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Biomedical subjects

A Ponzetto

Publications and source records attributed to A Ponzetto.

At least 37 records · Page 2Linked to original sources
PubMed2001

Seroprevalence of Helicobacter pylori infection among blood donors in Torino, Italy.

BACKGROUND: Helicobacter pylori (H. pylori) infection is one of the most common infections world-wide. A cohort effect model has been proposed to clarify the differences in the prevalence among the different age-class with a rate of infection higher in old individuals than in younger ones. The source of bacterial acquisition as well as the mode of transmission (oral-oral or fecal-oral) are still unknown and studies have confirmed the role of socio-economic factors and characteristics of childhood living conditions for the acquisition of H. pylori. In this study we analysed the age and gender-specific prevalence of H. pylori infection in a population of apparently healthy subjects, i.e. blood donors attending the blood bank of our hospital. METHODS: From April 1995 to July 1995, 619 consecutive volunteer blood donors (523 males, 96 females, mean age 47+/-5.3 years, range 18-65 years), attending the Molinette Hospital's Blood Bank (Torino), were recruited. H. pylori seroprevalence was assessed by presence of antibodies (IgG) against the bacterium in serum, by means of a commercial enzyme linked immunosorbent assay (ELISA, Helori-test Eurospital). RESULTS: The overall H. pylori seroprevalence in the population was 47%: 265/523 males (51%) were seropositive versus 26/96 females (27%) (p<0.0001, OR 2.77 [confidence interval 95% 1.674.61]). When subdivided into sex and decade of age-groups the difference was significative in three subgroups: among male subjects between 20-29 years, male subjects between 40-49 years and male subjects between 50-59 years. The seroprevalence was also significatively higher in older than younger both in males than females. CONCLUSIONS: This study confirms the cohort effect and for a future survey an equilibrated number of persons belonging to the different groups will be planned.

Journal Article↗
PubMed2001

Diagnosis of Helicobacter pylori infection: validation of a commercial non invasive salivary test against urea breath test and serology.

BACKGROUND: Helicobacter pylori (H. pylori) infection plays an important role in the pathogenesis of chronic gastritis, peptic ulcer disease, MALT lymphoma and gastric cancer. Recently Helicobacter spp. infection has been correlated with cirrhosis, hepatocellular carcinoma and acute myocardial infarction. Several invasive and non-invasive tests have been proposed for the detection of the bacterium. In clinical practice, the selection of the appropriate test will depend on the disease and on cost-effectiveness. Aim of the study was to validate a rapid, salivary test for detecting the presence of antibodies against H. pylori in a population of patients undergoing to the 13C-urea breath test (13C-UBT). METHODS: Saliva and serum samples were obtained from 91 patients (47 females, mean age 53+/-6.7 years) attending the 13C-UBT service between 15 September and 31 November 1999. Thirty-five of them had had a previous diagnosis of peptic ulcer at endoscopy and 46 out of 91 had a diagnosis of histologically confirmed chronic gastritis. 39 out of 91 were dyspeptic patients with no symptoms suspect for peptic ulcer or cancer. Patients were excluded from the 13C-UBT if they had been treated with inhibitors of acid secretion and antibiotics within 30 days before testing. Breath sample were collected at baseline and 30 minutes after the ingestion of orange juice and a 75 mg dose of 13C-labeled urea. The presence in serum of antibodies (IgG) against the bacterium was assessed by means of a commercial enzyme immunosorbent assay with a reported sensitivity of 94% and specificity of 87%. Saliva was collected using a sterile absorbent pad placed between the mandibular gum and the cheek in the mouth and assayed for H. pylori antibodies by an immunochromatographic rapid method. RESULTS: Thirty-seven of the 91 patients were defined positive by 13C-UBT and serological test. Twenty-nine of these 37 were identified as positive by the salivary test. Fifty-four patients were defined as negative but the salivary test identified 13 of them as positive, thereby sensitivity and specificity were 78.3 and 75.9% respectively. The accuracy was 76.9%. Positive predictive value was 69% and negative predictive value 83.6%. CONCLUSIONS: The salivary test could be considered in the ambulatory setting, as a non-invasive tool for the screening of H. pylori infection, when more accurate methods are not available.

