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R M Genta

Publications and source records attributed to R M Genta.

At least 19 recordsLinked to original sources
PubMed2004

Screening for gastric cancer: does it make sense?

Gastric cancer remains the second most frequent and lethal malignancy worldwide, with a wide range of incidence rates in different populations. Reducing its incidence is a priority in many high-risk countries, and screening programmes are often advocated as an option. An effective screening programme should have the following characteristics: (i) the disease should be common in the population, otherwise the individual benefit will not offset the risk, cost and inconvenience of screening of the rest of the population; (ii) the diagnostic test(s) used should be safe, simple, inexpensive and reliable; and (iii) effective treatment should be available. With respect to gastric cancer, these conditions are not fulfilled completely in any population and therefore population-based screening does not appear to be a viable approach to the prevention of this neoplasia. In contrast, gastroscopic screening in selected high-risk subjects would seem appropriate. A more effective strategy, particularly in high-incidence populations, could be the widespread screening and treatment for Helicobacter pylori infection. This could result in the virtually complete elimination of chronic gastritis and its associated conditions, including most peptic ulcers, primary gastric B-cell lymphomas and a major portion of gastric epithelial tumours.

Early Diagnosis↗
PubMed2003

Review article: the role of rebamipide in the management of inflammatory disease of the gastrointestinal tract.

Rebamipide stimulates the generation of endogenous prostaglandins in the gastric mucosa and is reported to accelerate ulcer healing. This review discusses whether rebamipide can prevent Helicobacter pylori infection, reduce inflammation, accelerate healing after eradication, promote ulcer healing, and prevent progression of preneoplastic lesions. Furthermore, we evaluate its usefulness in other inflammatory conditions of the gastrointestinal tract. We conclude that rebamipide is an important candidate for long-term suppression of gastro-intestinal inflammation, particularly if reducing the complications of H. pylori infection without eradicating the organism becomes accepted. If its ability to accelerate mucosal normalization is confirmed, rebamipide could be added to eradication regimens. Little information exists on whether such therapy could help limit the development of pre-neoplastic lesions. In light of the dearth of effective drugs to control inflammation in idiopathic inflammatory bowel disease, the potential of any promising new and safe compound deserves to be fully explored. The next step is to devise a targeted plan of translational research, so that results from the bench may be used to design rigorously controlled international clinical trials.

Alanine↗
PubMed2002

Helicobacter pylori infection and expression of the angiogenic factor platelet-derived endothelial cell growth factor by pre-neoplastic gastric mucosal lesions and gastric carcinoma.

BACKGROUND: Expression of the angiogenic factor platelet-derived endothelial cell growth factor is induced in some gastric carcinomas. Whether angiogenesis is induced early in the development of gastric pre-neoplastic lesions and whether Helicobacter pylori infection affects platelet-derived endothelial cell growth factor expression is not known. AIM: To assess whether chronic gastritis, intestinal metaplasia, gastric dysplasia and gastric carcinomas express platelet-derived endothelial cell growth factor and whether Helicobacter pylori infection might affect the expression of platelet-derived endothelial cell growth factor in these lesions. PATIENTS AND METHODS: Patients with gastric carcinomas, atrophic gastritis with associated intestinal metaplasia, dysplasia and controls without infection or carcinoma were studied. RESULTS: Platelet-derived endothelial cell growth factor was detected by immunohistochemistry in 9 out 19 gastric carcinomas (45%). Only focal immunostaining was detected in intestinal metaplasia adjacent to dysplasia and in dysplastic cells. Of the tumours, 90% contained platelet-derived endothelial cell growth factor-positive interstitial cells. A significant correlation was found between active Helicobacter pylori infection and a larger number of platelet-derived endothelial cell growth factor-positive interstitial cells in areas of intestinal metaplasia (p<0.05). CONCLUSION: Helicobacter pylori infection does not influence the expression of platelet-derived endothelial cell growth factor, once gastric cancer has developed. However, Helicobacter pylori infection may increase the extension of expression of platelet-derived endothelial cell growth factor by infiltrating interstitial cells in premalignant lesions, such as intestinal metaplasia, which may help create a favourable environment for tumour development. This may possibly be due to non-specific increase in recruitment of inflammatory cells caused by Helicobacter pylori infection. Further studies, with a larger number of samples, are now needed in order to confirm this finding.

