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排序方式: 共有3210条查询结果,搜索用时 15 毫秒
81.
目的探讨左向右分流型先天性心脏病患儿心肺功能的交互作用。方法选择左向右分流型先天性心脏病患儿62例为先心组,健康体检儿童40例为对照组,进行肺功能检查与血气分析(PaO2、PaCO2、pH值)及血C-反应蛋白(CRP)测定,并进行相关性分析。结果先心组患儿的呼吸频率(RR)高于对照组,每千克体质量潮气量(VT/kg)、潮气呼吸峰流速(PTEF)、达到峰流速的时间与呼吸时间的比值(TPTEF/Te)、达到呼气峰流速时呼出的气体容积与呼气容积的比值(VPEF/Ve)水平均低于对照组;从单纯先天性心脏病到先天性心脏病合并肺炎、到合并肺炎与心力衰竭,RR水平越来越高,VT/kg、PTEF、TPTEF/Te、VPEF/Ve水平则越来越低;单纯先天性心脏病,先天性心脏病合并肺炎、合并肺炎与心力衰竭患儿与对照组比较,PaO2水平逐渐降低,CRP水平逐渐升高。结论肺功能测定能够反映左向右分流型先天性心脏病患儿心肺功能的病理生理特点,血气分析及血CRP测定能反映患儿疾病的严重程度。  相似文献   
82.
目的:通过体外和体内方法研究β-casomorphin-7对小鼠脾脏淋巴细胞和腹腔巨噬细胞的作用.方法:利用脾细胞增殖试验和腹腔巨噬细胞中NO浓度的变化来研究体外不同的β-casomorphin-7浓度对脾脏淋巴细胞的增殖和腹腔巨噬细胞中NO浓度变化的影响,以及腹腔注射β-casomorphin-7和饮用β-casomorphin-7溶液对上述两个指标的影响.结果:体外试验表明,β-casomorphin-7在不同浓度对脾脏淋巴细胞的增殖显示了刺激和抑制的双向作用,而对NO的产生显示了明显的抑制作用(P<0.01).体内试验表明,β-casomorphin-7通过腹腔注射和饮用两种给药方式对脾淋巴细胞和腹腔巨噬细胞的作用是一致的.β-casomorphin-7显著地增强了脾淋巴细胞的增殖反应(P<0.01),且抑制了腹腔巨噬细胞NO的产生.结论:当前的试验表明,β-casomorphin-7具有免疫调节作用,且小鼠在2~3周龄时,可吸收入血发挥免疫调节作用.  相似文献   
83.
The association between MSHR coding region variation and hair colour in humans has been examined by genotyping 25 red haired and 62 non-red Caucasians, all of whom were 12 years of age and members of a twin pair study. Twelve amino acid substitutions were seen at 11 different sites, nine of these being newly described MSHR variants. The previously reported Val92Met allele shows no association with hair colour, but the three alleles Arg151Cys, Arg160Trp and Asp294His were associated with red hair and one Val60Leu variant was most frequent in fair/blonde and light brown hair colours. Variant MSHR genotypes are associated with lighter skin types and red hair (P < 0.001). However, comparison of the MSHR genotypes in dizygotic twin pairs discordant for red hair colour indicates that the MSHR gene cannot be solely responsible for the red hair phenotype, since five of 13 pairs tested had both haplotypes identical by state (with three of the five having both identical by descent). Rather, it is likely that additional modifier genes exist, making variance in the MSHR gene necessary but not always sufficient, for red hair production.   相似文献   
84.
Susceptibility to autoimmune insulin-dependent (type 1) diabetes mellitus is determined by a combination of environmental and genetic factors, which include variation in MHC genes on chromosome 6p21 (IDDM1) and the insulin gene on chromosome 11p15 (IDDM2). However, linkage to IDDM1 and IDDM2 cannot explain the clustering of type 1 diabetes in families, and a role for other genes is inferred. In the present report we describe linkage and association of type 1 diabetes to the CTLA-4 gene (cytotoxic T lymphocyte associated-4) on chromosome 2q33 (designated IDDM12). CTLA-4 is a strong candidate gene for T cell- mediated autoimmune disease because it encodes a T cell receptor that mediates T cell apoptosis and is a vital negative regulator of T cell activation. In addition, we provide supporting evidence that CTLA-4 is associated with susceptibility to Graves' disease, another organ- specific autoimmune disease.   相似文献   
85.
