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The present study was aimed to investigate the role of GluN2B-BDNF pathway in the cerebrospinal fluid-contacting nucleus (CSF-CN) in neuropathic pain. Intra-lateral ventricle injection of cholera toxin subunit B conjugated with horseradish peroxidase (CBHRP) was used to label the CSF-CN. Double-labeled immunofluorescent staining and Western blot were used to observe the expression of GluN2B and BDNF in the CSF-CN. Chronic constriction injury of sciatic nerve (CCI) rat model was used to duplicate the neuropathic pain. Pain behavior was scored to determine the analgesic effects of GluN2B antagonist Ro 25-6981 and BDNF neutralizing antibody on CCI rats. GluN2B and BDNF were expressed in the CSF-CN and their expression was up-regulated in CCI rats. Intra-lateral ventricle injection of GluN2B antagonist Ro 25-6981 or BDNF neutralizing antibody notably alleviated thermal hyperalgesia and mechanical allodynia in CCI rats. Moreover, the increased expression of BDNF protein in CCI rats was reversed by intra-lateral ventricle injection of Ro 25-6981. These results suggest that GluN2B and BDNF are expressed in the CSF-CN and alteration of GluN2B-BDNF pathway in the CSF-CN is involved in the modulation of the peripheral neuropathic pain.
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Animals , Rats , Brain-Derived Neurotrophic Factor , Hyperalgesia , Neuralgia , Rats, Sprague-Dawley , Sciatic NerveABSTRACT
The present study aimed to improve the processing of data acquired from laser speckle contrast imaging (LSCI) to provide a standardization method to explore changes in regional cerebral blood flow (rCBF) and to determine the correlations among rCBF, cerebral ischemic lesion volume and microvascular density over time in a focal ischemic region. C57BL/6J mice were subjected to focal photothrombotic (PT) ischemia. rCBF was measured using LSCI at different time points before and after PT ischemia through an intact skull. Standardized rCBF (SrCBF), defined as the ratio of rCBF measured in the ipsilateral region of interest (ROI) to that in the corresponding contralateral region, was calculated to evaluate potential changes. In addition, the volume of the ischemic lesion and the microvascular density were determined using Nissl staining and immunofluorescence, respectively. The relationships among the ischemic lesion volume, microvascular density and SrCBF were analyzed over time. The results showed that the cortical rCBF measured using LSCI following PT ischemia in the C57BL/6J mice gradually increased. Changes in the cerebral ischemic lesion volume were negatively correlated with SrCBF in the ischemic region. Changes in the microvascular density were similar to those observed in SrCBF. Our findings indicate that LSCI is a practical technique for observing changes in murine cortical rCBF without skull opening and for analyzing the relationships among the ischemic lesion volume, microvascular density and SrCBF following focal cerebral ischemia. Preliminary results also suggest that the use of LSCI to observe the formation of collateral circulation is feasible.
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Obstructive sleep apnea (OSA) is an independent risk factor for cardiovascular diseases. Aldosterone was reported to be increased in patients with OSA and correlated with OSA severity. Many studies investigated the effect of continuous positive airway pressure (CPAP) therapy on plasma aldosterone concentrations (PAC) in OSA patients. The results, however, were inconsistent. In the present study, we aimed to evaluate the effects of CPAP therapy on PAC by performing a meta-analysis. Literature search was carried out in electronic databases including PubMed/Medline, Cochrane Library, Embase and Web of Science. Eligible full-text articles were identified, and important data were extracted. Pooled analysis was performed using the STATA12.0 and RevMan 5.2. Standardized mean difference (SMD) was calculated to estimate the treatment effects. A total of eight studies involving 219 patients were included for our final analysis. PAC was found unchanged after CPAP treatment in OSA patients (SMD=-0.36, 95% CI:-0.91 to 0.18, Z=1.32, P=0.19). Meanwhile, CPAP therapy showed no impact on PAC (SMD=-0.21, 95% CI:-0.85 to 0.42, Z=0.66, P=0.51) in a separate meta-analysis including 3 randomized controlled trials. In conclusion, the evidence for the use of CPAP therapy to decrease PAC in OSA patients is low, and further studies are still warranted.