Journal Article↗
PubMed2000

Helicobacter pylori seroprevalence in cirrhotic patients with hepatitis B virus infection.

Liver cirrhosis is a significant cause of death in Italy and one of the most frequent causes of hospitalization. The burden of cirrhotic patients on the National Health System is extremely high due to the frequent need for medical care. Acute peptic ulcer and upper gastrointestinal bleeding reportedly occur in over one-third of cirrhotic patients. Since Helicobacter pylori (H. pylori) infection strongly correlates with peptic ulcer, we wished to ascertain the prevalence of H. pylori infection in cirrhotic patients. In a case-control study we looked for this infection in 45 consecutive male patients suffering from hepatitis B virus (HBV)-related cirrhosis and 310 sex and age matched blood donors resident in the same area. Antibodies against H. pylori were present in 40/45 (89%) patients and 183/310 (59%) blood donors (P<0.001). This very high prevalence of H. pylori may explain the frequent occurrence of gastroduodenal ulcer in cirrhotic patients. (See Editorial p. 203)

Adult↗
PubMed2000

Helicobacter pylori seroprevalence in hepatitis C virus positive patients with cirrhosis.

BACKGROUND/AIMS: Liver cirrhosis is a significant cause of death in Italy and one of the most frequent causes of hospitalization. Acute peptic ulcer and upper gastrointestinal bleeding reportedly occur in over one-third of cirrhotic patients. Since Helicobacter pylori (H. pylori) infection strongly correlates with peptic ulcer, we sought to ascertain the prevalence of H. pylori infection in cirrhotic patients. METHODS: In a case-control study, we examined 254 consecutive patients (127 male and 127 female, age range 30-82 years) suffering from hepatitis C virus (HCV)-related cirrhosis and 463 sex- and age-matched patients admitted to the Department of Emergency Care of our hospital (254 male, 209 female, age range 30-79 years) resident in the same area. RESULTS: Antibodies to H. pylori were present in 226/254 (89%) cirrhotic patients and in 275/463 (59%) controls (p<0.0001). The difference was significant both in males and in females. CONCLUSIONS: The very high prevalence of H. pylori infection may explain the frequent occurrence of gastroduodenal ulcer in cirrhotic patients and may possibly determine the prognosis of those who are also infected with HCV.

Adult↗
PubMed2000

Helicobacter infection and cirrhosis in hepatitis C virus carriage: is it an innocent bystander or a troublemaker?

Since it has been shown that Helicobacter hepaticus causes both chronic hepatitis and hepatocellular carcinoma (HCC) in mice, it is suggested that differences in the progression of chronic hepatitis C may be due to a cofactor stemming from co-infection by bacteria, especially Helicobacter pylori, and/or other Helicobacter species. An assessment was made of the prevalence of H. pylori infection in HCV-positive cirrhotic patients. The presence of Helicobacter species (spp). was evaluated in resected liver tissue from HCC patients. Serum anti-H. pylori IgG antibodies were determined in 70 males with a clinical and/or histological diagnosis of cirrhosis and HCV infection and in 310 age-matched male blood donors. The prevalences of H. pylori antibody were 77% (54/70) and 59% (183/310) (P 0.004). Primers identifying 26 Helicobacter species were used to determine the presence of the genomic 16S rRNA of this genus in liver tissue resected from 25 cirrhotic HCC patients. Genomic sequences corresponding to H. pylori and H. pullorum were identified in 23 of these 25 livers. Together, these findings support the proposal that H. pylori is implicated in the pathogenesis and progression of cirrhosis, particularly in HCV-infected individuals. Involvement of Helicobacter spp. in HCC also seems highly possible.

