Ascorbic acid efficiently enhances neuronal synthesis of norepinephrine from dopamine

Ascorbic acid enhances synthesis of norepinephrine from dopamine in adrenal chromaffin cells by serving as a co-factor for chromaffin granule dopamine β-hydroxylase (DβH). However, there is controversy regarding in situ kinetics of the ascorbate effect in chromaffin cells, as well as whether they apply to neuronal cells. In this study we evaluated the stimulation of norepinephrine synthesis from dopamine in cultured SH-SY5Y neuroblastoma cells. These cells contained neither ascorbate nor norepinephrine in culture, but when provided with dopamine, they generated intracellular norepinephrine at rates that were stimulated several-fold by intracellular ascorbate. Ascorbate-induced increases in norepinephrine synthesis in dopamine-treated cells were linear over 60 min, despite saturation of intracellular ascorbate. Norepinephrine accumulation after 60 min of incubation with 100 μM dopamine was half-maximal at intracellular ascorbate concentrations of 0.2–0.5 mM, which fits well with the literature K_m for ascorbate of DβH using dopamine as a substrate. Moreover, these ascorbate concentrations were generated by initial extracellular ascorbate concentrations of less than 25 μM due to concentrative accumulation by the ascorbate transporter. Treatment with 100 μM dopamine acutely increased cellular superoxide generation, which was prevented by ascorbate loading, but associated with a decrease in intracellular ascorbate when the latter was present at concentrations under 1 mM. These results show that ascorbate promptly enhances norepinephrine synthesis from dopamine by neuronal cells that it does so at physiologic intracellular concentrations in accord with the kinetics of DβH, and that it both protects cells from superoxide and by providing electrons to DβH.     

2005—2011年天津市河东区麻疹流行病学分析

目的了解天津市河东区麻疹流行病学特征,为控制和消除麻疹提供科学依据。方法对天津市河东区2005—2011年的麻疹发病资料进行描述流行病学分析。结果 2005—2011年河东区共报告麻疹病例565例,年平均发病率11.67/10万,病例以0～4岁组的婴儿和25～30岁组的成人为主,分别占29.2%、19.12%。发病时间集中在3—5月,占总病例数的61.24%;5月份达到高峰,占总病例数的21.95%。33.45%的病例无免疫史,18.94%的病例有免疫史,47.61%免疫史不详。结论适时开展8月龄～14周岁儿童强化免疫接种能有效地提高目标儿童的保护率,巩固和提高常规免疫工作,做好成人麻疹的预防控制工作,尤其是育龄妇女的免疫接种,加强监测和控制院内感染是控制和消除麻疹的重要手段。     

Evaluation of a school entry immunization record check strategy in 4 counties of Ningxia and Hubei provinces,China

China has a national requirement that children's vaccination status is to be checked upon entry to kindergarten and school; children who have missed vaccine doses are to be referred to vaccination clinics to receive the necessary vaccinations. Most provinces have Immunization Information Systems (IIS) that contain and manage vaccination records of children served by immunization clinics. We conducted an evaluation in Hubei and Ningxia provinces using IIS data to determine the effect of their school entry immunization record checking strategy (SECS) on vaccination coverage and rate of catch-up for selected vaccines.We selected two counties with well-functioning IISs from each province. Names and demographic information of children enrolled in 185 kindergartens and 125 primary school in 2016 were used to identify children in the IIS and obtain their vaccination records. We calculated vaccination coverage before and after implementation of the SECS and determined catch-up rates for 5 vaccines, of which 3 are given before 2 years of age and 2 are given after 2 years of age.Among the 20,215 newly-enrolled children, 75% were able to be matched with IIS records. Few children who had missed one or more doses of the 3 vaccines recommended in the first two years of life received catch-up doses after SECS. For vaccines scheduled after 2 years of age, there was a statistically significant (p < 0.05) coverage increase in both provinces following the school-entry record check. Among children who were age-eligible for the selected vaccines before SCES, the catch-up rate was <50%.SECS provides opportunities to identify incompletely vaccinated children, improve coverage, and remind families of school-age children about up-coming vaccinations; SECS has potential to improve completeness of IIS data and enrollment of children in immunization clinics. Evidence-based policy with implementation guidance and routine monitoring are necessary to improve China’s school entry checking strategy.     

