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Biomedical subjects

I Varga

Publications and source records attributed to I Varga.

At least 91 records · Page 5Linked to original sources
PubMed1995

Potentiation of ionophorous anticoccidials with dihydroquinolines: compatibility of lasalocid and semduramicin with duokvin.

Three battery tests were conducted to reveal whether or not there is an interaction between the new dihydroquinoline antioxidant, duokvin and lasalocid or the new anticoccidial, semduramicin, similar to that observed with some other ionophorous anticoccidials. In terms of body weight gain, no significant difference due to toxic interaction between duokvin and any dose of lasalocid or semduramicin was detected in chickens experimentally infected with oocysts of Eimeria tenella and E. mitis. Anticoccidial efficacy at reduced doses of both lasalocid and semduramicin in combination with duokvin showed numerical improvement; however, this again proved to be insignificant. The lack of incompatibility of this antioxidant with lasalocid or semduramicin allows their simultaneous administration on the one hand, but it fails to enable a substantial reduction of the chemoprophylactic concentration of anticoccidials in the broiler ration on the other.

Animals↗
PubMed1995

Potentiation of ionophorous anticoccidials with duokvin: battery trials against Cryptosporidium baileyi in chickens.

Three battery tests, employing 444 Arbor Acres chickens, were conducted to study the anticryptosporidial efficacy of the polyether ionophorous anticoccidials alone and in combination with a new dihydroquinoline antioxidant, duokvin. The following efficacy percentages for the ionophores at the recommended level were established on the basis of oocyst output: lasalocid 45, monensin 37, semduramicin 29, narasin 23, and maduramicin and salinomycin 21. The efficacy of the ionophores, with the exception of lasalocid, could be increased to 36-88% by combination with duokvin. However, these combinations resulted in a significant weight gain reduction due to toxic interaction. Efficacy showed a strong negative correlation with body weight gain and bursa weight, suggesting an indirect mode of action against the parasite. It has been concluded that neither ionophorous anticoccidials nor their combinations with duokvin can be recommended for chemoprophylaxis against avian cryptosporidiosis.

Animals↗
PubMed1995

Age-dependent resistance to Cryptosporidium baileyi infection in chickens.

The age-dependent aspects of resistance to Cryptosporidium baileyi were studied in chickens orally inoculated with C. baileyi oocysts at 1 and 9 wk of age. The prepatent period was significantly shorter and the patency was significantly longer in younger birds. Chickens infected at 1 wk of age excreted 3 times the number of oocysts excreted by those inoculated at 9 wk of age. There was a good correlation between the length of the patent period and the total oocyst output of chickens. These results indicate that both innate and acquired resistance to C. baileyi are age-related. The numbers of animals needed per experimental group to estimate the length of the prepatent period, the patency, and the total oocyst output were assessed. Relatively small numbers of animals are required for the estimation of the mean length of the prepatent period, in contrast with the large numbers of birds needed for the estimation of the mean length of the patent period or that of the total oocyst excretion.

Age Factors↗
PubMed1994

[Thyroid-stimulating hormone-secreting pituitary adenoma].

A 40-year-old male patient with a 2 years history of recurring hyperthyroidism is presented with clinical hyperthyroidism and diffuse goiter. Despite thyreostatic treatment and surgical thyroid ablation the hyperthyroidism recurred. The patient had laboratory evidence of hyperthyroidism and his serum TSH was persistently and enormously elevated (T4:214 nmol/l, T3:6.9 nmol/l, TSH:218 mIU/l)> Computed tomography and magnetic resonance imaging confirmed a pituitary mass of 7 cm in a-p diameter, with supra-, parasellar and sphenoidal extension. The pituitary adenoma was partially resected by transsphenoidal surgery, which failed to result in a substantial decrease in the serum thyrotropin level. Pituitary irradiation and a long-term somatostatin analog octreotide treatment (300-600 micrograms/die) combined with bromocriptine therapy resulted in a significant, but still incomplete suppression of thyrotropin secretion (TSH level about 15 mIU/l) and persisting mild hyperthyroidism. The size of the adenoma was unchanged during the two years of highdose octreotide treatment period. According to our best knowledge this is the first reported case of a thyrotropin-secreting pituitary adenoma in Hungary.

Adult↗
PubMed1994

[Splenic infarction and abscess as a complication of atrial fibrillation].

The case of a 64 year old man is presented by the authors whose spleen infarction developed in connection with atrial fibrillation was transformed into splenic abscess in spite of the applied conservative treatment. According to the overviewed literature the etiology, symptoms, diagnostic and therapeutic possibilities, as well as prognosis of these two entities related to spleen are described hereby.

Abscess↗
PubMed1994

Potentiation of ionophorous anticoccidials with dihydroquinolines: reduction of adverse interactions with antimicrobials.

