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61.
Large-scale proliferation and multi-lineage differentiation capabilities make neural stem cells (NSCs) a promising renewable source of cells for therapeutic applications. However, the practical application for neuronal cell replacement is limited by heterogeneity of NSC progeny, relatively low yield of neurons, predominance of astrocytes, poor survival of donor cells following transplantation and the potential for uncontrolled proliferation of precursor cells. To address these impediments, we have developed a method for the generation of highly enriched immature neurons from murine NSC progeny. Adaptation of the standard differentiation procedure in concert with flow cytometry selection, using scattered light and positive fluorescent light selection based on cell surface antibody binding, provided a near pure (97%) immature neuron population. Using the purified neurons, we screened a panel of growth factors and found that bone morphogenetic protein-4 (BMP-4) demonstrated a strong survival effect on the cells in vitro, and enhanced their functional maturity. This effect was maintained following transplantation into the adult mouse striatum where we observed a 2-fold increase in the survival of the implanted cells and a 3-fold increase in NeuN expression. Additionally, based on the neural-colony forming cell assay (N-CFCA), we noted a 64 fold reduction of the bona fide NSC frequency in neuronal cell population and that implanted donor cells showed no signs of excessive or uncontrolled proliferation. The ability to provide defined neural cell populations from renewable sources such as NSC may find application for cell replacement therapies in the central nervous system.  相似文献   
62.
The objective was to identify legume shrub species for development of agroforestry technologies based on seed and forage (leaves and twigs < 10 mm diameter) yield, and determinants of forage quality. Ten individual plants of Bituminaria bituminosa ‘Ecotypes 1’, B. bituminosa ‘Ecotypes 2’, Medicago citrina, and M. arborea from Spain; Colutea istria and Onobrychis aurantiaca from Syria; C. istria from Jordan; Chamaecytisus mollis from Morocco; and Coronilla glauca from France were randomly selected from plots established in a non-tropical dryland environment in northwest Syria in 2000. Five individual plants of each species were cut back to 0.5 m above ground in March 2004. Coppice regrowths were pruned in December 2004 and April 2005 to determine forage yield and proportion of forage in the total above ground biomass (PEFB). Forage samples were analyzed for concentrations of crude protein (CP), lignin(sa), acid detergent fibre (ADFom), neutral detergent fibre (aNDFom), in vitro organic matter (OM) digestibility (IVOMD), and in vitro 24 h gas production (IVGP24h). Matured seeds were hand harvested from the remaining five plants of each species to estimate seed yield. Forage (21–250 kg DM/ha) and seed (0–200 kg DM/ha) yields; PEFB (0.22–0.96); and concentrations of CP (85–115 g/kg DM), lignin(sa) (14–42 g/kg DM), ADFom (94–170 g/kg DM), aNDFom (122–217 g/kg DM), IVOMD (456–617 g/kg OM), and IVGP24h (27–42 ml 200 mg/DM) varied (P<0.05) among shrub species. The IVOMD and IVGP24h were positively correlated (r = 0.75, P<0.032), whereas IVOMD and IVGP24h were negatively correlated with ADFom, lignin(sa) and aNDFom. In terms of forage and seed yields and determinants of forage quality, C. istria from Jordan, M. arborea, B. bituminosa ‘Ecotype-2’, C. istria and O. aurantiaca have higher potential than C. mollis, C. glauca and B. Bituminosa ‘Ecotype-1’ for the development of agroforestry technologies in non-tropical dry areas.  相似文献   
63.
Gastrokine 1 (GKN1) plays an important role in the gastric mucosal defense mechanism and also acts as a functional gastric tumor suppressor. In this study, we examined the effect of GKN1 on the expression of inflammatory mediators, including NF‐κB, COX‐2, and cytokines in GKN1‐transfected AGS cells and shGKN1‐transfected HFE‐145 cells. Lymphocyte migration and cell viability were also analyzed after treatment with GKN1 and inflammatory cytokines in AGS cells by transwell chemotaxis and an MTT assay, respectively. In GKN1‐transfected AGS cells, we observed inactivation and reduced expression of NF‐κB and COX‐2, whereas shGKN1‐transfected HFE‐145 cells showed activation and increased expression of NF‐κB and COX‐2. GKN1 expression induced production of inflammatory cytokines including IL‐8 and ‐17A, but decreased expression of IL‐6 and ‐10. We also found IL‐17A expression in 9 (13.6%) out of 166 gastric cancer tissues and its expression was closely associated with GKN1 expression. GKN1 also acted as a chemoattractant for the migration of Jurkat T cells and peripheral B lymphocytes in the transwell assay. In addition, GKN1 significantly reduced cell viability in both AGS and HFE‐145 cells. These data suggest that the GKN1 gene may inhibit progression of gastric epithelial cells to cancer cells by regulating NF‐κB signaling pathway and cytokine expression. J. Cell. Biochem. 114: 1800–1809, 2013. © 2013 Wiley Periodicals, Inc.  相似文献   
64.
