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Biomedical subjects

A Baldwin

Publications and source records attributed to A Baldwin.

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

Child and family factors that ameliorate risk between 4 and 13 years of age.

Protective processes in at-risk children between 4 and 13 years of age were examined in a longitudinal study. A multiple risk index was used at 4 years to identify 50 high-risk children and 102 who were at low risk. Cognitive and social-emotional status were measured at each time point. The following indicators of protective processes were related to positive change in cognitive and/or social-emotional function in the high-risk children between 4 and 13 years: mother-child interaction; child perceived competence, locus of control, life events, and social support; and maternal parenting values, social support, depression, and expressed emotion. Many of these factors were also related to improvement in the low-risk children. Some variables showed an interaction effect, where impact was substantially higher in the high-risk group compared with the low-risk group. The utility of multiple risk constructs and process oriented approaches to protective factors are discussed.

Adolescent↗
PubMed1990

Use of a bacterial sampler for rapid transfer of microvolumes into microplates.

A method has been devised to transfer very small volumes of serum from microplates prepared during routine screening of blood into microplates containing diluent. Simultaneous transfer of 96 samples is achieved without the need for disposable tips, while still avoiding carry-over between different plates. Using this method a mean transfer volume of 0.9 microliters (cv 8.9%) was obtained, which lent itself conveniently to testing for high-titre anti-microbial antibodies for which high dilution factors are required.

Humans↗
PubMed1987

Survey of population coverage in cervical cancer screening in the Oxford region.

A postal survey of a random sample of 3307 women aged 18-64 years living in the Oxford region (the Oxford healthy life survey) revealed age and social class differences in the proportion of women reporting an up-to-date cervical smear test. Although 86% of women in the 25-34 years age group reported a test in -the previous five years, the proportion dropped to 53% among the 55-64 year olds. Women in social classes 4 and 5 were significantly less likely to report a recent smear test (P<0.01) than women in higher social classes. An audit of the general practice notes of 176 of the respondents suggested that these self-reported results are likely to be reasonably accurate.A reduction in the number of deaths from cervical cancer will largely depend on the efforts of primary health care teams to screen women who are at relatively high risk of developing the disease, namely older women and those of lower social class.

Adolescent↗
PubMed1985

Progression of cardiovascular disease in acromegalic patients treated by external pituitary irradiation.

Cardiovascular complications are a major cause of morbidity and mortality in acromegaly and seem to be related to the long duration of the disorder. Conventional external pituitary irradiation for acromegaly produces a consistent, but slow, fall in elevated serum growth hormone (GH) levels. It has not been established whether such treatment is effective in preventing the development of cardiovascular complications. The evolution of cardiovascular disease has therefore been studied in 11 acromegalic patients followed up for a mean 10 years (range 3-17) after external pituitary irradiation. At the final follow-up fasting serum GH were significantly (P less than 0.01) lower than pre-irradiation levels, but cardiovascular events (myocardial infarction, dysrhythmias, hypertension, major arterial disease, heart failure) increased significantly in prevalence (P less than 0.01) during this period. Electrocardiographic abnormalities also increased in prevalence. At the final follow-up 6 patients had cardiomegaly on chest X-ray and echocardiographs (10 patients) were abnormal in every case. All 11 patients had evidence of complete or partial anterior hypopituitarism. We confirm that external pituitary irradiation is effective in reducing elevated serum GH levels in acromegaly, but suggest that such a slow reduction in serum GH levels does not retard the development of cardiovascular complications.

Acromegaly↗
PubMed1983

Effect of noradrenaline, sodium nitrite and isosorbide dinitrate on albumin transport in the wall of the excised rabbit common carotid artery.

The effects of noradrenaline (NA), sodium nitrite (NaNO2) and isosorbide dinitrate (ISDN) on the steady state distribution of 125I-labelled albumin in the wall of excised rabbit common carotid arteries were studied. The vessels were incubated in Tyrodes solution either at relaxed length and zero transmural pressure (non-pressurized) or at in vivo length and a transmural pressure of 70 mm Hg (pressurized). Label was applied in the same concentration at both the luminal and outer surfaces. The mean medial uptake in pressurized vessels was greater after treatment with 10(-7) M NA than after additional treatment with either 10(-3) M NaNO2 or 10(-3) M ISDN. The opposite was found for non-pressurized vessels. The medial uptake by NA-treated pressurized vessels was greater than that by NA-treated non-pressurized vessels, while the reverse was found for NaNO2- or ISDN-treated vessels. We conclude that the different patterns of uptake seen in these vessels results from the relative effects of externally applied stress (elongation and pressurization), smooth muscle tone and convection through the wall, on the properties of the interstitium, and possibly from the effects of the vasoactive agents on endothelial permeability.

Albumins↗
PubMed1982

Effects of particle size and perfusate composition on the uptake of colloidal gold by the rabbit thoracic aorta perfused in situ.

The influence has been investigated of particle size on the uptake of radioactive gold colloid by the rabbit thoracic aorta perfused in situ. Particles ranging in diameter from 14 nm to 40 nm were suspended in 0.9% NaCl and infused either at a pressure of 15 mm Hg for times of between 2 1/2 and 60 min or at pressure of between 15 and 160 mm Hg for 5 min. Uptake by the whole intima-media increased with perfusion time and hydrostatic pressure but did not depend on particle size. Radioactive assay of serial sections across the aortic wall also showed that particle size did not influence the distribution of tracer. An effect of perfusate composition on uptake was demonstrated in further experiments in which particles either 14 or 40 nm in diameter were suspended in pooled rabbit serum and infused at pressures of between 15 and 140 mm Hg for 5 min. Uptake and transmural distribution were again independent of particle size, but uptake was 4-5-fold less than when the particles were perfused in saline. Under all perfusion conditions radioactivity fell steeply across the intima and then rose gradually across the media and adventitia. Radioactivity in the outer media and adventitia increased with perfusion time but little change could be detected in intimal activity. In transmission electron micrographs, particles in the intima were not seen to penetrate the internal elastic lamella and in the outer media particles remained extracellular and did not enter collagen bundles. Autoradiographs showed that particles in the intima were uniformly distributed around the circumference of the vessel but in the outer media and adventitia particles usually clustered close to the vasa vasorum.

Animals↗