胆碱相对水平在胶质瘤术前分级的价值及与细胞增殖活性的相关性研究

目的：探讨Cho相对水平在胶质瘤术前分级的价值及与肿瘤细胞增殖活性的相关性。材料与方法搜集行1H-MRS检查并经病理证实的脑胶质瘤患者58例,分为Ⅰ～Ⅱ级(低级别)、Ⅲ级、Ⅳ级3组,其中Ⅲ～Ⅳ级为高级别胶质瘤。选取肿瘤实质Cho/Cr最大处及对侧正常表现白质为感兴趣区,获得肿瘤实质Cho/NAA、Cho/Cr、rCho/NAA及rCho/Cr值。根据Ki-67标记指数将Ki-67分级定义为阴性(－)、弱阳性(+)、阳性(++)和强阳性(+++)4级。分析不同级别胶质瘤肿瘤实质Cho相对水平各参数的组间差异性并采用受试者特征曲线(ROC)确定诊断阈值。分析Ki-67级别与胶质瘤肿瘤级别、Cho相对水平各参数的相关性。结果Ⅲ级及Ⅳ级胶质瘤实质部分Cho相对水平各参数显著高于Ⅰ～Ⅱ级胶质瘤(P<0.05),但Ⅲ级与Ⅳ级间无统计学差异性(P>0.05),高低级别胶质瘤各参数组间有统计学差异性(P<0.05);区分高低级别胶质瘤的Cho相对水平各指标中,Cho/NAA的诊断准确率最高,为81.0%,诊断界值为3.04,rCho/Cr曲线下面积最大,为0.823。不同级别胶质瘤Ki-67分级存在显著差异性,两者呈显著正相关(r=0.741, P<0.05)。Cho/NAA、Cho/Cr及rCho/Cr与Ki-67分级呈轻度正相关(r分别为0.313、0.444和0.336,P均<0.05)。结论 Cho相对水平可作为反映胶质瘤细胞增殖状态、评价肿瘤恶性程度的指标。     

CD36 palmitoylation disrupts free fatty acid metabolism and promotes tissue inflammation in non-alcoholic steatohepatitis

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Focal differences in lipid metabolism of the young pig aorta : Part 2. Synthesis from [2-C]ethanolamine and [1,2-C]choline

The ability of normal young pig aortic tissue to synthesize phospholipids from [2-¹⁴C]ethanolamine and [1,2-¹⁴C]choline, in vitro, has been examined in areas of focal Evans Blue accumulation (blue areas) and adjacent areas of no dye accumulation (white areas).

Incorporation of [2-¹⁴C]ethanolamine into total lipid was linear for 3 h of incubation in both blue and white areas. At 3 h, ethanolamine incorporation into phosphatidyl ethanolamine was significantly less in blue than in white areas.

[1,2-¹⁴C]Choline incorporation into total lipid was linear for 3 h of incubation in blue areas but not in white areas. At 30 min, choline incorporation into phosphatidyl choline was significantly less in blue than in white areas; at 1 h choline incorporation into phosphatidyl choline was similar in blue and white areas, while after 3 h of incubation incorporation was significantly greater in blue than in white areas.

With both [2-¹⁴C]ethanolamine and [1,2-¹⁴C]choline, the percentage distribution of label among individual phospholipids was similar in blue and white areas.

Phospholipid content of blue and white areas was similar.

The results presented demonstrate further focal metabolic differences within the same geographical region of the normal young pig aorta.     

A C-terminal truncated mutation of licC attenuates the virulence of Streptococcus pneumoniae

LicC has been identified as a virulence factor of Streptococcus pneumoniae. However, its role in virulence is still not fully understood because deletion of licC is lethal for the bacterium. In this study, a mutant with 78-bp truncation at the C-terminus of licC was obtained from a signature-tagged mutagenesis (STM) library. The mutant was viable with a large reduction in enzymatic activity as CTP:phosphocholine cytidylyltransferase detected in vitro using a firefly luciferase assay. The mutation attenuated the adhesion and invasion of S. pneumoniae ST556 (serotype 19F) to epithelial cells by 72% and 80%, respectively, and increased the phagocytosis by macrophages for 16.5%, compared to the parental strain. When the mutation was introduced into the encapsulated D39 strain (serotype 2), it led to attenuated virulence in mouse models either by intranasal colonization or by intraperitoneal infection. In addition, the phosphocholine (PCho) on cell surface was decreased, and the choline binding proteins (CBPs) were impaired, which may explain the attenuated virulence of the mutant. These observations indicate that C-terminus of licC is accounted for the main activity of LicC in PCho metabolism and is essential for the virulence of S. pneumoniae, which provides a novel target for drug design against pneumococcal infection.     

