PubMed Health⌕ Search

Biomedical subjects

L Prónai

Publications and source records attributed to L Prónai.

At least 19 recordsLinked to original sources
PubMed1998

[Computerized speech recognition-based endoscopic findings].

Discrete, Hidden Markov model based speech recognition and phoneme based speech synthesis techniques were applied for gastroscopy reporting and machine control. The authors developed a special program for grammatical analysis of the sentences. Altogether 100 patient findings were grammatically analysed. The sentences were grouped according to the topographical order of the investigation: oesophagus, cardia, fundus, corpus, antrum, pylorus, bulbus, postbulbar section, and the pathological findings: erosion, ulceration, malignancy. Speech samples from 3 deep voiced male investigators were collected. The recognition rate was above 95%. A simulation program was also developed for dictation and controlling of the different equipment (monitor, printer, video, endoscope) in the gastroscopy laboratory by speech recognition. Speech synthesis was applied for the evaluation of understanding. This module artificially synthesizes the answer of the system giving backup for the understood information. With additional developments the discrete word speech 'recognition' achieved the level of routine application in medical reporting. However, ready-to-use developments need the joint activity of speech technology and endoscopy industry with end-user teams.

Diagnosis, Computer-Assisted↗
PubMed1997

Ebrotidine versus ranitidine in the healing and prevention of relapse of duodenal ulcer. A multicentre, double-blind, parallel, randomized, controlled study.

Two hundred and fifty patients were included in a double-blind, parallel, randomized, controlled clinical trial. Duodenal ulcer treatment lasted up to 8 weeks. Forty-nine patients were followed up for prevention of ulcer relapse for up to one year. All patients received either ranitidine (300 mg/day in the healing phase and 150 mg/day in the follow-up phase) or ebrotidine (N-[(E)-[[2-[[[2-[(diaminomethylene)amino]-4 -thiazolyl]methyl]thio]ethyl]amino]methylene]-4-bromo-benzenesulfonamide , CAS 100981-43-9, FI-3542) (400 mg/day in both phases) as a single dose at bedtime. Both groups were matched in all demographic parameters, except for a significantly higher percentage of smokers in the ranitidine group. The percentage of total healing was almost the same with both products. Healing occurred in a higher percentage with ebrotidine at weeks 4 (75% versus 66.7%) and 6 (87% versus 79.7%). A higher effect of ebrotidine on the incidence of duodenitis was identified during the whole study, but only reached statistical significance at week 6. The relapse rate during the follow-up phase showed no differences between the two study treatments, relapse percentage figures being 25% for ebrotidine and 24% for ranitidine. There were no differences in the number of unscheduled visits between the two groups, although 57% of patients in the ranitidine group had to make a second follow-up visit, as compared with 33% in the ebrotidine group. Both drugs caused hardly any side effects, affecting only one patient from each group: one patient with ebrotidine suffered from diarrhoea and one patient with ranitidine developed a skin rash on the limbs. Administration of ebrotidine in a single dose (400 mg/d) was at least as effective and safe as ranitidine both for healing and relapse prevention in patients with duodenal ulcer.

Adult↗
PubMed1996

[Possibilities of drug therapy of acute hemorrhage of the upper digestive system].

Early detection of bleeding site by immediate endoscopy is the key of effective treatment in massive upper gastrointestinal (GI) bleeding. Upper GI endoscopy gives useful information about the risk, re-bleeding and mortality. Algorithm of treatment is also based on findings upon early endoscopy. Meta-analysis of prospective, randomized, multicenter clinical trials assessing H2-receptor antagonists and proton pump-inhibitors in the treatment of peptic ulcers suggest that these drugs cannot be justified for stopping bleeding or prevent re-bleeding. Other drugs, such as somatostatin, might be effective, but further studies are needed to prove their effectiveness. Both vasopressin and somatostatin are also successfully employed the treatment of bleeding related to portal hypertension, and a recent meta-analysis found significant benefit for beta-blockade in the prevention of recurrent bleeding. Although beta-blocker therapy does not improve survival, it reduces re-bleeding rate, therefore, it can be used as prophylactic therapy for esophageal varices. As for the treatment of erosions, none of the drugs currently employed are effective in reducing or preventing clinically significant bleeding.

Acute Disease↗
PubMed1996

[Connection between Helicobacter pylori infection and chronic gastrointestinal urticaria].

