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Biomedical subjects

R D Stewart

Publications and source records attributed to R D Stewart.

At least 109 records · Page 6Linked to original sources
PubMed1983

Mammalian bites. Rational approach to management.

When a mammal's bite breaks the skin, aggressive management is indicated to prevent infection and provide for a good cosmetic and functional result. Vigorous irrigation and thorough debridement play a more important role than antibiotics in preventing infection. Whether antibiotics have prophylactic value in this situation remains controversial, but semisynthetic penicillins or cephalosporins may be worth a try in high-risk cases. Suturing may or may not be advisable, depending on cosmetic considerations and risk of infection. Prophylaxis against tetanus is a must, and hepatitis and rabies prophylaxis may also be necessary in selected cases.

Adolescent↗
PubMed1983

Data base management system for tracking occupational health.

An Occupational Health Information System (OHIS), a data base management system for tracking occupational health, has been developed. A primary feature is its ability to correlate employee workplace environment with health. Hardware implementation of OHIS is on a minicomputer with application programs written in ANSI standard MUMPS language. OHIS integrates personnel, medical and industrial hygiene/toxicology information into one data base. The personnel module is comprised of demographic information collected and updated by the personnel department. The medical module utilizes an interactive video display terminal (VDT)-driven questionnaire and multiphasic testing subsystems which are accessed selectively by authorized users. The backbone of OHIS is a parameter dictionary of all possible data elements. A final medical report includes a medical history summary, physical findings and X-ray interpretation, highlighted and normal test findings, computer interpretations, and a final one-page summary of problem and health-risk information. Information characterizing the workplace environment is captured and reported by the questionnaire subsystem. This questionnaire is designed to define: 1) monitoring conditions, 2) sample analysis, 3) measurement results, and 4) personal protective equipment used. These data provide a means of assigning environmental exposure measurements to appropriate employees.

Adult↗
PubMed1983

Patient-controlled inhalational analgesia in prehospital care: a study of side-effects and feasibility.

A clinical trial of a 50:50 mixture of nitrous oxide and oxygen for pain relief was carried out to determine the feasibility of its use in a field setting and the side-effects produced by this sedative/analgesic. The gas mixture was delivered from a single-tank system using a demand-valve apparatus which was triggered by the patient's inspiratory effort. This "patient-controlled" sedation/analgesia was provided to 1243 patients over a period of 18 months. Of the 1201 patients evaluated, 20.6% reported minor side-effects consisting of nausea or vomiting (5.7%), dizziness or lightheadedness (10.3%), excitement (3.7%), and numbness (0.3%). Ninety-one (7.6%) patients became drowsy or fell into a light sleep but all were readily aroused by verbal command. All retained the ability to cough or swallow on command. No consistent or clinically adverse changes were found in BP or pulse rates. The trial supports the concept that this agent is a promising sedative/analgesic for the relief of mild to moderate pain and anxiety. Because of its safety, it is particularly suited to use in prehospital emergency care.

Analgesia↗
PubMed1982

Increase of beta-endorphin concentrations in the plasma and pituitary neuro-intermediate lobe of the rat on the afternoon of proestrus.

Beta-endorphin (beta-EP) concentrations in the plasma and the anterior and neuro-intermediate lobes of the pituitary (AP and NIL) were quantitated by radioimmunoassay (RIA) and gel filtration chromatography in female rats at 1000, 1400, and 1900 h on the day of proestrus and diestrus day-1. There were no significant changes in beta-EP in the plasma, AP, or NIL on diestrus day-1. On proestrus, beta-EP in the plasma and NIL, but not the AP, increased significantly from 1000 to 1400 h and returned to basal levels by 1900 h. The time course of this increase of beta-EP in the NIL and plasma is consistent with the temporal sequence of the prolactin and gonadotropin surges on the afternoon of proestrus, suggesting that beta-EP in the NIL may be involved in the regulation of these neuroendocrine events.

Animals↗
PubMed1982

Amniotic fluid beta-endorphin and alpha-melanocyte--stimulating hormone immunoreactivity in normal and complicated pregnancies.

beta-Endorphin (beta-EP) and alpha-melanocyte--stimulating hormone (alpha-MSH) are members of a family of peptides which are found in the intermediate lobe of the fetal pituitary gland and placenta. In the present study, concentrations of immunoreactive beta-EP (i beta-EP) and alpha-MSH were determined by radioimmunoassay in the amniotic fluid compartment of both normal (n = 72) and complicated (n = 44) pregnancies. In normal pregnancies, there was a significant (p less than 0.05) fall in the mean amniotic fluid i beta-EP from the second to third trimester (from 175 to 132 pg/ml). A similar, but not statistically significant, decline in the mean amniotic fluid concentrations of alpha-MSH (from 46 to 34 pg/ml) was also noted. Concentrations of amniotic fluid i beta-EP showed a significant correlation with alpha-MSH (r = 0.61, p less than 0.001). Significant elevations of mean amniotic fluid i beta-EP but not alpha-MSH were found in pregnancies complicated by intrauterine growth retardation (215 pg/ml, p less than 0.001) and premature labor (225 pg/ml, p less than 0.001). Our findings suggest that levels of i beta-EP and alpha-MSH in amniotic fluid decrease from the second to the third trimester of pregnancy, and that elevation in i beta-EP concentration in amniotic fluid, in all probability, reflects the secretion of beta-EP by the fetus in response to fetal distress.

Amniotic Fluid↗
PubMed1982

Evidence for insulin degradation by muscle and fat tissue in an insulin resistant diabetic patient.

