• 【分解代谢质粒pjp4中重组事件的分子和种群分析。】 复制标题 收藏 收藏
    DOI:10.1128/JB.00869-06 复制DOI
    作者列表:Larraín-Linton J,De la Iglesia R,Melo F,González B
    BACKGROUND & AIMS: :Cupriavidus necator JMP134(pJP4) harbors a catabolic plasmid, pJP4, which confers the ability to grow on chloroaromatic compounds. Repeated growth on 3-chlorobenzoate (3-CB) results in selection of a recombinant strain, which degrades 3-CB better but no longer grows on 2,4-dichlorophenoxyacetate (2,4-D). We have previously proposed that this phenotype is due to a double homologous recombination event between inverted repeats of the multicopies of this plasmid within the cell. One recombinant form of this plasmid (pJP4-F3) explains this phenotype, since it harbors two copies of the chlorocatechol degradation tfd gene clusters, which are essential to grow on 3-CB, but has lost the tfdA gene, encoding the first step in degradation of 2,4-D. The other recombinant plasmid (pJP4-FM) should harbor two copies of the tfdA gene but no copies of the tfd gene clusters. A molecular analysis using a multiplex PCR approach to distinguish the wild-type plasmid pJP4 from its two recombinant forms, was carried out. Expected PCR products confirming this recombination model were found and sequenced. Few recombinant plasmid forms in cultures grown in several carbon sources were detected. Kinetic studies indicated that cells containing the recombinant plasmid pJP4-FM were not selectable by sole carbon source growth pressure, whereas those cells harboring recombinant plasmid pJP4-F3 were selected upon growth on 3-CB. After 12 days of repeated growth on 3-CB, the complete plasmid population in C. necator JMP134 apparently corresponds to this form. However, wild-type plasmid forms could be recovered after growing this culture on 2,4-D, indicating that different plasmid forms can be found in C. necator JMP134 at the population level.
    背景与目标: : Cupriavidus necatator JMP134(pJP4) 具有分解代谢质粒pJP4,该质粒赋予了在氯芳族化合物上生长的能力。在3-氯苯甲酸酯 (3-CB) 上重复生长导致选择重组菌株,该菌株可以更好地降解3-CB,但不再在2,4-二氯苯氧乙酸 (2,4-d) 上生长。我们先前已经提出,这种表型是由于该质粒在细胞内的多胞菌的反向重复之间发生了双重同源重组事件。这种质粒的一种重组形式 (pJP4-F3) 解释了这种表型,因为它包含两个拷贝的氯邻苯二酚降解tfd基因簇,这两个拷贝对于在3-CB上生长是必不可少的,但是已经失去了tfdA基因,编码2,4-d降解的第一步。另一个重组质粒 (pJP4-FM) 应该包含两个拷贝的tfdA基因,但没有拷贝的tfd基因簇。进行了分子分析,使用多重PCR方法将野生型质粒pJP4与其两种重组形式区分开。发现并测序了证实该重组模型的预期PCR产物。在几种碳源中生长的培养物中,几乎没有检测到重组质粒形式。动力学研究表明,含有重组质粒pJP4-FM的细胞不能通过唯一的碳源生长压力来选择,而那些具有重组质粒pJP4-F3的细胞在3-CB上生长时被选择。在3-CB上重复生长12天后,C. necator JMP134中的完整质粒群体显然对应于这种形式。但是,在2,4-d上生长该培养物后,可以恢复野生型质粒形式,这表明在种群水平上在C. necator JMP134中可以发现不同的质粒形式。
  • 【通过分子动力学模拟研究了水对螺旋肽展开动力学的作用。】 复制标题 收藏 收藏
    DOI:10.1016/S0006-3495(97)78889-1 复制DOI
    作者列表:Doruker P,Bahar I
    BACKGROUND & AIMS: Molecular dynamics simulations have been carried out with four polypeptides, Ala13, Val(13), Ser13, and Ala4Gly5Ala4, in vacuo and with explicit hydration. The unfolding of the polypeptides, which are initially fully alpha-helix in conformation, has been monitored during trajectories of 0.3 ns at 350 K. A rank of Ala < Val < Ser < Gly is found in the order of increasing rate of unwinding. The unfolding of Ala13 and Val(13) is completed in hundreds of picoseconds, while that of Ser13 is about one order of magnitude faster. The helix content of the peptide containing glycine residues falls to zero within a few picoseconds. Ramachandran plots indicate quite distinct equilibrium distributions and time evolution of dihedral angles in water and in vacuum for each residue type. The unfolding of polyalanine and polyvaline helices is accelerated due to solvation. In contrast, polyserine is more stable in water compared to vacuum, because its side chains can form intramolecular hydrogen bonds with the backbone more readily in vacuum, which disrupts the helix. Distribution functions of the spatial and angular position of water molecules in the proximity of the polypeptide backbone polar groups reveal the stabilization of the coiled structures by hydration. The transition from helix to coil is characterized by the appearance of a new peak in the probability distribution at a specific location characteristic of hydrogen bond formation between water and backbone polar groups. No significant insertion of water molecules is observed at the precise onset of unwinding, while (i, i+3) hydrogen bond formation is frequently detected at the initiation of alpha-helix unwinding.

