Depletion of CXCR2 inhibits tumor growth and angiogenesis in a murine model of lung cancer

The Glu-Leu-Arg(+) (ELR(+)) CXC chemokines are potent promoters of angiogenesis and have been demonstrated to induce a significant portion of nonsmall cell lung cancer-derived angiogenic activity and support tumorigenesis. ELR(+) CXC chemokines share a common chemokine receptor, CXCR2. We hypothesized that CXCR2 mediates the proangiogenic effects of ELR(+) CXC chemokines during tumorigenesis. To test this postulate, we used syngeneic murine Lewis lung cancer (LLC; 3LL, H-2(b)) heterotopic and orthotopic tumor model systems in C57BL/6 mice replete (CXCR2(+/+)) and deficient in CXCR2 (CXCR2(-/-)). We first demonstrated a correlation of the expression of endogenous ELR(+) CXC chemokines with tumor growth and metastatic potential of LLC tumors. Next, we found that LLC primary tumors were significantly reduced in growth in CXCR2(-/-) mice. Moreover, we found a marked reduction in the spontaneous metastases of heterotopic tumors to the lungs of CXCR2(-/-) mice. Morphometric analysis of the primary tumors in CXCR2(-/-) mice demonstrated increased necrosis and reduced vascular density. These findings were further confirmed in CXCR2(+/+) mice using specific neutralizing Abs to CXCR2. The results of these studies support the notion that CXCR2 mediates the angiogenic activity of ELR(+) CXC chemokines in a preclinical model of lung cancer.     

Septin 3 (G-septin) is a developmentally regulated phosphoprotein enriched in presynaptic nerve terminals

The septins are GTPase enzymes with multiple roles in cytokinesis, cell polarity or exocytosis. The proteins from the mammalian septin genes are called Sept1-10. Most are expressed in multiple tissues, but the mRNA for Sept5 (CDCrel-1) and Sept3 (G-septin) appear to be primarily expressed in brain. Sept3 is phosphorylated by cGMP-dependent protein kinase I (PKG-I) and the cGMP/PKG pathway is involved in presynaptic plasticity. Therefore to determine whether Sept3 specifically associates with neurones and nerve terminals we investigated its distribution in rat brain and neuronal cultures. Sept3 protein was detected only in brain by immunoblot, but not in 12 other tissues examined. Levels were high in all adult brain regions, and reduced in those enriched in white matter. Expression was developmentally regulated, being absent in the early embryo, low in late embryonic rat brain and increasing after birth. Like dynamin I, Sept3 was specifically enriched in synaptosomes compared with whole brain, and was only found in a peripheral membrane extract and not in the soluble or membrane extracts. Sept3 was particularly abundant in mossy fibre nerve terminals in the hippocampus. In primary cultured hippocampal neurones Sept3 immunoreactivity was punctate in neurites and predominantly localized to presynaptic terminals, strongly colocalizing with synaptophysin and dynamin I. The specific nerve terminal localization was confirmed by immunogold electron microscopy. Together this shows that Sept3 is a neurone-specific protein highly enriched in nerve terminals which supports a secretory role in synaptic vesicle recycling.     

Linkage analysis using co-phenotypes in the BRIGHT study reveals novel potential susceptibility loci for hypertension

Identification of the genetic influences on human essential hypertension and other complex diseases has proved difficult, partly because of genetic heterogeneity. In many complex-trait resources, additional phenotypic data have been collected, allowing comorbid intermediary phenotypes to be used to characterize more genetically homogeneous subsets. The traditional approach to analyzing covariate-defined subsets has typically depended on researchers' previous expectations for definition of a comorbid subset and leads to smaller data sets, with a concomitant attrition in power. An alternative is to test for dependence between genetic sharing and covariates across the entire data set. This approach offers the advantage of exploiting the full data set and could be widely applied to complex-trait genome scans. However, existing maximum-likelihood methods can be prohibitively computationally expensive, especially since permutation is often required to determine significance. We developed a less computationally intensive score test and applied it to biometric and biochemical covariate data, from 2,044 sibling pairs with severe hypertension, collected by the British Genetics of Hypertension (BRIGHT) study. We found genomewide-significant evidence for linkage with hypertension and several related covariates. The strongest signals were with leaner-body-mass measures on chromosome 20q (maximum LOD = 4.24) and with parameters of renal function on chromosome 5p (maximum LOD = 3.71). After correction for the multiple traits and genetic locations studied, our global genomewide P value was .046. This is the first identity-by-descent regression analysis of hypertension to our knowledge, and it demonstrates the value of this approach for the incorporation of additional phenotypic information in genetic studies of complex traits.     

门诊妇女阴道乳酸菌对临床常用抗生素耐药性的初步研究

目的研究临床常用抗生素类药物对妇女生殖道正常菌群乳酸菌的影响,为临床医生选用抗生素治疗妇科疾病提供初步参考,并为微生态学治疗和预防相关疾病提供理论依据。方法采用K-B法（纸片扩散法）,以临床采集到的12株阴道乳酸菌为试验菌,研究其对临床常用9大类13种抗生素的耐药性。结果在所测试的抗生索中,试验菌对甲硝唑形成的耐药环直径最小,对头孢噻肟形成的耐药直径最大。除甲硝唑外不同菌株对不同抗生索形成的耐药环直径差异较大。结论在该试验的条件下,乳酸菌对甲硝唑耐药性最强,可作为治疗阴道感染的首选药物;乳酸菌对头孢噻肟最敏感,因而在治疗阴道感染时,应尽量避免使用该药物。     

