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Biomedical subjects

M Franceschi

Publications and source records attributed to M Franceschi.

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

Quantification of tissue damage in AD using diffusion tensor and magnetization transfer MRI.

The authors measured mean diffusivity (D) and magnetization transfer ratio (MTR) of the brain from 18 patients with AD and 16 healthy control subjects. The peak heights of cortical gray matter (cGM) D (p < 0.001) and MTR (p < 0.001) histograms were lower and average cGM D (p < 0.01) higher in patients with AD than in control subjects. A composite MR score based on brain volume and cGM MTR peak height was correlated with patient cognitive impairment (r = 0.65, p = 0.003). This preliminary study presents a novel approach to quantify AD-related tissue damage in-vivo.

Aged↗
PubMed2001

Prevalence of intestinal metaplasia in the distal oesophagus, oesophagogastric junction and gastric cardia in symptomatic patients in north-east Italy: a prospective, descriptive survey. The Italian Ulcer Study Group "GISU".

BACKGROUND: Incidence of adenocarcinoma of distal oesophagus and gastric cardia, probably arising from areas of intestinal metaplasia, has been increasing rapidly. AIMS: To define prevalence of intestinal metaplasia of distal oesophagus, oesophagogastric junction and gastric cardia and to evaluate potential associated factors, by means of a prospective multicentre study including University and teaching hospitals, and primary and tertiary care centres. PATIENTS: Each of 24 institutions involved in study enrolled 10 consecutive patients undergoing first-time routine endoscopy for dyspeptic symptoms. METHODS: Patients answered symptom questionnaires and underwent gastroscopy Three biopsies were taken from distal oesophagus, oesophago-gastric junction and gastric cardia, and were stained with haematoxylin and eosin. Specimens were also evaluated for Helicobacter pylori infection. RESULTS: A total of 240 patients (124 male, 116 female; median age 56 years, range 20-90) were enrolled in study. Intestinal metaplasia affected distal oesophagus in 5, oesophago-gastric junction in 19 and gastric cardia in 10 patients. Low-grade dysplasia was found at distal oesophagus and/or oesophago-gastric junction of 3/24 patients with intestinal metaplasia vs 2/216 without intestinal metaplasia (p<0.05). A significant association was found between symptoms and presence of intestinal metaplasia, regardless of location, and between Helicobacter pylori infection and intestinal metaplasia at oesophago-gastric junction. CONCLUSIONS: Intestinal metaplasia of distal oesophagus, oesophagogastric-junction and gastric cardia is found in a significant proportion of symptomatic patients undergoing gastroscopy and is associated with dysplasia in many cases. Although prevalence of dysplasia seems to decrease when specialized columnar epithelium is found in short segment, or even focally in oesophago-gastric junction, these small foci of intestinal metaplastic cells may represent source of most adenocarcinomas of cardia.

Barrett Esophagus↗
PubMed2001

Prevention of acute NSAID-related gastroduodenal damage: a meta-analysis of controlled clinical trials.

