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M Menegatti

Publications and source records attributed to M Menegatti.

At least 37 records · Page 2Linked to original sources
PubMed1999

Effect of adenosine derivatives on in vitro thrombus formation induced by shear stress.

BACKGROUND AND OBJECTIVE: Shear-stress is considered to be the first event of platelet aggregation in vivo and platelet adhesion may be enhanced under pathologic conditions (e.g. arterial occlusion). DESIGN AND METHODS: We wanted to test the effect of adenosine derivatives on platelet aggregation induced by shear-stress. By increasing platelet cAMP adenosine derivatives inhibit platelet activation. This in turn leads to P-selectin (CD62P) exposure, which is known to play a fundamental role in the binding of platelets to leukocytes. This gives rise to thrombus formation. RESULTS: The levels of cAMP (pmol/mL) prior to and after treating blood with the following compounds were respectively: PGE1 4.67+/-0.29, 9.33+/-0. 58; SP64 5.2+/-0.34, 6.83+/-0.52; 2-Cl-adenosine 5.83+/- 0.58, 7. 45+/-0.55; NECA 7.00+/-2.29, 8.00+/-1.76. INTERPRETATION AND CONCLUSIONS: High shear rate was studied using a filteraggregometer which could be a good test for analyzing what happens under physiologic conditions compared to other systems in which platelet aggregation only occurs after adding aggregating agents (Born aggregometer).

Adenosine↗
PubMed1998

Clinical significance of Helicobacter pylori seropositivity and seronegativity in asymptomatic blood donors.

To determine the clinical significance of Helicobacter pylori seropositivity and seronegativity in healthy blood donors, we carried out a serological evaluation of Helicobacter pylori status and endoscopy in a healthy blood donors population. In all, 1010 donors were screened for Helicobacter pylori by IgG ELISA and assessed for pepsinogen I and gastrin levels by RIA; 298 IgG seropositive and 61 seronegative subjects underwent endoscopy with biopsies. Of 359, 165 were also tested for CagA by western blotting. Of the 298 IgG seropositives, 274 were shown to be infected on biopsy testing. Endoscopy revealed 70 peptic ulcers, 41 cases of erosive duodenitis, and two gastric cancers. In all 105 seropositive donors were tested for CagA and 69 were CagA positive [34/58 gastritis (58.6%), 24/35 duodenal ulcer (68.6%) and 11/12 gastric ulcer (91.6%)]. Histologically active/chronic gastritis was associated with CagA: 88.4% vs 50% (CagA seropositive vs seronegative). Of the 61 IgG seronegatives, 59 were negative on biopsy testing. At endoscopy three had duodenitis. Of the 60/61 IgG seronegatives tested for CagA, one had a moderate reaction. Duodenal ulcer donors showed higher pepsinogen I levels than donors without duodenal ulcers (97.7 microg/ml vs 80.9 microg/ml respectively). Screening for Helicobacter pylori and anti-CagA seropositivity and pepsinogen I can identify individuals likely to have gastroduodenal pathology even in the absence of symptoms.

Adolescent↗
PubMed1998

Blood tests in the management of Helicobacter pylori infection. Italian Helicobacter pylori Study Group.

There are three main types of blood test available for the management of Helicobacter pylori infection: those that detect an antibody response; tests of the pathophysiological state of the stomach; and those that indicate an active infection. Enzyme linked immunosorbent assay (ELISA) based kits are the most numerous of the commercially available tests. Originally the kits used crude antigen preparations but many of the newer kits use a more purified antigen preparation giving increased specificity but a lower sensitivity. The sensitivity, specificity, and predictive values of the tests can also be affected by the population under test and coexistent disease in the patients. Near patient test kits are based on either latex agglutination or immunochromatography. Generally, they have low sensitivities compared with laboratory tests. Commercial western blotting kits have also been developed and are used to detect the presence of specific virulence markers. The exact role of serology in the management of Helicobacter infection has still to be defined, although there is evidence that, used as a screening procedure, it can reduce endoscopy cost and workload. Gastrin and pepsinogen blood concentrations may provide valuable information on the pathophysiological state of the stomach--for example, the presence of inflammation or gastric atrophy. A combination of serology and serum concentrations of gastrin and pepsinogen may be used effectively to detect serious gastroduodenal disease in patients.

