesion, proliferation and cell morphology of endothelial cell cultured on poly-L-lactide acid (PLLA) modified by heavy ion irradiation. Thin films of PLLA samples were irradiated with sulfur (S) at energies of 75 MeV and gold (Au) at 18 MeV ion-beams. Ion beams were provided by the Tandar (Buenos Aires, Argentina) and Tandetron (Porto Alegre, Brazil) accelerators, respectively. The growth of a monolayer of bovine aortic endothelial cells (BAEC) onto unirradiated and irradiated surfaces has been studied by in vitro techniques in static culture. Cell viability and proliferation increased on modified substrates. But the results on unirradiated samples, indicate cell death (necrosis/apoptosis) with the consequent decrease in proliferation. We analyzed the correlation between irradiation parameters and cell metabolism and morphology.

  14. Effects of irradiated biodegradable polymer in endothelial cell monolayer formation

    International Nuclear Information System (INIS)

    Arbeitman, Claudia R.; Grosso, Mariela F. del; Behar, Moni; García Bermúdez, Gerardo

    2013-01-01

    In this work we study cell adhesion, proliferation and cell morphology of endothelial cell cultured on poly-L-lactide acid (PLLA) modified by heavy ion irradiation. Thin films of PLLA samples were irradiated with sulfur (S) at energies of 75 MeV and gold (Au) at 18 MeV ion-beams. Ion beams were provided by the Tandar (Buenos Aires, Argentina) and Tandetron (Porto Alegre, Brazil) accelerators, respectively. The growth of a monolayer of bovine aortic endothelial cells (BAEC) onto unirradiated and irradiated surfaces has been studied by in vitro techniques in static culture. Cell viability and proliferation increased on modified substrates. But the results on unirradiated samples, indicate cell death (necrosis/apoptosis) with the consequent decrease in proliferation. We analyzed the correlation between irradiation parameters and cell metabolism and morphology

  15. Study on cell survival, induction of apoptosis and micronucleus formation in SCL-II and RTiV3 cells after exposure to the Auger electron emitter Tc-99m

    International Nuclear Information System (INIS)

    Kadenbach, K.; Kriehuber, R.; Weiss, D.G.

    2003-01-01

    Full text: Cell survival, induction of apoptosis and micronucleus (MN) formation have been investigated in the human squamous cell carcinoma cell line SCL-II and in the rat tracheal cell line RTiV3 after exposure to the Auger electron emitter Tc-99m. Cells were either acutely gamma(Co-60)-irradiated (0.78 Gy/min) or exposed to Tc-99m-Pertechnetate (25-300 MBq/20ml) for 24 h under cell culture conditions and assayed for cell survival (Colony-forming assay), micronucleus formation (Cytochalasin B assay) and the frequency of apoptotic cells (Fluorescence microscopy). Analytical dosimetrical models have been applied to derive the absorbed dose corresponding to the accumulated decays of Tc-99m. Absorbed doses up to 1.3 Gy could be achieved after Tc-99m exposure leading to no significant cell killing in this dose range except at one dose point (0.25 Gy) in SCL-II cells. MN formation was consistently lower when compared to Co-60 irradiated cells and showed a linear dose-response. The apoptotic response in SCL-II cells after Tc-99m exposure was described best by a 3rd order polynomial and increased apoptosis induction could be observed at much lower doses (0.25 Gy) in comparison to the reference radiation (0.8 Gy). The relative biological effectiveness (RBE) has been determined for MN formation and apoptosis induction and was found to be in the range of 0.1- 1.3 for both investigated biological endpoints, depending on which mathematical model for describing the dose-effect curve was used. Up-take experiments revealed an activity concentration ratio cells vs. medium of 1.2 after 16 h up to 24 h of exposure. No increased biological effectiveness of Tc-99m applied as Sodium-Pertechnetate could be observed in the investigated cell lines in comparison to gamma-irradiation. Induction of apoptosis is slightly increased after Tc-99m exposure in SCL-II cells and it has to be further evaluated, if this is due to the emitted Auger-component. A passive up-take mechanism of Tc-99m is

  16. Glycosaminoglycan-sac formation in vitro. Interactions between normal and malignant cells

    OpenAIRE

    Logothetou-Rella, H.

    1994-01-01

    The interaction of monolayer normal human or normal rat cells with suspension Walker rat tumor cells was demonstrated cytologically, during a cocultivation period of thirty days. At ten days, Walker rat tumor cells were interiorized in the cytoplasm of the normal monolayer host cells. At twenty days, degeneration of the interiorized tumor cells followed by mucification led to glycosaminoglycan-sac formation. At thirty days, tumor nodules and protease (a,- c...

  17. Hypochlorite- and hypobromite-mediated radical formation and its role in cell lysis

    DEFF Research Database (Denmark)

    Hawkins, C L; Brown, B E; Davies, Michael Jonathan

    2001-01-01

    . In this study it is shown that HOBr induces red blood cell lysis at approximately 10-fold lower concentrations than HOCl, whereas with monocyte (THP1) and macrophage (J774) cells HOCl and HOBr induce lysis at similar concentrations. The role of radical formation during lysis has been investigated by EPR spin...... trapping, and it is shown that reaction of both oxidants with each cell type generates cell-derived radicals. Red blood cells exposed to nonlytic doses of HOCl generate novel nitrogen-centered radicals whose formation is GSH dependent. In contrast, HOBr gives rise to nitrogen-centered, membrane......-derived protein radicals. With lytic doses of either oxidant, protein (probably hemoglobin)-derived, nitrogen-centered radicals are observed. Unlike the red blood cells, treatment of monocytes and macrophages with HOCl gives significant radical formation only under conditions where cell lysis occurs concurrently...

  18. Effect of oxygen on formation of micronuclei and binucleated cells and cell survival in γ-irradiated 3T3 cells

    International Nuclear Information System (INIS)

    Zhang Peng; Zheng Xiulong

    1991-01-01

    Formation of micronuclei and binucleate cells and their relationships with cell survival were studied in the aerobically- and anaerobically-irradiated 3T3 cells. The results showed taht frequency of micronuclei, percentage of micronucleus cells and percentage of binucleate cells increased linearly with the radiation dose in certain range. Oxygen enhancement ratios (OER) of micronucleus frequency, percentage of micronucleus cells, percentage of binucleate cells and cell survival were 2.02, 1.96, 1.87 and 1.83 respectively. The percentage of micronucleus cells or the percentage of micronucleus cells plus binucleate cells correlated negatively well with cell survival. The mechanism of oxygen effect in the radiation response of 3T3 cells and the significance of formation of micronuclei and binucleate cells were discussed

  19. Stem cells catalyze cartilage formation by neonatal articular chondrocytes in 3D biomimetic hydrogels.

    Science.gov (United States)

    Lai, Janice H; Kajiyama, Glen; Smith, Robert Lane; Maloney, William; Yang, Fan

    2013-12-19

    Cartilage loss is a leading cause of disability among adults and effective therapy remains elusive. Neonatal chondrocytes (NChons) are an attractive allogeneic cell source for cartilage repair, but their clinical translation has been hindered by scarce donor availability. Here we examine the potential for catalyzing cartilage tissue formation using a minimal number of NChons by co-culturing them with adipose-derived stem cells (ADSCs) in 3D hydrogels. Using three different co-culture models, we demonstrated that the effects of co-culture on cartilage tissue formation are dependent on the intercellular distance and cell distribution in 3D. Unexpectedly, increasing ADSC ratio in mixed co-culture led to increased synergy between NChons and ADSCs, and resulted in the formation of large neocartilage nodules. This work raises the potential of utilizing stem cells to catalyze tissue formation by neonatal chondrocytes via paracrine signaling, and highlights the importance of controlling cell distribution in 3D matrices to achieve optimal synergy.

  20. Effect of Emdogain enamel matrix derivative and BMP-2 on the gene expression and mineralized nodule formation of alveolar bone proper-derived stem/progenitor cells.

    Science.gov (United States)

    Fawzy El-Sayed, Karim M; Dörfer, Christof; Ungefroren, Hendrick; Kassem, Neemat; Wiltfang, Jörg; Paris, Sebastian

    2014-07-01

    The objective of this study was to evaluate the effect of Emdogain (Enamel Matrix Derivative, EMD) and Bone Morphogenetic Protein-2 (BMP-2), either solely or in combination, on the gene expression and mineralized nodule formation of alveolar bone proper-derived stem/progenitor cells. Stem/progenitor cells were isolated from human alveolar bone proper, magnetically sorted using STRO-1 antibodies, characterized flowcytometrically for their surface markers' expression, and examined for colony formation and multilineage differentiation potential. Subsequently, cells were treated over three weeks with 100 μg/ml Emdogain (EMD-Group), or 100 ng/ml BMP-2 (BMP-Group), or a combination of 100 ng/ml BMP-2 and 100 μg/ml Emdogain (BMP/EMD-Group). Unstimulated stem/progenitor cells (MACS(+)-Group) and osteoblasts (OB-Group) served as controls. Osteogenic gene expression was analyzed using RTq-PCR after 1, 2 and 3 weeks (N = 3/group). Mineralized nodule formation was evaluated by Alizarin-Red staining. BMP and EMD up-regulated the osteogenic gene expression. The BMP Group showed significantly higher expression of Collagen-I, III, and V, Alkaline phosphatase and Osteonectin compared to MACS(+)- and OB-Group (p < 0.05; Two-way ANOVA/Bonferroni) with no mineralized nodule formation. Under in-vitro conditions, Emdogain and BMP-2 up-regulate the osteogenic gene expression of stem/progenitor cells. The combination of BMP-2 and Emdogain showed no additive effect and would not be recommended for a combined clinical stimulation. Copyright © 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  1. Formation and action of oxygen activated species in cell cultures

    International Nuclear Information System (INIS)

    Hoffmann, M.E.; Meneghini, R.

    1982-01-01

    The differences of hydrogen peroxide sensibility of mammal cell lineages (man, mouse, chinese hamster) in culture are studied. The cellular survival and the frequency of DNA induced breaks by hydrogen peroxide are analysed. The efficiency of elimination of DNA breaks by cells is determined. The possible relation between the cell capacity of repair and its survival to hydrogen peroxide action is also discussed. (M.A.) [pt

  2. Methanofullerene elongated nanostructure formation for enhanced organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Reyes-Reyes, M. [Instituto de Investigacion en Comunicacion Optica, Universidad Autonoma de San Luis Potosi, Alvaro Obregon 64, San Luis Potosi (Mexico)], E-mail: reyesm@cactus.iico.uaslp.mx; Lopez-Sandoval, R. [Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la presa San Jose 2055, CP 78216. San Luis Potosi (Mexico); Arenas-Alatorre, J. [Instituto de Fisica, UNAM, Apartado Postal 20-364, 01000, Mexico, D.F. (Mexico); Garibay-Alonso, R. [Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la presa San Jose 2055, CP 78216. San Luis Potosi (Mexico); Carroll, D.L. [Center for Nanotechnology and Molecular Materials, Department of Physics. Wake Forest University, Winston-Salem NC 27109 (United States); Lastras-Martinez, A. [Instituto de Investigacion en Comunicacion Optica, Universidad Autonoma de San Luis Potosi, Alvaro Obregon 64, San Luis Potosi (Mexico)

    2007-11-01

    Using transmission electron microscopy (TEM) and Z-contrast imaging we have demonstrated elongated nanostructure formation of fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) within an organic host through annealing. The annealing provides an enhanced mobility of the PCBM molecules and, with good initial dispersion, allows for the formation of exaggerated grain growth within the polymer host. We have assembled these nanostructures within the regioregular conjugated polymer poly(3-hexylthiophene) (P3HT). This PCBM elongated nanostructure formation maybe responsible for the very high efficiencies observed, at very low loadings of PCBM (1:0.6, polymer to PCBM), in annealed photovoltaics. Moreover, our high resolution TEM and electron energy loss spectroscopy studies clearly show that the PCBM crystals remain crystalline and are unaffected by the 200-keV electron beam.

  3. Methanofullerene elongated nanostructure formation for enhanced organic solar cells

    International Nuclear Information System (INIS)

    Reyes-Reyes, M.; Lopez-Sandoval, R.; Arenas-Alatorre, J.; Garibay-Alonso, R.; Carroll, D.L.; Lastras-Martinez, A.

    2007-01-01

    Using transmission electron microscopy (TEM) and Z-contrast imaging we have demonstrated elongated nanostructure formation of fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) within an organic host through annealing. The annealing provides an enhanced mobility of the PCBM molecules and, with good initial dispersion, allows for the formation of exaggerated grain growth within the polymer host. We have assembled these nanostructures within the regioregular conjugated polymer poly(3-hexylthiophene) (P3HT). This PCBM elongated nanostructure formation maybe responsible for the very high efficiencies observed, at very low loadings of PCBM (1:0.6, polymer to PCBM), in annealed photovoltaics. Moreover, our high resolution TEM and electron energy loss spectroscopy studies clearly show that the PCBM crystals remain crystalline and are unaffected by the 200-keV electron beam

  4. Programmed cell death for defense against anomaly and tumor formation

    International Nuclear Information System (INIS)

    Kondo, Sohei; Norimura, Toshiyuki; Nomura, Taisei

    1995-01-01

    Cell death after exposure to low-level radiation is often considered evidence that radiation is poisonous, however small the dose. Evidence has been accumulating to support the notion that cell death after low-level exposure to radiation results from activation of suicidal genes open-quote programmed cell death close-quote or open-quote apoptosis close-quote - for the health of the whole body. This paper gives experimental evidence that embryos of fruit flies and mouse fetuses have potent defense mechanisms against teratogenic or tumorigenic injury caused by radiation and carcinogens, which function through programmed cell death

  5. A branching process model for the analysis of abortive colony size distributions in carbon ion-irradiated normal human fibroblasts

    International Nuclear Information System (INIS)

    Sakashita, Tetsuya; Kobayashi, Yasuhiko; Hamada, Nobuyuki; Kawaguchi, Isao; Hara, Takamitsu; Saito, Kimiaki

    2014-01-01

    A single cell can form a colony, and ionizing irradiation has long been known to reduce such a cellular clonogenic potential. Analysis of abortive colonies unable to continue to grow should provide important information on the reproductive cell death (RCD) following irradiation. Our previous analysis with a branching process model showed that the RCD in normal human fibroblasts can persist over 16 generations following irradiation with low linear energy transfer (LET) γ-rays. Here we further set out to evaluate the RCD persistency in abortive colonies arising from normal human fibroblasts exposed to high-LET carbon ions (18.3 MeV/u, 108 keV/μm). We found that the abortive colony size distribution determined by biological experiments follows a linear relationship on the log–log plot, and that the Monte Carlo simulation using the RCD probability estimated from such a linear relationship well simulates the experimentally determined surviving fraction and the relative biological effectiveness (RBE). We identified the short-term phase and long-term phase for the persistent RCD following carbon-ion irradiation, which were similar to those previously identified following γ-irradiation. Taken together, our results suggest that subsequent secondary or tertiary colony formation would be invaluable for understanding the long-lasting RCD. All together, our framework for analysis with a branching process model and a colony formation assay is applicable to determination of cellular responses to low- and high-LET radiation, and suggests that the long-lasting RCD is a pivotal determinant of the surviving fraction and the RBE. (author)

  6. Granulocyte-Macrophage Colony-Stimulating Factor Amplification of Interleukin-1β and Tumor Necrosis Factor Alpha Production in THP-1 Human Monocytic Cells Stimulated with Lipopolysaccharide of Oral Microorganisms

    OpenAIRE

    Baqui, A. A. M. A.; Meiller, Timothy F.; Chon, Jennifer J.; Turng, Been-Foo; Falkler, William A.

    1998-01-01

    Cytokines, including granulocyte-macrophage colony-stimulating factor (GM-CSF), are used to assist in bone marrow recovery during cancer chemotherapy. Interleukin-1β (IL-1β) and tumor necrosis factor alpha (TNF-α) play important roles in inflammatory processes, including exacerbation of periodontal diseases, one of the most common complications in patients who undergo this therapy. A human monocyte cell line (THP-1) was utilized to investigate IL-1β and TNF-α production following GM-CSF suppl...

  7. Endothelial cell motility, coordination and pattern formation during vasculogenesis.

    Science.gov (United States)

    Czirok, Andras

    2013-01-01

    How vascular networks assemble is a fundamental problem of developmental biology that also has medical importance. To explain the organizational principles behind vascular patterning, we must understand how can tissue level structures be controlled through cell behavior patterns like motility and adhesion that, in turn, are determined by biochemical signal transduction processes? We discuss the various ideas that have been proposed as mechanisms for vascular network assembly: cell motility guided by extracellular matrix alignment (contact guidance), chemotaxis guided by paracrine and autocrine morphogens, and multicellular sprouting guided by cell-cell contacts. All of these processes yield emergent patterns, thus endothelial cells can form an interconnected structure autonomously, without guidance from an external pre-pattern. © 2013 Wiley Periodicals, Inc.

