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儿茶酚-O-甲基转移酶(catechol-O-methyl transferase,COMT)是儿茶酚胺类神经递质的主要代谢酶.COMT是儿茶酚-O-甲基转移酶的编码基因,其第4外显子的一个G/A转换可产生不同活性的等位基因.许多遗传学研究报道,这种功能多态性与人类精神类疾病相关.文章利用PCR扩增技术和限制性片段长度多态(Restriction fragmentlength polymorphism,RFLP)方法,研究中国秦巴山区精神发育迟滞(Mental Retardation,MR)儿童与正常对照儿童的COMT基因功能多态情况,探讨COMT基因功能多态性与儿童认知能力水平的相关性.病例-对照分析结果显示,COMT基因的不同活性等位基因型与秦巴山区儿童MR无相关性(x2=0.776,P>0.05),其等位基因频率与儿童MR也未呈现出相关性(x2=0.335,P>0.05).但是,在研究中还发现,该地区智商分(IQ)不小于55分的儿童群体中,COMT基因的多态性分布与儿童的智力呈现出相关的趋势.在智力正常组儿童中(IQ≥85),COMT高活性等位基因纯合体(COMTHH)频率及其等位基因(COMTH)频率较高,分别为60.98%、79.28%.在智力边缘组儿童(70≤IQ<85)中,其频率分别为46.67%、70.67%,相应地也低于正常组的频率(0.10>P>0.05).结果提示,在中国秦巴山区人群中,COMT基因的功能多态性与儿童MR的形成无明显相关性,但它对正常儿童的认知能力可能有一定影响.  相似文献   

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Catechol-O-methyl transferase (COMT) plays an important role in the metabolism of neurotransmitters. Two alleles of the COMT gene as a result of a G/A transition in the exon 4 can lead to different COMT enzymatic activities. Much genetic research has revealed that this COMT functional polymorphism was related to human psychiatric disorders. Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) methods were used to discern the relationships among the functional polymorphism of COMT, mental retardation (MR), and general cognitive ability of children. The results of the case-control analysis showed that there was no association between the frequencies of genotypes of COMT and MR (x2=0.776, P>0.05) or between the frequency of COMT alleles and MR (x2=0.335, P>0.05). COMT polymorphism was found in children whose intelligence quotient (IQ) was above 55. In normal children (IQ≥85), the frequencies of high-activity allele COMTH and the homozygote genotype COMTHH were 60.98% and 79.28%, respectively. Both were higher than those of the borderline group (46.67% and 70.67%, 0.10 > P>0.05). Therefore, the result of this study suggests that this functional polymorphism is not an important risk factor for MR, but the COMTHH genotype may have a positive effect on cognitive performance in normal children in the Qinba area.  相似文献   

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The objective of the paper is to evaluate the effect of acellular nerve allografts (ANA) seeded with Schwann cells to promote nerve regeneration after bridging the sciatic nerve defects of rats and to discuss its acting mechanisms. Schwann cells were isolated from neonatal Wistar rats. In vitro Schwann cells were microinjected into acellular nerve allografts and co-cultured. Twenty-four Wistar rats weighing 180–220 g were randomly divided into three groups with eight rats in each group: ANA seeded with Schwann cells (ANA + SCs), ANA group and autografts group. All the grafts were, respectively, served for bridging a 10-mm long surgically created sciatic nerve gap. Examinations of regeneration nerve were performed after 12 weeks by transmission electron microscope (TEM), scanning electron microscope (SEM), and electrophysiological methods, and then analyzed statistically. The results obtained indicated that in vitro Schwann cells displayed the feature of bipolar morphology with oval nuclei. Compared with ANA group, the conduction velocity of ANA + SCs group and autograft group was faster after 12 weeks, latent period was shorter, and wave amplitude was higher (P < 0.05). The difference between ANA + SCs group and autograft group is not significant (P > 0.05). Regeneration nerve myelinated fiber number, myelin sheath thickness, and myelinated fibers/total nerves (%) in both ANA + SCs group and autograft group are higher than that in ANA group; the difference is significant (P < 0.05). The difference between the former two is not significant (P > 0.05). In conclusion, ANA seeded with SCs could improve nerve regeneration and functional recovery after bridging the sciatic nerve gap of rats, which offers a novel approach for the repair peripheral nerve defect.  相似文献   

