Biomedical subjects
Publications and source records attributed to M A Wilson.
A 22% incidence of renal pelvis or calyceal "hot spot" anomalies was found incidental to routine bone scanning. The majority of these anomalies were due to bilateral or right renal pelvis visualization, and statistical analysis determined there to be a significant female incidence, and persistence in repeat studies. This suggests an anatomical or functional basis for this finding.
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The case study of a patient with prolonged partial epilepsy is presented. There was a discrepancy between the extent of the abnormality seen on the radionuclide angiogram and that seen on the static brain scan.
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The objective of this investigation was to characterize organismic, organ and mitochondrial alterations in rats over the course of 27 days at 0.4 atm. In the adjustment phase (day 1 through 5) a significant decrease in systemic oxygen uptake and body weight (23% of pre-altitude values) occurred. In the acclimating state (day 7 to 27) body weight was regained but oxygen consumption remained depressed. Hematocrit increased hyperbolically from 45% in 0-day rats to 79% in 27-day rats. Liver, kidney and heart weights and total organ protein paralleled the changes observed in body weight. Total organ succinic dehydrogenase activity showed a wave-like oscillation for liver and kidney; activity was decreased in both organs by day 5, showed a transient but significant increase on days 16 through 18 and a return to diminished activity on day 27. Succinic dehydrogenase activity for heart became depressed in the adjustment phase but showed a stable level comparable to pre-altitude values in the accliminating phase, days 7 through 27. Liver mitochondrial protein mass was unchanged from pre-altitude values on days 5 and 27 even though succinic dehydrogenase activity was significantly depressed. Therefore, the changes in succinic dehydrogenase activity are not representative of altered mitochondrial mass but suggest that mitochondrial function was altered.
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An analysis of starvation and starvation followed by refeeding was undertaken to characterize some organismic, organ, and mitochondrial responses to these two circumstances. Body weight, organismic respiration as well as weight protein and succinic dehydrogenase activity for liver, kidney, and heart were determined over the course of 6 days of starvation and 5 days refeeding for adult male rats. Assays of marker enzyme activities for mitochondria (cytochrome oxidase), lysosomes (acid phosphatase), endoplasmic reticulum (glucose-6-phosphatase), and plasma membranes (5'-nucleotidase) were conducted for liver in addition to quantitations of mitochondrial protein. All enzyme determinations were done on whole tissue homogenates and reported as total organ activity. Liver mitochondria were harvested quantitatively directly from whole liver homogenates by zonal centrifugation for determination of mitochondrial protein. Starvation resulted in a major loss of body weight, organ weight, and organ protein; liver greater than kidney greater than heart. These changes were accompanied by a major reduction in organ succinic dehydrogenase activity; liver greater than kidney. In heart, succinic dehydrogenase was doubled in activity at day 2 of starvation and subsequently diminished to values not significantly lower than controls. In liver, mitochondrial mass (protein) was severely diminished. From analysis of marker enzyme activities, it appeared that lysosomes, endoplasmic reticulum, and plasma membrane were also decreased. Refeeding restored the greatest part of these losses within 5 days.
A psychologically normal blind man, living and working in normal society, suffered from a severe cyclic sleep-wake disorder. Investigations showed that he had circadian rhythms of body temperature, alertness, performance, cortisol secretion, and urinary electrolyte excretion which were desynchronized from the 24-hour societal schedule. These rhythms all had periods which were longer than 24 hours and indistinguishable from the period of the lunar day.
The purpose of this study was to investigate the problem of mitochondrial biogenesis in rat liver. The approach consisted of isolating mitochondria from control, 6 day starved and 6 day starved-5 day refed rats and comparing their DNA, RNA and protein content. This was performed by isolating the mitochondria by reorienting rate zonal centrifugation in sucrose gradients. It was found that six days of starvation resulted in a loss of 30% of the body weight, 55% of the liver weight, 40% of the mitochondrial protein, 60% of the mitochondrial RNA, but only 20% of the mitrochondrial DNA. It was also shown that refeeding of the rats for five days resulted in a restoration to normal or near normal levels in all the parameters measured. Further experiments employing the incorporation of 3H-TTP into into isolated mitochondria indicated that the maintenance of mitochondrial DNA was not the result of continuous DNA sythesis.
The public's right to quality health care requires that health practitioners be competent to carry successfully the responsibilities of the positions they seek to fill, and that individuals seeking to practice must be evaluated as possessing the required expertise. The proficiency examination is used to judge the possession of such expertise. This article describes the proficiency examination, its characteristics, the basis upon which it is developed, and how it contributes to the assurance that practitioners are competent. Common misconceptions that practitioners may have about the proficiency examination are also discussed. The proficiency examination is defined as a criterion-referenced appraisal of the individual's possession of the performance knowledge and skill competencies required to execute the role responsibilities of the given practitioner generic position.
This concept of a competency assurance program, originated by the author, projects a structure capable of assuring the competency of the individual practitioners in a field. The components of such a program are role delineation, initial competency education, practitioner assessment, subsequent competency education, and practitioner evaluation. This article describes these components, defines their relationship, and emphasizes the importance of their contribution to competency assurance.
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Serial habituation of visual fixations in 2-, 3-, and 4-month-old infants was investigated through a design permitting cross-sectional, within-subject longitudinal, cohort longitudinal, and time-lag analyses. The components of the standard stimulus were displayed individually before and after successive exposures of the standard for familiarization. Relative saliencies of the components for each child were indexed by magnitude of responding to these parts in the initial presentation. Comparisons of the pre- and postexposure fixation times suggest that for all ages habituation was under way to the parts of the stimulus in orders of the relative saliencies. The nature of the data in general did not appear to be influenced significantly by any 1 methodology.
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