Parthenotes have been proposed as a source of embryonic stem cells but they lack the centriole which is inherited through the sperm in all mammalian species, except for rodents. We investigated the centrosome of parthenotes and parthenogenetic embryonic stem cells using parthenogenetic and biparental pig pre-implantation embryos, human and pig parthenogenetic and biparental embryonic stem cells, sheep fibroblasts derived from post implantation parthenogenetic and biparental embryos developed in vivo. We also determined the level of aneuploidy in parthenogenetic cells. Oocytes of all species were activated using ionomycin and 6-dimethylaminopurine (6-DMAP). Over 60?% of parthenogenetic blastomeres were affected by an excessive number of centrioles. Centrosome amplification, was observed by microscopical and ultrastructural analysis also in parthenogenetic cell lines of all three species. Over expression of PLK2 and down regulation of CCNF, respectively involved in the stimulation and inhibition of centrosome duplication, were present in all species. We also detected down regulation of spindle assembly checkpoint components such as BUB1, CENPE and MAD2. Centrosome amplification was accompanied by multipolar mitotic spindles and all cell lines were affected by a high rate of aneuploidy. These observations indicate a link between centrosome amplification and the high incidence of aneuploidy and suggest that parthenogenetic stem cells may be a useful model to investigate how aneuploidy can be compatible with cell proliferation and differentiation.  相似文献   
86.
慢性乙型肝炎患者肝组织中HBV抗原表达特征及其临床意义   总被引:5,自引:0,他引:5  
目的探讨慢性乙型病毒性肝炎肝活检组织中检测乙肝表面抗原(HBsAg)和乙肝核心抗原(HBcAg)表达强度及表达方式的必要性。方法采用EnVision免疫组织化学法检测196例慢性乙型肝炎患者肝穿组织中HBsAg和HBcAg的表达水平,并用荧光定量PCR检测其血清中的HBV DNA的含量。对肝组织进行炎症活动度分级和纤维化分期。结果肝组织中的HBsAg表达强度和表达方式与炎症分级、纤维化分期和血清乙肝病毒载量均无相关性(P>0.05)。HBcAg表达强度与炎症分级无相关性(r=-0.02,P>0.05);与纤维化分期呈负相关(r=-0.28,P<0.01);与血清乙肝病毒载量呈正相关(r=0.53,P<0.01)。HBcAg表达方式与炎症分级为负相关(r=-0.27,P<0.01),其中浆型组炎症活动度分级高于核型组和混合型组(P<0.01),混合型组高于核型组(P<0.01)。HBcAg表达方式与纤维化分期亦呈较弱的负相关(r=-0.23,P<0.01),其中浆型组纤维化分期高于核型组和混合型组(P<0.05)。HBcAg表达方式与血清乙肝病毒载量呈正相关(r=0.22,P<0.01)。结论区分肝组织中的HBsAg表达强度和表达方式无益于了解慢性乙型肝炎患者肝损害的程度,而检测肝组织中的HBcAg则有助于临床抗病毒治疗。  相似文献   
87.
West Nile Virus (WNV) is a mosquito-borne flavivirus that was introduced into the U.S. in the New York City area in 1999. Despite its successful establishment and rapid spread in a naive environment, WNV has undergone limited evolution since its introduction. This evolutionary stability has been attributed to compromises made to permit alternating cycles of viral replication in vertebrate hosts and arthropod vectors. Outbreaks of a close relative of WNV, St. Louis encephalitis virus (SLEV), occur in the U.S. periodically and are also characterized by limited genetic change overtime. We measured both phenotypic and genotypic changes in WNV and SLEV serially passaged in mosquito cell culture in order to clarify the role of an individual host cell type in flavivirus adaptation and evolution. Genetic changes in passaged WNV and SLEV were minimal but led to increased relative fitness and replicative ability of the virus in the homologous cell line C6/36 mosquito cells. Similar increases were not measured in the heterologous cell line DF-1 avian cells. These phenotypic changes are consistent with the concept of cell-specific adaptation in flaviviruses.  相似文献   
88.
