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Biomedical subjects

P Draper

Publications and source records attributed to P Draper.

At least 37 records · Page 2Linked to original sources
PubMed1985

The free lipids of Mycobacterium leprae harvested from experimentally infected nine-banded armadillos.

The free lipids of a sample of Mycobacterium leprae were extracted by a procedure designed to produce separate non-polar and polar fractions. The composition of these lipids was analysed semi-quantitatively by five special thin-layer chromatographic systems covering the total range of mycobacterial lipid polarities. In order of increasing polarity, the major lipids were dimycocerosates of phthiocerol A, phthiocerol B and phthiodiolone A, glycosyl phenolphthiocerol dimycocerosates and phospholipids, including monoacylphosphatidylinositol di- and pentamannosides. The diacylated forms of these latter lipids, found in most mycobacteria, were not present. The composition of the free lipids of the leprosy bacillus, surveyed over the total polarity range for the first time, showed that the patterns were particularly related to those of Mycobacterium bovis, Mycobacterium kansasii and Mycobacterium marinum.

Animals↗
PubMed1985

Quantitative comparison of the mycolic and fatty acid compositions of Mycobacterium leprae and Mycobacterium gordonae.

The mycolic and fatty acids of three samples each of Mycobacterium leprae and Mycobacterium gordonae were compared. Acids released by whole-organism alkaline hydrolysis were converted to 4-nitrobenzyl esters and mycolic acids were further derivatized to t-butyldimethylsilyl ethers. Thin-layer chromatography of the derivatized long-chain extracts showed that all three M. leprae preparations contained so-called alpha-mycolates and ketomycolates but that the M. gordonae samples had a methoxymycolate in addition to the above types. Silica gel normal-phase high-performance liquid chromatography of the total mycolic acid derivatives confirmed the lack of detectable amounts of methoxymycolates in M. leprae and reverse-phase chromatography of the individual mycolate types demonstrated the homogeneity of the chain lengths of the mycolic acids in each species. Non-hydroxylated fatty acid 4-nitrobenzyl esters were transformed to methyl esters and examined by gas chromatography. Tuberculostearic (10-methyloctadecanoic) acid was a major component of the lipids of all three M. leprae preparations but it was absent in one M. gordonae strain and a very minor component in the other representatives of this latter species. On the basis of fatty and mycolic acid compositions, therefore, a previously suggested close relationship between M. leprae and M. gordonae was not supported.

Animals↗
PubMed1985

Steroid secretion by rat testes perfused with perfluorochemicals as oxygen carriers.

Organs perfused in vitro are important experimental models for physiological studies. Perfusion medium supplemented with artificial oxygen carriers would at physiological flow rates supply sufficient oxygen to organs and would be superior to medium containing erythrocytes because it is more defined. Perfluorotributylamine (FC-43), a perfluorochemical, is an artificial oxygen carrier that has been previously reported to be ineffective in maintaining endocrine organs perfused in vitro. The purpose of this study was to determine the efficacy of FC-43 as an oxygen carrier for rat testes perfused in vitro. The effects of FC-43 on testicular function and structure were assessed by comparing the results of experiments using perfusion medium containing either FC-43 or erythrocytes. The results suggest that perfusion medium containing perfluorochemicals must be prepared by standardized procedures and defined as to its physiochemical parameters. The study resulted in the first successful in vitro perfusion of an endocrine organ with perfluorochemicals as oxygen carriers. The results not only provide the basis for an improved perfusion medium but also support in vitro perfused testes as effective experimental tools for testing perfluorochemical-based blood substitutes.

Animals↗
PubMed1985

Changes in circulating antibody levels to the major phenolic glycolipid during erythema nodosum leprosum in leprosy patients.

Circulating antibody levels to the phenolic glycolipid from Mycobacterium leprae and soluble M. leprae antigens were monitored before, during and following ENL episodes in 12 patients. It was observed that during ENL reaction, there was a fall in circulating antibody levels to the phenolic glycolipid but not to the soluble antigens from M. leprae. When the patients had recovered from their ENL reactions, the anti-glycolipid antibody levels usually increased again to levels similar to those observed before the ENL reaction.

Antibodies, Bacterial↗
PubMed1985

Use of gas chromatography to differentiate Mycobacterium leprae from cultivable armadillo-derived mycobacteria, M. avium/intracellulare, and M. lepraemurium by analysis of secondary alcohols.

Two long-chain secondary alcohols, 2-octadecanol and 2-eicosanol, were demonstrated by gas chromatography in hydrolysates of Mycobacterium avium/intracellulare, in cultivable, armadillo-derived mycobacteria, and in M. lepraemurium grown in vivo, but they were not found in purified suspensions of M. leprae isolated from experimentally infected armadillos. Gas chromatographic analysis of these alcohols constitutes a method for rapid detection and quantification of contaminating mycobacteria in preparations of M. leprae intended, for example, for vaccine use. The technique may also be of value for critical evaluation of cultures of "in vitro-grown" M. leprae.