国内外食品安全风险监测发展状况

随着人民生活水平的不断提高,百姓餐桌越来越丰富多样,对食品安全性的关注度越来越高。食品安全是维系社会和谐稳定的重要因素。为了有效预防和化解重大食品安全风险,制定和更新国家食品安全标准,积累和分析食品污染及人群患病相关数据,我国制定并实施最严格的《食品安全法》,在此基础上建立起由政府牵头的食品安全风险监测体系。本文通过国外部分发达国家或国际组织、国内部分省市在食品安全风险监测工作机制的介绍,在信息平台建设、检验检测资源整合、仪器设备投入、专家队伍培养等方面,分析和展望今后食品安全风险监测的发展方向,为百姓筑起一道食品安全的坚固防线。     

血液分析仪在血液检验中存在的问题与解决办法总结

血液分析仪作为目前临床血液学广泛应用的一种检验方法,在很大程度上促进了临床血液检验发展的新方向,使其更加规范化与自动化,但由于检测技术并非参考方法,因此做好质量方面的控制具有重要意义。由于血液分析仪在血液检验过程中仍然存在部分问题,导致检验结果受到影响,因此需总结相应问题,并提出相应解决办法。     

病原实验室生物安全建设及风险评估概述

实验室生物安全涉及多个学科和领域,是实践性和操作性较强的工作。随着我国实验室生物安全工作的深入开展和相关科研工作的不断进行,应不断丰富实验室人员的生物安全知识,提高实际操作技能和水平。《生物安全实验室建筑技术规范》是我国生物安全实验室建设非常重要的、可操作的规范文件。《微生物和生物医学实验室生物安全通用准则》、《实验室生物安全通用要求》,对不同安全水平实验室的设施都做了详细的规定,是生物安全实验室建设和改造的主要依据。《病原微生物实验室生物安全管理条例》和《实验室生物安全通用要求》又是管理生物安全实验室的活动及制定各项组织制度措施重要依据。通过开展实验室生物安全风险评估、确定实验室级别和个人防护装备、制定相应的操作规程和应急预案等措施,将会减少或避免实验室感染事件的发生。实验室安全与管理相辅相承,只有通过严格的管理、规范的操作,才能保证实验室的安全运行。     

Measles and rubella IgG seroprevalence in persons 6 month-35 years of age,Mongolia, 2016

BackgroundIn 2015–2016, Mongolia experienced an unexpected large measles outbreak affecting mostly young children and adults. After two nationwide vaccination campaigns, measles transmission declined. To determine if there were any remaining immunity gaps to measles or rubella in the population, a nationally representative serosurvey for measles and rubella antibodies was conducted after the outbreak was over.MethodsA nationwide, cross-sectional, stratified, three-stage cluster serosurvey was conducted in November-December 2016. A priori, four regional strata (Ulaanbaatar, Western, Central, and Gobi-Eastern) and five age strata (6 months-23 months, 2–7 years, 8–17 years, 18–30 years, and 31–35 years) were created. Households were visited, members interviewed, and blood specimens were collected from age-appropriate members. Blood specimens were tested for measles immunoglobulin G (IgG) and rubella IgG (Enzygnost® Anti-measles Virus/IgG and Anti-rubella Virus/IgG, Siemens, Healthcare Diagnostics Products, GmbH Marburg, Germany). Factors associated with seropositivity were evaluated.ResultsAmong 4598 persons aged 6 months to 35 years participating in the serosurvey, 94% were measles IgG positive and 95% were rubella IgG positive. Measles IgG seropositivity was associated with increasing age and higher education. Rubella IgG seropositivity was associated with increasing age, higher education, smaller household size, receipt of MMR in routine immunization, residence outside the Western Region, non-Muslim religious affiliation, and non-Kazakh ethnicity. Muslim Kazakhs living in Western Region had the lowest rubella seroprevalence of all survey participants.ConclusionsNationally, high immunity to both measles and rubella has been achieved among persons 1–35 years of age, which should be sufficient to eliminate both measles and rubella if future birth cohorts have ≥ 95% two dose vaccination coverage. Catch-up vaccination is needed to close immunity gaps found among some subpopulations, particularly Muslim Kazakhs living in Western Region.     

2009年临沂市河东区手足口病病例资料分析

[目的]了解临沂市河东区手足口病流行特征,以便制定有效的防控措施。[方法]对2009年河东区手足口病病例资料进行分析。[结果]2009年河东区报告手足口病1 700例,其中经流行病学调查确诊的1 554例,发病率为245.09/10万。手足口病发病率,男性为300.82/10万,女性为187.91/10万(P<0.01);<6岁为2 406.32/10万,2岁儿童高达5 104.01/10万;城乡结合部乡镇平均为324.87/10万,其他乡镇平均为232.54/10万(P<0.01)。1 554例中,散居儿童占90.54%,幼托儿童占7.79%,学生占1.61%,其他占0.06%;5～6月发病的占52.64%;整体呈散发状态;重症病例占13.58%,病死率为0.13%。[结论]2009年河东区手足口病发病率处于较高水平,并出现死亡病例。