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Biomedical subjects

B Brown

Publications and source records attributed to B Brown.

At least 307 records · Page 17Linked to original sources
PubMed1982

Effect of ovarian hormones on the phagocytic response of ovariectomized mares.

The reaction between ovarian hormones and experimental uterine infection (Streptococcus zooepidemicus) was investigated in 3 groups, each containing 6 ovariectomized mares. Group 1 served as controls ('anoestrus'), Group 2 mares were injected with oestrogen ('oestrus') and Group 3 with progesterone ('dioestrus') over a period of 5 weeks. All mares received an intrauterine inoculation of the bacteria 1 week after the start of hormonal treatment, and the results of the challenge were examined by endometrial biopsy and swabs once weekly. At the end of Week 1 no bacteria were recovered from the mares in Group 2. Group 1 mares were free of bacteria at the end of Week 2 but all Group 3 mares remained infected at least for the total period examined. Streptococcal phagocytosis was quantitated by chemiluminescence. Before the challenge-inoculation, phagocytosis was not significantly different in the 3 groups of mares. Bacterial cultures were negative for all three groups. However, within 48 h after infection, there was a significant increase (P less than 0.01) in phagocytosis in Group 2 and a significant suppression (P less than 0.05) in Group 3 mares. Patterns of streptococcal clearance from the uterus closely paralleled the changes in the magnitude of chemiluminescence response. The results suggest that ovarian hormonal status can modulate the phagocytic response in episodes of streptococcal-induced endometritus in mares.

Animals↗
PubMed1982

Taking the mystique out of low vision.

Rehabilitation of the partially sighted patient is often a difficult problem from both a physical and psychological point of view. The physical aspect is addressed, providing a concise and practical approach to low vision evaluation and management that avoids discussions of optics and complex theory. Suggestions are given for patient examination procedures, determination of their low vision needs, and making referrals to rehabilitation agencies. Recommended vendors, agency addresses, and other useful information are provided. A suggested method of low vision evaluation in an office or clinic that uses the help of ophthalmic assistants or nurses and maximizes assistance to the patient is presented.

Adult↗
PubMed1982

Incidental pituitary adenomas: a retrospective study.

A retrospective study was performed to study the incidence, morphology, and endocrine activity of incidental pituitary tumors in 500 consecutive autopsied subjects. Forty-two pituitary glands were found to have occult pituitary adenomas. These tumors were more frequently found in patients who died in the sixth or seventh decade of life. There was no obvious sex predominance. Of these patients 48% were obese, 34% were diabetic, and 57% were hypertensive. However, in only one case a pituitary lesion was clinically questioned but specific endocrine functions were not performed. The tumor size ranged from 1 to 15 mm, with 62% of tumors being less than 3 mm. In 34 cases the tumors were located along the lateral aspect of the gland, and 36% of these tumors stained positive for the presence of prolactin. Suspicious or abnormal areas were found in 11 of 17 cases in which skull x-rays were taken. In this article we discuss the factors that may affect the recovery incidence of occult pituitary adenomas. The biologic behavior of these microadenomas, especially those classified as prolactinomas, is unclear, but there clinical effects appears to be relatively benign.

Adenoma↗
PubMed1982

Effects of benactyzine hydrochloride on dynamic vision functions.

We have investigated the effects of an anticholinergic drug, benactyzine HCl on vision and vision function. Our experiments assess the time course and severity of benactyzine effects on visual acuity for static and moving targets, amplitude and dynamics of accommodation, pupil response to light and the spatial contrast sensitivity function. A single dose of the drug (4.14 mg/70 kg body weight, which is within the therapeutic range) and placebo were administered intramuscularly to 12 subjects. Large and significant decrements in visual function were demonstrated after the administration of benactyzine, particularly for those functions performed at near focus. The drug effect was rapid in onset, beginning 7-10 min after injection, peaked at approximately 30-40 min, and declined to baseline values over the next 2 h. The drug increased pulse rate and blood pressure, and induced an intoxicated state involving loss of concentration, attention, and short-term memory.

Accommodation, Ocular↗
PubMed1982

Effects of an anticholinergic drug, benactyzine hyrochloride, on vision and vision performance.

