Biomedical subjects

A F Heck

Publications and source records attributed to A F Heck.

At least 19 recordsLinked to original sources

PubMed1990

Permeability of intracranial blood vessels to endogenous serum albumin.

The blood-brain barrier to endogenous serum albumin labeled with Evans blue was studied by standard fluorescence microscopic techniques in cats. Systematic studies confirm that, except in certain well-known loci (hypothalamic median eminence, subfornical organ, area postrema, etc.), blood vessels within brain tissue are impermeable to endogenous albumin. But studies also demonstrate that in virtually all arteries at the base and over the surface of the brain and brain stem, labeled albumin passes readily through endothelium and the vascular wall to the adventitia. These observations are discussed in the context of current concepts of intracranial vascular permeability and, in terms of general biology, the possible consequences of the permeability to serum albumin of intracranial, extraparenchymal blood vessels on the composition and physiology of cerebrospinal fluid and in the pharmacokinetics of antibiotics, anticonvulsants, and antineoplastic and vasoactive agents.

Animals↗

PubMed1989

Neurologic aspects of mitral valve prolapse.

Mitral valve prolapse (MVP), the most frequently encountered valvular condition in the population, has been reported in an increasing variety of neurologic, muscular, and psychiatric disorders during the last twelve years. Extensive review of reports indicates this has resulted from observations of either (1) inordinate incidence of MVP in well-defined neurologic entities or (2) development of neurologic or ophthalmologic complications attributed to MVP. In the review presented, basis is found for categorizing MVP by its association with (1) well-defined, genetically determined neurologic disorders; (2) disorders characterized by structural abnormalities, many genetically determined, or inflammatory processes of connective tissues; (3) "mechanical" prolapse resulting from disproportion of mitral valve annulus and left ventricular size, which is, at times, reversible; and (4) a generally asymptomatic state that, at times, is associated with ischemic, thrombotic, embolic, and infectious disorders of the brain and eye. The paradox between the large number of persons with MVP in the general population who remain healthy and a subpopulation of patients with complications of MVP (eg, stroke) or other entities has been identified. A second paradox is found between the well-known increased incidence of MVP, especially in young patients with stroke, and the apparent rarity of stroke among patients with both common (eg, migraine) and unusual (eg, myotonic dystrophy) neurologic entities in which an extraordinary high prevalence of MVP is known to exist.

Cerebrovascular Disorders↗

PubMed1983

Driving with epilepsy: a contemporary perspective.

A committee of concerned neurologists in cooperation with the Tennessee Department of Safety and other agencies reviewed the present state licensing rules for epileptics and offered recommendations for amendments. Epileptics, diabetics, and patients with cerebrovascular disease have an accident rate of approximately twice that of the general population. Seizures probably account for approximately .02% of all vehicle accidents and only .5% to .01% of the fatal accidents. Accidents caused by seizures involve the driver's vehicle alone or an immovable object 80% of the time and occur in less populated and developed areas than controls. The number of seizures within the first three months of therapy is a powerful prognostic indicator. With knowledgeable individual consideration, licensing epileptics to drive could be done much earlier than previously allowed, without affecting road safety. Physicians giving recommendations for licensing in good faith should be protected by law from liability for unforeseen seizure recurrence.

Accidents, Traffic↗

PubMed1979

Intracranial neurosarcoidosis.

Neuroradiological findings in two cases of histologically confirmed intracranial sarcoidosis are presented, one with periaqueductal granulomata causing aqueduct obstruction. The granulomatous aggregation was of slightly greater attenuation than normal brain parenchyma and did enhance homogeneously following contrast medium administration. No direct signs of basal arachnoiditis could be found on computed tomography (CT) in the other case in which hydrocephalus was produced by a granulomatous infiltration of the fourth ventricle and cisterna magna. The neuropathological and pertinent clinical and laboratory manifestations of neurosarcoidosis are reviewed as a means of predicting recognizable CT patterns of the entity.

Adult↗

PubMed1973