  8. Delayed cell death, giant cell formation and chromosome instability induced by X-irradiation in human embryo cells

    International Nuclear Information System (INIS)

    Roy, K.; Kodama, Seiji; Suzuki, Keiji; Watanabe, Masami

    1999-01-01

    We studied X-ray-induced delayed cell death, delayed giant cell formation and delayed chromosome aberrations in normal human embryo cells to explore the relationship between initial radiation damage and delayed effect appeared at 14 to 55 population doubling numbers (PDNs) after X-irradiation. The delayed effect was induced in the progeny of X-ray survivors in a dose-dependent manner and recovered with increasing PDNs after X-irradiation. Delayed plating for 24 h post-irradiation reduced both acute and delayed lethal damage, suggesting that potentially lethal damage repair (PLDR) can be effective for relieving the delayed cell death. The chromosome analysis revealed that most of the dicentrics (more than 90%) observed in the progeny of X-ray survivors were not accompanied with fragments, in contrast with those observed in the first mitosis after X-irradiation. The present results indicate that the potentiality of genetic instability is determined during the repair process of initial radiation damage and suggest that the mechanism for formation of delayed chromosome aberrations by radiation might be different from that of direct radiation-induced chromosome aberrations. (author)

  9. Strong homeostatic TCR signals induce formation of self-tolerant virtual memory CD8 T cells.

    Science.gov (United States)

    Drobek, Ales; Moudra, Alena; Mueller, Daniel; Huranova, Martina; Horkova, Veronika; Pribikova, Michaela; Ivanek, Robert; Oberle, Susanne; Zehn, Dietmar; McCoy, Kathy D; Draber, Peter; Stepanek, Ondrej

    2018-05-11

    Virtual memory T cells are foreign antigen-inexperienced T cells that have acquired memory-like phenotype and constitute 10-20% of all peripheral CD8 + T cells in mice. Their origin, biological roles, and relationship to naïve and foreign antigen-experienced memory T cells are incompletely understood. By analyzing T-cell receptor repertoires and using retrogenic monoclonal T-cell populations, we demonstrate that the virtual memory T-cell formation is a so far unappreciated cell fate decision checkpoint. We describe two molecular mechanisms driving the formation of virtual memory T cells. First, virtual memory T cells originate exclusively from strongly self-reactive T cells. Second, the stoichiometry of the CD8 interaction with Lck regulates the size of the virtual memory T-cell compartment via modulating the self-reactivity of individual T cells. Although virtual memory T cells descend from the highly self-reactive clones and acquire a partial memory program, they are not more potent in inducing experimental autoimmune diabetes than naïve T cells. These data underline the importance of the variable level of self-reactivity in polyclonal T cells for the generation of functional T-cell diversity. © 2018 The Authors. Published under the terms of the CC BY 4.0 license.

  10. The role of Rap1 in cell-cell junction formation

    NARCIS (Netherlands)

    Kooistra, M.R.H.

    2008-01-01

    Both epithelial and endothelial cells form cell-cell junctions at the cell-cell contacts to maintain tissue integrity. Proper regulation of cell-cell junctions is required for the organisation of the tissue and to prevent leakage of blood vessels. In endothelial cells, the cell-cell junctions are

  11. A Theoretical Model of Jigsaw-Puzzle Pattern Formation by Plant Leaf Epidermal Cells.

    Science.gov (United States)

    Higaki, Takumi; Kutsuna, Natsumaro; Akita, Kae; Takigawa-Imamura, Hisako; Yoshimura, Kenji; Miura, Takashi

    2016-04-01

    Plant leaf epidermal cells exhibit a jigsaw puzzle-like pattern that is generated by interdigitation of the cell wall during leaf development. The contribution of two ROP GTPases, ROP2 and ROP6, to the cytoskeletal dynamics that regulate epidermal cell wall interdigitation has already been examined; however, how interactions between these molecules result in pattern formation remains to be elucidated. Here, we propose a simple interface equation model that incorporates both the cell wall remodeling activity of ROP GTPases and the diffusible signaling molecules by which they are regulated. This model successfully reproduces pattern formation observed in vivo, and explains the counterintuitive experimental results of decreased cellulose production and increased thickness. Our model also reproduces the dynamics of three-way cell wall junctions. Therefore, this model provides a possible mechanism for cell wall interdigitation formation in vivo.

  12. Proliferation-stimulating effect of colony stimulating factor 2 on porcine trophectoderm cells is mediated by activation of phosphatidylinositol 3-kinase and extracellular signal-regulated kinase 1/2 mitogen-activated protein kinase.

    Directory of Open Access Journals (Sweden)

    Wooyoung Jeong

    Full Text Available Colony-stimulating factor 2 (CSF2, also known as granulocyte macrophage colony-stimulating factor, facilitates mammalian embryonic development and implantation. However, biological functions and regulatory mechanisms of action of porcine endometrial CSF2 in peri-implantation events have not been elucidated. The aim of present study was to determine changes in cellular activities induced by CSFs and to access CSF2-induced intracellular signaling in porcine primary trophectoderm (pTr cells. Differences in expression of CSF2 mRNA in endometrium from cyclic and pregnant gilts were evaluated. Endometrial CSF2 mRNA expression increases during the peri-implantation period, Days 10 to 14 of pregnancy, as compared to the estrous cycle. pTr cells obtained in Day 12 of pregnancy were cultured in the presence or absence of CSF2 (20 ng/ml and LY294002 (20 µM, U0126 (20 µM, rapamycin (20 nM, and SB203580 (20 µM. CSF2 in pTr cell culture medium at 20 ng/ml significantly induced phosphorylation of AKT1, ERK1/2, MTOR, p70RSK and RPS6 protein, but not STAT3 protein. Also, the PI3K specific inhibitor (LY294002 abolished CSF2-induced increases in p-ERK1/2 and p-MTOR proteins, as well as CSF2-induced phosphorylation of AKT1. Changes in proliferation and migration of pTr cells in response to CSF2 were examined in dose- and time-response experiments. CSF2 significantly stimulated pTr cell proliferation and, U0126, rapamycin and LY294002 blocked this CSF2-induced proliferation of pTr cells. Collectively, during the peri-implantation phase of pregnancy in pigs, endometrial CSF2 stimulates proliferation of trophectoderm cells by activation of the PI3K-and ERK1/2 MAPK-dependent MTOR signal transduction cascades.

  13. Mechanical Model of Geometric Cell and Topological Algorithm for Cell Dynamics from Single-Cell to Formation of Monolayered Tissues with Pattern

    KAUST Repository

    Kachalo, Sëma

    2015-05-14

    Geometric and mechanical properties of individual cells and interactions among neighboring cells are the basis of formation of tissue patterns. Understanding the complex interplay of cells is essential for gaining insight into embryogenesis, tissue development, and other emerging behavior. Here we describe a cell model and an efficient geometric algorithm for studying the dynamic process of tissue formation in 2D (e.g. epithelial tissues). Our approach improves upon previous methods by incorporating properties of individual cells as well as detailed description of the dynamic growth process, with all topological changes accounted for. Cell size, shape, and division plane orientation are modeled realistically. In addition, cell birth, cell growth, cell shrinkage, cell death, cell division, cell collision, and cell rearrangements are now fully accounted for. Different models of cell-cell interactions, such as lateral inhibition during the process of growth, can be studied in detail. Cellular pattern formation for monolayered tissues from arbitrary initial conditions, including that of a single cell, can also be studied in detail. Computational efficiency is achieved through the employment of a special data structure that ensures access to neighboring cells in constant time, without additional space requirement. We have successfully generated tissues consisting of more than 20,000 cells starting from 2 cells within 1 hour. We show that our model can be used to study embryogenesis, tissue fusion, and cell apoptosis. We give detailed study of the classical developmental process of bristle formation on the epidermis of D. melanogaster and the fundamental problem of homeostatic size control in epithelial tissues. Simulation results reveal significant roles of solubility of secreted factors in both the bristle formation and the homeostatic control of tissue size. Our method can be used to study broad problems in monolayered tissue formation. Our software is publicly

  14. Analysis of Colonial Currency

    Science.gov (United States)

    Kurkowski, Michael; Cangany, Catherine; Jordan, Louis; Manukyan, Khachatur; Schultz, Zachary; Wiescher, Michael

    2017-09-01

    This project entailed studying the cellulose in paper, the ink, colorants, and other materials used to produce American colonial currency. The technique primarily used in this project was X-Ray Fluorescence Spectroscopy (XRF). XRF mapping was used to provide both elemental analysis of large-scale objects as well as microscopic examination of individual pigment particles in ink, in addition to the inorganic additives used to prepare paper. The combination of elemental mapping with Fourier Transform Infrared (FTIR) and Raman Spectroscopies permits an efficient analysis of the currency. These spectroscopic methods help identify the molecular composition of the pigments. This combination of atomic and molecular analytical techniques provided an in-depth characterization of the paper currency on the macro, micro, and molecular levels. We have identified several of pigments that were used in the preparation of inks and colorants. Also, different inorganic crystals, such as alumina-silicates, have been detected in different papers. The FTIR spectroscopy allowed us to determine the type of cellulose fiber used in the production of paper currency. Our future research will be directed toward revealing important historical relationships between currencies printed throughout the colonies. ISLA Da Vinci Grant.

  15. Matrix elasticity of void-forming hydrogels controls transplanted-stem-cell-mediated bone formation

    Science.gov (United States)

    Huebsch, Nathaniel; Lippens, Evi; Lee, Kangwon; Mehta, Manav; Koshy, Sandeep T.; Darnell, Max C.; Desai, Rajiv M.; Madl, Christopher M.; Xu, Maria; Zhao, Xuanhe; Chaudhuri, Ovijit; Verbeke, Catia; Kim, Woo Seob; Alim, Karen; Mammoto, Akiko; Ingber, Donald E.; Duda, Georg N.; Mooney, David J.

    2015-12-01

    The effectiveness of stem cell therapies has been hampered by cell death and limited control over fate. These problems can be partially circumvented by using macroporous biomaterials that improve the survival of transplanted stem cells and provide molecular cues to direct cell phenotype. Stem cell behaviour can also be controlled in vitro by manipulating the elasticity of both porous and non-porous materials, yet translation to therapeutic processes in vivo remains elusive. Here, by developing injectable, void-forming hydrogels that decouple pore formation from elasticity, we show that mesenchymal stem cell (MSC) osteogenesis in vitro, and cell deployment in vitro and in vivo, can be controlled by modifying, respectively, the hydrogel’s elastic modulus or its chemistry. When the hydrogels were used to transplant MSCs, the hydrogel’s elasticity regulated bone regeneration, with optimal bone formation at 60 kPa. Our findings show that biophysical cues can be harnessed to direct therapeutic stem cell behaviours in situ.

  16. Chinese herb derived-Rocaglamide A is a potent inhibitor of pancreatic cancer cells

    OpenAIRE

    Wang, Baochun; Li, Yixiong; Tan, Fengbo; Xiao, Zhanxiang

    2016-01-01

    Pancreatic cancer ranks No.1 in mortality rate worldwide. This study aims to identify the novel anti-pancreatic cancer drugs. Human pancreatic carcinoma cell lines were purchased from ATCC. CPE-based screening assay was used to examine the cell viability. Patient derived tumor xenografts in SCID mice was established. The Caspase-3 and 7 activities were measured using the Caspase Glo 3/7 Assay kit. Soft agar colony formation assay was used to evaluate the colony formation. Wound healing assay ...

  17. Seabird Colonies in Western Greenland

    DEFF Research Database (Denmark)

    Boertmann, D.; Mosbech, A.; Falk, K.

    About 1 million seabirds (indvs) breed in 1032 colonies distributed along the coasts of western Greenland (Fig. 1). However, this figure does not include the little auk colonies in Avanersuaq. These colonies are roughly estimated to hold about 20 mill. pairs. All the basic information on seabird...... colonies in Greenland is compiled in a database maintained by NERI-AE. This report presents data on distribution, population numbers and population trends of 19 species of breeding colonial seabirds in western Greenland. Distributions are depicted on maps in Fig. 18-39. It is apparent that the major...... colonies are found in the northern part of the region, viz. Upernavik and Avanersuaq. The numbers of birds recorded in the database for each species are presented in Tab. 4, and on the basis of these figures estimates of the populations in western Greenland are given (Tab. 5). The most numerous species...

  18. Cell formation by myxozoan species is not explained by dogma

    Science.gov (United States)

    Morris, David J.

    2010-01-01

    Eukaryotes form new cells through the replication of nuclei followed by cytokinesis. A notable exception is reported from the class Myxosporea of the phylum Myxozoa. This assemblage of approximately 2310 species is regarded as either basal bilaterian or cnidarian, depending on the phylogenetic analysis employed. For myxosporeans, cells have long been regarded as forming within other cells by a process referred to as endogenous budding. This would involve a nucleus forming endoplasmic reticulum around it, which transforms into a new plasma membrane, thus enclosing and separating it from the surrounding cell. This remarkable process, unique within the Metazoa, is accepted as occurring within stages found in vertebrate hosts, but has only been inferred from those stages observed within invertebrate hosts. Therefore, I conducted an ultrastructural study to examine how internal cells are formed by a myxosporean parasitizing an annelid. In this case, actinospore parasite stages clearly internalized existing cells; a process with analogies to the acquisition of endosymbiotic algae by cnidarian species. A subsequent examination of the myxozoan literature did not support endogenous budding, indicating that this process, which has been a central tenet of myxozoan developmental biology for over a century, is dogma. PMID:20392735

  19. Cell formation by myxozoan species is not explained by dogma.

    Science.gov (United States)

    Morris, David J

    2010-08-22

    Eukaryotes form new cells through the replication of nuclei followed by cytokinesis. A notable exception is reported from the class Myxosporea of the phylum Myxozoa. This assemblage of approximately 2310 species is regarded as either basal bilaterian or cnidarian, depending on the phylogenetic analysis employed. For myxosporeans, cells have long been regarded as forming within other cells by a process referred to as endogenous budding. This would involve a nucleus forming endoplasmic reticulum around it, which transforms into a new plasma membrane, thus enclosing and separating it from the surrounding cell. This remarkable process, unique within the Metazoa, is accepted as occurring within stages found in vertebrate hosts, but has only been inferred from those stages observed within invertebrate hosts. Therefore, I conducted an ultrastructural study to examine how internal cells are formed by a myxosporean parasitizing an annelid. In this case, actinospore parasite stages clearly internalized existing cells; a process with analogies to the acquisition of endosymbiotic algae by cnidarian species. A subsequent examination of the myxozoan literature did not support endogenous budding, indicating that this process, which has been a central tenet of myxozoan developmental biology for over a century, is dogma.

  20. Regulation of CCR7-dependent cell migration through?CCR7 homodimer formation

    OpenAIRE

    Kobayashi, Daichi; Endo, Masataka; Ochi, Hirotaka; Hojo, Hironobu; Miyasaka, Masayuki; Hayasaka, Haruko

    2017-01-01

    The chemokine receptor CCR7 contributes to various physiological and pathological processes including T cell maturation, T cell migration from the blood into secondary lymphoid tissues, and tumor cell metastasis to lymph nodes. Although a previous study suggested that the efficacy of CCR7 ligand-dependent T cell migration correlates with CCR7 homo- and heterodimer formation, the exact extent of contribution of the CCR7 dimerization remains unclear. Here, by inducing or disrupting CCR7 dimers,...

  1. 3D tissue formation : the kinetics of human mesenchymal stem cells

    NARCIS (Netherlands)

    Higuera Sierra, Gustavo

    2010-01-01

    The main thesis in this book proposes that physical phenomena underlies the formation of three-dimensional (3D) tissue. In this thesis, tissue regeneration with mesenchymal stem cells was studied through the law of conservation of mass. MSCs proliferation and 3D tissue formation were explored from

  2. Quantum dot-based molecular imaging of cancer cell growth using a clone formation assay.

    Science.gov (United States)

    Geng, Xia-Fei; Fang, Min; Liu, Shao-Ping; Li, Yan

    2016-10-01

    This aim of the present study was to investigate clonal growth behavior and analyze the proliferation characteristics of cancer cells. The MCF‑7 human breast cancer cell line, SW480 human colon cancer cell line and SGC7901 human gastric cancer cell line were selected to investigate the morphology of cell clones. Quantum dot‑based molecular targeted imaging techniques (which stained pan‑cytokeratin in the cytoplasm green and Ki67 in the cell nucleus yellow or red) were used to investigate the clone formation rate, cell morphology, discrete tendency, and Ki67 expression and distribution in clones. From the cell clone formation assay, the MCF‑7, SW480 and SGC7901 cells were observed to form clones on days 6, 8 and 12 of cell culture, respectively. These three types of cells had heterogeneous morphology, large nuclear:cytoplasmic ratios, and conspicuous pathological mitotic features. The cells at the clone periphery formed multiple pseudopodium. In certain clones, cancer cells at the borderline were separated from the central cell clusters or presented a discrete tendency. With quantum dot‑based molecular targeted imaging techniques, cells with strong Ki67 expression were predominantly shown to be distributed at the clone periphery, or concentrated on one side of the clones. In conclusion, cancer cell clones showed asymmetric growth behavior, and Ki67 was widely expressed in clones of these three cell lines, with strong expression around the clones, or aggregated at one side. Cell clone formation assay based on quantum dots molecular imaging offered a novel method to study the proliferative features of cancer cells, thus providing a further insight into tumor biology.

  3. MECHANICAL VIBRATION INHIBITS OSTEOCLAST FORMATION BY REDUCING DC-STAMP RECEPTOR EXPRESSION IN OSTEOCLAST PRECURSOR CELLS

    OpenAIRE

    Kulkarni, R.N.; Voglewede, P.A.; Liu, D.

    2013-01-01

    It is well known that physical inactivity leads to loss of muscle mass, but it also causes bone loss. Mechanistically, osteoclastogenesis and bone resorption have recently been shown to be regulated by vibration. However, the underlying mechanism behind the inhibition of osteoclast formation is yet unknown. Therefore, we investigated whether mechanical vibration of osteoclast precursor cells affects osteoclast formation by the involvement of fusion-related molecules such as dendritic cell-spe...

  4. Dynamics of vegetative cytoplasm during generative cell formation and pollen maturation in Arabidopsis thaliana

    Science.gov (United States)

    Kuang, A.; Musgrave, M. E.

    1996-01-01

    Ultrastructural changes of pollen cytoplasm during generative cell formation and pollen maturation in Arabidopsis thaliana were studied. The pollen cytoplasm develops a complicated ultrastructure and changes dramatically during these stages. Lipid droplets increase after generative cell formation and their organization and distribution change with the developmental stage. Starch grains in amyloplasts increase in number and size during generative and sperm cell formation and decrease at pollen maturity. The shape and membrane system of mitochondria change only slightly. Dictyosomes become very prominent, and numerous associated vesicles are observed during and after sperm cell formation. Endoplasmic reticulum appears extensively as stacks during sperm cell formation. Free and polyribosomes are abundant in the cytoplasm at all developmental stages although they appear denser at certain stages and in some areas. In mature pollen, all organelles are randomly distributed throughout the vegetative cytoplasm and numerous small particles appear. Organization and distribution of storage substances and appearance of these small particles during generative and sperm cell formation and pollen maturation are discussed.

