Microsatellite instability and gastric cancer subtypes.
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Adult↗
Biomedical subjects
M Rugge
Publications and source records attributed to M Rugge.
Epstein-Barr virus: a possible accomplice in gastric oncogenesis.
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Gastritis↗
Gastric precancerous lesions: heading for an international consensus.
As pathological criteria lie at the foundation for the classification of many diseases, a crucial requisite for such classifications to be valid is that their morphological basis be standardised. Inadequately standardised diagnostic criteria result in unacceptable interobserver variation, a factor that may influence both individual patient care and the evaluation of clinical protocols. One of the most important goals in gastric diseases today is to establish whether cure of Helicobacter pylori is an effective preventive measure against gastric cancer. To tackle this issue it is necessary to measure reliably intermediate outcomes, specifically gastric atrophy and dysplasia. However, there is little agreement on what gastric atrophy and atrophic gastritis are, and treatment and follow up results obtained at one clinical centre are often radically different from those obtained at another. Similarly, studies that examine the fate of dysplastic lesions in the stomach show a great divergence of outcomes between Europe and North America and Japan, where the concept of dysplasia has different connotations. To reach a consensus on the definitions and diagnostic criteria for atrophy and atrophic gastritis, a group of gastrointestinal pathologists and gastroenterologists met in Houston, Texas, USA, in February 1998. Substantive progress was made, but several problems remained, and a study aimed at resolving the issues that seem to stand in the way of an international agreement is currently underway. To fulfil the need for a broad discussion on the diagnostic differences of gastric dysplasia and cancer between East and West, an international group of pathologists gathered in Padova, Italy, in the spring of 1998. Their main objectives were: (1) to agree on the definitions of the spectrum of gastric preneoplastic lesions; (2) to establish an international glossary for gastric precancerous lesions; and (3) to test the consensus and eventually generate guidelines useful to clinicians for the development of management strategies. A consensus was achieved on the definition of gastric dysplasia as preinvasive neoplasia. Other validation studies are underway. The experiences achieved in the search for an international consensus on the phenotypes of atrophic gastritis and gastric dysplasia may represent a model in dealing with the new scenario of a modern evidence-based pathology.
Atrophy↗
Helicobacter pylori non-cytotoxic genotype enhances mucosal gastrin and mast cell tryptase.
AIMS: To determine the association, if any, between H pylori genotype and the gastric mucosal variations in the levels of gastrin, somatostatin, tryptase, and histamine. METHODS: 49 patients affected by duodenal ulcer and 48 by non-ulcer dyspepsia were studied. To identify the H pylori genotype, the presence of the cagA gene and vacA alleles m1, m2, s1, and s2 were analysed by polymerase chain reaction. Gastrin, somatostatin, tryptase, and histamine were measured in antral mucosal biopsies. RESULTS: 57 patients were infected with H pylori (30 with duodenal ulcer and 27 with non-ulcer dyspepsia). Gastrin and tryptase were increased in patients with H pylori infection, although the variations were statistically significant only for gastrin; somatostatin and histamine were not influenced by H pylori infection. In patients with non-ulcer dyspepsia the absence of the cagA gene and the presence of vacA alleles s2 and m2 were associated with higher values of tryptase and to a lesser extent of gastrin. These associations were not found in patients with duodenal ulcer. CONCLUSIONS: The cagA negative s2m2 strain of H pylori may be less dangerous for the gastric mucosa than other H pylori strains since it enhances tryptase production by gastric mucosal mast cells; this enzyme is thought to stimulate tissue turnover and favour wound healing.
Adolescent↗
Origin of spurious multiple bands in the amplification of microsatellite sequences.
Multiple band artifacts are seen commonly in the analyses of short repetitive sequences, also known as microsatellites, using the polymerase chain reaction (PCR). In this study, the conditions of PCR were examined for five microsatellite loci (D2S119, D2S123, D5S409, D11S904, and interferon alpha) in an attempt to eliminate this artifact. In addition, and a possible mechanism for the formation of the multiple band artifact in non-denaturing polyacrylamide gel electrophoresis was also explored. The intensity of multiple bands increased when the numbers of PCR cycles were increased. The multiple bands were abolished simply by reducing PCR cycle numbers and were reproduced from single specific PCR products undergoing alternate denaturation and reassociation without primer extension. This finding suggests that formation of multiple bands in non-denaturing gel electrophoresis is a result of improper annealing of PCR fragments, rather than being the result of polymerase slippage and 3' non-template extension, as has been reported previously.
