Toxicokinetic of HEMA in guinea pigs

Objective. Unconverted 2-hydroxyethylmethacrylate (HEMA) can be released from dental resin materials and can enter the body in humans. In the present study the uptake, distribution and excretion of ¹⁴C-HEMA applied via different routes were examined in vivo in guinea pigs.

Methods. HEMA (0.02 mmol/kg bw labelled with a tracer dose ¹⁴C-HEMA 0.3 Bq/g bw) was administered by gastric tube or by subcutaneous injection. Urine, feces, and exhaled carbon dioxide were collected for 24 h after administration. Guinea pigs were killed 24 h after the beginning of the experiment and various organs removed and ¹⁴C radioactivity measured.

Results. Low fecal ¹⁴C levels (about 2% of the dose) and urinary levels of about 15% after 24 h were noted with either route of administration. Direct measurement of exhaled CO₂ showed that about 70% of the dose left the body via the lungs. Two pathways for the metabolism of ¹⁴C-HEMA can be described. It is likely that ¹⁴C-pyruvate is formed in vivo resulting in the formation of toxic ¹⁴C-HEMA intermediates. ¹⁴C-HEMA was taken up rapidly from the stomach and small intestine after gastric administration and was widely distributed in the body following administration by each of the routes.

Conclusions. Clearance from most tissues following gastric and intradermal administration was essentially complete within one day. The peak HEMA levels in all tissues examined after 24 h were at least onemillion-fold less than known toxic levels.     

Detection and determination of anabolic steroids in nutritional supplements

A method is described for the determination of anabolic steroids including testosterone, 19-nor-4-androstene-3,17-dione, 4-androstene-3,17-dione and nandrolone in food supplements. Initial clean-up is done by HPLC followed by determination with GC/MS. A ‘contaminated’ food supplement was analysed and appeared to contain 19-nor-4-androstene-3,17-dione and 4-androstene-3,17-dione. One capsule of this nutritional supplement was ingested by five male volunteers. Urine samples were collected and analysed by GC/MS and GC/MS-MS. Neither the ratio testosterone/epitestosterone, nor the ratio androstenedione/epitestosterone increased significantly. Concentrations above 2 ng/ml for norandrosterone, the major metabolite of nandrolone, were detected until 48–144 h after ingestion of the food supplement.     

乳果糖溶液通便功能人体试食试验研究

目的观察乳果糖溶液的通便功能。方法采用双盲法将127例受试者按其便秘症状随机分为试食组和对照组，试食样品组服用受试样品，对照组不进行任何处理。连续服用7d后，观察两组排便次数、排便状况和粪便性状的变化。结果对照组试食前后排便次数均为0.3次／d，排便状况积分均为1.7分／便次，粪便性状积分均为1.1分／便次，差别无统计学意义；试食样品组试食前后排便次数分别为0.3次／d和0.7次／d，排便状况积分分别为1．7和0.5分／便次，粪便性状积分分别为1．1和0.4分／便次，差别均有统计学意义（P〈0．01）；试食后试食样品组与对照组的排便次数、排便状况和粪便性状差别均有统计学意义（P〈0．01）。试验前后对照组和试食组均未见不良反应，各项安全性指标均未见异常。结论乳果糖溶液对人体具有明显通便功能，且对机体健康无不良影响。     

甲磺酸左氧氟沙星的药代动力学研究

用微生物法测定了ＭＳＡＬＶＬＸ在狗体内的药代动力学过程符合二室模型。４、８和１６ｍｇ／ｋｇ口服给药的Ｃｍａｘ分别为１．７３、２．８９和８．２８ｍｇ／Ｌ,ＡＵＣ值分别为１５．４３、３１．９５和７０．２ｍｇｈ／Ｌ,ＭＲＴ分别为６．９６、７．５８和６６２８ｈ。大鼠口服２０ｍｇ／ｋｇ的Ｃｍａｘ为２．８６ｍｇ／Ｌ,ｔ１／２β为２．２ｈ,ＡＵＣ为７．４ｍｇｈ／Ｌ,ＭＲＴ为３ｈ。大鼠口服后７２ｈ的尿中排泄率为４２％,而７２ｈ胆汁排泄率为３８．２％。     

The melamine excretion effect of the electrolyzed reduced water in melamine-fed mice

Our hypothesis is that the intake of functional water, electrolyzed reduced water (ERW) can excrete melamine in body was evoked by melamine-tainted feed (MTF). To address this issue, we investigated the effect of ERW in MTF-mice model by way of body weight gain, incidence of urinary crystals and bladder stone, biochemical and haematological examination, histopathologic finding of kidney and urinary bladder, and the evaluation of bladder stone.We found that the rate of body weight gain was significantly more increased in MTF + ERW group than MTF + PW group. Accordingly, the number of immunocytes such as leukocyte, neutrophil and monocyte as well as the mean weight of spleen was significantly increased in MTF + ERW group. The incidence of urinary crystals was significantly higher in MTF + ERW group, whereas the incidence of urinary bladder stones was lower in MTF + ERW group (52.4%) than in MTF + PW group (38.1%). Also, urinary crystals were more precipitated in MTF + ERW group than MTF + PW group, and urinary bladder stone consists of 100% melamine. Collectively, our data clearly show that ERW intake is helpful to excrete of melamine in MTF mice model and this is the first report on the melamine excretion and clinically implying the safer fluid remedy for melamine-intoxicated hosts.     

