Search PubMed⌕ Search

Biomedical subjects

I Nagy

Publications and source records attributed to I Nagy.

At least 145 records · Page 8Linked to original sources
PubMed1990

[A rapid test for the analysis of lactase and sucrase activity in the jejunum (a comparative study)].

Jejunal lactase and sucrase activities were demonstrated in biopsy specimens obtained endoscopically using a rapid test which had been developed previously. The results were compared with enzyme activities determined by Dahlquist's method. The data suggest that the rapid test is suitable for the demonstration about the presence of lactase and sucrase, and the results are correlated with enzyme activities measured by assay. The main advantage of the test, that it is rapid, simple and cheap, no special equipments are necessary, so it can be used in every endoscopic department.

Adolescent↗
PubMed1990

ADP-iron as a Fenton reactant: radical reactions detected by spin trapping, hydrogen abstraction, and aromatic hydroxylation.

A mixture of ADP, ferrous ions, and hydrogen peroxide (H2O2) generates hydroxyl radicals (OH) that attack the spin trap DMPO (5,5-dimethyl-pyrollidine-N-oxide) to yield the hydroxyl free radical spin-adduct, degrade deoxyribose and benzoate with the release of thiobarbituric acid-reactive material, and hydroxylate benzoate to give fluorescent products. Inhibition studies, with scavengers of the OH radical, suggest that the behavior of iron-ADP in the reaction is complicated by the formation of ternary complexes with certain scavengers and detector molecules. In addition, iron-ADP reacting with H2O2 appears to release a substantial number of OH radicals free into solution. During the generation of OH radicals the ADP molecule was, as expected, damaged by the iron bound to it. Damage to the iron ligand in this way is not normally monitored in reaction systems that use specific detector molecules for OH radical damage. Under certain reaction conditions the ligand may be the major recipient of OH radical damage thereby leading to the incorrect assumption that the iron ligand is a poor Fenton reactant.

Adenosine Diphosphate↗
PubMed1990

The effect of CR 1409, a potent CCK receptor antagonist, on basal and stimulated pancreatic secretion in rat.

The effect of a specific cholecystokinin (CCK) receptor blocker from Rotta Research Laboratorium (Monza/Milano, Italy), CR 1409 (Lorglumide), on pancreatic secretion was investigated. CR 1409 caused a rightward and parallel shift in the dose-response curve of CCK-8-stimulated pancreatic protein secretion in anesthetized rats, demonstrating a competitive mechanism of inhibition. The mean pA2 value, showing the 50% inhibitory dose of CR 1409, was 6.4. CR 1409 proved to be about 1,000 times more potent as a CCK receptor blocker than proglumide, the first glutaramic acid analogue with anti-CCK potential. In conscious rats, pancreatic protein and water secretion were significantly diminished for about 2 h in response to 300 micrograms/kg of CR 1409 given subcutaneously during diversion of pancreatic juice, demonstrating inhibition of endogenous CCK by this new glutaramic acid derivative. By contrast, during reintroduction of precollected pancreatic juice into the duodenum, when the release of CCK is almost totally eliminated, pancreatic secretion was not modified by the same dose.

Animals↗
PubMed1990

The effect of long-term administration of lorglumide (CR 1409) on rat pancreatic growth and enzyme composition.

The effects of lorglumide (CR 1409), a potent cholecystokinin (CCK) receptor blocker developed recently by the Rotta Research Laboratories, were studied on pancreatic growth and enzyme composition. In secretory studies, the inhibitory effect of 4 mg/kg of lorglumide administered subcutaneously proved to last more than 3 h. The trophic effect of exogenous CCK (600 ng/kg given three times daily for 2 weeks) was significantly decreased by the simultaneous administration of 4 mg/kg of lorglumide. To study the role of endogenous CCK released by feeding while maintaining pancreatic trophism, 4 mg/kg of lorglumide was administered subcutaneously four times daily during the feeding period for 2 weeks. Lorglumide significantly decreased pancreatic weight, pancreatic content of soluble protein, trypsinogen, and chymotrypsinogen, while decreases in DNA, lipase, and amylase failed to reach statistical significance. According to our experiments, high-doses of lorglumide could inhibit not only the trophic effect of exogenous CCK but also the effect of endogenous CCK released by food and lorglumide itself.