No consensus exists as to whether cotherapy is effective in the short-term prevention of severe NSAID-related gastroduodenal damage. The aim of this study was to provide a quantitative systematic review of the efficacy of gastroprotective drugs, such as misoprostol, H2-blockers, and proton pump inhibitors (PPI) in preventing the severe acute NSAID-related gastroduodenal damage. Placebo-controlled randomized clinical trials on the use of misoprostol, H2-blockers, and PPIs as preventative agents published between January 1986 and May 1999 were identified through Medline and reference lists from clinical reviews. Studies on patients or healthy subjects were considered to be eligible for data pooling if they were performed in acute NSAID users (not longer than 30 days) and with at least one endoscopic evaluation during therapy that reported results specifically for gastric and duodenal damage. Risk difference (RD), heterogeneity chi2 test, publication bias assessment and number needed to treat (NnT) were calculated for each meta-analysis by a customized program. Twenty-one trials met the inclusion criteria evaluating a total of 636 healthy subjects and 1904 patients with arthritis randomized to active drug or placebo. The baseline risk of NSAID-related gastric (68% vs 16.6%, P < 0.001) and duodenal (22% vs 8.5%, P < 0.001) damage was higher in healthy subjects compared to patients with arthritis. Meta-analysis demonstrated a significant heterogeneity between trials performed in the two populations (P < 0.0001). In healthy subjects the active drug treatment induced a significant prevention of severe gastric (misoprostol RD = 69%, 95% CI = 60.3-77.7, H2-blocker RD = 38.3%, 95% CI = 17.8-58.9 and PPI RD = 43%, 95% CI = 28.2-57.7) and duodenal damage (misoprostol RD = 22.3%, 95% CI = 13.6-31, H2-blocker RD = 13.2%, 95% CI = 5.2-21.3 and PPI RD = 17.7%, 95% CI = 3.5-31.8). NnT values were, respectively, 1, 3, and 2 for gastric and 4, 8, and 6 for duodenal damage. In patients with arthritis lower RD and higher NnT values were found compared to healthy subjects. In conclusions, cotreatment with gastroprotective drugs for short-term prevention of severe gastroduodenal NSAID-related damage was more effective in healthy subjects than in patients with arthritis; misoprostol and PPIs were more effective than H2-blockers in the prevention of both gastric and duodenal severe damage; more studies need to evaluate the role of short-term prevention in patients with arthritis who require acute NSAID treatment.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2001

Cure of Helicobacter pylori infection in elderly patients: comparison of low versus high doses of clarithromycin in combination with amoxicillin and pantoprazole.

BACKGROUND: Advancing age may influence clarithromycin's pharmacokinetics. No studies have yet compared the effects of different dosages of clarithromycin in combination with a proton pump inhibitor and amoxicillin in elderly patients. AIM: To compare the efficacy and tolerability of clarithromycin 250 mg vs. clarithromycin 500 mg twice daily (b.d.) in combination with pantoprazole and amoxicillin in elderly patients. METHODS: One hundred and fifty-four elderly patients with H. pylori-associated ulcer disease or chronic gastritis were consecutively randomized to receive pantoprazole 40 mg daily plus amoxicillin 1 g, and either clarithromycin 250 mg b.d. (PAC 250) or clarithromycin 500 mg b.d. (PAC 500). Two months after therapy, endoscopy and gastric biopsies were repeated. RESULTS: The cure rates of H. pylori infection in the PAC 250 and PAC 500 groups were, respectively, 83% and 79% (ITT analysis) and 94% and 88% (PP analysis) (P=N.S.). Significant decreases in chronic gastritis activity both in the body (P < 0.00001) and the antrum (P < 0.0001) of the stomach were found in H. pylori-cured patients, independently of clarithromycin dosage. Four patients in PAC 250 (5%) and seven in PAC 500 (9%) reported adverse events (P=N.S.). One patient in PAC 250 (25%) and three in PAC 500 (43%) discontinued the study because of these drug-related side-effects (P=N.S.). CONCLUSIONS: In elderly patients, 1-week triple therapy with a proton pump inhibitor, amoxicillin and clarithromycin is a highly effective and well tolerated anti-H. pylori treatment. With this combination, clarithromycin at the lower dose of 250 mg b.d. achieved excel- lent cure rates and minimized adverse events and costs.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2000

Synergistic interactions between nicotine and cocaine or methylphenidate depend on the dose of dopamine transporter inhibitor.

