Biomedical subjects

B Hunyady

Publications and source records attributed to B Hunyady.

28 records · Page 2Linked to original sources

PubMed1996

Diagnostic interpretation of 24-hour intragastric pH-metry using a pattern recognition method.

BACKGROUND: Intragastric pH-metry is a widely used method in the evaluation of gastric acidity, but the interpretation of these data is not standardized. METHODS: The pH-metry data of 60 patients were sorted retrospectively into three groups according to the maximal acid output (MAO) values measured after stimulation by pentagastrin: hypoacid group (MAO < 5 mmol/h, n = 17), normacid group (MAO 10-15 mmol/h, n = 18) and superacid group (MAO > 25 mmol/h, n = 25). Statistical effectiveness of several descriptive statistical values and predefined time-intervals in differentiation between the study groups was analysed by the pattern recognition by independent multicategory analysis (PRIMA) method. RESULTS: The mean pH, the integrated pH and the time-interval of pH > or = 3 values were the most effective parameters for discriminating between each pair of groups. Hypoacid-normacid-superacid: mean pH 6.1 +/- 0.2-4.2 +/- 0.23-1.5 +/- 0.07; integrated pH 8898 +/- 208-5987 +/- 339-2224 +/- 98 pH.min; and pH > or = 3 1440 +/- 0-392 +/- 44-80 +/- 11 min, respectively (+/- SEM). More than a 99.9% separation of the study groups was achieved using these three parameters concomitantly by the PRIMA method, even when comparing 6-h daytime periods of measurements. A relative disagreement was found when reclassifying the hypoacid and normacid patients on the basis of pH records, compared with the primary classification based on the MAO data (11 out of 35 patients, 31%). CONCLUSIONS: The analysis of the mean pH data (instead of medians or [H+]), the AUC-pH and the pH > or = 3 duration, either separately or most beneficially concomitantly, are recommended for the diagnostic interpretation of intragastric pH-metry data. The duration of the diagnostic intragastric pH-metry measurements might be decreased to 6 h by using the PRIMA method.

Gastric Acid↗

PubMed1996

Immunohistochemical signal amplification by catalyzed reporter deposition and its application in double immunostaining.

The biotinyl-tyramide substrate of the horseradish peroxidase enzyme has been recently introduced to amplify immunohistochemical signals. We applied either fluorochromeor biotin-conjugated tyramine to improve the detection of different antigens in sections of rat stomach, pancreas, and hypothalamus. A ten- to 100-fold increase in staining efficiency was achieved, depending on the antibody, with either fluorescent or peroxidase detection systems. The amplification method was particularly useful for increasing a weak signal of conventional immunostaining caused by suboptimal tissue fixation. At a very low concentration of the primary antibody, the antigen can no longer be detected by a conventional fluorescent secondary antibody but is still detectable after amplification. When an antibody is used at this very low concentration and is detected by a fluorescent amplification method, another primary antibody, raised in the same host species, can be used and demonstrated with a different fluorochrome in subsequent conventional immunostaining of the same section. In this way it becomes possible to immunostain the same section with two different primary antibodies raised in the same host species. Samples for such double immunostaining are demonstrated here using pairs of monoclonal antibodies (to tyrosine hydroxylase and oxytocin) in the hypothalamus and polyclonal antibodies (to glucagon and neurofilament M) in sections of rat pancreas. Because in many cases the availability of antibodies is limited, the amplification method can be a quick and efficient tool for double immunostaining with antibodies from the same host species.

Animals↗

PubMed1994

[Testing the acid-binding capacity of Tisacid suspension and tablets by intragastric pH determination in patients with hyperacidity].

The effect of a Hungarian Al-Mg-containing drug, called Tisacid was studied using of 2.0, 1.0 and 0.5 gram doses. Two administration forms, suspension and tablet were compared. Ten informed, adult hyperacid volunteers were included into the program and three times 5-hour intragastric pH-metry was carried out in a randomized, self-controlled open clinical study (Control, after administration of tablet or suspension). Both forms were found effective in gastric acid reduction at doses of 2.0 and 1.0 g. Tisacid suspension revealed a more pronounced efficacy at the dose of 2.0 g in comparison to the same dose of tablet form. The 0.5 g dose seemed insufficient in reduction of gastric acidity in hyperacid patients applied in tablet or suspension forms. The authors emphasize the role of continuous intragastric pH-metry in clinical practice and investigation of antacids and antisecretory drugs.

