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Biomedical subjects

G Sándor

Publications and source records attributed to G Sándor.

At least 19 recordsLinked to original sources
PubMed2000

[Perinatal origin of malignant diseases].

In the present days the molecular genetical investigations are the mainstream of establishing the etiology of malignant diseases. Beside these surveys, prenatal, neonatal, environmental and developmental risk factors for malignancy have repeatedly been investigated during the last few years. Mounting evidences show the importance of the intrauterine and perinatal period in tumor genesis and health quality in later life. This review article summarizes the results of traditional epidemiologic studies which identified a number of risk factors for malignancy. These easily detectable anamnestic data, developmental, physical features can further support the prenatal origin of tumors and can give new directions for the modern molecular genetical investigations.

Birth Weight↗
PubMed2000

Estimates of repolarization dispersion from electrocardiographic measurements.

BACKGROUND: Repolarization dispersion (Rd) is frequently mentioned as a predictor of cardiac abnormalities. We present a new measure of Rd based on the root-mean-square (RMS) curve of an ECG lead set and compare its performance with that of the commonly used QT dispersion (QTd) measure with the use of recovery times measured from directly recorded canine electrograms. METHODS AND RESULTS: Using isolated, perfused canine hearts suspended in a torso-shaped electrolytic tank, we simultaneously recorded electrograms from 64 epicardial sites and ECGs from 192 "body surface" sites. RMS curves were derived from 4 lead sets: epicardial, body surface, precordial, and a 6-lead optimal set. Repolarization was altered by changing cycle length, temperature, and activation sequence. Rd, calculated directly from recovery times of the 64 epicardial potentials, was then compared with the width of the T wave of the RMS curve and with QTd for each of these 4 lead sets. The correlation between T-wave width and Rd for each lead set, respectively, was epicardium, 0.91; body surface, 0.84; precordial, 0.72; and optimal leads, 0.81. The correlation between QTd and Rd for each lead set was epicardium, 0.46; body surface, 0.47; precordial, 0.17; and optimal leads, 0.11. CONCLUSIONS: RMS curve analysis provides an accurate method of estimating Rd from the body surface. In contrast, QTd analysis provides a poor estimate of Rd.

Animals↗
PubMed2000

Estimates of repolarization and its dispersion from electrocardiographic measurements: direct epicardial assessment in the canine heart.

This study investigates a technique to estimate dispersion based on the root mean square (RMS) signal of multiple electrocardiographic leads. Activation and recovery times were measured from 64 sites on the epicardium of canine hearts using acute in situ or Langendorff perfused isolated heart preparations. Repolarization and its dispersion were altered by varying cycle length, myocardial temperature, or ventricular pacing site. Mean and dispersion of activation and recovery times, and activation-recovery interval (ARI) were calculated for each beat. The waveform was then calculated from all leads. Estimates of mean and dispersion of activation and recovery times and mean ARI were derived using only inflection points from the RMS waveform. QT intervals were also measured and QT dispersion was determined. Estimates determined from the RMS waveform provided accurate estimates of repolarization and were, in particular, a better measure of repolarization dispersion than QT dispersion.

Animals↗
PubMed1999

Body surface potential field representation fidelity: analysis of map estimation procedures.

The first part of this study analyzed the spatial-temporal error distribution of the Lux-type limited lead system. Quantitative new evidence is reported that the 32-lead anterior subset estimates the further 160 leads with an average amplitude error less than 38.5 microV. The spatial error distribution revealed 8 sites where the error is the highest, primarily on the anterior side, independent of the clinical classification. The second part of the study examined inter-lead-system conversion strategies for interpolating the Lux-192 lead maps from the Montreal-63 data. The methodology based on the Laplacian interpolation yielded an average amplitude error of 143.7 microV and an average correlation of 0.87 for pattern fidelity. In this specific case a modified linear interpolation surpassed the Laplacian method. A presented example illustrates that even in cases when the fidelity of the signal information is heavily compromised the diagnostic information may remain less influenced.

Body Surface Potential Mapping↗
PubMed1998

Excess of mild errors of morphogenesis in childhood lymphoblastic leukemia.

The prevalence of 55 well-defined mild errors of morphogenesis (MEMs) was determined in 100 children with acute lymphoblastic leukemia (ALL), their 80 sibs, 91 mothers, and 76 fathers. Seventy-four patients were treated in Pécs (Hungary) and 26 in Tübingen (Germany). Only white Caucasian index cases were included in the study. Two-hundred children examined for acute infections served as controls. In addition, we analyzed the family history for birth defects and malignancies, associated major malformations, birth weight, birth order, and pretreatment height of the patients. The results of the Pécs and Tübingen patients were at first evaluated separately but since no differences were found only the cumulative data were analyzed further. A significantly increased prevalence of MEMs was found in the ALL patients and their sibs of both sexes: their MEM/subject ratios were 1.59 and 1.51, respectively, whereas the same parameter was 0.74 in the mothers, 0.67 in the fathers and 0.69 in the controls. The same tendency was observed when familial cases and/or age-dependent MEMs were excluded and when malformation-type and variant-type MEMs were evaluated separately. No association of ALL with specific MEMs or combinations was recorded. Family history, associated major malformations, parity and birth weight of the patients did not differ significantly from the local reference values, whereas the pretreatment height of the male probands proved to be greater than expected.

