大熊猫9个BAC的测序、注释和进化分析

本文构建了相当于大熊猫10倍基因组覆盖度的BAC文库, 并随机挑选了其中9个BAC进行测序和组装, 9个BAC的选择满足更多基因更少重复序列的原则. 这9个BAC的组装将为评估基于新一代Illumina GA测序技术的大熊猫全基因组测序及组装的准确性提供有效资源. 运用同源比对和从头预测的方法, 对9个BAC, 共约878 kb的序列进行了基因和重复序列的注释以及进化分析. 一共预测到12个蛋白编码基因, 其中, 7个基因匹配到同源基因的功能注释. 这7个基因平均大小约41 kb, 编码区平均大小约1.2 kb, 每个基因平均约含6个外显子. 同时预测到7个tRNA基因. 大约27%的序列被注释为重复序列. 同时, 基于邻接法, 构建了包含人、小鼠、狗、猫以及大熊猫5个物种的物种进化树, 结果显示狗的基因与其他4个物种相比距大熊猫最近. 本实验结果提供了大熊猫9个BAC的详细序列及注释信息, 为对大熊猫的研究提供了数据资源.     

Comparative nuclear and mitochondrial genome diversity in humans and chimpanzees

Restriction mapping and sequencing have shown that humans have substantially lower levels of mitochondrial genome diversity (d) than chimpanzees. In contrast, humans have substantially higher levels of heterozygosity (H) at protein-coding loci, suggesting a higher level of diversity in the nuclear genome. To investigate the discrepancy further, we sequenced a segment of the mitochondrial genome control region (CR) from 49 chimpanzees. The majority of these were from the Pan troglodytes versus subspecies, which was underrepresented in previous studies. We also estimated the average heterozygosity at 60 short tandem repeat (STR) loci in both species. For a total sample of 115 chimpanzees, d = 0.075 +/0 0.037, compared to 0.020 +/- 0.011 for a sample of 1,554 humans. The heterozygosity of human STR loci is significantly higher than that of chimpanzees. Thus, the higher level of nuclear genome diversity relative to mitochondrial genome diversity in humans is not restricted to protein-coding loci. It seems that humans, not chimpanzees, have an unusual d/H ratio, since the ratio in chimpanzees is similar to that in other catarrhines. This discrepancy in the relative levels of nuclear and mitochondrial genome diversity in the two species cannot be explained by differences in mutation rate. However, it may result from a combination of factors such as a difference in the extent of sex ratio disparity, the greater effect of population subdivision on mitochondrial than on nuclear genome diversity, a difference in the relative levels of male and female migration among subpopulations, diversifying selection acting to increase variation in the nuclear genome, and/or directional selection acting to reduce variation in the mitochondrial genome.      

液质连用分析重组胰高血糖素样肽-1受体激动剂肽图

目的：建立高效液相系统肽图分析法,用于重组胰高血糖素样肽-1受体激动剂（rExendin-4）的质量控制。方法：应用高效液相系统摸索最佳胰蛋白酶切和色谱条件,并采用液质联用系统分析肽段的精确相对分子量和氨基酸序列。结果：根据酶切条件摸索,确定酶切条件为：rExendin-4原液与胰蛋白酶按照质量比为100：1混匀,37℃酶切4小时,根据肽段的色谱保留时间、相对分子质量及对其碰撞诱导解离质谱的解析结果,归属出肽图中各肽段所在的色谱峰,与理论值完全一致。结论：本法精确度高、重复性好、自动化程度高,能够用于rExendin-4原液肽图分析。     

Quantitative and phenotypic analysis of bone marrow-derived cells in the intact and inflamed central nervous system

Bone marrow has been proposed as a possible source of cells capable of replacing injured neural cells in diseases such as Multiple Sclerosis (MS). Previous studies have reported conflicting results regarding the transformation of bone marrow cells into neural cells in vivo. This study is a detailed analysis of the fate of bone marrow derived cells (BMDC) in the CNS of C57Bl/6 mice with and without experimental autoimmune encephalomyelitis using flow cytometry to identify GFP-labeled BMDC that lacked the pan-hematopoietic marker CD45 and co-expressed neural markers polysialic acid-neural cell adhesion molecule or A2B5. A small number of BMDC displaying neural markers and lacking CD45 expression was identified within both the non-inflamed and inflamed CNS. However, the majority of BMDC exhibited a hematopoietic phenotype.Key words: bone marrow, transplantation, transdifferentiation, central nervous system, green fluorescence protein, experimental autoimmune encephalomyelitis, multiple sclerosis     

