Biomedical subjects

M Franceschi

Publications and source records attributed to M Franceschi.

At least 91 records · Page 5Linked to original sources

PubMed1995

The effect of aging on oro-cecal transit time in normal subjects and patients with gallstone disease.

To ascertain whether aging and/or cholelithiasis can influence oro-cecal transit time (OCTT), we studied a total of 70 subjects, i.e., 10 healthy young adult controls, 22 healthy elderly controls, 18 elderly cholelithiasis patients and 20 elderly subjects with a history of cholecystectomy for gallstones. OCTT was measured by means of the hydrogen breath test after administering a liquid meal of 10 g of lactulose in 200 mL of water, and collecting exhaled breath samples every 10 minutes for 200 minutes. Of all subjects in the group of patients with a history of cholecystectomy, 6/20 were non-hydrogen producers, and therefore were not included in the study. The OCTT was found to be significantly longer in healthy elderly controls, than in healthy young adult controls; the elderly subjects who had undergone cholecystectomy had a longer OCTT than the healthy elderly controls, while no difference was detected when compared to elderly patients with gallstones. In conclusion, OCTT seems to increase in healthy aging. Cholecystectomy also increases OCTT in the elderly, suggesting a link between intestinal motility and the biliary tract which may be of pathophysiological significance.

Adult↗

PubMed1995

Increased interictal cerebral glucose metabolism in a cortical-subcortical network in drug naive patients with cryptogenic temporal lobe epilepsy.

Positron emission tomography with [18F]-2-fluoro-2-deoxy-D-glucose ([18F]FDG) has been used to assess the pattern of cerebral metabolism in different types of epilepsies. However, PET with [18F]FDG has never been used to evaluate drug naive patients with cryptogenic temporal lobe epilepsy, in whom the mechanism of origin and diffusion of the epileptic discharge may differ from that underlying other epilepsies. In a group of patients with cryptogenic temporal lobe epilepsy, never treated with antiepileptic drugs, evidence has been found of significant interictal glucose hypermetabolism in a bilateral neural network including the temporal lobes, thalami, basal ganglia, and cingular cortices. The metabolism in these areas and frontal lateral cortex enables the correct classification of all patients with temporal lobe epilepsy and controls by discriminant function analysis. Other cortical areas--namely, frontal basal and lateral, temporal mesial, and cerebellar cortices--had bilateral increases of glucose metabolism ranging from 10 to 15% of normal controls, although lacking stringent statistical significance. This metabolic pattern could represent a pathophysiological state of hyperactivity predisposing to epileptic discharge generation or diffusion, or else a network of inhibitory circuits activated to prevent the diffusion of the epileptic discharge.

3-O-Methylglucose↗

PubMed1994

Long term treatment with omeprazole 20 mg three days a week or 10 mg daily in the prevention of duodenal ulcer relapse.

BACKGROUND: The aim of this study was to compare omeprazole 10 mg o.m. (daily) with omeprazole 20 mg o.m. on Friday to Sunday inclusive (weekend) in the prevention of duodenal ulcer relapse over a 6-month period. METHODS: After an open healing phase (4 to 8 weeks) with omeprazole 20 mg o.m., 81 patients entered the follow-up phase. Forty-two were randomized in a double-blind double-dummy technique, to omeprazole 10 mg o.m., and 39 to omeprazole 20 mg at weekends. At 3 and 6 months or on symptomatic relapse the patients underwent endoscopy with gastric biopsies (quantitative assessment of argyrophilic and gastrin cells), symptom evaluation, and laboratory screening with fasting serum gastrin. RESULTS: Five patients in the 10 mg group and four in the weekend group were lost to follow-up. The estimated relapse rates over six months in the two groups receiving 10 mg daily or 20 mg at weekends were 19% and 31%, respectively (95% CI of percentage difference: -33% to 8%: intention-to-treat analysis, P = N.S.). During the follow-up phase, symptoms tended to be milder in the omeprazole 10 mg daily group compared to the weekend group. Gastrin levels increased significantly during the healing phase but then stayed almost constant in the omeprazole 10 mg group, and significantly decreased with weekend treatment. The median number of argyrophilic cells showed a slight but statistically significant increase in the omeprazole 10 mg daily group, but did not change in the weekend group. Both the healing and long-term therapies were well tolerated. CONCLUSIONS: Our data do not show a clear difference between the two treatment regimens, but there was a tendency towards a lower recurrence rate with omeprazole 10 mg daily compared with 20 mg weekend therapy.

Adult↗

PubMed1994

High-resolution technetium-99m-HMPAO SPECT in patients with probable Alzheimer's disease: comparison with fluorine-18-FDG PET.

