基因芯片检测与苯中毒相关的信号传导通路中基因的差异表达

目的检测苯中毒信号转导相关基因的表达，探讨苯引起的血液系统损害的发病机理。方法应用含4265条信号转导基因的cDNA芯片检测7例苯中毒患者和7例无苯接触的正常人的外周血白细胞基因表达谱，观察其在基因表达谱上的差异。进行了基因表达谱聚类分析。结果在4265条基因中，存在明显差异表达的基因176条。至少在六张芯片结果中有显著性表达上调的基因35个，主要包括有PTPRC、STAT4、IFITM1等。至少在5张芯片结果中有显著性表达下调的基因45个，主要包括有ARHB、PPP3CB、CDC37等。结论微矩阵基因芯片在检测苯中毒信号转导相关基因的改变时．具有快速、高通量、高灵敏度等特点．细胞信号转导的障碍在苯中毒发病中起一定的作用。     

Morphology, toxin composition and pigment content of Prorocentrum lima strains isolated from a coastal lagoon in southern UK.

Prorocentrum lima was isolated from the coastal Fleet lagoon, Dorset, UK in 2000 and a number of clonal cultures established. These were analyzed for okadaic acid (OA), dinophysistoxin-1 (DTX-1), DTX-2, DTX-4 and diol esters by liquid chromatography coupled to mass spectrometry. OA concentrations varied from 0.4 to 17.1pg OAcell(-1) and DTX-1 from 0.4 to 11.3pg DTX-1cell(-1); DTX-2 was not detected in these isolates. OA and DTX-1 were detected in the culture media, as a result of toxin excretion. DTX-4 and a selection of DTX-4 diol esters were identified using selected ion monitoring, although not all strains produced these compounds. Cell size and number of marginal and valve pores of each strain were observed using scanning electron microscopy. OA and DTX-1 concentrations, pigment content and changes in nitrate and phosphate concentrations in the culture media were followed during growth of one strain of P. lima in batch culture. Diarrhetic shellfish poisoning (DSP) toxins have been previously detected in shellfish cultivated in the Fleet lagoon, but in the absence of any Dinophysis sp. cells. The identification of toxic P. lima strains from the Fleet suggests that this dinoflagellate is the most probable source of occasional DSP detected in the lagoon.     

Salinity effect on growth and toxin production of four tropical Alexandrium species (Dinophyceae).

Four tropical PSP toxins-producing dinoflagellates, Alexandrium minutum, Alexandrium tamiyavanichii, Alexandrium tamarense and Alexandrium peruvianum from Malaysian waters were studied to investigate the influences of salinity on growth and toxin production. Experiments were conducted on constant temperature 25 degrees C, 140 microE mol m(-2) s(-1) and under 14:10 light:dark photo-cycle with salinity ranged from 2 to 30 psu. The PSP-toxin congeners, GTX 1-6, STX, dcSTX, NEO and C1-C2 were analysed by high performance liquid chromatography. Salinity tolerance of the four species in decreasing order is A. minutum>A. peruvianum>A. tamarense>A. tamiyavanichii. Specific growth rates and maximum densities varied among these species with A. minutum recorded as the highest, 0.5 day(-1) and 6 x 10(4) cells L(-1). Toxin content decreased with elevated salinities in A. minutum, the highest toxin content was about 12 fmole cell(-1) at 5 psu. In A. tamiyavanichii, toxin content peaked at optimal growth salinity (20 and 25 psu). Toxin content of A. tamarense, somehow peaked at sub-optimal growth salinity (15 and 30 psu). Results of this study implied that salinity fluctuation not only influenced the growth physiology but also toxin production of these species.     

Phospholipid composition and levels are altered in Down syndrome brain

Individuals chronically exposed to low levels of organophosphate insecticides may present with subtle impairments in cognition. In addition, low level diisopropylflurophosphate (DFP) exposure (0.25 mg/kg per day for 2 weeks) in rats resulted in protracted working memory impairment [29]. The current studies attempt to show a temporal relationship between the DFP-induced impairment in performance of a spatial memory task and the protracted decrease in the expression of cholinergic receptors and acetylcholinesterase in specific brain regions. Cholinergic receptors labeled with the ligands [(3)H]epibatidine and [(3)H]AFDX-384 were affected to a much greater extent and for a longer period of time than were both acetylcholinesterase activities and cholinergic receptors labeled with [(3)H]QNB. Pre-testing administration of nicotine was shown to completely reverse this DFP-induced impairment in memory-related task performance. Additionally, prophylaxis with pyridostigmine bromide (PB) caused DFP-treated animals to exhibit near normal levels of memory-related task performance. These results are consistent with the development of a protracted phase of learning impairment to sub-acute DFP exposure, which may involve the loss of hippocampal nicotinic receptors, and may be prevented or reversed by PB or nicotine, respectively.     