  5. Fibrinogen-Induced Streptococcus mutans Biofilm Formation and Adherence to Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Telma Blanca Lombardo Bedran

    2013-01-01

    Full Text Available Streptococcus mutans, the predominant bacterial species associated with dental caries, can enter the bloodstream and cause infective endocarditis. The aim of this study was to investigate S. mutans biofilm formation and adherence to endothelial cells induced by human fibrinogen. The putative mechanism by which biofilm formation is induced as well as the impact of fibrinogen on S. mutans resistance to penicillin was also evaluated. Bovine plasma dose dependently induced biofilm formation by S. mutans. Of the various plasma proteins tested, only fibrinogen promoted the formation of biofilm in a dose-dependent manner. Scanning electron microscopy observations revealed the presence of complex aggregates of bacterial cells firmly attached to the polystyrene support. S. mutans in biofilms induced by the presence of fibrinogen was markedly resistant to the bactericidal effect of penicillin. Fibrinogen also significantly increased the adherence of S. mutans to endothelial cells. Neither S. mutans cells nor culture supernatants converted fibrinogen into fibrin. However, fibrinogen is specifically bound to the cell surface of S. mutans and may act as a bridging molecule to mediate biofilm formation. In conclusion, our study identified a new mechanism promoting S. mutans biofilm formation and adherence to endothelial cells which may contribute to infective endocarditis.

  6. Ectopic bone formation in bone marrow stem cell seeded calcium phosphate scaffolds as compared to autograft and (cell seeded allograft

    Directory of Open Access Journals (Sweden)

    J O Eniwumide

    2007-08-01

    Full Text Available Improvements to current therapeutic strategies are needed for the treatment of skeletal defects. Bone tissue engineering offers potential advantages to these strategies. In this study, ectopic bone formation in a range of scaffolds was assessed. Vital autograft and devitalised allograft served as controls and the experimental groups comprised autologous bone marrow derived stem cell seeded allograft, biphasic calcium phosphate (BCP and tricalcium phosphate (TCP, respectively. All implants were implanted in the back muscle of adult Dutch milk goats for 12 weeks. Micro-computed tomography (µCT analysis and histomorphometry was performed to evaluate and quantify ectopic bone formation. In good agreement, both µCT and histomorphometric analysis demonstrated a significant increase in bone formation by cell-seeded calcium phosphate scaffolds as compared to the autograft, allograft and cell-seeded allograft implants. An extensive resorption of the autograft, allograft and cell-seeded allograft implants was observed by histology and confirmed by histomorphometry. Cell-seeded TCP implants also showed distinct signs of degradation with histomorphometry and µCT, while the degradation of the cell-seeded BCP implants was negligible. These results indicate that cell-seeded calcium phosphate scaffolds are superior to autograft, allograft or cell-seeded allograft in terms of bone formation at ectopic implantation sites. In addition, the usefulness of µCT for the efficient and non-destructive analysis of mineralised bone and calcium phosphate scaffold was demonstrated.

  7. Cdc42 is not essential for filopodium formation, directed migration, cell polarization, and mitosis in fibroblastoid cells

    DEFF Research Database (Denmark)

    Czuchra, Aleksandra; Wu, Xunwei; Meyer, Hannelore

    2005-01-01

    of Cdc42 did not affect filopodium or lamellipodium formation and had no significant influence on the speed of directed migration nor on mitosis. Cdc42-deficient cells displayed a more elongated cell shape and had a reduced area. Furthermore, directionality during migration and reorientation of the Golgi...

  8. Vascular endothelial growth factor modified macrophages transdifferentiate into endothelial-like cells and decrease foam cell formation.

    Science.gov (United States)

    Yan, Dan; He, Yujuan; Dai, Jun; Yang, Lili; Wang, Xiaoyan; Ruan, Qiurong

    2017-06-30

    Macrophages are largely involved in the whole process of atherosclerosis from an initiation lesion to an advanced lesion. Endothelial disruption is the initial step and macrophage-derived foam cells are the hallmark of atherosclerosis. Promotion of vascular integrity and inhibition of foam cell formation are two important strategies for preventing atherosclerosis. How can we inhibit even the reverse negative role of macrophages in atherosclerosis? The present study was performed to investigate if overexpressing endogenous human vascular endothelial growth factor (VEGF) could facilitate transdifferentiation of macrophages into endothelial-like cells (ELCs) and inhibit foam cell formation. We demonstrated that VEGF-modified macrophages which stably overexpressed human VEGF (hVEGF 165 ) displayed a high capability to alter their phenotype and function into ELCs in vitro Exogenous VEGF could not replace endogenous VEGF to induce the transdifferentiation of macrophages into ELCs in vitro We further showed that VEGF-modified macrophages significantly decreased cytoplasmic lipid accumulation after treatment with oxidized LDL (ox-LDL). Moreover, down-regulation of CD36 expression in these cells was probably one of the mechanisms of reduction in foam cell formation. Our results provided the in vitro proof of VEGF-modified macrophages as atheroprotective therapeutic cells by both promotion of vascular repair and inhibition of foam cell formation. © 2017 The Author(s).

  9. Singlet oxygen-mediated formation of protein peroxides within cells

    International Nuclear Information System (INIS)

    Wright, A.; Policarpio, V.

    2003-01-01

    Full text: Singlet oxygen is generated by a number of cellular, enzymatic and chemical reactions as well as by exposure to UV, or visible light in the presence of a sensitizer; as a consequence this oxidant has been proposed as a damaging agent in a number of pathologies including photo-aging and skin cancer. Proteins are major targets for singlet oxygen as a result of their abundance and high rate constants for reaction. In this study it is shown that illumination of viable, sensitizer-loaded, THP-1 (human monocyte-like) cells with visible light gives rise to intra-cellular protein-derived peroxides. The peroxide yield increases with illumination time, requires the presence of the sensitizer, is enhanced in D 2 O, and decreased by azide; these data are consistent with the mediation of singlet oxygen. The concentration of peroxides detected, which is not affected by glucose or ascorbate loading of the cells, corresponds to ca. 1.5 nmoles peroxide per 10 6 cells using rose bengal as sensitizer, or 10 nmoles per mg cell protein and account for up to ca. 15% of the O 2 consumed by the cells. Similar peroxides have been detected on isolated cellular proteins exposed to light in the presence of rose bengal and oxygen. After cessation of illumination, the cellular protein peroxide levels decreases with t 1/2 ca. 4 hrs at 37 deg C, and this is associated with increased cell lysis. Decomposition of protein peroxides formed within cells, or on isolated cellular proteins, by metal ions, gives rise to radicals as detected by EPR spin trapping. These protein peroxides, and radicals derived from them, can inactivate key cellular enzymes (including caspases, GAPDH and glutathione reductase) and induce DNA base oxidation, strand breaks and DNA-protein cross-links. These studies demonstrate that exposure of intact cells to visible light in the presence of a sensitizer gives rise to novel long-lived, but reactive, intra-cellular protein peroxides via singlet oxygen

  10. Rap1 integrates tissue polarity, lumen formation, and tumorigenicpotential in human breast epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Masahiko; Nelson, Celeste M.; Myers, Connie A.; Bissell,Mina J.

    2006-09-29

    Maintenance of apico-basal polarity in normal breast epithelial acini requires a balance between cell proliferation, cell death, and proper cell-cell and cell-extracellular matrix signaling. Aberrations in any of these processes can disrupt tissue architecture and initiate tumor formation. Here we show that the small GTPase Rap1 is a crucial element in organizing acinar structure and inducing lumen formation. Rap1 activity in malignant HMT-3522 T4-2 cells is appreciably higher than in S1 cells, their non-malignant counterparts. Expression of dominant-negative Rap1 resulted in phenotypic reversion of T4-2 cells, led to formation of acinar structures with correct apico-basal polarity, and dramatically reduced tumor incidence despite the persistence of genomic abnormalities. The resulting acini contained prominent central lumina not observed when other reverting agents were used. Conversely, expression of dominant-active Rap1 in T4-2 cells inhibited phenotypic reversion and led to increased invasiveness and tumorigenicity. Thus, Rap1 acts as a central regulator of breast architecture, with normal levels of activation instructing apical polarity during acinar morphogenesis, and increased activation inducing tumor formation and progression to malignancy.

  11. LncRNA TUG1 influences papillary thyroid cancer cell proliferation, migration and EMT formation through targeting miR-145.

    Science.gov (United States)

    Lei, Hongwei; Gao, Yan; Xu, Xiaoying

    2017-07-01

    LncRNA TUG1, a tumor oncogene associated with various human cancers, has been reported to be involved in regulating various cellular processes, such as proliferation, apoptosis and invasion through targeting multiple genes. However, its biological function in thyroid cancer cells has not been elucidated. The aim of this study is to measure TUG1 expression level and evaluate its function in thyroid cancer cells. LncRNA TUG1 expression levels in thyroid cancer tissues and three thyroid cancer cell lines (the ATC cell lines SW1736 and KAT18 and the FTC cell line FTC133) were assessed by qRT-PCR and compared with that of the human normal breast epithelial cell HGC-27. MTT assay, colony formation assay, transwell assay and western blot analysis were performed to assess the effects of TUG1 on proliferation, metastasis and EMT formation in thyroid cancer cells in vitro. Rescue assay was performed to further confirm that TUG1 contributes to the progression of thyroid cancer cells through regulating miR-145/ZEB1 signal pathway. LncRNA TUG1 was found to be up-regulated in thyroid cancer tissues and thyroid cancer cells compared with that in the human normal breast epithelial cell HGC-27. Increased lncRNA TUG1 expression was found to significantly promote tumor cell proliferation, and facilitate cell invasion, while down-regulated TUG1 could obviously inhibit cell proliferation, migration/invasion and reverse EMT to MET. These results indicated that TUG1 may contribute to the progression of thyroid cancer cells by function as a ceRNA competitive sponging miR-145, and that lncRNA TUG1 is associated with tumor progression in thyroid cancer cells. © The Author 2017. Published by Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Monte Carlo model to simulate the effects of DNA damage resulting from accumulation of 125I decays during development of colonies and clonogenic survival assays

    International Nuclear Information System (INIS)

    Lobachevsky, P.; Karagiannis, T.; Martin, R.F.

    1998-01-01

    Full text: Exposure of cultured cells to an internal source of ionising radiation, such as a radioactive isotope, differs substantially from external irradiation in the determination of delivered dose. In some cases, the radioactive isotope cannot be quickly and completely removed from cells before plating for clonogenic survival assay. This provides an additional dose of irradiation which is not easy to calculate. The contribution of this phenomenon to the cell survival is especially important if a radioactive isotope is incorporated into DNA, or a DNA-binding ligand is labelled with the isotope. The correction of the cell survival due to additional dose cannot be calculated using a simple analytical expression, since the isotope is present in the cells during colony growth. We have developed a Monte Carlo model which simulates the process of the colony growth, and takes into account the extent of damage from isotope decays accumulated between consequent cell divisions. The model considers such factors as cell cycle time, radiosensitivity, colony growth inhibition, isotope specific (per cell) activity, partition of isotope in daughter cells, isotope half-life time, isotope efflux. The model allows estimation of the impact of the irradiation during colony formation on the distribution of colony size, and on the calculation of the survival correction factor, which depends mainly on the isotope cell-specific activity. We applied the model to interpret the difference in survival of K652 cells exposed to 125 I decays with various cell-specific activities: 0.45, 3.21 and 7.42 decays/cell/hour. The cells were treated with 125 I - labelled Hoechst 33258 which binds to DNA in cell nucleus. After accumulation of 125 I decays under non-growth conditions, cells were plated for clonogenic survival assay. The survival correction factors calculated from the model for the given values of 125 I cell-specific activity are in good correlation with differences between experimental

  13. Macrophage conditioned medium induced cellular network formation in MCF-7 cells through enhanced tunneling nanotube formation and tunneling nanotube mediated release of viable cytoplasmic fragments.

    Science.gov (United States)

    Patheja, Pooja; Sahu, Khageswar

    2017-06-15

    Infiltrating macrophages in tumor microenvironment, through their secreted cytokines and growth factors, regulate several processes of cancer progression such as cancer cell survival, proliferation, invasion, metastasis and angiogenesis. Recently, intercellular cytoplasmic bridges between cancer cells referred as tunneling nanotubes (TNTs) have been recognized as novel mode of intercellular communication between cancer cells. In this study, we investigated the effect of inflammatory mediators present in conditioned medium derived from macrophages on the formation of TNTs in breast adenocarcinoma cells MCF-7. Results show that treatment with macrophage conditioned medium (MɸCM) not only enhanced TNT formation between cells but also stimulated the release of independently migrating viable cytoplasmic fragments, referred to as microplasts, from MCF-7 cells. Time lapse microscopy revealed that microplasts were released from parent cancer cells in extracellular space through formation of TNT-like structures. Mitochondria, vesicles and cytoplasm could be transferred from parent cell body to microplasts through connecting TNTs. The microplasts could also be resorbed into the parent cell body by retraction of the connecting TNTs. Microplast formation inhibited in presence cell migration inhibitor, cytochalasin-B. Notably by utilizing migratory machinery within microplasts, distantly located MCF-7 cells formed several TNT based intercellular connections, leading to formation of physically connected network of cells. Together, these results demonstrate novel role of TNTs in microplast formation, novel modes of TNT formation mediated by microplasts and stimulatory effect of MɸCM on cellular network formation in MCF-7 cells mediated through enhanced TNT and microplast formation. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Eosinophilic spleen colonies are produced in rat-marrow-transplanted but not in murine-marrow-transplanted mice

    International Nuclear Information System (INIS)

    Szabo, L.G.; Kelemen, E.

    1988-01-01

    Differential counts of about 5000 splenic clusters and colonies developing in whole-body-irradiated mice and rats were made, using semi-serial histological sections prepared 9 to 12 d after transplantation with bone marrow haemopoietic cells. The investigated mouse and rat spleens were from syngeneically, allogeneically, or xenogeneically transplanted recipients. Splenic eosinophil clusters were always found when rat eosinophil-producing progenitors were present in the inoculum, whereas murine inocula failed to produce splenic eosinophilic clusters even in the syngeneic mouse. The limiting factor in the production pf splenic eosinophilic clusters was the appropriate donor progenitor/committed stem cell itself. Changes in the percentages of eosinophil clusters with the number of injected cells and with increased doses of irradiation, as well as formation of rat eosinophil colonies in mice, as against mainly clusters in rats, themselves show that regulatory mechanisms of the recipients also play a role. These regulatory mechanisms cannot be attributed to the splenic microenvironment. (author)

  15. Human DAZL, DAZ and BOULE genes modulate primordial germ cell and haploid gamete formation

    Science.gov (United States)

    Kee, Kehkooi; Angeles, Vanessa T; Flores, Martha; Nguyen, Ha Nam; Pera, Renee A Reijo

    2009-01-01

    The leading cause of infertility in men and women is quantitative and qualitative defects in human germ cell (oocyte and sperm) development. Yet, it has not been possible to examine the unique developmental genetics of human germ cell formation and differentiation due to inaccessibility of germ cells during fetal development. Although several studies have shown that germ cells can be differentiated from mouse and human embryonic stem cells, human germ cells differentiated in these studies generally did not develop beyond the earliest stages1-8. Here we used a germ cell reporter to quantitate and isolate primordial germ cells derived from both male and female hESCs. Then, by silencing and overexpressing genes that encode germ cell-specific cytoplasmic RNA-binding proteins (not transcription factors), we modulated human germ cell formation and developmental progression. We observed that human DAZL (Deleted in AZoospermia-Like) functions in primordial germ cell formation, whereas closely-related genes, DAZ and BOULE, promote later stages of meiosis and development of haploid gametes. These results are significant to the generation of gametes for future basic science and potential clinical applications. PMID:19865085

  16. Nanoscaffold's stiffness affects primary cortical cell network formation

    NARCIS (Netherlands)

    Xie, Sijia; Schurink, Bart; Wolbers, F.; Lüttge, Regina; Hassink, Gerrit Cornelis

    2014-01-01

    Networks of neurons cultured on-chip can provide insights into both normal and disease-state brain function. The ability to guide neuronal growth in specific, artificially designed patterns allows us to study how brain function follows form. Primary cortical cells cultured on nanograting scaffolds,

  17. Nature of leukemic stem cells in murine myelogenous leukemia

    International Nuclear Information System (INIS)

    Yoshida, K.; Nemoto, K.; Nishimura, M.; Hayata, I.; Inoue, T.; Seki, M.

    1986-01-01

    We investigated the nature of myelogenous leukemic stem cells in mice. L-8057, a megakaryoblastic leukemia cell line used in this study, produces in vivo and in vitro colonies. By means of typical chromosomal aberrations in L-8057, one can conveniently detect the origin of the cells in each colony derived from a leukemic stem cell. Direct evidence of whether cells from each colony had leukemogenicity in recipient mice was successfully obtained by the colony transplantation assay. Both leukemic colony-forming unit-spleen (L-CFU-s) and leukemic colony-forming unit-culture (L-CFU-c) in L-8057 may have belonged to the same differentiating stage in the stem cells because of their similar radiosensitivity, although some parts of the L-CFU of L-8057 seemed to have lost their capability to regenerate L-CFU-s when the cells were plated in dishes. This leukemic stem cell preserves high self-renewal ability in vitro after 10 passages. In addition, in vitro colony formation by this leukemic cell during the above course of serial passages did not require any additional exogenous stimulators. The same sort of trials have been made on other types of leukemias. Leukemic stem cells showed remarkable variety in their response to stimulating factors and in their self-renewal activity, which suggests that they may have consisted of heterogeneous populations

  18. Inhibition of Blumeria graminis germination and germling development within colonies of oat mildew

    DEFF Research Database (Denmark)

    Carver, T.L.W.; Roberts, P.C.; Thomas, B.J.

    2001-01-01

    Germination by Blumeria graminis. DC Speer ff. spp. avenae, hordei and tritici, was greatly suppressed when conidia fell within colonies of ff. spp. avenae or hordei established on susceptible oat or barley, respectively. On healthy oat or barley, and when distant from powdery mildew, colonies. all...... ff. spp. formed normal appressoria. This was also true When conidia germinated within established barley mildew colonies. Within barley mildew colonies, appressoria of f. sp. hordei penetrated epidermal cells formed haustoria more frequently than appressoria distant from colonies. Similarly, ff. spp....... avenae and tritici, normally unable to infect barley. frequently penetrated epidermal cells subtending established barley mildew colonies. Thus, colony, establishment induced barley epidermal cell accessibility, even to non-pathogenic ff. spp, In contrast. when all three ff. spp. germinated within...

