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Biomedical subjects

G D Daves

Publications and source records attributed to G D Daves.

At least 37 records · Page 2Linked to original sources
PubMed1978

Stereospecific antibodies to methadone. II. Synthesis of d- and 1-methadone antigens.

Diastereomeric methadols were prepared by reduction of the methadone enantiomers. Resulting methadols, after purification and characterization by mass spectrometry, were succinylated. The hemisuccinyl derivatives were conjugated with thyroglobulin via carbodiimide condensation. The conjugates of d- and of 1-methadol hemisuccinyl-thyroglobulin were employed as the antigens for immunization of white New Zealand rabbits in order to obtain specific anti d- and anti 1-methadone antisera.

Animals↗
PubMed1977

Gas chromatography mass spectrometry analysis of polyamines using deuterated analogs as internal standards.

Quantitative analyses of subnanomole quantities of the polyamines putrescine, cadaverine, spermidine and spermine by the gas chromatography mass spectrometry technique of selected ion monitoring are complicated by effects of the chromatographic column. These effects include sample retention by the column and chromatographic band broadening, and are sufficiently serious that spermine (as the trifluoroacetylated derivative) was not detectable at levels below 50 picomoles. Because the chromatographic behaviors of the four polyamines vary, quantiative analysis using a single internal standard is not feasible. The deuterated polyamine analogs, putrescine-2H4, cadaverine-2H4, spermidine-2H6 and spermine-2H8, have been synthesized and used to accomplish quantiative analyses of the corresponding isotopically natural abundance polyamines to the one picomole level. This enhancement in analytical sensitivity is accomplished by use of large excesses (greater than or equal to 100 picomoles) of the deuterated analogs to improve chromatographic band profiles. The use of such large molar excesses of deuterated analogs for selected ion monitoring analyses is possible because their electron impact spectra exhibit high mass ions ([M-F3C]+, [M-F3CCO]+) which possess greater than or equal to 4 deuterium atoms and have intensity ratios (I2H(max):IH) of 500 or greater.

Cadaverine↗
PubMed1977

Sample derivatization and structure analysis by field desorption mass spectrometry. Peptide methylation-methanolysis.

Analysis by field desorption mass spectrometry of reaction product mixtures produced by treatment of peptides with methanol and hydrogen chloride augments significantly structural data derived by direct field desorption mass spectrometry analysis of the peptides. Analyses of data obtained by three peptides, beta-Ala-HisOH, p-Glu-Ser-GlyOH and Glu-Ser-Gly-AspOH are used for illustration. Data from field desorption mass spectrometry of peptide methylation-methanolysis product mixtures are used to (a) distinguish [M]+- from [M + H]+ in peptide field desorption mass spectrometry spectra, (b) ascertain the number of carboxyl groups present in a peptide, (c) identify a pyro-glutamyl N-terminus and (d) derive peptide sequence information. Definitive assignments of ion relationships are facilitated by use of methanol and deuteromethanol in paired experiments.

Mass Spectrometry↗
PubMed1977

Hydantoin ring glucuronidation: characterization of a new metabolite of 5,5-diphenylhydantoin in man and the rat.

A new metabolite of 5,5-diphenylhydantoin has been found in human urine and in rat bile. This new metabolite arises by direct glucuronidation of 5,5-diphenylhydantoin (i.e. no prior aryl hydroxylation occurs) and is characterized as the N-3 glucuronide. This structure assignment is based on (a) study of mass spectra of permethyl, perdeuteriomethyl, N-methyl-per-O-deuteriomethyl and deuteriomethyl ester permethyl derivatives and (b) comparison of the reactions of the new glucuronide metabolite and 5,5-diphenyl-3-methylhydantoin with diazomethane. Prominent ions at m/e 322 and 378 in the mass spectrum of the permethylated derivative of the glucuronide metabolite arise via retro Diels-Alder reactions of the glycone ring.

Animals↗
PubMed1977

Human transfer factor: fractionation by electrofocusing and high pressure, reverse phase chromatography.

The biologically active fraction of human transfer factor (Sephadex G-25, fraction III) has been separated by exclusion chromatography into two component fractions (IIIa and IIIb). Fraction IIIa transferred donor reactivities to PPD or KLH into 9 of 9 recipients. Fraction IIIb did not transfer donor reactivities (0 of 8 transfers) but did produce both antigen-independent and antigen-dependent dermal reactions in recipients. Fractionation by electrofocusing and high pressure reverse phase chromatography revealed that IIIa has a major UV254 absorbing component and that fraction IIIb has at least three major and three minor UV absorbing components. The major component of IIIa was isolated by preparative electrofocusing, had an isoelectric point of 1.6, and transferred KLH reactivity to four of five recipients.

Chemical Fractionation↗
PubMed1976

Iodo-bis(quaternary ammonium) salts. Potential cartilage-selective x-ray contrast agents.

Bis(quaternary ammonium) compounds in which one or both quaternary nitrogens bear iodinated benzyl moieties and the charged centers are separated by 2, 4, 6, or 10 methylene units have been synthesized and evaluted for (a) binding to cartilaginous material, (b) radiocontrast characteristics, and (c) in vitro pharmacological effects. Also prepared was 1,5-diiodo-2,4-bis(beta-trimethylammonioethyl)benzene diiodide, an analogue in which the iodinated aryl group lies between the charged nitrogen centers. Biological studies show that these compounds bind to cartilage but at relatively slow rates and with low persistence, resulting in low and transient levels of radiopacity. In common with simpler bisquaternary compounds, these compounds block synaptic transmission.

Animals↗