The period before, during and after resistance to subcutaneous insulin in a 20-year-old, non-obese insulin-dependent patient with 'brittle' diabetes is documented and clinical observations are correlated with experimental results of insulin degradation in vitro. Treatment with intravenous but not subcutaneous aprotinin markedly reduced subcutaneous insulin requirements. Insulin resistance recurred following cessation of aprotinin. Serum free insulin levels were low during the subcutaneous resistant phase compared with those during the more sensitive phase. Insulin degradation in vitro by adipose tissue and muscle taken from the patient during a resistant phase was increased compared with degradation by tissue taken during a sensitive phase and by tissue from normal subjects. Chromatography of incubation media revealed that during the resistant phase, tissue from the patient degraded insulin to small fragments. It is concluded that, in this patient, insulin resistance was caused by excessive degradation in both muscle and adipose tissue.

Adipose Tissue↗
PubMed1982

Effects of synthetic corticotropin-releasing factor and dopamine on the release of immunoreactive beta-endorphin/beta-lipotropin and alpha-melanocyte-stimulating hormone from human fetal pituitaries in vitro.

The effects of synthetic corticotropin-releasing factor (CRF) and dopamine on immunoreactive beta-endorphin/beta-lipotropin (i beta-END/LPH) and alpha MSH release were studied in superfused human fetal pituitary glands. CRF (20 ng) stimulated the release of i beta-END/LPH in four anterior hemipituitaries from fetuses older than 20 weeks in gestation. There was no effect on three anterior hemipituitaries from fetuses of 19-20 weeks gestation. CRF had no effect on i beta-END/LPH or alpha MSH secretion from neurointermediate lobes regardless of fetal age. Dopamine (10(-6) M) had no effect on i beta-END/LPH or alpha MSH secretion from either anterior or neurointermediate lobes. The data suggest that anterior pituitary responsiveness to CRF develops at about 20 weeks gestation and that fetal neurointermediate lobe secretion of peptides is not regulated by CRF.

Corticotropin-Releasing Hormone↗
PubMed1981

Effect of daily supplements of selenium on patients with muscular complaints in Otago and Canterbury.

The alleged beneficial effect of selenium (Se) on fibromuscular rheumatism in residents of low soil-Se areas of New Zealand has been explored. Three dosing trials, two of them double blind trials, using physiological daily supplements (100 micrograms Se) of sodium selenite or selenomethionine and a placebo have been carried out. Blood Se and glutathione peroxidase (EC 1.11.1.9; GSHPX) activities were monitored and clinical assessment of the efficacy of the treatment was made during the trials. Blood Se and GSHPX activities rose in all patients who received Se whereas those in control groups remained more or less constant throughout the study. Clinical assessment of muscular symptoms showed that approximately half of the patients in both trial groups and placebo groups responded to treatment. Thus we have been unable to give conclusive evidence of a response to Se supplementation for relief of muscular complaints.

Adolescent↗
PubMed1980

Hemoglobin affinity for oxygen during short-term exhaustive exercise.

We assessed hemoglobin affinity for oxygen (standard P50: pH 7.40, PCO2 40 Torr, temperature 37 degrees C) in 3 series of studies of 16 male subjects who performed exhaustive treadmill exercise of 10 min duration. Standard P50 was significantly elevated (0.7--2.5 Torr) during the last minute of and for 30 min following exercise. Exercise while carboxyhemoglobin (HbCO) was acutely elevated to 5% did not affect std P50 any differently than exercise alone. 2,3-Diphosphoglycerate (2,3-DPG) was significantly elevated after exercise, but not during or 30 min postexercise, and it correlated significantly with P50 in 2 studies (r, 0.43--0.68). ATP (mumol/100 ml) was significantly elevated only 3 min postexercise. Serum [Na+], [K+], [Cl-], osmolarity, and hemoglobin (Hb) concentration were significantly elevated during exercise with [Na+] osmolarity, and [Hb] remaining significantly elevated postexercise. There was no significant correlation between std P50 and any of these variables. Multiple correlation regression analysis between P50 and 2,3-DPG, ATP, and [Na+] yields a coefficient of 0.86. We conclude this type of exercise is unique in causing a small change in std P50 that appears to be mediated by several factors.

Adult↗
PubMed1980

Localization and quantitation of beta-endorphin in human brain and pituitary.

The concentration of human beta-endorphin (beta h-EP)) was measured in various hypothalamic nuclei, in extrahypothalamic brain regions and in the anterior and posterior lobes of the pituitary using a specific radioimmunoassay (RIA) The beta h-EP concentrations in the arcuate nucleus (169 +/- 35 pg/100 micrograms protein, n = 7) and median eminence (163 +/- 32 pg/100 micrograms protein, n = 6) were among the highest in the 17 brain areas examined. The immunoreactive beta h-EP in the hypothalamus corresponded to authentic beta h-EP, as determined by gel exclusion chromatography. By chromatography and RIA the beta h-EP concentrations in anterior (1.53 X 10(5) +/- 0.51 X 10(5) pg/100 micrograms protein, n = 3) and posterior (1.41 X 10(5) +/- 0.38 X 10(5) g/100 micrograms protein, n - 5) pituitary were found to be approximately 1,000-fold higher than in hypothalamus. Within the pituitary beta h-EP was localized throughout the anterior lobe, in the pars intermedia and in that part of the posterior lobe nearest the pars intermedia, as judged by immunocytochemistry. Dense immunocytochemical staining was found along the perimeter of many blood vessels. Beta h-EP and adrenocorticotropin (ACTH) were co-localized in the same pituitary cells. The present data represent the first unequivocal localization and quantitation of beta h-EP in human brain and in the separate lobes of the human pituitary.

Brain Chemistry↗