Antibodies, Bacterial↗
PubMed1998

The European meeting on Helicobacter pylori: therapeutic news from Lisbon.

The current standard of Helicobacter pylori treatment has been confirmed by the studies presented at the Lisbon workshop--that is, one of three one week proton pump inhibitor (PPI) based triple therapies comprising a twice daily standard dose of a PPI in combination with two of the following antimicrobial agents: clarithromycin, amoxycillin, or a nitromidazole. This standard of treatment is also highly efficacious and cost-effective in routine community practice. The current data confirm the equivalence of ranitidine bismuth citrate to PPI, and of azithromycin to clarithromycin. The optimum dose for azithromycin has not yet been defined. There is some evidence that in certain regions treatment for more than one week may be advantageous. The reasons are still not clear. However, microbial resistance may be one important factor, as it has a substantial effect on treatment outcome and the prevalence of resistance varies considerably in different areas. The negative impact of resistance is increased by shortening the treatment time. At present, there is no general necessity to test for resistance before treatment. However, before selection of a second line treatment, testing for resistance is recommended.

Anti-Bacterial Agents↗
PubMed1998

Routes of transmission of Helicobacter pylori infection.

Helicobacter pylori is an important gastroduodenal pathogen, which has been recognized as a Class I carcinogen factor for gastric cancer and gastric mucosa associated lymphoid tissue lymphomas. In spite of the world-wide spread of the infection, the route of transmission is still not known. We reviewed data from several sero-epidemiological studies and aimed to identify potential sources of Helicobacter pylori infection. Available evidence strongly suggests an inverse correlation between socio-economic status and prevalence of Helicobacter pylori. The infection is acquired mostly during childhood in the third world, but is rare in children in developed countries, where the prevalence of Helicobacter pylori increases with age. Following the detection of the bacterium in saliva, faeces, and gastric juice, oral-oral or faecal-oral transmission and iatrogenic spread, through the use of unsterile endoscopes, have been proposed as possible routes of infection. Helicobacter pylori has also been found in some domestic cats, but at present, the risk of infection from these animals appears slight. The mode of transmission of Helicobacter pylori, as is yet, not known. Available information support the hypothesis of spread through close personal contact, considering humans as the only significant reservoir of infection.

Age Factors↗
PubMed1998

Helicobacter pylori and diminished growth in children: is it simply a marker of deprivation?

Helicobacter pylori is an accepted gastroduodenal pathogen and has recently been investigated for possible implications in non gastroenterological diseases such as growth impairment coronary heart disease and diabetes. Infection by cytotoxic, i.e., CagA or VacA positive strains seems more likely to lead to more serious gastroduodenal diseases compared to infection by non cytotoxic strains, but the possible role of CagA or VacA positive strains in non gastroenterological diseases has not been investigated. Aim of the present study was to evaluate the prevalence of Helicobacter pylori infection as well as CagA and VacA positivity in three paediatric populations auxologically normal, hyposomic and diabetic children. Sera from a total of 522 children (auxologically normal: 246, hyposomic: 164, diabetic: 112) were analyzed by a novel Recombinant ImmunoBlot Assay-Strip Immunoblot Assay--RIBA SIA--which contain individual band for whole Helicobacter pylori lysate and recombinant CagA and VacA. The overall seroprevalence of reactivities against Helicobacter pylori lysate, CagA and VacA were: 7.3%, 9.3%, 6.9% vs 11.6%, 7.9%, 8.5% vs 14.3%, 13.4%, 8% (p = NS) in auxologically normal, hyposomic and diabetic children, respectively. Summarizing, we found a similar prevalence of reactivity against both whole Helicobacter pylori lysate as well as recombinant CagA and VacA between auxologically normal, hyposomic and diabetic children. Our data do not support a possible role of Helicobacter pylori in diminished growth in children.

Adolescent↗
PubMed1997

What is the role of Helicobacter pylori in complicated ulcer disease?