Animals↗
PubMed2000

Helicobacter pylori and stomach cancer: a case-control study in Venezuela.

The role of Helicobacter pylori infection in gastric cancer was evaluated in a high-risk population in Venezuela using serological assays in a study of 302 cases and 483 neighborhood controls. To investigate the claim that assays for H. pylori should use antigens derived from local strains, four different assays derived from Venezuelan and European strains were used. Prevalence of IgG H. pylori antibodies in controls was very high, with estimates between 72 and 92%. Prevalence was similar in cases and controls. However, cases had lower antibody titers. This effect was observed only in subjects with low pepsinogen (PG) levels PGI/PGII <3.0), which suggested that extensive atrophy in cases causes a loss of H. pylori infection, with a consequent reduction in antibody titer. In addition, advanced cases (stage II or higher) had lower antibody titers than less advanced cases, which indicated that the lower antibody titers in cases may be attributable partially to a diminished immune response. All of the four assays for anti-H. pylori antibodies gave similar results. No evidence was found for the superiority of the assay based on Venezuelan strains. These results are consistent with other case-control studies in high-risk populations and highlight the difficulties of investigating H. pylori infection in retrospective studies.

Adult↗
PubMed2000

Previous tuberculosis, hepatitis C virus and lichen planus. A report of 10 cases, a causal or casual link?

We report 10 cases of lichen planus (LP) and chronic liver disease linked to HCV. The mean age was 63.4 +/- 5.1 years (range 51-73), five were female; six patients had an established cirrhosis of the liver, as shown by either a liver biopsy or the ultrasonographic and biohumoral evidence. The remaining four patients had chronic hepatitis. Histological examination confirmed the presence of LP: the localization of the dermatosis was restricted to the skin in four patients, to the mucous membranes in five (4 atrophic erosive and one erosive) while the remaining had mucous-cutaneous localization. A type II cryoglobulinemia was demonstrated in two and a type III in one of the patients, while no one had otherwise circulating autoantibodies (anti-nuclear, anti-smooth muscle, anti-liver kidney microsomal type 1 and anti-mitochondrial antigens) such as other etiological factors of liver disease. In six of the patients the history was positive for previous Mycobacterium tuberculosis infection. In clinical practice the patients with chronic liver disease and HCV infection can also suffer from severe extrahepatic manifestations, including lichen planus.

Aged↗
PubMed2000

Ischemic cardiovascular disease and Helicobacter pylori. Where is the link?

Coronary heart disease (CHD) is the leading cause of death in western countries. Although several major risk factors have been identified, they fail to account for all the epidemiological variants of the disease, thus warranting research into novel causal agents. Cardiovascular diseases have long been associated with chronic infections acting through the activation of inflammatory pathways, and antibiotic therapy has been shown to produce a dramatic decrease in the rate of disease recurrence in patients with a history of myocardial infarction or unstable angina. The link between Helicobacter pylori (H. pylori) infection and CHD, first described by Mendall et al. in 1994, has been the subject of a multitude of epidemiological and clinical studies; however, these have been so heterogeneous that not two of them are based on a comparable selection of patients and focused on the same kind of disease, e.g. stable coronary heart disease or acute myocardial infarction. Evidence from animal studies supports the thesis that H. pylori plays an extremely important role in the acute phase of myocardial infarction: the bacterium causes platelet aggregation and induces pro-coagulant activity in experimentally infected mice. H. pylori may also contribute to atherosclerosis through an auto-immune process against endothelial cells or an increased concentration of homocysteine in the blood due to decreased levels of folic acid and cobalamin. The exact role of H. pylori cannot yet be fully assessed: there is a clear and present need for further studies with appropriate epidemiological and clinical approaches to investigate through prospective and interventional trial the possible causal relationship between H. pylori and CHD.

Animals↗
PubMed2000

[Ischemic cardiovascular diseases. Correlation with Helicobacter pylori infection].