UNLABELLED: SPECT studies of regional cerebral perfusion with a high-resolution system were compared to PET studies of regional cerebral glucose utilization (rCMRglc) in 21 patients with probable Alzheimer's disease (AD). Ten normal subjects were also evaluated with SPECT and 10 with PET. METHODS: rCMRglc (for PET) and counts (for SPECT) in the associative cortices were normalized to the average rCMRglc, and counts in the calcarine cortex and basal ganglia were considered as a "reference area" to obtain a ratio. The ratio differences between patients and controls were tested with ANOVA performed separately for PET and SPECT. RESULTS: The difference between probable AD patients and controls was significant for both PET (p < 0.00001) and SPECT (p < 0.005); this difference was significant for the frontal, temporal and parietal cortices (p < 0.0001) for PET, and for the temporal (p < 0.005) and parietal (p < 0.001) cortices for SPECT. Temporo-parietal defects were detected in all subjects with PET and in 90% with SPECT. CONCLUSION: PET and SPECT are able to detect characteristic temporo-parietal abnormalities in probable AD. However, the presence of abnormalities in other associative areas is better evaluated with PET.

Adult↗

PubMed1994

Pinhole SPECT: an approach to in vivo high resolution SPECT imaging in small laboratory animals.

UNLABELLED: The performance of pinhole SPECT and the application of this technology to investigate the localization properties of radiopharmaceuticals in vivo in small laboratory animals are presented. METHODS: System sensitivity and spatial resolution measurements of a rotating scintillation camera system are made for a low-energy pinhole collimator equipped with 1.0-, 2.0- and 3.3-mm aperture pinhole inserts. The spatial detail offered by pinhole SPECT for in vivo imaging was investigated in studies of the brain and heart in Fisher 344 rats by administering 201TICI, 99mTc-HMPAO, 99mTc-DTPA and 99mTc-MIBI. Image acquisition is performed using a rotating scintillation camera equipped with a pinhole collimator; projection data are acquired in conventional step-and-shoot mode as the camera is rotated 360 degrees around the subject. Pinhole SPECT images are reconstructed using a modified cone-beam algorithm developed from a two-dimensional fanbeam filtered backprojection algorithm. RESULTS: The reconstructed transaxial resolution of 2.8 mm FWHM and system sensitivity of 0.086 c/s/kBq with the 2.0-mm pinhole collimator aperture provide excellent spatial detail and adequate sensitivity for imaging the regional uptake of the radiopharmaceuticals in tumor, organs and other tissues in small laboratory animals. CONCLUSION: The resolution properties of pinhole SPECT are superior to those which have been achieved thus far with conventional SPECT or PET imaging technologies. Pinhole SPECT provides an important approach for investigating localization properties of radiopharmaceuticals in vivo.

Animals↗

PubMed1993

Effects of acute doses of oxiracetam in the scopolamine model of human amnesia.

The scopolamine model of amnesia has been used to test the pharmacodynamic efficacy of oxiracetam in 12 healthy volunteers. The subjects were divided into four experimental groups, according to a double-blind cross over incomplete randomized block design. After a baseline neuropsychological examination, each subject received in two separate sessions one of the following treatments, as acute oral doses: oxiracetam 800, 1600, 2400 mg or placebo. One hour after treatment scopolamine hydrobromide (0.5 mg) was given subcutaneously. The cognitive performance was tested before and 1, 2, 3 and 25 h after scopolamine administration. Scopolamine caused a deterioration of performance of verbal episodic memory, semantic memory and attention tests. In comparison to placebo, oxiracetam improved the overall test performance, with a statistically significant difference at the dose of 1600 mg on delayed recall of word lists, and showed dose-related antagonism of scopolamine-induced effects also on semantic memory and attention. The efficacy of an acute dose of oxiracetam in reducing scopolamine-induced cognitive impairment supports the potential usefulness of this pharmacological model of amnesia for studying the effects of cognition enhancers in humans.

Adult↗

PubMed1993

Evidence of multiple memory systems in the human brain. A [18F]FDG PET metabolic study.

