Search PubMed⌕ Search

Biomedical subjects

B M Davis

Publications and source records attributed to B M Davis.

At least 127 records · Page 7Linked to original sources
PubMed1981

Neuroendocrine and neurochemical measurements in depression.

The authors performed dexamethasone suppression tests (DST), TRH infusions, 72-hour urine collections, and lumbar punctures on a group of male depressed patients. Approximately 60% of the patients were DST positive and 33% had a blunted TSH response. Two biologic variables, the 8 a.m. postdexamethasone cortisol and the postprobenecid CSF 5-hydroxyindoleacetic acid (5-HIAA), accounted for over half of the variance in the behavioral measure, the Hamilton score. Plasma cortisol elevation was associated with high 3-methoxy-4-hydroxyphenyl glycol (MHPG) excretion; TSH blunting was associated with low urinary MHPG excretion. Comprehensive biologic measures showed certain significant interrelationships and correlations with the severity of depression.

Adult↗
PubMed1981

Lithium's effect of parathyroid hormone.

Lithium has been reported to raise serum calcium and lower serum phosphate concentrations and to increase urinary calcium excretion. Because these changes may be effects of parathyroid hormone (PTH), PTH was measured in 19 patients receiving lithium. PTH was significantly higher in these patients than in 150 normal subjects. For all patients serum calcium concentrations correlated significantly with serum lithium concentrations. These results indicate that lithium may cause biochemical hyperparathyroidism. Secondary hyperparathyroidism in certain patients with lithium nephrotoxicity is also possible.

Adult↗
PubMed1980

Contact urticaria and allergic contact dermatitis to benzocaine gel.

A 39-year-ole man developed edema and vesiculation of the oral mucosa following the application of benzocaine (Hurricaine) gel. Open testing demonstrated an immediate urticarial reaction. Closed patch tests were positive after 48 hours. The contact dermatitis was consistent with a delayed-type hypersensitivity. It appears, however, that a nonimmunologic mechanism caused the contact urticaria since passive transfer was negative.

Adult↗
PubMed1980

Treatment of tinea nigra palmaris with miconazole.

A patient with tinea nigra palmaris was successfully treated with 2% miconazole nitrate cream. In vitro studies demonstrated sensitivity of the causative agent, Exophiala werneckii, to this antifungal agent.

Adolescent↗
PubMed1980

CKholinergic mechanisms and anterior pituitary hormone secretion.

The study of the hypothalamic-pituitary axis has been a useful approach in assessing neurotransmitter function in man. Unfortunately, its utility in exploring cholinergic mechanisms is complicated by the induction of a stress response. However, the possibility that cholinergic transmission is a mediating factor in the stress response perhaps raises a more fundamental consideration.

Acetylcholine↗
PubMed1978

Hepatic insulin responsiveness in patients with endogenous hypertriglyceridaemia.

Plasma insulin response to oral glucose, insulin resistance, and insulin suppression of hepatic glucose production were studied in 11 normal subjects and 11 hypertriglyceridaemic patients. Patients with hypertriglyceridaemia had a significantly higher insulin response to oral glucose. Insulin resistance was also significantly greater in hypertriglyceridaemic subjects as determined by measuring the steady-state plasma glucose response during a continuous infusion of epinephrine, propranolol, glucose, and exogenous insulin. Insulin suppression of hepatic glucose production was calculated from the results of two studies in which glucose turnover rate was measured by a continuous infusion of 3H-2-glucose. The first study was performed under conditions of basal insulin secretion, and the second carried out at steady state exogenous insulin levels of approximately 100 muU/ml. The results indicated that basal hepatic glucose production was the same in both groups, and was suppressed to an equal degree by physiological levels of insulin. These data demonstrate that hepatic glucose production can be suppressed to an equal degree in normal and hypertriglyceridaemic subjects at comparable circulating insulin levels, at the same time that resistance to insulin-stimulated glucose uptake is observed in the hypertriglyceridaemic individuals.

Adult↗
PubMed1978

Materno-fetal transport of creatine in the rat.

The transfer of 14C-creatine to the rat fetus was studied following continuous i.v. infusion into the mother. In the presence of a relatively constant maternal plasma 14C-creatine concentration, creatine was accumulated by the chorioallantoic placenta and visceral yolk sac to concentrations higher than that found in maternal or fetal plasma. The ability of the extraembryonic membranes to accumulate creatine changed during gestation; nevertheless, these membranes concentrated creatine against a gradient throughout the period studied (14-22 days of gestation). Neither 14C-creatine nor 14C-urea were concentrated in the placentae or fetal plasma when compared to maternal plasma. Simultaneous infusion of beta-guanidinopropionic acid with 14C-creatine reduced both movement and accumulation of creatine into the fetoplacental unit. It is concluded that the accumulation of creatine by the chorioallantoic placenta and by the visceral yolk sac is an active process with creatine diffusing down its concentration gradient into the fetal circulation.

Animals↗
PubMedDate not supplied

Neurotrophins, nociceptors, and pain.

It is now well established that neurotrophins play a crucial role in the development of the nervous system. However, there is increasing evidence that the function of neurotrophins persists throughout adulthood. The broad scope of neurotrophin action is well documented in the case of nerve growth factor (NGF) and its effect on nociceptors and nociception. Here, we review the evidence for these multiple roles for NGF. Two manipulations influencing NGF levels are discussed in detail. The first involves the use of transgenic mice that overexpress or underexpress neurotrophins. A second strategy involves administration of NGF or its antibody in vivo to increase or decrease its level. During prenatal development, NGF is required for survival of nociceptors. In the early postnatal period, NGF is required for expression of the appropriate nociceptor phenotype. In adults, NGF acts as an important intermediate in inflammatory pain, contributing to both peripheral and central sensitization. The sensitization of peripheral nociceptors can be very rapid and can involve non-neural cells such as mast cells, neutrophils, fibroblasts, and macrophages. Recent evidence indicates that other neurotrophins also play key supporting roles in the development of nociceptors (e.g., NT-3) and in inflammatory pain (e.g., BDNF, NT-4/5). Furthermore, molecules from other superfamilies (e.g., GDNF) also are required to assure survival of certain classes of nociceptors. The diverse effects of neurotrophins on nociceptive processing emphasize their broad importance in the development and function of the nervous system.

Animals↗