There is a greater prevalence of cigarette smoking among cocaine-dependent individuals and hyperactive children treated with stimulants (e.g., methylphenidate, MP). However, little is known about the neurochemical basis of the interaction between nicotine and cocaine or MP. It is thought that the reinforcing effects of cocaine and MP are due partly to increases in synaptic DA in the nucleus accumbens (NAc). These measurable increases are secondary to the blockade of the DA transporter. In contrast, nicotine stimulates acetylcholine receptors located presynaptically on dopaminergic projections from the ventral tegmental area (VTA) to the NAc and increases DA transmission. Here we investigate the effects of nicotine on NAc DA in animals simultaneously injected with cocaine or MP. Coadministration of nicotine (0.4 mg/kg s.c.) and cocaine (10 mg/kg i.p.) or MP (5 mg/kg i.p.) increased the extracellular NAc DA levels in an additive manner, while coadministration of nicotine (0. 4 mg/kg s.c.) and a higher dose of cocaine (20 mg/kg) or MP (10 mg/kg) clearly produced a synergistic elevation in NAc DA. These findings suggest that the degree of DA transporter (DAT) occupancy contributes to the synergistic interaction between nicotine and cocaine or MP.

Animals↗
PubMed2000

Visual feedback has differential effects on reaching movements in Parkinson's and Alzheimer's disease.

We examine the role of visual feedback in the programming and execution of reaching movement in patients with Parkinson's disease without cognitive impairment and patients with Alzheimer's disease without extrapyramidal signs. Controls were normally aging subjects. All subjects moved a cursor to targets on a digitizing tablet without seeing their limb. Starting and target positions were always visible on a screen while, during movement, cursor position was either visible or blanked. They were instructed to make uncorrected movements, as fast and as accurate as possible without minimizing reaction time. In absence of visual feedback, movement accuracy in patients with AD was severely impaired. Hand paths of parkinsonian patients were as accurate as normal subjects' with similar temporal velocity profiles and movement speed. With cursor feedback, accuracy was the same in the three groups, although movement speed and transport phase in patients with Alzheimer's disease were significantly reduced compared to the other groups. Also, movements of parkinsonian patients showed shorter transport phase and lower mean velocity than controls'. The different characteristics of the motor performance suggests that in the two diseases visual information is used differently for both motor programming and execution: patients with Alzheimer's disease, while scarcely using feed forward commands, relied on continuous on-line external cues. The correlation of motor performance with cognitive impairment argues against the hypothesis of basal ganglia involvement in AD. The motor abnormalities we found may represent early subclinical manifestation of apraxic disturbance. Parkinsonian patients showed higher reliance on feedback commands only with cursor feedback: this could be explained by their difficulty in engaging effectively automatic routines when distractors are present.

Aged↗
PubMed2000

Effects of route of administration on cocaine induced dopamine transporter blockade in the human brain.

The route of administration influences the reinforcing effects of cocaine. Here we assessed whether there were differences in the efficacy of cocaine to block the dopamine transporters (major target for cocaine's reinforcing effects), as a function of route of administration. Positron emission tomography and [11C]cocaine, a dopamine transporter radioligand, were used to compare the levels of dopamine transporter blockade induced by intravenous, smoked and intranasal cocaine in 32 current cocaine abusers. In parallel, the temporal course for the self-reports of "high" were obtained. Cocaine significantly blocked dopamine transporters. The levels of blockade were comparable across all routes of administration and a dose effect was observed for intravenous and intranasal cocaine but not for smoked cocaine. For equivalent levels of cocaine in plasma and DAT blockade, smoked cocaine induced significantly greater self reports of "high" than intranasal cocaine and showed a trend for a greater effect than intravenous cocaine. The time to reach peak subjective was significantly faster for smoked (1.4+/-0.5 min) than for intravenous cocaine (3.1+/-0.9 min), which was faster than intranasal cocaine (14.6+/-8 min). Differences in the reinforcing effects of cocaine as a function of the route of administration are not due to differences in the efficacy of cocaine to block the dopamine transporters. The faster time course for the subjective effects for smoked than intravenous and for intravenous than for intranasal cocaine highlights the importance of the speed of cocaine's delivery into the brain on its reinforcing effects.

Administration, Inhalation↗
PubMed2000

Evidence that gingko biloba extract does not inhibit MAO A and B in living human brain.