    背景与目标: 已在真空中并在显式水合作用下使用四种多肽Ala13,Val(13),Ser13和Ala4Gly5Ala4进行了分子动力学模拟。在350 K处0.3 ns的轨迹期间,已经监测了最初在构象上完全为 α-螺旋的多肽的展开。Ala
  • 【来自 “进化峡谷” 的酿酒酵母自然种群中的分子遗传生物多样性: 微卫星多态性,倍性和有争议的性状态。】 复制标题 收藏 收藏
    DOI:10.1534/genetics.106.062745 复制DOI
    作者列表:Ezov TK,Boger-Nadjar E,Frenkel Z,Katsperovski I,Kemeny S,Nevo E,Korol A,Kashi Y
    BACKGROUND & AIMS: :The yeast S. cerevisiae is a central model organism in eukaryotic cell studies and a major component in many food and biotechnological industrial processes. However, the wide knowledge regarding genetics and molecular biology of S. cerevisiae is based on an extremely narrow range of strains. Studies of natural populations of S. cerevisiae, not associated with human activities or industrial fermentation environments, are very few. We isolated a panel of S. cerevisiae strains from a natural microsite, "Evolution Canyon" at Mount Carmel, Israel, and studied their genomic biodiversity. Analysis of 19 microsatellite loci revealed high allelic diversity and variation in ploidy level across the panel, from diploids to tetraploids, confirmed by flow cytometry. No significant differences were found in the level of microsatellite variation between strains derived from the major localities or microniches, whereas strains of different ploidy showed low similarity in allele content. Maximum genetic diversity was observed among diploids and minimum among triploids. Phylogenetic analysis revealed clonal, rather than sexual, structure of the triploid and tetraploid subpopulations. Viability tests in tetrad analysis also suggest that clonal reproduction may predominate in the polyploid subpopulations.
    背景与目标: : 酵母酿酒酵母是真核细胞研究中的中心模式生物,也是许多食品和生物技术工业过程中的主要组成部分。然而,关于酿酒酵母的遗传学和分子生物学的广泛知识是基于极其狭窄的菌株范围。与人类活动或工业发酵环境无关的酿酒酵母自然种群研究很少。我们从以色列卡梅尔山的自然微位点 “进化峡谷” 中分离了一组酿酒酵母菌株,并研究了它们的基因组生物多样性。对19个微卫星基因座的分析显示,从二倍体到四倍体,整个面板的等位基因多样性和倍性水平变化很高,通过流式细胞术证实。在来自主要地区或微型物种的菌株之间的微卫星变异水平上没有发现显着差异,而不同倍性的菌株在等位基因含量上显示出较低的相似性。在二倍体中观察到最大的遗传多样性,在三倍体中观察到最小。系统发育分析显示,三倍体和四倍体亚群的克隆而非性结构。tetrad分析中的生存力测试还表明,克隆繁殖可能在多倍体亚群中占主导地位。
  • 【水痘短缺对社区人口中18和24个月大的儿童的近期和长期影响。】 复制标题 收藏 收藏
    DOI:10.1186/1471-2296-7-51 复制DOI
    作者列表:Yawn BP,Schroeder C,Wollan P,Rocca L,Zimmerman R,Bardenheier B
    BACKGROUND & AIMS: BACKGROUND:Little is known about the impact of the recent varicella vaccine shortage. To assess the temporal trend in varicella vaccine administration before 18 and 24 months of age in a community cohort of children prior to, during and after the recent varicella vaccine shortage. And to compare the temporal trends in varicella vaccinations to trends of an older, more widely accepted vaccine, the MMR. METHODS:Community population-based birth cohorts were identified who were eligible for the varicella vaccination before, during and after the 2001 to 2002 varicella vaccine shortage. Only children (84% of all) who remained in the community through their second birthday were included. For each child in the cohort, the medical records and immunization registry records from both medical facilities in the county were reviewed to identify the dates and sites for all varicella immunizations given. In addition to varicella immunizations, the dates of all MMR vaccinations were recorded. Additional data abstracted included the child's birth date, gender and dates of any recognized cases of chickenpox up through age 24 months. RESULTS:Of the 2,512 children in the birth cohorts, 50.8% were boys. In the three cohorts combined, 81.1% of the boys and 79.3% of the girls (p = 0.30) received the varicella vaccine by age 24 months. The pre-shortage community rate of varicella immunization was 79.7% by 24 months of age. During the varicella vaccine shortage, the rate of varicella immunization by 24 months fell to 77.2%. Only 6 additional children received a "catch-up" immunization by 36 months of age. In the post shortage period the community 24-month immunization rate rebounded to a level higher than the pre-shortage rate 84.0%. During the almost three years of observation, the MMR immunization rate by age 24 months was constant (87%). CONCLUSION:The varicella shortage was associated with an immediate drop in the 24-month varicella immunizations rate but rebounded quickly to above pre-shortage rates. In this community the only long term impact of the varicella vaccine shortage may be on the small number of children who still had not received catch-up varicella immunizations by 36 months of age.
