Biomedical subjects
Publications and source records attributed to A Hoffmann.
In thrombin-induced DIC, acetylsalicylic acid (ASA) prevents the strong initial fall in platelet count and the obturation of the microvasculature of the lung with platelet aggregates. During the DIC reaction increasing inhibition of aggregability of circulating platelets against collagen and ADP is observed. Furthermore, ASA prevents the increase in the plasma haemoglobin level caused by DIC.
Combination effects of inhibitors of platelet function with different mechanisms of action such as adenosine, acetylsalicylic acid, papaverine, dipyridamole, and sodium nitroprusside were studied in vitro by means of ADP- and collagen-induced aggregation of human blood platelets. In case of ADP-induced aggregation, potentiation of the inhibitory effect was observed only with the combination adenosine-papaverine, whereas in case of collagen-induced aggregation the inhibitory effect was potentiated at various inhibitor combinations.
In the course of investigations concerning the mechanism of the thrombin platelet interaction the conditions for the appearance of a refractory behaviour of platelets towards thrombin were examined. As investigation of the platelet reactivity by determining the amine liberation showed that a continuous or discontinuous addition of slight amounts of thrombin will cause the refractory condition. The findings were analyzed in view of the interaction between the dissolved enzyme and the fixed substrate. It is assumed that the number of receptors diminished after the first thrombin contact will cause a decrease of the receptor occupation speed on the platelet surface, thus leading to a decreased platelet reactivity.
Between January 1975 and March 1978, 15 cases of sudden death or hospitalized medical emergencies occurred during cross-country skiing in the Engadine region, comprising 3 sudden deaths, 9 myocardial infarctions, and 3 neurovascular accidents. The total number is small as compared to the number of people practising this sport. Among participants of the Engadine Ski Marathon, the incidence was 1 emergency per 40,000 skiing hours and 1 death per 120,000 skiing hours. Patients suffering from myocardial infarctions were all vacationers from lower altitudes, in most whom several risk factors were present. Two cases of cerebrovascular accident demonstrate that competitive cross-country skiing may impose enormous stress on the cerebrosvascular system even in well-trained individuals.
The results of a study of active oral hygiene treatment in children between the ages of 4 and 12 was reported. It is absolutely imperative that both the children and the parents be highly motivated to carry out consistant oral hygiene. The basic level of oral hygiene for children can be considerably improved if the children are instructed in the appropiate technique for tooth brushing and allowed to practice; the children should be regularly checked by the dentist.
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The manual lymphdrainage is a special method of massage which is often used for cosmetical purposes. Methodology, mode of action and indications are presented and the results of treatment are reviewed.
The potentiating effect of adrenaline on thrombin-induced aggregation and release reaction of human blood platelets has been studied in vitro. Both reactions are inhibited by low doses of dihydroergotoxine. The inhibition of aggregation is of competitive type. The adrenaline-potentiated thrombin-induced platelet aggregation is inhibited also after intravenous injection of dihydroergotoxine. The pathophysiological implications of these findings are discussed.
To determine to what extent the effects of phentolamine (PHE) are mediated by the cardiac and vascular beta-receptors, the action of the drug was studied in anaesthetized cats pretreated with beta-blockers. Blockade of the cardiac beta-receptors with either propranolol or metoprolol entirely prevented the increases in heart rate, dP/dt and cardiac output caused by PHE. In animals pretreated with propranolol (in a dose blocking the vascular beta-receptors) or metoprolol (in a purely cardio-selective dose) PHE significantly lowered blood pressure to the same extent as in untreated controls. The effects of PHE on the heart are thus conditional on the integrity of cardiac beta-receptors, whereas it seems improbable that vascular beta-receptors have any part in its vasodilative action. Evidence presented in the literature rather suggests a predominantly central mode of action.
Microinjections of L-glutamic acid into the mesencephalic tegmentum and diencephalon of anesthetized toads evoked an excitatory response consisting of electrocephalographic and electromyographic activation, and a rise in arterial blood pressure. Electromyographic responses were reduced or absent in diencephalically injected toads. Except for this case, all other components of the response always appeared together and presented the same time course. L-glutamic acid was able to activate a group of neurons at different levels of the reticular system involved in an integrated response of ergotropic nature.
In the present paper a case of generalized scleroderma with concomitant central arterial occlusion is reported. To our knowledge this coincidence of generalized scleroderma and central arterial occlusion has not been described so far. As fibrinoid necrosis and proliferative changes of the choroidal vessels occur with generalized scleroderma the possibility is discussed that the central arterial occlusion may be an effect of the scleroderma.
In this paper is reported on two cases of paroxysmal ventricular tachycardia. The clinical and paraclinical examinations did not reveal any organic heart disease, the psychological one, however, found a very severe neurotic personality disorder. Antiarrhythmic drugs were ineffective in both cases. Meanwhile one female patient went through a brief psychotherapy which dismissed the arrhythmia.
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The average blood pressure measured in a representative sample of 8th grade juveniles (14-16 years) was 120/70 mm Hg. Mean systolic pressure was 5 mm Hg higher in boys. The 90th percentile was 135/80 mm Hg for both sexes. Systolic and diastolic pressure rose with increasing body weight. Correlation with height was less obvious. Difference in weight could not account for all the sex difference in blood pressure. Association of sexual maturation with higher blood pressure values was more pronounced in boys.
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