Amylases↗
PubMed1990

Is the proliferation inhibition of K562 cells by cisplatin also a membrane effect?

Using K562 tumour cells as model, the effect of cisplatin on cellular morphology and electrolyte balance was examined by scanning electron microscopy and energy-dispersive X-ray microanalysis. The data imply that the membrane surface alterations are a secondary effect following cross-linking reaction of this drug with DNA.

Cell Division↗
PubMed1990

[The significance of the determination of catecholamines and their metabolites in neuroblastomas].

A method for the determination of catecholamines and their metabolites in the urine was established. The specimens were previously cleaned by ion exchangers and the components were separated by a 'reversed phase' ionic pair chromatography, determined by an electrochemical 'wall-jet'-detector. This method was applied in order to find a diagnostic marker in case of neuroblastoma diseases. In 85 per cent of the patients (n = 13) we stated an increased ejection of dopamine.

Biomarkers, Tumor↗
PubMed1990

Measurement and demonstration of lactase and sucrase activities in jejunal mucosa.

Jejunal lactase and sucrase activities were demonstrated on endoscopically obtained biopsy specimens by a rapid test which had been developed earlier. The results were compared with enzyme activities found by Dahlquist's method. The data suggest that the rapid test is suitable for the semiquantitative determination of lactase and sucrase, and the results correlate with enzyme activities measured by the Dahlquist assay. The main advantage of the test is that it is rapid, simple, and cheap, and because no special equipment is necessary, it can be used in any endoscopic department.

Adolescent↗
PubMed1989

[Current diagnostic method for saccharose-isomaltose malabsorption].

The authors present the cases of 4 children who suffered from saccharose-isomaltose malabsorption. The clinical symptoms developed following artificial feeding. The diagnosis was made by the histological examination of small intestine samples and with the simultaneous measurement of disaccharide enzyme activity. The histological picture and activity of lactase enzyme were practically normal. The saccharose H2 breath test gave only in 1 case positive result. The treatment of the children required saccharose-free diet. The tolerance showed no improvement during the treatment.

Child, Preschool↗
PubMed1989

Identification of protein-bound riboflavin in rat hepatocyte plasma membrane as a source of autofluorescence.

The presence of flavin compound(s) giving a yellowish-green autofluorescence in rat hepatocyte plasma membrane has recently been reported (Nokubo, M. et al. (1988) Biochim. Biophys. Acta 939, 441-448). The fluorophore can quantitatively be extracted with water at 80 degrees C from isolated plasma membranes. Gel filtration of the extract eluted with water showed two peaks, the fluorescence of which closely resembled that of riboflavin. The major peak comigrated with proteins and the minor one displayed a position identical to authentic riboflavin. When the components of the major peak were rechromatographed after acetic acid treatment and eluted with 20 mM of acetic acid, the fluorescent compound separated from the proteins and eluted at the same position as riboflavin. In paper chromatography and HPLC, the behavior of the fluorescent compound (separated by acid treatment from the proteins) was identical to that of riboflavin. SDS gel filtration of subcellular fractions of rat liver revealed that riboflavin was the dominant flavin, whereas FAD and FMN were not detectable in the plasma membrane. Microsomes and mitochondria contain predominantly FAD and FMN, and only minor quantities of riboflavin. The presence of riboflavin in the plasma membrane is a novel finding, the functional significance of which is still unclear; however, a hypothesis can be forwarded on the basis of the ability of flavins to generate superoxide anion radicals during their autoxidation.

Animals↗
PubMed1989

[Congenital type I antithrombin III deficiency with serious complications in a 7-year-old girl].

This case report concerns a child admitted to the County Hospital of Zalaegerszeg with the symptoms of ataxia, focal convulsions and hemiparesis. Anticonvulsive therapy abolished the epileptic manifestations, but hemiparesis remained unchanged. At the age of six and half years progressive venous thrombosis developed first on the left and some days later on the right lower limb. Phlebography revealed on both sides thrombosis of the vena iliaca which led to stenosis of the right femoral vein and dilated venous collaterals on the abdomen and right thigh. Coeliacography showed an enlarged spleen and varicosity around the portal vein. Later thrombosis of the arteria dorsalis pedis developed indicated by the gangrene the fifth toe. At this stage the child was transfered to the Pediatric Department of the University of Pécs for further evaluation. Examination of the hemostasis showed hypercoagulability due to antithrombin III deficiency pointing towards a common cause, namely thromboembolism of the earlier and recent clinical manifestations. A reduced activity of the antithrombin III was also observed in the mother and two sisters of the child. The response to Syncumar therapy was beneficial, arterial thrombosis regressed and no further thromboembolic complications developed.

