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Biomedical subjects

L O Simpson

Publications and source records attributed to L O Simpson.

At least 73 records · Page 4Linked to original sources
PubMed1988

Altered blood rheology in the pathogenesis of diabetic and other neuropathies.

Although a substantial literature confirms the abnormal flow properties of diabetic blood, only in a few papers has the vasculitis of diabetic neuropathy been considered to have a hemorheological cause. It is proposed that the pathogenesis of nerve lesions involves an interaction between the specialized nerve vascular system and focal ischemic lesions resulting from rheologically induced stasis. The proposition is extended into other conditions with abnormal blood rheology such as hypothyroidism, uremia, dysglobulinemia, polyarteritis nodosa, and lepromatous leprosy. It is concluded that the treatment of such polyneuropathies should include an agent which would improve the flow properties of the blood.

Blood Viscosity↗
PubMed1988

The etiopathogenesis of premenstrual syndrome as a consequence of altered blood rheology: a new hypothesis.

The multisystem symptoms of premenstrual syndrome (PMS), the variable nature of their occurrence and their relatively rapid disappearance with the onset of bleeding are highly suggestive of a systemic factor as the causal agent of the disorder. Reports of increased blood viscosity and enhanced red blood cell (RBC) hydration provide a basis for proposing that PMS is the consequence of an aberration of the change in blood viscosity which occurs in the third week of the normal menstrual cycle. The seriousness of the viscosity-impaired capillary blood flow will be greatest in organs and capillary beds with the smallest capillaries. Such an assumption implies that those women who suffer from PMS will be individuals whose capillaries are smaller in size than non-sufferers. The frequency of occurrence of fluid retention as a symptom suggests that the specific etiologic agent could be a reduction in RBC deformability as a consequence of impaired linoleic acid metabolism or high levels of noradrenaline or hypothyroidism or combinations of the three factors. If poorly deformable RBCs are involved then the use of agents such as evening primrose oil or fish oil to improve RBC deformability could ameliorate the symptoms of PMS. It is speculated that similar changes in RBC deformability should occur at other times of hormonal change. Health problems occurring during pregnancy, or after parturition, or after cessation of ovarian function might be caused by or exacerbated by reduced RBC deformability.

Blood Pressure↗
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

Exercise testing.

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Electrocardiography↗
PubMed1987

IgA nephropathy.

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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↗