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Sample records for vitro des embryons

  1. GERMINATION ET POTENTIALITES ORGANOGENES DES EMBRYONS D’ARGANIER (Argania spinosa L. Skeel CULTIVES IN VITRO

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    B LOTMANI

    2002-12-01

    Full Text Available Les embryons d’argan (Argania spinosa (L. Skeels isolés de la graine et mis sur milieu de culture de Gamborg (B5 contenant des substances de croissance ANA/KIN et ANA/BAP peuvent évoluer en plants parfaitement constitués. Des pousses feuillées apparaissent après un mois de culture de microboutures constituées de bourgeons axillaires prélevées sur des vitroplants de la provenance de Mostaganem ou sur des plants élevés en pépinière pour la provenance de Tindouf sur milieu de culture de Gamborg (B5/2 additionné de deux équilibres hormonaux ANA/KIN et ANA/BAP aux concentrations de 0.5/0.5 mg L-1 pour les deux combinaisons. L’induction des racines sur les pousses nouvellement formées est possible mais difficile sur  l’écotype de Tindouf en présence d’ANA, alors que sur l’écotype de Mostaganem, elle est pratiquement impossible. A la base des boutures se développent des cals qui donneront parfois des racines sur l’écotype de Tindouf. Le pourcentage de survie après acclimatation est nul.

  2. Cryoconservation du sperme et des embryons de poissons

    OpenAIRE

    Maisse, Gérard; Labbé, Catherine; Ogier de Baulny, Bénédicte; Leveroni Calvi, Sylvia; Haffray, Pierrick

    1998-01-01

    Le développement des programmes de sélection génétique en pisciculture et la protection de la biodiversité de l’ichtyofaune sauvage justifient la création de cryo-banques de sperme et d’embryons de poissons. Les travaux sur la formulation des dilueurs de congélation montrent que l’on doit tenir compte à la fois de l’espèce cible, du type cellulaire concerné et des interactions entre les différents composants du dilueur. L’aptitude à la cryoconservation du sperme est très variable suivant les ...

  3. In vitro differentiation of mouse embryonic stem cells into functional ...

    African Journals Online (AJOL)

    In vitro differentiation of mouse embryonic stem cells into functional hepatocytes by sodium butyrate, hepatocyte growth factor and dexamethasone under ... under chemically defined conditions, which might be useful as an in vitro system for hepatocyte transplantation therapy and toxicity screening in drug discovery.

  4. Optimisation de l'induction de callogenèse à partir des embryons ...

    African Journals Online (AJOL)

    SARAH

    30 mai 2015 ... Optimisation de l'induction de callogenèse à partir des embryons excisés de mandariniers (Citrus spp.) 8300. Optimisation de l'induction de callogenèse à partir des embryons excisés de mandariniers (Citrus spp.) Label Kawtar 1/2, Handaji Najat1, Brhadda Najiba², Arsalane Najat1, Gmira Najib²,Essalhi ...

  5. In vitro differentiation of mouse embryonic stem cells into functional ...

    African Journals Online (AJOL)

    Jane

    2011-08-22

    Aug 22, 2011 ... Key words: Embryonic stem cells, hepatic-like cells, in vitro differentiation, sodium butyrate, hepatocyte growth factor, dexamethason. INTRODUCTION. The liver is the major organ that provides multiple metabolic functions critical for the maintenance of homeostasis. One of the major causes of morbidity and.

  6. Etude histologique des embryons avortés lors des croisements entre ...

    African Journals Online (AJOL)

    L'amélioration du haricot commun (Phaseolus vulgaris L.) requiert l'exploitation du pool génique secondaire de cette espèce, composée essentiellement de Phaseolus coccineus L. et de P. polyanthus G. La pollinisation par Phaseolus vulgaris L. présente de meilleures possibilités de maintien des caractères. Cependant ...

  7. In vitro differentiation of mouse embryonic stem cells into functional ...

    African Journals Online (AJOL)

    Jane

    2011-08-22

    Aug 22, 2011 ... Studies have shown that embryonic stem (ES) cells can be successfully differentiated into liver cells, which offer the potential unlimited cell source for a variety of end-stage liver disease. In our study, in order to induce mouse ES cells to differentiate into hepatocyte-like cells under chemically defined.

  8. In vitro pancreas organogenesis from dispersed mouse embryonic progenitors

    DEFF Research Database (Denmark)

    Greggio, Chiara; De Franceschi, Filippo; Figueiredo-Larsen, Evan Manuel

    2014-01-01

    the efficient expansion of dissociated mouse embryonic pancreatic progenitors. By manipulating the composition of the culture medium it is possible to generate either hollow spheres, mainly composed of pancreatic progenitors expanding in their initial state, or, complex organoids which progress to more mature...

  9. Viability Assessment of Genipa americana L. (Rubiaceae Embryonic Axes after Cryopreservation Using In Vitro Culture

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    Izulmé Rita Imaculada Santos

    2016-01-01

    Full Text Available Embryonic axes excised from seeds of Genipa americana L. desiccated to different water contents were successfully cryopreserved by rapidly plunging seed samples directly into liquid nitrogen. Control and cryopreserved embryonic axes were excised and grown in WPM culture medium for viability assessment. All control embryonic axes (−LN2 excised from fully hydrated seeds (43.89% moisture content germinated after 21 days of culture in vitro. These high germination percentages persisted even after the water content of the seeds was as low as 6.79%. After freezing in liquid nitrogen high germination percentages, 93%, 96%, and 93%, were observed for embryonic axes excised from seeds dehydrated to 13.26%, 9.57%, and 6.79 moisture content, respectively. The cryopreservation technique described here is recommended for long term conservation of G. americana germplasm.

  10. Endothelin-1 signalling controls early embryonic heart rate in vitro and in vivo.

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    Karppinen, S; Rapila, R; Mäkikallio, K; Hänninen, S L; Rysä, J; Vuolteenaho, O; Tavi, P

    2014-02-01

    Spontaneous activity of embryonic cardiomyocytes originates from sarcoplasmic reticulum (SR) Ca(2+) release during early cardiogenesis. However, the regulation of heart rate during embryonic development is still not clear. The aim of this study was to determine how endothelin-1 (ET-1) affects the heart rate of embryonic mice, as well as the pathway through which it exerts its effects. The effects of ET-1 and ET-1 receptor inhibition on cardiac contraction were studied using confocal Ca(2+) imaging of isolated mouse embryonic ventricular cardiomyocytes and ultrasonographic examination of embryonic cardiac contractions in utero. In addition, the amount of ET-1 peptide and ET receptor a (ETa) and b (ETb) mRNA levels were measured during different stages of development of the cardiac muscle. High ET-1 concentration and expression of both ETa and ETb receptors was observed in early cardiac tissue. ET-1 was found to increase the frequency of spontaneous Ca(2+) oscillations in E10.5 embryonic cardiomyocytes in vitro. Non-specific inhibition of ET receptors with tezosentan caused arrhythmia and bradycardia in isolated embryonic cardiomyocytes and in whole embryonic hearts both in vitro (E10.5) and in utero (E12.5). ET-1-mediated stimulation of early heart rate was found to occur via ETb receptors and subsequent inositol trisphosphate receptor activation and increased SR Ca(2+) leak. Endothelin-1 is required to maintain a sufficient heart rate, as well as to prevent arrhythmia during early development of the mouse heart. This is achieved through ETb receptor, which stimulates Ca(2+) leak through IP3 receptors. © 2013 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  11. Interaction des ions phosphate in vitro avec des particules inhalables d'oxyde de cerium

    Science.gov (United States)

    Matton, S.; Massiot, P.; Fritsch, P.

    1998-04-01

    Methods have been developed to quantify phosphorus in vitro adsorption on inhalable CeO2 particles. Two assays are potentially useful: adsorption measurement of 32P and X-ray spectrometry. Des méthodes in vitro pour quantifier l'adsorption du phosphore sur des particules inhalables de CeO2 ont été développées. Deux tests s'avèrent utilisables : la mesure de l'adsorption du 32P et la spectrométrie X.

  12. Functionally deficient neuronal differentiation of mouse embryonic neural stem cells in vitro

    NARCIS (Netherlands)

    Balasubramaniyan, [No Value; de Haas, AH; Bakels, R; Koper, A; Boddeke, HWGM; Copray, JM

    Embryonic mouse neural stem cells (NSCs) were isolated from E14 mice, multiplied in medium containing epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) and plated in laminin-coated wells in basic serum-free neurobasal medium. After 7 days in vitro, approximately 20% of the

  13. Identification and characterization of secondary neural tube-derived embryonic neural stem cells in vitro.

    Science.gov (United States)

    Shaker, Mohammed R; Kim, Joo Yeon; Kim, Hyun; Sun, Woong

    2015-05-15

    Secondary neurulation is an embryonic progress that gives rise to the secondary neural tube, the precursor of the lower spinal cord region. The secondary neural tube is derived from aggregated Sox2-expressing neural cells at the dorsal region of the tail bud, which eventually forms rosette or tube-like structures to give rise to neural tissues in the tail bud. We addressed whether the embryonic tail contains neural stem cells (NSCs), namely secondary NSCs (sNSCs), with the potential for self-renewal in vitro. Using in vitro neurosphere assays, neurospheres readily formed at the rosette and neural-tube levels, but less frequently at the tail bud tip level. Furthermore, we identified that sNSC-generated neurospheres were significantly smaller in size compared with cortical neurospheres. Interestingly, various cell cycle analyses revealed that this difference was not due to a reduction in the proliferation rate of NSCs, but rather the neuronal commitment of sNSCs, as sNSC-derived neurospheres contain more committed neuronal progenitor cells, even in the presence of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF). These results suggest that the higher tendency for sNSCs to spontaneously differentiate into progenitor cells may explain the limited expansion of the secondary neural tube during embryonic development.

  14. Reproductive effects of two neonicotinoid insecticides on mouse sperm function and early embryonic development in vitro.

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    Yi-Hua Gu

    Full Text Available Acetamiprid (ACE and imidacloprid (IMI are two major members in the family of neonicotinoid pesticides, which are synthesized with a higher selectivity to insects. The present study determined and compared in vitro effects of ACE, IMI and nicotine on mammalian reproduction by using an integrated testing strategy for reproductive toxicology, which covered sperm quality, sperm penetration into oocytes and preimplantation embryonic development. Direct chemical exposure (500 µM or 5 mM on spermatozoa during capacitation was performed, and in vitro fertilization (IVF process, zygotes and 2-cell embryos were respectively incubated with chemical-supplemented medium until blastocyst formation to evaluate the reproductive toxicity of these chemicals and monitor the stages mainly affected. Generally, treatment of 500 µM or 5 mM chemicals for 30 min did not change sperm motility and DNA integrity significantly but the fertilization ability in in vitro fertilization (IVF process, indicating that IVF process could detect and distinguish subtle effect of spermatozoa exposed to different chemicals. Culture experiment in the presence of chemicals in medium showed that fertilization process and zygotes are adversely affected by direct exposure of chemicals (PIMI>ACE, whereas developmental progression of 2-cell stage embryos was similar to controls (P>0.05. These findings unveiled the hazardous effects of neonicotinoid pesticides exposure on mammalian sperm fertilization ability as well as embryonic development, raising the concerns that neonicotinoid pesticides may pose reproductive risks on human reproductive health, especially in professional populations.

  15. Reproductive effects of two neonicotinoid insecticides on mouse sperm function and early embryonic development in vitro.

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    Gu, Yi-Hua; Li, Yan; Huang, Xue-Feng; Zheng, Ju-Fen; Yang, Jun; Diao, Hua; Yuan, Yao; Xu, Yan; Liu, Miao; Shi, Hui-Juan; Xu, Wen-Ping

    2013-01-01

    Acetamiprid (ACE) and imidacloprid (IMI) are two major members in the family of neonicotinoid pesticides, which are synthesized with a higher selectivity to insects. The present study determined and compared in vitro effects of ACE, IMI and nicotine on mammalian reproduction by using an integrated testing strategy for reproductive toxicology, which covered sperm quality, sperm penetration into oocytes and preimplantation embryonic development. Direct chemical exposure (500 µM or 5 mM) on spermatozoa during capacitation was performed, and in vitro fertilization (IVF) process, zygotes and 2-cell embryos were respectively incubated with chemical-supplemented medium until blastocyst formation to evaluate the reproductive toxicity of these chemicals and monitor the stages mainly affected. Generally, treatment of 500 µM or 5 mM chemicals for 30 min did not change sperm motility and DNA integrity significantly but the fertilization ability in in vitro fertilization (IVF) process, indicating that IVF process could detect and distinguish subtle effect of spermatozoa exposed to different chemicals. Culture experiment in the presence of chemicals in medium showed that fertilization process and zygotes are adversely affected by direct exposure of chemicals (PIMI>ACE, whereas developmental progression of 2-cell stage embryos was similar to controls (P>0.05). These findings unveiled the hazardous effects of neonicotinoid pesticides exposure on mammalian sperm fertilization ability as well as embryonic development, raising the concerns that neonicotinoid pesticides may pose reproductive risks on human reproductive health, especially in professional populations.

  16. From pluripotency to forebrain patterning: an in vitro journey astride embryonic stem cells.

    Science.gov (United States)

    Lupo, Giuseppe; Bertacchi, Michele; Carucci, Nicoletta; Augusti-Tocco, Gabriella; Biagioni, Stefano; Cremisi, Federico

    2014-08-01

    Embryonic stem cells (ESCs) have been used extensively as in vitro models of neural development and disease, with special efforts towards their conversion into forebrain progenitors and neurons. The forebrain is the most complex brain region, giving rise to several fundamental structures, such as the cerebral cortex, the hypothalamus, and the retina. Due to the multiplicity of signaling pathways playing different roles at distinct times of embryonic development, the specification and patterning of forebrain has been difficult to study in vivo. Research performed on ESCs in vitro has provided a large body of evidence to complement work in model organisms, but these studies have often been focused more on cell type production than on cell fate regulation. In this review, we systematically reassess the current literature in the field of forebrain development in mouse and human ESCs with a focus on the molecular mechanisms of early cell fate decisions, taking into consideration the specific culture conditions, exogenous and endogenous molecular cues as described in the original studies. The resulting model of early forebrain induction and patterning provides a useful framework for further studies aimed at reconstructing forebrain development in vitro for basic research or therapy.

  17. mRNA fragments in in vitro culture media are associated with bovine preimplantation embryonic development.

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    Kropp, Jenna; Khatib, Hasan

    2015-01-01

    In vitro production (IVP) systems have been used to bypass problems of fertilization and early embryonic development. However, embryos produced by IVP are commonly selected for implantation based on morphological assessment, which is not a strong indicator of establishment and maintenance of pregnancy. Thus, there is a need to identify additional indicators of embryonic developmental potential. Previous studies have identified microRNA expression in in vitro culture media to be indicative of embryo quality in both bovine and human embryos. Like microRNAs, mRNAs have been shown to be secreted from cells into the extracellular environment, but it is unknown whether or not these RNAs are secreted by embryos. Thus, the objective of the present study was to determine whether mRNAs are secreted into in vitro culture media and if their expression in the media is indicative of embryo quality. In vitro culture medium was generated and collected from both blastocyst and degenerate (those which fail to develop from the morula to blastocyst stage) embryos. Small-RNA sequencing revealed that many mRNA fragments were present in the culture media. A total of 17 mRNA fragments were differentially expressed between blastocyst and degenerate conditioned media. Differential expression was confirmed by quantitative real-time PCR for fragments of mRNA POSTN and VSNL-1, in four additional biological replicates of media. To better understand the mechanisms of mRNA secretion into the media, the expression of a predicted RNA binding protein of POSTN, PUM2, was knocked down using an antisense oligonucleotide gapmer. Supplementation of a PUM2 gapmer significantly reduced blastocyst development and decreased secretion of POSTN mRNA into the media. Overall, differential mRNA expression in the media was repeatable and sets the framework for future study of mRNA biomarkers in in vitro culture media to improve predictability of reproductive performance.

  18. Long-term maintenance of in vitro cultured honeybee (Apis mellifera embryonic cells

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    Aamodt Randi M

    2006-03-01

    Full Text Available Abstract Background In vitro cultivation of cells allows novel investigation of in vivo- mechanisms and is a helpful tool in developmental biology, biochemistry and functional genomics. Numerous cell lines of insect species, e.g., silkworm and mosquito, have been reported. However, this is not the case for successful long-term cultivation of cells in honeybees. Results Methods for cultivation of honeybee embryonic cells are discussed here. Pre-gastrula stage embryos were used to initiate cultures, and cells were reared on 96-wells microplates with Grace insect medium, supplemented with Fetal Bovine Serum. Cells proliferated in clusters, and maintained viable and mitotic for more than three months. Conclusion We report here, for the first time, long-term cultivation of honeybee cells. Results represent a highly useful in vitro-system for studying a model organism of increasing importance in areas such as aging, sociality and neurobiology.

  19. Regulation of embryonic size in early mouse development in vitro culture system.

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    Hisaki, Tomoka; Kawai, Ikuma; Sugiura, Koji; Naito, Kunihiko; Kano, Kiyoshi

    2014-08-01

    Mammals self-regulate their body size throughout development. In the uterus, embryos are properly regulated to be a specific size at birth. Previously, size and cell number in aggregated embryos, which were made from two or more morulae, and half embryos, which were halved at the 2-cell stage, have been analysed in vivo in preimplantation and post-implantation development in mice. Here, we examined whether or not the mouse embryo has the capacity to self-regulate growth using an in vitro culture system. To elucidate embryonic histology, cells were counted in aggregated or half embryos in comparison with control embryos. Both double- and triple-aggregated embryos contained more cells than did control embryos during all culture periods, and the relative growth ratios showed no growth inhibition in an in vitro culture system. Meanwhile, half embryos contained fewer cells than control embryos, but the number grew throughout the culture period. Our data suggest that the growth of aggregated embryos is not affected and continues in an in vitro culture system. On the other hand, the growth of half embryos accelerates and continues in an in vitro culture system. This situation, in turn, implied that post-implantation mouse embryos might have some potential to regulate their own growth and size as seen by using an in vitro culture system without uterus factors. In conclusion, our results indicated that embryos have some ways in which to regulate their own size in mouse early development.

  20. Embryonic stem-like cells derived from in vitro produced bovine blastocysts

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    Erika Regina Leal de Freitas

    2011-06-01

    Full Text Available The aim of this work was to study the derivation of bovine embryonic stem-like (ES-like cells from the inner cell mass (ICM of in vitro produced blastocysts. The ICMs were mechanically isolated and six out of seventeen (35% ICMs could attach to a monolayer of murine embryonic fibroblasts (MEF. Ten days after, primary outgrowths were mechanically dissected into several small clumps and transferred to a new MEF layer. Cells were further propagated and passaged by physical dissociation over a 60 days period. The pluripotency of the bovine ES-like cells was confirmed by RT-PCR of Oct-4 and STAT-3 gene markers. The colonies were weakly stained for alkaline phosphatase and the mesoderm and endoderm differentiation gene markers such as GATA-4 and Flk-1, respectively, were not expressed. Embryoid bodies were spontaneously formed at the seventh passage. Results showed that bovine ES-like cells could be obtained and passaged by mechanical procedures from the fresh in vitro produced blastocysts.

  1. In vitro germ cell differentiation from cynomolgus monkey embryonic stem cells.

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    Kaori Yamauchi

    Full Text Available BACKGROUND: Mouse embryonic stem (ES cells can differentiate into female and male germ cells in vitro. Primate ES cells can also differentiate into immature germ cells in vitro. However, little is known about the differentiation markers and culture conditions for in vitro germ cell differentiation from ES cells in primates. Monkey ES cells are thus considered to be a useful model to study primate gametogenesis in vitro. Therefore, in order to obtain further information on germ cell differentiation from primate ES cells, this study examined the ability of cynomolgus monkey ES cells to differentiate into germ cells in vitro. METHODS AND FINDINGS: To explore the differentiation markers for detecting germ cells differentiated from ES cells, the expression of various germ cell marker genes was examined in tissues and ES cells of the cynomolgus monkey (Macaca fascicularis. VASA is a valuable gene for the detection of germ cells differentiated from ES cells. An increase of VASA expression was observed when differentiation was induced in ES cells via embryoid body (EB formation. In addition, the expression of other germ cell markers, such as NANOS and PIWIL1 genes, was also up-regulated as the EB differentiation progressed. Immunocytochemistry identified the cells expressing stage-specific embryonic antigen (SSEA 1, OCT-4, and VASA proteins in the EBs. These cells were detected in the peripheral region of the EBs as specific cell populations, such as SSEA1-positive, OCT-4-positive cells, OCT-4-positive, VASA-positive cells, and OCT-4-negative, VASA-positive cells. Thereafter, the effect of mouse gonadal cell-conditioned medium and growth factors on germ cell differentiation from monkey ES cells was examined, and this revealed that the addition of BMP4 to differentiating ES cells increased the expression of SCP1, a meiotic marker gene. CONCLUSION: VASA is a valuable gene for the detection of germ cells differentiated from ES cells in monkeys, and the

  2. Peculiarities of Embryonic and Post-Embryonic Development of Оesophagostomum dentatum (Nematoda, Strongylidae Larvae Cultured in Vitro

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    Yevstafieva V. А.

    2017-02-01

    Full Text Available Morphometric peculiarities of the development of Оesophagostomum dentatum Rudolphi, 1803 from egg to infective larva were studied under laboratory conditions at various temperatures. The determined optimum temperature for embryonic and post-embryonic development of О. dentatum larvae from domestic pig (Sus scrofa domesticus Linnaeus, 1758 is 22 °С. At this temperature, 81 % of larvae develop to the third stage (L3 on the 10th day. Temperatures of 24 °С and 20 °С are less favorable for the development of the nematode, at those temperatures only 67 and 63 % of larvae, respectively, reached infective stage by the 10th day of cultivation. Embryonic development of О. dentatum eggs is characterized by their lengthening (by 8.87-9.50 %, р < 0.01 and widening (by 6.77-9.35 %, р < 0.05-0.01, and post-embryonic larval development is associated with lengthening (by 4.59-17.33 %, р < 0.01-0.001.

  3. Vitrification of in vitro produced bovine embryos: effect of embryonic block and developmental kinetics.

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    Asgari, V; Hosseini, S M; Forouzanfar, M; Hajian, M; Nasr-Esfahani, M H

    2012-12-01

    In order to investigate whether the kinetics and stage of embryo development affect cryosurvival of in vitro produced bovine embryos, cleaved embryos were categorized in six groups based on their developmental kinetics regarding the stage of embryonic block in bovine (8-16 cell stage): I and II--early (day 2) and late (day 3) 5-8 cell, III and IV--early (day 3) and late (day 4) 8-16 cell, and V and VI--early (day 4) and late (day 5) morula. The cryosurvival and developmental competence of these embryos were compared with each other and also with the corresponding control groups. The potential of 5-8 cell stage embryos to survive vitrification and further develop towards blastocyst stage was significantly lower than vitrified and un-vitrified 8-16 cell and morula stage embryos. These results suggest that, the survival rate and potential of embryos to develop towards blastocyst stage might be affected by the kinetic of the embryo development. Moreover, the results of this study indicated that the optimal stages of early embryo vitrification are post-embryonic block. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. [Effect of intermittent hypoxia of sleep apnea on embryonic rat cortical neurons in vitro].

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    Zhang, Chanjuan; Li, Yanzhong; Wang, Yan

    2015-05-01

    To investigate the effects of different pattens of intermittent hypoxia on the activity and apoptosis of primary cultured rat embryonic cortical neurons, and to evaluate the role of intermittent hypoxia in the mechanism of obstructive sleep syndrom induced cognitive function loss. The embryonic cerebral cortical neurons were cultured in vitro and were identified by immunofluorescence. Cultured neurons were randomly divided into intermittent hypoxia group, intermittent normal oxygen group, persistent hypoxia group and the control group, and intermittent hypoxia group was divided into five subgroups according to different frequency and time-bound. Neurons were exposed in different modes of hypoxia. MTT colorimetry was used to detect the viability of the neurons, and DAPI colorated measurement was used to calculate the percentages of neuron apoptosis. There were significantly different effects between all subgroups of intermittent hypoxia and the continued hypoxia group on neuronal activity and apoptosis (P Intermittent hypoxia groups with different frequency and time had no difference in neuronal activity and apoptosis (P > 0.05). The effect of intermittent hypoxia was more serious than that of continued hypoxia on neuronal activity and apoptosis; The impact of intermittent hypoxia on neuronal activity and apoptosis may be an important factor in obstructive sleep apnea related cognitive impairment.

  5. Effect of Dipeptides on In vitro Maturation, Fertilization and Subsequent Embryonic Development of Porcine Oocytes

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    Tareq, K. M. A.; Akter, Quzi Sharmin; Tsujii, Hirotada; Khandoker, M. A. M. Yahia; Choi, Inho

    2013-01-01

    The effects of amino acids and dipeptides on in vitro production of porcine embryos and accumulation of ammonia in culture medium during developmental stages were examined in this study. The maturation, fertilization and development of embryonic cultures were performed in modified Tissue culture medium (mTCM)-199 supplemented with 10% (v/v) porcine follicular fluid, modified Tyrode’s albumin lactate pyruvate (mTALP) medium, and modified North Carolina State University (mNCSU)-23 medium, respectively. In addition, amino acids and dipeptides of different concentrations and combinations were used to treat the embryos. The addition of L-alanyl-L-glutamine (AlnGln)+L-glycyl-L-glutamine (GlyGln) significantly (p<0.05) improved oocyte maturation, fertilization and the incorporation and oxidation of 14C(U)-glucose when compared to the control group and other treatment groups. Additionally, 2–4 cell, 8–16 cell, morula and blastocyst development increased significantly (p<0.05) following treatment with AlnGln+GlyGln when compared to the control group and other treatment groups, while this treatment reduced the accumulation of ammonia. Taken together, these findings suggest that treatment with AlnGln+GlyGln may play an important role in increasing the rate of porcine oocyte maturation, fertilization and embryonic development by reducing the level of accumulated ammonia measured in the culture media. PMID:25049815

  6. Human embryonic stem cell-derived neuronal cells form spontaneously active neuronal networks in vitro.

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    Heikkilä, Teemu J; Ylä-Outinen, Laura; Tanskanen, Jarno M A; Lappalainen, Riikka S; Skottman, Heli; Suuronen, Riitta; Mikkonen, Jarno E; Hyttinen, Jari A K; Narkilahti, Susanna

    2009-07-01

    The production of functional human embryonic stem cell (hESC)-derived neuronal cells is critical for the application of hESCs in treating neurodegenerative disorders. To study the potential functionality of hESC-derived neurons, we cultured and monitored the development of hESC-derived neuronal networks on microelectrode arrays. Immunocytochemical studies revealed that these networks were positive for the neuronal marker proteins beta-tubulin(III) and microtubule-associated protein 2 (MAP-2). The hESC-derived neuronal networks were spontaneously active and exhibited a multitude of electrical impulse firing patterns. Synchronous bursts of electrical activity similar to those reported for hippocampal neurons and rodent embryonic stem cell-derived neuronal networks were recorded from the differentiated cultures until up to 4 months. The dependence of the observed neuronal network activity on sodium ion channels was examined using tetrodotoxin (TTX). Antagonists for the glutamate receptors NMDA [D(-)-2-amino-5-phosphonopentanoic acid] and AMPA/kainate [6-cyano-7-nitroquinoxaline-2,3-dione], and for GABAA receptors [(-)-bicuculline methiodide] modulated the spontaneous electrical activity, indicating that pharmacologically susceptible neuronal networks with functional synapses had been generated. The findings indicate that hESC-derived neuronal cells can generate spontaneously active networks with synchronous communication in vitro, and are therefore suitable for use in developmental and drug screening studies, as well as for regenerative medicine.

  7. Promotion of human early embryonic development and blastocyst outgrowth in vitro using autocrine/paracrine growth factors.

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    Kawamura, Kazuhiro; Chen, Yuan; Shu, Yimin; Cheng, Yuan; Qiao, Jie; Behr, Barry; Pera, Renee A Reijo; Hsueh, Aaron J W

    2012-01-01

    Studies using animal models demonstrated the importance of autocrine/paracrine factors secreted by preimplantation embryos and reproductive tracts for embryonic development and implantation. Although in vitro fertilization-embryo transfer (IVF-ET) is an established procedure, there is no evidence that present culture conditions are optimal for human early embryonic development. In this study, key polypeptide ligands known to be important for early embryonic development in animal models were tested for their ability to improve human early embryo development and blastocyst outgrowth in vitro. We confirmed the expression of key ligand/receptor pairs in cleavage embryos derived from discarded human tri-pronuclear zygotes and in human endometrium. Combined treatment with key embryonic growth factors (brain-derived neurotrophic factor, colony-stimulating factor, epidermal growth factor, granulocyte macrophage colony-stimulating factor, insulin-like growth factor-1, glial cell-line derived neurotrophic factor, and artemin) in serum-free media promoted >2.5-fold the development of tri-pronuclear zygotes to blastocysts. For normally fertilized embryos, day 3 surplus embryos cultured individually with the key growth factors showed >3-fold increases in the development of 6-8 cell stage embryos to blastocysts and >7-fold increase in the proportion of high quality blastocysts based on Gardner's criteria. Growth factor treatment also led to a 2-fold promotion of blastocyst outgrowth in vitro when day 7 surplus hatching blastocysts were used. When failed-to-be-fertilized oocytes were used to perform somatic cell nuclear transfer (SCNT) using fibroblasts as donor karyoplasts, inclusion of growth factors increased the progression of reconstructed SCNT embryos to >4-cell stage embryos. Growth factor supplementation of serum-free cultures could promote optimal early embryonic development and implantation in IVF-ET and SCNT procedures. This approach is valuable for infertility

  8. In Vitro Osteogenic Potential of Green Fluorescent Protein Labelled Human Embryonic Stem Cell-Derived Osteoprogenitors

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    Intekhab Islam

    2016-01-01

    Full Text Available Cellular therapy using stem cells in bone regeneration has gained increasing interest. Various studies suggest the clinical utility of osteoprogenitors-like mesenchymal stem cells in bone regeneration. However, limited availability of mesenchymal stem cells and conflicting evidence on their therapeutic efficacy limit their clinical application. Human embryonic stem cells (hESCs are potentially an unlimited source of healthy and functional osteoprogenitors (OPs that could be utilized for bone regenerative applications. However, limited ability to track hESC-derived progenies in vivo greatly hinders translational studies. Hence, in this study, we aimed to establish hESC-derived OPs (hESC-OPs expressing green fluorescent protein (GFP and to investigate their osteogenic differentiation potential in vitro. We fluorescently labelled H9-hESCs using a plasmid vector encoding GFP. The GFP-expressing hESCs were differentiated into hESC-OPs. The hESC-OPsGFP+ stably expressed high levels of GFP, CD73, CD90, and CD105. They possessed osteogenic differentiation potential in vitro as demonstrated by increased expression of COL1A1, RUNX2, OSTERIX, and OPG transcripts and mineralized nodules positive for Alizarin Red and immunocytochemical expression of osteocalcin, alkaline phosphatase, and collagen-I. In conclusion, we have demonstrated that fluorescently labelled hESC-OPs can maintain their GFP expression for the long term and their potential for osteogenic differentiation in vitro. In future, these fluorescently labelled hESC-OPs could be used for noninvasive assessment of bone regeneration, safety, and therapeutic efficacy.

  9. Transplantation of human embryonic stem cells onto a partially wounded human cornea in vitro.

    Science.gov (United States)

    Hanson, Charles; Hardarson, Thorir; Ellerström, Catharina; Nordberg, Markus; Caisander, Gunilla; Rao, Mahendra; Hyllner, Johan; Stenevi, Ulf

    2013-03-01

    The aim of this study was to investigate whether cells originating from human embryonic stem cells (hESCs) could be successfully transplanted onto a partially wounded human cornea. A second aim was to study the ability of the transplanted cells to differentiate into corneal epithelial-like cells. Spontaneously, differentiated hESCs were transplanted onto a human corneal button (without limbus) with the epithelial layer partially removed. The cells were cultured on Bowman's membrane for up to 9 days, and the culture dynamics documented in a time-lapse system. As the transplanted cells originated from a genetically engineered hESC line, they all expressed green fluorescent protein, which facilitated their identification during the culture experiments, tissue preparation and analysis. To detect any differentiation into human corneal epithelial-like cells, we analysed the transplanted cells by immunohistochemistry using antibodies specific for CK3, CK15 and PAX6. The transplanted cells established and expanded on Bowman's membrane, forming a 1-4 cell layer surrounded by host corneal epithelial cells. Expression of the corneal marker PAX6 appeared 3 days after transplantation, and after 6 days, the cells were expressing both PAX6 and CK3. This shows that it is possible to transplant cells originating from hESCs onto Bowman's membrane with the epithelial layer partially removed and to get these cells to establish, grow and differentiate into corneal epithelial-like cells in vitro. © 2012 The Authors. Acta Ophthalmologica © 2012 Acta Ophthalmologica Scandinavica Foundation.

  10. Optimisation de l'induction de callogenèse à partir des embryons ...

    African Journals Online (AJOL)

    SARAH

    30 mai 2015 ... développement des cals : MT+ 1mg/l 2.4D + 0.5mg/l Glutamine, MT+ 1mg/l 2,4D + 0,5mg/l. Asparagine,MT+1mg/l 2,4D +0,5mg/l BAP, MT+ 1mg/l 2,4D + 0,5mg/l ANA, MT+ 1mg/l 2,4D + 0,5mg/l kinétine. Résultats et discussion : Aucune réactivité n'a été observée sur le milieu de base MT sans régulateurs ...

  11. Acclimatation des vitro-plants de bananier ( Musa sp .) sous tunnels ...

    African Journals Online (AJOL)

    Cependant, le manque de matériel végétal de bonne qualité sanitaire est l'une des contraintes majeures de l'extension et de la pérennisation des plantations de bananiers. Pour lever cette contrainte, les techniques de multiplication rapide du matériel végétal utilisent la micropropagation par bourgeonnement in vitro, qui ...

  12. mRNA Fragments in In-Vitro Culture Media are Associated with Bovine Preimplantation Embryonic Development

    Directory of Open Access Journals (Sweden)

    Jenna eKropp

    2015-08-01

    Full Text Available In vitro production (IVP systems have been used to bypass problems of fertilization and early embryonic development. However, embryos produced by IVP are commonly selected for implantation based on morphological assessment, which is not a strong indicator of establishment and maintenance of pregnancy. Thus, there is a need to identify additional indicators of embryonic developmental potential. Previous studies have identified microRNA expression in in vitro culture media to be indicative of embryo quality in both bovine and human embryos. Like microRNAs, mRNAs have been shown to be secreted from cells into the extracellular environment, but it is unknown whether or not these RNAs are secreted by embryos. Thus, the objective of the present study was to determine whether mRNAs are secreted into in vitro culture media and if their expression in the media is indicative of embryo quality. In vitro culture medium was generated and collected from both blastocyst and degenerate (those which fail to develop from the morula to blastocyst stage embryos. Small-RNA sequencing revealed that many mRNA fragments were present in the culture media. A total of 17 mRNA fragments were differentially expressed between blastocyst and degenerated conditioned media. Differential expression was confirmed by quantitative real-time PCR for

  13. Engineering human cell spheroids to model embryonic tissue fusion in vitro.

    Science.gov (United States)

    Epithelial-mesenchymal interactions drive embryonic fusion events during development and upon perturbation can result in birth defects. Cleft palate and neural tube defects can result from genetic defects or environmental exposures during development, yet very little is known abo...

  14. Data for human cell spheroid model of embryonic tissue fusion in vitro.

    Data.gov (United States)

    U.S. Environmental Protection Agency — Epithelial-mesenchymal interactions drive embryonic fusion events during development and upon perturbation can result in birth defects. Cleft palate and neural tube...

  15. A feeder-free, human plasma-derived hydrogel for maintenance of a human embryonic stem cell phenotype in vitro

    Directory of Open Access Journals (Sweden)

    Lewis Fiona C

    2012-08-01

    Full Text Available Abstract Background Human embryonic stem cells (hESCs represent a tremendous resource for cell therapies and the study of human development; however to maintain their undifferentiated state in vitro they routinely require the use of mouse embryonic fibroblast (MEF feeder-layers and exogenous protein media supplementation. Results These well established requirements can be overcome and in this study, it will be demonstrated that phenotypic stability of hESCs can be maintained using a novel, human plasma protein-based hydrogel as an extracellular culture matrix without the use of feeder cell co-culture. hESCs were resuspended in human platelet poor plasma (PPP, which was gelled by the addition of calcium containing DMEM-based hESC culture medium. Phenotypic and genomic expression of the pluripotency markers OCT4, NANOG and SOX2 were measured using immunohistochemistry and qRT-PCR respectively. Typical hESC morphology was demonstrated throughout in vitro culture and both viability and phenotypic stability were maintained throughout extended culture, up to 25 passages. Conclusions PPP-derived hydrogel has demonstrated to be an efficacious alternative to MEF co-culture with its hydrophilicity allowing for this substrate to be delivered via minimally invasive procedures in a liquid phase with polymerization ensuing in situ. Together this provides a novel technique for the study of this unique group of stem cells in either 2D or 3D both in vitro and in vivo.

  16. Role of Mael in early oogenesis and during germ-cell differentiation from embryonic stem cells in mice in vitro.

    Science.gov (United States)

    Bahena, I; Xu, E; Betancourt, M; Casas, E; Ducolomb, Y; González, C; Bonilla, E

    2014-11-01

    In a previous study, we have identified a set of conserved spermatogenic genes whose expression is restricted to testis and ovary and that are developmentally regulated. One of these genes, the transcription factor Mael, has been reported to play an essential role in mouse spermatogenesis. Nevertheless, the role of Mael in mouse oogenesis has not been defined. In order to analyse the role of Mael in mouse oogenesis, the expression of this gene was blocked during early oogenesis in mouse in vitro using RNAi technology. In addition, the role of Mael during differentiation of embryonic stem cells (ESC) into germ cells in vitro was analysed. Results show that downregulation of Mael by a specific short interfering RNA disrupted fetal oocyte growth and differentiation in fetal ovary explants in culture and the expression of several germ-cell markers in ESC during their differentiation. These results suggest that there is an important role for Mael in early oogenesis and during germ-cell differentiation from embryonic stem cells in mouse in vitro.

  17. Spontaneously differentiated GATA6-positive human embryonic stem cells represent an important cellular step in human embryonic development; they are not just an artifact of in vitro culture.

    Science.gov (United States)

    Lee, Jun Ho; Hong, Ki Sung; Mantel, Charlie; Broxmeyer, Hal E; Lee, Man Ryul; Kim, Kye-Seong

    2013-10-15

    In this study, we isolated and characterized spontaneously differentiated human embryonic stem cells (SD-hESCs) found in hESC colonies in comparison to the morphologically premature ESCs in the colonies to investigate the potential role of SD-hESCs in embryogenesis. SD-hESCs were distinguished from undifferentiated hESCs by their higher expression of GATA6, a marker for primitive endoderm and transthyretin, a marker visceral endoderm in embryoid bodies (EBs). SD-hESCs expressed OCT4 and NANOG, markers for pluripotent stem cells, at significantly lower levels than undifferentiated hESCs. EBs derived from isolated SD-hESCs were morphologically distinct from cells directly derived from the undifferentiated hESCs; they contained higher number of cysts compared to EBs from undifferentiated hESC-derived EBs (42% vs. 20%). Furthermore, the extracellular signal molecule, BMP2/4, induced a higher GATA4/6 expression and cystic EB formation than control and noggin-treated EBs. Since cystic formation in EBs play a role in primitive endoderm formation during embryogenesis, the SD-hESC may be a relevant cell type equipped to differentiate into primitive endoderm. Our results suggest that SD-ESCs generated during routine hESC culture are not just an artifact of in vitro culture and these cells could serve as a useful model to study the process of embryogenesis.

  18. An Abbreviated Protocol for In Vitro Generation of Functional Human Embryonic Stem Cell-Derived Beta-Like Cells

    DEFF Research Database (Denmark)

    Massumi, Mohammad; Pourasgari, Farzaneh; Nalla, Amarnadh

    2016-01-01

    developed an abbreviated five-stage protocol (25-30 days) to generate human Embryonic Stem Cell-Derived Beta-like Cells (ES-DBCs). We showed that Geltrex, as an extracellular matrix, could support the generation of ES-DBCs more efficiently than that of the previously described culture systems......The ability to yield glucose-responsive pancreatic beta-cells from human pluripotent stem cells in vitro will facilitate the development of the cell replacement therapies for the treatment of Type 1 Diabetes. Here, through the sequential in vitro targeting of selected signaling pathways, we have...... positive cells, 1% insulin and glucagon positive cells and 30% insulin and NKX6.1 co-expressing cells. Functionally, ES-DBCs were responsive to high glucose in static incubation and perifusion studies, and could secrete insulin in response to successive glucose stimulations. Mitochondrial metabolic flux...

  19. In vitro generation of motor neuron precursors from mouse embryonic stem cells using mesoporous nanoparticles

    DEFF Research Database (Denmark)

    Garcia-Bennett, Alfonso E; König, Niclas; Abrahamsson, Ninnie

    2014-01-01

    Aim: Stem cell-derived motor neurons (MNs) are utilized to develop replacement strategies for spinal cord disorders. Differentiation of embryonic stem cells into MN precursors involves factors and their repeated administration. We investigated if delivery of factors loaded into mesoporous...

  20. In vitro study of disinfectants on the embryonation and survival of Toxascaris leonina eggs.

    Science.gov (United States)

    El-Dakhly, Kh M; Aboshinaf, A S M; Arafa, W M; Mahrous, L N; El-Nahass, E; Gharib, A F; Holman, P J; Craig, T M

    2017-10-04

    The effect of six available and commercial disinfectants on the embryonation and larval development of Toxascaris leonina eggs was studied. Dettol® and Virkon® both induced a 100% reduction in larval development (P ≤ 0.05). Dettol® resulted in deformed eggshells and a halt in embryonal development at 1 week post exposure. All Virkon®-treated eggs showed an early embryonic lysis 24 h post exposure. TH4+ and 70% ethanol both significantly (P ≤ 0.05) affected larval development, with 58.8 and 85.8% reduction, respectively. Neither sodium hypochlorite nor phenol significantly affected larval development (2.8 and 21.0%, respectively). Sodium hypochlorite treatment caused a visible decortication of the eggshell; however, phenol-treated embryonated Toxascaris eggs appeared more or less morphologically normal. In conclusion, the disinfectants tested induced variable degrees of decortication and suppression of larval development. Virkon®S was the most effective disinfectant against Toxascaris eggs, suggesting that it is the most advisable one to use. To the best of our knowledge, this is the first report of the use of Virkon®S as an ovicide and/or larvicide of helminths, particularly Toxascaris leonina.

  1. Homozygous mutation of focal adhesion kinase in embryonic stem cell derived neurons: normal electrophysiological and morphological properties in vitro

    Directory of Open Access Journals (Sweden)

    Komiyama NH

    2006-06-01

    Full Text Available Abstract Background Genetically manipulated embryonic stem (ES cell derived neurons (ESNs provide a powerful system with which to study the consequences of gene manipulation in mature, synaptically connected neurons in vitro. Here we report a study of focal adhesion kinase (FAK, which has been implicated in synapse formation and regulation of ion channels, using the ESN system to circumvent the embryonic lethality of homozygous FAK mutant mice. Results Mouse ES cells carrying homozygous null mutations (FAK-/- were generated and differentiated in vitro into neurons. FAK-/- ESNs extended axons and dendrites and formed morphologically and electrophysiologically intact synapses. A detailed study of NMDA receptor gated currents and voltage sensitive calcium currents revealed no difference in their magnitude, or modulation by tyrosine kinases. Conclusion FAK does not have an obligatory role in neuronal differentiation, synapse formation or the expression of NMDA receptor or voltage-gated calcium currents under the conditions used in this study. The use of genetically modified ESNs has great potential for rapidly and effectively examining the consequences of neuronal gene manipulation and is complementary to mouse studies.

  2. Effects of transforming growth factor on the developing embryonic ureter: An in-vitro megaureter model in mice.

    Science.gov (United States)

    Ozturk, E; Telli, O; Gokce, M I; Ozcan, C; Okutucu, T M; Soygur, T; Burgu, B

    2016-10-01

    It is generally agreed that the cause of a megaureter is narrowing at the vesicoureteral junction, with a functional obstruction arising from an aperistaltic, juxtavesical segment that is unable to transport urine at an acceptable rate. Histological examinations of megaureter specimens have reported several histological analyses, and the pathogenic role of transforming growth factor is still a matter of speculation. To evaluate whether transforming growth factor-beta (TGF-β) and its receptors (TGFRs) are expressed during ureterovesical junction (UVJ) and lower ureter development in mice, and whether exogenous TGF-β might postpone the maturation of smooth muscle cells, in the pathogenesis of megaureter using an embryonic organ-culture model. Expression of TGF-β and TGFRs on the lower ureter and UVJ were determined at different embryonic days (E) (E16, 18, 20 and postnatal day 1). The functional studies were performed by harvesting ureters from wild-type mice at embryonic day 16 (E16), which were grown in serum-free organ-culture; some cultures were supplemented with TGF-β (2 and 20 ng/ml) and/or with soluble TGFR, which blocks bioactivity. Organs were harvested after 6 days and the expression of CD31 and Ki67 were assessed using immunohistochemistry. The muscle content of the UVJ and ureter were analyzed by flowcytometry. The TGF-β and TGFR positive cells were immune detected in embryonic ureters. The TGF-β expression was highest on E18 and decreased postnatally. Exogenous TGF-β decreased ureterovesical (UV) muscle differentiation and proliferation. The longitudinal muscle fibers were significantly less in TGF-β explants. The TGF-β also decreased the proportions of cells expressing α smooth muscle actin (α-SMA). Soluble TGFR blocked the effects of exogenous TGF-β. In organ culture, exogenous TGF-β postpones the UV smooth muscle proliferation and affects the muscular structure. Whether the effects of TGF-β are direct or indirect, these form an in-vitro

  3. Detection, characterization, and spontaneous differentiation in vitro of very small embryonic-like putative stem cells in adult mammalian ovary.

    Science.gov (United States)

    Parte, Seema; Bhartiya, Deepa; Telang, Jyoti; Daithankar, Vinita; Salvi, Vinita; Zaveri, Kusum; Hinduja, Indira

    2011-08-01

    The present study was undertaken to detect, characterize, and study differentiation potential of stem cells in adult rabbit, sheep, monkey, and menopausal human ovarian surface epithelium (OSE). Two distinct populations of putative stem cells (PSCs) of variable size were detected in scraped OSE, one being smaller and other similar in size to the surrounding red blood cells in the scraped OSE. The smaller 1-3 μm very small embryonic-like PSCs were pluripotent in nature with nuclear Oct-4 and cell surface SSEA-4, whereas the bigger 4-7 μm cells with cytoplasmic localization of Oct-4 and minimal expression of SSEA-4 were possibly the tissue committed progenitor stem cells. Pluripotent gene transcripts of Oct-4, Oct-4A, Nanog, Sox-2, TERT, and Stat-3 in human and sheep OSE were detected by reverse transcriptase-polymerase chain reaction. The PSCs underwent spontaneous differentiation into oocyte-like structures, parthenote-like structures, embryoid body-like structures, cells with neuronal-like phenotype, and embryonic stem cell-like colonies, whereas the epithelial cells transformed into mesenchymal phenotype by epithelial-mesenchymal transition in 3 weeks of OSE culture. Germ cell markers like c-Kit, DAZL, GDF-9, VASA, and ZP4 were immuno-localized in oocyte-like structures. In conclusion, as opposed to the existing view of OSE being a bipotent source of oocytes and granulosa cells, mammalian ovaries harbor distinct very small embryonic-like PSCs and tissue committed progenitor stem cells population that have the potential to develop into oocyte-like structures in vitro, whereas mesenchymal fibroblasts appear to form supporting granulosa-like somatic cells. Research at the single-cell level, including complete gene expression profiling, is required to further confirm whether postnatal oogenesis is a conserved phenomenon in adult mammals.

  4. Effets des sources de carbone (sucrose, glucose), et des doses de ...

    African Journals Online (AJOL)

    SARAH

    31 janv. 2014 ... Mazinga et al. J. Appl. Biosci. 2014. Effets des sources de carbone sur l'induction de la rhizogénèse chez l'hybride FHIA-01 du bananier en culture in vitro. 5998 inhibe la germination des embryons somatiques chez certains cultivars d'olivier tel que ' Dolce agogia '. Chez d'autres espèces comme le pêcher ...

  5. High doses of lipid-core nanocapsules do not affect bovine embryonic development in vitro.

    Science.gov (United States)

    Lucas, Caroline G; Remião, Mariana H; Bruinsmann, Franciele A; Lopes, Isadora A R; Borges, Morgana A; Feijó, Ana Laura S; Basso, Andrea Cristina; Pohlmann, Adriana R; Guterres, Silvia S; Campos, Vinicius F; Seixas, Fabiana K; Collares, Tiago

    2017-12-01

    The improvement of in vitro embryo production by culture media supplementation has been a potential tool to increase blastocyst quality and development. Recently, lipid-core nanocapsules (LNC), which were developed for biomedical applications as a drug-delivery system, have demonstrated beneficial effects on in vitro embryo production studies. LNCs have a core composed of sorbitan monostearate dispersed in capric/caprylic triglyceride. Based on that, we firstly investigated if LNCs supplemented during in vitro oocyte maturation had affinity to the mineral oil placed over the top of the IVM media. Also, the effects of LNC supplementation in different concentrations (0; 0.94; 4.71; 23.56; 117.80 and 589.00μg/mL) during the in vitro maturation protocol were evaluated in oocytes and blastocysts by in vitro tests. LNCs seemed not to migrate to the mineral oil overlay during the in vitro oocyte maturation. Interestingly, LNCs did not show toxic effects in the oocyte in vitro maturation rate, cumulus cells expansion and oocyte viability. The highest LNCs concentration tested (589μg/mL) generated the lowest ROS and GSH levels, and reduced apoptosis rate when compared to the control. Additionally, toxic effects in embryo development and quality were not observed. The LNC supramolecular structure demonstrated to be a promising nanocarrier to deliver molecules in oocytes and embryos, aiming the improvement of the embryo in vitro development. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Criteria that optimize the potential of murine embryonic stem cells for in vitro and in vivo developmental studies.

    Science.gov (United States)

    Brown, D G; Willington, M A; Findlay, I; Muggleton-Harris, A L

    1992-01-01

    Cultured mouse embryonic stem (ES) cells are used for both in vitro and in vivo studies. The uncommitted pluripotent cells provide a model system with which to study cellular differentiation and development; they can also be used as vectors to carry specific mutations into the mouse genome by homologous recombination. To ensure successful integration into the germ line, competent totipotent diploid ES cell lines are selected using a cell injection bioassay that is both time consuming and technically demanding. The prolonged in vitro culture of rapidly dividing ES cells can lead to accumulated changes and chromosomal abnormalities that will compromise the biological function and abrogate germ line transmission of chimeric mice carrying novel genetic mutations. Such in vitro conditions will vary between individual laboratories; for example, differences in the serums used for maintenance. Using a number of different criteria we attempt in this paper to define the parameters that we found to be key factors for optimization of the biological potential of established ES cell lines. The successful integration into the germ line is dependant on acquiring or deriving a competent totipotent mouse ES diploid cell line. In this paper parameters and criteria are defined which we found to be key factors for the optimization of the biological potential of established ES cell lines.

  7. Effects of In Vivo and In Vitro Treatment of Ascaris suum Eggs with Anthelmintic Agents on Embryonation and Infectivity for Mice.

    Science.gov (United States)

    Zhao, Jianguo; Han, Qian; Liao, Chenghong; Wang, Jinhua; Wu, Lili; Liu, Qun; Lindsay, David S

    2017-10-01

    Ascaris suum is an important intestinal nematode causing economic losses in swine. Anthelminthic treatment is used to control A. suum infections and is part of normal production practices. Treatment with anthelminthic agents results in expulsion of adult worms from the intestinal tract and ends further contamination of the environment with eggs. The present study was conducted to determine the effects of drug treatment on the embryonation of A. suum eggs collected from worms obtained from pigs treated with 4 different commercially available anthelmintics. The effects of treatment with abamectin, doramectin, ivermectin, flubendazole, or no treatment on embryonation of A. suum eggs collected from female A. suum expelled in the feces was determined. The embryonation of eggs obtained from pigs treated with abamectin, doramectin, and ivermectin was not significantly (P > 0.05) different from eggs from non-treated control pigs. In contrast, the embryonation of A. suum eggs collected from worms from pigs treated with flubendazole demonstrated inhibited development, and most eggs remained in the 1-cell stage (85.5%) and only 6.3% of eggs developed larvae. In another experiment, we examined the direct effects of doramectin and flubendazole added to solutions of A. suum eggs collected from non-treated control pigs. Egg cultures were exposed to direct in vitro treatment with 0.04-parts per million (ppm) doramectin or 1.0-ppm flubendazole for 24 hr (highest concentrations [Cmax] of drugs in serum) and then embryonation and infectivity for mice was determined. Treatment of eggs in vitro did not significantly effect (P > 0.05) larval development or oral infectivity for mice. Our study demonstrates that flubendazole fed to pigs results in inhibited embryonation of A. suum eggs. However, direct treatment of A. suum eggs in culture for 24 hr with flubendazole did not inhibit embryonation or oral infectivity of in vitro treated eggs. Anthelmintic treatment of pigs in vivo with

  8. Matrix accumulation and retention in embryonic cartilage and in vitro chondrogenesis.

    Science.gov (United States)

    Maleski, M P; Knudson, C B

    1996-01-01

    Since hyaluronan anchors the proteoglycan-rich pericellular matrix to chondrocytes, hyaluronan-cell interactions may direct cartilage matrix assembly. To test this hypothesis, the competitive binding of hyaluronan hexasaccharides for native hyaluronan during matrix assembly, accumulation and retention in embryonic cartilage was studied. Chondrocytes released from explants with collagenase P retained pericellular matrices, but chondrocytes appeared "matrix-free" when released from hexasaccharide-treated explants. Decreased safranin O staining was also observed in the hexasaccharide-treated explants. This loss of proteoglycan retention was demonstrated quantitatively in the cartilage extracts and recovered in the media. The continual presence of hexasaccharides in micromass cultures resulted in decreased proteoglycan deposition. Increased proteoglycan retention, indicative of matrix repair, occurred following hexasaccharide wash-out. Thus, native hyaluronan-chondrocyte interactions are important for the assembly and maintenance of cartilage matrix.

  9. Toxicity evaluation of ethanol treatment during in vitro maturation of porcine oocytes and subsequent embryonic development following parthenogenetic activation and in vitro fertilization.

    Science.gov (United States)

    Lee, Sanghoon; Kim, Eunhye; Hyun, Sang-Hwan

    2014-11-01

    Ethanol is frequently used as a solvent in several techniques for in vitro production (IVP). It is also used for the parthenogenetic activation (PA) of oocytes. Although a number of studies have suggested that ethanol has detrimental effects on fibroblasts and neuronal cells, little attention has been paid to the effects of ethanol on porcine oocytes. Thus, the aim of this study was to evaluate the effects of the addition of ethanol to in vitro maturation (IVM) medium. We investigated the effects of ethanol (0, 1 and 3%) on the following parameters: nuclear maturation, intracellular glutathione (GSH) and reactive oxygen species (ROS) levels, and subsequent embryonic development following PA and in vitro fertilization (IVF). After 44 h of IVM, the 3% group showed a significant (Pethanol group showed significantly (Pethanol group had significantly (P1% ethanol during IVM exerts a toxic effect on the developmental potential of PA and IVF porcine embryos by decreasing the intracellular GSH level, thereby increasing the intracellular ROS level and upregulating the expression of apoptosis‑related genes.

  10. Early embryonic development and in vitro culture of in vivo produced embryos in the farmed European polecat (Mustela putorius).

    Science.gov (United States)

    Lindeberg, H; Järvinen, M

    2003-09-15

    Early embryonic development and in vitro culture of in vivo produced embryos in the farmed European polecat (Mustela putorius) was investigated as a part of an ex situ conservation program of the endangered European mink (Mustela lutreola), using the European polecat as a model species. The oestrus cycles of 34 yearling polecat females were monitored by visual examination of the vulval swelling and, to induce ovulation, the females were mated once daily on two consecutive days. Sixteen yearling males were used for mating. The females were humanely killed 3-14 days after the first mating and the uteri and oviducts were collected for embryo recovery. Uterine and oviductal flushings yielded a total number of 295 embryos, representing developmental stages from the 1-cell stage to large expanded and hatched blastocysts. On Day 3 after the first mating, only 1-16-cell stage embryos were recovered. Between Days 4 and 6 after the first mating, 1-16-cell stage embryos and morulae were found. The first blastocysts were recovered on Day 7 after the first mating. The first implanted blastocysts were detected on Day 11 after the first mating. A total number of 85 embryos were in vitro cultured after recovery. Blastocyst production rates for in vitro cultured 1-16-cell stage embryos and for morulae/compact morulae were 68 and 84%, respectively. For all cultured embryos, the hatching rate was 15%. The in vitro culture requirements for the preimplantation embryos of the farmed European polecat remain to be determined before further utilization of the technique.

  11. In vitro preparation of radionuclides labeled blood cells: Status and requirements; Preparation in vitro des cellules du sang marquees par des radionucleides: statut et recommandations

    Energy Technology Data Exchange (ETDEWEB)

    Couret, I. [Service de medecine nucleaire et radiopharmacie, hopital Lapeyronie, CHU de Montpellier, 34 - Montpellier (France); Desruet, M.D. [Service de medecine nucleaire et radiopharmacie, CHU de Grenoble, 38 - Grenoble (France); Bolot, C. [Service de pharmacie, hospices civils de Lyon, groupement hospitalier Est, 69 - Bron (France); Chassel, M.L. [Service de pharmacie et radiopharmacie, centre hospitalier de Chambery, 73 - Chambery (France); Pellegrin, M. [Inserm U896, CRLC Val-d' Aurelle-Paul-Lamarque, IRCM, universite Montpellier 1, 34 - Montpellier (France)

    2010-11-15

    Labelled blood cells permit nuclear medicine imaging using their physiological behaviours. The radiolabeling must be performed in vitro because of the lack of specific markers and requires several highly technical stages of preparation. Labelled blood cells have not the medication drug status, so that the nuclear physician conducting the nuclear test is fully liable. In most cases, the physician delegates the technical responsibility to radio-pharmacists. Although the status of radiolabelled autologous cells is not legally defined and in the absence of a specific repository, it is essential that their preparation is subject to the requirements of the rules of French Good Manufacturing Practice published by Agence francaise de securite sanitaire des produits de sante (Afssaps). It would be desirable to harmonize the practices of radiolabeling cellular blood components by editing a repository. (authors)

  12. Effects of Feeder Cell Types on Culture of Mouse Embryonic Stem Cell In Vitro.

    Science.gov (United States)

    Park, Yun-Gwi; Lee, Seung-Eun; Kim, Eun-Young; Hyun, Hyuk; Shin, Min-Young; Son, Yeo-Jin; Kim, Su-Young; Park, Se-Pill

    2015-09-01

    The suitable feeder cell layer is important for culture of embryonic stem (ES) cells. In this study, we investigated the effect of two kinds of the feeder cell, MEF cells and STO cells, layer to mouse ES (mES) cell culture for maintenance of stemness. We compare the colony formations, alkaline phosphatase (AP) activities, expression of pluripotency marker genes and proteins of D3 cell colonies cultured on MEF feeder cell layer (D3/MEF) or STO cell layers (D3/STO) compared to feeder free condition (D3/-) as a control group. Although there were no differences to colony formations and AP activities, interestingly, the transcripts level of pluripotency marker genes, Pou5f1 and Nanog were highly expressed in D3/MEF (79 and 93) than D3/STO (61and 77) or D3/- (65 and 81). Also, pluripotency marker proteins, NANOG and SOX-2, were more synthesized in D3/MEF (72.8±7.69 and 81.2±3.56) than D3/STO (32.0±4.30 and 56.0±4.90) or D3/- (55.0±4.64 and 62.0±6.20). These results suggest that MEF feeder cell layer is more suitable to mES cell culture.

