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Biomedical subjects

J M Nicholas

Publications and source records attributed to J M Nicholas.

16 recordsLinked to original sources
PubMed2001

Skin only or silo closure in the critically ill patient with an open abdomen.

BACKGROUND: The morbidity and mortality of various open abdominal techniques remains unclear. METHODS: A retrospective review was made of all trauma or general surgery patients who underwent an open abdominal closure from January 1997 to December 2000, at a large urban acute care hospital. Data are mean +/- SD. RESULTS: From 1997 to 2000, 181 patients (aged 39.8 +/- 16.5 years) had an open abdomen for abdominal infection, planned reexploration, abdominal compartment syndrome, inability to reapproximate fascia, or as part of a "damage control" procedure. Twenty-three patients went on to develop an abdominal compartment syndrome. Gastrointestinal fistulas occurred in 26 patients, and 9 patients had a dehiscence. The overall mortality was 44.7%. Of the survivors, 52% went on to fascial closure, requiring 1 to 7 additional abdominal operations. CONCLUSIONS: The morbidity of the open abdomen varies with the particular indication. Gastrointestinal fistulas are the most common acute complication and an abdominal wall hernia, the most common chronic complication.

Abdomen↗
PubMed1995

Nonoperative management of gunshot wounds of the abdomen.

Nonoperative management of stab wounds of the abdomen is currently practiced in many trauma centers; this report examines the role of expectant management of gunshot wounds to the abdomen in a select patient population. Patients presenting to a single trauma service from 5/91 to 1/94 at Detroit Receiving Hospital with a gunshot wound (GSW) to the abdomen fulfilling the following criteria were observed: 1) single GSW to the right upper quadrant, 2) stable vital signs, 3) reliable examination with minimal abdominal tenderness and available team/operating room, and 4) minimal or no abdominal tenderness. There were 12 patients fulfilling the study criteria; all were successfully observed. One nontherapeutic laparotomy was done due to abdominal tenderness. The role of expectant therapy of abdominal gunshot wounds is cautiously advanced. With appropriate criteria, this technique appears safe and efficacious.

Abdominal Injuries↗
PubMed1995

A proposed profile of the effective leader in human spaceflight based on findings from analog environments.

This paper presents a literature review of leader characteristics and associated outcomes from four environments considered as analogs to long-duration spaceflight: aviation, submersibles, polar stations, and expeditions. Evidence from 23 sources indicates that, despite differences in the analog settings, effective leaders share a common core of personal traits and leadership-style attributes. The general profile that emerges is a person who works hard to achieve mission objectives, is optimistic, holds the respect of the crew, ordinarily uses participative decision-making but takes charge during critical situations, is sensitive to and makes crew members feel valued for their expertise and their personal qualities, and maintains group harmony and cohesion. Results have implications for selecting leaders for future long-duration space missions.

Arctic Regions↗
PubMed1989

Interpersonal and group-behavior skills training for crews on space station.

With the advent of space station, planners must come to terms with the inevitable psychosocial crew problems that accompany long-term confinement. Although some problems may be resolvable with the assistance of an on-board professional therapist-consultant, others can only be settled by whole-crew training in interpersonal, emotional-support, and group-interaction skills. This article describes problems situations, kinds of skills training needed to resolve them, and the resistance that proposals for behavioral training might encounter.

Extraterrestrial Environment↗
PubMed1987

Steady state absorption kinetics and pharmacodynamics of furosemide in congestive heart failure.

Furosemide, a potent loop diuretic, is commonly used in the treatment of congestive heart failure (CHF). Unpredictability in the diuretic effect following oral doses has been attributed to variable and incomplete absorption and to variability in the pharmacodynamic response to furosemide. The present study is undertaken to investigate the absorption kinetics and pharmacodynamics of furosemide in patients with CHF during chronic medication. Ten patients with congestive heart failure were maintained on 40 to 160 mg furosemide for a month. The final dose at the end of this period was administered on an empty stomach. Plasma and urine were collected and assayed for furosemide, potassium, chloride, sodium and creatinine. Urine flow was also measured as a function of time. Plasma furosemide concentration-time data were fit to a two-compartment model with either two consecutive, discontinuous first order absorption rate constants or with a single monoexponential input; the former absorption model describing the data better than the latter. Average values of the half-life (205 +/- 28 min) and renal clearance (0.8 +/- 0.09 ml/min/kg) were similar to those reported by previous investigators. Drug excretion-response curves were lower and shifted to the right compared to data reported for normal subjects. Furthermore, a clockwise hysteresis was evident indicating acute within-dose tolerance.

