Search PubMed⌕ Search

Biomedical subjects

P T Flute

Publications and source records attributed to P T Flute.

At least 19 recordsLinked to original sources
PubMed1988

Functional studies of cell-mediated immunity in haemophilia and other bleeding disorders.

Defects of immunoregulation which occur in haemophilia, reflected by numerical changes in T lymphocyte subsets, have been further investigated in functional studies. Polyclonal T-cell activation by the mitogen phytohaemagglutinin (PHA) and specific stimulation by cytomegalovirus (CMV) or herpes simplex type 2 (HSV-2) in previously sensitized subjects were studied in peripheral blood lymphocyte and in T4-cell-enriched cultures. Compared with 12 controls, the responses of 11 patients (nine with haemophilia A and two with von Willebrand's disease) to PHA were significantly reduced both in unfractionated and in T4-cell-enriched peripheral blood lymphocyte cultures. Reduced responses to PHA were found in HIV (HTLV III)-seronegative as well as -seropositive patients. There were no significant differences between the response of patients' unfractionated and T4-enriched peripheral blood lymphocytes to CMV/HSV-2 recall antigen and the control subjects, although there was evident variation in the magnitude of patients' unfractionated and T4-enriched lymphocyte responses.

Antigens, Viral↗
PubMed1987

Effect of defibrinogenation on the early patency rate of experimental small calibre arterial grafts.

The effect of defibrinogenation with Arvin was studied in a new animal model of early thrombosis of a 3 mm diameter polytetrafluoroethylene (PTFE) graft with a poor run-off. Fifteen control animals were compared with fourteen animals treated with subcutaneous Arvin 20 units kg-1 body weight day-1, starting 2 days before surgery and continuing for 2 days postoperatively. The peroperative fibrinogen level in the controls was 2.8 +/- 0.9 gl-1 compared with 0.4 +/- 0.3 gl-1 in the treated group. There was no significant difference in the peroperative or postoperative platelet count or haematocrit value between the two groups. Plasma viscosity and whole blood viscosity (at a low shear rate of 0.7s-1) were significantly less during and after surgery in the defibrinogenated group. The degree of defibrinogenation in these animals produced no problems with haemostasis during surgery or in the postoperative period. The cumulative patency rates of the controls at 24 h, 48 h, and 4 days were 43 per cent, 28 per cent and 28 per cent compared with 86 per cent (P less than 0.05), 73 per cent (P less than 0.05) and 73 per cent (P less than 0.05) respectively in the defibrinogenated group. In this model of a narrow PTFE graft with a poor run-off, defibrinogenation was a safe and effective method of improving early patency of small calibre arterial grafts.

Ancrod↗
PubMed1987

Serial studies of T-lymphocyte subpopulations in HIV seropositive haemophiliacs.

Serial determinations of the numbers of peripheral blood T-lymphocyte subpopulations (T-helper/inducer and T-suppressor/cytotoxic cells) were made using monoclonal antibodies in 12 patients with haemophilia who were HIV antibody positive. Eleven patients were clinically severe and one clinically moderate. Follow-up studies for 12-42 months in nine patients showed persisting abnormalities in five patients, abnormalities which developed in three patients who were initially normal, and a return to normal findings in one patient who was initially abnormal. The remaining three patients were followed up for 3-4 months; two showed persisting abnormalities and one a return to normal. Persistent generalized lymphadenopathy was found in one patient who showed raised levels of T-suppressor cells initially and low levels of T-helper cells in the follow-up, but low T-helper cells persisting for up to 12 months were not necessarily associated with disease.

Antibodies, Monoclonal↗
PubMed1986

The effect of normovolaemic haemodilution on the early patency rate of small calibre vascular prostheses studied in a new animal model.

A new animal model has been developed to study early thrombosis in small calibre vascular prostheses. It consists of an ePTFE graft 2 cm long and of 3mm internal diameter inserted into a rabbit abdominal aorta in which the distal run-off is reduced by narrowing both common iliac arteries using clips with a standard gap. Scanning electron microscopy and in vivo gamma imaging of the graft using labelled autologous platelets showed that, as in the human, platelets played a primary role in the model graft thrombosis. This model was used to study the effect of haemodilution on early graft patency. Moderate normovolaemic haemodilution dramatically improved the early patency rate.

Animals↗
PubMed1985

Initial filtration rate and initial clogging in the Hemorheometre.

The role of different factors contributing to red cell filterability in the Hemorheometre has been investigated. Although the original method uses a small volume of suspension to determine red cell filterability, the present experiments showed that the results obtained are still significantly affected by filter clogging. Consequently a change in filterability could be due to a change in filter clogging possibly by residual leucocytes. An adaptation of filter chamber and filling method is described, resulting in a simpler and faster measuring procedure. The inaccuracy in measuring low haematocrits contributes significantly to experimental errors. Therefore a definition of red cell filterability based on the red cell count (instead of haematocrit) of the suspension is suggested.

