Biomedical subjects
Publications and source records attributed to J T Black.
We present 2 cases of spinal cord intramedullary cavernous hemangioma; 1 patient is the 1st reported case of multiple spinal cord lesions. Diagnosis is greatly enhanced by the use of MRI.
A recently developed Bayesian regression program was compared with three other aminoglycoside pharmacokinetic dosing programs available for clinical use. From 30 adult patients, 152 measured serum gentamicin concentrations (SGC) were evaluated retrospectively (78 peak and 74 trough). Predictive performance was compared for each method by using the first peak and trough SGC pair to predict subsequent serum concentrations, making a total of 92 predictions (48 peak and 44 trough). The two Bayesian programs (Brater and Koup) were further evaluated using only one initial peak or trough SGC to make the same predictions. Mean predicted error (ME), mean absolute error (MAE), and root mean squared error (RMSE) were calculated for each method. Prediction bias and precision were compared statistically, between each method, by calculating the 95% confidence intervals for the delta ME and delta MAE, respectively. No statistically significant differences were found in the MAEs among any of the methods for predicting peak SGCs, with the exception of the Brater program, using a single trough SGC, which was statistically less precise (less than 0.05). There were few statistically significant differences in the MAEs for trough SGCs; however, Koup's Bayesian program using a single trough concentration yielded statistically more precise predictions than the other methods. The ME was found to differ significantly (p less than 0.05) among estimates for peak and trough SGCs provided by some of the predictive methods.(ABSTRACT TRUNCATED AT 250 WORDS)
Monheit, Hagan, Berk, and Farley, in an earlier issue of this journal, made a major contribution to our understanding of health system problems of access and uncompensated care by correcting the widespread misimpression that lack of health insurance coverage is predominantly related to unemployment. Their research, based on the 1977 National Medical Care Expenditure Survey, indicated that 75% of the uninsured were workers and their dependents. The authors observed that industry, unionization, full- or part-time status, and geographic region are among the interrelated factors that influence the availability of employment-related health insurance coverage. This comment augments their findings through an examination of U.S. employment trends since 1977 as well as projections of future employment.
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Seventeen patients who had undergone surgical procedures in the posterior triangle of the neck were examined between one day and four years after operation. Eleven patients were studied with electromyography. Clinical and electromyographic evidence of 11th cranial nerve paresis was present in 12 patients. Partial nerve injuries and entrapments, as suggested by delayed symptoms and incomplete denervation on electromyographic studies, were frequent. Physiotherapy was effective in restoring a satisfactory, although in many cases an incomplete, return of function. The spinal accessory nerve appears to be vulnerable to injury despite careful preservation during surgical dissection.
Histochemical, ultrastructural and biochemical studies were performed on muscle biopsy specimens from a 30-year-old man with proximal limb weakness. Modified Gomori trichome stains of anterior tibial muscle revealed accumulations of red-staining material in the subsarcolemmal and intermyofibrillar regions of virtually every fiber (ragged-red fibers); these accumulations were rich in oxidative enzymes. Electron microscopy of this muscle showed that the red-staining areas consisted of large collections of abnormal-appearing mitochondria. Mitochondria isolated from the quadriceps muscle showed lack of respiratory control with alpha-glycerophosphate as substrate. However, the lack of respiratory control with alpha-glycerophosphate must be interpreted with caution since the quadriceps muscle was severely degenerated, and biochemical alterations of mitochondria may occur secondary to muscle degeneration itself. Nevertheless, this is the second reported case of lack of respiratory control with alpha-glycerophosphate in a patient with ragged-red fibers. Further interpretation of this defect and its significance must await more studies to determine whether this muscle mitochondrial abnormality is a common finding in the disorders in which ragged-red fibers are encountered.
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A patient with a brain abscess due to Candida albicans is reported. This patient had three episodes of systemic candidiasis in spite of the fact that she had no underlying debilitating disease and had never received prior antibiotic or adrenocortical steroid therapy. A review of the literature reveals 42 cases of central nervous system Candida albicans infection. The salient features of these cases are tabulated and discussed. The clinical features, pathology, pathogenesis, treatment, and aetiology of cerebral candidiasis are also discussed.
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