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Biomedical subjects

J Brown

Publications and source records attributed to J Brown.

At least 847 records · Page 47Linked to original sources
PubMed1986

Inflation pressure effect on performance of air-filled wheelchair cushions.

Air-filled wheelchair cushions are frequently used in the prevention of pressure sores. Their effectiveness in reducing interface pressures and in redistributing body weight (BW) appears dependent on their internal inflation pressure. This pilot study examines and defines this relationship. Interface pressures were measured with the TIPE (Texas Interface Pressure Evaluator) system for 14 subjects while sitting on each of three commercially available air-filled wheelchair cushions. This relationship between interface pressure and internal pressure was then determined for each of the three body-build categories. In each category the interface pressure displayed a higher degree of sensitivity to underinflation than to overinflation. A high correlation found between BW and internal air pressure (IAP), may be useful in the design of a customized pressure indicator system. The study documents the influence of IAP on seating pressure and supports the need for further research in the development of an indicator system that alerts users to under- or overinflation of the cushion.

Air↗
PubMed1986

Testing for neurogenic impotence: a challenge.

The bulbocavernosus reflex and pudendal evoked responses were obtained in a group of control patients and impotent men in an attempt to assess their reliability and objectivity in diagnosing neurogenic erectile dysfunction.

Adult↗
PubMed1986

Thyroidal and prolactin secretion in agalactic mares.

A study was designed to examine serum concentrations of prolactin (PRL) and iodothyronines before and after thyrotropin releasing hormone (TRH) administration to agalactic (n = 26) and normally (n = 8) lactating mares. Two mg TRH was given intramuscularly (i.m.) twice daily on Day 1 (day of delivery) through Day 5. Jugular venous blood was collected on Days 1 and 5 before TRH (time 0) and at 1 and 3 h post-TRH. Basal serum concentrations of thyroxin (T(4)) were different (P < 0.05) on Day 1 (1.87 vs 1.37 mug/dl) and Day 5 (1.72 vs 1.13 mug/dl) in the normal mares and agalactic mares, respectively. There was no difference in the T(4) response to TRH. While basal serum concentrations of triiodothyronine (T(3)) were not different, agalactic mares responded with greater (P < 0.05) serum concentrations T(3) to TRH on Day 1. Following linear regression of the PRL response to TRH, slope of the lines between groups did not differ; however, elevations were significantly (P < 0.05) greater (1.79 vs 1.28 ng/ml) in control mares compared with agalactic mares, respectively, on Day 1.at 1 h post-TRH. A similar difference existed at time 0 and 1 h on Day 5. Consequently, agalactic mares had reduced basal serum T(4) values; the PRL data leads us to suggest that secretion of this hormone may be insufficient in agalactic mares.

Journal Article↗
PubMed1986

Immune complex-like disease in 23 persons following a booster dose of rabies human diploid cell vaccine.

Following a routine 0.1 ml booster dose of Merieux rabies human diploid cell vaccine (HDCV), administered intradermally, 23(10.2%) of 226 persons had signs and symptoms compatible with an immune complex-like disease. The disease had its onset from 3-13 days after the injection, lasted 1-5 days, and consisted primarily of urticaria (78.3%), macular rash (65.2%), angiooedema (39.1%), and arthralgia (17.4%). None of the cases were considered severe, and all recovered with no sequelae. There were significant differences in attack rates between men (78.3% of all cases) and women, and between those receiving vaccinations on different days. Similar reactions have been reported following intramuscular booster doses of HDCV. Since the Merieux HDCV is used worldwide, physicians administering HDCV must be aware of these adverse reactions and warn patients. Appropriate therapy should be instituted as warranted by severity of reactions.

Adult↗
PubMed1986

Radiotherapeutic prophylaxis of estrogen-induced gynecomastia: a study of late sequela.

Radiation therapy is an effective means of preventing the development of hormone-induced gynecomastia in men with cancer of the prostate. The efficacy and morbidity of this type of radiation was studied in a retrospective analysis of 87 patients referred for treatment from 1972 to 1982. Patients receiving DES as treatment for prostate carcinoma were treated with irradiation to the breast tissue. Patients were treated with 4 MV, 60Co superficial X rays. Doses range from 1200 to 1500 cGy in 3 fractions. The majority of patients had satisfactory results in terms of prevention of gynecomastia and mammalgia. There were few acute reactions noted and no evidence of long term sequela.

Aged↗
PubMed1986

Effect of EDTA-tris on an Escherichia coli isolate containing R plasmids.