Adenocarcinoma↗
PubMed2002

Symposium: Helicobacter pylori and clinical risks--focus on gastro-oesophageal reflux disease.

Helicobacter pylori is a gastric pathogen that is a major cause of peptic ulcer disease, has a role in mucosa-associated lymphoid tissue (MALT) lymphoma and is associated with gastric cancer. Yet, in a large proportion of the human population, H. pylori infection has no apparent adverse clinical consequences. Furthermore, recent research suggests that H. pylori may even confer protection against gastroesophageal reflux disease. The conflicting evidence surrounding H. pylori infection was discussed at a sponsored symposium in Helsinki, introduced by Professor P. Malfertheiner, with papers presented by Dr H. J. O'Connor, Professor R. M. Genta, Dr P. Unge and Professor A. T. R. Axon. Emerging epidemiological and retrospective evidence suggests that the presence of H. pylori infection may provide some protection against gastroesophageal reflux disease, but there is other evidence that shows no benefit of H. pylori for the protection of the oesophagus. It was felt that prospective, multicentre studies are needed to explore the H. pylori-gastroesophageal disease relationship further, to avoid confusing potential benefits with known risks. Following the symposium, a discussion on the relative risks and benefits for H. pylori eradication was provided by Professor Axon and Professor Blaser. Eradication of H. pylori has been recommended in a series of management guidelines issued by consensus groups. However, accurate estimates of the relative risks and benefits of H. pylori infection in the general population, as well as in specific patient groups, is essential in order to develop a management strategy.

Anti-Ulcer Agents↗
PubMed2002

Review article: after gastritis--an imaginary journey into a Helicobacter-free world.

This article explores the consequences of the world-wide trend that may result--at different times for different populations--in the disappearance of Helicobacter pylori and gastritis. After a brief historical introduction, some of the factors that contribute to the decrease in the prevalence of H. pylori are presented. The most apparent results of this trend in the industrialized world have been a decrease in the incidence of peptic ulcer and distal gastric adenocarcinoma. However, some other conditions of the upper digestive tract, such as acid reflux disease and adenocarcinoma of the cardio-oesophageal junction have been increasing. This simultaneous increase has led to the speculation that it may be causally related to the decreased prevalence of gastritis, and currents of thought supporting a laissez faire attitude with regards to H. pylori infection have developed. If these trends continue, future research aimed at understanding the pathogenesis of H. pylori-related conditions, including gastric carcinogenesis, will hinge on access to populations in which H. pylori is still highly prevalent, and on further refinement of the recently introduced Mongolian gerbil model.

Animals↗
PubMed2002

Gastric mucosal atrophy: interobserver consistency using new criteria for classification and grading.

BACKGROUND AND AIMS: Considerable difficulties persist amongst pathologists in agreeing on the presence and severity of gastric atrophy. An international group of pathologists pursued the following aims: (i) to generate an acceptable definition and a simple reproducible classification of gastric atrophy; and (ii) to develop guidelines for the recognition of atrophy useful for increasing agreement among observers. METHODS: After redefining atrophy as the 'loss of appropriate glands' and examining histological samples from different gastric compartments, three categories were identified: (i) negative; (ii) indefinite; (iii) atrophy, with and without intestinalization. Atrophy was graded on a three-level scale. Interobserver reproducibility of the classification was tested by kappa statistics (general and weighted) in a series of 48 cases. RESULTS: The medians of the general agreement and weighted kappa values were 0.78 and 0.73, respectively. The weighted kappa coefficients, obtained by cross-tabulating the evaluation of each pathologist against all others, were, with only one exception, > 0.4 (moderate to excellent agreement). CONCLUSIONS: By using the definition of atrophy as the loss of appropriate glands and distinguishing the two main morphological entities of metaplastic and non-metaplastic types, a high level of agreement was achieved by a group of gastrointestinal pathologists trained in different cultural contexts.