Adolescent↗
PubMed1998

Coccidioidomycosis in Hungary. The first import case.

A case of an isolated subcutaneous coccidioidomycosis in a 61-year-old man is presented. The patient has lived and worked in Arizona for 3 years previously but developed no apparent clinical signs of the disease. The painless, cavitating, tumor-like mass was surgically excised and the diagnosis was established by histological demonstration of the fungi and confirmed by serum counterimmunoelectrophoresis. This represents the first imported case of coccidioidomycosis in Hungary.

Arizona↗
PubMed1995

Detection of ochratoxin a in human blood and colostrum.

Ochratoxin A (OA) is one of the most frequent sources of mycotoxin contamination of feed plants in Hungary. It is produced by 10% of Aspergillus and 12% of Penicillium species, i.e. by the widely occurring "commonest" mould species. Human exposure to mycotoxins closely resembles that of swine. Fifty-two out of 100 human blood samples collected at random (52%) were found to contain ochratoxin A (0.2-12.9 ng/ml). Recent studies have clearly shown that OA has mutagenic, teratogenic and carcinogenic effects. Sensitivity to mycotoxins is known to be inversely related to age. Therefore, it was considered important to test human colostrum samples for OA content. Thirty-eight out of 92 colostrum samples (41.3%) collected from women in the first 24 hours post partum contained ochratoxin A (0.2-7.3 ng/ml). The HPLC method applied in this study is described in detail.

Aspergillus↗
PubMed1994

Face lifts and sprayed fibrin glue: an outcome analysis of 200 patients.

The use of aerosolised fibrin glue has been evaluated in a group of 100 consecutive patients undergoing face lift procedures and compared to a similar group of 100 consecutive patients who had face lifts but received no fibrin glue. There was a statistically significant decrease in the rate of major haematoma formation and presentation of ecchymosis associated with the use of fibrin glue. The incidence of total complications was unchanged between the two groups, despite the fact that there were no drains or postoperative dressings used in the fibrin glue treated group. Patients found the omission of drains and dressings to be most convenient.

Adult↗
PubMed1991

Changes induced in newborn piglets by the trichothecene toxin T-2.

Three pregnant sows, being in the last quarter of gestation, were used in an experiment to study the changes induced in newborn piglets by T-2 toxin. One sow was used as control (C). The other two received 24 mg (sow A) and 6 mg (sow B) T-2 toxin, respectively, mixed in the feed, daily, up to the time of farrowing. The piglets of sow A became ill by 48-72 h after birth, while the litters of sow B and C remained healthy. The clinical symptoms included faintness, diarrhoea, decreased blood glucose level, and collapse followed by death. The milk and urine of sow A and the stomach contents of affected and dead piglets contained T-2 toxin and its metabolites. Pathological changes seen at necropsy included acute enteritis, degeneration of the liver and kidneys, and oedema of the mesentery. The stomach was filled with clotted milk. Histopathological and electron-microscopic findings consisted of reduced glycogen content and pathological simple fatty infiltration of the liver cells, lymphocyte depletion and necrosis in the lymphoid follicles of the intestinal mucosa, atrophy of the thymic cortex, and hyperfunction of the adrenal and thyroid glands compared to the control.

Animals↗
PubMed1991

Subacute toxicity testing of ochratoxin A and citrinin in swine.

Fourteen pigs were fed ochratoxin A and citrinin through a stomach tube at daily doses of 0.02 and 0.01 mg/kg body mass for 57 days. These toxin doses correspond to the average toxin contamination level of feeds in Central Europe. The clinical status of the pigs was monitored and clinical laboratory, haematological and mycotoxin-analytical examinations were performed throughout the trial. At the end of the experiment gross and histopathological examinations were carried out. The results of ochratoxin A and citrinin determination in the blood, obtained by high-performance liquid chromatography (HPLC), are important from the food hygienic point of view. The sensitivity of the method was 2 and 10 ng/ml for ochratoxin A and citrinin, respectively. The recovery rate of the mycotoxins was above 60%.

Animals↗
PubMed1990

Mycotoxin research in the Hungarian Central Veterinary Institute.

