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951.
In breeding industries, a challenging problem is how to keep genetic diversity over generations. To investigate genetic variation and identify breeding signatures in mass selected lines of Pacific oyster (Crassostrea gigas), three sixth-generation selected lines and four wild populations were assessed using 103 single nucleotide polymorphism (SNP) markers. The genetic diversity data indicated that the selected lines exhibited a significant reduction in the observed heterozygosity and observed number of alleles per locus compared with the wild populations (P≤0.05), indicating the selected lines tended to lose genetic diversity contrasted with the wild populations. The unweighted pair-group method with arithmetic mean (UPGMA) analysis showed that the wild populations and selected lines were not separated into two groups. Using four outlier tests, a total of 17 loci were found under selection at two levels. The global outlier detection suggested that 4 common outlier loci were subject to selection using both the hierarchical island model and Bayesian likelihood approaches. At regional level, 3 SNPs were detected as outlier using at least two outlier tests and one outlier SNP (CgSNP309) was overlapped in the two wild-selected population comparisons. The candidate outlier SNPs provide valuable resources for future association studies in C. gigas. 相似文献
952.
Background
Multiple prior studies demonstrated that patients with early Chronic Kidney Disease (CKD) and positive estimated Glomerular Filtration Rate (eGFR) slopes experience increased risk of death. We sought to characterize patients with positive eGFR slopes, examine the renal function trajectory that follows the time period where positive slope is observed, and examine the association between different trajectories and risk of death.Methods and Findings
We built a cohort of 204,132 United States veterans with early CKD stage 3; eGFR slopes were defined based on Bayesian mixed-effects models using outpatient eGFR measurements between October 1999 and September 2004; to build renal function trajectories, patients were followed longitudinally thereafter (from October 2004) until September 2013. There were 41,410 (20.29%) patients with positive eGFR slope and they exhibited increased risk of death compared to patients with stable eGFR slope (HR = 1.33, CI:1.31–1.35). There was an inverse graded association between severity of albuminuria and the odds of positive eGFR slope (OR = 0.94, CI:0.90–0.98, and OR = 0.76, CI:0.69–0.84 for microalbuminuria and albuminuria; respectively). Following the time period where positive eGFR slope is observed, we characterized 4 trajectory phenotypes: high eGFR intercept and positive trajectory (HIPT) (12.42%), intermediate intercept and mild negative trajectory (IIMNT) (60.04%), low intercept and fast negative trajectory (LIFNT)(23.33%), and high intercept and fast negative trajectory (HIFNT) (4.20%). Compared to IIMNT (reference group), HIPT is associated with younger age, dementia, HIV, chronic lung disease, peripheral artery disease, weight loss, and inversely associated with albuminuria; LIFNT and HIFNT were associated with diabetes, hypertension, cardiovascular disease, peripheral artery disease, and albuminuria. The risk of death at 9 years was lowest in IIMNT (HR = 1.12, CI:1.09–1.14), highest in HIPT (HR = 1.71, CI:1.63–1.79), and intermediate in LIFNT (HR = 1.36, CI:1.32–1.40) and HIFNT (HR = 1.56, CI:1.45–1.68).Conclusions
Our results demonstrate that patients with positive eGFR slopes, when followed over longer period of time, follow 4 distinct trajectory phenotypes that have distinct demographic and clinical correlates and are differentially associated with risk of death. 相似文献953.
用汉坦病毒汉滩株(76-118)重组核蛋白作为免疫印迹法(WesternBlot以下简称WB)的诊断抗原,用于实验感染大鼠血清抗体效价测定。同时与用汉城株(SR-11)感染的Vero-E6细胞作抗原的间接免疫荧光法(以下简称IFA)进行比较。WB法对3/4标本在大鼠接种病毒后第3天测得血清IgM阳性,而IFA法仅1/4标本出现阳性,IFA效价为1:5120的血清,WB效价为1’:40960,且在血清1:10稀释时反应带亦清晰。两种方法分别测定64份大鼠血清。甩IFA法,44份(68.8%)出现类似阳性的荧光颗粒,而用WB法测定,无特异的反应带出现。非感染Vero-E6细胞作IFA抗原,30份(46.9%)与正常细胞抗原有反应,此结果表明WB法在特异性和敏感性方面均高于IFA法。IFA法中的非特异性反应系血清与细胞成份之反应。 相似文献
954.
四个籼稻(Oryza sativa L.)品种幼苗经1℃黑暗或光照250 μm ol·m - 2·s- 1处理后,抗冷的“桂山矮选3”比不抗冷的“青华6 号”幼苗存活率高,其子代是以“桂山矮选3”为母本的比“青华6 号”为母本的存活率较高。抽穗期剑叶经光照低温处理12、24 和36 h 后,光合作用是“桂山矮选3”和以“桂山矮选3”为母本的子代比“青华6 号”和以“青华6 号”为母本的子代下降较少。呼吸作用是前者比后者在处理12 h 时有明显升高现象。荧光参数Fv/Fo和Fv/Fm比值在处理24 h 时前者比后者下降明显,但在常温下恢复则是前者比后者明显较快。自然低温(寒露风)对叶绿素荧光的影响亦有相似的规律。对水稻后代的抗冷性倾向于母本进行了讨论 相似文献
955.
