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F Bonvicini

Publications and source records attributed to F Bonvicini.

At least 37 records · Page 2Linked to original sources
PubMed1997

Anti-CagA antibodies are associated with atrophic gastritis in a population at high gastric cancer risk: a morphometric study by computerized image analysis.

BACKGROUND: CagA-positive Helicobacter pylori strains appear to increase the risk for atrophic gastritis. AIM: To verify the association between CagA status and atrophic gastritis in the general population by means of computerized image analysis. SUBJECTS: Forty-five subjects were chosen out of a representative sample of a population at high gastric cancer risk. METHODS: Helicobacter pylori status was assessed by IgG ELISA, rapid urease test and histology. Serum anti-CagA antibodies were detected by western blotting. Subjects were subdivided into 3 groups: 15 subjects Helicobacter pylori positive CagA-positive, 15 Helicobacter pylori positive CagA-negative and 15 controls Helicobacter pylori negative. Biopsies were studied using the Sydney System score. A computerized image analysis was used to count inflammatory cells in the lamina propria and to measure the area of the gastric glands. RESULTS: Anti-CagA antibodies were associated with reduction of gland area (126,671 +/- 81,032 mu 2/mm2 vs 231,384 +/- 54,159; p = 0.0001), with increasing both of polymorphonuclear cells (426 +/- 238 cell/mm2 vs 136 +/- 69; p = 0.0001) and mononuclear cells (8675 +/- 1304 cell/mm2 vs 7141 +/- 1230; p = 0.003). CONCLUSIONS: The association of anti-CagA antibodies with a high grade of gastric atrophy further supports the hypothesis that Helicobacter pylori CagA-positive strains can promote the multifactorial process of gastric carcinogenesis.

Adult↗
PubMed1996

Clinical, pathological, and antibody pattern of latent celiac disease: report of three adult cases.

We report the clinical, pathological, and serological findings of three adult patients with latent celiac disease. The initial intestinal biopsies, which were normal, were carried out in the first case during an upper gastrointestinal endoscopy performed for a duodenal ulcer, in the second case for first-degree familiarity with a celiac patient, and in the third case because of the presence of malabsorption symptoms. In all three cases, intraepithelial lymphocytes were within the normal range in the first biopsy and cannot, therefore, be considered as a marker of latent celiac disease. In only two of the three patients was it possible to carry out the search for the serum antibodies connected with celiac disease at the time of the first biopsy. In both these cases, the antijejunal antibodies were present before the development of the intestinal lesions.

Adult↗
PubMed1995

Wheat deficient in gliadins: promising tool for treatment of coeliac disease.

The toxicity of two varieties of bread wheat, one poor in alpha and beta gliadins and the other poor in alpha, beta, gamma, and omega gliadins, has been tested. The peptic-tryptic digest of these wheats was assessed using coeliac mucosa in an in vitro organ culture system. A significantly lower toxicity was found in respect of bread wheat containing all gliadin fractions. These results suggest new opportunities for the treatment of coeliac disease.

Adult↗
PubMed1995

A population based study of Helicobacter pylori infection in a European country: the San Marino Study. Relations with gastrointestinal diseases.

Helicobacter pylori is present worldwide but few large population studies exist on the epidemiology of the infection. A random cross sectional study was performed of H pylori infection in the adult population of San Marino, a European country with high gastric cancer rate, to assess its prevalence and to evaluate its relations with gastrointestinal disease. In 2237 subjects (77% of the initial sample) H pylori IgG antibodies were detected with enzyme linked immunosorbent assay (ELISA) and immunoblotting. A questionnaire including questions about occupation, place of birth, and smoking was given to all subjects. Dyspepsia, peptic ulcer, and gastric cancer in the subjects, relatives, and partners as well as use of drug, dental treatment/prostheses, and gastrointestinal endoscopies, were evaluated by multivariate analysis. H pylori prevalence was of 51%, increased with age from 23% (20-29 years) to 68% (> or = 70 years), and was higher among manual workers. H pylori was independently associated with ulcer (OR = 1.63, 95% confidence intervals (CI) = 1.16 to 2.27), H2 antagonists (OR = 1.94, 95% CI = 1.21 to 3.10), and benzodiazepines (OR = 1.57, 95% CI = 1.02 to 2.42), dental prostheses (OR = 1.25, 95% CI = 1.05 to 1.49), gastroscopy in the past five years (OR = 1.50, 95% CI = 1.05 to 2.14), peptic ulcer in siblings (OR = 1.52, 95% CI = 1.09 to 2.12), gastric cancer in father (OR = 1.61, 95% CI = 1.02 to 2.52). The association of seropositivity with history of ulcer, gastric cancer in family, gastroscopy, and H2 antagonists suggests that H pylori is an epidemiological key factor in the pathogenesis of gastroduodenal diseases in this area.