Mycotoxin research conducted in the Hungarian Central Veterinary Institute is reviewed briefly. The effect of zearalenone was studied by experiments in several animal species (cattle, pig, sheep, chicken, goose, duck, guinea fowl, fish) and in cell cultures in vitro. The chicken (Gallus domesticus) has proved to be resistant to the toxin. In the susceptible species zearalenone causes the most severe damage to the sexual organs. The metabolism of zearalenone, T-2 toxin and diacetoxyscirpenol was also studied. These toxins are resistant to physicochemical factors but are easily transformed in biologically active environment. The acute toxicity study of trichothecene toxins is described along with morphological changes, with particular respect to those of the lymphoid and myeloid organs. Trichothecene toxins impair the natural defence mechanism of the organism and result in the manifestation of different diseases (swine dysentery, caecal coccidiosis). Deoxynivalenol contamination of the feeds, first of all of wheat, is common in Hungary. Its effect on pig fattening was investigated in a field trial. The toxins of different storehouse moulds were also examined.

Animals↗
PubMed1989

Simultaneous fluorometric determination of vitamins A and E in serum.

A simple fluorometric method suitable for serial determinations is reported for simultaneous determination of vitamins A and E in serum. The solvents are pretreated chemically and by distillation. After shaking with ascorbic acid in ethanol, the vitamins are extracted from the serum samples with petroleum ether. The extract is used for the determination. The sensitivity of the method is 20 micrograms/100 ml for vitamin A and 0.04 micrograms/ml for vitamin E. Recovery rates are between 87 and 106%. The method was tested on a total of 160 serum samples of healthy animals belonging to 8 different species. The results showed good agreement with the so-called reference values published in the literature.

Animals↗
PubMed1989

Interaction of T-2 fusariotoxin and monensin in broiler chickens infected with Coccidia.

Field observations suggest that coccidiosis is a common cause of death in broiler chicken flocks fed diets containing sufficient amounts of ionophore antibiotics (monensin, narasin, etc.) and contaminated with mycotoxins, particularly with T-2 fusariotoxin. To study this phenomenon, broiler chickens fed diets containing different amounts of T-2 toxin and free from monensin, or containing a preventive dose (100 mg/kg of feed) of monensin, were infected experimentally with coccidian oocysts. In all groups fed a diet containing monensin plus T-2 toxin severe clinical symptoms of coccidiosis (blood-stained faeces etc). occurred. Deaths and retarded growth depended on the toxin dose and were considerable. The body mass gain of chicks fed a diet containing monensin and T-2 toxin but not infected with coccidia was inferior to that of groups fed diets which contained either monensin or T-2 toxin (experiment 2). On the basis of these findings a negative interaction of the two compounds is assumed. This seems to be supported by the results of experiment 3, i. e. the finding that the lethal dose of narasin, a compound closely related to monensin both in chemical structure and mechanism of action, proved to be much lower (LD50 = 102 mg/kg body mass) for chickens fed a diet supplemented with T-2 toxin than for the control chickens (LD50 = 176 mg/kg body mass). The present results suggest that the feeding of diets severely contaminated with T-2 toxin may alter the anticoccidial efficacy of monensin.

Animals↗
PubMed1985

The time-structure of the anorectic effect of satietin.

The influence of anorectic doses of satietin, calcitonin, fenfluramine and amphetamine on the amount of food eaten, on the time elapsed before taking the first tablet (latency) and on the time-structure of food intake during a one hour feeding session, divided into four 15-minute periods, was measured in rats after one day starvation with a pellet-detecting eatometer. In contrast to fenfluramine, amphetamine significantly increased the time elapsed before taking the first tablet, indicating the stimulation of a satiety mechanism by fenfluramine and the inhibition of a feeding mechanism by amphetamine. In this test satietin and calcitonin acted like fenfluramine. The time-course of food intake was significantly different in the amphetamine and fenfluramine-treated animals, the latter ate more during the first 15-minute period. Satietin and calcitonin acted like fenfluramine in this test, too. The results are consistent with the view that satietin acts by activating a satiety mechanism.

Amphetamine↗
PubMed1982

The selectivity of the anorectic effect of satietin. II. Ineffectiveness of satietin on the water intake in food deprived rats. Effect of satietin in "conditioned aversion" paradigm.

The effect of satietin, a potent endogenius anorexigenic agent, on the water intake of fed and food deprived rats was studied and compared with the effects of calcitonin. In rats deprived of food for 96 h and supplied with water ad libitum, no change in the water intake of intracerebroventricularly (icvtr) administered satietin (2 units/rat), calcitonin (1 unit/rat) and saline (0.2 ml/rat), respectively, was observed. In animals deprived of food and water for 23 h, satietin (2 units/rat, icvtr) left water consumption unchanged, whereas calcitonin (1 unit/rat, icvtr) inhibited the intake of water significantly. The possible role of an aversive reaction in the anorexigenic effect of satietin was also studied using the "conditioned aversion" paradigm of Garcia et al. [3]. Satietin (250 units/kg, intravenously) did not elicit aversion for food.

Amphetamine↗