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The range of defects and disabilities in thalidomide children is very much wider than is generally realized. The defects of 154 children are described and classified. Their disabilities range from incapacitating to negligible.  相似文献   

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Background

The main objective was to investigate the burden of birth defects among alive infants and explore the impact of maternal lifestyle during pregnancy on the burden of birth defects in Northwest China.

Methods

A stratified multi-stage sampling method was used to study infants born during 2010–2013 (and their mothers) in Shaanxi province of Northwest China. Socio-demographic information was collected using a structured questionnaire, and medical records from the local hospitals were used to determine the final diagnosis of birth defects. Poisson regression analysis was performed to assess the association between maternal lifestyles during pregnancy and the burden of birth defects, while adjusting for potential confounders.

Results

We sampled 29098 infants, of whom 629 (i.e. 216.17 per 10000) were observed to have congenital defects. Cardiovascular system defects (77.32 per 10000) were found to be the most common. Mothers who had ever consumed alcohol during pregnancy were found to have infants with a higher prevalence of some categories of birth defects, including nervous system (Prevalence Rate Ratio, PRR:14.67, 95%CI:1.94, 110.92), cardiovascular system (PRR:3.22, 95%CI: 1.02, 10.16) and oral clefts (PRR:9.02, 95%CI: 2.08, 39.10) in contrast to infants of mothers without any alcohol consumption. Maternal passive smoking during pregnancy lead to the increased burden of malformations of eye, ear, face and neck (PRR:1.95, 95%CI:1.15, 3.33), cardiovascular system (PRR:1.70, 95%CI: 1.25, 2.31) and respiratory system (PRR:9.94, 95%CI: 2.37, 41.76) in their newborns. Further, tea or coffee consumption during pregnancy was positively correlated with the burden of specific birth defects, such as cardiovascular system (PRR: 2.44, 95%CI: 1.33, 4.46) and genital organs (PRR:14.72, 95%CI: 1.87, 116.11) among infants.

Conclusions

The prevalence of birth defects was high in Shaanxi province of Northwest China. The unhealthy lifestyles of mothers during pregnancy may increase the prevalence of congenital malformations. These findings in future may have some important implications for prevention of birth defects in Northwest China.  相似文献   

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神经生长因子与冻干异体神经桥接大鼠神经缺损的研究   总被引:3,自引:0,他引:3  
实验采用冻干处理的异体神经与外源性神经生长因子(NGF)结合来桥接大鼠的坐骨神经1.0cm的缺损。用雄性Wistar大鼠进行的四组实验结果表明:冻干处理的异体神经可降低其抗原性,但处理后并不损害雪旺氏细胞(SC)基底膜的完整性,在移植后可能成为轴突再生的通道和支架;外源性NGF与冻干神经结合形成的复合体,可为神经的再生提供一个较好的微环境,具有成为理想桥接材料的可能性  相似文献   

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Bacteria adapting to living in a host cell caused the most salient events in the evolution of eukaryotes, namely the seminal fusion with an archaeon, and the emergence of both mitochondrion and chloroplast. A bacterial clade that may hold the key to understanding these events is the deep-branching gammaproteobacterial order Legionellales—containing among others Coxiella and Legionella—of which all known members grow inside eukaryotic cells. Here, by analyzing 35 novel Legionellales genomes mainly acquired through metagenomics, we show that this group is much more diverse than previously thought, and that key host-adaptation events took place very early in its evolution. Crucial virulence factors like the Type IVB secretion (Dot/Icm) system and two shared effector proteins were gained in the last Legionellales common ancestor (LLCA). Many metabolic gene families were lost in LLCA and its immediate descendants, including functions directly and indirectly related to molybdenum metabolism. On the other hand, genome sizes increased in the ancestors of the Legionella genus. We estimate that LLCA lived approximately 1.89 Ga, probably predating the last eukaryotic common ancestor by approximately 0.4–1.0 Gy. These elements strongly indicate that host adaptation arose only once in Legionellales, and that these bacteria were using advanced molecular machinery to exploit and manipulate host cells early in eukaryogenesis.  相似文献   

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Objective

To examine microcystic inner nuclear layer (INL) changes in glaucomatous eyes and to determine associated factors.