Coronary heart disease is the primary cause of mortality in western countries. The well-established ("classical") risk factors cannot fully explain epidemiological variations of this disease. From several years infections have been linked to ischemic vascular events and recent studies pointed to the role of Helicobacter pylori (H. pylori), a spiral Gram negative bacterium, that chronically infects human stomach and is involved in the pathogenesis of gastritis and peptic ulceration. Systematic reviews of studies have suggested the existence of a possible weakly positive association between this bacterium and coronary heart disease, but this could be due to confounding bias and influenced by the degree of investigations heterogeneity. Experiments from animal studies demonstrated that H. pylori infection in mice induces the formation of platelet aggregates and in contrast to Chlamydia pneumoniae it has not been found in the plaque: therefore, the role of H. pylori, could be even more important in the acute phase of myocardial infarction. There is the need for extensive prospective studies to evaluate the incidence of these diseases in relation to the presence of H. pylori infection. Appropriately randomized studies employing an antibiotic treatment for patients affected by ischemic vascular disease will answer the question of whether H. pylori has a causal role in the pathogenesis of acute myocardial infarction and ischemic stroke.

Coronary Disease↗
PubMed1999

Acute myocardial infarction and Helicobacter pylori seropositivity.

Infectious agents including Helicobacter pylori, have been linked to coronary heart diseases on epidemiological and pathogenetic grounds. Classical risk factors fail to explain all the epidemiological variations of the disease. Our aim was to investigate the association of acute myocardial infarction with Helicobacter pylori infection in a case-control study by comparing a group of male patients with a control group of blood donors matched for sex and age. We investigated the classical cardiovascular risk factors in all patients. We studied 44 consecutive male patients, aged 40-65 years, admitted for acute myocardial infarction to the Coronary Care Unit at Novi Ligure Hospital in northern Italy. Helicobacter pylori infection was assessed by measurement of antibodies (IgG) against Helicobacter pylori in blood. Volunteer blood donors attending Molinette Hospital Blood Bank in Turin, northern Italy served as controls. Among the patients we investigated the presence of hypertension, cholesterol and glucose levels in serum, fibrinogen in plasma, smoking habits, and social class. Helicobacter pylori infection was present in 34 of 44 (77%) patients and in 183 of 310 (59%) controls (P<0.05); the odds ratio was 2.36 (95% confidence interval 1.08-5.31). Classical cardiovascular risk factors did not differ among patients with and without Helicobacter pylori infection. In conclusion, patients with acute myocardial infarction had a significantly higher prevalence of Helicobacter pylori infection than the control population. The classical risk factors for cardiovascular diseases were equally distributed among patients irrespective of their Helicobacter pylori status.

Adult↗
PubMed1999

Mixed cryoglobulinaemia associated with hepatitis C virus infection: a predictor factor for treatment with interferon?

BACKGROUND AND AIMS: Mixed cryoglobulinaemia (MC) is a frequent finding among patients infected with hepatitis C virus (HCV). The response to treatment with alpha-interferon (alpha-IFN) in these patients is linked to predictive factors. The aim of this study was to ascertain whether the presence of MC was a predictive factor of response in patients treated with alpha-IFN for chronic hepatitis due to HCV. METHODS: Thirty-two patients with MC and HCV infection (24 with chronic hepatitis and eight with cirrhosis) were compared with 30 patients with HCV infection without MC (23 chronic hepatitis, seven cirrhosis) of a similar mean age. All were treated with lymphoblastoid alpha-IFN, at 3 MU, t.i.w., for 6-12 months and then followed up. RESULTS: No statistical difference was observed between the two groups in terms of sustained response (P = 0.83), relapse (P = 0.88) and non-response (P = 0.92). The mean follow up was 24.3 months (range 17-28) for patients with sustained response and for the patients with MC and 22.6 months (range 15-26) for patients without MC. CONCLUSIONS: The presence of cryoglobulinaemia does not influence the response to alpha-IFN in patients with chronic HCV infection.