Subject(s)
Humans , Aldosterone , Blood , Continuous Positive Airway Pressure , Randomized Controlled Trials as Topic , Sleep Apnea, Obstructive , Blood , TherapeuticsABSTRACT
The present study aimed to improve the processing of data acquired from laser speckle contrast imaging (LSCI) to provide a standardization method to explore changes in regional cerebral blood flow (rCBF) and to determine the correlations among rCBF, cerebral ischemic lesion volume and microvascular density over time in a focal ischemic region. C57BL/6J mice were subjected to focal photothrombotic (PT) ischemia. rCBF was measured using LSCI at different time points before and after PT ischemia through an intact skull. Standardized rCBF (SrCBF), defined as the ratio of rCBF measured in the ipsilateral region of interest (ROI) to that in the corresponding contralateral region, was calculated to evaluate potential changes. In addition, the volume of the ischemic lesion and the microvascular density were determined using Nissl staining and immunofluorescence, respectively. The relationships among the ischemic lesion volume, microvascular density and SrCBF were analyzed over time. The results showed that the cortical rCBF measured using LSCI following PT ischemia in the C57BL/6J mice gradually increased. Changes in the cerebral ischemic lesion volume were negatively correlated with SrCBF in the ischemic region. Changes in the microvascular density were similar to those observed in SrCBF. Our findings indicate that LSCI is a practical technique for observing changes in murine cortical rCBF without skull opening and for analyzing the relationships among the ischemic lesion volume, microvascular density and SrCBF following focal cerebral ischemia. Preliminary results also suggest that the use of LSCI to observe the formation of collateral circulation is feasible.
Subject(s)
Animals , Male , Mice , Brain Ischemia , Diagnostic Imaging , Cerebrovascular Circulation , Diagnostic Imaging , Methods , Intracranial Thrombosis , Diagnostic Imaging , Laser-Doppler Flowmetry , Methods , Light , Mice, Inbred C57BLABSTRACT
Induced pluripotent stem cells (iPSCs) can be propagated indefinitely, while maintaining the capacity to differentiate into all cell types in the body except for the extra-embryonic tissues. This iPSC technology not only represents a new way to use individual-specific stem cells for regenerative medicine but also constitutes a novel method to obtain large numbers of disease-specific cells for biomedical research. However, the low efficiency of reprogramming and genomic integration of oncogenes and viral vectors limit the potential application of iPSCs. Chemical-induced reprogramming offers a novel approach to generating iPSCs. In this study, a new combination of small-molecule compounds (SMs) (sodium butyrate, A-83-01, CHIR99021, Y-27632) under conditions of transient folate deprivation was used to generate iPSC. It was found that transient folate deprivation combined with SMs was sufficient to permit reprogramming from mouse embryonic fibroblasts (MEFs) in the presence of transcription factors, Oct4 and Klf4, within 25 days, replacing Sox2 and c-Myc, and accelerated the generation of mouse iPSCs. The resulting cell lines resembled mouse embryonic stem (ES) cells with respect to proliferation rate, morphology, pluripotency-associated markers and gene expressions. Deprivation of folic acid, combined with treating MEFs with SMs, can improve the inducing efficiency of iPSCs and reduce their carcinogenicity and the use of exogenous reprogramming factors.
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Induced pluripotent stem cells (iPSCs) can be propagated indefinitely, while maintaining the capacity to differentiate into all cell types in the body except for the extra-embryonic tissues. This iPSC technology not only represents a new way to use individual-specific stem cells for regenerative medicine but also constitutes a novel method to obtain large numbers of disease-specific cells for biomedical research. However, the low efficiency of reprogramming and genomic integration of oncogenes and viral vectors limit the potential application of iPSCs. Chemical-induced reprogramming offers a novel approach to generating iPSCs. In this study, a new combination of small-molecule compounds (SMs) (sodium butyrate, A-83-01, CHIR99021, Y-27632) under conditions of transient folate deprivation was used to generate iPSC. It was found that transient folate deprivation combined with SMs was sufficient to permit reprogramming from mouse embryonic fibroblasts (MEFs) in the presence of transcription factors, Oct4 and Klf4, within 25 days, replacing Sox2 and c-Myc, and accelerated the generation of mouse iPSCs. The resulting cell lines resembled mouse embryonic stem (ES) cells with respect to proliferation rate, morphology, pluripotency-associated markers and gene expressions. Deprivation of folic acid, combined with treating MEFs with SMs, can improve the inducing efficiency of iPSCs and reduce their carcinogenicity and the use of exogenous reprogramming factors.