Accuracy of maternal recall of gestational weight gain 4 to 12 years after delivery

There is growing interest in the relationship between gestational weight gain (GWG) and long-term maternal and child outcomes, yet little is known about the accuracy of long-term maternal recall of GWG. Our objective was to assess the accuracy of maternal recall of GWG at 4-12 years postpartum (mean, 8 years) compared with medical-record documented GWG, and compare recalled GWG to documented GWG with respect to their associations with adverse pregnancy outcomes including small for gestational age (SGA) birth, preterm birth, cesarean delivery, and postpartum weight retention (PPWR) (n = 503). Adequacy of recalled and documented GWG was assessed according to the 2009 Institute of Medicine (IOM) guidelines. We observed moderate agreement between documented and maternal self-reported GWG as continuous variables (r = 0.63, P < 0.01). When recalled GWG was used to categorize women, 45, 53, and 20% of women with inadequate, adequate, and excessive documented GWG were misclassified, respectively. When comparing models fitted with documented or recalled GWG, there were no meaningful differences in associations between inadequate GWG and SGA birth (odds ratio 2.2 (95% confidence interval: 1.3, 3.7) vs. 2.1 (1.2, 3.8), respectively) or excessive GWG and PPWR (2.5 (1.6, 3.9) vs. 2.5 (1.5, 4.0), respectively). However, the use of recalled GWG attenuated associations between inadequate GWG and PPWR (documented: 0.5 (0.3, 0.9) vs. recalled GWG: 1.3 (0.7, 2.3)) and excessive GWG and preterm birth (documented: 2.5 (1.4, 4.5) vs. recalled GWG: 1.5 (0.9, 2.7)). Our data suggest a varying degree of bias when using recalled GWG to study selected adverse outcomes.     

Tooth loss and dental caries in community-dwelling older adults in northern Manhattan

doi: 10.1111/j.1741‐2358.2011.00502.x Tooth loss and dental caries in community‐dwelling older adults in northern Manhattan Objective: To examine tooth loss and dental caries by sociodemographic characteristics from community‐based oral health examinations conducted by dentists in northern Manhattan. Background: The ElderSmile programme of the Columbia University College of Dental Medicine serves older adults with varying functional capacities across settings. This report is focused on relatively mobile, socially engaged participants who live in the impoverished communities of Harlem and Washington Heights/Inwood in northern Manhattan, New York City. Materials and Methods: Self‐reported sociodemographic characteristics and health and health care information were provided by community‐dwelling ElderSmile participants aged 65 years and older who took part in community‐based oral health education and completed a screening questionnaire. Oral health examinations were conducted by trained dentists in partnering prevention centres among ElderSmile participants who agreed to be clinically screened (90.8%). Results: The dental caries experience of ElderSmile participants varied significantly by sociodemographic predictors and smoking history. After adjustment in a multivariable logistic regression model, older age, non‐Hispanic Black and Hispanic race/ethnicity, and a history of current or former smoking were important predictors of edentulism. Conclusion: Provision of oral health screenings in community‐based settings may result in opportunities to intervene before oral disease is severe, leading to improved oral health for older adults.     

Digital epidemiology

Mobile, social, real-time: the ongoing revolution in the way people communicate has given rise to a new kind of epidemiology. Digital data sources, when harnessed appropriately, can provide local and timely information about disease and health dynamics in populations around the world. The rapid, unprecedented increase in the availability of relevant data from various digital sources creates considerable technical and computational challenges.     

Endogenous opiates and behavior: 2006

This paper is the 29th consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning 30 years of research. It summarizes papers published during 2006 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular–biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurological disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17).     

Genetic elements associated with antimicrobial resistance in enteropathogenic <Emphasis Type="Italic">Escherichia coli</Emphasis> (EPEC) from Brazil

Background  

We recently observed an association of resistance with a certain enteropathogenic Escherichia coli (EPEC) serotypes and identified a conjugative plasmid, similar to plasmid pED208, that was conserved among archival O111:H2/NM and O119:H2 strains of diverse geographical origin. In this study, we sought to determine the prevalence and distribution of this plasmid among a collection of EPEC isolates from Brazil, as well as to study the susceptibilities of these isolates to antimicrobial agents.