    背景与目标:
  • 【百草枯在小肠,肝脏和肾脏中的免疫组织化学定位和动力学。】 复制标题 收藏 收藏
    DOI:10.1016/0300-483x(90)90040-n 复制DOI
    作者列表:Nagao M,Takatori T,Inoue K,Shimizu M,Terazawa K,Akabane H
    BACKGROUND & AIMS: :Immunohistochemical techniques were used to observe the localization of paraquat in the small intestine, liver and kidney, organs that absorb and eliminate chemicals. Paraquat-poisoned rats were killed 3 h, 12 h, 24 h, 3 days, 7 days and 10 days after intravenous administration of paraquat. Three hours after injection, paraquat was localized in hepatocytes and in the kidney in the epithelial cells of the distal tubule. The amount of paraquat in the liver and kidney increased by 24 h after the administration and thereafter decreased with time, suggesting that paraquat is secreted into bile and urine. In the intestine, 3 h after injection, paraquat was localized in the epithelial cells. The same finding was also made in rats with a cannulated bile duct. Therefore, it is likely that paraquat is secreted into the gut lumen from epithelial cells and that paraquat secreted from liver into the duodenum is reabsorbed into the epithelial cells of the intestine.
    背景与目标: : 免疫组织化学技术用于观察百草枯在小肠,肝脏和肾脏,吸收和消除化学物质的器官中的定位。静脉注射百草枯后3 h,12 h,24 h,3天,7天和10天杀死百草枯中毒的大鼠。注射三小时后,百草枯位于肝细胞和远端小管上皮细胞的肾脏中。给药后24小时,肝脏和肾脏中的百草枯量增加,此后随时间减少,这表明百草枯分泌到胆汁和尿液中。在肠中,注射后3小时,百草枯位于上皮细胞中。在具有插管胆管的大鼠中也有相同的发现。因此,百草枯很可能从上皮细胞分泌到肠腔中,而百草枯从肝脏分泌到十二指肠被重新吸收到肠的上皮细胞中。
  • 【自我收集的宫颈阴道采样,用于基于HPV的初级宫颈癌筛查的护理地点: 在服务不足的希腊农村人群中的一项初步研究。】 复制标题 收藏 收藏
    DOI:10.1080/01443615.2017.1323197 复制DOI
    作者列表:Chatzistamatiou K,Chatzaki Ε,Constantinidis Τ,Nena E,Tsertanidou A,Agorastos T
    BACKGROUND & AIMS: :In the present pilot study, the feasibility of a site-of-care cervicovaginal self-sampling methodology for HPV-based screening was tested in 346 women residing in underserved rural areas of Northern Greece. These women provided self-collected cervicovaginal sample along with a study questionnaire. Following molecular testing, using the cobas® HPV Test, Roche®, HPV positive women, were referred to colposcopy and upon abnormal findings, to biopsy and treatment. Participation rate was 100%. Regular pap-test examination was reported for 17.1%. Among hrHPV testing, 11.9% were positive and colposcopy/biopsy revealed 2 CIN3 cases. Non-compliance was the most prevalent reason for no previous attendance. Most women reported non-difficulty and non-discomfort in self-sampling (77.6% and 82.4%, respectively). They would choose self-sampling over clinician-sampling (86.2%), and should self-sampling being available, they would test themselves more regularly (92.3%). In conclusion, self-sampling is feasible and well-accepted for HPV-based screening, and could increase population coverage in underserved areas, helping towards successful prevention.
