模糊数学方法用于职业危害因素的综合评价

模糊数学方法用于职业危害因素的综合评价徐新云（湖南省劳动卫生职业病研究所，长沙４１０００７）用模糊数学方法进行综合评价时，首先要确定评判等级，各评判因素在不同等级中的取值，以及各评判因素的权重系数三方面内容。本文将评判等级定为优、良、一般、差、很差５...     

起搏器更换时原起搏电极导线参数及更换指标分析

目的:分析74例更换起搏器时电极导线的各项参数的变化并探讨导线更换指标。方法:本组年龄12~87(62.8±18.4)岁,其中病窦综合征45例,房室传导阻滞29例,均为单腔VVI起搏。结果:至测量时原心室起搏电极导线的埋置时间60~148(97.4±22.8)月,首次埋置时起搏阈值为(0.48±0.24)V,更换时为(1.29±0.64)V(P(0.01),增加0.81V,增幅为168%,首次植入时R波幅为(7.8±3.6)mV,更换时为(5.9±3.4)mV(P(0.05)。植入时电极导线阻抗为(664±122)Ω,更换时阻抗为(726±148)Ω,增幅9.3%(P(0.05)。7例因起搏阈值大于2.0 V或阻抗大于1 250Ω而重新植入电极导线。原电极导线使用率为90.5%。结论:埋置起搏电极导线8~9年后,90.5%原电极导线仍在可使用的范围内,能否支持到再次更换需进一步随访。     

冶金炼铁炉前工人职业性皮损调查研究

冶金炼铁炉前工人职业性皮损调查研究关虹，王溪鸿，杨玉萍（辽宁省本溪钢铁公司劳动卫生研究所，１１７０２１）作者对炼铁炉前工人＂熊猫眼＂样皮损病因及特异部位皮损进行研究，为改善劳动条件，防治职业性皮肤病提供一些依据。以某炼铁厂５号炉前工人为观察组，以炼钢...     

国外用体内X射线荧光技术对人体骨铅含量研究的概况

通过介绍国外人体骨铅测量的历史背景、多种器官铅含量的对比以及体内X射线荧光技术(In vivoXRF)测定骨铅研究的近期发展状况,探讨人体骨铅含量体内X射线荧光非损伤性测定的重要意义。     

甲基叔丁基醚无铅汽油肾脏毒性的实验研究

目的：了解甲基叔丁基醚（MTBE）无铅汽油对肾脏的毒性及毒作用机制。方法：昆明种小鼠经呼吸道静式染毒，MTBE无铅汽油22．9、11．4及2．3g/m^3每天一次，连续2h，共22d亚急性染毒。日立－7150型全自动生化仪检测血清中尿素氮（BUN）、肌酐（Cr）含量；肾组织均浆中丙二醛（MDA）和超氧化物歧化酶（SOD）含量分别用荧光法，邻苯三酚自氧化固定时间法测定；电镜观察肾皮质区超微结构的变化，结果：22.9g/m^3染毒组雌性小鼠血清中BUN含量与阴性对照组间比较差异有显著性（P＜0．05）；电镜观察到22.9g/m^3染色毒对照组雌雄性小鼠的肾小球基底膜，肾小管细胞线粒体及绒毛均未见显著异常改变。结论：MTBE无铅汽油对肾小球的滤过功能有一定的影响，雌性小鼠可能更为敏感。     

A method for partitioning cancer mortality trends by factors associated with diagnosis: An application to female breat cancer

U.S. cancer mortality data derived from information recorded on death certificates are frequently relied upon as an indicator of progress against cancer. A limitation of this measure is the lack of information pertaining to the onset of disease, such as year-of-diagnosis, age-at-diagnosis, stage of disease at diagnosis and histology of lesions. However, population-based cancer registries collect these types of data and allow the calculation of an incidence-file based mortality rate. This incidence-based mortality rate allows a partitioning of mortality by variables associated with the cancer onset. Breast cancer incidence-based mortality measures are created and compared to mortality rates based on death certificates over a comparable time period. Novel mortality measures, such as mortality rates by stage-at-diagnosis, age-at-diagnosis and year-of-diagnosis, are used to illustrate the value of this approach.     

