Risk factors for intrapair birth weight discordance in twins

Objectives: To determine the risk factors for birth weight discordance in twins. Methods: We used the United States (1995-97) Matched Multiple Birth File (n = 294 568) to assess the association between birth weight discordance and maternal sociodemographic, pregnancy and infant characteristics. Results: Eighty-four per cent of the twins were 0-19% discordant, 11.1% were 20-29% discordant, 3.4% were 30-39% discordant, and 1.8% were ≥ 40% discordant. The risk factors for birth weight discordance for same-sex twins were eclampsia (odds ratio (OR) 1.39, 95% confidence interval (CI) 1.20, 1.61), pre-eclampsia (OR 1.31, 95% CI 1.24, 1.38), pre-existing hypertension (OR 1.32, 95% CI 1.12, 1.56), diabetes (OR 1.13, 95% CI 1.04, 1.24) and certain congenital anomalies. For opposite-sex twins, the risk factors for birth weight discordance were pre-eclampsia (OR 1.17, 95% CI 1.09, 1.27), pre-existing hypertension (OR 1.59, 95% CI 1.32, 1.91), and certain congenital anomalies. Also, smoking and increased maternal age were associated with birth weight discordance in both same-sex and opposite-sex twins. Conclusions: Maternal hypertensive disorders, smoking and delayed childbearing were associated with intrapair birth weight discordance. The mechanisms of these associations deserve further investigation.     

Thrombotic complications in von Willebrand disease

Thrombotic events occur rarely in patients with von Willebrand disease (VWD). In this review we analyze the data reported in the literature, selected through a PubMed search, on thrombotic complications in VWD patients. On the basis of this analysis, we conclude that thrombotic complications in VWD patients often have a multi-factorial pathogenesis resulting from a complex interaction between acquired (coagulation factor replacement, surgery, cardiovascular risk factors) and/or inherited (thrombophilic gene mutations) prothrombotic risk factors.     

HIV pre-exposure prophylaxis trials: socio-economic and ethical perspectives for sub-Saharan Africa

The advent of HIV pre-exposure prophylaxis (PrEP) as a HIV-prevention strategy has received optimistic support among HIV researchers. However, discourse on PrEP trials has tended to be dominated by the disputes arising between some activist groups and researchers about the research methodologies. Instead, this paper discusses other issues oftentimes neglected in discussions relating to PrEP trials. Specifically, I focus on the possible ethical implications and the potential impact of sub-Saharan Africa's socio-economic conditions on the promised benefits of PrEP trials for the region and the continent. I argue that the concept of PrEP as a affordable and practical HIV-prevention intervention presents challenges and questions that urgently need addressing as we await results from several ongoing trials. If research is undertaken with no plans on how the results of specific trials can render actual HIV-prevention-benefits — especially for the world's poor — then such endeavours risk being merely information-acquiring ventures.     

School-based Resilience: How an Urban Public High School Reduced Students' Risk Exposure and Promoted their Social-Emotional Development and Academic Success

This article is drawn from a qualitative case study that examined interactive resilience processes within an urban public charter high school that serves a population of primarily low-income, African American students. Resilience describes ‘the process of, capacity for, and/or outcome of successful adaptation despite challenging or threatening circumstances’ (Masten et al 1990, p426). The purpose of the study was to identify and understand the school-based factors and processes that helped students to achieve academic success and healthy social-emotional development despite the presence of numerous risk factors in their lives. The spotlighting of oft-marginalized students’ voices as they reflected upon the most influential school-based factors represents a critical addition to the literature.     

青年和老年乳癌的预后分析

目的　探讨青年和老年乳癌的预后。方法　对作者３ 所医院２０ 年间（１９７０ ～１９９０ 年） 随诊资料完整的３５ 岁以下青年乳癌１９７ 例和６５ 岁以上老年乳癌２６６ 例的临床特征及预后进行回顾性分析。结果　青年和老年乳癌发病率有所上升，其５ 年生存率分别为５５．３％（１０９／１９７）及６５．４％ （１７４／２６６） ，两者间无显著性差异（ Ｐ＞ ０．０５）。原发肿瘤＞ ５ ．０ ｃｍ ，临床Ⅲ期，腋淋巴结转移＞ ５ 枚或妊娠、哺乳期者，青年组预后较老年组差（ Ｐ ＜ ０ ．０１） 。结论　提高乳癌生存率的关键是早期发现，早期综合治疗，对青年乳癌的意义尤为重要。在临床Ⅱ，Ⅲ期青年组，通过综合治疗后可提高生存率。     

趋化因子MIP 2在大鼠肝缺血/再灌注损伤后的表达

目的　研究趋化因子巨噬细胞炎性蛋白 -2 (MIP 2 )在肝缺血 /再灌注损伤中 (I/R )的作用。方法　 3 2只大鼠随机分为 4组 ,每组 8只。即假手术 (对照 )组 ,部分肝脏缺血 90min再灌注 3 ,9,2 4h组。用RT PCR法检测肝组织中MIP 2的mRNA表达 ,ELISA法测定血浆中MIP 2蛋白表达 ,萘酚AS D氯醋酸盐酯酶特染技术检测肝组织内中性粒细胞浸润 ,并测定丙氨酸转氨酶 (ALT )。结果　缺血再灌注肝组织中MIP 2mRNA表达高于非缺血肝组织 (P <0 .0 1) ,9h组高于 3h组 (P <0 .0 1) ,2 4h组高于 9h组 (P <0 .0 1) ;MIP 2血浆蛋白表达、肝内中性粒细胞浸润、ALT也与MIP 2mR NA呈一致性的变化。MIP 2mRNA表达、血浆MIP 2蛋白水平与肝组织中性粒细胞浸润呈正相关 ,(r= 0 .88和 0 .83 ,P <0 .0 1)。结论　MIP 2在大鼠肝缺血 /再灌注损伤中作为中性粒细胞的趋化因子之一起着重要的上调作用。