Michaela Vickers

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The epidemiological characteristics of platelet aggregability were established in 958 participants in the Northwick Park Heart Study. The main analyses were based on the dose of adenosine diphosphate at which primary aggregation occurred at half its maximum velocity. Aggregability increased with age in both sexes, was greater in whites than blacks(More)
Results from the Northwick Park Heart Study (NPHS) suggest that physiological levels of plasma fibrinogen may influence platelet aggregability. This possibility has been further studied by the addition of purified fibrinogen to the blood of 17 study participants with low plasma fibrinogen levels. The results, which were highly consistent between different(More)
Mortality from coronary heart disease in civil servants in the lowest grade of employment has been found to be about three times that of men in the highest grade of employment. As part of an investigation of this finding several haemostatic variables were measured in a sample of 29 men in lower grades of employment and 45 men in higher grades. There was a(More)
A standardized method for performing dose response platelet aggregation has been developed, and has been used in about 1000 subjects in a large prospective study of ischaemic heart disease. A computer program has been used to fit a sigmoidal relationship between primary aggregation response rate and the log dose of aggregating reagent. Estimates of the(More)
Levels of haemostatic variables that may be involved in thrombogenesis have been compared in groups of men of similar mean age in communities at very low (Gambia), high (England and Czechoslovakia) or very high (Scotland and Finland) risk of ischaemic heart disease (IHD). There was a consistent gradient of higher factor VII levels with higher IHD risk and(More)
An experiment designed to assess the components of variability of a number of measures of platelet aggregability showed that the ADP ED50 (the estimated dose of adenosine diphosphate at which primary aggregation occurs at half its maximum velocity) had the least method error of any of the parameters measured, but that none had a very high between-person(More)
Normal platelets display a log normal size distribution pattern when analysed by an automated cell counter. Considerable changes in the platelet size distribution occurs during collection, processing and storage. This is easily monitored by the variation seen in the cellular indices or size distribution patterns. Platelet activation leads to a shift to the(More)
The quality of platelet concentrates (PC) collected by the Autopheresis C cell separator was assessed in two Regional Transfusion Centres taking part in a multicentre study. This study also enabled the assessment of a new simple, rapid test of platelet function and comparison with more established tests, such as aggregation to adenosine diphosphate, as a(More)