Artifacts↗
Intrahepatic expression of hepatitis B virus antigens: effect of hepatitis C virus infection.
Coinfection with hepatitis B and C viruses (HBV, HCV) is not uncommon, but the expression of HBV antigens in the liver of patients with concomitant HCV infection has not been investigated. This study aimed to evaluate the effects of concomitant HCV infection on the intrahepatic expression of HBV antigens in chronic hepatitis. HBV surface and core antigens (HBsAg, HBcAg) were immunohistochemically evaluated and semiquantitatively scored in liver biopsy specimens from patients with chronic hepatitis, comprising 17 cases with dual HBV/HCV infection and 25 with HBV infection alone. The prevalence of HBV Ag expression proved significantly lower in the group with dual infection. In the presence of active HBV replication (HBV DNA-positive serum) the prevalence of HBsAg and HBcAg immunoreaction was similar in the two groups, though a significantly lower percentage of cells expressed HBcAg in the group of coinfected patients. HBV Ag was not detected at all among HBV DNA-negative/HCV RNA-positive cases. In conclusion, these observations suggest that HCV might influence HBV antigen expression in the liver and that either partial or complete suppression might occur.
Adolescent↗
Loss of FHIT expression in gastric carcinoma.
Loss of heterozygosity involving the short arm of chromosome 3 has been reported in gastric and other human tumors. We have cloned and mapped a candidate tumor suppressor gene, FHIT (fragile histidine triad), to this chromosomal region (3p14.2). To investigate the role of FHIT gene alterations in the development of gastric carcinoma, we examined 8 gastric carcinoma-derived cell lines and 32 primary adenocarcinoma samples by Southern blot analysis. We also analyzed the integrity of FHIT transcripts by reverse transcription-PCR. The occurrence of alterations in the FHIT gene and its transcript correlated with the absence of Fhit protein expression by immunoblot analysis in the cancer cell lines. Four of eight cell lines showed deletion or rearrangement within the FHIT gene, together with the absence of the wild-type transcript and the Fhit protein. Among the primary gastric carcinomas, rearrangement of the FHIT gene and/or aberrant reverse transcription-PCR products were detected in 17 of 32 (53%) tumors, and 20 of 30 (67%) samples exhibited an absence of Fhit protein expression. Gastric cancer is thought to develop from carcinogenic exposure, possibly explaining the high frequency of abnormalities in the FHIT gene, a fragile locus exhibiting susceptibility to carcinogen-induced alterations. The consequent absence or reduction of Fhit protein expression is consistent with the proposal that the FHIT gene is a preferential target of environmental carcinogens and that FHIT inactivation plays a role in the development of gastric cancer.
Acid Anhydride Hydrolases↗
Cytogenetic analysis of hepatoblastoma: hypothesis of cytogenetic evolution in such tumors and results of a multicentric study.
Hepatoblastoma is a rare pediatric malignant tumor of the liver. Previous cytogenetic reports are sporadic. We karyotyped nine consecutive hepatoblastomas from the Italian centers participating in a multicentric study on hepatic tumors (SIOPEL 1). Six cases showed abnormal karyotypes. The most common abnormalities were trisomies of chromosomes 2 and 20. Four cases showed abnormalities of chromosome 1. On the basis of findings, we speculate the possibility of a cytogenetic evolutive pattern of hepatoblastomas.
Child, Preschool↗
Chronic hepatitis C in children: the pathological and clinical spectrum.
