Search PubMed⌕ Search

Biomedical subjects

J Harkness

Publications and source records attributed to J Harkness.

At least 37 records · Page 2Linked to original sources
PubMed1984

On the capillary-tube viscometry of placental blood.

This work was done as the first part of a continuing study of neonatal blood. In a recent paper (1), two parameters, "A" (relative whole-blood viscosity at unit rate of shear and 1% haematocrit) and "beta" (shear-sensitivity exponent) were proposed, as characteristics of a given blood-sample. Here, some 60 placentae yielded (after plasma-manipulation) 130 sub-samples having haematocrits ranging from 3% to 90%. Their viscosities were measured in a capillary viscometer set for a constant wall shear-stress of 1855 mPa. "A" and "beta" were calculated by the method given in (1). Multiple calculations on a number of sub-samples revealed systematic variations within any one blood; but when every A/beta ratio is plotted against the corresponding A, the results follow a smooth curve. This curve occupies a striking, almost central location when A-and-beta values from adult normal and pathological bloods (rotational viscometry) are superimposed on the diagram. An analytic form for the close correlation between haematocrit and relative placental blood-viscosity is given by the adoption of a single "group A" and "group beta" for all 130 results.

Blood Viscosity↗
PubMed1984

Phenol alcohol technique for permanent matricectomy.

A simple technique for partial or complete destruction of the nail matrix with the use of phenol alcohol is outlined. A retrospective analysis of 30 random patients suggests that it has a low morbidity, is easy to perform, and has a high success rate. Therefore, it offers an excellent option to cold steel surgery, especially for the nonsurgically oriented dermatologist.

Administration, Topical↗
PubMed1983

Bone marrow transplantation in 33 patients with malignant blood diseases and severe aplastic anaemia.

Allogeneic bone marrow transplantation using HLA-identical sibling donors was performed in 29 patients with malignant blood diseases and in four patients with severe aplastic anaemia. Twenty-five patients received immunosuppressive therapy with cyclosporin A to minimize graft-versus-host disease (GVHD) and eight received methotrexate. Twenty-one of 29 patients (72%) with malignant blood diseases and three of the four patients with severe aplastic anaemia remained alive and disease-free from 0.5 to 16 (median, seven) months after transplantation. Acute GVHD, predominantly of the skin, occurred in 25 of 28 evaluable cyclosporin A recipients (of whom two died), and in all five evaluable methotrexate recipients. Mild chronic GVHD occurred in 10 of 16 evaluable patients. Interstitial pneumonitis occurred in five patients, of whom two died. HLA-identical sibling marrow transplantation is associated with a mortality similar to that of induction chemotherapy for acute leukaemia, and should be considered in adults with acute leukaemia in remission or relapse, chronic myelogenous leukaemia in metamorphosis or blastic transformation, lymphoma unresponsive to conventional therapy, and in severe aplastic anaemia.

Adolescent↗
PubMed1982

Plasma viscosity, haematocrit and red-cell transport.

An erythrocyte transport function (ETF) is proposed, as an index of the efficiency of the circulation of red cells. Under defined conditions, this ETF is shown to be proportional to the ratio of haematocrit to whole-blood viscosity (phi/eta), a ratio already used by Chien. The variations of phi/eta with phi, at selected driving pressures in a capillary viscometer, are presented, both for normal and for pathological blood samples. Maximal values of phi/eta appear generally to occur at haematocrits of about 42%, and are strongly dependent upon plasma viscosity. They are also influenced by shear. The concept of 'isograds' (curves of phi/eta against phi at constant velocity gradient) is introduced, and is analysed in technical appendices which also deal with rates of shear in capillary and rotational viscometers when Newtonian or shear-sensitive liquids are measured.

Adult↗
PubMed1982

Lymphocyte studies in rheumatoid arthritis. V. Suppressor cell function in peripheral blood.

