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Biomedical subjects

H Schenk

Publications and source records attributed to H Schenk.

At least 91 records · Page 5Linked to original sources
PubMed1978

[A method for the evaluation of nitroblue tetrazolium reduction in human platelets (author's transl)].

A long term incubation in NBT-solution leads not only to NBT-reduction by polymorphnuclear leukocytes and monocytes, but also in washed human platelets. The reaction is enhanced by ADP and to a smaller and very variable extent also by Thrombin and Ristocetin. It is inhibited by incubation in plasma environment as well by DBcAMP and PGE1. After a detailed demonstration of the applied method, some possible biochemical mechanisms of the NBT-reduction in human platelets are discussed.

Adenosine Diphosphate↗
PubMed1978

[Cardiotoxicity of mianserin, an antidepressant (author's transl)].

The effect of mianserin on cardiac function was investigated on 60 adults with known heart disease, the drug previously having been shown not to influence the action of phenprocoumon. After satisfactory anticoagulation had been established, all patients were given additionally two different dosage regimens of mianserin or a placebo in a double-blind trial lasting three weeks. The dose was gradually increased to a maximal daily level of 30 mg or 60 mg, respectively, on the sixth day. Heart rate, blood pressure and electrocardiogram were obtained before and after mianserin had been added. There was no statistically significant difference between the three trial groups with respect to the three measured variables.

Adult↗
PubMed1978

Phenprocoumon requirement, whole blood coagulation time, bleeding time and plasma gamma-GT in patients receiving mianserin.

A possible interaction between the tetracyclic antidepressant mianserin and a coumarin derivative has been investigated. Sixty-three subjects, 61 of whom required anticoagulant therapy for a variety of medical conditions, were treated for 5 consecutive weeks with phenprocoumon, in a dose adjusted to reduce the prothrombin time to 15%-25%. After an initial control period of one week, subjects were randomly treated under double-blind conditions with mianserin 3 X 10 mg daily or 3 X 20 mg daily, or with a matching placebo. The dose of mianserin was gradually increased to reach the maximum by the 6th day. Three subjects dropped out and 60 completed the trial. The dose of phenprocoumon and the prothrombin, bleeding, and coagulation times were not significantly affected by administration of mianserin. It can be concluded that there is no clinically important interaction between phenprocoumon and doses of mianserin effective in depression. Sedation was more frequent in patients taking mianserin than in those given placebo.

4-Hydroxycoumarins↗
PubMed1978

Studies on the hypertriglyceridemia in the pregnant rat.

The in vivo tracer method and in vitro incorporation experiments were used to obtain information on the mechanism responsible for the hypertriglyceridemia found in 21 days pregnant rats. The results indicate that the uptake of plasma free fatty acids (FFA) by liver triglycerides of pregnant rats (2.0 mumoles FFA/min/300 g) did not differ from that of non-pregnant rats (2,1 mumoles FFA/min/300 g). The rate of liver fatty acid synthesis in pregnant rats (0,4 mumoles fatty acids/min/liver) is higher than that of non-pregnant rats (0,05 mumoles fatty acids/min/liver). In non-pregnant female and pregnant rats the turnover rates of plasma chylomicron and VLDL triglycerides were almost identical (about 2.8 mumoles triglyceride fatty acids/min/300 g, and about 2.3 mumoles triglyceride fatty acids/min/300 g, respectively). These various observations, when taken together, strongly suggest that increased hepatic triglyceride production cannot be the mechanism responsible for the hypertriglyceridemia in pregnant rats.

Animals↗
PubMed1978

The effect of Org GC 94 on thrombocyte function, blood coagulation and the fibrinolytic system in man.

The effect of a 14 day treatment with Org GC 94 in rising dosage to a maximum of 45 mg/day on thrombocyte function, blood coagulation and the fibrinolytic system was investigated in 16 healthy volunteers in a double-blind comparative trial with placebo. At the same time the influence on some liver function tests and on the general condition of the subjects was followed. Analysis of the data obtained in tests pertaining to platelet function, blood coagulation, fibrinolysis and liver function did not indicate unwanted or harmful effects of Org GC 94. No significant difference in effect between Org GC 94 and placebo was detectable. The general physical condition including appetite and body weight was not affected by Org GC 94. A mild, transient sedative effect of the maximum dose of Org GC 94 is likely and some influence upon concentration (decrease) and mood (indifference or elevation) in some subjects cannot be excluded.

