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Biomedical subjects

A Bruce

Publications and source records attributed to A Bruce.

At least 55 records · Page 3Linked to original sources
PubMed1993

Salen-manganese complexes are superoxide dismutase-mimics.

Complexes of manganese have previously been shown to exhibit SOD activity. In this study, we tested the ability of several (salen)-manganese complexes to scavenge O2.. Both neutral and cationic complexes were determined to be SOD-mimics. The activity of the complexes was not affected by the presence of bovine serum albumin in the assay. For most compounds, the activity was inhibited by the addition of EDTA. The stability and high catalytic activity of some of these molecules suggest that they might have potential use in a variety of conditions which involve overproduction of oxygen free radicals.

Edetic Acid↗
PubMed1993

Radial ray defect and Robin sequence: a new syndrome?

We report an infant with the principal features of bilateral radial defects, club foot deformity, micrognathia and cleft palate. Other dysmorphic manifestations include the presence of bilateral clinodactyly, medial displacement of the thumb, low set ears and an unusually long 2nd toe. This constellation of signs has not been previously reported and may constitute a new syndrome.

Abnormalities, Multiple↗
PubMed1992

Effects of different designs and extension of a food frequency questionnaire on response rate, completeness of data and food frequency responses.

The authors studied how the introduction of several modifications to a basic food frequency questionnaire can influence the results of dietary surveys. Modifications covered eight combinations based on three levels: increasing versus decreasing order of frequency categories; questionnaires without versus with questions about portion sizes, and questionnaires without versus with extra non-dietary questions. The sample included 6783 women between the ages of 40 and 70 years who took part in mammography screening. The women were randomly assigned to one of the eight study groups. All of the women in each group received one of the eight differently modified questionnaires. The forms extended in length by extra non-dietary questions and portion size categories resulted in a 20% higher total non-response compared to the shorter basic form. Partial non-response was significantly lower for all four questionnaire types that included portion sizes. When portion sizes were included in the questionnaire, the reported mean frequency of consumption was significantly reduced for fat (-10 times per month), milk (-6), bread (-5), vegetables (-2) and fish (-0.4). The decreasing order of responses to the frequency categories was associated with a statistically significant increase in the frequency responses for bread (2.6 times per month), vegetables (2) and fish (0.6). These data provide evidence that the design and extension of food frequency questionnaires influence the results of dietary studies.

Adult↗
PubMed1989

Cardiovascular-risk reduction: initial diuretic therapy compared with calcium-antagonist (felodipine) therapy for primary hypertension.

Drug therapy for hypertension has failed to demonstrate a significant reduction in coronary mortality. We compared a calcium-antagonist agent, felodipine, with diuretic therapy as a first-line antihypertensive treatment in a randomized study, to assess the effects of six months of each regimen on over-all cardiovascular risk. Both regimens lowered blood pressure to less than 85 mmHg by one month. Felodipine alone was sufficient to control blood pressure in 90% of patients, while 50% of patients who were receiving diuretic therapy required a second agent for control. Diuretic therapy produced a 10% fall in serum potassium levels (P less than 0.001) and a three-fold increase in plasma renin activity (P less than 0.005) by one month; and a 6% rise in serum cholesterol levels (P less than 0.05) and a 38% rise in serum triglyceride levels (P less than 0.05) by three months. Felodipine did not influence these measurements, but caused a 43% increase in plasma noradrenaline levels by one month of therapy (P less than 0.025). In both groups, a significant fall occurred in the risk percentile score at six months, as calculated from the Multiple Risk Factor Intervention Trial data. However, the decrease was significantly greater in the felodipine group at six months (45% compared with 29%; P less than 0.05). Thus, when doses were titrated to achieve equivalent effects on blood pressure, felodipine had the advantages over diuretic treatment of being effective as monotherapy, of having fewer metabolic effects, and of reducing cardiovascular risk to a greater degree.

Adult↗
PubMed1989

Influence of albumin and non-esterified fatty acids on serum prostacyclin binding in pregnancy.

We investigated the etiology of the previously documented decrease in serum prostocyclin binding during pregnancy. Addition of albumin to the serum of pregnant women failed to raise binding to non-pregnant levels. Pregnancy serum bound significantly more prostacyclin following the removal of non-esterified fatty acids and the addition of fatty acid free albumin resulted in a rise in binding to non-pregnant levels. We conclude that serum protein prostacyclin binding is affected by both albumin concentration and non-esterified fatty acids.

Blood Proteins↗
PubMed1989

Serum prostacyclin binding and half-life in normal and hypertensive pregnant women.

The effective half-life of prostacyclin in human serum is highly dependent on binding to serum proteins. Abnormalities in prostacyclin binding appear to be important in some patients with thrombotic thrombocytopenic purpura. We investigated prostacyclin binding and half-life in normotensive and hypertensive pregnant women and in nonpregnant controls. Pregnancy was associated with a decrease in serum prostacyclin binding and a shorter prostacyclin half-life. This decrease was even greater in women with hypertensive disorders. The decrease in prostacyclin half-life in hypertensive disorders may play an important role in the pathogenesis of these disorders. Measurement of both production and metabolism, however, will be required to adequately assess the role of prostacyclin in normal and abnormal gestation.

Adult↗
PubMed1988

Serum prostacyclin binding and half-life in the umbilical circulation.

Serum prostacyclin binding and half-life was measured in twenty pairs of maternal and umbilical venous samples and in twenty non-pregnant controls. When compared to non-pregnant values both umbilical and maternal samples demonstrated significantly lower albumin concentrations, percentage of prostacyclin binding and shorter prostacyclin half-life.

Epoprostenol↗
PubMed1987

Platelet inhibitory activity in placentas from normal and abnormal pregnancies.

Retroplacental blood flow requires inhibition of coagulation in the absence of an endothelial lining. We confirmed that trophoblast releases an inhibitor of platelet aggregation which functions via degradation of adenosine diphosphate. This inhibitor appears to be deficient in some pregnancies with abruptio placentae and intrauterine growth retardation. Unimpeded retroplacental blood flow may depend upon the local inhibition of platelet aggregation. Placental tissue contains an inhibitor of platelet aggregation which appears to be an adenosine diphosphatase distinct from heat-stable alkaline phosphatase. Placental tissue from patients with abruptio placentae contains abnormally low amounts of this enzyme.

Abruptio Placentae↗