炭疽实验室生物安全

近年来,炭疽自然疫情和实验室相关事故频发,有关炭疽生物安全问题再次引发关注。本文简要介绍炭疽芽胞杆菌基本特点和目前对炭疽的治疗及预防概况,再结合历年来炭疽实验室典型生物安全事故,分析并总结国内外实验室生物安全管理的经验教训,针对性地提出炭疽实验室管理问题及对策,供炭疽实验活动和实验室生物安全管理参考。     

高等级生物安全实验室风险案例分析和思考

随着我国首个生物安全四级实验室正式投入使用,我国已有能力开展一类病原体病毒培养和动物感染的研究工作。通过汇总近年来欧美发达国家高等级生物安全实验室的事故案例,分析了高等级生物安全实验室面临的安全风险,结合实验室生物安全管理的要求,探讨了防控高等级生物安全实验室安全风险的控制策略。     

疾病预防控制系统及医疗微生物实验室生物安全管理探析

目的:探寻医疗微生物实验室生物安全管理以及疾病预防控制系统的建设。方法:分析当前生物安全出现的原因及预防措施,采用列举的方法,对相关体系的完善提出建议。结果:由于传染病毒具有扩散块、毒力强的特点,因此生物安全的建设逐步受到社会的重视,其中疾病控制、疾病预防系统的建设及实验室的医疗安全检测具有格外重要的意义。通过调查发现,加强二者的安全管理,必须加强五个方面的建设,即严格遵守疾病控制系统与实验室安全管理规定,对有关的实验设备进行完善与升级,对实验室病菌实验严格把控,对医疗人员、技术人员及检验人员进行定期的安全培训,对实验室废弃物进行管理。讨论:由于当前传染病毒的危害越来越严重,因此,关注生物安全,完善相关的体系建设具有十分重要的意义,国家及医疗部门需要对此给予足够的重视。     

传染病医院检验科生物安全管理及防护措施探讨

目的:探讨传染病医院检验科生物安全管理及防护措施.方法:对传染病医院检验科实验室相关人员的职责进行明确分工,使其进一步了解实验室生物操作风险的种类及来源,并在实验室配备必要的安全防护措施,对标本施行严格的管理制度.结果:严格施行检验科实验室生物安全管理,增加防护措施,可以有效的避免生物安全事故的发生.结论:对检验科实验室生物安全管理进行规范后可以有效地减少实验室工作人员的风险,同时也有效避免了病源微生物的外泄,最大限度的保障了实验室的生物安全.     

高等级生物安全实验室风险及其对策

高等级生物安全实验室的建设和发展也伴随着风险。我们结合生物安全实验室事故案例的分析和国内外生物安全实验室管理的经验教训,分析高等级生物安全实验室存在的主要风险,并针对性地提出风险控制对策,供生物安全实验室建设和管理参考。     

试析实验室生物安全与人员必备素质

本文针对实验室生物安全与人员必备素质问题,对实验室生物安全重要性、防护等级、设备实施要求以及人员所具素质、化学药品安全使用等方面进行了简单分析。     

关于高级别生物安全实验室若干管理要素的探讨

目前,我国已有两家生物安全四级实验室和五十多家生物安全三级实验室完成建造并通过实验室认可。生物安全管理体系的技术要素和管理要素是确保高级别生物安全实验室生物安全的关键。本文探讨了高级别生物安全实验室区别于其他体系实验室(如ISO 17025检测和校准实验室与ISO 15189医学实验室)的若干个特征性管理要素,这些要素包括潜在污染的周期性评估、失活验证实验、分子诊断实验的无生物风险的阳性对照、微生物的不同封闭措施及生物安全文化。潜在污染的周期性评估与失活验证实验是高级别生物安全实验室日常管理的强制性措施。分子诊断实验的无生物风险的阳性对照与微生物的不同封闭措施应用于微生物实验(尤其是病毒学实验)从而降低暴露风险。生物安全文化应全面施行,以预防生物安全事件的再次发生。     

北美国家大动物生物安全实验室的建设与管理

目的 为提高动物实验室生物安全意识,供大动物生物安全实验室设计、施工、使用和管理借鉴.方法 采用考察和分析的方法了解了北美国家大动物生物安全实验室的设计理念、设备、设施、动物试验及动物实验室管理.结果 大动物生物安全实验宝与我国畜牧业健康发展和社会稳定密切相关,我国与国外大动物生物安全实验室存在较大的差距.结论 我国应借鉴国外大动物生物安全实验室设计的理念,完善大动物实验室基础设施,增设相应的设备和提升动物实验室工作人员的生物安全意识.     

