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Biomedical subjects

G Coleman

Publications and source records attributed to G Coleman.

84 records · Page 5Linked to original sources
PubMed1969

Effect of potassium ions on the attachment of polyribosomes to the membranes in lysates of exponential-phase cells of Bacillus amyloliquefaciens.

1. The distribution of ribosomal components between the soluble and membrane fractions of a preparation of exponential-phase cells of Bacillus amyloliquefaciens lysed with lysozyme in 0.05m-tris buffer, pH7.6, containing 0.01m-Mg(2+), was strongly influenced by the addition of K(+) to the buffer, in the range 0-0.1m. 2. In the absence of K(+), 37% of the ribosomal material was bound to the membrane and was not removed by repeated washing with the lysing buffer. The amount of bound material was progressively decreased on increasing the K(+) concentration to 0.1m, when only 5% of ribosomal components remained attached to the membrane. 3. About 87% of the material that remained bound to the washed membranes prepared in the absence of added K(+) was removed on suspension of the membranes in a buffer containing 0.1m-potassium chloride. 4. In the absence of K(+), washed membranes, containing no detectable ribosomal material, were able to re-attach no more than half as much material as was found associated with membranes in the same buffer immediately after lysis. 5. There was no evidence of binding of specific components to the membrane. 6. In the presence of 0.05m-tris buffer, pH7.6, maximum incorporation of amino acids into protein by B. amyloliquefaciens polyribosomes is effected in the presence of 0.01m-Mg(2+) and 0.07-0.1m-K(+), under which conditions less than 10% of the ribosomal material of a cell lysate would be membrane-bound.

Amino Acids↗
PubMedDate not supplied

A comparison of the distribution of extracellular proteins produced by the protease-secreting organism Aeromonas salmonicida during aerobic and anaerobic growth.

Aeromonas salmonicida was grown aerobically and anaerobically in supplemented 3% (w/v) tryptone soya broth medium for 24 h at 25 degrees C. Although the bacterial density achieved was 4.9 times higher in the aerobic culture, the exoprotein produced per unit of bacterial dry weight was only 1.9 times higher than in the anaerobic culture. However, the protease activity of the exoprotein showed a marked reduction anaerobically, being only one-tenth of that of the exoprotein produced aerobically. This finding was consistent with the differing SDS-PAGE patterns of the extracellular proteins from the two cultures, which also showed marked loss and reinforcement of other, as yet unidentified extracellular products.

Aerobiosis↗
PubMedDate not supplied

Addressing environmental health concerns near Trecatti landfill site, United Kingdom.

Residents near the Trecatti landfill site located in South Wales, United Kingdom, expressed concern about odors and health effects they attributed to site emissions. The authors compared routinely collected, population-based, health data from potentially exposed electoral wards (i.e., United Kingdom electoral tracts) with data from both wards nearby, matched for socioeconomic deprivation scores, and with wards where residents were likely to attend the same hospital. Mortality rates were higher for all causes and neoplastic diseases (but not respiratory disease) in the exposed wards, but there was no change in rates after the site opened. Hospital data revealed a transient increase in admissions for asthma during the 3 yr that preceded the peak in odor complaints. The birth prevalence of congenital malformations was raised in the exposed wards, but the authors could not exclude a possible artifact resulting from differences in reporting practices between hospitals. The absence of environmental monitoring in the community during the period of public concern was a significant weakness of this study.

Abortion, Spontaneous↗
PubMedDate not supplied

Attitudes that predict antinuclear-war activity in medical students.

The possibility of nuclear war may be the most significant threat to health in the world. Medical practitioners have played, and should continue to play, a leading role in raising awareness of this danger. In the present study, the attitudes that predict a specific antinuclear-war behaviour (that is, signing a letter to the Prime Minister of Australia to request more active political effort to prevent nuclear war) were studied in a group of 143 undergraduate medical students. Attitudes towards that particular behaviour were assessed by means of a questionnaire, and the differences in attitude between students who chose to sign and those who chose not to sign the letter were analysed statistically by means of discriminant analysis. The key differences in attitude between signers and non-signers of the letter was in their belief that such an action would achieve tangible positive outcomes. The results are discussed in terms of the need to target strategies of change for the specific attitudes which are likely to modify behaviour and to promote antinuclear behaviours in medical practitioners, which in turn may alter the behaviour of politicians.

Attitude of Health Personnel↗