Benactyzine is an anticholinergic agent which has been used in past years in psychiatry, but is little used today. It has central and peripheral anticholinergic effects, and when administered intramuscularly, it has a rapid onset of action. This may make it useful as an antidote for organophosphate poisoning, in spite of side-effects such as deficits of short term memory, concentration, and attention. As an anticholinergic drug it could also be expected to produce vision changes by its action on the intraocular musculature controlling the pupil and lens accommodation. We tested the drug on six volunteer subjects to establish the visual side-effects of intramuscular administration. We found that it reduced static and dynamic visual acuity, increased pupil size, reduced amplitude of accommodation and contrast sensitivity, while having little or no effect on glare recovery, color vision, intraocular pressure, stereoacuity, oculomotor tracking, and distance heterophoria. Benactyzine produced reductions in visual performance for up to 3 h and had the greatest effects on functions which have significant cognitive components. The present results suggest that the drug is unsuitable for treatment for oganophosphate poisoning when continuous performance is required, although a definitive test of ths suggestion would require that performance should be tested when benactyzine and the organophosphate of interest were combined.

Adult↗
PubMed1981

5-fluorouracil, adriamycin, and mitomycin-C (Hi-FAM) chemotherapy for adenocarcinoma of the lung.

Thirty patients with unresectable adenocarcinoma of the lung were treated with high doses of 5-fluorouracil, Adriamycin, and mitomycin-C (Hi-FAM). Objective responses were seen in ten patients (one complete and nine partial remissions). No patient with pleural disease responded to treatment. Responses were seen in all other sites of involvement including liver. In a subgroup of patients younger than 65 years, who had not had prior treatment, and who had a performance status of greater than 60 (Karnofsky), an overall response rate of 50% was realized. The overall median survival for responding patients was 10+ months while nonresponders had a median survival of 5.21 months. Patients who had had prior irradiation had a median survival of 4.81 months compared with patients who had not had any prior treatment, whose median survival was 8.45 months. Toxicity was substantial and included primarily bone marrow suppression and stomatitis. Elderly patients with poor performance status and prior treatment tolerated therapy less well. These results indicate that Hi-FAM is useful in selected groups of patients with advanced adenocrcinoma of the lung.

Adenocarcinoma↗
PubMed1981

Reading performance in low vision patients: relation to contrast and contrast sensitivity.

Closed circuit television (CCTV) systems have proven useful in professional and recreational rehabilitation of the partially sighted. However, the parameters for optimum performance on such systems have not been examined. This investigation shows that contrast is an important parameter in CCTV reading performance; for many patients, even slight contrast reductions significantly reduce reading performance. Distance acuity is not a good predictor of CCTV reading performance, nor is performance on conventional contrast sensitivity measures. However, a commercially available test for contrast sensitivity (the Arden plates) may be useful for predicting CCTV reading performance.

Aged↗
PubMed1980

A theory of distortion of the reaction zone.

A cylindrical detonating explosive behaves like a non-Newtonian viscous fluid emerging from a cylindrical pipe. The expression for non-Newtonian viscous flow has been applied to detonating explosives. The resultant fit to emerging flame fronts from detonation is excellent for a wide variety of detonating explosives both for transients (at various times) and for steady state. The quantities k'(lambda/lambda(1))(2/B) and 1/B and the rate constant k' increase abruptly at a time supporting a change in mechanism from deflagration to detonation in the transient during initiation. All of these parameters are temperature sensitive, indicating an abrupt temperature increase as a condition or indicator in the deflagration-to-detonation transition. Furthermore, a straight line results when log particle velocity u is plotted against log radial distance r, indicating that, for the explosives studied, the hyperbolic cosine wave front can be replaced by a parabolic wave front within the accuracy of the available experimental data.

Journal Article↗
PubMed1980

Early heart failure as a cause of growth and tissue disorders in children with congenital heart disease.

Height, weight, total body fat, lean body mass, size of fat cells and total number of lipid-containing fat cells were compared in two groups of children, ages 2-6 years, with congenital heart disease. Twelve children who developed heart failure in infancy made up one group and 14 asymptomatic patients made up the other. No patient was cyanotic or had undergone surgical repair. Patients with heart failure were shorter and lighter than asymptomatic patients. Whereas both fat and lean tissues were less in the heart failure group, reduction in body fat was more important in producing underweight. Although there was no difference in the size of fat cells, the number of lipid-laden fat cells was diminished in the children who had early heart failure. Thus hypocellularity of fat cells appeared to be the major determinant of diminished body fat with heart failure. Because shortness and decreased lean tissue were associated with these adipose tissue abnormalities, it is likely that widespread changes are caused by early heart failure. As previously reported with hypoxemia, the early development of heart failure seems to produce tissue changes that handicap growth.

Adipose Tissue↗