纳豆菌糖肽对小鼠腹腔巨噬细胞炎症因子分泌的影响

<正>免疫调节和抗癌作用被认为是多糖和糖蛋白最有发展前景的生理活性功能[1]。云芝糖肽[2],金平菇糖蛋白[3],拓树果实糖蛋白[4],灵芝肽多糖[5]等多种天然糖蛋白有良好的免疫调节作用,且无明显毒副作用。纳豆是日本的传统发酵食品,由蒸煮大豆经纳豆芽孢杆菌(Bacillus natto)在一定温度、湿度下发酵制备而成。近年来研究显示,纳豆具有溶血栓、抗肿瘤、降血压、抗氧化、抗菌消炎等保健功能[6]。此外,纳豆仍有许多活性成分及其     

Increased Production of Proinflammatory Cytokines by Murine Macrophages Following Oral Exposure to Sodium Selenite But Not to Seleno-L-Methionine

Selenium (Se) is an essential as well as a toxic trace element in animal and human nutrition. The immune system is a known target of Se intoxication. The objectives of the present study were to determine the effects of oral exposure to inorganic and organic forms of Se on the murine immune system and to compare the relative toxicity of the different chemical forms. Male BALB/c mice, 6–7 weeks of age, were exposed continuously to 0, 1, 3 or 9 ppm of Se as sodium selenite or seleno-L-methionine in the drinking water for 14 days. Following the treatment period mice were euthanized; trunk blood, spleen, thymus, liver and kidney were aseptically collected and organs weighed. Single-cell splenocyte cultures were made from the spleens and used to determine the effects of Se treatment on mitogen-induced lymphocyte blastogenesis and cytokine production. There were no changes in the 0 and 1 ppm Se groups as selenite. The thymus/body weight ratio was significantly reduced at 3 ppm Se as sodium selenite, and all other parameters remained unaffected. Exposure to 9 ppm of Se as sodium selenite resulted in marked decrease in body weight gain and relative organ weights. Treatment of mice with 9 ppm Se as sodium selenite increased erythrocyte counts in peripheral blood, reduced splenic cellularity, but increased the basal rate of splenocyte proliferation and induced a dose-dependent increase in phytohemagglutinin-P-induced lymphocyte proliferation. Sodium selenite at this dose increased the production of proinflammatory cytokines, tumor necrosis factor α and interleukin-1β, in lipopolysaccharide-stimulated splenic macrophages. Mice exposed to Se as seleno-L-methionine in the drinking water did not display any effects on the parameters examined at the dose range in this study. Results indicated that splenic macrophages and lymphocytes are sensitive to Se intoxication and there is a disparity in the immune system toxicity of inorganic and organic forms of Se administered via the drinking water, inorganic Se being more toxic. Received: 7 October 1999/Accepted: 28 February 2000     

职业性铅接触与各生物接触指标间的关系评估

本文在对蓄电池厂１００名铅接触者的健康监护中，各项生物监测按规定的质量控制要求进行。并了其间的剂理效应关系。结果发现，空气中铅尘、铅烟低于最高容许浓度；接触者的血铅、尿铅和ＦＥＤ呈非常显著相关。（Ｐ〈０．０１）其中血铅能较好地定量反映接触铅工人体仙的铅负荷，并提出了血铅的可接受水平。     

Toxic Exposure of Songbirds to Lead in the Southeast Missouri Lead Mining District