血站实验室生物安全与防护

血站实验室每天要检测大量无偿献血者的血液样本,而血液样本都具有潜在的生物危害,如乙型肝炎病毒、丙型肝炎病毒、梅毒和艾滋病病毒等。最新研究表明,血站检验人员存在职业暴露的危险因素,极易通过采血针刺伤、试管划伤、血液或粘膜污染等途径感染病毒[1]。随着社会的发展,医疗卫生与健康问题已成为社会关注焦点。所谓实验室生物安全是指在从事病原微生物实验活动的实验室中避免病原微生物对工作人员和相关人员的伤害。为保障实验室工作人员及献血者的安全,血站必须建立符合生物安全要求的实验室,对实验室进行生物安全管理的同时还要重视实验室生物安全防护[2]。本文就血站实验室生物安全及防护措施在人员培训、关键物料、环境和制度等方面提出自己的一些思考和建议。     

埃博拉病毒实验室事故的教训与启示

随着我国四级实验室的建成和即将投入使用,将有条件开展埃博拉病毒等一类病原微生物的培养和动物感染实验等实验活动。本文通过汇总并分析历史上埃博拉病毒实验室事故,总结教训,并结合实验室生物安全管理的通用要求,探讨了生物安全四级实验室防范实验室人员感染事件的策略。     

Effects of Feeding and Drinking on Acetylcholine Release in the Nucleus Accumbens, Striatum, and Hippocampus of Freely Behaving Rats

Extracellular levels of acetylcholine (ACh) were measured in the nucleus accumbens (NAC), striatum (STR), and hippocampus (HIPP) using microdialysis in 30-min intervals before, during, and after free-feeding in 20-h food-deprived rats. The effects on ACh in the NAC and STR were also observed in response to water intake in 20-h water-deprived animals. Neostigmine was used in the perfusate to improve ACh recovery. Basal ACh was sensitive to tetrodotoxin and low calcium, and therefore largely neuronal in origin. Feeding caused a 38% increase in extracellular ACh in the NAC and no change in the STR or HIPP. Dopamine was also increased in the NAC (48%) and to a lesser extent in the STR (21%) following feeding. Drinking caused 18-20% increases in ACh release in both the NAC and STR. In a separate experiment, ACh release in the NAC was monitored in 10-min intervals during free-feeding; ACh increased in the interval immediately following maximal food intake. These results suggest a site-specific increase in ACh release following feeding that cannot be solely attributed to the activation associated with this behavior.     

Effects of insecticide applications on macroinvertebrate density and biomass in rice-fields in the Rhône-delta,France

The density of 23 macroinvertebrate species and the total macroinvertebrate biomass were compared between rice-fields treated with lindane and diazinon in June and alphamethine in August and untreated controls. The macroinvertebrates could be divided into four groups: (1) Taxa, in which the densities were lower in the insecticide treatment in July and August than in the non-insecticide treatment. (2) The Culicidae which occurred in the insecticide treatment in significantly lower density in July, but in significantly higher density in August. (3) Ischnura elegans (Vander L.) which was found in July after the lindane application in significantly higher numbers in the insecticide treatments, but in significantly lower numbers in the insecticide treatment in August after the application of the pyrethroid. In these three groups, we assumed that direct effects due to the insecticides toxicity were the reason for the differences in density. (4) The fourth group included three taxa in which the densities were significantly higher in the insecticide treatment in July and August than in the control. For this, indirect effects due to reduced biotic interactions may be responsible. The biomass was higher in the insecticide treatments in July, mainly because of a high increase in gastropod density, during the rest of the season it was similar between treatments and controls.     

