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关键词： 胚胎干细胞   心肌细胞   肝细胞生长因子   小鼠  

摘要： 目的观察肝细胞生长因子(HGF)在胚胎干细胞(ESC)向心肌细胞分化过程中的作用。方法制备小鼠胚胎成纤维细胞饲养层(FL),复苏的E14细胞接种在FL上,经直接悬浮法形成拟胚体(EBs),诱导组每孔加2m L胚体完全培养液再加15 ng/m L HGF,对照组只加入胚体完全培养液每孔2ml,免疫荧光染色激光共聚焦扫描显微镜下观察细胞心肌特异性蛋白Mlc-1v的表达,透射电子显微镜下观察分化细胞的超微结构特征。结果制备的FL细胞为长梭型,呈条索状或漩涡状排列,复苏在FL上的ES-E14细胞呈圆形、椭圆形克隆,经悬浮培养后即可见球形悬浮状EBs。诱导分化后第12d的细胞其心肌Mlc-1v蛋白表达阳性,透射电子显微镜下可见细胞核的周围有许多不规则成束的肌丝分布。结论肝细胞生长因子可以促进胚胎干细胞分化为心肌样细胞。

关键词： S-ADENOSYLMETHIONINE METHYLTRANSFERASE   BIOTRANSFORMATION   VOLATILIZATION   SOIL   METHYLATION   EXPRESSION   ROXARSONE   TOXICITY   CHINA   GENE  

摘要： Organic manures may contain high levels of arsenic (As) due to the use of As-containing growth-promoting substances in animal feed. To develop a bioremediation strategy to remove As from organic waste, Bacillus subtilis 168, a bacterial strain which can grow at high temperature but is unable to methylate and volatilize As, was genetically engineered to express the arsenite S-adenosylmethionine methyltransferase gene (CmarsM) from the thermophilic alga Cyanidioschyzon merolae. The genetically engineered B. subtilis 168 converted most of the inorganic As in the medium into dimethylarsenate and trimethylarsine oxide within 48 h and volatized substantial amounts of dimethylarsine and trimethylarsine. The rate of As methylation and volatilization increased with temperature from 37 to 50 degrees C. When inoculated into an As-contaminated organic manure composted at 50 degrees C, the modified strain significantly enhanced As volatilization. This study provides a proof of concept of using genetically engineered microorganisms for bioremediation of As-contaminated organic waste during composting.

关键词： Quadriplegia   Paraplegia   hESC   Stem cell therapy   TRANSPLANTATION   OLIGODENDROCYTES   DIFFERENTIATION   EPIDEMIOLOGY  

摘要： Background: Spinal cord injury (SCI) is a neurological condition which paralyses the patient below the level of injury and could occur due to damage, infection and tumors. Presently, there is no cure for SCI. The treatment options used for SCI include corticosteroid (methylprednisolone sodium succinate), surgical interventions, and physiotherapy and lowering of body temperature. The research on treatment options for SCI has been shifted to cell-based therapies. Use of human embryonic stem cells (hESCs) have been explored in animal models in which these cells have been found to hold a potential to repair and regenerate. Purpose: We wanted to assess the safety and efficacy of hESCs in the treatment of patients with spinal cord injury. Methods: Five patients who were either paraplegic or quadriplegic were treated with hESC therapy. Results: Following the treatment, all patients showed significant improvement in their sitting balance, control and sensation of bowel and bladder, power and movement of limbs (lower limbs and upper limbs). No adverse events were reported. Conclusion: In conclusion, hESC is safe and effective therapy for SCI.

关键词： INTERKINETIC NUCLEAR MIGRATION   BRAIN  

摘要： Neural stem cells (NSCs) are progenitor cells for brain development, where cellular spatial composition (cytoarchitecture) and dynamics are hypothesized to be linked to critical NSC capabilities. However, understanding cytoarchitectural dynamics of this process has been limited by the difficulty to quantitatively image brain development in vivo. Here, we study NSC dynamics within Neural Rosettes-highly organized multicellular structures derived from human pluripotent stem cells. Neural rosettes contain NSCs with strong epithelial polarity and are expected to perform apical-basal interkinetic nuclear migration (INM)-a hallmark of cortical radial glial cell development. We developed a quantitative live imaging framework to characterize INM dynamics within rosettes. We first show that the tendency of cells to follow the INM orientation-a phenomenon we referred to as radial organization, is associated with rosette size, presumably via mechanical constraints of the confining structure. Second, early forming rosettes, which are abundant with founder NSCs and correspond to the early proliferative developing cortex, show fast motions and enhanced radial organization. In contrast, later derived rosettes, which are characterized by reduced NSC capacity and elevated numbers of differentiated neurons, and thus correspond to neurogenesis mode in the developing cortex, exhibit slower motions and decreased radial organization. Third, later derived rosettes are characterized by temporal instability in INM measures, in agreement with progressive loss in rosette integrity at later developmental stages. Finally, molecular perturbations of INM by inhibition of ACTIN or NON-MUSCLE MYOSIN-II (NMII) reduced INM measures. Our framework enables quantification of cytoarchitecture NSC dynamics and may have implications in functional molecular studies, drug screening, and iPS cell-based platforms for disease modeling.

