SSTR-2、E-cad与不明原因的反复自然流产相关性研究

目的:研究生长抑素2型受体(SSTR2)、E-钙粘附素(E-cad)与不明原因的反复自然流产相关性。方法:选取2011年1月到2014年12月我院收治的不明原因反复自然流产患者60例(研究组),另选同期早期正常孕妇且准备流产者60例(对照组),应用免疫组化技术检测两组蜕膜组织中的SSTR2和E-cad表达,并进行比较。结果:研究组蜕膜组织中SSTR-2阳性细胞平均光密度显著高于对照组,而E-cad阳性细胞平均光密度显著低于对照组,两组比较差异具有统计学意义(P0.05);研究组蜕膜组织中SSTR-2与E-cad水平呈负相关关系,对照组蜕膜组织中SSTR-2与E-cad水平呈正相关关系(P0.05)。结论:蜕膜组织中SSTR-2高表达与E-cad低表达可能与不明原因的反复自然流产有关。     

Recurrent epidemics in small world networks

The effect of spatial correlations on the spread of infectious diseases was investigated using a stochastic susceptible-infective-recovered (SIR) model on complex networks. It was found that in addition to the reduction of the effective transmission rate, through the screening of infectives, spatial correlations have another major effect through the enhancement of stochastic fluctuations, which may become considerably larger than in the homogeneously mixed stochastic model. As a consequence, in finite spatially structured populations significant differences from the solutions of deterministic models are to be expected, since sizes even larger than those found for homogeneously mixed stochastic models are required for the effects of fluctuations to be negligible. Furthermore, time series of the (unforced) model provide patterns of recurrent epidemics with slightly irregular periods and realistic amplitudes, suggesting that stochastic models together with complex networks of contacts may be sufficient to describe the long-term dynamics of some diseases. The spatial effects were analysed quantitatively by modelling measles and pertussis, using a susceptible-exposed-infective-recovered (SEIR) model. Both the period and the spatial coherence of the epidemic peaks of pertussis are well described by the unforced model for realistic values of the parameters.     

Changes in DNA-marker frequencies associated with response to contrasting selection methods in Arabidopsis

 Recurrent selection for specific combining ability (RS-SCA) and S1 family performance (RS-S1) were compared in replicated selection programs initiated from a common C0 base population of Arabidopsis. Three cycles of selection for aerial biomass were completed in each of two replicate programs of each selection method. Response to selection was measured on the basis of per se, S1 progeny, and testcross performance with a common tester. All selection programs improved testcross performance. Testcross gain per cycle in RS-S1 (7.15% cycle^-1) and RS-SCA (5.31% cycle^-1) were not significantly different. Performance of S1 progeny and populations per se significantly improved over cycles of selection using RS-S1 but were unchanged by RS-SCA. Codominant molecular marker-allele frequencies were recorded for each population at 22 polymorphic loci. Trends in marker-allele frequencies were tested by linear regression. Significant trends in marker-allele frequencies pooled over replicate programs were detected at 8 and 7 loci in the RS-S1 and RS-SCA programs, respectively. Marker alleles at 2 loci significantly changed frequency in response to both RS-S1 and RS-SCA programs. Marker alleles at 6 loci significantly changed frequency only in response to RS-SCA. Marker alleles at 6 other loci showed significant linear trends pooled over replicates only in RS-S1. No markers revealed increases in the frequency of different marker alleles within loci using the two selection methods. Possible genetic causes of marker frequency changes are discussed, as well as breeding implications.     

Hyper-CVAD/MA治疗复发或难治性弥漫大B 细胞淋巴瘤的临床研究

目的:探讨Hyper-CVAD/MA方案治疗复发或难治弥漫大B细胞淋巴瘤(diffuse large B-cell lymphoma,DLBCL)的疗效及安全性。方法:观察26例经系统化疗后复发或难治的DLBCL患者接受Hyper-CVAD/MA方案化疗,21-28天为1周期,连续2个周期评价疗效及安全性,分析生存情况。结果:全组26例患者中,总有效率为46.15%,其中完全缓解(complete remission,CR)3例(11.54%),部分缓解(partial remission,PR)9例(34.61%),全组患者中位生存时间为10(2-25)个月,1年和2年总生存率分别为28.57%、14.29%。不良反应主要表现为III-IV度骨髓抑制及继发的肺部感染,其他包括胃肠道反应、口腔炎、肝功能异常等。结论:Hyper-CVAD/MA治疗复发难治DLBCL有一定的疗效,且患者可耐受,可作为二线方案的一个选择。     

Valuing Stillbirths

Estimates of the burden of disease assess the mortality and morbidity that affect a population by producing summary measures of health such as quality‐adjusted life years (QALYs) and disability‐adjusted life years (DALYs). These measures typically do not include stillbirths (fetal deaths occurring during the later stages of pregnancy or during labor) among the negative health outcomes they count. Priority‐setting decisions that rely on these measures are therefore likely to place little value on preventing the more than three million stillbirths that occur annually worldwide. In contrast, neonatal deaths, which occur in comparable numbers, have a substantial impact on burden of disease estimates and are commonly seen as a pressing health concern. In this article we argue in favor of incorporating unintended fetal deaths that occur late in pregnancy into estimates of the burden of disease. Our argument is based on the similarity between late‐term fetuses and newborn infants and the assumption that protecting newborns is important. We respond to four objections to counting stillbirths: (1) that fetuses are not yet part of the population and so their deaths should not be included in measures of population health; (2) that valuing the prevention of stillbirths will undermine women's reproductive rights; (3) that including stillbirths implies that miscarriages (fetal deaths early in pregnancy) should also be included; and (4) that birth itself is in fact ethically significant. We conclude that our proposal is ethically preferable to current practice and, if adopted, is likely to lead to improved decisions about health spending.     

