麻痹性贝类毒素在大鼠体内的分布与累积

目的检测低剂量摄入麻痹性贝类毒素(PSP)后,多种毒素在大鼠内脏器官中的分布和累积情况,为进一步完善贝类水产品中麻痹性贝毒的安全标准提供依据。方法按美国公职分析化学家协会(AOAC)推荐的麻痹性贝毒小鼠测定法从自然毒化的海湾扇贝和华贵栉孔扇贝中提取PSP粗毒素,分别给大鼠灌胃51.2,25.6和10.2小鼠单位.kg-1,每天1次,连续28d。同时设溶剂(未毒化贝组织的盐酸提取液)对照组和空白对照组。停毒后的d1,d3和d14心脏取血,处死大鼠,收集肝、肾、脾和脑等组织,采用高效液相色谱法检测各组织中PSP的种类和含量。结果在所检测的4个内脏组织中,3个剂量的肝和肾脏组织中均检测出PSP,并且在停毒d14时仍有毒素存留,在脑和脾脏组织未检测出PSP。肝和肾组织中累积的PSP种类不同,所检测的各类PSP中,膝沟藻毒素4最易在大鼠肝和肾脏中累积。结论低剂量经口染毒的PSP可分布于大鼠的肝和肾脏,且在肝和肾脏中累积。     

监护仪常见故障及排除方法

随着科学技术的不断发展，各种无创性监护仪广泛应用于临床，其具有操作简单、无创性等优点。我科新进一台北京产ＫＭＩ－１０００型多参数监护仪，在临床应用中由于缺乏经验和相关知识，出现了一些故障，在此总结一些经验以供参考。１　临床资料 ２０００－０４－２００１－１０监护病人１０９例，男６０例，女４９例，其中高血压脑出血４８例，脑干损伤５例，蛛网膜下腔出血２２例，脑肿瘤２１例，重型颅脑损伤合并脑疝１３例。监护时间最短２ｈ，最长１１３ｈ，平均２６ｈ。２ 常见故障 ①心电图干扰或消失。多因电极片与皮肤接触不良（…     

库尔特JT-IR型全血细胞分析仪常见故障及排除方法

我院于1997年购买Coulter公司JT-IR型全血细胞分析仪,是Coulter公司T系列中的产品,是具有测定18项参数的三分类仪器,具有测定速度快、结果准确、重复性好、性能稳定等优点,是做血常规检验的理想仪器,现将我们在使用该仪器遇到的常见故障及排除方法介绍如下.     

溴氰菊酯的毒性及其检验方法

溴氰菊酯(Deltamethrin,Decamethrin),代号为NRD—161,Ru—22974,WHO—1998。是一种新型拟除虫菊酯类农药,于1974年由英国Elliott等人合成。于1975年由法国Roussel—Uclaf公司投入生产。农用杀虫剂敌杀死(Decis)是其2.5%的乳剂,     

KX-21血细胞分析仪3则故障及排除方法

日本东亚医用电子株式会杜(现改名为希森美康)生产的SYSMEX系列血细胞分析仪是全球三大著名品牌之一,其中的KX-21血细胞分析仪在我国的一些大中型医院使用比较普遍,虽然它从设计上把液路系统和气路系统分开,减少了故障的发生率,并且利用高压电灼烧进行排阻,降低了阻孔的产生,但它仍然会出现一些问题,现把我们平时工作中遇到的3则故障及排除方法介绍如下。     

AM-4290尿液自动分析仪一则疑难故障及排除方法

尿液自动分析仪的应用提高了尿常规检验的质量与速度。在日常工作中由于维护保养工作没有做好，或人为因素使仪器出现一些故障，这就要求维护、保养人员必须掌握常见故障的排除方法，同时也应具备通过仔细研究、查阅工具书等排除一些疑难故障的能力。本室尿液自动分析仪曾出现一则疑难故障，现将其故障及排除方法介绍如下以供参考。1一般资料1.1仪器及试带条日本产AM-4290尿液自动分析仪及配套试带条。1.2故障无规律性不进行测试、不打印结果，其他状态正常，仪器未报故障信息。2排除方法2.1原因分析检查打印机及打印纸均正常，查阅操作手…     

药用柠檬酸三丁酯质量标准及检验方法

<正>2005年,保鲜膜事件成为中国食品卫生监管领域的重大突发事件。而保鲜膜的不合格指标正是增塑剂。增塑剂是食品及药用高分子材料中常用的添加助剂。传统的增塑剂是酞酸酯、偏苯三酸酯、磷丙酯等,以改善塑料材料的特性。但这类增塑剂若用于医药、食品包装、玩具等,有诱发致畸风险。     

胸腔积液检验方法的改进及临床应用

目的对胸腔积液细胞形态学检验方法进行改进，使之更简便、快速、灵敏。方法细胞形态学检查时涂片5～6张，其中2～3张平行尾涂片；在瑞姬染液中加入部分表面活性剂，促进细胞着色。结果90例胸腔积液中15例查见癌细胞，1例查见霉菌；癌细胞主要分布于涂片的尾部，每张涂片仅有2～5个癌细胞时、亦可明确诊断。结论该法简便、快速、准确，适于基层医院的推广应用。     

真空采血试管采集血标本常见故障及排除方法

<正>静脉采血是临床护理工作中常见的技术操作,过去一直采用注射器采血方法,既费时费力,又容易污染,而且因为试管不密封容易造成血标本的污染,影响检验的结果,特别是消化科乙型肝炎患者比较多,易传染。真空采血由于其操作     

Analysis of paralytic shellfish poisoning toxin congeners by a sodium channel receptor binding assay.