Subject(s)
Animals , Mice , Amides , Pharmacology , Butyric Acid , Pharmacology , Cell Differentiation , Cell Line , Cell Proliferation , Extraembryonic Membranes , Cell Biology , Folic Acid , Pharmacology , Induced Pluripotent Stem Cells , Cell Biology , Kruppel-Like Transcription Factors , Metabolism , Octamer Transcription Factor-3 , Metabolism , Proto-Oncogene Proteins c-myc , Metabolism , Pyrazoles , Pharmacology , Pyridines , Pharmacology , Pyrimidines , Pharmacology , SOXB1 Transcription Factors , Metabolism , Thiocarbamates , Pharmacology , ThiosemicarbazonesABSTRACT
Various stem cells, including neural stem cells (NSCs), have been extensively studied in stroke models, but how to increase neuronal differentiation rate of NSCs remains unresolved, particularly in a damaged environment. The purpose of this study was to investigate the effects of cerebral microvascular endothelial cells (CMECs) on the neurogenesis of NSCs with or without oxygen-glucose deprivation (OGD). The NSCs acquired from primary culture were immunostained to prove cell purity. Survival and proliferation of NSCs were determined after the co-culture with CMECs for 7 days. After removing the CMECs, NSCs were randomly divided into two groups as follows: OGD and non-OGD groups. Both groups were maintained in differentiation culture for 4 days to evaluate the differentiation rate. Mouse embryo fibroblast (MEF) cells co-cultured with NSCs served as control group. NSCs co-cultured with CMECs had an increase in size (on the 7th day: 89.80±26.12 μm vs. 73.08±15.01 μm, P<0.001) (n=12) and number [on the 7th day: 6.33±5.61/high power objective (HP) vs. 2.23±1.61/HP, P<0.001] (n=12) as compared with those co-cultured with MEF cells. After further differentiation culture for 4 days, NSCs co-cultured with CMECs had an increase in neuronal differentiation rate in OGD and non-OGD groups, but not in the control group (15.16% and 16.07% vs. 8.81%; both P<0.001) (n=6). This study provided evidence that OGD could not alter the effects of CMECs in promoting the neuronal differentiation potential of NSCs. These findings may have important implications for the development of new cell therapies for cerebral vascular diseases.
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Various stem cells, including neural stem cells (NSCs), have been extensively studied in stroke models, but how to increase neuronal differentiation rate of NSCs remains unresolved, particularly in a damaged environment. The purpose of this study was to investigate the effects of cerebral microvascular endothelial cells (CMECs) on the neurogenesis of NSCs with or without oxygen-glucose deprivation (OGD). The NSCs acquired from primary culture were immunostained to prove cell purity. Survival and proliferation of NSCs were determined after the co-culture with CMECs for 7 days. After removing the CMECs, NSCs were randomly divided into two groups as follows: OGD and non-OGD groups. Both groups were maintained in differentiation culture for 4 days to evaluate the differentiation rate. Mouse embryo fibroblast (MEF) cells co-cultured with NSCs served as control group. NSCs co-cultured with CMECs had an increase in size (on the 7th day: 89.80±26.12 μm vs. 73.08±15.01 μm, P<0.001) (n=12) and number [on the 7th day: 6.33±5.61/high power objective (HP) vs. 2.23±1.61/HP, P<0.001] (n=12) as compared with those co-cultured with MEF cells. After further differentiation culture for 4 days, NSCs co-cultured with CMECs had an increase in neuronal differentiation rate in OGD and non-OGD groups, but not in the control group (15.16% and 16.07% vs. 8.81%; both P<0.001) (n=6). This study provided evidence that OGD could not alter the effects of CMECs in promoting the neuronal differentiation potential of NSCs. These findings may have important implications for the development of new cell therapies for cerebral vascular diseases.
