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.     

大兴安岭南部山地苔藓植物区系多样性研究

于2009～2012年对大兴安岭南部山地6个自然保护区的苔藓植物进行了野外实地调查,对所采集的1 800余号标本进行室内分析鉴定,并计算分析其种类组成、区系地理成分、地区之间相似性系数和相异系数的欧氏距离比较,及其8种生境中苔藓植物多样性指数、丰富度指数、均匀度指数和优势度指数等,为保护区的管理和建设提供基础资料。结果表明:(1)大兴安岭南部山地6个自然保护区共有苔藓植物48科,134属,330种,其中苔类16科,21属,38种,1变种;藓类32科,113属,274种,14变种,2变型,1亚种。(2)首次发现中国新记录4种:长柄紫萼藓(Grimmia longirostris Hook.),毛尖连轴藓[Schistidium lancifolium(Kindb.)Blom.],平叶真藓(Bryumlaevifilum Syed.),凹叶毛灰藓[Homomallium adnatum(Hedw.)Broth.],首次发现本地区新记录12种。(3)以丛藓科为代表的旱生藓类在本区占有优势地位;区系地理成分以温带成分(60.79%)和东亚成分(16.19%)为主。(4)大兴安岭南部山地与兴安北部和燕山北部山地亲缘关系较近;生境条件的变化对苔藓植物多样性产生了一定的影响,湿润土生和石生生境为本区苔藓植物最丰富的生境,水生生境中苔藓植物分布最少。研究发现,大兴安岭南部山地苔藓植物区系是连接华北区、东北区、蒙新区和阴山地区的过渡性地带;与燕山北部和兴安北部相比,大兴安岭南部山地大面积苔藓植物地被层分布较少的主要原因是森林密度和湿度较低。因此,建立保护区对保护大兴安岭南部山地脆弱的森林、草原过渡生态系统,保护中国野生动植物类群及其他珍稀动植物的繁衍均具有十分重要的意义。     

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。     

Maternal Transmission of Human Immunodeficiency Virus Escape Mutations Subverts HLA-B57 Immunodominance but Facilitates Viral Control in the Haploidentical Infant

