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Biomedical subjects

J Papp

Publications and source records attributed to J Papp.

At least 19 recordsLinked to original sources
PubMed1999

[Helicobacter pylori infection and cancer of the stomach].

Although the incidence of gastric cancer has declined in the past few decades in developed countries, it has remained one of the most frequent malignomas with high mortality. Epidemiological, clinical and basic research studies confirm the role of Helicobacter pylori in the pathogenesis of the tumors of the distal stomach and low-grade MALT lymphomas. On the contrary more and more data suggest a possible protective role of the infection in the gastro-oesophageal reflux disease, tumors of the cardia and adenocarcinoma of the distal oesophagus. The intensive research being done in the past few years prove our previous concept, that the pathogenesis of gastric cancer is a multifactorial process, which is affected by Helicobacter pylori ("a major environmental factor") together with distinct environmental, social and genetic factors. The interaction of these factors and the importance of them urge further investigations, which may differ in different populations.

Helicobacter Infections↗
PubMed1999

[Pathophysiology of Helicobacter pylori infection].

The (re)discovery of the gastric pathogen Helicobacter pylori almost one and a half decade ago completely changed our conception on gastroduodenal ulcer disease and gastric cancer. The most important issue is that Helicobacter pylori induces a mild, antrum dominant chronic pangastritis without increased risk of severe diseases in most of the cases. A smaller part of the infected develops antrum dominant gastritis with increased risk of duodenal ulcer. In a few cases the corpus is also affected, pangastritis occurs with increased risk to develop gastric ulcer and gastric cancer. Until now it is not quite obvious why some of the infected patients get ill while others not, and why different diseases develop in different patients. 1. From the bacterial point of view it is ascertained that toxin-producing strains (VacA, CagA positive) are more likely to induce ulcer formation and gastric carcinoma. 2. Genetic phenotype of the infected patients (blood-group and HLA antigens) may also be of importance. 3. Environmental factors may affect (promote or inhibit) disease development. All of these factors determine the complex immunological, functional and morphological changes characteristic for the developing disease.

Gastric Acid↗
PubMed1999

Pacing-induced delayed protection against arrhythmias is attenuated by aminoguanidine, an inhibitor of nitric oxide synthase.

1. Cardiac pacing, in anaesthetized dogs, protects against ischaemia and reperfusion-induced ventricular arrhythmias when this is initiated 24 h after the pacing stimulus. Now we have examined whether this delayed cardioprotection afforded by cardiac pacing is mediated through nitric oxide. 2. Twenty-two dogs were paced (4 x 5 min periods at 220 beats min(-1)) by way of the right ventricle, 24 h prior to a 25 min period of coronary artery occlusion. Nine of these dogs were given the inhibitor of induced nitric oxide synthase, aminoguanidine (50 mg kg(-1) i.v.), 0.5 h prior to coronary artery occlusion. Sham-operated non-paced dogs with and without aminoguanidine treatment served as controls. 3. Pacing markedly (P<0. 05) reduced arrhythmia severity (ventricular fibrillation, VF, during occlusion 15%; survival from the combined ischaemia-reperfusion insult 62%) compared to control, sham-operated, unpaced dogs (VF during occlusion 58%; survival 17%). This protection was attenuated by the administration of aminoguanidine prior to coronary artery occlusion (survival from the combined ischaemia-reperfusion insult 11%, which was significantly (P<0.05) less than in the paced dogs not given aminoguanidine and similar to the controls). Aminoguanidine had no significant effects on coronary artery occlusion when given to dogs that had not been paced. In the dose used aminoguanadine transiently elevated systemic arterial pressure by a mean of 20 mmHg and reduced heart rate by a mean of 22 beats min(-1). 4. These results suggest that nitric oxide, probably derived from induced nitric oxide synthase, contributes significantly to the delayed cardioprotection afforded by cardiac pacing.

Animals↗
PubMed1998

Consortium study on 1280 breast carcinomas: allelic loss on chromosome 17 targets subregions associated with family history and clinical parameters.

The pattern of loss of heterozygosity (LOH) on chromosome 17 in human breast cancer is complicated and shows many different regions of loss. In an attempt to narrow down the relevant regions of LOH on chromosome 17, we have studied the deletion pattern and its association with clinical parameters in 1280 breast carcinoma-venous blood lymphocyte pairs. In total, 42 different chromosome 17 loci were investigated, and between 25 and 625 cases were analyzed at each locus. The frequency of LOH observed on the p arm was much higher than that observed on the q arm. The opposite effect was observed in 52 ovarian cancer cases investigated, with less LOH on 17p than on 17q. Patterns of loss consistent with interstitial and terminal deletions, as well as loss of either the p or q arm or monosomy 17 were observed. To determine whether loss at particular loci may be associated with biological features of breast tumors, clinical data including age of onset, family history of breast cancer, tumor histopathology, tumor size, estrogen receptor (ER) status, and occurrence of lymph node or distant metastases were collected for each case. Overall, large-sized, ER-negative, lymph node-positive ductal tumors showed the highest frequencies of LOH, with ER-negative and ductal tumors showing LOH for markers along the majority of the chromosome. Eight regions of chromosome 17 appear to be associated with human breast cancer, two on 17p and six on 17q. These regions were not necessarily in the areas exhibiting the highest frequencies of LOH but were defined by interstitial and terminal deletions in multiple independent cases. Seven of these regions showed statistically significant differences in LOH associated with clinical parameters. These data strongly suggest that loci on chromosome 17 may determine aspects of tumor presentation and disease behavior in human breast cancer and pinpoint candidate tumor suppressor gene loci.