Mining and smelting in the Southeast Missouri Lead Mining District has caused widespread contamination of soils with lead (Pb) and other metals. Soils from three study sites sampled in the district contained from approximately 1,000–3,200 mg Pb/kg. Analyses of earthworms [33–4,600 mg Pb/kg dry weight (dw)] collected in the district showed likely high Pb exposure of songbirds preying on soil organisms. Mean tissue Pb concentrations in songbirds collected from the contaminated sites were greater (p < 0.05) than those in songbirds from reference sites by factors of 8 in blood, 13 in liver, and 23 in kidney. Ranges of Pb concentrations in livers (mg Pb/kg dw) were as follows: northern cardinal (Cardinalis cardinalis) = 0.11–3.0 (reference) and 1.3–30 (contaminated) and American robin (Turdus migratorius) = 0.43–8.5 (reference) and 7.6–72 (contaminated). Of 34 adult and juvenile songbirds collected from contaminated sites, 11 (32 %) had hepatic Pb concentrations that were consistent with adverse physiological effects, 3 (9 %) with systemic toxic effects, and 4 (12 %) with life-threatening toxic effects. Acid-fast renal intranuclear inclusion bodies, which are indicative of Pb poisoning, were detected in kidneys of two robins that had the greatest renal Pb concentrations (952 and 1,030 mg/kg dw). Mean activity of the enzyme delta-aminolevulinic acid dehydratase (ALAD) in red blood cells, a well-established bioindicator of Pb poisoning in birds, was decreased by 58–82 % in songbirds from the mining sites. We conclude that habitats within the mining district with soil Pb concentrations of ≥1,000 mg Pb/kg are contaminated to the extent that they are exposing ground-feeding songbirds to toxic concentrations of Pb.     

铅接触对神经行为功能影响的研究

运用世界卫生组织推荐的神经行为核心测试组合的６项分测验并采用因子分析法研究铅接触对神经行为功能的影响。铅接触工人共７８名，平均血铅浓度为２．１４μｍｏｌ／Ｌ；对照工人共７６名，平均血铅浓度为０．２０μｍｏｌ／Ｌ。两组除工龄、人均月收入外，其他因素均差异无显著性。对铅接触工人研究发现，在血铅≥２．７２μｍｏｌ／Ｌ时，运动协调功能和记忆力发生改变。分组研究发现，血铅水平与５种因子得分存在剂量－反应关系     

Biochemical Tests for the Appraisal of Exposure to Lead

Increases in the rate of the excretion of δ-aminoievulinic acid and, to a slightly lesser extent, increase in the excretion of coproporphyrin, in the urine of persons subjected to occupational exposure to lead, parallel the increase in the excretion of lead in the urine (and the concentration of lead in the blood). Data derived from a study of groups of workmen subjected to varying degrees of exposure have been assembled to demonstrate the gradation of these several responses to graduated occupational exposure to lead, and to provide collective criteria for the establishment of threshold limits.     

铅暴露与阿尔茨海默病

阿尔茨海默病(Alzheimer s Disease,AD)是常见的神经变性疾病之一,其发病机制不十分明确,也无从特效治疗,严重影响中老年人的身心健康,因而成为医学的研究热点。实验研究发现,铅暴露与AD发病有关[1]。铅(Pb)是广泛分布在自然环境中的有毒重金属,吸收过量可引起铅中毒。目前,铅污染的特点是浓度低、范围广,对人群健康的影响是低剂量、长期暴露而引起的慢性损害。低浓度Pb具有神经毒性,可对认知学习和记忆等高级脑功能产生有害影响,而且可能是发生AD的病因之一。现就国内外关于铅暴露与AD关系的研究作一综述。1铅暴露与AD职业性和生活性…     

Retinoic Acid Induces Transglutaminase In Mouse Macrophages

Retinoic acid bound to retinol-binding protein induces transglutaminase in mouse peritoneal macrophages.     

化学法尿铅作为铅接触指标的价值评价

评价化学法尿铅筛选职业性铅接触的价值。收集１５７名同一铅接触工人的血标本及尿标本,同时测定血铅,悄铅,红细胞游离原卟啉,锌卟啉,尿δ－氨基酮戊酸,以血铅≥４０μｇ／ｄｌ,≥６０μｇ／ｄｌ的铅接触水平为金标准。用Ｒｅｃｅｉｖｅｒ－Ｏｐｅｒａｔｉｎｇ Ｃｈａｒａｃｔｅｒｉｓｔｉｃ曲线分析软件评价化学法尿负及其它测定指标的准确性。     

