Search PubMed⌕ Search

Biomedical subjects

J Brown

Publications and source records attributed to J Brown.

At least 1,009 records · Page 56Linked to original sources
PubMed1981

Vagal release of IR-VIP and IR-gastrin from the isolated perfused rat stomach.

The effects of electrical stimulation of the vagus at varying pulse widths on the release of immunoreactive VIP (IR-VIP) and IR-gastrin have been investigated, using the isolated perfused rat stomach preparation. Electrical stimulation of vagal trunks at a pulse width of 0.1 msec duration yielded no change in basal IR-VIP levels whereas a pulse width of 5.0 msec produced a prompt sustained increase. Stimulation at either pulse width evoked gastrin release. Atropine blocked the vagal release of IR-gastrin but not IR-VIP whereas hexamethonium blocked both responses. Exogenously administered porcine VIP, at concentrations mimicking endogenously released levels, was used in an attempt to reproduce the effects observed by vagal stimulation. Exogenous VIP had no effect on gastrin or somatostatin-like immunoreactivity (SLI) release. These in vitro studies support a role for VIP as a neurotransmitter released from the stomach by low-threshold non-cholinergic vagal fibres, but involving autonomic ganglia.

Animals↗
PubMed1981

Diffusion of calcium ions in retinal rods. A theoretical calculation.

The Fick diffusion equation is combined with the Langmuir adsorption isotherm and the relevant equations from the Gouy-Chapman theory of the electrical diffuse double layer to demonstrate that the effective diffusion coefficient of calcium ions, both in the cytoplasm of the rod outer segment and within the aqueous space bounded by the disk membrane, should be reduced by a factor of 10-100 because these ions adsorb to phospholipids present in the disk membrane.

Calcium↗
PubMed1981

Perioperative management of diabetes mellitus.

Hourly plasma glucose concentrations in 191 diabetic patients undergoing 200 operations were measured. The glucose infusion rate was controlled. Insulin-taking diabetics given no insulin or a fraction of their usual dose preoperatively developed rising plasma glucose concentrations beginning with the start of operation. The mean rate was 22 mg.dl-1.h-1 (no insulin) and 17 mg.dl-1.h-1 (one-half to one-fourth the usual dose of insulin). Eight per cent of the patients achieved plasma glucose concentrations greater than 400 mg/dl. Patients given regular insulin during the operation had no hourly rise in plasma glucose. However, hypoglycemia occurred in 5.5 per cent of these patients. The authors suggest that arbitrary management regimens should be abandoned. Plasma glucose levels should be measured frequently and insulin and/or sugar should be given to each patient as needed.

Aged↗
PubMed1981

Recovery and function of human fetal pancreas frozen to -196 C.

Human fetal pancreases were dissected into 1- to 2- mm3 fragments and frozen to -196 C using a modification of procedures previously used successfully for cryopreservation of the rat fetal pancreas. Freeze-recovered pancreatic pieces were able to incorporate radioactive amino acids into proteins. When placed into organ culture, nonfrozen control and freeze-recovered pancreas tissue secreted radioimmoassayable insulin in response to glucose plus theophylline, but not to glucose alone. Freeze-killed pancreatic pieces were totally inactive functionally. With respect to those parameters tested, freeze-recovered pancreas tissues were equivalent to nonfrozen tissue.

Cell Survival↗
PubMed1981

Brief psychosomatic therapy for consummation of marriage.

We describe the treatment of sexual problems by Members of the Institute of Psychosexual Medicine who are trained to recognise and use therapeutically the doctor-patient interaction. A prospective study of long-standing cases of nonconsummation was chosen for evaluation of therapy as there was a definite outcome. Of 50 couples, most of whom had previously had many unsuccessful consultations, 64 per cent consummated within six months and 72 per cent in 14 months. Among those who had failed actually to consummate at six months, one third had increased their ability to enjoy sexual activity. The average number of attendances was six, involving altogether about four hours' work. These findings compare well with those reported in other studies and suggest that referral of such cases to a doctor specially trained in brief psychosomatic therapy tends to bring the best results.

Adolescent↗
PubMed1981

A progressive diagnostic schema for alcoholism with evidence of clinical efficacy.

A diagnostic schema for alcoholism is described. Based upon the National Council on Alcoholism criteria for alcoholism diagnosis, this schema permits the classification of any client into one of five mutually exclusive diagnostic categories. The schema is applied to data from an independent study. A significant client-type by treatment-type interaction is reported as evidence of the schema's clinical utility. The discussion outlines the need for further diagnostic refinements within the criteria and suggests possible uses of the schema as a research tool.

Alcoholism↗
PubMed1981

Sensitivity to avian purified protein derivative in cattle from farms having a high prevalence of swine mycobacteriosis.

On two farms in North Georgia a large percentage of the swine was infected with organisms of the Mycobacterium avium-intracellulare-scrofulaceum complex. The hypothesis that the cattle on these farms, which are maintained separately from the swine, would not be sensitive to avian purified protein derivative was rejected. It was concluded that the source of the M. avium-intracellulare-scrofulaceum complex of each animal population is environmental.

Animals↗
PubMed1981

Effects of an integrated physical education/music program in changing early childhood perceptual-motor performance.

Two approaches to facilitating perceptual-motor development in children, ages 4 to 6 yr., were investigated. The experimental group (n = 15) received 24 sessions of integrated physical education/music instruction based upon concepts of Kodaly and Dalcroze. The control group (n = 15) received 24 sessions of movement exploration and self-testing instruction. Analysis of covariance indicated that significant improvement occurred only in the experimental group, with discharges changes in the motor, auditory, and language aspects of perceptual-motor performance as well as total score.