Extracts of Ginkgo biloba have been reported to reversibly inhibit both monoamine oxidase (MAO) A and B in rat brain in vitro leading to speculation that MAO inhibition may contribute to some of its central nervous system effects. Here we have used positron emission tomography (PET) to measure the effects of Ginkgo biloba on human brain MAO A and B in 10 subjects treated for 1 month with 120 mg/day of the Ginkgo biloba extract EGb 761, using [11C]clorgyline and [11C]L-deprenyl-D2 to measure MAO A and B respectively. A three-compartment model was used to calculate the plasma to brain transfer constant K1 which is related to blood flow, and lambdak3, a model term which is a function of the concentration of catalytically active MAO molecules. Ginkgo biloba administration did not produce significant changes in brain MAO A or MAO B suggesting that mechanisms other than MAO inhibition need to be considered as mediating some of its CNS effects.

Adult↗
PubMed2000

Incidence of secondary Helicobacter pylori resistance to antibiotics in treatment failures after 1-week proton pump inhibitor-based triple therapies: a prospective study.

BACKGROUND: Antibiotic-resistant Helicobacter pylori strains are becoming increasingly prevalent, although it is not clear to what extent the new resistant organisms will spread. AIM: To evaluate the incidence of secondary Helicobacter pylori resistance to metronidazole, clarithromycin and/or amoxycillin after one-week proton pump inhibitor based triple therapy failure in patients who were, before therapy infected with Helicobacter pylori strains susceptible to these antibiotics. PATIENTS AND METHODS: Enrolled in the study were 97 consecutive Helicobacter pylori-positive subjects infected by Helicobacter pylori strains susceptible to metronidazole, clarithromycin and amoxycillin. Activity of tested antibiotics was determined by means of the E-test. Patients were treated for seven days with a proton pump inhibitor, omeprazole 20 mg twice daily or pantoprazole 40 mg once daily, plus clarithromycin 250 mg twice daily and metronidazole 250 mg four times daily; or with a proton pump inhibitor plus amoxycillin 1 g twice daily and clarithromycin 500 mg twice daily. Two months after completion of therapy, endoscopy and gastric biopsies for histology, rapid urease test and culture were repeated. RESULTS: Four patients were dropped from the study Overall Helicobacter pylori cure rates expressed as both intention-to-treat and per-protocol analyses, were, respectively 80% (40/50) and 81.6% (40/49) with proton pump inhibitor, clarithromycin and metronidazole and 76.6% (36/47) and 81.8% (36/44) with proton pump inhibitor amoxycillin and clarithromycin. No significant differences were observed between the two treatments. Subjects in whom treatment failed were significantly younger and had less active ulcer than cured patients. Of treatment failures, 70.6% (12 out of 17 subjects) de veloped a secondary resistance to metronidazole (35.33% and/or clarithromycin (64.7%). Secondary antibiotic resistance occurred in 77. 8% of treatment failures treated with proton pump inhibitor, clarithromycin and metronidazole and in 62.5% of those treated with proton pump inhibitor, amoxycillin and clarithromycin. Considering all patients treated, the overall incidence of secondary metronidazole and/or clarithromycin resistance after therapy was reported in 12.9% of subjects (12 out of 93 treated patients). CONCLUSIONS: Secondary Helicobacter pylori resistances to metronidazole and/or clarithromycin occurred in large percentages in patients with treatment failure after the one-week proton pump inhibitor-based triple therapies, proton pump inhibitor, clarithromycin and metronidazole and proton pump inhibitor, amoxycillin and clarithromycin. It is likely that new antibiotics or treatment strategies will be needed in the near future to successfully treat Helicobacter pylori infection.

Adult↗
PubMed2000

Prevalence of Helicobacter pylori resistance to antibiotics in Northeast Italy: a multicentre study. GISU. Interdisciplinary Group for the Study of Ulcer.

