山西省出生缺陷高发区土壤元素分布特征

目的 了解出生缺陷高发区土壤中元素分布特征,为出生缺陷的干预和治疗提供理论依据.方法 于2005年1-5月,选择山西省吕梁山区出生缺陷高发的中阳县和交口县作为出生缺陷高发区,以人口相对集中的河道两侧为采样点,共涉及8个乡镇,79个行政村;选择晋中盆地出生缺陷低发的祁县作为出生缺陷对照区,采样点均匀分布,共涉及6个乡镇,27个行政村.采集距耕地表层10～20cm深的土壤,共采集样品131件.采用ICP-电感耦合等离子发射光谱法,对土壤样品中的16种元素进行测定.结果 高发区土壤中元素总量明显高于低发区.与祁县相比,交口县土壤中元素含量偏高的有As、Mo、Pb、Ni、V,含量偏低的元素有Se,差异均有统计学意义(P＜0.05);中阳县土壤中含量偏高的元素为Sn、Se、Mo、Zn、Sr、Pb、Ni、Fe、V、Ca、Cu、Al,偏低的元素为Mg和Na,差异均有统计学意义(P＜0.05).土壤中元素含量(μg/g)与出生缺陷发病率的(1/万)逐步回归分析显示,交口县土壤中Mo、Al、As、Ni、Pb、Zn元素对病情影响有统计学意义(均P＜0.01),其标准的逐步回归判别方程为:y=-1.321 1.106 Mo-0.509 Al 0.117 As 0.663 Ni-0.429 Pb-0.262 Zn(R2a=0.891);中阳县土壤中Pb、Mg、Ca、Al、Zn元素对病情影响有统计学意义(均P＜0.05),其标准回归方程为:y=-1.757 0.441 Pb-0.264Mg 0.309 Ca-0.186Al 0.162Zn (R2a2=0.839).结论 交口县和中阳县土壤中Pb、Mo、Al等含量异常可能是两县出生缺陷高发的原因之一.     

土壤环境基因组技术及其在新药发现中的应用

土壤是微生物最重要的生境，土壤微生物具有极大的多样性。然而传统培养技术只能得到约1％的微生物纯培养，其余都是未被纯培养微生物。利用土壤环境基因组技术，可以把未被纯培养微生物的基因克隆到载体中并在宿主中进行表达，获得比已培养微生物丰富的代谢产物多样性，这为我们发现新颖结构先导化合物以及新药开辟了新的道路。本文介绍应用环境基因组技术构建土壤DNA文库的思路和方法。     

1株诱变枯草杆菌溶栓酶性质研究的初探

目的 对从1株诱变的枯草杆菌的发酵液中，通过分离纯化得到的一种活性较高的纤溶酶进行性质研究。方法 按胰酶活性测定法测其水解酪蛋白活性，用SDS-PAGE测定分子量，等电聚焦测定其等电点。采用硫酸酚法测定糖含量，并对其药理性质进行研究。结果 其水解酪蛋白活性为2.1U/mg，分子量为62kDa。等电点为8.5。含糖量为32%，并且发现该酶具有直接降解纤维蛋白的活性。结论 此纤溶酶具有较高的活性及药理价值。     

Vertical profile of Cs in soil

In this paper, a vertical distribution of ¹³⁷Cs in undisturbed soil was investigated experimentally and theoretically. Soil samples were taken from the surroundings of the city of Kragujevac in central Serbia during spring-summer of 2001. The sampling locations were chosen in such a way that the influence of soil characteristics on depth distribution of ¹³⁷Cs in soil could be investigated. Activity of ¹³⁷Cs in soil samples was measured using a HpGe detector and multi-channel analyzer. Based on vertical distribution of ¹³⁷Cs in soil which was measured for each of 10 locations, the diffusion coefficient of ¹³⁷Cs in soil was determined. In the next half-century, ¹³⁷Cs will remain as the source of the exposure. Fifteen years after the Chernobyl accident, and more than 30 years after nuclear probes, the largest activity of ¹³⁷Cs is still within 10 cm of the upper layer of the soil. This result confirms that the penetration of ¹³⁷Cs in soil is a very slow process. Experimental results were compared with two different Green functions and no major differences were found between them. While both functions fit experimental data well in the upper layer of soil, the fitting is not so good in deeper layers. Although the curves obtained by these two functions are very close to each other, there are some differences in the values of parameters acquired by them.     

