对讲机微波辐射对作业人员心脑功能影响的研究

目的探讨对讲机(TPR)微波辐射对人心脑功能的影响.方法随机选择145例男性使用TPR者(接触组)进行心电图(ECG)、脑血流图(REG)、血清心肌5酶谱测定和工作位置微波辐射测定.另选择60例不使用TPR和手机的男性健康者作为对照组.结果接触组ECG总异常率、窦性心动过缓和窦性心律不齐的检出率均显著高于对照组(P＜0.01或P＜0.05),高剂量组ECG总异常率较低剂量组增高(P＜0.01).接触组REG总异常率、转折波的检出率均显著高于对照组(P＜0.01或P＜0.05).高剂量组REG总异常率、转折波检出率均显著高于低剂量组(P＜0.01或P＜0.05).接触组肌酸激酶(CK)含量显著高于对照组(P＜0.05).结论长期接触TPR微波辐射可引致作业人员神经衰弱综合征,ECG的窦性心动过缓、窦性心律不齐和REG的转折波等改变,可能造成潜在健康危害,应注意做好防护工作.     

电子废弃物回收拆解业工人健康调查

目的 了解从事电子废弃物回收拆解业人群的健康状况,探讨电子废弃物对人体可能的危害.方法 选择汕头市贵屿镇5个从事电子废弃物回收拆解业的自然村作为调查点,对226名电子废弃物回收拆解业工人（拆解业组）及172名非电子废弃物回收拆解人员（对照组）进行健康调查.结果 拆解业组人员头痛头晕（47.7%）、皮疹瘙痒（15.0%）、恶心（11.1%）、失眠（9.7%）、记忆力下降（5.3%）、鼻塞（5.3%）、结膜充血（4.8%）等症状与体征的发生率高于对照组,且有工种差异.电路板回收处理组中,失眠发生率随工作年限的增长有上升的趋势（r=0.998）.结论 不科学的电子废弃物回收拆解方式对从业人员健康有一定影响.     

A simple method for preparing radioactive capsules in colon transit study

Colon transit study is currently performed by delivering technetium-99m or indium-111 labelled activated charcoal to the colon in a methacrylate-coated capsule (coated capsule). However, the coating procedure is complicated and methacrylate has not been approved by the Food and Drug Administration. Therefore, a simpler method is needed for the clinical routine use of colon transit study. In this study, we used a commercial empty enteric capsule and a coated capsule for the measurement of colon transit time. We compared the in vitro stability and in vivo scintigraphy of 99mTc-labelled activated charcoal in the coated capsule and the enteric capsule to evaluate the possibility of clinical usage of the enteric capsule for colon transit time study. Activated charcoal powder was mixed with 49mTc-diethylene triamine pentaacetic acid (DTPA) and vaporized to dryness. The dry 99mTc-DTPA activated charcoal was loaded into the coated capsule and the enteric capsule. In vitro stability study was performed by immersing these capsules in a colourless buffer of variable pH which mimicked the conditions in the stomach and the small bowel. Capsule disruption was determined. Colon transit scintigraphy with 99mTc-DTPA charcoal was performed in five normal volunteers using these two capsules. The in vitro stability of these two types of capsule was similar and the colon transit scintigraphy findings were almost identical. Most capsules dissolved in the ascending colon and very few in the terminal ileum. It is concluded that enteric capsule is a suitable alternative to coated capsule for measurement of colon transit.     