Child↗
PubMed1981

Serological responses to Mycoplasma synoviae in chickens infected with virulent or avirulent strains of Marek's disease virus.

The pathogenicity and immunosuppressive capability of five strains of Marek's disease herpesvirus (MDHV) was examined. Three of the strains (ALA, MISS, NCS) were isolated from flocks experiencing vaccine breaks while the other two strains (GA, HN) represented prototype virulent and avirulent viruses. Pathogenicity of MDHV strains was evaluated on their ability to cause mortality, their ability to cause gross or microscopic lesions, and the median latent period to death (MLPD) for each strain. Antibody responses to Mycoplasma synoviae (MS) were tested by the serum plate agglutination and hemagglutination inhibition tests. Chicks infected with the virulent strains of MDHV had greater mortality, greater lesion incidence, and shorter MLPD that did chicks infected with the avirulent HN strain. Infection with virulent strains reduced the antibody response to MS and caused severe bursal lesions. Chicks infected with the avirulent HN strain exhibited a slight immunosuppression, but they had no evidence of bursal destruction.

Animals↗
PubMed1981

Computer-aided alcoholism diagnosis in obstetric-gynecologic medical settings.

A computer-aided Alcoholism Diagnostic ALGOrithm (ADALGO) based on the NCA criteria for the diagnosis of alcoholism is applied in 233 obstetric and gynecologic patients. Alcoholism symptoms in the patients were intensively investigated by means of a 10-page, self-administered questionnaire, a 45-minute interview, and a medical record review. Alcoholism diagnoses based on the resulting set of 43 NCA symptoms are compared with ADALGO diagnoses utilizing an average of 26 symptoms. Agreement was achieved in 95.7% of the cases for dichotomous, alcoholic-nonalcoholic diagnoses and in 91% of the cases using a five-category alcoholism diagnostic schema. The feasibility of routinely screening for and diagnosing alcohol-related problems in ambulatory care settings using ADALGO and the NCA criteria is discussed.

Alcoholism↗
PubMed1981

Regulation of pathways of ornithine metabolism. Effects of thyroid hormone and diabetes on the activity of enzymes at the "ornithine crossroads' in rat liver.

There is a significant increase in four of the urea cycle enzymes in liver from hypothyroid rats, arginase alone showed an opposite trend; these changes are reversed by physiological doses of thyroxine; hyperthyroidism results in a significant decrease in ornithine transcarbamoylase activity. The pattern of change in thyroidectomized and alloxan-diabetic rats showed marked similarities in respect to urea cycle and ornithine-metabolizing enzymes which are discussed in the light of the common feature of hypoinsulinism of diabetes and depressed response to insulin in hypothyroidism. The profile of ornithine-metabolizing enzymes is consonant with the decreased protein synthesis and turnover in hypothyroidism.

Animals↗
PubMed1980

Pharmacokinetics of gallium nitrate in man.

Gallium nitrate is a new antineoplastic agent that has shown activity in a number of in vitro tumor systems. During a Phase I clinical trial, the pharmacokinetics of two methods of administration of gallium nitrate were studied: a seven-day continuous intravenous infusion, and a weekly rapid intravenous infusion. During the continuous infusion of 200 mg/M2 of gallium nitrate, plasma gallium concentrations of 0.9 +/- 0.2 microgram/ml in one patient, and 1.9 +/- 0.4 microgram/ml in a second were noted. Urine excretion of gallium approximated the daily administered dose by day 2-3. Overall, 68-107% of the total administered dose was recovered in the urine. Following a rapid intravenous infusion, a biphasic curve was generated. The T1/2 alpha ranged from 8.3-26 minutes; the T1/2 beta from 6.3-196 hours. From 69-91% of the administered dose was recovered in the urine. The effects of gallium nitrate on tissue localization and body retention of 67Ga are also presented.

Adolescent↗
PubMed1980

Effects of alpha-adrenoceptor agonists and antagonists and of antidepressant drugs on pre- and postsynaptic alpha-adrenoceptors.

The effects of alpha-adrenoceptor agonists and antagonists and of antidepressant drugs were studied on pre- and postsynaptic alpha-adrenoceptors. The rat vas deferens, stimulated at low frequency (0.1 Hz) was used for presynaptic studies. The rat anococcygeus muscle was used in postsynaptic studies. In the agonist studies clonidine and guanfacine were selective for presynaptic alpha-adrenoceptors, methoxamine and phenylephrine were selective for postsynaptic alpha-adrenoceptors and noradrenaline and alpha-methylnoradrenaline were equipotent at pre- and post-synaptic alpha-adrenoceptors. In the antagonist studies piperoxane and yohimbine were selective for presynaptic alpha-adrenoceptors, phentolamine was equipotent at pre- and postsynaptic alpha-adrenoceptors and prazosin was a selective postsynaptic alpha-adrenoceptor antagonist. In the series of antidepressants studied, mianserin was the most potent antagonist at presynaptic alpha-adrenoceptors, followed by trazodone, amitriptyline and nortriptyline in descending order of potency. Mianserin was approximately two hundred times less potent than piperoxane as a presynaptic alpha-adrenoceptor antagonist. Viloxazine and desipramine were inactive. With the exception of viloxazine all of the antidepressants examined possessed postsynaptic alpha-adrenoceptor antagonist properties.

Adrenergic alpha-Agonists↗