Adult↗

PubMed1994

Dynamism of cytoprotective and antisecretory drugs in patients with unhealed gastric and duodenal ulcers.

A continuous multiclinical, randomized and prospective study has been carried out in our department to compare the efficacy of different cytoprotective (sucralfate, DE-NOL, Vitamin A) and antisecretory drugs (atropine, cimetidine, ranitidine, famotidine, pirenzepine) on ulcer healing in patients with chronic gastric ulcer (GU) and duodenal ulcer (DU). A total of 441 patients were randomized in different groups. The patients were treated with atropine (1 mg/day), cimetidine (1000 mg/day), ranitidine (300 mg/day), famotidine (80 mg/day), pirenzepine (50 mg/day), sucralfate (1000 mg/day), Vitamin A (3 x 50,000 IU/day) alone or in combination with cyproheptadinum (3 x 4 mg/day) DE-NOL (3 x 5 mL/day) and Tisacid (Al-Mg-hydroxycarbonicum; in different doses). Endoscopy (planimetric evaluation of ulcer sizes), measurements of clinical changes in patients' complaints, antacid consumption and laboratory tests (blood counts, urine, kidney and liver functions, electrolytes, pH status) were carried out at the beginning and 2, 4 and 6 weeks after treatment with different drugs. The incidence of ulcers, changes of ulcer sizes, subjective pain score and antacid consumption were noted at the abovementioned times. There were 20 or more patients in each group. The dynamism of ulcer healing rate was studied on the unhealed GU and DU. Our results showed that the ulcer size decreased significantly in all groups in GU and DU patients treated with cytoprotective and antisecretory drugs. Summed pain score (expressed as per cent of basic values) and antacid consumption decreased significantly in all groups. As well, some differences were found in the dynamism of ulcer healing at 2 weeks after the treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Antacids↗

PubMed1990

Effects of a novel Hungarian antacid containing Al and Mg (Tisacid) on mucosal prostaglandin generation and oxygen free radicals in normal rats.

A new patented chemical agent (Al-Mg-hydroxy-carbonate; acid-binding capacity greater than 30 mmol/g) was produced by our work-team. After our preliminary pharmacological and some prospective, randomized, multicentre, controlled clinical studies, this antacid was registered (Tisacid tablet and suspension; Alkaloida, Hungary). A cumulative ulcer healing rate of 80-85% was proved by Tisacid monotherapy applied in low doses (from 80 to 160 mmol/day) in patients with duodenal ulcer. The aims of this study were: (i) to determine the role of different antacids on the genesis of mucosal prostaglandins (PGs) (PGE2 and 6-keto-PGF1 alpha) in normal rats; (ii) to evaluate the effects of indomethacin pre-treatment (20 mg/kg b.w.,s.c.) on the Tisacid-induced alterations of gastric mucosal PG-contents; (iii) to analyse the generation of oxygen free radicals and lipid peroxidation in the rat oxyntic mucosa by the application of different doses of Tisacid (activities of CAT, GSH-px and SOD, contents of MDA and red. GSH). It was found that: Tisacid has a potent gastroproprotective effect in gastric mucosa, via (a) an increase in the mucosal levels of PGs, and (b) a scavenging-like effect in normal rat gastric mucosa. It is concluded that the gastroprotective effect of Tisacid appears because of the following: (i) excellent acid-neutralizing capacity; (ii) mucosal generation of PGs (PGE2 and PGI2); (iii) free radical scavenging; (iv) its possible activity as a Ca-antagonist (Mg-containing compound).

6-Ketoprostaglandin F1 alpha↗

PubMedDate not supplied

Vesicular monoamine transporters in the rat stomach.