Adult↗
PubMed1994

Eosinophilic gastroenteritis in a patient with large-cell anaplastic lung carcinoma: a paraneoplastic syndrome?

A 39-year-old man was hospitalized with abdominal pain and diarrhoea. The total eosinophil count was 11,800/dL; the jejunal biopsy showed diffuse and patchy eosinophils and plasma cell infiltration of the lamina propria; symptoms and hypereosinophilia disappeared after steroid therapy. Two months later the symptoms reappeared together with left supraclavicular lymphnode enlargement. The chest X-ray showed a mass within the left lung apex. Lymph node biopsy showed metastases from large-cell anaplastic carcinoma. The possibility of eosinophilic gastroenteritis as a paraneoplastic manifestation is discussed.

Adult↗
PubMed1990

Ultrastructural aspects of aging rat hippocampus after long-term administration of acetyl-L-carnitine.

In aged rats a decrease in axosomatic synapses of granule cells as well as a decrease in the number of synaptic vesicles of giant synapses was found. These phenomena were supposed to be correlated on the basis of a feed-back circuit existing at the level of the dentate gyrus. In fact the axosomatic synapses of the granules are inhibitory gamma-aminobutyric acid-ergic terminals of interneurons. Interneurons receive excitatory afferences from granules via the giant synapses of the mossy fibre collaterals. This results in a feed-back regulation of granule cell activity. The long-term administration of acetyl-L-carnitine to aged rats restores a synaptic pattern comparable to that of young rats. This effect on synaptic plasticity is transient.

Acetylcarnitine↗
PubMed1990

Protection of the upper gastrointestinal mucosa: the role of antacids.

Experiments performed in animals and in healthy human subjects suggest that antacids increase prostaglandin synthesis and have a cytoprotective effect on gastroduodenal mucosa. To investigate this hypothesis, the ability was evaluated of an antacid containing an aluminium/magnesium hydroxide combination (Maalox TC) to modify prostanoid production at the gastric level in 28 patients with gastric antral ulcer of various sizes in different stages of activity with or without erosive gastritis. After the antacid treatment, a significant prostaglandin E2 reduction was observed, together with a significant 6-keto-prostaglandin F1 alpha increase, but there was no thromboxane B2 variation at antrum level, nor any significant modification of prostanoid production at body level. The decreased prostaglandin E2 levels, detected after treatment with the antacid combination, may be due to lesion improvement, decreased synthesis or increased catabolism by mucosal cells, to a drop in this prostaglandin production by inflammatory cells. As far as 6-keto-prostaglandin F1 alpha is concerned, the obtained data confirm the results reported by other authors in healthy human subjects. The increase of this prostaglandin could enhance blood flow, resulting in a protective effect.

6-Ketoprostaglandin F1 alpha↗
PubMed1989

The lectin-gold technique: an overview of applications to pathological problems.

Lectins are proteins, mainly of vegetal origin, which recognize glycosidic residues with high specificity; for this property they have been used for many studies of molecular biology. The colloidal gold represents at present the most popular electron dense marker employed in immunocytochemistry, since it offers intrinsic and unique characteristics which are superior to those displayed by the other markers. The cytochemical method which utilizes the gold-labelled lectins takes advantages from both the two systems, in order to optimize the localization of the glycoconjugates. The present paper reviews both the technical aspects of the preparation of the lectin-gold complex and its application to some selected pathological problems. In particular, the papers concerning the eye and ear tissues, the urinary, reproductive, nervous and digestive systems and the blood cells are quoted.

Animals↗
PubMed1989

Scanning electron microscopy in the study of Campylobacter pylori associated gastritis.