Patients with global amnesia of different aetiologies (n = 11), and patients with probable Alzheimer's disease of recent onset and mild to moderate severity (n = 18) underwent extensive neuropsychological examination, which included the evaluation of multiple components of memory, and a measurement of regional cerebral glucose metabolism with [18F]fluoro-deoxyglucose ([18F]FDG) and PET. In the neuropsychological tests, both global amnesia and Alzheimer's disease patients had impaired episodic long-term memory, while deficits of short-term, semantic and implicit memory were present only in Alzheimer's disease. When local metabolic rates for glucose were compared with values from age- and education-matched normal controls, a common pattern of bilateral hypometabolism was present in the hippocampus, cingulate and frontal basal cortex of both global amnesia and Alzheimer's disease patients. On the other hand, significant hypometabolism was found in the thalamus in only global amnesia, and in the frontal, parietal and temporal associative cortex in only Alzheimer's disease. The results of a multivariate regression analysis of test scores with metabolic data indicated that different clusters of cerebral areas were associated with each of the main components of memory function. These data are in agreement with 'neural network' models of the neural basis of cognition, according to which complex functions are subserved by multiple interconnected cortical and subcortical structures.

Aged↗

PubMed1993

SPET imaging of cerebral perfusion in patients with non-refractory temporal lobe epilepsy.

The pattern of regional cerebral blood flow was assessed by single photon emission tomography and (99mTc)HM-PAO in 28 patients with clinical diagnosis of non-refractory cryptogenic temporal lobe epilepsy on chronic treatment with carbamazepine. Each patient underwent a magnetic resonance imaging study of the brain. An EEG was performed concurrently with the assessment of cerebral blood flow. Areas of focal hypoperfusion were observed in 8/28 patients, and a concurrent EEG focus was identified in 10/28 patients. Areas of hypoperfusion and the EEG foci were consistent in 6 of the 10 patients with EEG abnormalities; in 2 patients hypoperfusion and the EEG abnormalities were on opposite sides, though in homologous areas; in 2 patients the perfusion pattern was normal in spite of the EEG abnormalities. The number of clinical seizures and EEG abnormalities was higher for the patients presenting with cerebral hypoperfusion than for those with normal perfusion. It is concluded that the evaluation of cerebral blood flow may provide useful information for both diagnostic and prognostic assessment of these patients.

Adult↗

PubMed1993

Omeprazole and high dose ranitidine in the treatment of refractory reflux oesophagitis.

Thirty two consecutive patients (age range 6 months-13.4 years) with severe reflux oesophagitis were randomised to a therapeutic trial for eight weeks during which they received either standard doses of omeprazole (40 mg/day/1.73 m2 surface area) or high doses of ranitidine (20 mg/kg/day). Twenty five patients completed the trial (12 on omeprazole, 13 on ranitidine). At entry and at the end of the trial patients underwent symptomatic score assessment, endoscopic and histological evaluation of the oesophagus, and simultaneous oesophageal and gastric pH measurement; results are given as median (range). Both therapeutic regimens were effective in decreasing clinical score (omeprazole before 24.0 (15-33), after 9.0 (0-18); ranitidine before 19.5 (12-33), after 9.0 (6-12)), in improving the histological degree of oesophagitis (omeprazole before 8.0 (6-10), after 2.0 (0-60); ranitidine before 8.0 (8-10), after 2.0 (2-6), and in reducing oesophageal acid exposure, measured as minutes of reflux at 24 hour pH monitoring (omeprazole before 129.4 (84-217), after 44.6 (0.16-128); ranitidine before 207.3 (66-306), after 58.4 (32-128)) as well as intragastric acidity, measured as median intragastric pH (omeprazole before 2.1 (1.0-3.0), after 5.1 (2.2-7.4); ranitidine before 1.9 (1.6-4), after 3.4 (2.3-5.3)). Serum gastrin concentration was > 150 ng/l in four patients on omeprazole and in three patients on ranitidine. It is concluded that in children with refractory reflux oesophagitis high doses of ranitidine are comparable with omeprazole for the healing of oesophagitis and relief of symptoms; both drugs resulted in efficacious reduction of intragastric acidity and intra-oesophageal acid exposure.

Adolescent↗

PubMed1993

Crossed aphasia: a PET follow up study of two cases.

Two cases of aphasia after right hemispheric stroke in right handed patients are described. The first patient had a severe mixed transcortical aphasia, apraxia and neglect after a lesion involving the right lenticular nucleus and periventricular white matter; aphasia was still present after three months. The second patient had a mild, transient fluent aphasia after a small right hemispheric periventricular lesion. Studies with [18F]FDG and positron emission tomography (PET) showed functional depression extending to the structurally unaffected left hemisphere in both patients in the acute stage. After three months, in the patient with persistent aphasia, metabolism was still reduced in the right hemisphere, with some recovery of hypometabolism on the left, while metabolic values had returned to normal in the patient with full language recovery. A close parallelism between glucose metabolism and clinical course in crossed aphasia is shown, as well as the presence of a functional involvement of the structurally unaffected left hemisphere in the acute stage.

Aged↗

PubMed1993

Effects of omeprazole therapy on peptic disease and serum gastrin levels in hemodialysis patients. A preliminary study.

