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Biomedical subjects

B I Shand

Publications and source records attributed to B I Shand.

11 recordsLinked to original sources
PubMed1992

Effect of angiotensin converting enzyme inhibitors on erythropoietin concentrations in healthy volunteers.

The possibility that the ACE inhibitors, enalapril and captopril, may decrease plasma EPO concentrations was studied in a single-blind, cross-over study in 10 healthy volunteers. Plasma EPO concentrations, haemoglobin concentration, red blood cell count, plasma creatinine concentration and mean arterial pressure were measured at baseline and after 28 days treatment with both ACE inhibitors. A significant fall in mean plasma EPO concentration occurred with both ACE inhibitors and returned to baseline after stopping the drugs. It is likely that ACE inhibitors decrease EPO formation, by inhibition of angiotensin-II production. This effect could be important in patients with renal failure, renal transplantation or other chronic conditions with an associated anaemia. Haematological parameters should be monitored in such patients when they are treated with an ACE inhibitor.

Adult↗
PubMed1991

Changes in red cell shape in healthy elderly subjects taking low dose fish oil: pilot study.

OBJECTS: to investigate the effects of low dose fish oil on red cell shape and blood pressure in healthy elderly subjects during a 16 week treatment and an eight week follow-up. METHODS: red cell shape analysis by scanning electron microscopy with data analysis by repeated measures analysis of variance. RESULTS: in the preoil blood samples the percentage of cells with surface changes was much higher than that of younger healthy subjects (24.0% vs 14.4%). While taking fish oil the percentage of cells with surface changes declined to a minimum at the end of the eighth week, steadily increased during the next eight weeks then declined during the eight week follow up. Mean blood pressures were not altered by the fish oil although that of five subjects taking different types of antihypertensive drugs tended to show greater fall in blood pressure than those not on drugs. CONCLUSION: that dietary supplementation with low dose fish oil was associated with changes in red cell shape. The observed changes are currently inexplicable.

Aged↗
PubMed1988

Factors influencing the cyclical symptoms relating to the menstrual cycle.

One hundred and thirty-four volunteers were asked to weigh themselves at the same time each day and to make a daily assessment of a small number of symptoms related to their menstrual cycles. Details were requested of the nature of any pain relieving drugs used and of the days on which they were taken. In addition they were asked to provide information about their age, smoking habits and regular medication. Information relating to 346 cycles was obtained in this way. Symptom scores based upon the frequency and severity of 6 common symptoms occurring between days 5 and 14 compared with the symptoms scores for the last 5 days of the cycle provided a basis for categorising cycles into 3 groups. Group A cycles had a virtual absence of symptoms. Group B cycles were characterised by symptoms which were clustered towards the end of the cycle while group C had symptoms throughout the cycle. Women with cyclical symptoms (group B) were not different in age, menstrual characteristics or smoking habits from women whose cycles fell into groups A and C but their premenstrual changes in bodyweight were greater. The use of pain relieving drugs was not related to symptoms grouping and was similar in all groups. It is concluded that the scores from 6 common symptoms relating to 2 or 3 successive cycles can identify women with cyclical symptoms which may be diagnostic of premenstrual syndrome and the method could be useful in selecting subjects for studies of the syndrome.

Adolescent↗
PubMed1988

Blood rheology in IgA nephropathy.

Blood rheology was measured in 35 patients with IgA nephropathy (IgAN) and compared with age and sex-matched normal controls. Whole blood viscosity, red blood cell deformability and plasma viscosity were significantly altered in patients with IgAN. A correlation between determinants of blood rheology and clinical indices of IgAN was found. The factor(s) causing the rheological abnormalities was (were) not defined. Increased blood viscosity may cause intraglomerular pressure to rise and filtration to increase and may contribute to the development of mesangial lesions. It is proposed that abnormal blood rheology may be a causal factor in the pathogenesis of IgAN.

Blood Viscosity↗
PubMed1987

IgA nephropathy.

Explore the source record for details and available documents.

Blood Viscosity↗
PubMed1987

Red cell and hemorheological changes in multiple sclerosis.

Blood rheology in multiple sclerosis (MS) was investigated in 15 subjects with varying degrees of locomotor difficulties who were members of the local MS Society. Control data were obtained from blood samples from 25 male and 25 female normal blood donors. Whole blood viscosity was measured and blood filterability was assessed. Six MS females provided blood samples for scanning electron microscopy. Erythrocyte membrane fatty acids and phospholipids were assayed. Whole blood viscosity in MS females was higher than controls at 3 of 4 shear rates (p less than 0.001) but in MS males blood viscosity was higher only at shear rate of 1.0 s-1 (p less than 0.05). MS erythrocyte filtration rates were significantly lower than controls (p less than 0.001). Leucocyte counts in MS were greater than controls both in males (p less than 0.01) and females (p less than 0.001). MS erythrocyte morphology was greatly different from controls (p less than 0.0001) and erythrocyte membranes contained less sphingomyelin than controls (p less than 0.01) but more phosphatidylinositol plus phosphatidylserine (p less than 0.02). We conclude that, because our findings indicate an identifiable and potentially correctable abnormality, it is possible to envisage an inhibition of the progressive nature of MS, with the hope of a better prognosis for patients.

Adult↗
PubMed1986

Blood rheology and myalgic encephalomyelitis: a pilot study.

The blood rheology of EDTA-anticoagulated blood samples from blood donors and subjects considered to have myalgic encephalomyelitis was assessed by multiple shear rate viscometry and by multiple-pressure filterability. Although average viscosities of the two groups were different, the differences did not reach statistical significance. In contrast, the data from multiple-pressure filtration of whole blood showed significant differences between females at the lowest (2.5 cm of water) filtration pressure. It appears that the acute phase of the disorder is associated with changes in blood rheology which could impair microcirculatory blood flow. In contrast, the chronic state does not appear to be associated with rheological abnormalities.

Blood Viscosity↗
PubMedDate not supplied

A reappraisal of the influence of blood rheology on glomerular filtration and its role in the pathogenesis of diabetic nephropathy.

The basic assumptions concerning the mechanisms of normal glomerular filtration are discussed. Attention is drawn to blood rheologic changes that follow glomerular filtration and influence postglomerular blood flow adversely. It is proposed that the blood rheologic changes will increase the resistance to flow in the peritubular plexus commensurate with the dimensions of the capillaries and blood viscosity in accordance with the general principles of the Poiseuille formula, even though blood is a non-Newtonian fluid. For this reason, the conditions of flow in the plexus must be a determinant of intraglomerular capillary pressure. When blood rheology is abnormal, as in insulin-dependent diabetic patients, the abnormality will be amplified by glomerular filtration and it is suggested that the consequences will be manifest as problems of blood flow in the peritubular plexus. As the increase in postglomerular intravascular pressure needed to restore the rate of blood flow to normal necessitates dilation of the afferent arteriole and possibly more proximal vessels, such changes will result in an increase in intraglomerular pressure. The increase in pressure that increases filtration is therefore a direct consequence of abnormal blood rheology. This concept provides a basis for understanding the mechanism of diabetic proteinuria and for other proteinurias associated with abnormal blood rheology. A possible role for altered blood rheology in the pathogenesis of both focal and total glomerulosclerosis is discussed, and the potential benefits of agents that improve blood rheology are outlined.

Blood Flow Velocity↗