The close association between Campylobacter pylori (CP), gastritis and peptic ulcer is now well established. Moreover increasing evidence has been collected of a major etiological role of CP in type B chronic gastritis. For this reason, searching for CP is essential in all patients with upper gastrointestinal symptoms. Scanning electron microscopy (SEM) is a most reliable technique for studying the distribution of microorganisms and their relationship to the gastric mucosal surface. The aim of this paper is to compare SEM to other routine methods of detection for CP, such as Giemsa staining on histological sections and Urease Microtiter Test (MT) on fresh tissue and to investigate the surface morphology of gastric mucosa colonized by CP and to correlate it with the histopathological picture. Thirty-seven biopsies taken from the gastric body and the antrum of 22 patients were used for each type of determination. The different parameters were graded semiquantitatively. Histology showed a normal mucosa in 4 cases, chronic superficial gastritis in 12 and chronic atrophic gastritis in 21 cases. SEM was more sensitive than histology and Urease MT in detecting Campylobacter pylori. This is due to the patchy distribution of this bacterium on gastric mucosa. For this reason SEM should always be performed when routine tests are negative. The presence of CP correlated significantly (p less than 0.001, Spearman Rank Correlation Test) with the neutrophilic infiltrate, thus with the "activity" of the gastritis. The CP associated gastritis has no distinctive surface features other than the presence of the bacterium. SEM morphology of surface gastric mucous cells suggests that CP does not damage the lining epithelium directly. Neutrophils and inflammatory mediators could be involved in the production of the mucosal lesions.

Adult↗
PubMed1987

Light and electron microscopy investigation of glycoconjugates of rat hippocampus by lectin-gold technique.

The distribution of glycoconjugates in rat hippocampus was investigated by light and electron microscopy using gold-labelled lectins with different sugar specificities: ConA, WGA, PNA and LTA. A morphological correlation with cytochemical data was performed, and revealed the presence of intensely-stained (dark), unstained (light) and weakly-stained (intermediate) neurons both in Ammon's horn and in the dentate gyrus. The glycoconjugates are located in the nucleus, the perikaryal cytoplasm and the cytoskeleton of axons and dendrites: they are probably involved in the mechanisms of transport towards the synaptic membrane. The presence or absence of glycoconjugates corresponds to the particular ultrastructural aspect of the cell. This suggests the existence of different functional states of the neurons, probably correlated with the synthesis of neurotransmitter precursors or receptors.

Animals↗
PubMed1987

Ultrastructural aspects of ageing rat hippocampus and effects of L-acetyl-carnitine treatment.

The ageing rat hippocampus undergoes ultrastructural changes, including the loss of axosomatic synapses of the granule cells. These synapses are supposed to take part in a feed-back regulation of granule cell activity, as they are inhibitory terminals of interneurons which receive afferences from the granules themselves via the giant synapses formed by the collaterals of the mossy fibres. In the present study the authors performed a quantitative analysis of axosomatic and giant synapses at the ultrastructural level in aged rats as compared with young animals. In aged rats a decrease both in axosomatic synapses and in giant synapsis vesicles was found, giving further support to the postulated feed-back mechanism. Both young and old rats were treated with L-acetyl-carnitine, a drug which favours the synthesis of acetylcholine, the main neurotransmitter deficient in old age. In aged rats the drug restored a normal number of both axosomatic synapses and giant bouton vesicles. The authors hypothesize that the drug, by a cholinergic-type mechanism, restores the excitatory afferences to the granule whose axon would thus form normal giant boutons with the interneuron, reestablishing the feed-back regulation. In young rats the drug induced a decrease only of the axosomatic synapses, suggesting that an "over-excitation" might impair the information to the local-circuit neurons, thus interrupting feed-back control.

Acetylcarnitine↗
PubMed1986

Detection of mucus glycoconjugates in human conjunctiva by using the lectin colloidal gold technique in TEM. I. A quantitative study in normal subjects.

We applied a specific cytochemical reaction to characterize the glycoconjugates produced by goblet and non-goblet epithelial cells of normal human conjunctiva. For this purpose we utilized the lectins, proteins of vegetal origin, which are extremely sensitive in binding glycosidic residues. In particular, we used WGA, PNA, SBA and ConA conjugated with colloidal gold as ultrastructural marker for Transmission Electron Microscopy. This technique allowed us also to perform a quantitative analysis, by counting colloidal gold particles present on mucus granules. In this way we analyzed the content both of goblet and non-goblet epithelial cells. In the former, WGA, PNA, SBA and ConA receptors, here reported in decreasing density, were present. In the latter WGA was always positive, SBA and PNA sometimes were negative, ConA was always negative. We speculate the different contribution to mucus production by these two sources may be important in evaluating tear film stability alterations occurring in those diseases in which non-goblet epithelial cell vesicles increase.

Carbohydrate Metabolism↗
PubMed1986

Characterization of mucus glycoconjugates in normal human conjunctiva by lectins in light microscopy, transmission and scanning electron microscopy.