Solutions of ethylenediaminetetraacetate (EDTA)-tris combined with antibiotics have been shown to be effective in treating selected cases of persistent bacterial infections. Basic techniques in microbial genetics, including mating frequencies, chemical elimination of R plasmids, isolation of plasmid DNA and agarose gel electrophoresis, were used to determine if EDTA-tris has a curing effect on an R plasmid as part of its clinical action. Results of this study indicated that EDTA-tris by itself eliminated an antibiotic resistance marker from a clinical isolate of Escherichia coli and when combined with another chemical curing agent altered the isolate's mating frequency.

Conjugation, Genetic↗
PubMed1986

Gadolinium-DTPA in the assessment of liver tumours by magnetic resonance imaging.

The effect of gadolinium-DTPA (Gd-DTPA, Schering AG) as a magnetic resonance imaging (MRI) contrast agent was studied in 15 patients with liver tumours. A dose of 0.1 mmol/kg was used. An analysis of the time-course of enhancement, a comparison of four different pulse sequences, and a dose-comparison study were carried out with monitoring of haematological and biochemical parameters before and after injection of Gd-DTPA. Maximum enhancement, that is, increase in signal intensity, was noted on IR1400/400/13 between 10 and 20 min after injection while on SE580/40 and SE580/80 maximum enhancement was noted 30 min after injection. In some cases enhancement was noted up to 120 minutes after injection. SR1000/13f sequences showed very little enhancement. On comparison with contrast-enhanced X-ray computed tomography (CT), enhancement was greater on MRI in seven cases, equal in six and less in two, as assessed subjectively. Additional lesions were shown in one case using Gd-DTPA compared to precontrast enhanced MRI scans. However, no additional lesions were seen on contrast-enhanced MRI scans compared to contrast-enhanced CT scans. Gd-DTPA is capable of enhancing liver tumours on MRI and may have a place in the assessment of the operability of such lesions.

Contrast Media↗
PubMed1986

The patient-centred clinical method. 2. Definition and application.

In this article, the patient-centred clinical method is described in operational terms. Definitions are given for the patient's expectations, feelings and fears. The physician behaviours described are: facilitations, acknowledgements, cut-offs and returns. Using the definitions, a method was devised for scoring video-taped interviews for the degree of 'patient-centredness'. The method proved to have good inter-observer reliability.

Attitude to Health↗
PubMed1986

The patient-centred clinical method. 3. Changes in residents' performance over two months of training.

A method for assessing the patient-centred approach was used to identify changes taking place in the interviewing behaviour of 13 residents during two months in a teaching practice. The descriptive study confirmed the prediction that the residents' approach would become more patient-centred. A statistically significant change from August to October was found in the number of facilitating behaviours shown by residents (P less than 0.05) and there was a change in the number of fears expressed by patients (P less than 0.10). Increases in the number of expectations, feelings and prompts were noted but were not significant. The frequency with which residents cut off patients' expressions increased on the whole, although not significantly. The findings suggest that while these residents had succeeded in increasing their facilitating behaviours over two months (one-sixth of their family medicine experience) they had not yet found ways of responding to the many problems elicited.

Family Practice↗
PubMed1986

Studies with fenoldopam, a dopamine receptor DA1 agonist, in essential hypertension.

A series of studies were undertaken to assess the effect of oral fenoldopam, a specific DA1 dopamine receptor agonist on blood pressure and renal function in patients with mild essential hypertension. Six patients with essential hypertension were entered into a dose-ranging study and received either placebo, 25, 50 or 100 mg fenoldopam. A significant, dose-related reduction in diastolic blood pressure, and increase in heart rate was demonstrated (both P less than 0.05), maximal at 45 min to 1 h. Fenoldopam increased plasma renin activity. In a double-blind study, seven patients received a single dose of fenoldopam 100 mg or placebo. Fenoldopam produced a significant fall in systolic (P less than 0.05) and diastolic (P less than 0.01) blood pressure and renal vascular resistance (P less than 0.01). Urine flow rate (P less than 0.05), sodium excretion (P less than 0.01), plasma renin activity (P less than 0.05) and plasma aldosterone (P less than 0.05) increased. Five patients underwent measurement of the above parameters following a single dose of fenoldopam 100 mg with a repeat of these measurements after they had taken fenoldopam 100 mg four times daily for 1 month. The acute response of blood pressure to the single dose appeared unchanged but tachyphylaxis was evident in the responses of heart rate, plasma renin activity and plasma aldosterone.

Adult↗
PubMed1986

Domperidone treatment in man inhibits the fall in plasma renin activity induced by intravenous gamma-L-glutamyl-L-dopa.

