Excretion of 1,2,4-benzenetriol in the urine of workers exposed to benzene

Urine samples were collected from 152 workers (64 men, 88 women) who had been exposed to benzene, 53 workers (men only) exposed to a mixture of benzene and toluene, and 213 non-exposed controls (113 men, 100 women). The samples were analysed for 1,2,4-benzentriol (a minor metabolite of benzene) by high performance liquid chromatography. The time weighted average solvent exposure of each worker was monitored by diffusive sampling technique. The urinary concentration of 1,2,4-benzentriol related linearly to the intensity of exposure to benzene both in men and women among workers exposed to benzene, and was suppressed by toluene co-exposure among male workers exposed to a mixture of benzene and toluene. A cross sectional balance study in men at the end of the shift of a workday showed that only 0.47% of benzene absorbed will be excreted into urine as 1,2,4-benzenetriol, in close agreement with previous results in rabbits fed benzene. The concentration of 1,2,4-benzenetriol in urine was more closely related to the concentration of quinol than that of catechol. The fact that phenol and quinol, but not catechol, are precursors of 1,2,4-benzentriol in urine was further confirmed by the intraperitoneal injection of the three phenolic compounds to rats followed by urine analysis for 1,2,4-benzenetriol.     

国产脑复康对家兔颅内压影响的研究

应用侧脑室插管方法,观察静脉注射脑复康对正常和已经增高的家兔颅内压的影响。实验结果提示,脑复康有降低家兔颅内压的作用,并且对硝酸甘油引起的颅内压升高有明显的防治作用。     

视网膜缺血对兔视神经纤维损害的定量研究

目的：定量研究视网膜缺血对视神经的损害。方法：通过计算机图像分析定量测算视神经纤维数量；通过前房灌注平衡液，造成超高眼压，形成兔视网膜完全缺血模型，观察视神经纤维数量的变化。结果：正常兔眼平均视神经轴突数为１０９６０８±１４５６１（ｎ＝２２）；视网膜缺血眼视神经纤维数量明显减少（Ｐ〈０．００１）。结论：急性高眼压造成的视网膜缺血可使视神经节细胞及轴突的数量明显减少，应用计算机图像分析可定量检测这种     

超液化碘油混合抗癌药物栓塞治疗中晚期肝癌

本文报告超液化碘油混合抗癌药物经皮肝动脉栓塞治疗51例中晚期肝癌。术后50例临床病情改善,治疗2次后肿瘤显著缩小(>50%)16例,中度缩小(20～50%)21例,轻度缩小(<20%)7例;5例为弥漫型难以判定肿块大小,另2例未复查。所有肿瘤缩小的病例均可见肿瘤血管减少。治疗后3个月、6个月、9个月和1年以上生存率分别为100%、82.4%、59.8%和23.5%,其中生存期大于9个月者均为团块型或多结节型。     

壬苯醇醚避孕药膜的临床研究

894对健康、已育的育龄夫妇,随机分两组:447对使用壬苯醇醚方型膜,447对使用帽型膜,经两年连续观察。按生命表统计法处理数据。总使用妇女月,方型组9601,帽型组9382,随访率100%。累计停用率、妊娠率和续用率,方型组分别为16.8%、15.3%和83.2%,帽型组为18.4%、15.6%和81.6%,两组无显著差异(p>0.05)。临床和实验室资料表明壬苯醇醚药膜是安全、有效、简便、易于推广的避孕药具之一。     

Contributions of ion conductances to the onset responses of octopus cells in the ventral cochlear nucleus: simulation results

The onset response pattern displayed by octopus cells has been attributed to intrinsic membrane properties, low membrane impedance, and/or synaptic inputs. Although the importance of a low membrane impedance generally is acknowledged as an essential component, views differ on the role that ion channels play in producing the onset response. In this study, we use a computer model to investigate the contributions of ion channels to the responses of octopus cells. Simulations using current ramps indicate that, during the "ramp-up" stage, the membrane depolarizes, activating a low-threshold K(+) channel, K(LT), which increases membrane conductance and dynamically increases the current required to evoke an action potential. As a result, the model is sensitive to the rate that membrane potential changes when initiating an action potential. Results obtained when experimentally recorded spike trains of auditory-nerve fibers served as model inputs (simulating acoustic stimulation) demonstrate that a model with K(LT) conductance as the dominant conductance produces realistic onset response patterns. Systematically replacing the K(LT) conductance by a h-type conductance (which corresponds to a hyperpolarization-activated inward rectifier current, I(h)) or by a leakage conductance reduces the model's sensitivity to rate of change in membrane potential, and the model's response to "acoustic stimulation" becomes more chopper-like. Increasing the h-type conductance while maintaining a large K(LT) conductance causes an increase in threshold to both current steps and acoustic stimulation but does not significantly affect the model's sensitivity to rate of change in membrane potential and the onset response pattern under acoustic stimulation. These findings support the idea that K(LT), which is activated during depolarization, is the primary membrane conductance determining the response properties of octopus cells, and its dynamic role cannot be provided by a static membrane conductance. On the other hand, I(h), which is activated during hyperpolarization, does not play a large role in the basic onset response pattern but may regulate response threshold through its contribution to the membrane conductance.     

拟除虫菊酯浸泡大网孔门窗帘毒杀侵入实验小屋蚊虫的研究

本研究采用牛房实验小屋，加装不透光百叶窗和透光门廊，从而全面观察药帘对侵入实验小屋蚊虫毒杀情况，包括蚊虫入屋前接触药帘时和屋内蚊虫外逸出屋外后的死亡情况。结果表明，澳氰菊酯、二氯苯醚菊酯毒效强和持效长，浸泡门窗帘后６个月１８次试验，对侵入屋内蚊虫毒杀，平均死亡率分别为８９．４％和９０．６％。两药对入屋内蚊虫的吸血率均没有明显减少，可能与诱饵动物的吸引力有关。二氯苯醚菊酯有明显驱避作用，其减少蚊虫入屋率，按蚊为７０．６％，库蚊为７５．２％均没有明显减少，阿蚊却没有效应。     

Evaluation of endothelial cell migration with a novel in vitro assay system

In this study we introduce a novel in vitro 'oil-drop' assay system for the measurement of endothelial cell (EC) migration, based on the original concept of the Teflon fence assay (Pratt et al., 1984; Am. J. Pathol. 117: 349–354). An aliquot of 15–20,000 human umbilical vein EC (HUVEC) is pipetted through a layer of mineral oil. The cells readily attach, spread and migrate on the surface of a matrix-coated tissue culture dish as a confluent circular monolayer. Migration is measured as the net increase in the total area covered at 24 hours. We have used this system to quantify EC migration on matrices composed of a mixture of type I collagen and either von Willebrand factor (vWF) or fibronectin (FN) in the presence or absence of tumor necrosis factor (TNF). Plating efficiency on both vWF/collagen and FN/collagen, measured by counting cells after attachment and spreading, is about 80%. With this method, migration on vWF/collagen was about 6.4 mm² and 5.3 mm² for TNF-treated and untreated HUVEC, respectively. HUVEC migration on FN/collagen was slightly greater – 6.4 mm² and 6.5 mm² with and without TNF treatment, respectively. During the 24 hour time period, HUVEC numbers increased 30–40% on vWF/collagen, and 60–80% on FN/collagen, with increased proliferation observed with TNF- treatment. EC proliferation could be completely inhibited by 2 mM hydroxyurea. This assay system has proven useful in our studies to quantify cell migration and proliferation.