太钢1998～2002年放射工作人员个人剂量监测分析

目的为进一步调查太钢放射工作人员外照射剂量大小，以评价太钢近几年来放射管理和放射防护效果，降低放射危害，保护放射工作人员身体健康。方法根据GB5294-85《放射工作人员个人剂量监测方法》将1998-2002年在太钢从事放射的工作人员分为4组：医用X射线、工业X射线、工业γ射线和医用同位素组，进行外照射个人剂量监测，并计算1998-2002年各年度平均年剂量当量。每年监测4个周期，每个周期为3个月，并对监测结果进行分析。结果①5个年度平均年剂量当量为1．46mSv，1998年最高，从2000年起有逐渐下降的趋势；并且除2002年与2000、2001年比较，U检验差异无统计学意义外，其余各年度之间比较，差异均有统计学意义（P〈0．01）；②1998-2002年各工种之间年个人剂量当量监测结果，以工业γ射线组均值最低，医用X射线组最高。U检验，工业γ射线组与其他3个组比较，差异有统计学意义（P〈0．01），医用X射线组与工业X射线组比较，差异亦有统计学意义；③1998-2002年各年度年个人有效剂量频数分组分布，〈1mSv／a组占受检总数的27.11％，〉5mSv／a的占0．31％，〈5mSv／a的占99．69％。经χ^2检验，各年度之间比较，差异有统计学意义（χ^2=377．33，P〈0．01）；④各工种个人剂量当量分组频数分布情况：〈1mSv／a占受检总数的26．49％，1-2mSv／a组占59．89％．2-3mSv／a占10．52％，〈5mSv／a的占99．69％，〉5mSv／a仅3例，为医用X线组。各工种之间比较，χ^2检验有统计学意义（χ^2=1030．79，P〈0．001）。结论1998-2002年平均剂量当量远低于国家标准，并逐年下降，说明近5年太钢加强放射工作人员的健康和防护设施管理的工作，放射工作环境是安全的。     

67Ga心肌炎症显像对小儿病毒性心肌炎的诊断价值

目的 :探讨6 7Ga心肌显像对小儿病毒性心肌炎 (VMC)诊断的临床价值。方法 :静脉注射6 7Ga 枸橼酸盐 ,48h、72h后开始显像 ,观察心脏部位放射性浓聚情况 ,并计算心 /肺 (H/L)指数 ,根据H/L指数判断心肌炎性病变的严重程度 (H/L指数 >1.2为阳性 )。结果 :78例病毒性心肌炎患儿中 ,50例阳性 (占 64% ) ,其中急性期阳性率为 84% ,恢复期阳性率为 50 % ,慢性期为 2 9% ,急性期阳性率明显高于恢复期和慢性期 (P<0 .0 5)。结论 :心肌6 7Ga放射性浓聚与心肌炎病变程度呈正相关 ,直接反映了病变心肌的炎症反应情况 ,对诊断VMC有较高的临床价值 ,并对VMC治疗、预后有指导作用     

Kinetics of acetylcholine recovery in Torpedo electromotor synapses depleted of synaptic vesicles

Isolated fragments of Torpedo electric organ perfused with choline-free Ringer and stimulated by application of up to 1500 pulses at 1 Hz lost 58% of their synaptic vesicles and 65% of their acetylcholine. The stimulated terminals showed ultrastructural changes of varying intensity which were reversed during rest. The numbers of synaptic vesicles returned to control values by 5 h and total acetylcholine reached the control levels only after 20 h incubation in medium containing excess of choline. Net synthesis of acetylcholine as well as acquisition of acetylcholine by the reformed vesicles followed first order kinetics with respect to the degree of unsaturation of the total acetylcholine pool and the vesicular compartment, respectively.A possible interpretation of these results is that the degree of depletion of the vesicular compartment may regulate the rate of net acetylcholine synthesis, and that the vesicular compartment may account for at least 80% of total acetylcholine in the terminals.     