In two experiments, the compatibility of the anticoccidial combinations of monensin and duokvin, as well as that of maduramicin and duokvin, with some antimicrobials widely used in the broiler production was studied in cockerels. The monensin-duokvin combination was found to be fully compatible with erythromycin, sulphachlorpyrazine, and sulphaquinoxaline. With tiamulin, a slight interaction was observed, but it was far less severe than the toxic interaction between monensin and the diterpene antibiotic. The maduramicin-duokvin combination proved to be compatible with all of the chemotherapeutics tested, including tiamulin. The results of the studies indicate that the adverse interactions of monensin and maduramicin with certain antimicrobials can be considerably diminished or even abolished by using them in reduced doses in combination with the dihydroquinoline compound duokvin.

Animals↗
PubMed1994

Potentiation of ionophorous anticoccidials with dihydroquinolines: battery trials against Eimeria tenella in chickens.

Seven battery tests, employing a total of 1344 Hybro cockerels, were conducted in order to study the interaction between ionophorous anticoccidials and a new dihydroquinoline-type antioxidant known as duokvin. A significant, non-selective, toxic interaction was established, resulting in growth depression and improved anticoccidal efficacy against Eimeria tenella and E. mitis in these chickens. The duokvin itself showed no appreciable activity against the coccidia. The adverse effects of the interaction were eliminated, and the anticoccidial efficacy of the approved levels of ionophores was maintained, when the dietary levels of monovalent cation ionophorous monensin, salinomycin and narasin were reduced to approximately 12% in the presence of 120 p.p.m. duokvin. No adverse effects on the growth of chickens appeared in the combination with maduramicin, yet the enhancement of anticoccidial activity allowed an approx. 50% reduction of this ionophore as well.

Animals↗
PubMed1993

[Flow-cytometric study of the DNA content in adrenal cortex tumors].

Flow cytometric deoxyribonucleic acid measurements were performed on 26 adrenocortical tumours and 9 non-tumours adrenals. All but one tumours were classified both histologically and clinically as benign, however, two thirds of them had abnormal deoxyribonucleic acid stemlines. Proliferative indices of adenomatous tissues were significantly higher than those of non-tumorous adrenals (p < 0.01). When compared to tumors smaller than 5 cm in size, tumours larger than 5 cm displayed significantly higher proliferative indices (p < 0.01). Thus, flow cytometry appears to have only a limited value in distinguishing between benign and malignant adrenocortical tumours, but it may provide additional information about the prognosis of these tumours.

Adenoma↗
PubMed1993

["Medicina 2000"].

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Ambulatory Care Facilities↗
PubMed1993

Pathological and experimental investigations in a case of gigantism.

A pituitary adenoma was transsphenoidally removed from a 4.5-year-old girl suffering from gigantism. Prior to the operation both the growth hormone (GH) and the prolactin (PRL) levels in the serum were elevated. By light microscopy the tumor appeared to be an acidophilic adenoma. Two distinct cell types, the densely granulated and the sparsely granulated cells, could be distinguished by electron microscopy. Double immunolabeling revealed the presence of GH alone in some densely granulated cells and PRL alone in some sparsely granulated cells, as well as GH and PRL co-localized in both of the morphologically distinguished cell types. Both cell types were identified in the monolayer and the suspension cultures by electron microscopy. GH and PRL concentrations in the culture media were measured by radioimmunoassay. The basal secretion of growth hormone was almost uniform during the 3-week cell culture period. GH and PRL release was significantly inhibited by bromocriptine. Our studies revealed a bimorphous and bihormonal mixed adenoma in childhood.

Adenoma, Acidophil↗
PubMed1993

Direct inhibitory effect of etomidate on corticosteroid secretion in human pathologic adrenocortical cells.

Etomidate has been shown to inhibit corticosteroid secretion in the normal adrenal gland, but its direct effect in human pathologic adrenals has not been clearly established. In the present study the effect of varying doses of etomidate (10(-11)-10(-5) M) was investigated on basal and adrenocorticotrophic hormone (ACTH)-stimulated corticosteroid secretions in isolated adrenocortical cells obtained from two patients with primary aldosteronism (adenoma and micronodular hyperplasia) and in those from a patient with Cushing's syndrome (adenoma). In cells from primary aldosteronism, increasing concentrations of etomidate (10(-11)-10(-5) M) produced a dose-dependent decrease of basal and ACTH-stimulated cortisol, aldosterone, 18-hydroxycorticosterone, and corticosterone secretions (ED50: 10(-9)-10(-8) M for each of these corticosteroids). In the same cells, the secretions of 11-deoxycortisol and deoxycorticosterone were increased in the presence of low (10(-9)-10(-7) M) but not high doses of etomidate (10(-6)-10(-5) M). In cells from Cushing's syndrome the changes in corticosteroid secretion were similar to those found in primary aldosteronism except that aldosterone and 18-hydroxycorticosterone could not be determined due to their low levels. Thus the potent inhibition of corticosteroids in human pathologic adrenocortical cells in the presence of low concentrations of etomidate may be predominantly due to inhibition of the 11 beta-hydroxylase enzyme, whereas higher doses of the drug may inhibit earlier steps of the corticosteroid biosynthetic pathway.

