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Biomedical subjects

K Tóth

Publications and source records attributed to K Tóth.

At least 163 records · Page 9Linked to original sources
PubMed1983

[Importance of environmental factors for the development of liver cirrhosis].

The frequency of cirrhoses drastically increased in the seventies. This increase was predominantly due to an augmentation of alcoholic cirrhosis in men. Cirrhosis is significantly more wide-spread in men than in women. Most of the cirrhoses in women are of unknown origin. Morphologically, the alcoholic cirrhoses are of the micronodular types in their great majority. Combined with HBsAg positivity, the macronodular type is most frequent. The classification in micro- and macronodular cirrhoses do not imply a different etiology but it may indicate different stages in cirrhosis of identic origin. Histologically, the signs of alcoholic hepatitis particularly help to trace back the alcoholic etiology. If HBsAg can be detected and the margins of the pseudolobules are moth- eatenlike , this speaks for a hepatitic origin. The lowest average age was observed in cases of alcoholic cirrhoses, the highest in HBsAg positive cirrhoses of women. Men suffering from cirrhosis die earlier than women. In the case of alcoholic origin, the bulk of the cirrhotic livers are eutrophic while, beside HBsAg positivity, the atrophic livers are prevailing. The two most frequent environmental causes of cirrhosis are alcoholic beverages and hepatitis. Better exploration of the environmental factors and clearing up the origin of cryptogenic cirrhoses are essential tasks of the future.

Adult↗
PubMed1982

Mutagenicity of dibromodulcitol (DBD), an alkylating anticancer drug) and its mono- and bifunctional conversion products studied by the Salmonella/microsome assay.

Dibromodulcitol (DBD) and one of its most important bifunctional transformation products, dianhydrogalactitol (DAG) with similar cytostatic effect, were tested by the Salmonella/microsome assay on strains TA 1535, TA 1538, TA 98 and TA 100 using the plate incorporation technique. Both drugs were direct mutagens in strains TA 1535 and TA 100 and non-mutagenic in other strains. Their mutagenic effect was not influenced by S-9 mix from rat liver. Mutagenicity of DAG was very limited because of its marked toxicity. The other monofunctional alkylating derivatives, i.e., 1-bromo-3,6-anhydrodulcitol and 1,2-epoxy-3,6-anhydrodulcitol were highly mutagenic in strains TA 1535 and TA 100 with and without S-9 mix despite having no anticancer effect. Anticancer activity was exerted only by the bifunctional alkylating hexitols (DBD, DAG) which showed moderate mutagenic activity compared to the monofunctional derivatives. No correlation could be established between the mutagenic and anticancer effect of the four structurally related hexitols. Mutagenicity of urine and bile from rats after a single administration of the maximum tolerated (450 mg/kg) dose of DBD was also examined, and the hexitol components of the same urine sample were identified by t.l.c. DBD and its mutagenic transformation products were excreted in urine and not through the bile. The mutagenic effect of DBD observed cannot be attributed exclusively to DBD observed cannot be atributed exclusively to DBD itself, because the parent molecule, like other alkylating agents, easily undergoes spontaneous decomposition under in vitro and in vivo conditions to release both bi- and monofunctional alkylating solvolysis products and there highly reactive derivatives may play a role in this effect. No significant difference in the relative mutagenicity was detected between DBD and cyclophosphamide, used as a reference substance.

Animals↗
PubMed1982

Interrelations between the fluoride concentrations in dental plaque and enamel, and exposure to fluoride.

The F concentrations in plaque and in underlying enamel were determined in a sample of 99 schoolchildren aged 8.4 years (S.D. = 0.37), comprising four groups, exposed life-long to contrasting concentrations of F in the water (range less than or equal to 0.12 ppm to 2.8 ppm) and to supplements of 350 mg F/kg domestic salt. The mean total F concentrations in plaque (dry wt) increased consistently with increasing exposure to F, but the absolute differences were small and the individual variation was high within each group. Significant inverse associations were demonstrated between individual plaque and surface enamel values within two groups, supported by consistent inverse trends (ns) in the remaining groups. These associations and trends are considered to reflect transfer of F from plaque to underlying surface enamel and concommitant reduction in plaque F concentration.

Child↗
PubMed1982

The fluoride content of human tooth enamel in relation to environmental exposure to fluoride.

Double-layer superimposed biopsies were used for sampling sound labial enamel of upper permanent central incisor teeth of 189 children (mean age 8.4 years, SD = 0.36), comprising five groups, representing life-long exposure to contrasting concentrations of F in the water (range less than or equal to 0.12 ppm to 2.8 ppm) and to supplements of 200 or 350 mg F/kg domestic salt. The mean F concentrations of enamel ranged through the groups from 924 ppm to 2401 ppm in the surface layer (average central depth = 0.49 micron) and from 450 ppm to 1428 ppm in the subsurface layer (average central depth = 2.62 microns). The differences between the mean F concentrations of the groups were significant in each instance and the values consistently reflected the extent of F exposure. It was concluded that the F content of enamel is a reliable indicator of environmental exposure to F for populations, but not for every individual.

Child↗
PubMed1980

Effect of fluorine content of drinking water on fluorine concentration of foods.

Foods originating from areas where the drinking water contains 1 mg F per litre since at least 30 years were examined for their fluorine content. In the F content, no difference was found between raw vegetables, cereals, and dishes of cooked meat whether they originated from areas where the drinking water was F-poor or containing 1 mg F per litre, despite the fact that in the latter areas the vegetable gardens were watered regularly with this F-rich water for 3 decades. The mean F content of the foods originating from the F-rich water for 3 decades. The mean F content of the foods originating from the F-rich areas were 0.28 mg per kg, 0.27 mg per kg, and 0.27 mg per kg, respectively. The mean F content of soups from F-rich places was 1.5 mg per kg, and that of the dishes of cooked vegetables, though lower, was still high enough: 0.40 mg per kg. It is pointed out that watering with water containing 1 mg F per litre does not increase the F content of the foods. The higher F content found in the foods and cooked vegetables came from the drinking water used for cooking.

Fluoridation↗