Microglial activation-mediated delayed and progressive degeneration of rat nigral dopaminergic neurons: relevance to Parkinson's disease 总被引:28,自引:0,他引:28
The etiology of sporadic Parkinson's disease (PD) remains unknown. Increasing evidence has suggested a role for inflammation in the brain in the pathogenesis of PD. However, it has not been clearly demonstrated whether microglial activation, the most integral part of the brain inflammatory process, will result in a delayed and progressive degeneration of dopaminergic neurons in substantia nigra, a hallmark of PD. We report here that chronic infusion of an inflammagen lipopolysaccharide at 5 ng/h for 2 weeks into rat brain triggered a rapid activation of microglia that reached a plateau in 2 weeks, followed by a delayed and gradual loss of nigral dopaminergic neurons that began at between 4 and 6 weeks and reached 70% by 10 weeks. Further investigation of the underlying mechanism of action of microglia-mediated neurotoxicity using rat mesencephalic neuron-glia cultures demonstrated that low concentrations of lipopolysaccharide (0.1-10 ng/mL)-induced microglial activation and production of neurotoxic factors preceded the progressive and selective degeneration of dopaminergic neurons. Among the factors produced by activated microglia, the NADPH oxidase-mediated release of superoxide appeared to be a predominant effector of neurodegeneration, consistent with the notion that dopaminergic neurons are particularly vulnerable to oxidative insults. This is the first report that microglial activation induced by chronic exposure to inflammagen was capable of inducing a delayed and selective degeneration of nigral dopaminergic neurons and that microglia-originated free radicals play a pivotal role in dopaminergic neurotoxicity in this inflammation-mediated model of PD. 相似文献
956.
Well-spread meiotic pachytene bivalents were obtained by using the prolonged hypotonic treatment combined with high chloroform Carnory's fixative solution from cells of the testes of domestic pigs. Comparison in the division index and length of pachytene bivalents with metaphase chromosomes showed that those of the former are 5 times higher and 3.42(1.87-5.98) times longer than those of the latter. Comparative studies on chromomere maps of bivalents and mitotic chromosomal G-bands were conducted by using the chromosome 12 as a example. Sex vesicle and various shapes of synaptic sex chromosomes have been observed. Two-color PRimed IN Situ (PRINS) labeling has been conducted successfully on pachytene bivalents of pigs. 相似文献
957.
Different effects of rat interferon alpha, beta and gamma on rat hepatic stellate cell proliferation and activation 总被引:1,自引:0,他引:1
Background
Liver fibrosis is the common sequel of chronic liver diseases. Recent studies have identified hepatic stellate cells as the primary cell type mediating hepatic fibrogenesis. It has been demonstrated that hepatic stellate cells undergo a process of activation during the development of liver fibrosis. During the activation process, hepatic stellate cells acquire myofibroblast-like phenotype featuring the expression of smooth muscle alpha actin. Interferons have been employed for the treatment of viral hepatitis. However, it is unclear what is the effect of interferons on the prevention and treatment of liver fibrosis. Moreover, it is not clear whether there are any differences among interferon alpha, interferon beta, and interferon gamma in the treatment of liver fibrosis. Therefore, our objective in current study is to investigate the effects of rat interferon-α, interferon-β, and interferon-γ on the proliferation and activation of rat hepatic stellate cells. 相似文献958.
Adhiraj Roy Salman Hashmi Zerui Li Angela D. Dement Kyu Hong Cho Jeong-Ho Kim 《Molecular biology of the cell》2016,27(5):862-871
Methylglyoxal (MG) is a cytotoxic by-product of glycolysis. MG has inhibitory effect on the growth of cells ranging from microorganisms to higher eukaryotes, but its molecular targets are largely unknown. The yeast cell-surface glucose sensors Rgt2 and Snf3 function as glucose receptors that sense extracellular glucose and generate a signal for induction of expression of genes encoding glucose transporters (HXTs). Here we provide evidence that these glucose sensors are primary targets of MG in yeast. MG inhibits the growth of glucose-fermenting yeast cells by inducing endocytosis and degradation of the glucose sensors. However, the glucose sensors with mutations at their putative ubiquitin-acceptor lysine residues are resistant to MG-induced degradation. These results suggest that the glucose sensors are inactivated through ubiquitin-mediated endocytosis and degraded in the presence of MG. In addition, the inhibitory effect of MG on the glucose sensors is greatly enhanced in cells lacking Glo1, a key component of the MG detoxification system. Thus the stability of these glucose sensors seems to be critically regulated by intracellular MG levels. Taken together, these findings suggest that MG attenuates glycolysis by promoting degradation of the cell-surface glucose sensors and thus identify MG as a potential glycolytic inhibitor. 相似文献
959.
Yucong Geng Yuanjie Deng Feilong Chen Hong Jin Taiping Hou 《Preparative biochemistry & biotechnology》2016,46(8):747-754
A three-phase bed bioreactor including a mix of immobilized microbes was used to degrade isopropanol (IPA). The immobilization method was studied and cells immobilized with calcium alginate, polyvinyl alcohol, activated carbon, and SiO2 were demonstrated to be the best immobilization method for the degradation of 90% of 2?g/L IPA in just 4 days, 1 day earlier than with free cells. Acetone was monitored as an indicator of microbial IPA utilization as the major intermediate of aerobic IPA biodegradation. The bioreactor was operated at hydraulic retention time (HRT) values of 32, 24, 16, 12, and 10?hr, which correspond to membrane fluxes of 0.03, 0.04, 0.06, 0.08, and 0.10?L/m2/hr, respectively. The chemical oxygen demand (COD) removal efficiencies were maintained at 98.0, 97.8, 89.1, 80.6, and 71.1% at a HRT of 32, 24, 16, 12, and 10?hr, respectively, while the IPA degradations were 98.6, 98.3, 90.3, 81.6, and 73.3%, respectively. With a comprehensive consideration of COD removal and economy, the optimal HRT was 24?hr. The results demonstrate the potential of immobilized mixed bacterial consortium in a three-phase fluidized bed reactor system for the aerobic treatment of wastewater containing IPA. 相似文献
960.