The role of Helicobacter pylori in the pathogenesis of duodenal and gastric ulcer and ulcer recurrence is widely known. Bleeding, perforation, and obstruction represent the most serious, potentially life-threatening manifestations of ulcer disease (hemorrhage in 15%-20%). The lifetime prevalence of perforation and obstruction is much lower (approximately 5% and 2%, respectively). Despite improved diagnostic and therapeutic options, bleeding-related mortality rates remain at 6%-7% in the United States and between 4% and 14% in Europe. H. pylori and nonsteroidal anti-inflammatory drugs are now recognized as the two primary causes of ulcer disease. Eradication of H. pylori in patients with uncomplicated ulcers results in recurrence rates of < 10%, suggesting that eradication of H. pylori in patients with bleeding ulcers may virtually prevent recurrence of both the disease and its complications. Although the prevalence of H. pylori infection is almost 100% in duodenal and 80%-90% in gastric ulcer patients not using nonsteroidal anti-inflammatory drugs, the prevalence of the organism in bleeding duodenal and gastric ulcers does not reach 70% and 60%, respectively, which may be due to false-negative test results.

Anti-Ulcer Agents↗
PubMed1997

High prevalence of Helicobacter pylori in liver cirrhosis: relationship with clinical and endoscopic features and the risk of peptic ulcer.

In 153 consecutive patients with cirrhosis we assessed: (1) the prevalence of IgG to Helicobacter pylori and compared it with that found in 1010 blood donors resident in the same area; and (2) the relationships of IgG to Helicobacter pylori with clinical and endoscopic features and with the risk of peptic ulcer. The IgG to Helicobacter pylori prevalence of cirrhotics was significantly higher than in blood donors (76.5% vs 41.8%; P < 0.0005) and was not associated with sex, cirrhosis etiology, Child class, gammaglobulins and hypertensive gastropathy. In both groups, the prevalence of IgG to Helicobacter pylori was significantly higher in subjects over 40. Among patients with cirrhosis a significantly higher prevalence of Helicobacter pylori was found in patients with previous hospital admission (P = 0.02) and/or upper gastrointestinal endoscopy (P = 0.01) and patients with peptic ulcer (P = 0.0004). Multivariate analysis identified increasing age and male sex as risk factors for a positive Helicobacter pylori serology and no independent risk factors for peptic ulcer. The high prevalence of Helicobacter pylori-positive serology found in the present series is related to age and sex and might also be explained by previous hospital admissions and/or upper gastrointestinal endoscopy. Our results do not confirm the role of Helicobacter pylori as risk factor for peptic ulcer in patients with liver cirrhosis.

Adult↗
PubMed1997

A serologic survey of Helicobacter pylori infection in 3281 Italian patients endoscoped for upper gastrointestinal symptoms. The Italian Helicobacter Pylori Study Group.

AIM: To assess the seroprevalence of Helicobacter pylori infection in a large series of patients with upper gastrointestinal symptoms referred for their first upper gastrointestinal endoscopy, and to evaluate any association with disease. METHODS: A large survey of 3281 dyspeptic patients undergoing their first endoscopic examination was undertaken, involving 93 centres in Italy. A blood sample was taken from each participant, for measuring IgG antibodies against H. pylori using a commercially available kit, and two biopsies of the antral gastric mucosa were obtained for evaluating a Giemsa-stained specimen. RESULTS: Endoscopic macroscopic diagnoses included normal mucosa (25.3%), gustroduodenitis (51.6%), gastric and duodenal ulcers (3.7 and 14.9%, respectively) and other conditions, including gastric cancer (0.8%). Overall, the seroprevalence result was 71.3% with a strong positive association with increasing age and male sex and a negative one with educational level. According to endoscopic diagnoses, the association with H. pylori seropositivity was highest for duodenal and gastric ulcer (multivariate odds ratio: 6.1 and 2.2) and lowest for carcinoma. The comparison between the results of serology and the single Giemsa-stained specimen showed good reliability of H. pylori IgG, particularly in a subgroup (n = 2056) for which the interpretation was performed by a single dedicated pathologist: sensitivity and specificity were 92 and 78%, respectively. CONCLUSION: Commercial IgG serology is a reliable tool for the assessment of H. pylori infection in large-scale multicentre surveys. A very high seroprevalence among dyspeptic patients was confirmed, particularly in the presence of peptic disease. Factors associated with the infection were very similar to those usually reported in the general population, but male patients showed a significantly higher prevalence.