This study was carried out to characterize the detection and quantitation of several paralytic shellfish poisoning (PSP) toxin congeners using a receptor binding assay (RBA). This involved competitive binding of the toxin congeners against tritium-labeled STX for receptor sites on rat brain sodium channels. Competitive binding curves were described by a four-parameter logistic equation. Half-saturation values (EC(50)) ranged from 4.38 nM for STX to 142 nM for GTX5. Receptor binding affinity was in the order STX>GTX1/4>neoSTX>GTX2/3>dcSTX>GTX5, and this was similar to the order of mouse toxicity of these congeners. Predicted toxin concentrations from observed STXeq values and EC(50) ratios relative to STX were within 20% or better of the actual concentrations used in the assay. In contrast predicted toxin concentrations using mouse toxicity ratios relative to STX did not provide a good match to actual concentrations, except for GTX1/4. This study has shown that the rat brain sodium channel RBA will provide a reliable integration of total toxicity of various PSP toxin congeners present in a sample.     

Advances in monitoring and toxicity assessment of brevetoxins in molluscan shellfish

Herein, we describe advancements in monitoring of brevetoxins in molluscan shellfish, with respect to exposure management and control of neurotoxic shellfish poisoning (NSP). Current knowledge of the fate of brevetoxins in molluscan shellfish, and the toxic potency of brevetoxin metabolites, is presented. We review rapid assays for measuring composite brevetoxins, and methodology for measuring constituent brevetoxins, in contaminated shellfish. The applicability of in vitro methods for estimating brevetoxin burden and composite toxicity in shellfish is assessed. Specific and measurable biomarkers of brevetoxin exposure and toxicity in shellfish, and of human intoxication, are described. Their utility in regulatory monitoring of toxic shellfish and in clinical diagnosis of NSP is evaluated.     

Comparative determination of paralytic shellfish toxins (PSTs) using five different toxin detection methods in shellfish species collected in the Aleutian Islands, Alaska

Paralytic shellfish poisoning (PSP), a human illness caused by the ingestion of shellfish contaminated with paralytic shellfish toxins (PSTs), has been reported in Alaska for decades. These poisoning incidents have resulted in losses to local economies due to shellfish harvest closures. Thus the development of an effective biotoxin monitoring program designed specifically for the remote regions of Alaska would provide protection for public health and allow for a viable shellfish industry. The present study provides data useful for the development of an effective toxin screening protocol by comparing PST levels quantified in shellfish by many of the currently available PST detection techniques. Seven bivalve species were collected along beaches of the Aleutian Islands from June 2006 to September 2007. The concentration of PSTs was quantified and compared using five different analytical methods: the mouse bioassay, high performance liquid chromatography (HPLC), receptor-binding assay, the commercially available Jellett Rapid PSP Test strips, and an enzyme linked immunosorbent assay technique. The Association of Official Analytical Chemists (AOAC)-approved HPLC method proved to be valuable for characterizing the suite of individual PSTs in each species for research purposes, but was not considered practical for rapid toxin screening in remote Alaskan regions due to its time-consuming nature and requirement of expensive equipment and considerable expertise. In the present study, Jellett test strips were shown to be an effective tool for rapid screening, however due to the high percentage of false positives, subsequent validation via AOAC-approved methods would be required to prevent unnecessary closures.     

Biomarkers of neurotoxic shellfish poisoning

Urine specimens from patients diagnosed with neurotoxic shellfish poisoning (NSP) were examined for biomarkers of brevetoxin intoxication. Brevetoxins were concentrated from urine by using solid-phase extraction (SPE), and analyzed by enzyme-linked immunosorbent assay (ELISA) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Urine extracts were fractionated by LC, and fractions analyzed for brevetoxins by ELISA. In subsequent LC-MS/MS analyses, several brevetoxin metabolites of B-type backbone were identified, with elution profiles consistent with those of ELISA. The more abundant brevetoxin metabolites in urine were characterized structurally by LC-MS/MS. With the exception of BTX-3, brevetoxin metabolites in urine differed from those found in shellfish and in shellfish meal remnants. Proposed structures of these major urinary metabolites are methylsulfoxy BTX-3, 27-epoxy BTX-3, and reduced BTX-B5. BTX-3 was found in all specimens examined. BTX-3 concentrations in urine, as determined by LC-MS/MS, correlated well with composite toxin measurements by ELISA (r(2)=0.96). BTX-3 is a useful biomarker for confirmation of clinical diagnosis of NSP.     

