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Biomedical subjects

K Tóth

Publications and source records attributed to K Tóth.

At least 109 records · Page 6Linked to original sources
PubMed1990

[The role of fluorides in the prevention of dental caries].

By searching for the cause of mottled enamel--which was known already in Italy of the Roman period--the researchers Churchill, Smith, Lantz and Velu were almost simultaneously led to the recognition that the surplus fluoride in drinking water is the cause of the phenomenon. Thereafter, by Dean and his collaborators it was proved by means of mass caries screenings and chemical analyses of drinking water that if the drinking water contains 1 mg F-ion by litre then there is no mottle on the enamel while the condition of the teeth is substantially by about 50 to 60% better than those of consumers of drinking water poor in fluorine. The safely tolerable dose is 1.5 to 2.0 mg by litre. Obviously this is a populational resume drinking water which is natural or artificially enriched with fluoride. Employment of the fluorides has considerably been extended in the course of research and development. The methods can be grouped in several manners. In the author's opinion the best grouping is: a) collective and b) individual methods. The element F belongs to the group of the + type poisoning elements which, however, does not occur in nature because when getting into nature it immediately combines with ther elements and, therefore, in nature only its various salts are met with. Chronical fluorosis is caused by consuming 5 to 10 mg fluoride through many years. 100 to 200 mg is a lightly poisoning dose with children or adults. A mortal dose is 1200 to 2500 mg.

Administration, Oral↗
PubMed1989

[Duplex ultrasonography of the portal circulation before and after sclerotherapy of esophageal varices].

Authors examined 40 patients suffered from portal hypertension before and after sclerotherapy of esophageal varices with duplex ultrasonography. The patients were divided into four groups: the first and recurrently bleeding patients and those who were treated with propranolol. The average velocity of the main portal vein before the treatment was significantly lower in the patient group, than in the normal control group. There were no significant changes observed after treatment. The portal blood flow increased in the first bleeding patients who did not take propranolol. The diameter of the main portal vein increased in the recurrently bleeding patients. The conclusion is, that the duplex ultrasonography of the portal circulation is a valuable noninvasive method. One has to take into consideration the limits of this technique and further data are needed for the diagnostic and prognostic accuracy.

Esophageal and Gastric Varices↗
PubMed1989

Subacute toxicological examination of Dithane M-45.

A subacute toxicological study of the effects of the ethylene-bisdithiocarbamate-containing fungicide Dithane M-45 (80% mancozeb) was carried out in male Wistar rats. The rats were given Dithane mixed in the feed at doses of 0, 10, 50, 75, 113, 169, 253 or 379 mg/kg body weight for 12 wk. One-third of the rats given 379 mg Dithane/kg body weight died, and doses of greater than or equal to 169 mg/kg decreased the growth of the rats as well as the nutrient utilization. The relative weights of the liver and thyroid were significantly increased in rats given greater than or equal to 75 mg Dithane/kg body weight, and those of the kidneys, adrenals and testes were significantly increased in the two highest dose groups. The serum cholesterol level was increased significantly in groups given greater than or equal to 75 mg/kg, and doses of 113, 169 or 253 mg/kg caused the elevation of the triglyceride content of the liver. The two highest doses of Dithane decreased the detoxicating capacity of the liver. The function of the thyroids was impaired even by very small doses of Dithane: at a dose of 10 mg/kg body weight the quantity of iodine stored in the thyroids was decreased by 20%. At doses of greater than or equal to 50 mg/kg statistically significant decreases in thyroid iodine content were observed. Histological examination of the thyroids showed dose-dependent hyperplasia in rats treated with Dithane.

Animals↗
PubMed1989

[Treatment of scaphoido-trapezial arthrosis by arthrodesis using small-size Ender plates].

Authors have performed in the treatment of arthrosic complaints a scaphoideo-trapezial arthrodesis. The axial compression was reached with the application of small Ender plates without damaging the articular surface of the neighbouring small joints of the wrist. In the literature, describing the scaphoideo-trapezial arthrodesis, no similar operative technique was found.

Arthrodesis↗
PubMed1989

[The condition of the permanent teeth of students 15 to 17 years of age in secondary schools in Csongrád County].

The teeth of altogether 1253 students studying in 38 secondary educational establishments of the County of Csongrád have been examined. The number of the examined amounts in case of the 15 years old to 13.51% and in case of the 17 years old to 8.8% of the total number of youth of similar age living in the County. The caries frequency is 98.95% at the age of 15 years, and 98.78% at the age of 17 years. The DMF-T index is 10.35 for the 15 years old, and 10.93 for the 17 years old. With respect to the DMF-T indices found with people of the same year in Szeged in 1961 the present data are higher by 39.11% (15 years old) and by 29.66% (17 years old), respectively.

Adolescent↗
PubMed1988

Loosening of the phage structure in a low ionic strength environment.

Structural parameters of phage T7 were compared in two frequently used Tris buffers of high and low ionic strength, in order to explain the different biological activity and drug-binding characteristics. Characteristics of the whole phage geometry were obtained by viscosimetry, static and quasi-elastic light-scattering and small-angle X-ray scattering. The latter method revealed dissimilarities in the intraphage DNA compactness, consistent with the findings of the optical absorption melting studies. Alterations in the particle dimensions determined in the same sample by different methods are discussed, and a model is constructed to explain the structural modifications that occur on lowering the ionic strength.

