Variations in the C3, C3a receptor, and C5 genes affect susceptibility to bronchial asthma

Bronchial asthma (BA) is a common chronic inflammatory disease characterized by hyperresponsive airways, excess mucus production, eosinophil activation, and the production of IgE. The complement system plays an immunoregulatory role at the interface of innate and acquired immunities. Recent studies have provided evidence that C3, C3a receptor, and C5 are linked to airway hyperresponsiveness. To determine whether genetic variations in the genes of the complement system affect susceptibility to BA, we screened single nucleotide polymorphisms (SNPs) in C3, C5, the C3a receptor gene (C3AR1), and the C5a receptor gene (C5R1) and performed association studies in the Japanese population. The results of this SNP case-control study suggested an association between 4896C/T in the C3 gene and atopic childhood BA (P=0.0078) as well as adult BA (P=0.010). When patient data were stratified according to elevated total IgE levels, 4896C/T was more closely associated with adult BA (P=0.0016). A patient-only association study suggested that severity of childhood BA was associated with 1526G/A of the C3AR1 gene (P=0.0057). We identified a high-risk haplotype of the C3 gene for childhood (P=0.0021) and adult BA (P=0.0058) and a low-risk haplotype for adult BA (P=0.00011). We also identified a haplotype of the C5 gene that was protective against childhood BA (P=1.4×10^–6) and adult BA (P=0.00063). These results suggest that the C3 and C5 pathways of the complement system play important roles in the pathogenesis of BA and that polymorphisms of these genes affect susceptibility to BA.     

An improved transformation protocol for studying gene expression in hairy roots of sugar beet (Beta vulgaris L.)

A transformation protocol, based on co-inoculation with two strains of Agrobacterium, Agrobacterium tumefaciens LBA4404 and A. rhizogenes 15834 containing a binary vector with the GUS gene, was established for the induction of transgenic hairy roots from sugar beet (Beta vulgaris L.) explants. It resulted in marked improvement in the formation of hairy roots and the integration of the binary vector T-DNA into the host genome. Of 250 inoculated sugar beet hypocotyls, 84% yielded hairy roots 5–7 days after inoculation, of which 70% were co-transformed with the binary vector T-DNA. To determine stable expression of alien genes in hairy roots, the nematode resistance gene Hs1 ^pro-1 was used as a reporter gene. In addition, molecular marker analysis was applied to monitor stable incorporation of a translocation from the wild beet B. procumbens. The molecular analysis and the nematode (Heterodera schachtii) resistance test in vitro demonstrated that the genomic structure and the expression of the Hs1 ^pro-1 -mediated nematode resistance were well-maintained in all hairy root cultures even after repeated sub-culture. Received: 25 November 1997 / Revision received: 26 May 1998 / Accepted: 15 June 1998     

白化病的遗传流行病学研究

本文应用分离分析和血缘分析方法,对山东省１００余万人群遗传病调查中发现的３７个白化病核心家系进行了分析。结果表明：白化病存在遗传异质性,为多基因常染色体隐性遗传,最小基因数为８,平均基因频率为０．００２３,群体中致病基因携带者频率为０．０３８３;近亲结婚大大提高白化病的患病率。     

Dynamic patterns of histone H3 lysine 4 methyltransferases and demethylases during mouse preimplantation development

Extensive and dynamic chromatin remodeling occurs after fertilization, including DNA methylation and histone modifications. These changes underlie the transition from gametic to embryonic chromatin and are thought to facilitate early embryonic development. Histone H3 lysine 4 methylation (H3K4me) is an important epigenetic mechanism that associates with gene-specific activation and functions in development. However, dynamic regulation of H3K4me during early embryonic development remains unclear. Herein, the authors examined the dynamic changes of H3K4me and its key regulators (Ash1l, Ash2l, Kmt2a, Kmt2b, Kmt2c, Setd1a, Setd7, Kdm1a, Kdm1b, Kdm5a, Kdm5b, Kdm5c, and Kdm5d) in mouse oocytes and preimplantation embryos. An increase in levels of H3K4me2 and me3 was observed at the one- to two-cell stages (P?P?P?相似文献   

子宫颈糜烂病毒病因的探讨

491份宫颈拭子病毒分离结果表明:糜烂宫颈单纯疱疹病毒(HSV)分离阳性率(30.8％)是正常宫颈(2.6％)的11.8倍,用人干扰素治疗一个疗程后,病毒分离率下降至疗前的1/4.36例糜烂宫颈活体组织DNA分子杂交表明,乳头瘤病毒16型(HPV-16)阳性者占52.8和,HPV-18占17.9％,HPV-6B占28.1％,HPV-11占7.7％,251例宫颈糜烂患者经人(?)D型基因工程干扰素双盲对比治疗后,总有效率达93.8％,显效率达60％,分析临床疗效与HSV分离率的变化表明,临床有效病例中有35％(49/140)在治疗后病毒阴转,有57％在疗前疗后均未分离出HSV,有5％在疗前疗后保持阳性不变,有2.9％疗前阴性,疗后阳性,上述结果表明,HSV和HPV与慢性宫颈炎有一定关系。     