  13. Suppression of morphogenesis in embryonic mouse limbs exposed in vitro to excess gravity

    Science.gov (United States)

    Duke, Jackie C.

    1983-01-01

    The effect of excess gravity on in vitro mammalian limb chondrogenesis is studied. Limb buds from mice of various gestational stages were exposed to excess gravity (2.6G) using a culture centrifuge. Both forelimbs and hind limbs were cultured, and the development of various limb elements was scored after four to six days. The 2.6G force significantly depressed the development of limb elements when applied during the teratogen-sensitive period of chondrogenesis.

  14. Chemoablated mouse seminiferous tubular cells enriched for very small embryonic-like stem cells undergo spontaneous spermatogenesis in vitro.

    Science.gov (United States)

    Anand, Sandhya; Patel, Hiren; Bhartiya, Deepa

    2015-04-18

    Extensive research is ongoing to empower cancer survivors to have biological parenthood. For this, sperm are cryopreserved prior to therapy and in younger children testicular biopsies are cryopreserved with a hope to mature the germ cells into sperm later on for assisted reproduction. In addition, lot of hope was bestowed on pluripotent embryonic and induced pluripotent stem cells to differentiate into sperm and oocytes. However, obtaining functional gametes from pluripotent stem cells still remains a distant dream and major bottle-neck appears to be their inefficient differentiation into primordial germ cells (PGCs). There exists yet another population of pluripotent stem cells termed very small embryonic-like stem cells (VSELs) in adult body organs including gonads. We have earlier reported that busulphan (25 mg/Kg) treatment to 4 weeks old mice destroys actively dividing cells and sperm but VSELs survive and differentiate into sperm when a healthy niche is provided in vivo. Mouse testicular VSELs that survived busulphan treatment were cultured for 3 weeks. A mix of surviving cells in seminiferous tubules (VSELs, possibly few spermatogonial stem cells and Sertoli cells) were cultured using Sertoli cells conditioned medium containing fetal bovine serum, follicle stimulating hormone and with no additional growth factors. Stem cells underwent proliferation and clonal expansion in culture and spontaneously differentiated into sperm whereas Sertoli cells attached and provided a somatic support. Transcripts specific for various stages of spermatogenesis were up-regulated by qRT-PCR studies on day 7 suggesting VSELs (Sca1) and SSCs (Gfra) proliferate (Pcna), undergo spermatogenesis (spermatocyte specific marker prohibitin), meiosis (Scp3) and differentiate into sperm (post-meiotic marker protamine). Process of spermatogenesis and spermiogenesis was replicated in vitro starting with testicular cells that survived busulphan treatment. We have earlier reported similar

  15. Differentiation of murine embryonic stem and induced pluripotent stem cells to renal lineage in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Morizane, Ryuji [Department of Internal Medicine, Keio University School of Medicine, Tokyo (Japan); Monkawa, Toshiaki, E-mail: monkawa@sc.itc.keio.ac.jp [Department of Internal Medicine, Keio University School of Medicine, Tokyo (Japan); Itoh, Hiroshi [Department of Internal Medicine, Keio University School of Medicine, Tokyo (Japan)

    2009-12-25

    Embryonic stem (ES) cells which have the unlimited proliferative capacity and extensive differentiation potency can be an attractive source for kidney regeneration therapies. Recent breakthroughs in the generation of induced pluripotent stem (iPS) cells have provided with another potential source for the artificially-generated kidney. The purpose of this study is to know how to differentiate mouse ES and iPS cells into renal lineage. We used iPS cells from mouse fibroblasts by transfection of four transcription factors, namely Oct4, Sox2, c-Myc and Klf4. Real-time PCR showed that renal lineage markers were expressed in both ES and iPS cells after the induction of differentiation. It also showed that a tubular specific marker, KSP progressively increased to day 18, although the differentiation of iPS cells was slower than ES cells. The results indicated that renal lineage cells can be differentiated from both murine ES and iPS cells. Several inducing factors were tested whether they influenced on cell differentiation. In ES cells, both of GDNF and BMP7 enhanced the differentiation to metanephric mesenchyme, and Activin enhanced the differentiation of ES cells to tubular cells. Activin also enhanced the differentiation of iPS cells to tubular cells, although the enhancement was lower than in ES cells. ES and iPS cells have a potential to differentiate to renal lineage cells, and they will be an attractive resource of kidney regeneration therapy. This differentiation is enhanced by Activin in both ES and iPS cells.

  16. Effects of the porcine oviduct-specific glycoprotein on fertilization, polyspermy, and embryonic development in vitro.

    Science.gov (United States)

    Kouba, A J; Abeydeera, L R; Alvarez, I M; Day, B N; Buhi, W C

    2000-07-01

    This study evaluated the effects of porcine oviduct-specific glycoprotein (pOSP) on in vitro fertilization (IVF), polyspermy, and development to blastocyst. Experiment 1 evaluated the effects of various concentrations (0-100 microgram/ml) of purified pOSP on fertilization parameters, including penetration, polyspermy, male pronuclear formation, and mean number of sperm penetrated per oocyte. Experiment 2 examined the ability of an anti-pOSP immunoglobulin G to inhibit the observed effects of pOSP on fertilization parameters. Experiments 3 and 4 examined various concentrations of pOSP (0-100 microgram/ml) on zona pellucida solubility and sperm binding, respectively. Lastly, experiment 5 assessed the effects of various concentrations of pOSP (0-100 microgram/ml) on the in vitro embryo cleavage rate and development to blastocyst. Pig oocytes matured and fertilized in vitro were used for all experiments. An effect of treatment (P polyspermy, and mean number of sperm per oocyte. Concentrations for pOSP of 0-50 microgram/ml had no effect on sperm penetration rates; however, compared with the control, 100 microgram/ml significantly decreased the penetration rate (74% vs. 41%). Addition of 10-100 microgram/ml significantly reduced the polyspermy rate compared with the control (61% vs. 24-29%). The decrease in polyspermy achieved by addition of pOSP during preincubation and IVF was blocked with a specific antibody to pOSP. No effect of treatment was observed on zona digestion time relative to the control; however, the number of sperm bound to the zona pellucida was significantly decreased by treatment (P polyspermy in pig oocytes, reduces the number of bound sperm, and increases postcleavage development to blastocyst.

  17. Incidence des plantes régénérées in vitro sur les huiles essentielles ...

    African Journals Online (AJOL)

    SARAH

    31 mars 2016 ... essentielles de deux espèces de Ocimum cultivées au Bénin. Méthodologie et résultats : Les huiles essentielles des feuilles fraîches de Ocimum basilicum et de Ocimum gratissimum cultivés en serre constituent le témoin et celles des mêmes espèces produites en culture in vitro sont extradites (vitroplants).

  18. Incidence des plantes régénérées in vitro sur les huiles essentielles ...

    African Journals Online (AJOL)

    L'objectif de ce travail est d'évaluer l'impact de la culture in vitro sur la production des huiles essentielles de deux espèces de Ocimum cultivées au Bénin. Méthodologie et résultats: Les huiles essentielles des feuilles fraîches de Ocimum basilicum et de Ocimum gratissimum cultivés en serre constituent le témoin et celles ...

  19. Incidence des plantes régénérées in vitro sur les huiles essentielles ...

    African Journals Online (AJOL)

    SARAH

    31 mars 2016 ... RESUME. Objectif : Les Ocimum sont des plantes médicinales d'importance capitale due à leur composition en huiles essentielles. L'objectif de ce travail est d'évaluer l'impact de la culture in vitro sur la production des huiles essentielles de deux espèces de Ocimum cultivées au Bénin. Méthodologie et ...

  20. Teratogenic effects of bis-diamine on early embryonic rat heart: an in vitro study.

    Science.gov (United States)

    Nishijima, S; Nakagawa, M; Fujino, H; Hanato, T; Okamoto, N; Shimada, M

    2000-08-01

    Bis-diamine induces cardiac defects, including conotruncal anomalies in rat embryos when the agent is administered to the mother. To evaluate the teratogenic effects and mechanism of bis-diamine, we performed morphological and immunohistochemical analyses of early rat embryos cultured in medium containing bis-diamine. The embryos were removed from mother rats on gestational day 10.5 and cultured in medium containing 1 mg of bis-diamine for 6 hr. The embryos were then cultured in medium only for another 6, 12, 18, and 42 hr, corresponding to embryonic day (ED) 11.0, 11.25, 11.5, and 12.5, respectively. Some embryos from the same mothers were used as controls and were cultured in medium only for the corresponding periods to the embryos exposed to bis-diamine. Some mother rats were given a single oral dose of 200 mg of bis-diamine on gestational day 10.5. Embryos from these pregnant rats were removed 6 hr after the oral administration of bis-diamine, and were also cultured in medium only for 6, 12, 18, and 42 hr. No cardiac abnormalities were detected in the controls at any stage of development. Thirty-three of 51 (65%) embryos exposed to bis-diamine and 15 of 20 (75%) embryos removed from bis-diamine-administered mothers showed abnormal cardiac development, including dilated ventricle, elongation of outflow tract, and pericardial defect on ED 11.5. Four of six (67%) embryos exposed to bis-diamine, and five of seven (71%) removed from bis-diamine-administered mothers also presented almost the same cardiac abnormalities on ED 12.5. No cardiac abnormalities were detected in bis-diamine-treated embryos before ED 11.5. In addition, the expression of neural cell adhesion molecule (N-CAM) was examined using immunohistochemical methods. Fewer N-CAM immunoreactive cells were detected in the third and fourth aortic arches in the bis-diamine-treated embryos than in controls on ED 11.5. However, more N-CAM immunoreactive cells were detected in the bis-diamine-treated embryos

  1. Relative developmental toxicity potencies of retinoids in the embryonic stem cell test compared with their relative potencies in in vivo and two other in vitro assays for developmental toxicity

    NARCIS (Netherlands)

    Louisse, J.; Gönen, S.; Rietjens, I.M.C.M.; Verwei, M.

    2011-01-01

    The present study determines the relative developmental toxicity potencies of retinoids in the embryonic stem (ES)-D3 cell differentiation assay of the embryonic stem cell test, and compares the outcomes with their relative potencies in in vivo and two other in vitro assays for developmental

  2. Aberrant gene expression and sexually incompatible genomic imprinting in oocytes derived from XY mouse embryonic stem cells in vitro.

    Science.gov (United States)

    Nitta, Mai; Imamura, Masanori; Inoue, Yu; Kunitomo, Yasuo; Lin, Zachary Yu-Ching; Ogawa, Takuya; Yogo, Keiichiro; Ishida-Kitagawa, Norihiro; Fukunaga, Noritaka; Okano, Hideyuki; Sato, Eimei; Takeya, Tatsuo; Miyoshi, Jun

    2013-01-01

    Mouse embryonic stem cells (ESCs) have the potential to differentiate into germ cells (GCs) in vivo and in vitro. Interestingly, XY ESCs can give rise to both male and female GCs in culture, irrespective of the genetic sex. Recent studies showed that ESC-derived primordial GCs contributed to functional gametogenesis in vivo; however, in vitro differentiation techniques have never succeeded in generating mature oocytes from ESCs due to cryptogenic growth arrest during the preantral follicle stages of development. To address this issue, a mouse ESC line, capable of producing follicle-like structures (FLSs) efficiently, was established to investigate their properties using conventional molecular biological methods. The results revealed that the ESC-derived FLSs were morphologically similar to ovarian primary-to-secondary follicles but never formed an antrum; instead, the FLSs eventually underwent abnormal development or cell death in culture, or formed teratomas when transplanted under the kidney capsule in mice. Gene expression analyses demonstrated that the FLSs lacked transcripts for genes essential to late folliculogenesis, including gonadotropin receptors and steroidogenic enzymes, whereas some other genes were overexpressed in FLSs compared to the adult ovary. The E-Cadherin protein, which is involved in cell-to-cell interactions, was also expressed ectopically. Remarkably, it was seen that oocyte-like cells in the FLSs exhibited androgenetic genomic imprinting, which is ordinarily indicative of male GCs. Although the FLSs did not express male GC marker genes, the DNA methyltransferase, Dnmt3L, was expressed at an abnormally high level. Furthermore, the expression of sex determination factors was ambiguous in FLSs as both male and female determinants were expressed weakly. These data suggest that the developmental dysfunction of the ESC-derived FLSs may be attributable to aberrant gene expression and genomic imprinting, possibly associated with uncertain sex

  3. Aberrant gene expression and sexually incompatible genomic imprinting in oocytes derived from XY mouse embryonic stem cells in vitro.

    Directory of Open Access Journals (Sweden)

    Mai Nitta

    Full Text Available Mouse embryonic stem cells (ESCs have the potential to differentiate into germ cells (GCs in vivo and in vitro. Interestingly, XY ESCs can give rise to both male and female GCs in culture, irrespective of the genetic sex. Recent studies showed that ESC-derived primordial GCs contributed to functional gametogenesis in vivo; however, in vitro differentiation techniques have never succeeded in generating mature oocytes from ESCs due to cryptogenic growth arrest during the preantral follicle stages of development. To address this issue, a mouse ESC line, capable of producing follicle-like structures (FLSs efficiently, was established to investigate their properties using conventional molecular biological methods. The results revealed that the ESC-derived FLSs were morphologically similar to ovarian primary-to-secondary follicles but never formed an antrum; instead, the FLSs eventually underwent abnormal development or cell death in culture, or formed teratomas when transplanted under the kidney capsule in mice. Gene expression analyses demonstrated that the FLSs lacked transcripts for genes essential to late folliculogenesis, including gonadotropin receptors and steroidogenic enzymes, whereas some other genes were overexpressed in FLSs compared to the adult ovary. The E-Cadherin protein, which is involved in cell-to-cell interactions, was also expressed ectopically. Remarkably, it was seen that oocyte-like cells in the FLSs exhibited androgenetic genomic imprinting, which is ordinarily indicative of male GCs. Although the FLSs did not express male GC marker genes, the DNA methyltransferase, Dnmt3L, was expressed at an abnormally high level. Furthermore, the expression of sex determination factors was ambiguous in FLSs as both male and female determinants were expressed weakly. These data suggest that the developmental dysfunction of the ESC-derived FLSs may be attributable to aberrant gene expression and genomic imprinting, possibly associated with

  4. Effect of rapamycin treatment during post-activation and/or in vitro culture on embryonic development after parthenogenesis and in vitro fertilization in pigs.

    Science.gov (United States)

    Elahi, F; Lee, H; Lee, J; Lee, S T; Park, C K; Hyun, S-H; Lee, E

    2017-10-01

    This study investigated the effects of early induction of autophagy on embryonic development in pigs. For this, oocytes or embryos were treated with an autophagy inducer, rapamycin (RP), during post-activation (Pa), in vitro fertilization (IVF) and/or in vitro culture (IVC). When parthenogenesis (PA) embryos were untreated (control) or treated with various concentrations of RP for 4 hr during Pa, 100 nm RP showed a higher blastocyst formation (48.8 ± 2.7%) than the control (34.6 ± 3.0%). When PA embryos were treated during the first 24 hr of IVC, blastocyst formation was increased (p < .05) by 1 and 10 nm RP (61.9 ± 3.0 and 59.6 ± 3.0%, respectively) compared to the control (43.2 ± 1.8%) and 100 nm RP (47.8 ± 3.2%), with a higher embryo cleavage in response to 10 nm RP (87.3 ± 2.4%) than the control (74.1 ± 3.2%). RP treatment during IVC and Pa + IVC showed increased blastocyst formation (44.7 ± 2.5 and 44.1 ± 2.0%, respectively) compared to the control (33.2 ± 2.0%). In addition, RP treatment during Pa and/or IVC increased glutathione content and inversely reduced reactive oxygen species. In IVF, RP treatment for 6 hr during IVF significantly increased embryonic development (34.0 ± 2.6%) compared to the control (24.8 ± 1.6%), but treatment during IVC for 24 hr with RP did not (23.0 ± 3.8%). Autophagy was significantly increased in PA oocytes by the RP treatment during Pa but not altered by the treatment during the first 24 hr of IVC. Overall, RP treatment positively regulated the pre-implantation development of pig embryos, probably by regulating cellular redox state and stimulating autophagy. © 2017 Blackwell Verlag GmbH.

  5. In vitro culture of embryonic mouse intestinal epithelium: cell differentiation and introduction of reporter genes

    Directory of Open Access Journals (Sweden)

    Hornsey Mark A

    2006-05-01

    Full Text Available Abstract Background Study of the normal development of the intestinal epithelium has been hampered by a lack of suitable model systems, in particular ones that enable the introduction of exogenous genes. Production of such a system would advance our understanding of normal epithelial development and help to shed light on the pathogenesis of intestinal neoplasia. The criteria for a reliable culture system include the ability to perform real time observations and manipulations in vitro, the preparation of wholemounts for immunostaining and the potential for introducing genes. Results The new culture system involves growing mouse embryo intestinal explants on fibronectin-coated coverslips in basal Eagle's medium+20% fetal bovine serum. Initially the cultures maintain expression of the intestinal transcription factor Cdx2 together with columnar epithelial (cytokeratin 8 and mesenchymal (smooth muscle actin markers. Over a few days of culture, differentiation markers appear characteristic of absorptive epithelium (sucrase-isomaltase, goblet cells (Periodic Acid Schiff positive, enteroendocrine cells (chromogranin A and Paneth cells (lysozyme. Three different approaches were tested to express genes in the developing cultures: transfection, electroporation and adenoviral infection. All could introduce genes into the mesenchyme, but only to a small extent into the epithelium. However the efficiency of adenovirus infection can be greatly improved by a limited enzyme digestion, which makes accessible the lateral faces of cells bearing the Coxsackie and Adenovirus Receptor. This enables reliable delivery of genes into epithelial cells. Conclusion We describe a new in vitro culture system for the small intestine of the mouse embryo that recapitulates its normal development. The system both provides a model for studying normal development of the intestinal epithelium and also allows for the manipulation of gene expression. The explants can be cultured for up

  6. Oncogenic functions of hMDMX in in vitro transformation of primary human fibroblasts and embryonic retinoblasts

    Directory of Open Access Journals (Sweden)

    van der Burg Marja JM

    2011-09-01

    Full Text Available Abstract Background In around 50% of all human cancers the tumor suppressor p53 is mutated. It is generally assumed that in the remaining tumors the wild-type p53 protein is functionally impaired. The two main inhibitors of p53, hMDM2 (MDM2 and hMDMX (MDMX/MDM4 are frequently overexpressed in wild-type p53 tumors. Whereas the main activity of hMDM2 is to degrade p53 protein, its close homolog hMDMX does not degrade p53, but it represses its transcriptional activity. Here we study the role of hMDMX in the neoplastic transformation of human fibroblasts and embryonic retinoblasts, since a high number of retinoblastomas contain elevated hMDMX levels. Methods We made use of an in vitro transformation model using a retroviral system of RNA interference and gene overexpression in primary human fibroblasts and embryonic retinoblasts. Consecutive knockdown of RB and p53, overexpression of SV40-small t, oncogenic HRasV12 and HA-hMDMX resulted in a number of stable cell lines representing different stages of the transformation process, enabling a comparison between loss of p53 and hMDMX overexpression. The cell lines were tested in various assays to assess their oncogenic potential. Results Both p53-knockdown and hMDMX overexpression accelerated proliferation and prevented growth suppression induced by introduction of oncogenic Ras, which was required for anchorage-independent growth and the ability to form tumors in vivo. Furthermore, we found that hMDMX overexpression represses basal p53 activity to some extent. Transformed fibroblasts with very high levels of hMDMX became largely resistant to the p53 reactivating drug Nutlin-3. The Nutlin-3 response of hMDMX transformed retinoblasts was intact and resembled that of retinoblastoma cell lines. Conclusions Our studies show that hMDMX has the essential properties of an oncogene. Its constitutive expression contributes to the oncogenic phenotype of transformed human cells. Its main function appears to be p53

  7. Sperm DNA damage has a negative effect on early embryonic development following in vitro fertilization

    Directory of Open Access Journals (Sweden)

    Wei-Wei Zheng

    2018-01-01

    Full Text Available Sperm DNA damage is recognized as an important biomarker of male infertility. To investigate this, sperm DNA damage was assessed by the sperm chromatin dispersion (SCD test in semen and motile spermatozoa harvested by combined density gradient centrifugation (DGC and swim-up in 161 couples undergoing in vitro fertilization (IVF. Semen analysis and sperm DNA damage results were compared between couples who did or did not achieve pregnancy. The sperm DNA damage level was significantly different between the two groups (P < 0.05 and was negatively correlated with IVF outcomes. Logistic regression analysis confirmed that it was an independent predictor for achieving clinical pregnancy. The effects of different levels of sperm DNA damage on IVF outcomes were also compared. There were significant differences in day 3 embryo quality, blastocyst formation rate, and implantation and pregnancy rates (P < 0.05, but not in the basic fertilization rate between the two groups. Thus, sperm DNA damage as measured by the SCD appears useful for predicting the clinical pregnancy rate following IVF.

  8. An in vitro mechanism study on the proliferation and pluripotency of human embryonic stems cells in response to magnesium degradation.

    Directory of Open Access Journals (Sweden)

    Thanh Yen Nguyen

    Full Text Available Magnesium (Mg is a promising biodegradable metallic material for applications in cellular/tissue engineering and biomedical implants/devices. To advance clinical translation of Mg-based biomaterials, we investigated the effects and mechanisms of Mg degradation on the proliferation and pluripotency of human embryonic stem cells (hESCs. We used hESCs as the in vitro model system to study cellular responses to Mg degradation because they are sensitive to toxicants and capable of differentiating into any cell types of interest for regenerative medicine. In a previous study when hESCs were cultured in vitro with either polished metallic Mg (99.9% purity or pre-degraded Mg, cell death was observed within the first 30 hours of culture. Excess Mg ions and hydroxide ions induced by Mg degradation may have been the causes for the observed cell death; hence, their respective effects on hESCs were investigated for the first time to reveal the potential mechanisms. For this purpose, the mTeSR®1 hESC culture media was either modified to an alkaline pH of 8.1 or supplemented with 0.4-40 mM of Mg ions. We showed that the initial increase of media pH to 8.1 had no adverse effect on hESC proliferation. At all tested Mg ion dosages, the hESCs grew to confluency and retained pluripotency as indicated by the expression of OCT4, SSEA3, and SOX2. When the supplemental Mg ion dosages increased to greater than 10 mM, however, hESC colony morphology changed and cell counts decreased. These results suggest that Mg-based implants or scaffolds are promising in combination with hESCs for regenerative medicine applications, providing their degradation rate is moderate. Additionally, the hESC culture system could serve as a standard model for cytocompatibility studies of Mg in vitro, and an identified 10 mM critical dosage of Mg ions could serve as a design guideline for safe degradation of Mg-based implants/scaffolds.

  9. Des

    NARCIS (Netherlands)

    van Bree, L.G.J.; Rijpstra, W.I.C.; Al-Dhabi, N.A.; Verschuren, D.; Sinninghe Damsté, J.S.; de Leeuw, J.W.

    2016-01-01

    We studied the high-resolution and well-dated 25,000 year sedimentary record of Lake Challa, a deeptropical crater lake in equatorial East Africa, to explore new proxies for paleoenvironmental and paleohydrologicalchange. Sedimentary biomarker analysis revealed the presence of des-A-triterpenoids

  10. Initial cell seeding density influences pancreatic endocrine development during in vitro differentiation of human embryonic stem cells.

    Science.gov (United States)

    Gage, Blair K; Webber, Travis D; Kieffer, Timothy J

    2013-01-01

    Human embryonic stem cells (hESCs) have the ability to form cells derived from all three germ layers, and as such have received significant attention as a possible source for insulin-secreting pancreatic beta-cells for diabetes treatment. While considerable advances have been made in generating hESC-derived insulin-producing cells, to date in vitro-derived glucose-responsive beta-cells have remained an elusive goal. With the objective of increasing the in vitro formation of pancreatic endocrine cells, we examined the effect of varying initial cell seeding density from 1.3 x 10(4) cells/cm(2) to 5.3 x 10(4) cells/cm(2) followed by a 21-day pancreatic endocrine differentiation protocol. Low density-seeded cells were found to be biased toward the G2/M phases of the cell cycle and failed to efficiently differentiate into SOX17-CXCR4 co-positive definitive endoderm cells leaving increased numbers of OCT4 positive cells in day 4 cultures. Moderate density cultures effectively formed definitive endoderm and progressed to express PDX1 in approximately 20% of the culture. High density cultures contained approximately double the numbers of PDX1 positive pancreatic progenitor cells and also showed increased expression of MNX1, PTF1a, NGN3, ARX, and PAX4 compared to cultures seeded at moderate density. The cultures seeded at high density displayed increased formation of polyhormonal pancreatic endocrine cell populations co-expressing insulin, glucagon and somatostatin. The maturation process giving rise to these endocrine cell populations followed the expected cascade of pancreatic progenitor marker (PDX1 and MNX1) expression, followed by pancreatic endocrine specification marker expression (BRN4, PAX4, ARX, NEUROD1, NKX6.1 and NKX2.2) and then pancreatic hormone expression (insulin, glucagon and somatostatin). Taken together these data suggest that initial cell seeding density plays an important role in both germ layer specification and pancreatic progenitor commitment, which

  11. Affect of Bioglass {sup trademark} repeat dosage on mineralisation of embryonic bone 'in vitro'

    Energy Technology Data Exchange (ETDEWEB)

    Maroothynaden, J. [Imperial Coll. of Medicine, London (United Kingdom). Microgravity Tissue Engineering Lab.; Hench, L.L. [Imperial Coll. of Science, Technology and Medicine, London (United Kingdom). Dept. of Materials

    2001-07-01

    Utilising 45S5 Bioglass {sup trademark} extracts, as described previously, 16-day gestation embryonic mouse long-bones were cultured for 4-days while exposed to the same Bioglass{sup circledR} soluble extract solution for two different exposure times. In the first culture, all embryonic femurs were exposed to fresh 45S5 Bioglass {sup trademark} extract every 98 hours. In the second, the long-bones were exposed to fresh 45S5 Bioglass {sup trademark} extract solution every 48 hours. A simultaneous control culture was performed. All embryonic long-bone cultures mineralised after 4-days culture. Increasing the frequency of 45S5 Bioglass {sup trademark} exposure, from one exposure every 96 hrs to fresh exposures every 48 hrs, significantly increased the length and mineral content of the embryonic long-bones. (orig.)

  12. In vitro culture and characterization of putative porcine embryonic germ cells derived from domestic breeds and yucatan mini pig embryos at days 20-24 of gestation

    DEFF Research Database (Denmark)

    Petkov, Stoyan Gueorguiev; Marks, Hendrik; Klein, Tino

    2011-01-01

    Embryonic germ cells (EGC) are cultured pluripotent cells derived from primordial germ cells (PGC). This study explored the possibility of establishing porcine EGC from domestic breeds and Yucatan mini pigs using embryos at Days 17-24 of gestation. In vitro culture of PGC from both pooled......-Seq expression profiling showed no expression of the core pluripotency markers OCT4, SOX2, and NANOG, although most other pluripotency genes were expressed at levels comparable to those of mouse embryonic stem cells (ESC). Moreover, germ-specific genes such as BLIMP1 retained their expression. Functional......, their injection into immunodeficient mice did not result in teratoma formation. Our results suggest that the PGC-derived cells described in this study are EGC-like, but seem to be multipotent rather than pluripotent cells. Nevertheless, the thorough characterization of these cells in this study, and especially...

  13. Connective-Tissue Growth Factor (CTGF/CCN2 Induces Astrogenesis and Fibronectin Expression of Embryonic Neural Cells In Vitro.

    Directory of Open Access Journals (Sweden)

    Fabio A Mendes

    Full Text Available Connective-tissue growth factor (CTGF is a modular secreted protein implicated in multiple cellular events such as chondrogenesis, skeletogenesis, angiogenesis and wound healing. CTGF contains four different structural modules. This modular organization is characteristic of members of the CCN family. The acronym was derived from the first three members discovered, cysteine-rich 61 (CYR61, CTGF and nephroblastoma overexpressed (NOV. CTGF is implicated as a mediator of important cell processes such as adhesion, migration, proliferation and differentiation. Extensive data have shown that CTGF interacts particularly with the TGFβ, WNT and MAPK signaling pathways. The capacity of CTGF to interact with different growth factors lends it an important role during early and late development, especially in the anterior region of the embryo. ctgf knockout mice have several cranio-facial defects, and the skeletal system is also greatly affected due to an impairment of the vascular-system development during chondrogenesis. This study, for the first time, indicated that CTGF is a potent inductor of gliogenesis during development. Our results showed that in vitro addition of recombinant CTGF protein to an embryonic mouse neural precursor cell culture increased the number of GFAP- and GFAP/Nestin-positive cells. Surprisingly, CTGF also increased the number of Sox2-positive cells. Moreover, this induction seemed not to involve cell proliferation. In addition, exogenous CTGF activated p44/42 but not p38 or JNK MAPK signaling, and increased the expression and deposition of the fibronectin extracellular matrix protein. Finally, CTGF was also able to induce GFAP as well as Nestin expression in a human malignant glioma stem cell line, suggesting a possible role in the differentiation process of gliomas. These results implicate ctgf as a key gene for astrogenesis during development, and suggest that its mechanism may involve activation of p44/42 MAPK signaling

  14. Characterization of 3D embryonic C57BL/6 and A/J mouse midbrain micromass in vitro culture systems for developmental neurotoxicity testing.

    Science.gov (United States)

    Park, Julie Juyoung; Weldon, Brittany A; Hong, Sungwoo; Workman, Tomomi; Griffith, William C; Park, Julie H; Faustman, Elaine M

    2017-12-18

    In vitro micromass culture systems have been proposed as an alternative method for developmental toxicity assessment to reduce the need for resource-intensive in vivo toxicity testing. In this study, a three-dimensional in vitro embryonic mouse midbrain culture system is characterized in two mouse strains to facilitate gene x environment considerations. Gestational day (GD) 11 C57BL/6 or GD 12 A/J mouse midbrain cells were isolated and cultured in high-density micromass format for 22days in vitro (DIV). Hematoxylin intensity and protein content revealed that neuronal differentiation increases linearly over time in both C57BL/6 and A/J cultures. Protein expression showed time-dependent proliferation markers (PCNA) increased significantly between DIV 4-6 compared to DIV 1. Early and late differentiation markers (e.g. β-tubulin III and NMDAɛ1) were expressed between DIV 6-8 and DIV 8-15, respectively. Immunohistochemistry and protein expression results for proliferation and differentiation markers were concordant. Protein expression patterns for the two mouse strain micromass systems were similar. This study characterizes a novel method for investigating early neurogenesis and may be used to characterize neurodevelopmental toxicity in vitro. Our findings show how the use of different mouse strains in neurodevelopmental studies may extend test systems for gene and environment interaction studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Porcine embryonic stem cells

    DEFF Research Database (Denmark)

    Hall, Vanessa Jane

    2008-01-01

    The development of porcine embryonic stem cell lines (pESC) has received renewed interest given the advances being made in the production of immunocompatible transgenic pigs. However, difficulties are evident in the production of pESCs in-vitro. This may largely be attributable to differences...

  16. Directed Differentiation of Human Embryonic Stem Cells into Prostate Organoids In Vitro and its Perturbation by Low-Dose Bisphenol A Exposure.

    Directory of Open Access Journals (Sweden)

    Esther L Calderon-Gierszal

    Full Text Available Studies using rodent and adult human prostate stem-progenitor cell models suggest that developmental exposure to the endocrine disruptor Bisphenol-A (BPA can predispose to prostate carcinogenesis with aging. Unknown at present is whether the embryonic human prostate is equally susceptible to BPA during its natural developmental window. To address this unmet need, we herein report the construction of a pioneer in vitro human prostate developmental model to study the effects of BPA. The directed differentiation of human embryonic stem cells (hESC into prostatic organoids in a spatial system was accomplished with precise temporal control of growth factors and steroids. Activin-induced definitive endoderm was driven to prostate specification by combined exposure to WNT10B and FGF10. Matrigel culture for 20-30 days in medium containing R-Spondin-1, Noggin, EGF, retinoic acid and testosterone was sufficient for mature prostate organoid development. Immunofluorescence and gene expression analysis confirmed that organoids exhibited cytodifferentiation and functional properties of the human prostate. Exposure to 1 nM or 10 nM BPA throughout differentiation culture disturbed early morphogenesis in a dose-dependent manner with 1 nM BPA increasing and 10 nM BPA reducing the number of branched structures formed. While differentiation of branched structures to mature organoids seemed largely unaffected by BPA exposure, the stem-like cell population increased, appearing as focal stem cell nests that have not properly entered lineage commitment rather than the rare isolated stem cells found in normally differentiated structures. These findings provide the first direct evidence that low-dose BPA exposure targets hESC and perturbs morphogenesis as the embryonic cells differentiate towards human prostate organoids, suggesting that the developing human prostate may be susceptible to disruption by in utero BPA exposures.

  17. Kidney specific protein-positive cells derived from embryonic stem cells reproduce tubular structures in vitro and differentiate into renal tubular cells.

    Science.gov (United States)

    Morizane, Ryuji; Monkawa, Toshiaki; Fujii, Shizuka; Yamaguchi, Shintaro; Homma, Koichiro; Matsuzaki, Yumi; Okano, Hideyuki; Itoh, Hiroshi

    2014-01-01

    Embryonic stem cells and induced pluripotent stem cells have the ability to differentiate into various organs and tissues, and are regarded as new tools for the elucidation of disease mechanisms as well as sources for regenerative therapies. However, a method of inducing organ-specific cells from pluripotent stem cells is urgently needed. Although many scientists have been developing methods to induce various organ-specific cells from pluripotent stem cells, renal lineage cells have yet to be induced in vitro because of the complexity of kidney structures and the diversity of kidney-component cells. Here, we describe a method of inducing renal tubular cells from mouse embryonic stem cells via the cell purification of kidney specific protein (KSP)-positive cells using an anti-KSP antibody. The global gene expression profiles of KSP-positive cells derived from ES cells exhibited characteristics similar to those of cells in the developing kidney, and KSP-positive cells had the capacity to form tubular structures resembling renal tubular cells when grown in a 3D culture in Matrigel. Moreover, our results indicated that KSP-positive cells acquired the characteristics of each segment of renal tubular cells through tubular formation when stimulated with Wnt4. This method is an important step toward kidney disease research using pluripotent stem cells, and the development of kidney regeneration therapies.

  18. The effect of aloe vera on the expression of wound healing factors (TGFβ1 and bFGF) in mouse embryonic fibroblast cell: In vitro study.

    Science.gov (United States)

    Hormozi, Maryam; Assaei, Raheleh; Boroujeni, Mandana Beigi

    2017-04-01

    Aloe vera (A.v) have been used traditionally for topical treatment of wounds and burns in different countries for centuries, but the mechanism of this effect is not well understood. Various growth factors are implicated in the process of wound healing. Among the different growth factors involved in the process, TGFβ1 and bFGF are the most importantly expressed in fibroblast cells. The aim of this study was to evaluate the effect of A.v on the expression of angiogenesis growth factors in mouse embryonic fibroblast cells. We exposed mouse embryonic fibroblast cells to different concentrations of A.v (50, 100 and 150μg/ml) at two different time of 12 and 24h. Fibroblast cell without A.v treatment serves as the control. The expression of TGFβ1and bFGF was measured by real time-polymerase chain reaction (real-time-PCR) and enzyme-linked immunosorbent assay (ELISA) at the level of gene and protein. We observed that A.v gel at first up-regulated the expression of TGFβ1 and bFGF, but, these genes were later repressed after a particular time. Our results demonstrated that A.v was dose-dependent and time-dependent on the expression of bFGF and TGFβ1 in fibroblast cell in vitro. This mechanism can be employed in the prospective treatment of physical lesion. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  19. Criblage in vitro des graines d'accessions locales de ricin ( Ricinus ...

    African Journals Online (AJOL)

    Le ricin (Ricinus communis L.) est une plante peu exigeante dont la culture offre d'énormes potentialités économiques pour les exploitants agricoles sénégalais. L'identification de génotypes performants avec des rendements acceptables en conditions de stress salin constitue une des solutions pour promouvoir cette ...

  20. Three Huntington's Disease Specific Mutation-Carrying Human Embryonic Stem Cell Lines Have Stable Number of CAG Repeats upon In Vitro Differentiation into Cardiomyocytes.

    Directory of Open Access Journals (Sweden)

    Laureen Jacquet

    Full Text Available Huntington disease (HD; OMIM 143100, a progressive neurodegenerative disorder, is caused by an expanded trinucleotide CAG (polyQ motif in the HTT gene. Cardiovascular symptoms, often present in early stage HD patients, are, in general, ascribed to dysautonomia. However, cardio-specific expression of polyQ peptides caused pathological response in murine models, suggesting the presence of a nervous system-independent heart phenotype in HD patients. A positive correlation between the CAG repeat size and severity of symptoms observed in HD patients has also been observed in in vitro HD cellular models. Here, we test the suitability of human embryonic stem cell (hESC lines carrying HD-specific mutation as in vitro models for understanding molecular mechanisms of cardiac pathology seen in HD patients. We have differentiated three HD-hESC lines into cardiomyocytes and investigated CAG stability up to 60 days after starting differentiation. To assess CAG stability in other tissues, the lines were also subjected to in vivo differentiation into teratomas for 10 weeks. Neither directed differentiation into cardiomyocytes in vitro nor in vivo differentiation into teratomas, rich in immature neuronal tissue, led to an increase in the number of CAG repeats. Although the CAG stability might be cell line-dependent, induced pluripotent stem cells generated from patients with larger numbers of CAG repeats could have an advantage as a research tool for understanding cardiac symptoms of HD patients.

  1. Effects of a very low dose rate of chronic ionizing radiation on the division potential of human embryonic lung fibroblasts in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Croute, F.; Vidal, S.; Soleilhavoup, J.P.; Vincent, C.; Serre, G.; Planel, H.

    1986-01-01

    Among the various parameters that are supposed to play a role in aging at the cellular level, the ''free radical theory'' involves biochemical modifications that can be induced by radiation. Human embryonic lung fibroblasts were serially subcultivated at low density under chronic low dose rate irradiation (40 mrad/day) and in a normal environment. Irradiation increases cell attachment and the population doubling/day throughout their entire in vitro lifespan. Consequently, the doubling potential reached by irradiated cells was higher than that of control cultures. Finally, the total number of cells produced under chronic irradiation was 8-14 times higher than in a normal environment. These results are discussed with respect to the increased enzymatic activities (superoxidismutase, catalase, glutathion-reductase, G6PD) found in some irradiated organisms.

  2. In vitro culture and characterization of putative porcine embryonic germ cells derived from domestic breeds and Yucatan mini pig embryos at Days 20-24 of gestation.

    Science.gov (United States)

    Petkov, Stoyan G; Marks, Hendrik; Klein, Tino; Garcia, Rodrigo S; Gao, Yu; Stunnenberg, Henk; Hyttel, Poul

    2011-05-01

    Embryonic germ cells (EGC) are cultured pluripotent cells derived from primordial germ cells (PGC). This study explored the possibility of establishing porcine EGC from domestic breeds and Yucatan mini pigs using embryos at Days 17-24 of gestation. In vitro culture of PGC from both pooled and individual embryos resulted in the successful derivation of putative EGC lines from Days 20 to 24 with high efficiency. RT-PCR showed that gene expression among all 31 obtained cell lines was very similar, and only minor changes were detected during in vitro passaging of the cells. Genome-wide RNA-Seq expression profiling showed no expression of the core pluripotency markers OCT4, SOX2, and NANOG, although most other pluripotency genes were expressed at levels comparable to those of mouse embryonic stem cells (ESC). Moreover, germ-specific genes such as BLIMP1 retained their expression. Functional annotation clustering of the gene expression pattern of the putative EGC suggests partial differentiation toward endo/mesodermal lineages. The putative EGC were able to form embryoid bodies in suspension culture and to differentiate into epithelial-like, mesenchymal-like, and neuronal-like cells. However, their injection into immunodeficient mice did not result in teratoma formation. Our results suggest that the PGC-derived cells described in this study are EGC-like, but seem to be multipotent rather than pluripotent cells. Nevertheless, the thorough characterization of these cells in this study, and especially the identification of various genes and pathways involved in pluripotency by RNA-Seq, will serve as a rich resource for further derivation of porcine EGC. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Similarities in Gene Expression Profiles during In Vitro Aging of Primary Human Embryonic Lung and Foreskin Fibroblasts

    Directory of Open Access Journals (Sweden)

    Shiva Marthandan

    2015-01-01

    Full Text Available Replicative senescence is of fundamental importance for the process of cellular aging, since it is a property of most of our somatic cells. Here, we elucidated this process by comparing gene expression changes, measured by RNA-seq, in fibroblasts originating from two different tissues, embryonic lung (MRC-5 and foreskin (HFF, at five different time points during their transition into senescence. Although the expression patterns of both fibroblast cell lines can be clearly distinguished, the similar differential expression of an ensemble of genes was found to correlate well with their transition into senescence, with only a minority of genes being cell line specific. Clustering-based approaches further revealed common signatures between the cell lines. Investigation of the mRNA expression levels at various time points during the lifespan of either of the fibroblasts resulted in a number of monotonically up- and downregulated genes which clearly showed a novel strong link to aging and senescence related processes which might be functional. In terms of expression profiles of differentially expressed genes with age, common genes identified here have the potential to rule the transition into senescence of embryonic lung and foreskin fibroblasts irrespective of their different cellular origin.

  4. Tetranectin is a novel marker for myogenesis during embryonic development, muscle regeneration, and muscle cell differentiation in vitro

    DEFF Research Database (Denmark)

    Wewer, U M; Iba, K; Durkin, M E

    1998-01-01

    Tetranectin, a plasminogen-binding protein with a C-type lectin domain, is found in both serum and the extracellular matrix. In the present study we report that tetranectin is closely associated with myogenesis during embryonic development, skeletal muscle regeneration, and muscle cell......, and both cytoplasmic and cell surface tetranectin immunostaining become apparent. Finally, we demonstrate that while tetranectin mRNA is translated to a similar degree in developing limbs and lung, the protein does not seem to be tissue associated in the lung as it is in the limbs. This indicates...... is observed in normal adult muscle. However, during skeletal muscle regeneration induced by the intramuscular injection of the myotoxic anesthetic Marcaine, myoblasts, myotubes, and the stumps of damaged myofibers exhibit intense tetranectin immunostaining. Tetranectin is also present in regenerating muscle...

  5. Etude in vitro de l'effet des tanins de Newbouldia laevis et de ...

    African Journals Online (AJOL)

    Un témoin négatif (tampon PBS) a été inclus dans chaque test. L'observation sous microscope et le dénombrement des L3 ayant migré par rapport au nombre total de larves déposées dans l'insert ont permis de calculer le taux de la migration larvaire. Les extraits de Newbouldia laevis et de Zanthoxylum zanthoxyloïdes ...

  6. PDGFRα(+) Cells in Embryonic Stem Cell Cultures Represent the In Vitro Equivalent of the Pre-implantation Primitive Endoderm Precursors.

    Science.gov (United States)

    Lo Nigro, Antonio; de Jaime-Soguero, Anchel; Khoueiry, Rita; Cho, Dong Seong; Ferlazzo, Giorgia Maria; Perini, Ilaria; Abon Escalona, Vanesa; Aranguren, Xabier Lopez; Chuva de Sousa Lopes, Susana M; Koh, Kian Peng; Conaldi, Pier Giulio; Hu, Wei-Shou; Zwijsen, An; Lluis, Frederic; Verfaillie, Catherine M

    2017-02-14

    In early mouse pre-implantation development, primitive endoderm (PrE) precursors are platelet-derived growth factor receptor alpha (PDGFRα) positive. Here, we demonstrated that cultured mouse embryonic stem cells (mESCs) express PDGFRα heterogeneously, fluctuating between a PDGFRα+ (PrE-primed) and a platelet endothelial cell adhesion molecule 1 (PECAM1)-positive state (epiblast-primed). The two surface markers can be co-detected on a third subpopulation, expressing epiblast and PrE determinants (double-positive). In vitro, these subpopulations differ in their self-renewal and differentiation capability, transcriptional and epigenetic states. In vivo, double-positive cells contributed to epiblast and PrE, while PrE-primed cells exclusively contributed to PrE derivatives. The transcriptome of PDGFRα(+) subpopulations differs from previously described subpopulations and shows similarities with early/mid blastocyst cells. The heterogeneity did not depend on PDGFRα but on leukemia inhibitory factor and fibroblast growth factor signaling and DNA methylation. Thus, PDGFRα(+) cells represent the in vitro counterpart of in vivo PrE precursors, and their selection from cultured mESCs yields pure PrE precursors. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  7. Comparative evaluation of different in vitro systems that stimulate germ cell differentiation in human embryonic stem cells.

    Science.gov (United States)

    Richards, Mark; Fong, Chui-Yee; Bongso, Ariff

    2010-02-01

    To explore several culture systems that may prove efficient in driving human embryonic stem cells (hESCs) toward a germ cell lineage. Embryoid bodies (EBs) derived from a female hESC line [HES-3 (XX)] and male hESC line [HES-4 (XY)] were cultured in six different culture conditions: [1] mitotically inactivated porcine ovarian fibroblasts (POF), [2] 100% conditioned medium from POF, [3] 50% conditioned medium from POF, [4] forskolin, [5] trans-retinoic acid (RA), and [6] forskolin and RA. Department of Obstetrics and Gynecology, National University of Singapore Research Laboratories, Singapore. None. None. None. Expression data for both HES-3 and HES-4 differentiating cultures strongly indicated that inactivated POFs encouraged differentiation of hESC EBs into a germ cell lineage. VASA and other germ cell markers were found to be elevated in all six culture conditions. Overall, POFs proved to be the best system for initiating germ cell differentiation, as shown by increases in the expression of several germ cell marker genes in EBs that were cocultured with POFs. Copyright 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  8. Evaluation of human embryonic stem cells and their differentiated fibroblastic progenies as cellular models for in vitro genotoxicity screening.

    Science.gov (United States)

    Vinoth, Kumar Jayaseelan; Manikandan, Jayapal; Sethu, Swaminathan; Balakrishnan, Lakshmidevi; Heng, Alexis; Lu, Kai; Hande, Manoor Prakash; Cao, Tong

    2014-08-20

    This study evaluated human embryonic stem cells (hESC) and their differentiated fibroblastic progenies as cellular models for genotoxicity screening. The DNA damage response of hESCs and their differentiated fibroblastic progenies were compared to a fibroblastic cell line (HEPM, CRL1486) and primary cultures of peripheral blood lymphocytes (PBL), upon exposure to Mitomycin C, gamma irradiation and H2O2. It was demonstrated that hESC-derived fibroblastic progenies (H1F) displayed significantly higher chromosomal aberrations, micronuclei formation and double strand break (DSB) formation, as compared to undifferentiated hESC upon exposure to genotoxic stress. Nevertheless, H1F cell types displayed comparable sensitivities to genotoxic challenge as HEPM and PBL, both of which are representative of somatic cell types commonly used for genotoxicity screening. Subsequently, transcriptomic and pathways analysis identified differential expression of critical genes involved in cell death and DNA damage response upon exposure to gamma irradiation. The results thus demonstrate that hESC-derived fibroblastic progenies are as sensitive as commonly-used somatic cell types for genotoxicity screening. Moreover, hESCs have additional advantages, such as their genetic normality compared to immortalized cell lines, as well as their amenability to scale-up for producing large, standardized quantities of cells for genotoxicity screening on an industrial scale, something which can never be achieved with primary cell cultures. Copyright © 2014. Published by Elsevier B.V.

  9. Efficient differentiation of embryonic stem cells into hepatic cells in vitro using a feeder-free basement membrane substratum.

    Directory of Open Access Journals (Sweden)

    Nobuaki Shiraki

    Full Text Available The endoderm-inducing effect of the mesoderm-derived supportive cell line M15 on embryonic stem (ES cells is partly mediated through the extracellular matrix, of which laminin α5 is a crucial component. Mouse ES or induced pluripotent stem cells cultured on a synthesized basement membrane (sBM substratum, using an HEK293 cell line (rLN10-293 cell stably expressing laminin-511, could differentiate into definitive endoderm and subsequently into pancreatic lineages. In this study, we investigated the differentiation on sBM of mouse and human ES cells into hepatic lineages. The results indicated that the BM components played an important role in supporting the regional-specific differentiation of ES cells into hepatic endoderm. We show here that knockdown of integrin β1 (Itgb1 in ES cells reduced their differentiation into hepatic lineages and that this is mediated through Akt signaling activation. Moreover, under optimal conditions, human ES cells differentiated to express mature hepatocyte markers and secreted high levels of albumin. This novel procedure for inducing hepatic differentiation will be useful for elucidating the molecular mechanisms controlling lineage-specific fates during gut regionalization. It could also represent an attractive approach to providing a surrogate cell source, not only for regenerative medicine, but also for pharmaceutical and toxicologic studies.

  10. Efficiency of embryonic development after intrafollicular and intraoviductal transfer of in vitro and in vivo matured horse oocytes.

    Science.gov (United States)

    Deleuze, S; Goudet, G; Caillaud, M; Lahuec, C; Duchamp, G

    2009-07-15

    In vivo techniques, such as intraoviductal oocyte transfer (OT) and intrafollicular oocyte transfer (IFOT), can be considered as alternatives to bypass the lack of efficient superovulation treatments and the inadequacy of conventional in vitro fertilization techniques in the horse. We compared embryo production after transfer of in vivo recovered oocytes (1) into a recipient's oviduct or (2) into her preovulatory follicle either immediately after ovum pick-up or (3) after in vitro maturation (IVM). Recipients were inseminated with fresh semen of a stallion with a known normal fertility. Ten days after surgery, rates of embryos collected in excess to the number of ovulations were calculated and compared for each group. Embryo collection rates were 32.5% (13 of 40), 5.5% (3 of 55), and 12.8% (6 of 47) for OT, post-IVM IFOT, and immediate IFOT, respectively. Oocyte transfer significantly yielded more embryos than did immediate IFOT and post-IVM IFOT. We also showed that in vitro matured oocytes could successfully be used for IFOT. Our results also suggest that improvement of the IFOT technique could turn it into an inexpensive and easy-to-perform procedure that could be an answer to the inefficiency of superovulation treatments in the mare.

  11. In Vitro T-Cell Generation From Adult, Embryonic, and Induced Pluripotent Stem Cells: Many Roads to One Destination.

    Science.gov (United States)

    Smith, Michelle J; Webber, Beau R; Mohtashami, Mahmood; Stefanski, Heather E; Zúñiga-Pflücker, Juan Carlos; Blazar, Bruce R

    2015-11-01

    T lymphocytes are critical mediators of the adaptive immune system and have the capacity to serve as therapeutic agents in the areas of transplant and cancer immunotherapy. While T cells can be isolated and expanded from patients, T cells derived in vitro from both hematopoietic stem/progenitor cells (HSPCs) and human pluripotent stem cells (hPSCs) offer great potential advantages in generating a self-renewing source of T cells that can be readily genetically modified. T-cell differentiation in vivo is a complex process requiring tightly regulated signals; providing the correct signals in vitro to induce T-cell lineage commitment followed by their development into mature, functional, single positive T cells, is similarly complex. In this review, we discuss current methods for the in vitro derivation of T cells from murine and human HSPCs and hPSCs that use feeder-cell and feeder-cell-free systems. Furthermore, we explore their potential for adoption for use in T-cell-based therapies. © 2015 AlphaMed Press.

  12. Effect of recombinant-LH and hCG in the absence of FSH on in vitro maturation (IVM) fertilization and early embryonic development of mouse germinal vesicle (GV)-stage oocytes.

    Science.gov (United States)

    Dinopoulou, Vasiliki; Drakakis, Peter; Kefala, Stella; Kiapekou, Erasmia; Bletsa, Ritsa; Anagnostou, Elli; Kallianidis, Konstantinos; Loutradis, Dimitrios

    2016-06-01

    During in vitro maturation (IVM), intrinsic and extrinsic factors must co-operate properly in order to ensure cytoplasmic and nuclear maturation. We examined the possible effect of LH/hCG in the process of oocyte maturation in mice with the addition of recombinant LH (r-LH) and hCG in our IVM cultures of mouse germinal vesicle (GV)-stage oocytes. Moreover, the effects of these hormones on fertilization, early embryonic development and the expression of LH/hCG receptor were examined. Nuclear maturation of GV-stage oocytes was evaluated after culture in the presence of r-LH or hCG. Fertilization rates and embryonic development were assessed after 24h. Total RNA was isolated from oocytes of different stages of maturation and from zygotes and embryos of different stages of development in order to examine the expression of LH/hCG receptor, using RT-PCR. The in vitro nuclear maturation rate of GV-stage oocytes that received hCG was significantly higher compared to the control group. Early embryonic development was increased in the hCG and LH cultures of GV oocytes when LH was further added. The LH/hCG receptor was expressed in all stages of in vitro matured mouse oocytes and in every stage of early embryonic development. Addition of hCG in IVM cultures of mouse GV oocytes increased maturation rates significantly. LH, however, was more beneficial to early embryonic development than hCG. This suggests a promising new technique in basic science research or in clinical reproductive medicine. Copyright © 2016 Society for Biology of Reproduction & the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  13. Mise au point d'une technique de culture in vitro d'embryons immatures de Phaseolus

    Directory of Open Access Journals (Sweden)

    Véronique Schmit

    1997-01-01

    Full Text Available Development of an in vitro culture technique for immature Phaseolus embryos. In the interspecific crosses Phaseolus polyanthus (or P. coccineus (i? x P. vulgaris, the hybrid embryos abort very early. Therefore, it is essentiel to develop an in vitro culture technique that allows the rescue of beau embryos at globular or early heart-shaped stages. After several trials conceming the salts composition, the sugar rate and the amino acid concentration of différent in vitro culture media, a technique has been developed for heart-shaped Phaseolus embryos. This technique consists of two stages. In a first step, embryos are cultivated under darkness until their germination on a medium containing the salts of Gamborg et al. (1968, 400 mg . 1` (5mM - 1 -' NHNO,, 1 mg . 1-' thiamine HCI, 5 mg . l` nicotinic acid, 0.5 mg - l` pyridoxine, 1,000 mg . l` -glutamine, 1,000 mg . l` casein hydrolysate, 100 mg . l` myo-inositol, 0.028 mg . P N6-benzyladenine, 30 g . l` sucrase, and 8 g -1-' DIFCO agar. After germination, the embryos are cultivated under light on a second medium that does not contain any NHNO, complément and is poorer in amino acids (100 mg • 1-' L-glutamine. Developed with six deys old heart-shaped embryos of the P. vulgaris Bico de Ouro (NI 637 variety, this technique has proved its efficiency with other P. vulgaris and P. polyanthus génotypes. It allows an average régénération rate of 30% from the total number of cultivated embryos.

  14. Effect of the cryopreservation method used, the embryonic stage and the use of conjugated linoleic acid isomers on the cryotolerance of in vitro-produced bovine embryos

    Directory of Open Access Journals (Sweden)

    Luciana Simões Rafagnin Marinho

    2015-12-01

    Full Text Available Conjugated linoleic acid (CLA might be able to improve the cryotolerance of in vitro-produced (IVP embryos. The effect of two CLA isomers on the cryotolerance of bovine IVP embryos, as well as that of the stage of embryonic development and the method used for cryopreservation was evaluated by three experiments. In Experiment 1, oocytes (n = 3,917 were fertilized in vitro and cultured with 0, 50, 100, or 200 ?M trans-10, cis-12 (t10, c12 CLA. In Experiment 2, fertilized oocytes (n = 2,131 were cultured with 100 ?M t10, c12 or cis-9, trans-11 (c9, t11 CLA, or a combination of both isomers. The embryos were vitrified at the blastocyst (BL or the expanded blastocyst (EB stage. In Experiment 3, oocytes (n = 1,720 were fertilized and cultured with or without 100 ?M t10, c12 CLA, and the blastocysts were vitrified or frozen. Blastocyst development rate as well as the rates of re-expansion and hatching after thawing was recorded. Moreover, the mean cell number and mRNA expression of acetyl-CoA carboxylase (ACC1 and stearoyl-CoA desaturase (SCD1 as well as fatty acid synthase (FASN multienzyme complex were determined. In Experiment 1, the highest concentration of t10, c12 CLA that did not reduce blastocyst development rate was 100 ?M. In Experiment 2, the rates of re-expansion and hatching among the EBs obtained through IVP after supplementation with t10, c12 CLA (73.1% and 57.7%, with c9, t11 CLA (80.0% and 68.6%, with the combination (78.3% and 52.2%, and with the control group (85.4% and 58.3% were similar. At the BL stage, the rates of re-expansion and hatching were lower than those at the EB stage, and CLA combination allowed a hatching rate (8.0% lower than that observed in the control group (40.0%. In Experiment 3, the hatching rates for vitrified EBs (vitrified control; 67.4% and vitrified CLA EBs (65.8% were higher than those obtained for frozen EBs, exposed (13.3% or not exposed (28.6% to CLA. In addition, in Experiment 3, the hatching rate was

  15. The effects of pyridaben pesticide on the DNA integrity of sperms and early in vitro embryonic development in mice

    Directory of Open Access Journals (Sweden)

    Ghodrat Ebadi Manas

    2013-01-01

    Full Text Available Background: Pyridaben, a pyridazinone derivative, is a new acaricide and insecticide for control of mites and some insects such as white flies, aphids and thrips. Objective: This study was designed to elucidate how pyridaben can affect the sperms' morphological parameters, its DNA integrity, and to estimate the effect of various quantities of pyridaben on in vitro fertilization rate. Materials and Methods: In this study, 80 adult male Balb/C strain mice were used. Animals were divided into control and two test groups. Control group received distilled water. The test group was divided into two subgroups, viz, high dose (212 mg/kg/day and low dose (53 mg/kg/day and they received the pyridaben, orally for duration of 45 days. The spermatozoa were obtained from caudae epididymides on day 45 in all groups. Sperm viability, protamin compression (nuclear maturity, DNA double-strand breaks, and in vitro fertilizing (IVF ability were examined. Results: The pyridaben treatment provoked a significant decrease in sperm population and viability in epididymides. The data obtained from this experiment revealed that, the pyridaben brings about negative impact on the sperm maturation and DNA integrity in a time-dependent manner, which consequently caused a significant (p<0.05 reduction in IVF capability. Embryo developing arrest was significantly (p<0.05 higher in treated than the control group. Conclusion: Theses results confirmed that, the pyridaben is able to induce DNA damage and chromatin abnormalities in spermatozoa which were evident by low IVF rate.

  16. MicroRNA Profiling Reveals Unique miRNA Signatures in IGF-1 Treated Embryonic Striatal Stem Cell Fate Decisions in Striatal Neurogenesis In Vitro

    Directory of Open Access Journals (Sweden)

    Soumya Pati

    2014-01-01

    Full Text Available The striatum is considered to be the central processing unit of the basal ganglia in locomotor activity and cognitive function of the brain. IGF-1 could act as a control switch for the long-term proliferation and survival of EGF + bFGF-responsive cultured embryonic striatal stem cell (ESSC, while LIF imposes a negative impact on cell proliferation. The IGF-1-treated ESSCs also showed elevated hTERT expression with demonstration of self-renewal and trilineage commitment (astrocytes, oligodendrocytes, and neurons. In order to decipher the underlying regulatory microRNA (miRNAs in IGF-1/LIF-treated ESSC-derived neurogenesis, we performed in-depth miRNA profiling at 12 days in vitro and analyzed the candidates using the Partek Genome Suite software. The annotated miRNA fingerprints delineated the differential expressions of miR-143, miR-433, and miR-503 specific to IGF-1 treatment. Similarly, the LIF-treated ESSCs demonstrated specific expression of miR-326, miR-181, and miR-22, as they were nonsignificant in IGF-treated ESSCs. To elucidate the possible downstream pathways, we performed in silico mapping of the said miRNAs into ingenuity pathway analysis. Our findings revealed the important mRNA targets of the miRNAs and suggested specific interactomes. The above studies introduced a new genre of miRNAs for ESSC-based neuroregenerative therapeutic applications.