BACKGROUND & AIMS: Apart from the high-risk groups, the pathology of chronic hepatitis C in children is not well known. The aim of this study was to investigate the morphology of chronic hepatitis C in children without any underlying systemic disease and to evaluate its relationship to clinicovirological factors. METHODS: Liver biopsy specimens from 80 children positive for antibody to hepatitis C virus were evaluated using a semiquantitative scoring system. RESULTS: Chronic hepatitis was mild in most cases but had high-grade activity in 17 children (21.2%). A significant association was found between the grade of focal necrosis and alanine transaminase levels (P < 0.003). Fibrosis was absent in 22 cases (27.5%), mild in 44 (55%), and moderate in 13 (16.2%). Only 1 patient had cirrhosis. A significant relationship was detected between fibrosis scores and (1) duration of disease (P < 0.03); (2) portal inflammation (P < 0. 002); and (3) interface hepatitis (P < 0.003). CONCLUSIONS: In otherwise healthy children, chronic hepatitis C is a morphologically mild disease in most cases. Fibrosis increases with the duration of disease, suggesting that end-stage disease may develop in young adulthood. Alanine transaminase levels correlate with intralobular focal necrosis but not with other lesions. In this respect, liver biopsy retains its importance in the management of chronic hepatitis C in children.
Adolescent↗
H. pylori eradication and gastric precancerous lesions.
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Gastric Mucosa↗
Prevalence of upper gastrointestinal lesions and Helicobacter pylori infection in Crohn's disease.
Crohn's disease can affect the upper gut with reported variable frequency, although concurrent Helicobacter pylori infection has been reported to be low. We prospectively investigated the prevalence of esophageal, gastric, and duodenal lesions and Helicobacter pylori infection in 67 Crohn's disease, 41 ulcerative colitis patients, and 43 controls. Symptoms, esophagogastroduodenoscopy, and multiple biopsies were performed on all patients consecutively. Endoscopic lesions were found in 63% of Crohn's disease patients, with a Helicobacter pylori prevalence of 28%. Granulomas were found in three patients. Twenty-two percent of the ulcerative colitis patients had lesions, with a 29% prevalence of Helicobacter pylori infection. Half of the controls had pathological endoscopy, and Helicobacter pylori was positive in 40% of the cases. Subjective symptoms did not predict the presence of endoscopic lesions or Helicobacter pylori infection in inflammatory bowel disease patients. Chronic gastritis and duodenitis are common in Crohn's disease patients, and the majority are not associated with Helicobacter pylori infection.
Adult↗
The immunobiology of H. pylori: from pathogenesis to prevention
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Journal Article↗
Low dose of clarithromycin in triple therapy for the eradication of Helicobacter pylori: one or two weeks?
The aims of this pilot study were: (i) to compare the efficacy of low-dose clarithromycin (250 mg twice daily) for 1 or 2 weeks; and (ii) to evaluate possible therapeutic advantages in associating the low-dose clarithromycin with an anti-secretory agent or tripotassium dicitrate bismuthate (De Nol; Yamanouchi Pharm, Corugate Milano, Italy). A prospective, randomized, open trial was carried out on consecutive outpatients with dyspeptic symptoms and Helicobacter pylori infection. We enrolled 129 patients in one of the following schedules: (A) De Nol 120 mg q.i.d., clarithromycin 250 mg b.i.d. and metronidazole 250 mg q.i.d. for 2 weeks; (B) omeprazole 20 mg b.i.d., clarithromycin 250 mg b.i.d. and metronidazole 250 mg q.i.d. for 2 weeks; or (C) omeprazole 20 mg b.i.d., clarithromycin 250 mg b.i.d. and metronidazole 250 mg q.i.d. for 1 week. Results were evaluated by Per Protocol (PP) and Intention-To-Treat analysis (ITT). Eradication rate was 100% after treatment A, 92.6% after treatment B and 86.5% after treatment C by PP and 83.3, 75.7, and 68.1%, respectively by ITT. Side effects were reported by 16 subjects: 26.6% in group A; 9.1% in group B; and 7.5% in group C; in two cases side effects led to the withdrawal of the treatment. In conclusion, 500 mg clarithromycin per day in association with omeprazole and metronidazole, for 1 week gave comparable results to the same schedule for a 2 week period. The use of clarithromycin with bismuth and metronidazole produced a therapeutic gain compared with both of the anti-secretory schedules, although this was not statistically significant.
