The myogenic response in isolated rat cerebrovascular arteries: vessel model

We develop an integrated model of isolated rat arterial resistance vessel (RV), which can simulate its major property of myogenic response. The vascular smooth muscle cell is an important component of the wall of this vessel, and serves as a vasomotor organ providing the active tension generation that underlies the myogenic response of the wall to stretch. In the previous study, we focused on the development of a smooth muscle cell model that can mimic the strain-sensing and force-generating features of the myogenic mechanism. In the current model, we embed this cell model in a larger vessel wall configuration, and couple the time course of cellular contractile activation to macroscopic changes in vessel diameter. The integrated model is used to mimic published pressure-vessel diameter data obtained from isolated RVs that are mounted in a hydraulic test apparatus. The model provides biophysically based insights into the myogenic mechanism as it responds to changes in transmural pressure, in the presence and absence of Ca2+ blockers applied to the bathing fluid.It mimics measured data very well and provides a model that is able to link events at subcellular level to macroscopic changes in vessel diameter. The model initiates a mechanistic approach to investigate myogenic response, which has not been taken previously by any other models.     

临床分离产IMP-1型金属酶非发酵菌的耐药机制研究

从临床收集耐亚胺培南的铜绿假单胞菌和鲍曼不动杆菌共50株,进行头孢他啶和2-巯基乙醇的表型协同试验(CAZ ME),然后进行金属酶IMP-1基因的PCR检测。选取IMP-1阳性株测序,用PCR方法检测有无一类整合子基因(IntI1)。表型的检测发现有28株为协同阳性,其中铜绿假单胞菌27株,鲍曼不动杆菌1株。PCR和测序检测出其中一株铜绿假单胞菌含有IMP-1基因,同时也含有IntI1基因。首次在中国西部地区发现产IMP-1型金属酶、同时也含有一类整合子的铜绿假单胞菌,对于临床上研究细菌的耐药性传播具有重要意义。     

CTLA4Ig基因转染猪皮治疗中小面积浅Ⅱ度烧伤创面的随机对照试验

目的探讨CTLA4Ig基因转染猪皮治疗中小面积浅Ⅱ度烧伤创面的临床疗效与安全性。方法将自2005年5月～2007年5月我院收治的浅Ⅱ度烧伤患者60例随机分为2组，每组30例。基因转染猪皮治疗组：伤后创面简单清创，去除水疱，用复温后的基因转染猪皮覆盖创面。对照组：创面简单清创，除颜面、会阴部位创面外，均予包扎治疗，保留水疱皮，其后常规换药治疗。结果基因转染猪皮治疗组创面愈合时间5～10d，对照组为8～14d。基因转染猪皮治疗组疼痛明显减轻，未观察到寒战、高热等全身不良反应及局部排斥反应。两组均未出现瘢痕，但对照组部分病例出现色素改变。结论应用基因转染猪皮治疗中小面积浅Ⅱ度烧伤创面能明显缩短创面愈合时间，能明显减轻创面疼痛，减少换药次数，预防色素改变及瘢痕形成。     

IV型II类反式激活因子基因新变异体的克隆、鉴定和功能测定

为获取有功能的IV型II类反式激活因子基因 (CIITA IV ) ,诱导肿瘤细胞表达MHCII类分子 ,从IFN γ刺激的THP 1细胞中以RT PCR获得CIITA IV ,将其连接到pGEMT easy载体。对所构建的pcDNA3 1 CIITA IV型表达载体进行反复测序后发现 ,所获得的CIITA IV基因存在结构变异 ,在 2 87位插入了 3个核苷酸TAG ,使 2 86 2 88位的AAG改变成为ATAGAG(2 86 2 90 ) ,并引起其他 8个座位核苷酸 (及推导的氨基酸残基 )发生改变。将表达载体转入原先不表达MHCII类分子的HeLa细胞中 ,检测到所获得的IV型CIITA变异体具有诱导人II类分子HLA DR表达的能力。空载体和CIITA IV基因导入的HeLa细胞中 ,DR阳性细胞百分率分别为 0 0 1 %和 37 6 4 %。该基因已从GenBank得到登录号 ,表明这是一个具有诱导HLA DR分子表达功能的IV型CIITA新基因。     

Survivin反义核酸对SMMC-7721细胞增殖和凋亡的影响

Survivin是凋亡抑制蛋白（IAP）家族的一个成员，具有强大的抗细胞凋亡功能，在几乎所有肿瘤组织中特异性表达，而在正常成年终末分化组织中低表达甚至不表达。本研究针对Survivin mRNA序列设计了反义寡核甘酸，RT—PCR检测表明，该序列反义寡核苷酸可明显降低细胞中survivin基因的mRNA含量；Western印迹显示Survivin蛋白水平也被降低。MTT比色实验法检测结果说明人Survivin反义寡核苷酸抑制SMMC-7721细胞增殖，抑制率为43％，远高于无义寡核苷酸组和空白对照组。反义寡核苷酸还显著增强SMMC-7721细胞对于抗肿瘤药高三尖杉酯碱的敏感性，TUNEL法检测结果显示，在较低高三尖杉酯碱浓度下，反义寡核苷酸转染细胞的凋亡率明显高于其它对照组。本研究结果提示，survivin表达的靶向抑制有望应用于肿瘤的辅助治疗之中。     