Atrophy↗
PubMed2002

Role of alpha-1-antichymotrypsin deficiency in promoting cirrhosis in two siblings with heterozygous alpha-1-antitrypsin deficiency phenotype SZ.

BACKGROUND: Alpha-1-antitrypsin (A1AT) deficiency is the most common inherited metabolic disorder with the potential to cause injury in the lung and liver. Recent reports suggested that alpha-1-antichymotrypsin (A1AC) deficiency may also be a possible cause of chronic liver disease. However, it has received little attention and is rarely investigated in the clinical setting. AIMS: To assess the role of A1AC deficiency in the pathogenesis of chronic liver disease in two siblings with heterozygous A1AT phenotype Pi SZ. PATIENTS: Two adult siblings with an A1AT Pi SZ phenotype and reduced levels of A1AC consistent with heterozygosity who developed cirrhosis and underwent liver transplantation. METHODS AND RESULTS: A1AT and A1AC levels in plasma measured by electroimmunoassay were 74 mg/dl and 90 mg/dl (140-470) and 0.12 mg/ml and 0.14 mg/ml (0.173-0.46), respectively. Immunohistochemistry revealed an apparent accumulation of both A1AT and A1AC in hepatocytes. A previously reported point mutation in exon III (Pro(229) to Ala substitution) of the A1AC gene was not detected by polymerase chain reaction amplification and a single strand conformation polymorphism analysis. CONCLUSIONS: Our report represents the first case of two siblings with A1CA phenotype Pi SZ who developed cirrhosis and underwent liver transplantation. Both siblings were heterozygous for A1AT and A1AC deficiency suggesting that combined deficiency of these two major serine protease inhibitors may enhance the risk of developing liver disease.

Adult↗
PubMed2001

Review article: pre-neoplastic states of the gastric mucosa--a practical approach for the perplexed clinician.

The sequence leading to gastric cancer can be schematically reduced to Helicobacter pylori infection-chronic gastritis-atrophy-intestinal metaplasia-dysplasia-neoplasia. Although clinicians have not yet developed a uniform approach to the treatment of gastritis (when should H. pylori infection be treated?), the entity itself is not the subject of controversy. All other lesions are still the focus of debate. There are no guidelines for the management of patients with intestinal metaplasia; pathologists are still searching for universal diagnostic criteria for atrophic gastritis; dysplasia and early neoplasia have elicited scientific diatribes between Japanese and Western pathologists. Amidst such controversies and in the absence of guidelines to regulate the management of gastric lesions, the responsibility to provide sensible clinical advice is often bestowed upon pathologists. This review discusses whether pathologists have access to sufficient evidence to provide the requested advice, and whether a consensus on the management of gastric "pre-neoplastic" states is within reach. We conclude that, although many sensible and useful definitions, criteria and classifications are being generated, the final decision on how to manage the individual patient with gastric lesions will continue to be based on the communication between pathologist and clinician.

Adenocarcinoma↗
PubMed2001

Morphometric assessment of gastric antral atrophy: comparison with visual evaluation.

