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Biomedical subjects

J L Laseter

Publications and source records attributed to J L Laseter.

36 records · Page 2Linked to original sources
PubMed1976

Identification of some volatile endogenous constituents in rat brain tissue and the effects of lithium carbonate and chloral hydrate.

Nine endogenous volatile compounds were found in rat brain tissue, and were identified by mass spectrometry as chloroform, a 5-C-aldehyde, dimethyl disulphide, 2,5-dimethyl tetrahydrofuran, a 8-C-alkane, xylene, 2-heptanone, heptaldehyde and 2-n-pentylfuran. Using gas chromatographic and gas chromatographic mass spectrometric techniques, it was established that lithium carbonate did not induce the production of detectable amounts of any new volatile compounds in brain tissue. However, after administration of chloral hydrate, trichloroethanol, a compound not normally present in rat brain tissue, was found to be present.

Animals↗
PubMed1975

Gas chromatographic evaluation of the volatile constituents of lung, brain and liver tissues.

Volatile metabolites from rat liver, lung and brain tissues were compared using gas chromatography. Volatiles released from the homogenized tissues at 95-100 degrees C were collected on a poly phenyl ether solid adsorbent. The adsorbed volatiles were examined by high-resolution gas chromatography. Markedly differing overall volatile profiles were observed for the tissue types examined, and it appears that certain constituents may be characteristic of a particular tissue.

Animals↗
PubMed1975

Halogenated hydrocarbons in New Orleans drinking water and blood plasma.

Volatile organics from New Orleans drinking water and pooled plasma were collected on a solid phenyl ether polymer and analyzed by gas chromatographic and mass spectrometric techniques. Thirteen halogenated hydrocarbons were identified in the drinking water. Five halogenated compounds were found in the plasma. Tetrachloroethylene and carbon tetrachloride were found in both the plasma and the drinking water. Considerable variation in the relative concentrations of the halogenated hydrocarbons was noted from day to day in the drinking water.

Adult↗
PubMed1975

Use of high-resolution open tubular glass capillary columns to separate acidic metabolites in urine.

We used high-resolution glass capillary columns to study the trimethylsilyl derivatives of some acidic metabolites found in pooled urine specimens form control and postpartum subjects. About 30 compounds were identified by gas chromatography-mass spectrometry-computer techniques. In general, open tubular capillary columns effect better resolution of trimethylsilyl derivatives of organic acids than do conventional packed columns. GESE-30 proved to be a good general-purpose stationary phase, whereas OV-17 offered certain advantages in resolving aromatic acid components.

Adult↗
PubMed1973

Reactions of singlet oxygen with pine pollen.

Exposure of pine pollen to single oxygen, generated in an aqueous environment, resulted in a decrease in the relative quantities of unsaturated fatty acids that could be recovered by solvent extraction of surface and near surface pollen lipids. The involvement of excited oxygen was confirmed by substitution of deuterium oxide for water, which led to a twofold greater decrease in the unsaturated acids. The potential environmental and biomedical implications of these observations are discussed in terms of this model system.

Air Pollution↗
PubMed1970

Lipids of Rhizopus arrhizus Fischer.

The lipids of Rhizopus arrhizus Fischer mycelia and sporangiospores were extracted, isolated, and separated by thin-layer, liquid, and gas chromatography. Structural confirmations of the compounds were made by a gas chromatographmass spectrometer combination. The n-heptane fraction contained squalene (1%) as a major hydrocarbon constituent. Other major lipid classes detected were free fatty acids, naturally occurring methyl esters of fatty acids, triglycerides, sterols, and polar lipids. The polar lipids (44.4%) were found in the highest concentrations, and the triglycerides (22.1%), sterols (16.7%), and free fatty acids (11.7%) were present in lesser concentrations. This is the first report of naturally occuring methyl esters of long-chain fatty acids being present in fungal mycelium. There appears to be a preference for incorporation of unsaturated acids into the complex lipids, with the exception of the triglycerides. The major saturated fatty acids in the mycelium were palmitic (C(16)) and arachidic (C(20)), whereas the major unsaturated acids were oleic (C(18:1)) and linoleic (C(18:2)), respectively.

Alkanes↗
PubMed1966

Alkanes in fungal spores.

The chlamydospores of Ustilago maydis, U. nuda, and Sphacelotheca reiliana were analyzed by gas chromatography and mass spectrometry for their hydrocarbon contents. For the first time we observed that they contain paraffinic hydrocarbons; the average contents were 42, 58, and 146 parts per million, respectively. n-Alkanes having odd numbers of carbon atoms predom-inate, with carbon-chain lengths ranging from C(14) to C(37). The major alkanes are n-C(27) in U. maydis, n-C(27) and n-C(35) in U. nuda, and n-C(29) in S. reiliana. Each type of spore carried a distinctly characteristic population of hydrocarbons.

Alkanes↗
PubMedDate not supplied

Determination of trace levels of hexachlorocyclopentadiene and octachlorocyclopentene in body fluids.

A simple, rapid and sensitive method for the analysis of hexachlorocyclopentadiene (C5-Cl6) and octachlorocyclopentene (C5-Cl8) in blood and urine is described. The procedure requires 5.0 mL of blood or urine, and involves the isolation of the compounds from the sample by liquid-liquid extraction, followed by screening and quantification via glass-capillary column gas chromatography with electron-capture detection and confirmation by gas chromatography-mass spectrometry. The assays are suitable for the detection and identification of nanogram quantities of these compounds in body fluids with a lower detection limit of 50 ng/mL for blood and 10 ng/mL for urine.

Body Fluids↗
PubMedDate not supplied

Trace analysis of 2,6-disubstituted anilines in blood by capillary gas chromatography.

A simple, rapid, and sensitive procedure for the detection of 2,6-disubstituted anilines in the low nanogram range in blood is described. These aromatic amines were extracted from blood and converted to the corresponding N-hepta-fluorobutyramides, which were confirmed by gas chromatography/mass spectrometry (GC/MS). The derivatives yielded excellent electron capture detection (ECD) responses that allowed the identification and detection of these compounds at the low nanogram level by glass capillary GC/ECD. The procedure, which was tested in an in vivo system, is suitable for pharmacokinetic studies and toxicological investigations, and may be adapted for the quantitative determination of other substituted anilines and similar compounds in blood and other body fluids.

Aniline Compounds↗