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Biomedical subjects

R Barrow

Publications and source records attributed to R Barrow.

9 recordsLinked to original sources
PubMed2001

Allelopathy, DIMBOA production and genetic variability in accessions of Triticum speltoides.

A screening was conducted to study the allelopathic potential of Australian-held accessions of Triticum speltoides. Of 26 accessions, four were found to inhibit root growth in the indicator species, lettuce (Lactuca sativa). The methanol leaf extracts of these accessions significantly reduced the root length of wild oat (Avena spp.). In all but one case, alellopathic accessions contained higher amounts of DIMBOA than did nonallelopathic accessions. Since some variation in allelopathic response was detected within lines, random amplified polymorphic DNA (RAPD) markers were used to estimate genetic diversity between and within the allelopathic accessions of Triticum speltoides L. The average genetic similarity between all possible pairs of selected accessions was found to be 55% and ranged from 44% to 88%. Comparison of DNA extracted from different single seedlings within the same accession revealed significant intraaccession genetic diversity (4-24%), although this was much less than that observed between accessions tested. This intraaccession diversity has significant implications for the selection of T. speltoides accessions in breeding or screening programs.

Benzoxazines↗
PubMed1996

Changes in haemodynamic parameters following Tai Chi Chuan and aerobic exercise in patients recovering from acute myocardial infarction.

In this study, 126 patients (90 males, average age 56 years, range 39-80) were randomised to Wu Chian-Ch'uan style Tai Chi (38), aerobic exercise (41) or a non-exercise support group (47) following acute myocardial infarction. Patients attended twice weekly for three weeks then weekly for a further five weeks. Heart rate and blood pressure were recorded before and after each session. Over the 11 sessions of exercise there was a negative trend in diastolic blood pressure only in the Tai Chi group (Rs = 0.79, p < 0.01). Significant trends in systolic blood pressure occurred in both exercise groups (Rs = 0.64 and 0.63, both p < 0.05). Only four (8%) patients completed the support group eight-week programme which was less than the number completing Tai Chi (82%; p < 0.001) and aerobic exercise groups (73%; p < 0.001).

Adult↗
PubMed1994

Cadmium-induced sexual dysfunction does not involve increased hepatic metabolism of testosterone nor increased circulating levels of corticosterone.

Sexually experienced male rats were injected IP with 0, 0.3, 1.5, 3.0, or 6.0 mg/kg cadmium chloride. The highest dose was fatal within 48 h of injection. A dose-related deficit in erectile function was observed in ex copula tests 48 h after injection. Copulatory dysfunction was evident in mating tests 72 h after injection. Hepatic mixed function oxidase activity after 0.3 mg/kg injections was not different from controls, but was diminished by 50% in rats treated with 3.0 mg/kg. The higher cadmium doses (1.5 and 3.0 mg/kg) were associated with equivalent and marked reductions in circulating testosterone levels, and lesser decrements in circulating corticosterone levels. The rats treated with 1.5 or 3.0 mg/kg cadmium chloride lost weight (32 +/- 12 and 39 +/- 9 g, respectively). Relative decapsulated adrenal gland weights were markedly increased in rats treated with 3.0 mg/kg. These data indicate that exposure to cadmium is associated with alterations in sexual, hepatic, and adrenal function, with erectile dysfunction occurring at the lowest dose. The effects on copulatory behavior are especially striking because it requires some weeks for copulatory behavior to wane following castration.

Adrenal Glands↗
PubMed1993

Estradiol stimulates cortisol production by adrenal cells in estrogen-dependent primary adrenocortical nodular dysplasia.

Adrenal glands from a patient with ACTH-independent Cushing's syndrome, whose symptoms worsened during pregnancy and oral contraceptive use, were cultured in different concentrations of estradiol. Estradiol stimulated cortisol secretion in a dose-response manner in the absence of ACTH. Since immunoglobulins G from this patient did not stimulate corticosterone production in a mouse adrenal bioassay, an adrenal-stimulating immunoglobulin is unlikely to be the cause of adrenal hyperfunction in this case. This is the first description of estradiol stimulation of cortisol production by cultured adrenal cells in ACTH-independent Cushing's syndrome.

Adrenal Cortex↗
PubMed1985

Segmental infarction of the omentum: diagnosis by ultrasound.

Pre-operative diagnosis of segmental infarction of the omentum is difficult because of its rarity and non-specific clinical features. We present a case of omental infarction and suggest that ultrasound scan may be helpful in the diagnosis of this entity.

Adult↗
PubMedDate not supplied

Cold stress response in patients with severe burns after beta-blockade.

Adrenergic receptor blockade has been shown to be of benefit in the treatment of adverse cardiovascular changes in patients with burns during the hypermetabolic phase. This article examines the stress response to cold exposure in adults and children with 33% to 95% total body surface area burns with and without beta-blockade. Resting energy expenditures were measured by indirect calorimetry; the test subjects were exposed to mean temperatures of 27.5 degrees C (room temperature) or 24.6 degrees C (cold). The mean resting energy expenditure at ambient room temperature in patients with burns without beta-blockade was 1411 +/- 70 kcal/m2/day (mean +/- SEM). This value was 142% of that predicted for normal control subjects without burns. When placed in a cold temperature, patients with burns significantly increased their resting energy expenditures by 160% of predicted values, whereas patients with similar burns and beta-blockade increased their resting energy expenditures by 156%. Adults with septic burns had a mean resting energy expenditure 198% of the predicted value. These patients did not significantly increase their resting energy expenditures when they were exposed to cold either with or without beta-blockade. Data suggest that patients with septic burns already have a maximal metabolic response and that cold stress does not further increase this response. Males, ages 17 to 54 years, were found to increase their resting energy expenditures by 11.4 kcal/m2/day for each percent total body surface area burn. We conclude that beta-blockade with propranolol in therapeutic doses may be used in patients with burns without adversely affecting the cold stress response.

Adrenergic beta-Antagonists↗