Acenocoumarol↗
PubMed1989

[Two cases of Richter's syndrome].

Two cases of Richter's syndrome were observed by the authors between April and August 1987. The patients were treated previously because of chronic lymphoid leukemia. The histological findings indicated in both cases immunoblast transformation of CLL. The patients were non-respondent to intensive chemotherapy and died within a short time.

Aged↗
PubMed1989

Calcium ion uptake, somatotropin release, and fine structure of somatotrophs in cultures of the rat anterior pituitary upon the action of an oligopeptide (Boc-Gln-Leu-Lysinal).

Cultured cells from the anterior pituitary glands of adult rats were treated with the tripeptide aldehyde proteinase inhibitor, Boc-Gln-Leu-Lys-H. The oligopeptide had a profound releasing effect on growth hormone, whereas the prolactin release remained unchanged at 10(-3) mol/l drug concentration after an incubation for 2 h. In the presence of the oligopeptide a time- and dose-dependent calcium influx into cultured cells has been shown which was proved to be almost completely antagonized with magnesium ions but not with Nifedipine. In addition, radioactive calcium ions could be detected in a number of cells by light microscopic autoradiography when cultures were treated with Boc-Gln-Leu-Lys-H for short periods. The selective Gel action of the oligopeptide on growth hormone producing cells has been demonstrated also in fine structural investigations: multigranular and single exocytotic profiles have been observed. Accordingly, we have postulated that Boc-Gln-Leu-Lysinal mimics the effects of the known ionophores. Its mode of action needs, however, further studies especially on isolated somatotrophs.

Animals↗
PubMed1989

Mechanisms of action of alcohol administration on the trophic effect of soybean trypsin inhibitor and cholecystokinin octapeptide in rat.

Influence of alcohol administration on the trophic effect of cholecystokinin-octapeptide and soybean trypsin inhibitor administration was examined in male Wistar rats. Two x 4 mL of 20% alcohol given intragastrically during 2 wk did not significantly influence pancreatic weight, DNA, protein, trypsin, chymotrypsin, amylase, lipase, or trypsin inhibitor contents of the pancreas. It diminished the hypertrophy but not the hyperplasia seen after CCK-8 treatment, and eliminated the hyperplasia, as well as the hypertrophy provoked by SBTI administration. Secretory studies and CCK measurements demonstrated decreased CCK release in response to SBTI stimulation after 3-d alcohol administration. The results indicate that alcohol inhibits the enzyme synthesis of the CCK stimulated dividing and/or newly formed acinar cells and the endogenous CCK release.

Amylases↗
PubMed1989

Time-course of changes in pancreatic size and enzyme composition in rats during starvation.

The effect of starvation for 3, 5, or 7 d on body weight, fat stores, pancreatic weight, and enzyme composition was studied in 300 g rats and was compared with a 3-d fast in 200 g rats. In the 300 g animals, fasting led to a gradual hypotrophy of the pancreas with a marked, continuous decrease in amylase content. Pancreatic lipase, trypsinogen, chymotrypsinogen, proelastase, and secretory trypsin inhibitor contents increased temporarily, but by d 7, they declined to about the initial values. This decline in enzyme levels coincided with the exhaustion of fat stores. The decrease in amylase content could be related to decreases in circulating insulin levels, whereas the temporary increase in lipase content may be owing to changes in plasma free fatty acid concentrations. In 200 g rats, starvation for 3 d led to exhaustion of fat stores that was accompanied by greater losses of pancreatic weight, protein, and amylase contents. In addition, the levels of trypsinogen and chymotrypsinogen decreased and lipase was unchanged. These findings indicate that during starvation, changes in pancreatic secretory enzymes are time-dependent and vary with the age, body weight, and/or adipose tissue mass of the rats.

Adipose Tissue↗