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Biomedical subjects

R W Jackson

Publications and source records attributed to R W Jackson.

133 records · Page 8Linked to original sources
PubMed1965

Effects of toluene on Escherichia coli.

Jackson, Robert W. (University of California, San Diego, La Jolla), and J. A. DeMoss. Effects of toluene on Escherichia coli. J. Bacteriol. 90:1420-1425. 1965.-When toluene is added at appropriate levels to exponentially growing cultures of Escherichia coli, a time-dependent loss of turbidity is observed which is concurrent with a loss of material to the medium and with unmasking of beta-galactosidase. In addition, the galactoside permease system is totally destroyed. Electron micrographs confirm the indications that the cells are not being lysed by toluene, although the cytoplasm collapses to the interior of the cell. Included in the material lost from the cell after toluene treatment is 85% of the total ribonucleic acid (RNA), the principal source of which appears to be the ribosomes. The loss of RNA is temperature-dependent. Protein is also lost to the medium as a function of both temperature and available toluene. Up to 25% of the total protein is found in the medium, the precise amount depending on the level of toluene employed. Zone centrifugation studies of extracts from treated cells indicate that toluene elicits a rapid disaggregation of ribosomes that is terminated, at any stage, by disruption of the cells. The disaggregation is temperature-dependent and does not occur at 4 C. It appears to be distinct from the actual degradation of ribosomal RNA and is accompanied by an accumulation of small particles during the initial phases of treatment at 21 C. Toluene added to crude extracts of normal E. coli cells is unable to cause detectable ribosome destruction.

Carbon Isotopes↗
PubMed1962

Production of Fumaric Acid in 20-Liter Fermentors.

The conditions necessary for the production of fumaric acid in 20-liter fermentors by fermentation of glucose with Rhizopus arrhizus strain NRRL 2582 were determined. Continuous neutralization of fumaric acid was necessary for optimal yields. Yields of the calcium salt were in excess of 65 g of fumaric acid from 100 g of sugar consumed during fermentation of sugar concentrations of 10 to 16%. Conditions established for calcium fumarate production include a simple mineral salts medium, 0.5 v:v:min aeration rate, 300 rev/min agitation rate in a baffled tank, 33 C incubation temperature, CaCO(3) to neutralize the acid formed, and a 4 to 5% (v/v) vegetative inoculum. A suitable procedure and medium for the preparation of a vigorous vegetative inoculum were established. The tendency for calcium fumarate fermentations to foam excessively was controlled with a proper antifoam agent added prior to sterilization of the medium and again at daily intervals during fermentation. The production of soluble sodium or potassium fumarates was inhibited when the concentration of fumarates reached 3.5 to 4.0%. No means of overcoming this inhibition was found. Starches and certain other grain-derived carbohydrates were fermented to form calcium fumarate in flask experiments with approximately the same efficiency as was glucose.

Journal Article↗
PubMedDate not supplied

Sports for the physically disabled. The 1976 Olympiad (Toronto).

The 1976 Olympiad for the Physically Disabled was the first olympiad with full competition for blind, paralyzed, and amputee athletes. More than 1,500 from 38 countries took part in wheelchair (12 events), blind (8 events), and amputee (11 events) games. Participants were classified by an international team of doctors. The athletes were accomodated in university residences with small infirmaries. A school near the games site was used as a field hospital. Rest areas were also set up. Volunteers served on the medical staff (three doctors, three nurses, three receptionists, and three physical therapists on each of two shifts per day). In addition doctors, nurses, trainers, and physical therapists rotated around various venues at the games site. Physicians treated 285 patients (184 were athletes; others were spectators) for a variety of problems, physical therapists treated 119 athletes, and trainers treated 114 athletes. Contigency plans in case of mass disaster were made but were not needed. Disabled athletes are slightly more vulnerable to stress and fatigue than able-bodied athletes. The Toronto games will probably be remembered as the turning point in the emergence of sports for the disabled from a purely rehabilitation measure to a true sporting event in its own right.

Amputees↗
PubMedDate not supplied

Anterior cruciate ligament insufficiency: a dynamic three-dimensional motion analysis.

An electrogoniometer, capable of measuring all six degrees of freedom of knee movement, was developed in our laboratory. This Instrumented Spatial Linkage system was then used to generate data for a three-dimensional assessment of 20 ACL deficient and 30 normal subjects during level walking. The system proved to be a viable method for describing total knee motion. We found the ACL deficient knees to have increased anterior/posterior translation and significant pattern differences compared to the controls. The results of this study may have implications in the treatment of the ACL deficient patient.

Adult↗
PubMedDate not supplied

The sneaky plicae.

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Humans↗