  17. A well-refined in vitro model derived from human embryonic stem cell for screening phytochemicals with midbrain dopaminergic differentiation-boosting potential for improving Parkinson's disease.

    Science.gov (United States)

    Hsieh, Wen-Ting; Chiang, Been-Huang

    2014-07-09

    Stimulation of endogenous neurogenesis is a potential approach to compensate for loss of dopaminergic neurons of substantia nigra compacta nigra (SNpc) in patients with Parkinson's disease (PD). This objective was to establish an in vitro model by differentiating pluripotent human embryonic stem cells (hESCs) into midbrain dopaminergic (mDA) neurons for screening phytochemicals with mDA neurogenesis-boosting potentials. Consequently, a five-stage differentiation process was developed. The derived cells expressed many mDA markers including tyrosine hydroxylase (TH), β-III tubulin, and dopamine transporter (DAT). The voltage-gated ion channels and dopamine release were also examined for verifying neuron function, and the dopamine receptor agonists bromocriptine and 7-hydroxy-2-(dipropylamino)tetralin (7-OH-DPAT) were used to validate our model. Then, several potential phytochemicals including green tea catechins and ginsenosides were tested using the model. Finally, ginsenoside Rb1 was identified as the most potent phytochemical which is capable of upregulating neurotrophin expression and inducing mDA differentiation.

  18. A protocol for the differentiation of human embryonic stem cells into dopaminergic neurons using only chemically defined human additives: Studies in vitro and in vivo.

    Science.gov (United States)

    Iacovitti, Lorraine; Donaldson, Angela E; Marshall, Cheryl E; Suon, Sokreine; Yang, Ming

    2007-01-05

    Our ability to use human embryonic stem (hES) cells in cell replacement therapy for Parkinson's disease depends on the discovery of ways to simply and reliably differentiate a dopaminergic (DA) phenotype in these cells. Although several protocols exist for the differentiation of DA traits in hES, they involve the prolonged use of complex media with undefined components, cell conditioned media and/or co-culture with various cells, usually of animal origin. In this study, several well-characterized (H9, BG01) and several new uncharacterized (HUES7, HUES8) hES cell lines were studied for their capacity to differentiate into DA neurons in culture using a novel rapid protocol which uses only chemically-defined human-derived media additives and substrata. Within 3 weeks, cells from all 4 cell lines progressed from the undifferentiated state to beta-tubulin III positive cells expressing DA markers in vitro. Moreover, transplantation of these cells into the striata of 6-hydroxydopamine-treated rats at the neuronal progenitor stage resulted in the appearance of differentiated DA traits in vivo 2-3 weeks later.

  19. Evaluation in vitro de l'activité des écorces de tige de Anogeissus ...

    African Journals Online (AJOL)

    Les bactéries sont à l'origine de réel problème de santé publique à cause de leur implication dans de nombreuses maladies. Leur résistance aux antibiotiques est devenue l'un des problèmes les plus importants dans la lutte contre les maladies infectieuses dans le monde. L'objectif de ce travail est d'évaluer l'activité ...

  20. In vitro oocyte fertilization and subsequent embryonic development after cryopreservation of bovine ovarian tissue, using an effective approach for oocyte collection.

    Science.gov (United States)

    Faheem, Marwa S; Carvalhais, I; Chaveiro, A; Moreira da Silva, F

    2011-05-01

    This study was undertaken to assess dissection/puncture combined technique for collecting large number of oocytes from bovine ovaries and to determine the effect of ovarian tissue cryopreservation on the oocytes capability to undergo in vitro maturation, fertilization and subsequent embryonic development. Ovaries (n=31) of slaughtered cows were cut into small fragments using a scalpel blade and the ovarian tissues were randomly assigned to cryopreserved by slow freezing and vitrification and non cryopreserved (fresh) groups. Oocytes were collected from non-atretic follicles from fresh and post-thawing ovarian tissue by the puncture method. The advantage of this technique appeared through morphologically good quality cumulus-oocyte complex (COC) recovery rate from fresh tissue (31.7±2.0 oocytes/ovary). However, the cryopreservation affected the post thawing total and good quality COC recovery rates from slow freezing (26.6±2.0 and 23.5±2.3 oocytes/ovary, respectively) and vitrification groups (21.7±1.1 and 17.6±1.8 oocyte/ovary, respectively). The maturation rate resulted in significant differences between the fresh tissue (94.1±1.1%) and the two cryopreservation groups. Moreover, this rate was significantly higher in the slow freezing group (80.1±1.3%) than in the vitrification group (73.0±1.9%). No statistical differences were observed in the cleavage and the embryonic developmental rates between fresh tissue group and cryopreservation groups. Furthermore the number of embryos produced per animal was statistically higher for fresh tissues than for slow freezing and the vitrification groups (34.4±1.4, 27.8±3.1 and 22.0±0.7, respectively). In conclusion, dissection method followed by puncture of bovine ovaries greatly maximizes the number of good quality oocytes recovered, as well as the number of embryos obtained per animal. Ovarian tissue can be successfully cryopreserved by slow freezing and vitrification. Copyright © 2011 Elsevier B.V. All rights

  1. DNA oxidation as a potential molecular mechanism mediating drug-induced birth defects: phenytoin and structurally related teratogens initiate the formation of 8-hydroxy-2'-deoxyguanosine in vitro and in vivo in murine maternal hepatic and embryonic tissues.

    Science.gov (United States)

    Liu, L; Wells, P G

    1995-11-01

    A considerable number of teratogens, including the anticonvulsant drug phenytoin and structurally related drugs and environmental chemicals, may be bioactivated by peroxidases, such as prostaglandin H synthase (PHS) and lipoxygenases (LPOs), to a reactive free radical intermediate that initiates birth defects. However, the molecular targets of the reactive free radical intermediates mediating chemical teratogenesis, and hence the fundamental determinants of susceptibility, are poorly understood. In these studies, a teratogenic dose of phenytoin (65 mg/kg), when injected into pregnant CD-1 mice during organogenesis on gestational day 12, initiated the oxidation of DNA in maternal hepatic and embryonic nuclei, forming 8-hydroxy-2'-deoxyguanosine. Significant maternal and embryonic DNA oxidation occurred at 6 and 3 h, respectively, suggesting relative embryonic deficiencies in free radical-related cytoprotective enzymes, although the rates appeared similar. Maximal DNA oxidation in both maternal and embryonic tissues occurred at 6 h, presumably reflecting the balance of DNA oxidation and repair, the latter of which appeared similar in both tissues. Inhibition of phenytoin-initiated embryonic DNA oxidation by the free radical spin trapping agent alpha-phenyl-N-t-butylnitrone (41.5 mg/kg), and by acetylsalicylic acid (10 mg/kg), an inhibitor of the cyclooxygenase component of PHS, was consistent with the previously reported reduction by these inhibitors of phenytoin-initiated murine birth defects. In vitro studies using a horseradish peroxidase (0.5 mg/ml)-H2O2 (5.45 micrograms/ml) bioactivating system for drug-initiated oxidation of 2'-deoxyguanosine (3.74 mM), indicated that the potency of xenobiotic-initiated formation of 8-hydroxy-2'-deoxyguanosine for the structurally related drugs and metabolites phenytoin, 5-(p-hydroxyphenyl)-5-phenylhydantoin, trimethadione, dimethadione, l-mephenytoin, l-nirvanol, d-nirvanol (80 microM each), or thalidomide (64 micro

  2. Pharmacological targeting of the ephrin receptor kinase signalling by GLPG1790 in vitro and in vivo reverts oncophenotype, induces myogenic differentiation and radiosensitizes embryonal rhabdomyosarcoma cells

    Directory of Open Access Journals (Sweden)

    Francesca Megiorni

    2017-10-01

    Full Text Available Abstract Background EPH (erythropoietin-producing hepatocellular receptors are clinically relevant targets in several malignancies. This report describes the effects of GLPG1790, a new potent pan-EPH inhibitor, in human embryonal rhabdomyosarcoma (ERMS cell lines. Methods EPH-A2 and Ephrin-A1 mRNA expression was quantified by real-time PCR in 14 ERMS tumour samples and in normal skeletal muscle (NSM. GLPG1790 effects were tested in RD and TE671 cell lines, two in vitro models of ERMS, by performing flow cytometry analysis, Western blotting and immunofluorescence experiments. RNA interfering experiments were performed to assess the role of specific EPH receptors. Radiations were delivered using an x-6 MV photon linear accelerator. GLPG1790 (30 mg/kg in vivo activity alone or in combination with irradiation (2 Gy was determined in murine xenografts. Results Our study showed, for the first time, a significant upregulation of EPH-A2 receptor and Ephrin-A1 ligand in ERMS primary biopsies in comparison to NSM. GLPG1790 in vitro induced G1-growth arrest as demonstrated by Rb, Cyclin A and Cyclin B1 decrease, as well as by p21 and p27 increment. GLPG1790 reduced migratory capacity and clonogenic potential of ERMS cells, prevented rhabdosphere formation and downregulated CD133, CXCR4 and Nanog stem cell markers. Drug treatment committed ERMS cells towards skeletal muscle differentiation by inducing a myogenic-like phenotype and increasing MYOD1, Myogenin and MyHC levels. Furthermore, GLPG1790 significantly radiosensitized ERMS cells by impairing the DNA double-strand break repair pathway. Silencing of both EPH-A2 and EPH-B2, two receptors preferentially targeted by GLPG1790, closely matched the effects of the EPH pharmacological inhibition. GLPG1790 and radiation combined treatments reduced tumour mass by 83% in mouse TE671 xenografts. Conclusions Taken together, our data suggest that altered EPH signalling plays a key role in ERMS development and that

  3. Modelling Simple Experimental Platform for In Vitro Study of Drug Elution from Drug Eluting Stents (DES)

    Science.gov (United States)

    Kalachev, L. V.

    2016-06-01

    We present a simple model of experimental setup for in vitro study of drug release from drug eluting stents and drug propagation in artificial tissue samples representing blood vessels. The model is further reduced using the assumption on vastly different characteristic diffusion times in the stent coating and in the artificial tissue. The model is used to derive a relationship between the times at which the measurements have to be taken for two experimental platforms, with corresponding artificial tissue samples made of different materials with different drug diffusion coefficients, to properly compare the drug release characteristics of drug eluting stents.

  4. Chromosomes and irradiation: in vitro study of the action of X-rays on human lymphocytes; Chromosomes et radiations: etude in vitro de l'action des rayons X sur les lymphocytes humains

    Energy Technology Data Exchange (ETDEWEB)

    Mouriquand, C.; Patet, J.; Gilly, C.; Wolff, C

    1966-07-01

    Radioinduced chromosomal aberrations were studied in vitro on leukocytes of human peripheral blood after x irradiation at 25, 50, 100, 200, and 300 R. The numeric and structural anomalies were examined on 600 karyotypes. The relationship between these disorders and the dose delivered to the blood are discussed. An explanation on their mechanism of formation is tentatively given. (authors) [French] L'etude in vitro des anomalies chromosomiques radioinduites a ete pratiquee sur des leucocytes de sang peripherique preleve chez 4 sujets et irradie aux doses de 25, 50, 100, 200, 300 R. Les aberrations numeriques et structurales ont ete examinees sur 600 caryotypes. Les rapports entre ces anomalies et les doses appliquees sont etudies. Une hypothese sur leur mecanisme de formation est avancee. (auteurs)

  5. The Effect of Elevated CO2 and Increased Temperature on in Vitro Fertilization Success and Initial Embryonic Development of Single Male:Female Crosses of Broad-Cast Spawning Corals at Mid- and High-Latitude Locations

    Directory of Open Access Journals (Sweden)

    Miriam Schutter

    2015-05-01

    Full Text Available The impact of global climate change on coral reefs is expected to be most profound at the sea surface, where fertilization and embryonic development of broadcast-spawning corals takes place. We examined the effect of increased temperature and elevated CO2 levels on the in vitro fertilization success and initial embryonic development of broadcast-spawning corals using a single male:female cross of three different species from mid- and high-latitude locations: Lyudao, Taiwan (22° N and Kochi, Japan (32° N. Eggs were fertilized under ambient conditions (27 °C and 500 μatm CO2 and under conditions predicted for 2100 (IPCC worst case scenario, 31 °C and 1000 μatm CO2. Fertilization success, abnormal development and early developmental success were determined for each sample. Increased temperature had a more profound influence than elevated CO2. In most cases, near-future warming caused a significant drop in early developmental success as a result of decreased fertilization success and/or increased abnormal development. The embryonic development of the male:female cross of A. hyacinthus from the high-latitude location was more sensitive to the increased temperature (+4 °C than the male:female cross of A. hyacinthus from the mid-latitude location. The response to the elevated CO2 level was small and highly variable, ranging from positive to negative responses. These results suggest that global warming is a more significant and universal stressor than ocean acidification on the early embryonic development of corals from mid- and high-latitude locations.

  6. Interaktionen des Flavonoids Flavon mit dem P-glykoprotein 170 beeinflussen Parameter der Tumorentstehung in vitro und in vivo

    OpenAIRE

    Schumacher, Marco

    2014-01-01

    Die erhöhte Expression ATP-abhängiger Effluxpumpen, wie des Phosphoglykoproteins-170 (P-gp), des Multidrugresistance related proteins-2 (MRP 2) oder des Breast cancer resistance proteins (BCRP), im Tumorgewebe reduziert die intrazellulären Konzentrationen der transportierten Tumortherapeutika. Damit wird die Prognose einer erfolgreichen Therapie von Krebserkrankungen verschlechtert. Flavonoide aus Pflanzen könnten potente Inhibitoren der ABC Transporter darstellen und sich somit als reversing...

  7. Growth inhibition of mouse embryonic stem (ES) cells on the feeders ...

    African Journals Online (AJOL)

    Mouse embryonic stem cells (mESCs) can be propagated in vitro on the feeders of mouse embryonic fibroblasts. In this study, we found growth inhibition of mESCs cultured on embryonic fibroblast feeders derived from different livestock animals. Under the same condition, mESCs derived from mouse embryonic fibroblast ...

  8. Three step derivation of cartilage like tissue from human embryonic stem cells by 2D-3D sequential culture in vitro and further implantation in vivo on alginate/PLGA scaffolds.

    Science.gov (United States)

    Bai, Hai Yan; Chen, Gui An; Mao, Gen Hong; Song, Tian Ran; Wang, Yan Xia

    2010-08-01

    In this study a three step culture system, 2D-3D sequential culture in vitro and further implantation in vivo was developed to induce human embryonic stem cells (hESCs) into cartilage like tissues. Five-day-old embryoid bodies were plated for chondrogenic induction for 27 days (step1), then the cells were suspended in alginate and seeded onto polylactic-co-glycolic acid (PLGA) scaffolds for 3D cultivation for 7 days (step 2) and the cells/alginate/PLGA complexes were further transplanted into nude mice for 8 weeks (step 3). At same time, some of complexes were cultured in vitro up to 8 weeks. At the end of step 1, cells exhibited fibroblast-like morphology and expressed chondrocyte-specific markers, Sox 9 and collagen II. During the following 8 weeks of 3D cultivation in vitro, cells displayed spherical morphology, decreased immunoreactivity to Sox-9 and increased one to collagen II, demonstrated further differentiation to mature chondrocyte. In implanted grafts, not only cells appeared typical chondrocytes shape and markers but also cartilage like tissues were formed. These results indicate that 2D-3D sequential culture in vitro is an efficient protocol to induce hESCs differentiates into chondrocytes, while the three step culture system may be an appropriate procedure to derive cartilage like tissues from hESCs. (c) 2010 Wiley Periodicals, Inc.

  9. Higher O-GlcNAc Levels Are Associated with Defects in Progenitor Proliferation and Premature Neuronal Differentiation during in-Vitro Human Embryonic Cortical Neurogenesis

    Directory of Open Access Journals (Sweden)

    Shama Parween

    2017-12-01

    Full Text Available The nutrient responsive O-GlcNAcylation is a dynamic post-translational protein modification found on several nucleocytoplasmic proteins. Previous studies have suggested that hyperglycemia induces the levels of total O-GlcNAcylation inside the cells. Hyperglycemia mediated increase in protein O-GlcNAcylation has been shown to be responsible for various pathologies including insulin resistance and Alzheimer's disease. Since maternal hyperglycemia during pregnancy is associated with adverse neurodevelopmental outcomes in the offspring, it is intriguing to identify the effect of increased protein O-GlcNAcylation on embryonic neurogenesis. Herein using human embryonic stem cells (hESCs as model, we show that increased levels of total O-GlcNAc is associated with decreased neural progenitor proliferation and premature differentiation of cortical neurons, reduced AKT phosphorylation, increased apoptosis and defects in the expression of various regulators of embryonic corticogenesis. As defects in proliferation and differentiation during neurodevelopment are common features of various neurodevelopmental disorders, increased O-GlcNAcylation could be one mechanism responsible for defective neurodevelopmental outcomes in metabolically compromised pregnancies such as diabetes.

  10. Carcino-embryonic antigen in monitoring the growth of human colon adenocarcinoma tumour cells SK-CO-1 and HT-29 in vitro and in nude mice

    DEFF Research Database (Denmark)

    Sölétormos, G; Fogh, J M; Sehested-Hansen, B

    1997-01-01

    A set of experimental model systems were designed to investigate (a) the inter-relationship between growth of two human cancer cell lines (SK-CO-1, HT-29) and carcino-embryonic antigen (CEA) kinetics; and (b) whether neoplastic growth or CEA concentration is modulated by human growth hormone (h....... In conclusion, our results suggest that experimental models may be useful for investigating the role of serological markers as monitors of increasing tumour burden. It will be of interest to investigate the performance of those model systems in examining the effect of cytotoxic agents in neoplastic growth....

  11. Impact of homeopathic remedies on the expression of lineage differentiation genes: an in vitro approach using embryonic stem cells.

    Science.gov (United States)

    Jyoti, Saras; Tandon, Simran

    2016-05-01

    Well-documented studies of the potential effects and safety of homeopathic medicines in pregnancy are required. In this study, specific genes were studied which could serve as biomarkers for specification of three lineages to predict the safety of homeopathic remedies using mouse embryonic stem (ES) cells. Thus, the present work was to study the effects of homeopathic remedies taken during pregnancy using ES cells as the model. Mouse ES cells were exposed to 30C potency of Nux Vomica and Sepia, which are homeopathic medicines prescribed for the management of pregnancy related symptoms. Cytotoxicity studies were done using a modified Embryonic Stem cell test (EST). The expression levels of key genes and proteins were analyzed using real time polymerase chain reaction and immunocytochemistry, respectively. Homeopathic treatment led to modulations in the expression of certain lineage specific genes but this difference was not significant with respect to solvent control and showed normal differentiation as demonstrated by the expression of α/β MHC and α-actinin proteins in the differentiated ES cells. Our study for the first time has shown the feasibility of using ES cells in the developmental toxicity testing of remedies. The results suggest that they are not associated with developmental toxicity. Copyright © 2015 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

  12. The Effect of Lysophosphatidic Acid during In Vitro Maturation of Bovine Oocytes: Embryonic Development and mRNA Abundances of Genes Involved in Apoptosis and Oocyte Competence

    Directory of Open Access Journals (Sweden)

    Dorota Boruszewska

    2014-01-01

    Full Text Available In the present study we examined whether LPA can be synthesized and act during in vitro maturation of bovine cumulus oocyte complexes (COCs. We found transcription of genes coding for enzymes of LPA synthesis pathway (ATX and PLA2 and of LPA receptors (LPAR 1–4 in bovine oocytes and cumulus cells, following in vitro maturation. COCs were matured in vitro in presence or absence of LPA (10−5 M for 24 h. Supplementation of maturation medium with LPA increased mRNA abundance of FST and GDF9 in oocytes and decreased mRNA abundance of CTSs in cumulus cells. Additionally, oocytes stimulated with LPA had higher transcription levels of BCL2 and lower transcription levels of BAX resulting in the significantly lower BAX/BCL2 ratio. Blastocyst rates on day 7 were similar in the control and the LPA-stimulated COCs. Our study demonstrates for the first time that bovine COCs are a potential source and target of LPA action. We postulate that LPA exerts an autocrine and/or paracrine signaling, through several LPARs, between the oocyte and cumulus cells. LPA supplementation of maturation medium improves COC quality, and although this was not translated into an enhanced in vitro development until the blastocyst stage, improved oocyte competence may be relevant for subsequent in vivo survival.

  13. Effect of ROCK inhibitor Y-27632 on normal and variant human embryonic stem cells (hESCs) in vitro: its benefits in hESC expansion.

    Science.gov (United States)

    Gauthaman, Kalamegam; Fong, Chui-Yee; Bongso, Ariff

    2010-03-01

    The Rho associated coiled coil protein kinase (ROCK) dependent signaling pathway plays an important role in numerous physiological functions such as cell proliferation, adhesion, migration and inflammation. Human embryonic stem cells (hESCs) undergo differentiation and poor survival after single cell dissociation in culture thus limiting their expansion for cell based therapies. We evaluated the role of the selective ROCK inhibitor Y-27632 on hESC colonies and disassociated single hESCs from two different hESC lines. Karyotypically normal hESCs (HES3) and variant hESCs (BG01V) were treated with Y-27632 at 5, 10 and 20 muM concentrations for 72 h and its effects on hESC self renewal, colony morphology, cell cycle and pluripotency were evaluated. Increased cell proliferation of both HES3 and BG01V were observed for all three concentrations compared to untreated controls following passaging of cell clusters or dissociated single cells and some of these increases were statistically significant. Cell cycle assay demonstrated normal cell cycle progression with no peaks evident of apoptosis. No morphological differentiation was evident following treatment with the highest concentration of Y-27632 (20 muM) and the stemness related genes continued to be highly expressed in both HES3 and BG01V cells compared to untreated controls. The results confirmed that Y-27632 is a useful agent that aids in the expansion of undifferentiated hESC numbers for downstream applications in regenerative medicine.

  14. Neural differentiation of human embryonic stem cells as an in vitro tool for the study of the expression patterns of the neuronal cytoskeleton during neurogenesis.

    Science.gov (United States)

    Liu, Chao; Zhong, Yongwang; Apostolou, Andria; Fang, Shengyun

    2013-09-13

    The neural differentiation of human embryonic stem cells (ESCs) is a potential tool for elucidating the key mechanisms involved in human neurogenesis. Nestin and β-III-tubulin, which are cytoskeleton proteins, are marker proteins of neural stem cells (NSCs) and neurons, respectively. However, the expression patterns of nestin and β-III-tubulin in neural derivatives from human ESCs remain unclear. In this study, we found that neural progenitor cells (NPCs) derived from H9 cells express high levels of nestin and musashi-1. In contrast, β-III-tubulin was weakly expressed in a few NPCs. Moreover, in these cells, nestin formed filament networks, whereas β-III-tubulin was distributed randomly as small particles. As the differentiation proceeded, the nestin filament networks and the β-III-tubulin particles were found in both the cell soma and the cellular processes. Moreover, the colocalization of nestin and β-III-tubulin was found mainly in the cell processes and neurite-like structures and not in the cell soma. These results may aid our understanding of the expression patterns of nestin and β-III-tubulin during the neural differentiation of H9 cells. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Functional roles of Nurr1, Pitx3, and Lmx1a in neurogenesis and phenotype specification of dopamine neurons during in vitro differentiation of embryonic stem cells.

    Science.gov (United States)

    Hong, Sunghoi; Chung, Sangmi; Leung, Kaka; Hwang, Insik; Moon, Jisook; Kim, Kwang-Soo

    2014-03-01

    To elucidate detailed functional mechanisms of key fate-determining transcription factors (eg, Nurr1, Pitx3, and Lmx1a) and their functional interplay for midbrain dopamine (mDA) neurons, we developed highly efficient gain-of-function system by transducing the neural progenitors (NPs) derived from embryonic stem cells (ESCs) with retroviral vectors, allowing the analysis of downstream molecular and cellular effects. Overexpression of each factors, Nurr1, Pitx3, and Lmx1a robustly promoted the dopaminergic differentiation of ESC-NP cells exposed to sonic hedgehog (SHH) and fibroblast growth factor 8 (FGF8). In addition, each of these factors directly interacts with potential binding sites within the tyrosine hydroxylase (TH) gene and activated its promoter activity. Interestingly, however, overexpression of Nurr1, but not of Pitx3 or Lmx1a, generated a significant number of nonneuronal TH-positive cells. In line with this, Pitx3 and Lmx1a, but not Nurr1, induced expression of the Ngn2 gene, which is critical for neurogenesis. We also observed that Pitx3 directly bound to its potential binding sites within the Ngn2 gene and the pan-neuronal marker β-tubulin III gene, suggesting that Pitx3 contributes to mDA neurogenesis by directly regulating these genes. Taken together, our data demonstrate that key mDA regulators (Nurr1, Pitx3, and Lmx1a) play overlapping as well as distinct roles during neurogenesis and neurotransmitter phenotype determination of mDA neurons.

  16. Effect of long-term culturing on the potential of mouse embryonic stem cells for in vitro and in vivo development

    Energy Technology Data Exchange (ETDEWEB)

    Mitalipov, Sh.M.; Mitalipova, M.M.; Ivanov, V.I.

    1994-11-01

    We performed comparative analysis of in vitro and in vivo pluripotency for two clones of ES-D3 cells subjected to different number of passages after the beginning of subcloning. Both clones of ES cells produced characteristically shaped colonies and embryoid bodies during culturing in suspension. High activity of alkaline phosphatase was demonstrated in ES cells by cytochemical staining. The proportion of aneuploid ES cells increased with the increase in the number of passages, as shown by karyotyping. Experiments on producing chimeric mice using ES cells have shown that clone D3W (passage 17) exceeds clone D3M (passage 42) both in terms of chimera proportion among the offspring and in terms of the extent of coat chimerism (proportion of agouti coat color (ES component) in the coat of chimeras). 26 refs., 4 figs., 3 tabs.

  17. Cysteamine supplementation during in vitro maturation of slaughterhouse- and opu-derived bovine oocytes improves embryonic development without affecting cryotolerance, pregnancy rate, and calf characteristics.

    Science.gov (United States)

    Merton, J S; Knijn, H M; Flapper, H; Dotinga, F; Roelen, B A J; Vos, P L A M; Mullaart, E

    2013-09-01

    Optimization of ovum pick up (OPU) followed by in vitro embryo production (IVP) is strongly driven by the needs of both beef and dairy cattle breeders to enhance genetic improvement. The rapidly growing use of genomic selection in cattle has increased the interest in using OPU-IVP technology to increase the number of embryos and offspring per donor, thus allowing enhanced selection intensity for the next generation. The aim of this study was to optimize embryo production through supplementation of cysteamine during in vitro maturation (IVM) and in vitro culture (IVC) of both slaughterhouse- and OPU-derived oocytes. The effects on embryo production and on embryo cryotolerance, post-transfer embryo survival, and calf characteristics, including gestation length, birth weight, perinatal mortality, and sex ratio were studied. In study 1, immature slaughterhouse-derived cumulus-oocyte complexes (COCs) were matured in IVM medium supplemented with or without 0.1 mM cysteamine, fertilized and cultured for 7 days in 0.5 ml SOFaaBSA. In study 2, cysteamine was present during both IVM (0.1 mM) and IVC (0.01, 0.05, 0.1 mM) from Days 1 to 4. In study 3, OPU-derived COCs were matured in medium supplemented with or without 0.1 mM cysteamine in a 2 × 2 factorial design (OPU week and cysteamine treatment). Embryos were evaluated for stage and grade on Day 7 and, depending on the number of transferable embryos and recipients available, the embryos were transferred either fresh or frozen-thawed at a later date. The presence of cysteamine during IVM significantly increased the embryo production rate with slaughterhouse-derived COCs (24.0% vs. 19.4%). The higher number of embryos at Day 7 was due to an increased number of blastocysts, whereas the distribution of embryos among different quality grades and cryotolerance was not affected. Embryo production rate was negatively affected when cysteamine was present during both the processes of IVM and IVC during Days 1 to 4 of culture (13

  18. Sucrose stimulates branching morphogenesis of embryonic mouse lung in vitro: a problem of osmotic balance between lumen fluid and culture medium.

    Science.gov (United States)

    Nogawa, Hiroyuki; Hasegawa, Yoko

    2002-10-01

    In organ cultures of lung rudiments from 11-day mouse embryos, it was found that addition of sucrose to the culture medium stimulated branching morphogenesis and reduced lumen distension. Two possible roles of sucrose were postulated: one as a nutrient and another as a generator of osmotic pressure inducing osmosis of water from the lumen fluid to the culture medium across a simple columnar epithelial cell layer. To assess which was the case, branching morphogenesis was investigated in lung rudiments cultured in medium in which osmotic pressure was increased by the addition of lactose or NaCl rather than sucrose: similar acceleration of branching was observed in both. In another experiment, lumen fluid of cultured lung rudiments was mechanically drained each day, and significantly stimulated branching morphogenesis was observed even when sucrose was not added to the culture medium. Heparin is known to induce abnormal lumen distension and inhibits branching morphogenesis. Heparin-induced abnormal morphogenesis was prevented either by the addition of sucrose to the culture medium or by the mechanical drainage of lumen fluid. These results suggest that lumen distension caused by the accumulation of lumen fluid disrupts lung branching morphogenesis in vitro, even when the mechanism of branching morphogenesis is intact.

  19. Effects of fetal calf serum, phenazine ethosulfate and either glucose or fructose during in vitro culture of bovine embryos on embryonic development after cryopreservation.

    Science.gov (United States)

    Barceló-Fimbres, M; Seidel, G E

    2007-11-01

    This study investigated effects of hexoses, fetal calf serum (FCS), and phenazine ethosulfate (PES) during the culture of bovine embryos on blastocyst development and survival after cryopreservation by slow freezing or vitrification. The basal, control medium was chemically defined (CDM) plus 0.5% fatty acid-free BSA. In vitro-produced bovine zygotes were cultured in CDM-1 with 0.5 mM glucose; after 60 hr, 8-cell embryos were cultured 4.5 days in CDM-2. The 8-cell embryos were randomly allocated to a 2 x 3 x 2 x 3 factorial experimental design with two energy substrates (2 mM glucose or fructose); three additives (0.3 microM PES, 10% FCS, and control); two cryopreservation methods using no animal products (conventional slow freezing or vitrification); and semen from three bulls with two replicates for each bull. A total of 1,107 blastocysts were produced. Fructose resulted in 13% more blastocysts per oocyte than glucose (37.2% vs. 32.9%), and per 8-cell embryo (51.3% vs. 45.3%; P 0.1) control, FCS, or PES for blastocysts per oocyte or per 8-cell embryo. There was a significant interaction (P embryos with PES, which reduces cytoplasmic lipid content, improved cryotolerance of bovine embryos; post-cryopreservation survival of blastocysts averaged over vitrification and slow freezing (between which there was no difference) was 91.9%, 84.9%, and 60.2% of unfrozen controls (P < 0.01) for PES, control, and FCS groups, respectively. (c) 2007 Wiley-Liss, Inc.

  20. Replacement of serum with sericin in in vitro maturation and culture media: Effects on embryonic developmental competence of Sanjabi sheep embryo during breeding season.

    Science.gov (United States)

    Hajarian, H; Aghaz, F; Karami Shabankareh, H

    2017-04-01

    Sericin is a water-soluble component of silk and has been used as a biomaterial due to its antibacterial and ultraviolet radiation-resistant properties. This study was designed to evaluate the effect of sericin supplementation, as a serum replacement, in maturation and culture media on the meiotic competence of oocytes or in vitro culture of ovine embryos. In experiment 1, oocytes were matured in the presence of 10% fetal ovine serum (FOS), 0.1% polyvinyl alcohol (PVA) and different concentrations of sericin (0.1, 0.5, 1 and 2.5%), for 24 h. The addition of 0.5% sericin to maturation medium increased the rates of maturation to metaphase II of oocytes compared with those in cultures with 0.1% PVA. Following fertilization, blastocyst development was higher for oocytes matured with 0.5% of sericin compared with 0.1% PVA. However, the rates of nuclear maturation of oocytes and blastocyst development under FOS and 0.5% sericin were not significantly different. In experiment 2, presumptive zygotes were cultured in the presence of 10% FOS, 0.1% PVA and different concentrations of sericin (0.1, 0.5, 1 and 2.5%), for 7-8 days. The addition of 0.5% sericin to culture medium increased the blastocyst rate compared with those in cultures without sericin or addition of 0.1% PVA and 10% FOS. These results indicate the feasibility of sericin as an alternative protein supplement for IVM and IVC in ovine oocytes and zygotes. Copyright © 2016. Published by Elsevier Inc.

  1. In vitro Untersuchungen zur Wirkung von Phytopharmaka auf die Kontraktilität des Mäuse-Ileums: Mögliche Bedeutung für die Therapie des Reizdarmsyndroms

    OpenAIRE

    Hagelauer, Daniela

    2007-01-01

    Das Reizdarmsyndrom ist eine der häufigsten Erkrankungen des Gastrointestinaltrakts und durch vielfältige Symptome unterschiedlicher Pathogenese gekennzeichnet. Dabei steht eine gestörte Motilität, die zum einen durch Störungen des enterischen Nervensystems, zum anderen auf reflektorischem Weg durch eine erhöhte Sensibilität, aber auch durch inflammatorische Prozesse hervorgerufen sein kann, im Vordergrund. In der Therapie des Reizdarmsyndroms werden häufig Phytotherapeutika eingesetzt, so da...

  2. Identification des sources de tolérance au stress hydrique sur des espèces sauvages de la famille des Cucurbitacées en cutlture in vitro

    Directory of Open Access Journals (Sweden)

    Toudou A.

    2006-01-01

    Full Text Available Identification of tolerance sources to the water stress on wild species of the cucurbitaceous family in in vitro culture. The objective of this survey is to identify sources of tolerance to the water stress. This will permit to choose the adequate material allowing the transfer of genes governing the drought tolerance to the gene pool of the main cultivated species. Indeed, a method has been developed to evaluate the water stress tolerance in vitro. It is based on the capacity of the calus recuperation after dehydration under a laminar flux hot until a loss of 50% of their fresh weight as a basis. The study included nine accessions of wild species and three cultivated varieties of the cucurbitaceous family. It comes out that the three cultivated varieties (melon, cucumber and watermelon, as well as some wild species accessions are sensitive to the water stress. The wild accessions of Cucumis africanus (L4, Cucumis dipsaceus, Citrullus colocynthis (Saudi Arabia and Citrullus colocynthis (Niger are obviously tolerant.

  3. Role of adiponectin in delayed embryonic development of the short-nosed fruit bat, Cynopterus sphinx.

    Science.gov (United States)

    Anuradha; Krishna, Amitabh

    2014-12-01

    The aim of this study was to evaluate the role of adiponectin in the delayed embryonic development of Cynopterus sphinx. Adiponectin receptor (ADIPOR1) abundance was first observed to be lower during the delayed versus non-delayed periods of utero-embryonic unit development. The effects of adiponectin treatment on embryonic development were then evaluated during the period of delayed development. Exogenous treatment increased the in vivo rate of embryonic development, as indicated by an increase in weight, ADIPOR1 levels in the utero-embryonic unit, and histological changes in embryonic development. Treatment with adiponectin during embryonic diapause showed a significant increase in circulating progesterone and estradiol concentrations, and in production of their receptors in the utero-embryonic unit. The adiponectin-induced increase in estradiol synthesis was correlated with increased cell survival (BCL2 protein levels) and cell proliferation (PCNA protein levels) in the utero-embryonic unit, suggesting an indirect effect of adiponectin via estradiol synthesis by the ovary. An in vitro study further confirmed the in vivo findings that adiponectin treatment increases PCNA levels together with increased uptake of glucose by increasing the abundance of glucose transporter 8 (GLUT8) in the utero-embryonic unit. The in vitro study also revealed that adiponectin, together with estradiol but not alone, significantly increased ADIPOR1 protein levels. Thus, adiponectin works in concert with estradiol to increase glucose transport to the utero-embryonic unit and promote cell proliferation, which together accelerate embryonic development. © 2014 Wiley Periodicals, Inc.

  4. Obtention chez l'echalote (Allium cepa L var aggregatum) de plantes haploides gynogenetiques par culture in vitro de boutons floraux

    OpenAIRE

    Cohat, J.

    1994-01-01

    Des embryons d’origine gynogénétique ont été obtenus par culture in vitro de boutons floraux de plusieurs génotypes d’échalote sur milieu B5 de Gamborg riche en sucre et contenant de l’acide 2,4-dichlorophénoxyacétique et de la 6-benzylaminopurine. La production d’embryons a débuté une cinquantaine de jours après la mise en culture et a été maximale entre le 8 e2 jour et le 1 e16 jour. Les cultures de boutons floraux entiers et d’ovaires isolés ont donné des résultats équivalents. Le stade d’...

  5. Activites antimicrobiennes des extraits de trios plantes medicinales ...

    African Journals Online (AJOL)

    Les potentiels antibactériens des extraits ont été évalués in vitro par la méthode de dilution en milieu liquide associée à l'étalement sur le milieu gélosé Mueller ... Le test phytochimique montre que tous ces extraits contiennent des flavonoïdes, des saponosides, des tanins, des triterpènes et stéroïdes, à l'exception des ...

  6. Differentiation of Mouse Embryonic Stem Cells into Ventral Foregut Precursors

    DEFF Research Database (Denmark)

    Rothová, Michaela; Hölzenspies, Jurriaan J; Livigni, Alessandra

    2016-01-01

    Anterior definitive endoderm (ADE), the ventral foregut precursor, is both an important embryonic signaling center and a unique multipotent precursor of liver, pancreas, and other organs. Here, a method is described for the differentiation of mouse embryonic stem cells (mESCs) to definitive...... endoderm with pronounced anterior character. ADE-containing cultures can be produced in vitro by suspension (embryoid body) culture or in a serum-free adherent monolayer culture. ESC-derived ADE cells are committed to endodermal fates and can undergo further differentiation in vitro towards ventral foregut...

  7. Stepwise development of hematopoietic stem cells from embryonic stem cells.

    Directory of Open Access Journals (Sweden)

    Kenji Matsumoto

    Full Text Available The cellular ontogeny of hematopoietic stem cells (HSCs remains poorly understood because their isolation from and their identification in early developing small embryos are difficult. We attempted to dissect early developmental stages of HSCs using an in vitro mouse embryonic stem cell (ESC differentiation system combined with inducible HOXB4 expression. Here we report the identification of pre-HSCs and an embryonic type of HSCs (embryonic HSCs as intermediate cells between ESCs and HSCs. Both pre-HSCs and embryonic HSCs were isolated by their c-Kit(+CD41(+CD45(- phenotype. Pre-HSCs did not engraft in irradiated adult mice. After co-culture with OP9 stromal cells and conditional expression of HOXB4, pre-HSCs gave rise to embryonic HSCs capable of engraftment and long-term reconstitution in irradiated adult mice. Blast colony assays revealed that most hemangioblast activity was detected apart from the pre-HSC population, implying the early divergence of pre-HSCs from hemangioblasts. Gene expression profiling suggests that a particular set of transcripts closely associated with adult HSCs is involved in the transition of pre-HSC to embryonic HSCs. We propose an HSC developmental model in which pre-HSCs and embryonic HSCs sequentially give rise to adult types of HSCs in a stepwise manner.

  8. Magnesium and Embryonic Development

    OpenAIRE

    Komiya, Yuko; Su, Li-Ting; Chen, Hsiang-Chin; Habas, Raymond; Runnels, Loren W.

    2014-01-01

    Important for energy metabolism, neurotransmission, bone stability, and other cellular functions, Mg2+ has well-established and undisputedly critical roles in adult tissues. Its contributions to early embryonic development are less clearly understood. For decades it has been known that gestational Mg2+ deficiency in rodents produces teratogenic effects. More recent studies have linked deficiency in this vital cation to birth defects in humans, including spina bifida, a neural fold closure def...

  9. Directional differentiation of chicken embryonic stem cells into ...

    African Journals Online (AJOL)

    Chicken embryonic stem (ES) cells are useful for producing transgenic chickens and preserving genetic material in avian species. In this study, the differentiation potential of chicken ES cells was investigated in vitro. Chicken ES cells were differentiated into osteoblasts cultured for 15 to 21 days in the induction media ...

  10. Dynamic Proteomic Profiling of Extra-Embryonic Endoderm Differentiation in Mouse Embryonic Stem Cells.

    Science.gov (United States)

    Mulvey, Claire M; Schröter, Christian; Gatto, Laurent; Dikicioglu, Duygu; Fidaner, Isik Baris; Christoforou, Andy; Deery, Michael J; Cho, Lily T Y; Niakan, Kathy K; Martinez-Arias, Alfonso; Lilley, Kathryn S

    2015-09-01

    During mammalian preimplantation development, the cells of the blastocyst's inner cell mass differentiate into the epiblast and primitive endoderm lineages, which give rise to the fetus and extra-embryonic tissues, respectively. Extra-embryonic endoderm (XEN) differentiation can be modeled in vitro by induced expression of GATA transcription factors in mouse embryonic stem cells. Here, we use this GATA-inducible system to quantitatively monitor the dynamics of global proteomic changes during the early stages of this differentiation event and also investigate the fully differentiated phenotype, as represented by embryo-derived XEN cells. Using mass spectrometry-based quantitative proteomic profiling with multivariate data analysis tools, we reproducibly quantified 2,336 proteins across three biological replicates and have identified clusters of proteins characterized by distinct, dynamic temporal abundance profiles. We first used this approach to highlight novel marker candidates of the pluripotent state and XEN differentiation. Through functional annotation enrichment analysis, we have shown that the downregulation of chromatin-modifying enzymes, the reorganization of membrane trafficking machinery, and the breakdown of cell-cell adhesion are successive steps of the extra-embryonic differentiation process. Thus, applying a range of sophisticated clustering approaches to a time-resolved proteomic dataset has allowed the elucidation of complex biological processes which characterize stem cell differentiation and could establish a general paradigm for the investigation of these processes. © 2015 AlphaMed Press.

  11. Human embryonic stem cells and microenvironment

    Directory of Open Access Journals (Sweden)

    Banu İskender

    2014-09-01

    Full Text Available Human embryonic stem cells (hESCs possess a great potential in the field of regenerative medicine by their virtue of pluripotent potential with indefinite proliferation capabilities. They can self renew themselves and differentiate into three embryonic germ layers. Although they are conventionally grown on mitotically inactivated mouse feeder cells, there are in vitro culture systems utilizing feeder cells of human origin in order to prevent cross-species contamination. Recently established in vitro culture systems suggested that direct interaction with feeder cells is not necessary but rather attachment to a substrate is required to ensure long-term, efficient hESC culture in vitro. This substrate is usually composed of a mixture of extracellular matrix components representing in vivo natural niche. In hESC biology, the mechanism of interaction of hESCs with extracellular matrix molecules remained insufficiently explored area of research due to their transient nature of interaction with the in vivo niche. However, an in vitro culture system established using extracellular matrix molecules may provide a safer alternative to culture systems with feeder cells while paving the way to Good Manufacturing Practice-GMP production of hESCs for therapeutic purposes. Therefore, it is essential to study the interaction of extracellular matrix molecules with hESCs in order to standardize in vitro culture systems for large-scale production of hESCs in a less labor-intensive way. This would not only provide valuable information regarding the mechanisms that control pluripotency but also serve to dissect the molecular signaling pathways of directed differentiation for prospective therapeutic applications in the future. J Clin Exp Invest 2014; 5 (3: 486-495

  12. Magnesium and embryonic development.

    Science.gov (United States)

    Komiya, Yuko; Su, Li-Ting; Chen, Hsiang-Chin; Habas, Raymond; Runnels, Loren W

    2014-01-01

    Important for energy metabolism, neurotransmission, bone stability, and other cellular functions, Mg(2+) has well-established and undisputedly critical roles in adult tissues. Its contributions to early embryonic development are less clearly understood. For decades it has been known that gestational Mg(2+) deficiency in rodents produces teratogenic effects. More recent studies have linked deficiency in this vital cation to birth defects in humans, including spina bifida, a neural fold closure defect in humans that occurs at an average rate of 1 per 1000 pregnancies. The first suggestion that Mg(2+) may be playing a more specific role in early development arose from studies of the TRPM7 and TRPM6 ion channels. TRPM7 and TRPM6 are divalent-selective ion channels in possession of their own kinase domains that have been implicated in the control of Mg(2+) homeostasis in vertebrates. Disruption of the functions of these ion channels in mice as well as in frogs interferes with gastrulation, a pivotal process during early embryonic development that executes the emergence of the body plan and closure of the neural tube. Surprisingly, gastrulation defects produced by depletion of TRPM7 can be prevented by Mg(2+) supplementation, indicating an essential role for Mg(2+) in gastrulation and neural fold closure. The aim of this review is to summarize the data emerging from molecular genetic, biochemical and electrophysiological studies of TRPM6 and TRPM7 and provide a model of how Mg(2+), through these unique channel-kinases, may be impacting early embryonic development.

  13. Evaluation in vitro du potentiel bioprotecteur des champignons mycorhiziens à arbuscules contre le flétrissement bactérien de la tomate

    OpenAIRE

    Crozilhac, Patrice

    2013-01-01

    La bactérie tellurique Ralstonia solanacearum, responsable du flétrissement bactérien de la tomate, constitue une contrainte biotique majeure dans les systèmes de cultures maraîchères en Martinique comme dans toute la ceinture tropicale et subtropicale humide. Dans le contexte actuel de réduction de l’usage des produits phytosanitaires, le développement de stratégies alternatives de gestion des bioagresseurs est indispensable pour permettre aux agriculteurs de continuer à produire en quantité...

  14. An Embryonic Border: Racial Discourses and Compulsory Vaccination for Indian Immigrants at Ports in Colonial Burma, 1870-1937 Une frontière embryonnaire : discours raciaux et vaccination obligatoire des immigrants indiens dans les ports de la Birmanie coloniale, 1870-1937

    Directory of Open Access Journals (Sweden)

    Noriyuki Osada

    2012-10-01

    Full Text Available This paper examines how an administrative border emerged between historically and culturally different and geographically separate regions which nevertheless had been integrated into one state under the colonial power. As a result of three Anglo-Burmese wars in the 19th century, Burma was colonized by the British. During the course of its colonization, the country formally became a province of India. Hence no border had existed between Burma and the rest of India until 1937 when the former was separated from the latter. This connection with India brought Burma unrestricted labour supply from India which was necessary for the growth of the economy. But at the same time, such a vast flow of people included undesirable elements like criminals, beggars and people sick of infectious diseases which caused social problems in Burma. While the government of Burma attempted to deter or exclude those undesirable elements in order to maintain social order, these attempts were frustrated by several factors. In spite of these circumstances, the local government started taking more decisive policy for examinations of immigrants after the middle of the 1910s. No border existed yet, but port cities, especially Rangoon, gradually assumed function of checking people who came from “outside” into “inside”. I would like to call this phenomenon, tentatively, the emergence of an embryonic border. As a part of this phenomenon, this paper describes a history of sanitary regulations for Indian immigrant labourers in colonial Burma, by focusing on a case of implementation of compulsory vaccination at ports. And it points out that those regulations wereCet article montre comment une frontière administrative est apparue entre deux régions historiquement et culturellement différentes et géographiquement séparées réunies toutefois en un État par un pouvoir colonial. Après trois guerres anglo-birmanes au xixe siècle, la Birmanie devint une colonie

  15. Des abeilles et des fruits

    OpenAIRE

    2016-01-01

    La pollinisation est le transfert du pollen des étamines aux pistils suivi de l’acheminement des gamètes mâles (les noyaux spermatiques) via le pollen jusqu’aux ovules. Autrement dit, à part chez les espèces parthénocarpiques (qui produisent des fruits sans fécondation, et donc sans graine, comme le bananier) et les rares espèces apomictiques (qui produisent des graines sans fécondation comme certains agrumes), la pollinisation est un préambule clé à la production de fruits et de graines....

  16. Use of the L-proline analog, L-azetidine-2-carboxylic acid (LACA) to analyse embryonic growth and determination and expression of the chondrogenic phenotype in vivo and in vitro.

    Science.gov (United States)

    Hall, B K

    1978-02-01

    The L-proline analog, L-azetidine-2-carboxylic acid, (LACA) was injected into embryonated eggs of the common fowl, Gallus domesticus at daily doses of 350 microgram/egg on one or several days betweeh 8 and 12 days of incubation. Treatment at nine-days of incubation preferentially retarded embryonic growth to the twelfth day but recovery of growth rate occurred by 15 days of incubation. Relationships between growth and LACA-inhibited aspects of collagenogenesis are discussed. The earliest aged embryos from which isolated stem cells from membrane bones will form secondary cartilage is ten days of incubation. Secondary chondrogenesis on the quadratojugal, a membrane bone of the skull, was inhibited by treatment of whole embryos with LACA at nine days of incubation but not by treatment at eight days. We concluded that an event involving collagen began at nine days of incubation, was blocked by LACA and was part of the process of chondrogenic determination of these stem cells. Addition of LACA to the medium in which already determined stem cells from the quadratojugal were cultured prevented expression of the chondrogenic phenotype. This proline analog is then a useful probe for events relating both to determination and to expression of the differentiated state, and allows conclusions to be drawn regarding the role of collagenogenesis in these events.

  17. Embryonic mortality in buffalo cows

    Directory of Open Access Journals (Sweden)

    G. Neglia

    2010-02-01

    Full Text Available In buffalo species embryonic mortality is considered one of the major causes of fertility loss, especially in the animals that are not mated during their reproductive period. Embryonic loss in animals mated by artificial insemination (AI is 20-40% during seasons characterized by high number of light hours. Also in buffalo naturally mated the incidence of embryonic mortality is about 20% and a higher incidence is observed between 28- 60 days of gestation in buffaloes that conceive during increasing daylight length. A reduced capacity to secrete progesterone seems to explain in part this embryonic mortality but other as yet unidentified factors contribute between 40-50% to the embryonic losses. Treatments with hCG, GnRH agonist or progesterone on Days 5 after AI not always reduce embryonic mortality in buffalo species. Embryonic mortality in buffaloes appears to occur later (Day 25-40 than in cattle and P4 treatments should perhaps be applied later in buffaloes.

  18. 154 Modélisation des conditions d'environnement des bocaux de ...

    African Journals Online (AJOL)

    youness

    Modélisation des conditions d'environnement des bocaux de culture in vitro : bocaux avec agar et vitroplants. Yao TCHETCHE1*, Djézia François-Xavier BOUO BELLA1,. Huguette SALLANON2, Alain COUDRET2 et Harumi ISAKA3. 1 Université d'Abobo-Adjamé, UFR des Sciences fondamentales et appliquées, 02 BP 801 ...

  19. Melatonin regulates delayed embryonic development in the short-nosed fruit bat, Cynopterus sphinx.

    Science.gov (United States)

    Banerjee, Arnab; Meenakumari, K J; Udin, S; Krishna, A

    2009-12-01

    The aim of the present study was to evaluate the seasonal variation in serum melatonin levels and their relationship to the changes in the serum progesterone level, ovarian steroidogenesis, and embryonic development during two successive pregnancies of Cynopterus sphinx. Circulating melatonin concentrations showed two peaks; one coincided with the period of low progesterone synthesis and delayed embryonic development, whereas the second peak coincided with regressing corpus luteum. This finding suggests that increased serum melatonin level during November-December may be responsible for delayed embryonic development by suppressing progesterone synthesis. The study showed increased melatonin receptors (MTNR1A and MTNR1B) in the corpus luteum and in the utero-embryonic unit during the period of delayed embryonic development. The in vitro study showed that a high dose of melatonin suppressed progesterone synthesis, whereas a lower dose of melatonin increased progesterone synthesis by the ovary. The effects of melatonin on ovarian steroidogenesis are mediated through changes in the expression of peripheral-type benzodiazepine receptor, P450 side chain cleavage enzyme, and LH receptor proteins. This study further showed a suppressive impact of melatonin on the progesterone receptor (PGR) in the utero-embryonic unit; this effect might contribute to delayed embryonic development in C. sphinx. The results of the present study thus suggest that a high circulating melatonin level has a dual contribution in retarding embryonic development in C. sphinx by impairing progesterone synthesis as well as by inhibiting progesterone action by reducing expression of PGR in the utero-embryonic unit.

  20. Ultrastructure of the embryonic stem cells of the 8-day pig blastocyst before and after in vitro manipulation: development of junctional apparatus and the lethal effects of PBS mediated cell-cell dissociation.

    Science.gov (United States)

    Talbot, N C; Garrett, W M

    2001-09-01

    Ultrastructural examination of 8-day hatched pig blastocysts (large and small), their cultured inner cell mass (ICM), and cultured epiblast tissue (embryonic stem cells) was undertaken to assess the development of epiblast cell junctions and cytoskeletal elements. In small blastocysts, epiblast cells had no desmosomes or tight junction (TJ) connections and few organized microfilament bundles, whereas in large blastocysts the epiblast cells were connected by TJ and desmosomes with associated microfilaments. ICM isolation by immunodissection damaged the endoderm cells beneath the trophectoderm cells but did not appear to damage the epiblast cells or their associated endoderm cells. Epiblast cells in cultured ICMs were similar in character to those in the intact large blastocyst except that perinuclear microfilaments were observed. Isolated pig epiblasts, cultured for approximately 36 hr on STO feeder layers, formed a monolayer whose cells were connected by TJ, adherens junctions and desmosomes with prominent microfilament bundles running parallel to the apical cytoplasmic membranes. Perinuclear microfilaments were a consistent feature in the approximately 36 hr cultured epiblast cells. A feature characteristic of differentiation into notochordal cells, i.e., a solitary cilium, was also observed in the cultured epiblast. Exposure of the cultured epiblast cells to Ca(++)-Mg(++)-free phosphate buffered saline (PBS) for 5-10 min resulted in extensive cell blebbing and lysis. The results may indicate that pig epiblast cells could be more easily dissociated from early blastocysts ( approximately 400 microm in diameter) if immunodissection damage to the ICM can be avoided. It may be difficult, however, to establish them as embryonic stem cell lines because the cultured pig epiblast cells were easily lysed by standard cell-cell dissociation methods. Copyright 2001 Wiley-Liss, Inc.

  1. Embryonic Stem Cell Markers

    Directory of Open Access Journals (Sweden)

    Lan Ma

    2012-05-01

    Full Text Available Embryonic stem cell (ESC markers are molecules specifically expressed in ES cells. Understanding of the functions of these markers is critical for characterization and elucidation for the mechanism of ESC pluripotent maintenance and self-renewal, therefore helping to accelerate the clinical application of ES cells. Unfortunately, different cell types can share single or sometimes multiple markers; thus the main obstacle in the clinical application of ESC is to purify ES cells from other types of cells, especially tumor cells. Currently, the marker-based flow cytometry (FCM technique and magnetic cell sorting (MACS are the most effective cell isolating methods, and a detailed maker list will help to initially identify, as well as isolate ESCs using these methods. In the current review, we discuss a wide range of cell surface and generic molecular markers that are indicative of the undifferentiated ESCs. Other types of molecules, such as lectins and peptides, which bind to ESC via affinity and specificity, are also summarized. In addition, we review several markers that overlap with tumor stem cells (TSCs, which suggest that uncertainty still exists regarding the benefits of using these markers alone or in various combinations when identifying and isolating cells.

  2. Transcriptomic concentration-response evaluation of valproic acid, cyproconazole, and hexaconazole in the neural embryonic stem cell test (ESTn)

    NARCIS (Netherlands)

    Theunissen, P.; Robinson, J.F.; Pennings, J.L.A.; de Jong, E.; Claessen, S.M.H.; Kleinjans, J.C.S.; Piersma, A.H.

    2012-01-01

    Alternative developmental toxicity assays are urgently needed to reduce animal use in regulatory developmental toxicology. We previously designed an in vitro murine neural embryonic stem cell test (ESTn) as a model for neurodevelopmental toxicity testing (Theunissen et al., 2010). Toxicogenomic

  3. Chromosomal Aneuploidies and Early Embryonic Developmental Arrest

    Directory of Open Access Journals (Sweden)

    Maria Maurer

    2015-07-01

    Full Text Available Background: Selecting the best embryo for transfer, with the highest chance of achieving a vital pregnancy, is a major goal in current in vitro fertilization (IVF technology. The high rate of embryonic developmental arrest during IVF treatment is one of the limitations in achieving this goal. Chromosomal abnormalities are possibly linked with chromosomal arrest and selection against abnormal fertilization products. The objective of this study was to evaluate the frequency and type of chromosomal abnormalities in preimplantation embryos with developmental arrest. Materials and Methods: This cohort study included blastomeres of embryos with early developmental arrest that were biopsied and analyzed by fluorescence in-situ hybridization (FISH with probes for chromosomes 13, 16, 18, 21 and 22. Forty-five couples undergoing IVF treatment were included, and 119 arrested embryos were biopsied. All probes were obtained from the Kinderwunsch Zentrum, Linz, Austria, between August 2009 and August 2011. Results: Of these embryos, 31.6% were normal for all chromosomes tested, and 68.4% were abnormal. Eleven embryos were uniformly aneuploid, 20 were polyploid, 3 were haploid, 11 displayed mosaicism and 22 embryos exhibited chaotic chromosomal complement. Conclusion: Nearly 70% of arrested embryos exhibit chromosomal errors, making chromosomal abnormalities a major cause of embryonic arrest and may be a further explanation for the high developmental failure rates during culture of the embryos in the IVF setting.

  4. Polycomb enables primitive endoderm lineage priming in embryonic stem cells

    DEFF Research Database (Denmark)

    Illingworth, Robert S; Hölzenspies, Jurriaan J; Roske, Fabian V

    2016-01-01

    Mouse embryonic stem cells (ESCs), like the blastocyst from which they are derived, contain precursors of the epiblast (Epi) and primitive endoderm (PrEn) lineages. While transient in vivo, these precursor populations readily interconvert in vitro. We show that altered transcription is the driver...... polycomb with dynamic changes in transcription and stalled lineage commitment, allowing cells to explore alternative choices prior to a definitive decision....

  5. Embryonic stem cells in pig and cattle

    DEFF Research Database (Denmark)

    Maddox-Hyttel, Poul; Wolf, Xenia Asbæk; Rasmussen, Mikkel Aabech

    2007-01-01

    Porcine and bovine cell lines derived from the inner cell mass (ICM) or epiblasts of blastocysts have been maintained over extended periods of time and characterized by morphology, identification of some stem cell markers and, in few cases, by production of chimaeric offspring. However, germ line...... transmission in chimaeras has never been obtained. Due to this incomplete characterization of the cell lines, the expression embryonic stem (ES)-like cells is presently used in pig and cattle. The ICM or epiblast can be isolated from the blastocyst by whole blastocyst culture, mechanical isolation......, or immunosurgery, and they are generally cultured on feeder cells. The resulting ES-like cells may be differentiated in vivo by chimaera and teratoma formation or in vitro by embryoid body formation and monolayer induction. It is likely that more well characterized and stable porcine and bovine ES cell lines...

  6. LIF signal in mouse embryonic stem cells

    Science.gov (United States)

    Ohtsuka, Satoshi; Nakai-Futatsugi, Yoko; Niwa, Hitoshi

    2015-01-01

    Since the establishment of mouse embryonic stem cells (mESCs) in the 1980s, a number of important notions on the self-renewal of pluripotent stem cells in vitro have been found. In serum containing conventional culture, an exogenous cytokine, leukemia inhibitory factor (LIF), is absolutely essential for the maintenance of pluripotency. In contrast, in serum-free culture with simultaneous inhibition of Map-kinase and Gsk3 (so called 2i-culture), LIF is no longer required. However, recent findings also suggest that LIF may have a role not covered by the 2i for the maintenance of naïve pluripotency. These suggest that LIF functions for the maintenance of naïve pluripotency in a context dependent manner. We summarize how LIF-signal pathway is converged to maintain the naïve state of pluripotency. PMID:27127728

  7. [Progress in the research of germ cell from human embryonic stem cells].

