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Biomedical subjects

G O Guerrant

Publications and source records attributed to G O Guerrant.

15 recordsLinked to original sources
PubMed1990

Isoprenoid quinones of Campylobacter cryaerophila, C. cinaedi, C. fennelliae, C. hyointestinalis, C. pylori, and "C. upsaliensis".

The isoprenoid quinone contents of Campylobacter cryaerophila, C. cinaedi, C. fennelliae, C. hyointestinalis, C. pylori, and "C. upsaliensis" were determined by reverse-phase thin-layer and high-performance liquid chromatography. All six of these recently named Campylobacter species contained menaquinone-6 (MK-6), but only C. hyointestinalis and "C. upsaliensis" contained 2,[5 or 8]-dimethyl-3-farnesyl-farnesyl-1,4-naphthoquinone (*MK-6), a previously described novel menaquinone of the Campylobacter genus. C. cryaerophila, C. cinaedi, C. fennelliae, and C. pylori contained an unidentified quinone (Un-MK-6) with a molecular weight of 580 and a base peak ion of m/e = 225 by mass spectrometry but with chromatographic properties different from those of MK-6. *MK-6 and Un-MK-6 are important chemotaxonomic markers of Campylobacter and Campylobacter-like organisms.

Biomarkers↗
PubMed1986

Detection by gas chromatography of 3-deoxy-D-manno-2-octulosonic acid and L-glycero-D-manno-heptose in whole cells of Neisseria elongata.

Lipopolysaccharide components 3-deoxy-D-manno-2-octulosonic acid and L-glycero-D-manno-heptose were detected in hydrolysates from whole cells of Neisseria elongata by gas-liquid chromatography. Cells from a single plate were hydrolyzed, and carbohydrate components were converted to aldononitrile and O-methyloxime acetate derivatives for subsequent analyses by gas-liquid chromatography. 3-Deoxy-D-manno-2-octulosonic acid was well separated from other cell components as the O-methyloxime acetate derivative. With both derivatives, L-glycero-D-manno-heptose was readily identified by their different retention times. The procedure requires only a relatively small number of cells, and detection is accomplished without prior isolation of the lipopolysaccharide.

Chromatography, Gas↗
PubMed1983

Cellular fatty acid composition and ubiquinone content of Legionella feeleii sp. nov.

The cellular fatty acid composition of Legionella feeleii was determined by capillary gas-liquid chromatography, and the ubiquinone content was determined by reverse-phase high-pressure liquid chromatography. As in other Legionella species, this new species is characterized by relatively large amounts of branched-chain fatty acids and by major amounts of ubiquinones with more than 10 isoprene units in the side chain.

Chromatography, Gas↗
PubMed1982

Analysis of short-chain acids from anaerobic bacteria by high-performance liquid chromatography.

A standard mixture of 25 short-chain fatty acids was resolved by high-performance liquid chromatography, using an Aminex HPX-87 column. The acids produced in culture media by anaerobic bacteria were analyzed by high-performance liquid chromatography after extraction with ether and reextraction into a small volume of 0.1 N NaOH. The presence of fumaric acid in culture extracts of Peptostreptococcus anaerobius was confirmed by gas chromatography-mass spectrometry analysis of the trapped eluent fractions from the high-performance liquid chromatography column.

Bacteroides fragilis↗
PubMed1981

Gas-chromatographic analysis of mycolic acid cleavage products in mycobacteria.

Mycolic acids were detected in both reference strains and clinical isolates of mycobacteria using gas chromatography of fatty acid methyl esters prepared by acid methanolysis. The methyl esters were extracted with hexane, concentrated, and analyzed with a gas chromatograph by using two different injector temperatures. When the samples were analyzed at high injector temperatures of 300 to 350 degrees C, characteristic thermal cleavage products from mycolic acids, C22:0, C24:0, or C26:0 fatty acid methyl esters, were detected. When analyzed at injector temperatures of 235 degrees C or lower, the mycolic acids were heat stable and the characteristic methyl ester cleavage products were not observed.

Chromatography, Gas↗
PubMed1979

Identification of diaminopimelic acid in the Legionnaires disease bacterium.

Diaminopimelic acid was found to be a component of the cell wall of the Legionnaires disease bacterium, thus providing additional evidence that the organism is a bacterium. The presence of this amino acid was determined by gas-liquid chromatography and confirmed by gas chromatography-mass spectrometry.

Amino Acids↗
PubMed1977

Drug abuse proficiency testing.

Concerning drugs in general, proficiency testing has undoubtedly been a major contributing factor to improved detection. Some of the improvement may be due to advances in technology, and this is possibly the case with improvement in the detection of morphine and methadone. The improvement in the determination of methamphetamine within three surveys over six months can clearly be attributed to proficiency testing. In drug screening for cocaine abuse, the poor results in proficiency testing for the detection of the primary metabolite, benzoylecgonine, has clearly demonstrated that laboratories are not proficient in this screening.

Barbiturates↗
PubMedDate not supplied

Comparison of laboratory performance with blind and mail-distributed proficiency testing samples.

Simulated addict urine samples containing drugs were sent to collaborating hospital administrators and officials of methadone centers, who then forwarded the samples to their supporting laboratories as though they were ordinary specimens from patients. The laboratories, which were already participating in the proficiency testing program of the Center for Disease Control, received the identical test samples in the mail as part of a regular Center for Disease Control proficiency testing program. Most of the laboratories performed acceptably with the mail-distributed samples, but many performed poorly when the identical samples were sent to them as if they were specimens from patients. Because of the limitations of proficiency testing involving mail-distribution samples and the impracticality of extensive testing with blind samples on a national level, the Center for Disease Control proposes to compliment its regular proficiency testing program with a monitored, onsite program of performance evaluation.

Centers for Disease Control and Prevention, U.S.↗