Adult↗
PubMed1999

Helicobacter pylori: from the stomach to the heart.

A surprising number of extra-gastrointestinal diseases have been reported to be associated with Helicobacter pylori infection, including coronary heart disease and stroke. Since coronary heart disease is the principal cause of death in western countries, and since the known risk factors cannot fully explain the pathogenic mechanisms of the disease, the exploration of the role of possible causal agents has stimulated intense research. Infectious agents have been linked to coronary heart disease on epidemiological and pathogenic grounds. In 1994, H. pylori infection was reported to be one of them. Since then, a number of studies have been published with controversial results. Studies performed thus far show a high degree of heterogeneity in the selection of patients and also in the type of disease studied, i.e. coronary heart disease in general or acute myocardial infarction. Since the pathogenic development is most likely different for each of these two conditions (one chronic and the other acute) they should be studied separately. H. pylori infection can cause platelet aggregation and induces a procoagulant activity. H. pylori can also contribute to atherosclerosis, through increased concentration of homocysteine in the blood, caused by decreased levels of folic acid and cobalamin, or to an autoimmune process. Prospective cohort studies and interventional trials focusing separately on the chronic and acute phases of coronary heart disease and H. pylori infection should be performed in order to provide firm epidemiological data for a causal relationship.

Animals↗
PubMed1999

Patients with acute myocardial infarction in northern Italy are often infected by Helicobacter pylori.

BACKGROUND: The classical risk factors for acute myocardial infarction (AMI) fail to explain all the epidemiological variations of the disease. Among the new risk factors recently reported, several infectious agents appear to increase the risk of AMI. In particular, acute and chronic respiratory diseases due to Chlamydia pneumoniae, and Helicobacter pylori (H. pylori) infection seem to be strongly involved. The aim of this work is to determine the prevalence of H. pylori infection in a group of male patients with AMI, in a case-control study, where a group of blood donors matched for sex and age served as control. We searched for the classical risk factors in all patients. METHODS: We studied 212 consecutive male patients, aged 40-65 years, admitted for AMI at the Coronary Care Units at Hospitals in three towns of Northern Italy. H. pylori infection was assessed by the highly specific and sensitive 13C-urea breath test and by presence of antibodies (IgG) against H. pylori in circulation. Volunteer blood donors attending our Hospital Blood Bank served as controls. Among the patients we investigated the presence of hypertension, cholesterol and glucose levels in serum, fibrinogen in plasma and the smoking habit. RESULTS: H. pylori infection was present in 187/212 (88%) of the patients and in 183/310 (59%) of the control population (p < 0.0001). Classical risk factors for AMI did not differ among patients with and without H. pylori infection. CONCLUSION: Patients admitted to the Coronary Care Unit for acute myocardial infarction had a notably higher prevalence of H. pylori infection than the general population. The classical risk factors for coronary disease were equally present in all patients with AMI irrespective of H. pylori status.

Adult↗
PubMed1999

Management of duodenal ulcer disease in the era of H. pylori.

BACKGROUND: Today it is expected that the great majority of patients with duodenal ulcer (DU) respond to H. pylori eradication treatment without DU recurrence. The aim of the research is to identify patients who need a different therapeutic approach and the best management of their disease. METHODS: We examined retrospectively the medical history of 474 patients (326 males, mean age 61 years), followed up in 5 years in the outpatients department of a third level GI Center. From our research, 5 subgroups of patients emerged: 1) 63.5% carrying H. pylori infection, with successful eradication treatment and without DU recurrence; 2) 4% failing 3 courses of H.pylori eradication treatment; 3) 11% with DU lacking evidence of H. pylori infection or relapsing after verified eradication; 4) 8% being treated with NSAIDs; 5) 13% with DU complicated by hemorrhage or perforation. RESULTS: 23% of patients with DU need long-term therapy after H. pylori eradication treatment. Concerning this, the percentage of ulcerous recurrences in patients receiving anti-H2 therapy is 18.5%, but decreases considerably to 2% when PPI were used. CONCLUSIONS: Although representing the mainstay of DU therapy, H. pylori eradication treatment may not abolish all issue in DU management. Actually, of DU patients referred to a third level GI Center, 23% need a different therapeutic approach, which results from a thorough analysis of the medical history of the patient.