    Science.gov (United States)

    Guo, Xin; Cai, Zhi-Ming; Gui, Yao-Ting

    2006-01-01

    As the development of spontaneous differentiation of germ cells and gametogenesis from mouse embryonic stem cells (mES) in vitro, hES (human embryonic stem cells) also have potential to differentiated into germ cells in theory. This review focuses on the stem cells niches and genes regulating the hES differentiation toward germ cells, as well as the recent advance and application on the reproductive medicine and therapy of infertility.

  8. Des Balkans

    OpenAIRE

    Matvejević, Predrag

    2012-01-01

    Les Balkans témoignent de contradictions géographiques et politiques, perceptibles dans le changement d’appellation des lieux au cours de l’Histoire : de la péninsule illyrienne, grecque, byzantine à la « Turquie d’Europe » plus récente. Il est resté une dénomination venue des Turcs, les « Balkans ». Cette presqu’île n’offre pas de frontières naturelles difficiles à franchir. Les délimitations des géographes et historiens sont relatives et souvent arbitraires, et donc contestées. Sa définitio...

  9. Reprogramming Malignant Cancer Cells toward a Benign Phenotype following Exposure to Human Embryonic Stem Cell Microenvironment

    Science.gov (United States)

    Arena, Vincenzo; Arena, Manuel; Arena, Goffredo Orazio

    2017-01-01

    The embryonic microenvironment is well known to be non-permissive for tumor development because early developmental signals naturally suppress the expression of proto-oncogenes. In an analogous manner, mimicking an early embryonic environment during embryonic stem cell culture has been shown to suppress oncogenic phenotypes of cancer cells. Exosomes derived from human embryonic stem cells harbor substances that mirror the content of the cells of origin and have been reported to reprogram hematopoietic stem/progenitor cells via horizontal transfer of mRNA and proteins. However, the possibility that these embryonic stem cells-derived exosomes might be the main effectors of the anti-tumor effect mediated by the embryonic stem cells has not been explored yet. The present study aims to investigate whether exosomes derived from human embryonic stem cells can reprogram malignant cancer cells to a benign stage and reduce their tumorigenicity. We show that the embryonic stem cell-conditioned medium contains factors that inhibit cancer cell growth and tumorigenicity in vitro and in vivo. Moreover, we demonstrate that exosomes derived from human embryonic stem cells display anti-proliferation and pro-apoptotic effects, and decrease tumor size in a xenograft model. These exosomes are also able to transfer their cargo into target cancer cells, inducing a dose-dependent increase in SOX2, OCT4 and Nanog proteins, leading to a dose-dependent decrease of cancer cell growth and tumorigenicity. This study shows for the first time that human embryonic stem cell-derived exosomes play an important role in the tumor suppressive activity displayed by human embryonic stem cells. PMID:28068409

  10. Altered glucose transport to utero-embryonic unit in relation to delayed embryonic development in the Indian short-nosed fruit bat, Cynopterus sphinx.

    Science.gov (United States)

    Arnab, Banerjee; Amitabh, Krishna

    2011-02-10

    The aim of this study was to compare the changes in concentration of glucose and glucose transporters (GLUTs) in the utero-embryonic unit, consisting of decidua, trophoblast and embryo, during delayed and non-delayed periods to understand the possible cause of delayed embryonic development in Cynopterus sphinx. The results showed a significantly decreased concentration of glucose in the utero-embryonic unit due to decline in the expression of insulin receptor (IR) and GLUT 3, 4 and 8 proteins in the utero-embryonic unit during delayed period. The in vitro study showed suppressive effect of insulin on expression of GLUTs 4 and 8 in the utero-embryonic unit and a significant positive correlation between the decreased amount of glucose consumed by the utero-embryonic unit and decreased expression of GLUTs 4 (r=0.99; psphinx. Increased supply of fatty acid to the delayed embryo may be responsible for its survival under low glucose condition but unable to promote embryonic development in C. sphinx. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  11. Effects of leptin on in vitro maturation, fertilization and embryonic cleavage after ICSI and early developmental expression of leptin (Ob) and leptin receptor (ObR) proteins in the horse

    OpenAIRE

    Lange Consiglio, Anna; Dell'Aquila, Maria Elena; Fiandanese, Nadia; Ambruosi, Barbara; Cho, Yoon S; Bosi, Giampaolo; Arrighi, Silvana; Lacalandra, Giovanni M; Cremonesi, Fausto

    2009-01-01

    Abstract Background The identification of the adipocyte-derived obesity gene product, leptin (Ob), and subsequently its association with reproduction in rodents and humans led to speculations that leptin may be involved in the regulation of oocyte and preimplantation embryo development. In mice and pigs, in vitro leptin addition significantly increased meiotic resumption and promoted preimplantation embryo development in a dose-dependent manner. This study was conducted to determine whether l...

  12. Grundlagen des Tissue Engineering

    Science.gov (United States)

    Mayer, Jörg; Blum, Janaki; Wintermantel, Erich

    Die Organtransplantation stellt eine verbreitete Therapie dar, um bei krankheitsoder unfallbedingter Schädigung eines Organs die Gesamtheit seiner Funktionen wieder herzustellen, indem es durch ein Spenderorgan ersetzt wird. Organtransplantationen werden für die Leber, die Niere, die Lunge, das Herz oder bei schweren grossflächigen Verbrennungen der Haut vorgenommen. Der grosse apparative, personelle und logistische Aufwand und die Risiken der Transplantationschirurgie (Abstossungsreaktionen) sowie die mangelnde Verfügbarkeit von immunologisch kompatiblen Spenderorganen führen jedoch dazu, dass der Bedarf an Organtransplantaten nur zu einem sehr geringen Teil gedeckt werden kann. Sind Spenderorgane nicht verfügbar, können in einzelnen Fällen lebenswichtige Teilfunktionen, wie beispielsweise die Filtrationsfunktion der Niere durch die Blutreinigung mittels Dialyse ersetzt oder, bei mangelnder Funktion der Bauchspeicheldrüse (Diabetes), durch die Verabreichung von Insulin ein normaler Zustand des Gesamtorganismus auch über Jahre hinweg erhalten werden. Bei der notwendigen lebenslangen Anwendung apparativer oder medikamentöser Therapie können für den Patienten jedoch häufig schwerwiegende, möglicherweise lebensverkürzende Nebenwirkungen entstehen. Daher werden in der Forschung Alternativen gesucht, um die Funktionen des ausgefallenen Organs durch die Implantation von Zellen oder in vitro gezüchteten Geweben möglichst umfassend wieder herzustellen. Dies erfordert biologisch aktive Implantate, welche die für den Stoffwechsel des Organs wichtigen Zellen enthalten und einen organtypischen Stoffwechsel entfalten.

  13. Somatic donor cell type correlates with embryonic, but not extra-embryonic, gene expression in postimplantation cloned embryos.

    Directory of Open Access Journals (Sweden)

    Ryutaro Hirasawa

    Full Text Available The great majority of embryos generated by somatic cell nuclear transfer (SCNT display defined abnormal phenotypes after implantation, such as an increased likelihood of death and abnormal placentation. To gain better insight into the underlying mechanisms, we analyzed genome-wide gene expression profiles of day 6.5 postimplantation mouse embryos cloned from three different cell types (cumulus cells, neonatal Sertoli cells and fibroblasts. The embryos retrieved from the uteri were separated into embryonic (epiblast and extraembryonic (extraembryonic ectoderm and ectoplacental cone tissues and were subjected to gene microarray analysis. Genotype- and sex-matched embryos produced by in vitro fertilization were used as controls. Principal component analysis revealed that whereas the gene expression patterns in the embryonic tissues varied according to the donor cell type, those in extraembryonic tissues were relatively consistent across all groups. Within each group, the embryonic tissues had more differentially expressed genes (DEGs (>2-fold vs. controls than did the extraembryonic tissues (P<1.0 × 10(-26. In the embryonic tissues, one of the common abnormalities was upregulation of Dlk1, a paternally imprinted gene. This might be a potential cause of the occasional placenta-only conceptuses seen in SCNT-generated mouse embryos (1-5% per embryos transferred in our laboratory, because dysregulation of the same gene is known to cause developmental failure of embryos derived from induced pluripotent stem cells. There were also some DEGs in the extraembryonic tissues, which might explain the poor development of SCNT-derived placentas at early stages. These findings suggest that SCNT affects the embryonic and extraembryonic development differentially and might cause further deterioration in the embryonic lineage in a donor cell-specific manner. This could explain donor cell-dependent variations in cloning efficiency using SCNT.

  14. Des guides et des cartes

    Directory of Open Access Journals (Sweden)

    Patricia MATHIEU

    1987-12-01

    Full Text Available Consultés pour leurs références régionales ou locales, les guides touristiques donnent aussi une vision globale de la France qui est rarement perçue par l'utilisateur. Différents types de représentations cartographiques ont été choisis pour montrer, à partir d'informations simples, découpage en «régions» touristiques, étoilement des sites et des espaces touristiques, cette image de la France.

  15. Endothelial cells derived from human embryonic stem cells

    Science.gov (United States)

    Levenberg, Shulamit; Golub, Justin S.; Amit, Michal; Itskovitz-Eldor, Joseph; Langer, Robert

    2002-04-01

    Human embryonic stem cells have the potential to differentiate into various cell types and, thus, may be useful as a source of cells for transplantation or tissue engineering. We describe here the differentiation steps of human embryonic stem cells into endothelial cells forming vascular-like structures. The human embryonic-derived endothelial cells were isolated by using platelet endothelial cell-adhesion molecule-1 (PECAM1) antibodies, their behavior was characterized in vitro and in vivo, and their potential in tissue engineering was examined. We show that the isolated embryonic PECAM1+ cells, grown in culture, display characteristics similar to vessel endothelium. The cells express endothelial cell markers in a pattern similar to human umbilical vein endothelial cells, their junctions are correctly organized, and they have high metabolism of acetylated low-density lipoprotein. In addition, the cells are able to differentiate and form tube-like structures when cultured on matrigel. In vivo, when transplanted into SCID mice, the cells appeared to form microvessels containing mouse blood cells. With further studies, these cells could provide a source of human endothelial cells that could be beneficial for potential applications such as engineering new blood vessels, endothelial cell transplantation into the heart for myocardial regeneration, and induction of angiogenesis for treatment of regional ischemia.

  16. Effects of leptin on in vitro maturation, fertilization and embryonic cleavage after ICSI and early developmental expression of leptin (Ob and leptin receptor (ObR proteins in the horse

    Directory of Open Access Journals (Sweden)

    Arrighi Silvana

    2009-10-01

    Full Text Available Abstract Background The identification of the adipocyte-derived obesity gene product, leptin (Ob, and subsequently its association with reproduction in rodents and humans led to speculations that leptin may be involved in the regulation of oocyte and preimplantation embryo development. In mice and pigs, in vitro leptin addition significantly increased meiotic resumption and promoted preimplantation embryo development in a dose-dependent manner. This study was conducted to determine whether leptin supplementation during in vitro maturation (IVM to horse oocytes could have effects on their developmental capacity after fertilization by IntraCytoplasmic Sperm Injection (ICSI. Methods Compact and expanded-cumulus horse oocytes were matured in medium containing different concentrations (1, 10, 100, 1000 ng/ml of recombinant human leptin and the effects on maturation, fertilization and embryo cleavage were evaluated. Furthermore, early developmental expression of Ob and leptin receptor (Ob-R was investigated by immunocytochemical staining. Results In expanded-cumulus oocytes, the addition of leptin in IVM medium improved maturation (74% vs 44%, for 100 ng/ml leptin-treated and control groups, respectively; P Conclusion Leptin plays a cumulus cell-mediated role in the regulation of oocyte maturation in the mare. Species-specific differences may exist in oocyte sensitivity to leptin.

  17. Embryonic hematopoiesis under microscopic observation

    NARCIS (Netherlands)

    Klaus, Anna; Robin, Catherine

    2017-01-01

    Hematopoietic stem cells (HSCs) are at the origin of adult hematopoiesis, providing an organism with all blood cell types needed throughout life. During embryonic development a first wave of hematopoiesis (independent of HSCs) allows the survival and growth of the embryo until birth. A second wave

  18. Conditions de sélection in vitro de cals issus des disques foliaires et des protoplastes de Pelargonium tolérant plus la sécheresse

    Directory of Open Access Journals (Sweden)

    M. MOKHTARI

    2015-01-01

    Full Text Available To induce drought resistance, callus from leaf discs and protoplast of Pelargonium x hortorum (‘Deep Salmon’ and ‘Panaché Sud’ were grown in vitro in osmoticum rich medium. Percent survival of the callus varied with growth medium, variety and concentration of osmoticum. Compared to protoplasts, leaf discs were simple to handle. However, protoplasts growing requires enzymatic additives and delicate procedures. The protoplasts viability was 86% for ‘Deep Salmon’ and 90% for ‘Panaché Sud’. The yield was 5.67 x 106 protoplasts / g FM for ‘Deep Salmon’ and 11.35 x 106 for ‘Panaché Sud’. The callus from leaf discs of the variety Deep Salmon survived a maximum concentration of 0.5 M sucrose and 0.27 M mannitol or sorbitol. A dose of 0.6 M sucrose was the threshold limit for the survival of 12.5% ​​protoplasts with a division ratio of 2% for ‘Deep Salmon’ and 18.7% of protoplasts with a division ratio of 3.2% for ‘Panaché Sud’. For the mannitol, the maximum limit was 0.6 M for a 13.5% viability of protoplasts with a division ratio 3.6% for ‘Deep Salmon’ and 16.1% of protoplasts with a division factor 3 % respectively for ‘Panaché Sud’. The 20% PEG allowed the survival of 21.1% protoplast and a division rate of 0.2% in ‘Deep Salmon’, but it has totally inhibited protoplast division of ‘Panaché Sud’, even at 5%.

  19. Effects of leptin on in vitro maturation, fertilization and embryonic cleavage after ICSI and early developmental expression of leptin (Ob) and leptin receptor (ObR) proteins in the horse.

    Science.gov (United States)

    Lange Consiglio, Anna; Dell'Aquila, Maria Elena; Fiandanese, Nadia; Ambruosi, Barbara; Cho, Yoon S; Bosi, Giampaolo; Arrighi, Silvana; Lacalandra, Giovanni M; Cremonesi, Fausto

    2009-10-16

    The identification of the adipocyte-derived obesity gene product, leptin (Ob), and subsequently its association with reproduction in rodents and humans led to speculations that leptin may be involved in the regulation of oocyte and preimplantation embryo development. In mice and pigs, in vitro leptin addition significantly increased meiotic resumption and promoted preimplantation embryo development in a dose-dependent manner. This study was conducted to determine whether leptin supplementation during in vitro maturation (IVM) to horse oocytes could have effects on their developmental capacity after fertilization by IntraCytoplasmic Sperm Injection (ICSI). Compact and expanded-cumulus horse oocytes were matured in medium containing different concentrations (1, 10, 100, 1000 ng/ml) of recombinant human leptin and the effects on maturation, fertilization and embryo cleavage were evaluated. Furthermore, early developmental expression of Ob and leptin receptor (Ob-R) was investigated by immunocytochemical staining. In expanded-cumulus oocytes, the addition of leptin in IVM medium improved maturation (74% vs 44%, for 100 ng/ml leptin-treated and control groups, respectively; P fertilization after ICSI (56% vs 23% for 10 ng/ml leptin-treated and control groups, respectively; P < 0.05). However, the developmental rate and quality of 8-cell stage embryos derived from leptin-treated oocytes (100 ng/ml) was significantly reduced, in contrast to previous data in other species where leptin increased embryo cleavage. Ob and Ob-R proteins were detected up to the 8-cell stage with cortical and cytoplasmic granule-like distribution pattern in each blastomere. Leptin plays a cumulus cell-mediated role in the regulation of oocyte maturation in the mare. Species-specific differences may exist in oocyte sensitivity to leptin.

  20. No shortcuts to pig embryonic stem cells.

    Science.gov (United States)

    Brevini, T A L; Pennarossa, G; Gandolfi, F

    2010-09-01

    The establishment of embryonic stem cell (ESC) lines in domestic species could have great impact in the agricultural as well as in the biomedical field. In particular, derivation of pig ESC would find important applications aimed at improving health and production traits of this species through genetic engineering. Similarly, the immunological, morphological, physiological, and functional similarities to the human make the pig a very effective and suitable animal model for biomedical studies and pre-clinical trials. While proven blastocyst-derived mouse and human ESC lines have been established, no validated porcine ESC (pESC) lines are available. In the present manuscript we briefly discuss some of the factors that make the establishment of ESC lines in the pig, and in animal species other than mouse and human, a very slow process. The paucity of information related to morphology, pluripotency markers, differentiation capability hampers a thorough evaluation of the validity of putative lines. These difficulties are further increased by the lack of reliable antibodies, reagents, and in vitro culture systems that could ensure reliable results in the pig and allow for the screening and long-term maintenance of pESC. Data from the literature suggest that similar regulatory pathways are likely to exist among different species. Coupling of these pathways with their distinct expression patterns, the relative concentrations of pluripotency-related molecules, and timing of embryo development, along with supportive micro-environmental conditions, would appear to vary in a species-specific manner. We feel that the understanding of these subtle but meaningful diversities may provide beneficial information about the isolation of genuine porcine embryonic stem cells. Copyright 2010 Elsevier Inc. All rights reserved.

  1. ­A curated transcriptomic dataset collection relevant to embryonic development associated with in vitro fertilization in healthy individuals and patients with polycystic ovary syndrome [version 1; referees: 1 approved, 2 approved with reservations

    Directory of Open Access Journals (Sweden)

    Rafah Mackeh

    2017-02-01

    Full Text Available The collection of large-scale datasets available in public repositories is rapidly growing and providing opportunities to identify and fill gaps in different fields of biomedical research. However, users of these datasets should be able to selectively browse datasets related to their field of interest. Here we made available a collection of transcriptome datasets related to human follicular cells from normal individuals or patients with polycystic ovary syndrome, in the process of their development, during in vitro fertilization. After RNA-seq dataset exclusion and careful selection based on study description and sample information, 12 datasets, encompassing a total of 85 unique transcriptome profiles, were identified in NCBI Gene Expression Omnibus and uploaded to the Gene Expression Browser (GXB, a web application specifically designed for interactive query and visualization of integrated large-scale data. Once annotated in GXB, multiple sample grouping has been made in order to create rank lists to allow easy data interpretation and comparison. The GXB tool also allows the users to browse a single gene across multiple projects to evaluate its expression profiles in multiple biological systems/conditions in a web-based customized graphical views. The curated dataset is accessible at the following link: http://ivf.gxbsidra.org/dm3/landing.gsp.

  2. Embryonic Heart Progenitors and Cardiogenesis

    Science.gov (United States)

    Brade, Thomas; Pane, Luna S.; Moretti, Alessandra; Chien, Kenneth R.; Laugwitz, Karl-Ludwig

    2013-01-01

    The mammalian heart is a highly specialized organ, comprised of many different cell types arising from distinct embryonic progenitor populations during cardiogenesis. Three precursor populations have been identified to contribute to different myocytic and nonmyocytic cell lineages of the heart: cardiogenic mesoderm cells (CMC), the proepicardium (PE), and cardiac neural crest cells (CNCCs). This review will focus on molecular cues necessary for proper induction, expansion, and lineage-specific differentiation of these progenitor populations during cardiac development in vivo. Moreover, we will briefly discuss how the knowledge gained on embryonic heart progenitor biology can be used to develop novel therapeutic strategies for the management of congenital heart disease as well as for improvement of cardiac function in ischemic heart disease. PMID:24086063

  3. ANALYSE DES PERCEPTIONS LOCALES ET DES FACTEURS ...

    African Journals Online (AJOL)

    AISA

    1Faculté des Sciences Agronomiques (FSA), Université d'Abomey-Calavi (UAC), 01 BP 526 Cotonou Bénin. Email : cgbemavo@yahoo.fr. 2Institut National des Recherches Agricoles du Bénin, Centre de Recherches Agricoles d'Agonkanmey (CRA-A),. Laboratoire des Sciences du Sol, Eau et Environnement (LSSEE).

  4. Characterization of a protein tyrosine phosphatase (RIP) expressed at a very early stage of differentiation in both mouse erythroleukemia and embryonal carcinoma cells

    National Research Council Canada - National Science Library

    Chida, Dai; Kume, Tsutomu; Mukouyama, Yousuke; Tabata, Satoshi; Nomura, Nobuo; Thomas, Matthew L; Watanabe, Toshio; Oishi, Michio

    1995-01-01

    ... events leading to in vitro differentiation of both mouse erythroleukemia (MEL) and embryonal carcinoma (F9) cells. Among the PTPases, recent experiments suggest that a new PTPase (RIP) plays a c...

  5. Characterization of organotypic ventral mesencephalic cultures from embryonic mice and protection against MPP toxicity by GDNF

    DEFF Research Database (Denmark)

    Jakobsen, B; Gramsbergen, J B; Møller Dall, A

    2005-01-01

    We characterized organotypic ventral mesencephalic (VM) cultures derived from embryonic day 12 (E12) mice (CBL57/bL6) in terms of number of dopaminergic neurons, cell soma size and dopamine production in relation to time in vitro and tested the effects of 1-methyl-4-phenylpyridinium (MPP(+)) and ...

  6. AN EMBRYONIC CHICK PANCREAS ORGAN CULTURE MODEL: CHARACTERIZATION AND NEURAL CONTROL OF EXOCRINE RELEASE

    Science.gov (United States)

    An embryonic chick (Gallus domesticus) whole-organ pancreas culture system was developed for use as an in vitro model to study cholinergic regulation of exocrine pancreatic function. The culture system was examined for characteristic exocrine function and viability by measuring e...

  7. The effect of oxygen tension on porcine embryonic development is dependent on embryo type

    DEFF Research Database (Denmark)

    Booth, Paul J; Holm, Peter; Callesen, Henrik

    2005-01-01

    Reducing oxygen concentration from atmospheric levels during in vitro culture generally, but not invariably, improves embryonic development across a range of species. Since the few published reports of such an action in the pig are contradictory--perhaps a consequence of the derivation of the emb...

  8. Hematopoietic cell differentiation from embryonic and induced pluripotent stem cells

    Science.gov (United States)

    2013-01-01

    Pluripotent stem cells, both embryonic stem cells and induced pluripotent stem cells, are undifferentiated cells that can self-renew and potentially differentiate into all hematopoietic lineages, such as hematopoietic stem cells (HSCs), hematopoietic progenitor cells and mature hematopoietic cells in the presence of a suitable culture system. Establishment of pluripotent stem cells provides a comprehensive model to study early hematopoietic development and has emerged as a powerful research tool to explore regenerative medicine. Nowadays, HSC transplantation and hematopoietic cell transfusion have successfully cured some patients, especially in malignant hematological diseases. Owing to a shortage of donors and a limited number of the cells, hematopoietic cell induction from pluripotent stem cells has been regarded as an alternative source of HSCs and mature hematopoietic cells for intended therapeutic purposes. Pluripotent stem cells are therefore extensively utilized to facilitate better understanding in hematopoietic development by recapitulating embryonic development in vivo, in which efficient strategies can be easily designed and deployed for the generation of hematopoietic lineages in vitro. We hereby review the current progress of hematopoietic cell induction from embryonic stem/induced pluripotent stem cells. PMID:23796405

  9. Extracellular Matrix and Integrins in Embryonic Stem Cell Differentiation.

    Science.gov (United States)

    Wang, Han; Luo, Xie; Leighton, Jake

    2015-01-01

    Embryonic stem cells (ESCs) are pluripotent cells with great therapeutic potentials. The in vitro differentiation of ESC was designed by recapitulating embryogenesis. Significant progress has been made to improve the in vitro differentiation protocols by toning soluble maintenance factors. However, more robust methods for lineage-specific differentiation and maturation are still under development. Considering the complexity of in vivo embryogenesis environment, extracellular matrix (ECM) cues should be considered besides growth factor cues. ECM proteins bind to cells and act as ligands of integrin receptors on cell surfaces. Here, we summarize the role of the ECM and integrins in the formation of three germ layer progenies. Various ECM-integrin interactions were found, facilitating differentiation toward definitive endoderm, hepatocyte-like cells, pancreatic beta cells, early mesodermal progenitors, cardiomyocytes, neuroectoderm lineages, and epidermal cells, such as keratinocytes and melanocytes. In the future, ECM combinations for the optimal ESC differentiation environment will require substantial study.

  10. Cryopreservation of embryonic axes of groundnut ( Arachis ...

    African Journals Online (AJOL)

    An efficient cryopreservation protocol was developed for groundnut embryonic axes using vitrification technique. Embryonic axes obtained from seeds of four groundnut genotypes were dehydrated in Plant Vitrification Solution (PVS2) solution for different durations (0, 1, 2, 3, 4 and 5 h) before plunged into liquid nitrogen ...

  11. variabilite des productions et des revenus des exploitations ...

    African Journals Online (AJOL)

    La durabilité des systèmes de production à base de coton dans un contexte de variabilité des prix aux producteurs ... L'objectif visé est d'augmenter durablement ..... Village. EAF. (nbre). Revenus de la vente d'animaux sur pieds et du lait (Fcfa). Bovins. Petits. Ruminants. Volailles. Autres. Animaux. Total vente animaux. Lait.

  12. Properties and uses of embryonic stem cells: prospects for application to human biology and gene therapy.

    Science.gov (United States)

    Rathjen, P D; Lake, J; Whyatt, L M; Bettess, M D; Rathjen, J

    1998-01-01

    Embryonic stem cells are pluripotent cells derived from the early mouse embryo that can be propagated stably in the undifferentiated state in vitro. They retain the ability to differentiate into all cell types found in an embryonic and adult mouse in vivo, and can be induced to differentiate into many cell types in vitro. Exploitation of ES cell technology for the creation of mice bearing predetermined genetic alterations has received widespread attention because of the sophistication that it brings to the study of gene function in mammals. Analysis of cell differentiation in vitro has also been of value, leading to the identification of novel bioactive factors and the elucidation of cell specification mechanisms. In this paper, we summarise the features of pluripotent cell lines and their applications, foreshadowing the impact that these systems may have on human biology. While the isolation of definitive human pluripotent cell lines has not yet been achieved, potential applications for these cells in the study of human biology, particularly cell specification, can be envisaged. Of particular interest is the possibility that human embryonic stem cells with properties similar to mouse embryonic stem cells might provide a generic system for gene therapy.

  13. Efficient femtosecond driven SOX 17 delivery into mouse embryonic stem cells: Differentiation study

    CSIR Research Space (South Africa)

    Thobakgale, Setumo L

    2017-01-01

    Full Text Available Efficient femtosecond laser driven SOX 17 delivery into mouse embryonic stem cells: Differentiation study S.L Thobakgale1,2, S.L Manoto1, S. Ombinda-Lemboumba1, M. Maaza2, P. Mthunzi-Kufa1,2* 1Council for Scientific and Industrial Research (CSIR) National... and definitive endoderm in vitro. Development Growth and Differentiation, 50(7), pp.585–593 7. Berrill, A. et al., 2004. Assessment of stem cell markers during long-term culture of mouse embryonic stem cells. Cytotechnology, 44(1-2), pp.77–91. 8. Matthew J...

  14. Transcriptomic changes in mouse embryonic stem cells exposed to thalidomide during spontaneous differentiation

    Directory of Open Access Journals (Sweden)

    Xiugong Gao

    2015-09-01

    Full Text Available Thalidomide is a potent developmental toxicant that induces a range of birth defects, notably severe limb malformations. To unravel the molecular mechanisms underpinning the teratogenic effects of thalidomide, we used microarrays to study transcriptomic changes induced by thalidomide in an in vitro model based on the differentiation of mouse embryonic stem cells (mESCs, and published the major findings in a research article entitled “Thalidomide induced early gene expression perturbations indicative of human embryopathy in mouse embryonic stem cells” [1]. The data presented herein contains complementary information related to the aforementioned research article.

  15. Generation of stomach tissue from mouse embryonic stem cells.

    Science.gov (United States)

    Noguchi, Taka-aki K; Ninomiya, Naoto; Sekine, Mari; Komazaki, Shinji; Wang, Pi-Chao; Asashima, Makoto; Kurisaki, Akira

    2015-08-01

    Successful pluripotent stem cell differentiation methods have been developed for several endoderm-derived cells, including hepatocytes, β-cells and intestinal cells. However, stomach lineage commitment from pluripotent stem cells has remained a challenge, and only antrum specification has been demonstrated. We established a method for stomach differentiation from embryonic stem cells by inducing mesenchymal Barx1, an essential gene for in vivo stomach specification from gut endoderm. Barx1-inducing culture conditions generated stomach primordium-like spheroids, which differentiated into mature stomach tissue cells in both the corpus and antrum by three-dimensional culture. This embryonic stem cell-derived stomach tissue (e-ST) shared a similar gene expression profile with adult stomach, and secreted pepsinogen as well as gastric acid. Furthermore, TGFA overexpression in e-ST caused hypertrophic mucus and gastric anacidity, which mimicked Ménétrier disease in vitro. Thus, in vitro stomach tissue derived from pluripotent stem cells mimics in vivo development and can be used for stomach disease models.

  16. Le jeu des Kirlis et des Gourlus

    OpenAIRE

    Touati, Corinne

    2013-01-01

    National audience; Cet article présente un jeu éducatif a destination des lycéens ayant pour but de présenter quelques exemples contre-intuitifs de théorie des jeux (paradoxe de l'information). La résolution des scénarios leur permet de se familiariser avec l'utilisation d'arbres de décisions et de tableaux et de faire des calculs simples de probabilités.

  17. Des racines et des ailes

    Directory of Open Access Journals (Sweden)

    Stéphanie Vincent-Geslin

    2012-05-01

    Full Text Available Les mobilités pendulaires semblent être en augmentation en Europe depuis une dizaine d’années. Cette croissance du temps passé à se déplacer amène à remettre en question la conjecture de Zahavi et apparaît relativement inexplicable en regard du paradigme classique de l’acteur rationnel traditionnellement utilisé dans le champ des transports. Si, dans la littérature, les temps de déplacements sont principalement expliqués par le contexte résidentiel, la forme urbaine et le travail, ce cadre explicatif ne dit rien des processus de décision eux-mêmes qui amènent aux pendularités intensives.À partir d’une enquête qualitative menée auprès de pendulaires français, suisses et belges, cette contribution propose d’analyser les arbitrages et les éléments déterminants des processus de la grande pendularité. Les mobilités quotidiennes pendulaires apparaissent comme le résultat de compromis entre activité professionnelle, attachement résidentiel et choix de vie et prennent ainsi la forme de stratégies de conciliation entre vie privée et vie professionnelle. Ces mobilités spatiales permettent alors paradoxalement la préservation des ancrages résidentiels, sociaux et familiaux.Roots and wings. Long-distance commuting patterns, or how to conciliate professional and personal lifeLong-distance commuting patterns appear to be increasing in Europe over the last ten years. These raising mobility patterns lead to reappraise the Zahavi conjecture and appear largely inexplicable by the classical rational actor paradigm traditionally used in transportation research. In literature, commuting is mainly explained by residential contexts, urban forms and job. Nevertheless this theoretical frame says little about the decision-making processes themselves. Based on a qualitative survey conducted in three European countries - France, Belgium and Switzerland – among a population of high commuters, this paper proposes an analysis of

  18. Remittances | Transferts des migrants

    Directory of Open Access Journals (Sweden)

    2012-05-01

    Full Text Available Major Recipients of Remittances (in Million USD, 2008Principaux pays bénéficiaires des transferts des migrants (en millions USD, 2008­Migrants’ Remittances per Capita (in USD, 2008Transferts des migrants par habitant (en USD, 2008Source: World Bank, migration and remittances data.

  19. Des transformations cartographiques

    Directory of Open Access Journals (Sweden)

    Colette CAUVIN

    1998-03-01

    Full Text Available Cet article présente un des apports de l'informatique à la cartographie, les transformations cartographiques, en distinguant celles qui sont liées au changement d'état de la carte de celles qui introduisent des modifications dans les positions des lieux.

  20. Approche pragmaterminologique des termes des entreprises et des organisations

    Directory of Open Access Journals (Sweden)

    Dardo de Vecchi

    2016-09-01

    Full Text Available Les entreprises et les organisations façonnent la langue générale et spécialisée pour leurs propres besoins. Il en résulte un sociolecte : parler d’entreprise ou organisationnel, qui caractérise la culture et le savoir des entreprises ou organisations. Identifiés et suivis de manière adaptée – approche pragmaterminologique –, les termes deviennent une ressource identifiable (à rapprocher des actifs, notamment pour l’intégration, la communication et la gestion des connaissance.

  1. In vitro study of the influence of alpha particles irradiation on the pre-neoplastic transformation of rat trachea epithelial cells; Etude in vitro de l'influence d'une irradiation par des particules alpha sur la transformation preneoplasique des cellules epitheliales de trachee de rat

    Energy Technology Data Exchange (ETDEWEB)

    Kugel, C.

    2001-12-15

    Intern contamination by actinide oxide inhalation is potentially one health hazard during the nuclear fuel fabrication process. The aerosol particles can induce pulmonary lesions, such as epithelial cancers in particular. Their toxicity is mainly due to radiotoxicity of {alpha} irradiation. The aim of this work was to contribute, by an in vitro model, to the study of the apparition of pre-neoplastic states on epithelial cells after high LET irradiation. Primary cultures of rat tracheal epithelial cells were used. Two rat strain cells, SD TR for Sprague Dawley rats and WF TR for Wistar Furth I Fischer F344 rats, were compared after exposure to a dose range from 0 to 5 Gy. Reproductive cell death, i.e. senescent death, seems to be the main lethal way induced by {alpha} and {gamma} irradiations. The nuclear volume of WF TR cells is higher than that of SD TR ones, explaining the higher {alpha} radiation-induced lethality of these cells. These WF TR cells are also much sensitive to dose rate and {alpha} particles energy. In the same manner, pre-neoplastic transformation rate of the cells seems to depend on the physical parameters of irradiation. But, it mainly varies as a function of cell radiosensitivity, that means cell death. In fact, the transformation rate of sensitive WF TR cells is lower than that of SD TR ones. In term of transformation for SD TR cells, dose-effect relationship fits to a linear and infra linear function after {alpha} irradiation, whereas the curve fits to linear and quadratic function after {gamma} irradiation. The Relative Biological Efficiency (RBE) of {alpha} particles for lethality and pre-neoplastic transformation were determined for several levels of dose. A constant value of about 3 was found for RBE of lethality whatever the {alpha} dose. By contrast, the RBE of transformation has a value of about 10 up to 0.5 Gy and gradually decreases at higher doses to reach a value of 1 at 5 Gy. Similar shapes of dose-effect relationship can be

  2. ULTRASTRUCTURAL RESPONSE OF EMBRYONIC AXES OF Fortunella polyandra TO DEHYDRATION AND CRYOPRESERVATION.

    Science.gov (United States)

    Al Zoubi, Omar M; Normah, M N

    2015-01-01

    To further understand the survival characteristics of desiccation-sensitive excised embryonic axes of Fortunella polyandra to desiccation and cryopreservation it is necessary to study the impact of drying rates on both the ultrastructure and electrolyte leakage. To examine the effects of two different drying regimes (silica gel and ultra-rapid) on the survival, ultrastructure and membrane leakage characteristics of excised embryonic axes of F. polyandra before and after cryopreservation. The effects of the drying regimes on the survival, ultrastructure and membrane integrity of the excised embryonic axes of F. polyandra was determined. Survival was assessed in vitro, and the integrity of membranes following drying was estimated by electrolyte leakage and observation under the transmission electron microscope (TEM). Survival and ultrastructural changes were also observed after cryopreservation. Electrolyte leakage increased with decreasing water content of the embryonic axes, indicative of substantial subcellular damage, after both ultra-rapid dehydration (to water contents of shrinkage and disruption of cell membranes with longer dehydration periods. Normal seedling recovery of 50 to 47% for cryopreserved embryonic axes of F. polyandra was observed after ultra-rapid and silica gel drying respectively. Extreme cell injury was observed after exposure to liquid nitrogen at high moisture content. Although cells of dehydrated axes encountered stress during cryopreservation, the main damage occurred during the dehydration step. For surviving axes, the damage was less severe and the axes grew to become normal seedlings. Ultrastructural studies reveal the damage of the cells at different rates of dehydration and during cryopreservation.

  3. Cleaved Slit directs embryonic muscles.

    Science.gov (United States)

    Ordan, Elly; Volk, Talila

    2015-01-01

    The formation of functional musculoskeletal system relies on proper connectivity between muscles and their corresponding tendon cells. In Drosophila, larval muscles are born during early embryonic stages, and elongate toward tendons that are embedded within the ectoderm in later. The Slit/Robo signaling pathway had been implicated in the process of muscle elongation toward tendons. Here we discuss our recent findings regarding the critical contribution of Slit cleavage for immobilization and stabilization of the Slit signal on the tendon cells. Slit cleavage produces 2 polypeptides, the N-terminal Slit-N, which is extremely stable, undergoes oligomerization, and associates with the tendon cell surfaces, and the C-terminal Slit-C, which rapidly degrades. Slit cleavage leads to immobilization of Slit signaling on tendons, leading to a short-range repulsion, which eventually arrest further muscle elongation. Robo2, which is co-expressed with Slit by the tendon cells facilitates Slit cleavage. This activity does not require the cytoplasmic signaling domain of Robo2. We suggest that Robo2-dependent Slit cleavage, and the formation of Slit-N oligomers on the tendon cell surfaces direct muscle elongation, and provide a stop signal for the approaching muscle, through binding to Robo and Robo3 receptors expressed by the muscles.

  4. Maturation of spinal motor neurons derived from human embryonic stem cells.

    Directory of Open Access Journals (Sweden)

    Tomonori Takazawa

    Full Text Available Our understanding of motor neuron biology in humans is derived mainly from investigation of human postmortem tissue and more indirectly from live animal models such as rodents. Thus generation of motor neurons from human embryonic stem cells and human induced pluripotent stem cells is an important new approach to model motor neuron function. To be useful models of human motor neuron function, cells generated in vitro should develop mature properties that are the hallmarks of motor neurons in vivo such as elaborated neuronal processes and mature electrophysiological characteristics. Here we have investigated changes in morphological and electrophysiological properties associated with maturation of neurons differentiated from human embryonic stem cells expressing GFP driven by a motor neuron specific reporter (Hb9::GFP in culture. We observed maturation in cellular morphology seen as more complex neurite outgrowth and increased soma area over time. Electrophysiological changes included decreasing input resistance and increasing action potential firing frequency over 13 days in vitro. Furthermore, these human embryonic stem cell derived motor neurons acquired two physiological characteristics that are thought to underpin motor neuron integrated function in motor circuits; spike frequency adaptation and rebound action potential firing. These findings show that human embryonic stem cell derived motor neurons develop functional characteristics typical of spinal motor neurons in vivo and suggest that they are a relevant and useful platform for studying motor neuron development and function and for modeling motor neuron diseases.

  5. Maturation of Spinal Motor Neurons Derived from Human Embryonic Stem Cells

    Science.gov (United States)

    Takazawa, Tomonori; Croft, Gist F.; Amoroso, Mackenzie W.; Studer, Lorenz; Wichterle, Hynek; MacDermott, Amy B.

    2012-01-01

    Our understanding of motor neuron biology in humans is derived mainly from investigation of human postmortem tissue and more indirectly from live animal models such as rodents. Thus generation of motor neurons from human embryonic stem cells and human induced pluripotent stem cells is an important new approach to model motor neuron function. To be useful models of human motor neuron function, cells generated in vitro should develop mature properties that are the hallmarks of motor neurons in vivo such as elaborated neuronal processes and mature electrophysiological characteristics. Here we have investigated changes in morphological and electrophysiological properties associated with maturation of neurons differentiated from human embryonic stem cells expressing GFP driven by a motor neuron specific reporter (Hb9::GFP) in culture. We observed maturation in cellular morphology seen as more complex neurite outgrowth and increased soma area over time. Electrophysiological changes included decreasing input resistance and increasing action potential firing frequency over 13 days in vitro. Furthermore, these human embryonic stem cell derived motor neurons acquired two physiological characteristics that are thought to underpin motor neuron integrated function in motor circuits; spike frequency adaptation and rebound action potential firing. These findings show that human embryonic stem cell derived motor neurons develop functional characteristics typical of spinal motor neurons in vivo and suggest that they are a relevant and useful platform for studying motor neuron development and function and for modeling motor neuron diseases. PMID:22802953

  6. Embryonic stem cells and prospects for their use in regenerative medicine approaches to motor neurone disease.

    Science.gov (United States)

    Christou, Y A; Moore, H D; Shaw, P J; Monk, P N

    2007-10-01

    Human embryonic stem cells are pluripotent cells with the potential to differentiate into any cell type in the presence of appropriate stimulatory factors and environmental cues. Their broad developmental potential has led to valuable insights into the principles of developmental and cell biology and to the proposed use of human embryonic stem cells or their differentiated progeny in regenerative medicine. This review focuses on the prospects for the use of embryonic stem cells in cell-based therapy for motor neurone disease or amyotrophic lateral sclerosis, a progressive neurodegenerative disease that specifically affects upper and lower motor neurones and leads ultimately to death from respiratory failure. Stem cell-derived motor neurones could conceivably be used to replace the degenerated cells, to provide authentic substrates for drug development and screening and for furthering our understanding of disease mechanisms. However, to reliably and accurately culture motor neurones, the complex pathways by which differentiation occurs in vivo must be understood and reiterated in vitro by embryonic stem cells. Here we discuss the need for new therapeutic strategies in the treatment of motor neurone disease, the developmental processes that result in motor neurone formation in vivo, a number of experimental approaches to motor neurone production in vitro and recent progress in the application of stem cells to the treatment and understanding of motor neurone disease.

  7. Apoptosis during embryonic tissue remodeling is accompanied by cell senescence

    Science.gov (United States)

    Lorda-Diez, Carlos I.; Garcia-Riart, Beatriz; Montero, Juan A.; Rodriguez-León, Joaquín; Garcia-Porrero, Juan A; Hurle, Juan M.

    2015-01-01

    This study re-examined the dying process in the interdigital tissue during the formation of free digits in the developing limbs. We demonstrated that the interdigital dying process was associated with cell senescence, as deduced by induction of β-gal activity, mitotic arrest, and transcriptional up-regulation of p21 together with many components of the senescence-associated secretory phenotype. We also found overlapping domains of expression of members of the Btg/Tob gene family of antiproliferative factors in the regressing interdigits. Notably, Btg2 was up-regulated during interdigit remodeling in species with free digits but not in the webbed foot of the duck. We also demonstrate that oxidative stress promoted the expression of Btg2, and that FGF2 and IGF1 which are survival signals for embryonic limb mesenchyme inhibited Btg2 expression. Btg2 overexpression in vivo and in vitro induced all the observed changes during interdigit regression, including oxidative stress, arrest of cell cycle progression, transcriptional regulation of senescence markers, and caspase-mediated apoptosis. Consistent with the central role of p21 on cell senescence, the transcriptional effects induced by overexpression of Btg2 are attenuated by silencing p21. Our findings indicate that cell senescence and apoptosis are complementary processes in the regression of embryonic tissues and share common regulatory signals. PMID:26568417

  8. Enhanced expression of FNDC5 in human embryonic stem cell-derived neural cells along with relevant embryonic neural tissues.

    Science.gov (United States)

    Ghahrizjani, Fatemeh Ahmadi; Ghaedi, Kamran; Salamian, Ahmad; Tanhaei, Somayeh; Nejati, Alireza Shoaraye; Salehi, Hossein; Nabiuni, Mohammad; Baharvand, Hossein; Nasr-Esfahani, Mohammad Hossein

    2015-02-25

    Availability of human embryonic stem cells (hESCs) has enhanced the capability of basic and clinical research in the context of human neural differentiation. Derivation of neural progenitor (NP) cells from hESCs facilitates the process of human embryonic development through the generation of neuronal subtypes. We have recently indicated that fibronectin type III domain containing 5 protein (FNDC5) expression is required for appropriate neural differentiation of mouse embryonic stem cells (mESCs). Bioinformatics analyses have shown the presence of three isoforms for human FNDC5 mRNA. To differentiate which isoform of FNDC5 is involved in the process of human neural differentiation, we have used hESCs as an in vitro model for neural differentiation by retinoic acid (RA) induction. The hESC line, Royan H5, was differentiated into a neural lineage in defined adherent culture treated by RA and basic fibroblast growth factor (bFGF). We collected all cell types that included hESCs, rosette structures, and neural cells in an attempt to assess the expression of FNDC5 isoforms. There was a contiguous increase in all three FNDC5 isoforms during the neural differentiation process. Furthermore, the highest level of expression of the isoforms was significantly observed in neural cells compared to hESCs and the rosette structures known as neural precursor cells (NPCs). High expression levels of FNDC5 in human fetal brain and spinal cord tissues have suggested the involvement of this gene in neural tube development. Additional research is necessary to determine the major function of FDNC5 in this process. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Lack of Virus-Specific Bacterial Adherence to Bovine Embryonic Lung Cells Infected with Bovine Parainfluenza Virus Type 3 †

    OpenAIRE

    Toth, Thomas E.; Gates, Connie

    1983-01-01

    Infection of bovine embryonic lung cells with bovine parainfluenza virus type 3 did not induce in vitro, virus-specific, hemadsorption-related adherence of Corynebacterium pyogenes, Haemophilus somnus, Staphylococcus aureus, Streptococcus zooepidemicus, Pasteurella haemolytica, Listeria monocytogenes, Escherichia coli, Pasteurella multocida, Brucella sp., or Salmonella typhimurium.

  10. Effects of oxidative stress on human embryonic stem cells; global gene expression, advanced glycation end products and NEDD1 levels

    NARCIS (Netherlands)

    Barandalla Sobrados, M.

    2017-01-01

    A number of unfavorable conditions can affect the development of the early embryo inducing oxidative stress both in vivo, for instance in gestational diabetes, and in vitro, when embryos are derived from Assisted Reproductive Technologies (ART). Human Embryonic Stem Cells (hESCs) potentially offer a

  11. An optimized gene set for transcriptomics based neurodevelopmental toxicity prediction in the neural embryonic stem cell test

    NARCIS (Netherlands)

    Pennings, J.L.A.; Theunissen, P.T.; Piersma, A.H.|info:eu-repo/dai/nl/071276947

    2012-01-01

    The murine neural embryonic stem cell test (ESTn) is an in vitro model for neurodevelopmental toxicity testing. Recent studies have shown that application of transcriptomics analyses in the ESTn is useful for obtaining more accurate predictions as well as mechanistic insights. Gene expression

  12. A vector-based system for the differentiation of mouse embryonic stem cells toward germ-line cells

    Directory of Open Access Journals (Sweden)

    Reza Ebrahimzadeh-Vesal

    2014-08-01

    Conclusion: In this study, we demonstrated the in vitro generation of mouse embryonic stem cells to germ cells by using a backbone vector containing the fusion gene Stra8-EGFP. The Stra8 gene is a retinoic acid-responsive protein and is able to regulate meiotic initiation.

  13. Micro-ion beam analysis of physico-chemical reactions in vitro induced by nano-structured sol-gel derived bioactive glasses; Caracterisation par micro-faisceau d'ions des reactions physico-chimiques induites in vitro par des verres bioactifs nanostructures elabores par la methode sol-gel

    Energy Technology Data Exchange (ETDEWEB)

    Lao, J

    2007-07-15

    The study of bioactive glasses is a multi-field area of research aiming at a major goal: the development of new generation biomaterials that would be able to bond with host tissues through the formation of a strong interfacial bond, together with helping the body heal itself through the stimulation of specific cellular responses. Thus clinical applications of bioactive glasses mainly concern dental surgery and orthopedics, for filling osseous defects. For this purpose, we have elaborated bioactive glasses in the binary SiO{sub 2}-CaO system, ternary SiO{sub 2}-CaO-P{sub 2}O{sub 5} system, and for the first time, to our knowledge, strontium-doped SiO{sub 2}-CaO-SrO and SiO{sub 2}-CaO-P{sub 2}O{sub 5}-SrO glasses. The materials were elaborated using the sol-gel process, which allowed the synthesis of nano-porous materials with great purity and homogeneity. The bio-activity of the glasses was clearly demonstrated in vitro: in contact with biological fluids, the whole lot of mate-rials were able to induce the formation of a Ca-P-Mg layer a few microns thick at their surface. Our work is characterized by the use of PIXE-RBS nuclear microprobes to study the bioactive glass/biological fluids interface. Thanks to these methods we obtained chemical maps that made possible the analysis of major and trace elements concentrations at the interface. Moreover, quantitative information regarding the local reactivity of glasses were acquired. These data are important to evaluate the kinetics and amplitude of the physico-chemical reactions involved in the bio-activity process. Thus, we highlighted that the binary glass is the highest reactive regarding the dissolution of the glassy matrix as well as the first appearance of the Ca-P rich layer. However the Ca/P atomic ratio calculated at the glass/biological fluids interface decreases slowly, indicating that the Ca-P-Mg layer encounters difficulties to be changed into a more stable apatitic phase. For the P-containing glasses, the de

  14. The cell cycle as a brake for ?-cell regeneration from embryonic stem cells

    OpenAIRE

    El-Badawy, Ahmed; El-Badri, Nagwa

    2016-01-01

    The generation of insulin-producing ? cells from stem cells in vitro provides a promising source of cells for cell transplantation therapy in diabetes. However, insulin-producing cells generated from human stem cells show deficiency in many functional characteristics compared with pancreatic ? cells. Recent reports have shown molecular ties between the cell cycle and the differentiation mechanism of embryonic stem (ES) cells, assuming that cell fate decisions are controlled by the cell cycle ...

  15. Derivation of human embryonic stem cell from spinal muscular atrophy patient

    Directory of Open Access Journals (Sweden)

    Pingyuan Xie

    2016-03-01

    Full Text Available We established a human embryonic stem cell (hESC line chHES-427 from the abnormal embryo carrying homozygous deletion of exon 7 of survival motor neuron gene (SMN. This cell line maintained a normal karyotype 46, XX during long-term culture. Further characteristic analysis suggested that the cells expressed the pluripotency-related markers and had the capacity to differentiate into the derivatives from the three germ layers in vitro.

  16. Effect of passage number on electrophoretic mobility distributions of cultured human embryonic kidney cells

    Science.gov (United States)

    Kunze, M. E.

    1985-01-01

    A systematic investigation was undertaken to characterize population shifts that occur in cultured human embryonic kidney cells as a function of passage number in vitro after original explantation. This approach to cell population shift analysis follows the suggestion of Mehreshi, Klein and Revesz that perturbed cell populations can be characterized by electrophoretic mobility distributions if they contain subpopulations with different electrophoretic mobilities. It was shown that this is the case with early passage cultured human embryo cells.

  17. ANALYSE DES PERCEPTIONS LOCALES ET DES FACTEURS ...

    African Journals Online (AJOL)

    AISA

    (Euphorbiaceae). ANALYSE DES PERCEPTIONS LOCALES ET DES FACTEURS ... Une Analyse en Composantes Principales a été appliquée à la matrice .... valeur de la variable aléatoire normale pour un risque α égal à 0,05. La marge d'erreur d prévue pour tout paramètre à estimer à partir de l'enquête est de 3 %.

  18. Computer Simulation of Embryonic Systems: What can a ...

    Science.gov (United States)

    (1) Standard practice for assessing developmental toxicity is the observation of apical endpoints (intrauterine death, fetal growth retardation, structural malformations) in pregnant rats/rabbits following exposure during organogenesis. EPA’s computational toxicology research program (ToxCast) generated vast in vitro cellular and molecular effects data on >1858 chemicals in >600 high-throughput screening (HTS) assays. The diversity of assays has been increased for developmental toxicity with several HTS platforms, including the devTOX-quickPredict assay from Stemina Biomarker Discovery utilizing the human embryonic stem cell line (H9). Translating these HTS data into higher order-predictions of developmental toxicity is a significant challenge. Here, we address the application of computational systems models that recapitulate the kinematics of dynamical cell signaling networks (e.g., SHH, FGF, BMP, retinoids) in a CompuCell3D.org modeling environment. Examples include angiogenesis (angiodysplasia) and dysmorphogenesis. Being numerically responsive to perturbation, these models are amenable to data integration for systems Toxicology and Adverse Outcome Pathways (AOPs). The AOP simulation outputs predict potential phenotypes based on the in vitro HTS data ToxCast. A heuristic computational intelligence framework that recapitulates the kinematics of dynamical cell signaling networks in the embryo, together with the in vitro profiling data, produce quantitative pr

  19. Gene expression heterogeneities in embryonic stem cell populations

    DEFF Research Database (Denmark)

    Martinez Arias, Alfonso; Brickman, Joshua M

    2011-01-01

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

  20. GATA-1 directly regulates Nanog in mouse embryonic stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wen-Zhong; Ai, Zhi-Ying [College of Life Sciences, Northwest A& F University, Yangling 712100 (China); Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A& F University, Yangling 712100 (China); Wang, Zhi-Wei [School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027 (China); Chen, Lin-Lin [College of Life Sciences, Northwest A& F University, Yangling 712100 (China); Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A& F University, Yangling 712100 (China); Guo, Ze-Kun, E-mail: gzknwaf@126.com [College of Veterinary Medicine, Northwest A& F University, Yangling 712100 (China); Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A& F University, Yangling 712100 (China); Zhang, Yong, E-mail: zylabnwaf@126.com [College of Veterinary Medicine, Northwest A& F University, Yangling 712100 (China); Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A& F University, Yangling 712100 (China)

    2015-09-25

    Nanog safeguards pluripotency in mouse embryonic stem cells (mESCs). Insight into the regulation of Nanog is important for a better understanding of the molecular mechanisms that control pluripotency of mESCs. In a silico analysis, we identify four GATA-1 putative binding sites in Nanog proximal promoter. The Nanog promoter activity can be significantly repressed by ectopic expression of GATA-1 evidenced by a promoter reporter assay. Mutation studies reveal that one of the four putative binding sites counts for GATA-1 repressing Nanog promoter activity. Direct binding of GATA-1 on Nanog proximal promoter is confirmed by electrophoretic mobility shift assay and chromatin immunoprecipitation. Our data provide new insights into the expanded regulatory circuitry that coordinates Nanog expression. - Highlights: • The Nanog proximal promoter conceives functional element for GATA-1. • GATA-1 occupies the Nanog proximal promoter in vitro and in vivo. • GATA-1 transcriptionally suppresses Nanog.

  1. Culture in vitro chez l'igname ( Dioscorea sp .): Influence du milieu ...

    African Journals Online (AJOL)

    Culture in vitro chez l'igname ( Dioscorea sp .): Influence du milieu de culture sur la regeneration des microboutures. : In vitro culture of yam ( Dioscorea ): Influence of the culture medium on the regeneration of microcuttings.

  2. Diabetes-induced effects on cardiomyocytes in chick embryonic heart micromass and mouse embryonic D3 differentiated stem cells.

    Science.gov (United States)

    Mohammed, Omar J; Latif, Muhammad Liaque; Pratten, Margaret K

    2017-04-01

    Diabetes mellitus during pregnancy is a considerable medical challenge, since it is related to ‎augmented morbidity and mortality concerns for both the fetus ‎and the pregnant woman. Records show that the etiology of diabetic ‎embryopathy is complicated, as many teratological factors might be involved ‎in the mechanisms of diabetes mellitus-induced congenital malformation. ‎In this study, the potential cardiotoxic effect of hyperglycemia with hyperketonemia was investigated by using two in vitro models; primary chick embryonic cardiomyocytes and stem cell derived cardiomyocytes, where adverse effects were recorded in both systems. The cells were evaluated by changes in beating activity, cell activity, protein content, ROS production, DNA damage and differentiating stem cell migration. The diabetic formulae used produced an increase in DNA damage and a decline in cell migration in mouse embryonic stem cells. These results provide an additional insight into adverse effects during gestational diabetes mellitus and a recommendation for expectant mothers and maternity staff to monitor glycaemic levels months ahead of conception. This study also supports the recommendation of using antioxidants during pregnancy to prevent DNA damage by the production of ROS, which might result in heart defects as well as other developmental anomalies. Copyright © 2017. Published by Elsevier Inc.

  3. Uncoupled embryonic and extra-embryonic tissues compromise blastocyst development after somatic cell nuclear transfer.

    Directory of Open Access Journals (Sweden)

    Séverine A Degrelle

    Full Text Available Somatic cell nuclear transfer (SCNT is the most efficient cell reprogramming technique available, especially when working with bovine species. Although SCNT blastocysts performed equally well or better than controls in the weeks following embryo transfer at Day 7, elongation and gastrulation defects were observed prior to implantation. To understand the developmental implications of embryonic/extra-embryonic interactions, the morphological and molecular features of elongating and gastrulating tissues were analysed. At Day 18, 30 SCNT conceptuses were compared to 20 controls (AI and IVP: 10 conceptuses each; one-half of the SCNT conceptuses appeared normal while the other half showed signs of atypical elongation and gastrulation. SCNT was also associated with a high incidence of discordance in embryonic and extra-embryonic patterns, as evidenced by morphological and molecular "uncoupling". Elongation appeared to be secondarily affected; only 3 of 30 conceptuses had abnormally elongated shapes and there were very few differences in gene expression when they were compared to the controls. However, some of these differences could be linked to defects in microvilli formation or extracellular matrix composition and could thus impact extra-embryonic functions. In contrast to elongation, gastrulation stages included embryonic defects that likely affected the hypoblast, the epiblast, or the early stages of their differentiation. When taking into account SCNT conceptus somatic origin, i.e. the reprogramming efficiency of each bovine ear fibroblast (Low: 0029, Med: 7711, High: 5538, we found that embryonic abnormalities or severe embryonic/extra-embryonic uncoupling were more tightly correlated to embryo loss at implantation than were elongation defects. Alternatively, extra-embryonic differences between SCNT and control conceptuses at Day 18 were related to molecular plasticity (high efficiency/high plasticity and subsequent pregnancy loss. Finally

  4. Impaired embryonic development in mice overexpressing the RNA-binding protein TIAR.

    Directory of Open Access Journals (Sweden)

    Yacine Kharraz

    Full Text Available BACKGROUND: TIA-1-related (TIAR protein is a shuttling RNA-binding protein involved in several steps of RNA metabolism. While in the nucleus TIAR participates to alternative splicing events, in the cytoplasm TIAR acts as a translational repressor on specific transcripts such as those containing AU-Rich Elements (AREs. Due to its ability to assemble abortive pre-initiation complexes coalescing into cytoplasmic granules called stress granules, TIAR is also involved in the general translational arrest observed in cells exposed to environmental stress. However, the in vivo role of this protein has not been studied so far mainly due to severe embryonic lethality upon tiar invalidation. METHODOLOGY/PRINCIPAL FINDINGS: To examine potential TIAR tissue-specificity in various cellular contexts, either embryonic or adult, we constructed a TIAR transgenic allele (loxPGFPloxPTIAR allowing the conditional expression of TIAR protein upon Cre recombinase activity. Here, we report the role of TIAR during mouse embryogenesis. We observed that early TIAR overexpression led to low transgene transmission associated with embryonic lethality starting at early post-implantation stages. Interestingly, while pre-implantation steps evolved correctly in utero, in vitro cultured embryos were very sensitive to culture medium. Control and transgenic embryos developed equally well in the G2 medium, whereas culture in M16 medium led to the phosphorylation of eIF2alpha that accumulated in cytoplasmic granules precluding transgenic blastocyst hatching. Our results thus reveal a differential TIAR-mediated embryonic response following artificial or natural growth environment. CONCLUSIONS/SIGNIFICANCE: This study reports the importance of the tightly balanced expression of the RNA-binding protein TIAR for normal embryonic development, thereby emphasizing the role of post-transcriptional regulations in early embryonic programming.

  5. In vitro Activity of Ethanol, Cold Water and Hot Water Extracts of the ...

    African Journals Online (AJOL)

    An in vitro evaluation was performed to determine the efficacy of ethanol, cold water and hot water extracts of the stem bark of Canthium mannii (Rubiaceae) on un-embryonated and embryonated eggs of Ancylostoma caninum obtained from the faeces of naturally infected local dogs. The extracts were diluted in distilled ...