Adolescent↗
PubMed1997

Prospective screening of dyspeptic patients by Helicobacter pylori serology: a safe policy? The Italian Helicobacter pylori Study Group.

BACKGROUND AND STUDY AIMS: Endoscopic screening of all dyspeptic patients is not cost-effective, nor is it feasible in many health-care delivery systems. To select the most appropriate candidates, various preendoscopic screening strategies have been proposed, some of which include Helicobacter pylori serology and patient age. We assessed the value of these two criteria in preendoscopic screening of a large series of dyspeptic patients, and compared the results obtained in a referral hospital (university center with an extensive H. pylori research program) with those in nonreferral hospital (participating centers that did not have such a program). PATIENTS AND METHODS: Blood samples for determination of anti-H. pylori IgG antibody were collected from patients with uninvestigated dyspepsia undergoing endoscopy at one referral hospital and in 93 nonreferral hospitals throughout Italy. For IgG antibody assay, an in-house enzyme-linked immunosorbent assay (ELISA) technique was used in the referral hospital, while a commercial kit was used in the nonreferral hospitals. RESULTS: A total of 1638 patients were evaluated at the referral hospital (845 men and 793 women, mean age 46.1 years, range 18-89), and 3281 at the nonreferral hospitals (1718 men and 1563 women, mean age 48.8, range 18-96), respectively. If endoscopy had not been performed in patients who were seronegative for H. pylori and younger than 45 years, 19% versus 17.5% of the tests would have been avoided in the referral and nonreferral hospitals, respectively, while six of 304 ulcers (2%) and no cancers would have been missed versus 35 of 557 ulcers (6.3%) and two of 557 cancers (0.3%). CONCLUSIONS: A screening strategy based on age and H. pylori serology is a valid means of selecting dyspeptic patients for endoscopy; however, the policy needs further refinement for use in nonreferral hospitals.

Adolescent↗
PubMed1997

Usefulness of serology in preendoscopic screening. The Italian Helicobacter pylori Study Group.

BACKGROUND: Over the last 20 years, upper gastrointestinal endoscopy has become the investigation of choice for patients with symptoms referrable to the upper gastrointestinal tract. As the increasing number of patients referred for endoscopy has led to enlarged waiting lists and medical expenses, it has been recommended that preendoscopic screening strategies might identify patients at low risk of having major pathology. These patients could avoid prompt endoscopy and might safely undergo different management. Since the recognition of the major role played by Helicobacter pylori in gastroduodenal pathology, H. pylori serological and demographical features have been proposed as part of preendoscopic screening strategies in dyspeptic patients referred to endoscopy, in an attempt to reduce endoscopic workload and medical expenses. METHODS: We evaluate data presented in the literature and aim to give interpretations possibly helpful in the clinical practice. RESULTS: The analysis of the endoscopic findings showed that applying a preendoscopic strategy based on age and H. pylori status in local hospitals without a specific interest in H. pylori research would have meant missing a proportion of relevant pathology: 35 of 557 (6.3%) peptic ulcers (24 duodenal and 11 gastric ulcers) and two gastric cancers (0.3%). CONCLUSIONS: Although we do understand the need to increase the cost-effectiveness of endoscopy and realize that considering age and H. pylori status could help to get to this target, we conclude that similar preendoscopic screening strategies must be refined further before being adopted on a large scale.

Endoscopy, Gastrointestinal↗
PubMed1996

Serological response to Helicobacter pylori in gastric and non-gastric cancer.

