首诊成人强迫症脑3D-多体素氢质子磁共振波谱分析

目的探讨强迫症（OCD）患者不同区域脑组织代谢特点。方法选择17例首诊未经治疗的成人OCD患者为研究对象,并以性别、年龄、受教育程度匹配的17例健康志愿者为对照组,采用3D-多体素氢质子磁共振波谱分析OCD患者前扣带回、中扣带回、左右额叶白质、左右丘脑和左右豆状核中大脑代谢物N-乙酰门冬氨酸（NAA）、胆碱（Cho）和肌酸（Cr）浓度变化,并分析NAA/Cr、Cho/Cr与OCD、焦虑和抑郁量表评分的相关性。结果OCD患者中扣带回的Cho/Cr明显低于对照组（P＜0.05）,左额叶白质Cho/Cr明显高于对照组（P＜0.05）;中扣带回NAA/Cr与焦虑量表评分呈正相关（r=0.712,P＜0.05）。结论OCD患者中扣带回Cho浓度减少、左额叶白质Cho浓度增高,可能是OCD的病理现象或代偿反应;中扣带回NAA/Cr与焦虑量表评分呈正相关。     

Antibody to two forms of dihydrolipoamide acetyltransferase (PDC-E2) in primary biliary cirrhosis

ABSTRACT— Dihydrolipoamide acetyltransferase, the E2 subunit of the pyruvate dehydrogenase complex (PDC-E2), is the major autoantigen in primary biliary cirrhosis. By immunoblotting with sera from patients with primary biliary cirrhosis, we observed a double band, of molecular weight 70 and 74 kD for PDC-E2, when a preparation of bovine heart mitochondria was not boiled prior to electrophoresis. This double band could also be detected using antisera raised in rats or rabbits against intact PDC or PDC-E2, but not in antisera raised against a synthetic decamer representing the lipoic acid binding sequence of PDC-E2; the latter reacted only with the 74 kD component. Antibody eluted from either the 70 or 74 kD component reacted with both 70 and 74 kD components. By ELISA, sera from patients with primary biliary cirrhosis reacted more strongly with a non-boiled than a boiled PDC-E2, whereas immune animal sera reacted equally with both preparations. Thus, according to whether preparations of PDC are boiled or not, two conformationally alternative forms of the PDC-E2 protein can be revealed by immunoblotting. The two forms in non-boiled preparations migrate at molecular weights corresponding to 70 and 74 kD.     

Plasma homocysteine,dietary B vitamins,betaine, and choline and risk of peripheral artery disease

Objective

Few studies have examined the roles of homocysteine and related nutrients in the development of peripheral artery disease (PAD). We examined the associations between plasma homocysteine, dietary B vitamins, betaine, choline, and supplemental folic acid use and incidence of PAD.

Methods

We used two cohort studies of 72,348 women in the Nurses' Health Study (NHS, 1990–2010) and 44,504 men in the Health Professionals Follow-up Study (HPFS, 1986–2010). We measured plasma homocysteine in nested matched case–control studies of clinically recognized PAD within both cohorts, including 143 PAD cases and 424 controls within the NHS (1990–2010) and 143 PAD cases and 428 controls within the HPFS (1994–2008). We examined the association between diet and risk of incident PAD in the cohorts using a food frequency questionnaire and 790 cases of PAD over 3.1 million person-years of follow-up.

Results

Higher homocysteine levels were positively associated with risk of PAD in men (adjusted IRR 2.17; 95% CI, 1.08–4.38 for tertile 3 vs. 1). There was no evidence of an association in women (adjusted IRR 1.14; 95% CI, 0.61–2.12). Similarly, higher folate intake, including supplements, was inversely associated with risk of PAD in men (adjusted HR 0.90; 95% CI, 0.82–0.98 for each 250 μg increase) but not women (HR 1.01, 95% CI, 0.88–1.15). Intakes of the other B vitamins, betaine, and choline were not consistently associated with risk of PAD in men or women.

Conclusion

Homocysteine levels were positively associated and dietary folate intake was inversely associated with risk of PAD in men but not in women.     

Morphological and physiological properties of enhanced green fluorescent protein (EGFP)‐expressing wide‐field amacrine cells in the ChAT‐EGFP mouse line

