Dietary selenium's protective effects against methylmercury toxicity

Dietary selenium (Se) status is inversely related to vulnerability to methylmercury (MeHg) toxicity. Mercury exposures that are uniformly neurotoxic and lethal among animals fed low dietary Se are far less serious among those with normal Se intakes and are without observable consequences in those fed Se-enriched diets. Although these effects have been known since 1967, they have only lately become well understood. Recent studies have shown that Se-enriched diets not only prevent MeHg toxicity, but can also rapidly reverse some of its most severe symptoms. It is now understood that MeHg is a highly specific, irreversible inhibitor of Se-dependent enzymes (selenoenzymes). Selenoenzymes are required to prevent and reverse oxidative damage throughout the body, particularly in the brain and neuroendocrine tissues. Inhibition of selenoenzyme activities in these vulnerable tissues appears to be the proximal cause of the pathological effects known to accompany MeHg toxicity. Because Hg's binding affinities for Se are up to a million times higher than for sulfur, its second-best binding partner, MeHg inexorably sequesters Se, directly impairing selenoenzyme activities and their synthesis. This may explain why studies of maternal populations exposed to foods that contain Hg in molar excess of Se, such as shark or pilot whale meats, have found adverse child outcomes, but studies of populations exposed to MeHg by eating Se-rich ocean fish observe improved child IQs instead of harm. However, since the Se contents of freshwater fish are dependent on local soil Se status, fish with high MeHg from regions with poor Se availability may be cause for concern. Further studies of these relationships are needed to assist regulatory agencies in protecting and improving child health.     

肿瘤光动力学疗法的并发症及其防治

本文重点综述肿瘤光动力学疗法可能发生的并发症及其防治措施，如光敏药物过敏、皮肤光毒性反应、渗出、毛细血管渗漏综合征、空腔形器官穿孔、瘢痕狭窄、感染、出血和其他并发症。     

大肠癌临床分期相关蛋白的蛋白质组学研究

目的：筛选与大肠癌临床分期相关的蛋白，为大肠癌分子分期和预后预测提供依据。方法：将不同临床分期大肠癌组织蛋白进行二维凝胶电泳，选择部分差异表达蛋白进行MALDI-TOF质谱分析和生物信息学分析以鉴定差异表达蛋白;免疫组织化学方法验证筛选结果。结果： 建立了不同临床分期大肠癌组织的二维凝胶电泳图谱，其中Ⅰ，Ⅱ，Ⅲ，Ⅳ大肠癌组织平均蛋白质点数分别为970±41,980±32,1010±43,1240±34;以Ⅰ期大肠癌为参照，Ⅱ期大肠癌差异表达蛋白有52.00±12，Ⅲ期大肠癌差异表达蛋白42.00±11，Ⅳ期大肠癌差异表达蛋白72.00±15，通过进行质谱分析和生物信息学查询，鉴定30个显著差异表达的蛋白点，其中Ⅱ，Ⅲ，Ⅳ均上调的有3种蛋白：AnnexinⅡ,AnnexinⅣ,热休克蛋白27(HSP27)。而仅在Ⅳ期中上调蛋白有1种蛋白,即肝脂肪酸结合蛋白（LFABP)。AnnexinⅡ和肝型脂肪酸结合蛋白表达的免疫组化检测结果与蛋白质筛选结果基本一致。结论：不同临床分期的大肠癌中存在着差异表达蛋白，这些蛋白可能作为大肠癌分子分期和预后的标志物。     

小儿感染性腹泻病原与肿瘤坏死因子水平的关系

肿瘤坏死因子是非常重要的炎症介质。本文为观察小儿感染性腹泻时ＴＮＦ水平与病原的关系。对１９９５年６月￣１９９６年８月收治的４６例细菌感染性腹泻，３５例病毒感染性腹泻患儿进行检测，于入院第一天测定ＴＮＦ水平记录当天的最高体温及腹泻次数，同时进行粪便病原学检查，结果表明在两组具有可比性的情况下，细菌性腹泻组较病毒性腹泻组的ＴＮＦ水平显著增高。     

Effect of dietary selenium and vitamin E on the biomechanical properties of rabbit bones

Summary It is generally agreed that combined deficiency of selenium and vitamin E leads to several abnormalities including Kashin-Beck disease which is an endemic and chronic degenerative osteoarthrosis. The abnormalities can be reversed by the administration of various forms of selenium and vitamin E.The present study was designed to investigate the effects of dietary selenium and vitamin E on bone tissue and on the biomechanical properties of bone. Young rabbits of both sexes were fed with either a selenium- and vitamin E-adequate diet (control group), or a selenium- and vitamin E-deficient diet or a selenium-excess diet. The selenium-deficient diet resulted in a significant decrease in plasma selenium level and the selenium-excess diet resulted in a significant increase in the plasma selenium level with respect to the corresponding control values (p<0.05). The diets did not affect the blood cell counts considerably but erythrocyte glutathione peroxidase activity increased (decreased) relatively when the plasma selenium level increased (decreased) (p<0.05). The light microscopic investigations of the bone tissues of the two experimental groups indicate that the findings of the present work are compatible with osteomalacia. The biomechanical properties of the bones from the three groups were determined experimentally with bending tests. Both the Se-and vitamin E-deficient diet and the Se-excess diet decreased the biomechanical strength of the bones significantly while the bones belonging to the control group always had the largest modulus of elasticity (p<0.05).     

Selected monoclonal antibodies can increase the accuracy of cytodiagnosis of neoplastic effusions of cryptic origin expanded in a short term culture.

