[Platelet function and morphology during and after standardized ergometry at different ages (author's transl)]

Quantitative changes in platelet aggregation due to physiological and pathological factors and medication

Quantitative measurements of platelet aggregation in samples of venous blood were made in altogether 66 healthy volunteers by a modified version of the method of Wu and Hoak. The formation of aggregates was found to be unaffected or at the most barely affected by such factors as sex, age, smoking, fatty food, physical exertion and medication with isoprenaline or ovulation inhibitors. No difference in the number of aggregates formed was noted between 12 control patients and 16 patients with myocardial infarcts or 14 with other conditions predisposing to arterial thrombosis. Anticoagulant therapy had no effect on aggregation. It is suspected that aggregation in vitro due to methodological factors may obscure any quantitative alterations in the formation of aggregation present in vivo.

[The significance of platelet adhesiveness and aggregation and free fatty acids by functional disorders of the internal ear (author's transl)]

The significance of platelet adhesiveness and aggregation in the early phase of thrombosis as well as in the development of degenerative vascular wall processes has today become an established fact. In this connection the plasmalipids are of special interest, of which the free fatty acids (FFA) represent a sensitive indicator both for the adrenergic reactivity of the organism and the process of stress-conditioned circulatory reactions. In the present study 65 clinical cases with functional disorders of the internal ear were examined regarding to the platelet adhesiveness and FFA, differtiating only between sudden loss of hearing (n=28) and functional disorders of different symptomatology (n=37). Our preliminary statistics showed in 64% of the patients with a sudden loss of hearing mainly an average, and in 84% of the 37 examined functional disorders of different symptomatology a slight to a high increase in the adhesiveness. The FFA-concentrations increased in approximately 90% of the 23 examined cases with functional disorders of the internal ear. It is remarkable, that the measured adhesiveness and serum-FFA-concentrations are comparable to the high values obtained from atheromatous vascular processes, venous thrombosis, cardial and cerebral infarctions, intermittent cerebrovascular insufficiency as well as from transient impaired vision caused by microembolism. Even if the high percentage in the FFA-increase, under strictest observance of the patient's resting position at the time of the blood withdrawal, is presumably much below the measured value, it still indicates an increased tonus of the sympathetic nervous system in the majority of the examined patients. The clinical satisfactory results obtained after timely applications of numerous agents inhibiting aggregation and adhesiveness, as well as reducing the lipids, also indicate a process of stress-conditioned circulatory reactions and the existence of atheromatous respectively thrombo-embolic vascular processes in a number of acute or intermittent functional disorders of the internal ear.