Subject(s)
Animals , Mice , Animals, Newborn , Brain , Cell Differentiation , Physiology , Cell Proliferation , Cells, Cultured , Coculture Techniques , Methods , Endothelial Cells , Cell Biology , Metabolism , Glucose , Metabolism , Mice, Inbred C57BL , Microvessels , Cell Biology , Metabolism , Neural Stem Cells , Cell Biology , Metabolism , Oxygen , MetabolismABSTRACT
Totipotent and regionally non-specified embryonic stem (ES) cells provide a powerful tool to understand mechanisms controlling stem cell differentiation in different regions of the adult brain. As the development capacity of ES cells in the adult brain is still largely unknown, we grafted small amounts of mouse ES (mES) cells into adult rat brains to explore the survival and differentiation of implanted mES cells in different rat brain regions. We transplanted the green fluorescent protein (GFP)-positive mES cells into the hippocampus, septal area, cortex and caudate nucleus in rat brains. Then the rats were sacrificed 5, 14 and 28 d later. Of all the brain regions, the survival rate of the transplanted cells and their progeny were the highest in the hippocampus and the lowest in the septal area (P<0.01). The grafted ES cells could differentiate into nestin-positive neural stem cells. Nestin-positive/GFP-positive cells were observed in all brain regions with the highest frequency of nestin-positive cells in the hippocampus and the lowest in the medial septal area (P<0.01). mES cells differentiated into end cells such as neurons and glial cells in all transplantation sites in recipient brains. In the hippocampus, the ES cells differentiated into neurons in large amounts. These results demonstrate that only some brain regions permit survival of mES cells and their progeny, and form instructive environments for neuronal differentiation of mES cells. Thus, because of region specific presence of microenvironmental cues and their environmental fields, the characteristics of the recipient tissue were considerably important in formulating cell replacement strategies for neural disorders.
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Animals , Female , Mice , Rats , Brain , Cell Biology , Cell Differentiation , Physiology , Cell Survival , Embryonic Stem Cells , Cell Biology , Transplantation , Graft Survival , Rats, Sprague-Dawley , Transplantation, Heterologous , PhysiologyABSTRACT
<p><b>OBJECTIVE</b>To investigate the proteolytic mechanism of amyloid precursor protein (APP) and to explore amyloid-beta (A beta) generation in living neurons.</p><p><b>METHODS</b>DNA fragments were amplified by PCR or synthesized. The four fragments, CFP, 54bp, YFP and C99 were ligated into pcDNA3.0 vector to construct the recombinant plasmids pcDNA3.0-CFP-54bp-YFP and pcDNA3.0-CFP-54bp-YFP-C99. The SH-SY5Y cells were transiently transfected with pcDNA3.0-CFP-54bp-YFP or pcDNA3.0-CFP-54bp-YFP-C99. The expression of fusion gene was examined under a multiphoton laser scanning microscope. Fluorescence resonance energy transfer (FRET) was used to measure the beta cleavage and gamma cleavage of APP. A beta generation was confirmed by immunocytochemistry and multiphoton laser scanning microscopy. Cell viability was tested by MTT assay at different time points.</p><p><b>RESULTS</b>(1) The double restriction endonuclease digestion and sequencing analysis confirmed the authenticity of the recombinant plasmids pcDNA3.0-CFP-54bp-YFP and pcDNA3.0-CFP-54bp-YFP-C99. (2) Blue and yellow fluorescences were detected in the transfected cells. (3) FRET occurred in pcDNA3.0-CFP-54bp-YFP-transfected cells but not in pcDNA3.0-CFP-54bp-YFP-C99-transfected cells. (4) A beta was produced in the pcDNA3.0-CFP-54bp-YFP-C99 transfected cells. (5) A beta-deposition was widespread in the cell. (6) Cell viability decreased along with the intracellular A beta deposition.</p><p><b>CONCLUSION</b>C99 is important for the APP beta cleavage. A beta may be generated and deposited in cells at the early stage of Alzheimeros disease. Intracellular A beta accumulation brings deleterious effects on cells.</p>
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Humans , Amyloid beta-Peptides , Genetics , Metabolism , Amyloid beta-Protein Precursor , Genetics , Metabolism , Cell Line, Tumor , Fluorescence Resonance Energy Transfer , Immunohistochemistry , Microscopy, Confocal , Neurons , Metabolism , Peptide Fragments , Metabolism , Plasmids , Polymerase Chain Reaction , TransfectionABSTRACT
Early hematoma enlargement in intracerebral hemorrhage seriously influences the prognosis of patients.This article reviews the incidence,diagnostic criteria,influence factors and prevention and treatment of early hematoma enlargement in intracerebral hemorrhage.
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0.05).At different time points after ischemia-reperfusion,the expression of cytochrome C and activation of caspase-3 were lower in the transgen mice than that in the wild type rats.Conclusions Under standard condition,overexpression of bcl-xl could significantly reduce the infarct area and improve neurological function in transgene mice than those in the wild type rats.The effect of overexpression of bcl-xl might be realized through inhibiting the apoptosis of neuron,and the mechanism might be that the overexpression of bcl-xl inhibit the release of cytochrome C and the activation of caspase-3.