Adult↗
PubMed1984

Improving accuracy of co-axial viscometry.

Aggregation and sedimentation of the red cells in the viscometer makes it difficult to obtain good reproducibility at low shear rates. A simple method is described to obtain repeatable torque-time curves with the Contraves LS30. Before starting rotation, the blood sample is agitated by an up and down movement of the bob. This results in identical (within 1-2% of the actual amplitude) repeated tracings even at the lowest shear rates, even with extremely time-dependent samples. The subsequent torque-time curve of the disaggregated and unsettled samples provides an experimental basis for the quantitative description of blood viscoelasticity and for dynamic analysis of red cell aggregation: furthermore it results in more accurate measurements when comparing different samples and testing therapeutic effects. The method is applicable to any coaxial cylinder type viscometer with manual lowering of the bob.

Blood Physiological Phenomena↗
PubMed1981

Tentative protocol for the evaluation of coagulometers, based on one-stage prothrombin time.

Information on performance is invaluable to those who have to decide on the choice of an instrument. More interest is being shown in the use of coagulometers. Accordingly, a tentative protocol for the evaluation of coagulometers is presented for discussion. While it is based on the use of one-stage prothrombin time, principles of evaluation are laid down which should make it generally applicable. It is hoped that the tentative protocol will form the basis of a reference protocol and to this end comments are invited from users of coagulometers and suppliers. Comments for publication may be sent to the Editor of Clinical and Laboratory Haematology or to the Secretary of the Working Party.

Blood Coagulation Tests↗
PubMed1980

Changes in red cell deformability and other haemorrheological variables after myocardial infarction.

Haemorrheological variables were studied in 43 patients after acute myocardial infarction. Red cell deformability, by a filtration method, was significantly lower within 12 hours of infarction than subsequently. This drop was greater in the presence of haemodynamic complications. Blood viscosity, particularly when adjusted to a standard haematocrit, rose in the week after infarction, as did plasma viscosity and plasma fibrinogen. Haematocrit, however, fell over this period. These changes could increase myocardial ischaemia and lead to extension of the area of infarction.

Adult↗
PubMed1979

Haemorrheological response to plasma exchange in Raynaud's syndrome.

Eight patients with Raynaud's syndrome were treated by weekly plasma exchange for four weeks using a Haemonetics Model 30 Blood Processor. The mean whole-blood viscosity at a shear rate of 0.77/s was significantly lower after treatment, and the mean index of red-cell deformability was significantly improved. In four patients studied serially the mean percentage fall in whole-blood viscosity after a single plasma exchange was 49% at 0.77/s but only 14% at 91/s. All patients noticed symptomatic improvement including healing of ischaemic digital ulcers. In six patients the number of digital arterial segments containing detectable blood flow was measured by directional Doppler; in all six the number increased. It is concluded that plasma exchange is an effective means of haemorrheological treatment and may be beneficial in patients with digital ischaemia.

Blood Flow Velocity↗
PubMed1976

Pharmacological prophylaxis of venous thrombo-embolism.

The pathogenesis of venous thrombosis is briefly discussed as a basis for the understanding of preventive measures used in this condition. Prophylaxis in venous thrombosis is then reviewed with emphasis on pharmacological treatment, and more particularly on heparin.

Ancrod↗
PubMed1976

Criteria for successful thrombolysis by streptokinase.

Streptokinase treatment of deep vein thrombosis is reviewed, with emphasis on the mechanism of action of streptokinase, the bleeding caused by this agent, and incomplete thrombolysis. Criteria for successful thrombolysis and the advantages of intermittent streptokinase therapy to overcome the problems of bleeding and incomplete thrombolysis are discussed.

Drug Administration Schedule↗
PubMed1975

Fibrinogen metabolism in acute hepatitis and active chronic hepatitis.

Coagulation studies, including those of radioactive fibrinogen metabolism, were performed in seven patients with acute viral hepatitis and 12 patients with active chronic hepatitis. An increased fractional catabolic rate for fibrinogen was observed in four patients from the first group, and seven from the second. The catabolic rate was increased in those patients with the greatest degree of hepatic necrosis as demonstrated by the raised serum aminotransferase levels. There was no correlation between the rate of fibrinogen catabolism and the standard clotting tests, but the SDPS test (indicating the presence of fibrin monomers in the circulation) was consistently positive in those cases where the catabolic rate was increased.

Acute Disease↗