Changes in the biochemical and biophysical parameters of cholinergic synaptic vesicles on transmitter release and during a subsequent period of rest

Synaptic vesicles were isolated on sucrose density gradients from perfused blocks of Torpedo electric organ under varying experimental conditions. Newly synthesized acetylcholine was labelled with [³H]acetate in order to distinguish synaptic vesicles which had been recycled during stimulation-induced transmitter release and, in consequence, had become smaller and denser from the larger, lighter vesicles characteristic of unstimulated tissue. After 1800 pulses at 0.1 Hz, the density of these smaller vesicles increased from a pre-stimulation value of 1.056 g.ml^?1 to 1.067 g.ml^?1, whereas their water space (measured as the space occupied by the permeant solute glycerol), decreased by 34% from 65% to 43% of vesicle volume. During a subsequent 12 h rest period, these changes were partially reversed; water space returned to 52% of control and this change was highly correlated with a decrease in vesicle density and an increase in vesicular acetylcholine. The diameter of vesicles in whole tissue sections showed corresponding changes. An additional 12 h rest period did not lead to further significant recovery, suggesting that the preparation had a limited suitability for following long term processes depending on normal energy metabolism.The results can be explained on the assumption that when vesicles reform after releasing transmitter their core has a lower osmotic pressure than that of fully loaded vesicles. Reloading is accompanied by osmotically induced rehydration.     

重组水蛭素在大鼠体内的药动学研究

目的研究重组水蛭素iv给药在大鼠体内的药动学。方法采用125-标记的放射性同位素法(RA法)、三氯醋酸沉淀结合放射性检测法(TCA-RA法)研究重组水蛭素iv给药在大鼠体内的药动学。结果大鼠iv0.5、1.0和2.0mg/kg重组水蛭素,以RA法检测,该药的消除半衰期(t1/2ke)分别为162.8、147.5和172.8min,AUC分别为264.9、429.9和1112.9(μg·min)/mL;以TCA-RA法检测,该药的t1/2ke分别为100、101和107min,AUC分别为160.7、327.7和551.3(μg·min)/mL。两种方法所得结果均证明AUC与剂量呈正相关,相关系数均大于0.99。大鼠iv重组水蛭素1.0mg/kg后用RA法和TCA-RA法测定不同组织的药物质量浓度,在各时间点以肾脏含药量显著高于其他组织,肺、胃、脾、心、肝、性腺等组织次之,脑、脂肪最少。大鼠iv重组水蛭素1.0mg/kg后,用RA法测定不同时间段内尿、粪的放射性总量,在96h内70.16%放射性从尿中回收,1.35%从粪中回收到,24h内胆汁排泄量为3.46%。结论RA法和TCA-RA法测得重组水蛭素在大鼠体内的药动学结果不同,但整体趋势一致;重组水蛭素主要由尿排泄。     

土壤中砷含量与非砷职业暴露人群肺癌发病关系研究

[目的]探讨土壤中砷含量与非砷职业暴露人群肺癌发病率的关系。[方法]测定污染区与对照区土壤中砷含量,收集其非砷职业暴露人群与砷职业暴露人群肺组织中砷含量及其肺癌发病率,并进行统计学分析。[结果]污染区土壤砷含量是对照区的14.3-19.7倍。[结论]土壤中砷含量与非砷职业暴露人群肺癌发病呈显著及非常显著的正相关(r=0.9281-0.963,P<0.05-0.01)。