关键词： DRB1   major histocompatibility complex Class II   polymerase chain reaction-restriction fragment length polymorphism   Rohilkhandi goat   sequencing  

摘要： Aim: To study the major histocompatibility complex (MHC) Class II DRB1 gene polymorphism in Rohilkhandi goat using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and nucleotide sequencing techniques. Materials and Methods: DNA was isolated from 127 Rohilkhandi goats maintained at sheep and goat farm, Indian Veterinary Research Institute, Izatnagar, Bareilly. A 284 bp fragment of exon 2 of DRB1 gene was amplified and digested using BsaI and TaqI restriction enzymes. Population genetic parameters were calculated using Popgene v 1.32 and SAS 9.0. The genotypes were then sequenced using Sanger dideoxy chain termination method and were compared with related breeds/species using MEGA 6.0 and Megalign (DNASTAR) software. Results: TaqI locus showed three and BsaI locus showed two genotypes. Both the loci were found to be in Hardy-Weinberg equilibrium (HWE), however, population genetic parameters suggest that heterozygosity is still maintained in the population at both loci. Percent diversity and divergence matrix, as well as phylogenetic analysis revealed that the MHC Class II DRB1 gene of Rohilkhandi goats was found to be in close cluster with Garole and Scottish blackface sheep breeds as compared to other goat breeds included in the sequence comparison. Conclusion: The PCR-RFLP patterns showed population to be in HWE and absence of one genotype at one locus (BsaI), both the loci showed excess of one or the other homozygote genotype, however, effective number of alleles showed that allelic diversity is present in the population. Sequence comparison of DRB1 gene of Rohilkhandi goat with other sheep and goat breed assigned Rohilkhandi goat in divergence with Jamanupari and Angora goats.

关键词： Blood Donors   Hepatitis B Core Antigens   Hepatitis B Vaccine  

摘要： BACKGROUND It is important to differentiate whether isolated anti-HBc is due to false positive results or the prior exposure to hepatitis B virus, because individuals with false-positive anti-HBc can benefit from vaccination and their blood can be safely transfused. To distinguish between these two conditions, we evaluated the serologic response to hepatitis B vaccine. METHODS Ninety subjects with isolated anti-HBc (cases) and 100 subjects with totally negative hepatitis B serologic markers (controls) were recruited to receive three doses of hepatitis-B (HB) vaccine. Thirty days after the first dose of the vaccine, anti-HBs titers were checked and individuals with anti-HBs titer >50 mIU/mL did not receive additional doses of the vaccine. However, others completed the vaccination course, and another blood sample was collected 30 days after the third dose to measure anti-HBs level. RESULTS Nineteen (21.1%) cases and three (3%) controls had no sero-conversion (anti-HBs titers <10 mIU/mL) 30 days after the third dose (p<0.0001). Primary response, defined as the development of anti-HBs antibody titers ≥10 mIU/mL 30 days after the third dose, was observed in 43 (47.8%) cases and 92 (92%) controls (p<0.0001). Also, 31.1% of cases developed anti-HBs titers ≥ 50 mIU/mL 30 days after the first dose of vaccine, but the rate was significantly lower (5%) in the control group (p<0.0001). Furthermore, half of the individuals with positive isolated anti-HBc developed protective levels of anti-HBs after three doses of HB vaccination. CONCLUSION More than 75% of individuals with positive isolated anti-HBc can benefit from vaccination and can be included in donor pool. Also, one fifth seemed to have occult HBV infection. So HB vaccination may be used as a diagnostic tool for clarifying the situation of the subjects with isolated anti-HBc.

关键词： ACTIVATED PROTEIN-KINASE   DOUBLE-STRANDED-RNA   SELF-RENEWAL   MESSENGER-RNA   TRANSCRIPTION FACTOR   INITIATION FACTOR-2-ALPHA   DEPENDENT STIMULATION   TRANSLATIONAL CONTROL   MOUSE   GCN4  

摘要： Growth factors and transcription factors are well known to regulate pluripotent stem cells, but less is known about translational control in stem cells. Here, we use embryonic stem cells (ESCs) to investigate a connection between ESC growth factors and eIF2 alpha-mediated translational control (eIF2 alpha phosphorylation promotes protein expression from mRNAs with upstream open-reading frames, or uORFs). We find abundant phosphorylated P-eIF2 alpha (P-eIF2 alpha) in both pluripotent mouse and human ESCs, but little P-eIF2 alpha in ESCs triggered to differentiate. We show that the growth factors LIF (leukemia inhibitory factor) and BMP4 (bone morphogenic protein 4) both maintain P-eIF2 alpha in mESCs, but use distinct mechanisms: LIF inhibits an eIF2 alpha phosphatase whereas BMP4 activates an eIF2 alpha kinase. The mRNAs encoding the pluripotency factors Nanog and c-Myc possess uORFs while Oct4 mRNA does not. We find that salubrinal, a chemical that increases eIF2 alpha phosphorylation, promotes Nanog and c-Myc expression, but not Oct4 expression. These experiments connect ESC growth factors to eIF2 alpha phosphorylation and suggest a chemical substitute for LIF to enhance Nanog and c-Myc expression.