Animals↗
PubMed1984

Phenolic glycolipid 1 of Mycobacterium leprae causes nonspecific inflammation but has no effect on cell-mediated responses in mice.

The involvement of the phenolic glycolipid from Mycobacterium leprae in cell-mediated immunity has been investigated in this study. The phenolic glycolipid itself does not appear to stimulate cell-mediated immunity directly, as shown by its failure to elicit a classical delayed-type hypersensitivity response in mice immunized with M. leprae or to stimulate M. leprae-immune lymph node cells in a lymphoproliferative assay. Intradermal vaccination with the phenolic glycolipid failed to influence the growth of M. leprae in mouse footpads. A nonspecific inflammatory response to the sonicated glycolipid was observed in mice vaccinated with whole M. leprae and in control animals. No evidence was obtained for any adjuvant or suppressive effect on cell-mediated immunity by the phenolic glycolipid either to M. leprae or an unrelated antigen (sheep erythrocytes); neither sensitization nor elicitation to either antigen was affected.

Adjuvants, Immunologic↗
PubMed1984

Analysis of the major antigenic determinants of the characteristic phenolic glycolipid from Mycobacterium leprae.

Antibodies to the major phenolic glycolipid purified from Mycobacterium leprae have been demonstrated previously in sera of leprosy but not tuberculosis patients using an ELISA. The major antigenic determinants on this molecule were investigated using antisera raised in rabbits to the purified glycolipid and with a pool of sera from human lepromatous leprosy patients. A small, but significant cross-reaction was observed with the glycolipids from M. bovis and M. kansasii, which contain the phenolphthiocerol dimycocerosate part of the molecule but have different sugars, and also with a semi-synthetic 'attenuation indicator lipid' which shares the phenolphthiocerol but has no sugars. There was however no cross-reaction with phthiocerol dimycocerosate. The disaccharide, corresponding to the two terminal sugars of the M. leprae glycolipid has been chemically synthesized and shown to inhibit the reaction between glycolipid and antibody in the ELISA. The cross-reactivity observed with the M. bovis and M. kansasii glycolipids was not inhibited by the synthetic disaccharide. These findings suggest that the cross-reactivity is associated with the phenol ring and implies the disaccharide may be a unique antigenic determinant of M. leprae.

Animals↗
PubMed1983

Isolation of a characteristic phthiocerol dimycocerosate from Mycobacterium leprae.

A characteristic mycobacterial wax, phthiocerol dimycocerosate, has been isolated from liver of armadillos experimentally infected with Mycobacterium leprae. The structure of this wax is generally similar to that produced by Mycobacterium tuberculosis, but the homologous phthiocerol and the mycocerosic acid components from M. leprae are significantly different from those of M. tuberculosis.

Animals↗
PubMed1983

Serological activity of a characteristic phenolic glycolipid from Mycobacterium leprae in sera from patients with leprosy and tuberculosis.

Serological activity against a purified phenolic glycolipid from Mycobacterium leprae, which may be obtained in large amounts from M. leprae infected armadillo liver, was investigated using immunodiffusion and an enzyme linked immunosorbent assay (ELISA). Generally a good correlation was obtained between these techniques, but the ELISA was more sensitive and convenient. Relatively high IgG and IgM anti-glycolipid antibody levels were found in lepromatous leprosy patients. The antibody titres to the glycolipid were, however, low when compared with antibody titres to crude sonicates. Since the glycolipid is present in large quantities, this suggests that it is not very immunogenic. Antibody against the glycolipid especially of the IgM class, was demonstrable in some tuberculoid leprosy patients, although at much lower titres than in the lepromatous leprosy sera. In lepromatous leprosy patients that were skin smear negative after more than 5 years of treatment the IgG anti-M. leprae derived glycolipid activity had decreased markedly. The anti-IgG and IgM glycolipid antibody levels in tuberculosis patients did not differ significantly from the levels in appropriate normal healthy subjects. The glycolipid antibody levels in patients infected with M. kansasii, M. avium or M. intracellulare also fell within the range of normal healthy individuals.

Animals↗
PubMed1982

Studies on the mycolic acids from the walls of Mycobacterium microti.

Mycobacterium microti walls contained three types of mycolic acids, very similar to those found in Mycobacterium tuberculosis. An alpha-mycolate with two cyclopropane rings, a methoxymycolate with one cyclopropane ring and a methoxyl group, and a ketomycolate with one cyclopropane ring and a keto group were partially characterized. The mycolates made up 34% (by weight) of the peptidoglycan-arabinogalactan-mycolate wall skeleton. Young exponential phase cultures and organisms harvested from mouse lungs contained high proportions of ketomycolates; older cultures had roughly equal proportions of keto- and methoxymycolates. The proportion of alpha-mycolates increased slightly with age of culture, but was always less than one-third of the total.

Cell Wall↗