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Objective To study the immunogenicity of human embryonic stem cells(hESCs)and the derived neural stem cells(NSCs)in vitro.Methods The constitutive expression of human leucocyte antigen(HLA)Ⅰ and Ⅱ in hESCs and the NSCs derived from these hESCs were detected by flow cytometry (FCM), as well as the expression of HLA-Ⅰ,Ⅱin NSCs induced by 30 ng/ml recombination human interferon-?(IFN-?).Meanwhile, the NSCs before and after induction of IFN-? were co-cultured with peripheral blood lymphocyte obtained from healthy person.Lymphocyte proliferation standing for the immunoreactivity of NSCs was then investigated.Results The hESCs slightly expressed HLA-Ⅰ(6.18%) and hardly any HLA-Ⅱ before differentiation.However, the NSCs expressed more HLA-Ⅰ(23.56%)as well as HLA-Ⅱ(1.28%, 1.73%)than the hESCs did.Both HLA-Ⅰ(46.43%)and HLA-Ⅱ(8.73%, 10.57%)expressed by the NSCs after they were induced by IFN-? were up-regulated.Conclusions hESCs express certain level of HLA-Ⅰ molecules but do not constitutively express HLA-Ⅱ molecules.The derived NSCs express heavy HLA-Ⅰ and a little HLA-Ⅱ, when treated by IFN-? they can inducibly up- regulated both molecules.The NSCs derived from HESCs are of immunogenicity, which induce rejection aiming at HLA-Ⅰ molecules or even at HLA-Ⅱ molecules when the host is inflammative or under stress, which can result in a failure of cellular transplantation.
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Objective To explore a kind of simple and high efficient approach to differentiate human embryonic stem cells(hESCs)into neural stem cells(NSCs).Methods hESCs were cultured in bacterial culture dish filled with serum free medium to gain embryoid bodies.Then the mature embryoid bodies grew in the special medium including B27 and noggin by adherent culture to differentiate into NSCs. Results The hESCs kept floating in the bacterial culture dish and growing all the time and then formed mature embryoid bodies 7 to 10 days later.The embryoid bodies could be differentiated into highly pure (96.4%)nestin positive cells.And these cells were differentiated into all kinds of neural cells if cultured further.Conclusions This kind of method is less time-consuming,cheaper,and more efficient than those of the results in literatures reported.It affords very good source of seed cells for cell transplantation therapy in the future.
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<p><b>OBJECTIVE</b>To look for a gene delivery route to the treatment of Duchenne muscular dystrophy(DMD).</p><p><b>METHODS</b>The recombinant adeno-associated virus vector(rAAV) carrying a LacZ reporter gene was constructed. rAAVLacZ was delivered into the skeletal muscle tissue of C57/BL6 mice by intramuscular injection. Then an intraarterial delivery route was taken to reveal whether rAAVLacZ could transduce muscle tissue.</p><p><b>RESULTS</b>(1) The LacZ gene was efficiently transduced and expressed persisting for 5 months after intramuscular injection. (2) The membrane of muscle and smooth muscle of vessel was widely transduced by intra-arterial delivery rAAVLacZ.</p><p><b>CONCLUSION</b>These data provide the evidence that rAAVLacZ can efficiently transduce muscle for a long period. Improving intraarterial gene delivery will be promising means for rAAV-mediated gene therapy for generalized skeletal muscle of DMD.</p>
Subject(s)
Animals , Humans , Mice , Cell Line , Dependovirus , Genetics , Embryo, Mammalian , Gene Expression , Genes, Reporter , Genetic Vectors , Injections, Intramuscular , Kidney , Cell Biology , Metabolism , Lac Operon , Physiology , Mice, Inbred C57BL , Muscle, Skeletal , Cell Biology , Metabolism , Recombinant Proteins , Metabolism , Transfection , MethodsABSTRACT
Objective To observe the effect of movement exercise combined with electroaeupuneture on the expression of Nestin in the hippocampus dentate gyrus (DG) after cerebral ischemia-repeffusion.Methods Fifty- four Wistar rats were used and randomly divided into a control group (Group A),an exercise training group (Group B),and an exercise training combined with electroacupuncture group (Group C).The middle cerebral arteries (MCA) of all the rats were occluded for 1 h,followed by reperfusion for 7,14 and 21 davs.Immunohistochemistry method was used to detect the expression of Nestin in the hippoeampus dentate gyrus.Results The number of Nes- tin-positive cells peaked in DG in all groups on the 7th day after cerebral isehemia-reperfusion.The number of Nes- tin-positive cells in DG ipsilateral to the ischemia-reperfusion lesion were significantly more than those in the opposite side at various time points (P
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Objective To investigate the therapeutic effects of electroacupuncture (EA) on post stroke depres- sion (PSD) after lacunar infarction (LI).Methods Seventy-five PSD patients with lacular infarction were recruited and randomly divided into a control group and an EA group.All patients were treated with Fluoxetine,in addition to EA treat- ment in the EA group.Then all patients were evaluated using the Hamilton Depression Scale (HAMD),the Chinese stroke scale (CSS) and the Barthel Index (BI).The evaluations were carried out at 0,14 and 28 days.Results Depression symptoms (DSs) in the EA group were improved by day 14 of the treatment,and their HAMD scores had decreased.DSs in both groups had improved significantly by day 28,and the HAMD scores in the EA group were then significantly lower than those in the control group.Improvements in neurological impairment and in the activities of daily living were observed earlier in the EA group.Conclusion The combination of EA and Fluoxetine is helpful for PSD with complex patho- genesis and clinical symptoms.Therapeutic effects are enhanced and side effects are reduced.