Light↗
PubMed1988

Carcinogenicity and genotoxicity of the herbicide 2,4,5-trichlorophenoxyethanol (TCPE) contaminated with dioxin.

In an earlier study 2,4,5-trichlorophenoxythanol (TCPE) contaminated with dioxin, a component of the Hungarian herbicide Buvinol, was found to be hepatocarcinogenic. In the present work, the hepatocarcinogenicity of TCPE was compared to its possible genotoxicity in vitro, using the Salmonella/microsome test for mutagenicity and for its DNA-damaging effect, the induction of sister chromatid exchanges (SCE) in Chinese hamster cells in vitro. It was found that purified TCPE (with 0.1 ppm dioxin content) was under no conditions mutagenic by the Ames test, i.e., it belongs to the group of false-negative chemicals. TCPE was, however, genotoxic; its DNA-damaging effect was demonstrated by an increase in the frequency of SCE, while pure dioxin of corresponding amount was ineffective. However, elevated SCE frequency and the toxicity on bacteria and mammalian cells by TCPE were significantly decreased by the metabolic activation system (S-9 mix) isolated from liver. This observation indicates that in the detoxication of TCPE in vitro, a key role is to be attributed to the hepatic microsomal enzymes. It is presumed that TCPE is hepatocarcinogenic only in a dose range which has exhausted the detoxicating capacity of the liver.

2,4,5-Trichlorophenoxyacetic Acid↗
PubMed1988

The fluoride content of selected foods in relation to the fluoride concentration of water.

The F content of foods and beverages comprising a substantial proportion of the Hungarian diet has been determined. Vegetables and fruits grown in three areas where the mean F content of water was 0.09 mg/l, 0.81 mg/l and 1.91 mg/l did not reflect these differences. In contrast, the F content of cooking water has made demonstrable contribution to the F content of cooked foods. Significant elevation in F concentration was also found in some meat products, where the inclusion of bone dust or fragments is suggested by corresponding increase in Ca content.

Beverages↗
PubMed1988

Daily fluoride intake from the diet of Hungarian children in fluoride deficient and naturally fluoridated areas.

Average daily dietary intakes of F were determined for 67 kindergarten children (X age 3.9 years) and 118 schoolchildren (X age 14.0 years), resident in one of three areas where the concentration of naturally occurring F in the household water ranged 0.06-0.11 mg/l, 0.05-1.10 mg/l and 1.6-3.1 mg/l. Mean daily F intakes increased consistently and significantly with increasing F content of the water in all dietary categories in both age groups. Due to relatively low water and high milk consumption, F from foods has made a greater contribution to total F intake (40-53% over the whole sample) than F in water ingested as such, or in beverages. The total amount of F ingested from dietary sources is considered safe even at the highest intake levels found (X = 0.44 mg/day, SD = 0.11 at 3.9 years; 1.49 mg/day, SD = 0.35 at 14.0 years).

Adolescent↗
PubMed1988

Aluminium, calcium and magnesium content of Hungarian foods and dietary intakes by children aged 3.9 and 14 years.

The Al, Ca and Mg content of 147 kinds of foods and beverages, representing a large proportion of the Hungarian diet, has been determined using replicate samples. Dietary intakes of these minerals by 67 kindergarten children and 139 schoolchildren have been assessed. The richest sources of Al were: parsley, celery, gherkins, barley-malt; of Ca: dairy products, celery, parsley, savoy; of Mg: dried beans and peas, parsley, dill, maize-flour, rice, gherkins, chocolate. Flavouring agents (e.g. salt, pepper, paprika, caraway-seed) had very high concentrations of all three minerals and poppy-seeds that of Ca and Mg. The presence of bone-dust or fragments elevated the Ca content of some meats and cooked dishes. The main source of dietary intake of all three minerals was food; as opposed to F, the contribution of water-borne Al, Ca and Mg was negligible. Based on average values, the daily intake of all three minerals was satisfactory in both age groups. Mg intake was marginally below the recommended limit for a few children, but no signs of Mg deficiency were seen.

Adolescent↗
PubMed1988

Fluoride intake and utilization by Hungarian children: associations and interrelationships.

Selected interactions were examined between F, Al, Ca and Mg intakes and their manifestations in dental health parameters and biological samples relating to Hungarian children. The prevalence (DMFT, DMFS) and severity (SR) of caries were inversely related to the F concentration of household water and to the amount of F ingested from foods, beverages and tap or well water. Dental fluorosis and the F content of enamel, plaque, saliva, urine, nails and hair were directly related to the F content of water and to dietary F intake. The high significance levels and absolute consistency of associations lend strong support to the biological interdependence of the variables involved. In contrast, no associations were found between Mg ingestion and F utilization. Despite numerous inverse trends and some statistically significant inverse associations suggesting that dietary Al and Ca interfere with F uptake, the biological significance of the latter findings needs further exploration. Inhaled F amounted to less than 0.17% of the total F intake. The F content of frequently prescribed non-dental medicines ranged from below 0.00001 to 0.014 mg/g; their contribution to total F intake is considered insignificant.

Adolescent↗