The Deuterator: software for the determination of backbone amide deuterium levels from H/D exchange MS data

Background  

The combination of mass spectrometry and solution phase amide hydrogen/deuterium exchange (H/D exchange) experiments is an effective method for characterizing protein dynamics, and protein-protein or protein-ligand interactions. Despite methodological advancements and improvements in instrumentation and automation, data analysis and display remains a tedious process. The factors that contribute to this bottleneck are the large number of data points produced in a typical experiment, each requiring manual curation and validation, and then calculation of the level of backbone amide exchange. Tools have become available that address some of these issues, but lack sufficient integration, functionality, and accessibility required to address the needs of the H/D exchange community. To date there is no software for the analysis of H/D exchange data that comprehensively addresses these issues.     

Prevalence of risk factors for cardiovascular disease in Canadians 55 to 74 years of age: results from the Canadian Heart Health Surveys, 1986-1992

BACKGROUND: By 2016, the proportion of Canadians older than 65 years of age will increase to 16%, and there will be an increase in the absolute number of cases of cardiovascular disease in older Canadians. The Canadian Heart Health Surveys database provides information about this population upon which health policy related to cardiovascular disease can be based. This paper presents for the first time population-based data on the risk factors for cardiovascular disease in older Canadians. METHODS: Canadians from all 10 provinces participated in surveys of cardiovascular risk factors; health insurance registries were used as sampling frames. In each province, probability samples of 2200 adults 18 to 74 years old not living in institutions, on reserves or in military camps were asked to participate in interviews and to undergo testing at clinics for major risk factors for cardiovascular disease. RESULTS: A total of 2739 men (response rate 70%) and 2617 women (response rate 66%) aged 55 to 74 years participated in the survey and also provided follow-up clinical measurements at the clinic. Overall, 52% of participants were hypertensive, 26% had isolated systolic hypertension, and 30% had a total blood cholesterol level of 6.2 mmol/L or greater. Rates of current smoking were lower in women than men (17% v. 22%). Overall, 87% of men and 78% of women who were current smokers smoked at least 10 cigarettes per day. Only slightly more than half of participants exercised at least once a week for at least 15 minutes, and almost half had a body mass index of 27 or greater. In only 4% was no major risk factor for cardiovascular disease detected. INTERPRETATION: Significant numbers of older Canadians have one or more major risk factors for cardiovascular disease. Many of these risk factors are amenable to modification.     

Benthic insects in Swedish lake-outlet streams: patterns in species richness and assemblage structure

1. We studied how species richness of three hierarchical insect species groups, namely all benthic, lotic and filtering taxa, were related to a number of environmental variables in a data set from fifteen Swedish lake outlets. 2. In partial least-squares analyses, we found that size-related factors (stream width, discharge) and velocity-related factors (current velocity, substratum particle size) were positively associated, and productivity-related factors (chlorophyll a, seston energy, conductivity) negatively associated, with the species richness of the three groups. 3. The weak and negative relationship of richness with productivity largely negated theoretical predictions, whereas the species-environment results corroborated earlier findings from running water systems. 4. The most important factors associated with the species composition of the lake outlets studied included pH, lake area, discharge, channel width and detritus. 5. Of the filter feeders, most species of blackflies (Diptera: Simuliidae) showed a negative relationship with pH. 6. A nested subset analysis demonstrated that species-poor sites did not have a subset of species found at more species-rich sites in any of the three hierarchical groups.     

四种独立通风笼具（IVC）的检测

目的比较4种独立通风笼具（individually ventilated cages,IVC）的环境参数。方法参考GB14925-2001的检测方法对分别来自4个厂家生产的4种不同的IVC进行环境检测。结果4种IVC在空气洁净度、落下菌、噪声和照度等4个指标检测数据较为一致;在梯度压差、换气次数、气流速度等3个指标存在较大的差别;而温湿度等指标取决于IVC所处的外部环境。结论目前缺乏国家标准对IVC环境指标进行限定,各厂家所生产的IVC存在差异,需要在此方面加强研究,以促进IVC的标准化,更好的服务于实验动物行业。     

大鼠肠内容物细菌基因组DNA提取方法的比较

目的比较两种肠内容物前处理和两种提取方法对清洁级SD大鼠肠内容物细菌基因组DNA提取效率。方法分别选用PBS多次离心漂洗、液氮破细胞两种前处理方法和酚/氯仿抽提、试剂盒过柱法两种提取方法进行组合分析,对4份肠内容物和16份含金黄色葡萄球菌肠内容物进行随机提取。结果大鼠肠内容物细菌基因组DNA含量和纯度测定结果显示,与PBS反复离心相比,液氮研磨前处理能显著提高大鼠肠内容物基因组DNA。荧光定量PCR表明,液氮研磨前处理较PBS反复离心能更好地收集细菌基因组DNA,其Ct值最低。结论研究结果表明,采用液氮研磨试剂盒法在大鼠肠内容物DNA提取中是较为优良的方法,该方法为建立实验动物中微生物的定量PCR检测方法打下了基础。     

草地贪夜蛾对不同品种玉米的适应性比较研究

为了解不同玉米品种对草地贪夜蛾生长发育的影响,本文通过比较草地贪夜蛾Spodoptera frugiperda取食2种糯质型玉米(明玉1203和苏玉糯5号)与3种普通玉米(苏玉29、苏玉30和郑单958)后的发育历期、死亡率、蛹重、成虫畸形率、繁殖力与幼虫取食选择率等生物学参数,分析了草地贪夜蛾对不同品种玉米的适应性差...     

Using microwave irradiation in Marchi's method for demonstrating degenerated myelin

Conventional methods for histological preparation of degenerated myelin are time-consuming and difficult. The purpose of our study was to shorten the time required for the procedure and to obtain better quality results for light microscopic demonstration of degenerated myelin in the central and peripheral nervous systems by using microwave irradiation. Rat brain and sciatic nerve were used for the study. The middle cerebral artery was occluded and the sciatic nerve was cut to produce myelin degeneration. Marchi's method was used for staining degenerated myelin. Fixation for light microscopy that would take two days using the conventional procedure was completed in 16.5-18.5 min using microwave irradiation. While staining of degenerated myelin requires 10 days for the conventional Marchi method, we decreased it to 7 h for brain tissue and 1 h for sciatic nerve by using the microwave oven. Moreover, a better quality preparation was achieved in the groups stained under microwave irradiation than those prepared by the conventional method.