The spindle checkpoint is a surveillance mechanism that regulates the metaphase-anaphase transition during somatic cell division through inhibition of the APC/C ensuring proper chromosome segregation. We show that the conserved spindle checkpoint protein BubR1 is required during early embryonic development. BubR1 is maternally provided and localises to kinetochores from prophase to metaphase during syncytial divisions similarly to somatic cells. To determine BubR1 function during embryogenesis, we generated a new hypomorphic semi-viable female sterile allele. Mutant females lay eggs containing undetectable levels of BubR1 show early developmental arrest, abnormal syncytial nuclear divisions, defects in chromosome congression, premature sister chromatids separation, irregular chromosome distribution and asynchronous divisions. Nuclei in BubR1 mutant embryos do not arrest in response to spindle damage suggesting that BubR1 performs a checkpoint function during syncytial divisions. Furthermore, we find that in wild-type embryos BubR1 localises to the kinetochores of condensed polar body chromosomes. This localisation is functional because in mutant embryos, polar body chromatin undergoes cycles of condensation-decondensation with additional rounds of DNA replication. Our results suggest that BubR1 is required for normal synchrony and progression of syncytial nuclei through mitosis and to maintain the mitotic arrest of the polar body chromosomes after completion of meiosis.  相似文献   
65.
Low reaction yields and the high cost of obtaining a single type of pure CD make γ-CD costly. Using rational design and with the aid of 3D modeling structures, recombinant CGTase from Bacillus sp. G1 was molecularly engineered with the aim of producing a higher percentage of γ-CD. A single mutation at subsite −3, denoted H43T, was found to increase γ-CD production from 10% to approximately 39% using tapioca starch. This novel increment was probably the result of reduced steric hindrance to the formation of γ-CD because of the shortened side chain together with the shortened loop at positions 86–89, at substrate-binding subsite −3. A mutation (Tyr188 → Trp) and a deletion at loop 139–144 showed little effect on product specificity; however, mutagenesis at these sites affected cyclization, coupling and hydrolysis activities as well as the kinetic properties of the mutant CGTase. Based on rational design, three further mutations of the mutant H43T (denoted H43T/Δ(139–144)/S134T/A137V/L138D/V139I, H43T/S85G and H43T/Y87F) were constructed and produced γ-CD with yields of 20%, 20% and 39%, respectively. The mutant H43T/Δ(139–144)/S134T/A137V/L138D/V139I had very low cyclization and coupling activities, however their hydrolysis activity was retained. Double mutation (H43T/S85G) caused the enzyme to exhibit higher starch hydrolysis activity, approximately 26 times higher than the native CGTase G1. Although the mutants H43T and H43T/Y87F could produce the same percentage (39%) of γ-CD, the latter was more efficient as the total amount of CD produced was higher based on the Vmax and kcat values.  相似文献   
66.
Phytoremediation of contaminated calcareous desert land in the United Arab Emirates has been investigated. Soils from 12 northern UAE sites, suspected of metal contamination, were acid-extracted and analyzed by ICP-OES for Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn. Twenty-two plants naturally growing at contaminated sites were sampled and analyzed for their uptake of Co, Cr, Cu, Mn, Ni, Pb, and Zn and eight commercially available plants, grown under controlled conditions, were also studied for their phytoextraction capabilities. The concentration of available Cr was found to be 1300 ± 150 mg/kg in the soil of the Ajman Industrial Zone and 80 ± 10 mg/kg of Pb was found at Bithna. Among the plants investigated, Portulaca oleracea and Iresine herbstii showed potential for Cr(VI) and Pb(II) accumulation, respectively, with bioconcentration factors (BCF) greater than unity. Atriplex halimus accumulated Co(II), Cr(III), and Cu(II) each with a BCF > 1.  相似文献   
67.