Adult↗
Helicobacter pylori cytotoxic genotype is associated with peptic ulcer and influences serology.
OBJECTIVE: We studied 146 patients with peptic ulcer disease (n = 72), antral gastritis (n = 58), or duodenitis (n = 16) to ascertain whether the cytotoxic genotype of Helicobacter pylori (Hp) is associated with peptic ulcer disease and/or antral gastritis and whether it influences the circulating levels of total anti-Hp antibodies, anti-cagA antibodies, and pepsinogens. METHODS: A gastric juice sample was obtained from each patient. After DNA extraction, polymerase chain reaction was used to amplify the genes urease A (ureA), cagA, and vacA of Hp. RESULTS: A significant association was found between peptic ulcer disease and the cytotoxic genotypes, characterized by the presence of s1 and m1 alleles of vacA and by cagA. Patients with a cagA-positive genotype showed a significant increase in anti-cagA antibodies and also had significantly increased circulating levels of pepsinogen C. CONCLUSIONS: Cytotoxic Hp strains are mainly involved in determining peptic ulcer disease, but not antral gastritis. The higher levels of circulating pepsinogen C found in patients infected with cytotoxic genotypes may reflect the higher degree of inflammation sustained by these strains.
Adult↗
Hepatoblastoma: DNA nuclear content, proliferative indices, and pathology.
Hepatoblastoma (HB) is the most frequent malignant liver tumor in infancy, and both its biological features and its prognostic behavior are still under investigation. DNA content and proliferative activity of the tumor have been considered as biological parameters related to the tumor's aggressiveness. The present study attempts to investigate the possible association between histologic subtype, DNA content, and proliferative indices in HB. DNA content and the proportion of cells in the S-phase were assessed by flow cytometry in 34 cases of HB (14 prior to chemotherapy, 20 after chemotherapy), using formalin-fixed, paraffin-embedded archival samples. The proliferative cell nuclear antigen (PCNA) labeling index was also evaluated by immunohistochemistry, and both the flow cytometry (FC) and the immunohistochemical data were correlated with tumor pathology. A significant association was found between histological type, DNA content and the percentage of cells in the S-phase, with aneuploidy and the highest proportions of S-phase cells significantly associated with embryonal tumors. The PCNA labeling index was found to be significantly higher in embryonal than in fetal phenotype. The biological heterogeneity of HB is Confirmed by the different nuclear content of the fetal (diploid) and embryonal (aneuploid) epithelial components of the tumor, also ruling out the likelihood of fetal (diploid) clones deriving from the embryonal (aneuploid) neoplastic cells. Since the highly proliferative neoplastic clones (i.e., embryonal) are thought to be more sensitive to antimitotic drugs, further studies are indicated to determine the relationship between ploidy, proliferative indices and chemoresponsiveness.
Child↗
Oxidative DNA damage accumulation in gastric carcinogenesis.
BACKGROUND: Gastric carcinogenesis is a multifactorial, multistep process, in which chronic inflammation plays a major role. AIMS: In order to ascertain whether free radical mediated oxidative DNA damage is involved in such a process, concentrations of 8-hydroxydeoxyguanosine (8OHdG), a mutagenic/carcinogenic adduct, and thiobarbituric acid reactive substances (TBARS), as an indirect measure of free radical mediated damage, were determined in biopsy specimens from patients undergoing endoscopy. PATIENTS: Eighty eight patients were divided into histological subgroups as follows: 27 with chronic non-atrophic gastritis, 41 with atrophic gastritis, six with gastric cancer, and 14 unaffected controls. METHODS: Intestinal metaplasia, Helicobacter pylori infection, and disease activity were semiquantitatively scored. 8OHdG concentrations were assessed by HPLC with electrochemical detection, and TBARS concentrations were fluorimetrically assayed. RESULTS: 8OHdG concentrations (mean number of adducts/10(5) dG residues) were significantly higher in chronic atrophic gastritis (p = 0.0009). Significantly higher concentrations were also detected in the presence of severe disease activity (p = 0.02), intestinal metaplasia (p = 0.035), and H pylori infection (p = 0.001). TBARS concentrations were also higher in atrophic gastritis, though not significantly so. In a multiple logistic regression analysis, 8OHdG concentrations correlated best with the presence and severity of H pylori infection (r = 0.53, p = 0.002). CONCLUSION: Chronic gastritis is characterised by the accumulation of oxidative DNA damage with mutagenic and carcinogenic potential. H pylori infection is the major determinant for DNA adduct formation.
