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21.
为阐明中国沿海浒苔的亲缘关系及地理分布特点,采集青岛栈桥、盐城弶港、宁波象山、温州平阳四地浒苔样本,克隆测序得到ITS1、5.8SrDNA和ITS23种不同长度序列片段。四个地区的rbcL目的片段,长度均为1201bp。分析核苷酸差异和遗传距离,采用邻接法建立系统发生树。结果显示,ITS序列进化速率较快,rbcL序列相当保守。ITS区较短,GC含量均在65%以上,5.8SrDNA的CG含量在50%左右,ITS1区的序列差异大于ITS2区。四个地区的浒苔存在一定的地理差异,盐城和青岛的样本间的亲缘关系较近;宁波和温州的样本间的亲缘关系较近。石莼属(Ulva)和浒苔属(Enteromorpha)的物种没有聚成各自独立的分枝,而是相互混合在一起,应是两个亲缘关系相近的属。引起青岛绿潮的海藻很可能是来自盐城海域的Enteromorpha linza或Enteromorpha prolifera。 相似文献
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采用正反相硅胶、Sephadex LH-20凝胶、MCI树脂等层析技术从中药益智95%乙醇提取物的乙酸乙酯部位分离得到13个化合物,运用现代波谱技术分别鉴定为:益智酮甲(1,yakuchinone A)、益智醇(2,oxyphyllacin-ol)、白杨素(3,chrysin)、rhamnocitrin(4)、oxyphyllenodiol A(5)、oxyphyllenodiol B(6)、nootkatone(7)、dehydro-noot-katone(8)、7-epi-teucrenone(9)、oxyphyllenone A(10)、oxyphyllenone B(11)、原儿茶酸(12,protocatechuic acid)和琥珀酸(13,succinic acid)。其中化合物4、13为首次从该植物中分得,化合物8为新的天然产物。 相似文献
24.
P73 is a structural and functional homologue of p53, and plays an important role in regulating cell cycle and apoptosis. A
potentially functional polymorphism (designated as p73 G4C14-to-A4T14) has been identified in a region in exon 2 of the p73 gene, which may theoretically form a stem-loop structure and thereby affect p73 expression. Several investigations have reported the correlation between p73 G4C14-to-A4T14 polymorphism and cancer risk.
However, the results are inconclusive. To further assess the association between p73 polymorphism and cancer risk, we performed
meta-analysis of the data sets obtained from 26 individual studies involving 8,148 cancer patients and 8,150 controls. The
association between p73 G4C14-to-A4T14 polymorphism and cancer risk was determined by crude odd ratios (OR) with 95% CI (confidential
interval). AT-allele carriers were found to have a significantly increased risk of cervical cancer (AT/GC vs. GC/GC, OR = 1.63,
95% CI = 1.14–2.33; AT/AT + AT/GC vs. GC/GC, OR = 1.49, 95% CI = 1.05–2.10), colorectal cancer (AT/AT vs. AT/GC + GC/GC, OR = 1.98,
95% CI = 1.25–3.12), head and neck cancer (AT/AT + AT/GC vs. GC/GC, OR = 1.44, 95% CI = 1.06–1.96) and other cancers (AT/AT
vs. GC/GC, OR = 1.78, 95% CI = 1.24–2.57; AT/AT vs. AT/GC + GC/GC, OR = 1.80, 95% CI = 1.26–2.56). In the stratified analysis
of ethnicity, a significantly elevated cancer risk was found in Caucasians (AT/AT + AT/GC vs. GC/GC, OR = 1.18, 95% CI = 1.08–1.30;
allele AT vs. allele GC, OR = 1.15, 95% CI = 1.06–1.24). No significant association of p73 polymorphism with the cancer risk
of smoking was detected by stratified analysis by smoking status. Together, our data suggest that the p73 G4C14-to-A4T14 may
be a risk factor of cancer especially in Caucasians. 相似文献
25.
Food restriction (FR) is hypothesized to decrease body fat content of an animal and thus prevent obesity. However, the response of energy budget to a continuous (CFR) or discontinuous FR (DFR) remains inconsistent. In the present study, effects of CFR or DFR and refeeding on energy budget and behavior were examined in male Swiss mice. CFR significantly decreased the energy expenditure associated with basal metabolic rate (BMR) and activity behavior, but not sufficiently to compensate for energy deficit and thus resulted in lower body mass and fat content. DFR mice had a significantly higher food intake on ad libitum days and showed increases in BMR and activity after 4 weeks’ DFR, which might resulted in lower body mass and less body fat than controls. After being refed ad libitum, both CFR and DFR mice had similar body mass, BMR, and behavioral patterns to controls but had 95% and 75% higher fat content. This suggested that not only CFR but also DFR would be a significant factor in the process of obesity for animals that were refed ad libitum. It also indicated that food restriction interrupted many times by periods of ad libitum feeding had the same long-term effects like continuous underfeeding. 相似文献
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27.