Chronic urticaria is a disease of unknown etiology. One type of the disease is accompanied by gastrointestinal complaints. The aim of the present study was to determine the prevalence of Helicobacter pylori (H. pylori) infection in patients with chronic urticaria, and measure the effectiveness of eradication of HP on the skin disease. Patients with chronic urticaria of other origin were excluded from the study. Forty patients out of 95 studied fulfilled the criteria of gastrointestinal urticaria. H. pylori was measured both by measuring H. pylori-specific IgG in the serum and by direct staining of biopsy specimen taken upon endoscopy prior to and after the treatment. Seventeen patients out of 40 with gastrointestinal urticaria were H. pylori positive which incidence (43%) is not higher than that of the age matched healthy population in Hungary. H. pylori positive patients were treated with amoxycillin (4 x 500 mg/die), bismuth subsalicilate (3 x 512 mg/die) and metronidazole (2 x 500 mg/die) for two weeks, respectively, and those remaining positive were treated by omeprazole (2 x 20 mg/die) and amoxycillin for additional two weeks. Eradication of HP infection was successful in all patients. Follow-up was conducted from 6-18 months for urticaria (frequency, duration) and antihistamine drug requirement. Chronic urticaria did not disappeared after the eradication of H. pylori, but there was a significant reduction both in frequency, duration of urticaria and the need for antihistamine therapy after eradication of H. pylori. It was concluded that H. pylorilinfection has no effect on the course of chronic urticaria. Reduction in frequency of urticaria symptoms and reduction of antihistamine requirement is partly due to the natural course of the disease and likely due to the altered bacterial flora of the gut following the combined antibiotic treatment.

Adolescent↗
PubMed1996

[Nitric oxide. Basic research and possible clinical use].

The journal Science considered nitric oxide (NO) the molecule of the year 1992. This small, instable, potentially toxic gas freely crosses cell membranes. NO is produced from L-arginine by NO-synthase. The various physiological and pathological effects of NO can be explained by its reactivity and different routes of formation and metabolism. In mammals, at least three isoenzymes of NO-synthase (neuronal, endothelial and inducible forms) are known. NO exerts different effects in acidic, neutral and basic pH conditions, it is cell-protective when produced is small quantities whereas it is toxic when exceeds millimolar concentrations. Both the overproduction and suppression of NO release may have harmful effects. As a neurotransmitter, it plays important role in cell-signaling, in the erection of penis and also in the learning process. When produced by endothelial cells, it is a potent vasodilatator, and phagocytes use NO to kill microorganisms. NO also may play pathological role in chronic inflammations, immune processes and tumour generation. Based an our current knowledge, NO can be used in the therapy of pulmonary hypertension, cerebral ischemia and relaxation disturbances of smooth muscle sphincters, and the blockade of NO synthase activity may help in the management of septic shock, hypotension and inflammations.

Animals↗
PubMed1993

[Lactulose and its derivatives--treatment of hepatic encephalopathy and other possible indications for its use].

Lactulose and lactitol, the synthetic compounds of lactose, are poorly absorbed from the small intestine, and both are almost exclusively metabolized by the bacterial flora of the colon. These disaccharides shorten the small bowel transit time mechanically and lower the pH of the bowel, both by their osmotic effects and by the acidic pH of their metabolites. Lactulose and lactitol diminish the absorption of ammonia and metabolites of other toxic proteins by two distinct mechanisms; by exerting a cathartic effect and by suppressing the dissociation of ammonia. Lactulose and lactitol are the classical therapy of choice for the treatment of hepatic encephalopathy since 1964 and since 1982, respectively. Another indication is, the treatment of constipation. Because lactulose decreases the concentration of cholic acid and may prevent its absorption, the drug was recently suggested to be successful for the prevention of recurrence of cholesterol stone formation, and to be useful as an anticarcinogenic agent.

Cholic Acid↗
PubMed1993

[The role of free radical scavengers in gastrointestinal diseases].

Be it ever so complex the natural antioxidant scavenger system of the organism, the protection provided by it seems to be inappropriate in certain diseases of the gastrointestinal mucus membrane, such as chronic inflammation, immune- and malignant diseases of the bowel. Despite the wide range of therapeutic attempts, the treatment of these diseases has not yet been solved, and the anti-inflammatory-, immunomodulatory-, cytostatic drugs currently used, have several side effects. Therefore, the so called natural- and synthetic antioxidants have been more widely employed for additional and adjuvant treatment. It also has become clear that the direct free radical scavenging effect and/or the membrane protection play an important role in the action mechanism of several old-established drugs. The recent report lists those natural and synthetic antioxidants which have been successfully employed in the clinical treatment of bowel diseases. Among the natural antioxidants, a protective effect of vitamins A, C and E have been demonstrated in the treatment of gastroduodenal ulcer and gastric cancer. Among the synthetic antioxidants, 5-amino-salicylic acid was the most effective drug in the treatment of chronic inflammations of the bowel. With getting the more precise knowledge about details of free radical reactions and with clearing up their role in pathological processes, it is possible to develop new and effective synthetic antioxidants, and widely employ them therapeutically.

