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Biomedical subjects

H Schenk

Publications and source records attributed to H Schenk.

At least 19 recordsLinked to original sources
PubMed1991

Morphometric study of synaptic patterns in the rat caudate nucleus and hippocampus under haloperidol treatment.

A morphometric study of the synapses on dendritic shafts and spines was performed in the rat caudate nucleus and the CAI area of the hippocampus under chronic haloperidol treatment. In the nucleus caudatus, the synaptic density on dendritic shafts increased by 83% and those on spines by 53%. Most of the parameters measured in axospinous synapses were significantly increased: the area of presynaptic axon terminals (20%), the number of mitochondria per axon terminal (51%), the length of active zone (11%), the area of postsynaptic density (23%), and the perimeter of postsynaptic density (12.5%). The area of postsynaptic spines showed no changes. In the synapses on dendritic shafts, the area of presynaptic terminals decreased (31%), the area of mitochondria per terminal decreased (40%), the length of active zone increased (14%), and other parameters were unchanged. There were no significant differences in the same parameters measured in the hippocampus. The data are discussed as morphological correlates of behavioral supersensitivity and dopamine D2 receptor up-regulation.

Animals↗
PubMed1991

Changes of brain gangliosides in the frontal cortex of rats chronically treated with amphetamine, clozapine, haloperidol and ethanol.

Rats were injected intraperitoneally daily for 20 days with amphetamine, haloperidol, clozapine and ethanol to investigate the participation of gangliosides in the reactivity of the brain to these drugs. All of these substances are able to modulate the ganglioside pattern of the frontal cortex. The major changes were observed after amphetamine and clozapine treatment. In both cases, GQ1b was significantly increased, whereas GM2 and GM3 were significantly diminished. Moreover, GD1a (after amphetamine) and GM1 (after clozapine) were decreased with respect to the controls. After haloperidol treatment both GQ1b and GT1b augmented, while after ethanol, only GM3 was increased.

Amphetamine↗
PubMed1991

[Rumania January 1990: acute medical deficits and chronic shortage--an evaluation at the site].

Between January 4 and 8, 1990, a medical delegation of the University Hospital Zurich (three surgeons, one OT-nurse) was sent to Bukarest. They escorted a large sending of surgical and pharmacological equipment. The assignment was 1. to evaluate the situation in the hospitals around the Bukarest area; 2. to determine the feasibility and the need of medical emergency support; 3. to assess the usefulness and practicability of medium-term relief. A total of 11 hospitals were visited in Bukarest, Pitesti, Racovita and Schitu-Golesti. It was found that 1. a sufficient number of doctors and medical personnel is available; 2. emergency aid is important regarding pharmaceuticals (local anesthetics, analgetics, insulin), infusions, dressing material, surgical instruments and external fixation equipment; 3. medium-term support is need for the complete medical equipment (syringes, injection and infusion sets, probes, suture material, etc.). Local medical literature and journals are worthless. Doctors long for high-quality medical books and periodicals. We can help!

Developing Countries↗
PubMed1990

The effect of abstinence in alcoholics of erythrocyte gangliosides.

The pattern of gangliosides in membranes of erythrocytes was examined in healthy and in alcoholic subjects on the second and on the 28th day of detoxification therapy. The GM3 and GD3 fraction were decreased significantly in alcoholics on the 2nd day. After 4 weeks of abstinence all changes had returned to the level of healthy subjects.

Adult↗
PubMed1990

[Use of computer technique in occupational health inspection].

An organisation concept of an inspectorate of occupational hygiene is described. Its development was started any years ago, but it is reached a temporary optimum just by the introduction of computers. The present state is described in characteristics, also is concise indicated the possible and desirable further development. Interested persons may demand comprehensive informations about the total concept and documentations about the individual part-programs from the authors under send in of a diskette.

Documentation↗
PubMed1990

[Altered composition of gangliosides in the erythrocyte membrane and in the plasma of alcoholic patients].

Gangliosides were isolated from plasma and membranes of erythrocytes of alcoholics. The pattern of gangliosides were compared with the data of healthy donors. Up to 7 fractions of gangliosides could been detected after extraction, purification by column chromatography and fractionation by TLC. In alcoholics the main ganglioside fractions of plasma GM3 were increased (52.6%) and GD3 were decreased (17.5%). The GM3 and GD1b fraction of erythrocytes membranes were decreased significantly in alcoholics.

Adult↗
PubMed1990

[The neuraminic acid/protein quotient in amniotic fluid: indicator for fetal maturity].

The concentration of neuraminic acid and proteins was determined in amniotic fluid of 207 pregnancies during the amniocentesis, performed in the 16.-21. week of gestation, 17 prematurities and 101 deliveries in time. The neuraminic acid/protein quotient increases significantly at term. Than, its reference range is 51.3-154.8 mumol/g (2.5-97.5 percentile). The neuraminic acid/protein quotient can be an useful prenatal indicator of the fetal maturity because of its high diagnostic specificity (97%) and sensitivity (88%).

Amniocentesis↗
PubMed1990

Synaptic plasticity in rat medial prefrontal cortex under chronic haloperidol treatment produced behavioral sensitization.

Morphometric analysis of the population of synapses in medial prefrontal cortex (layer VI) of rat treated daily with haloperidol in a dose of 1.0 mg/kg during 3 weeks was performed on the electronmicroscopic level. The density of synapses on dendritic shafts increased on 29% and on the head of spine it increased on 20%. Nearly all the parameters measured in axo-spinous synapses were significantly decreased (area of presynaptic terminal, summarized area of mitochondriae per terminal, number of synaptic vesicles near the active zone, area of postsynaptic spine). There were no differences between the parameters of axo-dendritic synapses in control and haloperidol-treated rats. The data suggest that haloperidol might have induced the formation of the new synapses and may have changed the efficacy of the synaptic transmission in axo-spinous synapses on the head of spine.

Animals↗
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↗