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Biomedical subjects

H Parker

Publications and source records attributed to H Parker.

At least 37 records · Page 2Linked to original sources
PubMed1992

Race and ethnicity in health research.

'Race' and 'ethnicity' are increasingly being used as variables in health research. However, studies have been mainly descriptive and have not been used to develop and evaluate strategies to improve health care. In part this reflects the poor analytical standards. The status of the concepts of 'race' and 'ethnicity' as research tools are rarely considered and there is poor consistency in terminology. This paper gives an overview of the research literature and raises questions about the validity of 'race' and 'ethnicity' as epidemiological variables. The tendency to collect routine ethnic data and include ethnic variables in an ad hoc and uncritical way in the United Kingdom and other countries may help transform minorities into mere statistical categories and produce data and findings which reinforce stereotypes. Multiculturalist ethnic health explanations also tend to displace more material explanations of health outcomes. It is concluded that more thought and care is needed before data are routinely categorized by ethnicity, or race or ethnicity are included as variables in research.

Epidemiologic Methods↗
PubMed1983

Prognosis of patients with acute pulmonary edema and normal ejection fraction after acute myocardial infarction.

To assess the prognostic importance of resting left ventricular function in survivors of acute myocardial infarction with pulmonary edema, we retrospectively identified 39 consecutive patients who presented with acute pulmonary edema and myocardial infarction. Sixteen patients had radionuclide ejection fractions 10 +/- 2 days postinfarction of greater than 0.45 (group A, mean 0.55 +/- 0.06), and 23 patients had ejection fractions less than or equal to 0.45 (group B, 0.32 +/- 0.06). There were no significant differences between the two groups for age or sex, but group A patients had a significantly greater incidence of first myocardial infarction predominantly inferior in location. The calculated stroke work index during the acute event was significantly greater in group A than in group B (33.4 +/- 2.4 vs 23.4 +/- 2.0) (p less than 0.05). During a follow-up of 9 +/- 3 months, mortality was not significantly different between the two groups: Four (25%) died in group A and seven (30%) died in group B. In addition, eight patients (50%) in group A were hospitalized for recurrent angina, new myocardial infarction or recurrent pulmonary edema, compared with 11 (48%) in group B (NS). Three deaths in group A were preceded by infarction of the anterior wall of the left ventricle, confirmed at autopsy, and two nonfatal infarctions were anterior by electrocardiography. Four patients in group A had coronary arteriography performed during the follow-up period because of unstable angina, and all had significant (greater than or equal to 70% stenosis) three-vessel disease and two had left main coronary artery disease. Therefore, the predischarge ejection fraction did not predict prognosis for this group of patients. Patients with acute pulmonary edema in the course of myocardial infarction form a high-risk group despite good resting left ventricular function at discharge. They have a significant incidence of recurrent myocardial infarction and death and, because they have good residual left ventricular function, are excellent candidates for surgical intervention.

Acute Disease↗
PubMed1983

Rupture of a spontaneous aortoduodenal fistula visualized with Tc-RBC scintigraphy.

We present what we believe is the first reported case of a spontaneous aortoduodenal fistula, with massive rupture into the duodenum during the performance of a radionuclide study of gastrointestinal bleeding. Our experience suggests that nuclear scintigraphy with labeled red blood cells can help in the diagnosis of this disorder by demonstrating both the presence of an abdominal aortic aneurysm and bleeding in the gut.

Aged↗
PubMed1980

Social perspectives in Huntington's chorea.

The social implications of Huntington's chorea are serious and far-reaching, affecting all members of the family and the community as a whole. The relativly common occurrence of suicide and of major and minor crimes are cause for concern. The disease imposes a significant economic burden on both the family and society. The minimum direct cost to the state of a single affected prson with Huntington's chorea in South Africa is estimated at R23 000.

Crime↗
PubMed1980

N-isopropyl-[123I] p-iodoamphetamine: single-pass brain uptake and washout; binding to brain synaptosomes; and localization in dog and monkey brain.

The kinetics of N-isopropyl-p-[123I]iodoamphetamine in rat brains were determined by serial measurements of brain uptake index (BUI) after intracarotid injection; also studied were its effects on amine uptake and release in rat's brain cortical synaptosomes; and its in vivo distribution in the dog and monkey. Serial BUI correspond to a first-pass extraction efficiency of 100% and a washout half-time of approximately 318 sec. The S-(+)-isomer inhibited norepinephrine uptake in synaptosomes as strongly as D-amphetamine, but was more potent in inhibiting synaptosomal uptake of serotonin. Both isomers were comparable to D-amphetamine in causing release of serotonin from synaptosomes, but the S-(+)-isomer promoted release of dopamine, whereas D-amphetamine did not. No specific localization in brain nuclei of the dog was seen, but there was progressive accumulation in the eyes. Rapid initial brain uptake in the ketamine-sedated monkey was noted, and further slow brain uptake occurred during the next 20 min but without retinal localization. High levels of brain activity were maintained for several hours. The quantitative initial single-pass clearance of the agent in the brain suggests its use in evaluation of regional brain perfusion. Its interaction with brain amine-binding sites suggests its possible application in studies of cerebral amine metabolism.

Amphetamines↗
PubMed1978

Carotid-cavernous fistula. Demonstration of asymptomatic vascular "steal".

Abnormal distribution of cerebral vascular flow was studied in a patient who had a traumatic carotid-cavernous sinus fistula. Serial studies were performed using a method for determining relative cerebral vascular flow:99mtechnetium-diethylenetriamine pentaacetic acid (99mTc-DTPA) was injected intravenously and flow data were processed by a digital computer. Serial studies documented the occurrence of a vascular "steal" during temporary carotid occlusion; postoperative studies showed disappearance of the steal and obliteration of thiling arterial structures and capillary filling in the brain, and in demonstrating alteration in the cerebral circulation.

Adult↗
PubMed1977

Neurologic diagnosis using the 80-lens optical camera.

This article describes the clinical application of the 80-lens optical camera in the diagnosis of cerebral infarction, subdural hematoma, intracranial tumor, and hydrocephalus. The 80-lens camera is a simple noncomputerized addition to the Anger scintillation camera that permits an estimation of the cerebral blood flow. The study is noninvasive and quick, minimizing the effect of movement artifact and showing areas of either increased or decreased blood flow. Abnormal tumor vessels appear, and subdural hematomas show brain displacement away from the skull edge. Interpretation of blood flow pattern is not affected by scalp or skull trauma, eliminating a source of error incurred with static scans.

Aged↗
PubMed1975

Rationale and indications for the "hanging hip" procudure: a clinical and experimental study.

A series of 71 patients treated by "hanging hip" procedures was followed for up to 12 years. The procedure provided a satisfactory result in patients even with severe hip joint degeneration as long as the congruity of the joint is preserved and there was no concentration of stress. When these conditions are not fulfilled the results are poor. An experimental study was carried out to try and ascertain the physiological rationale for the "healing" seen in patients with good preoperative indications. The articular cartilage of one hip in cats was denuded with a curette. This was accompanied in half the animals with a "hanging hip" procedure. The hips of the animals with "hanging hip" went onto fibrocartilaginous and chondroid healing of their articular surfaces and clinically did well. The hips of the animals who did not have multiple tenotomies developed osteoarthrosis. Full thickness cartilage defects in weight-bearing areas in adult animals are capable of functional healing if the mechanical stress on the joint is sufficiently decreased. The "hanging hip" operation should no longer be considered a salvage procedure. A physiological rationale exists for it in properly selected patients and represents a reasonable alternative to total hip replacement.

Adolescent↗