  6. Embryonic Stem Cells: Isolation, Characterization and Culture

    Science.gov (United States)

    Amit, Michal; Itskovitz-Eldor, Joseph

    Embryonic stem cells are pluripotent cells isolated from the mammalian blastocyst. Traditionally, these cells have been derived and cultured with mouse embryonic fibroblast (MEF) supportive layers, which allow their continuous growth in an undifferentiated state. However, for any future industrial or clinical application hESCs should be cultured in reproducible, defined, and xeno-free culture system, where exposure to animal pathogens is prevented. From their derivation in 1998 the methods for culturing hESCs were significantly improved. This chapter wills discuss hESC characterization and the basic methods for their derivation and maintenance.

  7. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    3) Laboratoire de Mécanique, Structures et Energétique, ... This work consists in detecting two combined defects, simulated on gears using continuous wavelet ..... Vibration, Vol. 234, Issue 1, 2000, p.135-. 148. [15] A. Boulenger, C. Pachaud, Aide- mémoire, Surveillance des machines par analyse des vibrations, Ed. Dunod, ...

  8. Gestion des risques

    CERN Document Server

    Louisot, Jean-Paul

    2009-01-01

    Depuis le début du lie siècle, la gestion des risques connaît une véritable révolution culturelle. Jusqu'alors fonction technique, centrée autour de l'achat de couverture d'assurances, elle est devenue une discipline managériale et transversale : une valise d'instruments que chaque manager doit connaître et appliquer quels que soient son domaine de compétence et ses missions au sein de l'organisation. En effet, la gestion des risques est une culture qui doit être assimilée par chacun des acteurs. C'est précisément l'ambition des 101 questions rassemblées dans cet ouvrage : apporter à chaque manager d'entreprise, de collectivité, d'établissement de santé..., des réponses claires au " pourquoi " et au " comment " : Comment identifier les risques ? Comment analyser les risques ? Quels sont les objectifs de la gestion des risques ? Une carte des risques pour quoi faire ? Pourquoi faut-il financer les risques ? Les entreprises ont-elles des responsabilités pénales ? En quoi consiste la gestion...

  9. Technologien des Spektakels

    NARCIS (Netherlands)

    Röttger, K.; Ritzer, I.; Schulze, P.W.

    2016-01-01

    Mit dem vorliegenden Artikel möchte ich den Vorschlag unterbreiten, über transmediale Genre-Passagen aus der Perspektive des Spektakels nachzudenken. Denn der Begriff des Spektakels eignet sich meines Erachtens einerseits zur Analyse und Beschreibung verschiedener Massenmedien wie Film, Radio,

  10. Potenziale des Bankenplatzes Basel

    OpenAIRE

    Gantenbein, Pascal; Weder, Rolf

    2011-01-01

    Aufbauend auf der Studie "Bedeutung des Bankenplatzes Basel" (WWZ-Studie 10/03), welche im Dezember 2010 publiziert und seither mehrfach vorgestellt wurde, ist es das Ziel der vorliegenden Untersuchung, die Potenziale und Entwicklungsmöglichkeiten des Basler Bankenplatzes zu analysieren.

  11. peste des petits ruminants

    African Journals Online (AJOL)

    HP USER

    of antibodies to peste des petits ruminants. (PPR) virus. Veterinary. Research. Communications, 30:325-330. Singh RK, Balauirjgal V, Bhamuprakash V, Sanen A,. Saravanan P, & Yadev MP (2009). Possible control and eradication of peste des petits ruminants from India: technical aspect. Veterinaria Italiana, 45 (3), ...

  12. Gestion des ressources naturelles

    International Development Research Centre (IDRC) Digital Library (Canada)

    environnement et l'accès aux ressources naturelles est un enjeu crucial. Ces 40 dernières années, des chercheurs appuyés par le CRDI ont trouvé des moyens novateurs de réduire la pauvreté tout en protégeant les ressources naturelles dont ...

  13. Diversification des moyens de subsistance des petits producteurs de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Diversification des moyens de subsistance des petits producteurs de tabac grâce à la culture de l'arachide (Malawi). L'économie du Malawi repose essentiellement sur la culture du tabac, qui représente plus de 70 % des revenus d'exportation. Pour 60 % des 100 000 membres de la National Smallholder Farmers' ...

  14. La gouvernance des risques naturels et la problematique des ...

    African Journals Online (AJOL)

    Depuis quelques années, la gouvernance des risques naturels dus aux inondations remet en cause les processus de mise en oeuvre des politiques urbaines et la qualité de la structure des aménagements dans les grandes villes du Golfe de Guinée. La perception de la gouvernance et l'application des politiques de ...

  15. Arabidopsis LEAFY COTYLEDON1 controls cell fate determination during post-embryonic development

    Directory of Open Access Journals (Sweden)

    Mingkun eHuang

    2015-11-01

    Full Text Available Arabidopsis LEAFY COTYLEDON1 (LEC1 transcription factor is a master regulator that shapes plant embryo development and post-embryonic seedling establishment. Loss-of-function of LEC1 alters the cotyledon identity, causing the formation of ectopic trichomes, which does not occur in wild-type seedlings, implying that LEC1 might regulate embryonic cell fate determination during post-embryonic development. To test this hypothesis, we compared the expression of trichome development-related genes between the wild-type and the lec1 mutant. We observed that transcripts of GL1, GL2 and GL3, genes encoding the positive regulators in trichome development, were significantly upregulated, while the TCL2, ETC1 and ETC2 genes, encoding the negative regulators in trichome development, were downregulated in the lec1 mutant. Furthermore, overexpression of LEC1 activated the expressions of TCL2, CPC and ETC1, resulting in production of cotyledonary leaves with no or fewer trichomes during vegetative development. In addition, we demonstrated that LEC1 interacts with TCL2 in yeast and in vitro. A genetic experiment showed that loss-of-function of GL2 rescued the ectopic trichome formation in the lec1 mutant. These findings strongly support that LEC1 regulates trichome development, providing direct evidence for the role of LEC1 in cell fate determination during post-embryonic development.

  16. Clathrin assembly proteins AP180 and CALM in the embryonic rat brain.

    Science.gov (United States)

    Schwartz, Catherine M; Cheng, Aiwu; Mughal, Mohamed R; Mattson, Mark P; Yao, Pamela J

    2010-09-15

    Clathrin-coated vesicles are known to play diverse and pivotal roles in cells. The proper formation of clathrin-coated vesicles is dependent on, and highly regulated by, a large number of clathrin assembly proteins. These assembly proteins likely determine the functional specificity of clathrin-coated vesicles, and together they control a multitude of intracellular trafficking pathways, including those involved in embryonic development. In this study, we focus on two closely related clathrin assembly proteins, AP180 and CALM (clathrin assembly lymphoid myeloid leukemia protein), in the developing embryonic rat brain. We find that AP180 begins to be expressed at embryonic day 14 (E14), but only in postmitotic cells that have acquired a neuronal fate. CALM, on the other hand, is expressed as early as E12, by both neural stem cells and postmitotic neurons. In vitro loss-of-function studies using RNA interference (RNAi) indicate that AP180 and CALM are dispensable for some aspects of embryonic neurogenesis but are required for the growth of postmitotic neurons. These results identify the developmental stage of AP180 and CALM expression and suggest that each protein has distinct functions in neural development.

  17. EVA1A/TMEM166 Regulates Embryonic Neurogenesis by Autophagy.

    Science.gov (United States)

    Li, Mengtao; Lu, Guang; Hu, Jia; Shen, Xue; Ju, Jiabao; Gao, Yuanxu; Qu, Liujing; Xia, Yan; Chen, Yingyu; Bai, Yun

    2016-03-08

    Self-renewal and differentiation of neural stem cells is essential for embryonic neurogenesis, which is associated with cell autophagy. However, the mechanism by which autophagy regulates neurogenesis remains undefined. Here, we show that Eva1a/Tmem166, an autophagy-related gene, regulates neural stem cell self-renewal and differentiation. Eva1a depletion impaired the generation of newborn neurons, both in vivo and in vitro. Conversely, overexpression of EVA1A enhanced newborn neuron generation and maturation. Moreover, Eva1a depletion activated the PIK3CA-AKT axis, leading to the activation of the mammalian target of rapamycin and the subsequent inhibition of autophagy. Furthermore, addition of methylpyruvate to the culture during neural stem cell differentiation rescued the defective embryonic neurogenesis induced by Eva1a depletion, suggesting that energy availability is a significant factor in embryonic neurogenesis. Collectively, these data demonstrated that EVA1A regulates embryonic neurogenesis by modulating autophagy. Our results have potential implications for understanding the pathogenesis of neurodevelopmental disorders caused by autophagy dysregulation. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  18. Kisspeptin regulates ovarian steroidogenesis during delayed embryonic development in the fruit bat, Cynopterus sphinx.

    Science.gov (United States)

    Anuradha; Krishna, Amitabh

    2017-11-01

    Cynopterus sphinx, a fruit bat, undergoes delayed embryonic development during the winter months, a period that corresponds to low levels of progesterone and estradiol synthesis by the ovary. Kisspeptins (KPs) are a group of neuropeptide hormones that act via G-protein coupled receptor 54 (GPR54) to stimulate hypothalamic secretion of Gonadotropin-releasing hormone, thereby regulating ovarian steroidogenesis, folliculogenesis, and ovulation. GPR54 is also expressed in the ovary, suggesting a direct role for KPs in ovarian steroidogenesis. The aim of present study was to determine if a low serum level of KP is responsible for reduced progesterone and estradiol levels during the period of delayed embryonic development in C. sphinx. Indeed, low serum KP abundance corresponded to reduced expression of GPR54 in ovarian luteal cells during the period of delayed development compared to normal development. In vitro and in vivo treatment with KP increased GPR54 abundance, via Extracellular signal regulated kinase and its downstream mediators, leading to increased progesterone synthesis in the ovary during delayed embryonic development. KP treatment also increased cholesterol uptake and elevated expression of Luteinizing hormone receptor and Steroid acute regulatory protein in the ovary, suggesting that elevation in circulating KP during delayed embryonic development may reactivate luteal activity. KPs may also enhance cell survival (BCL-2, reduced Caspase 3 activity) and angiogenesis (Vascular endothelium growth factor) during this period. The findings of this study thus demonstrate a regulatory role for KPs in the maintenance of luteal steroidogenesis during pregnancy in C. sphinx. © 2017 Wiley Periodicals, Inc.

  19. Pitx2 in Embryonic and Adult Myogenesis

    Directory of Open Access Journals (Sweden)

    Amelia E. Aranega

    2017-05-01

    Full Text Available Skeletal muscle is a heterogeneous tissue that represents between 30 and 38% of the human body mass and has important functions in the organism, such as maintaining posture, locomotor impulse, or pulmonary ventilation. The genesis of skeletal muscle during embryonic development is a process controlled by an elaborate regulatory network combining the interplay of extrinsic and intrinsic regulatory mechanisms that transform myogenic precursor cells into functional muscle fibers through a finely tuned differentiation program. However, the capacity of generating muscle still remains once these fibers have matured. Adult myogenesis resembles many of the embryonic morphogenetic episodes and depends on the activation of satellite cells that have the potential to differentiate into new muscle fibers. Pitx2 is a member of the bicoid family of homeodomain transcription factors that play an important role in morphogenesis. In the last decade, Pitx2 has emerged as a key element involved in the fine-tuning mechanism that regulates skeletal-muscle development as well as the differentiation and cell fate of satellite cells in adult muscle. Here we present an integrative view of all aspects of embryonic and adult myogenesis in which Pitx2 is involved, from embryonic development to satellite-cell proliferation, fate specification, and differentiation. Those new Pitx2 functions on satellite-cell biology might open new perspectives to develop therapeutic strategies for muscular disorders.

  20. Pitx2 in Embryonic and Adult Myogenesis.

    Science.gov (United States)

    Hernandez-Torres, Francisco; Rodríguez-Outeiriño, Lara; Franco, Diego; Aranega, Amelia E

    2017-01-01

    Skeletal muscle is a heterogeneous tissue that represents between 30 and 38% of the human body mass and has important functions in the organism, such as maintaining posture, locomotor impulse, or pulmonary ventilation. The genesis of skeletal muscle during embryonic development is a process controlled by an elaborate regulatory network combining the interplay of extrinsic and intrinsic regulatory mechanisms that transform myogenic precursor cells into functional muscle fibers through a finely tuned differentiation program. However, the capacity of generating muscle still remains once these fibers have matured. Adult myogenesis resembles many of the embryonic morphogenetic episodes and depends on the activation of satellite cells that have the potential to differentiate into new muscle fibers. Pitx2 is a member of the bicoid family of homeodomain transcription factors that play an important role in morphogenesis. In the last decade, Pitx2 has emerged as a key element involved in the fine-tuning mechanism that regulates skeletal-muscle development as well as the differentiation and cell fate of satellite cells in adult muscle. Here we present an integrative view of all aspects of embryonic and adult myogenesis in which Pitx2 is involved, from embryonic development to satellite-cell proliferation, fate specification, and differentiation. Those new Pitx2 functions on satellite-cell biology might open new perspectives to develop therapeutic strategies for muscular disorders.

  1. Embryonic Stem Cells and their Genetic Modification

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 2. Embryonic Stem Cells and their Genetic Modification - The Nobel Prize in Physiology or Medicine 2007. Mitradas M Panicker. General Article Volume 13 Issue 2 February 2008 pp 172-180 ...

  2. Autophagy in human embryonic stem cells.

    Directory of Open Access Journals (Sweden)

    Thien Tra

    Full Text Available Autophagy (macroautophagy is a degradative process that involves the sequestration of cytosolic material including organelles into double membrane vesicles termed autophagosomes for delivery to the lysosome. Autophagy is essential for preimplantation development of mouse embryos and cavitation of embryoid bodies. The precise roles of autophagy during early human embryonic development, remain however largely uncharacterized. Since human embryonic stem cells constitute a unique model system to study early human embryogenesis we investigated the occurrence of autophagy in human embryonic stem cells. We have, using lentiviral transduction, established multiple human embryonic stem cell lines that stably express GFP-LC3, a fluorescent marker for the autophagosome. Each cell line displays both a normal karyotype and pluripotency as indicated by the presence of cell types representative of the three germlayers in derived teratomas. GFP expression and labelling of autophagosomes is retained after differentiation. Baseline levels of autophagy detected in cultured undifferentiated hESC were increased or decreased in the presence of rapamycin and wortmannin, respectively. Interestingly, autophagy was upregulated in hESCs induced to undergo differentiation by treatment with type I TGF-beta receptor inhibitor SB431542 or removal of MEF secreted maintenance factors. In conclusion we have established hESCs capable of reporting macroautophagy and identify a novel link between autophagy and early differentiation events in hESC.

  3. Embryonic Development In Clarias gariepinus (Buchell, 1822 ...

    African Journals Online (AJOL)

    The embryonic development in Clarias gariepinus was studied under laboratory conditions. The development stages of eggs starting from first cleavage to hatching were examined microscopically. The accurate timing and detailed description of each stage were recorded. Photomicrograph of important stages, segmentation ...

  4. Embryonal rhabdomyosarcoma of the cervix | Ocheke | African ...

    African Journals Online (AJOL)

    Embryonal rhabdomyosarcoma (sarcoma botyroides) of the cervix, which is rare, is described in a 16-yearold. The combined use of chemotherapy, radiotherapy and surgery has markedly improved survival in those with this condition. However, our patient did not benefit from this treatment modality due to late presentation ...

  5. Transcriptome Landscapes of Mammalian Embryonic Cells

    NARCIS (Netherlands)

    Brinkhof, B.

    2015-01-01

    This thesis describes research on gene expression profiles from different embryonic stages and cell types to identify genes involved in pluripotency or differentiation in bovine and porcine cells. The results are compared with data from other mammals. RNA expression profiles of morula and blastocyst

  6. From cilia hydrodynamics to zebrafish embryonic development.

    Science.gov (United States)

    Supatto, Willy; Vermot, Julien

    2011-01-01

    Embryonic development involves the cellular integration of chemical and physical stimuli. A key physical input is the mechanical stress generated during embryonic morphogenesis. This process necessitates tensile forces at the tissue scale such as during axis elongation and budding, as well as at the cellular scale when cells migrate and contract. Furthermore, cells can generate forces using motile cilia to produce flow. Cilia-driven flows are critical throughout embryonic development but little is known about the diversity of the forces they exert and the role of the mechanical stresses they generate. In this chapter, through an examination of zebrafish development, we highlight what is known about the role of hydrodynamics mediated by beating cilia and examine the physical features of flow fields from the modeling and experimental perspectives. We review imaging strategies to visualize and quantify beating cilia and the flow they generate in vivo. Finally, we describe the function of hydrodynamics during left-right embryonic patterning and inner ear development. Ideally, continued progress in these areas will help to address a key conceptual problem in developmental biology, which is to understand the interplay between environmental constraints and genetic control during morphogenesis. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Physiopathology of human embryonic implantation: clinical incidences.

    Directory of Open Access Journals (Sweden)

    Pauline Demailly

    2010-01-01

    Full Text Available Embryo implantation consists of a series of events promoting the invasion of the endometrium and then the uterine arterial system by the extra-embryonic trophoblast. In order for this semi-heterologous implantation to succeed, the endometrium has to first undergo a number of structural and biochemical changes (decidualization. The decidua's various constituents subsequently play a role in the embryonic implantation. The third step is the transformation of the uterine vascular system and the growth of the placenta, which will provide the foetoplacental unit with nutrients. Several physiopathological aspects will be discussed: 1 the implantation window, regulated by maternal and embryonic hormonal secretions and thus influenced by any defects in the latter: dysharmonic luteal phase, 21-hydroxylase block, abnormal integrin expression, 2 the successive trophoblast invasions of uterine vessels which, when defective, lead to early embryo loss or late-onset vascular pathologies, as preeclampsia, 3 the pregnancy's immunological equilibrium, with a spontaneously tolerated semi-allogeneic implant, 4 the impact of pro-coagulant factors (thrombophilia on the pregnancy's progression, 5 the environment of the uterus, ranging from hydrosalpinx to uterine contractions. In summary, the least anatomical or physiological perturbation can interfere with human embryonic implantation - a very particular phenomenon and a true biological paradox.

  8. Culture du bambou : diversification des moyens de subsistance des ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... des producteurs de tabac et des producteurs de bambou, et produit des plans d'action communautaires pour la diversification des moyens de subsistance. Leur recherche a révélé que la production du tabac ne contribuait guère à améliorer le niveau de vie des agriculteurs, que lorsque cultivé dans les mêmes conditions ...

  9. Potential applications of keratinocytes derived from human embryonic stem cells.

    Science.gov (United States)

    Movahednia, Mohammad M; Kidwai, Fahad K; Jokhun, Doorgesh S; Squier, Christopher A; Toh, Wei Seong; Cao, Tong

    2016-01-01

    Although skin grafting is one of the most advanced cell therapy technique, wide application of skin substitutes is hampered by the difficulty in securing sufficient amount of epidermal substitute. Additionally, in understanding the progression of skin aging and disease, and in screening the cosmetic and pharmaceutical products, there is lack of a satisfactory human skin-specific in vitro model. Recently, human embryonic stem cells (hESCs) have been proposed as an unlimited and reliable cell source to obtain almost all cell types present in the human body. This review focuses on the potential off-the-shelf use of hESC-derived keratinocytes for future clinical applications as well as a powerful in vitro skin model to study skin function and integrity, host-pathogen interactions and disease pathogenesis. Furthermore, we discuss the industrial applications of hESC-derived keratinized multi-layer epithelium which provides a human-like test platform for understanding disease pathogenesis, evaluation of new therapeutic modalities and assessment of the safety and efficacy of skin cosmetics and therapeutics. Overall, we conclude that the hESC-derived keratinocytes have great potential for clinical, research and industrial applications. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Factors affecting the development of in vitro fertilization in camelids

    Directory of Open Access Journals (Sweden)

    Trasorras VL

    2016-12-01

    Full Text Available In any program of in vitro embryo production, the ultimate goal is to develop high quality embryos being able to get a normal pregnancy and finally resulting in the birth of a healthy offspring, goal not reach yet in camelids. The application of assisted reproductive techniques, such as in vitro fertilization and subsequent in vitro embryo culture, can extend the knowledge of early embryonic development and make possible the increase of the population of genetically superior animals.

  11. Congenital diaphragmatic hernia candidate genes derived from embryonic transcriptomes

    DEFF Research Database (Denmark)

    Russell, Meaghan K; Longoni, Mauro; Wells, Julie

    2012-01-01

    expression profiling of developing embryonic diaphragms would help identify genes likely to be associated with diaphragm defects. We generated a time series of whole-transcriptome expression profiles from laser captured embryonic mouse diaphragms at embryonic day (E)11.5 and E12.5 when experimental...

  12. Identification of Thalidomide-Specific Transcriptomics and Proteomics Signatures during Differentiation of Human Embryonic Stem Cells

    Science.gov (United States)

    Meganathan, Kesavan; Jagtap, Smita; Wagh, Vilas; Winkler, Johannes; Gaspar, John Antonydas; Hildebrand, Diana; Trusch, Maria; Lehmann, Karola; Hescheler, Jürgen; Schlüter, Hartmut; Sachinidis, Agapios

    2012-01-01

    Embryonic development can be partially recapitulated in vitro by differentiating human embryonic stem cells (hESCs). Thalidomide is a developmental toxicant in vivo and acts in a species-dependent manner. Besides its therapeutic value, thalidomide also serves as a prototypical model to study teratogenecity. Although many in vivo and in vitro platforms have demonstrated its toxicity, only a few test systems accurately reflect human physiology. We used global gene expression and proteomics profiling (two dimensional electrophoresis (2DE) coupled with Tandem Mass spectrometry) to demonstrate hESC differentiation and thalidomide embryotoxicity/teratogenecity with clinically relevant dose(s). Proteome analysis showed loss of POU5F1 regulatory proteins PKM2 and RBM14 and an over expression of proteins involved in neuronal development (such as PAK2, PAFAH1B2 and PAFAH1B3) after 14 days of differentiation. The genomic and proteomic expression pattern demonstrated differential expression of limb, heart and embryonic development related transcription factors and biological processes. Moreover, this study uncovered novel possible mechanisms, such as the inhibition of RANBP1, that participate in the nucleocytoplasmic trafficking of proteins and inhibition of glutathione transferases (GSTA1, GSTA2), that protect the cell from secondary oxidative stress. As a proof of principle, we demonstrated that a combination of transcriptomics and proteomics, along with consistent differentiation of hESCs, enabled the detection of canonical and novel teratogenic intracellular mechanisms of thalidomide. PMID:22952932

  13. Confrontation cultures of embryonic stem cells with multicellular tumor spheroids to study tumor-induced angiogenesis.

    Science.gov (United States)

    Wartenberg, Maria; Finkensieper, Andreas; Hescheler, Jürgen; Sauer, Heinrich

    2006-01-01

    Human embryonic stem cells efficiently differentiate blood vessels, which allows using this in vitro model to study the interaction of blood vessels with adjacent tissues. Herein, we introduce confrontation cultures of human embryonic stem cells with multicellular tumor spheroids to investigate molecular mechanisms of tumor-induced angiogenesis. Vascularization of tumor tissue by the host is a prerequisite for tumor growth, which has led to the development of antiangiogenic therapy. This promising anti-cancer therapy intends to reduce, halt, or even regress tumor growth by deprivation from blood, oxygen, and nutrient supply. Confrontation cultures of human embryonic stem cells with multicellular tumor spheroids allow the investigation of the time course of endothelial cell invasion into the tumor tissue, the concomitant analysis of changes in angiogenesis-related gene expression, and analysis of the cellular microenvironment (i.e., pericellular oxygen pressure, tissue pH, and levels of tissue reactive oxygen species). The in vitro model of confrontation cultures is suitable for routine screening of antiangiogenic agents in pre-clinical trials and may be used to replace animal experiments applied in antiangiogenesis research.

  14. Droit des organisations internationales

    CERN Document Server

    Sorel, Jean-Marc; Ndior, Valère

    2013-01-01

    Cet ouvrage collectif offre aux enseignants et chercheurs en droit international, aux praticiens et aux étudiants, une analyse actualisée du droit des organisations internationales. Il dresse en cinq parties un tableau, illustré par des exemples variés, des problématiques que soulève le phénomène polymorphe d institutionnalisation de la société internationale. La première partie est consacrée au phénomène des « organisations internationales », sous l angle à la fois de l institutionnalisation progressive des relations internationales et de la difficulté à cerner une catégorie unifiée. La deuxième partie rend compte de la création, de la disparition et des mutations des organisations internationales, ici envisagées comme systèmes institutionnels et ordres juridiques dérivés. La troisième partie analyse l autonomie que l acquisition de la personnalité juridique et de privilèges et immunités, un organe administratif intégré, un personnel ou un budget propres confèrent aux organi...

  15. Photonique des Morphos

    CERN Document Server

    Berthier, Serge

    2010-01-01

    La photonique est déjà présente dans notre vie quotidienne, et on attend maintenant que la manipulation des photons permette aussi le traitement logique des informations. Cependant, l’élément de base qui permet cette manipulation de la lumière, le cristal photonique, est d’une réalisation complexe et mal contrôlée. Dans la course à la maîtrise de la lumière, les structures photoniques naturelles ont beaucoup à nous apprendre. C’est ce que nous montre Serge Berthier qui étudie dans ce livre la structure des écailles des Morphos. Tenant compte de l’essor récent des approches biomimétiques, il présente de manière détaillée plus de dix-huit techniques expérimentales utilisées pour ses analyses, ainsi que les diverses approches théoriques développées pour la modélisation de structures multi-échelles complexes. Première étude quasi-exhaustive des structures fines d’un genre et des propriétés optiques ainsi que colorimétriques générées, ce livre fournit aux entomologiste...

  16. Approfondissement des connaissances et renforcement des ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    approfondissement des connaissances sur les sexospécificités au sein du programme Communautés et société de l'information en Afrique (ACACIA) et procéder à une évaluation de la stratégie de ce programme en matière de sexospécificités.

  17. ANALYSE DES MODES DE GESTION DES ENTREPRISES ...

    African Journals Online (AJOL)

    Administrateur

    la triade : gestion commerciale, contrôle de l'Etat et reconnaissance du but non lucratif, proposée ici comme un ... MOTS CLES : Algérie - Théâtre - Gestion des entreprises - Culture. JEL CLASSIFICATION: L32 ... institutionnelle (Journal of Cultural Economics, 1977; Cultural. Trends, 1989; Journal of Arts Management, Law, ...

  18. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    démodulation ou bien l‟analyse des résonances repérées dans le spectre. En pratique, ce n‟est pas ... domaine temporel pour la détection des défauts qui génèrent des signaux impulsionnels. Il est très sensible à ... attrait à la détection de défauts de types chocs. Lin et Zuo ont appliqué le Kurtosis pour la recherche du ...

  19. Viaducto Des Rocs

    OpenAIRE

    Fernández Álvarez del Buergo, Alejandro

    2012-01-01

    El presente proyecto presenta las actuaciones a llevar a cabo para la Construcción del Viaducto des Rocs en la ciudad de Poitiers (Francia). El emplazamiento del viaducto está ocupado actualmente por la pasarela des Rocs, una pasarela peatonal que conecta los barrios occidentales con el centro histórico de Poitiers, sobrevolando el valle de la Boivre, marcado por la presencia de una playa de vías propiedad de la SNCF (Societé Nationale des Chemins de Fer). Las malas condiciones de esta infrae...

  20. Laser fusion of mouse embryonic cells and intra-embryonic fusion of blastomeres without affecting the embryo integrity.

    Directory of Open Access Journals (Sweden)

    Alexander Krivokharchenko

    Full Text Available Manipulation with early mammalian embryos is the one of the most important approach to study preimplantation development. Artificial cell fusion is a research tool for various biotechnological experiments. However, the existing methods have various disadvantages, first of them impossibility to fuse selected cells within multicellular structures like mammalian preimplantation embryos. In our experiments we have successfully used high repetition rate picosecond near infrared laser beam for fusion of pairs of oocytes and oocytes with blastomeres. Fused cells looked morphologically normal and keep their ability for further divisions in vitro. We also fused two or three blastomeres inside four-cell mouse embryos. The presence of one, two or three nuclei in different blastomeres of the same early preimplantation mouse embryo was confirmed under UV-light after staining of DNA with the vital dye Hoechst-33342. The most of established embryos demonstrated high viability and developed in vitro to the blastocyst stage. We demonstrated for the first time the use of laser beam for the fusion of various embryonic cells of different size and of two or three blastomeres inside of four-cell mouse embryos without affecting the embryo's integrity and viability. These embryos with blastomeres of various ploidy maybe unique model for numerous purposes. Thus, we propose laser optical manipulation as a new tool for investigation of fundamental mechanisms of mammalian development.

  1. Sourcing human embryos for embryonic stem cell lines: Problems & perspectives

    Directory of Open Access Journals (Sweden)

    Rajvi H Mehta

    2014-01-01

    Full Text Available The ability to successfully derive human embryonic stem cells (hESC lines from human embryos following in vitro fertilization (IVF opened up a plethora of potential applications of this technique. These cell lines could have been successfully used to increase our understanding of human developmental biology, transplantation medicine and the emerging science of regenerative medicine. The main source for human embryos has been ′discarded′ or ′spare′ fresh or frozen human embryos following IVF. It is a common practice to stimulate the ovaries of women undergoing any of the assisted reproductive technologies (ART and retrieve multiple oocytes which subsequently lead to multiple embryos. Of these, only two or maximum of three embryos are transferred while the rest are cryopreserved as per the decision of the couple. In case a couple does not desire to ′cryopreserve′ their embryos then all the embryos remaining following embryo transfer can be considered ′spare′ or if a couple is no longer in need of the ′cryopreserved′ embryos then these also can be considered as ′spare′. But, the question raised by the ethicists is, "what about ′slightly′ over-stimulating a woman to get a few extra eggs and embryos? The decision becomes more difficult when it comes to ′discarded′ embryos. As of today, the quality of the embryos is primarily assessed based on morphology and the rate of development mainly judged by single point assessment. Despite many criteria described in the literature, the quality assessment is purely subjective. The question that arises is on the decision of ′discarding′ embryos. What would be the criteria for discarding embryos and the potential ′use′ of ESC derived from the ′abnormal appearing′ embryos? This paper discusses some of the newer methods to procure embryos for the derivation of embryonic stem cell lines which will respect the ethical concerns but still provide the source material.

  2. Human embryonic stem cells as models for aneuploid chromosomal syndromes.

    Science.gov (United States)

    Biancotti, Juan-Carlos; Narwani, Kavita; Buehler, Nicole; Mandefro, Berhan; Golan-Lev, Tamar; Yanuka, Ofra; Clark, Amander; Hill, David; Benvenisty, Nissim; Lavon, Neta

    2010-09-01

    Syndromes caused by chromosomal aneuploidies are widely recognized genetic disorders in humans and often lead to spontaneous miscarriage. Preimplantation genetic screening is used to detect chromosomal aneuploidies in early embryos. Our aim was to derive aneuploid human embryonic stem cell (hESC) lines that may serve as models for human syndromes caused by aneuploidies. We have established 25 hESC lines from blastocysts diagnosed as aneuploid on day 3 of their in vitro development. The hESC lines exhibited morphology and expressed markers typical of hESCs. They demonstrated long-term proliferation capacity and pluripotent differentiation. Karyotype analysis revealed that two-third of the cell lines carry a normal euploid karyotype, while one-third remained aneuploid throughout the derivation, resulting in eight hESC lines carrying either trisomy 13 (Patau syndrome), 16, 17, 21 (Down syndrome), X (Triple X syndrome), or monosomy X (Turner syndrome). On the basis of the level of single nucleotide polymorphism heterozygosity in the aneuploid chromosomes, we determined whether the aneuploidy originated from meiotic or mitotic chromosomal nondisjunction. Gene expression profiles of the trisomic cell lines suggested that all three chromosomes are actively transcribed. Our analysis allowed us to determine which tissues are most affected by the presence of a third copy of either chromosome 13, 16, 17 or 21 and highlighted the effects of trisomies on embryonic development. The results presented here suggest that aneuploid embryos can serve as an alternative source for either normal euploid or aneuploid hESC lines, which represent an invaluable tool to study developmental aspects of chromosomal abnormalities in humans.

  3. Metastable primordial germ cell-like state induced from mouse embryonic stem cells by Akt activation

    Energy Technology Data Exchange (ETDEWEB)

    Yamano, Noriko [Graduate School of Frontier Biosciences, Osaka University, 2-2 Yamada-oka, Suita, Osaka 565-0871 (Japan); Kimura, Tohru, E-mail: tkimura@patho.med.osaka-u.ac.jp [Department of Pathology, Medical School, Osaka University, 2-2 Yamada-oka, Suita, Osaka 565-0871 (Japan); Watanabe-Kushima, Shoko [Graduate School of Frontier Biosciences, Osaka University, 2-2 Yamada-oka, Suita, Osaka 565-0871 (Japan); Shinohara, Takashi [Department of Molecular Genetics, Graduate School of Medicine, Kyoto University, Kyoto 606-8501 (Japan); Nakano, Toru, E-mail: tnakano@patho.med.osaka-u.ac.jp [Graduate School of Frontier Biosciences, Osaka University, 2-2 Yamada-oka, Suita, Osaka 565-0871 (Japan); Department of Pathology, Medical School, Osaka University, 2-2 Yamada-oka, Suita, Osaka 565-0871 (Japan)

    2010-02-12

    Specification to primordial germ cells (PGCs) is mediated by mesoderm-induction signals during gastrulation. We found that Akt activation during in vitro mesodermal differentiation of embryonic stem cells (ESCs) generated self-renewing spheres with differentiation states between those of ESCs and PGCs. Essential regulators for PGC specification and their downstream germ cell-specific genes were expressed in the spheres, indicating that the sphere cells had commenced differentiation to the germ lineage. However, the spheres did not proceed to spermatogenesis after transplantation into testes. Sphere cell transfer to the original feeder-free ESC cultures resulted in chaotic differentiation. In contrast, when the spheres were cultured on mouse embryonic fibroblasts or in the presence of ERK-cascade and GSK3 inhibitors, reversion to the ESC-like state was observed. These results indicate that Akt signaling promotes a novel metastable and pluripotent state that is intermediate to those of ESCs and PGCs.

  4. Primordial germ cell specification from embryonic stem cells.

    Directory of Open Access Journals (Sweden)

    Wei Wei

    Full Text Available BACKGROUND: Primordial germ cell (PGC specification is the first crucial step in germ line development. However, owing to significant challenges regarding the in vivo system, such as the complex cellular environment and potential problems with embryo manipulation, it is desirable to generate embryonic stem (ES cells that are capable of overcoming these aforementioned limitations in order to provide a potential in vitro model to recapitulate the developmental processes in vivo. METHODOLOGY AND PRINCIPAL FINDINGS: Here, we studied the detailed process of PGC specification from stella-GFP ES cells. We first observed the heterogeneous expression of stella in ES cells. However, neither Stella-positive ES cells nor Stella-negative ES cells shared a similar gene expression pattern with either PGCs or PGC precursors. Second, we derived PGCs from ES cells using two differentiation methods, namely the attachment culture technique and the embryoid body (EB method. Compared with PGCs derived via the attachment culture technique, PGCs derived via the EB method that had undergone the sequential erasure of Peg3 followed by Igf2r resulted in a cell line in which the expression dynamics of T, Fgf8 and Sox17, in addition to the expression of the epiblast markers, were more similar to the in vivo expression, thus demonstrating that the process of PGC derivation was more faithfully recapitulated using the EB method. Furthermore, we developed an in vitro model of PGC specification in a completely chemically defined medium (CDM that indicated that BMP4 and Wnt3a promoted PGC derivation, whereas BMP8b and activinA had no observable effect on PGC derivation. CONCLUSIONS AND SIGNIFICANCE: The in vitro model we have established can recapitulate the developmental processes in vivo and provides new insights into the mechanism of PGC specification.

  5. Thalidomide induced early gene expression perturbations indicative of human embryopathy in mouse embryonic stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Xiugong, E-mail: xiugong.gao@fda.hhs.gov; Sprando, Robert L.; Yourick, Jeffrey J.

    2015-08-15

    Developmental toxicity testing has traditionally relied on animal models which are costly, time consuming, and require the sacrifice of large numbers of animals. In addition, there are significant disparities between human beings and animals in their responses to chemicals. Thalidomide is a species-specific developmental toxicant that causes severe limb malformations in humans but not in mice. Here, we used microarrays to study transcriptomic changes induced by thalidomide in an in vitro model based on differentiation of mouse embryonic stem cells (mESCs). C57BL/6 mESCs were allowed to differentiate spontaneously and RNA was collected at 24, 48, and 72 h after exposure to 0.25 mM thalidomide. Global gene expression analysis using microarrays revealed hundreds of differentially expressed genes upon thalidomide exposure that were enriched in gene ontology (GO) terms and canonical pathways associated with embryonic development and differentiation. In addition, many genes were found to be involved in small GTPases-mediated signal transduction, heart development, and inflammatory responses, which coincide with clinical evidences and may represent critical embryotoxicities of thalidomide. These results demonstrate that transcriptomics in combination with mouse embryonic stem cell differentiation is a promising alternative model for developmental toxicity assessment. - Highlights: • Studied genomic changes in mouse embryonic stem cells upon thalidomide exposure • Identified gene expression changes that may represent thalidomide embryotoxicity • The toxicogenomic changes coincide well with known thalidomide clinical outcomes. • The mouse embryonic stem cell model is suitable for developmental toxicity testing. • The model has the potential for high-throughput screening of a multitude of compounds.

  6. Dental Encounter System (DES)

    Data.gov (United States)

    Department of Veterans Affairs — Dental Encounter System (DES) is an automated health care application designed to capture critical data about the operations of VA Dental Services. Information on...

  7. Des trottoirs à Manille.

    Directory of Open Access Journals (Sweden)

    Jacques Lévy

    2006-11-01

    Full Text Available On pourrait bien sûr montrer d’abord cette photographie, et si on ne le faisait pas, on nous le reprocherait, en partie à raison. Cela existe et c’est un bidonville comme on l’imagine. Des constructions précaires en matériaux de récupération, il y en a à Manille, mais ce n’est pas la majorité des quartiers informels. L’essentiel du quartier de Tondo, le plus grand et le plus connu des slums de la capitale des Philippines ressemble plutôt à cette deuxième photo. Il ...

  8. Human embryonic stem cell-derived pancreatic endoderm alleviates diabetic pathology and improves reproductive outcome in C57BL/KsJ-Lep(db/+) gestational diabetes mellitus mice.

    Science.gov (United States)

    Xing, Baoheng; Wang, Lili; Li, Qin; Cao, Yalei; Dong, Xiujuan; Liang, Jun; Wu, Xiaohua

    2015-07-01

    Gestational diabetes mellitus is a condition commonly encountered during mid to late pregnancy with pathologic manifestations including hyperglycemia, hyperinsulinemia, insulin resistance, and fetal maldevelopment. The cause of gestational diabetes mellitus can be attributed to both genetic and environmental factors, hence complicating its diagnosis and treatment. Pancreatic progenitors derived from human embryonic stem cells were shown to be able to effectively treat diabetes in mice. In this study, we have developed a system of treating diabetes using human embryonic stem cell-derived pancreatic endoderm in a mouse model of gestational diabetes mellitus. Human embryonic stem cells were differentiated in vitro into pancreatic endoderm, which were then transplanted into db/+ mice suffering from gestational diabetes mellitus. The transplant greatly improved glucose metabolism and reproductive outcome of the females compared with the control groups. Our findings support the feasibility of using differentiated human embryonic stem cells for treating gestational diabetes mellitus patients. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    structure cubique centrée avec une distance réticulaire a = 2,86 ±0.002 Ẳ proche de celle du fer α. Cependant pour les films à forte teneur en Si (32 at. %Si et plus) les diffractogrammes des rayons X présentent des structures amorphes. La micrographie par microscopie électronique à balayage (MEB) de la figure 1.a ...

  10. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    Etude de l'activité antibactérienne des huiles essentielles de la Sauge officinale : Salvia officinalis L. sur quelques entérobactéries pathogènes. Salah Benkherara, Ouahiba Bordjiba & Ali Boutlelis Djahra. Laboratoire de Biologie Végétale et Environnement, Faculté des Sciences, Département de. Biologie, Université Badji ...

  11. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    Laboratoire Biologie et Physiologie des. Organismes. Faculté des Sciences ... concerné la prolifération cellulaire ainsi que quelques paramètres cellulaires et nucléaires. Cette étude met en ... milieu enrichi en glucose ainsi qu‟une augmentation de leur diamètre, de leurs grands et petits axes nucléaires et du nombre de ...

  12. Role of leptin in delayed embryonic development in the Indian short-nosed fruit bat, Cynopterus sphinx.

    Science.gov (United States)

    Banerjee, A; Meenakumari, K J; Krishna, A

    2010-08-01

    An adiposity-associated rise in leptin occurs at the time of delayed embryonic development in Cynopterus sphinx. The aim of present study was to examine the mechanism by which leptin may inhibit progesterone, and therefore could be responsible for delayed development. The study showed a significant increase in circulating leptin level during the period of increased fat accumulation, which coincided with significant decrease in serum progesterone level and delayed embryonic development in C. sphinx. The study showed increased Ob-R expression in the corpus luteum and in the utero-embryonic unit during the period of delayed embryonic development. The in vitro study showed suppressive effect of leptin on progesterone synthesis. The effect of high dose of leptin on ovarian steroidogenesis was found to be mediated through decreased expression of StAR and LH-R proteins in the ovary. The treatment with leptin caused increased expression of STAT 3 and iNOS proteins in the ovary, which correlated with decreased expression of StAR protein in the ovary. The inhibitory effects of leptin on progesterone synthesis in the ovary are thus mediated through STAT 3 and iNOS-NO signaling pathways. This study further demonstrated low expression of PCNA coinciding with the increased concentration of the leptin receptor in the utero-embryonic unit and high circulating leptin level during November. In conclusion, adiposity associated increased leptin level during November-December might play role in suppressing progesterone synthesis in the corpus luteum as well as suppressing the rate of cell-proliferation in the utero-embryonic unit thereby causing delayed embryonic development in C. sphinx. Copyright 2010 Elsevier Inc. All rights reserved.

  13. Pleiotropic activity of hepatocyte growth factor during embryonic mouse testis development.

    Science.gov (United States)

    Ricci, G; Catizone, A; Galdieri, M

    2002-10-01

    The hepatocyte growth factor (HGF) is a pleiotropic cytokine whose action is mediated by c-met, a glycoproteic receptor with tyrosine kinase activity which transduces its multiple biological activities including cell proliferation, motility and differentiation. During embryonic development HGF acts as a morphogenetic factor as previously demonstrated for metanephric and lung development. Recently, culturing male genital ridges, we demonstrated that HGF is able to support in vitro testicular cord formation. In the present paper we report the expression pattern of the HGF gene during embryonic testis development and the multiple roles exerted by this factor during the morphogenesis of this organ. Northern blot analysis reveals a positive signal in urogenital ridges isolated from 11.5 days post coitum (dpc) embryos and in testes isolated from 13.5 and 15.5 dpc male embryos. On the contrary HGF mRNA is undetectable in ovaries isolated from 13.5 and 15.5 dpc embryos. Moreover, we demonstrate that HGF is synthesized and secreted by the male gonad and is biologically active. These data indicate a male specific biological function of HGF during embryonic gonadal development. This hypothesis is supported by the in vitro demonstration that HGF acts as a migratory factor for male mesonephric cells which is a male specific event. In addition we demonstrate that during testicular development, HGF acts as a morphogenetic factor able to reorganize dissociated testicular cells which, under HGF stimulation, form a tridimensional network of cord-like structures. Finally, we demonstrate that HGF induces testicular cell proliferation in this way being responsible for the size increase of the testis. All together the data presented in this paper demonstrate that HGF is expressed during the embryonic development of the testis and clarify the multiple roles exerted by this factor during the morphogenesis of the male gonad.

  14. Preserving and using germplasm and dissociated embryonic cells for conserving Caribbean and Pacific coral.

    Directory of Open Access Journals (Sweden)

    Mary Hagedorn

    Full Text Available Coral reefs are experiencing unprecedented degradation due to human activities, and protecting specific reef habitats may not stop this decline, because the most serious threats are global (i.e., climate change, not local. However, ex situ preservation practices can provide safeguards for coral reef conservation. Specifically, modern advances in cryobiology and genome banking could secure existing species and genetic diversity until genotypes can be introduced into rehabilitated habitats. We assessed the feasibility of recovering viable sperm and embryonic cells post-thaw from two coral species, Acropora palmata and Fungia scutaria that have diffferent evolutionary histories, ecological niches and reproductive strategies. In vitro fertilization (IVF of conspecific eggs using fresh (control spermatozoa revealed high levels of fertilization (>90% in A. palmata; >84% in F. scutaria; P>0.05 that were unaffected by tested sperm concentrations. A solution of 10% dimethyl sulfoxide (DMSO at cooling rates of 20 to 30°C/min most successfully cryopreserved both A. palmata and F. scutaria spermatozoa and allowed producing developing larvae in vitro. IVF success under these conditions was 65% in A. palmata and 53% in F. scutaria on particular nights; however, on subsequent nights, the same process resulted in little or no IVF success. Thus, the window for optimal freezing of high quality spermatozoa was short (∼5 h for one night each spawning cycle. Additionally, cryopreserved F. scutaria embryonic cells had∼50% post-thaw viability as measured by intact membranes. Thus, despite some differences between species, coral spermatozoa and embryonic cells are viable after low temperature (-196°C storage, preservation and thawing. Based on these results, we have begun systematically banking coral spermatozoa and embryonic cells on a large-scale as a support approach for preserving existing bio- and genetic diversity found in reef systems.

  15. Preserving and using germplasm and dissociated embryonic cells for conserving Caribbean and Pacific coral.

    Science.gov (United States)

    Hagedorn, Mary; Carter, Virginia; Martorana, Kelly; Paresa, Malia K; Acker, Jason; Baums, Iliana B; Borneman, Eric; Brittsan, Michael; Byers, Michael; Henley, Michael; Laterveer, Michael; Leong, Jo-Ann; McCarthy, Megan; Meyers, Stuart; Nelson, Brian D; Petersen, Dirk; Tiersch, Terrence; Uribe, Rafael Cuevas; Woods, Erik; Wildt, David

    2012-01-01

    Coral reefs are experiencing unprecedented degradation due to human activities, and protecting specific reef habitats may not stop this decline, because the most serious threats are global (i.e., climate change), not local. However, ex situ preservation practices can provide safeguards for coral reef conservation. Specifically, modern advances in cryobiology and genome banking could secure existing species and genetic diversity until genotypes can be introduced into rehabilitated habitats. We assessed the feasibility of recovering viable sperm and embryonic cells post-thaw from two coral species, Acropora palmata and Fungia scutaria that have diffferent evolutionary histories, ecological niches and reproductive strategies. In vitro fertilization (IVF) of conspecific eggs using fresh (control) spermatozoa revealed high levels of fertilization (>90% in A. palmata; >84% in F. scutaria; P>0.05) that were unaffected by tested sperm concentrations. A solution of 10% dimethyl sulfoxide (DMSO) at cooling rates of 20 to 30°C/min most successfully cryopreserved both A. palmata and F. scutaria spermatozoa and allowed producing developing larvae in vitro. IVF success under these conditions was 65% in A. palmata and 53% in F. scutaria on particular nights; however, on subsequent nights, the same process resulted in little or no IVF success. Thus, the window for optimal freezing of high quality spermatozoa was short (∼5 h for one night each spawning cycle). Additionally, cryopreserved F. scutaria embryonic cells had∼50% post-thaw viability as measured by intact membranes. Thus, despite some differences between species, coral spermatozoa and embryonic cells are viable after low temperature (-196°C) storage, preservation and thawing. Based on these results, we have begun systematically banking coral spermatozoa and embryonic cells on a large-scale as a support approach for preserving existing bio- and genetic diversity found in reef systems.

  16. Pharmacological inhibition of EZH2 as a promising differentiation therapy in embryonal RMS

    Science.gov (United States)

    2014-01-01

    Background Embryonal Rhabdomyosarcoma (RMS) is a pediatric soft-tissue sarcoma derived from myogenic precursors that is characterized by a good prognosis in patients with localized disease. Conversely, metastatic tumors often relapse, leading to a dismal outcome. The histone methyltransferase EZH2 epigenetically suppresses skeletal muscle differentiation by repressing the transcription of myogenic genes. Moreover, de-regulated EZH2 expression has been extensively implied in human cancers. We have previously shown that EZH2 is aberrantly over-expressed in RMS primary tumors and cell lines. Moreover, it has been recently reported that EZH2 silencing in RD cells, a recurrence-derived embryonal RMS cell line, favors myofiber-like structures formation in a pro-differentiation context. Here we evaluate whether similar effects can be obtained also in the presence of growth factor-supplemented medium (GM), that mimics a pro-proliferative microenvironment, and by pharmacological targeting of EZH2 in RD cells and in RD tumor xenografts. Methods Embryonal RMS RD cells were cultured in GM and silenced for EZH2 or treated with either the S-adenosylhomocysteine hydrolase inhibitor 3-deazaneplanocin A (DZNep) that induces EZH2 degradation, or with a new class of catalytic EZH2 inhibitors, MC1948 and MC1945, which block the catalytic activity of EZH2. RD cell proliferation and myogenic differentiation were evaluated both in vitro and in vivo. Results Here we show that EZH2 protein was abnormally expressed in 19 out of 19 (100%) embryonal RMS primary tumors and cell lines compared to their normal counterparts. Genetic down-regulation of EZH2 by silencing in GM condition reduced RD cell proliferation up-regulating p21Cip1. It also resulted in myogenic-like differentiation testified by the up-regulation of myogenic markers Myogenin, MCK and MHC. These effects were reverted by enforced over-expression of a murine Ezh2, highlighting an EZH2-specific effect. Pharmacological inhibition

  17. La revolution des savants

    CERN Document Server

    Chavanne, A

    1989-01-01

    Premiere cassette : - 1666 : impact de la creation de l'Academie des Sciences par Colbert, trente ans apres le proces de Galile, et au moment des disparitions de Pascal, Descartes et Fermat. Elle dirigee par le hollandais Huyggens jusqu'a sa fuite de France au moment de la revocation de l'Edit de Nantes. - 1750 : l'Encyclopedie (ou "Dictionnaire raisonne des Sciences, des Arts et des Metiers") de Diderot et d'Alembert, soutenus par Malherbes, Buffon, Condorcet et Rousseau. - 1789 : Revolution francaise. - 8 aout 1793 : l'Assemblee, par une declaration de Marat, dissout l'Academie des Sciences. Celle-ci continue cependant ses travaux pour les poids et mesures jusqu'en 1795. - la Terreur : la condamnation a mort, pas au nom d'une "Revolution qui n'a pas besoin de savants" mais pour d'autres raisons, de trois grands hommes de science : Lavoisier, Bailly et Condorcet. - 1793-1794 : Au printemps 93, le Comite de Salut Publique s'inquiete du demi-million de soldats etrangers de toutes les pays frontaliers qui essai...

  18. Optical pacing of the embryonic heart

    Science.gov (United States)

    Jenkins, M. W.; Duke, A. R.; Gu, S.; Doughman, Y.; Chiel, H. J.; Fujioka, H.; Watanabe, M.; Jansen, E. D.; Rollins, A. M.

    2010-09-01

    Light has been used to non-invasively alter the excitability of both neural and cardiac tissue. Recently, pulsed laser light has been shown to be capable of eliciting action potentials in peripheral nerves and in cultured cardiomyocytes. Here, for the first time, we demonstrate optical pacing of an intact heart in vivo. Pulsed 1.875-µm infrared laser light was used to lock the heart rate to the pulse frequency of the laser. A laser Doppler velocimetry signal was used to verify the pacing. At low radiant exposures, embryonic quail hearts were reliably paced in vivo without detectable damage to the tissue, indicating that optical pacing has great potential as a tool with which to study embryonic cardiac dynamics and development. In particular, optical pacing can be used to control the heart rate, thereby altering stresses and mechanically transduced signalling.

  19. Embryonic vaccines against cancer: an early history.

    Science.gov (United States)

    Brewer, Bradley G; Mitchell, Robert A; Harandi, Amir; Eaton, John W

    2009-06-01

    Almost 100 years have passed since the seminal observations of Schöne showing that vaccination of animals with fetal tissue would prevent the growth of transplantable tumors. Many subsequent reports have affirmed the general idea that immunologic rejection of transplantable tumors, as well as prevention of carcinogenesis, may be affected by vaccination with embryonic/fetal material. Following a decade of intense research on this phenomenon during approximately 1964-1974, interest appears to have waned. This earlier experimental work may be particularly pertinent in view of the rising interest in so-called cancer stem cells. We believe that further work - perhaps involving the use of embryonic stem cells as immunogens - is warranted and that the results reviewed herein support the concept that vaccination against the appearance of cancers of all kinds is a real possibility.

  20. Embryonic stem cells and property rights.

    Science.gov (United States)

    Andersson, Anna-Karin M

    2011-06-01

    This article contributes to the current debate on human embryonic stem cell researchers' possible complicity in the destruction of human embryos and the relevance of such complicity for the issue of commodification of human embryos. I will discuss if, and to what extent, researchers who destroy human embryos, and researchers who merely use human embryos destroyed by others, have moral use rights, and/or moral property rights, in these embryos. I argue that the moral status of the human embryo, however justified, places few restrictions on the latter researchers' use of it, and property rights in it, once it is destroyed. I argue that the former researchers have no property rights in the destroyed embryo but use rights in it to the extent allowed by the legitimate owners of the destroyed embryo. I discuss the implications of this account for previous and current US federal law regulating human embryonic stem cell research.

  1. Cytokine signalling in embryonic stem cells

    DEFF Research Database (Denmark)

    Kristensen, David Møbjerg; Kalisz, Mark; Nielsen, Jens Høiriis

    2006-01-01

    Cytokines play a central role in maintaining self-renewal in mouse embryonic stem (ES) cells through a member of the interleukin-6 type cytokine family termed leukemia inhibitory factor (LIF). LIF activates the JAK-STAT3 pathway through the class I cytokine receptor gp130, which forms a trimeric...... pathways seem to converge on c-myc as a common target to promote self-renewal. Whereas LIF does not seem to stimulate self-renewal in human embryonic stem cells it cannot be excluded that other cytokines are involved. The pleiotropic actions of the increasing number of cytokines and receptors signalling...... via JAKs, STATs and SOCS exhibit considerable redundancy, compensation and plasticity in stem cells in accordance with the view that stem cells are governed by quantitative variations in strength and duration of signalling events known from other cell types rather than qualitatively different stem...

  2. ETUDE COMPAREE DES COMPLICATIONS DES AVORTEMENTS ...

    African Journals Online (AJOL)

    Ndombi I, Mendome G. Audit des décès maternels au Centre Hospitalier de Libreville (2005 à 2007). Journal de la SAGO 2007; 8 :29-33. 14.Guillaume A, William M. L'avortement provoqué en. Afrique : un problème mal connu, lourd de conséquences.LaboratoirePopulation-. Environnement-Développement. Unité mixte de.

  3. Approfondissement des connaissances et renforcement des ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    'échelon du programme et à celui des projets. À la deuxième étape, il y aura tenue d'ateliers en français et en anglais afin d'accroître la sensibilisation aux sexospécificités, de favoriser la réflexion et l'apprentissage mutuel et d'élaborer un ...

  4. Embryonic mortality in buffalo naturally mated

    Directory of Open Access Journals (Sweden)

    G. Campanile

    2010-02-01

    Full Text Available The aim of this work was to evaluate the incidence of embryonic mortality in three different period of year in buffaloes naturally mated. The trial was carried out in a buffalo farm located in Caserta province between 2000-2006. In this period were registered natural insemination on 200 buffaloes. Pregnancy diagnosis was carried out on Day 30, confirmed on Day 45 and every 15th days until 90 days after natural mating. Buffaloes that were pregnant on Day 30 but not on Day 45 or Day 90 were considered to have undergone embryonic (EM or fetal mortality (FM respectively. EM and FM were 8.8% and 13.4% respectively throughout the experimental period. A high incidence (P<0.01 of FM was found in the transitional period (December-March than in other months of the year. The incidence of embryonic mortality was significantly (P<0.01 higher between 28-60 days of gestation and lower after 71 day of gestation. The higher fetal mortality found in this study could be due the lower serum levels of progesterone normally found in transitional period in buffalo cows.

  5. À propos des occasionnalismes

    Directory of Open Access Journals (Sweden)

    Dal Georgette

    2016-01-01

    Full Text Available Les occasionnalismes (nonce formations ou contextual formations dans la terminologie anglo-saxonne, qu’on définira provisoirement comme de “new complex word[s] created by a speaker/writer on the spur of the moment to cover some immediate need” (Bauer, 1983 : 45 ont, à notre connaissance, peu retenu l’attention des morphologues du domaine francophone. Pourtant, toutes les conditions sont désormais réunies pour que cet objet, invisible lorsqu’il s’agissait de décrire le système morphologique du français (ou d’autres langues à partir de ressources dictionnairiques, émerge en tant qu’observable dans une morphologie puisant ses données dans le réel langagier des locuteurs. Par définition en effet, on s’attend à ce qu’un occasionalisme soit absent des dictionnaires (nous verrons que, dans les faits, la situation est plus complexe que cela, et que ces contextual formations ne puissent pas être étudiées en dehors du contexte dans lequel elles ont été produites. À cet égard, la Toile et les produits qui en dérivent constituent des ressources de choix. C’est particulièrement vrai des forums, dans lesquels les internautes s’expriment librement, laissant libre cours à leur potentiel créatif (ou ce qu’ils pensent tel. Dans la présente communication, après avoir défini la notion d’occasionalisme, nous utiliserons un corpus constitué au fil d’autres recherches pour dégager des motifs récurrents propices à leur apparition, autrement dit pour établir une grammaire des occasionnalismes.

  6. Caractéristiques cliniques, moléculaires et prise en charge des Rhabdomyosarcomes de l'adulte et identification d'une polythérapie ciblée in vitro

    OpenAIRE

    Dumont, Sarah

    2013-01-01

    Rhabdomyosarcoma is a rare entity adult patient with unfavourable outcome. This work describes the clinical and molecular specificities of adolescent and adult type of rhabdomyosarcoma and investigates the optimal integration of targetd therapy combinations on small cell sarcoma cell lines in vitro. We retrospectively analyzed 239 patients, 10 years of age and greater, diagonsed withrhabdomyosarcoma at MD Anderson Cancer Center from 1957 trough 2003 and their PAX-FOXO1 fusion gene status by f...

  7. The cell cycle as a brake for β-cell regeneration from embryonic stem cells.

    Science.gov (United States)

    El-Badawy, Ahmed; El-Badri, Nagwa

    2016-01-13

    The generation of insulin-producing β cells from stem cells in vitro provides a promising source of cells for cell transplantation therapy in diabetes. However, insulin-producing cells generated from human stem cells show deficiency in many functional characteristics compared with pancreatic β cells. Recent reports have shown molecular ties between the cell cycle and the differentiation mechanism of embryonic stem (ES) cells, assuming that cell fate decisions are controlled by the cell cycle machinery. Both β cells and ES cells possess unique cell cycle machinery yet with significant contrasts. In this review, we compare the cell cycle control mechanisms in both ES cells and β cells, and highlight the fundamental differences between pluripotent cells of embryonic origin and differentiated β cells. Through critical analysis of the differences of the cell cycle between these two cell types, we propose that the cell cycle of ES cells may act as a brake for β-cell regeneration. Based on these differences, we discuss the potential of modulating the cell cycle of ES cells for the large-scale generation of functionally mature β cells in vitro. Further understanding of the factors that modulate the ES cell cycle will lead to new approaches to enhance the production of functional mature insulin-producing cells, and yield a reliable system to generate bona fide β cells in vitro.

