Comparative study on the bioactivation mechanisms and cytotoxicity of Te-phenyl-L-tellurocysteine,Se-phenyl-L-selenocysteine,and S-phenyl-L-cysteine

Tellurium compounds are effective antioxidants and chemoprotectors, even more active than their selenium and sulfur analogues. In addition to these properties, some selenium compounds, such as selenocysteine Se-conjugates, possess significant chemopreventive and antitumor activities, and selenol metabolites are considered as active species. In the present study, we have synthesized Te-phenyl-L-tellurocysteine and evaluated its bioactivation and cytotoxicity. The activities of this compound were compared with those of the corresponding selenium and sulfur analogues. Te-Phenyl-L-tellurocysteine is bioactivated into its corresponding tellurol, as detected by GC-MS, by cysteine conjugate beta-lyase and amino acid oxidase, analogously to what has been shown previously for Se-phenyl-L-selenocysteine. The rate of beta-elimination may reflect the bond strength of the corresponding C-S, C-Se, and C-Te bond. Bioactivation of Te-phenyl-L-tellurocysteine and its selenium and sulfur analogues by oxidative enzymes was evaluated by measuring NADPH-dependent activation of hepatic mGST and inhibition of EROD. Te-Phenyl-L-tellurocysteine and Se-phenyl-L-selenocysteine displayed strong and time-dependent mGST activation, while S-phenyl-L-cysteine resulted in no significant activation. Te-Phenyl-L-tellurocysteine was also a strong inhibitor of EROD activity. In addition to EROD inhibition, Te-phenyl-L-tellurocysteine was the strongest inhibitor of several human cytochrome P450 isoenzymes followed by Se-phenyl-L-selenocysteine, while S-phenyl-L-cysteine was the weakest inhibitor. Interestingly, Te-phenyl-L-tellurocysteine selectively inhibited cytochrome P450 1A1 directly, which is, for example, responsible for the activation of several procarcinogens. Preliminary cytotoxicity studies with Te-phenyl-L-tellurocysteine in freshly isolated rat hepatocytes showed a time-dependent depletion of GSH and LDH leakage comparable with the relatively nontoxic drug paracetamol, while the selenium and sulfur analogues were nontoxic toward rat hepatocytes. In conclusion, because the chemopreventive and antitumor activities of selenium compounds are thought to be mediated via their selenol metabolites and tellurium compounds might be even more active than selenium compounds, tellurocysteine Te-conjugates might be an interesting novel class of prodrugs for the formation of biologically active tellurols.     

那屈肝素钙治疗不同发病时间的急性脑梗死

目的 :研究那屈肝素钙治疗不同发病时间脑梗死的疗效。方法 :5 0例发病 12h以内的脑梗死病人 ,随机分为治疗A组和对照A组各 2 5例 ;6 0例发病 12～ 4 8h ,随机分为治疗B组和对照B组各 30例。以上各组均予以丹参注射液 2 0mL +氯化钠注射液 2 5 0mL ,ivdrip ,qd。治疗组加用那屈肝素钙4 10 0IU ,sc ,q 12h。 4组疗程均 10d。治疗前、治疗后 1mo和 3mo测定病人神经功能缺损程度评分(NFDS)和日常生活活动能力评分 (ADL)。结果 :1mo和 3mo后 ,治疗A组和B组NFDS为 10± 4 ,5± 4和 13± 6 ,8± 3;与对照A组 (13± 5 ,10± 5 )和B组 (14± 7,12± 4 )比较 ,P <0 .0 5或P <0 .0 1。ADL评分和血液流变学指标各组均有改善 ,但以治疗A组尤为明显 ,P <0 .0 5或P <0 .0 1。结论 :那屈肝素钙能有效治疗急性脑梗死 ,早期应用效果更佳     

Impact of treatment of dyslipidemia on renal function,fat deposits and scarring in patients with persistent nephrotic syndrome

In this study 43 patients with idiopathic nephrotic syndrome were randomly distributed into 2 age- and sex-matched groups. The first group was given fluvastatin while the second was used as control. The cases in the 2 groups were evaluated clinically, biochemically (creatinine clearance, albumin, 24-hour proteinuria, and lipogram), neurologically, and histopathologically (examination of renal biopsies obtained basally and after 1 year of treatment with fluvastatin). In the fluvastatin-treated group but not in the control group, we observed a significant reduction in cholesterol, low-density lipoprotein, and triglyceride. Clinical and laboratory assessment showed satisfactory tolerance of the drug by the patients. Proteinuria, serum albumin and creatinine clearance values were significantly better in the statin-treated patients. There was no difference in glomerular sclerosis between the 2 groups while interstitial fibrosis and renal fat deposits were less in the statin-treated group. The reduction in renal fat deposits in the statin-treated group was highly significant, while that of interstitial fibrosis was not. We conclude that: (1) statin can be safely and effectively used in the treatment of dyslipidemia in patients with persistent idiopathic nephrotic syndrome; (2) control of dyslipidemia in nephrotic patients is associated with better control of proteinuria and creatinine clearance; (3) statin treatment may cause regression of renal fat deposits in patients with nephrotic syndrome, and (4) longer term studies are still required to study further possible beneficial effects on renal histology and disease progression.     