Adult↗
PubMed1997

[Evaluation of the effectiveness of pantoprazole and ranitidine in the treatment of duodenal ulcer. Result of an international multicenter study].

A double-blind, randomized, multicenter, multicountry study (Poland, Chech Republic, Hungary) was carried out in 1995 on patients (n = 326) with endoscopically confirmed duodenal ulcer treated with ranitidine vs. pantoprazole. In Hungary-in 4 gastroenterology centers-123 patients have been involved (age 18-75 years). The treatment schedule has been 300 mgs of ranitidine or 40 mgs of pantoprazole q. d. for 2 or if necessary for 4 weeks. In the Hungarian study 60 DU patients were treated with pantoprazole vs. 63 ones with ranitidine. Having finished the two-week schedule the healing rates of duodenal ulcer were as follows: pantoprazole 71%/72% (Hungary/International) vs ranitidine 57%/51%, (p < 0.001). After 4 weeks the corresponding values showed the following: pantoprazole 98%/94% vs. ranitidine 88%/86%, respectively, (p < 0.005). Both drugs have shown to be effective and safe to cure duodenal ulcer however in our study pantoprazole was significantly more efficacious and provided quicker healing than ranitidine.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1996

Allele loss from large regions of chromosome 17 is common only in certain histological subtypes of ovarian carcinomas.

Using a panel of ten polymorphic markers, we examined the frequency of loss of heterozygosity (LOH) on chromosome 17 in 55 sporadic ovarian tumours. LOH on 17p and 17q was observed to be 50% and 62% respectively. LOH at D17S5 was detected in 24/36 (67%) of malignant cases and in 19/43 (44%) at TP53; the marker D17S855 intragenic to the BRCA1 gene showed allele loss in 50% (20/40) cases. The data presented here suggest that loss of the whole chromosome 17 is a relatively frequent event (30%) in ovarian carcinomas and this observation is especially frequent for serous, transitional cell and anaplastic histological subtypes. Mucinous and endometrioid ovarian tumours showed only short interstitial deletions (4/11, 36%). The overall frequency of the short deletions was relatively low (7/43, 16%) in our panel of carcinomas. Amplification of c-erbB-2/neu oncogene was detected in 32% (11/34) of the carcinomas tested; the gene was amplified only in those histological subtypes in which high incidence of LOH on chromosome 17 was observed, and was associated with advanced stages of the disease. We conclude that different histological types of tumour may have different aetiological mechanisms, and tumour-suppressor genes on chromosome 17 might be associated specifically with serous and transitional cell ovarian carcinomas.

Alleles↗
PubMed1995

[Helicobacter pylori in benign gastroduodenal diseases].

(A light- and electronmicroscopic study). We have examined the occurrence of Helicobacter pylori (HP) in 2937 gastric antral biopsy specimens from 979 patients with upper gastrointestinal symptoms. The incidence of HP proved to be 50.5%. The endoscopic diagnoses were: gastritis (62 cases), gastric erosion (425), gastric ulcer (51), duodenitis (22), duodenal erosion (119), duodenal ulcer (122) and the HP incidence was 29, 46, 63,, 50, 66 and 73%, respectively. Microscopic findings were: chronic gastritis (442), chronic active gastritis (356) and normal mucosa (181). The prevalence of HP in these groups was 43%, 78% and 11%, respectively. The activity of gastritis was in good correlation with HP infection. We did not see epithelial damage, and found only a few instances of mucus depletion. Electronmicroscopic examination was performed in order to investigate the morphology of bacterium and its relation to the mucosal cells. We observed mild loss of microvilli on the cell surface and did not see any cell invasion by bacteria.

Adolescent↗
PubMed1995

Contribution of p53 gene alterations to development of metastatic forms of follicular thyroid carcinoma.

Alterations of p53 suppressor gene as a possible indicator of the metastatic potential of thyroid carcinomas were evaluated in a cohort of 45 thyroid carcinomas. Well-differentiated papillary and follicular carcinomas were evaluated; the poorly differentiated and the undifferentiated forms were excluded from the studies. Tumors were divided into two groups: those giving no metastasis for > 10 years and those developing metastasis within 5 years. Gene alterations were tested by immunocytochemical detection of p53 gene expression and by determining loss of heterozygosity (LOH). Considering the two methods together, p53 damages were observed in two out of 11 papillary carcinomas without metastasis (18.1%), one out of nine papillary carcinomas with metastasis (11.1%), two out of 14 follicular carcinomas without metastasis (14.2%), and five out of 11 follicular carcinomas with metastasis (45.4%). Statistical X2 test showed significantly (p = 0.05) only between follicular carcinomas with and without metastasis thus p53 damage may have an impact for metastatic potential of follicular thyroid carcinomas.