动物组织中磺胺二甲嘧啶残留ELISA试剂盒研制

采用重氮化法和戊二醛法,将磺胺二甲嘧啶分别与牛血清白蛋白和辣根过氧化物酶偶联制备了免疫原和酶标半抗原,免疫兔获得了特异性抗体,成功建立了相关动物产品中磺胺二甲嘧啶残留ELISA定量检测方法及商品化试剂盒,并对试剂盒的灵敏度、准确度、精密度和稳定性进行了研究。试剂盒检测线性范围为62.5~0.54 ng/mL。在待测样品中各添加500、200、100、50 ng/g SMZ,测试的回收率平均为89.0%~134.8%;试剂盒测定结果与色谱的平均符合率99.8%~126.0%;对比定性测试15份色谱检测为阴性的样品,均未出现假阳性。试剂盒存放在37℃10 d和2~8℃5个月,质量稳定。     

酸提高绿茶提取物对脂肪酸合酶的抑制活性

脂肪酸合酶和肥胖、癌症等人类重大疾病相关.获取高活性脂肪酸合酶抑制剂有重要应用价值.50％乙醇的绿茶提取物具有抑制脂肪酸合酶和经口服降低大、小鼠体重的功能.该提取物在酸的作用下可明显地提高其抑制脂肪酸合酶的能力.采用1 mol/L硫酸或盐酸在100℃下处理绿茶提取物,发现该提取物对脂肪酸合酶的抑制活性随时间逐步提高.在25℃至120℃温度下,提高处理温度使抑制活性提高的速度加快和程度加大. 用1 mol/L盐酸120℃处理35 min或3 mol/L盐酸100℃处理30 min可使绿茶提取物抑制脂肪酸合酶的半抑制浓度下降20倍左右,达到1 μg/ml以下.用pKa值4.76至1.27的1 mol/L浓度的4种有机酸在100℃作用150 min使绿茶提取物抑制活性分别提高到1.48至5.84倍.提高酸的浓度也使被作用的提取物的抑制活性提高的更多.表现抑制活性提高的速度及程度和氢离子浓度正相关.判断绿茶提取物在酸作用下抑制活性的提高来源于其中所含儿茶素在氢离子作用下发生了化学变化.初步实验表明其变化过程比较复杂,确定其分子机制还需进一步的研究工作.     

光合细菌M-01的培养条件优化研究

对光合细菌M-01的培养条件进行了优化研究,结果表明:菌株的生长温度为30℃时,最适培养光照为3000lx,最低接种浓度为6%。培养基正交试验研究表明其最优培养基配方为:氯化铵2.00g,磷酸氢二钾0.20g,乙酸钠4.00g,碳酸氢钠2.00g,氯化钠1.00g,酵母膏0.15g,硫酸镁0.20g,T.M储液少量,蒸馏水1000mL;其中乙酸钠为最大影响因子。     

抗人胎盘酸性铁蛋白单链抗体的构建、表达与鉴定

目的:制备人胎盘酸性铁蛋白(PAF),构建、表达并鉴定抗人PAF单链可变区抗体片段(scFv)。方法:设计以SfiⅠ、NotⅠ为酶切位点、以(Gly4Ser)3为linker的2对引物,从抗人PAF单克隆抗体可变区基因的克隆载体中扩增VH和VL基因,用重叠延伸PCR在VH和VL基因间引入连接短肽,构建VH-linker-VL的scFv基因。经SfiⅠ、NotⅠ酶切后克隆到原核分泌型表达载体pUC19/119上,转化大肠杆菌TG1和筛选后测序验证,IPTG诱导表达,SDS-PAGE鉴定其相对分子质量(Mr)。以人PAF为抗原,scFv为一抗,抗His单克隆抗体为二抗,间接ELISA鉴定其抗体活性。结果:重叠延伸PCR扩增产物经凝胶电泳可见约700bp的条带,DNA序列分析证明2株抗体具有完整的scFv序列,并含有c-myc和His。IPTG诱导阳性菌表达产物经SDS-PAGE鉴定有Mr约27000的显示条带,符合scFv与表达标签融合蛋白的理论值;间接ELISA证明表达产物可与PAF结合。结论:成功构建并表达了抗人PAF单链抗体,为进一步建立检测PAF的间接ELISA奠定了基础。     

半胱氨酸蛋白酶拟肽抑制剂设计新进展

半胱氨酸蛋白酶包括多种酶,这些酶在广泛的生命过程中发挥作用。人类正常的半胱氨酸蛋白酶表达失调,寄生虫、病毒的半胱氨酸蛋白酶表达与多种病理情况相关。对于这类疾病,抑制半胱氨酸蛋白酶是一个可行的药物治疗策略。当前这类药物设计的目标是3种结构不同的半胱氨酸蛋白酶,即木瓜蛋白酶家族、半胱氨酸-天冬氨基特异性蛋白酶家族(caspases)和小核糖核酸病毒科半胱氨酸蛋白酶抑制剂家族。本文综述了近年来有关半胱氨酸蛋白酶抑制剂的设计思路。     

二硝基氟苯修饰的黑色素瘤细胞激活树突状细胞诱导特异性T细胞反应

目的:探索半抗原二硝基氟苯(DNP)修饰的恶性黑色素瘤细胞(恶黑)激活树突状细胞(DC)后,在体外诱导特异性T细胞反应的抗肿瘤效应。方法:采用DNP修饰恶黑细胞M3(H-2d),然后在体外激活BALB/c小鼠(H-2d)外周血来源的DC,用于激发自体的T细胞,观察对T细胞的增殖和特异性T细胞的杀伤功能。结果:经DNP修饰的M3细胞激活的DC,其诱发的T细胞增殖能力和对M3细胞的特异性杀伤效应均明显高于未修饰的M3细胞组和DC组。结论:DNP修饰M3所激活的DC可以诱导更强的恶黑特异性T细胞效应。