    背景与目标: : 在本试点研究中,对居住在希腊北部服务不足的农村地区的346名妇女进行了基于HPV筛查的护理现场宫颈阴道自采样方法的可行性进行了测试。这些妇女提供了自我收集的宫颈阴道样本以及研究问卷。在分子测试之后,使用cobas®罗氏HPV检测®HPV阳性女性被转诊至阴道镜检查和异常发现后,进行活检和治疗。参与率为100%。报告定期进行17.1% 巴氏试验检查。在hrHPV检测中,11.9% 例为阳性,阴道镜/活检显示2例CIN3。不遵守是以前没有出席的最普遍原因。大多数妇女报告说,自我取样没有困难,也没有不适 (分别为77.6% 和82.4%)。他们将选择自采样而不是临床医生采样 (86.2%),并且如果自采样可用,他们将更定期地测试自己 (92.3%)。总之,自我采样对于基于HPV的筛查是可行的且被广泛接受,并且可以增加服务不足地区的人口覆盖率,从而有助于成功预防。
  • 【挪威乳腺癌患者术后放疗后乏力过程-与普通人群的比较。】 复制标题 收藏 收藏
    DOI:10.3109/0284186X.2012.742563 复制DOI
    作者列表:Reidunsdatter RJ,Albrektsen G,Hjermstad MJ,Rannestad T,Oldervoll LM,Lundgren S
    BACKGROUND & AIMS: INTRODUCTION:Fatigue after treatment for breast cancer (BC) is common, but poorly understood. We examined the fatigue levels during first year after radiotherapy (RT) according to the extent of RT (local or locoregional), hormonal therapy (HT) and chemotherapy (CT). The impact of comorbidity was also explored. Moreover, we compared fatigue levels in patients with the general population (GenPop) data. MATERIAL AND METHODS:BC patients (n = 250) referred for post-operative RT at St. Olavs Hospital, Trondheim, Norway, were enrolled. Fatigue was measured by the EORTC QLQ-C30-fatigue subscale, ranging from 0 to 100, before RT (baseline), after RT, and at three, six, and 12 months. Clinical and treatment-related factors were recorded at baseline. GenPop data was available from a previous survey (n = 652). Linear mixed models and analysis of covariance were applied. RESULTS:Compliance ranged from 87% to 98%. At baseline, mean value (SD) of fatigue in BC patients was 26.8 (23.4). The level increased during RT (mean change 8.3, 95% CI 5.5-11.1), but declined thereafter and did not differ significantly from pre-treatment levels at subsequent time points. In age-adjusted analyses, locoregional RT accounted for more overall fatigue than local RT (mean difference 6.6, 95% CI 1.2-12.0), but the association was weakened and not statistical significant when adjusting for CT and HT. Similar pattern was seen for CT and HT. The course of fatigue differed significantly by CT (p < 0.001, interaction test). At baseline, fatigue levels were higher in patients with than without CT, but at subsequent time points similar levels were evident, indicating a temporary adverse effect of CT. Comorbidity was significantly associated with increased level of fatigue, independent of other factors (mean difference 8.1, 95% CI 2.2-14.1). BC-patients were not significantly more fatigued than GenPop, except for immediately after ending RT, and then only among those without comorbidity (mean 35.9 vs. 25.8, p < 0.001). CONCLUSION:Comorbidity seems to be a more important determinant for fatigue levels than the cancer treatment.
    背景与目标:
  • 【缺铁性贫血是台湾骨质疏松症的危险因素: 一项基于全国人群的研究。】 复制标题 收藏 收藏
    DOI:10.3390/nu9060616 复制DOI
    作者列表:Pan ML,Chen LR,Tsao HM,Chen KH
    BACKGROUND & AIMS: :The cause-effect relationship between iron deficiency anemia (IDA) and osteoporosis has not been established in the general population. Thus, the current longitudinal study determined the role of IDA as a risk factor for osteoporosis by analyzing a large nationwide population-based sample. In a sample of 1,000,000 randomly sampled individuals from the 1998-2012. Taiwan National Health Insurance Research Database, patients with IDA (case group (n = 35,751)) and individuals without IDA (control group (n = 178,755)) were compared. Patients who were <20 years of age and who had pre-existing osteoporosis prior to the diagnosis of IDA were excluded. Each patient with IDA was age- and gender-matched to five individuals without IDA. The diagnoses of IDA and osteoporosis (coded using ICD-9CM) were further confirmed with blood test results and X-ray bone densitometry to ensure the accuracy of the diagnoses. Osteoporosis occurred more often among patients with IDA compared to individuals without IDA (2.27% vs. 1.32%, p < 0.001). Cox proportional hazard analysis revealed that the risk for osteoporosis was significantly higher in the case than the control group (hazard ratio (HR) = 1.74; 95% CI = 1.61-1.88) and remained similar after adjustment for covariates (adjusted HR = 1.81; 95% CI = 1.67-1.97). Compared with individuals without IDA, the risk for osteoporosis was even higher for patients with IDA who received intravenous ferrum therapy (adjusted HR = 2.21; 95% CI = 1.85-2.63). In contrast, the risk for osteoporosis was reduced for patients with IDA who received a blood transfusion (adjusted HR = 1.47; 95% CI = 1.20-1.80). As a predictor, prior IDA is a significant and independent risk factor for development of osteoporosis.