Adolescent↗
PubMed1977

[The effect of oral contraceptives on levels of thyroid hormone, blood coagulation and ceruloplasmin (author's transl)].

The effect of various hormonal contraceptives on the thyroid hormone level, plasmatic and thrombocytic coagulation, cholesterol and ceruloplasmin levels and the activity of gamma-glutamyl transpeptidase was investigaged by the changes produced by long term cyclic estrogen-gestagen therapy on the metabolism of the organism. The free thyroxine index and the total cholesterol were within the normal range. The thyroxine binding index at 44% was above the normal level and the mean value was significantly raised. The ceruloplasmin concentration in the serum was also significantly increased. Pointers to a general hypercoagulability could not be ascertained with a statistical significance.

Adolescent↗
PubMed1977

[Continuity of life situation and "successful" aging (author's transl)].

The determinants of "successful" aging have been a main concern in social gerontological research. The Continuity Hypothesis suggests that there is a relationship between an older person's life satisfaction and the similarity of his social life situation in middle adulthood and in old age. The old person is the more likely to score low in life satisfaction the less similar his old age situation to his life situation in middle adulthood. This hypothesis has been tested in summer 1973 in Cologne with a sample of 406 people aged 65 and over. Findings indicate that continuity of life situation may be an important variable accounting for life satisfaction in old age. Moreover, it could be shown that the various negatively experienced life changes since adulthoood formed a complex of interacting variables, thereby increasing the negative effect on the old person's life satisfaction. Health proved to be one of the most important variables. The continuity hypothesis as stated here represents a modified version of activity theory.

Adaptation, Psychological↗
PubMed1977

Tracer kinetic studies on in vivo fatty acid metabolism in white adipose tissue of well-fed and starving newborn rabbits during acute or prolonged exposure to cold.

Pool size (M), and specific radioactivities (SA) of lipids of white adipose tissue (WAT), as well as the flow rates (ms) of free fatty acids (FFA) from plasma into WAT were studied by injecting 14C-1-palmitate (20.10(6) cpm/100 g body weight) into 7-day-old rabbits reared in a thermoneutral (Group I) or a cold environment (Group II) or subjected to starvation at an ambient temperature (Ta) of 35 degrees C (Group III) or at Ta 20 degrees C (Group IV). Experiments were carried out at Ta 20 degrees C in all four groups of rabbits. The pool size of esterified and non-esterified fatty acids of WAT was reduced in both the well-fed animals raised in the cold and in the starving ones. The SA of tissue FFA and phospholipid fatty acid (PL-FA) was highest in Group III and Group IV indicating an increased FFA metabolism of WAT in animals subjected to starvation prior to acute exposure to cold. The flow rate (ms) of FFA between plasma and WAT increased twofold in Group IV but remained about one fifth that of the ms between plasma and brown adipose tissue (BAT) indicating that the contribution of WAT to cold-induced calorigenesis of the whole animal must be regarded as of secondary importance.

Adipose Tissue↗
PubMed1976

Lupus cardiomyopathy: cardiac mechanics, hemodynamics, and coronary blood flow in uncomplicated systemic lupus erythematosus.

Right and left heart pressures, left ventricular volumes, indices of contractility, myocardial wall stiffness, and coronary blood flow were determined in five young women with systemic lupus erythematosus (SLE) during diagnostic right and left heart catheterization. Examinations revealed (1) increases of right and left ventricular enddiastolic pressures; (2) decreases of cardiac output, stroke volume, ejection fraction, contractility indices, diastolic left ventricular volume inflow; (3) decreases of pharmacologically induced coronary vasodilation in SLE. The results demonstrate impaired pump function, reduced contractility, increased myocardial wall stiffness, and decreased coronary vascular reserve in SLE. It is concluded that lupus cardiomyopathy associated with an impairment of left ventricular function may be apparent in young women with SLE who have no clinical signs of cardiac dysfunction.

Adult↗
PubMed1975

[Cardiomyopathy in uncomplicated systemic lupus erythematosus (author's transl)].