Evaluation of thrombolysis and angioplasty in a porcine iliac artery thrombosis model: application of endovascular stent-graft-induced thrombosis

PURPOSE: To develop a novel endovascular thrombosis model in the porcine iliac artery for the evaluation of thrombolysis and angioplasty. MATERIALS AND METHODS: A stent-inversion-graft (SIG) model combining either a 3-mm or 5-mm tapered expandable polytetrafluoroethylene (ePTFE) graft attached within a self-expandable, 10-mm nitinol stent was placed in the left common iliac artery via an ipsilateral common femoral artery approach in 24 pigs. When the iliac artery was thrombosed, urokinase (250,000 IU) plus heparin (1,000 units) were pulse sprayed via a contralateral femoral approach (n = 12). Saline pulse-spray was used as a control group (n = 12). Balloon angioplasty was performed to eliminate the stenotic tapered graft within the stent after successful thrombolysis. The efficacy of the thrombolysis was assessed with use of intravascular ultrasound (IVUS) and arteriogram. RESULTS: Both the 3-mm tapered and 5-mm tapered SIG models caused iliac artery occlusion in 22 +/- 5 and 41 +/- 9 minutes, respectively, after the deployment. Luminal patency was re-established successfully in all occluded arteries after urokinase infusion. Angioplasty was successful in eliminating the tapered stenosis and restoring the normal diameter in all iliac arteries treated with urokinase. Complete thrombolysis was achieved in both models treated with urokinase. CONCLUSION: This novel endovascular approach of inducing arterial thrombosis is simple to perform and reliably produces arterial thrombosis. The intraluminal stenosis is also amenable to angioplasty. This model is useful for the evaluation of antithrombotic treatment modality and adjunctive endovascular interventions.     

Induction of CYP1A in the beagle dog by an inhibitor of kinase insert domain-containing receptor: differential effects in vitro and in vivo on mRNA and functional activity.

Compound I [3-[5-(4-methanesulfonyl-piperazin-1-ylmethyl)-1H-indol-2-yl]-1H-quinolin-2-one] is a potent inhibitor of human kinase insert domain-containing receptor (KDR kinase), which is under investigation for the treatment of cancer. Bile duct-cannulated male beagle dogs were administered 6 mg/kg compound I q.d. for 14 days. There was an approximately 2.5-fold decrease in the mean plasma area under the curve of I on days 7 and 14 (approximately 11.3 microM . h), relative to day 1 (28.2 microM . h). In the dog, compound I was eliminated by metabolism, with a major pathway being aromatic hydroxylation and subsequent sulfation to form the metabolite M3. Metabolic profiling suggested that the pathway leading to the formation of the sulfated conjugate M3 was induced upon multiple dosing of I. Studies conducted in vitro suggested that CYP1A1/2 was responsible for the formation of the hydroxylated metabolite, which is sulfated to yield M3. Additional studies confirmed induction of CYP1A protein and activity in the livers of dogs treated with I. However, studies in a dog hepatocyte model of induction showed a surprising decrease both in CYP1A mRNA and enzymatic activity in the presence of I, emphasizing the need to consider the results from a variety of in vitro and in vivo studies in deriving an understanding of the metabolic fate of a drug candidate. It is concluded that the autoinduction observed after multiple treatments with compound I occurs since compound I is both an inducer and a substrate for dog CYP1A.     

咳喘平颗粒抗炎部分作用的实验研究

目的:观察咳喘平颗粒的抗炎作用.方法:(1)采用二甲苯致小鼠耳炎症的方法观察其抗炎作用.(2)采用醋酸致小鼠腹腔毛细血管通透性增加的方法观察其抗炎作用.(3)采用角叉菜胶致大鼠足肿胀的方法观察其抗炎作用.结论:咳喘平颗粒对二甲苯所致的小鼠耳肿胀有明显的抑制作用,对醋酸所致的小鼠腹腔毛细血管通透性增加有明显的抑制作用,并对角叉菜胶所致的大鼠足跖肿胀有明显的抑制作用.     

醒神胶囊对抗小鼠中枢及躯体疲劳的作用初探

目的:研究中药制剂醒神胶囊(茶叶、人参等)抗小鼠中枢及躯体疲劳的作用.方法:连续给药6d,分别观察第1、第6天小鼠的体重、自主活动、转棒耐力以及戊巴比妥钠对其的催眠效应.结果:醒神胶囊可以明显增加小鼠自主活动次数,延长小鼠转棒耐力时间,延长戊巴比妥钠催眠的潜伏时间、缩短其睡眠时间;其作用呈剂量依赖和时间依赖性.结论:醒神胶囊有良好的提神醒脑健体功效.     