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Objective MR microscopy technique was used to study the visualization of senile plaque deposition in brains of the Alzheimer disease(AD)transgenic mice.Methods Two transgenic mice and 2 wild type mice at the age of 17 months were scanned in vivo using T_2 weighted image.After MR imaging,the brains were cut serially and immunostained according to the orthogonal pilot images.MR T_2 weighted images and immunohistological images of the senile plaque were observed and matched.Results The MR images showed that some black spots were visible in the hippocampus and cerebral cortex of the AD transgenic mice and some spots were consistent with the senile plaques on immunohistological sections.There were no spots in the MR images and the immunohistological sections of the wild type mice.Conclusion It is possible that MR microscopy can be used to detect the deposition of the senile plaque and diagnose AD specifically.
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Objective To determine whether cleavage developmentally retarded embryos have not cleaved during a 24 hour period could develop into blastocysts and produce hESC cell lines.Methods A total of 120 such embryos were cultured to blastocyst stage by sequential culture.Blastocysts formation rate and quality of blastocyst were detected under microscope.The relation between blastocyst formation rate and blastomere number,the fragment of blastomere and blastomere symmetry were analyzed by stepwise Logistical regression analysis.Inner cell masses(ICMs)were isolated by immunosurgery.Colonies derived from the ICMs were passed every 4-7 days and the derivatives were passaged and identified.Results A total of 22 blastocysts were obtained from 120 embryos.The blastulation rate was 18.7%.Early blatocyst, blastocyst,full blastocyst,expanded blastocyst,hatching blastoeyst and hatched blastocyst accounted for 5.9%,23.5%,35.3%,23.5%,5.9%,and 5.9% respectively.The grade of ICM and trophoblast was mostly scored C or B.Blastocyst formation rate was related to cell number and blastomere symmetry but not fragment.Immunosurgery resulted in the formation of 7 ICMs and 3 primary colonies,which produced 2 cell lines.The cell lines satisfied the criteria that characterize pluripotent hESC cells.Undifferentiated cells were positive for AKP,SSEA-4,TRA-1-60,and TRA-1-81.It could continue to proliferate in vitro and form embryoid bodies when cultured in suspension.It had capability to form teratoma in SCID mice.Both cell lines had normal karyotypes after 45 and 34 passages respectively.Conclusions Our results suggest that a subset of developmentally retarded embryos can form blastocysts and give rise to hESC cell lines.
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Objective To investigate the role of synapsin-I in the differentiation of the embryonic stem cells (ESC) into the neuron,and to seek a controllable point for the ESC neural differentiation in vitro.Methods Neural differentiation of ESC was induced with the "five step approach",synapsin-I antisense oligonucleotides (AS ONs) was employed to inhibit the synapsin-I expression at different stages. At different time points,morphology,differentiation efficiency and neural specific markers were compared among the normal group and the transfected groups.A tumor cell line called PC12 cell was compared with the ESC at the same time.Results After the synapsin-I AS ONs were used in ESC differentiation, considerable decreases of neurite growth rate and neural precursor cells (nestin (+)) percentage were observed at Stage 3(68.5%?4.2% vs 76.2%?5.1% and 75.8%?4.9%,P