前路椎体次全切在治疗颈椎后纵韧带骨化中的应用

目的：探讨颈前路椎体次全切治疗颈椎后纵韧带骨化的手术减压范围。方法：采用前路椎体次全切植骨融合术治疗颈椎后纵韧带骨化56例，其中完全切除骨化者47例，用“漂浮法”处理者9例，并针对不同个体及病变特点采用不同的减压范围。结果：54例获得3个月-6a随访，平均28个月。植骨均于术后3-5个月内获得骨性融合。JOA评分由术前8．5分提高到术后14．1，平均改善率74％，优良率80．2％。结论：行椎体次全切术治疗颈椎后纵韧带骨化时应针对不同个体及病变特点采用不同的足够的减压范围，可以减少并发症，并获得较佳的疗效。     

Reversible blockade of experience-dependent plasticity by calcineurin in mouse visual cortex

Numerous protein kinases have been implicated in visual cortex plasticity, but the role of serine/threonine protein phosphatases has not yet been established. Calcineurin, the only known Ca2+/calmodulin-activated protein phosphatase in the brain, has been identified as a molecular constraint on synaptic plasticity in the hippocampus and on memory. Using transgenic mice overexpressing calcineurin inducibly in forebrain neurons, we now provide evidence that calcineurin is also involved in ocular dominance plasticity. A transient increase in calcineurin activity is found to prevent the shift of responsiveness in the visual cortex following monocular deprivation, and this effect is reversible. These results imply that the balance between protein kinases and phosphatases is critical for visual cortex plasticity.     

Adult-onset type II citrullinemia and idiopathic neonatal hepatitis caused by citrin deficiency: involvement of the aspartate glutamate carrier for urea synthesis and maintenance of the urea cycle

Citrin is a mitochondrial aspartate glutamate carrier primarily expressed in the liver, heart, and kidney. We found that adult-onset type II citrullinemia is caused by mutations in the SLC25A13 gene that encodes for citrin. In this report, we describe the frequency of SLC25A13 mutations, the roles of citrin as a member of the urea cycle and as a member of the malate-aspartate shuttle, the relationship between its functions and symptoms of citrin deficiency, and therapeutic issues.     

Failure to produce conditioning with low-dose trimethylthiazoline or cat feces as unconditioned stimuli

Trimethylthiazoline (TMT), a derivative of fox feces, has been reported to fail to produce aversive conditioning as an unconditioned stimulus (UCS) when presented in large amounts (I. S. McGregor, L. Schrama, P. Ambermoon, & R. A. Dielenberg, 2002). Experiment I evaluated very low TMT levels that nonetheless produced defensive behaviors in rats during exposure. Although each level (0.01, 0.05, and 0.10 microl TMT) produced significant change in defensiveness, none resulted in significant changes the following day in the absence of TMT. Experiment 2 evaluated cat urine, cat feces, and cat fur/skin odor against a no-odor control. Urine produced no significant changes, but feces and fur/skin odors elicited virtually identical changes in defensive behaviors during exposure. When tested the next day in the absence of odor, the fur/skin odor-exposed group showed significant differences on the same behaviors as during exposure, but the feces-exposed group showed no differences on any measure. Results suggest that lack of conditioning to TMT may relate to the type of predator odor rather than the amount, predator species, or possible lack of odor components in TMT that are present in natural feces. Predator feces may also be less effective as a UCS because they are poorly predictive of the actual presence of the predator, suggesting the need for a reevaluation of UCS functions in aversive conditioning.     

The mutational spectrum of brachydactyly type C

Growth/differentiation factor-5 (GDF5), also known as cartilage-derived morphogenetic protein-1 (CDMP-1), is a secreted signaling molecule that participates in skeletal morphogenesis. Heterozygous mutations in GDF5, which maps to human chromosome 20, occur in individuals with autosomal dominant brachydactyly type C (BDC). Here we show that BDC is locus homogeneous by reporting a GDF5 frameshift mutation segregating with the phenotype in a family whose trait was initially thought to map to human chromosome 12. We also describe heterozygous mutations in nine additional probands/families with BDC and show nonpenetrance in a mutation carrier. Finally, we show that mutant GDF5 polypeptides containing missense mutations in their active domains do not efficiently form disulfide-linked dimers when expressed in vitro. These data support the hypothesis that BDC results from functional haploinsufficiency for GDF5.