  8. Human embryonic stem cells differentiate into functional renal proximal tubular-like cells.

    Science.gov (United States)

    Narayanan, Karthikeyan; Schumacher, Karl M; Tasnim, Farah; Kandasamy, Karthikeyan; Schumacher, Annegret; Ni, Ming; Gao, Shujun; Gopalan, Began; Zink, Daniele; Ying, Jackie Y

    2013-04-01

    Renal cells are used in basic research, disease models, tissue engineering, drug screening, and in vitro toxicology. In order to provide a reliable source of human renal cells, we developed a protocol for the differentiation of human embryonic stem cells into renal epithelial cells. The differentiated stem cells expressed markers characteristic of renal proximal tubular cells and their precursors, whereas markers of other renal cell types were not expressed or expressed at low levels. Marker expression patterns of these differentiated stem cells and in vitro cultivated primary human renal proximal tubular cells were comparable. The differentiated stem cells showed morphological and functional characteristics of renal proximal tubular cells, and generated tubular structures in vitro and in vivo. In addition, the differentiated stem cells contributed in organ cultures for the formation of simple epithelia in the kidney cortex. Bioreactor experiments showed that these cells retained their functional characteristics under conditions as applied in bioartificial kidneys. Thus, our results show that human embryonic stem cells can differentiate into renal proximal tubular-like cells. Our approach would provide a source for human renal proximal tubular cells that are not affected by problems associated with immortalized cell lines or primary cells.

  9. Etude des interactions entre les differents acteurs des interventions ...

    African Journals Online (AJOL)

    Les chefs de ménages ont une perception acceptable de la qualité des prestations des ASC. Seuls environ 60% des ASC ont été sélectionnés par leur communauté au cours d'une assemblée générale. Les chefs de ménages ont une connaissance acceptable des ASC et de leurs activités mais leur comportement ...

  10. Promouvoir l'entrepreneuriat inclusif des jeunes et des femmes ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Le projet vise à analyser la contribution réelle et potentielle de l'entrepreneuriat inclusif au bien-être des jeunes et des femmes en Côte d'Ivoire, au Burkina Faso et au Kenya. Après un état des lieux de la pratique de l'entrepreneuriat inclusif dans chacun des pays ciblés, l'équipe de recherche étudiera son incidence sur ...

  11. Comportement des polluants des eaux pluviales urbaines en ...

    African Journals Online (AJOL)

    [9] Azzaoui S., 1999. Métaux lourds dans le bassin versant du Sebou, Géochimie, source de pollution et impact sur la qualité des eaux de surface. Thèse de Doctorat en chimie. Université d'IbnTofail, Maroc. 130p. [10] Louhi A., 2006. Pollution des eaux et des sols. Cas de la région de Annaba, étude des interférences et ...

  12. Uncovering the post-embryonic functions of gametophytic- and embryonic-lethal genes.

    Science.gov (United States)

    Candela, Héctor; Pérez-Pérez, José Manuel; Micol, José Luis

    2011-06-01

    An estimated 500-1 000 Arabidopsis (Arabidopsis thaliana) genes mutate to embryonic lethality. In addition, several hundred mutations have been identified that cause gametophytic lethality. Thus, a significant fraction of the ∼25,000 protein-coding genes in Arabidopsis are indispensable to the early stages of the diploid phase or to the haploid gametophytic phase. The expression patterns of many of these genes indicate that they also act later in development but, because the mutants die at such early stages, conventional methods limit the study of their roles in adult diploid plants. Here, we describe the toolset that allows researchers to assess the post-embryonic functions of plant genes for which only gametophytic- and embryonic-lethal alleles have been isolated. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Effets des extraits vegetaux sur la dynamique de populations des ...

    African Journals Online (AJOL)

    La présente étude se propose de trouver une alternative de l'utilisation des pesticides chimiques en testant l'effet insecticide des extraits aqueux des feuilles de Hyptis suaveolens, graines de Ricinus communis et de Azadirachta indica contre les ravageurs du niébé en conditions de champ en utilisant le cyperméthrine ...

  14. La fabrique des sciences des institutions aux pratiques

    CERN Document Server

    Benninghoff, Martin; Crettaz von Roten, Fabienne; Merz, Martina

    2006-01-01

    Aujourd'hui, les façons de produire, d'organiser, d'évaluer et d'utiliser les savoirs sont en profond débat. De plus en plus, l'Etat, la société civile et l'économie tentent d'influencer les activités des universités et des laboratoires de recherche. Ces développements mettent à l'épreuve tout à la fois les fondements des systèmes d'enseignement supérieur et de recherche, l'autonomie des institutions scientifiques, la définition des frontières des savoirs et l'acceptation des sciences. Dans des contextes suisses et européens, cet ouvrage s'intéresse aux manières dont les sciences et les technologies sont fabriquées, en analysant leurs institutions et les pratiques. A partir d'une approche relationnelle, les sciences et les technologies sont conçues comme des phénomènes profondément sociaux, culturels et politiques. Une telle démarche déstabilise les visions parfois idéalisées et stéréotypées de la construction des savoirs. Des études de cas détaillées décrivent des phénomè...

  15. Modernisation des marchés agroalimentaires - inclusion des petits ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Modernisation des marchés agroalimentaires - inclusion des petits exploitants aux marchés dynamiques. Les marchés agroalimentaires connaissent de rapides changements dans les pays en développement et les pays en transition. Sous l'influence de la libéralisation du commerce et des nouvelles technologies de ...

  16. A comparison of the embryonic stem cell test and whole embryo culture assay combined with the BeWo placental passage model for predicting the embryotoxicity of azoles.

    NARCIS (Netherlands)

    Dimopoulou, Myrto; Verhoef, Aart; Gomes, Caroline A; van Dongen, Catharina W; Rietjens, Ivonne M C M; Piersma, Aldert H; van Ravenzwaay, Bennard

    2018-01-01

    In the present study, we show the value of combining toxico-dynamic and -kinetic in vitro approaches for embryotoxicity testing of azoles. Both the whole embryo culture (WEC) and the embryonic stem cells test (EST) predicted the in vivo potency ranking of twelve tested azoles with moderate accuracy.

  17. Leukemia inhibitory factor (LIF) enhances MAP2 + and HUC/D + neurons and influences neurite extension during differentiation of neural progenitors derived from human embryonic stem cells.

    Science.gov (United States)

    Leukemia Inhibitory Factor (L1F), a member of the Interleukin 6 cytokine family, has a role in differentiation of Human Neural Progenitor (hNP) cells in vitro. hNP cells, derived from Human Embryonic Stem (hES) cells, have an unlimited capacity for self-renewal in monolayer cultu...

  18. Relative developmental toxicity of glycol ether alkoxy acid metabolites in the embryonic stem cell test as compared with the in vivo potency of their parent compounds

    NARCIS (Netherlands)

    Jong, E. de; Louisse, J.; Verwei, M.; Blaauboer, B.J.; Sandt, J.J.M. van de; Woutersen, R.A.; Rietjens, I.M.C.M.; Piersma, A.H.

    2009-01-01

    The embryonic stem cell test (EST) has been proposed as an in vitro assay that might reduce animal experimentation in regulatory developmental toxicology. So far, evaluation of the EST was not performed using compounds within distinct chemical classes. Evaluation within a distinct class of

  19. ENHANCEMENT OF CISPLATIN AND ETOPOSIDE CYTOTOXICITY AFTER ALL-TRANS-RETINOIC-ACID-INDUCED CELLULAR-DIFFERENTIATION OF A MURINE EMBRYONAL CARCINOMA CELL-LINE

    NARCIS (Netherlands)

    GUCHELAAR, HL; TIMMERBOSSCHA, H; DAMMEIRING, A; UGES, DRA; OOSTERHUIS, JW; DEVRIES, EGE; MULDER, NH

    1993-01-01

    The potential of a combination of differentiation induction and chemotherapy was analyzed. Treatment of the murine embryonal carcinoma (EC) cell line PCC4 in vitro with all-trans-retinoic acid (RA) was followed by exposure to cisplatin (CDDP) or etoposide (VP-16). The expression of EC-cell-specific

  20. Generation of KCL035 research grade human embryonic stem cell line carrying a mutation in HBB gene

    Directory of Open Access Journals (Sweden)

    Heema Hewitson

    2016-03-01

    Full Text Available The KCL035 human embryonic stem cell line was derived from an embryo donated for research that carried a mutation in the HBB gene, which is linked to the β-thalassemia syndrome. The ICM was isolated using laser microsurgery and plated on γ-irradiated human foreskin fibroblasts. Both the derivation and cell line propagation were performed in an animal product-free environment. Pluripotent state and differentiation potential were confirmed by in vitro assays.

  1. Generation of human embryonic stem cells from abnormal blastocyst diagnosed with adrenoleukodystrophy.

    Science.gov (United States)

    Ouyang, Qi; Zhou, Xiaoying; Chen, Jing; Du, Juan; Lu, Guangxiu; Lin, Ge; Sun, Yi

    2016-11-01

    Human embryonic stem cell (hESC) line chHES-480 was derived from abnormal blastocyst diagnosed with adrenoleukodystrophy (ALD) after preimplantation genetic diagnosis (PGD) treatment. DNA sequencing analysis confirmed that chHES-480 cell line carried a hemizygous missense mutation c.1825G>A(p.Glu609Lys) of ABCD1 gene. Characteristic tests proved that the chHES-480 cell line presented typical markers of pluripotency and had the capability to form the three germ layers both in vitro and in vivo. Copyright © 2016 Michael Boutros, German Cancer Research Center, Heidelberg, Germany. Published by Elsevier B.V. All rights reserved.

  2. Derivation of the human embryonic stem cell line RCe010-A (RC-6

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-03-01

    Full Text Available The human embryonic stem cell line RCe010-A (RC-6 was derived from a frozen and thawed blastocyst voluntarily donated as unsuitable and surplus to fertility requirements following ethics committee approved informed consent under licence from the UK Human Fertilisation and Embryology Authority. The cell line shows normal pluripotency marker expression and differentiation to the three germ layers in vitro. It has a normal 46XY male karyotype and microsatellite PCR identity, HLA and blood group typing data are available.

  3. Derivation of the human embryonic stem cell line RCe006-A (RC-2

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-03-01

    Full Text Available The human embryonic stem cell line RCe006-A (RC-2 was derived from a frozen and thawed blastocyst voluntarily donated as surplus to fertility requirements following ethics committee approved informed consent under licence from the UK Human Fertilisation and Embryology Authority. The cell line exhibits expression of expected pluripotency markers and in vitro differentiation potential to three germinal lineage representative cell populations. It has a male trisomy 12 karyotype (47XY, +12. Microsatellite DNA marker identity and HLA and blood group typing data are available.

  4. Derivation of the human embryonic stem cell line RCe014-A (RC-10

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-03-01

    Full Text Available The human embryonic stem cell line RCe014-A (RC-10 was derived from a fresh oocyte voluntarily donated as unsuitable and surplus to fertility requirements following ethics committee approved informed consent under licence from the UK Human Fertilisation and Embryology Authority. The cell line shows normal pluripotency marker expression and differentiation to the three germ layers in vitro. It has a mixed 46XY and 47XY +12 male karyotype and microsatellite PCR identity, HLA and blood group typing data is available.

  5. Derivation of the human embryonic stem cell line RCe012-A (RC-8

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-03-01

    Full Text Available The human embryonic stem cell line RCe012-A (RC-8 was derived from a frozen and thawed day 5 embryo cultivated to the blastocyst stage. The embryo was voluntarily donated as unsuitable and surplus to fertility requirements following ethics committee approved informed consent under licence from the UK Human Fertilisation and Embryology Authority. The cell line shows normal pluripotency marker expression and differentiation to the three germ layers in vitro. It has a normal 46XX female karyotype and microsatellite PCR identity, HLA and blood group typing data is available.

  6. Derivation of the clinical grade human embryonic stem cell line RCe013-A (RC-9

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-07-01

    Full Text Available The human embryonic stem cell line RCe013-A (RC-9 was derived under quality assured compliance with UK regulation, European Union Directives and International guidance for tissue procurement, processing and storage according to Good Manufacturing Practice (GMP standards. The cell line was derived from a failed to fertilise oocyte voluntarily donated as unsuitable and surplus to fertility requirements following informed consent. RCe013-A (RC-9 shows normal pluripotency marker expression and differentiation to the three germ layers in vitro and in vivo. It has a normal 46XY male karyotype and microsatellite PCR identity, HLA and blood group typing data are available.

  7. Derivation of the clinical grade human embryonic stem cell line RCe016-A (RC-12

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-05-01

    Full Text Available The human embryonic stem cell line RCe016-A (RC-12 was derived under quality assured compliance with UK regulations, EU Directives and International guidance for tissue procurement, processing and storage according to good manufacturing practice (GMP standards. The cell line was derived from a cryopreserved blastocyst stage embryo voluntarily donated as surplus to fertility requirements following informed consent. RCe016-A (RC-12 shows normal pluripotency marker expression and differentiation to three germ layers in vitro. Karyology revealed a mixed male karyotype at early passage (P15, which resolved as normal 46XY by passage 33. Microsatellite PCR identity, HLA and blood group typing data is available.

  8. Derivation of the clinical grade human embryonic stem cell line RCe019-A (RC-15

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-05-01

    Full Text Available The human embryonic stem cell line RCe019-A (RC-15 was derived under quality assured compliance with UK regulation, European Union Directives and International guidance for tissue procurement, processing and storage according to Good Manufacturing Practice (GMP standards. The cell line was derived from a cleavage stage embryo voluntarily donated as unsuitable or surplus to fertility requirements following informed consent. RCe019-A (RC-15 shows normal pluripotency marker expression and differentiation to the three germ layers in vitro. It has a mixed 46XX/47XX, +8 female karyotype and microsatellite PCR identity, HLA and blood group typing data is available.

  9. Derivation of the clinical grade human embryonic stem cell line RCe018-A (RC-14

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-05-01

    Full Text Available The human embryonic stem cell line RCe018-A (RC-14 was derived under quality assured compliance with UK regulation, European Union Directives and International guidance for tissue procurement, processing and storage according to Good Manufacturing Practice (GMP standards. The cell line was derived from a blastocyst stage embryo voluntarily donated as unsuitable or surplus to fertility requirements following informed consent. RCe018-A (RC-14 shows normal pluripotency marker expression and differentiation to the three germ layers in vitro. It has a male karyotype with an extra copy of chromosome 8 (47XY, +8. Microsatellite PCR identity, HLA and blood group typing data are available.

  10. Derivation of the clinical grade human embryonic stem cell line RCe015-A (RC-11

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-07-01

    Full Text Available The human embryonic stem cell line RCe015-A (RC-11 was derived under quality assured compliance with UK regulation, European Union Directives and International guidance for tissue procurement, processing and storage according to Good Manufacturing Practice (GMP standards. The cell line was derived from a fragmented cleavage stage embryo voluntarily donated as unsuitable or surplus to fertility requirements following informed consent. RCe015-A (RC-11 shows normal pluripotency marker expression and differentiation to the three germ layers in vitro and in vivo. It has a normal 46XX female karyotype and microsatellite PCR identity, HLA and blood group typing data are available.

  11. Derivation of the clinical grade human embryonic stem cell line RCe017-A (RC-13

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-05-01

    Full Text Available The human embryonic stem cell line RCe017-A (RC-13 was derived under quality assured compliance with UK regulation, European Union Directives and International guidance for tissue procurement, processing and storage according to Good Manufacturing Practice (GMP standards. The cell line was derived from a frozen and thawed blastocyst stage embryo voluntarily donated as unsuitable or surplus to fertility requirements following informed consent. RCe017-A (RC-13 shows normal pluripotency marker expression and differentiation to the three germ layers in vitro. It has a mixed 47XY, +12/48XY, +1, +12 male karyotype and microsatellite PCR identity, HLA and blood group typing data are available.

  12. Derivation of the clinical grade human embryonic stem cell line RCe020-a (RC-16

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-05-01

    Full Text Available The human embryonic stem cell line RCe020-A (RC-16 was derived under quality assured compliance with UK regulation, European Union Directives and International guidance for tissue procurement, processing and storage according to Good Manufacturing Practice (GMP standards. The cell line was derived from a failed to fertilise oocyte voluntarily donated as unsuitable or surplus to fertility requirements following informed consent. RCe020-A (RC-16 shows normal pluripotency marker expression and differentiates to mesoderm and potentially ectoderm in vitro. It has an abnormal 47XX, +14, i(20(q10 female karyotype and microsatellite PCR identity, HLA and blood group typing data is available.

  13. Derivation of the clinical grade human embryonic stem cell line RCe021-A (RC-17

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-07-01

    Full Text Available The human embryonic stem cell line RCe021-A (RC-17 was derived under quality assured compliance with UK regulation, European Union Directives and International guidance for tissue procurement, processing and storage according to Good Manufacturing Practice (GMP standards. The cell line was derived from a day 3 embryo voluntarily donated as unsuitable or surplus to fertility requirements following informed consent. RCe021-A (RC-17 shows normal pluripotency marker expression and differentiation to the three germ layers in vitro. It has a normal 46XX female karyotype and microsatellite PCR identity, HLA and blood group typing data are available.

  14. Liste des figures

    OpenAIRE

    2017-01-01

    1. Schéma pédagogique de l’économie circulaire 2. La criticité potentielle des ressources minérales 3. Comparaison des émissions de contaminants entre l’économie linéaire et l’économie circulaire 4. Schéma de l’économie circulaire de la Fondation Ellen MacArthur 5. Le cycle intégrateur de réemploi et de redistribution 6. La recirculation des ressources par recyclage, compostage et valorisation énergétique 7. Une unité de production de biocarburant 8. Une bioraffinerie intégrée 9. Les stratégi...

  15. Les lueurs des sables

    CERN Multimedia

    Les lueurs des sables

    2013-01-01

    Two CERN ladies are getting ready for the “Trophée Roses des Sables” rally adventure: Julie and Laetitia are finalizing the last details before setting off on Monday 7th October 2013. Julie from EN-MEF group and Laetitia from DGS-SEE group, met at the CERN Rugby club. This year, they are participating in the 100 % female rally which will take place in Morocco from 10 to 20 October. They will be carrying along 100 kg of humanitarian donation for children such as some clothes, books and medical material. Do not hesitate to show your support at their farewell party to be held on Monday 7 October, from 4 to 6 pm in front of the St Genis-Pouilly Mairie (city Hall). Follow their exciting adventure on the blog leslueursdessables.trophee-roses-des-sables.org and on their association’s Facebook page Les Lueurs des Sables.

  16. Electrophysiological properties of embryonic stem cell-derived neurons.

    Directory of Open Access Journals (Sweden)

    Jessica R Risner-Janiczek

    Full Text Available In vitro generation of functional neurons from embryonic stem (ES cells and induced pluripotent stem cells offers exciting opportunities for dissecting gene function, disease modelling, and therapeutic drug screening. To realize the potential of stem cells in these biomedical applications, a complete understanding of the cell models of interest is required. While rapid advances have been made in developing the technologies for directed induction of defined neuronal subtypes, most published works focus on the molecular characterization of the derived neural cultures. To characterize the functional properties of these neural cultures, we utilized an ES cell model that gave rise to neurons expressing the green fluorescent protein (GFP and conducted targeted whole-cell electrophysiological recordings from ES cell-derived neurons. Current-clamp recordings revealed that most neurons could fire single overshooting action potentials; in some cases multiple action potentials could be evoked by depolarization, or occurred spontaneously. Voltage-clamp recordings revealed that neurons exhibited neuronal-like currents, including an outward current typical of a delayed rectifier potassium conductance and a fast-activating, fast-inactivating inward current, typical of a sodium conductance. Taken together, these results indicate that ES cell-derived GFP(+ neurons in culture display functional neuronal properties even at early stages of differentiation.

  17. La cogestion des Ressources naturelles

    International Development Research Centre (IDRC) Digital Library (Canada)

    'extraordinaire diversité des espèces vivantes, unies par des liens que souvent nous comprenons à peine, voilà de quoi dépend l'existence même des populations de la terre. Or, il suffit de jeter un bref coup d'oeil à presque n'importe quel ...

  18. Analyse des performances thermomecaniques des huiles de ...

    African Journals Online (AJOL)

    Les résultats ont montré que les huiles pures ont permis d'obtenir un rendement thermomécanique supérieur à 25% à puissance nominale de 3,5 kW, avec une consommation de 1,3 L/h environ. Les mélanges en volumes à 25% d'huile de coton (resp. 25% d'huile de palmiste) avec le gasoil 75%, ont permis d'obtenir des ...

  19. Influence des caracteristiques generales des gestantes ...

    African Journals Online (AJOL)

    Sur le plan descriptif, 34,5% des enquêtées ont entre 32 et 36 ans; majoritairement de l'ethnie Adja (30,0%) ; de la religion Catholique (54,5%). Elles sont mariées (85,5%) ; 37,3% d'entre elles sont non instruites ; 41,8% ont déclaré ne pas avoir un revenu mensuel. Sur le plan analytique, il ressort de cette étude qu'aucune ...

  20. Neural Progenitor Cells Derived from Human Embryonic Stem Cells as an Origin of Dopaminergic Neurons

    Directory of Open Access Journals (Sweden)

    Parinya Noisa

    2015-01-01

    Full Text Available Human embryonic stem cells (hESCs are able to proliferate in vitro indefinitely without losing their ability to differentiate into multiple cell types upon exposure to appropriate signals. Particularly, the ability of hESCs to differentiate into neuronal subtypes is fundamental to develop cell-based therapies for several neurodegenerative disorders, such as Alzheimer’s disease, Huntington’s disease, and Parkinson’s disease. In this study, we differentiated hESCs to dopaminergic neurons via an intermediate stage, neural progenitor cells (NPCs. hESCs were induced to neural progenitor cells by Dorsomorphin, a small molecule that inhibits BMP signalling. The resulting neural progenitor cells exhibited neural bipolarity with high expression of neural progenitor genes and possessed multipotential differentiation ability. CBF1 and bFGF responsiveness of these hES-NP cells suggested their similarity to embryonic neural progenitor cells. A substantial number of dopaminergic neurons were derived from hES-NP cells upon supplementation of FGF8 and SHH, key dopaminergic neuron inducers. Importantly, multiple markers of midbrain neurons were detected, including NURR1, PITX3, and EN1, suggesting that hESC-derived dopaminergic neurons attained the midbrain identity. Altogether, this work underscored the generation of neural progenitor cells that retain the properties of embryonic neural progenitor cells. These cells will serve as an unlimited source for the derivation of dopaminergic neurons, which might be applicable for treating patients with Parkinson’s disease.

  1. Thalidomide induced early gene expression perturbations indicative of human embryopathy in mouse embryonic stem cells.

    Science.gov (United States)

    Gao, Xiugong; Sprando, Robert L; Yourick, Jeffrey J

    2015-08-15

    Developmental toxicity testing has traditionally relied on animal models which are costly, time consuming, and require the sacrifice of large numbers of animals. In addition, there are significant disparities between human beings and animals in their responses to chemicals. Thalidomide is a species-specific developmental toxicant that causes severe limb malformations in humans but not in mice. Here, we used microarrays to study transcriptomic changes induced by thalidomide in an in vitro model based on differentiation of mouse embryonic stem cells (mESCs). C57BL/6 mESCs were allowed to differentiate spontaneously and RNA was collected at 24, 48, and 72h after exposure to 0.25mM thalidomide. Global gene expression analysis using microarrays revealed hundreds of differentially expressed genes upon thalidomide exposure that were enriched in gene ontology (GO) terms and canonical pathways associated with embryonic development and differentiation. In addition, many genes were found to be involved in small GTPases-mediated signal transduction, heart development, and inflammatory responses, which coincide with clinical evidences and may represent critical embryotoxicities of thalidomide. These results demonstrate that transcriptomics in combination with mouse embryonic stem cell differentiation is a promising alternative model for developmental toxicity assessment. Published by Elsevier Inc.

  2. Paf receptor expression in the marsupial embryo and endometrium during embryonic diapause.

    Science.gov (United States)

    Fenelon, Jane C; Shaw, Geoff; O'Neill, Chris; Frankenberg, Stephen; Renfree, Marilyn B

    2014-01-01

    The control of reactivation from embryonic diapause in the tammar wallaby (Macropus eugenii) involves sequential activation of the corpus luteum, secretion of progesterone that stimulates endometrial secretion and subsequent changes in the uterine environment that activate the embryo. However, the precise signals between the endometrium and the blastocyst are currently unknown. In eutherians, both the phospholipid Paf and its receptor, platelet-activating factor receptor (PTAFR), are present in the embryo and the endometrium. In the tammar, endometrial Paf release in vitro increases around the time of the early progesterone pulse that occurs around the time of reactivation, but whether Paf can reactivate the blastocyst is unknown. We cloned and characterised the expression of PTAFR in the tammar embryo and endometrium at entry into embryonic diapause, during its maintenance and after reactivation. Tammar PTAFR sequence and protein were highly conserved with mammalian orthologues. In the endometrium, PTAFR was expressed at a constant level in the glandular epithelium across all stages and in the luminal epithelium during both diapause and reactivation. Thus, the presence of the receptor appears not to be a limiting factor for Paf actions in the endometrium. However, the low levels of PTAFR in the embryo during diapause, together with its up-regulation and subsequent internalisation at reactivation, supports earlier results suggesting that endometrial Paf could be involved in reactivation of the tammar blastocyst from embryonic diapause.

  3. Extrauterine listeriosis in the gravid mouse influences embryonic growth and development.

    Directory of Open Access Journals (Sweden)

    M Mitsu Suyemoto

    Full Text Available Gravid mice and other rodents inoculated with Listeria monocytogenes typically fail to clear an intrauterine infection and either succumb or expel their intrauterine contents. We took advantage of this property to investigate the effects of an extrauterine infection on parameters of pregnancy success. Pregnant mice were selected for our study if they showed no clinical signs of listeriosis following oral inoculation at 7.5 gestational days (gd, and had no detectable intrauterine colony forming units (cfu at near term (18.5 gd. The range of oral doses employed was 10⁶-10⁸ cfu per mouse for two listerial serotype strains (4nonb and 1/2a. At all doses, inoculation resulted in a decrease in average near-term (18.5 gd fetal weight per litter compared to sham inoculated controls. Additionally, embryonic death (indicated by intrauterine resorptions was exhibited by some inoculated mice but was absent in all sham inoculated animals. In parallel experiments designed to detect possible loss of placental function, gravid uteruses were examined histopathologically and microbiologically 96 h after oral inoculation. Placental lesions were associated with high (> 10⁶, but not low (< 10² or absent intrauterine cfu. In vitro, mouse embryonic trophoblasts were indistinguishable from mouse enterocytes in terms of their sensitivity to listerial exposure. A model consistent with our observations is one in which products (host or bacterial generated during an acute infection enter embryos transplacentally and influences embryonic survival and slows normal growth in utero.

  4. Fokale Therapie des Prostatakarzinoms

    Directory of Open Access Journals (Sweden)

    Roosen A

    2013-01-01

    Full Text Available Die EAU bezeichnet die fokale Therapie des Prostatakarzinoms als die therapeutische Option mit dem größten Zukunftspotenzial, auch wenn es sich dabei derzeit nicht um ein Standardverfahren handelt. Sie vermag bei Patienten mit einem niedrigmalignen, fokal begrenzten Prostatakarzinom die Lücke zu schließen zwischen potenzieller Übertherapie durch die radikalen Standardverfahren und der onkologischen Unsicherheit einer ,,Active surveillance“. Dieser Überblick gibt den derzeitigen Kenntnisstand bei der fokalen Therapie des Prostatakarzinoms wieder.

  5. Highly efficient differentiation of neural precursors from human embryonic stem cells and benefits of transplantation after ischemic stroke in mice.

    Science.gov (United States)

    Drury-Stewart, Danielle; Song, Mingke; Mohamad, Osama; Guo, Ying; Gu, Xiaohuan; Chen, Dongdong; Wei, Ling

    2013-08-08

    Ischemic stroke is a leading cause of death and disability, but treatment options are severely limited. Cell therapy offers an attractive strategy for regenerating lost tissues and enhancing the endogenous healing process. In this study, we investigated the use of human embryonic stem cell-derived neural precursors as a cell therapy in a murine stroke model. Neural precursors were derived from human embryonic stem cells by using a fully adherent SMAD inhibition protocol employing small molecules. The efficiency of neural induction and the ability of these cells to further differentiate into neurons were assessed by using immunocytochemistry. Whole-cell patch-clamp recording was used to demonstrate the electrophysiological activity of human embryonic stem cell-derived neurons. Neural precursors were transplanted into the core and penumbra regions of a focal ischemic stroke in the barrel cortex of mice. Animals received injections of bromodeoxyuridine to track regeneration. Neural differentiation of the transplanted cells and regenerative markers were measured by using immunohistochemistry. The adhesive removal test was used to determine functional improvement after stroke and intervention. After 11 days of neural induction by using the small-molecule protocol, over 95% of human embryonic stem-derived cells expressed at least one neural marker. Further in vitro differentiation yielded cells that stained for mature neuronal markers and exhibited high-amplitude, repetitive action potentials in response to depolarization. Neuronal differentiation also occurred after transplantation into the ischemic cortex. A greater level of bromodeoxyuridine co-localization with neurons was observed in the penumbra region of animals receiving cell transplantation. Transplantation also improved sensory recovery in transplant animals over that in control animals. Human embryonic stem cell-derived neural precursors derived by using a highly efficient small-molecule SMAD inhibition

  6. Embryonic oxidative stress as a mechanism of teratogenesis with special emphasis on diabetic embryopathy.

    Science.gov (United States)

    Ornoy, Asher

    2007-07-01

    Reactive oxygen species (ROS) are involved in the etiology of numerous diseases including cardio-vascular diseases and diabetes mellitus. There is evidence that several teratogens affect the developing embryo by increasing its oxidative stress and, because of its relatively weak antioxidant defense, especially at the early stages of organogenesis, result in severe embryonic damage. This mechanism seems to operate in diabetes-induced embryonic damage as well as in the mechanism of teratogenicity caused by ionizing radiation, hypoxia, alcohol and cocaine use and cigarette smoking. We studied the role of oxidative stress in diabetic induced embryopathy, both in vivo and in vitro. Under diabetic condition there was a significant decrease in the activity of endogenous antioxidant enzymes and of vitamins C and E in the embryos and their yolk sacs. The lowest activity was observed in the malformed experimental embryos when compared to experimental embryos without anomalies. Similar results were obtained in the Cohen diabetic rats, where the diabetic prone (CDs) rats were unable to increase their antioxidant enzyme activity in spite of the diabetes. Studies performed by other investigators show similar results. Human and animal studies show that the main mechanism of fetal damage induced by high levels of ionizing irradiation, cocaine and alcohol abuse, hypoxia and cigarette smoking is also by increased embryonic oxidative stress. Similarly, several drugs exert their teratogenic activity via embryonic oxidative stress. Abnormal placentation may also cause enhanced placental oxidative stress, resulting in embryonic death, preeclampsia or congenital anomalies. Inability of the developing embryo to cope with that stress may result in embryonic death and/or congenital anomalies. Animal studies also show that a variety of antioxidants are effective in decreasing the damaging effects of heightened oxidative stress induced by teratogens. Effective antioxidants, which might also

  7. Identification et surveillance des individus

    OpenAIRE

    Aghroum, Christian; Bonelli, Laurent; Dufief, Vincent; Thorel, Jérôme; Tsoukala, Anastassia; Vitran, Jean-Claude; Alberganti, Michel; Ceyhan, Ayse; Charrier, Philippe; Denis, Vincent; Laurent, Sébastien; Piazza, Pierre; Preuss-Laussinotte, Sylvia; Rousselin, Thierry

    2014-01-01

    « Big Brother is watching you ! » Cet avertissement placardé sur les murs de la cité imaginaire d'Océania dans le roman 1984 de Georges Orwell peut-il s'appliquer à nos sociétés contemporaines ? Passeport biométrique, fichage informatisé des individus, multiplication des caméras de surveillance, utilisation de puce dans des objets de la vie quotidienne, ou pour suivre les criminels en liberté surveillée, les mesures d'identification, de fichage et de surveillance des individus par des techniq...

  8. Gelatin–PMVE/MA composite scaffold promotes expansion of embryonic stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Chhabra, Hemlata [Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai (India); Gupta, Priyanka [Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai (India); IITB-Monash Research Academy, Mumbai (India); Department of Chemical Engineering, Monash University, Melbourne (Australia); Verma, Paul J. [Turretfield Research Centre, South Australian Research and Development Institute, Rosedale, South Australia (Australia); Jadhav, Sameer; Bellare, Jayesh R. [Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai (India)

    2014-04-01

    We introduce a new composite scaffold of gelatin and polymethyl vinyl ether-alt-maleic anhydride (PMVE/MA) for expansion of embryonic stem cells (ESCs) in an in vitro environment. To optimize the scaffold, we prepared a gelatin scaffold (G) and three composite scaffolds namely GP-1, GP-2, and GP-3 with varying PMVE/MA concentrations (0.2–1%) and characterized them by scanning electron microscopy (SEM), swelling study, compression testing and FTIR. SEM micrographs revealed interconnected porous structure in all the scaffolds. The permissible hemolysis ratio and activation of platelets by scaffolds confirmed the hemocompatibility of scaffolds. Initial biocompatibility assessment of scaffolds was conducted using hepatocarcinoma (Hep G2) cells and adhesion, proliferation and infiltration of Hep G2 cells in depth of scaffolds were observed, proving the scaffold's biocompatibility. Further Oct4B2 mouse embryonic stem cells (mESCs), which harbor a green fluorescence protein transgene under regulatory control of the Oct4 promotor, were examined for expansion on scaffolds with MTT assay. The GP-2 scaffold demonstrated the best cell proliferation and was further explored for ESC adherence and infiltration in depth (SEM and confocal), and pluripotent state of mESCs was assessed with the expression of Oct4-GFP and stage-specific embryonic antigen-1 (SSEA-1). This study reports the first demonstration of biocompatibility of gelatin–PMVE/MA composite scaffold and presents this scaffold as a promising candidate for embryonic stem cell based tissue engineering. - Highlights: • Composite scaffolds of gelatin and PMVE/MA were prepared by freeze-drying method. • SEM micrographs showed porous structure in all scaffolds of varying pore dimension. • GP-2 composite exhibited better cellular response in comparison to other scaffolds. • mESCs proliferated and expressed Oct-4 and SSEA-1, when cultured on GP-2 scaffold.

  9. Cyclin‑dependent kinase inhibitor p21 does not impact embryonic endochondral ossification in mice.

    Science.gov (United States)

    Chinzei, Nobuaki; Hayashi, Shinya; Hashimoto, Shingo; Kanzaki, Noriyuki; Iwasa, Kenjiro; Sakata, Shuhei; Kihara, Shinsuke; Fujishiro, Takaaki; Kuroda, Ryosuke; Kurosaka, Masahiro

    2015-03-01

    Endochondral ossification at the growth plate is regulated by a number of factors and hormones. The cyclin‑dependent kinase inhibitor p21 has been identified as a cell cycle regulator and its expression has been reported to be essential for endochondral ossification in vitro. However, to the best of our knowledge, the function of p21 in endochondral ossification has not been evaluated in vivo. Therefore, the aim of this study was to investigate the function of p21 in embryonic endochondral ossification in vivo. Wild‑type (WT) and p21 knockout (KO) pregnant heterozygous mice were sacrificed on embryonic days E13.5, E15.5 and E18.5. Sagittal histological sections of the forearms of the embryos were collected and stained with Safranin O and 5‑bromo‑2'‑deoxyuridine (BrdU). Additionally, the expression levels of cyclin D1, type II collagen, type X collagen, Sox9, and p16 were examined using immunohistochemistry, and the expression levels of p27 were examined using immunofluorescence. Safranin O staining revealed no structural change between the cartilage tissues of the WT and p21KO mice at any time point. Type II collagen was expressed ubiquitously, while type X collagen was only expressed in the hypertrophic zone of the cartilage tissues. No differences in the levels of Sox9 expression were observed between the two groups at any time point. The levels of cyclin D1 expression and BrdU uptake were higher in the E13.5 cartilage tissue compared with those observed in the embryonic cartilage tissue at subsequent time points. Expression of p16 and p27 was ubiquitous throughout the tissue sections. These results indicate that p21 may not be essential for embryonic endochondral ossification in articular cartilage of mice and that other signaling networks may compensate for p21 deletion.

  10. ETUDE DE LA DISTRIBUTION DES CATIONS ECHANGEABLES

    African Journals Online (AJOL)

    SEI Joseph

    Le suivi des modifications morphologiques en fonction des saisons de G. sesquipedale est effectué sur des échantillons représentatifs des 100 thalles prélevés ..... La période de septembre à janvier correspond à une phase de vieillissement des frondes qui se termine en janvier avec une détérioration des extrémités des ...

  11. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    ensemble des communautés vivantes. Le réchauffement climatique affecte les espèces exploitées. Les pêcheurs le constatent de plus en plus, le contenu de leurs filets évolue sous l‟impact du réchauffement. Ces changements ne sont.

  12. REPRISE DES COURS - Yoga

    CERN Document Server

    Club de Yoga

    2015-01-01

    REPRISE DES COURS – Venez nombreux ! Yoga, Sophrologie, Tai Chi La liste des cours pour le semestre allant du 1er septembre 2015 au 31 janvier 2016 est disponible sur notre site web : http://club-yoga.web.cern.ch Lieu Les cours ont lieu dans la salle des clubs, à l’entresol du restaurant No 2, Bât. 504 (dans la salle no 3 pour la Sophrologie). Prix des cours Le prix pour le semestre (environ 18 leçons) est fixé à 220 CHF plus 10 CHF d’adhésion annuelle au Club. Couple : 200 CHF par personne. 2 cours par semaine : 400 CHF. Inscriptions Les inscriptions aux cours seront prises directement auprès du professeur, lors de la 1ère séance. Avant de s’inscrire pour le semestre, il est possible d’essayer une séance gratuitement. Informations : http://club-yoga.web.cern.ch ----------------------------------------- cern.ch/club-yoga/

  13. La physique des infinis

    CERN Document Server

    Bernardeau, Francis; Laplace, Sandrine; Spiro, Michel

    2013-01-01

    Écrire l'histoire de l'Univers, tel est l'objectif commun des physiciens des particules et des astrophysiciens. Pour y parvenir, deux approches s'épaulent : la voie de l'infiniment petit, que l'on emprunte via de gigantesques accélérateurs de particules, et celle de l'infiniment grand, dont le laboratoire est l'Univers. Un Univers qui est bien loin d'avoir livré tous ses secrets. On connaît à peine 4,8 % de la matière qui le constitue, le reste étant composé de matière noire (25,8 %) et d'énergie noire (69,4 %), toutes deux de nature inconnue. Et si la récente découverte du boson de Higgs valide le Modèle standard de la physique des particules, celui-ci est toujours incomplet et doit être étendu à ou dépassé. Est-on arrivé au bout du jeu de poupées russes de la matière ? Quelles sont les particules manquantes ? Faut-il revoir les lois fondamentales ? Quels instruments faut-il mettre en œuvre pour accéder à cette « nouvelle physique » ? Comment parler de Super Big Science aux citoye...

  14. Praxis des Klebens

    CERN Document Server

    Theuerkauff, Petra

    1989-01-01

    Bei diesem Buch handelt es sich um einen Leitfaden fur Klebepraktiker. Es werden die verschiedenen Einzelschritte beim kleben beschrieben, als auch die vorbereitenden Massnahmen und anschliessenden Prufverfahren auf Festigkeit behandelt. Das Buch sollte an keinem Arbeitsplatz fehlen, wo man sich mit Problemen der Fugetechnik des Klebens beschaftigt.

  15. Diethylstilbestrol (DES) and Cancer

    Science.gov (United States)

    ... Español 1-800-4-CANCER Live Chat Publications Dictionary Menu Contact Dictionary Search About Cancer Causes and Prevention Risk Factors ... or DES granddaughters) ( 6 ). The National Institute of Environmental Health Sciences (NIEHS) is leading laboratory studies to ...

  16. Cytomegalovirus induces abnormal chondrogenesis and osteogenesis during embryonic mandibular development

    Directory of Open Access Journals (Sweden)

    Bringas Pablo

    2008-03-01

    Full Text Available Abstract Background Human clinical studies and mouse models clearly demonstrate that cytomegalovirus (CMV disrupts normal organ and tissue development. Although CMV is one of the most common causes of major birth defects in humans, little is presently known about the mechanism(s underlying CMV-induced congenital malformations. Our prior studies have demonstrated that CMV infection of first branchial arch derivatives (salivary glands and teeth induced severely abnormal phenotypes and that CMV has a particular tropism for neural crest-derived mesenchyme (NCM. Since early embryos are barely susceptible to CMV infection, and the extant evidence suggests that the differentiation program needs to be well underway for embryonic tissues to be susceptible to viral infection and viral-induced pathology, the aim of this study was to determine if first branchial arch NCM cells are susceptible to mCMV infection prior to differentiation of NCM derivatives. Results E11 mouse mandibular processes (MANs were infected with mouse CMV (mCMV for up to 16 days in vitro. mCMV infection of undifferentiated embryonic mouse MANs induced micrognathia consequent to decreased Meckel's cartilage chondrogenesis and mandibular osteogenesis. Specifically, mCMV infection resulted in aberrant stromal cellularity, a smaller, misshapen Meckel's cartilage, and mandibular bone and condylar dysmorphogenesis. Analysis of viral distribution indicates that mCMV primarily infects NCM cells and derivatives. Initial localization studies indicate that mCMV infection changed the cell-specific expression of FN, NF-κB2, RelA, RelB, and Shh and Smad7 proteins. Conclusion Our results indicate that mCMV dysregulation of key signaling pathways in primarily NCM cells and their derivatives severely disrupts mandibular morphogenesis and skeletogenesis. The pathogenesis appears to be centered around the canonical and noncanonical NF-κB pathways, and there is unusual juxtaposition of abnormal stromal

  17. Plant regeneration and stimulation of in vitro flowering in Eruca ...

    African Journals Online (AJOL)

    Explants such as apical buds, axillary buds, cotyledons, cotyledonary nodes, leaves, hypocotyls and immature embryonal axes from in vitro-grown plantlets were inoculated on the Murashige and Skoog (MS) medium supplemented with 4.44 μM 6-benzylaminopurine in combination with 2.85 μM indole-3-acetic acid.

  18. File list: ALL.Emb.50.AllAg.Embryonic_megakaryocytes [Chip-atlas[Archive

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  18. File list: Oth.Emb.05.AllAg.Embryonic_palates [Chip-atlas[Archive

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  19. Pathways in pluripotency and differentiation of embryonic cells

    NARCIS (Netherlands)

    du Puy, L.

    2010-01-01

    Pluripotency - the potential to differentiate into derivatives of the three embryonic germ layers endoderm, ectoderm and mesoderm - is the main characteristic of embryonic stem (ES) cells. ES cells are derived from the inner cell mass (ICM) of a pre-implantation blastocyst and can self-renew

  20. Spontaneous cyclic embryonic movements in humans and guinea pigs

    NARCIS (Netherlands)

    Felt, R.H.; Mulder, E.J.; Lüchinger, A.M.; van Kan, C.M.; Taverne, M.A.; de Vries, J.I.P.

    2012-01-01

    Motility assessment before birth can be used to evaluate the integrity of the nervous system. Sideways bending (SB) of head and/or rump, the earliest embryonic motility in both humans and guinea pigs, can be visualized sonographically. We know from other species that early embryonic motility is

  1. Cryopreservation of embryonic axes of maize ( Zea mays L.) by ...

    African Journals Online (AJOL)

    A storage protocol at cryogenic temperature was established for embryonic axes of maize using a basic vitrification protocol with direct immersion in liquid nitrogen (-196ºC). The response of isolated embryonic axes of five maize genotypes to plant vitrification solution (PVS2) at different concentrations was studied. Recovery ...

  2. Sox2 in Embryonic Stem Cells and Lung Development

    NARCIS (Netherlands)

    C.G. Pardo (Cristina Gontan)

    2009-01-01

    markdownabstract__Abstract__ Sox2 is a fascinating transcription factor with multiple roles during embryonic development. In early embryonic development, Sox2 is one of the key transcription factors in the maintenance of the pluripotent status of the cells of the inner cell mass (ICM). Sox2 is

  3. Embryonic adaptations and nutrition in the viviparous teleost Clinus ...

    African Journals Online (AJOL)

    Embryos of Clinus dorsalis absorb nutrients from the embiyotrophe, secreted by the follicular epithelium. Autoradiographic studies revealed that the principal areas of nutrient absorption are the embryonic gut and epidermis. A histological and electron microscopic study of embryonic structure revealed an extensively ...

  4. Embryonic stem cells: testing the germ-cell theory.

    Science.gov (United States)

    Hochedlinger, Konrad

    2011-10-25

    The exact cellular origin of embryonic stem cells remains elusive. Now a new study provides compelling evidence that embryonic stem cells, established under conventional culture conditions, originate from a transient germ-cell state. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Mise au point d'un test in vitro de comportement au sel de quatre ...

    African Journals Online (AJOL)

    agrumes, en termes de résistance à la salinité in vitro au niveau des cals et des cellules cultivées parallèlement sur milieu liquide et solide. Méthodologie et résultat : À cet égard, des cals de quatre génotypes d'agrumes : mandarinier Cléopâtre ...

  6. Art des mets… art des mots

    OpenAIRE

    Parizot, Anne

    2014-01-01

    Cette étude, effectuée dans le cadre d’une recherche en sciences de la communication, s’intéresse à la raison pour laquelle un convive choisit un plat en fonction de son énoncé, dans un restaurant gastronomique. La dénomination des plats sur un menu est un élément déclencheur du désir du convive, mais également le reflet de l’identité du chef. Nous replacerons donc l’intitulé dans le contexte de création du chef qui, par-delà les mots, nous livre une part de son identité. Ensuite nous présent...

  7. Rupture des temps, union des espaces

    Directory of Open Access Journals (Sweden)

    Emmanuelle Tricoire

    2004-06-01

    Full Text Available Berlin, Staatsbibliothek, preußischer Kulturbesitz. Musée de Sachsenhausen, Oranienburg. (1 1925, Ostpreußen. Selbstbestimmung oder Gewalt . « Prusse orientale. L'auto-détermination ou la violence ». Exposée dans le camp de concentration de Sachsenhausen, près de Berlin, édifié par les nazis avant de servir aux Soviétiques jusqu'en 1954, la carte témoigne des dégâts que firent les frontières définies par le traité de Versailles. La violence de la paranoïa que ...

  8. Modulation of ovarian steroidogenesis by adiponectin during delayed embryonic development of Cynopterus sphinx.

    Science.gov (United States)

    Anuradha; Krishna, Amitabh

    2014-09-01

    The aim of present study was to evaluate role of adiponectin in ovarian steroidogenesis during delayed embryonic development of Cynopterus sphinx. This study showed significantly low circulating adiponectin level and a decline in expression of adiponectin receptor 1 (AdipoR1) in the ovary during the period of delayed embryonic development as compared with the normal development. The adiponectin treatment in vivo during the period of delayed development caused significantly increased in circulating progesterone and estradiol levels together with increased expression of AdipoR1 in the ovary. The in vitro study confirmed the stimulatory effect of adiponectin on progesterone synthesis. Both in vivo and in vitro studies showed that the effects of adiponectin on ovarian steroidogenesis were mediated through increased expression of luteinizing hormone-receptor, steroidogenic acute regulatory protein and 3β-hydroxyl steroid dehydrogenase enzyme. The adiponectin treatment may also promote progesterone synthesis by modulating ovarian angiogenesis, cell survival and rate of apoptosis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Rat embryonic fibroblasts immortalized by MRPS18-2 protein are target for NK-cells.

    Science.gov (United States)

    Mushtaq, Muhammad; Pangigadde, Pradeepa N; Darekar, Suhas; Dissen, Erik; Kashuba, Elena

    2017-09-12

    Overexpression of the human mitochondrial ribosomal protein MRPS18-2 (S18-2) led to immortalization of primary rat embryonic fibroblasts (REFs). The derived cells (18IM) expressed embryonic stem cell markers. Noteworthy, genes encoding the COX family proteins were up-regulated significantly. It is known that the COX family proteins are involved in the regulation of immune response. In the present work we demonstrate that 18IM cells behave like stem cells when subjected to directed differentiation in vitro. However, unlike stem cells, 18IM cells do not develop tumors in vivo, in SCID mice. This phenomenon is observed due to the strong natural killer (NK) cell immunogenicity. 18IM cells were better recognized by NK cells, compared with primary REFs, as was shown by a standard NK killing assay. Our data explain asymmetry in behavior of stem-like cells in vivo and in vitro, and this support the notion that stem and/or cancer-initiating cells are preferred targets for NK-cells. Concluding, the S18-2 protein is a putative target for cancer vaccines.

  10. [Establishment of feeder-free culture system of human parthenogenetic embryonic stem cells].

    Science.gov (United States)

    Liang, Rui; Wang, Zhiqiang; Chen, Tianxing; Zhu, Jing; Zhu, Shu; Li, Ying; Yang, Long; Zhu, Baosheng

    2013-05-01

    To establish a safe, effective, and economic feeder'-free culture system which is suitable for the culture of human parthenogenetic embryonic stem cells (hPESCs) in vitro. hPESCs were cultured with mTeSR 1 medium (control group) and human foreskin fibroblasts-conditional medium (hFFs-CM) (experimental group). The growth status of hPESCs in both feeder-free culture systems were observed with inverted microscope. Alkaline phosphatase (ALP) analysis and karyotype analysis were used to study the biological characteristics of hPESCs. The expression of hPESCs pluripotent marker Oct-4 was analyzed by RT-PCR. Differentiation experiment in vivo and in vitro was applied to observe the differentiation potential of hPESCs into three germ layers. hPESCs had regular morphology with difficulty in differentiation in both culture systems. No obvious difference was observed in morphology and expansion speed of hPESCs between 2 groups. After subcultured for 15 passages in vitro, hPESCs in 2 groups could maintain normal female diploid karyotype 46, XX and pluripotency. The expression of Oct-4 mRNA was positive in 2 groups. hPESCs in 2 groups could form embryonic body in differentiation experiment in vitro and could develop into teratomas containing three germ layers in nude mice. Feeder-free culture system of hFFs-CM can sustain the growth of hPESCs and keep hPESCs undifferentiated state for long. A feeder-free culture system of hPESCs is successfully established, which can support the growth of hPESCs, reduce the contamination from animals, decrease the cost of culture, and satisfy the clinical large-scale application.

  11. 4D embryonic cardiography using gated optical coherence tomography

    Science.gov (United States)

    Jenkins, M. W.; Rothenberg, F.; Roy, D.; Nikolski, V. P.; Hu, Z.; Watanabe, M.; Wilson, D. L.; Efimov, I. R.; Rollins, A. M.

    2006-01-01

    Simultaneous imaging of very early embryonic heart structure and function has technical limitations of spatial and temporal resolution. We have developed a gated technique using optical coherence tomography (OCT) that can rapidly image beating embryonic hearts in four-dimensions (4D), at high spatial resolution (10-15 μm), and with a depth penetration of 1.5 - 2.0 mm that is suitable for the study of early embryonic hearts. We acquired data from paced, excised, embryonic chicken and mouse hearts using gated sampling and employed image processing techniques to visualize the hearts in 4D and measure physiologic parameters such as cardiac volume, ejection fraction, and wall thickness. This technique is being developed to longitudinally investigate the physiology of intact embryonic hearts and events that lead to congenital heart defects.

  12. Aspects des Onychomycoses chez des patients camerounais de ...

    African Journals Online (AJOL)

    ... biologiques et évolutifs des onychomycoses chez des patients camerounais. Méthode : Il s'agit d'une étude rétrospective et descriptive menée de mars 2011 à mars 2014 dans l'unité de dermatologie de l'hôpital général de Douala (HGD), incluant des patients chez lesquels le diagnostic d'onychomycose avait été posé.

  13. Etat des controverses des approches cognitive et ecologique en ...

    African Journals Online (AJOL)

    Cette revue de question vise à présenter dans le champ de l'apprentissage moteur, le sens des postulats des approches cognitive et écologique de même que les critiques formulées à leur encontre. Des documents scientifiques et articles de revues indexées et publiés dans la banque de données MEDLINE, ont été ...

  14. Prevision des ventes et efficacite des chaines logistiques - Essai de ...

    African Journals Online (AJOL)

    Il s'agit aussi de clarifier le mode d'utilisation des données de prévision, dans la modélisation mathématique des chaines logistiques, qui se distinguent par la multiplicité des objectifs. L'application de ces méthodes se fera dans une entreprise algérienne (la laiterie de RIO) spécialisée dans la production du yaourt.

  15. Collection d'entretiens avec des chercheurs participant à des ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Entretien avec…propose des entrevues vidéos avec des chercheurs participant à des projets portant sur l'adaptation aux changements climatiques réalisés en Afrique, en Asie ainsi qu'en Amérique latine et dans les Caraïbes que le CRDI subventionne par le truchement de son programme Changements climatiques et eau ...

  16. Contribution a l'amelioration des techniques de diagnostic des ...

    African Journals Online (AJOL)

    Ces vecteurs transmettent à l'homme des maladies bactériennes, telles que les borrélioses. La borréliose se manifeste par une fièvre élevée avec des céphalées, des vomissements, de la fatigue et une sensation de froid. Ces symptômes la font soit confondre avec le paludisme soit ranger parmi les fièvres non paludiques ...

  17. Regroupement des statistiques sur le secteur des TIC et analyse ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Regroupement des statistiques sur le secteur des TIC et analyse axée sur les politiques. La présence et l'influence des technologies de l'information et de la communication (TIC) continuent de s'élargir et de s'accroître, tout comme leurs répercussions sur le développement économique. Toutefois, il reste encore beaucoup ...

  18. Commercialisation des pintades dans la region des savanes au ...

    African Journals Online (AJOL)

    Au Togo et plus précisément dans la Région des Savanes, l'élevage des pintades occupe une place capitale dans la vie économique des paysans à travers sa commercialisation. Ce travail vise à étudier le système de commercialisation de ces volailles dans cet espace géographique du Togo. Pour atteindre cet objectif, ...

  19. Impact des microcredits sur les conditions sociosanitaires des ...

    African Journals Online (AJOL)

    échantillonnage est raisonné et la méthode de signifiance des cas a été utilisée pour la collecte des données. Les données collectées ont été soumises aux traitements statistiques. L'analyse des résultats est la dernière étape de la démarche. Les résultats ...

  20. Conditions environnementales des maladies des enfants de moins ...

    African Journals Online (AJOL)

    Les résultats révèlent une dominance du paludisme (49%), suivi des IRA (26%), les anémies (13%), les affections gastro-intestinales (7%) et les maladies diarrhéiques (5%) dans un contexte de manque d'assainissement où la nature demeure le mode de gestion des ordures (95%) et des excrétas (92%). Les liens entre ...

  1. Analyse Des Perceptions Locales Et Des Facteurs Determinant L ...

    African Journals Online (AJOL)

    Une Analyse en Composantes Principales a été appliquée à la matrice des données de fréquences des organes utilisés. Une régression logistique binaire a été utilisée pour identifier les facteurs déterminant le souhait des populations à cultiver J. curcas. Les résultats ont montré que les populations locales consentissent ...

  2. Etude des comportements rheologiques des melanges de farine ble ...

    African Journals Online (AJOL)

    Des tests de panification à base de farines composées incorporant 20 % des farines issues des différentes variétés de sorgho ont été effectués aussi au niveau de la boulangerie pilote de l'Institut de Technologie Alimentaire de Dakar. Les pains obtenus ont présenté un bon volume, une bonne texture de la mie, de la ...

  3. Mapping the stem cell state: eight novel human embryonic stem and embryonal carcinoma cell antibodies

    DEFF Research Database (Denmark)

    Wright, A; Andrews, N; Bardsley, K

    2011-01-01

    The antigenic profile of human embryonic stem (ES) and embryonal carcinoma (EC) cells has served as a key element of their characterization, with a common panel of surface and intracellular markers now widely used. Such markers have been used to identify cells within the 'undifferentiated state...... of reactivity for all antibodies against both ES and EC cells, suggesting that these markers will afford recognition of unique sub-states within the undifferentiated stem cell compartment....... and EC cells, and herein describe their characterization. The reactivity of these antibodies against a range of cell lines is reported, as well as their developmental regulation, basic biochemistry and reactivity in immunohistochemistry of testicular germ cell tumours. Our data reveal a range...

  4. Somatic muscle specification during embryonic and post-embryonic development in the nematode C. elegans.

    Science.gov (United States)

    Krause, Michael; Liu, Jun

    2012-01-01

    Myogenesis has proved to be a powerful paradigm for understanding cell fate specification and differentiation in many model organisms. Studies of somatic bodywall muscle (BWM) development in Caenorhabditis elegans allow us to define, with single cell resolution, the distinct hierarchies of transcriptional regulators needed for myogenesis throughout development. Although all 95 BWM cells appear uniform after differentiation, there are several different regulatory cascades employed embryonically and post-embryonically. These, in turn, are integrated into multiple extrinsic cell signaling events. The convergence of these different pathways on the key nodal point, that is the activation of the core muscle module, commits individual cells to myogenesis. Comparisons of myogenesis between C. elegans and other model systems provide insights into the evolution of contractile cell types, demonstrating the conservation of regulatory schemes for muscles throughout the animal kingdom. Copyright © 2011 Wiley Periodicals, Inc.

  5. in vitro technique for selecting onion for white rot disease

    African Journals Online (AJOL)

    ACSS

    change in the genomes of somaclones toward the required character. The objective of this study was to ... de façon á préserver le caractère desiré, ou, en créant des conditions particulières visant á modifier le genome afin dans le sens des caractères ...... vitro selection of calli of Citrus jambhiri. Lush. for tolerance to culture ...

  6. Will embryonic stem cells change health policy?

    Science.gov (United States)

    Sage, William M

    2010-01-01

    Embryonic stem cells are actively debated in political and public policy arenas. However, the connections between stem cell innovation and overall health care policy are seldom elucidated. As with many controversial aspects of medical care, the stem cell debate bridges to a variety of social conversations beyond abortion. Some issues, such as translational medicine, commercialization, patient and public safety, health care spending, physician practice, and access to insurance and health care services, are core health policy concerns. Other issues, such as economic development, technologic progress, fiscal politics, and tort reform, are only indirectly related to the health care system but are frequently seen through a health care lens. These connections will help determine whether the stem cell debate reaches a resolution, and what that resolution might be.

  7. Human embryonic stem cells and patent protection

    Directory of Open Access Journals (Sweden)

    Radovanović Sanja M.

    2015-01-01

    Full Text Available Given the importance of biotechnological research in modern diagnostics and therapeutics, on the one hand, and stimulative function of a patent, on the other hand, this work deals with the question of the possibility of pa-tent protection of human embryonic stem cells. Taking into account that this is a biotechnological invention, the key question that this paper highlights is the interpretation of the provisions of their patentability. Namely, thanks to the advanced methods of isolation, purification and preparation for implementation, modern patent systems do not exclude a priori living organisms from patent protection. Therefore, the analysis of representative administrative decisions or court rulings sought to define the criteria that would be applied in order to give patent protection to a certain biotechnological invention (stem cells while others do not.

  8. Human embryonic stem cells: preclinical perspectives

    Directory of Open Access Journals (Sweden)

    Sarda Kanchan

    2008-01-01

    Full Text Available Abstract Human embryonic stem cells (hESCs have been extensively discussed in public and scientific communities for their potential in treating diseases and injuries. However, not much has been achieved in turning them into safe therapeutic agents. The hurdles in transforming hESCs to therapies start right with the way these cells are derived and maintained in the laboratory, and goes up-to clinical complications related to need for patient specific cell lines, gender specific aspects, age of the cells, and several post transplantation uncertainties. The different types of cells derived through directed differentiation of hESC and used successfully in animal disease and injury models are described briefly. This review gives a brief outlook on the present and the future of hESC based therapies, and talks about the technological advances required for a safe transition from laboratory to clinic.