Maintenance of tear film in normal conditions is dependent on mucus layer integrity and the presence and distribution of conjunctival epithelial cell microvilli. In the present work a new methodology has been developed to gain correlative information about microprojection assessment and mucus composition, from the same specimen, by Light Microscopy (LM), Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). We have characterized the glycosidic residues secreted by goblet cells in normal human conjunctiva, by means of four lectins (WGA, ConA, PNA and SBA), conjugated with FITC for LM and with colloidal gold for TEM and SEM. The cytochemical reactions were performed on histological sections of paraffin-embedded material and on semithin and ultrathin sections of both Epon embedded material directly processed for TEM and of blocks recovered from SEM and reprocessed for TEM. WGA, ConA, PNA and SBA receptors were found to be constituents of the mucus produced by goblet cells in human conjunctiva. The granules of the so-called "second mucus system" (SMS) cells were labelled mainly by WGA. A difference in the quality of glycoconjugates between goblet cells and SMS cells has been also demonstrated. Our results provide an improved method to evaluate alterations of tear film that occur in many conjunctival diseases.

Carbohydrates↗
PubMed1986

Correlative scanning electron microscopy in the study of human gastric mucosa.

We studied two aspects of the human gastric mucosa: the surface morphology of mucous cells, as viewed by scanning electron microscopy (SEM); the glycosidic components of intracellular mucins, characterized by means of lectins. The latter were conjugated with fluorescein isothiocyanate and with colloidal gold-silver for the visualization of the reaction products in light microscopy (LM) and in SEM (backscattered mode) respectively. The surface morphology of mucous cells appears to be correlated to the secretory state. In gastric ulcers we found a prevalence of non-secreting cells. A decrease in glycosidic receptors for fucose-binding lectin and galactose-(1-3)-N-acetyl-galactosamine-binding lectin was also observed. This suggests the presence of an impaired mucus secretion which may play a role in the pathogenesis of gastric ulcer. Spiral bacteria, supposed to be aetiologically related to peptic ulcer and gastritis, were easily detected by SEM. Intestinal metaplasia defined "complete" in LM showed surface morphology and glycosidic components different from those of true intestinal mucosa. This implies the necessity of taking into account also these parameters when classifying this lesion. The same applies to polyps. Our data indicate that correlative SEM may contribute further information on the pathogenesis and pathology of gastric diseases.

Adult↗
PubMed1986

S.E.M. study I: Gastric and duodenal lesions induced by non-steroidal anti-inflammatory drugs (aspirin, piroxicam) in man.

A scanning electron microscopy (SEM) study was performed on the gastric and duodenal mucosa of 14 patients treated with Aspirin or Piroxicam. Six patients with normal mucosal morphology were treated with either 1.5 g/day of Aspirin (3 patients) or 20 mg/day or Piroxicam (3 patients) for one month. In addition, 8 rheumatic patients were treated with a similar dose of Aspirin (4 patients) or Piroxicam (4 patients) for at least 4 months. SEM was used to evaluate the following parameters: mucosal structure, cellular exfoliation and anisocytosis, alteration of the microvilli (blebs). The mucosa showed various aspects of alterations ranging from minimal changes (microvillar alteration) to a completely subverted structure both in the stomach and in the duodenum. Mucosal changes, both on the edge of the macroscopic lesions and at a distance from these, were visible with SEM even when endoscopy was normal. Piroxicam appeared slightly less damaging than Aspirin, and no difference was observed between short-term and long-term treated patients, either with Aspirin or with Piroxicam.

Adult↗
PubMed1986

S.E.M. study II: Protective effect of ranitidine against gastric and duodenal lesions induced by non-steroidal anti-inflammatory drugs.

The effect of Ranitidine on the gastric and duodenal lesions induced by Aspirin or Piroxicam was studied by scanning electron microscopy (SEM). Twelve patients were entered into the study. The first group consisted of 6 patients with normal basic morphology, of which 3 were treated with 1.5 g of Aspirin and Ranitidine 300 mg/day, and 3 with 20 mg of Piroxicam and Ranitidine 300 mg/day, for one month. The second group was composed of 6 rheumatic patients, 3 of which took 1.5 g of Aspirin and the other 3 received 20 mg of Piroxicam per day for at least four months. Ranitidine (300 mg/day) was then administered concomitantly for one month to all these 6 patients. Overall, Ranitidine appeared to have a positive effect in preventing the development of gastroduodenal lesions induced by these anti-inflammatory drugs in the first group of patients. No differences were observed in the ability of Ranitidine to promote the healing of lesions induced by chronic treatment. Ranitidine, however, appeared to be more effective in preventing lesions induced by Aspirin rather than those induced by Piroxicam.

Adult↗