Hemodialysis patients are frequently affected by peptic disease, and in many cases they have high serum levels of gastrin. The aim of this study was to evaluate the effects of omeprazole, an inhibitor of gastric parietal cells hydrogen pump, on peptic disease and gastric secretion of 16 selected dialysis patients. H2-receptors blocking drugs or gastric acidity buffers were withdrawn for 2 weeks, then omeprazole was administered for 4 weeks at a daily dosage of 20 mg. Before and after the omeprazole therapy, registration of subjective peptic symptoms, baseline serum gastrin dosage and endoscopy of upper digestive tract were performed. Before starting omeprazole, the serum gastrin value was 515 +/- 180 pg/l, all the patients complained of peptic symptoms, and endoscopy showed: 8 cases of duodenal ulcer, 3 cases of pyloric ulcer and 5 cases of antral erosive gastritis. At the end of the omeprazole treatment period, a slight but statistically not significant increase of serum gastrin level (537 +/- 198 pg/l) was observed. Twelve patients reported the total disappearance of symptoms of peptic disease, 3 patients a partial reduction, and 1 patient had no improvement. Control endoscopy showed the healing (white scar) of all the ulcers, and the disappearance of all the erosive lesions. In conclusion, our results show that a 20 mg/day omeprazole short-term therapy can be given safely to uremic patients undergoing hemodialysis and is effective for a quick healing of active peptic lesions.

Adult↗

PubMed1993

Antisecretory effect of three premeal doses of cimetidine 400 mg versus a single morning dose of omeprazole 20 mg: pathophysiological implications for duodenal ulcer treatment.

The success of omeprazole in the healing of duodenal ulcer has been attributed to its profound and almost around-the-clock inhibition of acid, but the relevance of reducing meal-stimulated acid secretion exclusively has recently been emphasized in several clinical trials. For this reason, we used 24-h continuous intragastric pH monitoring to compare the pharmacodynamic effects of placebo, three fractioned premeal doses of cimetidine 400 mg and omeprazole 20 mg mane. Fifteen patients with duodenal ulcer in clinical remission were randomized to receive the above medications in single-blind fashion on three separate occasions, at least 2 wk apart. Both active regimens produced higher pH values (p < 0.05-0.001) than placebo, but omeprazole was much more effective than cimetidine (p < 0.01-0.001) during the various time intervals analyzed (24 h, evening, nighttime, daytime). The greater effectiveness of omeprazole was confirmed by its longer-lasting antisecretory action, insofar as the drug increased gastric pH above 3.0 units for about 21 h, whereas the daytime cimetidine regimen maintained this threshold for 7.30 h (p < 0.001) over the circadian cycle. As these markedly different pharmacodynamic effects have been proven to produce similar fast rates of duodenal ulcer healing in clinical trials, it is reasonable to assume that a small but well addressed reduction of gastric acidity can ensure the same therapeutic benefit as a strong and continuous acid inhibition. In this light, the acid peaks in response to meals seem to be important pathophysiological events, whose control is sufficient to permit quick ulcer healing.

Adult↗

PubMed1992

Short-term treatment of refractory reflux esophagitis with different doses of omeprazole or ranitidine.

Sixty patients who presented with erosive/ulcerative refractory reflux esophagitis were randomized to receive a 4- to 8-week treatment with omeprazole 20 mg daily, or ranitidine 150 mg twice daily. Patients not healed after treatment were given the same drugs at doubled doses for a second period of equal duration. Patients still unhealed after this received open treatment with omeprazole 20 mg twice daily for a third period of 4 to 8 weeks. Endoscopic assessment and clinical and laboratory evaluation were performed every 4 weeks until there was complete esophageal mucosal repair. After 4 weeks, complete healing was observed in 50% of patients on omeprazole 20 mg daily, compared with 20.7% on ranitidine 150 mg twice per day (p < 0.01). After 8 weeks, the figures were 79.3% versus 34.5% (p < 0.5). With doubled doses after 4 weeks, complete healing was achieved in 96.6% of patients on omeprazole 40 mg daily, compared with 64.2% on ranitidine 300 mg twice per day (p < 0.05). The eight still "refractory" patients (one omeprazole, seven ranitidine) healed completely with 8 more weeks of omeprazole 20 mg twice daily. Patients treated with omeprazole experienced faster relief of heartburn, which disappeared in 60% of patients after 4 weeks, as compared to 21% of patients treated with ranitidine (p < 0.006). Apart from the mode of treatment, the only factor that proved to be related to healing at multivariate analysis was the pretreatment severity of gastroesophageal reflux, as measured by esophageal pH monitoring. Our study confirms that omeprazole, even at a low dosage, is the choice for refractory reflux esophagitis.