Expression of HLA-B57 is associated with restricted replication of human immunodeficiency virus (HIV), but the mechanism for its protective effect remains unknown. If this advantage depends upon CD8 T-cell recognition of B57-restricted epitopes, mother-to-child transmission of escape mutations within these epitopes could nullify its protective effect. However, if the B57 advantage is largely mediated by selection for fitness-attenuating viral mutations within B57-restricted epitopes, such as T242N in TW10-Gag, then the transmission of such mutations could facilitate viral control in the haploidentical infant. We assessed the consequences of B57-associated mutations on replication capacity, viral control, and clinical outcome after vertical transmission in 13 mother-child pairs. We found that expression of HLA-B57 was associated with exceptional control of HIV during infancy, even when mutations within TW10 and most other B57-restricted epitopes were transmitted, subverting the natural immunodominance of HLA-B57. In contrast, most B57-negative infants born to B57-positive mothers progressed rapidly to AIDS. The presence of T242N led to a reproducible reduction in viral fitness, as demonstrated by in vitro assays using NL4-3 constructs encoding p24 sequences from individual mothers and infants. Associated compensatory mutations within p24-Gag were observed to reverse this impairment and to influence the propensity of T242N to revert after transmission to B57-negative hosts. Moreover, primary failure to control viremia was observed in one infant to whom multiple compensatory mutations were transmitted along with T242N. These parallel in vivo and in vitro data suggest that HLA-B57 confers its advantage primarily by driving and maintaining a fitness-attenuating mutation in p24-Gag.Expression of HLA-B57 is associated with low levels of viremia and prolonged survival after human immunodeficiency virus (HIV) infection, but the mechanism underlying this association is not well understood. Because the principal role of class I HLA molecules is to bind viral peptides for presentation to cytotoxic CD8⁺ T cells, numerous studies have sought to identify quantitative or qualitative features of the B57-restricted CD8 T-cell response to HIV that correlate with effective viral containment. However, despite exhaustive studies of the HIV-specific CD8 response in B57-positive individuals, few differences in the frequency, function, or epitope specificity of CD8 cells have been identified that reliably distinguish B57-positive controllers from the many B57-positive individuals with progressive HIV infection (1, 28-30). Early in the course of HIV infection, CD8 cells consistently select for a T242N substitution in the B57-restricted epitope TW10, which lies in a highly conserved region of p24-Gag capsid protein. Although this mutation permits the virus to escape from CD8 T-cell surveillance, it incurs a cost to viral replicative capacity (5, 24, 26). Thus, it has been hypothesized that the B57 advantage may be an indirect effect of CD8 response, whereby viral control does not rely on active surveillance by B57-restricted CD8 T cells but instead upon an “imprint” of the B57-restricted CD8 response that forces the viral capsid protein into a less fit state. Recent studies have suggested that such escape mutations may even result in lower HIV RNA levels in the next host to whom the virus is transmitted (9, 18). Selection for T242N is frequently followed by the emergence of upstream mutations at residues H219, I223, and M228 in the cyclophilin A (CypA) binding loop that have been shown to partially compensate for its fitness defect (5, 24, 26, 32), which may explain why many B57-positive individuals ultimately develop high viral loads despite the presence of T242N. The timing with which these compensatory mutations emerge and accumulate varies among B57-positive individuals, possibly due to constraints imposed by interacting Gag residues (7), and this variability may contribute to the observed heterogeneity in clinical outcomes.Mother-to-child transmission of HIV affords a unique model for differentiating between the impact of CD8 T cells and the viral escape mutations that they induce. Because transmission occurs between a haploidentical mother-child pair, it is possible to assess the impact of CD8 T-cell responses to, and mutations within, epitopes restricted by shared and unshared HLA molecules. Each infant expresses at least three HLA molecules shared with his or her mother, and vertical transmission of maternally selected escape mutations within epitopes restricted by these shared HLA molecules may effectively eliminate these potential cytotoxic-T-lymphocyte (CTL) targets from the infecting viral inoculum. However, infants also express paternally inherited HLA molecules for which no viral “imprint” exists. If the HLA-B57 advantage depends upon active surveillance by CD8 cells, mother-to-child transmission of B57-associated escape mutations may nullify this benefit among infants who share the B57 allele with their mothers, as has been demonstrated in the case of another protective HLA class I allele B*27, where transmission of a mutation within the highly dominant KK10-Gag epitope leads to failure of viral control in B27-positive infants (20). On the other hand, if viral attenuation is a major contributor to the B57 advantage, then the advantage associated with HLA-B57 expression would likely be passed along to the child, who would benefit from the reduced replication capacity of the transmitted virus.We assessed HIV sequence evolution and clinical outcomes in 13 HIV-infected mother-child pairs, one or both of whom expressed HLA-B*B57, in order to determine the impact of viral sequence changes that occur when B57-mediated immune pressure is introduced, or removed, after transmission.     

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.     

豆科黄结属模式及其相关种名的考证

长期以来,Ｔermopsis lanceolata R.Br.被误认为是黄华属的模式。根据有关文献考证和国际植物命名法规,作者为认Ｔ.;lanceoltata是一个不合法名,黄华属的合法模式应为Ｔhermopsis Lupinoides(L.)Link.分布于东北亚,花具互生花的黄华长期被误定为Ｔ。lupinoides(L.)Link,应更正为Ｔhermopsis fabacea(Pall)DC.。     

商州产大马士革玫瑰精油研究

采用ISO9842:2003玫瑰油标准,对陕西商州引种的保加利亚主栽玫瑰品种“Kazanluk”(RosadamascenaMiller)精油进行分析。结果表明,该玫瑰精油香气具有天然玫瑰花香,香气细腻、柔和、飘逸。油为液体,淡黄色,相对密度(20/20℃)0.8599,折光指数(20℃)1.4592,旋光度(20℃)-4.3°,冻点20.6℃,酯值11.9,这些物理指标达到了标准要求。大量主香成分相对含量:乙醇0.5%,香茅醇45.5%,橙花醇4.5%,香叶醇7.6%,苯乙醇2.9%,十七烷烃1.13%,十九烷烃15.5%,二十一烷烃5.0%。这些成分含量与原产地保加利亚玫瑰油成分范围有一定差异,但与摩洛哥同类玫瑰油标准相符,可以作为商品油在国际市场销售。