AIMS: As part of a multinational effort to reach a consensus in the definition and evaluation of atrophic gastritis, we applied morphometric techniques to 22 antral biopsy specimens examined visually by 12 experienced gastrointestinal pathologists. METHODS AND RESULTS: Atrophy was defined as loss of glands. Each pathologist graded atrophy with both non-standardized and standardized approaches. Discriminant function analyses of morphometric measurements were conducted to validate and grade atrophy. Kappa statistics were used to compare the performance of each pathologist against the group mode and against the discriminant functions' grading of atrophy. Three morphometric indexes showed significant differences among categories of atrophy utilizing non-standardized as well as standardized visual atrophy grades: (i) the ratio of glandular length to total mucosal thickness; (ii) the proportion of the secretory compartment area occupied by glands; and (iii) the number of glandular cross sections per 40x microscopic field. The discriminant function analyses verified all cases classified visually as either non-atrophic, or moderately/severely atrophic; it verified as mildly atrophic 40% of the cases classified visually as mildly atrophic; and classified the remaining 60% as moderately or severely atrophic. The kappa statistics were good or excellent for the majority of pathologists. CONCLUSIONS: The evaluation of antral atrophy, simply defined as loss of glands, can be reliable and reproducible. The visual grading of atrophy as absent, moderate and severe is entirely consistent with objective morphometric observations.

Atrophy↗
PubMed2001

Role of N-methyl-N-nitrosourea in the induction of intestinal metaplasia and gastric adenocarcinoma in Mongolian gerbils infected with Helicobacter pylori.

BACKGROUND: Progression from intestinal metaplasia to neoplasia has not been demonstrated experimentally. The hypothesis that gastric adenocarcinoma arises from intestinal metaplasia was tested in a Mongolian gerbil model of Helicobacter pylori (H. pylori) infection. METHODS: One hundred and fourteen specific pathogen-free gerbils were divided in five groups. A and D: infected with H. pylori and administered the carcinogen N-methyl-N-nitrosourea (MNU); C and E: received MNU; B: H. pylori, but no MNU. Animals were killed at 41 weeks, stomachs were mapped, and the relationship between metaplasia and cancer was assessed. RESULTS: Intestinal metaplasia occurred more frequently in the H. pylori-infected, MNU-treated gerbils than in those receiving H. pylori inoculation only (P < 0.01). Carcinomas arose only in H. pylori-infected animals receiving MNU (8 well differentiated, 2 poorly differentiated, and 10 signet ring). Intestinal metaplasia occurred more frequently in association with intestinal-type carcinoma. CONCLUSIONS: Intestinal metaplasia and adenocarcinoma arise in stomachs subjected to the same injuries (in this study, H. pylori and MNU). Only two intestinal-type carcinomas were contiguous to intestinal metaplasia; all other tumors developed most commonly at non-metaplastic sites. This suggests that in this animal model H. pylori and MNU induce several phenotypes of gastric cancer, but intestinal metaplasia may be a direct precursor only in a subset of the intestinal-type tumors.

Adenocarcinoma↗
PubMed2001

One more dysplasia.

Gastric epithelial dysplasia is the earliest visible stage of neoplasia. Most histopathologists can recognize or at least suspect it, and a set of established clinical responses follow its detection. In contrast, proliferations and dysplastic changes of gastric endocrine cells are difficult to identify and generally neglected. Such changes are known to predispose to the development of carcinoid tumours and usually arise in patients with corpus-predominant atrophic gastritis and elevated gastrin levels. A report in this issue suggests that patients with dysplasia of the enterochromaffin-like cells have a much greater risk of developing carcinoid tumours than previously suspected. These carcinoids (known as type I) tend to have an indolent course, are almost never functional and have a favourable prognosis; nevertheless, they need to be detected and excised endoscopically. Because of the small numbers of patients in this series and the relatively short follow-up time of the study, it would be premature to issue guidelines on the long-term management of patients with atrophic gastritis and hypergastrinaemia. However, it is incumbent on clinical researchers with access to well-defined cohorts, such as the one studied here, to continue the follow-up studies that will lead to a more precise definition of risk and to the development of usable evidence-based clinical strategies.

Enterochromaffin-like Cells↗
PubMed2001

The phenotype of gastric mucosa coexisting with Barrett's oesophagus.