Relationship between the population of viable sclerotia ofSclerotium rolfsii in soil to cropping sequence in the Nigerian savanna

Populations of viable sclerotia ofSclerotium rolfsii were highest in soil in a field in which tomato was planted for three successive years before sampling and in one in which tomato followed groundnut in the 2 years prior to this study. The lowest sclerotial numbers were recorded in fields in which groundnut followed maize or in which maize or sorghum was the last crop before sampling.     

Genetic variance in temperature dependent adult size deriving from physiological genetic variation at temperature boundaries

An increase in genetic variation in body size has often been observed under stress; an increase in dominance variance and interaction variance as well as in additive genetic variance has been reported. The increase in genetic variation must be caused by physiological mechanisms that are specific to adverse environments. A model is proposed to explain the occurrence of an increase in genetic variation in body size in Drosophila at extreme temperatures. The model has parameters specific to the low- and high-temperature regions of the viable range. Additive genetic variation in the boundary temperatures leads to a marked increase in additive genetic variation in development rate and body size at extreme temperatures. Additive genetic variation in the temperature sensitivity in the low- and high-temperature regions adds non-additive genetic variation. Development rate shows patterns in additive genetic variation that differ from the patterns of genetic variation in body size; therefore, the genetic correlation between development rate and body size changes sign repeatedly as a function of temperature. The existence of dominance in the genetic variation in the boundary temperatures or in the low- and high-temperature sensitivities leads to a higher total genetic variance due to higher dominance and interaction variance, for both development rate and body size. This revised version was published online in July 2006 with corrections to the Cover Date.     

Light Induced Enhancement in Proline Levels Under Stress is Regulated by Non-Photosynthetic Events

Vigna radiata (L.) seedlings (5-d-old) were exposed to different concentrations of NaCl in light and in dark. The content of proline in the shoots increased with an increase in NaCl concentration, in light as well as in dark. But, irrespective of the concentration of NaCl, proline accumulation in the shoots was higher in light than in dark. Pretreatment of seedlings with dichlorophenyl dimethyl urea (DCMU) did not make any significant difference in light promoted stress induced proline accumulation. As DCMU is a potent inhibitor of photosynthetic electron transport, the light reaction of photosynthesis was not responsible for the observed light promotion of stress induced proline accumulation. In another set of experiments, 5-d-old green as well as etiolated seedlings were exposed to NaCl stress in the presence of different concentrations of sucrose. Irrespective of the concentration of sucrose used, proline content in shoots of stressed seedlings was higher in light than in dark. Although, sucrose enhanced NaCl stress induced increase in proline content in dark by about 32 %, this enhancement was not comparable to the 286 % increase in proline content brought about by light. These results showed that certain factors other than photosynthesis play a role in light promotion of stress induced proline accumulation.     

Effects of ammonium sulphate application on the rhizosphere,fine-root and needle chemistry in aPicea abies (L.) Karst. stand

Rhizosphere, fine-root and needle chemistry were investigated in a 28 year old Norway spruce stand in SW Sweden. The uptake and allocation pattern of plant nutrients and aluminium in control plots (C) and plots repeatedly treated with ammonium sulphate (NS) were compared. Treatments started in 1988. Current year needles, one-year-old needles and cylindrical core samples of the LFH-layer and the mineral soil layers were sampled in 1988, 1989 and 1990. Compared to the control plots, pH decreased significantly in the rhizosphere soil in the NS plots in 1989 and 1990 while the SO₄-S concentration increased significantly. Aluminium concentration in the rhizosphere soil was generally higher in the NS plots in all soil layers, except at 0–10 cm depths, both in 1989 and 1990. Calcium, Mg and K concentrations also increased after treatment with ammonium sulphate. Ammonium ions may have replaced these elements in the soil organic matter. The NS treatment significantly reduced Mg concentrations in fine roots in all layers in 1990. A similar trend was found in the needles. Ca concentrations in fine roots were significantly lower in the NS plots in the LFH layer in 1990 and the same pattern was found in the current needles. The N and S concentrations of both fine roots and needles were significantly higher in the NS plots. It was suggested that NS treatment resulted in displacement of Mg, Ca and K from exchange sites in the LFH layer leading to leaching of these cations to the mineral soil. Further application of ammonium sulphate may damage the fine roots and consequently adversely affect the water and nutrient uptake of root systems.     