Cellular distribution of vesicular monoamine transporters (VMATs), known to regulate vesicular storage and release of biogenic amines (i.e., catecholamines, serotonin, histamine, etc.), have been studied in the rat stomach using in situ hybridization histochemistry (ISHH) and immunohistochemical (IHC) techniques. 35S-UTP labeled riboprobes showed that mRNAs of both VMATs are expressed in the gastric mucosa. A combination of ISHH and IHC verified that most of the parietal cells (among other epithelial cells) express mRNA of the peripheral type transporter (VMAT1) while enterochromaffin-like cells (ECL) of the fundic mucosa express mRNA of the central type (VMAT2). In addition, with double fluorescent IHC we detected VMAT1 protein in serotoninergic enterochromaffin cells (EC) of the stomach and in gastrin producing G cells of the antral mucosa. Similarly to the fundus, VMAT2 protein was present in ECL cells and in the enteric plexus. Surprisingly, serotonin- and/or histamine-containing cells in the connective tissue compartments of the stomach (i.e., lamina propria and submucosa), immunoreactive for a mast cell specific antigen, displayed neither VMATI nor VMAT2 immunoreactivity. Distribution of VMATs in the rat stomach support our previous observations on aminergic properties of two important gastrointestinal (GI) epithelial cell populations primarily known for other specific secretory products, i.e. dopaminergic properties of acid producing parietal cells and histaminergic properties of gastrin producing G cells. These data emphasize the existence of a non-neuronal, intrinsic aminergic system in the GI tract.

Animals↗

PubMedDate not supplied

13C-Urea breath test is superior in sensitivity to detect Helicobacter pylori infection than either antral histology or rapid urease test.

There is no single technique which fulfils the criterion for a reference method to detect Helicobacter pylori (Hp) infection. The aim was to compare the results of antral histology (H), rapid urease test (U) and urea breath test (UBT) from antral biopsy samples in patients having gastric or duodenal lesions during upper GI endoscopy. We used the following methods: 1) biopsy specimens for histology (Warthin-Starry staining); 2) rapid urease test; and 3) 13C-urea breath test with infrared spectrometry. The total number of patients was 166 examined by H, U, and UBT. H, U and UBT were negative (-) in 64 patients and positive (+) in 51. The true positivity and false negativity (%, number of patients in parentheses) of each method based upon the positivity of the other two tests were: H+, U+ (54): UBT+, 94.4% (51) and UBT-, 5.6% (3); H+, UBT+ (57): U+, 89.5% (51) and U-, 10.5% (6); U+, UBT+ (65): H+, 78.5% (51) and H-, 21.5% (14). If Hp infection is considered to be positive when at least two tests detect the presence of Hp, UBT shows the highest sensitivity in comparison to histology of biopsy specimens and urease test. UBT is highly recommended as a screening test for Hp infection in patients presenting upper GI endoscopic alterations.

Breath Tests↗

PubMedDate not supplied

Susceptibility of dopamine D5 receptor targeted mice to cysteamine.

BACKGROUND: Recently we demonstrated that gastric mucosa of rats can synthesize, store and release dopamine. Out of five different subtypes, mRNA of D5 (=D1b) dopamine receptor is very abundant in the gastric epithelium. D1 receptor selective dopamine agonists have been shown to protect against experimental gastro-duodenal lesions. AIMS: To test the hypothesis that protective effects of dopamine involve D5 receptors, mucosal lesions were induced in D5 receptor deficient (KO) and wild-type (WT) mice using cysteamine. Morphology and gastric acid secretion of D5 KO mice were also studied. METHODS: Single doses of 600 mg/kg, 300 mg/kg cysteamine or vehicle were administered subcutaneously to fasted animals. After 24 h, number and severity of gastro-duodenal lesions were analyzed. Basal and histamine-induced maximal gastric acid output were measured by a stomach-sac wash-through method. RESULTS: All the KOs in the 600 mg/kg cysteamine group died within 4 h showing symptoms of toxicity while three out of four WTs survived (P<0.05). Mortality after 300 mg/kg cysteamine was significantly higher in KOs versus the WTs: 6/14 versus 2/11, P<0.05. Gastric lesion-index was also significantly higher in KOs (median, middle quartile): four (3-9) versus 0 (0-0), P<0.05. Duodenal lesions did not develop from this single dose of cysteamine in either genotype. Basal and histamine-induced maximal gastric acid output were comparable in the two genotypes. CONCLUSIONS: This study demonstrates that loss of D5 receptor causes mucosal vulnerability and increased toxicity of cysteamine in genetically manipulated mice. Thus, D5 receptor subtype is indeed likely to be involved in protective effects of dopamine in the stomach.