rhEPO、rhG-CSF对芥子气全身吸收中毒犬疗效观察

目的　评价重组人红细胞生成素 (rhEPO)、重组人粒细胞集落刺激因子 (rhG CSF)对芥子气全身吸收中毒犬的治疗效果。方法　以成年家犬为中毒模型 ,共 10条 ,中毒剂量为 12mg kg,皮下注射。随机分为中毒对照组 4条 ,治疗组 6条 ,治疗组动物在中毒后 30min即进行相应的药物治疗。中毒前所有犬各测一次血常规的基础值 ,中毒后每日监测血常规的动态变化 ,持续 1周。结果　对照组犬于 3天内死亡 3条 ,治疗组犬全部成活。对照组白细胞计数 (WBC)在中毒后第 3开始剧烈下降 ,红细胞计数 (RBC)在中毒后即有轻度上升 ,之后回落 ;而治疗组WBC、RBC在中毒后 1周内均无显著变化。两组的淋巴细胞计数 (LYM)在中毒后都有显著下降 ,治疗组稍好于对照组。治疗组的网织红细胞计数 (RC)于中毒后第 2天开始显著增长 ,之后维持在高水平 1周左右。治疗组的RC变化不明显。结论　犬芥子气中毒后 ,应用rhEPO、rhG CSF能明显改善中毒犬的部分血常规指标     

一起金黄色葡萄球菌肠毒素引起食物中毒的调查

目的 :了解导致幼儿园食物中毒原因及研究中毒菌株的生物特性。方法 :按国标方法将呕吐物 ,剩余的食物进行分离培养 ,对菌株进行生化试验和毒力试验。结果 :分离到 2株的金黄色葡萄球菌 ,一株精氨酸双解酶阴性 ,对幼猫致病性较强 ,另一株精氨酸双解酶阳性 ,对幼猫致病性较弱。结论 :金黄色葡萄球菌肠毒素导致幼儿园食物中毒发生     

顺德地区0～6岁儿童铅中毒及其相关因素调查

【目的】　调查顺德地区 0～ 6岁儿童铅中毒的流行率以及引起铅中毒的相关因素。　【方法】　采集 3个镇城乡共 6间托儿所、幼儿园儿童的静脉血标本 3 49人 ,新生儿之脐血标本 10 8人 ;并收集工业区污水、乡村河涌水、鱼塘水 ,乡村田边土、交通繁忙的主干道及大街边尘土 ,铅皮牙膏、药膏及塑料皮牙膏 ,汽油等标本进行铅含量检测。对每个抽血对象的家长进行相关因素问卷调查。　【结果】　铅中毒的流行率为 42 .7% ,其中农村儿童铅中毒为3 9 .4% ;城镇儿童铅中毒为 46.2 % ;脐血铅超标达 42 .6%。相关因素有 :小儿及孕妇常吃罐装食品、饮料、皮蛋 ,小儿喜欢咬玩具、吮手指、咬铅笔、进食前不常洗手 ,父母亲从事铅暴露作业 ,家住大街边及大马路边等有关。工业区污水、鱼塘水、交通繁忙的主干道及大街边尘土、铅皮牙膏、药膏的铅含量明显高于乡村河涌水、乡村田边土、塑料皮牙膏。　【结论】　铅中毒与环境污染、小儿或孕妇饮食嗜好、不良习惯、父母从事铅暴露作业以及家住大街边有关。     

419名铅中毒儿童贫血发生率的调查

目的 :进行儿童铅中毒患儿贫血发生率的调查 ,了解铅对儿童血液系统的影响。方法 :测定 5 4 0名儿童的血铅水平(BPb) ,根据血铅水平分成非铅中毒组 (BPb<10 0μg/ L )和铅中毒组 (BPb≥ 10 0μg/ L ) ,同时对两组儿童进行血细胞分析 ,测定红细胞 (RBC)、血红蛋白 (HGB)、红细胞平均容积 (MCV)、红细胞平均血红蛋白量 (MCH)、红细胞平均血红蛋白浓度 (HCHC)水平。结果 :两组的 RBC、HGB、MCV、MCH、MCHC的水平差异无显著性 (P>0 .0 5 )。结论 :较低水平铅中毒患儿贫血发生率无显著升高。     

光气染毒造成小鼠肺脏的氧化损伤

目的　研究小鼠光气染毒后不同时间对肺脏的氧化损伤作用。方法　 4 0只雄性小鼠 ,随机分为 4组。正常对照组小鼠以空气为对照 ,染毒组小鼠给予 11.9mg/L剂量的光气 ,时间为5min ,分别染毒后 2h、4h、8h ,测定各组小鼠肺脏的湿干比和肺匀浆液的丙二醛 (MDA)含量、总超氧化物歧化酶 (T SOD)活力、还原型谷胱甘肽 (GSH)含量。结果　随着光气染毒时间的增加 ,小鼠肺脏的湿干比显著增加 (P <0 .0 5 ) ;染毒后 4h ,肺组织MDA含量和T SOD活力显著升高(P <0 .0 5 ) ,GSH含量在染毒后 2h显著降低 (P <0 .0 5 )。结论　光气染毒可引起小鼠肺水肿和肺脏氧化损伤。     

儿童铅暴露相关危险因素Logistic逐步回归分析

目的:了解珠江三角洲中心地区儿童铅暴露水平及相关因素。方法:对1 866例1-3岁入托体检儿童进行静脉血铅、锌、钙、铁、铜、锰测定,并做铅暴露危险因素问卷调查。结果:儿童血铅水平均数为116.72 μg／L,≥100 μg／L者占48.77％,年龄、喜饮罐装饮料、母亲职业、居住的楼龄及楼层、居住环境是儿童铅暴露的危险因素,血锌是保护因素。结论:环境铅污染是儿童铅暴露的主要来源,环境污染对儿童已构成严重的威胁,应引起社会的关注。