保留瓣下结构的几种机械瓣下游血流动力学多普勒超声研究

了解二尖瓣置换术mitralvalvereplacement,MVR保留瓣下结构对不同类型机械瓣下游血流动力学的影响,为合理选择术式以最大限度减少手术并发症提供科学依据。方法采用彩色多普勒超声结合计算机图像分析技术,对保留瓣下结构的不同类型机械瓣置换术后患者机械瓣下游湍流剪应力turbulentshearstress,TSS等指标进行体内定量研究。结果无论保留全瓣或后瓣,跨瓣血流边界位点TSS在两种不同构型机械瓣组间均存在显著性差异(P<0.05),单叶机械瓣(单叶瓣)TSS较双叶机械瓣(双叶瓣)高。对于单叶瓣,TSS在保留全瓣瓣下结构组(保留全瓣组)、保留后瓣瓣下结构组(保留后瓣组)与未保留瓣下结构组(未保留组)间均存在显著差异(P<0.05)。而对于双叶瓣,保留全瓣组TSS均高于其它2组(P<0.05)。结论保留瓣下结构可改善术后患者心功能,但却在一定程度上增加跨瓣血流扰动性,使下游TSS增大。这种影响以全瓣保留者为著,单叶瓣甚于双叶瓣。对于心功能较差,有必要保留全瓣瓣下结构者,可尽量使用双叶瓣,以减轻对人工心瓣下游血流动力学可能产生的不良影响。     

细胞低温显微图象的计算机处理及定量分析

本文用计算机图象处理技术对细胞显微图象进行处理和定量分析,求出了细胞面积在低温保存中极其重要的参数。实验证明,计算机测量比人工精度高,误差小,同时新颖的标号去噪方法也非常有效。     

股骨上端形态曲线的测量、参数化与统计分析

通过对84根完好的中国人成人股骨标本进行正位和侧位两个方向的X线摄影，得到股骨正、侧两方位的X光片。对X光片上股骨上端髓腔内侧形态进行描绘，将描绘好的图像输入计算机，由计算机进行图像预处理后提取其曲线形态数据，并将形态数据参数化，从而得到可比较的、能准确表现股骨形态的量化数据，为股骨形态的分类分析和系列型人工髋关节的参数设计打下基础。     

人Nanog基因的克隆及其在COS-7L细胞中的表达

目的 :克隆人Nanog基因 ,构建其真核表达载体 ,并观察其在哺乳动物细胞COS 7L中的表达。方法 :利用HE2 93细胞的人基因组DNA为模板 ,以LA PCR技术 ,扩增Nango的基因 ,定向克隆到带Flag标签的pCMV载体中 ,测序后 ,挑选序列正确的真核表达质粒pFlag Nanog转染COS 7L细胞。用抗Flag标签的抗体 ,进行Westernblot和间接免疫荧光染色法检测Nango蛋白的表达。结果 :从人基因组DNA中克隆到序列正确的Nanog全长编码序列。所构建的Nanog质粒在COS 7L细胞中获得高效表达。结论 :人Nanog基因的克隆、真核表达载体的构建及在COS 7L中的表达均获得成功 ,为进一步研究其功能 ,尤其是探讨其在神经干细胞中的作用奠定了基础。     

Missense mutation in a von Willebrand factor type A domain of the alpha 3(VI) collagen gene (COL6A3) in a family with Bethlem myopathy

The Bethlem myopathy is a rare autosomal dominant proximal myopathy characterized by early childhood onset and joint contractures. Evidence for linkage and genetic heterogeneity has been established, with the majority of families linked to 21q22.3 and one large family linked to 2q37, implicating the three type VI collagen subunit genes, COL6A1 (chromosome 21), COL6A2 (chromosome 21) and COL6A3 (chromosome 2) as candidate genes. Mutations of the invariant glycine residues in the triple-helical domain-coding region of COL6A1 and COL6A2 have been reported previously in the chromosome 21-linked families. We report here the identification of a G-->A mutation in the N-terminal globular domain-coding region of COL6A3 in a large American pedigree (19 affected, 12 unaffected), leading to the substitution of glycine by glutamic acid in the N2 motif, which is homologous to the type A domains of the von Willebrand factor. This mutation segregated to all affected family members, to no unaffected family members, and was not identified in 338 unrelated Caucasian control chromosomes. Thus mutations in either the triple-helical domain or the globular domain of type VI collagen appear to cause Bethlem myopathy.      

doublecortin is the major gene causing X-linked subcortical laminar heterotopia (SCLH)

Subcortical laminar heterotopia (SCLH), or 'double cortex', is a cortical dysgenesis disorder associated with a defect in neuronal migration. Clinical manifestations are epilepsy and mental retardation. This disorder, which mainly affects females, can be inherited in a single pedigree with lissencephaly, a more severe disease which affects the male individuals. This clinical entity has been described as X- SCLH/LIS syndrome. Recently we have demonstrated that the doublecortin gene, which is localized on the X chromosome, is implicated in this disorder. We have now performed a systematic mutation analysis of doublecortin in 11 unrelated females with SCLH (one familial and 10 sporadic cases) and have identified mutations in 10/11 cases. The sequence differences include nonsense, splice site and missense mutations and these were found throughout the gene. These results provide strong evidence that loss of function of doublecortin is the major cause of SCLH. The absence of phenotype-genotype correlations suggests that X-inactivation patterns of neuronal precursor cells are likely to contribute to the variable clinical severity of this disorder in females.      