BACKGROUND/AIMS: Barrett's oesophagus complicates the gastro-oesophageal acid reflux. Helicobacter pylori infection, particularly with cagA positive strains, induces inflammatory/atrophic lesions of the gastric mucosa, which may impair acid output. No systematic study has investigated the phenotype of the gastric mucosa coexisting with Barrett's oesophagus. This study was designed to identify the phenotype of gastric mucosa associated with Barrett's oesophagus. METHODS: In this retrospective case control study, the phenotype of the gastric mucosa was histologically characterised in 53 consecutive patients with Barrett's oesophagus and in 53 (sex and age matched) non-ulcer dyspeptic controls. Both patients and controls underwent extensive sampling of the gastric mucosa (two antral, one incisural, and two oxyntic biopsies). Intestinal metaplasia (IM) was categorised (type I, complete IM; types II and III, incomplete IM) by the high iron diamine stain; cagA status was ascertained by genotyping. RESULTS: Helicobacter pylori was present in 19 of the 53 patients with Barrett's oesophagus and in 30 of the 53 controls (p < 0.02); eight of the 19 patients with Barrett's oesophagus and 28 of the 35 controls harboured cagA positive H pylori (p < 0.03). The histological severity of non-atrophic gastritis detected in the controls was significantly higher than that detected in the patients with Barrett's oesophagus (p < 0.0001). Multifocal atrophic gastritis was present in 4% of the patients with Barrett's oesophagus and in 23% of controls (p < 0.01). The odds ratio for the association between multifocal atrophic gastritis and Barrett's oesophagus was 0.20 (95% confidence interval, 0.006 to 0.60). Gastric IM was detected in 13.2% of the patients with Barrett's oesophagus and in 30.1% of the controls (p < 0.03). Type III IM at the gastric mucosa was only detected among controls. CONCLUSIONS: Barrett's oesophagus is associated with a low prevalence of H pylori cagA positive infection and multifocal atrophic gastritis. This pathobiological pattern is considered to be associated with a low risk of distal gastric cancer.

Adult↗
PubMed2000

Thrombocytopenic purpura associated with brucellosis: report of 2 cases and literature review.

Mild hematologic abnormalities are common in the course of human brucellosis; however, they generally resolve promptly with treatment of the disease. Occasionally, thrombocytopenia is severe and can be associated with bleeding into the skin (purpura) and from mucosal sites. We describe 2 patients infected with Brucella melitensis who presented with thrombocytopenic purpura, and we review 41 additional cases from the literature. Patients ranged in age from 2 to 77 years, and both sexes were affected equally. In the majority of cases, examination of the bone marrow revealed abundant megakaryocytes. Possible mechanisms involved in thrombocytopenia include hypersplenism, reactive hemophagocytosis, and immune destruction of platelets. Recognition of this complication is essential, since hemorrhage into the central nervous system is associated with a high mortality rate.

Adolescent↗
PubMed2000

Role of Helicobacter pylori gastritis in gastric atrophy, intestinal metaplasia, and gastric neoplasia.

Helicobacter pylori is the major cause of chronic gastritis worldwide. With an estimated rate of infection of over one half of the world's population, it is responsible for extensive morbidity and mortality. Infection with this organism does not appear to spontaneously resolve. Instead it reaches a chronic stage from which a number of outcomes are possible. This article reviews those outcomes that have been linked to H. pylori and explores the pathogenesis while attempting to resolve the discrepant paths infection can take. The associations include duodenal and gastric ulcers and the majority of gastric lymphomas of B-cell type derived from the mucosa-associated lymphoid tissue (MALT). Chronic gastritis has also been shown to evolve into atrophy with intestinal metaplasia in certain populations. This change in the gastric epithelium has been linked with an increased risk of gastric adenocarcinoma. Microsc. Res. Tech. 48:313-320, 2000. Published 2000 Wiley-Liss, Inc.

Atrophy↗
PubMed2000

Dysplasia east and west.

Between 1996 and 1998, several small international studies were conducted in which pathologists in group settings were asked to identify various cancers from previously prepared slides. It was hoped that these sessions would lead to international consensus with regard to terminology and help to explain the previously noted differences in diagnoses reported between Western and Japanese practitioners. This article reviews the findings of the various groups and their implications for practicing gastroenterologists.

Europe↗