Jie Xu Rui Zhang Pingping Zuo Nan Yang Chao Ji Weiran Liu Yun Wang Hui Wang Anshi Wu Yun Yue Yanyong Liu 《Cellular and molecular neurobiology》2012,32(8):1343-1351
Some anesthetics have been suggested to induce Alzheimer??s disease (AD) neuro-pathogenesis. Increasing evidence indicates that hyperphosphorylated tau plays a key role in the pathogenic events that occur in AD. Isoflurane has been shown to induce apoptosis, which leads to accumulation of amyloid-?? (A??). We set out to investigate whether isoflurane can induce apoptosis by increasing hyperphosphorylated tau in A??25?C35-induced cells and the underlying mechanism. Cultured rat pheochromocytoma cells (PC12) were exposed to 20?mM A??25?C35 alone or with 2?% isoflurane for 6?h. The cell viability was determined by MTT assay, and the apoptosis rate was detected by flowcytometry. Western blotting and immunocytochemical staining were performed to observe the protein expression of Bcl-2 family, tau phosphorylation of different sites, tau protein kinases and phosphatases. Additionally, lithium chloride was administered to all above groups to investigate the changes of apoptosis rate and protein expression. The apoptosis rate was significantly increased in A??25?C35 group compared with the others groups, which was accompanied by bcl-2 decline, and the phosphorylation of glycogen synthase kinase-3??(GSK-3??) and tau of two sites increased. LiCl attenuated the cellular apoptosis by inhibition the level of tau phosphorylation. Isoflurane upregulated the level of phosphorylated GSK-3??, which phosphorylate tau at different sites, and aggravated the apoptotic rate of the A??25?C35-induced PC12 cells. It indicated that isoflurane-induced tau phosphorylation might play a role in the AD-like development. 相似文献
28.
Jing Yang Chenghang Yang Jiahui Qian Facai Li Junlong Zhao Rui Fang 《Microbial biotechnology》2020,13(6):2057-2069
Individuals with inhibited immunity may develop lethal toxoplasmosis; thus, a safe and effective vaccine is urged to be developed. Toxoplasma gondii (T. gondii) α-amylase (α-AMY) is one of the enzymes responsible for starch digestion. In the present study, we first generated a ME49Δα-amy mutant and discovered that loss of α-AMY robustly grew in vitro but contributed to significant virulence attenuation in vivo. Therefore, we established a mouse model to explore the protective immunity of Δα-amy mutant against acute and chronic toxoplasmosis. The results indicated that the survival rates of short-term or long-term immunized mice re-infected with the tachyzoites of multiple T. gondii strains were nearly 100%. ME49Δα-amy not only could provide protective immunity against tachyzoites infection but also could resist the infection of tissue cysts. Furthermore, we detected that ME49Δα-amy vaccination could effectively eliminate the proliferation of parasites in mice and prevent the formation of cysts. The significant increases of Th1-type cytokines, Th2-type cytokines and specific total IgG and IgG subclasses (IgG2a and IgG1) confirmed efficiency of a combination of cellular and humoral immunity against infection. In conclusion, ME49Δα-amy attenuated strain can produce strong immune responses to provide efficient protection against toxoplasmosis, which signifies that ME49Δα-amy mutant may be a potential vaccine candidate. 相似文献
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Objective : To determine the relative validity of specific bioelectrical impedance analysis (BIA) prediction equations and BMI as predictors of physiologically relevant general adiposity. Research Methods and Procedures : Subjects were >12, 000 men and women from the Third National Health and Nutrition Examination Survey population. We examined the correlations between BMI and percentage body fat based on 51 different predictive equations, blood pressure, and blood levels of glucose, high‐density lipoprotein cholesterol, and triglycerides, which are known to reflect adiposity, while controlling for other determinants of these physiological measures. Results : BMI consistently had one of the highest correlations across biological markers, and no BIA‐based measure was superior. Percent body fat estimated from BIA was minimally predictive of the physiological markers independent of BMI. Discussion : These results suggest that BIA is not superior to BMI as a predictor of overall adiposity in a general population. 相似文献