Total nitrogen and free amino acids in Morus alba stems from autumn through spring

During leaf senescence and abscission, total nitrogen in leaves of mulberry ( Morus alba L. ev. Shin-ichinose) declined substantially whereas total nitrogen in buds, bark and stem wood increased markedly, suggesting translocation of nitrogen from senescent leaves in the autumn. After leaf abscission the winter buds and stems remained almost unchanged with respect to fresh and dry weight and total nitrogen until bud break in spring. In burst buds these parameters then increased drastically during the new growth while they decreased markedly in stems. Free arginine in the stem bark accumulated in parallel with the accumulation of total nitrogen in buds and stems in the autumn. Accumulation of proline in the wood, bark and buds also started in October but continued even after leaf-fall, increasing until mid-January (wood), mid-February (bark) and the new growth (buds). Prior to and in the early stage of bud break, proline in bark and wood decreased significantly and arginine in stem bark decreased slightly. Simultaneously, proline and arginine in the dormancy-releasing buds and asparagine, aspartic acid and glutamic acid in the buds and stems increased appreciably, suggesting that this increase in free amino acids was mainly derived from free amino acids (proline and arginine) stored in stems. The resulting marked decrease in total nitrogen and the drastic increase in asparagine in the stems and sprouting buds/new shoots were primarily due to a breakdown of protein stored in stems.     

社鼠组织器官同工酶的研究

用聚丙烯酰胺凝胶等电聚焦电泳方法,分析了社鼠的肝、肾、心肌、骨骼肌、肺、脾和脑等多种组织器官的ＬＤＨ、ＡＤＨ、ＥＳＴ、和ＳＯＤ４种同工酶,对各组织器官的酶带数目和分布,以及酶活性进行了比较研究。结果表明,社鼠的ＬＤＨ同工酶、ＡＤＨ同工酶和ＥＳＴ同工酶具有比较明显的组织特异性,而ＳＯＤ同工酶的组织特异性较低。肺和脾除ＥＳＴ同工酶活性较高外,脑除ＬＤＨ同工酶活性较高外,其它３种同工酶的活性均较低;而肝和肾中４种同工酶的活性普遍很高。心肌和骨骼肌因氧张力不同而使ＬＤＨ同工酶酶谱存在明显差异,但其它３种同工酶酶谱却非常相似。同工酶的组织特异性与各组织器官所执行的生理功能是相一致的     

Sex and estrous cycle-dependent differences in glial fibrillary acidic protein immunoreactivity in the adult rat hippocampus

Sex differences in the morphology and function of the hippocampus have been reported in several species, but it is unknown whether a sexual dimorphism exists in glial fibrillary acidic protein (GFAP) expression in the rat hippocampus. We analyzed GFAP immunoreactivity in the hippocampus of intact adult male rats as well as in females during diestrus and proestrus phases of the estrous cycle. We found that in CA1, CA3, and dentate gyrus, GFAP immunoreactivity was higher in proestrus females as compared with males and diestrus females. In CA1, a similar GFAP immunoreactivity was found in males and in diestrus females, but in dentate gyrus, males presented the lowest GFAP content. Interestingly, differences in astrocyte morphology were also found. Rounded cells with numerous and short processes were mainly observed in the hippocampus during proestrus whereas cells with stellate shape with few and long processes were present in the hippocampus of males and diestrus females. The marked sex and estrous cycle-dependent differences in GFAP immunoreactivity density and in astrocyte number and morphology found in the rat hippocampus, suggest the involvement of sex steroid hormones in the sexually dimorphic functions of the hippocampus, and in the change in its activity during the estrous cycle.