Adult↗

PubMed1992

Omeprazole versus famotidine in the short-term treatment of duodenal ulcer disease.

The efficacy and safety of omeprazole, in 241 patients with active recurrent duodenal ulcer from 21 Italian centres, was studied in a multicentre double-blind randomized trial comparing 20 mg omeprazole o.m. or 40 mg famotidine nocte with endoscopic examination, symptom recording, laboratory screening and gastrin assay. In a per protocol analysis, the duodenal ulcer healing rates for omeprazole and famotidine, documented by endoscopy, were 62% (68/109) and 33% (39/117) after 2 weeks of treatment (P less than 0.001), 92% (96/104) and 80% (86/108) cumulative after 4 weeks (P less than 0.05), and 99% (102/103) and 92% (96/104) after 6 weeks (P less than 0.05), respectively. The results of this trial demonstrate that 20 mg omeprazole o.m. is superior to 40 mg famotidine nocte in duodenal ulcer healing.

Abdominal Pain↗

PubMed1992

Respiration and heart rate variability during sleep in untreated Parkinson patients.

Twenty-six patients with untreated mild to moderate Parkinson's disease (PD) lasting 5 years or less, were investigated in the sleep laboratory. Sleep architecture and respiration during sleep did not significantly differ from age-matched controls. PD patients showed defective cardiac autonomic control during sleep, mainly parasympathetic but also sympathetic in nature, although they had normal results in conventional autonomic tests during wakefulness. Therefore, autonomic cardiac involvement seems to be an early sign of PD.

Aged↗

PubMed1992

Omeprazole-induced changes in gastric mucus secretion.

The influence of omeprazole treatment on gastric mucus secretion in man was examined in two separate studies. 24 outpatients with endoscopic duodenitis but normal gastric mucosa were treated under double-blind conditions with either omeprazole 20 mg o.m. or placebo for four weeks. Omeprazole was found to induce a significant reduction (p less than 0.001) in the amount of neutral and total mucoproteins into the gastric juice and in the viscous and protective properties of mucus as assessed by a Mucoprotective Index. In a subsequent study 12 omeprazole-treated patients were re-examined either 10 days (6 patients) or 15 days (6 patients) after the drug withdrawal. A trend towards normalization of mucus secretion was detectable already after 10 days, but only at 15 days did gastric mucus fully revert to normal. The results suggest that the decrease in the quantity and quality of mucus secretion observed with omeprazole is a transient phenomenon, secondary to the sustained acid suppression induced by the drug and clinically irrelevant.

Adult↗

PubMed1991

A dihydrofolate reductase gene from Candida albicans: molecular cloning.

The dihydrofolate reductase gene from Candida albicans has been cloned and partially characterized. A genomic bank from C. albicans strain 10127/5 was constructed in Escherichia coli and screened for trimethoprim resistance. A plasmid pMF1, carrying the resistance marker was isolated and characterized by restriction mapping and Southern blotting. Cells harbouring pMF1 were as sensitive as the parental cells to a wide spectrum of antibacterial agents, except for trimethoprim; the dihydrofolate reductase activity from these cells was trimethoprim resistant.

Candida albicans↗

PubMed1991

Effects of loprazolam on cognitive functions.

The effects of oral loprazolam (1, 2 mg) on vigilance, attention, immediate memory, short-term memory, learning, long-term non-consolidated and long-term consolidated memory were determined. Twelve healthy young male volunteers were given all the treatments, placebo or loprazolam, on three different occasions, in a double-blind, random latin-square sequence, crossing over every 2 weeks. Volunteers completed a battery of tests at night, 3.5 h after drug administration, and in the morning, 10 h after drug administration, to test recall of some of the material presented at night (long-term memory) and residual effects. Loprazolam did not significantly impair any of the functions tested at night. On the other hand, 2 mg loprazolam caused impairment of long-term memory, both consolidated and not. This reduction of long-term memory does not seem to be related to the impairments of vigilance, attention or learning. The 2 mg dose of loprazolam, which did not modify the mean scores and improved vigilance, attention and learning in some of the subjects, reduced long-term memory. Therefore, although caution in interpreting the results should be used, mainly because it is possible that differences in sensitivity of the tests cannot be overcome and because the relative small number of subjects, our results indicate that loprazolam might induce selective impairment of long-term memory. Since there were no differences between the effects on consolidated and non-consolidated memory, the amnesic effect of loprazolam seems to be due to a decrease in the storage of memory traces. There were no clear generalized residual effects in the morning after administration.

Adult↗