The use of a selected panel of monoclonal antibodies (MoAb) to tumor associated antigens (TAA) in immunocytochemical (IIC) tests has been shown, in a preliminary study, to be a powerful diagnostic tool for the identification of the primary solid tumor causing metastatic effusion. Despite this improvement in a minority of neoplastic fluids a number of different causes may still determine false negative (FN) immunocytochemical diagnoses. The aim of the present study was to confirm the diagnostic accuracy of this panel of MoAb. This was done by analyzing in IIC tests a larger number of effusions and by evaluating whether the expansion in short term culture of those fluids with an uncertain malignant morphology could provide an adequate cellular substrate for immunocytodiagnosis. The analysis of 314 effusions confirmed the results of the pilot study and demonstrated that the combination of short term culture and immunocytochemical assays can further increase the sensitivity of this novel diagnostic procedure from 84.3% to 95.3%.     

Perioperative tumor localization for laparoscopic colorectal surgery

Background: Because of the inability to palpate colonic tumors during laparoscopy, their location must be precisely identified before resection is undertaken. Method: A retrospective study was performed of 58 patients in order to be able to describe our methods of tumor localization for laparoscopic colorectal operations and to review their effectiveness. Results: In all patients, the entire colon was examined preoperatively by colonoscopy. In one patient, preoperative colonoscopic localization was inaccurate. In 31 patients, tumors were easily detectable at surgery. In five patients with the tumor in the right colon, even though the lesion was not detectable at surgery, right colectomy was performed without marking because preoperative colonoscopy reliably identified the lesion adjacent to the ileocecal valve. Twenty-two patients required some type of procedure to localize the tumor. The procedures and their problems were as follows: preoperative tattoo (five)—tattoo not visualized (one); intraoperative colonoscopy alone (six), combined with intraoperative tattoo (four) or clip (three)—poor operative exposure due to bowel distension (nine), hard to see the clip (three), dislodged clip (two), inadequate resection margin (one); intraoperative proctoscopy alone (two), combined with laparoscopic stitch (two)—no problems. In no patient was tumor present at a resection line and in no patient was the wrong segment resected. Conclusions: Reliable preoperative identification of the tumor adjacent to the ileocecal valve can permit right colectomy without marking. Lesions in the upper rectum can be approached via intraoperative proctoscopy ± suture placement. If the surgeon anticipates intraoperative localization may be difficult, lesions other than rectal or cecal ones should probably be marked by preoperative tattooing. Further studies regarding the technique of tattooing are warranted. Received: 18 July 1996/Accepted: 10 March 1997     

Quality of life research in patients with rectal cancer: traditional approaches versus a problem-solving oriented perspective

The present paper critically appraises two recent overviews of the literature on rectal cancer and quality of life (QL). These reviews focus on the Anglo-American literature, largely neglect research from other countries, and provide little stimulus regarding future research directions. As an alternative perspective we propose the concept of problem-solving oriented QL research. The major theme is that the QL concept must be integrated into the clinical arena. To begin with, QL researchers must make themselves understandable. We outline several ways in which this can be achieved: (a) placing QL in a broader concept together with outcomes that are more familiar to clinicians; (b) depicting individual patients in the form of QL profiles; (c) clarifying the psychosocial/clinical correlates of particular QL scores of interest; and (d) conducting studies with a definitive practical goal in mind and integrating practitioners and patients into the study group. We illustrate the feasibility of such a research program by performance data from our Marburg-Biedenkopf field trial. Pursuing an ambitious research strategy that integrates experimental and applied research, the QL movement will have the chance to show that it is not merely l'art pour l'art, but indeed is beneficial to society. Received: 28 September 1998 / Accepted: 14 October 1998     

Cerebrospinal fluid-filtration reduces TNF alpha in bacterial meningitis-CSF

A 37 year old male was admitted with the diagnosis of bacterial meningitis. Pneumococci were seen in the Gram stain of the cerebrospinal fluid. The clinical condition did not suggest severely raised intracranial pressure, there were no localizing signs and symptoms. CSF was turpid, with 20.100/3/mm³, mainly polymorphonuclear cells. Tumor necrosis factor alpha in CSp was greatly increased with 813 pg/ml. Parallel to the application of intravenous Penicillin G a CSF filtration was carried out. Within 214 h 225 ml CSF were filtrated through a Pall-filter, using a bidirectional pump. Cell count dropped to 720/3 cells/mm³, TNF-alpha to 39 pg/ml. The clinical course was uneventful, on day 12 the patient could be discharged without sequelae. CSF filtration may be a highly effective method to reduce from the CSF pathogenetically important cytokines, such as TNF-alpha, being responsible for intrathecal/meningeal inflammatory processes and triggered by cell-wall components of bacteria, e.g. pneumococci.     

血清肿瘤标志物联合检测在肺癌诊断中的应用

目的：探讨血清19片段角蛋白((2YFRA21-1)、神经元特异性烯醇化酶(NSE)、癌胚抗原((CEA)、β2微球蛋白(β2-MG)联合检测提高肺癌的阳性率，为临床提供早期诊断、治疗的依据。方法：采用电化学发光和免疫比浊法检测155例肺癌、72例肺良性疾病和50例正常人血清CYFRA21-1、NSE、CEA和β2-MG的水平。结果：肺癌4项标志物联合检测阳性率明显高于肺良性疾病组和健康人正常对照组，其中CYFRA21-1阳性率以鳞癌最高(77．7％)，与其它型肺癌存在显著差异。NSE阳性率以小细胞性肺癌最高(78．4％)，与其它型肺癌存在显著差异。结论：CYFRA21-1、NSE、CEA、β2-MG是诊断肺癌有价值的肿瘤标志物组合，有助于提高肺癌诊断的阳性率、特异性和准确性。