Energy intake and adiponectin gene expression

Hypoadiponectinemia and decreased adiponectin gene expression in white adipose tissue (WAT) have been well observed in obese subjects and animal models. However, the mechanism for obesity-associated hypoadiponectinemia is still largely unknown. To investigate the regulatory role of energy intake, dietary fat, and adiposity in adiponectin gene expression and blood adiponectin level, a series of feeding regimens was employed to manipulate energy intake and dietary fat in obese-prone C57BL/6, genetically obese ob/ob, obese-resistant A/J and peroxisome proliferator-activated receptor-α gene knockout (PPARα KO) mice. Adiponectin gene expression in WAT and circulating adiponectin levels were studied in these dietary intervention-treated mice. Our study showed that calorie restriction (CR) robustly increased adiponectin gene expression in epididymal fat and blood adiponectin levels in both low-fat (LF) and high-fat (HF) diet-fed C57BL/6 mice. Although HF pair-fed C57BL/6 mice received the same amount of calories as LF ad libitum-fed mice, HF diet clearly increased adiposity but showed no significant effects on adiponectin gene expression and blood adiponectin level. CR also significantly increased blood adiponectin levels in ob/ob and A/J mice. Neither CR nor HF feeding displayed any significant effect on blood adiponectin half-life in C57BL/6 mice. Interestingly, CR increased PPARα expression in epididymal fat of C57BL/6 mice. Low levels of blood adiponectin and adiponectin gene expression in WAT were observed in PPARα KO mice. PPARα agonist treatment increased adiponectin mRNA levels in 3T3-L1 adipocytes. Furthermore, CR failed to increase adiponectin gene expression and blood adiponectin levels in PPARα KO mice. Therefore, our study demonstrated that energy intake, not dietary fat, plays an important role in regulating adiponectin gene expression and blood adiponectin level. PPARα mediates CR-enhanced adiponectin gene expression in WAT.     

H9N2禽流感病毒反向遗传系统转录／表达载体的构建和验证

设计带有BsmBI、BsaI或AarI酶切位点的引物,用RT-PCR扩增H9N2亚型禽流感病毒(AIV)的8个基因全长片段,克隆入双向转录/表达载体pHW2000,并在PB2、PB1和NA基因中共引入了3个沉默突变标签。将其2个表面基因(HA和NA基因)加上任意1个内部基因,而其它5个内部基因来自A/WSN/33,进行了6种3 5组合形式的基因重排,把相应组合的转录/表达质粒共转染COS-1细胞,均产生了预期组合、有感染性的H9N2亚型流感病毒,表明亲缘关系遥远的流感病毒可以互相获取基因片段产生重组病毒,提示表面结构基因和单个内部基因不足以限制H9N2AIV在哺乳动物细胞上的宿主范围,同时也验证了构建的8个转录/表达载体均能有效工作,为进一步研究H9N2亚型AIV基因结构与功能、AIV与宿主之间的关系打下了基础。     

四氯化碳损伤成年大鼠肝细胞后原癌基因（c－fos／c－jun）表达的观察

用四氯化碳（ＣＣｌ４）损伤正常大鼠后,采用Ｗｅｓｔｅｒｎ印迹法和免疫组化法观察肝细胞原癌基因（ｃ－ｆｏｓ／ｃ－ｊｕｎ）的表达。Ｗｅｓｔｅｒｎ印迹法表明,当成年大鼠的静息期肝细胞受到ＣＣｌ４损伤性刺激后,ｃ－ｆｏｓ／ｃ－ｊｕｎ产物（Ｆｏｓ和Ｊｕｎ）水平升高,在ＣＣｌ４处理后３０ｍｉｎ开始升高,在４ｈ时消失。８ｈ后Ｆｏｓ／Ｊｕｎ再度出现,并持续２４ｈ以上。ＩＣＣ法表明,Ｊｕｎ阳性细胞为靠近肝中央静脉区的肝实质细胞。根据上述资料推测,肝受ＣＣｌ４损伤后肝细胞的原癌基因ｃ－ｆｏｓ／ｃ－ｊｕｎ出现即时的与滞后的两次表达,这与肝细胞进入细胞周期有关,这种基因表达也许可作为肝再生过程中识别特殊体液因子的标志。     

极耐热性乳酸脱氢酶高效表达、纯化及酶学性质

从海栖热袍菌扩增出编码乳酸脱氢酶的基因并将其插入热激载体pHsh构建表达质粒,在大肠杆菌Escherichia coli中进行表达产生极耐热性乳酸脱氢酶Tm-LDH。基因表达产物通过热处理,可以一步获得接近电泳纯的重组酶。酶学性质研究表明,Tm-LDH的最适反应温度为95℃,最适pH 7.0;纯酶在90℃的半衰期为2 h,在pH 5.5–8.0之间最稳定;SDS-PAGE结果显示分子量为33 kDa,与理论推算值相吻合。以丙酮酸和NADH为底物时,相对于丙酮酸的Km值1.7 mmol/L,Vmax为3.8×104 U/mg;相对于NADH的Km值7.2 mmol/L,Vmax值为1.1×105 U/mg。Tm-LDH基因在T7载体中未能实现高效表达,但是在热激载体pHsh中得到了可溶性超量表达,表达水平达到340 mg/L。该酶在65℃反应条件下,活性达到最高活性的50%,并能保持活性不变,这使该酶能够与常温酶匹配,在辅酶NAD再生体系的建立中具有广泛的用途。     

益生菌在结直肠癌患者中的应用

结直肠癌(colorectal cancer,CRC)的发病率及病死率在多国多年居高不下,肠道微生态的失衡在CRC的发生发展中所起的作用被许多学者所证实。专家一致认为,积极纠正肠道微生态失衡是可取的。CRC患者术前肠道菌群已经出现改变,术后肠道菌群失衡加重,化疗会进一步加重这种失衡状态。肠道微生态的稳态对机体肠道功能和免疫功能等起着重要作用。益生菌作为一种可调节肠道菌群的微生态制剂,已显现出在CRC患者治疗中的应用价值,现对益生菌在CRC患者中的应用进展作一综述。