Quantitative assessment of the normal cerebral microvasculature by endothelial barrier antigen (EBA) immunohistochemistry: application to focal cerebral ischemia

Cerebrovascular endothelium participates importantly in the pathophysiology of ischemic injury. Endothelial barrier antigen (EBA) is a protein located in the luminal plasma membrane of normal central and peripheral nervous-system endothelium. In this study, we assessed the sensitivity and specificity of EBA as a quantitative marker of normal endothelium and characterized alterations of EBA immunohistochemistry following focal cerebral ischemia. Anesesthetized, non-ischemic control rats (N=6) were studied. Other animals (N=5) received 90 min of middle cerebral artery occlusion (MCAo) followed by 3-day survival. Brains were prepared by perfusion-fixation and paraffin-embedding. For EBA immunohistochemistry, a monoclonal antibody (1:2000 dilution) was used. Adjacent sections were reacted for activated microglia by isolectin immunochemistry. Morphometric image-analysis was carried out in standardized microscopic fields. In control brains, pial and parenchymal blood vessels of all sizes were distinctly and selectively immunolabeled for EBA; background staining was absent. EBA-positive vascular profiles occupied 4.3+/-0.36% (mean+/-S.D.) of the microscopic field. The mean area of each identified profile was 51+/-13 micromter(2). The low coefficients of variation for both numbers of profiles (17%) and fractional areas (8%) denoted high inter-animal consistency. In brains with prior MCAo, numbers of EBA-immunoreactive vascular profiles in infarcted cortex and striatum were reduced by 39 and 46%, respectively, and their fractional areas were decreased by 63 and 76%, respectively, compared to contralateral hemisphere. Activated microglia were prominent in zones of frank infarction and in adjacent paramedian cortex; the latter region, however, showed normal-appearing EBA-immunostaining. EBA-immunohistochemistry provides a sensitive and specific index of normal cerebrovascular endothelial structures of all sizes. The technique lends itself well to quantitative morphometry and is applicable to perfusion-fixed paraffin-embedded material. EBA immunoreactivity declines in zones of ischemic infarction.     

Expression of immunoregulatory cytokines in neurons of the lateral hypothalamic area and amygdaloid nuclear complex of rats immunized against human IgG

Present results showed that interleukin-1 (IL-1), IL-6 and transforming growth factor-beta (TGF-beta) were constitutively expressed in the supraoptic and paraventricular nuclei of the rat hypothalamus. Immunoreactive cells were also detected, but to a lesser extent, in other parts of hypothalamus as well as in the cerebral cortex. In rats immunized with IgG, there was moderate increase in immunoreactivities of the cytokines. A notable feature, however, was the induction of the cytokine expression in the lateral hypothalamic area and the amygdaloid nuclear complex, suggesting that the neurons in these two areas are involved in possible immune regulation.     

Artery and vein separation using susceptibility-dependent phase in contrast-enhanced MRA

In magnetic resonance angiography, contrast agents are frequently used to help highlight arteries over background tissue. Unfortunately, enhancing veins hamper the visualization of arteries when data are collected over a long period of time after the arterial phase of the contrast agent. To overcome this problem, we have developed a novel imaging and postprocessing method that is capable of eliminating veins by utilizing the susceptibility difference between veins and surrounding tissue. This method was applied in the peripheral vasculature where the vessels are predominantly parallel to the main field and where the blood oxygen level-dependent effect is most pronounced. Results are presented for both long (15.8 msec) and short echo times (7.8 msec) and for sequential and centrally reordered acquisition schemes. The short echo scan approach appears to be the most promising, making it possible to obtain good suppression of the venous signal even when the timing is not perfect or when repeat scans are necessary.