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J Vácha

Publications and source records attributed to J Vácha.

At least 73 records · Page 4Linked to original sources
PubMed1985

German constitutional doctrine in the 1920s and 1930s and pitfalls of the contemporary conception of normality in biology and medicine.

From the end of the First World War, a broad discussion took place within the framework of the revived German constitutional teaching on the question of the physical normality of man. The founder of the so-called statistical concept of normality, which preceded the still widespread normal (reference) interval concept, is H. Rautmann, who gave it the character of a tool for discriminating between health and disease. Among some of his successors (Bauer, Borchardt, Günther), however, it was considered more a means of establishing a type, without supposing any precise relation between the frequency of a character in the population and the probability of the occurrence of disease. The concept of a statistical norm as a certain region of the variation range of a character determined by the parameters of Gaussian distribution was criticized both by the supporters of the ideal norm (Hildebrandt) and those who were in favour of a 'personal' norm (Grote). The underlying motifs of these three conceptions of normality influenced German constitutional doctrine until after the end of the Second World War, but without a satisfactory solution to the diagnosis of physical normality being found. Since the 1950s, world medicine has moved more and more in the direction of prevention, with the emphasis on a study of individual dispositions to disease and its precursors. In this connection a new view of health has gained importance whereby it is considered a smoothly gradated condition, not sharply distinguished from disease ('continual' model of health and disease as opposed to the previous 'alternative' model). The purpose of diagnostic characters is no longer merely to place patients in clearly defined categories as healthy or affected by one disease or another, but has taken on the function of indices of the disposition to disease among those who exhibit 'gross normality'. Discrimination between the alternative and continuous models allows a clarification to be made of the sources of the confusion in which the pre-war concept of statistical normality had found itself. Today many exceptions are known to the rule that the functional optimum lies in the region of the population mean, both for the population as a whole and for individuals; and immense variability has been found in the manner in which individuals in the population attain health.(ABSTRACT TRUNCATED AT 400 WORDS)

Anthropometry↗
PubMed1984

Effect of glycosaminoglycan polysulphate on the metabolism of cartilage ribonucleic acid.

The effect of glycosaminoglycan polysulphate (GAGPS, Arteparon) on the metabolism of cartilage ribonucleic acid (RNA), collagen, and proteoglycan was studied. GAGPS stimulated the synthesis of collagen and the both components of proteoglycan. The effect of GAGPS on RNA was compared with those of chondroitin sulphate and heparin. All three investigated substances enhanced the RNA synthesis, GAGPS, however, had a comparable effect in concentrations ten times smaller.

Animals↗
PubMed1983

The distribution of the haeme and non-haeme fractions of iron in individual regions of the erythropoietic system of intact and acutely irradiated mice.

In male mice of the strain C57BL/10ScSnPh, both intact and X-irradiated with a whole-body sublethal dose, the distribution of the content of total and haeme iron was studied in individual bones, the spleen, liver, plasma and erythrocytes, using an original mineralization and extraction technique. In the erythropoietic organs as a whole and in the individual bones the haeme and non-haeme iron compartments were distinguished, and within these the iron accounted for by circulating plasma and by erythrocytes and erythrocyte precursors. In the radiation-depleted marrow there were quantitative and qualitative changes in the compartments, particularly the creation of an important compartment of non-circulating (fixed) erythrocytes.

Animals↗
PubMed1982

The distribution of erythropoiesis over the various anatomical regions of the erythropoietic system in some inbred strains of mice.

The extraction of 59Fe bound to the heme in the erythropoietic organs by means of acid ethylacetate was used to establish the proportion of erythropoiesis for which individual bones and the spleens of some inbred mouse strains are responsible. The proportion of splenic erythropoiesis differs from strain to strain, being in the range 9-42% of total erythropoiesis. In the strain BALB/c erythropoiesis is shifted in comparison with C57B1/10 strain towards the spine and away from the bones of the skull, the long bones of the limbs and the pelvis. Calculations of the erythroid cellularity and/or the intensity of erythropoiesis of the total bone marrow on the basis of a single bone should take into account both these interstrain differences in the participation of different regions and the possibility of various proportions of red and white blood cells and cells containing non-heme iron existing in different regions (bones).

Animals↗
PubMed1981

The effect of chloramphenicol on erythropoiesis in X-irradiated mice.

Mice irradiated with a dose of 4,78 Gy X-radiation were treated 3 or 5 days with a thrice-daily dose of chloramphenicol of 160 or 320 mg/kg. Observation of the incorporation of 59Fe into the heme fraction suggested that chloramphenicol has a depressive effect on erythropoiesis in the spleen of nonirradiated animals, and clearly proved this in irradiated ones. Depression in the bone marrow of nonirradiated animals was not observed, in irradiated animals a depressive effect was shown, though less strong than in the spleen. As benefits these findings there is an accentuation of postirradiational anemia after chloramphenicol treatment of irradiated animals, and signs of incipient anemia in nonirradiated animals. All the effects mentioned were repaired within 14 days of the end of chloramphenicol treatment.