    背景与目标: : 在普通人群中,缺铁性贫血 (IDA) 与骨质疏松症之间的因果关系尚未建立。因此,当前的纵向研究通过分析大量全国基于人群的样本来确定IDA作为骨质疏松症危险因素的作用。在从1998-2012中随机抽取的1,000,000个样本中。对台湾全民健康保险研究数据库、IDA患者 (病例组 (n = 35,751)) 和无IDA患者 (对照组 (n = 178,755)) 进行比较。年龄 <20岁且在诊断IDA之前已有骨质疏松症的患者被排除。每位IDA患者的年龄和性别与五名没有IDA的患者相匹配。通过血液检查结果和x射线骨密度法进一步确认IDA和骨质疏松症 (使用ICD-9CM编码) 的诊断,以确保诊断的准确性。与没有IDA的个体相比,IDA患者中更经常发生骨质疏松症 (2.27% vs. 1.32%,p <0.001)。Cox比例风险分析显示,该病例的骨质疏松症风险显着高于对照组 (风险比 (HR) = 1.74; 95% CI = 1.61-1.88),并且在校正协变量后保持相似 (调整后HR = 1.81; 95% CI = 1.67-1.97)。与没有IDA的个体相比,接受静脉铁治疗的IDA患者的骨质疏松症风险更高 (调整后的HR = 2.21; 95% CI = 1.85-2.63)。相比之下,接受输血的IDA患者的骨质疏松症风险降低 (调整后的HR = 1.47; 95% CI = 1.20-1.80)。作为预测因素,先前的IDA是骨质疏松症发生的重要且独立的危险因素。
  • 【抗pdgfr α 人单克隆抗体Olaratumab在晚期和/或转移性癌症患者中的群体药代动力学模型。】 复制标题 收藏 收藏
    DOI:10.1007/s40262-017-0562-0 复制DOI
    作者列表:Mo G,Baldwin JR,Luffer-Atlas D,Ilaria RL Jr,Conti I,Heathman M,Cronier DM
    BACKGROUND & AIMS: BACKGROUND AND OBJECTIVES:Olaratumab is a recombinant human monoclonal antibody that binds to platelet-derived growth factor receptor-α (PDGFRα). In a randomized phase II study, olaratumab plus doxorubicin met its predefined primary endpoint for progression-free survival and achieved a highly significant improvement in overall survival versus doxorubicin alone in patients with advanced or metastatic soft tissue sarcoma (STS). In this study, we characterize the pharmacokinetics (PKs) of olaratumab in a cancer patient population. METHODS:Olaratumab was tested at 15 or 20 mg/kg in four phase II studies (in patients with nonsmall cell lung cancer, glioblastoma multiforme, STS, and gastrointestinal stromal tumors) as a single agent or in combination with chemotherapy. PK sampling was performed to measure olaratumab serum levels. PK data were analyzed by nonlinear mixed-effect modeling techniques using NONMEM®. RESULTS:The PKs of olaratumab were best described by a two-compartment PK model with linear clearance (CL). Patient body weight was found to have a significant effect on both CL and central volume of distribution (V 1), whereas tumor size significantly affected CL. A small subset of patients developed treatment-emergent anti-drug antibodies (TE-ADAs); however, TE-ADAs did not have any effect on CL or PK time course of olaratumab. There was no difference in the PKs of olaratumab between patients who received olaratumab as a single agent or in combination with chemotherapy. CONCLUSION:The PKs of olaratumab were best described by a model with linear disposition. Patient body weight and tumor size were found to be significant covariates. The PKs of olaratumab were not affected by immunogenicity or chemotherapeutic agents.