1. We aimed to evaluate the seroprevalence of Helicobacter pylori (H. pylori) in gastric cancer, non-gastric cancer and outpatients by ELISA and iso-electric focusing, and to compare histology and serology for H. pylori in gastric cancer and outpatients. 2. In 124 patients with gastric cancer, 78 patients with non-gastric cancer and 110 outpatients, H. pylori seroprevalence was assessed by ELISA and isoelectric focusing. Gastric cancer and outpatients underwent endoscopy with biopsies. 3. Seroprevalence by ELISA was significantly higher in gastric cancer compared with non-gastric cancer (84% versus 56%, P < 0.001) but not with outpatients (84% versus 74%). Iso-electric focusing detection of H. pylori was comparable to ELISA: 85, 51 and 75% in gastric cancer, non-gastric cancer and outpatients respectively. Oligoclonal iso-electric focusing was significantly more frequent in gastric cancer compared with non-gastric cancer and outpatients: 69% versus 45 and 46% respectively, P < 0.01. The reliability of H. pylori detection by antral biopsy was significantly lower in gastric cancer compared with outpatients: 36% versus 74% (P < 0.001). In gastric cancer, ELISA and iso-electric focusing were significantly more reliable than histology in H. pylori detection (84 and 85% versus 36% respectively) (P < 0.001). 4. Serological immune response to H. pylori in gastric cancer, non-gastric cancer and outpatients seems different both quantitatively and qualitatively; serology was more reliable than histology in detection of H. pylori in gastric cancer.

Adult↗
PubMed1996

Prevention with sucralfate gel of NSAID-induced gastroduodenal damage in arthritic patients.

OBJECTIVES: To evaluate the efficacy of a new formulation of sucralfate as gel (Gastrogel) in the short-term prevention of gastroduodenal lesions in arthritic patients receiving nonsteroidal anti-inflammatory drugs. METHODS: One hundred seven patients with arthritis (M/F 18/89, mean age 55.2 +/- 9.7 yr) enrolled in two centers were considered eligible for the study if initial endoscopy showed the absence of any relevant mucosal damage. Patients were randomly allocated to receive diclofenac 200 mg/day or naproxen 1 g/day plus either sucralfate gel 1 g b.i.d. (N = 53) or identical placebo (N = 54) for 14 days in a randomized double-blind study. Repeated assessment of GI symptoms and endoscopy were performed at the end of the study period. RESULTS: At final endoscopy the incidence of erosion and the mean endoscopic score for both stomach and duodenum were significantly lower in the sucralfate gel group compared with placebo group (p < 0.05). Both heartburn and epigastric pain were significantly less frequent in patients receiving sucralfate gel than placebo (51 vs 30% and 49 vs 28% for heartburn and epigastric pain, respectively, p < 0.05). No differences were observed in the incidence or in the mean score for nausea. An unexplained difference in the incidence of ulcers was found between the two centers, but in both a similar reduction in the incidence of ulcers was observed between patients receiving sucralfate gel compared with those receiving placebo. The overall difference (8% in sucralfate-treated patients, 28% in patients receiving placebo) of gastroduodenal ulcers was statistically significant (p < 0.05). CONCLUSIONS: Sucralfate gel reduces both the incidence of acute gastroduodenal mucosal lesions and symptoms in patients with arthritis receiving short-term nonsteroidal anti-inflammatory drugs.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1995

Helicobacter pylori status, endoscopic findings, and serology in HIV-1-positive patients.

We have carried out a large prospective study of the frequency of H. pylori infection and HIV-1 status in a community of ex-drug abusers including subjects with (N = 210) and without (N = 259) upper gastrointestinal symptoms, endoscopy and serology. Control groups were patients with upper gastrointestinal symptoms not at high risk of HIV-1 infection (N = 219) and asymptomatic blood donors (n = 322). H. pylori was present in 52% of symptomatic community residents having endoscopy and 55% of the control patients with symptoms but not at high risk of HIV-1 infection. H. pylori was less common in HIV-1-positive patients (40%) than those who were negative (66%; P < 0.001). In patients with AIDS (33%), the frequency of H. pylori infection was reduced compared to HIV-1-positive patients without AIDS (53%; P = 0.05). All the residents with AIDS had upper gastrointestinal symptoms. In community residents, peptic ulcer was always associated with H. pylori infection. By H. pylori serology, there was no difference in the frequency of infection in asymptomatic residents (56%) whether HIV-1 positive (55%) or HIV-1 negative (58%) compared with those residents with symptoms. Overall, H. pylori was less common in HIV-1-positive residents (49%) than those who were HIV-1 negative (61%; p < 0.05). This difference was due mainly to the low frequency of infection in residents with AIDS (33%). H. pylori infection is common in HIV-1 positive patients, and only slightly reduced when compared with at-risk HIV-1-negative subjects. Peptic ulcer is associated with H. pylori in HIV-1 infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1995

The susceptibility of Helicobacter pylori to the rifamycin, rifaximin.

