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Biomedical subjects

J Pearce

Publications and source records attributed to J Pearce.

At least 217 records · Page 12Linked to original sources

Neural factors influence the degeneration of muscle fibers in the chelae of snapping shrimps.

The asymmetric pincer and snapper claws in the snapping shrimp differ in external morphology and musculature. The snapper is a massive claw used for displays and defense; the pincer is small and slender, used for feeding and burrowing. The snapper has only slow muscle fibers; the pincer has both slow and fast. Removal or denervation of the snapper claw induces transformation of the contralateral pincer to a snapper type of claw at the subsequent molt. A removed claw regenerates as a pincer type, as long as the innervation of the remaining claw is intact. Fast muscle fibers, found exclusively in the pincer claw, normally degenerate completely within 10 d after the moult, which transforms the pincer to a snapper. Morphological transformation of the pincer following removal of the snapper claw can occur even if the pincer claw is denervated. Denervation of the pincer, however, delays degeneration of the fast fibers, increasing the estimated half-time of muscle degeneration, for 4.4 +/- 0.2 to 19.5 +/- 0.8. d after the transforming moult. Neural influences therefore are involved both in the determination of the morphology of the claw and in the induction of degenerative changes during the remodeling of an existing claw.

Animals↗

The effect of intracisternally injected ouabain on perilymph electrolyte concentrations.

A means for altering the ionic composition of perilymph utilizing the cochlear aqueduct and cerebrospinal fluid in chinchillas is introduced. A decrease in sodium and an increase in potassium concentration in perilymph was observed after ouabain was injected into cerebrospinal fluid. The time course of changes in the perilymph paralleled the CSF change but with a time lag which had not reached equilibrium within 60 minutes.

Animals↗

Current electrosurgical practice: hazards.

The beneficial aspects of electrosurgical cutting and coagulating techniques are nearly too numerous to list. The major contribution and electrosurgery has been to drastically reduce both blood loss and operative time resulting in reduced morbidity and mortality. There are, as well, procedures which would not be possible without electrosurgery. Nonetheless, as a source of high energy in the operating theatre, there are hazards attendant to the use of electrosurgery. Moreover, since high frequency signals are involved, the nature of the machine-patient interactions creating a potentially hazardous situation many not be easily identifiable. The significant hazards of electrosurgery in use are: explosions of combustible mixtures including anaesthesia gas and bowel gas; interference with instruments and pacemakers; stimulation of excitable tissues which on occasion has apparently caused ventricular fibrillation; and accidental radio frequency burns. Though the rate of incidents is low--in terms of the number per 100 000 procedures--individual accidents tend to be fairly catastrophic and traumatic to both the patient and surgical team. Frequently, litigation results from these accidents. Though the hazards cannot be eliminated, the probability of an incident can be minimized by careful technique.

Burns↗

A computer-administered health screening interview for hospital personnel.

We developed a computer-administered health screening interview for the employees of an urban teaching hospital. The interview is part of the integrated Center for Clinical Computing (CCC) clinical information system used throughout the hospital, and is available on any of 2000 terminals. Conducted in private and with protection of confidentiality, the interview seeks information on medical problems and patterns of living for which behavioral change is considered desirable. In a four-year period ending in May 1994, 1937 employees completed the interview. The results showed that stress and unhappiness were common: 57% of the employees reported high levels of stress, and 42% reported feeling sad, discouraged, or hopeless in the previous month; 6% indicated that life sometimes did not seem worth living. Eighty-six percent of the employees expressed an interest in the health-related programs offered by the hospital: 72% were interested in the fitness center, and 37% in the stress-reduction program. We conclude that if interactive health-promotion programs are easily available, they will be used and appreciated in the work place. The programs can be written to reveal the employees' health concerns and stimulate their interest in promoting their own health.

Boston↗