  19. Number and proliferative capacity of osteogenic stem cells are maintained during aging and in patients with osteoporosis

    DEFF Research Database (Denmark)

    Stenderup, Karin; Justesen, J.; Eriksen, E.F.

    2001-01-01

    Decreased bone formation is an important pathophysiological mechanism responsible for bone loss associated with aging and osteoporosis. Osteoblasts (OBs), originate from mesenchymal stem cells (MSCs) that are present in the bone marrow and form colonies (termed colony-forming units-fibroblastic [...

  20. Complement Activation Induces Neutrophil Adhesion and Neutrophil-Platelet Aggregate Formation on Vascular Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Magdalena Riedl

    2017-01-01

    Discussion: Therefore, our findings of (i neutrophils adhering to complement-activated endothelial cells, (ii the formation of neutrophil-platelet aggregates on endothelial cells, and (iii the ability of aHUS serum to induce similar effects identify a possible role for neutrophils in aHUS manifestation.

  1. Formation of newly synthesized adeno-associated virus capsids in the cell nucleus.

    Science.gov (United States)

    Bell, Peter; Vandenberghe, Luk H; Wilson, James M

    2014-06-01

    Adeno-associated virus (AAV) particles inside the nucleus of a HEK 293 cell are shown by electron microscopy. Cells have been triple-transfected for vector production and were analyzed for capsid formation three days later. Newly assembled particle are visible as seemingly unstructured conglomerates or crystal-like arrays.

  2. Hard tissue formation of STRO-1-selected rat dental pulp stem cells in vivo.

    NARCIS (Netherlands)

    Yang, X.; Walboomers, X.F.; Beucken, J.J.J.P van den; Bian, Z.; Fan, M.; Jansen, J.A.

    2009-01-01

    The objective of this study was to examine hard tissue formation of STRO-1-selected rat dental pulp-derived stem cells, seeded into a calcium phosphate ceramic scaffold, and implanted subcutaneously in mice. Previously, STRO-1 selection was used to obtain a mesenchymal stem cell progenitor

  3. Arabidopsis R-SNARE proteins VAMP721 and VAMP722 are required for cell plate formation.

    Directory of Open Access Journals (Sweden)

    Liang Zhang

    Full Text Available BACKGROUND: Cell plate formation during plant cytokinesis is facilitated by SNARE complex-mediated vesicle fusion at the cell-division plane. However, our knowledge regarding R-SNARE components of membrane fusion machinery for cell plate formation remains quite limited. METHODOLOGY/PRINCIPAL FINDINGS: We report the in vivo function of Arabidopsis VAMP721 and VAMP722, two closely sequence-related R-SNAREs, in cell plate formation. Double homozygous vamp721vamp722 mutant seedlings showed lethal dwarf phenotypes and were characterized by rudimentary roots, cotyledons and hypocotyls. Furthermore, cell wall stubs and incomplete cytokinesis were frequently observed in vamp721vamp722 seedlings. Confocal images revealed that green fluorescent protein-tagged VAMP721 and VAMP722 were preferentially localized to the expanding cell plates in dividing cells. Drug treatments and co-localization analyses demonstrated that punctuate organelles labeled with VAMP721 and VAMP722 represented early endosomes overlapped with VHA-a1-labeled TGN, which were distinct from Golgi stacks and prevacuolar compartments. In addition, protein traffic to the plasma membrane, but not to the vacuole, was severely disrupted in vamp721vamp722 seedlings by subcellular localization of marker proteins. CONCLUSION/SIGNIFICANCE: These observations suggest that VAMP721 and VAMP722 are involved in secretory trafficking to the plasma membrane via TGN/early endosomal compartment, which contributes substantially to cell plate formation during plant cytokinesis.

  4. De novo formation of centrosomes in vertebrate cells arrested during S phase

    NARCIS (Netherlands)

    Khodjakov, A; Rieder, CL; Sluder, G; Cassels, G; Sibon, O; Wang, CL

    2002-01-01

    The centrosome usually replicates in a semiconservative fashion, i.e., new centrioles form in association with preexisting "maternal" centrioles. De novo formation of centrioles has been reported for a few highly specialized cell types but it has not been seen in vertebrate somatic cells. We find

  5. Fibroblast Cluster Formation on 3D Collagen Matrices Requires Cell Contraction-Dependent Fibronectin Matrix Organization

    Science.gov (United States)

    da Rocha-Azevedo, Bruno; Ho, Chin-Han; Grinnell, Frederick

    2012-01-01

    Fibroblasts incubated on 3D collagen matrices in serum or lysophosphatidic acid (LPA)-containing medium self-organize into clusters through a mechanism that requires cell contraction. However, in platelet-derived growth factor (PDGF)-containing medium, cells migrate as individuals and do not form clusters even though they constantly encounter each other. Here, we present evidence that a required function of cell contraction in clustering is formation of fibronectin fibrillar matrix. We found that in serum or LPA but not in PDGF or basal medium, cells organized FN (both serum and cellular) into a fibrillar, detergent-insoluble matrix. Cell clusters developed concomitant with FN matrix formation. FN fibrils accumulated beneath cells and along the borders of cell clusters in regions of cell-matrix tension. Blocking Rho kinase or myosin II activity prevented FN matrix assembly and cell clustering. Using siRNA silencing and function-blocking antibodies and peptides, we found that cell clustering and FN matrix assembly required α5β1 integrins and fibronectin. Cells were still able to exert contractile force and compact the collagen matrix under the latter conditions, which showed that contraction was not sufficient for cell clustering to occur. Our findings provide new insights into how procontractile (serum/LPA) and promigratory (PDGF) growth factor environments can differentially regulate FN matrix assembly by fibroblasts interacting with collagen matrices and thereby influence mesenchymal cell morphogenetic behavior under physiologic circumstances such as wound repair, morphogenesis and malignancy. PMID:23117111

  6. Fibroblast cluster formation on 3D collagen matrices requires cell contraction dependent fibronectin matrix organization.

    Science.gov (United States)

    da Rocha-Azevedo, Bruno; Ho, Chin-Han; Grinnell, Frederick

    2013-02-15

    Fibroblasts incubated on 3D collagen matrices in serum or lysophosphatidic acid (LPA)-containing medium self-organize into clusters through a mechanism that requires cell contraction. However, in platelet-derived growth factor (PDGF)-containing medium, cells migrate as individuals and do not form clusters even though they constantly encounter each other. Here, we present evidence that a required function of cell contraction in clustering is formation of fibronectin (FN) fibrillar matrix. We found that in serum or LPA but not in PDGF or basal medium, cells organized FN (both serum and cellular) into a fibrillar, detergent-insoluble matrix. Cell clusters developed concomitant with FN matrix formation. FN fibrils accumulated beneath cells and along the borders of cell clusters in regions of cell-matrix tension. Blocking Rho kinase or myosin II activity prevented FN matrix assembly and cell clustering. Using siRNA silencing and function-blocking antibodies and peptides, we found that cell clustering and FN matrix assembly required α5β1 integrins and fibronectin. Cells were still able to exert contractile force and compact the collagen matrix under the latter conditions, which showed that contraction was not sufficient for cell clustering to occur. Our findings provide new insights into how procontractile (serum/LPA) and promigratory (PDGF) growth factor environments can differentially regulate FN matrix assembly by fibroblasts interacting with collagen matrices and thereby influence mesenchymal cell morphogenetic behavior under physiologic circumstances such as wound repair, morphogenesis and malignancy. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Spatial Arrangement of Colonies in Intact Biofilms from a Model Cooling Water System

    Directory of Open Access Journals (Sweden)

    Michael Taylor

    2013-01-01

    Full Text Available There is disagreement among microbiologists about whether Legionella requires a protozoan host in order to replicate. This research sought to determine where in biofilm Legionellae are found and whether all biofilm associated Legionella would be located within protozoan hosts. While it is accepted that Legionella colonizes biofilm, its life cycle and nutritional fastidiousness suggest that Legionella employs multiple survival strategies to persist within microbial systems. Fluorescent in situ hybridization (FISH and confocal laser scanning microscopy (CLSM demonstrated an undulating biofilm surface architecture and a roughly homogenous distribution of heterotrophic bacteria with clusters of protozoa. Legionella displayed 3 distinct spatial arrangements either contained within or directly associated with protozoa, or dispersed in loosely associated clusters or in tightly packed aggregations of cells forming dense colonial clusters. The formation of discreet clusters of tightly packed Legionella suggests that colony formation is influenced by specific environmental conditions allowing for limited extracellular replication. This work represents the first time that an environmentally representative, multispecies biofilm containing Legionella has been fluorescently tagged and Legionella colony morphology noted within a complex microbial system.

  8. Neuropeptide substance P stimulates the formation of osteoclasts via synovial fibroblastic cells

    International Nuclear Information System (INIS)

    Matayoshi, Takaaki; Goto, Tetsuya; Fukuhara, Eiji; Takano, Hiroshi; Kobayashi, Shigeru; Takahashi, Tetsu

    2005-01-01

    The present study was designed to evaluate the effects of neuropeptide substance P (Sp) on the formation of osteoclasts via synovial fibroblastic cells. Synovial fibroblastic cells derived from rat knee joint expressed the Sp receptor, neurokinin-1 receptor (NK 1 -R). The addition of Sp stimulated the proliferation of synovial fibroblastic cells and this effect was inhibited by Sp or NK 1 -R antagonists. Increased expression of the receptor activator of nuclear factor κB ligand (Rankle) in synovial fibroblastic cells after the addition of Sp was demonstrated by reverse transcriptase-polymerase chain reaction and immunofluorescence staining. Osteoprotegerin expression in synovial fibroblastic cells was decreased after incubation with SP. In co-cultures of synovial fibroblastic cells and rat peripheral blood monocytes, SP stimulated osteoclastogenesis. These results suggest that SP in the joint cavity may cause both hypertrophy of the synovium and induction of increased osteoclast formation through the increased expression of RANKL in the synovium

  9. Statistical analysis of clone formation in cultures of human stem cells.

    Science.gov (United States)

    Bochkov, N P; Vinogradova, M S; Volkov, I K; Voronina, E S; Kuleshov, N P

    2011-08-01

    We performed a statistical analysis of clone formation from aneuploid cells (chromosomes 6, 8, 11, X) in cultures of bone marrow-derived human multipotent mesenchymal stromal cells by spontaneous level of aneuploidy at different terms of culturing (from 2 to 19 cell cycles). It was found that the duration of cell cycle increased from 65.6 h at passages 2-3 to 164.5 h at passage 12. The expected ratio of aneuploid cells was calculated using modeled 5, 10, 20 and 30% selective preference in reproduction. The size of samples for detecting 10, 25, and 50% increased level of aneuploidy was calculated. The presented principles for evaluation of aneuploid clone formation may be used to distinguish clones of any abnormal cells.

  10. Centriole triplet microtubules are required for stable centriole formation and inheritance in human cells

    Science.gov (United States)

    Wang, Jennifer T; Kong, Dong; Hoerner, Christian R; Loncarek, Jadranka

    2017-01-01

    Centrioles are composed of long-lived microtubules arranged in nine triplets. However, the contribution of triplet microtubules to mammalian centriole formation and stability is unknown. Little is known of the mechanism of triplet microtubule formation, but experiments in unicellular eukaryotes indicate that delta-tubulin and epsilon-tubulin, two less-studied tubulin family members, are required. Here, we report that centrioles in delta-tubulin and epsilon-tubulin null mutant human cells lack triplet microtubules and fail to undergo centriole maturation. These aberrant centrioles are formed de novo each cell cycle, but are unstable and do not persist to the next cell cycle, leading to a futile cycle of centriole formation and disintegration. Disintegration can be suppressed by paclitaxel treatment. Delta-tubulin and epsilon-tubulin physically interact, indicating that these tubulins act together to maintain triplet microtubules and that these are necessary for inheritance of centrioles from one cell cycle to the next. PMID:28906251

  11. Centriole triplet microtubules are required for stable centriole formation and inheritance in human cells.

    Science.gov (United States)

    Wang, Jennifer T; Kong, Dong; Hoerner, Christian R; Loncarek, Jadranka; Stearns, Tim

    2017-09-14

    Centrioles are composed of long-lived microtubules arranged in nine triplets. However, the contribution of triplet microtubules to mammalian centriole formation and stability is unknown. Little is known of the mechanism of triplet microtubule formation, but experiments in unicellular eukaryotes indicate that delta-tubulin and epsilon-tubulin, two less-studied tubulin family members, are required. Here, we report that centrioles in delta-tubulin and epsilon-tubulin null mutant human cells lack triplet microtubules and fail to undergo centriole maturation. These aberrant centrioles are formed de novo each cell cycle, but are unstable and do not persist to the next cell cycle, leading to a futile cycle of centriole formation and disintegration. Disintegration can be suppressed by paclitaxel treatment. Delta-tubulin and epsilon-tubulin physically interact, indicating that these tubulins act together to maintain triplet microtubules and that these are necessary for inheritance of centrioles from one cell cycle to the next.

  12. Cell wall changes during the formation of aerenchyma in sugarcane roots.

    Science.gov (United States)

    Leite, D C C; Grandis, A; Tavares, E Q P; Piovezani, A R; Pattathil, S; Avci, U; Rossini, A; Cambler, A; De Souza, A P; Hahn, M G; Buckeridge, M S

    2017-11-10

    Aerenchyma develops in different plant organs and leads to the formation of intercellular spaces that can be used by the plant to transport volatile substances. Little is known about the role of cell walls in this process, although the mechanism of aerenchyma formation is known to involve programmed cell death and some cell wall modifications. We assessed the role that cell wall-related mechanisms might play in the formation of aerenchyma in sugarcane roots. Sections of roots (5 cm) were subjected to microtomography analysis. These roots were divided into 1-cm segments and subjected to cell wall fractionation. We performed analyses of monosaccharides, oligosaccharides and lignin and glycome profiling. Sections were visualized by immunofluorescence and immunogold labelling using selected monoclonal antibodies against polysaccharide epitopes according to the glycome profiles. During aerenchyma formation, gas spaces occupied up to 40 % of the cortex cross-section within the first 5 cm of the root. As some of the cortex cells underwent dissolution of the middle lamellae, leading to cell separation, cell expansion took place along with cell death. Mixed-linkage β-glucan was degraded along with some homogalacturonan and galactan, culminating in the formation of cell wall composites made of xyloglucan, arabinoxylans, cellulose and possibly lignin. The composites formed seem to play a role in the physical-chemical properties of the gas chambers, providing mechanical resistance to forces acting upon the root and at the same time decreasing permeability to gases. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  13. Methods for studying biofilm formation: flow cells and confocal laser scanning microscopy

    DEFF Research Database (Denmark)

    Tolker-Nielsen, Tim; Sternberg, Claus

    2014-01-01

    In this chapter methods for growing and analyzing biofilms under hydrodynamic conditions in flow cells are described. Use of flow cells allows for direct microscopic investigation of biofilm formation. The flow in these chambers is essentially laminar, which means that the biofilms can be grown u......, inoculation of the flow cells, running of the system, confocal laser scanning microscopy and image analysis, and disassembly and cleaning of the system....

  14. Statistical Characterization of 18650-Format Lithium-Ion Cell Thermal Runaway Energy Distributions

    Science.gov (United States)

    Walker, William Q.; Rickman, Steven; Darst, John; Finegan, Donal; Bayles, Gary; Darcy, Eric

    2017-01-01

    Effective thermal management systems, designed to handle the impacts of thermal runaway (TR) and to prevent cell-to-cell propagation, are key to safe operation of lithium-ion (Li-ion) battery assemblies. Critical factors for optimizing these systems include the total energy released during a single cell TR event and the fraction of the total energy that is released through the cell casing vs. through the ejecta material. A unique calorimeter was utilized to examine the TR behavior of a statistically significant number of 18650-format Li-ion cells with varying manufacturers, chemistries, and capacities. The calorimeter was designed to contain the TR energy in a format conducive to discerning the fractions of energy released through the cell casing vs. through the ejecta material. Other benefits of this calorimeter included the ability to rapidly test of large quantities of cells and the intentional minimization of secondary combustion effects. High energy (270 Wh/kg) and moderate energy (200 Wh/kg) 18650 cells were tested. Some of the cells had an imbedded short circuit (ISC) device installed to aid in the examination of TR mechanisms under more realistic conditions. Other variations included cells with bottom vent (BV) features and cells with thin casings (0.22 1/4m). After combining the data gathered with the calorimeter, a statistical approach was used to examine the probability of certain TR behavior, and the associated energy distributions, as a function of capacity, venting features, cell casing thickness and temperature.