胞磷胆碱在血管性认知损害中的治疗作用

血管性认知损害是指所有与血管性疾病有关的认知损害综合征,包括从轻度认知损害到血管性痴呆在内的重度认知损害.胞磷胆碱是神经元细胞膜的重要组成成分磷脂酰胆碱生物合成的必需中间体.实验研究显示,胞磷胆碱在脑缺血中具有神经保护和神经修复作用.临床研究显示,胞磷胆碱有可能改善血管性认知损害患者的认知功能.     

The hinge region in androgen receptor control

The region between the DNA-binding domain and the ligand-binding domain of nuclear receptors is termed the hinge region. Although this flexible linker is poorly conserved, diverse functions have been ascribed to it. For the androgen receptor (AR), the hinge region and in particular the (629)RKLKKL(634) motif, plays a central role in controlling AR activity, not only because it acts as the main part of the nuclear translocation signal, but also because it regulates the transactivation potential and intranuclear mobility of the receptor. It is also a target site for acetylation, ubiquitylation and methylation. The interplay between these different modifications as well as the phosphorylation at serine 650 will be discussed here. The hinge also has an important function in AR binding to classical versus selective androgen response elements. In addition, the number of coactivators/corepressors that might act via interaction with the hinge region is still growing. The importance of the hinge region is further illustrated by the different somatic mutations described in patients with androgen insensitivity syndrome and prostate cancer. In conclusion, the hinge region serves as an integrator for signals coming from different pathways that provide feedback to the control of AR activity.     

胃酸分泌的调节

胃酸分泌是一个动态且复杂的过程,壁细胞H＋-K＋-ATP酶是泌酸的最终和最关键环节。刺激胃酸分泌的主要途径包括旁分泌（肠嗜铬细胞分泌的组胺）、内分泌（G细胞分泌的胃泌素）、神经内分泌（肠神经节后神经纤维分泌的胆碱能）,上述因子结合壁细胞膜上相应受体,通过细胞内第二信使（钙离子、cAMP等）激活蛋白激酶．使壁细胞胞浆管状囊泡运载H＋-K＋-ATP酶向壁细胞顶膜移行并最终使酶嵌入壁细胞顶膜,在H＋-K＋-ATP酶的作用下与胞外K＋交换,泵出H＋。本文就壁细胞胃酸分泌相关受体及其信号通路作一概述。     

N‐acetyl cysteine attenuates diazinon exposure‐induced oxidative stress in rat testis

The aim of this study was to investigate the gonadotoxic effects of diazinon and its mechanism of action with special reference to its possible reactive oxygen species generating potential in rat testis and the protective effect of N‐Acetyl Cysteine (NAC) on the exposure of diazinon. The vehicle was given orally to the control group and NAC, diazinon, combination of NAC and diazinon were given to three treatment groups for 4 weeks. Testis lipid peroxidation levels were higher in diazinon group than in control although lipid peroxidation levels were lower in diazinon + NAC group than in diazinon group. The reduced glutathione (GSH) levels were lower in diazinon group than in control and NAC group although its levels were higher in diazinon + NAC group than in diazinon group. Vitamin C, Vitamin E and β‐carotene concentrations were also lower in diazinon group than in control and NAC groups. Vitamin E and β‐carotene concentrations were higher in diazinon + NAC group than diazinon group. Glutathione peroxidase activity and vitamin A concentrations in the testis did not show any difference between the four groups. In conclusion, we observed that NAC treatment modulated diazinon‐induced oxidative injury in the rat testis. These findings suggest that NAC supplementation can be useful in testis oxidative injury caused by the organophosphate insecticides.