Design

Retrospective, cross-sectional, observational study.

Methods

Two hundred seventeen eyes of 133 patients with primary open angle glaucoma (POAG), 41 eyes of 32 patients with preperimetric glaucoma and 181 normal eyes of 117 subjects were ultimately included. Microcystic INL lesions were examined with infrared fundus images and with 19 vertical spectral domain optical coherence tomography (SD-OCT) images in the macular area.

Results

Microcystic INL changes were observed in 6.0% of eyes with POAG, but none of the normal eyes or eyes with preperimetric glaucoma showed microcystic INL changes. The proportion of eyes with advanced glaucoma was significantly larger (P = 0.013) in eyes with microcystic lesions than without. The visual field mean deviation (MD) slope was also significantly worse (P = 0.027) in eyes with microcystic lesions. No significant differences were observed in age, sex, refraction, axial length, intraocular pressure, or MD value between eyes with and without microcystic INL lesions. In several cases, microcystic INL lesions occurred along with glaucomatous visual field progression. The retinal nerve fiber layer (RNFL) thickness (P = 0.013) and ganglion cell layer (GCL) + inner plexiform layer thickness (P = 0.023) were significantly lower in areas with microcystic lesions than without. The INL was also significantly thicker (P = 0.002) in areas with microcystic lesions.

Conclusions

Microcystic INL lesions in glaucomatous eyes are closely associated with RNFL and GCL thinning and correlated with worse MD slope. These INL lesions may indicate focal and progressive damage in glaucoma.  相似文献   

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摘要 目的:探讨集体语言训练联合经颅直流电刺激(tDCS)对语言发育迟缓患儿发育水平、言语功能及神经中枢营养因子水平的影响。方法:采用信封抽签法将郴州市第一人民医院2021年2月到2023年2月期间收治的90例语言发育迟缓患儿分为对照组(n=45,常规语言训练联合tDCS)和研究组(n=45,集体语言训练联合tDCS)。对比两组疗效、发育水平、言语功能、神经中枢营养因子及生活质量。结果:与对照组相比,研究组的临床总有效率更高(P<0.05)。两组干预后动作能、应物能、言语能、应人能评分均升高,且研究组高于对照组(P<0.05)。两组干预后复述、听理解、口头表达、出声读、抄写、阅读、描写、听写以及计算评分均升高,且研究组高于对照组(P<0.05)。两组干预后血清脑源性神经营养因子(BDNF)、胶质细胞源性神经营养因子(GDNF)、神经生长因子(NGF)、神经营养因子-3(NT-3)较干预前升高(P<0.05)。两组干预后血清BDNF、NGF、GDNF、NT-3组间对比未见差异(P>0.05)。两组干预后生理功能、社会功能、情感功能、角色功能评分升高,且研究组高于对照组(P<0.05)。结论:集体语言训练联合tDCS干预语言发育迟缓患儿,可改善言语功能和神经功能,提高其发育水平和生活质量。  相似文献   

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Longitudinal analysis of the spectral power of the main EEG bands was performed in the wakeful state with the eyes open and the eyes closed in children with mental disorders at various stages of correction by transcranial direct current stimulation (tDCS). A significant increase in the power of α-rhythm in the parietal-occipital areas and a significant decrease in the slow wave activity in the left frontotemporal areas were observed in the course of the correction process. The data obtained can be considered as the neurophysiological markers of the tDCS effects (formation of age-related EEG parameters in children with mental disorders). The data also prove the relations between the described phenomena and the cortical mechanisms of speech disorders and other psychic processes caused by perinatal CNS disorders.  相似文献   

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