微创颅内血肿清除术治疗脑出血65例

我科于1999年10月以来,对各种原因引起的脑出血(出血量≥30 ml)的患者采用贾保祥[1]教授研制的微创颅内血肿清除术进行治疗,取得了良好效果。现报告如下。1临床资料1.1一般资料本组65例,男38例,女27例,发病年龄32岁-83岁,平均年龄56.2岁。其中高血压引起的脑出血63例,急性硬膜下血肿2例,超早期(发病7 h内)就诊28例,早期(发病7 h~3 d)就诊35例,延期(发病3 d以上)2例。1.2临床表现大部分患者发病早期均有头痛或头晕,其中呕吐52例,有高血压史者59例,有头部外伤史2例。神志清醒者17例,昏迷48例,其中深昏迷18例,中度昏迷21例,浅昏迷9例。61例偏瘫…     

Hippocampal NMDA receptor mRNA undergoes subunit specific changes during developmental lead exposure

The N-methyl- -aspartate (NMDA) receptor has shown to play an important role in the cognitive deficits associated with developmental lead (Pb) exposure. In this study, we examined the effects of low-level Pb exposure on NMDA receptor subunit gene expression in the developing rat brain. The pattern of NR1, NR2A, NR2B, and NR2C subunit mRNA in situ hybridization was consistent with previous studies. Brain levels of NR1 and NR2A mRNAs were lowest shortly after birth, increasing to reach peak levels by 14 or 21 days of age and subsequently decreasing at 28 days of age. NR2B mRNA levels were highest during early development and decreased as the animals aged. NR2C subunit mRNA was restricted to the cerebellum and a signal was not detectable until the second week of life. Lead exposure resulted in significant and opposite effects in NR1 and NR2A subunit mRNA expression with no changes in NR2B or NR2C subunit expression. The Pb-induced changes in NR1 and NR2A subunit mRNA were mainly present in the hippocampus. Hippocampal NR1 mRNA levels were significantly increased in the CA1 (15.3%) and CA4 (26.8%) pyramidal cells from 14-day-old Pb-exposed rats. At 21 days of age, only the NR1 mRNA at the CA4 subfield remained significantly elevated (10.3%). Lead exposure caused reductions of NR2A mRNA levels (11.9–19.3%) in the pyramidal and granule cell layers of the hippocampus at 14 and 21 days of age. NR1 mRNA levels were also significantly increased (14.0%) in the cerebellum of 28-day-old rats with no change in NR2A mRNA at any age. No significant changes in subunit mRNA levels were present in cortical or subcortical regions at any age. The Pb-induced changes in hippocampal NMDA receptor subunit mRNA expression measured in the present study may lead to modifications in receptor levels or subtypes and alter the development of defined neuronal connections which require NMDA receptor activation.     

Effects of lead on red blood cell membrane proteins

Summary The effects of lead on red blood cell (RBC) membrane proteins were studied in two groups of workers with different lead exposure levels: Group 1 (6 subjects employed in a battery plant) with a mean blood lead of 40.1 (SD = 3.7) g/100 ml; Group II(5 workers employed in different industries) with a mean blood lead of 60.6 (SD = 8.0) g/100 ml, compared with a control group with mean blood lead of 15.6 (SD = 9.3) g/100 ml. The analysis of RBC membrane polypeptides was carried out by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and by using a densitometer for percentage measurement of the bands corresponding to protein fractions. The results show a very significant decrease in Band 3 (anion channel) and 4.1 in more exposed workers (Group II) only. The effects of lead on RBC membrane proteins seem to be evident at blood-lead levels higher (> 50 g/100 ml) than those previously reported in literature. These results confirm the effects of lead on membrane proteins, even if the exact mechanism, particularly the influence of proteolysis and the meaning of the interference, still needs to be investigated thoroughly.     

The distribution of lead in human hemopoietic tissue and spongy bone after lead poisoning and Ca-EDTA chelation therapy

Two iliac crest needle biopsies were taken from a 43-year-old lead-poisoned woman during and after completion of a Ca-EDTA treatment. By atomic absorption spectroscopy the first and second biopsy were found to contain 56, respectively 41.6 g lead/g wet tissue. In both biopsies 36% of the lead was extractable in 0.1 N HCl. Electron microbeam X-ray analysis proved to have too low sensitivity for quantitation of the lead in these biopsies. Laser microbeam mass analysis (LAMMA), performed only on the second biopsy, revealed a high and fairly constant residual lead concentration in all bone marrow cell nuclei (approximately 55 g/g) and a low lead concentration in the cytoplasm of the same cells (4–12 (g/g). The extracellular bone matrix lead was greatly concentrated in the superficial 3–6 m osteoid zone of the bony trabeculae and totally absent from deeper parts of the mineralized matrix. The LAMMA results are in good agreement with those of subcellular fractionation experiments and atomic absorption spectroscopy, provided that the relative volume fraction of nucleus and cytoplasm is accounted for. The high residual osteoid lead after completed chelation therapy indicates that lead has a stronger affinity for the organic than the mineral components of bone matrix.