  15. Cellular metabolic responses of the marine diatom Pseudo-nitzschia multiseries associated with cell wall formation.

    Science.gov (United States)

    Xu, Bin; Luo, Chun-Shan; Liang, Jun-Rong; Chen, Dan-Dan; Zhuo, Wen-Hao; Gao, Ya-Hui; Chen, Chang-Ping; Song, Si-Si

    2014-08-01

    In this study a comparative proteomics approach involving a mass spectrometric analysis of synchronized cells was employed to investigate the cellular-level metabolic mechanisms associated with siliceous cell wall formation in the pennate diatom Pseudo-nitzschia multiseries. Cultures of P. multiseries were synchronized using the silicate limitation method. Approximately 75% of cells were arrested at the G2+M phase of the cell cycle after 48 h of silicate starvation. The majority of cells progressed to new valve synthesis within 5h of silicon replenishment. We compared the proteome of P. multiseries at 0, 4, 5, and 6h of synchronization progress upon silicon replenishment using two-dimensional gel electrophoresis. Forty-eight differentially expressed protein spots were identified in abundance (greater than two-fold change; Pwall formation. The proteomic profile analysis suggests that P. multiseries most likely employs multiple synergistic biochemical mechanisms for cell wall formation. These results improve our understanding of the molecular mechanisms underlying silicon cell wall formation and enhance our understanding of the important role played by diatoms in silicon biogeochemical cycling. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. The MP65 gene is required for cell wall integrity, adherence to epithelial cells and biofilm formation in Candida albicans

    Directory of Open Access Journals (Sweden)

    Girolamo Antonietta

    2011-05-01

    Full Text Available Abstract Background The MP65 gene of Candida albicans (orf19.1779 encodes a putative β-glucanase mannoprotein of 65 kDa, which plays a main role in a host-fungus relationship, morphogenesis and pathogenicity. In this study, we performed an extensive analysis of a mp65Δ mutant to assess the role of this protein in cell wall integrity, adherence to epithelial cells and biofilm formation. Results The mp65Δ mutant showed a high sensitivity to a range of cell wall-perturbing and degrading agents, especially Congo red, which induced morphological changes such as swelling, clumping and formation of hyphae. The mp65Δ mutant showed an activation of two MAPKs (Mkc1p and Cek1p, a high level of expression of two stress-related genes (DDR48 and SOD5, and a modulated expression of β-glucan epitopes, but no gross changes in cell wall polysaccharide composition. Interestingly, the mp65Δ mutant displayed a marked reduction in adhesion to BEC and Caco-2 cells and severe defects in biofilm formation when compared to the wild type. All of the mentioned properties were totally or partially recovered in a revertant strain, demonstrating the specificity of gene deletion. Conclusions We demonstrate that the MP65 gene of Candida albicans plays a significant role in maintaining cell wall integrity, as well as in adherence to epithelia and biofilm formation, which are major virulence attributes of this fungus.

  17. HOXB4 Promotes Hemogenic Endothelium Formation without Perturbing Endothelial Cell Development

    Directory of Open Access Journals (Sweden)

    Nadine Teichweyde

    2018-03-01

    Full Text Available Summary: Generation of hematopoietic stem cells (HSCs from pluripotent stem cells, in vitro, holds great promise for regenerative therapies. Primarily, this has been achieved in mouse cells by overexpression of the homeotic selector protein HOXB4. The exact cellular stage at which HOXB4 promotes hematopoietic development, in vitro, is not yet known. However, its identification is a prerequisite to unambiguously identify the molecular circuits controlling hematopoiesis, since the activity of HOX proteins is highly cell and context dependent. To identify that stage, we retrovirally expressed HOXB4 in differentiating mouse embryonic stem cells (ESCs. Through the use of Runx1(−/− ESCs containing a doxycycline-inducible Runx1 coding sequence, we uncovered that HOXB4 promoted the formation of hemogenic endothelium cells without altering endothelial cell development. Whole-transcriptome analysis revealed that its expression mediated the upregulation of transcription of core transcription factors necessary for hematopoiesis, culminating in the formation of blood progenitors upon initiation of Runx1 expression. : In this article, Klump and colleagues demonstrate that the human homeotic selector protein HOXB4 promotes ESC-derived hematopoiesis by inducing hemogenic endothelium formation, in vitro. It propels hematopoietic specification by upregulating the transcription of genes essential for hematopoietic development, such as those encoding members of the so-called heptad transcription factors. Keywords: HOXB4, hematopoietic stem cells, hemangioblast, hemogenic endothelium, hematopoietic specification, EHT, RUNX1, pluripotent stem cells

  18. Collective motion of cells mediates segregation and pattern formation in co-cultures.

    Directory of Open Access Journals (Sweden)

    Elod Méhes

    Full Text Available Pattern formation by segregation of cell types is an important process during embryonic development. We show that an experimentally yet unexplored mechanism based on collective motility of segregating cells enhances the effects of known pattern formation mechanisms such as differential adhesion, mechanochemical interactions or cell migration directed by morphogens. To study in vitro cell segregation we use time-lapse videomicroscopy and quantitative analysis of the main features of the motion of individual cells or groups. Our observations have been extensive, typically involving the investigation of the development of patterns containing up to 200,000 cells. By either comparing keratocyte types with different collective motility characteristics or increasing cells' directional persistence by the inhibition of Rac1 GTP-ase we demonstrate that enhanced collective cell motility results in faster cell segregation leading to the formation of more extensive patterns. The growth of the characteristic scale of patterns generally follows an algebraic scaling law with exponent values up to 0.74 in the presence of collective motion, compared to significantly smaller exponents in case of diffusive motion.

  19. Troglitazone induced apoptosis via PPARγ activated POX-induced ROS formation in HT29 cells.

    Science.gov (United States)

    Wang, Jing; Lv, XiaoWen; Shi, JiePing; Hu, XiaoSong; DU, YuGuo

    2011-08-01

    In order to investigate the potential mechanisms in troglitazone-induced apoptosis in HT29 cells, the effects of PPARγ and POX-induced ROS were explored. [3- (4, 5)-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay, Annexin V and PI staining using FACS, plasmid transfection, ROS formation detected by DCFH staining, RNA interference, RT-PCR & RT-QPCR, and Western blotting analyses were employed to investigate the apoptotic effect of troglitazone and the potential role of PPARγ pathway and POX-induced ROS formation in HT29 cells. Troglitazone was found to inhibit the growth of HT29 cells by induction of apoptosis. During this process, mitochondria related pathways including ROS formation, POX expression and cytochrome c release increased, which were inhibited by pretreatment with GW9662, a specific antagonist of PPARγ. These results illustrated that POX upregulation and ROS formation in apoptosis induced by troglitazone was modulated in PPARγ-dependent pattern. Furthermore, the inhibition of ROS and apoptosis after POX siRNA used in troglitazone-treated HT29 cells indicated that POX be essential in the ROS formation and PPARγ-dependent apoptosis induced by troglitazone. The findings from this study showed that troglitazone-induced apoptosis was mediated by POX-induced ROS formation, at least partly, via PPARγ activation. Copyright © 2011 The Editorial Board of Biomedical and Environmental Sciences. Published by Elsevier B.V. All rights reserved.

  20. Febrile Neutropenia Risk Assessment and Granulocyte-Colony Stimulating Factor Support in Patients with Diffuse Large B Cell Lymphoma Receiving R-CHOP Regimens

    DEFF Research Database (Denmark)

    Salar, Antonio; Haioun, Corinne; Rossi, Francesca Gaia

    2009-01-01

    BACKGROUND: ASCO and EORTC guidelines recommend granulocyte colony-stimulating factor (G-CSF) primary prophylaxis for cancer patients with a ≥20% overall risk of febrile neutropenia (FN), and to support delivery of dose-dense regimens. CHOP-like regimens (with rituximab [R]) are the current...... standard of care for the management of aggressive non-Hodgkin lymphoma (NHL), but they are often associated with significant myelosuppression. Neutropenic events, particularly febrile neutropenia (FN), can be life-threatening and may lead to dose delays or reductions that compromise the efficacy......-CSF primary prophylaxis. Across all cycles, 29% of R-CHOP-21 patients had an unplanned hospitalization, with neutropenia/FN being the main reason. Subsequently, 67% of patients achieved a relative dose intensity (RDI) of ≥90% of their planned treatment (with respect to cyclophosphamide, doxorubicin...

  1. Artificial induction of Sox21 regulates sensory cell formation in the embryonic chicken inner ear.

    Directory of Open Access Journals (Sweden)

    Stephen D Freeman

    Full Text Available During embryonic development, hair cells and support cells in the sensory epithelia of the inner ear derive from progenitors that express Sox2, a member of the SoxB1 family of transcription factors. Sox2 is essential for sensory specification, but high levels of Sox2 expression appear to inhibit hair cell differentiation, suggesting that factors regulating Sox2 activity could be critical for both processes. Antagonistic interactions between SoxB1 and SoxB2 factors are known to regulate cell differentiation in neural tissue, which led us to investigate the potential roles of the SoxB2 member Sox21 during chicken inner ear development. Sox21 is normally expressed by sensory progenitors within vestibular and auditory regions of the early embryonic chicken inner ear. At later stages, Sox21 is differentially expressed in the vestibular and auditory organs. Sox21 is restricted to the support cell layer of the auditory epithelium, while it is enriched in the hair cell layer of the vestibular organs. To test Sox21 function, we used two temporally distinct gain-of-function approaches. Sustained over-expression of Sox21 from early developmental stages prevented prosensory specification, and abolished the formation of both hair cells and support cells. However, later induction of Sox21 expression at the time of hair cell formation in organotypic cultures of vestibular epithelia inhibited endogenous Sox2 expression and Notch activity, and biased progenitor cells towards a hair cell fate. Interestingly, Sox21 did not promote hair cell differentiation in the immature auditory epithelium, which fits with the expression of endogenous Sox21 within mature support cells in this tissue. These results suggest that interactions among endogenous SoxB family transcription factors may regulate sensory cell formation in the inner ear, but in a context-dependent manner.

  2. The inhibition of macrophage foam cell formation by tetrahydroxystilbene glucoside is driven by suppressing vimentin cytoskeleton.

    Science.gov (United States)

    Yao, Wenjuan; Huang, Lei; Sun, Qinju; Yang, Lifeng; Tang, Lian; Meng, Guoliang; Xu, Xiaole; Zhang, Wei

    2016-10-01

    Macrophage foam cell formation triggered by oxLDL is an important event that occurs during the development of atherosclerosis. 2,3,5,4'-Tetrahydroxystilbene-2-O-β-d-glucoside (TSG) exhibits significant anti-atherosclerotic activity. Herein we used U937 cells induced by PMA and oxLDL in vitro to investigate the inhibitory effects of TSG on U937 differentiation and macrophage foam cell formation. TSG pretreatment markedly inhibited cell differentiation induced by PMA, macrophage apoptosis and foam cell formation induced by oxLDL. The inhibition of vimentin expression and cleavage was involved in these inhibitory effects of TSG. The suppression of vimentin by siRNA in U937 significantly inhibited cell differentiation, apoptosis and foam cell formation. Using inhibitors for TGFβR1 and PI3K, we found that vimentin production in U937 cells is regulated by TGFβ/Smad signaling, but not by PI3K-Akt-mTOR signaling. Meanwhile, TSG pretreatment inhibited both the expression of TGFβ1 and the phosphorylation of Smad2 and Smad3, and TSG suppressed the nuclear translocation of Smad4 induced by PMA and oxLDL. Furthermore, TSG attenuated the induced caspase-3 activation and adhesion molecules levels by PMA and oxLDL. PMA and oxLDL increased the co-localization of vimentin with ICAM-1, which was attenuated by pretreatment with TSG. These results suggest that TSG inhibits macrophage foam cell formation through suppressing vimentin expression and cleavage, adhesion molecules expression and vimentin-ICAM-1 co-localization. The interruption of TGFβ/Smad pathway and caspase-3 activation is responsible for the downregulation of TSG on vimentin expression and degradation, respectively. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  3. Pectinous cell wall thickenings formation - A common defense strategy of plants to cope with Pb.

    Science.gov (United States)

    Krzesłowska, Magdalena; Rabęda, Irena; Basińska, Aneta; Lewandowski, Michał; Mellerowicz, Ewa J; Napieralska, Anna; Samardakiewicz, Sławomir; Woźny, Adam

    2016-07-01

    Lead, one of the most abundant and hazardous trace metals affecting living organisms, has been commonly detected in plant cell walls including some tolerant plants, mining ecotypes and hyperaccumulators. We have previously shown that in tip growing Funaria sp. protonemata cell wall is remodeled in response to lead by formation of thickenings rich in low-methylesterified pectins (pectin epitope JIM5 - JIM5-P) able to bind metal ions, which accumulate large amounts of Pb. Hence, it leads to the increase of cell wall capacity for Pb compartmentalization. Here we show that diverse plant species belonging to different phyla (Arabidopsis, hybrid aspen, star duckweed), form similar cell wall thickenings in response to Pb. These thickenings are formed in tip growing cells such as the root hairs, and in diffuse growing cells such as meristematic and root cap columella cells of root apices in hybrid aspen and Arabidopsis and in mesophyll cells in star duckweed fronds. Notably, all analyzed cell wall thickenings were abundant in JIM5-P and accumulated high amounts of Pb. In addition, the co-localization of JIM5-P and Pb commonly occurred in these cells. Hence, cell wall thickenings formed the extra compartment for Pb accumulation. In this way plant cells increased cell wall capacity for compartmentalization of this toxic metal, protecting protoplast from its toxicity. As cell wall thickenings occurred in diverse plant species and cell types differing in the type of growth we may conclude that pectinous cell wall thickenings formation is a widespread defense strategy of plants to cope with Pb. Moreover, detection of natural defense strategy, increasing plant cell walls capacity for metal accumulation, reveals a promising direction for enhancing plant efficiency in phytoremediation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Different Effects of BORIS/CTCFL on Stemness Gene Expression, Sphere Formation and Cell Survival in Epithelial Cancer Stem Cells.

    Directory of Open Access Journals (Sweden)

    Loredana Alberti

    Full Text Available Cancer stem cells are cancer cells characterized by stem cell properties and represent a small population of tumor cells that drives tumor development, progression, metastasis and drug resistance. To date, the molecular mechanisms that generate and regulate cancer stem cells are not well defined. BORIS (Brother of Regulator of Imprinted Sites or CTCFL (CTCF-like is a DNA-binding protein that is expressed in normal tissues only in germ cells and is re-activated in tumors. Recent evidences have highlighted the correlation of BORIS/CTCFL expression with poor overall survival of different cancer patients. We have previously shown an association of BORIS-expressing cells with stemness gene expression in embryonic cancer cells. Here, we studied the role of BORIS in epithelial tumor cells. Using BORIS-molecular beacon that was already validated, we were able to show the presence of BORIS mRNA in cancer stem cell-enriched populations (side population and spheres of cervical, colon and breast tumor cells. BORIS silencing studies showed a decrease of sphere formation capacity in breast and colon tumor cells. Importantly, BORIS-silencing led to down-regulation of hTERT, stem cell (NANOG, OCT4, SOX2 and BMI1 and cancer stem cell markers (ABCG2, CD44 and ALDH1 genes. Conversely, BORIS-induction led to up-regulation of the same genes. These phenotypes were observed in cervical, colon and invasive breast tumor cells. However, a completely different behavior was observed in the non-invasive breast tumor cells (MCF7. Indeed, these cells acquired an epithelial mesenchymal transition phenotype after BORIS silencing. Our results demonstrate that BORIS is associated with cancer stem cell-enriched populations of several epithelial tumor cells and the different phenotypes depend on the origin of tumor cells.

  5. Bmi1 overexpression in the cerebellar granule cell lineage of mice affects cell proliferation and survival without initiating medulloblastoma formation

    Directory of Open Access Journals (Sweden)

    Hourinaz Behesti

    2013-01-01

    BMI1 is a potent inducer of neural stem cell self-renewal and neural progenitor cell proliferation during development and in adult tissue homeostasis. It is overexpressed in numerous human cancers – including medulloblastomas, in which its functional role is unclear. We generated transgenic mouse lines with targeted overexpression of Bmi1 in the cerebellar granule cell lineage, a cell type that has been shown to act as a cell of origin for medulloblastomas. Overexpression of Bmi1 in granule cell progenitors (GCPs led to a decrease in cerebellar size due to decreased GCP proliferation and repression of the expression of cyclin genes, whereas Bmi1 overexpression in postmitotic granule cells improved cell survival in response to stress by altering the expression of genes in the mitochondrial cell death pathway and of Myc and Lef-1. Although no medulloblastomas developed in ageing cohorts of transgenic mice, crosses with Trp53−/− mice resulted in a low incidence of medulloblastoma formation. Furthermore, analysis of a large collection of primary human medulloblastomas revealed that tumours with a BMI1high TP53low molecular profile are significantly enriched in Group 4 human medulloblastomas. Our data suggest that different levels and timing of Bmi1 overexpression yield distinct cellular outcomes within the same cellular lineage. Importantly, Bmi1 overexpression at the GCP stage does not induce tumour formation, suggesting that BMI1 overexpression in GCP-derived human medulloblastomas probably occurs during later stages of oncogenesis and might serve to enhance tumour cell survival.

  6. Streptococcus sanguinis induces foam cell formation and cell death of macrophages in association with production of reactive oxygen species.

    Science.gov (United States)

    Okahashi, Nobuo; Okinaga, Toshinori; Sakurai, Atsuo; Terao, Yutaka; Nakata, Masanobu; Nakashima, Keisuke; Shintani, Seikou; Kawabata, Shigetada; Ooshima, Takashi; Nishihara, Tatsuji

    2011-10-01

    Streptococcus sanguinis, a normal inhabitant of the human oral cavity, is a common streptococcal species implicated in infective endocarditis. Herein, we investigated the effects of infection with S. sanguinis on foam cell formation and cell death of macrophages. Infection with S. sanguinis stimulated foam cell formation of THP-1, a human macrophage cell line. At a multiplicity of infection >100, S. sanguinis-induced cell death of the macrophages. Viable bacterial infection was required to trigger cell death because heat-inactivated S. sanguinis did not induce cell death. The production of cytokines interleukin-1β and tumor necrosis factor-α from macrophages was also stimulated during bacterial infection. Inhibition of the production of reactive oxygen species (ROS) resulted in reduced cell death, suggesting an association of ROS with cell death. Furthermore, S. sanguinis-induced cell death appeared to be independent of activation of inflammasomes, because cleavage of procaspase-1 was not evident in infected macrophages. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  7. Influence of patterned topographic features on the formation of cardiac cell clusters and their rhythmic activities

    International Nuclear Information System (INIS)

    Wang, L; Liu, L; Magome, N; Agladze, K; Chen, Y

    2013-01-01

    In conventional primary cultures, cardiac cells prepared from a newborn rat undergo spontaneous formation of cell clusters after several days. These cell clusters may be non-homogeneously distributed on a flat surface and show irregular beating which can be recorded by calcium ion imaging. In order to improve the cell cluster homogeneity and the beating regularity, patterned topographic features were used to guide the cellular growth and the cell layer formation. On the substrate with an array of broadly spaced cross features made of photoresist, cells grew on the places that were not occupied by the crosses and thus formed a cell layer with interconnected cell clusters. Accordingly, spatially coordinated regular beating could be recorded over the whole patterned area. In contrast, when cultured on the substrate with broadly spaced but inter-connected cross features, the cardiac cell layer showed beatings which were neither coordinated in space nor regular in time. Finally, when cultured on the substrate with narrowly spaced features, the cell beating became spatially coordinated but still remained irregular. Our results suggest a way to improve the rhythmic property of cultured cardiac cell layers which might be useful for further investigations. (paper)

  8. Colony-stimulating factor (CSF) radioimmunoassay: detection of a CSF subclass stimulating macrophage production

    International Nuclear Information System (INIS)

    Stanley, E.R.