Ultraviolet radiation (UV) from sunlight is the primary cause of skin and ocular neoplasia. Brahma (BRM) is part of the SWI/SNF chromatin remodeling complex. It provides energy for rearrangement of chromatin structure. Previously we have found that human skin tumours have a hotspot mutation in BRM and that protein levels are substantially reduced. Brm−/− mice have enhanced susceptibility to photocarcinogenesis. In these experiments, Brm−/− mice, with both or a single Trp53 allele were exposed to UV for 2 or 25 weeks. In wild type mice the central cornea and stroma became atrophic with increasing time of exposure while the peripheral regions became hyperplastic, presumably as a reparative process. Brm−/−, Trp53+/−, and particularly the Brm−/− Trp53+/− mice had an exaggerated hyperplastic regeneration response in the corneal epithelium and stroma so that the central epithelial atrophy or stromal loss was reduced. UV induced hyperplasia of the epidermis and corneal epithelium, with an increase in the number of dividing cells as determined by Ki-67 expression. This response was considerably greater in both the Brm−/− Trp53+/+ and Brm−/− Trp53+/− mice indicating that Brm protects from UV-induced enhancement of cell division, even with loss of one Trp53 allele. Cell division was disorganized in Brm−/− mice. Rather than being restricted to the basement membrane region, dividing cells were also present in the suprabasal regions of both tissues. Brm appears to be a tumour suppressor gene that protects from skin and ocular photocarcinogenesis. These studies indicate that Brm protects from UV-induced hyperplastic growth in both cutaneous and corneal keratinocytes, which may contribute to the ability of Brm to protect from photocarcinogenesis.  相似文献   
68.
The effect of DMSO on cholesterol and bile acid metabolism was studied in rats. Male Sprague-Dawley rats were randomly assigned to one of two groups and given either tap water or 2% DMSO (v/v) in tap water to drink for 9 days. Both food (stock rat diet) and water were available ad libitum. Animals in both groups gained weight equally throughout the study. They also had similar liver weights (g/100 g body wt) at the end of the study (control: 5.0 +/- 0.1 (N = 6) vs DMSO: 4.9 +/- 0.1 (N = 6]. The activity of hepatic cholesterol 7 alpha-hydroxylase (pmole/mg/min), the rate-limiting enzyme of bile acid biosynthesis, was significantly (P less than 0.005) reduced in the treated animals (control: 9.7 +/- 1.0 (N = 6) vs DMSO: 4.3 +/- 0.7 (N = 6)). Plasma cholesterol (mg/dl) was significantly (P less than 0.005) elevated in the treated animals (control: 90 +/- 3 (N = 6) vs DMSO: 107 +/- 4 (N = 6)), a finding consistent with the reduced CH-7 alpha hydroxylase activity in this group. DMSO treatment did not affect either microsomal cholesterol content or hepatic glutathione content. Thus, this study has shown that DMSO treatment per se can affect cholesterol and bile acid metabolism. However, the precise mechanisms whereby DMSO exerts the observed effects are not known.  相似文献   
69.
2-Naphthylsulfonylhydrazine was reacted with aromatic aldehydes or aldehydo sugars to give the corresponding hydrazones which undergo Michael addition reactions with malononitrile or ethyl cyanoacetate to form pyrazole derivatives.  相似文献   
70.
Polycomb-repressive complex 1 (PRC1)-mediated histone ubiquitylation plays an important role in aberrant gene silencing in human cancers and is a potential target for cancer therapy. Here we show that 2-pyridine-3-yl-methylene-indan-1,3-dione (PRT4165) is a potent inhibitor of PRC1-mediated H2A ubiquitylation in vivo and in vitro. The drug also inhibits the accumulation of all detectable ubiquitin at sites of DNA double-strand breaks (DSBs), the retention of several DNA damage response proteins in foci that form around DSBs, and the repair of the DSBs. In vitro E3 ubiquitin ligase activity assays revealed that PRT4165 inhibits both RNF2 and RING 1A, which are partially redundant paralogues that together account for the E3 ubiquitin ligase activity found in PRC1 complexes, but not RNF8 nor RNF168. Because ubiquitylation is completely inhibited despite the efficient recruitment of RNF8 to DSBs, our results suggest that PRC1-mediated monoubiquitylation is required for subsequent RNF8- and/or RNF168-mediated polyubiquitylation. Our results demonstrate the unique feature of PRT4165 as a novel chromatin-remodeling compound and provide a new tool for the inhibition of ubiquitylation signaling at DNA double-strand breaks.  相似文献   
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