AIMS: To evaluate prevalence of primary Helicobacter pylori antibiotic resistances in Northeast Italy and to identify risk factors associated with this resistance. MATERIALS AND METHODS: A total of 248 patients undergoing upper gastrointestinal endoscopy were enrolled from 19 Endoscopy Units over a 6-month period. From each patient, 4 gastric biopsies were taken for histology and 2 were sent to the Central Referral Microbiological Laboratory for culture and determination of antibiotic activity against Helicobacter pylori by means of E-test. Strains were considered resistant when minimum inhibitory concentration was >8 microg/ml for metronidazole and >1 microg/ml for clarithromycin. No cut-off value was predefined for amoxycillin. RESULTS: Culture of Helicobacter pylori was successfully performed in 167 patients. Primary resistance to metronidazole, clarithromycin or amoxycillin was 14.9%, 1.8% and 0%, respectively Patients infected with Helicobacter pylori strains resistant to antibiotics were more frequently females than males (70.3% vs 41.4%), had a significantly lower coffee intake (66.6% vs 86.6%) and lower body mass index (23.7+/-2.6 vs 25.3+/-3.6) than patients with susceptible Helicobacter pylori strains. Age, smoking, alcohol use, family history of Helicobacter pylori infection, concomitant diseases and treatments, endoscopic diagnoses, Helicobacter pylori density and histological activity of chronic gastritis were not associated with antibiotic resistance. Multivariate analysis confirmed that female gender (odds ratio = 2.74, 95% confidence interval = 1.03-7.27) was the only significant risk factor associated with antibiotic resistance. CONCLUSIONS: In this population, primary Helicobacter pylori resistance to metronidazole was higher than resistance to clarithromycin, and female gender was significantly associated with this resistance. The low prevalence of resistance to metronidazole, clarithromycin and amoxycillin identified in this geographical area suggests that proton pump inhibitor-based triple regimens including these antibiotics may still be used as first line therapies against Helicobacter pylori infection.

Adult↗
PubMed2000

Pantoprazole versus one-week Helicobacter pylori eradication therapy for the prevention of acute NSAID-related gastroduodenal damage in elderly subjects.

AIM: To compare the efficacy of pantoprazole vs. a one-week Helicobacter pylori eradication therapy for the prevention of NSAID-related gastroduodenal damage. METHODS: Patients over 60 years old with symptoms and/or a history of ulcer who needed NSAID treatment were evaluated by endoscopy. H. pylori positive subjects who had no severe gastroduodenal lesions were randomized to take, concomitantly with NSAID therapy, either: (i) pantoprazole 40 mg daily plus amoxycillin 1 g b.d. and clarithromycin 250 mg b.d. for 1 week (35 subjects, Group PAC) or (ii) pantoprazole 40 mg daily for 1 month (34 subjects, Group P). Endoscopy was repeated after 1 month. RESULTS: A significantly higher incidence of severe gastroduodenal damage was found in Group PAC than in Group P (29% vs. 9%, P<0.05). The percentages of patients worsened, unchanged and improved after 1 month were, respectively: Group PAC: 46%, 46%, and 9% and Group P: 7%, 65%, and 29% (P<0.0008). The percentage of H. pylori-negative subjects was 89% in Group PAC and 52% in Group P (P=0.0009). The incidence of gastroduodenal damage was higher in Group PAC treatment failures than in cured patients (50% vs. 25.8%, P=ns). CONCLUSION: One month of pantoprazole was more effective than a proton pump inhibitor-based triple therapy in the prevention of gastroduodenal damage in elderly H. pylori-positive NSAID users.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2000

Noninvasive diagnosis of Helicobacter pylori infection in older subjects: comparison of the 13C-urea breath test with serology.

