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Biomedical subjects

J Teske

Publications and source records attributed to J Teske.

6 recordsLinked to original sources
PubMed2002

Determination of cannabinoids by gas chromatography-mass spectrometry and large-volume programmed-temperature vaporiser injection using 25 microl of biological fluid.

This paper presents a GC-MS confirmation method, based on large-volume programmed-temperature vaporisation (PTV) injection, for the determination of cannabinoids in plasma samples (or whole blood) with deuterium-labelled internal standards using only 25 microl of biological fluid. The analytes, Delta(9)-tetrahydrocannabinol (THC), 11-hydroxy-Delta(9)-tetrahydrocannabinol (11-OH-THC) and 11-nor-9-carboxy-Delta 9-tetrahydrocannabinol (THC-COOH), were enriched by means of solid-phase extraction cartridges containing octadecyl-bonded silica and were, subsequently, methylated. A 20 microl aliquot of an extract in hexane was injected into a PTV in solvent split mode. Method development and the results of the analyses of standard reference material and real samples are presented and discussed. This micro-method is precise and sensitive enough to assess relevant cannabinoid levels in human blood for forensic investigations as well as for clinical applications.

Adolescent↗
PubMed1999

Programmed temperature vaporiser-based injection in capillary gas chromatography.

The application of programmed temperature vaporisation (PTV) in capillary gas chromatographic analysis is reviewed. The development of the different strategies as well as the state of the art are described. As the analytes are normally enriched in the PTV insert, the quoted papers are subdivided depending on whether the enrichment was carried out from organic solvents, from water or from gaseous media. Furthermore, the possibilities of PTVs for on-line coupling with sample preparation methods or other separation techniques and their use as thermoreactors are mentioned.

Chromatography, Gas↗
PubMed1999

Introduction to the application of capillary gas chromatography of performance-enhancing drugs in doping control.

Performance-enhancing drugs banned by antidoping rules are detected in doping control preferably by hyphenated chromatographic techniques, capillary gas chromatography in particular. Based on the prohibited classes of substances and on the general aspects of sample collection and preparation, a survey is given about the usual procedures of screening, identification and confirmation of the most important doping agents: stimulants, narcotics, anabolics, diuretics, beta-blockers. In addition to gas chromatography itself, the application of various MS techniques doping is outlined.

Adrenergic beta-Antagonists↗
PubMed1988

Mortality among agricultural extension agents.

The mortality experience of agricultural extension agents in the Cooperative Extension Service (CES) of the U.S. Department of Agriculture who died during the period January 1, 1970-December 31, 1979 (n = 1,495 white males) was evaluated in proportionate-mortality and case-control studies. The proportionate-mortality analysis was used to identify cancers that might be elevated in this occupational group compared with the U.S. white male population. All cancers with a significantly elevated proportionate-mortality ratio were more thoroughly evaluated in the case-control study, where there is presumably less of a selection bias in the comparison. In the case-control study, leukemia demonstrated a statistically significant linear trend with duration of employment as an extension agent. Smaller, but nonsignificant, trends were seen for non-Hodgkin's lymphoma, multiple myeloma, and brain cancer. The odds ratio for Hodgkin's disease and cancers of the colon, prostate, and kidney did not vary with the number of years on the job. These patterns resemble cancer risks seen among farmers, suggesting that agricultural factors may also play a role in the origin of these tumors among extension agents.

Adult↗
PubMedDate not supplied

Mortality among forest and soil conservationists.

The mortality of forest conservationists and soil conservationists in the United States Department of Agriculture (USDA) who died during January 1, 1970-December 31, 1979 (N = 1,411 white males) while actively employed or while receiving a pension was evaluated. The proportionate mortality analysis was used to identify cancers that might be elevated in this occupational group compared to the total U.S. white male population, whereas case-control analyses more rigorously evaluated the disease association with occupation. Controls were selected from employees at USDA who died of any cause of death other than that cause of death represented by the case. In case-control analyses, non-Hodgkin's lymphoma (NHL) and colon cancer demonstrated a statistically significant linear trend (p less than .05) with duration of employment as either a forest or soil conservationist, which suggests an occupational etiology for both diseases. Soil conservationists who were last employed after 1960 experienced significantly elevated risks for NHL (OR = 2.6) and colon cancer (OR = 1.8), whereas those last employed before 1960 were not at an increased risk. Among forest conservationists, the risk for both NHL and colon cancer appeared to be elevated before and after 1960.

Colonic Neoplasms↗