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Biomedical subjects

J Reid

Publications and source records attributed to J Reid.

At least 271 records · Page 15Linked to original sources
PubMedDate not supplied

Mineral and nitrogen balance study: results of metabolic observations on Skylab II 28-day orbital mission.

Prediction that the various stresses of flight, particularly weightlessness, would bring about significant derangements in the metabolism of the musculoskeletal system has been based on various observations of long-term immobilized or inactive bed rest. The only attempt at controlled measurement of metabolic changes in space prior to Skylab, a study during the 14-day Gemini VII flight, revealed rather modest losses of important elements. The three astronauts of Skylab II consumed a planned day-by-day, quite constant, dietary intake of major metabolic elements in mixed foods and beverages and provided virtually complete collections of excreta for 31 days preflight, during the 28 days inflight, and for 17 days postflight. Analyses showed that, in varying degree among the crewmen, urinary calcium increased gradually during flight in a pattern similar to that observed in bed-rest studies: the mean plateau peak of urinary calcium excretion in the latter part of flight was double preflight levels. Fecal calcium excretion did not change significantly, but calcium balance, owing to the urinary calcium rise, became either negative or less positive than in preflight measurement. Increased excretion and negative balance of nitrogen and phosphorus indicated appreciable loss of muscle tissue in all three crewmen. Significant losses also occurred inflight in potassium, sodium, and magnesium. Based on the similarity in pattern and degree between these observations and those in bed rest of the losses in calcium, phosphorus, and nitrogen, musculoskeletal integrity would not be threatened in space flights of up to at least 3 months. However, if similar changes occur, indicative of continuing losses of these elements, in the planned Skylab flights for considerably more than 28 days, concern for capable musculoskeletal function should be serious for flights of very many months' duration, and greater research attention will need to be given to development of protective counter-measures.

Aerospace Medicine↗
PubMedDate not supplied

Analysis of the ligand binding site of the 5-HT3 receptor using site directed mutagenesis: importance of glutamate 106.

The 5-HT3 receptor is a ligand-gated ion channel with significant structural similarity to the nicotinic acetylcholine receptor. Several regions that form the ligand binding site in the nicotinic acetylcholine receptor are partially conserved in the 5-HT3 receptor, presumably reflecting the conserved signal transduction mechanism. Specific amino acid differences in these regions may account for their distinct ligand recognition properties. Using site-directed mutagenesis, we have replaced one of these residues, glutamate 106 (E106), with aspartate (D), asparagine (N), alanine (A) or glutamine (Q) and characterized the ligand-binding and electrophysiological properties of the mutant receptors after transient expression in HEK-293 cells. The affinity for the selective 5-HT3 receptor antagonist [3H]GR65630 was decreased 14-fold in the mutant E106D (Kd = 3.69 +/- 0.32 nM) when compared to wildtype (WT, E106) 5-HT3 receptor (0.27 +/- 0.03 nM), while the affinity for E106N was unchanged (0.42 +/- 0.07 nM, means +/- SEM, n = 3-10). Decreased affinities for both E106D and E106N were observed for the antagonists granisetron, ondansetron and renzapride and for the agonists 5-HT (130- and 30-fold) and 2-methyl-5-HT (250- and 20-fold), respectively. Both mutants still formed 5-HT-activatable ion channels, but the high Hill coefficient of the concentration effect curves in wildtype (2.0) was decreased to unity in both cases. The EC50 of 5-HT was increased seven-fold in E106N (8.7 microM) when compared to wildtype (1.2 microM), but unchanged in E106D, and the potency of the antagonist ondansetron for both mutants was decreased. E106A and E106Q expressed poorly preventing a detailed characterization. These data suggest that E106 contributes to the ligand-binding site of the 5-HT3 receptor and may form an ionic or hydrogen bond interaction with the primary ammonium group of 5-HT.

Animals↗
PubMedDate not supplied

DSM-III-R classification of psychiatric symptoms in systemic lupus erythematosus.

DSM-III-R criteria applied in the evaluation of 88 systemic lupus erythematosus patients revealed a point prevalence rate of 18.2% for psychiatric disorders, the most common diagnosis being adjustment disorder (11.4%). No patients had disorders compatible with a functional psychosis. Psychiatric morbidity was not associated with increased disease activity, corticosteroid use, brain magnetic resonance imaging abnormalities, or electroencephalogram abnormalities. High scores on a life event scale were associated with psychiatric disorders, suggesting that psychosocial stress is etiologically important. Cognitive testing showed that poor performance on the Stroop Colour-Word Inference Test was associated with psychiatric disorders.

Adolescent↗
PubMedDate not supplied

A pharmacodynamic study of propofol or propofol and ketamine infusions in ponies undergoing surgery.