    1979-01-01

    Colony-stimulating factors (CSFs) stimulate the differentiation of immature precursor cells to mature granulocytes and macrophages. Purified 125 I-labeled murine L cell CSF has been used to develop a radioimmunoassay (RIA) that detects a subclass of CSFs that stimulates macrophage production. Murine CSF preparations that contain this subclass of CSF compete for all of the CSF binding sites on anti-L cell CSF antibody. With the exception of mouse serum, which can contain inhibitors of the bioassay, there is complete correspondence between activities determined by RIA and those determined by bioassay. The RIA is slightly more sensitive than the bioassay, detecting approximately 0.3 fmol of purified L cell CSF. It can also detect this subclass of CSF in chickens, rats, and humans. In the mouse, the subclass is distinguished from other CSFs by a murine cell bioassay dose-response curve in which 90% of the response occurs over a 10-fold (rather than a 100-fold) increase in concentration, by stimulating the formations of colonies contaning a high proportion of mononuclear (rather than granulocytic) cells, and by certain physical characteristics

  9. The adaptor molecule SAP plays essential roles during invariant NKT cell cytotoxicity and lytic synapse formation.

    Science.gov (United States)

    Das, Rupali; Bassiri, Hamid; Guan, Peng; Wiener, Susan; Banerjee, Pinaki P; Zhong, Ming-Chao; Veillette, André; Orange, Jordan S; Nichols, Kim E

    2013-04-25

    The adaptor molecule signaling lymphocytic activation molecule-associated protein (SAP) plays critical roles during invariant natural killer T (iNKT) cell ontogeny. As a result, SAP-deficient humans and mice lack iNKT cells. The strict developmental requirement for SAP has made it difficult to discern its possible involvement in mature iNKT cell functions. By using temporal Cre recombinase-mediated gene deletion to ablate SAP expression after completion of iNKT cell development, we demonstrate that SAP is essential for T-cell receptor (TCR)-induced iNKT cell cytotoxicity against T-cell and B-cell leukemia targets in vitro and iNKT-cell-mediated control of T-cell leukemia growth in vivo. These findings are not restricted to the murine system: silencing RNA-mediated suppression of SAP expression in human iNKT cells also significantly impairs TCR-induced cytolysis. Mechanistic studies reveal that iNKT cell killing requires the tyrosine kinase Fyn, a known SAP-binding protein. Furthermore, SAP expression is required within iNKT cells to facilitate their interaction with T-cell targets and induce reorientation of the microtubule-organizing center to the immunologic synapse (IS). Collectively, these studies highlight a novel and essential role for SAP during iNKT cell cytotoxicity and formation of a functional IS.

  10. Colony mapping: A new technique for monitoring crevice-nesting seabirds

    Science.gov (United States)

    Renner, H.M.; Renner, M.; Reynolds, J.H.; Harping, A.M.A.; Jones, I.L.; Irons, D.B.; Byrd, G.V.

    2006-01-01

    Monitoring populations of auklets and other crevice-nesting seabirds remains problematic, although numerous methods have been attempted since the mid-1960s. Anecdotal evidence suggests several large auklet colonies have recently decreased in both abundance and extent, concurrently with vegetation encroachment and succession. Quantifying changes in the geographical extent of auklet colonies may be a useful alternative to monitoring population size directly. We propose a standardized method for colony mapping using a randomized systematic grid survey with two components: a simple presence/absence survey and an auklet evidence density survey. A quantitative auklet evidence density index was derived from the frequency of droppings and feathers. This new method was used to map the colony on St. George Island in the southeastern Bering Sea and results were compared to previous colony mapping efforts. Auklet presence was detected in 62 of 201 grid cells (each grid cell = 2500 m2) by sampling a randomly placed 16 m2 plot in each cell; estimated colony area = 155 000 m2. The auklet evidence density index varied by two orders of magnitude across the colony and was strongly correlated with means of replicated counts of birds socializing on the colony surface. Quantitatively mapping all large auklet colonies is logistically feasible using this method and would provide an important baseline for monitoring colony status. Regularly monitoring select colonies using this method may be the best means of detecting changes in distribution and population size of crevice-nesting seabirds. ?? The Cooper Ornithological Society 2006.

  11. Correlation of proliferative and clonogenic tumor cells in multiple myeloma

    International Nuclear Information System (INIS)

    Karp, J.E.; Burke, P.J.; Saylor, P.L.; Humphrey, R.L.

    1984-01-01

    To expand on the findings from previous clinical trials that the growth of residual tumor is increased at a predictable time following initial drug administration, malignant plasma cells from bone marrows of patients with multiple myeloma (MM) were examined for changes in proliferation and clonogenicity induced in vivo by cyclophosphamide and in vitro by drug-induced humoral stimulatory activity. Peak plasma cell [ 3 H]thymidine labeling index (LI) occurred predictably following drug and paralleled changes in agar colony formation by marrow cells obtained during therapy. Colony-forming capacity of pretreatment MM marrow populations was enhanced when those cells were cultured with humoral stimulatory activity, similar to the increased colony formation detected in Day 9 postcyclophosphamide marrows at the time of peak plasma cell LI. To further define a relationship between proliferative plasma cells and colony-forming tumor cells, MM marrows were fractionated by sedimentation on an isokinetic gradient. Enrichment of a proliferative tumor cell cohort was achieved, evidenced by [ 3 H]thymidine LI. Colony-forming cells were also enriched by isokinetic gradient sedimentation, and agar colony formation by MM marrow cell fractions correlated with the kinetic characteristics of the isolated subpopulations. These studies of whole and fractionated human MM marrow cell populations suggest that the kinetically active cells which are induced to proliferate in vivo and in vitro are closely related to the clonogenic tumor cells which produce colonies in agar and which, like those cells measured by [ 3 H]thymidine LI, respond to growth stimulation by drug-induced humoral stimulatory activity

  12. Volumetric Analysis of 3-D-Cultured Colonies in Wet Alginate Spots Using 384-Pillar Plate.

    Science.gov (United States)

    Lee, Dong Woo; Choi, Yea-Jun; Lee, Sang-Yun; Kim, Myoung-Hee; Doh, Il; Ryu, Gyu Ha; Choi, Soo-Mi

    2018-06-01

    The volumetric analysis of three-dimensional (3-D)-cultured colonies in alginate spots has been proposed to increase drug efficacy. In a previously developed pillar/well chip platform, colonies within spots are usually stained and dried for analysis of cell viability using two-dimensional (2-D) fluorescent images. Since the number of viable cells in colonies is directly related to colony volume, we proposed the 3-D analysis of colonies for high-accuracy cell viability calculation. The spots were immersed in buffer, and the 3-D volume of each colony was calculated from the 2-D stacking fluorescent images of the spot with different focal positions. In the experiments with human gastric carcinoma cells and anticancer drugs, we compared cell viability values calculated using the 2-D area and 3-D volume of colonies in the wet and dried alginate spots, respectively. The IC 50 value calculated using the 3-D volume of the colonies (9.5 μM) was less than that calculated in the 2-D area analysis (121.5 μM). We observed that the colony showed a more sensitive drug response regarding volume calculated from the 3-D image reconstructed using several confocal images than regarding colony area calculated in the 2-D analysis.

  13. An improved model for nucleation-limited ice formation in living cells during freezing.

    Directory of Open Access Journals (Sweden)

    Jingru Yi

    Full Text Available Ice formation in living cells is a lethal event during freezing and its characterization is important to the development of optimal protocols for not only cryopreservation but also cryotherapy applications. Although the model for probability of ice formation (PIF in cells developed by Toner et al. has been widely used to predict nucleation-limited intracellular ice formation (IIF, our data of freezing Hela cells suggest that this model could give misleading prediction of PIF when the maximum PIF in cells during freezing is less than 1 (PIF ranges from 0 to 1. We introduce a new model to overcome this problem by incorporating a critical cell volume to modify the Toner's original model. We further reveal that this critical cell volume is dependent on the mechanisms of ice nucleation in cells during freezing, i.e., surface-catalyzed nucleation (SCN and volume-catalyzed nucleation (VCN. Taken together, the improved PIF model may be valuable for better understanding of the mechanisms of ice nucleation in cells during freezing and more accurate prediction of PIF for cryopreservation and cryotherapy applications.

  14. The Lncrna-TUG1/EZH2 Axis Promotes Pancreatic Cancer Cell Proliferation, Migration and EMT Phenotype Formation Through Sponging Mir-382.

    Science.gov (United States)

    Zhao, Liang; Sun, Hongwei; Kong, Hongru; Chen, Zongjing; Chen, Bicheng; Zhou, Mengtao

    2017-01-01

    Pancreatic carcinoma (PC) is the one of the most common and malignant cancers worldwide. LncRNA taurine upregulated gene 1 (TUG1) was initially identified as a transcript upregulated by taurine, and the abnormal expression of TUG1 has been reported in many cancers. However, the biological role and molecular mechanism of TUG1 in PC still needs further investigation. Quantitative real-time PCR (qRT-PCR) was performed to measure the expression of TUG1 in PC cell lines and tissues. MTT and colony formation assays were used to measure the effect of TUG1 on cell proliferation. A wound healing assay, transwell assay and western blot assay were employed to determine the effect of TUG1 on cell migration and the epithelial mesenchymal transition (EMT) phenotype. RNA-binding protein immunoprecipitation (RIP) and a biotin-avidin pulldown system were performed to confirm the interaction between miR-328 and TUG1. A gene expression array analysis using clinical samples and RT-qPCR suggested that enhancer of zeste homolog 2 (EZH2) was a target of miR-382 in PC. In this study, we reported that TUG1 was overexpressed in PC tissues and cell lines, and high expression of TUG1 predicted poor prognosis. Further experiments revealed that overexpressed TUG1 promoted cell proliferation, migration and contributed to EMT formation, whereas silenced TUG1 led to opposing results. Additionally, luciferase reporter assays, an RIP assay and an RNA-pulldown assay demonstrated that TUG1 could competitively sponge miR-382 and thereby regulate EZH2. Collectively, these findings revealed that TUG1 functions as an oncogenic lncRNA that promotes tumor progression, at least partially, by functioning as an endogenous 'sponge' and competing for miR-382 binding to the miRNA target EZH2. © 2017 The Author(s). Published by S. Karger AG, Basel.

  15. The Lncrna-TUG1/EZH2 Axis Promotes Pancreatic Cancer Cell Proliferation, Migration and EMT Phenotype Formation Through Sponging Mir-382

    Directory of Open Access Journals (Sweden)

    Liang Zhao

    2017-08-01

    Full Text Available Background/Aims: Pancreatic carcinoma (PC is the one of the most common and malignant cancers worldwide. LncRNA taurine upregulated gene 1 (TUG1 was initially identified as a transcript upregulated by taurine, and the abnormal expression of TUG1 has been reported in many cancers. However, the biological role and molecular mechanism of TUG1 in PC still needs further investigation. Methods: Quantitative real-time PCR (qRT-PCR was performed to measure the expression of TUG1 in PC cell lines and tissues. MTT and colony formation assays were used to measure the effect of TUG1 on cell proliferation. A wound healing assay, transwell assay and western blot assay were employed to determine the effect of TUG1 on cell migration and the epithelial mesenchymal transition (EMT phenotype. RNA-binding protein immunoprecipitation (RIP and a biotin-avidin pulldown system were performed to confirm the interaction between miR-328 and TUG1. A gene expression array analysis using clinical samples and RT-qPCR suggested that enhancer of zeste homolog 2 (EZH2 was a target of miR-382 in PC. Results: In this study, we reported that TUG1 was overexpressed in PC tissues and cell lines, and high expression of TUG1 predicted poor prognosis. Further experiments revealed that overexpressed TUG1 promoted cell proliferation, migration and contributed to EMT formation, whereas silenced TUG1 led to opposing results. Additionally, luciferase reporter assays, an RIP assay and an RNA-pulldown assay demonstrated that TUG1 could competitively sponge miR-382 and thereby regulate EZH2. Conclusion: Collectively, these findings revealed that TUG1 functions as an oncogenic lncRNA that promotes tumor progression, at least partially, by functioning as an endogenous ‘sponge’ and competing for miR-382 binding to the miRNA target EZH2.

  16. Coilin phosphomutants disrupt Cajal body formation, reduce cell proliferation and produce a distinct coilin degradation product.

    Directory of Open Access Journals (Sweden)

    Zunamys I Carrero

    Full Text Available Coilin is a nuclear phosphoprotein that accumulates in Cajal bodies (CBs. CBs participate in ribonucleoprotein and telomerase biogenesis, and are often found in cells with high transcriptional demands such as neuronal and cancer cells, but can also be observed less frequently in other cell types such as fibroblasts. Many proteins enriched within the CB are phosphorylated, but it is not clear what role this modification has on the activity of these proteins in the CB. Coilin is considered to be the CB marker protein and is essential for proper CB formation and composition in mammalian cells. In order to characterize the role of coilin phosphorylation on CB formation, we evaluated various coilin phosphomutants using transient expression. Additionally, we generated inducible coilin phosphomutant cell lines that, when used in combination with endogenous coilin knockdown, allow for the expression of the phosphomutants at physiological levels. Transient expression of all coilin phosphomutants except the phosphonull mutant (OFF significantly reduces proliferation. Interestingly, a stable cell line induced to express the coilin S489D phosphomutant displays nucleolar accumulation of the mutant and generates a N-terminal degradation product; neither of which is observed upon transient expression. A N-terminal degradation product and nucleolar localization are also observed in a stable cell line induced to express a coilin phosphonull mutant (OFF. The nucleolar localization of the S489D and OFF coilin mutants observed in the stable cell lines is decreased when endogenous coilin is reduced. Furthermore, all the phosphomutant cells lines show a significant reduction in CB formation when compared to wild-type after endogenous coilin knockdown. Cell proliferation studies on these lines reveal that only wild-type coilin and the OFF mutant are sufficient to rescue the reduction in proliferation associated with endogenous coilin depletion. These results emphasize

  17. Adhesion, biofilm formation, cell surface hydrophobicity, and antifungal planktonic susceptibility: relationship among Candida spp.

    OpenAIRE

    Silva-Dias, Ana; Miranda, Isabel M.; Branco, Joana; Monteiro-Soares, Matilde; Pina-Vaz, Cid?lia; Rodrigues, Ac?cio G.

    2015-01-01

    We have performed the characterization of the adhesion profile, biofilm formation, cell surface hydrophobicity (CSH) and antifungal susceptibility of 184 Candida clinical isolates obtained from different human reservoirs. Adhesion was quantified using a flow cytometric assay and biofilm formation was evaluated using two methodologies: XTT and crystal violet assay. CSH was quantified with the microbial adhesion to hydrocarbons test while planktonic susceptibility was assessed accordingly the C...

  18. Genetic diversity affects colony survivorship in commercial honey bee colonies

    Science.gov (United States)

    Tarpy, David R.; vanEngelsdorp, Dennis; Pettis, Jeffrey S.

    2013-08-01

    Honey bee ( Apis mellifera) queens mate with unusually high numbers of males (average of approximately 12 drones), although there is much variation among queens. One main consequence of such extreme polyandry is an increased diversity of worker genotypes within a colony, which has been shown empirically to confer significant adaptive advantages that result in higher colony productivity and survival. Moreover, honey bees are the primary insect pollinators used in modern commercial production agriculture, and their populations have been in decline worldwide. Here, we compare the mating frequencies of queens, and therefore, intracolony genetic diversity, in three commercial beekeeping operations to determine how they correlate with various measures of colony health and productivity, particularly the likelihood of queen supersedure and colony survival in functional, intensively managed beehives. We found the average effective paternity frequency ( m e ) of this population of honey bee queens to be 13.6 ± 6.76, which was not significantly different between colonies that superseded their queen and those that did not. However, colonies that were less genetically diverse (headed by queens with m e ≤ 7.0) were 2.86 times more likely to die by the end of the study when compared to colonies that were more genetically diverse (headed by queens with m e > 7.0). The stark contrast in colony survival based on increased genetic diversity suggests that there are important tangible benefits of increased queen mating number in managed honey bees, although the exact mechanism(s) that govern these benefits have not been fully elucidated.

  19. BMP9-Induced Osteogenetic Differentiation and Bone Formation of Muscle-Derived Stem Cells

    Directory of Open Access Journals (Sweden)

    Li Xiang

    2012-01-01

    Full Text Available Efficient osteogenetic differentiation and bone formation from muscle-derived stem cells (MDSCs should have potential clinical applications in treating nonunion fracture healing or bone defects. Here, we investigate osteogenetic differentiation ability of MDSCs induced by bone morphogenetic protein 9 (BMP9 in vitro and bone formation ability in rabbit radius defects repairing model. Rabbit's MDSCs were extracted by type I collagenase and trypsin methods, and BMP9 was introduced into MDSCs by infection with recombinant adenovirus. Effects of BMP9-induced osteogenetic differentiation of MDSCs were identified with alkaline phosphatase (ALP activity and expression of later marker. In stem-cell implantation assay, MDSCs have also shown valuable potential bone formation ability induced by BMP9 in rabbit radius defects repairing test. Taken together, our findings suggest that MDSCs are potentiated osteogenetic stem cells which can be induced by BMP9 to treat large segmental bone defects, nonunion fracture, and/or osteoporotic fracture.

