Virginia medical quarterly : VMQ最新文献

Unlike the peripheral nervous system (PNS), the mammalian central nervous system (CNS) clearly lacks the robust regenerative characteristics and capacity of the former. Despite this fact, two unique regions of the adult mammalian CNS possess such regenerative potential and are capable of active regeneration following injury or structural compromise. These unique areas are the olfactory system and the neurohypophyseal system of the endocrine hypothalamus. Furthermore, it has been clearly demonstrated that primordial neuroblasts regarded as stem cells emerge from the subependymal parenchyma of the walls and floor of the third cerebral ventricle, migrate to the ventricular surface and undergo compensatory synaptogenesis within one week following hypophysectomy. In situ hybridization studies have unequivocally demonstrated that the up-regulation of nitric oxide synthase (NOS) is essential for neural (axonal) regeneration and neuronal (stem cell) migration to occur. Moreover, neuronal migration is reliably inhibited following the administration of the NO antagonist, nitroarginine. The current investigation serves to confirm a remarkable degree of plasticity and regeneration in the adult mammalian neurohypophyseal system coupled with the emergence of primordial neuroblasts that undergo apparent differentiation, migration and compensatory synaptogenesis in response to the up-regulation of NO that occurs following the trauma of hypophysectomy. Evidence from the current investigation appears to confirm that specialized glia of the neurohypophyseal system, the so-called pituicyte, proliferate following hypophysectomy and may serve as a growth matrix or structural template that may target and direct regenerating Supraoptic (SON) and Paraventricular (PVN) axons toward endothelial primordia in the regenerating neural stem and lobe.

Selected issues for hospital epidemiology are presented. The issues of infection control, employee health and quality assessment cross the traditional department and reporting lines and require a multidisciplinary approach utilizing the epidemiological method. Programs seeking enhanced value--high quality outcomes per dollar cost--will likely support such an approach.

There are three concurrent processes involved in the withdrawal from alcohol in an alcohol-dependent person. The first process is the hippocampal calcium channel mechanism diagnosed by the coarse tremor leading, sometimes precipitously, to convulsions. The second process is commonly referred to as alcoholic hallucinosis, and involves the psychoactive biogenic amine, harmine. The third process involves the locus coeruleus and presents as irritability, a fine tremor, autonomic storm, and diaphoresis. Magnesium and phenobarbital are usually sufficient to treat the syndrome of alcohol withdrawal, although neuroleptics may be required.

Latex is a natural product obtained from rubber trees. Sensitization and subsequent exposure to latex products can lead to allergic (immediate hypersensitivity) reactions including anaphylaxis. Gloves are the largest source of latex exposure, and the majority of serious latex reactions occur in medical settings. Allergen testing and avoidance in history positive or high risk groups (medical personnel, spina bifida patients and rubber workers) is presently the best treatment option.