Aminosalicylic Acids↗
PubMed1993

The reactions of 3,5-dibromo-4-nitrosobenzenesulfonate and its biological applications.

Recently, 5,5-dibromo-4-nitrosobenzenesulfonate (DBNBS) has been applied to detect biological free radicals. However, DBNBS has various non-specific reactions which lead to preplexing results. Thus, we investigated some basic reactions of DBNBS in combination of other nitroso spin traps to assign DBNBS spin adducts derived from human platelets which presumably related to the endothelium-derived relaxing factor (EDRF). The collagen activated platelets yielded four spin adducts (ST, LT, SS, and LS) in the presence of DBNBS (40 mM). The broad triplet due to ST was also observed by bubbling NO gas into a DBNBS solution. To identify ST, nitrosobenzene (NB) in dry dioxane was mixed with NO-saturated dioxane. The NB-NO spin adduct was observed but decomposed into diphenyl aminoxyl by the addition of H2O indicating that the primary adduct formed by the reaction of NO and DBNBS is unstable and turns into a dimerization product. Although ST could be eliminated by the inhibitor of EDRF, ST was shown to be produced by non-specific reactions. Another triplet was assigned to an S-centered radical because thiyl radicals which were generated from either the decomposition of S-nitrosothiol, or glutathione oxidation exhibited almost identical triplet signals. The other two sextets were assigned to C-centered radical adducts. Thus, DBNBS detected NQ-related, S-centered, and two C-centered radicals derived from human platelets. Special cautions are necessary for the identification of DBNBS spin adducts in a biological system to exclude artifactual radicals.

Benzenesulfonates↗
PubMed1993

Effect of the natural bioflavonoid antioxidant silymarin on superoxide dismutase (SOD) activity and expression in vitro.

The in vitro effects of the bioflavonoid antioxidant silymarin on the expression and activity of superoxide dismutase (SOD) enzyme was studied in erythrocytes and lymphocytes from patients with chronic alcoholic liver disease. In vitro incubation with the agent in a concentration corresponding to the usual therapeutic dosage markedly increased the SOD expression of lymphocytes as measured by flow-cytofluorimetry following staining with monoclonal anti-Cu/Zn-SOD antibody and FITC-conjugated anti-mouse Ig, as well as erythrocyte and lymphocyte SOD activities. The data indirectly suggest that antioxidant activity might be one of the important factors in the hepatoprotective action of this bioflavonoid.

Adult↗
PubMed1992

[Incidence of hepatitis C in chronic liver diseases following tattooing].

The seroprevalence of hepatitis C virus (HCV) was investigated in 16 tattooed men with chronic liver diseases using the Ortho-Chiron HCV antibody ELISA system. In 11 out of the 16 men, the result was positive, which was significantly higher as compared with that of presumably healthy blood donors in the Tokyo area, i. e., 1.14% of 2470 donors tested. These results suggest that HCV infection occurred at the time of tattooing in these 11 patients.

Adult↗
PubMed1992

Time course of superoxide generation by leukocytes--the MCLA chemiluminescence system.

This study was performed to examine the pattern of superoxide (O2-.) generation from leukocytes using the O2-. specific chemiluminescence (CL) method. Cypridina luciferin analog, 2-methyl-6-(p-methoxyphenyl)-3,7-dihydroimidazo [1,2-alpha]pyrazin-3-one (MCLA) was used as a CL probe. The appropriate conditions of the MCLA method was first determined for the evaluation of the time course of O2-. generation by leukocytes. The time course of O2-. generation obtained by the MCLA-CL system was compared with that by the luminol-dependent CL, electron spin resonance (ESR)/spin trapping, and cytochrome c systems. Following stimulation by three different stimulants (PMA, OZ, FMLP), leukocytes continuously generated O2-. for up to 5 h in the MCLA-CL system, irrespective of the kind of stimulation. The curves obtained by generation ceased more rapidly in the luminol-CL, ESR/spin trapping, and cytochrome c systems. A 50% activity of the initial value was observed at 70 min in the MCLA-CL system, but 30, 10 and 35 min in the other systems, respectively. The CL or O2-. generation value decreased to less than 1% (possible termination) at 300, 90, 120 and 180 min, respectively. With the exception of ESR studies with OZ, the cell viability was not significantly affected in any of the trials. These results indicate that leukocytes can generate O2-. much longer than previously estimated and that the MCLA-CL-system is the most suitable system for the measurement of the O2-. generation by leukocytes.