  9. Epigenetic control of embryonic stem cell fate

    DEFF Research Database (Denmark)

    Christophersen, Nicolaj Strøyer; Helin, Kristian

    2010-01-01

    Embryonic stem (ES) cells are derived from the inner cell mass of the preimplantation embryo and are pluripotent, as they are able to differentiate into all cell types of the adult organism. Once established, the pluripotent ES cells can be maintained under defined culture conditions, but can also...... be induced rapidly to differentiate. Maintaining this balance of stability versus plasticity is a challenge, and extensive studies in recent years have focused on understanding the contributions of transcription factors and epigenetic enzymes to the "stemness" properties of these cells. Identifying...... the molecular switches that regulate ES cell self-renewal versus differentiation can provide insights into the nature of the pluripotent state and enhance the potential use of these cells in therapeutic applications. Here, we review the latest models for how changes in chromatin methylation can modulate ES cell...

  10. etude epidemiologique clinique et therapeutique des fractures des plataux tibiaux

    OpenAIRE

    BEKHALED, FATIMA ZOHRA; BENMIMOUN, SAMIHA

    2013-01-01

    Il est important de réaliser un bilan clinique initial complet dans le cadre des fractures des plateaux tibiaux. Le bilan para clinique comprendra au minimum des radiographies simples, et au besoin un scanner afin de définir le type de fracture. L'IRM permet surtout l'analyse des structures ligamentaires, ainsi que la mise en évidence de fractures occultes. Le traitement est orthopédique ou chirurgical. La chirurgie per - cutanée assistée ou non par arthroscopie est parfo...

  11. Des Chiffres et des Lettres : distraction, variations, habitudes

    Directory of Open Access Journals (Sweden)

    Barbara Laborde

    2011-04-01

    Full Text Available Cet article envisage une des émissions les plus anciennes du Paysage Audiovisuel Français : Des Chiffres et des Lettres. La sérialité que l’émission met en œuvre au cours de son histoire est faite de variations qui témoignent à la fois des évolutions des techniques audiovisuelles, des logiques de programmations, des attentes spectatorielles. Ce jeu télévisé, toujours le même et pourtant toujours différent, permet à la fois la reconnaissance immédiate et la perception d'un changement, double adresse qui explique sans doute sa longévité et fait de ce programme un parangon de la sérialité télévisuelle.This article considers one of the oldest programs in the French media landscape: « Des Chiffres et des Lettres ». Seriality that implements the program in its history is made changes that reflect both the evolution of audiovisual techniques, of logic programming and expectations spectatorial. This TV show, always the same and yet still different, allows both the immediate recognition and perception of a change which probably explains its longevity and made this program a paragon of seriality in television.

  12. Intestinal lineage commitment of embryonic stem cells.

    Science.gov (United States)

    Cao, Li; Gibson, Jason D; Miyamoto, Shingo; Sail, Vibhavari; Verma, Rajeev; Rosenberg, Daniel W; Nelson, Craig E; Giardina, Charles

    2011-01-01

    Generating lineage-committed intestinal stem cells from embryonic stem cells (ESCs) could provide a tractable experimental system for understanding intestinal differentiation pathways and may ultimately provide cells for regenerating damaged intestinal tissue. We tested a two-step differentiation procedure in which ESCs were first cultured with activin A to favor formation of definitive endoderm, and then treated with fibroblast-conditioned medium with or without Wnt3A. The definitive endoderm expressed a number of genes associated with gut-tube development through mouse embryonic day 8.5 (Sox17, Foxa2, and Gata4 expressed and Id2 silent). The intestinal stem cell marker Lgr5 gene was also activated in the endodermal cells, whereas the Msi1, Ephb2, and Dcamkl1 intestinal stem cell markers were not. Exposure of the endoderm to fibroblast-conditioned medium with Wnt3A resulted in the activation of Id2, the remaining intestinal stem cell markers and the later gut markers Cdx2, Fabp2, and Muc2. Interestingly, genes associated with distal gut-associated mesoderm (Foxf2, Hlx, and Hoxd8) were also simulated by Wnt3A. The two-step differentiation protocol generated gut bodies with crypt-like structures that included regions of Lgr5-expressing proliferating cells and regions of cell differentiation. These gut bodies also had a smooth muscle component and some underwent peristaltic movement. The ability of the definitive endoderm to differentiate into intestinal epithelium was supported by the vivo engraftment of these cells into mouse colonic mucosa. These findings demonstrate that definitive endoderm derived from ESCs can carry out intestinal cell differentiation pathways and may provide cells to restore damaged intestinal tissue. Copyright © 2010 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.

  13. Embryonic environment and transgenerational effects in quail.

    Science.gov (United States)

    Leroux, Sophie; Gourichon, David; Leterrier, Christine; Labrune, Yann; Coustham, Vincent; Rivière, Sandrine; Zerjal, Tatiana; Coville, Jean-Luc; Morisson, Mireille; Minvielle, Francis; Pitel, Frédérique

    2017-01-26

    Environmental exposures, for instance to chemicals, are known to impact plant and animal phenotypes on the long term, sometimes across several generations. Such transgenerational phenotypes were shown to be promoted by epigenetic alterations such as DNA methylation, an epigenetic mark involved in the regulation of gene expression. However, it is yet unknown whether transgenerational epigenetic inheritance of altered phenotypes exists in birds. The purpose of this study was to develop an avian model to investigate whether changes to the embryonic environment had a transgenerational effect that could alter the phenotypes of third-generation offspring. Given its impact on the mammalian epigenome and the reproductive system in birds, genistein was used as an environment stressor. We compared several third-generation phenotypes of two quail "epilines", which were obtained from genistein-injected eggs (Epi+) or from untreated eggs (Epi-) from the same founders. A "mirrored" crossing strategy was used to minimize between-line genetic variability by maintaining similar ancestor contributions across generations in each line. Three generations after genistein treatment, a significant difference in the sexual maturity of the females, which, after three generations, could not be attributed to direct maternal effects, was observed between the lines, with Epi+ females starting to lay eggs later. Adult body weight was significantly affected by genistein treatment applied in a previous generation, and a significant interaction between line and sex was observed for body weight at 3 weeks. Behavioral traits, such as evaluating the birds' reaction to social isolation, were also significantly affected by genistein treatment. Yet, global methylation analyses revealed no significant difference between the epilines. These findings demonstrate that embryonic environment affects the phenotype of offspring three generations later in quail. While one cannot rule out the existence of some

  14. Energy and nutrient utilisation by embryonic reptiles.

    Science.gov (United States)

    Thompson, Michael B; Speake, Brian K

    2002-11-01

    Most reptiles are oviparous, with the developing embryos relying on the contents of the yolk to sustain development until hatching (lecithotrophy). The yolk is composed primarily of lipid and protein, which act as an energy source and the essential components to build embryonic tissue. Nevertheless, yolk and the resulting embryos contain many other nutrients, including inorganic ions, vitamins, carotenoids, water and hormones. Apart from water and oxygen, which may be taken up by eggs, and some inorganic ions that can come from the eggshell or even from outside the egg, everything required by the embryo must be in the egg when it is laid. Approximately 20% of squamate reptiles are viviparous, exhibiting a variety of placental complexities. Species with complex placentae have reduced yolk volumes, with the mother augmenting embryonic nutrition by provision across the placenta (placentotrophy). Despite assumed advantages of placentotrophy, only 5 out of approximately 100 lineages of viviparous squamates exhibit substantial placentotrophy. This paper reviews available and recent information on the yolk contents of a variety of squamate reptiles to ask the question, how are nutrients transported from the yolk to the embryo or across the placenta? Although, current available data suggest that, in broad terms, yolk is taken up by embryos without discrimination of the nutrients, there are some apparent exceptions, including the very long chain polyunsaturated fatty acids. In addition, fundamental differences in the patterns of energy utilisation in lizards and snakes suggest fundamental differences in lipid profiles in these taxa, which appear to reflect the differences between placentotrophic and lecithotrophic viviparous lizards.

  15. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    Unité de Recherche des Matériaux et des Energies Renouvelables (U.R.M.E.R). Université Abou –Baker Belkaid B.p : 119 Tlemcen 13000 Algerie. 2. Unité de Développement de la Technologie Du Silicium. UDTS, BP 399, Alger, Algérie. Accepté le : 08/06/2011. صخلم. داوﻣﻟا نﻣ ﻲﺗﻟا ﺔﺻﺎﺧو ،ﺔﻋﺎﻧﺻ يأ رﯾوطﺗ ﻲﻓ ﺎﯾﺳﯾﺋر ﻼﻣﺎﻋ ةرﯾﺧﻷا تاوﻧﺳﻟا ...

  16. Ethique des affaires

    OpenAIRE

    2011-01-01

    L’affaire Enron aura redynamisé outre-Rhin la réflexion sur l’éthique des affaires. Mais la globalisation aussi apporte son lot de questions : un patron a-t-il moralement le droit de fermer un site qui n’est plus rentable ? Les impératifs de compétitivité exigent-ils de lui qu’il le fasse ? Comment juger des performances d’un collaborateur ? C’est à toute une série de questions de ce type que tente de répondre un président de directoire allemand, ancien consultant au cabinet Boston Consulting...

  17. PORTAIL DES JEUX EDUCATIFS

    OpenAIRE

    BENSLIMANE, ABDALLAH

    2015-01-01

    Un monde sans jeux vidéo semble impossible de nos jours. L'industrie des jeux est considérée comme l’une des plus importantes avec un impact affectant tous les domaines (économie, l'éducation, la culture, ...). Notre objectif est de faire la conception et la réalisation d’un produit destiné particulièrement à notre société. Nous avons remarqué qu’il existe un très grand nombre de jeux, mais malheureusement très peu d’entre eux sont dotés d’une version en langue arabe. Ceci n...

  18. Chimie des processus biologiques

    OpenAIRE

    Fontecave, Marc

    2016-01-01

    Enseignement Cours : Clusters métalliques et enzymes : le vivant inorganique Il est communément considéré que la matière vivante est organique. En réalité, on sait aujourd’hui qu’une très grande quantité de processus naturels dépendent de l’intervention d’un ou de plusieurs ions métalliques. Par exemple, près de 40 % des protéines ne fonctionnent que parce qu’elles fixent un ou plusieurs ions métalliques (sodium, magnésium, calcium, fer, zinc, cuivre, etc.) On les appelle des métalloprotéines...

  19. Human embryonic stem cells and embryonal carcinoma cells have overlapping and distinct metabolic signatures.

    Directory of Open Access Journals (Sweden)

    Raed Abu Dawud

    Full Text Available While human embryonic stem cells (hESCs and human embryonal carcinoma cells (hECCs have been studied extensively at the levels of the genome, transcriptome, proteome and epigenome our knowledge of their corresponding metabolomes is limited. Here, we present the metabolic signatures of hESCs and hESCs obtained by untargeted gas chromatography coupled to mass spectrometry (GC-MS. Whilst some metabolites are common to both cell types, representing the self-renewal and house-keeping signatures, others were either higher (e.g., octadecenoic acid, glycerol-3-phosphate, 4-hydroxyproline or lower (e.g., glutamic acid, mannitol, malic acid, GABA in hESCs (H9 compared to hECCs (NTERA2, these represent cell type specific signatures. Further, our combined results of GC-MS and microarray based gene expression profiling of undifferentiated and OCT4-depleted hESCs are consistent with the Warburg effect which is increased glycolysis in embryonic cells and tumor cells in the presence of O(2 while oxidative phosphorylation (OXPHOS is impaired or even shut down. RNAi-based OCT4 knock down mediated differentiation resulted in the activation of the poised OXPHOS machinery by expressing missing key proteins such as NDUFC1, UQCRB and COX, increase in TCA cycle activity and decreased lactate metabolism. These results shed light on the metabolite layer of pluripotent stem cells and could potentially establish novel metabolic markers of self renewal and pluripotency.

  20. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    It is suggested that Si contributes greatly to passivation in case of high iron silicon alloys. Key words: cathode sputtering magnetron; thin films; nanostructure; corrosion; alloys Fe-Si. 1. ... Anode : Intensité (A)/ Tension (V). 40/20. 5/25. Distance cible-substrat (mm). 80. Vitesse de dépôt (µm.h-1). 5. 2.2 Caractérisation des ...

  1. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    Laboratoire de Biologie Végétale et Environnement, Faculté des Sciences, Département de Biologie ... Le parc national d‟El Kala (Nord est algérien) est caractérisé par une grande biodiversité génétique. Dans le cadre de nos ... Mots clés: Biodiversité ;Lichen ; Parc National dEl Kala- nord- est algérien ; Algérie. Abstract.

  2. Die Problematik des Pauschalurteils

    OpenAIRE

    Hansen, Klaus P.

    2009-01-01

    Klaus P. Hansen betont in seinem Beitrag über die "Problematik des Pauschalurteils", dass sich Verallgemeinerungen über ein Kollektiv nur auf die partiellen Gemeinsamkeiten dieser Gruppe, nicht aber auf Individuen beziehen dürfen. Der Kulturtheoretiker erinnert an die menschliche Multikollektivität, plädiert für eine dichte Zuschreibung beobachteter Merkmale zu einzelnen Gruppenmitgliedschaften und entwirft eine Typologie unterschiedlicher Kollektivformen. Nationen konzipiert er als Dachkolle...

  3. Table des figures

    OpenAIRE

    2014-01-01

    1. Carte générale de Colombie 733 2. Le Nouveau Royaume de Grenade 734 3. Nouvelle Grenade — Région centre 735 4. Nouvelle Grenade — Région nord 736 5. Nouvelle Grenade — Région sud-ouest 737 6. Schéma des institutions chargées de l’implantation de la foi dans le Nouveau Monde 738

  4. Fokale Therapie des Prostatakarzinoms

    OpenAIRE

    Roosen A

    2013-01-01

    Die EAU bezeichnet die fokale Therapie des Prostatakarzinoms als die therapeutische Option mit dem größten Zukunftspotenzial, auch wenn es sich dabei derzeit nicht um ein Standardverfahren handelt. Sie vermag bei Patienten mit einem niedrigmalignen, fokal begrenzten Prostatakarzinom die Lücke zu schließen zwischen potenzieller Übertherapie durch die radikalen Standardverfahren und der onkologischen Unsicherheit einer ,,Active surveillance. Dieser Überblick gibt den derzeitigen Kenntnisstand ...

  5. In vitro propagation of three commercial passionfruit varieties in ...

    African Journals Online (AJOL)

    Ceci est aggravé par l'inexistence en quantité suffisante des semences de qualité. La propagation In vitro au moyen des sections nodales, est un procédé qui a connu du succès dans la production rapide des semences de bonne qualité chez les plantes à propagation vegetative. La présente étude a été réalisée afin de ...

  6. Dictionnaire des risques psychosociaux

    CERN Document Server

    Zawieja, Philippe

    2014-01-01

    Stress, suicide, harcèlement, épuisement professionnel, workaholism... Au-delà de la souffrance qu'elles désignent, ces notions souvent récentes constituent une approche inédite, et demandent à mieux être comprises, dans leur ensemble et isolément. C'est tout l'enjeu de ce dictionnaire, pionnier en son genre. Le lecteur y trouvera représentés, avec les 314 entrées (rédigées par 251 contributeurs) qui le composent, tous les champs disciplinaires s'intéressant à la souffrance au travail : psychologie du travail et des organisations, psychologie sociale et psychosociologie, psychanalyse, psychopathologie et psychiatrie, ergonomie, sociologie du travail et des organisations, médecine du travail, droit du travail et de la sécurité sociale, sciences de gestion, philosophie... Y sont détaillés les principaux concepts, notions, approches, méthodes, théories, outils, études, etc., ayant cours dans l'étude des risques psychosociaux, mais aussi certaines professions emblématiques (infirmières,...

  7. Rac1 modulates cardiomyocyte adhesion during mouse embryonic development

    Energy Technology Data Exchange (ETDEWEB)

    Abu-Issa, Radwan, E-mail: rabuissa@umich.edu

    2015-01-24

    Highlights: • Conditional knockout of Rac1 using Nkx2.5 Cre line is lethal at E13.5. • The myocardium of the mutant is thin and disorganized. • The phenotype is not due to cardiomyocyte low proliferation or apoptosis. • The phenotype is due to specific defect in cardiomyocyte adhesion. - Abstract: Rac1, a member of the Rho subfamily of small GTPases, is involved in morphogenesis and differentiation of many cell types. Here we define a role of Rac1 in cardiac development by specifically deleting Rac1 in the pre-cardiac mesoderm using the Nkx2.5-Cre transgenic driver line. Rac1-conditional knockout embryos initiate heart development normally until embryonic day 11.5 (E11.5); their cardiac mesoderm is specified, and the heart tube is formed and looped. However, by E12.5-E13.5 the mutant hearts start failing and embryos develop edema and hemorrhage which is probably the cause for the lethality observed soon after. The hearts of Rac1-cKO embryos exhibit disorganized and thin myocardial walls and defects in outflow tract alignment. No significant differences of cardiomyocyte death or proliferation were found between developing control and mutant embryos. To uncover the role of Rac1 in the heart, E11.5 primary heart cells were cultured and analyzed in vitro. Rac1-deficient cardiomyocytes were less spread, round and loosely attached to the substrate and to each other implying that Rac1-mediated signaling is required for appropriate cell–cell and/or cellmatrix adhesion during cardiac development.

  8. Molecular Imaging of Human Embryonic Stem Cells Stably Expressing Human PET Reporter Genes After Zinc Finger Nuclease-Mediated Genome Editing.

    Science.gov (United States)

    Wolfs, Esther; Holvoet, Bryan; Ordovas, Laura; Breuls, Natacha; Helsen, Nicky; Schönberger, Matthias; Raitano, Susanna; Struys, Tom; Vanbilloen, Bert; Casteels, Cindy; Sampaolesi, Maurilio; Van Laere, Koen; Lambrichts, Ivo; Verfaillie, Catherine M; Deroose, Christophe M

    2017-10-01

    Molecular imaging is indispensable for determining the fate and persistence of engrafted stem cells. Standard strategies for transgene induction involve the use of viral vectors prone to silencing and insertional mutagenesis or the use of nonhuman genes. Methods: We used zinc finger nucleases to induce stable expression of human imaging reporter genes into the safe-harbor locus adeno-associated virus integration site 1 in human embryonic stem cells. Plasmids were generated carrying reporter genes for fluorescence, bioluminescence imaging, and human PET reporter genes. Results: In vitro assays confirmed their functionality, and embryonic stem cells retained differentiation capacity. Teratoma formation assays were performed, and tumors were imaged over time with PET and bioluminescence imaging. Conclusion: This study demonstrates the application of genome editing for targeted integration of human imaging reporter genes in human embryonic stem cells for long-term molecular imaging. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  9. Etude in vitro de la biohydrogénation ruminale des acides gras d'un mélange graine de colza - tourteau de colza et de la graine de soja chez la vache laitière : influence de l'extrusion

    OpenAIRE

    Eynard, Philippe

    2002-01-01

    La supplémentation de la ration des vaches laitières en matière grasse a non seulement un impact sur les performances laitières, mais aussi sur la composition des acides gras de la matière grasse du lait. Une ration riche en acides gras polyinsaturés à 18 carbones induit une augmentation des quantités d'acide linoléique conjugé, agent anticarcinogène, et de ses précurseurs dans le lait. L'acide linoléique conjugé et ses précurseurs sont des intermédiaires de biohydrogénation ruminale des acid...

  10. Reticulation des fibres lignocellulosiques

    Science.gov (United States)

    Landrevy, Christel

    Pour faire face à la crise économique la conception de papier à valeur ajoutée est développée par les industries papetières. Le but de se projet est l'amélioration des techniques actuelles de réticulation des fibres lignocellulosiques de la pâte à papier visant à produire un papier plus résistant. En effet, lors des réactions de réticulation traditionnelles, de nombreuses liaisons intra-fibres se forment ce qui affecte négativement l'amélioration anticipée des propriétés physiques du papier ou du matériau produit. Pour éviter la formation de ces liaisons intra-fibres, un greffage sur les fibres de groupements ne pouvant pas réagir entre eux est nécessaire. La réticulation des fibres par une réaction de « click chemistry » appelée cycloaddition de Huisgen entre un azide et un alcyne vrai, catalysée par du cuivre (CuAAC) a été l'une des solutions trouvée pour remédier à ce problème. De plus, une adaptation de cette réaction en milieux aqueux pourrait favoriser son utilisation en milieu industriel. L'étude que nous désirons entreprendre lors de ce projet vise à optimiser la réaction de CuAAC et les réactions intermédiaires (propargylation, tosylation et azidation) sur la pâte kraft, en milieu aqueux. Pour cela, les réactions ont été adaptées en milieu aqueux sur la cellulose microcristalline afin de vérifier sa faisabilité, puis transférée à la pâte kraft et l'influence de différents paramètres comme le temps de réaction ou la quantité de réactifs utilisée a été étudiée. Dans un second temps, une étude des différentes propriétés conférées au papier par les réactions a été réalisée à partir d'une série de tests papetiers optiques et physiques. Mots Clés Click chemistry, Huisgen, CuAAC, propargylation, tosylation, azidation, cellulose, pâte kraft, milieu aqueux, papier.

  11. Distinct gene expression signatures in human embryonic stem cells differentiated towards definitive endoderm at single-cell level

    DEFF Research Database (Denmark)

    Norrman, Karin; Strömbeck, Anna; Semb, Henrik

    2013-01-01

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

  12. Effet des techniques de conservation des eaux et des sols, zaï ...

    African Journals Online (AJOL)

    Effet des techniques de conservation des eaux et des sols, zaï forestier et cordons pierreux, sur la réhabilitation de la végétation herbacée à l'Ouest du Burkina Faso. ... et Loudetia arundinacea Hochst. ex Steud. dans les espaces aménagés. Ceci témoigne d'une restauration progressive de ces parcelles aménagées.

  13. Évaluation des pratiques agricoles des légumes feuilles : le cas des ...

    African Journals Online (AJOL)

    Objectif : La présente étude vise à évaluer les pratiques phytosanitaires des maraîchers et à fournir une meilleure connaissance des risques liés aux pratiques de ... Conclusion et application : La gestion et l'utilisation très peu rigoureuses des pesticides constatés dans ces sites pourraient constituer une menace pour le ...

  14. Low oxygen levels slow embryonic development of Limulus polyphemus

    DEFF Research Database (Denmark)

    Funch, Peter; Wang, Tobias; Pertoldi, Cino

    2016-01-01

    The American horseshoe crab Limulus polyphemus typically spawns in the upper intertidal zone, where the developing embryos are exposed to large variations in abiotic factors such as temperature, humidity, salinity, and oxygen, which affect the rate of development. It has been shown that embryonic...... development is slowed at both high and low salinities and temperatures, and that late embryos close to hatching tolerate periodic hypoxia. In this study we investigated the influence of hypoxia on both early and late embryonic development in L. polyphemus under controlled laboratory conditions. Embryos were...... pronounced hypoxia in later embryonic developmental stages, but also in earlier, previously unexplored, developmental stages....

  15. Prolactin modulates luteal activity in the short-nosed fruit bat, Cynopterus sphinx during delayed embryonic development.

    Science.gov (United States)

    Anuradha; Krishna, Amitabh

    2017-07-01

    The aim of this study was to evaluate the role of prolactin as a modulator of luteal steroidogenesis during the period of delayed embryonic development in Cynopterus sphinx. A marked decline in circulating prolactin levels was noted during the months of November through December coinciding with the period of decreased serum progesterone and delayed embryonic development. The seasonal changes in serum prolactin levels correlated positively with circulating progesterone (P) level, but inversely with circulating melatonin level during first pregnancy showing delayed development in Cynopterus sphinx. The results also showed decreased expression of prolactin receptor-short form (PRL-RS) both in the corpus luteum and in the utero-embryonic unit during the period of delayed embryonic development. Bats treated in vivo with prolactin during the period of delayed development showed significant increase in serum progesterone and estradiol levels together with significant increase in the expression of PRL-RS, luteinizing hormone receptor (LH-R), steroidogenic acute receptor protein (STAR) and 3β-hydroxysteroid dehydrogenase (3β-HSD) in the ovary. Prolactin stimulated ovarian angiogenesis (vascular endothelial growth factor) and cell survival (B-cell lymphoma 2) in vivo. Significant increases in ovarian progesterone production and the expression of prolactin-receptor, LH-R, STAR and 3β-HSD proteins were noted following the exposure of LH or prolactin in vitro during the delayed period. In conclusion, short-day associated increased melatonin level may be responsible for decreased prolactin release during November-December. The decline in prolactin level might play a role in suppressing P and estradiol-17β (E2) estradiol levels thereby causing delayed embryonic development in C. sphinx. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Diversification des moyens de subsistance des petits producteurs de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    L'économie du Malawi repose essentiellement sur la culture du tabac, qui représente plus de 70 % des revenus d'exportation. Pour 60 % des 100 000 membres de la National Smallholder Farmers' Association of Malawi (NASFAM), le tabac est la seule et unique source de revenus. Les cultivateurs de tabac, au Malawi ...

  17. Meconnaissance des traumatismes des voies urinaires dans un ...

    African Journals Online (AJOL)

    Meconnaissance des traumatismes des voies urinaires dans un contexte de poly traumatisme: a propos de deux observations. ... They insist on good clinical assessment of abdominal trauma doubled the achievement of imaging tests to not overlook lesions of the urinary tract that can put patient's life threatening. Keywords: ...

  18. Roles et taches des accompagnateurs des patients hospitalises ...

    African Journals Online (AJOL)

    Le soutien logistique represente par le soutien materiel, l'approvisionnement en medicaments, le nettoyage des locaux, le brancardage, occupaient des taux respectifs de 100 %, 91 %, 42% et 73 %. La sollicitation fmanciere et le soutien psychologique de 1' accompagnateur ont ete soulignes respectivement dans 68 % et ...

  19. Establishment of goat embryonic stem cells from in vivo produced blastocyst-stage embryos.

    Science.gov (United States)

    Behboodi, E; Bondareva, A; Begin, I; Rao, K; Neveu, N; Pierson, J T; Wylie, C; Piero, F D; Huang, Y J; Zeng, W; Tanco, V; Baldassarre, H; Karatzas, C N; Dobrinski, I

    2011-03-01

    Embryonic stem (ES) cells with the capacity for germ line transmission have only been verified in mouse and rat. Methods for derivation, propagation, and differentiation of ES cells from domestic animals have not been fully established. Here, we describe derivation of ES cells from goat embryos. In vivo-derived embryos were cultured on goat fetal fibroblast feeders. Embryos either attached to the feeder layer or remained floating and expanded in culture. Embryos that attached showed a prominent inner cell mass (ICM) and those that remained floating formed structures resembling ICM disks surrounded by trophectodermal cells. ICM cells and embryonic disks were isolated mechanically, cultured on feeder cells in the presence of hLIF, and outgrown into ES-like colonies. Two cell lines were cultured for 25 passages and stained positive for alkaline phosphatase, POU5F1, NANOG, SOX2, SSEA-1, and SSEA-4. Embryoid bodies formed in suspension culture without hLIF. One cell line was cultured for 2 years (over 120 passages). This cell line differentiated in vitro into epithelia and neuronal cells, and could be stably transfected and selected for expression of a fluorescent marker. When cells were injected into SCID mice, teratomas were identified 5-6 weeks after transplantation. Expression of known ES cell markers, maintenance in vitro for 2 years in an undifferentiated state, differentiation in vitro, and formation of teratomas in immunodeficient mice provide evidence that the established cell line represents goat ES cells. This also is the first report of teratoma formation from large animal ES cells. Copyright © 2011 Wiley-Liss, Inc.

  20. Etude des niches alimentaires des lombriciens dans un contexte urbain.

    OpenAIRE

    Diemby, Marie Virginie

    2005-01-01

    Dans ce travail, les préférences alimentaires pour les espèces végétales consommées par les lombriciens peuplant certains îlots des pelouses de l’avenue Roosevelt ont été étudiées. L’analyse des contenus digestifs et des fèces des vers a montré que les plantes identifiées dans les pelouses ne sont pas toutes consommées. Mesurée par l’indice d’Ivlev, la sélectivité des items végétaux est variable en fonction de l’espèce de ver, de la classe d’âge et de la saison. Lorsque les dicotylédones s...

  1. ESSA1 embryonic stem like cells from gilthead seabream: a new tool to study mesenchymal cell lineage differentiation in fish.

    Science.gov (United States)

    Parameswaran, Vijayakumar; Laizé, Vincent; Gavaia, Paulo J; Leonor Cancela, M

    2012-10-01

    Embryonic stem (ES) cells are a promising tool for generation of transgenic animals and an ideal experimental model for in vitro studies of embryonic cell development, differentiation and gene manipulation. Here we report the development and initial characterization of a pluripotent embryonic stem like cell line, designated as ESSA1, derived from blastula stage embryos of the gilthead seabream (Sparus aurata, L). ESSA1 cells are cultured in Leibovitz's L-15 medium supplemented with 5% fetal bovine serum and, unlike other ES cells, without a feeder layer. They have a round or polygonal morphology, grow exponentially in culture and form dense colonies. ESSA1 cells also exhibit intense alkaline phosphatase activity, normal karyotype and are positive for stage-specific embryonic antigen-1 (SSEA1) and octamer-binding transcription factor 4 (Oct4) markers for up to 30 passages. Upon treatment with all-trans retinoic acid, ESSA1 cells differentiate into neuron-like, oligodendritic, myocyte and melanocyte cells; they can also form embryoid bodies when seeded in bacteriological plates, a characteristic usually associated with pluripotency. The capacity of ESSA1 cells to differentiate into osteoblastic, chondroblastic or osteoclastic cell lineages and to produce a mineralized extracellular matrix in vitro was demonstrated through histochemical techniques and further confirmed by immunocytochemistry using lineage-specific markers. Furthermore, ESSA1 cells can be used to produce chimera, where they contribute to the development of a variety of tissues including the trunk and gut of zebrafish embryos and fry. Thus, ESSA1 cells represent a promising model for investigating bone-lineage cell differentiation in fish and also highlight the potential of piscine stem cell research. Copyright © 2012 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.

  2. Evolution of embryonic development in nematodes

    Directory of Open Access Journals (Sweden)

    Schulze Jens

    2011-09-01

    Full Text Available Abstract Background Nematodes can be subdivided into basal Enoplea (clades 1 and 2 and more derived Chromadorea (clades 3 to 12. Embryogenesis of Caenorhabditis elegans (clade 9 has been analyzed in most detail. Their establishment of polarity and asymmetric cleavage requires the differential localization of PAR proteins. Earlier studies on selected other nematodes revealed that embryonic development of nematodes is more diverse than the essentially invariant development of C. elegans and the classic study object Ascaris had suggested. To obtain a more detailed picture of variations and evolutionary trends we compared embryonic cell lineages and pattern formation in embryos of all 12 nematode clades. Methods The study was conducted using 4-D microscopy and 3-D modeling of developing embryos. Results We found dramatic differences compared to C. elegans in Enoplea but also considerable variations among Chromadorea. We discovered 'Polarity Organizing Centers' (POCs that orient cleavage spindles along the anterior-posterior axis in distinct cells over consecutive cell generations. The resulting lineally arranged blastomeres represent a starting point for the establishment of bilateral symmetry within individual lineages. We can discern six different early cleavage types and suggest that these variations are due to modifications in the activity of the POCs in conjunction with changes in the distribution of PAR proteins. In addition, our studies indicate that lineage complexity advanced considerably during evolution, that is we observe trends towards an increase of somatic founder cells, from monoclonal to polyclonal lineages and from a variable (position-dependent to an invariable (lineage-dependent way of cell fate specification. In contrast to the early phase of embryogenesis, the second half ('morphogenesis' appears similar in all studied nematodes. Comparison of early cleavage between the basal nematode Tobrilus stefanskii and the tardigrade

  3. 212 Analyse de la dynamique des pâturages autour des ouvrages ...

    African Journals Online (AJOL)

    Ali B. Béchir

    ils ont permis de lever les contraintes qui empêchent leur exploitation en saison sèche. Toutefois, leur ... permettre l'exploitation des pâturages pendant la saison sèche, plusieurs puits pastoraux y ont été installés depuis des ... des plaines, des chaines de montagnes, des ravins, des dunes et des bas-fonds. Les sols sont ...

  4. Caracteristiques microbiologiques des peritonites aigues ...

    African Journals Online (AJOL)

    Dans notre serie, une sensibilire plus elevee des germes ala gentamicine, ala ceftriaxone eta la Ciprofloxacine a ere notee. Ces resultats suggerent une antibiotherapie probabiliste des peritonites dans notre contexte associant les cephalosporines de troisieme generation (C3G) aux aminosides plus un imidazole pour ...

  5. Philosophie des Protestantismus: Immanuel Kant

    OpenAIRE

    Graf, Friedrich W. (Prof.)

    1990-01-01

    Philosophie des Protestantismus: Immanuel Kant : 1724-1804 / Friedrich Wilhelm Graf u. Klaus Tanner. - In: Profile des neuzeitlichen Protestantismus / hrsg. von Friedrich Wilhelm Graf. - Gütersloh : Mohn. - Bd. 1. Aufklärung, Idealismus, Vormärz. - 1990. - S. 86-112. - (Gütersloher Taschenbücher Siebenstern ; 1430)

  6. Human Embryonic Stem Cell Research Debates: A Confucian Argument

    National Research Council Canada - National Science Library

    D. F.-C. Tsai

    2005-01-01

    Human embryonic stem cell research can bring about major biomedical breakthroughs and thus contribute enormously to human welfare, yet it raises serious moral problems because it involves using human...

  7. Embryonic adaptations and nutrition in the viviparous teleost Clinus ...

    African Journals Online (AJOL)

    Perciformes: Clinidae) ... extensive embryonic adaptations for the uptake of nutrients secreted by the follicular epithelium. Specialized ..... Cellular surface projections in C. dorsalis are virtually confined to the pericardial region of the embryo and ...

  8. Graphene for enhanced embryonic stem cell photo-transfection efficiency

    CSIR Research Space (South Africa)

    Mthunzi, P

    2013-04-01

    Full Text Available Due to their pluripotency properties, embryonic stem (ES) cells possess great potential in regenerative therapy. Since reported a promising tissue engineering scaffold material, here, graphene is demonstrated to significantly improve the ES cell...

  9. PROFILS IMMUNOLOGIQUES DES PATHOLOGIES ...

    African Journals Online (AJOL)

    L'échantillonnage a été réalisé en fonction du système d'élevage (battérie ou sol) et des classes d'âge. Au sujet de la prévalence ... Despite the fact that some breeding haven't been infected and of which the set title is zero, some birds on the contrary revealed 21720 for AE, 25342 for REO and 19990 for AIV.The result of ...

  10. Die Versprachlichung des Sakralen

    DEFF Research Database (Denmark)

    Larsen, Øjvind

    2011-01-01

    in religion and which is of fundamental significance for the integration of pre-modern societies is taken over by modern societies in forms of deliberation. Habermas develops his thesis in a discussion of Durkheim’s religious-sociological considerations. Habermas presents his thesis about the linguistic......Habermas claims in connection with his development of the theory of communicative action that the sacred is transformed in a positive way and can take the form of free deliberation in society, the so-called Versprachlichung des Sakralen. The thesis is that the authority which could be found...

  11. The liberation of embryonic stem cells.

    Directory of Open Access Journals (Sweden)

    Kathryn Blair

    2011-04-01

    Full Text Available Mouse embryonic stem (ES cells are defined by their capacity to self-renew and their ability to differentiate into all adult tissues including the germ line. Along with efficient clonal propagation, these properties have made them an unparalleled tool for manipulation of the mouse genome. Traditionally, mouse ES (mES cells have been isolated and cultured in complex, poorly defined conditions that only permit efficient derivation from the 129 mouse strain; genuine ES cells have not been isolated from another species in these conditions. Recently, use of small molecule inhibitors of glycogen synthase kinase 3 (Gsk3 and the Fgf-MAPK signaling cascade has permitted efficient derivation of ES cells from all tested mouse strains. Subsequently, the first verified ES cells were established from a non-mouse species, Rattus norvegicus. Here, we summarize the advances in our understanding of the signaling pathways regulating mES cell self-renewal that led to the first derivation of rat ES cells and highlight the new opportunities presented for transgenic modeling on diverse genetic backgrounds. We also comment on the implications of this work for our understanding of pluripotent stem cells across mammalian species.

  12. Microglia Modulate Wiring of the Embryonic Forebrain

    Directory of Open Access Journals (Sweden)

    Paola Squarzoni

    2014-09-01

    Full Text Available Dysfunction of microglia, the tissue macrophages of the brain, has been associated with the etiology of several neuropsychiatric disorders. Consistently, microglia have been shown to regulate neurogenesis and synaptic maturation at perinatal and postnatal stages. However, microglia invade the brain during mid-embryogenesis and thus could play an earlier prenatal role. Here, we show that embryonic microglia, which display a transiently uneven distribution, regulate the wiring of forebrain circuits. Using multiple mouse models, including cell-depletion approaches and cx3cr1−/−, CR3−/−, and DAP12−/− mutants, we find that perturbing microglial activity affects the outgrowth of dopaminergic axons in the forebrain and the laminar positioning of subsets of neocortical interneurons. Since defects in both dopamine innervation and cortical networks have been linked to neuropsychiatric diseases, our study provides insights into how microglial dysfunction can impact forebrain connectivity and reveals roles for immune cells during normal assembly of brain circuits.

  13. Ovarian Embryonal Carcinoma in a Dog.

    Science.gov (United States)

    Banco, B; Ferrari, R; Stefanello, D; Groppetti, D; Pecile, A; Faverzani, S; Longo, M; Zani, D D; Ravasio, G; Caniatti, M; Grieco, V

    2017-11-01

    A 17-month-old female doberman pinscher was referred for an abdominal mass and ascites. Exploratory laparotomy revealed the presence of a large neoplastic mass replacing the right ovary and associated with multiple mesovarian, mesometrial and peritoneal nodules. An ovariohysterectomy was performed. Grossly, the tumour was soft and multilocular with large areas of haemorrhage and necrosis. Microscopically, it was infiltrative and composed of round and polygonal cells arranged respectively in solid sheets or forming distorted tubular structures separated by thick fibrovascular septae. Tubules contained necrotic debris, proteinaceous fluid or small endoluminal papillary structures. Marked cellular atypia, multiple neoplastic emboli and high mitotic count were observed. Immunohistochemically, the round cells uniformly expressed placental alkaline phosphatase, while the polygonal cells arranged in tubules and papillae expressed cytokeratin (CK) AE1/AE3 and CK7. A final diagnosis of metastasizing ovarian embryonal carcinoma (EC), a primitive germ cell tumour characterized by rudimentary epithelial differentiation was made. Canine ovarian EC should be considered as a differential diagnosis for undifferentiated aggressive ovarian tumours in young dogs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Évaluation échographique des complications au premier trimestre de grossesse.

    Science.gov (United States)

    Morin, Lucie; Cargill, Yvonne M; Glanc, Phyllis

    2016-10-01

    RéSULTATS: SOURCES DE DONNéES: Nous avons effectué des recherches dans MEDLINE et un examen de la bibliographie des articles recensés. Le Comité d'imagerie diagnostique de la Société des obstétriciens et gynécologues du Canada a passé en revue les données probantes recueillies. Les recommandations reposent sur les lignes directrices élaborées par le Groupe d'étude canadien sur les soins de santé préventifs (tableau 1). AVANTAGES, DéSAVANTAGES ET COûTS: Les femmes qui présentent des saignements durant le premier trimestre peuvent recevoir un diagnostic incorrect d'avortement manqué. En outre, on risque de ne pas détecter une grossesse ectopique ou de les rassurer à tort sur la viabilité de l'embryon. L'amélioration de la détection des repères échographiques du développement embryonnaire normal et de la connaissance des facteurs de risque liés à l'échec de grossesse sur le plan échographique pourrait donner lieu à l'élaboration de stratégies de prise en charge mieux adaptées à chaque cas. Le diagnostic d'une grossesse ectopique suspectée repose souvent sur l'évaluation de marqueurs hormonaux et de caractéristiques échographiques. Par ailleurs, le diagnostic précoce de grossesse ectopique peut réduire la morbidité et la mortalité maternelles. RECOMMANDATIONS. Copyright © 2016 The Society of Obstetricians and Gynaecologists of Canada/La Société des obstétriciens et gynécologues du Canada. Published by Elsevier Inc. All rights reserved.

  15. Des hommes incomplets à Java

    OpenAIRE

    Headley, Stephen C.

    2005-01-01

    Les mythes des personnes incomplètes à Java décrivent leur naissance, la nourriture spéciale qui leur est donnée et la façon dont ils se sont rassemblés. Présentés dans une première partie, ces mythes concernent : un roi et son royaume (Jarasanda) ; un demi-dieu mangeur d’hommes (Kala) ; la déesse du riz (Sri) ; des femmes fécondées par des météores ; des fils qui cherchent leur père Allah. Dans la seconde partie, les mythes des moitiés d’hommes sont abordés dans leurs variations balinaise, m...

  16. Embryonic miRNA Profiles of Normal and Ectopic Pregnancies

    OpenAIRE

    Dominguez, Francisco; Moreno-Moya, Juan Manuel; Lozoya, Teresa; Romero, Ainhoa; Martínez, Sebastian; Monterde, Mercedes; Gurrea, Marta; Ferri, Blanca; Núñez, Maria Jose; Simón, Carlos; Pellicer, Antonio

    2014-01-01

    Our objective was to investigate the miRNA profile of embryonic tissues in ectopic pregnancies (EPs) and controlled abortions (voluntary termination of pregnancy; VTOP). Twenty-three patients suffering from tubal EP and twenty-nine patients with a normal ongoing pregnancy scheduled for a VTOP were recruited. Embryonic tissue samples were analyzed by miRNA microarray and further validated by real time PCR. Microarray studies showed that four miRNAs were differentially downregulated (hsa-mir-19...

  17. A Focused Microarray for Screening Rat Embryonic Stem Cell Lines

    OpenAIRE

    Hong, James; He, Hong; Bui, Phuoc; Ryba-White, Ben; Rumi, Mohammad A.K.; Soares, Michael J.; Dutta, Debasree; Paul, Soumen; Kawamata, Masaki; Ochiya, Takahiro; Ying, Qi-Long; Rajanahalli, Pavan; Mark L. Weiss

    2012-01-01

    Here, we describe a focused microarray for screening rat embryonic stem cells (ESCs) and provide validation data that this array can distinguish undifferentiated rat ESCs from rat trophoblast stem (TS) cells, rat extraembryonic endoderm cells, mouse embryonic fibroblast feeder cells, and differentiated rat ESCs. Using this tool, genuine rat ESC lines, which have been expanded in a conventional rat ESC medium containing two inhibitors (2i), for example, glycogen synthase kinase 3 (GSK3) and mi...

  18. Embryonic epigenetic reprogramming by a pioneer transcription factor in plants.

    Science.gov (United States)

    Tao, Zeng; Shen, Lisha; Gu, Xiaofeng; Wang, Yizhong; Yu, Hao; He, Yuehui

    2017-11-02

    Epigenetic modifications, including chromatin modifications and DNA methylation, have a central role in the regulation of gene expression in plants and animals. The transmission of epigenetic marks is crucial for certain genes to retain cell lineage-specific expression patterns and maintain cell fate. However, the marks that have accumulated at regulatory loci during growth and development or in response to environmental stimuli need to be deleted in gametes or embryos, particularly in organisms such as plants that do not set aside a germ line, to ensure the proper development of offspring. In Arabidopsis thaliana, prolonged exposure to cold temperatures (winter cold), in a process known as vernalization, triggers the mitotically stable epigenetic silencing of the potent floral repressor FLOWERING LOCUS C (FLC), and renders plants competent to flower in the spring; however, this silencing is reset during each generation. Here we show that the seed-specific transcription factor LEAFY COTYLEDON1 (LEC1) promotes the initial establishment of an active chromatin state at FLC and activates its expression de novo in the pro-embryo, thus reversing the silenced state inherited from gametes. This active chromatin state is passed on from the pro-embryo to post-embryonic life, and leads to transmission of the embryonic memory of FLC activation to post-embryonic stages. Our findings reveal a mechanism for the reprogramming of embryonic chromatin states in plants, and provide insights into the epigenetic memory of embryonic active gene expression in post-embryonic phases, through which an embryonic factor acts to 'control' post-embryonic development processes that are distinct from embryogenesis in plants.

  19. Utilisation sans risque des eaux usées, des excréta et des eaux ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Les responsables de ce projet piloteront l'application et l'adaptation des principes directeurs relatifs à l'utilisation sans risque des eaux usées, des excreta et des eaux grises en agriculture et en aquaculture (Guidelines for the Safe Use of Wastewater, Excreta and Greywater in Agriculture and Aquaculture), que ...

  20. Sertad1 encodes a novel transcriptional co-activator of SMAD1 in mouse embryonic hearts

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Yin [Department of Genetics, The University of Alabama at Birmingham, Birmingham, AL 35294 (United States); Zhao, Shaomin [Department of Genetics, The University of Alabama at Birmingham, Birmingham, AL 35294 (United States); School of Traditional Chinese Medicine, Capital Medical University, Beijing 100069 (China); Song, Langying [Department of Genetics, The University of Alabama at Birmingham, Birmingham, AL 35294 (United States); Wang, Manyuan [School of Traditional Chinese Medicine, Capital Medical University, Beijing 100069 (China); Jiao, Kai, E-mail: kjiao@uab.edu [Department of Genetics, The University of Alabama at Birmingham, Birmingham, AL 35294 (United States)

    2013-11-29

    Highlights: •SERTAD1 interacts with SMAD1. •Sertad1 is expressed in mouse embryonic hearts. •SERTAD1 is localized in both cytoplasm and nucleus of cardiomyocytes. •SERTAD1 enhances expression of BMP target cardiogenic genes as a SMAD1 co-activator. -- Abstract: Despite considerable advances in surgical repairing procedures, congenital heart diseases (CHDs) remain the leading noninfectious cause of infant morbidity and mortality. Understanding the molecular/genetic mechanisms underlying normal cardiogenesis will provide essential information for the development of novel diagnostic and therapeutic strategies against CHDs. BMP signaling plays complex roles in multiple cardiogenic processes in mammals. SMAD1 is a canonical nuclear mediator of BMP signaling, the activity of which is critically regulated through its interaction partners. We screened a mouse embryonic heart yeast two-hybrid library using Smad1 as bait and identified SERTAD1 as a novel interaction partner of SMAD1. SERTAD1 contains multiple potential functional domains, including two partially overlapping transactivation domains at the C terminus. The SERTAD1-SMAD1 interaction in vitro and in mammalian cells was further confirmed through biochemical assays. The expression of Sertad1 in developing hearts was demonstrated using RT-PCR, western blotting and in situ hybridization analyses. We also showed that SERTAD1 was localized in both the cytoplasm and nucleus of immortalized cardiomyocytes and primary embryonic cardiomyocyte cultures. The overexpression of SERTAD1 in cardiomyocytes not only enhanced the activity of two BMP reporters in a dose-dependent manner but also increased the expression of several known BMP/SMAD regulatory targets. Therefore, these data suggest that SERTAD1 acts as a SMAD1 transcriptional co-activator to promote the expression of BMP target genes during mouse cardiogenesis.

  1. Inhibition of polyamine synthesis causes entry of the mouse blastocyst into embryonic diapause.

    Science.gov (United States)

    Fenelon, Jane C; Murphy, Bruce D

    2017-07-01

    Embryonic diapause is a common reproductive strategy amongst mammals, requiring an intimate cross-talk between the endometrium and the blastocyst. To date, the precise molecular signals responsible are unknown in the mouse or any other mammal. Previous studies in the mink implicate polyamines as major regulators of the control of diapause. In the mouse, inhibiting the rate-limiting enzyme of polyamine synthesis, ornithine decarboxylase (ODC1) during early pregnancy largely prevents implantation, but the fate of the nonimplanted embryos is unknown. To determine whether polyamines control mouse embryonic diapause, we treated pregnant mice with an ODC1 inhibitor from d3.5 to d6.5 postcoitum. At d7.5, 72% of females had no signs of implantation whilst the remaining females exhibited disrupted placental formation and degenerate embryos. In the females with no implantation, we obtained viable blastocysts that had attenuated cell proliferation, indicating a state of diapause. When cultured in vitro, these exhibited trophoblast outgrowth, indicative of reactivation of embryogenesis. In contrast, direct culture of d3.5 blastocysts with an ODC1 inhibitor failed to cause entry into diapause. Examination of the polyamine pathway enzymes and a number of implantation factors indicated inhibition of ODC1 resulted in a uterine phenotype that resembled diapause, with some compensatory increases in crucial genes. Thus, we conclude that an absence or paucity of polyamines induces the uterine quiescence that causes entry of the blastocyst into embryonic diapause. © The Authors 2017. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. The impact of caffeine on connexin expression in the embryonic chick cardiomyocyte micromass culture system.

    Science.gov (United States)

    Ahir, Bhavesh K; Pratten, Margaret K

    2016-07-01

    Cardiomyocytes are electrically coupled by gap junctions, defined as clusters of low-resistance multisubunit transmembrane channels composed of connexins (Cxs). The expression of Cx40, Cx43 and Cx45, which are present in cardiomyocytes, is known to be developmentally regulated. This study investigates the premise that alterations in gap junction proteins are one of the mechanisms by which teratogens may act. Specifically, those molecules known to be teratogenic in humans could cause their effects via disruption of cell-to-cell communication pathways, resulting in an inability to co-ordinate tissue development. Caffeine significantly inhibited contractile activity at concentrations above and including 1500 μm (P cell viability and total protein, in the embryonic chick cardiomyocyte micromass culture system. The effects of caffeine on key cardiac gap junction protein (Cx40, Cx43 and Cx45) expression were analysed using immunocytochemistry and in-cell Western blotting. The results indicated that caffeine altered the expression pattern of Cx40, Cx43 and Cx45 at non-cytotoxic concentrations (≥2000 μm), i.e., at concentrations that did not affect total cell protein and cell viability. In addition the effects of caffeine on cardiomyocyte formation and function (contractile activity score) were correlated with modulation of Cxs (Cx40, Cx43 and Cx45) expression, at above and including 2000 μm caffeine concentrations (P < 0.05). These experiments provide evidence that embryonic chick cardiomyocyte micromass culture may be a useful in vitro method for mechanistic studies of perturbation of embryonic heart development. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  3. Alternatively spliced tissue factor is not sufficient for embryonic development.

    Directory of Open Access Journals (Sweden)

    Susanna H M Sluka

    Full Text Available Tissue factor (TF triggers blood coagulation and is translated from two mRNA splice isoforms, encoding membrane-anchored full-length TF (flTF and soluble alternatively-spliced TF (asTF. The complete knockout of TF in mice causes embryonic lethality associated with failure of the yolk sac vasculature. Although asTF plays roles in postnatal angiogenesis, it is unknown whether it activates coagulation sufficiently or makes previously unrecognized contributions to sustaining integrity of embryonic yolk sac vessels. Using gene knock-in into the mouse TF locus, homozygous asTF knock-in (asTFKI mice, which express murine asTF in the absence of flTF, exhibited embryonic lethality between day 9.5 and 10.5. Day 9.5 homozygous asTFKI embryos expressed asTF protein, but no procoagulant activity was detectable in a plasma clotting assay. Although the α-smooth-muscle-actin positive mesodermal layer as well as blood islands developed similarly in day 8.5 wild-type or homozygous asTFKI embryos, erythrocytes were progressively lost from disintegrating yolk sac vessels of asTFKI embryos by day 10.5. These data show that in the absence of flTF, asTF expressed during embryonic development has no measurable procoagulant activity, does not support embryonic vessel stability by non-coagulant mechanisms, and fails to maintain a functional vasculature and embryonic survival.

  4. Évaluation des pratiques agricoles des légumes feuilles : le cas des ...

    African Journals Online (AJOL)

    SARAH

    30 sept. 2017 ... l'État serait l'initiation de programmes de sensibilisation des producteurs par rapport à une gestion plus rigoureuse des pesticides. Mots-clés : pratiques paysannes, cultures maraîchères, pesticides, risques, Burkina Faso. Evaluation of farming practices of leafy vegetables: the case of uses of pesticides and ...

  5. Le silence des agneaux

    Directory of Open Access Journals (Sweden)

    BERNARD ROY

    2012-01-01

    Full Text Available Ce texte est avant tout une réflexion sur la notion d'obéissance, initiée à partir de deux évènements impliquant étroitement des membres de la profession infirmière. L'auteur se réjouit de la prise de parole et de l'implication directe d'infirmières dans le contexte du printemps érable. Il estime que la posture de ces infirmières s'inscrit dans ce que l'éthicien Guy Durand, appelle une obéissance autonome qui peut, du coup, mener à la désobéissance civile, à l'objection de conscience. En prenant exemple sur le silence des infirmières dans le contexte de la fermeture de postes d'infirmières en Minganie, l'auteur estime que cette posture est marginale chez les infirmières qui, majoritairement, adoptent une position de soumission et d'obéissance hétéronome.

  6. Chirurgie des grassmanniennes

    CERN Document Server

    Lafforgue, Laurent

    2003-01-01

    Les compactifications diverses de variétés de modules sont un thème important et récurrent des mathématiques modernes, et elles connaissent un grand nombre d'applications. Ce livre traite le cas de cellules de Schubert minces, qui sont de sous-variétés naturelles de grassmanniennes. L'auteur a été amené à traiter ces questions par un cas particulier lié à ses travaux sur le programme de Langlands. Dans cette monographie, il en développe une théorie plus systématique, présentant le fortes similarités avec celle des modules du courbes stables. The various compactifications of moduli spaces are an important recurrent theme of modern mathematics, and they have a large number of applications. This book treats the case of thin Schubert varieties, which are natural subvarieties of Grassmannians. The author was led to these questions by a particular case linked to his work on the Langlands program. In this monograph, he develops the theory in a more systematic way, which exhibits strong similarities...

  7. Mécanique des sols et des roches

    CERN Document Server

    Vullier, Laurent; Zhao, Jian

    2016-01-01

    La mécanique des sols et la mécanique des roches sont des disciplines généralement traitées séparément dans la littérature. Pour la première fois, un traité réunit ces deux spécialités, en intégrant également les connaissances en lien avec les écoulements souterrains et les transferts thermiques. A la fois théorique et pratique, cet ouvrage propose tout d'abord une description détaillée de la nature et de la composition des sols et des roches, puis s'attache à la modélisation de problèmes aux conditions limites et présente les essais permettant de caractériser les sols et les roches, tant d'un point de vue mécanique qu'hydraulique et thermique. La problématique des sols non saturés et des écoulements multiphasiques est également abordée. Une attention particulière est portée aux lois de comportement mécanique et à la détermination de leurs paramètres par des essais in situ et en laboratoire, et l'ouvrage offre également une présentation détaillée des systèmes de classi...

  8. Agent des projets et des partenariats (h/f) | CRDI - Centre de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Gestion de projets. L'agent(e) : fournit un encadrement technique, notamment en analysant les rapports d'étape, en participant à des ateliers, en effectuant des recherches documentaires, en trouvant et dirigeant des personnes-ressources et des consultants afin d'appuyer des projets;. passe en revue les rapports finaux ...

  9. Contamination des eaux souterraines par le lixiviat des décharges ...

    African Journals Online (AJOL)

    La percolation du lixiviat en provenance des dechets des decharges constitue une source de pollution des ressources en eau souterraine par infiltration, constituant ... un modele type de deterioration des ressources en eaux par un effet de contamination du lixiviat en provenance de la decharge et des pratiques agricoles.

  10. Effets comparés des pratiques paysannes et des bonnes pratiques ...

    African Journals Online (AJOL)

    Effets comparés des pratiques paysannes et des bonnes pratiques agricoles de gestion de la fertilité des sols sur les propriétés des sols et les rendements des cultures dans la zone sud soudanienne du Burkina Faso.

  11. Gestion des ressources naturelles : des solutions avantageuses à ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Des variétés résistantes de bambou et de rotin au coeur d'un renouveau environnemental. En Asie, en Afrique et en Amérique latine, des initiatives de premier plan axées sur le bambou et le rotin permettent de contrer le réchauffement de la planète, d'enrayer l'érosion des sols, de protéger les forêts et d'améliorer l'accès ...

  12. Gestion des dechets biomedicaux a cotonou : Etat des lieux et ...

    African Journals Online (AJOL)

    La présente recherche est une contribution à la bonne gestion des déchets biomédicaux dans la ville de Cotonou. La démarche méthodologique utilisée comprend l'observation directe sur le terrain, la collecte des données, leur traitement et l'analyse des résultats. L'enquête socio-anthropologique a été menée en utilisant ...

  13. LA PARTICIPATION DES POPULATIONS ANALPHABETES A L ...

    African Journals Online (AJOL)

    La planification a été, pendant longtemps, l'oeuvre des structures d'intervention et dans une moindre mesure des populations rurales lettrées. C'est dans le souci de combler cette insuffisance que nous avons choisi, dans le cadre des planifications sectorielles, de travailler dans un secteur dominé par des analphabètes.

  14. Mycotrophie Et Connaissances Paysannes Des Essences ...

    African Journals Online (AJOL)

    Une comparaison des modes de gestion des terres au Sud Cameroun montre que les agroforêts-cacao sont moins dommageables à l'environnement que les autres formes de gestion des sols. A cet effet, une étude en vue de valider les perceptions paysannes des essences ligneuses fertilitaires associées dans les ...

  15. Mechanosensitivity of Embryonic Neurites Promotes Their Directional Extension and Schwann Cells Progenitors Migration

    Directory of Open Access Journals (Sweden)

    Gonzalo Rosso

    2017-11-01

    Full Text Available Background/Aims: Migration of Schwann cells (SCs progenitors and neurite outgrowth from embryonic dorsal root ganglions (DRGs are two central events during the development of the peripheral nervous system (PNS. How these two enthralling events preceding myelination are promoted is of great relevance from basic research and clinical aspects alike. Recent evidence demonstrates that biophysical cues (extracellular matrix stiffness and biochemical signaling act in concert to regulate PNS myelination. Microenvironment stiffness of SCs progenitors and embryonic neurites dynamically changes during development. Methods: DRG explants were isolated from day 12.5 to 13.5 mice embryos and plated on laminin-coated substrates with varied stiffness values. After 4 days in culture and immunostaining with specific markers, neurite outgrowth pattern, SCs progenitors migration, and growth cone shape and advance were analyzed with confocal fluorescence microscopy. Results: We found out that growing substrate stiffness promotes directional neurite outgrowth, SCs progenitors migration, growth cone advance and presumably axons fasciculation. Conclusions: DRG explants are in vitro models for the research of PNS development, myelination and regeneration. Consequently, we conclude the following: Our observations point out the importance of mechanosensitivity for the PNS. At the same time, they prompt the investigation of the important yet unclear links between PNS biomechanics and inherited neuropathies with myelination disorders such as Charcot-Marie-Tooth 1A and hereditary neuropathy with liability to pressure palsies. Finally, they encourage the consideration of mechanosensitivity in bioengineering of scaffolds to aid nerve regeneration after injury.

  16. Effect of Dipeptides on Maturation, Fertilization and Subsequent Embryonic Development of Porcine Oocytes

    Directory of Open Access Journals (Sweden)

    K. M. A. Tareq

    2013-04-01

    Full Text Available The effects of amino acids and dipeptides on in vitro production of porcine embryos and accumulation of ammonia in culture medium during developmental stages were examined in this study. The maturation, fertilization and development of embryonic cultures were performed in modified Tissue culture medium (mTCM-199 supplemented with 10% (v/v porcine follicular fluid, modified Tyrode’s albumin lactate pyruvate (mTALP medium, and modified North Carolina State University (mNCSU-23 medium, respectively. In addition, amino acids and dipeptides of different concentrations and combinations were used to treat the embryos. The addition of L-alanyl-L-glutamine (AlnGln+L-glycyl-L-glutamine (GlyGln significantly (p<0.05 improved oocyte maturation, fertilization and the incorporation and oxidation of 14C(U-glucose when compared to the control group and other treatment groups. Additionally, 2–4 cell, 8–16 cell, morula and blastocyst development increased significantly (p<0.05 following treatment with AlnGln+GlyGln when compared to the control group and other treatment groups, while this treatment reduced the accumulation of ammonia. Taken together, these findings suggest that treatment with AlnGln+GlyGln may play an important role in increasing the rate of porcine oocyte maturation, fertilization and embryonic development by reducing the level of accumulated ammonia measured in the culture media.

