1,25-Dihydroxyvitamin D3 enhances degranulation of mast cells

Copper sulfate is one of the most widely used algicides for the control of phytoplankton in lakes, reservoirs, and ponds. It is also used for aquatic weed control. To study the toxic effects of copper on carp (Cyprinus carpio L.), toxicity tests were carried out. Fish recovery in copper-free water was followed. After a 14-day period of exposure to five concentrations of copper sulfate (0.25-4.0 mg/L CuSO4, values ranging from approximately 5 to 70% of the 96-h LC-50) and a recovery period of the same duration, activities of the functional enzymes alkaline phosphatase (AP), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) in the blood serum and gills were determined. Because the gills are the known target organ for copper, changes in gill structure were investigated as well. In all exposure groups for all the enzymes studied, an increase in activity was noted after 14 days. The increase in AP activity was the most pronounced in both gills and serum of carp exposed to the highest concentration tested (4 mg/L). After a "recovery" period, compared with the end of treatment, a decrease in enzyme activities was recorded, indicating eventual recovery from the Cu-induced stress (the only exception being the ALT activity in gills in the highest CuSO4 concentration). The results of biochemical analysis were confirmed by histopathology. Lesions such as epithelial hyperplasia, curling of secondary lamellae, and changes in chloride cells were observed on the gills, and their severity increased with increased toxicant concentration. Most of the changes were reversible, as exhibited by gill histopathology after the recovery period.     

Effect of lead on hepatic delta-aminolaevulinic acid synthetase activity in the rat: a model for drug sensitivity in intermittent acute porphyria

The hereditary hepatic porphyrias are disorders of porphyrin and haem synthesis characterized by a marked idiosyncrasy towards a variety of lipid soluble drugs. Most of these agents are inducers of the haemoprotein cytochrome P450, the terminal oxidase in drug metabolism. The primary genetic defect in intermittent acute porphyria is a partial deficiency of uroporphyrinogen I synthetase, which may result in a secondary derepression of delta-aminoaevulinic acid synthetase, the rate-limiting enzyme in the haem pathway. Analogous defects at more distant sites may explain the other hereditary hepatic porphyrias. As drug sensitivity may be related to the defect in haem synthesis, we investigated the effects of experimental partial blocks in haem synthesis produced by lead in rats. Drug effects on delta-aminolaevulinic acid synthetase, cytochrome P450, And drug metabolism were studied. Our findings indicate: a) While partial impairment of haem biosynthesis has only minor effects on delta-aminolaevulinic acid synthetase activity, it greatly enhances the sensitivity of delta-aminolaevulinic acid synthetase to induction by drugs and steroids, which when given alone, have little or no inducing effect on the enzyme. b) The experimental partial block in haem synthesis delays and impairs drug-mediated induction cytochrome P450 and drug metabolism in vitro. The findings may explain why a large number of structurally unrelated compounds with little effect on normal liver can precipitate "aucte porphyria".     

Belief in supernatural causes of mental illness among Malay patients: impact on treatment

The authors focused their attention on residual changes in patients with glomerulonephritis who have a zero or only "physiological" proteinuria (under 0.15 g/24 hours), normal or slightly elevated s-creatinine and who do not suffer from hypertension. In these patients microalbuminuria in urine per 24 hours was assessed. Patients with albuminuria under 20 micrograms/min were included in the group with normal albuminuria (13 patients) and patients with albuminuria of more than 20 micrograms/min in the microalbuminuric group (11 patients). The two groups did not differ significantly as to age, sex, duration of the disease, maximum levels of proteinuria and s-creatinine values at the onset of the disease. S-creatinine and blood pressure values at the time of investigation were also comparable. The groups differed, however, significantly as to the period of "absolute" remission which the authors defined as the period during which proteinuria did not exceed the "physiological" limit. This period was in the normoalbuminuric group significantly longer--on average 5.1 years--while in the microalbuminuric group it was 2.1 years (difference at the 1% level of significance).     