Study of cytoskeletal changes induced by okadaic acid in HL‐7702 liver cells and development of a fluorimetric microplate assay for detecting diarrhetic shellfish poisoning

Diarrhetic shellfish poisoning (DSP) is a gastrointestinal illness with symptoms such as diarrhea, nausea, vomiting, headache, chills and moderate to severe abdominal pain. DSP has been recognized as a worldwide public health problem, causing great concern to the shellfish industry. Accumulation of DSP in shellfish is an unpredictable phenomenon that necessitates the implementation of a widespread collection and thorough monitoring program for mollusk toxicity. Therefore, development of accurate analytical protocols for the rapid determination of toxicity levels would be necessary. In this study we investigated cytoskeletal changes induced by okadaic acid in HL‐7702 Liver Cells and developed a new cytotoxicity assay for detection and quantitation of DSP. This assay is based on fluorometric of F‐actin depolymerization induced by okadaic acid (OA) compounds in HL‐7702 liver cell line. The measurable range of OA was 2.5 ～ 40 nmol/L. The detection limit of the F‐actin assay for OA was 2.01 μg/100 g muscles in shellfish extracts. The performance of this assay has been evaluated by comparative analysis of shellfish samples by the fluorescent assay, mouse bioassay, and ELISA assay. Comparison of the results by all three methods revealed excellent consistency, the results of fluorescent assay were in significant correlation with ELISA assay (R² = 0.830). Examination of F‐actin assay is very convenient, rapid, and sensitive, which can be used to quantify the amount of OA in shellfish samples. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2013.     

Surveillance of algal toxins in shellfish from Scottish waters.

Shellfish samples were collected from coastal and offshore aquaculture sites and harvesting areas in Scottish waters between March 2003 and September 2004. Samples were analysed for the presence of algal toxins using traditional mouse bioassays for the detection of paralytic shellfish poisoning (PSP) toxins and diarrhetic shellfish poisoning (DSP) toxins; immuno-lateral flow chromatography for the detection of PSP toxins in the form of the Jellett Rapid Test; high-performance liquid chromatography (HPLC) with UV diode-array for the detection of amnesic shellfish poisoning (ASP) toxins; and liquid chromatography with mass spectrometry (LC-MS) for the detection of multiple lipophilic shellfish toxins (LSTs) including pectenotoxins (PTXs), yessotoxins (YTXs), azaspiracids (AZAs) and toxins from the 'traditional' DSP toxin group, okadaic acid (OA) and dinophysistoxins (DTXs). In order to investigate the presence of OA esters, alkaline hydrolysis was performed. All toxin groups were detected with a geographically widespread distribution. ASP toxins were the most prevalent occurring in 69% of samples. Using the PSP mouse bioassay, PSP toxins were detected in 5% of shellfish samples from coastal waters around the islands and the east coast. The Jellett Rapid Test for PSP toxins revealed a wider distribution (24% of samples) including the west coast of Scotland. Toxins from the 'traditional' DSP toxin group (OA/DTXs) and/or other LST groups (PTXs, YTXs and AZAs) were detected by LC-MS in 63% of the shellfish analysed. PSP, ASP toxins and LSTs occurred concurrently in a limited sample set, highlighting the importance of using methods capable of detecting multiple algal toxin groups in Scottish shellfish monitoring programmes.     

近年来戒毒药物的研究进展

目的对近年来戒毒药物的研究进展作一综述。方法查阅近年来国内外公开发表的有关研究论文 ,按戒毒药物的作用靶点分类汇总。结果与结论目前戒毒药物的作用靶点主要包括阿片受体、α2 受体、DA2 受体、M受体、NMDA受体以及钙离子通道等 ,与此相对应的戒毒药物均具有较好的疗效。寻找有效的成瘾药物治疗的作用靶点以及在分子水平上研制新的戒毒药物是目前此类工作的研究方向     

Adopting alternatives for the regulatory monitoring of shellfish for paralytic shellfish poisoning in Canada: Interface between federal regulators, science and ethics

To ensure the safety of Canada’s shellfish, the Canadian Shellfish Sanitation Program (CSSP) relies on the mouse bioassay to detect toxins known to cause paralytic shellfish poisoning (PSP). This assay uses a large number of mice and requires death as an endpoint. Canadian research has led to the development of a pre-column High Performance Liquid Chromatography (HPLC) method that is more sensitive and more reliable than the mouse bioassay. However, it is not being used by Canadian regulators despite its acceptance by the AOAC and adoption by the United Kingdom. An ethnography study of stakeholders in the CSSP was conducted to determine the opportunities and obstacles to adopting analytical testing methods.The results of the study indicate that the major obstacles are a lack of certified reference materials (CRMs) and the direction of resources towards the development of new instrument-based methods rather than towards the refinement of the existing pre-column HPLC method for regulatory use. To move away from the mouse bioassay, Canada should invest in: basic research to develop a complete set of CRMs for PSP toxins; method refinement to increase sample throughput; and exercises to gain international acceptance of the pre-column HPLC method.