Retinal detachment due to macular hole: therapeutic problems

To compare the success rate and the visual improvement of different surgical techniques for treating 21 retinal detachments due to macular hole in highly myopic eyes. METHODS: Twelve patients were treated by gas tamponade alone, 5 patients underwent vitrectomy with gas tamponade, 4 patients underwent vitrectomy with epiretinal membrane pealing and gas or oil silicone tamponade. RESULTS: Fifty eight % of patients were successfully treated after gas tamponade alone, and 75% after vitrectomy, epiretinal membrane pealing and gas or silicone oil tamponade. After retreatment in 7 patients, the final reattachment rate was 80%. Visual acuity was inchanged in 12 cases, improved to 1/20-1/10 in 8 case and reached 3/10 in 1 case. CONCLUSION: A therapeutic scheme is suggested according to the type of retinal detachment, macular vitreoretinal traction and pigment epithelium and chorioretinal degeneration condition.     

Potomania associated with schizophrenia: a case report

The potomania or primary polydipsia is associated to schizophrenia in 20% of cases. Authors reports a case of a patient 27 old years, that suffering from hebephrenia who presented potomania. It was necessary to eliminate secondary polydipsia. The main complication resulting from potomania is water intoxication. Neurobiological or psychological hypothesis were suggested related to the etiopathogeny of this association. Some biological or comportemental therapy were effective in this context.     

"Double imaging" for the diagnostic work-up of alveolar soft part sarcoma with Tc-99m MIBI

The authors report a case of alveolar soft-part sarcoma with lung metastases demonstrated by "double imaging" with Tc-99m HDP and Tc-99m MIBI. The tumor originated in the soft tissue with direct invasion to the right scapula, which was hypoactive on bone scan and hyperactive on Tc-99m MIBI images. A focus of dense accumulation of Tc-99m MIBI in the lungs, suggesting metastasis was also demonstrated.     

Crescentic glomerulonephritis in Egypt: clinical and histopathological risk factors

We followed up 128 patients with crescentic glomerulonephritis (CGN), having sufficient clinical and histopathological data for a mean period of 34 +/- 28 months. There were 49 males and 79 females, mean age 22.7 +/- 14 years. We studied the effects of clinical, laboratory and histopathological parameters on kidney function and survival at the end point of the study. Multivariate analysis indicated that serum creatinine at presentation, nephrotic range proteinuria during the follow-up period, percentage of glomeruli with crescents, percentage of fibrous crescents and absence of cellular infiltration were significant risk factors affecting kidney function at the end of the study. The only risk factor significantly correlated with mortality was serum creatinine at last follow-up.     

Theory and Applications of Biotelemetry

In this study, biotelemetry and its evolution is explained in detail. Bioelectric and physiological variables could be measured by biotelemetry systems. The development of a biotelemetry system and its principal operation are presented. The components of a biotelemetry system are explained. Biomedical data has been telemetered through every medium between two sites by using a variety of modulated energy forms. Designing of the link between transmitter and receiver is described. Important factors in designing a backpack or implanted telemeter are explained. The main features of implanted biotelemetry units are determined. Single-channel and multichannel biotelemetry systems are defined. The types of telemetry, and a comparison thereof, are given. The power sources of biotelemetry systems and features of different power sources are explained. A survey of biotelemetry applications on humans and animals is presented and advantages of using biotelemetry systems are determined.     

叶托马尾藻中的生物活性甾体成分

目的 研究褐藻叶托马尾藻的活性成分。方法 采用稻瘟霉模型生物活性追踪方法，应用多种色谱手段和光普分析方法分离和鉴定化合物。结果 鉴定了7个甾体类化合物，分别为岩藻甾醇（Ⅰ）,24－乙基－4，24（28）－胆甾二烯－3－酮（Ⅱ），24－乙基－4，24（28）－胆甾二烯－3，6－二酮（Ⅲ），马尾藻甾醇（Ⅳ），24R，28R－和24S，28S－环氧－24－乙基胆甾醇（Ⅴ），胆甾醇－24－酮（Ⅵ）和豆甾醇（－3－O－葡萄糖苷（Ⅶ）。结论 Ⅱ－Ⅶ为首次从该海藻中分离得到，Ⅰ和Ⅲ－Ⅵ具有诱导稻瘟霉菌比来形活性。