Biomedical subjects

J Horský

Publications and source records attributed to J Horský.

At least 19 recordsLinked to original sources

PubMed1991

[Histochemistry of exopeptidase activity in the brain using a natural substrate method].

The location and properties of brain exopeptidase activities are determined with the method of so-called natural substrates. The activities of enzymes cleaving dipeptides (leu-leu, tyr-tyr, tyr-phe, met-ala, met-arg and gly-pro) are compared with both the activities and character of enzymes cleaving chromogenic leu-4M2NA substrate. The present work demonstrates a broad spectrum of exopeptidase activities localized in glia, neurons, neuropile and cerebral vessels. The cleavage of tyr-tyr and tyr-phe substrates is preferred with exopeptidases localized in neurons and their fibrillar protrusions. The leu-leu and leu-4M2NA substrates are cleaved in some definite portions of capillaries and thicker vessels. In the present work the question is discussed of substrate specificities of determined enzymatic activities in relation with detection specificity of M aminopeptidase.

Animals↗

PubMed1990

Role of interaction of the tanycytes of the third ventricle of the brain with the vascular bed endothelium in enzymatic activation of the parkinsonism-inducing proneurotoxin MPTP in rat brain.

The authors describe the localization of monoaminooxidases oxidizing the protoxin MPTP to the active neurotoxic MPP+ ion, which induces parkinsonism by destroying the dopaminergic neurons of the nigrostriatum. Apart from some types of magnocellular neurons of the hypothalamus, enzymatic activity is localized in the endothelium of segments of the circumventricular vascular bed communicating with the enzymatically equally positive processes of the tanycytes of the third brain ventricle. The findings are briefly discussed from the aspect of the pathogenesis of experimental parkinsonism.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

PubMed1989

[The effect of Saponinum album Merck on changes in the hemolytic resistance of erythrocytes in relation to age in healthy persons].

The authors elaborated a method for the assessment of the haemolytic resistance of erythrocytes which tests them from the aspect of resistance of their membranes against the haemolytic action of Saponinum album Merck. The physicochemical principle of this method is quite different from the routine test of osmotic resistance of red cells. By the described method red cells of healthy male and female donors aged 4 to 77 years were evaluated. By means of linear regression a significant relationship (with a confidence of 0.999) was proved between parameter M (saponin concentration producing 50% haemolysis (and age). From the evaluation it is apparent that with advancing age in man the resistance of red cell membranes against saponin action declines. From this and from known findings on the mechanism of saponin haemolysis it may be concluded that red cells of all age groups cannot be considered equal as regards the quality of membranes and that these cells undergo certain changes in the course of the lifetime of the individual.

Adolescent↗

PubMed1989

[Analogs of gonadoliberin in the treatment of endometriosis and uterine myoma. Comparison of daily subcutaneous treatment and intramuscular depot therapy].

Seven women with endometriosis and three women with uterine myomas were treated for six months with tryptoreline (Decapeptyl, Decapeptyl Depot, Ferring). In six patients with endometriosis improvement was achieved according to the AFS classification and the finding on palpation and ultrasonic examination. In three patients with uterine myoma a reduction by 25-100% was recorded. Dysmenorrhoea and pain in the hypogastrium disappeared completely in all patients except one. The LH and FSH levels declined and E2 levels were similar as in the menopause. The menstrual cycle disappeared in the course of treatment and all women experienced flushes. Daily s. c. and monthly depot doses gave similar results. Four months after treatment the hormonal levels and the menstrual cycle were normal. Endometriosis disappeared twice, four times minor endometriotic nodes persisted, once a uterine myoma of half the size reappeared. Treatment with LH-RH agonists in endometriosis matches danazole treatment in uterine myomas it is suitable for special cases.

Adult↗

PubMed1989

Localization of 2-glucuronidase in the marginal sinus of rat spleen.

The study demonstrated lysosomal 2-glucuronidase activity localized in the marginal sinus epithelium of rat spleen. Immunologically, the marginal sinus is a key structure of the spleen and its enzymatic apparatus differs from that of the cells of the red pulp venous sinuses. The possible physiological significance of this finding is briefly discussed.

Animals↗

PubMed1988