BACKGROUND: The potential influence of cognitive status, physical activities, comorbidity and cotreatments on the feasibility and diagnostic accuracy of two noninvasive diagnostic tests for Helicobacter pylori (Hp) infection, i.e., the 13C-urea breath test (13C-UBT) and serology (immunoglobulin G [IgG] anti-Hp antibodies), in older subjects is not known. METHOD: The study involved 100 consecutive symptomatic elderly subjects (mean age, 78.3 years; range, 65-96 years), who had undergone an upper gastrointestinal endoscopy. Patients were considered Hp positive if at least two of the three invasive methods, i.e. histology, culture, and/or the rapid urease test were positive for Hp infection. Patients were considered Hp negative if all three invasive methods were negative. The 13C-UBT was performed according to the European standard method and the assaying of IgG anti-Hp antibodies by enzyme-linked immunosorbent assay. Cognitive status and functional activities were determined by the Mini-Mental State Examination (MMSE), the activities of daily living (ADLs) and instrumental ADLs (IADLs). RESULTS: According to invasive methods, 49 patients were Hp positive and 47 were Hp negative (4 subjects were excluded from the study). Hp-positive patients demonstrated a significantly higher prevalence of peptic ulcers (p =.02) and activity of chronic gastritis (p<.0001) than Hp-negative subjects. The 13C-UBT demonstrated a sensitivity of 100%, a specificity of 95.7%, and a diagnostic accuracy of 97.9%. Serology had significantly lower sensitivity (74.4%), specificity (59%), and diagnostic accuracy (67%, p<.001) than the 13C-UBT. The feasibility and the diagnostic accuracy of the 13C-UBT were not altered by the cognitive status (MMSE) and functional activities (ADL, IADL) of the patients, their drug consumption, or the prevalence of concomitant diseases. CONCLUSIONS: In older subjects, the 13C-UBT had a significantly higher diagnostic accuracy than serology without influence of cognitive function, disability, comorbidity and cotreatments. This method may be considered an excellent, clinically useful, noninvasive test for the diagnosis of Hp infection in older subjects.

Aged↗
PubMed2000

Apolipoprotein E polymorphism and serum concentration in Alzheimer's disease in nine European centres: the ApoEurope study. ApoEurope group.

As part of the ApoEurope Project, apolipoprotein E (apo E) common polymorphism and serum concentration were determined in 489 Alzheimer's disease patients and 429 controls. Patients and controls were recruited through nine centres in eight European countries. Age, sex ratios and education levels of both case and control populations were similar, although discrete differences appeared between centres. The prevalence of the epsilon4 allele was higher in Alzheimer's disease than in controls (increased by 140%), while serum apo E concentration was lower by 11.2% (p<0.001). In addition, serum total cholesterol and triglyceride concentrations were lower in Alzheimer's disease (p<0.001), while that of apo Al was not affected. The decrease in serum apo E concentration was not accounted for by the epsilon4 allele, age or gender, suggesting that apo E concentration might represent an additional risk factor for Alzheimer's disease, complementary and independent of the epsilon4 allele. Further analysis will be aimed at determining whether the quantitative link between apo E concentration and Alzheimer's disease occurs through the effect of apo E genotype on lipid parameters or by other mechanisms.

Age Factors↗
PubMed2000

Association of early-onset Alzheimer's disease with an interleukin-1alpha gene polymorphism.

Overexpression of the pluripotent cytokine interleukin-1 (IL-1) by microglial cells correlates with formation of neuritic beta-amyloid plaques in Alzheimer's disease (AD). We evaluated polymorphisms in the genes coding for the IL-1alpha, IL-1beta, and IL-1 receptor antagonist cytokines, and tested their association with the occurrence and age at onset of sporadic AD. We found a strong association between the IL-1A T/T genotype and AD onset before 65 years of age (odds ratio, 4.86), with carriers of this genotype showing an onset of disease 9 years earlier than IL-1A C/C carriers. A weaker association with the age at onset was also shown for the IL-1B and IL-1RN genes. These data suggest either a direct effect of the IL-1 gene family, mainly IL-1A, on the clinical onset of AD, or a linkage dysequilibrium with an unknown locus relevant to AD on chromosome 2.

Adult↗