纳米碳酸钙亚慢性染毒对大鼠神经行为的影响

[目的]通过观察纳米碳酸钙亚慢性染毒对大鼠自发活动和学习记忆能力的影响,初步探讨纳米碳酸钙的神经毒性。[方法]选取50只健康雄性SD大鼠,随机分为溶剂对照组、微米碳酸钙组（200 mg/kg）和纳米碳酸钙12.5、50、200 mg/kg组5组,每组10只。滴鼻法每天染毒1次,每周5 d,间歇2 d,持续12周;采用旷场试验和Morris水迷宫试验测试各组大鼠自发活动和学习记忆功能。[结果]微米碳酸钙和纳米碳酸钙组大鼠精神萎靡,但各组间大鼠体质量和脑体比差异均无统计学意义（P＞0.05）。旷场试验,各组大鼠在暗箱中中央活动时间、中央运动总路程、站立次数差异均无统计学意义（F值分别为0.799、0.623和0.251,P值均大于0.05）。Morris水迷宫试验,各组大鼠平均潜伏期、平均总路程、穿越平台次数、平台象限滞留时间差异均无统计学意义（F值分别为0.475、0.345、0.046和0.252,P值均大于0.05）。[结论]在本实验剂量条件下,纳米碳酸钙对大鼠自发活动和学习记忆能力无明显影响。     

砷铅共存对人体的遗传学效应

为了探讨砷铅同时存在时对人体的遗传学效应,我们对砷铅污染区产妇及其新生儿作了外周血淋巴细胞姊妹染色单体交换(SCB)和微核试验;同时对该污染区有皮肤过度角化体征者进行了1:2配对的病例对照回顾性分析。结果显示:砷铅污染区产妇和新生儿的SCE率与对照区相比,差异有显著性(P相似文献   

Scalp Hair as a Monitor of Community Exposure to Lead

Lead was measured by photon activation analysis in scalp hair from three population groups with varied types of environmental exposure. Concentrations of lead in hair increased from rural to urban to smelter areas with medians of 9.1,15.3, and 48.5 ppm, respectively. Boys under 16 residing near smelters showed consistently higher lead levels than girls of the same age group and from the same area. A history of exposure to lead was deduced from the distribution of concentration along the hair length by analyzing 1- or 2-cm segments of hair strands. A reasonably good blood lead-hair lead correlation was obtained for individuals who appeared to be in a steady state with respect to intake and excretion of lead. The analytical method for the photonuclear determination of lead in hair, the hair washing procedure, and the advantages of using hair as an epidemiologic monitor are described.     

Cerebral Damage Following a Single High Exposure to Carbon Disulphide

A formerly healthy 48-year-old man was accidentally exposedfor approximately 20 minutes to a high concentration of carbondisulphide (minimum concentration, 400 parts/10⁶; maximum, 470000 parts/10⁶), and was unconscious for approximately 10 minutes.Serious persistent cerebral deterioration developed. Computerizedtomography scanning showed cerebral atrophy, neuro-psychologicalexamination established dementia, and measurement of cerebralflow showed reduced cortical flow in the right hemisphere. Possible mechanisms for the cerebral damage are discussed, andpersons who are at risk from such accidental poisoning are listed. Accepted        1 August 1981     

Relationship Between Prenatal Lead Exposure and Infant Blood Lead Levels

Recent literature has shown that analyzing newborn dried blood spots (DBS) may be effective in assessing some prenatal environmental exposures, such as exposure to lead. The purpose of this study was to evaluate the relationship between prenatal exposure to lead (as measured by newborn DBS results) and blood lead levels (BLLs) in infants 6?months of age or younger, using public health registry data for infants born in Texas from July 2002 through July 2006. The Texas Child Lead Registry (TCLR) was used to identify infants with documented elevated BLLs of 10?μg/dL or higher as well as infants with documented low BLLs. BLLs for these children were compared to their corresponding newborn DBS results using Pearson correlation coefficients and exact logistic regression models. Overall, a significant but weak positive correlation was found between infant BLLs and corresponding newborn DBS lead levels (r?=?0.48). However, the odds of an infant with an elevated newborn DBS lead level having an elevated BLL at 6?months of age or younger were much greater than for an infant with a low newborn DBS lead level of <5?μg/dL (adjusted odds ratio 27.95, 95% CI: 5.52-277.28). Although an association was observed between newborn DBS lead levels and BLLs in infants tested between 0 to 6?months of age, our findings suggest that prenatal exposure may not be the only significant source of lead exposure for infants ≤6?months of age.