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Biomedical subjects

J Náfrádi

Publications and source records attributed to J Náfrádi.

At least 19 recordsLinked to original sources
PubMed1994

[Therapeutic possibilities in the management of gastrointestinal bleeding in thrombocytopenic patients].

Gastrointestinal bleeding is often fatal in elderly. The danger could be multiplied by thrombocytopenia or by other disorder of the coagulation system. In a thrombocytopenic patient with myelodysplastic syndrome life threatening gastrointestinal bleeding occurred which could not be controlled by conventional methods (cimetidine, antacids, aminocaproic acid, platelet transfusions, blood transfusion 400-1200 ml/day). Continuous i.v. infusion of somatostatin [250 micrograms/hour Stilamin (Serono)] and per os omeprazole [2 x 1 capsule Losec (Astra)] resulted in the cessation of bleeding in 24 hours. Adverse effect was not observed.

Aged↗
PubMed1986

Changes of endogenous prostacyclin-level in different experimental gastroduodenal ulcer models of rat.

It seems that the gastric antral mucosa either in normal, physiological circumstances, or in IND or STR induced gastric ulcer models, contains significantly more endogenous PG-I2 than that of gastric fundic mucosa, while the duodenal mucosa contains significantly lower endogenous PG-I2-level compared to the gastric antral or fundic level. Either in gastric or in duodenal ulceration the endogenous PG-I2 level basically decreased proportionally to the degree of ulceration - therefore it is tempting to speculate that the endogenous PG-I2 is most probably one of the natural protective substances in the gastrointestinal mucosa.

6-Ketoprostaglandin F1 alpha↗
PubMed1984

Gastrointestinal mucosal gamma-glutamyl transpeptidase activity changes in different ulcer models of rat.

The experiments presented gave evidence that changes in gamma-glutamyl transpeptidase activity-under experimental circumstances-seem to be in close connection with gastro-intestinal ulceration. In the pre-ulcerative period in both gastric and duodenal ulcer models, the mucosal gamma-glutamyl transpeptidase activity is higher than normal, while in the definitive ulcerative stage the gastric gamma-glutamyl transpeptidase activity is significantly decreased but in the duodenum it remained on normal level. This phenomenon may reflect to a difference in the pathomechanism of the gastric and duodenal ulceration.

Animals↗
PubMed1984

The effect of different prostaglandins on cysteamine-induced duodenal ulcer in the rat.

Most of the experiments have verified the cytoprotective effect of prostaglandins on the gastric mucosa and only few observations are known to deal with "cytoprotection" exerted on the duodenal or intestinal mucosa. Duodenal ulcers were produced by cysteamine (CEA). The treatment with different prostaglandins (PGI2, PGF2 alpha, PGE2) was carried out every six hours during the 48-hour experimental period. The obtained results indicate that neither prostacyclin nor prostaglandin-F2 alpha has any significant effect on CEA-induced duodenal ulceration, while prostaglandin-E2 exerts a slight anti-ulcerogenic effect. It is possible that cytoprotection is not the result of the same process in the duodenal and gastric mucosa: alternatively, three prostaglandins are not involved in the pathomechanism of CEA-induced duodenal ulceration.

Animals↗
PubMed1983

The effect of naloxone in different gastroduodenal ulcer models.

On the basis of our investigations it seems that: The opiate antagonist naloxone in a dose of 5.0 mg/kg has a significant protective effect in stress-ulcer model in the rat; No such effect was seen in drug (indomethacin) or cysteamine induced (duodenal) ulcer models; The interaction of naloxone with indomethacin seems to show a sex-difference.

Animals↗
PubMed1980

[Early gastric carcinoma detection by endoscopy and biopsy; clinical experiences (author's transl)].

This report presents the clinical features of 15 cases of early gastric cancer detected amont altogether 144 gastric cancers diagnosed with the aid of gastroscopy and directed biopsy in a series of 2953 patients. Since the clinical and laboratory data of the patients with early gastric cancer do not provide satisfactory diagnostic evidence, careful X-ray examination must be carried out in all cases with long-standing symptoms relating to the upper part of the abdomen, especially in patients over 40 years old. Gastroscopy is essential in the clarification of any suspected pathological signs indicated by the radiologists and, furthermore, in all cases in which no radiological diagnosis was reached to account for the patient's symptoms. During gastroscopy multiple biopsy specimens should be taken from all lesions which may mask any type of the early cancers. The importance of regular endoscopic examination of high-risk persons for gastric cancer is emphasized.

Adult↗
PubMed1979

[Effect of urethane and penthobarbital on the behaviour of the renin-angiotensin-system in rat (author's transl)].

The behaviour of the renin-angiotensin-system was investigated after urethane and penthobarbital anaesthesia in rats. The recent results support the early observation that urethane increases the plasma-renin-activity and the haematocrit. It was further shown that urethane in the customary anaesthetic dose causes hypoproteinaemia and a decrease in the pressor response to angiotensin and in renin substrate concentration. Based on these results, its use as an anaesthetic in experiments connected with the renin-angiotensin-system does not appear to be appropriate.

Anesthesia↗
PubMed1978

Pentagastrin analogs containing alpha-aminooxy acids, I. Synthesis of analogs substituted at the N-terminus.

Nine new pentagastrin analogs containing a free or protected alpha-aminooxy acid at the N-terminus were synthesized stepwise. Analogs containing leucyl, norleucyl, norvalyl, L- and D-2-aminodecanoyl residues instead of methionyl residue were also prepared. The peptides were synthesized by the active ester method with subsequent removal of the protecting groups. The purification of the end products was performed by crystallization or column chromatography on silica gel.

Amino Acid Sequence↗
PubMed1978

Pentagastrin analogs containing alpha-aminooxy acids, II. Simultaneous substitutions at the N- and C-terminus.

Twenty-seven new pentagastrin analogs containing free or protected aminooxy acids at the N-terminus and D-2-aminooxy-3-phenyl-propionic acid, L-(4-chlorophenyl)glycine, L- and D-phenylglycine, or L- or D-cyclohexyglycine instead of the C-terminal L-phenylalanine and analogs extended by aminooxyacetic acid at the C-terminus, were synthesized stepwise. The end products were purified by chromatography on DEAE-cellulose or silica gel.

Amino Acid Sequence↗
PubMed1978

Pentagastrin analogs containing alpha-aminooxy acids, III. Biological studies and structure-activity relationships.

The stimulation of gastric acid flow by thirty-six new pentagastrin analogs administered intravenously, intrajejunally and intrarectally was determined in rats. Some of the analogs are several times more active than the pentagastrin (Peptavlon, I.C.I.) used as control. Unlike the control, some analogs are absorbed in active form from the jejunum. The N-terminal substitution with alpha-aminooxy acids seems to increase the gastric secretory response, probably by improving the enzymatic resistance of the molecule to various enzymes. None of the analogs tested significantly inhibit the gastric acid output in rats induced by pentagastrin. Structure-activity relationships are discussed.

Animals↗