The dopamine pro-drug gamma-L-glutamyl-L-dopa (gludopa) was administered intravenously to six normal subjects at a dose of 12.5 micrograms min-1 kg-1, either with or without the dopamine antagonist domperidone. A control was provided by the intravenous infusion of domperidone and saline on a separate occasion. Intravenous gludopa produced a significant natriuresis, whether administered alone or in combination with domperidone. After gludopa infusion, there was a significant fall in plasma renin activity, an effect which was attenuated significantly by concomitant treatment with domperidone. These observations suggest that blockade of renal DA2 dopamine receptors has little or no effect on gludopa-induced natriuresis, but that at least part of the dopaminergic inhibition of renin release is mediated by renal DA2 receptors.

Adult↗
PubMed1986

Cellular mechanisms involved in recovery from acute malaria in Gambian children.

This paper reports the results of in vitro experiments which attempt to elucidate the mechanisms whereby Gambian children control acute infections of Plasmodium falciparum. It was shown initially that mononuclear cells from children with acute malaria, in the presence of specific antibody, caused a marked reduction in in vitro parasite growth. IgM antibodies appeared to be considerably more effective than IgG. T or B lymphocytes were ineffective in the system; adherent cells alone had some effect, but much less than the unfractionated cell population. Adherent cells were however fully effective after exposure to supernatants from T cells activated either non-specifically by phytohaemagglutinin (PHA), or specifically by P. falciparum antigens. Depression of parasite growth was also observed, independent of anti-malarial antibody. This was achieved when adherent cells from healthy Europeans, as well as those from infected children, were exposed to the supernatants from previously stimulated T cells before adding to the culture. Furthermore, intra-erythrocytic parasite death occurred after a short exposure to the supernatants of 'activated' adherent cells from both infected children and Europeans.

Adolescent↗
PubMed1986

A single atrial extrastimulus can distinguish sinus tachycardia from 1:1 paroxysmal tachycardia.

We have developed a tachycardia detection scheme for use in an antitachycardia pacemaker in which the use of a properly timed atrial extrastimulus provides a means of discriminating sinus tachycardia from pace-terminable 1:1 tachycardias. An atrial extrastimulus is delivered in late diastole (80 ms premature), and the ventricular response is monitored. In sinus tachycardia, the ventricular response is expected to appear early as well, but in pace-terminable tachycardias, such as AV reentrant and ventricular with VA conduction, the ventricular rhythm will be unperturbed. Testing of the algorithm was performed in 34 patients. In 29 patients, atrial extrastimuli were delivered during sinus tachycardia, and in 22 patients during various types of 1:1 paroxysmal tachycardia. In one patient the procedure was completely automated, i.e., delivery of the atrial extrastimuli and diagnosis were microcomputer controlled. In 28/29 cases, the delivery of an atrial extrastimulus 80 to 120 ms early during sinus tachycardia elicited a ventricular response at least 28 ms early. In 22/22 patients with 1:1 paroxysmal tachycardia, atrial extrastimuli 80 to 120 ms early failed to produce a significant change in ventricular cycle length. This technique appears to be promising for prevention of inadvertent pacing of sinus tachycardia in an antitachycardia pacemaker.

Diagnosis, Computer-Assisted↗
PubMed1986

Clinical value of radionuclide oesophageal transit measurement.

We have reviewed our experience of 150 patients to assess the clinical value of radionuclide oesophageal transit measurements in relation to established oesophageal motility investigations. Achalasia and conditions characterised by incoordinate oesophageal motor activity were detected with equal frequency by manometry and radionuclide transit measurement. Radionuclide transit measurements identified abnormalities not detected by manometry in 18 patients, and manometry was abnormal in 26 patients with normal radionuclide studies, including all patients with nutcracker oesophagus and most with hypertensive lower oesophageal sphincter. The overall sensitivity of radionuclide transit measurements in detecting oesophageal dysmotility was 75%, the sensitivity of manometry was 83% and that of conventional barium radiology 30%. We conclude that radionuclide transit measurement is a useful test for patients with suspected oesophageal motility disorders. Although it has limitations as a screening test, it provides additional information which complements oesophageal manometry.

Adolescent↗
PubMed1986

Research on human embryos--a justification.

The philosophical debate surrounding the moral status of the embryo has reached the public arena. The author of this paper examines some of the common arguments against embryo experimentation, including an influential article by Professor Ian Kennedy. He concludes that these arguments do not succeed in demonstrating that the intentional creation of embryos for research purposes is wrong, unless they also succeed in demonstrating that contemporary liberal abortion laws are also wrong. The author also criticises the conclusions of the Warnock Report, and suggests that the reasons for permitting embryo research must be given a wider public audience.

Abortion, Induced↗