Pharmacokinetics,tissue distribution and excretion of porcine fibrinogen after intraperitoneal injection of a porcine-derived fibrin glue to rats

The aim of the present study was to characterize the preclinical pharmacokinetics, tissue distribution and excretion profiles of porcine fibrinogen in rats after intraperitoneal injection of a porcine-derived fibrin glue. A sensitive and rapid isotope-labeled assay method was developed and validated for quantitative analysis in biological analysis. Porcine fibrinogen, the major composition of the fibrin glue, was radioiodinated with Na¹²⁵I using the Iodo-Gen method. Following the purification and identification of ¹²⁵I-porcine fibrinogen, the fibrin glue containing ¹²⁵I-porcine fibrinogen was intraperitoneally administered to rats at three single dosages (100, 200, 400 mg/kg of porcine fibrinogen). The results showed that the ¹²⁵I-labeled assay method was suitable for the quantification of porcine fibrinogen in plasma samples, tissue samples and excreta samples with satisfactory linear (r² > 0.998), precision (<13%), accuracy (95.9–104.2%) and recovery (>85%). After three single administrations, plasma concentration profiles showed a slow absorption phase with the mean t_max of 1.83–5.67 h and a slow elimination proceeding with the terminal elimination half-life (T_1/2) of 84.5–96.3 h. Porcine fibrinogen was widely distributed to most of the tissues examined after a single intraperitoneal administration at 200 mg/kg to rats. The radioactive porcine fibrinogen showed substantial disposition in liver, kidneys, stomach and intestine. Approximately 79.3% and 17.2% of administered radioactivity were recovered in urine and feces within 528 h post-dosing, which indicated the major elimination route was urinary excretion.     

皂苷类成分吸收分布和代谢及排泄研究进展

皂苷是一类具有多种药理活性的重要天然产物,但由于其生物利用度普遍较低,体内的药效物质基础和作用机制研究尚不够深入,影响了该类成分的新药开发与应用。本文对近年来国内外关于皂苷类化合物体内外代谢等过程研究的文献进行综述,有利于深入探索该类成分的体内药效物质基础和作用机制,为新药研发提供一定的理论依据。     

Plasma pharmacokinetics,tissue distribution and excretion study of 6-gingerol in rat by liquid chromatography–electrospray ionization time-of-flight mass spectrometry

A rapid resolution liquid chromatography coupled with electrospray ionization (ESI) time-of-flight mass spectrometry method was developed and validated for quantitative analysis of 6-gingerol in plasma and various tissues. Liquid–liquid extraction was employed as sample preparation technique. Biological samples were separated on an Agilent Zorbax StableBond-C₁₈ column (4.6 mm × 50 mm, 1.8 μm) and detected by TOF/MS with electrospray ionization (ESI) interface in positive ion mode. Calibration curves (1/x² weighted) offered satisfactory linearity (r² > 0.995) within the test range. The lower limit of quantification in different matrices was in a range of 10–100 ng/mL. Inter- and intra-day precision were in the range of 0.91–11.90% and 0.75–10.23%, respectively. Recoveries in plasma, urine and tissues ranged from 72.5% to 90.4%. Glucuronide of 6-gingerol, the major metabolite of 6-gingerol, was further determined after β-glucuronidase hydrolyzation. This developed method was successfully applied to pharmacokinetics, tissue distribution and excretion studies of 6-gingerol after oral or intraperitoneal administration in rats.     

盐酸他可林在大鼠体内的分布和排泄

目的 研究盐酸他可林（ＴＨＡ）在大鼠体内的分布和排泄。方法 大鼠以剂量８ｍｇ／ｋｇ灌胃给予盐酸他可林后，在规定时间摘取各脏器，收集尿粪，提取后用高效液相法测定浓度，分别计算药物在各组织的分布和排泄。结果 ６９％的药物由尿排泄，２４％的药物由粪排泄。在尿粪中原形药ＴＨＡ仅占３．１％。而１－ＯＨ－ＴＨＡ和２－ＯＨ－ＴＨＡ分别为４２．０％放３５．５％，结论 盐酸他可林在大鼠体内的清除途径以羟代谢为主，药     

肾结核误诊分析

目的探讨肾结核误诊原因。方法回顾性分析26例延误诊断肾结核的临床资料。结果延误诊断的成因主要是由于症状不典型、忽视肾结核症状、混淆合并感染或其它泌尿系统疾病及缺乏系统检查有关。结论提高对肾结核特别是对症状不典型肾结核的认识,尿沉渣检查是诊断肾结核的有效方法,PPD试验、B超辅以排泄性尿路造影及CT检查可协助诊断。