8-Hydroxy-2'-Deoxyguanosine↗
p16/CDKN2 alterations and pRb expression in oesophageal squamous carcinoma.
BACKGROUND: Upregulation of the cell cycle associated genes, p16/CDKN2 and the retinoblastoma susceptibility gene (Rb), is commonly seen during the proliferation of normal cells. An inverse relation between the expression of p16/CDKN2 and Rb has been noted in many tumours, but has not yet been determined in oesophageal squamous carcinoma. AIMS: To investigate p16/CDKN2 genetic alterations and both the p16/CDKN2 and the Rb protein (pRb) immunophenotypes in oesophageal squamous carcinoma. METHODS: Twenty primary oesophageal squamous carcinomas were examined for mutations in p16/CDKN2 by the polymerase chain reaction, single stranded conformational polymorphism, and DNA sequencing. Synthesis of p16/CDKN2 and pRb proteins was determined by immunohistochemistry in 19 specimens of formalin fixed, paraffin wax embedded tissues. RESULTS: Mutations of p16/CDKN2 were not detected in exons 1 and 2. In only one case, G to C and C to T base changes were detected in a non-coding region of exon 3. Expression of p16/CDKN2 and Rb was observed in both normal and neoplastic areas of tissue sections, indicating neither consistent homozygous deletion nor consistent hypermethylation of the genes in tumours. Fourteen tumours showed an inverse expression of p16/CDKN2 and Rb. An increased percentage of cells that immunostained positively for p16/CDKN2 but not for pRb was observed in eight tumours, five of which had no detectable pRb, suggesting defective Rb expression in these oesophageal squamous carcinomas. CONCLUSIONS: These results indicate that p16/CDKN2 mutations occur infrequently in oesophageal squamous carcinoma. The alteration of the Rb gene is suggested as an important step in the development of these tumours.
Aged↗
Helicobacter pylori and the liver: any relationship?
Helicobacter pylori infection is being correlated to a number of human diseases, among which also those of the liver. From a clinical point of view, 4 "areas of interest" for the suggested correlation can be identified: 1. Helicobacter pylori and portal hypertension-related congestive gastropathy in cirrhotics. There are, in the literature, at least 7 studies confirming that the microorganism has no role in causing or worsening the disease. 2. Helicobacter pylori and duodenal ulcer in cirrhotic patients. Apparently, in the cirrhotic patient, the microorganism has no role in causing duodenal ulcer. 3. Helicobacter pylori, ammonia production and hepatic encephalopathy. In this case, there are at least three studies showing that Helicobacter pylori infection increases the risk of developing encephalopathy in the cirrhotic patient, this being a somewhat expected finding. 4. Helicobacter pylori infection in chronic liver disease and its diagnosis. Evidence in the literature suggests: a) that hypertensive gastropathy might not represent a favourable environment for Helicobacter pylori thus making the diagnostic sensitivity of the biopsy lower than expected, and b) that even serological diagnosis might provide data of difficult interpretation, as shown in non alcoholic cirrhosis and, by our own group, in primary biliary cirrhosis. More intriguing are the data generated with respect to the potential capacity of Helicobacter pylori and Helicobacter pylori-like bacteria such as, in particular, Helicobacter hepaticus to damage the liver by producing toxins with a granulating effect on liver cell lines which, in vivo, through the portal tract, might reach the liver, thus causing hepatocellular damage. The point has been addressed by a number of investigators and autoimmune mechanisms have also been suggested. In summary, from the clinical point of view, some evidence suggests that Helicobacter pylori infection might be relevant in the pathogenesis of hepatic encephalopathy in cirrhosis. The data being generated with respect to a direct hepatotoxicity are, at present, stimulating but only speculative.
Ammonia↗