Partial characterization of low density lipoprotein preparations isolated from fresh and frozen plasma after radiolabeling by seven different methods

Four 99mTc and three 123I labeling methods were evaluated for their suitability to label low density lipoproteins (LDL) for the purpose of scintigraphic biodistribution studies. For 99mTc these methods were: direct incorporation in LDL of 99mTcO4- using sodium dithionite (dithionite method); a method using first N,N-dimethylformamide to prepare...

Preemployment medical examinations in a large occupational health service

Several hundreds of thousands of preemployment medical examinations are performed in The Netherlands each year, with the objective of screening for obvious risks for the applicants or others. Neither the efficacy of these examinations nor determinants for rejection are known. Altogether 101,754 preemployment medical examinations of applicants...

Procedure for the determination of design resistance from tests. Background report to Eurocode 3 "Common unified rules for Steelstructures"

The application of a flame photometric detector in packed microcapillary liquid chromatography: Detection of organophosphates

A commercially available flame photometric detector (FPD) designed for gas chromatography has been investigated for its applicability in microcolumn liquid chromatography. The column effluent is evaporated and subsequently introduced into the detector using a home-made interface. The influence of the mode of effluent introduction into the flame,...

Fluorometric determination of retinol in human tear fluid using high-performance liquid chromatography

A fast and sensitive high-performance liquid chromatographic (HPLC) method for the determination of vitamin A (all-trans retinol) in 50 ??l human tear fluid is described. After deproteinization with ethanol and extraction with n-hexane, retinol is separated from the extract on a straight-phase HPLC column and detected fluorometrically. Vitamin A...

Relevance of parameters related to fertility and reproduction in toxicity testing

Toxicity data of 37 compounds tested in both a subchronic study and one or more studies focused on reproduction were evaluated to obtain information on the significance of fertility and reproduction parameters in setting no-effect levels (NEL). It appeared that a) the test system aimed at reproduction and development was more sensitive than the...

Short-term tests in the framework of carcinogen risk assessment to man

Short-term tests designed to detect possible carcinogenicity have been extensively refined during the last years. Presently, many more or less simple and convenient systems are available to detect mutations, chromosome effects, DNA damage, and malignant transformation. Although their relevance to carcinogenicity is often reasonably good,...

Arbeidshygiëne in Nederland; Taak en plaats

Extracorporeal irradiation of the blood in a rat model for human acute myelocytic leukemia. Comparative evaluation of three treatment regimens with emphasis on cell compartment analysis

Results of three different regimens of extracorporeal irradiation of the blood (ECIB) are compared (1 X 20,2 X 10, and 4 X 5hr) in a rat model for human acute myelocytic leukemia. The D0 for X rays of leukemic cells in the blood was 68 cGy. The transit dose varied from 380 to 660 cGy. Evaluation was performed by follow-up of the number of...

Mutagenicity screening: General principles and minimal criteria. Report of a committee of the European Environmental Mutagen Society

A statement of general principles and minimal criteria for the screening of chemicals for potential mutagenicity in man that may be used as guidelines for regulatory agencies and industrial organisations. To make clear the potentialities and current limitations of short-term mutagenicity testing for the prediction of genetic and carcinogenic...

Cholesterol determinations: A comparative study of methods with special reference to enzymatic procedures

Two enzymatic methods for the determination of cholesterol in serum have been modified for automatic use. These methods utilize the colour reactions according to Kageyama or Trinder to measure the hydrogen peroxide resulting from the enzymatic reaction. The procedures have been compared with the classical methods according to Abell and to Huang....

Verdediging tegen mogelijke chemische aanvallen blijft noodzakelijk

Pitfalls in determination of acetylcholine from brain by pyrolysis gas chromatography/mass spectrometry

Demethylation by sodium benzenethiolate has been used to analyse mixtures of isotopic variants of acetylcholine (ACh) by gas chromatography/mass spectrometry (GC/MS). The present experiments show that demethylation by pyrolysis is also suitable for the simultaneous determination of deuterium labelled variants of ACh by means of GC/MS. However,...