Overview of enzymes of drug metabolism

Most pharmacologically active molecules are lipophilic and remain un-ionized or only partially ionized at physiological pH. Biotransformation means that a lipid-soluble xenobiotic or endobiotic compound is enzymatically transformed into polar, water-soluble, and excretable metabolites. The major organ for drug biotransformation is the liver. The metabolic products often are less active than the parent drug or inactive. However, some biotransformation products (metabolites) may have enhanced activity or toxic effects. Thus biotransformation may include both "detoxication" and "toxication" processes. One of the major enzyme systems that determines the organism's capability of dealing with drugs and chemicals is represented by the cytochrome P450 monooxygenases. Studies in the last 15 years have provided evidence that cytochrome P450 occurs in many different forms or "isozymes" which differ in spectral, chemical, and immunological properties and have different substrate affinities. These isozymes also differ in their regulation and tissue distribution. Recombinant DNA studies indicate that between 40 and 60 structural genes code for different cytochrome P450 isozymes in a single organism. Other enzyme systems include dehydrogenases, oxidases, esterases, reductases, and a number of conjugating enzyme systems including glucuronosyltransferases, sulfotransferases, glutathione S-transferases, etc. Environmental and genetic factors cause interindividual and intraindividual differences in drug metabolism and may alter the balance between toxification and detoxification reactions. Genetic polymorphisms lead to subpopulations of patients with decreased, absent, or even increased activities of certain reactions (e.g., CYP2D6, CYP2C19, N-acetyltransferase polymorphism). Environmental factors such as other drugs, steroids, dietary factors, alcohol, and cigarette smoke can induce or inhibit drug-metabolizing enzymes and cause intraindividual variation.     

基于图像处理的三维测量方法

三维测量通过对景物立体信息的获取可以精确地描述景物的几何形状，基于图像的三维测量是计算机立体视觉中的一项关键技术。本文介绍了利用图像进行三维测量的方法，分析了各种方法的基本原理，并说明了它们各自的特点。     

一种新颖的光纤光栅位移传感的研究

本文提出了一种新颖有效的光纤光栅位移传感方法 ,将光纤布喇格光栅在梯度应变作用下产生的啁啾效应用于传感测量 ,理论上分析了传感的原理 ,实验上得到了线性度很高的响应 .研究表明 ,本传感系统结构简单 ,操作方便 ,线性好 (0 .9992 )     

渐进性球囊扩张联合胆道持续引流治疗胆肠吻合术后吻合口良性狭窄

【摘要】 目的 评价渐进性球囊扩张联合胆道持续引流治疗胆肠吻合术后吻合口良性狭窄的安全性和可行性。方法 回顾性分析2008年1月至2014年3月收治的49例胆肠吻合术后吻合口良性狭窄患者临床及影像学资料。所有患者术前均行彩色超声、MR和/或增强CT及内镜下或DSA下吻合口活检病理证实为吻合口良性狭窄,其中23例患者采用经皮肝穿渐进性球囊（初始直径8 mm;第2个月直径10 mm;第3个月直径12 mm）扩张联合引流管持续引流（6个月）方式治疗（研究组）;26例患者采用单次经皮肝穿球囊（直径6或8 mm球囊）扩张联合引流管置入（6个月）治疗（对照组）。比较两组患者术后临床症状缓解情况,术后并发症的发生率以及吻合口通畅时间。结果 所有患者手术操作均顺利完成,未见手术相关并发症,如胆道出血,穿孔等发生。术后1周两组患者的血清胆红素下降明显,组间比较未见明显差异（P<0.05）。3个月时两组患者吻合口通畅率未见明显差异,但在6、12和24个月时研究组的吻合口通畅率显著高于对照组（P<0.05）。研究组中,3例患者分别于11.2、14.3和17.6个月出现复发黄疸,MRI及增强CT证实吻合口狭窄复发,给予再次的球囊扩张和引流管置入治疗。对照组16例患者在球囊扩张术后3.1至17.1个月再次出现黄疸,其中1例患者死于播散性血管内凝血,余15例患者给予再次的球囊扩张和引流管置入治疗。结论 渐进性球囊扩张联合胆道持续引流是治疗胆肠吻合术后吻合口良性狭窄的安全、有效的微创手术。

     

Detecting undetected HIV-1 variants in African children using degenerate polymerase chain reaction and sequence analyses

CONTEXT: Scientific journals issue press releases to disseminate scientific news about articles they publish. OBJECTIVE: To assess whether press releases about journal articles were associated with publication of subsequent newspaper stories. DESIGN: Retrospective content analysis of newspaper stories, journal press releases, and journal tables of contents. From December 1, 1996, to February 28, 1997, press releases and tables of contents were collected from BMJ, Nature, Science, and The Lancet, along with newspaper stories on scientific research published in The New York Times (United States), Le Figaro and Le Monde (France), El País and La Vanguardia (Spain), La Repubblica (Italy), and the International Herald Tribune. MAIN OUTCOME MEASUREMENTS: Number of newspaper stories that contained reference to articles appearing in the 4 scientific journals, number of newspaper stories that referred to journal articles described in press releases, and the order in which journal articles were mentioned in press releases. RESULTS: Of the 1060 newspaper stories analyzed, 142 referred to journal articles; of these, 119 (84%) referred to articles mentioned in press releases and 23 (16%) referred to journal articles not mentioned in press releases (comparison of proportions, P=.03). Articles described first or second were referenced in more newspapers than articles described later in the press release (P=.01 by chi2 analysis). CONCLUSIONS: Journal articles described in press releases, in particular those described first or second in the press release, are associated with the subsequent publication of newspaper stories on the same topic.