  17. Characterization and comparison of embryonic stem cell-derived KDR+ cells with endothelial cells.

    Science.gov (United States)

    Sun, Xuan; Cheng, Lamei; Duan, Huaxin; Lin, Ge; Lu, Guangxiu

    2012-09-01

    Growing interest in utilizing endothelial cells (ECs) for therapeutic purposes has led to the exploration of human embryonic stem cells (hESCs) as a potential source for endothelial progenitors. In this study, ECs were induced from hESC lines and their biological characteristics were analyzed and compared with both cord blood endothelial progenitor cells (CBEPCs) and human umbilical vein endothelial cells (HUVECs) in vitro. The results showed that isolated embryonic KDR+ cells (EC-KDR+) display characteristics that were similar to CBEPCs and HUVECs. EC-KDR+, CBEPCs and HUVECs all expressed CD31 and CD144, incorporated DiI-Ac-LDL, bound UEA1 lectin, and were able to form tube-like structures on Matrigel. Compared with CBEPCs and HUVECs, the expression level of endothelial progenitor cell markers such as CD133 and KDR in EC-KDR+ was significantly higher, while the mature endothelial marker vWF was lowly expressed in EC-KDR+. In summary, the study showed that EC-KDR+ are primitive endothelial-like progenitors and might be a potential source for therapeutic vascular regeneration and tissue engineering. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Defining the earliest step of cardiovascular progenitor specification during embryonic stem cell differentiation

    Science.gov (United States)

    Bondue, Antoine; Tännler, Simon; Chiapparo, Giuseppe; Chabab, Samira; Ramialison, Mirana; Paulissen, Catherine; Beck, Benjamin; Harvey, Richard

    2011-01-01

    During embryonic development and embryonic stem cell (ESC) differentiation, the different cell lineages of the mature heart arise from two types of multipotent cardiovascular progenitors (MCPs), the first and second heart fields. A key question is whether these two MCP populations arise from differentiation of a common progenitor. In this paper, we engineered Mesp1–green fluorescent protein (GFP) ESCs to isolate early MCPs during ESC differentiation. Mesp1-GFP cells are strongly enriched for MCPs, presenting the ability to differentiate into multiple cardiovascular lineages from both heart fields in vitro and in vivo. Transcriptional profiling of Mesp1-GFP cells uncovered cell surface markers expressed by MCPs allowing their prospective isolation. Mesp1 is required for MCP specification and the expression of key cardiovascular transcription factors. Isl1 is expressed in a subset of early Mesp1-expressing cells independently of Mesp1 and acts together with Mesp1 to promote cardiovascular differentiation. Our study identifies the early MCPs residing at the top of the cellular hierarchy of cardiovascular lineages during ESC differentiation. PMID:21383076

  19. 1 | Page INITIATIVE DES CONSEILS SUBVENTIONNAIRES DE LA ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    khaled fourati

    Le présent prospectus est destiné à des organisations comme des instituts de recherche, des centres universitaires, des think tanks, des organisations non gouvernementales (ONG), des académies scientifiques et des parties prenantes qui exprimeront leur intérêt à collaborer à une nouvelle initiative visant à renforcer les.

  20. High frequency electromagnetic fields (GSM signals) affect gene expression levels in tumor suppressor p53-deficient embryonic stem cells.

    Science.gov (United States)

    Czyz, Jaroslaw; Guan, Kaomei; Zeng, Qinghua; Nikolova, Teodora; Meister, Armin; Schönborn, Frank; Schuderer, Jürgen; Kuster, Niels; Wobus, Anna M

    2004-05-01

    Effects of electromagnetic fields (EMF) simulating exposure to the Global System for Mobile Communications (GSM) signals were studied using pluripotent embryonic stem (ES) cells in vitro. Wild-type ES cells and ES cells deficient for the tumor suppressor p53 were exposed to pulse modulated EMF at 1.71 GHz, lower end of the uplink band of GSM 1800, under standardized and controlled conditions, and transcripts of regulatory genes were analyzed during in vitro differentiation. Two dominant GSM modulation schemes (GSM-217 and GSM-Talk), which generate temporal changes between GSM-Basic (active during talking phases) and GSM-DTX (active during listening phases thus simulating a typical conversation), were applied to the cells at and below the basic safety limits for local exposures as defined for the general public by the International Commission on Nonionizing Radiation Protection (ICNIRP). GSM-217 EMF induced a significant upregulation of mRNA levels of the heat shock protein, hsp70 of p53-deficient ES cells differentiating in vitro, paralleled by a low and transient increase of c-jun, c-myc, and p21 levels in p53-deficient, but not in wild-type cells. No responses were observed in either cell type after EMF exposure to GSM-Talk applied at similar slot-averaged specific absorption rates (SAR), but at lower time-averaged SAR values. Cardiac differentiation and cell cycle characteristics were not affected in embryonic stem and embryonic carcinoma cells after exposure to GSM-217 EMF signals. Our data indicate that the genetic background determines cellular responses to GSM modulated EMF. Bioelectromagnetics 25:296-307, 2004. Copyright 2004 Wiley-Liss, Inc.

  1. Synthesis and evaluation of new organic and phosphorous derivatives against ionizing radiation: study of the in vitro mechanism of action; Synthese et evaluation de nouveaux composes organiques et phosphores contre les effets des rayonnements ionisants. Etude de leur mecanisme d'action in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Prouillac, C

    2006-10-15

    This work falls under a research program. The aim was to synthesize new organic phosphorylated compounds having an interesting radio pharmacological activity without toxicity. That is why, we carried out the synthesis of new benzothiazole and thiadiazole N-substituted derivatives as thiols, amino thiols, acids thio-sulfonic and phosphoro thioates. All these compounds were characterized by NMR (proton, carbon, phosphorus, 2D), by mass spectrometry, elementary analyzes and for some of them by diffraction of x-rays. The activity of the majority of them was evaluated by in vitro tests. The experimental results were confirmed by theoretical study: the aim of D.F.T. calculation was the study of the mechanism of capture of the free radicals by our compounds. In addition, a study of relation structure activity (Q.S.A.R.) was carried out. Our results allow us to create a model making it possible to establish structure-activity relationship. (author)

  2. Nucleosome Organization in Human Embryonic Stem Cells.

    Directory of Open Access Journals (Sweden)

    Puya G Yazdi

    Full Text Available The fundamental repeating unit of eukaryotic chromatin is the nucleosome. Besides being involved in packaging DNA, nucleosome organization plays an important role in transcriptional regulation and cellular identity. Currently, there is much debate about the major determinants of the nucleosome architecture of a genome and its significance with little being known about its role in stem cells. To address these questions, we performed ultra-deep sequencing of nucleosomal DNA in two human embryonic stem cell lines and integrated our data with numerous epigenomic maps. Our analyses have revealed that the genome is a determinant of nucleosome organization with transcriptionally inactive regions characterized by a "ground state" of nucleosome profiles driven by underlying DNA sequences. DNA sequence preferences are associated with heterogeneous chromatin organization around transcription start sites. Transcription, histone modifications, and DNA methylation alter this "ground state" by having distinct effects on both nucleosome positioning and occupancy. As the transcriptional rate increases, nucleosomes become better positioned. Exons transcribed and included in the final spliced mRNA have distinct nucleosome profiles in comparison to exons not included at exon-exon junctions. Genes marked by the active modification H3K4m3 are characterized by lower nucleosome occupancy before the transcription start site compared to genes marked by the inactive modification H3K27m3, while bivalent domains, genes associated with both marks, lie exactly in the middle. Combinatorial patterns of epigenetic marks (chromatin states are associated with unique nucleosome profiles. Nucleosome organization varies around transcription factor binding in enhancers versus promoters. DNA methylation is associated with increasing nucleosome occupancy and different types of methylations have distinct location preferences within the nucleosome core particle. Finally, computational

  3. Embryonic and genetic manipulation in fish.

    Science.gov (United States)

    Zhu, Z Y; Sun, Y H

    2000-03-01

    Fishes, the biggest and most diverse community in vertebrates are good experimental models for studies of cell and developmental biology by many favorable characteristics. Nuclear transplantation in fish has been thoroughly studied in China since 1960s. Fish nuclei of embryonic cells from different genera were transplanted into enucleated eggs generating nucleo-cytoplasmic hybrids of adults. Most importantly, nuclei of cultured goldfish kidney cells had been reprogrammed in enucleated eggs to support embryogenesis and ontogenesis of a fertile fish. This was the first case of cloned fish with somatic cells. Based on the technique of microinjection, recombinant MThGH gene has been transferred into fish eggs and the first batch of transgenic fish were produced in 1984. The behavior of foreign gene was characterized and the onset of the foreign gene replication occurred between the blastula to gastrula stages and random integration mainly occurred at later stages of embryogenesis. This eventually led to the transgenic mosaicism. The MThGH-transferred common carp enhanced growth rate by 2-4 times in the founder juveniles and doubled the body weight in the adults. The transgenic common carp were more efficient in utilizing dietary protein than the controls. An "all-fish" gene construct CAgcGH has been made by splicing the common carp beta-actin gene (CA) promoter onto the grass carp growth hormone gene (gcGH) coding sequence. The CAgcGH-transferred Yellow River Carp have also shown significantly fast-growth trait. Combination of techniques of fish cell culture, gene transformation with cultured cells and nuclear transplantation should be able to generate homogeneous strain of valuable transgenic fish to fulfil human requirement in 21st century.

  4. Multiple growth factors regulate coronary embryonic vasculogenesis.

    Science.gov (United States)

    Tomanek, R J; Zheng, W; Peters, K G; Lin, P; Holifield, J S; Suvarna, P R

    2001-07-01

    Mechanisms regulating coronary vascularization are not well understood. To test hypotheses regarding the influence of key growth factors and their interactions, we studied vascular tube formation (vasculogenesis) in collagen gels onto which quail embryonic ventricles were placed and incubated in the presence of growth factors or inhibitors. Vasculogenesis in this model is dependent on tyrosine kinase receptors, since tube formation was totally blocked by genestein. Tube formation was attenuated when anti-bFGF or anti-VEGF neutralizing antibodies were added to the medium and nearly completely inhibited when the both were added. The attenuation associated with anti-VEGF was due primarily to a decrease in assembly of endothelial cells, while that associated with bFGF was primarily due to a reduction in endothelial cells. Soluble tie-2, the receptor for angiopoietins, also had an inhibitory effect and, when added with either anti-bFGF or anti-VEGF, markedly attenuated tube formation. At optimal doses, tube formation was enhanced 6.5-fold by bFGF and 2.5-fold by VEGF over the controls. Each of these growth factors was dependent upon the other for optimal induction of tube formation, since neutralizing antibodies to one markedly reduced the potency of the other. VEGF potency was also markedly reduced when soluble tie-2 was added to the medium. Tube formation was virtually totally blocked by exogenous TGF-beta at doses > 1 ng/ml, while neutralizing TGF-beta antibodies enhanced tube formation 2-fold in the 30 ng-30 microg range. These data provide the first documentation of multiple growth factor regulation of coronary tube formation. Copyright 2001 Wiley-Liss, Inc.

  5. Immunostaining of dissected zebrafish embryonic heart.

    Science.gov (United States)

    Yang, Jingchun; Xu, Xiaolei

    2012-01-10

    Zebrafish embryo becomes a popular in vivo vertebrate model for studying cardiac development and human heart diseases due to its advantageous embryology and genetics. About 100-200 embryos are readily available every week from a single pair of adult fish. The transparent embryos that develop ex utero make them ideal for assessing cardiac defects. The expression of any gene can be manipulated via morpholino technology or RNA injection. Moreover, forward genetic screens have already generated a list of mutants that affect different perspectives of cardiogenesis. Whole mount immunostaining is an important technique in this animal model to reveal the expression pattern of the targeted protein to a particular tissue. However, high resolution images that can reveal cellular or subcellular structures have been difficult, mainly due to the physical location of the heart and the poor penetration of the antibodies. Here, we present a method to address these bottlenecks by dissecting heart first and then conducting the staining process on the surface of a microscope slide. To prevent the loss of small heart samples and to facilitate solution handling, we restricted the heart samples within a circle on the surface of the microscope slides drawn by an immEdge pen. After the staining, the fluorescence signals can be directly observed by a compound microscope. Our new method significantly improves the penetration for antibodies, since a heart from an embryonic fish only consists of few cell layers. High quality images from intact hearts can be obtained within a much reduced procession time for zebrafish embryos aged from day 2 to day 6. Our method can be potentially extended to stain other organs dissected from either zebrafish or other small animals. Copyright © 2012 Journal of Visualized Experiments

  6. Des changements en Asie, surtout pour les femmes | CRDI - Centre ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    23 mars 2016 ... J'ai eu l'occasion de rencontrer des penseurs, des industriels, des politiciens, des représentants des médias, des ONG, et des chercheurs. Le dénominateur ... La violence sexuelle et familiale ainsi que l'impunité sont des sujets qui ne sont abordés que tout récemment en Asie. De bien des façons, ...

  7. Generation of an ASGR1 homozygous mutant human embryonic stem cell line WAe001-A-6 using CRISPR/Cas9

    Directory of Open Access Journals (Sweden)

    Yingying Xu

    2017-07-01

    Full Text Available The gene asialoglycoprotein receptor 1 (ASGR1 encodes a subunit of the asialoglycoprotein receptor. Here we report the generation of a human embryonic stem cell line WAe001-A-6 harbouring homozygous ASGR1 mutations using CRISPR/Cas9. The mutation involves a 37 bp deletion, resulting in a frame shift. The homozygous knockout WA01 cell line maintains a normal karyotype, typical stem cell morphology, pluripotency and differentiation potential in vitro.

  8. Effets biocides des alcaloïdes, des saponines et des flavonoïdes extraits de Capsicum frutescens L. (Solanaceae) sur Bemisia tabaci (Gennadius) (Homoptera : Aleyrodidae)

    National Research Council Canada - National Science Library

    Aziz Bouchelta; Abelali Blenzar; Ahmed Boughdad

    2005-01-01

    ... et des flavonoïdes extraits des fruits de Capsicum frutescens L. sur la survie des œufs et des adultes de Bemisia tabaci infestant les plants de tomates, Lycopersicon esculentum Mill. var. Daniella, a été...

  9. ROCK Inhibitor (Y27632) Increases Apoptosis and Disrupts the Actin Cortical Mat in Embryonic Avian Corneal Epithelium

    OpenAIRE

    Svoboda, Kathy K. H.; Moessner, Petra; Field, Tamara; Acevedo, Jesus

    2004-01-01

    The embryonic chicken corneal epithelium is a unique tissue that has been used as an in vitro epithelial sheet organ culture model for over 30 years (Hay and Revel [1969] Fine structure of the developing Avian cornea. Basel, Switzerland: S. Karger A.G.). This tissue was used to establish that epithelial cells could produce extracellular matrix (ECM) proteins such as collagen and proteoglycans (Dodson and Hay [1971] Exp Cell Res 65:215–220; Meier and Hay [1973] Dev Biol 35:318–331; Linsenmayer...

  10. Generation of KCL035 research grade human embryonic stem cell line carrying a mutation in HBB gene.

    Science.gov (United States)

    Hewitson, Heema; Wood, Victoria; Kadeva, Neli; Cornwell, Glenda; Codognotto, Stefano; Stephenson, Emma; Ilic, Dusko

    2016-03-01

    The KCL035 human embryonic stem cell line was derived from an embryo donated for research that carried a mutation in the HBB gene, which is linked to the β-thalassemia syndrome. The ICM was isolated using laser microsurgery and plated on γ-irradiated human foreskin fibroblasts. Both the derivation and cell line propagation were performed in an animal product-free environment. Pluripotent state and differentiation potential were confirmed by in vitro assays. Copyright © 2016 University of Texas at Austin Dell Medical School. Published by Elsevier B.V. All rights reserved.

  11. Generation of KCL028 research grade human embryonic stem cell line carrying a mutation in the HTT gene

    Directory of Open Access Journals (Sweden)

    Laureen Jacquet

    2016-03-01

    Full Text Available The KCL028 human embryonic stem cell line was derived from an embryo donated for research that carried an autosomal dominant mutation affecting one allele of the HTT gene encoding huntingtin (43 trinucleotide repeats; 21 for the normal allele. The ICM was isolated using laser microsurgery and plated on γ-irradiated human foreskin fibroblasts. Both the derivation and cell line propagation were performed in an animal product-free environment. Pluripotent state and differentiation potential were confirmed by in vitro and in vivo assays.

  12. Generation of KCL018 research grade human embryonic stem cell line carrying a mutation in the DMPK gene

    Directory of Open Access Journals (Sweden)

    Cristian Miere

    2016-03-01

    Full Text Available The KCL018 human embryonic stem cell line was derived from an embryo donated for research that carried an autosomal dominant mutation affecting one allele of the DMPK gene encoding the dystrophia myotonica protein kinase (2200 trinucleotide repeats; 14 for the normal allele. The ICM was isolated using laser microsurgery and plated on γ-irradiated human foreskin fibroblasts. Both the derivation and cell line propagation were performed in an animal product-free environment. Pluripotent state and differentiation potential were confirmed by in vitro assays.

  13. Establishment of human embryonic stem cell line with a complex abnormal karyotype and the stable XIST expression.

    Science.gov (United States)

    Deng, Leiyu; Cheng, Dehua; Lu, Guangxiu; Lin, Ge

    2016-11-01

    The embryonic stem cell line chHES-3XISTa was derived from heterogeneous chHES-3 cells. chHES-3XISTa showed a new abnormal karyotype of 46,XX with 8 derivation chromosomes and expressed X inactive specific transcript (XIST) in continual culture. Tri-methylation of H3 Lys-27 (H3K27me3) punctate enrichment located in RNA Polymerase II hole was also found in all chHES-3XISTa cells. Pluripotent markers and differentiate capability in vitro were confirmed by immunochemistry staining. Copyright © 2016 Michael Boutros, German Cancer Research Center, Heidelberg, Germany. Published by Elsevier B.V. All rights reserved.

  14. CXXC Finger Protein 1 Contains Redundant Functional Domains That Support Embryonic Stem Cell Cytosine Methylation, Histone Methylation, and Differentiation▿

    OpenAIRE

    Tate, Courtney M.; Lee, Jeong-Heon; Skalnik, David G.

    2009-01-01

    CXXC finger protein 1 (Cfp1) is a regulator of both cytosine methylation and histone methylation. Murine embryonic stem (ES) cells lacking Cfp1 exhibit a decreased plating efficiency, decreased cytosine methylation, elevated global levels of histone H3-Lys4 trimethylation, and a failure to differentiate in vitro. Remarkably, transfection studies reveal that expression of either the amino half of Cfp1 (amino acids 1 to 367 [Cfp11-367]) or the carboxyl half of Cfp1 (Cfp1361-656) is sufficient t...

  15. Generation of KCL025 research grade human embryonic stem cell line carrying a mutation in NF1 gene

    Directory of Open Access Journals (Sweden)

    Heema Hewitson

    2016-03-01

    Full Text Available The KCL025 human embryonic stem cell line was derived from an embryo donated for research that carried an autosomal dominant mutation in the NF1 gene encoding neurofibromin (c.3739–3742 ΔTTTG. Mutations in this gene have been linked to neurofibromatosis type 1, juvenile myelomonocytic leukemia and Watson syndrome. The ICM was isolated using laser microsurgery and plated on γ-irradiated human foreskin fibroblasts. Both the derivation and cell line propagation were performed in an animal product-free environment. Pluripotent state and differentiation potential were confirmed by in vitro assays.

  16. Adaptation des organismes communautaires d'approvisionnement ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Sur la base de cette analyse, l'équipe mènera ensuite une enquête auprès des ménages et des fournisseurs d'eau des trois pays et évaluera les coûts et les avantages ... Des spécialistes canadiens participent à des travaux de recherche portant sur les risques auxquels sont exposés les milieux humides le long de la côte ...

  17. Approche historique des classifications en psychiatrie

    OpenAIRE

    Garrabé, J.

    2011-01-01

    Resume Des le milieu du xixe siecle s?est posee la question des criteres de classification des maladies. Pour les maladies mentales, diverses classifications ont alors ete proposees par des auteurs francais (Morel) et allemands (Kahlbaum, Kraepelin). A partir de la fin du xixe siecle, le Bureau International de Statistique (Paris) a publie a une Classification Internationale des Maladies, a revision decennale (J. Bertillon). Cette tache a ete poursuivie dans l?entre-deux-guerres pa...

  18. Materialwissenschaftliche Untersuchung des Dragierverhaltens von Zuckeralkoholen

    OpenAIRE

    Haseleu, Andrea

    2003-01-01

    Ziel der vorliegenden Arbeit ist die Untersuchung des komplexen und komplizierten Dragierprozesses, um nach der systematischen Analyse des Prozeses einfache und nachvollziehbare Zusammenhänge ableiten zu können. Aus diesem Grund wird der Prozeß in drei Hauptuntersuchungsgebiete aufgeteilt: Beschaffenheit des Kernrohlings; Formulierung des Dragiermediums und Prozeßparameter des Dragierens; und in jedem Gebiet materialwissenschaftliche Kennwerte ermittelt. Darüber hinaus wird ein vierter Bereic...

  19. Virginie Albe, Enseigner des controverses

    OpenAIRE

    Blanchard, Antoine

    2011-01-01

    Alors que les sujets controversés (OGM, créationnisme...) sont généralement redoutés par les enseignants et médiateurs scientifiques, qui se trouvent démunis et optent pour le retrait, des didacticiens tentent depuis la fin des années 1990 d'attaquer de front l'enseignement des controverses (ou "questions socialement vives"). En France, l'ENS Cachan, l'École nationale de formation agronomique de Toulouse et l'université de Provence sont les hauts lieux de cette pédagogie qui s'inscrit dans la...

  20. Une approche des structurations symboliques

    OpenAIRE

    Matamoros Ponce, Fernando

    2010-01-01

    Los seres humanos hacen su propia historia,aunque bajo circunstancias influidas por el pasado Karl Marx (1818-1883) Les espaces de lutte, de réforme et de contre-réforme sont une partie du Tout Social. Ils sont le lieu d’une mémoire conflictuelle où se définissent subjectivement les accords et les désaccords. Ainsi, pour comprendre la mise en place de la politique des États et des institutions religieuses, nous devons partir des contradictions inhérentes aux mouvements sociaux en lutte, qui r...

  1. TRAUMATISMES DES BOURSES: A PROPOS

    African Journals Online (AJOL)

    pas de signe de gravité (hématocèie, rup— ture de l'albuginée, volumineux hématome intra testiculaire)? Les altérations du sper— mogramme observées ont été rapportées dans le suivi des patients ayant présenté un traumatisme des bourses et s'expliqueraient par l'atrophie testiculaire avec réduction de l'activité des ...

  2. Artificial niche substrates for embryonic and induced pluripotent stem cell cultures.

    Science.gov (United States)

    Joddar, Binata; Ito, Yoshihiro

    2013-10-20

    Stem cells possess the ability to self-renew and differentiate into other cell types. In vivo, stem cells reside in their own anatomic niches in a defined physiological environment, from which they are released to differentiate into a required cell type when deemed appropriate. While a resident within the niche, the stem cell receives signals that in turn maintain the cell in a pluripotent state. In addition, the niche also provides nourishment to the cell. Physically, the niche also serves to anchor the cell via various ECM components and cell-adhesion molecules. Therefore, in vitro models that replicate the in vivo niche will lead to a better understanding of stem cell fate and turnover. In turn, this will help inform attempts to culture stem cells in vitro on artificial niche-like substrates. In this review, we have highlighted recent studies describing artificial niche-like substrates used to culture embryonic and induced pluripotent stem cells in vitro. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  3. SCL/TAL1-mediated transcriptional network enhances megakaryocytic specification of human embryonic stem cells.

    Science.gov (United States)

    Toscano, Miguel G; Navarro-Montero, Oscar; Ayllon, Veronica; Ramos-Mejia, Veronica; Guerrero-Carreno, Xiomara; Bueno, Clara; Romero, Tamara; Lamolda, Mar; Cobo, Marien; Martin, Francisco; Menendez, Pablo; Real, Pedro J

    2015-01-01

    Human embryonic stem cells (hESCs) are a unique in vitro model for studying human developmental biology and represent a potential source for cell replacement strategies. Platelets can be generated from cord blood progenitors and hESCs; however, the molecular mechanisms and determinants controlling the in vitro megakaryocytic specification of hESCs remain elusive. We have recently shown that stem cell leukemia (SCL) overexpression accelerates the emergence of hemato-endothelial progenitors from hESCs and promotes their subsequent differentiation into blood cells with higher clonogenic potential. Given that SCL participates in megakaryocytic commitment, we hypothesized that it may potentiate megakaryopoiesis from hESCs. We show that ectopic SCL expression enhances the emergence of megakaryocytic precursors, mature megakaryocytes (MKs), and platelets in vitro. SCL-overexpressing MKs and platelets respond to different activating stimuli similar to their control counterparts. Gene expression profiling of megakaryocytic precursors shows that SCL overexpression renders a megakaryopoietic molecular signature. Connectivity Map analysis reveals that trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA), both histone deacetylase (HDAC) inhibitors, functionally mimic SCL-induced effects. Finally, we confirm that both TSA and SAHA treatment promote the emergence of CD34(+) progenitors, whereas valproic acid, another HDAC inhibitor, potentiates MK and platelet production. We demonstrate that SCL and HDAC inhibitors are megakaryopoiesis regulators in hESCs.

  4. Toxic and DNA damaging effects of a functionalized fullerene in human embryonic lung fibroblasts.

    Science.gov (United States)

    Ershova, E S; Sergeeva, V A; Chausheva, A I; Zheglo, D G; Nikitina, V A; Smirnova, T D; Kameneva, L V; Porokhovnik, L N; Kutsev, S I; Troshin, P A; Voronov, I I; Khakina, E A; Veiko, N N; Kostyuk, S V

    2016-07-01

    Water-soluble fullerenes have been studied as potential nanovectors and therapeutic agents, but their possible toxicity is of concern. We have studied the effects of F-828, a soluble fullerene [C60] derivative, on diploid human embryonic lung fibroblasts (HELFs) in vitro. F-828 causes complex time-dependent changes in ROS levels. Inhibition of Nox4 activity by plumbagin blocks F-828-dependent ROS elevation. F-828 induces DNA breaks, as measured by the comet assay and γH2AX expression, and the activities of the transcription factors NF-kB and p53 increase. F-828 concentrations>25μM are cytotoxic; cell death occurs by necrosis. Expression levels of TGF-β, RHOA, RHOC, ROCK1, and SMAD2 increase following exposure to F-828. Our results raise the possibility that fullerene F-828 may induce pulmonary fibrosis in vivo. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Single-Step Generation of Conditional Knockout Mouse Embryonic Stem Cells

    Directory of Open Access Journals (Sweden)

    Matyas Flemr

    2015-07-01

    Full Text Available Induction of double-strand DNA breaks (DSBs by engineered nucleases, such as CRISPR/Cas9 or transcription activator-like effector nucleases (TALENs, stimulates knockin of exogenous DNA fragments via homologous recombination (HR. However, the knockin efficiencies reported so far have not allowed more complex in vitro genome modifications such as, for instance, simultaneous integration of a DNA fragment at two distinct genomic sites. We developed a reporter system to enrich for cells with engineered nuclease-assisted HR events. Using this system in mouse embryonic stem cells (mESCs, we achieve single-step biallelic and seamless integration of two loxP sites for Cre recombinase-mediated inducible gene knockout, as well as biallelic endogenous gene tagging with high efficiency. Our approach reduces the time and resources required for conditional knockout mESC generation dramatically.

  6. Molecular cytogenetics: making it safe for human embryonic stem cells to enter the clinic.

    Science.gov (United States)

    Josephson, Richard

    2007-07-01

    Regenerative therapies based on transplantation of cells derived from human embryonic stem cells (hESC) are currently being prepared for clinical trials. Unfortunately, recent evidence indicates that many kinds of changes can occur to hESC during expansion in culture, and alterations to the growth control mechanisms may be required to establish hESC lines at all. Changes in the genome and epigenome can affect the validity of in vitro and animal studies, and put transplant recipients at increased risk of cancer. New molecular cytogenetic technologies enable us to examine the whole human genome with ever-finer resolution. This review describes several techniques for whole-genome analysis and the information they can provide about hESC lines. Adoption of high-resolution genotyping into routine characterization may prevent highly discouraging clinical outcomes.

  7. Neurotrophin receptor-mediated death of misspecified neurons generated from embryonic stem cells lacking Pax6.

    Science.gov (United States)

    Nikoletopoulou, Vassiliki; Plachta, Nicolas; Allen, Nicolas D; Pinto, Luisa; Götz, Magdalena; Barde, Yves-Alain

    2007-11-01

    Pax6-positive radial glial (RG) cells are the progenitors of most glutamatergic neurons in the cortex, a lineage that can be recapitulated in vitro using embryonic stem (ES) cells. We show here that ES cells lacking Pax6, a transcription factor long known to be essential for cortical development, generate Mash1-positive RG cells that differentiate in GABAergic neurons. These neurons express high levels of the neurotrophin receptor p75NTR causing their rapid death. Pax6 function was also investigated following transplantation of ES cells in the developing chick telencephalon and in mice lacking both Pax6 and p75NTR. Taken together, our results indicate that reliable predictions can be made with cultured ES cells when used to explore the role of genes impacting early aspects of mammalian neurogenesis. They also provide a novel opportunity to compare the molecular constituents of glutamatergic with those of GABA-ergic neurons and to explore the mechanisms of their generation.

  8. Analysis of mouse embryonic gene library for the frequency of single and multiple copy genes.

    Science.gov (United States)

    Mory, Y Y; Keshet, E; Ram, D; Kaminchik, Y

    1980-12-31

    A gene library was constructed from embryonic mouse DNA by ligating DNA fragments generated by partial Eco RI digestion with Charon 4A vector and in vitro packaging. A special consideration was given to randomization of target DNA. The general applicability of a gene library prepared in this manner was assessed through cloning a variety of genes of known reiteration frequency in the mouse genome. The survey included a single copy gene--C region of the immunoglobulin heavy chain, and genes that appear in more than one copy--V region of the immunoglobulin light chain genes and the endogenous retrovirus related genes. In all cases tested the frequency of clone isolation was in good agreement with the expected incidence based on the number of genome equivalents screened and the reiteration frequency of that particular gene. Moreover, we found no preference with regard to the clonability of genes contained in fragments of a wide-size range.

  9. Single-Step Generation of Conditional Knockout Mouse Embryonic Stem Cells.

    Science.gov (United States)

    Flemr, Matyas; Bühler, Marc

    2015-07-28

    Induction of double-strand DNA breaks (DSBs) by engineered nucleases, such as CRISPR/Cas9 or transcription activator-like effector nucleases (TALENs), stimulates knockin of exogenous DNA fragments via homologous recombination (HR). However, the knockin efficiencies reported so far have not allowed more complex in vitro genome modifications such as, for instance, simultaneous integration of a DNA fragment at two distinct genomic sites. We developed a reporter system to enrich for cells with engineered nuclease-assisted HR events. Using this system in mouse embryonic stem cells (mESCs), we achieve single-step biallelic and seamless integration of two loxP sites for Cre recombinase-mediated inducible gene knockout, as well as biallelic endogenous gene tagging with high efficiency. Our approach reduces the time and resources required for conditional knockout mESC generation dramatically. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  10. In vitro

    Science.gov (United States)

    Ohta, Hiroshi; Kurimoto, Kazuki; Okamoto, Ikuhiro; Nakamura, Tomonori; Yabuta, Yukihiro; Miyauchi, Hidetaka; Yamamoto, Takuya; Okuno, Yukiko; Hagiwara, Masatoshi; Shirane, Kenjiro; Sasaki, Hiroyuki; Saitou, Mitinori

    2017-07-03

    The expansion of primordial germ cells (PGCs), the precursors for the oocytes and spermatozoa, is a key challenge in reproductive biology/medicine. Using a chemical screening exploiting PGC-like cells (PGCLCs) induced from mouse embryonic stem cells (ESCs), we here identify key signaling pathways critical for PGCLC proliferation. We show that the combinatorial application of Forskolin and Rolipram, which stimulate cAMP signaling via different mechanisms, expands PGCLCs up to ~50-fold in culture. The expanded PGCLCs maintain robust capacity for spermatogenesis, rescuing the fertility of infertile mice. Strikingly, during expansion, PGCLCs comprehensively erase their DNA methylome, including parental imprints, in a manner that precisely recapitulates genome-wide DNA demethylation in gonadal germ cells, while essentially maintaining their identity as sexually uncommitted PGCs, apparently through appropriate histone modifications. By establishing a paradigm for PGCLC expansion, our system reconstitutes the epigenetic "blank slate" of the germ line, an immediate precursory state for sexually dimorphic differentiation. © 2017 The Authors.

  11. Importance de la nature des substrats de culture dans la précision ...

    African Journals Online (AJOL)

    ... some herbicides according to the nature of substrats, tests are led under glasshouse. A preliminary study in vitro allow to determine the germinating rates of lettuce and some competitive weeds seeds namely laiteron des champs, capselle bourse à Pasteur, matricaire camomile, galinsoga palmiflora and seneçon vulgaire.

  12. Modernisation des marchés agroalimentaires - inclusion des petits ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Les marchés agroalimentaires connaissent de rapides changements dans les pays en développement et les pays en transition. Sous l'influence de la libéralisation du commerce et des nouvelles technologies de transformation des aliments et de commerce de détail, les marchés agroalimentaires évoluent vers une plus ...

  13. Evaluation des pratiques de gestion des adventices en riziculture ...

    African Journals Online (AJOL)

    Le riz est l'aliment principal pour la quasi-totalité des populations vivant en Côte d'Ivoire. Cependant, les adventices sont considérées comme la contrainte biologique la plus importante faisant obstacle à la production rizicole. L'objectif de cette étude menée en 2015 était d'évaluer différentes techniques de gestion des ...

  14. Etude Des Lesions Rencontrees Sur Des Carcasses De Petits ...

    African Journals Online (AJOL)

    Sur les 277 saisies de poumons, il y a 12 suspicions de tuberculose, 101 de parasitoses, 96 de pneumopathies et 68 dues à des abcès divers. Les lésions suspectées de tuberculose sont très rares (0;15 et 0,07%) respectivement chez les ovins et caprins. La tuberculose des petits ruminants à ce niveau de prévalence

  15. Promouvoir l'entrepreneuriat inclusif des jeunes et des femmes ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Promouvoir l'entrepreneuriat inclusif des jeunes et des femmes : Une étude de cas sur le Burkina Faso, le Kenya et la Côte d'Ivoire. Le projet vise à analyser la contribution réelle et ... Institution. Centre ivoirien de recherches économiques et sociales. Pays d' institution. Ivory Coast. Site internet. http://www.cires-ci.org ...

  16. Optimisation structurelle des gridshells

    OpenAIRE

    Bouhaya, Lina

    2010-01-01

    Le terme gridshell désigne une coque discrète qui est obtenue par déformation élastique d'une grille bidirectionnelle continue plane sans rigidité en cisaillement puis rigidifiée par une troisième direction de barres. Ainsi défini, un gridshell a un potentiel structural intéressant et peut répondre à des exigences architecturales complexes. La recherche de forme de ces structures a été menée à travers l'histoire principalement par deux méthodes, la méthode du filet inversé et la relaxation dy...

  17. Code des baux 2018

    CERN Document Server

    Vial-Pedroletti, Béatrice; Kendérian, Fabien; Chavance, Emmanuelle; Coutan-Lapalus, Christelle

    2017-01-01

    Le code des baux 2018 vous offre un contenu extrêmement pratique, fiable et à jour au 1er août 2017. Cette 16e édition intègre notamment : le décret du 27 juillet 2017 relatif à l’évolution de certains loyers dans le cadre d’une nouvelle location ou d’un renouvellement de bail, pris en application de l’article 18 de la loi n° 89-462 du 6 juillet 1989 ; la loi du 27 janvier 2017 relative à l’égalité et à la citoyenneté ; la loi du 9 décembre 2016 relative à la transparence, à la lutte contre la corruption et à la modernisation de la vie économique ; la loi du 18 novembre 2016 de modernisation de la justice du xxie siècle

  18. Le fiacre des propositions

    Directory of Open Access Journals (Sweden)

    Cyrille Michon

    2012-07-01

    Full Text Available Après avoir identifié quelques arguments pour illustrer ce dont traite la philosophie analytique de la religion, je défends que celle-ci a la pertinence de la spéculation classique sur le contenu de la foi. L’une et l’autre reposent sur la contrainte logique qui suit de l’acceptation d’une proposition — refus de ce qui la contredit, acceptation de ses conséquences — et sur le fait que la Révélation chrétienne contient des propositions, certaines paradoxales. J’illustre cette pertinence par trois exemples pris dans la « philosophie continentale de la religion ».

  19. Beat Rate Variability in Murine Embryonic Stem Cell-Derived Cardiomyocytes: Effect of Antiarrhythmic Drugs.

    Science.gov (United States)

    Niehoff, Julius; Matzkies, Matthias; Nguemo, Filomain; Hescheler, Jürgen; Reppel, Michael

    2016-01-01

    Heart rate variability (HRV) refers to the fluctuation of the time interval between consecutive heartbeats in humans. It has recently been discovered that cardiomyocytes derived from human embryonic and induced pluripotent stem cells show beat rate variability (BRV) that is similar to the HRV in humans. In the present study, clinical aspects of HRV were transferred to an in vitro model. The aims of the study were to explore the BRV in murine embryonic stem cell (mESC)-derived cardiomyocytes and to demonstrate the influence of antiarrhythmic drugs on BRV as has been shown in clinical trials previously. The Microelectrode Array (MEA) technique was used to perform short-term recordings of extracellular field potentials (FPs) of spontaneously beating cardiomyocytes derived from mESCs (D3 cell line, αPig-44). Offline analysis was focused on time domain and nonlinear methods. The Poincaré-Plot analysis of measurements without pharmacological intervention revealed that three different shapes of scatter plots occurred most frequently. Comparable shapes have been described in clinical studies before. The antiarrhythmic drugs Ivabradine, Verapamil and Sotalol augmented BRV, whereas Flecainide decreased BRV parameters at low concentrations (SDSD 79.0 ± 8.7% of control at 10(-9) M, p < 0.05) and increased variability measures at higher concentrations (SDNN 258.8 ± 42.7% of control at 10(-5) M, p < 0.05). Amiodarone and Metoprolol did not alter BRV significantly. Spontaneously beating cardiomyocytes derived from mESCs showed BRV that appears to be similar to the HRV known from humans. Antiarrhythmic drugs affected BRV parameters similar to clinical observations. Therefore, our study demonstrates that this in vitro model can contribute to a better understanding of electrophysiological properties of mESC-derived cardiomyocytes and might serve as a valuable tool for drug safety screening. © 2016 The Author(s) Published by S. Karger AG, Basel.

  20. Beat Rate Variability in Murine Embryonic Stem Cell-Derived Cardiomyocytes: Effect of Antiarrhythmic Drugs

    Directory of Open Access Journals (Sweden)

    Julius Niehoff

    2016-02-01

    Full Text Available Background/Aims: Heart rate variability (HRV refers to the fluctuation of the time interval between consecutive heartbeats in humans. It has recently been discovered that cardiomyocytes derived from human embryonic and induced pluripotent stem cells show beat rate variability (BRV that is similar to the HRV in humans. In the present study, clinical aspects of HRV were transferred to an in vitro model. The aims of the study were to explore the BRV in murine embryonic stem cell (mESC-derived cardiomyocytes and to demonstrate the influence of antiarrhythmic drugs on BRV as has been shown in clinical trials previously. Methods: The Microelectrode Array (MEA technique was used to perform short-term recordings of extracellular field potentials (FPs of spontaneously beating cardiomyocytes derived from mESCs (D3 cell line, αPig-44. Offline analysis was focused on time domain and nonlinear methods. Results: The Poincaré-Plot analysis of measurements without pharmacological intervention revealed that three different shapes of scatter plots occurred most frequently. Comparable shapes have been described in clinical studies before. The antiarrhythmic drugs Ivabradine, Verapamil and Sotalol augmented BRV, whereas Flecainide decreased BRV parameters at low concentrations (SDSD 79.0 ± 8.7% of control at 10-9 M, p -5 M, p Conclusions: Spontaneously beating cardiomyocytes derived from mESCs showed BRV that appears to be similar to the HRV known from humans. Antiarrhythmic drugs affected BRV parameters similar to clinical observations. Therefore, our study demonstrates that this in vitro model can contribute to a better understanding of electrophysiological properties of mESC-derived cardiomyocytes and might serve as a valuable tool for drug safety screening.

  1. Embryonic stem cells in science and medicine, part II: law, ethics, and the continuing need for dialogue.

    Science.gov (United States)

    Solomon, Louis M; Brockman-Lee, Sandra A

    2008-03-01

    Just as our first article, "Embryonic Stem Cells in Science and Medicine: An Invitation for Dialogue," in the December 2007 issue of Gender Medicine went to press, two groups of researchers had just announced that adult human somatic cells had been reprogrammed to behave like pluripotent stem cells, and that the reprogrammed cells were able to differentiate into cell types of the 3 germ layers in vitro and in a mouse model. A third group has since done so. Because the reprogrammed cells were not embryonic in origin, the announcements were heralded as "stunning" and "leaps forward," because, it was argued, the ability to generate stem cells, without destroying embryos in the process, would avoid the difficult ethical questions raised by human embryonic stem (hES) cell research. This article addresses the most recent announcements and briefly retraces the relevant history so that we may consider whether the moral, ethical, and social issues do in fact disappear as a result of these new advancements. We conclude that, despite the hoopla, little has changed. If indeed there were ethical issues surrounding hES cell research, they remain-and remain as urgent to address and resolve as they had been previously. Lastly, we argue that the medical and scientific communities continue to do themselves a disservice by failing to create a cohesive governing body to address and make concrete recommendations concerning the moral, ethical, and related social issues affecting their communities.

  2. A Bmp Reporter Transgene Mouse Embryonic Stem Cell Model as a Tool to Identify and Characterize Chemical Teratogens.

    Science.gov (United States)

    Kugler, Josephine; Tharmann, Julian; Chuva de Sousa Lopes, Susana M; Kemler, Rolf; Luch, Andreas; Oelgeschläger, Michael

    2015-08-01

    Embryonic stem cells (ESCs) were first isolated from mouse embryos more than 30 years ago. They have proven invaluable not only in generating genetically modified mice that allow for analysis of gene function in tissue development and homeostasis but also as models for genetic disease. In addition, ESCs in vitro are finding inroads in pharmaceutical and toxicological testing, including the identification of teratogenic compounds. Here, we describe the use of a bone morphogenetic protein (Bmp)-reporter ESC line, isolated from a well-characterized transgenic mouse line, as a new tool for the identification of chemical teratogens. The Bmp-mediated expression of the green fluorescent protein enabled the quantification of dose- and time-dependent effects of valproic acid as well as retinoic acid. Significant effects were detectable at concentrations that were comparable to the ones observed in the classical embryonic stem cell test, despite the fact that the reporter gene is expressed in distinct cell types, including endothelial and endodermal cells. Thus these cells provide a valuable new tool for the identification and characterization of relevant mechanisms of embryonic toxicity. © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  3. Effects of Cadmium and Zinc on the Gamete Viability, Fertilization, and Embryonic Development of Tripneustes gratilla (Linnaeus

    Directory of Open Access Journals (Sweden)

    Ivan Patrick B. Tualla

    2016-01-01

    Full Text Available Heavy metals are frequently reported for their mutagenic and teratogenic effects on benthic organisms. Thus, this study aimed to determine the toxicity of cadmium (Cd and zinc (Zn in the gametes of T. gratilla and to compare its fertilization and embryonic development under the highest nongametotoxic concentrations of these heavy metals. Gamete viability of T. gratilla under CdCl2 and ZnSO4 treatments was assayed through resazurin reduction test (RRT and was confirmed through gamete morphology assay. ZnSO4 was more toxic to T. gratilla gametes than CdCl2 and egg cells were more sensitive to both than the sperm cells. Higher concentrations of CdCl2 and ZnSO4 induced gamete apoptosis and necrosis while highest nongametotoxic concentrations were determined at 1 × 10−3 M and 1 × 10−4 M, respectively, and were used in an in vitro fertilization and embryonic development experiment. ZnSO4 treatment inhibited fertilization more than CdCl2 and yielded more deformed embryos, while both induced abnormalities and hindered further embryonic development. This study gives the first report on the specific concentrations of Cd and Zn that are toxic to T. gratilla gametes and has confirmed the teratogenic effects of these heavy metals.

  4. Prise en compte du gonflement des terrains dans le dimensionnement des revêtements des tunnels

    OpenAIRE

    Bultel, Frédéric

    2001-01-01

    Travail préparé au Laboratoire Central des Ponts et Chaussées (LCPC-Paris) dans le cadre d'une convention CIFRE avec la société Scetauroute,Composition du jury : MM. R. KASTNER professeur à l'Institut National des Sciences Appliquées de Lyon (rapporteur),I. SHAHROUR professeur à l'Ecole Universitaire Des Ingénieurs de Lille (rapporteur), P. EGGER professeur à l'Ecole Polytechnique Fédérale de Lausanne (Examinateur), B. GAUDIN expert géotechnique à Scetauroute-DTTS (Examinateur), J.P. MAGNAN D...

  5. Des équilibres instables

    OpenAIRE

    Schweisguth, Danielle; Plane, Mathieu; Blot, Christophe; Cochard, Marion; Le Bayon, Sabine

    2007-01-01

    Le déficit courant des États-Unis se dégrade continuellement depuis 1991 et a atteint un niveau record de 6,6 % du PIB en 2006. Il résulte en premier lieu d’un déséquilibre interne entre l’épargne nationale et l’investissement. La propension à consommer des ménages américains favorisée par l’envolée des cours boursiers à la fin des années 1990 puis le développement du marché hypothécaire ont modifié l’arbitrage entre consommation et épargne au détriment de cette dernière. Par ailleurs, les fi...

  6. Le valais, colonie des CFF

    Directory of Open Access Journals (Sweden)

    Bernard Debarbieux

    2010-09-01

    Full Text Available Voici une affiche placardée par les chemins de fer helvétiques (CFF pendant des semaines, au printemps 2009, dans les gares de Suisse romande. Un slogan l'accompagnait: «Rencontrez des peuples authentiques en Valais avec nos offres et excursions en Valais». L'image fait directement référence au célèbre carnaval du Lötschental et aux masques que l'on sculpte pour l'occasion depuis des générations. Au-delà elle s'enracine dans un imaginaire bien connu des peuples sauvages qui a fleuri à partir...

  7. Pourquoi faire des varietes synthetiques?

    OpenAIRE

    Gallais, A

    1992-01-01

    Dans cette discussion sur les variétés synthétiques, les avantages et les inconvénients connus de ce type de variétés sont rappelés. Puis la valeur des meilleures variétés synthétiques possibles à partir d’une population est comparée à la valeur des meilleures hybrides simples (ou des meilleurs clones) et à la valeur des meilleures lignées. Il est montré que les meilleurs variétés synthétiques sont toujours inférieures aux meilleurs hybrides simples et à peine supérieures (de 0 à 10%) à la va...

  8. Marais Des Cygnes Wildlife Area

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This brochure is for the Marais des Cygnes Wildlife Area, managed by Kansas Department of Wildlife, Parks and Tourism, and located in the floodplain of the Marais...

  9. Are there factors preventing cancer development during embryonic life

    Energy Technology Data Exchange (ETDEWEB)

    Einhorn, L. (Kungliga Karolinska Mediko-Kirurgiska Inst., Stockholm (Sweden))

    1983-01-01

    On the basis of the following literature observations, a hypothesis is advanced that the development of cancer is actively inhibited during embryonic life. Although the processes of cell differentiation and proliferation are - without comparison - most pronounced during embryonic life, cancer is rarely found in the newborn and is seldom a cause of neonatal death or spontaneous abortion. Attempts to induce cancer in early-stage animal embryos by irradiation or by transplacental chemical carcinogenesis have been unsuccessful, even when exposed animals have been observed throughout their lifetime. After the period of major organogenesis, however, the embryos become susceptible to carcinogenesis. In humans, the most common embryonic tumors arise in tissues which have an unusually late ongoing development and are still partly immature at or shortly before birth. For many human embryonic tumors the survival rates are higher, and spontaneous regression more frequent, in younger children, i.e. prognosis is age-dependent. Thus, although cancer generally appears in tissues capable of proliferation and differentiation, induction of malignancy in the developmentally most active tissues seems to be beset with difficulty. One possible explanation for this paradox could be that cancer is controlled by the regulators influencing development, regulators that are most active during embryonic life.

  10. Embryonic retinal cells and support to mature retinal neurons.

    Science.gov (United States)

    Stanke, Jennifer J; Fischer, Andy J

    2010-04-01

    Purpose. There is a paucity of neuron replacement studies for retinal ganglion cells. Given the complex phenotype of these neurons, replacement of ganglion cells may be impossible. However, transplanted embryonic cells could provide factors that promote the survival of these neurons. The authors sought to determine whether transplanted embryonic retinal cells from various stages of development influence the survival of mature ganglion cells Methods. Acutely dissociated retinal cells, obtained from chick embryos, were transplanted into the vitreous chamber of posthatch chicken eyes after the ganglion cells were selectively damaged. Eight days after transplantation, numbers of ganglion cells were determined Results. Embryonic retinal cells from embryonic day (E)7, E10, and E11 promoted the survival of ganglion cells, whereas cells from earlier or later stages of development or from other tissue sources did not. The environment provided by the posthatch eye did not support the proliferation of the embryo-derived cells, unlike the environment provided by culture conditions. Furthermore, cells that migrated into the retina failed to express neuronal or glial markers; those that remained in the vitreous formed aggregates of neuronal and glial cells Conclusions. The environment provided within the mature retina does not support the differentiation and proliferation of retinal progenitors. Furthermore, embryo-derived cells likely produce secreted factors that promote the survival of damaged ganglion cells. Therefore, embryonic retinal cells could be applied as a cell-based survival therapy to treat neurodegenerative diseases of the retina.

  11. Derivation of HVR1, HVR2 and HVR3 human embryonic stem cell lines from IVF embryos after preimplantation genetic diagnosis (PGD for monogenic disorder

    Directory of Open Access Journals (Sweden)

    Abdelkrim Hmadcha

    2016-05-01

    Full Text Available From 106 human blastocyts donate for research after in vitro fertilization (IVF and preimplantation genetic diagnosis (PGD for monogenetic disorder, 3 human embryonic stem cells (hESCs HVR1, HVR2 and HVR3 were successfully derived. HVR1 was assumed to be genetically normal, HVR2 carrying Becker muscular dystrophy and HVR3 Hemophilia B. Despite the translocation t(9;15(q34.3;q14 detected in HVR2, all the 3 cell lines were characterised in vitro and in vivo as normal hESCs lines and were registered in the Spanish Stem Cell Bank.

  12. (AJST) BIOSTRATIGRAPHIE DES FORAMINIFERES ET ...

    African Journals Online (AJOL)

    ARESUME:- 115 déblais de sondage et des logs éléctriques ont été soumis aux analyses biostratigraphiques et paléoenvironnementales pour déterminer la lithologie, l'âge, et l'environnement de dépôt des sédiments provenant du puits Opolo-1 dans le Delta du Niger, Nigeria. Les résultats montre que du bas vers le haut ...

  13. Die Moosgesellschaften des Nationalparks Harz

    OpenAIRE

    Schubert, Rudolf

    2013-01-01

    Die Auswertung der in den Jahren 2002–2007 erarbeiteten Vegetationsaufnahmen im Nationalpark Harz ergab ihre Einordnung in 77 unterschiedliche Moosgesellschaften. 17 Moosgesellschaften gehören zu den bedrohten Lebensgemeinschaften der Länder Niedersachsen und Sachsen-Anhalt, womit die Bedeutung des Nationalparks Harz für die Erhaltung und den Schutz der Moosflora des Harzes deutlich wird. The evaluation of vegetation mapping of moss-communities in the National Park Harz in 2002–2007 result...

  14. Déplacements des gouverneurs

    International Development Research Centre (IDRC) Digital Library (Canada)

    André Lavoie

    Transport. 1. Contexte a) Le Centre de recherches pour le développement international (CRDI) est une société d'État canadienne à laquelle la loi confère le mandat de lancer, d'encourager, d'appuyer et de mener des recherches sur les problèmes des régions du monde en voie de développement et sur la mise en.

  15. The effect of egg embryonation on field-use of a hookworm benzimidazole-sensitivity egg hatch assay in Yunnan Province, People's Republic of China.

    Directory of Open Access Journals (Sweden)

    Andrew C Kotze

    2011-06-01

    Full Text Available BACKGROUND: Current efforts to control human soil-transmitted helminths (STHs involve the periodic mass administration of benzimidazole drugs to school aged children and other at- risk groups. Given that high levels of resistance to these drugs have developed in roundworms of livestock, there is a need to monitor drug efficacy in human STHs. The current study aimed to evaluate an in vitro egg hatch assay for measuring the sensitivity of human hookworms to benzimidazole drugs in an isolated field setting in southern Yunnan province, People's Republic of China. METHODOLOGY/PRINCIPAL FINDINGS: Egg hatch assays were performed with hookworm (Necator americanus eggs extracted from 37 stool samples received from local school-aged children. The mean IC(50 was 0.10 ug/ml thiabendazole (95% CIs: 0.09-0.12 ug/ml. Observation of the eggs immediately prior to assay set-up revealed that a small percentage had embryonated in some samples. Scoring of % embryonation of eggs prior to the assay allowed for corrections to be made to IC(50, IC(95 and IC(99 values. Examination of the data with and without this correction revealed that the embryonation of a small number of eggs did not affect IC(50 values, but did increase IC(95 and IC(99 values for some samples. CONCLUSIONS/SIGNIFICANCE: This study has highlighted the impact of egg embryonation on the use of benzimidazole drug sensitivity assays for human hookworms in field settings. Given the greater flexibility required in human stool collection procedures compared to livestock studies, we suggest that embryonation of some eggs may be an unavoidable issue in some human studies. Hence, it needs to be measured and accounted for when analysing dose response data, particularly for generation of IC(95 and IC(99 values. The protocols used in this study and our suggested measures for accounting for egg embryonation should have widespread application in monitoring benzimidazole sensitivity at field sites worldwide.

  16. Embryonic mouse testis development: role of platelet derived growth factor (PDGF-BB).

    Science.gov (United States)

    Ricci, G; Catizone, A; Galdieri, M

    2004-09-01

    Platelet-derived growth factors (PDGFs) are paracrine growth factors mediating epithelial-mesenchymal interactions and exerting multiple biological activities which include cell proliferation, motility, and differentiation. As previously demonstrated, PDGFs act during embryonic development and recently, by culturing male genital ridges, we have demonstrated that PDGF-BB is able to support in vitro testicular cord formation. In the present paper, we report that PDGF-BB is present during embryonic testis development and, in organ culture, induces cord formation although with reduced diameters compared with the cords formed in the genital ridges cultured in the presence of HGF. Moreover we have analyzed the roles exerted by this growth factor during the morphogenesis of the testis. We demonstrate by immunohistochemical experiments that PDGF-BB and its receptors are synthesized by the male UGRs isolated from 11.5 and 13.5 dpc embryos and by Western blot that the factor is secreted in a biologically active form by testicular cells isolated from 13.5 dpc embryos. The biological roles of the factor have also been studied and we demonstrate that PDGF-BB acts as a migratory factor for male mesonephric cells whose migration is a male specific event necessary for a normal testicular morphogenesis. In addition we demonstrate that during testicular development, PDGF-BB induces testicular cell proliferation being in this way responsible for the increase in size of the testis. Finally we demonstrate that PDGF-BB is able to reorganize dissociated testicular cells inducing the formation of large cellular aggregates. However the structures formed in vitro under PDGF-BB stimulation never had a cord-like morphology similar to the cord-like structures formed in the presence of HGF (Ricci et al., 2002, Mech Dev 118:19-28), suggesting that this factor does not act as a morphogenetic factor during testicular development. All together the data presented in this paper demonstrate that PDGF

  17. The ethics of patenting human embryonic stem cells.

    Science.gov (United States)

    Chapman, Audrey R

    2009-09-01

    Just as human embryonic stem cell research has generated controversy about the uses of human embryos for research and therapeutic applications, human embryonic stem cell patents raise fundamental ethical issues. The United States Patent and Trademark Office has granted foundational patents, including a composition of matter (or product) patent to the Wisconsin Alumni Research Foundation (WARF), the University of Wisconsin-Madison's intellectual property office. In contrast, the European Patent Office rejected the same WARF patent application for ethical reasons. This article assesses the appropriateness of these patents placing the discussion in the context of the deontological and consequentialist ethical issues related to human embryonic stem cell patenting. It advocates for a patent system that explicitly takes ethical factors into account and explores options for new types of intellectual property arrangements consistent with ethical concerns.

  18. Impact of nutritional stress on early embryonic survival

    Directory of Open Access Journals (Sweden)

    Sukanta Mondal

    2015-09-01

    Full Text Available Background: Low reproductive efficiency is the most critical problem faced by the livestock industry across the globe. Early embryonic loss is one the major cause of poor reproductive efficiency resulting in delayed pregnancy, fewer calves born, reduced milk production, slower genetic progress and substantial financial loss to the beef or dairy industry. The establishment of pregnancy results from the interaction between the embryo and the dam and is the culmination of a series of events initiated with development of the follicle and gametes. Among numerous internal and external factors nutrition has the potency to alter the micro-environment of the oocyte and the embryo, making it more hostile to optimal fertilization and pre-implantation embryonic growth. Understanding the impact of nutritional stress on oocyte function, embryo development and reciprocal signaling networks between the embryo and uterus will lead to alleviation of the problems of early embryonic mortality.

  19. Ultrasonographic appearance of early embryonic mortality in buffalo (Bubalus bubalis

    Directory of Open Access Journals (Sweden)

    Giuseppe Catone

    2010-01-01

    Full Text Available Embryonic mortality is one of the main causes responsible of the decline in fertility that occurs in buffaloes during periods of increasing daylight length (out sexual breeding season. Transrectal ultrasonography for pregnancy diagnosis offers some advantages over palpation per rectum: earlier diagnosis of pregnancy/non-pregnancy, determination of embryo/fetus viability, reduction of misdiagnosis, and reduction of .potential. iatrogenic embryo/fetal attrition. Non pregnant buffaloes on Day 25 after AI showed higher Resistive Index (RI (P<0.05 and Pulsatility Index (P=0.07 values, registered on CL on Days 10 after AI, compared to pregnant buffaloes. RI values were significantly higher (P=0.02 in non pregnant buffaloes also on Day 45 after AI. Colour Doppler sonography could be used to gain specific information relating to the ovarian blood flow in predicting early embryonic loss and to describe the ultrasonographic features of early embryonic death in buffaloes.

  20. Vestibular dysfunction in a child with embryonic exposure to accutane.

    Science.gov (United States)

    Westerman, S T; Gilbert, L M; Schondel, L

    1994-05-01

    Children with a history of embryonic exposure to Accutane (isotretinoin) are at great risk for major physical malformations, brain malformations, and decreased intelligence. A case is presented of a 4-year 7-month-old black male with a history of embryonic exposure to Accutane who was born with embryopathy that includes bilateral major ear deformities. The child has a significant bilateral conductive hearing loss, and, in addition, a left sided sensorineural loss. Vestibular function testing revealed evidence of peripheral and central vestibular dysfunction. A course of diphenhydramine hydrochloride and Donnatal (phenobarbital, hyoscyamine sulfate, atropine sulfate, and scopolamine hydrobromide) significantly alleviated the symptoms of vestibular dysfunction. Otologic management of these children should include clinical documentation of the external deformities, evaluation of cochlear function, and early auditory habilitation. Vestibular function should also be evaluated in all children with a history of embryonic exposure to isotretinoin.