Haemodynamic functions, myocardial contractility, and coronary blood flow were measured in five young women with systemic lupus erythematosus. There had been no signs of cardiac involvement. Left and right heart catherterisation excluded abnormal pressure gradients and valvar regurgitation. But left ventricular end-diastolic pressures were considerably raised while cardiac output, stroke volume, ejection fraction, and left ventricular compliance were decreased. Isovolumic indices of myocardial contractility were altered, corresponding to a decreased contractile state of the myocardium. Coronary blood flow was moderately increased at rest, but pharmacologically induced coronary vascular reserve was markedly reduced. It is concluded that in young women with this disease there may be, in the absence of clinical signs of cardiac involvement, haemodynamic abnormalities which must be ascribed to the consequences of a lupus cardiomyopathy.

Adult↗
PubMed1975

Studies on plasma free-fatty-acid metabolism and triglyceride synthesis of brown adipose tissue in vivo during cold-induced thermogenesis of the newborn rabbit.

Parameters of plasma free fatty acid metabolism (pool size, half time, disappearance rate, turnover time and absolute turnover rate), the influx of plasma free fatty acids into the glycerides of brown adipose tissue and the pathway of triglyceride synthesis in brown adipose tissue (glycerol-1-phosphate versus monoglyceride pathway) were examined after intravenous injection of [1-14C]palmitate in newborn rabbits. In the thermoneutral environment of 35 degrees C the turnover rate of plasma free fatty acids was 10.20 mumol/min per 100 g body weight and its flux into the glycerides of brown adipose tissue 0.367 mumol/min per 100 g body weight. Cold exposure at an ambient temperature of 20 degrees C caused a decrease to 5.84 mumol/min and 0.207 mumol/min per 100 g body weight, respectively. Both under basal conditions at an ambient temperature of 35 degrees C and under cold-induced thermogenesis at an ambient temperature of 20 degrees C triglyceride synthesis in brown adipose tissue ran through the glycerol 1-phosphate pathway.

Adipose Tissue, Brown↗
PubMed1975

[Uptake of serum free fatty acids by lipids of the brown adipose tissue].

The flow rate of serum free fatty acids (FFA) into the lipids of brown adipose tissue (BAT) of newborn rabbits was determined by intravenous injection of [14C]-1-palmitate. For a normal 7 day old animal during acute cold exposure the flow rate is (1 hour in 20 degrees C ambient temperature) 0.209 mumol/minute, that is 3.6% of the serum FFA turnover. Prolonged cold exposure only induced an increase in FFA influx if the lipid depot had been depleted (48 hours starvation in 20 degrees C). Consequently, the BAT takes up serum FFA for heat production only after mobilisation of its lipid stores. It is supposed that the mechanism of the uptake of serum FFA by the BAT is connected with their esterification to triglycerides. The phospholipids of BAT which are not only membrane bound lipids are characterized by a high metabolism.

Adipose Tissue, Brown↗
PubMed1975

[Problems concerning the enucleation of both eyes in cases of incurable retinoblastoma (author's transl)].

Despite considerable advances in the treatment of retinoblastoma tumor growths cannot be arrested in a proportion of cases. The consent fro the removal of both eyes constitutes a burdensome decision on the part of the child's parents, so that it is quite frequently refused. A short movie illustrating the behaviour of a 6-year-old boy, who had undergone bilateral enucleation because of retinoblastoma should aid the parents having to face a similar situation.

Age Factors↗
PubMed1975

[The effect of cold and hunger on the free fatty acid metabolism in the serum of newborn rabbits].

A tracer kinetic study with [14C]-1-palmitic acid was carried out to study the influence of acute exposure to cold and starvation on free fatty acid (FFA) metabolism in serum of newborn rabbits. The turnover rate of serum FFA was 10.20 mumol/min in well fed rabbits kept in a thermoneutral environment (normal conditions). Cold exposure as well as starvation either in a cold or thermoneutral environment resulted in a diminution of the turnover rate, being the consequence of a significantly reduced pool of FFA. It was 9.57 mumol under normal conditions. The disappearance rate (1.07 min-1), half time (0.65 min) and turnover time (0.94 min) of well nourished animals was slightly, but mostly not significantly, influenced by cold exposure and starvation. The cold induced increase in serum FFA concentration and the decrease following restoration of thermoneutrality did not run parallel with changes in the absolute turnover rate.

Animals↗