Cell Separation↗
PubMed1992

Decreased plasma superoxide scavenging activity in immunological disorders--carboxyethylgermanium sesquioxide (Ge-132) as a promoter of prednisolone.

We investigated so-called superoxide scavenging activity (SSA) of plasma in patients with several immunological disorders, such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), polymyo-dermatomyositis (PM), progressive systemic sclerosis (PSS), myasthenia gravis (MG) and autoimmune thyroid disease (AT), using the electron paramagnetic resonance/spin trapping technique. Since carboxyethylgermanium sesquioxide, Ge-132, has been reported to modulate both the immune response and leukocyte functions, we have studied in vivo effect of Ge-132 on plasma SSA and other laboratory parameters in these disorders. The plasma SSA was significantly lower in RA, SLE, PM and PSS, but not in MG and AT, as compared with that in healthy controls. An inverse correlation was observed between plasma SSA and parameters such as erythrocytes sedimentation rates, absolute number of leukocytes, C-reactive protein and serum globulin levels. Furthermore, plasma SSA was significantly decreased in rheumatoid factor-positive patients as compared to negative patients. No correlation was observed between plasma SSA and factors such as ages, sex of patients or the other laboratory parameters, such as serum albumin, triglyceride, cholesterol, hemoglobin and serum iron levels. Patients treated with prednisolone, especially ones with RA, showed an increase of plasma SSA. It appears that Ge-132 promotes prednisolone effects. Our results indicate that a decrease in plasma SSA is not disease specific, but inversely correlates with the severity and activity of inflammation. The methodology to measure plasma SSA presented in this work provides a helpful tool for determining the actual activity of the diseases as well as in vivo studies of antiinflammatory agents.

Adolescent↗
PubMed1992

The oxygen-centered radicals scavenging activity of sulfasalazine and its metabolites. A direct protection of the bowel.

Oxygen-centered radicals, such as superoxide (O2-) and hydroxyl radicals (.OH) generated by phagocytes have been suggested to be involved in the pathogenesis of chronic inflammations of the bowel, such as Crohn's disease and colitis ulcerosa. Recently, sulfasalazine (SASP) and its metabolites have been reported to exert their effects as a direct scavenger of oxygen-centered radicals in the bowel. To scavenge oxygen-centered radicals in vivo, however, SASP and its metabolites have to react with O2- and/or .OH in vitro very rapidly, furthermore they have to reach an appropriate (possible millimolar) concentration range at the site of inflammation. To test this possibility, we investigated the direct O2- and .OH scavenging activity of SASP and its metabolites using the specific electron paramagnetic resonance/spin trapping method, and we compared the 50% inhibition rates of SASP and its metabolites with their known concentrations in the bowel and in the human plasma. It was found that SASP and its metabolites, such as 5-amino-salicylic acid (5-ASA), and acetyl-5-amino-salicylic acid (AC-5-ASA), but not sulfapyridine (SP) and acetyl-sulfapyridine (Ac-SP) have a direct O2- and .OH scavenging activity in vitro systems. Among the compounds, SASP and 5-ASA can reach a concentration which is appropriate to scavenge oxygen-centered radicals in the bowel but not in the human plasma. It was concluded that the in vivo antiinflammatory effects of SASP and its metabolites are, at least partly, due to the direct oxygen-centered scavenging activity of these drugs.

Free Radical Scavengers↗
PubMed1991

Investigation of the existence and biological role of L-arginine/nitric oxide pathway in human platelets by spin-trapping/EPR studies.