  20. Macroautophagy and microautophagy in relation to vacuole formation in mesophyll cells of Dendrobium tepals.

    Science.gov (United States)

    van Doorn, Wouter G; Kirasak, Kanjana; Ketsa, Saichol

    2015-04-01

    Prior to flower opening, mesophyll cells at the vascular bundles of Dendrobium tepals showed a large increase in vacuolar volume, partially at the expense of the cytoplasm. Electron micrographs indicated that this increase in vacuolar volume was mainly due to vacuole fusion. Macroautophagous structures typical of plant cells were observed. Only a small part of the decrease in cytoplasmic volume seemed due to macroautophagy. The vacuoles contained vesicles of various types, including multilamellar bodies. It was not clear if these vacuolar inclusions were due to macroautophagy or microautophagy. Only a single structure was observed of a protruding vacuole, indicating microautophagy. It is concluded that macroautophagy occurs in these cells but its role in vacuole formation seems small, while a possible role of microautophagy in vacuole formation might be hypothesized. Careful labeling of organelle membranes seems required to advance our insight in plant macro- and microautophagy and their roles in vacuole formation. Copyright © 2015 Elsevier GmbH. All rights reserved.

  1. Plant metabolism and cell wall formation in space (microgravity) and on Earth

    Science.gov (United States)

    Lewis, Norman G.

    1994-01-01

    Variations in cell wall chemistry provide vascular plants with the ability to withstand gravitational forces, as well as providing facile mechanisms for correctional responses to various gravitational stimuli, e.g., in reaction wood formation. A principal focus of our current research is to precisely and systematically dissect the essentially unknown mechanism(s) of vascular plant cell wall assembly, particularly with respect to formation of its phenolic constituents, i.e., lignins and suberins, and how gravity impacts upon these processes. Formation of these phenolic polymers is of particular interest, since it appears that elaboration of their biochemical pathways was essential for successful land adaptation. By extrapolation, we are also greatly intrigued as to how the microgravity environment impacts upon 'normal' cell wall assembly mechanisms/metabolism.

  2. Synergy of cell–cell repulsion and vacuolation in a computational model of lumen formation

    Science.gov (United States)

    Boas, Sonja E. M.; Merks, Roeland M. H.

    2014-01-01

    A key step in blood vessel development (angiogenesis) is lumen formation: the hollowing of vessels for blood perfusion. Two alternative lumen formation mechanisms are suggested to function in different types of blood vessels. The vacuolation mechanism is suggested for lumen formation in small vessels by coalescence of intracellular vacuoles, a view that was extended to extracellular lumen formation by exocytosis of vacuoles. The cell–cell repulsion mechanism is suggested to initiate extracellular lumen formation in large vessels by active repulsion of adjacent cells, and active cell shape changes extend the lumen. We used an agent-based computer model, based on the cellular Potts model, to compare and study both mechanisms separately and combined. An extensive sensitivity analysis shows that each of the mechanisms on its own can produce lumens in a narrow region of parameter space. However, combining both mechanisms makes lumen formation much more robust to the values of the parameters, suggesting that the mechanisms may work synergistically and operate in parallel, rather than in different vessel types. PMID:24430123

  3. Impaired respiration elicits SrrAB-dependent programmed cell lysis and biofilm formation in Staphylococcus aureus

    Science.gov (United States)

    Mashruwala, Ameya A; van de Guchte, Adriana; Boyd, Jeffrey M

    2017-01-01

    Biofilms are communities of microorganisms attached to a surface or each other. Biofilm-associated cells are the etiologic agents of recurrent Staphylococcus aureus infections. Infected human tissues are hypoxic or anoxic. S. aureus increases biofilm formation in response to hypoxia, but how this occurs is unknown. In the current study we report that oxygen influences biofilm formation in its capacity as a terminal electron acceptor for cellular respiration. Genetic, physiological, or chemical inhibition of respiratory processes elicited increased biofilm formation. Impaired respiration led to increased cell lysis via divergent regulation of two processes: increased expression of the AtlA murein hydrolase and decreased expression of wall-teichoic acids. The AltA-dependent release of cytosolic DNA contributed to increased biofilm formation. Further, cell lysis and biofilm formation were governed by the SrrAB two-component regulatory system. Data presented support a model wherein SrrAB-dependent biofilm formation occurs in response to the accumulation of reduced menaquinone. DOI: http://dx.doi.org/10.7554/eLife.23845.001 PMID:28221135

  4. The association between circulating endothelial progenitor cells and coronary collateral formation.

    Science.gov (United States)

    Tokgözoğlu, Lale; Yorgun, Hikmet; Gürses, Kadri Murat; Canpolat, Uğur; Ateş, Ahmet Hakan; Tülümen, Erol; Kaya, Ergün Barış; Aytemir, Kudret; Kabakçı, Giray; Tuncer, Murat; Oto, Ali

    2011-12-01

    We investigated the relationship between coronary collateral formation and circulating endothelial progenitor cells (EPC) in patients undergoing coronary angiography. Circulating CD133(+)/34(+) and CD34(+)/KDR(+) EPCs were determined in 68 patients (normal coronary vessels in 24 patients and coronary artery disease (CAD) in 44 patients) (age: 58.7 ± 10.1, 64.7% male). Circulating EPCs were higher among patients with normal coronary vessels compared to patients with CAD for CD133(+)/34(+) (p collateral formation (p collateral formation after adjustment for other cardiovascular risk factors and extent of CAD (p = 0.037). In patients with severe coronary stenosis, those with increased circulating EPCs had better collateral formation compared to those with lower EPC counts. Our findings implicate that in addition to presence of critical stenosis, intact response of bone marrow is necessary for collateral formation in CAD. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  5. Diversity in cell motility reveals the dynamic nature of the formation of zebrafish taste sensory organs.

    Science.gov (United States)

    Soulika, Marina; Kaushik, Anna-Lila; Mathieu, Benjamin; Lourenço, Raquel; Komisarczuk, Anna Z; Romano, Sebastian Alejo; Jouary, Adrien; Lardennois, Alicia; Tissot, Nicolas; Okada, Shinji; Abe, Keiko; Becker, Thomas S; Kapsimali, Marika

    2016-06-01

    Taste buds are sensory organs in jawed vertebrates, composed of distinct cell types that detect and transduce specific taste qualities. Taste bud cells differentiate from oropharyngeal epithelial progenitors, which are localized mainly in proximity to the forming organs. Despite recent progress in elucidating the molecular interactions required for taste bud cell development and function, the cell behavior underlying the organ assembly is poorly defined. Here, we used time-lapse imaging to observe the formation of taste buds in live zebrafish larvae. We found that tg(fgf8a.dr17)-expressing cells form taste buds and get rearranged within the forming organs. In addition, differentiating cells move from the epithelium to the forming organs and can be displaced between developing organs. During organ formation, tg(fgf8a.dr17) and type II taste bud cells are displaced in random, directed or confined mode relative to the taste bud they join or by which they are maintained. Finally, ascl1a activity in the 5-HT/type III cell is required to direct and maintain tg(fgf8a.dr17)-expressing cells into the taste bud. We propose that diversity in displacement modes of differentiating cells acts as a key mechanism for the highly dynamic process of taste bud assembly. © 2016. Published by The Company of Biologists Ltd.

  6. Mechanical Model of Geometric Cell and Topological Algorithm for Cell Dynamics from Single-Cell to Formation of Monolayered Tissues with Pattern

    KAUST Repository

    Kachalo, Së ma; Naveed, Hammad; Cao, Youfang; Zhao, Jieling; Liang, Jie

    2015-01-01

    development, and other emerging behavior. Here we describe a cell model and an efficient geometric algorithm for studying the dynamic process of tissue formation in 2D (e.g. epithelial tissues). Our approach improves upon previous methods by incorporating

  7. Clonal distribution of osteoprogenitor cells in cultured chick periostea: Functional relationship to bone formation

    International Nuclear Information System (INIS)

    McCulloch, C.A.; Fair, C.A.; Tenenbaum, H.C.; Limeback, H.; Homareau, R.

    1990-01-01

    Folded explants of periosteum from embryonic chick calvaria form bone-like tissue when grown in the presence of ascorbic acid, organic phosphate, and dexamethasone. All osteoblast-like cells in these cultures arise de novo by differentiation of osteoprogenitor cells present in the periosteum. To study the spatial and functional relationships between bone formation and osteoprogenitor cells, cultures were continuously labeled with [3H]thymidine for periods of 1-5 days. Radioautographs of serial 2-microns plastic sections stained for alkaline phosphatase (AP) showed maximal labeling of 30% of fibroblastic (AP-negative) cells by 3 days while osteogenic cells (AP-positive) exhibited over 95% labeling by 5 days. No differential shifts in labeling indices, grain count histograms of fibroblastic and osteogenic cells or numbers of AP-positive cells were observed, indicating no significant recruitment of cells from the fibroblastic to the osteogenic compartment. Despite the continuous presence of [3H]thymidine, less than 35% of both osteoblasts and osteocytes were labeled at 5 days, indicating that only one-third of the osteoprogenitor cells had cycled prior to differentiation. Spatial clustering of [3H]thymidine-labeled cells was measured by computer-assisted morphometry and application of the Poisson distribution to assess contagion. Cluster size and number of labeled cells per cluster did not vary between 1-3 days, but the number of clusters increased 20-fold between Day 1 and Day 3. Three-dimensional reconstruction from serial sections showed that clusters formed long, tubular arrays of osteogenic cells up to eight cells in length and located within 2-3 cell layers from the bone surface. Selective killing of S-phase cells with two pulse labels of high specific activity [3H]thymidine at 1 and 2 days of culture completely blocked bone formation

  8. Disinfection byproduct formation from chlorination of pure bacterial cells and pipeline biofilms.

    Science.gov (United States)

    Wang, Jun-Jian; Liu, Xin; Ng, Tsz Wai; Xiao, Jie-Wen; Chow, Alex T; Wong, Po Keung

    2013-05-15

    Disinfection byproduct (DBP) formation is commonly attributed to the reaction between natural organic matters and disinfectants, yet few have considered the contribution from disinfecting bacterial materials - the essential process of water disinfection. Here, we explored the DBP formation from chlorination and chloramination of Escherichia coli and found that most selected DBPs were detectable, including trihalomethanes, haloacetonitriles, chloral hydrate, chloropicrin, and 1,1,1-trichloro-2-propanone. A positive correlation (P = 0.08-0.09) between DBP formation and the log reduction of E. coli implied that breaking down of bacterial cells released precursors for DBP formation. As Pseudomonas aeruginosa is a dominant bacterial species in pipeline biofilms, the DBP formation potentials (DBPFPs) from its planktonic cells and biofilms were characterized. Planktonic cells formed 7-11 times greater trihalomethanes per carbon of those from biofilms but significantly lower (P biofilms on polyvinyl chloride compared to that on galvanized zinc. This study revealed both the in situ disinfection of bacterial planktonic cells in source water and ex situ reaction between biofilms and residual chlorine in pipeline networks as hitherto unknown DBP sources in drinking water. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Colonial Figures: Memories of Street Traders in the Colonial and Early Post-colonial Periods

    Directory of Open Access Journals (Sweden)

    Sheri Lynn Gibbings

    2012-12-01

    Full Text Available This article explores post-colonial memories about street traders among individuals who lived in the former colony of the Dutch East Indies. It argues that these narratives romanticize the relationship between Europeans and indigenous peoples. Street vendors are also used to differentiate between periods within colonial and post-colonial history. The nostalgic representation of interracial contact between Europeans and traders is contrasted with representations of other figures such as the Japanese and the nationalist. A recurring feature of these representations is the ability of Europeans to speak with street traders and imagine what they wanted and needed. The traders are remembered as a social type that transgressed politics and represented the neutrality of the economic sphere as a place for shared communication. The article concludes that the figure of the street vendor contributes to the nostalgic reinvention of the colony but is also used in narratives to differentiate between and mark changes across the colonial and post-colonial periods.

  10. Colony shape as a genetic trait in the pattern-forming Bacillus mycoides

    Directory of Open Access Journals (Sweden)

    Pisaneschi Giuseppe

    2002-11-01

    Full Text Available Abstract Background Bacillus mycoides Flügge, a Gram-positive, non-motile soil bacterium assigned to Bacillus cereus group, grows on agar as chains of cells linked end to end, forming radial filaments curving clock- or counter-clockwise (SIN or DX morphotypes. The molecular mechanism causing asymmetric curving is not known: our working hypothesis considers regulation of filamentous growth as the prerequisite for these morphotypes. Results SIN and DX strains isolated from the environment were classified as B. mycoides by biochemical and molecular biology tests. Growth on agar of different hardness and nutrient concentration did not abolish colony patterns, nor was conversion between SIN and DX morphotypes ever noticed. A number of morphotype mutants, all originating from one SIN strain, were obtained. Some lost turn direction becoming fluffy, others became round and compact. All mutants lost wild type tight aggregation in liquid culture. Growth on agar was followed by microscopy, exploring the process of colony formation and details of cell divisions. A region of the dcw (division cell wall cluster, including ftsQ, ftsA, ftsZ and murC, was sequenced in DX and SIN strains as a basis for studying cell division. This confirmed the relatedness of DX and SIN strains to the B. cereus group. Conclusions DX and SIN asymmetric morphotypes stem from a close but not identical genomic context. Asymmetry is established early during growth on agar. Wild type bacilli construct mostly uninterrupted filaments with cells dividing at the free ends: they "walk" longer distances compared to mutants, where enhanced frequency of cell separation produces new growing edges resulting in round compact colonies.

  11. Simulation of Escherichia coli Dynamics in Biofilms and Submerged Colonies with an Individual-Based Model Including Metabolic Network Information.

    Science.gov (United States)

    Tack, Ignace L M M; Nimmegeers, Philippe; Akkermans, Simen; Hashem, Ihab; Van Impe, Jan F M

    2017-01-01

    Clustered microbial communities are omnipresent in the food industry, e.g., as colonies of microbial pathogens in/on food media or as biofilms on food processing surfaces. These clustered communities are often characterized by metabolic differentiation among their constituting cells as a result of heterogeneous environmental conditions in the cellular surroundings. This paper focuses on the role of metabolic differentiation due to oxygen gradients in the development of Escherichia coli cell communities, whereby low local oxygen concentrations lead to cellular secretion of weak acid products. For this reason, a metabolic model has been developed for the facultative anaerobe E. coli covering the range of aerobic, microaerobic, and anaerobic environmental conditions. This metabolic model is expressed as a multiparametric programming problem, in which the influence of low extracellular pH values and the presence of undissociated acid cell products in the environment has been taken into account. Furthermore, the developed metabolic model is incorporated in MICRODIMS, an in-house developed individual-based modeling framework to simulate microbial colony and biofilm dynamics. Two case studies have been elaborated using the MICRODIMS simulator: (i) biofilm growth on a substratum surface and (ii) submerged colony growth in a semi-solid mixed food product. In the first case study, the acidification of the biofilm environment and the emergence of typical biofilm morphologies have been observed, such as the mushroom-shaped structure of mature biofilms and the formation of cellular chains at the exterior surface of the biofilm. The simulations show that these morphological phenomena are respectively dependent on the initial affinity of pioneer cells for the substratum surface and the cell detachment process at the outer surface of the biofilm. In the second case study, a no-growth zone emerges in the colony center due to a local decline of the environmental pH. As a result

  12. Simulation of Escherichia coli Dynamics in Biofilms and Submerged Colonies with an Individual-Based Model Including Metabolic Network Information

    Directory of Open Access Journals (Sweden)

    Ignace L. M. M. Tack

    2017-12-01

    Full Text Available Clustered microbial communities are omnipresent in the food industry, e.g., as colonies of microbial pathogens in/on food media or as biofilms on food processing surfaces. These clustered communities are often characterized by metabolic differentiation among their constituting cells as a result of heterogeneous environmental conditions in the cellular surroundings. This paper focuses on the role of metabolic differentiation due to oxygen gradients in the development of Escherichia coli cell communities, whereby low local oxygen concentrations lead to cellular secretion of weak acid products. For this reason, a metabolic model has been developed for the facultative anaerobe E. coli covering the range of aerobic, microaerobic, and anaerobic environmental conditions. This metabolic model is expressed as a multiparametric programming problem, in which the influence of low extracellular pH values and the presence of undissociated acid cell products in the environment has been taken into account. Furthermore, the developed metabolic model is incorporated in MICRODIMS, an in-house developed individual-based modeling framework to simulate microbial colony and biofilm dynamics. Two case studies have been elaborated using the MICRODIMS simulator: (i biofilm growth on a substratum surface and (ii submerged colony growth in a semi-solid mixed food product. In the first case study, the acidification of the biofilm environment and the emergence of typical biofilm morphologies have been observed, such as the mushroom-shaped structure of mature biofilms and the formation of cellular chains at the exterior surface of the biofilm. The simulations show that these morphological phenomena are respectively dependent on the initial affinity of pioneer cells for the substratum surface and the cell detachment process at the outer surface of the biofilm. In the second case study, a no-growth zone emerges in the colony center due to a local decline of the environmental p

  13. MECHANICAL VIBRATION INHIBITS OSTEOCLAST FORMATION BY REDUCING DC-STAMP RECEPTOR EXPRESSION IN OSTEOCLAST PRECURSOR CELLS

    Science.gov (United States)

    Kulkarni, R.N.; Voglewede, P.A.; Liu, D.

    2014-01-01

    It is well known that physical inactivity leads to loss of muscle mass, but it also causes bone loss. Mechanistically, osteoclastogenesis and bone resorption have recently been shown to be regulated by vibration. However, the underlying mechanism behind the inhibition of osteoclast formation is yet unknown. Therefore, we investigated whether mechanical vibration of osteoclast precursor cells affects osteoclast formation by the involvement of fusion-related molecules such as dendritic cell-specific transmembrane protein (DC-STAMP), and P2X7 receptor (P2X7R). RAW264.7 (a murine osteoclastic-like cell line) cells were treated with 20 ng/ml receptor activator of NF-κB ligand (RANKL). For 3 consecutive days, the cells were subjected to 1 hour of mechanical vibration with 20 µm displacement at a frequency of 4 Hz and compared to the control cells that were treated under the same condition but without the vibration. After 5 days of culture, osteoclast formation was determined. Gene expression of DC-STAMP and P2X7R by RAW264.7 cells were determined after 1 hour mechanical vibration, while protein production of the DC-STAMP was determined after 6 hours of post incubation after vibration. As a result, mechanical vibration of RAW264.7 cells inhibited the formation of osteoclasts. Vibration down-regulated DC-STAMP gene expression by 1.6-fold in the presence of RANKL and by 1.4-fold in the absence of RANKL. Additionally, DC-STAMP protein production was also down-regulated by 1.4-fold in the presence of RANKL and by 1.2-fold in the absence of RANKL in RAW264.7 cells in response to mechanical vibration. However, vibration did not affect P2X7R gene expression. Mouse anti-DC-STAMP antibody inhibited osteoclast formation in the absence of vibration. Our results suggest that mechanical vibration of osteoclast precursor cells reduce DC-STAMP expression in osteoclast precursor cells leading to the inhibition of osteoclast formation. PMID:23994170

  14. Mechanical vibration inhibits osteoclast formation by reducing DC-STAMP receptor expression in osteoclast precursor cells.