Peripheral blood lymphocytes from 30 patients with rheumatoid arthritis and 14 controls were examined for suppressor activity by two different assays. These were the Concanavalin-A-induced and the short-lived suppressor cell assays. There was no difference in suppressor activity between patients and controls, the suppressor activity of HLA-DR3 positive patients was no less than that of non-DR3 patients. However, patients with nodules showed reduced suppression in the short-lived suppressor cell assay when compared with patients without nodules.

Adult↗
PubMed1982

Whole-blood viscosity, as determined by plasma viscosity, haematocrit, and shear.

The viscometers used were: (a) a proprietary rotational coaxial-cylinder instrument; and (b) a Harkness capillary-tube viscometer. In (a), the mean shear-rate is selected by the choice of rotational speed. In (b), the wall shear-stress is selected by the choice of driving-pressure. If the viscosity is varied, the mean shear-rate varies, at constant wall shear-stress. The present paper attempts to show how, in principle, a complete family of "constant-rate" (rotational) curves can be computer-plotted from two suitably-spaced capillary-tube measurements. The reverse process, involving the correction of "playback" errors, is touched upon. A variable "Einstein coefficient" is derived from the principal parameters in the computer solution; and the basic problems of compatibility in "rates of shear" are discussed.

Blood Viscosity↗
PubMed1981

Some rheological properties of blood during anti-rheumatoid therapy.

A study was carried out to compare the whole blood and plasma viscosities in 11 patients with rheumatoid arthritis treated with hydroxychloroquine to the corresponding values in 10 patients with rheumatoid arthritis treated with either sodium aurothiomalate or D-penicillamine to determine whether hydroxychloroquine therapy altered the rheological properties of red blood cells. There was no significant difference for natural and corrected (PVC = 45%) whole blood viscosity measured by Contraves low shear viscometer and Harkness capillary viscometer, plasma viscosity, haematocrit, or erythrocyte sedimentation rate between the two group.

Arthritis, Rheumatoid↗
PubMed1980

The effect of improvement in diabetic control on plasma and whole blood viscosity.

Rheological studies were made on the blood of 12 diabetic patients after a period of poor diabetic control (HbA1 12.6 +/- 0.7% (mean +/- SD); mean home capillary blood glucose level 11.7 +/- 1.2 mmol/l), and after at least three months of improved control (HbA1 9.1 +/- 0.4%, p < 0.01; mean home capillary blood glucose level 9.2 +/- 0.6 mmol/l). There were significant decreases in plasma fibrinogen levels (4.1 +/- 0.6 to 3.7 +/- 0.6 g/l, p < 0.01), plasma viscosity (1.31 +/- 0.1 to 1.25 +/- 0.04, p < 0.001), and whole blood viscosity at low (22.8 +/- 2.7 to 20.2 +/- 2.9, p < 0.01) and high shear rates (3.4 +/- 0.2 to 3.1 +/- 0.2, p < 0.01). Ten diabetics with clinically evident complications were matched with diabetics of similar age, sex, duration and current control of diabetes. There were no significant differences in plasma or whole blood viscosities between the two groups. Hyperviscosity in diabetes seems strongly related to hyperglycaemia and to be influenced by the quality of diabetic control.

Adolescent↗
PubMed1975

Plasma viscosity in the elderly.

Plasma viscosity has been measured by a standardised technique in an unselected series of elderly subjects. Results have been grouped according to the severity of clinical disease and are found to give a good statistical differentiation between most groups, although with a wide overlap. Repeated tests show only a fair correlation with the course of an individual patient's illness. These results are compared with those previously reported. In general, values are lower in elderly than in younger subjects with diesease of comparable clinical severity. "Normal' values are, however, slightly higher in the elderly. Further studies are planned to analyse apparently anomalous results in an attempt to determine more exactly the clinical value of plasma viscosity estimation in the elderly.

Aged↗
PubMed1975

Why urinalysis?

Explore the source record for details and available documents.

Cardiovascular Diseases↗