Forty strains of Helicobacter pylori had an MIC(50) of 4 mg/L of the non-absorbably antibiotic, rifaximin. Neither synergy nor antagonism was demonstrated when the drug was combined with ampicillin, metronidazole and omeprazole and the rate of spontaneous mutation was less than 1 in 10(8). With these in-vitro characteristics, rifaximin should now be assessed for clinical efficacy.

Ampicillin↗
PubMed1995

Helicobacter pylori in patients with gastric and nongastric cancer.

OBJECTIVES: To compare the seroprevalence of Helicobacter pylori in gastric and nongastric carcinoma patients and to investigate the relationship between H. pylori, gastric cancer site, and histological type. METHODS: In a 24-month period, 307 gastric cancer patients (male/female: 185/122; age range 19-94 yr, mean 69 yr) were investigated by serology (IgG to H. pylori), histology, and urease test for H. pylori. One hundred and seventy-seven gastric cancers were in the antrum, 98 were in the corpus, and 32 were in the fundus; 227 were intestinal and 80 were diffuse type. In the same study period, we assessed the H. pylori seroprevalence in 162 patients with nongastric carcinoma (lung n = 41, breast n = 42, genitourinary n = 41, GI tract n = 22, others n = 16) (male/female: 84/78; age range 31-81 yr, mean 56 yr). RESULTS: The overall seroprevalence of H. pylori in gastric cancer and in nongastric cancer was 82 and 56%, respectively (p < 0.001). In asymptomatic blood donors (age range 55-65 yr) and in dyspeptic patients older than 60 yr, a seroprevalence of 55 and 58% was found, respectively, which is significantly lower (p > 0.001) than the gastric cancer patients but similar to the nongastric cancer population. No difference was found in the H. pylori status according to the gastric cancer site (83, 82, and 81% in the antrum, corpus, and fundus, respectively). Two hundred and twenty-seven gastric cancers [185 (81%) H. pylori-positive] were found to be of an intestinal type and 80 [66 (82%) H. pylori-positive] of a diffuse type (not significant). No age-related difference (below and above 60 yr) in H. pylori prevalence was observed within each cancer population, and, in both age groups, the seroprevalence of infection was higher in gastric cancer patients (86 and 81%) than in nongastric cancer patients (56 and 56%) (below and above 60 yr, respectively). CONCLUSION: H. pylori seroprevalence is significantly higher in gastric cancer compared with nongastric cancer patients. No differences were observed in H. pylori seroprevalence according to gastric cancer site or histological type. The higher H. pylori seroprevalence in gastric cancer patients is not age related.

Age Factors↗
PubMed1994

Prevalence of peptic ulcer in Helicobacter pylori positive blood donors.

This study aimed to determine the importance of raised antibodies to Helicobacter pylori in an asymptomatic population. A total of 128 asymptomatic blood donors who were seropositive for H pylori and consented to endoscopy were investigated. These subjects were from a population of 1010 blood donors screened for antibodies to H pylori. A questionnaire was completed to determine if any subjects had complained of symptoms, and they subsequently had endoscopy. Altogether 121 of 128 were positive for H pylori by histology and urease test and/or culture and all 121 had chronic active gastritis on histology. Twenty five of these subjects had peptic ulcer (20 duodenal, five gastric), a further 21 had erosive duodenitis, and two were found to have gastric cancer. H pylori associated peptic ulcer disease and duodenitis occur more frequently than previously recognised and this suggests that H pylori infection, even if asymptomatic, is of far greater clinical relevance than originally thought.

Adolescent↗