    Science.gov (United States)

    Kulkarni, Rishikesh N; Voglewede, Philip A; Liu, Dawei

    2013-12-01

    It is well known that physical inactivity leads to loss of muscle mass, but it also causes bone loss. Mechanistically, osteoclastogenesis and bone resorption have recently been shown to be regulated by vibration. However, the underlying mechanism behind the inhibition of osteoclast formation is yet unknown. Therefore, we investigated whether mechanical vibration of osteoclast precursor cells affects osteoclast formation by the involvement of fusion-related molecules such as dendritic cell-specific transmembrane protein (DC-STAMP) and P2X7 receptor (P2X7R). RAW264.7 (a murine osteoclastic-like cell line) cells were treated with 20ng/ml receptor activator of NF-κB ligand (RANKL). For 3 consecutive days, the cells were subjected to 1h of mechanical vibration with 20μm displacement at a frequency of 4Hz and compared to the control cells that were treated under the same condition but without the vibration. After 5days of culture, osteoclast formation was determined. Gene expression of DC-STAMP and P2X7R by RAW264.7 cells was determined after 1h of mechanical vibration, while protein production of the DC-STAMP was determined after 6h of postincubation after vibration. As a result, mechanical vibration of RAW264.7 cells inhibited the formation of osteoclasts. Vibration down-regulated DC-STAMP gene expression by 1.6-fold in the presence of RANKL and by 1.4-fold in the absence of RANKL. Additionally, DC-STAMP protein production was also down-regulated by 1.4-fold in the presence of RANKL and by 1.2-fold in the absence of RANKL in RAW264.7 cells in response to mechanical vibration. However, vibration did not affect P2X7R gene expression. Mouse anti-DC-STAMP antibody inhibited osteoclast formation in the absence of vibration. Our results suggest that mechanical vibration of osteoclast precursor cells reduces DC-STAMP expression in osteoclast precursor cells leading to the inhibition of osteoclast formation. © 2013 Elsevier Inc. All rights reserved.

  15. The Future Lunar Flora Colony

    Science.gov (United States)

    Goel, E. G.; Guven, U. G.

    2017-10-01

    A constructional design for the primary establishment for a lunar colony using the micrometeorite rich soil is proposed. It highlights the potential of lunar regolith combined with Earth technology for water and oxygen for human outposts on the Moon.

  16. Increased mobilization and yield of stem cells using plerixafor in combination with granulocyte-colony stimulating factor for the treatment of non-Hodgkin’s lymphoma and multiple myeloma

    Directory of Open Access Journals (Sweden)

    Louis M Pelus

    2011-02-01

    Full Text Available Louis M Pelus1, Sherif S Farag21Department of Microbiology and Immunology, 2Division of Hematology and Oncology, Department of Internal Medicine, Indiana University School of Medicine, Indianapolis, IndianaAbstract: Multiple myeloma and non-Hodgkin’s lymphoma remain the most common indications for high-dose chemotherapy and autologous peripheral blood stem cell rescue. While a CD34+ cell dose of 1 × 106/kg is considered the minimum required for engraftment, higher CD34+ doses correlate with improved outcome. Numerous studies, however, support targeting a minimum CD34+ cell dose of 2.0 × 106/kg, and an “optimal” dose of 4 to 6 × 106/kg for a single transplant. Unfortunately, up to 40% of patients fail to mobilize an optimal CD34+ cell dose using myeloid growth factors alone. Plerixafor is a novel reversible inhibitor of CXCR4 that significantly increases the mobilization and collection of higher numbers of hematopoietic progenitor cells. Two randomized multi-center clinical trials in patients with non-Hodgkin’s lymphoma and multiple myeloma have demonstrated that the addition of plerixafor to granulocyte-colony stimulating factor increases the mobilization and yield of CD34+ cells in fewer apheresis days, which results in durable engraftment. This review summarizes the pharmacology and evidence for the clinical efficacy of plerixafor in mobilizing hematopoietic stem and progenitor cells, and discusses potential ways to utilize plerixafor in a cost-effective manner in patients with these diseases.Keywords: plerixafor, mobilization, stem cells, lymphoma, myeloma

  17. Three-dimensional bioprinting of embryonic stem cells directs highly uniform embryoid body formation

    International Nuclear Information System (INIS)

    Ouyang, Liliang; Yao, Rui; Mao, Shuangshuang; Sun, Wei; Chen, Xi; Na, Jie

    2015-01-01

    With the ability to manipulate cells temporarily and spatially into three-dimensional (3D) tissue-like construct, 3D bioprinting technology was used in many studies to facilitate the recreation of complex cell niche and/or to better understand the regulation of stem cell proliferation and differentiation by cellular microenvironment factors. Embryonic stem cells (ESCs) have the capacity to differentiate into any specialized cell type of the animal body, generally via the formation of embryoid body (EB), which mimics the early stages of embryogenesis. In this study, extrusion-based 3D bioprinting technology was utilized for biofabricating ESCs into 3D cell-laden construct. The influence of 3D printing parameters on ESC viability, proliferation, maintenance of pluripotency and the rule of EB formation was systematically studied in this work. Results demonstrated that ESCs were successfully printed with hydrogel into 3D macroporous construct. Upon process optimization, about 90% ESCs remained alive after the process of bioprinting and cell-laden construct formation. ESCs continued proliferating into spheroid EBs in the hydrogel construct, while retaining the protein expression and gene expression of pluripotent markers, like octamer binding transcription factor 4, stage specific embryonic antigen 1 and Nanog. In this novel technology, EBs were formed through cell proliferation instead of aggregation, and the quantity of EBs was tuned by the initial cell density in the 3D bioprinting process. This study introduces the 3D bioprinting of ESCs into a 3D cell-laden hydrogel construct for the first time and showed the production of uniform, pluripotent, high-throughput and size-controllable EBs, which indicated strong potential in ESC large scale expansion, stem cell regulation and fabrication of tissue-like structure and drug screening studies. (paper)

  18. Three-dimensional bioprinting of embryonic stem cells directs highly uniform embryoid body formation.

    Science.gov (United States)

    Ouyang, Liliang; Yao, Rui; Mao, Shuangshuang; Chen, Xi; Na, Jie; Sun, Wei

    2015-11-04

    With the ability to manipulate cells temporarily and spatially into three-dimensional (3D) tissue-like construct, 3D bioprinting technology was used in many studies to facilitate the recreation of complex cell niche and/or to better understand the regulation of stem cell proliferation and differentiation by cellular microenvironment factors. Embryonic stem cells (ESCs) have the capacity to differentiate into any specialized cell type of the animal body, generally via the formation of embryoid body (EB), which mimics the early stages of embryogenesis. In this study, extrusion-based 3D bioprinting technology was utilized for biofabricating ESCs into 3D cell-laden construct. The influence of 3D printing parameters on ESC viability, proliferation, maintenance of pluripotency and the rule of EB formation was systematically studied in this work. Results demonstrated that ESCs were successfully printed with hydrogel into 3D macroporous construct. Upon process optimization, about 90% ESCs remained alive after the process of bioprinting and cell-laden construct formation. ESCs continued proliferating into spheroid EBs in the hydrogel construct, while retaining the protein expression and gene expression of pluripotent markers, like octamer binding transcription factor 4, stage specific embryonic antigen 1 and Nanog. In this novel technology, EBs were formed through cell proliferation instead of aggregation, and the quantity of EBs was tuned by the initial cell density in the 3D bioprinting process. This study introduces the 3D bioprinting of ESCs into a 3D cell-laden hydrogel construct for the first time and showed the production of uniform, pluripotent, high-throughput and size-controllable EBs, which indicated strong potential in ESC large scale expansion, stem cell regulation and fabrication of tissue-like structure and drug screening studies.

  19. Secondary cell wall formation in Cryptococcus neoformans as a rescue mechanism against acid-induced autolysis.

    Science.gov (United States)

    Farkas, Vladimír; Takeo, Kanji; Maceková, Danka; Ohkusu, Misako; Yoshida, Soichi; Sipiczki, Matthias

    2009-03-01

    Growth of the opportunistic yeast pathogen Cryptococcus neoformans in a synthetic medium containing yeast nitrogen base and 1.0-3.0% glucose is accompanied by spontaneous acidification of the medium, with its pH decreasing from the initial 5.5 to around 2.5 in the stationary phase. During the transition from the late exponential to the stationary phase of growth, many cells died as a consequence of autolytic erosion of their cell walls. Simultaneously, there was an increase in an ecto-glucanase active towards beta-1,3-glucan and having a pH optimum between pH 3.0 and 3.5. As a response to cell wall degradation, some cells developed an unusual survival strategy by forming 'secondary' cell walls underneath the original ones. Electron microscopy revealed that the secondary cell walls were thicker than the primary ones, exposing bundles of polysaccharide microfibrils only partially masked by an amorphous cell wall matrix on their surfaces. The cells bearing secondary cell walls had a three to five times higher content of the alkali-insoluble cell wall polysaccharides glucan and chitin, and their chitin/glucan ratio was about twofold higher than in cells from the logarithmic phase of growth. The cell lysis and the formation of the secondary cell walls could be suppressed by buffering the growth medium between pH 4.5 and 6.5.

  20. Cadmium-induced formation of multinucleated osteoclast-like cells in vitro

    International Nuclear Information System (INIS)

    Konz, R.P.; Choi, T.T.; Seed, T.M.

    1990-01-01

    Mononuclear, progenitor-enriched bone marrow cells fuse into multinucleated osteoclast-like (MN-OS) cells during 10 to 20 days of culture. As cadmium (Cd) exposure has been linked to increased bone resorption, we asked if Cd would increase (1) MN-OS cell formation and (2) 45 Ca release from bone, when marrow cells were cultured in the presence of 45 Ca-prelabeled dog femur slices. Results show that, on day 21, the percentage of MN-OS cells (≥3 nuclei/cell) was 1.4 ± 0.1% (mean ± SE, n=4) for control cultures (medium + bone slice + cells), 3.6 ± 0.1% for cultures with 10 nM parathyroid hormone (PTH) added, and 7.1 ± 1.5% with 10 nM Cd added. Starting on day 10, we found MN-OS cells with centrally located nuclei, a clear zone, and ruffled borders typical of activated osteoclasts; these activated cells appeared almost exclusively in the +Cd and +PTH cultures. During 21 days, 256 ± 9 CPM 45 Ca was released per well from the bone slices in cultures with cells, compared to 209 ± 11 CPM 45 Ca was released in cultures without cells (mean ± SE, n=16). However, neither Cd nor PTH significantly increased the cell-mediated release of 45 Ca. Thus, both Cd and PTH at 10 nM stimulated the formation of MN-OS cells; however, another factor may have been required to cause MN-OS cells of resorb bone

  1. MUC16 provides immune protection by inhibiting synapse formation between NK and ovarian tumor cells

    Directory of Open Access Journals (Sweden)

    Migneault Martine

    2010-01-01

    Full Text Available Abstract Background Cancer cells utilize a variety of mechanisms to evade immune detection and attack. Effective immune detection largely relies on the formation of an immune synapse which requires close contact between immune cells and their targets. Here, we show that MUC16, a heavily glycosylated 3-5 million Da mucin expressed on the surface of ovarian tumor cells, inhibits the formation of immune synapses between NK cells and ovarian tumor targets. Our results indicate that MUC16-mediated inhibition of immune synapse formation is an effective mechanism employed by ovarian tumors to evade immune recognition. Results Expression of low levels of MUC16 strongly correlated with an increased number of conjugates and activating immune synapses between ovarian tumor cells and primary naïve NK cells. MUC16-knockdown ovarian tumor cells were more susceptible to lysis by primary NK cells than MUC16 expressing controls. This increased lysis was not due to differences in the expression levels of the ligands for the activating receptors DNAM-1 and NKG2D. The NK cell leukemia cell line (NKL, which does not express KIRs but are positive for DNAM-1 and NKG2D, also conjugated and lysed MUC16-knockdown cells more efficiently than MUC16 expressing controls. Tumor cells that survived the NKL challenge expressed higher levels of MUC16 indicating selective lysis of MUC16low targets. The higher csMUC16 levels on the NKL resistant tumor cells correlated with more protection from lysis as compared to target cells that were never exposed to the effectors. Conclusion MUC16, a carrier of the tumor marker CA125, has previously been shown to facilitate ovarian tumor metastasis and inhibits NK cell mediated lysis of tumor targets. Our data now demonstrates that MUC16 expressing ovarian cancer cells are protected from recognition by NK cells. The immune protection provided by MUC16 may lead to selective survival of ovarian cancer cells that are more efficient in

  2. Survivin Modulates Squamous Cell Carcinoma-Derived Stem-Like Cell Proliferation, Viability and Tumor Formation in Vivo

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    Roberta Lotti

    2016-01-01

    Full Text Available Squamous Cell Carcinoma-derived Stem-like Cells (SCC-SC originate from alterations in keratinocyte stem cells (KSC gene expression and sustain tumor development, invasion and recurrence. Since survivin, a KSC marker, is highly expressed in SCC-SC, we evaluate its role in SCC-SC cell growth and SCC models. Survivin silencing by siRNA decreases clonal growth of SCC keratinocytes and viability of total, rapidly adhering (RAD and non-RAD (NRAD cells from primary SCC. Similarly, survivin silencing reduces the expression of stem cell markers (OCT4, NOTCH1, CD133, β1-integrin, while it increases the level of differentiation markers (K10, involucrin. Moreover, survivin silencing improves the malignant phenotype of SCC 3D-reconstruct, as demonstrated by reduced epidermal thickness, lower Ki-67 positive cell number, and decreased expression of MMP9 and psoriasin. Furthermore, survivin depletion by siRNA in RasG12V-IκBα-derived tumors leads to smaller tumor formation characterized by lower mitotic index and reduced expression of the tumor-associated marker HIF1α, VEGF and CD51. Therefore, our results indicate survivin as a key gene in regulating SCC cancer stem cell formation and cSCC development.

  3. Synthetic niches for differentiation of human embryonic stem cells bypassing embryoid body formation.

    Science.gov (United States)

    Liu, Yarong; Fox, Victoria; Lei, Yuning; Hu, Biliang; Joo, Kye-Il; Wang, Pin

    2014-07-01

    The unique self-renewal and pluripotency features of human embryonic stem cells (hESCs) offer the potential for unlimited development of novel cell therapies. Currently, hESCs are cultured and differentiated using methods, such as monolayer culture and embryoid body (EB) formation. As such, achieving efficient differentiation into higher order structures remains a challenge, as well as maintaining cell viability during differentiation into homogeneous cell populations. Here, we describe the application of highly porous polymer scaffolds as synthetic stem cell niches. Bypassing the EB formation step, these scaffolds are capable of three-dimensional culture of undifferentiated hESCs and subsequent directed differentiation into three primary germ layers. H9 hESCs were successfully maintained and proliferated in biodegradable polymer scaffolds based on poly (lactic-co-glycolic acid) (PLGA). The results showed that cells within PLGA scaffolds retained characteristics of undifferentiated pluripotent stem cells. Moreover, the scaffolds allowed differentiation towards the lineage of interest by the addition of growth factors to the culture system. The in vivo transplantation study revealed that the scaffolds could provide a microenvironment that enabled hESCs to interact with their surroundings, thereby promoting cell differentiation. Therefore, this approach, which provides a unique culture/differentiation system for hESCs, will find its utility in various stem cell-based tissue-engineering applications. © 2013 Wiley Periodicals, Inc.

  4. Gravity-induced buds formation from protonemata apical cells in the mosses

    Science.gov (United States)

    Kyyak, Natalia; Khorkavtsiv, Yaroslava

    The acceleration of moss protonemata development after the exit it to light from darkness is important gravidependent morphogenetic manifestation of the moss protonemata. The accelerated development of mosses shows in transformation of apical protonemata cells into the gametophores buds (Ripetskyj et al., 1999). In order to establish, that such reaction on gravitation is general property of gravisensity species, or its typical only for single moss species, experiments with the following moss species - Bryum intermedium (Ludw.) Brig., Bryum caespiticium Hedw., Bryum argenteum Hedw., Dicranodontium denudatum (Brid.) Britt. were carried out. All these species in response to influence of gravitation were capable to form rich bunches of gravitropical protonemata in darkness, that testified to their gravisensity. After the transference of Petri dishes with gravitropical protonemata from darkness on light was revealed, that in 3 of the investigated species the gametophores buds were absent. Only B. argenteum has reacted to action of gravitation by buds formation from apical cells of the gravitropical protonemata. With the purpose of strengthening of buds formation process, the experiments with action of exogenous kinetin (in concentration of 10 (-6) M) were carried out. Kinetin essentially stimulated apical buds formation of B. argenteum. The quantity of apical buds has increased almost in three times in comparison with the control. Besides, on separate stolons a few (3-4) buds from one apical cell were formed. Experimentally was established, that the gametophores buds formation in mosses is controlled by phytohormones (Bopp, 1985; Demkiv et al., 1991). In conditions of gravity influence its essentially accelerated. Probably, gravity essentially strengthened acropetal transport of phytohormones and formation of attractive center in the protonemata apical cell. Our investigations have allowed to make the conclusion, that gravi-dependent formation of the apical buds is

  5. Comparison of autologous cell therapy and granulocyte-colony stimulating factor (G-CSF) injection vs. G-CSF injection alone for the treatment of acute radiation syndrome in a non-human primate model

    International Nuclear Information System (INIS)

    Bertho, Jean-Marc; Frick, Johanna; Prat, Marie; Demarquay, Christelle; Dudoignon, Nicolas; Trompier, Francois; Gorin, Norbert-Claude; Thierry, Dominique; Gourmelon,