Biomedical subjects
Publications and source records attributed to A R Kessler.
Clonidine usually serves as a tic-suppressing agent in patients with Tourette syndrome. A case study is presented in which clonidine at subclinical concentrations led to an exacerbation of the tics and caused severe systemic heat sensations. Involvement of functional abnormalities of the hypothalamus in Tourette syndrome is hypothesized.
Is the federal government devoting sufficient resources to fighting the epidemic of human immunodeficiency virus (HIV) infection, and are these resources being spent appropriately? Some observers contend that the amounts have been inadequate, but until now there has been no overall accounting of federal activities and spending to combat the epidemic. We report expenditure data collected from federal agencies for the years 1982 to 1989. In all, $5.5 billion will have been spent on HIV-related illness during this period by the federal government, nearly 60 percent of it by the U.S. Public Health Service. Federal spending on HIV-related illness in 1989 will reach $2.2 billion, representing over one third of all estimated national (public and private) HIV expenditures, and tripling state expenditures. In 1992, federal spending on the epidemic will reach an estimated $4.3 billion. Although sizable, this will be just 1.8 percent of all 1992 federal health dollars. Similarly, in 1992, national (public and private) spending on HIV-related illness will consume roughly 1.6 percent of all health-related costs in the United States. Federal spending for HIV research and prevention is similar to funding for other major diseases, including some conditions, such as cancer and heart disease, that now have a greater impact on mortality.
In this account we report in vivo effects of a plant lipid preparation (MMPL) on brain cholesterol and the activity and learning performance of aging male rats. Three-month-old rats were fed for 3 months with a diet that was enriched with 3% MMPL. Another group of 18 month-old rats was fed for 6 months with a 3% MMPL-enriched diet. This food regime lowered markedly the cholesterol level in the hippocampal and cortical regions and increased their lipid membrane fluidity. The animals of both age groups also responded to MMPL with a higher activity and their learning performances, compared to normal diet-fed animals, improved notably. This improvement continued at least 4 months after terminating the supply of MMPL. Significant inverse correlationships were obtained between the length of the training period required to attain proper criteria and cholesterol levels of the hippocampal and cortical brain fractions.
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Studies were conducted to elucidate effects of learning on properties of brain membranes. Sprague-Dawley rats, (3-months-old) fed with normal Purina chow cakes, were trained in a T-maze. After reaching proper criteria, the animals were sacrificed, their brains dissected into hypothalamus, hippocampus, cortex and brainstem. The various brain regions were assayed for cholesterol, phospholipids and membrane lipid microviscosity. The salient findings were (a) a marked learning-induced decrease in the level of cholesterol in the hippocampal and cortical regions and (b) a learning-induced increase in the membrane lipid fluidity. We postulate that upon the learning impact, brain membranes undergo definite changes in the lipid membrane phase which participate in the transduction of the learning process into biochemical templates.
Vascular surgeons often suggest that combining renal arterial procedures with aortic replacement greatly increases morbidity and mortality. To evaluate this hypothesis we retrospectively reviewed 102 consecutive primary operations involving both renal arterial and aortic reconstruction. The patient population included 69 men and 33 women with an average age of 63 years. All aortic replacements were knitted Dacron grafts. One hundred twenty-eight renal arteries were revascularized with 104 vein or synthetic aortorenal bypass grafts, 12 arterial reimplantations, and three endarterectomies with vein patch. Thirty-five complications occurred in 24 patients with four hospital deaths. Postoperative hospitalization averaged less than 11 days. This study suggests that under optimal conditions renal arterial and aortic reconstructions can be combined without significantly increasing patient risk.