Promotion of U937 cell adhesion on polypropylene surfaces bearing phosphorylcholine functionalities

Phosphorylcholine (PC) groups were grafted onto ammonia plasma-treated biaxially-oriented polypropylene (BOPP) surfaces, via (a) reductive amination of phosphorylcholine glyceraldehyde and (b) a two-step procedure involving the chemical amplification of surface amine groups with tris(2-aminoethyl amine) and subsequent reductive amination of phosphorylcholine glyceraldehyde. The occurrence of grafting was ascertained by X-ray photoelectron spectroscopy (XPS) and attenuated total reflectance Fourier-transform infrared (ATR-FT-IR) spectroscopy. The wettability of PC-modified surfaces was assessed by dynamic contact-angle measurements using the Wilhelmy plate method. Human U937 macrophages adhered and proliferated to a significantly larger extent on PC-modified surfaces, compared to unmodified or ammonia plasma-modified BOPP.     

Defective Treg response in acute kidney injury was caused by a reduction in TIM-3+ Treg cells

Background: Despite years of research, the treatment of acute kidney injury (AKI) remains a significant challenge. Animal studies presented causal links between elevated regulatory T cell (Treg) response and better prognosis in AKI. Previous studies in mice and humans showed that TIM-3+ Treg cells were more potent than TIM-3- Treg cells. In this study, we investigated the role of TIM-3 in Treg in AKI patients.

Methods: Peripheral blood from AKI patients and healthy controls were gathered, and TIM-3+ Treg subset was examined.

Results: Compared to healthy controls, the AKI patients presented a significant upregulation in the frequency of circulating CD4+CD25+ T cells; however, the majority of this increase was from the CD4+CD25+TIM-3- subset, and the frequency of CD4+CD25+TIM-3+ T cells was downregulated in AKI patients. In both healthy controls and AKI patients, the CD4+CD25+TIM-3+ T cells expressed higher levels of Foxp3, and were more potent at expressing LFA-1, LAG-3, CTLA-4, IL-10 and TGF-β. In addition, the CD4+CD25+TIM-3+ T cells from both healthy controls and AKI patients presented higher capacity to suppress CD4+CD25- T cell proliferation than the CD4+CD25+TIM-3- T cells. Interestingly, the total CD4+CD25+ T cells from AKI patients presented significantly lower inhibitory capacity than those from healthy controls, indicating that the low frequency of CD4+CD25+TIM-3+ T cells was restricting the efficacy of the Treg responses in AKI patients.

Conclusions: We demonstrated that TIM-3 downregulation impaired the function of Treg cells in AKI. The therapeutic potential of CD4+CD25+TIM-3+ T cells in AKI should be investigated in future studies.     

严重急性呼吸综合征患者尸解肺标本的病理改变和致病机制研究

目的研究严重急性呼吸综合征（SARS）患者尸解肺标本的病理改变和致病机制。方法观察了2003年4-7月期间死于SARS的6例患者的肺标本,并采用光镜、电镜、Masson三色染色和免疫组织化学染色方法（EnVision法）进行研究。结果肺标本的病理形态改变：（1）6例的双肺均可见到弥漫性实变病灶,肺重量明显增加;（2）6例均可见到弥漫性肺泡损伤,包括透明膜形成、肺泡腔内水肿／出血、纤维素沉积和肺泡上皮细胞脱屑,AE1／AE3免疫组织化学染色显示肺泡上皮细胞的完整性明显破坏;（3）Ⅱ型肺泡上皮细胞轻度增生,有一定异型性,细胞体积增大,胞质呈双染性和颗粒状,胞质内可见小脂肪空泡聚集（5／6）;（4）6例中有5例可见巨细胞在肺泡内浸润,巨细胞大多AEl／AE3阳性（5／6）,少数CD68阳性（2／6）;（5）组织学形态和免疫组织化学染色证实肺泡腔内和肺泡间隔内有多量巨噬细胞浸润（6／6）;（6）6例中有5例可见巨噬细胞噬红细胞象;（7）6例中有5例可见肺纤维化,包括肺泡间隔和肺间质增宽（5／6）、肺泡腔内渗出物机化（6／6）和胸膜增厚（4／6）。Masson三色染色证实胶原纤维明显增生,免疫组织化学染色显示大多数为Ⅲ型胶原。光镜和免疫组织化学染色显示5例有明显的成纤维细胞／肌纤维母细胞增生灶;（8）5例可见支气管黏膜鳞状上皮化生;（9）6例患者均可见血栓;（10）2例同时合并其他感染,1例合并细菌感染,另1例合并真菌感染。此外,电镜发现在肺泡上皮细胞和肺血管内皮细胞的胞质内有冠状病毒样颗粒。结论SARS冠状病毒直接损伤肺泡上皮细胞、巨噬细胞明显浸润和成纤维细胞／肌纤维母细胞显著增生在SARS的致病机制中起重要作用。