Principles and Methods in Computational Membrane Protein Design

After decades of progress in computational protein design, the design of proteins folding and functioning in lipid membranes appears today as the next frontier. Some notable successes in the de novo design of simplified model membrane protein systems have helped articulate fundamental principles of protein folding, architecture and interaction in the hydrophobic lipid environment. These principles are reviewed here, together with the computational methods and approaches that were used to identify them. We provide an overview of the methodological innovations in the generation of new protein structures and functions and in the development of membrane-specific energy functions. We highlight the opportunities offered by new machine learning approaches applied to protein design, and by new experimental characterization techniques applied to membrane proteins. Although membrane protein design is in its infancy, it appears more reachable than previously thought.     

Assessment of DNA damage in relation to heavy metal induced oxidative stress in females with recurrent pregnancy loss (RPL)

Pregnancy termination consecutively for three or more times during the first trimester is termed as Recurrent pregnancy loss (RPL). In addition to the abnormal karyotype, heavy metal induced oxidative damage may contribute as prominent etiological factor in pregnancy termination. Oxidative stress is considered crucial in etiology underlying RPL with altered antioxidant status and subsequent DNA damage. The current case controlled study investigated Total antioxidant capacity (TAC), DNA damage (8OHdG) and heavy metals in RPL group (n = 30) and the women with successful pregnancies and no cases of miscarriage as control group (30 women). Heavy metals -Antimony (Sb) and Arsenic (As) were measured by Inductively Coupled Plasma Mass spectrophotometry (ICP-MS). There was significant decrease in levels of TAC in RPL group compared to healthy pregnant women (P < 0.05). On contrary, elevated levels of As and Sb were observed in RPL group with subsequent increase in the levels of 8OHdG (P < 0.001); indicating extensive DNA damage in these patients. Furthermore, increased levels of As and Sb in RPL group were positively correlated with 8OHdG and negatively with total antioxidant capacity. The outcome of the study provides clear insight of the role of metal induced oxidative stress that plays a vital role in the pathophysiology underlying RPL.     

Co-occurrences of polymorphic heterochromatin regions of chromosomes and effect on reproductive failure

Although the polymorphic heterochromatin regions of chromosomes (heteromorphisms) have been extensively studied for their phenotypic effects on humans, co-occurrences of chromosome 1, 9, 16 and Y heteromorphisms and of acrocentric variants have never been studied on humans with an objective scoring system. Here we compared the frequencies of individual heteromorphisms on a total of 602, 768 and 224 patients with the indications of infertility, recurrent miscarriage and in vitro fertilization (IVF) failure, respectively and on 272 controls. Then we examined whether there were significant co-occurrences between heteromorphisms within and between the groups. There were no statistically significant differences in the frequencies of heteromorphisms between the groups. Both statistically significant and non-significant correlations were observed within the non-acrocentric and certain acrocentric heteromorphisms in each group. When these co-occurrences were examined between the groups, a 2.2 fold increased risk of IVF failure in males in the presence of either chromosome 13 or chromosome 21 variants was observed (95 %CI:1.1–4.2). We conclude that the simultaneous manifestations of heteromorphisms have no effect on reproductive failure. There seems to be a correlation between the non-acrocentric heteromorphisms (1qh+, 9qh+, 16qh + and Yqh+/-), which might be the result of complex interactions of formation of these heterochromatin regions. The correlations observed between certain acrocentric chromosomes might be related to satellite association and nucleolus formation. The increased risk observed in males with IVF failure in the presence of either chromosome 13 or 21 variants should be interpreted cautiously due to the heterogeneity of the group.     

PAI-1基因4G/5G多态性与中国地区原因不明习惯性流产的Meta分析

目的:探讨PAI-A基因4G/5G多态性跟中国地区原因不明习惯性流产的关系.方法:采用Stata10.0对所有纳入结果进行异质性检验,敏感分析,影响分析和发表偏移检验.结果:6篇文章共540名病例和672名对照纳入研究.敏感性分析之后,4G/5G多态性跟习惯性流产明显相关(显性模型OR=1.934,95％CI=1.355-2.760,隐性模型OR=1.657,95％CI=1.142-2.405),共显性模型OR=1.604,95％CI=1.309-1.965).结论:PAI-1基因4G/5G可能与中国地区原因不明习惯性流产有关.但仍然需要更多的实验证实.