The pharmacodynamics of infusions of propofol alone (group 1) were compared with the pharmacodynamics of infusions of propofol and ketamine together (group 2) in eight ponies undergoing castration. Anaesthesia was induced with detomidine, 20 micrograms kg-1, followed by ketamine, 2.2 mg kg-1. Subsequently, a bolus dose of propofol, 0.5 mg kg-1, was administered intravenously to both groups, and an infusion of propofol was given for an average of 74 minutes to group 1, and an infusion of propofol and ketamine was given for 60 minutes to group 2. The mean (SD) infusion rates of propofol were 0.330 (0.050) mg kg-1 min-1 in group 1, and 0.124 (0.009) mg kg-1 in group 2, and the ketamine infusion rate was maintained constant at 40 micrograms kg-1 min-1. Arterial hypotension and marked respiratory depression were evident in some of the ponies receiving propofol alone, whereas in the ponies anaesthetised with propofol and ketamine, respiratory and cardiovascular parameters were well maintained. All the ponies in both groups recovered quickly from anaesthesia, with mean times to sternal recumbency and standing of 19.8 (8.0) minutes and 27.2 (7.4) minutes respectively for group 1 and 8.4 (3.2) min and 14.9 (10.1) minutes for group 2.

Analgesics↗
PubMedDate not supplied

Pesticide exposure in a farming village in Venezuela--a developing country.

This study was designed and performed by the Universidad de Carabobo, Centro de Investigaciones Toxicológicas, Venezuela, and the University of Cincinnati Department of Environmental Health. The authors tested methodology and analyzed preliminary data on demographics, pesticide use, health, environment, and lifestyles in a farming community in Venezuela (population = 386; sample size = 81) to determine if pesticide misuse might have been contributing to public health problems. Questionnaire and geographic information were collected. There were statistically significant incidences of pesticide-related symptoms (p < .01) in farmers versus nonfarmers (odds ratio = 5.7; 95% confidence interval = 2.9, 18.8). In addition, in one area there was a cluster of farmers who experienced symptoms that appeared to be the result of foul air and proximity to farms where there was pesticide use. The results of the study indicated that this public health problem may have been associated with pesticide misuse; however, additional studies are needed to corroborate the findings.

Adolescent↗
PubMedDate not supplied

A proficiency score for assessing the reliability of self blood glucose monitoring.

The reliability of self blood glucose analysis was studied in 83 insulin-treated diabetic patients. Reliability was assessed by laboratory analysis of capillary blood samples collected simultaneously on filter paper. Patient and laboratory results were compared using a scoring system which produces an easily understood Proficiency Score. The score was designed to highlight unreliable performance in measuring glucose concentrations in the euglycaemic as well as hypo- and hyperglycaemic ranges. Only 17% of patients achieved acceptable Proficiency Scores by maintaining adequate performance on five occasions.

Adolescent↗
PubMedDate not supplied

Asthma management in the emergency department.

OBJECTIVES: To evaluate various aspects of the management of adult patients who present to the emergency department with acute exacerbations of asthma and who are discharged from the emergency department without hospital admission. Further, to compare the results with accepted management guidelines for the emergency department treatment of asthma. DESIGN: A retrospective chart collection and review until each site contributed 50 patients to the survey. SETTING: Three tertiary care hospitals in the Saskatoon Health District, Saskatoon, Saskatchewan. The study period was from July 1, 1997 to November 18, 1997. POPULATION: Patients aged 17 years or older, who were discharged from the emergency department with the diagnosis of asthma. METHODS: Data were collected on 130 patients from 147 emergency department visits. RESULTS: A number of important physical examination findings were frequently not documented. In contrast to management guidelines, peak expiratory flow rates (44%) and spirometry (1%) were not commonly used in patient assessments. Only 59% of patients received treatment in the emergency departments with inhaled or systemic corticosteroids. Furthermore, specific follow-up plans were infrequently documented in the emergency department charts (37%). CONCLUSIONS: Adherence with published Canadian guidelines for the emergency department management of acute asthma exacerbations was suboptimal. Corticosteroid use in the emergency department was significantly less than recommended. Increased emphasis on education and implementation of accepted asthma management guidelines is necessary.

Administration, Inhalation↗
PubMedDate not supplied

Multidisciplinary clinical supervision.

Care of people with mental health problems demands a range of specialist skills from various disciplines. Although there is growing awareness of the issues surrounding the implementation of clinical supervision within mental health nursing, there is little published research about its use, either among or between other disciplines. This article examines the models and practice of clinical supervision among a group of professionals working in a mental health trust.

Humans↗