    背景与目标:
  • 【海地地震后的精神病理学: 一项基于人群的创伤后应激障碍和严重抑郁症研究。】 复制标题 收藏 收藏
    DOI:10.1002/da.22007 复制DOI
    作者列表:Cerdá M,Paczkowski M,Galea S,Nemethy K,Péan C,Desvarieux M
    BACKGROUND & AIMS: BACKGROUND:In the first population-based study of psychopathology conducted in Haiti, we documented earthquake-related experiences associated with risk for posttraumatic stress disorder (PTSD) and major depressive disorder (MDD) 2-4 months following the 2010 Haiti earthquake. METHODS:A population-based survey was conducted of 1,323 survivors randomly selected from the general nondisplaced community, internally displaced persons camps, and a community clinic. Respondents were from the Nazon area of Port-au-Prince, ∼20 miles from the epicenter. RESULTS:Respondents (90.5%) reported at least one relative/close friend injured/killed, 93% saw dead bodies, and 20.9% lost their job post-earthquake. The prevalence of PTSD (24.6%) and MDD (28.3%) was high. History of violent trauma was associated with risk of PTSD and MDD (adjusted odds ratio [AOR] 1.4, 95% confidence interval [CI], 1.0-1.9; AOR, 1.7, 95% CI 1.3, 2.2, respectively). Low social support (AOR, 1.7, 95% CI 1.2, 2.3; AOR 1.4, 95% CI 1.0, 1.9, respectively) increased risk of PTSD and MDD among women. Suffering damage to the home increased risk of MDD in males (AOR 2.8, 95% CI 1.5, 5.5). Associations between being trapped in rubble, major damage to house, job loss, and PTSD; and participation in rescue/recovery, friends/family injured/killed, and MDD varied based on prior history of violent trauma. CONCLUSIONS:Addressing mental health in a post-earthquake setting such as Haiti will require focusing resources on screening and treatment of identified vulnerable groups while targeting improvement of post-earthquake living conditions. Investment in sources of social support for women may make help mitigate the vulnerability of women to PTSD and MDD.
    背景与目标:
  • 【按年龄和性别划分的霍奇金淋巴瘤的体型和风险: 康涅狄格州和马萨诸塞州的一项基于人群的病例对照研究。】 复制标题 收藏 收藏
    DOI:10.1007/s10552-012-0100-1 复制DOI
    作者列表:Li Q,Chang ET,Bassig BA,Dai M,Qin Q,Gao Y,Zhang Y,Zheng T
    BACKGROUND & AIMS: PURPOSE:Descriptive studies have indicated a rising trend in Hodgkin's lymphoma (HL) incidence in young adults, especially females. Increasing evidence has suggested that some risk factors associated with HL may vary by age or gender. Recent studies have reported an increased risk of HL associated with increasing body mass index (BMI), but the results have been inconsistent. The objectives of this study were to examine whether the associations between measures of body size (height, weight, and BMI) and HL risk vary by age and/or gender. METHODS:A population-based case-control study was conducted in Connecticut and Massachusetts. A total of 567 HL cases and 679 controls were recruited in 1997-2000. Unconditional logistic regression was used to calculate odds ratios (ORs) and 95 % confidence intervals (CIs). RESULTS:Among younger women <35 years old, being overweight (25-29.9 kg/m(2)) versus normal weight (18.5-24.9 kg/m(2)) was significantly associated with an increased risk of HL (OR = 2.1, 95 % CI = 1.1-4.0). The risk increased with increasing weight and BMI (p trends <0.01). Among women ≥35 years old, by contrast, higher weight and BMI were associated with a reduced risk of HL (p trends <0.01). Conversely, there was no significant association between BMI and risk of HL in younger or older males. CONCLUSIONS:These findings show that the associations between body size and risk of HL vary by gender and age, and require confirmation in other populations.
    背景与目标:
  • 【印度丁酰胆碱酯酶变体L307P结构不稳定: 一项分子动力学模拟研究。】 复制标题 收藏 收藏
    DOI:10.1016/j.cbi.2012.10.010 复制DOI
    作者列表:David SM,Venkatesan SK,Boopathy R
    BACKGROUND & AIMS: :The human butyrylcholinesterase (BChE) activity is less than 1% in the serum of silent variant individuals of Vysya community in India. They are homozygous for a point mutation at codon 307 (CTT → CCT) resulting in the substitution of leucine 307 by proline. The reason for the disappearance of the protein in the serum has not been explicated till date. Based on this background, we performed molecular dynamics simulation to probe the structural stability of Indian variant (L307P) in comparison with wild and other BChE variants (D70G, E497V, V142M) having differential esterase activity. The simulation of all the mutants except D70G showed a much larger Cα root mean square deviation from the wild BChE crystal structure, showing the overall conformational disturbance. Further analysis revealed that secondary structure of the mutant proteins was not stable. The orientation of the catalytic triad is also distorted in all the mutants. The distance between δ nitrogen of His438 to ε oxygen of Glu325 and ε nitrogen of His438 to γ oxygen of Ser198 were highly altered in L307P mutant than the wild and other three variants throughout the simulation. Such disparity of distances between the catalytic residues may be due to the change in the protein conformation attributing to their differential catalytic activity. Our studies thus prove that the Indian BChE L307P mutant with negligible activity is possibly due to its structural instability when compared to other BChE variants.