Adenocarcinoma, Follicular↗
PubMed1993

Oncogene patterns in breast and ovarian carcinomas.

Nineteen paraffin-embedded breast cancer tissue samples selected for long survival (more than 5 years) were analysed for detecting the amplification of the c-erbB-2 (Her-2/neu) oncogene by Polymerase Chain Reaction (PCR). Strong correlation was elucidated between c-erbB-2 amplification and survival; such correlation was also observed with histopathologic types and nuclear grading. Because of the similarity of the breast and ovarian cancer in the etiology of the diseases, amplification of c-erbB-2, c-myc and Ki-ras genes was examined in 32 ovarian carcinoma samples (stage I-IV). In ovarian carcinomas c-erbB-2 amplification occurred in 34% (11/32) of the fresh tumour samples, and correlation between amplification and clinical staging at P < 0.05 significance level was observed. Amplification of c-myc was detected in 9% (3/32) and none of the tumours showed amplification of Ki-ras.

Base Sequence↗
PubMed1992

[Initial experience with ESWL therapy of pancreatic duct calculi].

Extracorporeal shock wave lithotripsy of pancreatic stones was performed in four patients with chronic pancreatitis and a dilated duct system harbouring stones 5-12 mm in diameter. The stones were disintegrated by shock waves using a Dornier lithotripter in one or more sessions. Disintegration of stones was achieved in 4/4 patients, initial (6-11 months) relief of pain in 3/4 patients, and total clearance of pancreatic duct in 3/4 patients. No complications were observed. In the first patient in whom ESWL was not completely successful, underwent an operation: a longitudinal pancreato-gastrostomy and the stones were found completely disintegrated. From these early data they conclude that ESWL of pancreatic duct stones is a provisional new alternative for surgery in the treatment of chronic pancreatitis.

Calculi↗
PubMed1992

Somatostatin versus secretin in the treatment of actively bleeding gastric erosions.

In a double-blind, prospective, randomized trial, 63 patients with actively bleeding gastric erosions were treated with somatostatin (31 patients) or secretin (32 patients). Both drugs were administered by intravenous infusions for 48 or 72 h. The active bleeding and the effect of the therapy was endoscopically established. Somatostatin had a significantly (p < 0.05) better effect on the control of bleeding (29 vs. 23 patients), transfusion requirements (5.8 vs. 7.4 units, p < 0.01) and on the need of surgery (1 vs. 6 patients, p < 0.01). The mortality and the rebleeding rate did not differ between the two groups. The results show that somatostatin is more effective than secretin in the control of active bleeding form gastric erosions.

Adolescent↗
PubMed1991

[Initial experience with ultrasonic examination of the rectum].

The authors report their initial results obtained by the use of transrectal sonography in examination of known or suspected rectal and perirectal masses. 42 patients were examined with commercially available endosonographic probes. 22 patients had known rectal cancer. 13 patients underwent surgical exploration. Malignant infiltration of perirectal fat were detected as accurately with US as with histology in 9 cases. Lymph node involvement was accurately identified in 11 cases. They recommend this new technique for the assessment of invasion of rectal tumours and lymph node involvement, for postoperative follow-up and for examination of benign diseases of the rectum.

Adult↗
PubMed1991

[Ultrasonic diagnosis with secretin stimulation in patients with pancreas divisum].

The diagnostic value of secretin provoked abdominal ultrasound was studied on 34 patients with pancreas divisum and on 20 control subjects. The patients received a 1.0 unit/kg body weight dose of secretin. The degree of ductal expansion and the time required to return to the initial state were registered and these values were compared to the clinical diagnosis. The control subject's ductal diameters prior to secretin administration were 1 mm in all cases (maximum expansion 2 mm, return to the initial value within 10 minutes). The pancreas divisum patients could be placed in two groups based on their initial ductal diameter. Fourteen patients had initial ductal diameters of 2 mm or greater (A group mean +/- SD: 2.4 +/- 0.3) while 21 patients had an initial value of less than 2 m (B group; 1.7 +/- 0.3). Following secretin administration the ductal diameter of the A group's patients increased on average +/- SD to 1.3 +/- 0.5 times the initial value and in the B group 3.2 +/- 1.1 times the initial value (p less than 0.01). In the A group the ductal diameter returned to its initial value within 10 minutes, while it took 35 minutes for the same to occur in the B group. A relationship can be observed between the clinical diagnosis, the initial ductal diameter, the degree of expansion following secretin administration and the time required to return to the initial state.

Adult↗