18-Hydroxycorticosterone↗
PubMed1993

Mineralocorticoid production of adrenal cortical adenomas.

We studied in vitro and in vivo corticosteroid production as well as the presence of symptoms of an increased mineralocorticoid effect in patients with 'silent' adrenal cortical adenomas, and compared these results to those found in patients with classical mineralocorticoid excess syndromes. We found that under in vitro conditions, cells from 'silent' adrenal cortical adenomas (n = 19) produced substantial amounts of both zona glomerulosa and fasciculata steroids, although the production of steroids in these cells was lower compared to that in mineralocorticoid-producing adenoma cells (n = 26). Patients with aldosterone-producing and 'silent' adenomas had significantly increased plasma atrial natriuretic peptide levels, which remained non-suppressible after upright posture and furosemide administration. Of the 25 patients with 'silent' adenomas, 11 had low and non-stimulable plasma renin activity (PRA) before but, in most cases, not after adrenal surgery. When compared to those with normal PRA (n = 14), patients with low PRA 'silent' adenomas (n = 11) had higher blood pressure which was significantly reduced after surgery, and a mild hypokalemia before but not after surgery. Although basal plasma concentrations of aldosterone, 18-hydroxy-corticosterone, corticosterone, deoxycorticosterone, 18-hydroxy-DOC, cortisol,11-deoxycortisol and 17-hydroxy-progesterone (17-OH-P) were not increased in either groups of 'silent' adenomas, ACTH stimulation produced a hyperreactive response for all measured steroids, of which an extremely high 17-OH-P seemed to be one of the most intriguing findings. We consider that these observations in 'silent' adrenal cortical adenomas may justify surgical intervention, irrespective of the size and potential malignancy of these adenomas.

Adenoma↗
PubMed1992

The effect of erythropoietin on the cellular defence mechanism of red blood cells in children with chronic renal failure.

The glutathione redox system, haemoglobin (Hb) oxidation, the activity of antioxidant enzymes and the lipid peroxidation product malonyl dialdehyde (MDA) were studied in red blood cells (RBCs) during administration of recombinant human erythropoietin (rhEPO) over 12 weeks in ten children maintained on haemodialysis. A rapid increase in the reticulocyte count was accompanied by a slower rise in total Hb concentration. The mean level of oxidized glutathione (GSSG) increased from 13.2 +/- 5.3 nmol/g Hb to 56.7 +/- 15.8 nmol/g Hb 4 weeks after the start of rhEPO (P < 0.001), followed by a fall to the basal value. Reduced glutathione (GSH) levels showed a smaller though constant elevation during rhEPO therapy (P < 0.001). Before rhEPO treatment, incubation of RBCs for 1 h with acetylphenylhydrazine induced a decrease in GSH concentration compared with controls (P < 0.001), which became more pronounced in the first few weeks of rhEPO therapy (P < 0.001). In addition, the percentage of Hb derivatives (metHb and haemichrome) increased in the first 4 weeks of rhEPO therapy (P < 0.001). Although there was no significant difference between the values obtained preEPO and during EPO treatment, MDA levels were continuously higher and superoxide dismutase, catalase and glutathione peroxidase concentrations were lower than in the controls (P < 0.001). These results are compatible with oxidative damage to the RBCs in the early period of rhEPO therapy in children with end-stage renal failure. The GSH-GSSG system, as an important cellular defence mechanism of the RBCs, appears to be severely affected.

Adolescent↗
PubMed1992

Interaction of T-2 fusariotoxin with anticoccidial efficacy of lasalocid in chickens.

Two battery tests were carried out to reveal whether or not there is an interaction between T-2 fusariotoxin and lasalocid, similar to that known with some ionophorous anticoccidials. In the first experiment, an excessive dose level of toxin (6 ppm) significantly reduced the anticoccidial efficacy of lasalocid at 75 ppm and almost completely eliminated that at 37.5 ppm in cockerels which had been infected with oocysts of Eimeria tenella and E. mitis. In the second experiment, the same dose of lasalocid was tested in combination with 0.5-1.25 ppm levels of toxin, i.e. levels occurring in the field, and all but the lowest level (0.5 ppm) significantly reduced the anticoccidial efficacy of lasalocid. Thus, in cases of outbreaks of coccidiosis, there is need to keep in mind such interaction between anticoccidials and mycotoxins.

Animals↗