Animals↗

PubMedDate not supplied

One year follow-up of patients after successful helicobacter pylori eradication therapy.

UNLABELLED: The aim of this study was to investigate the Helicobacter pylori (Hp) status of patients who underwent successful eradication therapy 1 year prior to the study and to evaluate their current symptoms. METHODS: all of the patients were initially evaluated by oesophago-gastro-bulboscopy and the Hp status was determined by at least two different methods [rapid urease test, histology or urea breath test (UBT)]. The Hp infection was treated with a 1-week triple therapy protocol, and the UBT was repeated 4-6 weeks later. We invited back 110 patients who had negative post-eradication UBT results 12+/-3 months prior to the study period. UBT was repeated and a questionnaire was completed about the previous and present complaints and medication. RESULTS: 80 of the 110 patients (73%) came back for the follow-up. Twenty five patients had peptic ulcer disease, 36 patients had gastritis or duodenitis without erosive lesions, and 19 patients had erosive form of gastritis or duodenitis initially. All of the patients except one in the erosive gastritis group had negative control UBT 1 year after the eradication, which means 1.25% recurrence rate within 1 year. The eradication therapy completely revealed the symptoms of 16 patients in the ulcer group (64%), 13 patients in the gastroduodenitis group (36%, P=0.03 vs. ulcer patients), 10 patients with erosive gastroduodenitis (52%), but this was only temporary. One year after the eradication therapy seven of the ulcer patients (28%), 11 patients with gastroduodenitis (31%) and seven patients with erosive gastroduodenitis (37%) were symptom-free. Most of the patients had epigastric pain (44%), heartburn (43%) and/or abdominal distension (33%). Nine ulcer patients (36%), 10 patients with gastroduodenitis (28%) and five patients with erosive gastroduodenitis (26%) were taking H(2)-blockers regularly. CONCLUSION: the 1-month post-eradication UBT was probable true negative in all of the evaluated cases, since 79 patients (98.75%) were also negative after 1 year. The Hp recurrence rate is very low (1.25%) in a 1-year period. The symptoms were relieved shortly after eradication therapy in the majority of patients with ulcer disease or erosive lesions. However, significantly smaller portion of the patients with gastroduodenitis became symptom-free. Only about one third of the treated patients remained symptom-free 1 year after the eradication.

Adult↗

PubMedDate not supplied

Dopaminergic characteristics of isolated parietal cells from rats.

Recently we have identified a dopamine-producing system in the gastric mucosa of rats. All the available morphological data suggest that parietal cells synthesize dopamine. In the present study we investigated the dopaminergic characteristics of isolated parietal cells by different methods. Mixed gastric mucosal cells were isolated and size-fractionated by elutriation. The proportion of neurons, parietal and endocrine cells in the fractions were determined by immunocytochemistry (ICC) using antibodies to neurofilament, proton pump and chromogranin A, respectively. No neurons were found in any of the cell preparations, while 56% parietal cell and 0.0% endocrine cell were achieved in the parietally enriched fraction. By Western blot, a tyrosine hydroxylase (TH, the rate-limiting enzyme of the catecholamine synthesis) immunoreactive protein species was demonstrated in isolated mucosal cells, comigrating with the TH immunoreactivity from PC12 cells. The TH immunoreactivity was colocalized to parietal cells by ICC. Dopamine transporter (DAT), a regulator of extracellular/intracellular dopamine balance in the nervous system, was also demonstrated in parietal cells. A significant amount of dopamine and DOPA were measured by HPLC (13.4 and 9.57 pg/10(6) cell, respectively) in parietally enriched cell fraction. Since this enriched cell fraction was virtually clear of both neurons and endocrine cells, demonstration of TH enzyme, DAT and dopamine in this fraction confirms that the parietal cell population might be a major source of dopamine in the rat stomach, supporting our previous results achieved using whole tissue samples.

Animals↗