Aged↗
PubMed1987

Small groups in orbit: group interaction and crew performance on Space Station.

Orbiting space stations herald a new era of enterprise, but they raise unprecedented issues about crew interaction and performance. It is argued that group interaction, despite its effect on crew performance, is an area largely ignored in current space planning. This article identifies these issues using a model of group interaction and findings from situations similar to orbiting stations. Directions for possible solutions and research are noted.

Group Structure↗
PubMed1986

Sex-differentiated enzyme levels and oestrogen uptake in adult rats treated neonatally with tamoxifen or CI-628.

Serum cholinesterase, hepatic histidase and monoamine oxidase activity levels are higher in adult female rats than in adult male rats. Exposure of neonatal rats to antioestrogen (tamoxifen or CI-628) resulted in increased serum cholinesterase in adult females only and no effect on hepatic histidase and monoamine oxidase in both sexes. Neonatal tamoxifen or CI-628 treatment resulted in reduced body weights in adult male rats and reduced uterine wet weights in adult female rats. Circulating oestrogen levels measured in adult female rats treated neonatally with tamoxifen were not significantly different from controls. Specific oestrogen uptake in the brain of adult male and female rats was found to be higher in the pituitary than in the preoptic-anterior hypothalamic area and the median eminence-basal hypothalamus than in the cerebral cortex. There was higher uptake of [3H]oestradiol-17 beta in male pituitaries than in female pituitaries. No other sex-difference was observed. Neonatal tamoxifen treatment did not alter the capacity of these brain tissues to take up oestrogen. It is suggested that neonatal antioestrogen exposure has altered the endocrine expression of serum cholinesterase in adult female rats by interfering with normal imprinting mechanisms.

Animals↗
PubMed1983

Phencyclidine exposure and the developing mouse: behavioral teratological implications.

The effects of perinatal exposure to phencyclidine (PCP) on the reflex development of the offspring of mothers given PCP during gestation and/or lactation were determined. ICR Swiss mice received daily injections of either PCP (5, 10, 20 mg/kg, PO) or saline during gestation and/or lactation. Thus, four groups of animals were studied; those exposed only prenatally, postnatally, both pre- and postnatally, or control. After birth, these offspring were observed daily until weaning for the appearance of certain reflexes, using a modification of the Fox battery. There was a delay in the disappearance of the cross extensor reflex and delayed appearance of reflexes, such as walking, crawling, vibrissal placement and vibrissal stroking in the offspring of PCP-treated mothers. Treated animals also showed slower righting times than control animals. Growth rate was decreased in PCP-exposed animals beginning at 3 days of age and continuing through 15 days of age. These results indicate that PCP exposure during gestation or nursing adversely affects the development of behavioral reflexes in mice and suggest that regular observation of reflex ontogeny in neonates may be a sensitive indicator of behavioral teratology.

Abnormalities, Drug-Induced↗
PubMed1982

Phencyclidine: its transfer across the placenta as well as into breast milk.

Phencyclidine (PCP) is a dangerous and unpredictable drug which is widely abused among young people. Acute placental transfer of this drug was studied in pregnant rabbits and mice where it was shown to cross the placenta readily. Rabbit fetal levels of radioactivity reached their peak 2 hours after parenteral administration of PCP to the doe. In the mouse, where actual PCP levels were determined, there was a tenfold higher concentration of PCP in fetal tissue than in maternal blood. In lactating mice, the drug was found to cross rapidly into breast milk where it reached concentrations which were 10 times that of plasma. As PCP may be teratogenic and has been shown to be harmful to the infant during the postnatal period, those treating pregnant women should be aware to these possible routes of exposure for the developing infant and should counsel their patients accordingly.

Animals↗
PubMedDate not supplied

Organization, selection, and training of crews for extended spaceflight: findings from analogs and implications.

Ample research evidence from space analogs points to the crucial role that teamwork plays in the performance of small groups in isolation and confinement. This paper surveys findings about the impacts of group behavior and social interaction on crew morale, coordination, and productivity. Implications for the organization, selection, and training of crews for extended spaceflight are discussed.

Astronauts↗