Animals↗
PubMed1980

The volume of plasma and erythrocytes in individual bones and in the spleen of mice under physiological conditions and with acute radiation-induced atrophy of the haemopoietic tissue.

Using labelled erythrocytes and human serum albumin, the volume of circulating erythrocytes and plasma was determined in the spleen and individual parts of the skeleton of mice under physiological conditions and 48 h after X-irradiation with a dose of 2,87 Gy. The results are significant for the interpretation of the method of incorporation of labelled iron into haemopoietic organs.

Animals↗
PubMed1980

Chloramphenicol toxicity in radiation disease.

The effect of chloramphenicol given in high therapeutic doses, in the course of postirradiation syndrome in irradiated mice of C57Bl/10 strain, is reported. Chloramphenicol treatment increased postirradiation mortality of animals and intensified suppression of the proliferating and differentiating processes in hemopoietic organs of the irradiated animals. The results support the assumption that postirradiation depression of hemopoiesis is a contraindication to the therapeutic employment of this antibiotic.

Animals↗
PubMed1978

Liver growth, biosynthesis of cytidine nucleotides and level of cytochrome P-450 in rat liver after administration of alpha-hexachlorocyclohexane.

The biosynthesis of cytidine nucleotides and the level of microsomal cytochrome P-450 in intact and regenerating rat liver after repeated administration of alpha-hexachlorocyclohexane (alpha-HCH) were compared. In alpha-HCH treated animals the utilization of [2-14C] orotic acid for the synthesis of cytidine nucleotides is suppressed. In 24-h regenerating liver the incorporation of labelled orotic acid into cytidine nucleotides is markedly activated; the degree of activation is lower in regenerating livers of alpha-HCH treated animals. The changes in the level of cytochrome P-450 vary inversely with the changes in the utilization of [2-14C] orotic acid for the synthesis of cytidine nucleotides. The activity of cytidine triphosphate synthetase of liver cytosol increases shortly after the administration of alpha-HCH; uridine-cytidine kinase is enhanced in the later stages of the drug action. Within 15-45 min after the administration of alpha-HCH the uptake of [U-14 C] cytidine into the liver and its incorporation into RNA cytosine are increased. After the administration of the drug the uptake of [2-14 C] uridine and its incorporation into RNA uracil is also enhanced whereas its utilization for the synthesis of cytidine nucleotides of the acid-soluble extract as well as for the RNA cytosine are suppressed.

Animals↗
PubMed1978

Pyrimidine nucleotide synthesis in rat liver after the administration of cycloheximide.

After the administration of cycloheximide (2 mg/kg) the utilization of [2(-14C)]orotic acid for the synthesis of pyrimidine nucleotides of acid-soluble extracts of the liver is not affected for about 7 h. The specific activities of uridine and cytidine components are increased later on, and this increase is higher in the case of cytidine components. Analogous changes undergoes the specific activity of RNA pyrimidine nucleotides. The increased utilization of labeled orotic acid for the synthesis of cytidine nucleotides can be observed also in the kidney and in the small intestine. The enhanced degree of labeling of cytidine nucleotides in vivo cannot be correlated with the activity of cytidine triphosphate synthetase (EC 6.3.4.2) of liver cytosol estimated in vitro. The amination of UTP is suppressed at later intervals after the application of cycloheximide. The same holds true for the activity of uridine phosphorylase (EC 2.4.2.3),5'-nucleotidase (EC 3.1.3.5) ATPase (EC 3.6.1.3) and of liver cytosol. The activity of uridine kinase (EC 2.7.1.48) is increased when tested both with uridine and cytidine as substrates. Cytidine deaminase activity (EC 3.5.4.5) raises markedly 3--5 h after the administration of drug; later on it decreases again.

Animals↗
PubMed1978

Comparison of life span of erythrocytes in some inbred strains of mouse using 14C-labelled glycine.

The erythrocyte life span in four inbred strains of mice--C57BL/10ScSnPh, B10.LP, BALB/c and CBA/JPh--was determined by means of erythrocyte labelling with 14C-glycine. Experimental data [decrease of 14C-activity of washed erythrocytes], corrected for blood loss, reincorporation of the label and delay in label incorporation during the initial period, were treated by a novel mathematical procedure based on the death probability function of the form: mu [t] = a + btlambda. The mean erythrocyte life span calculated using this function was, in the given sequence of strains, 42.1 +/- 0.6, 41.3 +/- 1.2, 39.3 +/- 0.9 and 38.6 +/- 0.6 days respectively. The rate of "random" destruction of erythrocytes was 1.20, 1.31, 0.70 and 0.63% of the total number of erythrocytes per day and a "mean potential" erthrocyte life span was found to be 58.9, 59.9, 46.2 and 44.5 days respectively. All the given parameters have similar numerical values in related strains and are apparently genetically conditioned. The erythrocyte life span determined simultaneously using DF32P labelling in the C57BL/10ScSnPh strain was 47.4 +/- 1.0 days. The implications of the results yielded by these two techniques is discussed.

Animals↗