Journal Article↗
PubMed1997

Molecular characterization and dynamics of hepatitis C virus replication in human fetal hepatocytes infected in vitro.

The molecular features of hepatitis C virus (HCV) replication in human fetal hepatocytes (HFHs) were addressed in this study. Using a competitive reverse-transcription polymerase chain reaction (RT-PCR) assay for the quantitation of HCV-RNA molecules, the highest level of viral replication was detected 30 days' postinfection. At this time point, viral particles of 41 to 45 nm in diameter accumulated in the cell cytoplasm. Their density in cell extracts and culture medium was distributed between heavy (1.180-1.360 g/cm3) and light fractions (1.105-1.050 g/cm3) of a sucrose gradient, while, in the serum inoculum, they had a positive fraction at 1.180 g/cm3. In infected HFHs, minus-strand HCV RNA was observed in fractions displaying a sedimentation coefficient of 28 S to 18 S, while plus-strand HCV RNA showed a peak restricted to the 21 S fraction; the HCV RNA of serum inoculum had a sedimentation coefficient of 38 to 40 S, which revealed the presence of HCV RNA of unique positive polarity. The 21 S RNA fraction of cell extracts was resistant to 20 minutes of RNase I digestion, while the same incubation time totally inactivated a comparable amount of HCV RNA purified from the serum inoculum, revealing the presence of completely and/or partially double-stranded HCV-RNA molecules in the infected cells. Detection in HFHs of replicative forms and replicative intermediates suggests that the dynamic profile of HCV replication in these cells is similar to that described in other flaviviruses.

Biomarkers↗
PubMed1997

Extended lymph node dissection for gastric cancer: results of a prospective, multi-centre analysis of morbidity and mortality in 118 consecutive cases.

This study reports interim data on post-operative morbidity, hospital mortality and duration of hospital stay of Italian patients undergoing extended lymph-node dissection combined with a pancreas-preserving technique for gastric cancer. Of the 218 patients admitted to one of eight general and/or university hospitals in North Italy, 118 were enrolled in the trial. Eligible patients presented with proven primary adenocarcinoma of the stomach without clinical evidence of distant, peritoneal and/or liver metastasis, or metastasis in para-aortic and retropancreatic nodes at intraoperative biopsy. Patients underwent the extended procedure as described by the Japanese Research Society for the Study of Gastric Cancer, following the Maruyama pancreas-preserving technique. A strict quality control system was used to ensure the performance of a standard surgical treatment. A surgeon of the reference centre (M.D.), who stayed at the National Cancer Center Hospital in Tokyo to learn the D2 technique from a specialist Japanese surgeon, became the trial supervisor and assisted each surgeon in all the Italian participating centres. The patients were staged according both to the TNM system and to the General Rules for the Gastric Cancer Study in Surgery and Pathology. Post-operative surgical complications developed in 21 patients (17.8%). The non-surgical complication rate was 2.5%. Reoperation was necessary in six patients (5%), all of whom survived. The 30-day mortality rate for the eligible group was 2.5%. The overall hospital mortality was the same. Total gastrectomy was associated with a slightly higher operative mortality (4.5% vs 1.3%). Only one patient died from an anastomotic leak. The rate of leakages was higher after total than after distal gastrectomy (15.9 vs 5.4%); the association of splenectomy and pancreatectomy worsened the morbidity rate. D2 lymphadenectomy with pancreas-preserving technique, when performed at experienced centres, seems a feasible and safe technique for the radical treatment of gastric cancer in selected Western patients.

Adenocarcinoma↗