We used an established isotope dilution gas chromatography-mass spectrometry method to measure blood volumes with an enriched stable isotope of chromium. The results were compared with those of the conventional method, which involves radioactive 51Cr. The two methods were compared simultaneously in two male subjects of different sizes, and essentially identical volumes were obtained. The isotop...

Chosen aspects of the safety of use of several herbs received from National Medicines Institute, which came from smuggling, have been examined. The analysis has been conducted in three different aspects: (1) Possibilities of contamination of plant-based raw materials by metals of heavy elements (As, Cd, Cu, Cr, Pb). (2) Conscious smuggling of intoxicating preparation or narcotics in plant-based...

OBJECTIVE The assay of DNA mismatch repair (MMR) activity can be used as a biomarker for environmental condition detection and human disease diagnosis. Radioactive ³²P-endlabeled DNA containing mismatch is extensively used as the substrate for MMR activity analyses. The aim of the present study is to develop a simple non-radioactive, but equally specific and sensitive method for the MMR activit...

In normal and lathyritic chick embryos bone collagen was synthesized primarily in the periosteum of the femurs, and was organized as radioactive spicules in these bones. Saline extraction of the lathyritic bones removed the radioactive spicules, although they eventually seemed to become non-extractable. Normal bone seemed to be unaffected by saline extraction. Marked variation in the degree of ...

Alterations of cholesterol homeostasis represent important risk factors for atherosclerosis and cardiovascular disease. Different clinical-experimental approaches have been devised to study the metabolism of cholesterol and particularly the synthesis of bile acids, its main catabolic products. Most evidence in humans has derived from studies utilizing the administration of labeled sterols; thes...

Mouse peritoneal macrophages take up I*-HSA from their medium during in vitro cultivation. Conditions which promote I*-HSA uptake are the same as those which stimulate formation of pinocytic vesicles. Autoradiography of cells pulsed with (125)I-HSA showed that intracellular isotope is localized in perinuclear granules, or secondary lysosomes. Following a pulse of (125)I-HSA, intracellular radio...

Compound-specific isotope analysis (CSIA) by isotope ratio mass spectrometry (IRMS) following on-line combustion (C) of compounds separated by gas chromatography (GC) is a relatively young analytical method. Due to its ability to measure isotope distribution at natural abundance level with great accuracy and high precision, GC-C-IRMS has increasingly become the method of choice in authenticity ...