    背景与目标: : 在印度Vysya社区的沉默变异个体的血清中,人丁酰胆碱酯酶 (BChE) 活性低于1%。它们在密码子307 (CTT → CCT) 处的点突变是纯合的,导致亮氨酸307被脯氨酸取代。到目前为止,尚未阐明血清中蛋白质消失的原因。基于此背景,我们进行了分子动力学模拟,以探索印度变体 (L307P) 与野生和其他具有不同酯酶活性的BChE变体 (D70G,E497V,V142M) 的结构稳定性。除D70G外,所有突变体的模拟均显示出与野生BChE晶体结构相比更大的c α 均方根偏差,显示出总体构象干扰。进一步的分析表明,突变蛋白的二级结构不稳定。在所有突变体中,催化三联体的方向也会扭曲。在整个模拟过程中,在L307P突变体中,His438的 δ 氮与Glu325的 ε 氧之间的距离和His438的 ε 氮与Ser198的 γ 氧之间的距离变化很大。催化残基之间距离的这种差异可能是由于蛋白质构象的变化归因于其不同的催化活性。因此,我们的研究证明,与其他BChE变体相比,活性可忽略的印度BChE L307P突变体可能是由于其结构不稳定所致。
  • 【腹腔镜胃旁路手术患者的种族差异: 基于人群的趋势分析2002年2008年。】 复制标题 收藏 收藏
    DOI:10.1007/s11695-012-0832-8 复制DOI
    作者列表:Worni M,Guller U,Maciejewski ML,Curtis LH,Gandhi M,Pietrobon R,Jacobs DO,Østbye T
    BACKGROUND & AIMS: BACKGROUND:Laparoscopic gastric bypass surgery (LGBS) has become the most widely used bariatric procedure due to its beneficial long-term outcomes for patients with morbid obesity. However, it is unclear whether racial differences in admission for LGBS have changed over time compared to racial differences in all other admissions. We aimed to investigate the trends and differences in the use of LGBS among white, African-American, and Hispanic patients from 2002 to 2008. METHODS:We performed a secondary analysis of data on obese adult patients operated between 2002 and 2008, using the Nationwide Inpatient Sample (NIS) database. The probability of being admitted for LGBS was estimated using logistic regression with race, year, and year by race interaction as predictors, controlling for numerous patient and hospital characteristics. RESULTS:Among 1,704,972 obese hospitalized patients captured through NIS from 2002 to 2008, 2.6 % underwent LGBS (2.8 % Whites, 1.7 % African-Americans, and 2.6 % Hispanics). In adjusted analysis, obese African-American (OR 0.48, p < 0.001) and Hispanic patients (OR 0.59, p < 0.001) were less likely to be admitted for LGBS than white patients in 2002. Race-year interactions showed that the odds of African-Americans undergoing LGBS significantly increased from 2002 to 2008 compared with Whites (annual OR 1.03, p < 0.001) while no such increase was detected for Hispanics (annual OR 1.02, p = 0.11). In 2008, African-American (OR 0.58, p < 0.001) and Hispanic patients (OR 0.65, p < 0.001) still had lower odds than white patients. CONCLUSIONS:This is the first study showing that the difference in the use of LGBS between obese African-American and white patients declined between 2002 and 2008. However, LGBS use still remained significantly lower for both African-American and Hispanic patients in 2008 compared with white patients.
    背景与目标:
  • 【维多利亚湖丽鱼科鱼快速辐射中不同适应,基因流和杂种形成的种群基因组特征。】 复制标题 收藏 收藏
    DOI:10.1111/mec.12083 复制DOI
    作者列表:Keller I,Wagner CE,Greuter L,Mwaiko S,Selz OM,Sivasundar A,Wittwer S,Seehausen O
    BACKGROUND & AIMS: :Adaptive radiations are an important source of biodiversity and are often characterized by many speciation events in very short succession. It has been proposed that the high speciation rates in these radiations may be fuelled by novel genetic combinations produced in episodes of hybridization among the young species. The role of such hybridization events in the evolutionary history of a group can be investigated by comparing the genealogical relationships inferred from different subsets of loci, but such studies have thus far often been hampered by shallow genetic divergences, especially in young adaptive radiations, and the lack of genome-scale molecular data. Here, we use a genome-wide sampling of SNPs identified within restriction site-associated DNA (RAD) tags to investigate the genomic consistency of patterns of shared ancestry and adaptive divergence among five sympatric cichlid species of two genera, Pundamilia and Mbipia, which form part of the massive adaptive radiation of cichlids in the East African Lake Victoria. Species pairs differ along several axes: male nuptial colouration, feeding ecology, depth distribution, as well as the morphological traits that distinguish the two genera and more subtle morphological differences. Using outlier scan approaches, we identify signals of divergent selection between all species pairs with a number of loci showing parallel patterns in replicated contrasts either between genera or between male colour types. We then create SNP subsets that we expect to be characterized to different extents by selection history and neutral processes and describe phylogenetic and population genetic patterns across these subsets. These analyses reveal very different evolutionary histories for different regions of the genome. To explain these results, we propose at least two intergeneric hybridization events (between Mbipia spp. and Pundamilia spp.) in the evolutionary history of these five species that would have lead to the evolution of novel trait combinations and new species.
