κ-阿片受体与β1-肾上腺素受体交互作用抑制异丙肾上腺素诱导的心肌肥大

目的:观察选择性kappa阿片受体(kappaopioidreceptor,κOR)与β肾上腺素受体(βadrenergicreceptor,βAR)在心肌细胞肥大方面的交互作用。方法:以体外培养的乳鼠心肌细胞为模型,10μmol·L-1的异丙肾上腺素(β肾上腺素受体激动剂,βAR)诱导心肌肥大,观察1μmol·L-1的U50,488H(κOR激动剂,U50)对其作用。进一步探索在100nmol·L-1ICI118,551(β2AR阻断剂)存在情况下,κOR的激活对心肌肥大的作用。用Lowry’s法测心肌细胞的蛋白质含量;用消化分离法,并利用计算机图象分析系统测心肌细胞的体积;用[3H]leucine掺入法测定心肌细胞蛋白的合成。结果:异丙肾上腺素使心肌细胞总蛋白含量、体积、蛋白合成明显增加;1μmol·L-1的U50,488H使ISO诱导的心肌细胞总蛋白含量、体积、蛋白合成减少,这种作用可被选择性κOR阻断剂norBNI(norbinaltorphimine)抑制。在ICI118,551存在的情况下,U50也能起到减弱ISO诱导心肌细胞肥大的作用。结论:U50,488H通过激活κOR与β1AR交互作用抑制ISO所诱导的心肌细胞肥大。     

分子信标PCR检测脲原体U.Parvum和U.Urealyticum

目的 建立2个快速、同步检测脲原体U．Parvum和U．Urealyticum的分子信标PCR反应体系。方法 依据脲原体尿素酶B基因序列，设计分别针对U．Parvum和U．Urealyticum的特异性分子信标探针及引物，建立2个分子信标PCR反应体系。通过对脲原体标准株扩增后荧光强度的检测、分子信标S／B值测定以及进行特异性和敏感性实验，对2个体系进行评价并设定2个分子信标PCR反应体系的cutoff值。结果 U．Parvum和U．Urealyticum的分子信标S／B值均〉20。2个分子信标PCR体系能够检测U．Parvum、U．Urcalyticum标准株DNA．与其他14株细菌（包括5株有尿素酶细菌）无交叉反应，检测限度均为10拷贝／μl的重组质粒DNA。U．Parvum分子信标PCR反应体系的cutoff值为3．89．U．Urealyticum分子信标PCR反应体系的cutoff为5．32。结论 2个分子信标PCR反应体系能够快速、同步进行脲原体的分种鉴别，具有高度特异性和灵敏性。     

草分枝杆菌F·U·36治疗反复发作呼吸道感染病儿45例

目的:观察草分枝杆菌F·U·36治疗反复呼吸道感染(RRSI)病儿临床疗效。方法:75例RRSI病儿分为2组,其中反复上呼吸道感染50例,反复下呼吸道感染25例。治疗组45例中男性25例,女性20例,年龄(6±s6)a,1.5~14.1a,给予青霉素及利巴韦林注射液,iv,gtt,bid,7~10d;在以上常规治疗的基础上,给予草分枝杆菌F·U·361.72μg,im,每周1次,1mo为一个疗程。对照组30例,男性17例,女性13例,年龄(6±7)a,1.4~14.5a,只给予常规治疗。观察2组临床疗效,并测定IgA,IgG,IgM,CD3+,CD4+,CD8+,CD4+/CD8+的水平。结果:治疗后治疗组,总有效率91%(41/45);对照组总有效率37%(11/30),2组比较差异有非常显著意义(P<0.01)。治疗组治疗后,IgA,IgG,IgM,CD3+,CD4+,CD8+,CD4+/CD8+值均明显增加(P<0.01)。结论:草分枝杆菌F·U·36用于防治RRSI有明显疗效,能有效地改善免疫学指标,无明显不良反应。     

美国疫苗不良事件报告系统

简要介绍了美国疫苗不良事件报告系统(VAERS)的建立及基本运行概况,对该系统收集到的病例报告情况进行了较为全面的分析,并概括总结了该系统的优势,对我国开展疫苗不良事件监测有良好的借鉴意义.     

Neuromedin U及其受体的研究进展

NeuromedinU作为一种脑肠多肽 ,其外周生物活性包括刺激平滑肌、增加血压、增加血流、改变小肠离子传输、控制局部血流、调节肾上腺皮质素等功能 ,已发现neuromedinU在中枢神经系统的作用为减少食物摄取和体重。该文就neuromedinU及其受体的结构、组织分布和生理学功能等研究进行综述。     

寡核苷酸表达谱揭示异烟肼耐药对结核分支杆菌致病性的影响

目的研究结核分支杆菌异烟肼耐药菌株与H37Rv异烟肼敏感菌株感染巨噬细胞后差异表达的基因. 方法利用高密度cDNA芯片检测巨噬细胞U937感染结核分支杆菌异烟肼耐药菌株与H37Rv后的基因表达谱的差异. 结果两者诱导巨噬细胞的差异表达基因有53条,异烟肼耐药菌株比敏感菌株诱导多种趋化因子和细胞免疫增强的细胞因子表达上调和免疫抑制细胞因子IL-10等表达下调. 结论异烟肼耐药对细菌毒力有明显的影响,异烟肼耐药菌株的致病力下降,异烟肼耐药菌株容易被宿主免疫系统清除;结果为耐多药结核病控制提供依据;骨桥接素和巨噬细胞趋化因子等,在抗异烟肼耐药结核分支杆菌感染免疫中的作用值得深入研究.     

Hydroxyl Radical-induced Strand Break Formation of Poly(U) in Anoxic Solution. Effect of Dithiothreitol and Tetranitromethane

Summary

The role of dithiothreitol (DTT) and tetranitromethane (TNM) on the yields of radiation-induced strand break formation in polyuridylic acid (poly(U)) was studied in anoxic aqueous solutions at neutral pH by low-angle laser light-scattering. From G (single-strand breaks) as a function of DTT concentration it follows that two different processes lead to OH radical-induced single-strand break (ssb) formation. Only one of the two processes, which accounts for 80 per cent of the ssb formation, is inhibited by DTT, the other one, 20 per cent, is not inhibited. The ‘repair’ process is attributed to H-donation to the C-6-yl radical of the uracil moiety. The C-6-yl radical is produced by OH addition to the C-5 position of the uracil moiety. It follows that the sugar radicals, in contrast to earlier suggestions, do not seem to be repaired by DTT at the low concentrations used. The strand break formation not inhibited by DTT is induced by radicals other than the uracil-6-yl radical, e.g. the uracil-5-yl or the OH radicals reacting with the sugar moiety. The strong reduction of G(ssb) from 2·3 to 0·2 on addition of TNM is also discussed.     

Barriers and Pathways to Diffusion of Methamphetamine Use Among African Americans in the Rural South

Abstract

There are no studies of African Americans', methamphetamine use in the South where it is widespread among whites. We describe factors that inhibit or facilitate the diffusion of methamphetamine use among African Americans based on qualitative interviews with 86 drug users in rural Arkansas and Kentucky. Results suggest low prevalence of methamphetamine use among African Americans, and interviewees cited several barriers to its diffusion which were linked to the drug's ingredients, psychoactive and physiological effects, difficulty in accessing distribution networks, and established African-American preference for cocaine. Fourteen African Americans reported methamphetamine use and discussed pathways to it. Possible increases in African-American methamphetamine use merits further investigation.