目的探讨尿微量白蛋白(MA)、尿α1-微球蛋白(α1-MG)、尿β2-微球蛋白(β2-MG)及血清β2-微球蛋白(β2-MG)在糖尿病肾病早期诊断中的意义。方法收集67例2型糖尿病患者和82名正常健康人的血清及尿液,分别利用化学发光法检测血清β2-MG、放射免疫法测定尿β2-MG及散射速率比浊法测定尿MA和尿α1-MG水平。结果与正常对照组相比,糖尿病组4组特定蛋白水平明显升高,结果有显著性差异(P均<0.05);此4组蛋白在正常对照组测得的结果无一例阳性,但在糖尿病组的阳性率分别为32.8%、47.8%、35.8%、34.3%;实验还发现随着病程的延长,糖尿病组4组蛋白的阳性率也相应升高(P<0.05)。结论测定尿液中MA、α1-MG、β2-MG及血清β2-MG水平对糖尿病肾病的早期诊断具有一定意义,能够帮助患者及早发现病情,减少疾病迁延。  相似文献   
89.
Recently, a hexanucleotide (GGGGCC) repeat expansion in the first intron of C9ORF72 was reported as the cause of chromosome 9p21‐linked frontotemporal dementia‐amyotrophic lateral sclerosis (FTD‐ALS). We here report the prevalence of the expansion in a hospital‐based cohort and associated clinical features indicating a wider clinical spectrum of C9ORF72 disease than previously described. We studied 280 patients previously screened for mutations in genes involved in early onset autosomal dominant inherited dementia disorders. A repeat‐primed polymerase chain reaction amplification assay was used to identify pathogenic GGGGCC expansions. As a potential modifier, confirmed cases were further investigated for abnormal CAG expansions in ATXN2. A pathogenic GGGGCC expansion was identified in a total of 14 probands. Three of these presented with atypical clinical features and were previously diagnosed with clinical olivopontocerebellar degeneration (OPCD), atypical Parkinsonian syndrome (APS) and a corticobasal syndrome (CBS). Further, the pathogenic expansion was identified in six FTD patients, four patients with FTD‐ALS and one ALS patient. All confirmed cases had normal ATXN2 repeat sizes. Our study widens the clinical spectrum of C9ORF72related disease and confirms the hexanucleotide expansion as a prevalent cause of FTD‐ALS disorders. There was no indication of a modifying effect of the ATXN2 gene.  相似文献   
90.
 目的:探讨乙型肝炎病毒(HBV)对肝内TGF-β1蛋白表达及Smads信号通路的作用,为制定慢性乙肝肝纤维化临床治疗策略提供理论依据。方法:(1)运用免疫组化PV-6000法检测对照组和慢性乙肝组肝组织中TGF-β1、HBsAg和HBcAg的表达,并采用荧光定量PCR法测定慢性乙肝患者血清HBV DNA含量。(2)应用体外细胞培养技术培养HBV刺激的人肝星状细胞系LX-2细胞,Western blotting方法测定其细胞内TGF-β1、Smad3和Smad7的蛋白表达。结果:(1)慢性乙肝组肝组织内TGF-β1的表达高于对照组(P<0.01);肝内TGF-β1表达水平与血清HBV DNA含量呈正相关(P<0.01),且HBcAg阳性肝组织水平较高(P<0.01)。(2)体外细胞学实验中,HBV刺激组LX-2细胞内TGF-β1和Smad3蛋白含量高于对照组和HBV+抗-TGF-β1组(P<0.01);Smad7蛋白表达差异无统计学意义(P>0.05)。结论:(1)TGF-β1在慢性乙肝患者肝组织中的表达与血清HBV DNA含量及肝内HBcAg的表达有关。(2)在TGF-β1/Smads信号通路中,HBV致纤维化作用机制以Smad3的正性调控为主,Smad7的作用不明显。  相似文献   
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