    背景与目标: : 适应性辐射是生物多样性的重要来源,通常以非常短的连续发生许多物种形成事件为特征。已经提出,这些辐射中的高物种形成率可能是由年轻物种之间杂交过程中产生的新型遗传组合推动的。可以通过比较从不同基因座子集推断出的系谱关系来研究此类杂交事件在群体进化史中的作用,但是到目前为止,此类研究经常受到浅遗传差异的阻碍,尤其是在年轻的适应性辐射中,以及缺乏基因组规模的分子数据。在这里,我们使用在限制性位点相关DNA (RAD) 标签中鉴定的snp的全基因组采样来研究Pundamilia和Mbipia这两个属的五个同族丽鱼科鱼物种之间共享祖先和适应性差异模式的基因组一致性,构成东非维多利亚湖丽鱼科鱼大规模适应性辐射的一部分。物种对沿几个轴不同: 雄性婚育颜色,摄食生态,深度分布以及区分两个属的形态特征和更细微的形态差异。使用异常值扫描方法,我们可以识别所有物种对之间不同选择的信号,其中许多基因座在属之间或雄性颜色类型之间的复制对比中显示平行模式。然后,我们创建了SNP子集,我们希望通过选择历史和中性过程对其进行不同程度的表征,并描述了这些子集的系统发育和种群遗传模式。这些分析揭示了基因组不同区域的进化历史非常不同。为了解释这些结果,我们在这五个物种的进化史中提出了至少两个属间杂交事件 (在Mbipia spp。和Pundamilia spp。之间),这将导致新的性状组合和新物种的进化。
  • 【北欧 (莱茵) 一项基于人群的研究中的职业暴露与新发哮喘。】 复制标题 收藏 收藏
    DOI:10.1093/annhyg/mes083 复制DOI
    作者列表:Lillienberg L,Andersson E,Janson C,Dahlman-Höglund A,Forsberg B,Holm M,Glslason T,Jögi R,Omenaas E,Schlünssen V,Sigsgaard T,Svanes C,Torén K
    BACKGROUND & AIMS: OBJECTIVES:In a large population-based study among adults in northern Europe the relation between occupational exposure and new-onset asthma was studied. METHODS:The study comprised 13 284 subjects born between 1945 and 1973, who answered a questionnaire 1989-1992 and again 1999-2001. Asthma was defined as 'Asthma diagnosed by a physician' with reported year of diagnose. Hazard ratios (HR), for new-onset adult asthma during 1980-2000, were calculated using a modified job-exposure matrix as well as high-risk occupations in Cox regression models. The analyses were made separately for men and women and were also stratified for atopy. RESULTS:During the observation period there were 429 subjects with new-onset asthma with an asthma incidence of 1.3 cases per 1000 person-years for men and 2.4 for women. A significant increase in new-onset asthma was seen for men exposed to plant-associated antigens (HR = 3.6; 95% CI [confidence interval] = 1.4-9.0), epoxy (HR = 2.4; 95% CI = 1.3-4.5), diisocyanates (HR = 2.1; 95% CI = 1.2-3.7) and accidental peak exposures to irritants (HR = 2.4; 95% CI = 1.3-4.7). Both men and women exposed to cleaning agents had an increased asthma risk. When stratifying for atopy an increased asthma risk were seen in non-atopic men exposed to acrylates (HR = 3.3; 95% CI = 1.4-7.5), epoxy compounds (HR = 3.6; 95% CI = 1.6-7.9), diisocyanates and accidental peak exposures to irritants (HR = 3.0; 95% CI = 1.2-7.2). Population attributable risk for occupational asthma was 14% for men and 7% for women. CONCLUSIONS:This population-based study showed that men exposed to epoxy, diisocyanates and acrylates had an increased risk of new-onset asthma. Non-atopics seemed to be at higher risk than atopics, except for exposure to high molecular weight agents. Increased asthma risks among cleaners, spray painters, plumbers, and hairdressers were confirmed.
    背景与目标:

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