Mammalian retinas comprise a variety of interneurons, among which amacrine cells represent the largest group, with more than 30 different cell types each exhibiting a rather distinctive morphology and carrying out a unique function in retinal processing. However, many amacrine types have not been studied systematically because, in particular, amacrine cells with large dendritic fields, i.e. wide‐field amacrine cells, have a low abundance and are therefore difficult to target. Here, we used a transgenic mouse line expressing the coding sequence of enhanced green fluorescent protein under the promoter for choline acetyltransferase (ChAT‐EGFP mouse) and characterized a single wide‐field amacrine cell population monostratifying in layer 2/3 of the inner plexiform layer (WA‐S2/3 cell). Somata of WA‐S2/3 cells are located either in the inner nuclear layer or are displaced to the ganglion cell layer and exhibit a low cell density. Using immunohistochemistry, we show that WA‐S2/3 cells are presumably GABAergic but may also release acetylcholine as their somata are weakly positive for ChAT. Two‐photon‐guided patch‐clamp recordings from intact retinas revealed WA‐S2/3 cells to be ON‐OFF cells with a homogenous receptive field even larger than the dendritic field. The large spatial extent of the receptive field is most likely due to the extensive homologous and heterologous coupling among WA‐S2/3 cells and to other amacrine cells, respectively, as indicated by tracer injections. In summary, we have characterized a novel type of GABAergic ON‐OFF wide‐field amacrine cell which is ideally suited to providing long‐range inhibition to ganglion cells due to its strong coupling.     

CRAT missense variants cause abnormal carnitine acetyltransferase function in an early‐onset case of Leigh syndrome

Leigh syndrome, or subacute necrotizing encephalomyelopathy, is one of the most severe pediatric disorders of the mitochondrial energy metabolism. By performing whole‐exome sequencing in a girl affected by Leigh syndrome and her parents, we identified two heterozygous missense variants (p.Tyr110Cys and p.Val569Met) in the carnitine acetyltransferase (CRAT) gene, encoding an enzyme involved in the control of mitochondrial short‐chain acyl‐CoA concentrations. Biochemical assays revealed carnitine acetyltransferase deficiency in the proband‐derived fibroblasts. Functional analyses of recombinant‐purified CRAT proteins demonstrated that both missense variants, located in the acyl‐group binding site of the enzyme, severely impair its catalytic function toward acetyl‐CoA, and the p.Val569Met variant also toward propionyl‐CoA and octanoyl‐CoA. Although a single recessive variant in CRAT has been recently associated with neurodegeneration with brain iron accumulation (NBIA), this study reports the first kinetic analysis of naturally occurring CRAT variants and demonstrates the genetic basis of carnitine acetyltransferase deficiency in a case of mitochondrial encephalopathy.     

胰岛素样生长因子-1对痴呆大鼠行为学及胆碱乙酰转移酶表达的影响

目的探讨胰岛素样生长因子（IGF-1）对痴呆模型大鼠学习记忆能力的影响及其对胆碱乙酰转移酶的保护作用。方法采用切断成年Wistar大鼠双侧穹窿海马伞（FF），建立隔-海马胆碱能系统损害的痴呆模型。分为痴呆治疗组、痴呆对照组和正常对照组三组。痴呆治疗组经侧脑室给予IGF-1，痴呆对照组给予生理盐水，正常对照组不给予处理。利用水迷宫和Y迷宫观察其行为学改变，利用原位杂交及图像分析测定大鼠脑内胆碱乙酰转移酶（ChAT）的表达。结果痴呆治疗组大鼠的学习记忆成绩优于痴呆对照组（P〈0．01），其脑内ChAT的表达量与痴呆对照组相比也明显增多（P〈0．01）。结论IGF-1对中枢胆碱能系统有保护作用，能改善学习记忆能力。     

丙酮酸脱氢酶复合物X蛋白的原核表达与血清学鉴定

目的获得丙酮酸脱氢酶复合物的X蛋白(Pro-X)的原核表达蛋白.方法采用RT-PCR技术从人淋巴细胞RNA中扩增出Pro-X的基因片段,克隆至pET28a( )表达载体进行诱导表达,并对表达产物进行Western blot和ELISA鉴定.结果成功构建了表达载体pET28a( )/Pro-X;表达产物能特异性的被原发性胆汁性肝硬化(primary biliary cirrhosis,PBC)患者血清中的抗线粒体抗体识别.结论获得Pro-X蛋白的原核高效表达,为利用原核表达的丙酮酸复合物对PBC患者进行血清学检测进一步奠定了基础.     

N-乙酰基转移酶基因多态性与帕金森病相关性研究

目的　探讨N -乙酰基转移酶 (NAT2 )基因多态性与散发性帕金森病 (Parkinson’sdisease ,PD)的关系。方法　应用自动实时荧光Light-Cycler技术 ,分析 88例PD患者和 112例健康人NAT2 4个位点的基因多态性 ,比较PD患者与对照组间频率差异。结果　早发PD组NAT2 6A等位基因频率与对照组比较有显著性差异 (P <0 .0 5 ) ,使患PD的危险度提高了 2 .0 8倍 (P <0 .0 5 ) ,NAT2 5A和NAT2 7A/B等位基因频率与对照组比较无显著性差异 (P >0 .0 5 ) ;晚发PD组NAT2 4个多态位点各等位基因频率与对照组比较无显著性差异 (P >0 .0 5 ) ;未检测到NAT2 14A等位基因。结论　NAT2 6A等位基因可能主要与早发PD的易感性相关 ,并参与了神经毒素的解毒。