The aim of the present study was to apply spin trapping/EPR spectroscopy to investigate the existence and biological role of the L-arginine/nitric oxide pathway in human platelet aggregation. Three different spin traps were used: two nitroso, 3,5-dibromo-4-nitrosobenzenesulfonate (DBNBS) and 2-methyl-2-nitrosopropane (MNP), and a nitrone, 5,5-dimethyl-1-pyrroline N-oxide (DMPO). The effect of spin-trap concentration on the collagen-induced human platelet aggregation was compared to the anti-aggregatory effect caused by L-arginine. The results show that the nitroso spin traps (DBNBS and MNP) are more effective than L-arginine in preventing platelet aggregation. DMPO has virtually no effect on the collagen-induced aggregation except at a high concentration (300 mM). Furthermore, activation of platelets with a low concentration of collagen (17 micrograms/ml) and in the presence of DBNBS or MNP yields several EPR-detectable spin adducts. Some of the observed spin adducts do not correspond to those originating from the interaction of a free radical, nitric oxide (NO.) gas, with the spin traps [Arroyo, C.M. & Kohno, M. (1991) Free Radical Res. Commun. 14, 145-155]. Only one adduct of DBNBS, with a relative intensity of 0.1, observed in the washed-platelet experiment and in the presence of superoxide dismutase, is similar to the EPR spectrum obtained following a reaction of pure NO. gas with DBNBS. This suggests that the EPR spectrum of the DBNBS adduct consisting of a triplet may originate from the production of NO. by these cells. Additional DBNBS and MNP spin adducts were generated during platelet activation in the presence of Ca2+ and of a cytosol-depleted L-arginine preparation from washed platelets to which L-arginine was subsequently added. The formation of these DBNBS and MNP spin adducts were inhibited by N omega-methyl-L-arginine (MeArg, 100 microM), suggesting that these originated from a product of NO synthase. Furthermore, the formation of DBNBS and MNP spin adducts in platelet suspensions was enhanced by the presence of superoxide dismutase; however, their formation was prevented by the endothelial-derived relaxing factor (EDRF) inhibitors methylene blue and hemoglobin. The results from the MeArg and EDRF inhibitor experiments support the existence of the L-arginine/NO pathway in platelets. In addition, the prevention of spin-adduct formation by EDRF inhibitors, suggests that the mechanisms of EDRF formation and the L-arginine/NO pathway in endothelial cells and platelets are similar.(ABSTRACT TRUNCATED AT 400 WORDS)

Arginine↗
PubMed1991

Protective effect of carboxyethylgermanium sesquioxide (Ge-132) on superoxide generation by 60Co-irradiated leukocytes.

The carboxyethylgermanium sesquioxide, Ge-132, is an organogermanium compound which has been shown to modulate leukocyte functions. In this study, we examined the effect of Ge-132 on the generation of superoxide radicals (O2-) either from leukocytes or in cell-free system, employing the highly sensitive 2-methyl-6-[p-methoxy-phenyl]-3,7-dihydroimidazo[1,2-alpha]pyra zin-3-one (MCLA)-dependent chemiluminescence method and the specific electron spin resonance/spin trapping method, respectively. In addition, the in vitro protective effect of Ge-132 on the leukocytes irradiated with 60Co was studied. The incubation with Ge-132 resulted in an increase in basal O2- release of intact leukocytes, but had no effect on O2- generation from leukocytes stimulated with phorbol myristate acetate (PMA). Irradiation with 60Co decreased the O2- generation from leukocytes in a dose-dependent manner. Ge-132 had no effect on basal O2- release from 60Co-irradiated leukocytes, but it prevented the decrease in PMA-stimulated O2- generation by irradiated leukocytes. Ge-132 itself had no superoxide scavenging activity in cell-free system. On the other hand, higher concentrations of Ge-132 had decreasing effects on both basal O2- release and PMA-stimulated O2- generation from leukocytes, but they did not affect leukocyte viability. Above results indicate that 1) Ge-132 can stimulate the basal O2- release from leukocytes, 2) Ge-132 can prevent the decrease of O2- generation by 60Co-irradiated leukocytes, 3) in higher concentrations, Ge-132 may have a membrane stabilizing effect.

Antineoplastic Agents↗
PubMed1991

BG-104 enhances the decreased plasma superoxide scavenging activity in patients with Behçet's disease, Sjögren's syndrome or hematological malignancy.

BG-104, a compound of Chinese herbs, has been reported to exert superoxide scavenging activity (SSA) in cell free systems. This report addresses in vivo effects of BG-104 in various disorders. The plasma SSA and laboratory parameters were determined in patients Behçet's disease (BD), Sjögren's syndrome (SjS) or hematological malignancy (M), and the effects of BG-104 treatment on these parameters were studied and compared with those of another antioxidant, vitamin E (alpha-tocopherol). The plasma SSA was significantly lower both in patients with BD and M, and in patients with SjS without antioxidant treatment as compared to that in healthy controls, and it showed an inverse correlation with disease activities. The treatment with BG-104 and/or vitamin E significantly enhanced the plasma SSA in all disorders studied. Both the erythrocyte sedimentation rates, the absolute number of neutrophils, as well as C-reactive protein levels were significantly lower in patients treated with BG-104 and/or vitamin E than those without these drugs. These results indicate that the BG-104 has an anti-inflammatory effect through enhancing plasma SSA in patients with BD, SjS or M.

Adult↗