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Biomedical subjects

P Giusti

Publications and source records attributed to P Giusti.

97 records · Page 6Linked to original sources
PubMedDate not supplied

An experimental study on dependence liability of zipeprol.

Zipeprol, a piperazine ethanol derivative, is a non-essential but widely used (paediatric) antitussive, which is not legally considered as being capable of creating dependence or abuse liability. A first group of experimental results was obtained assaying the displacement of 1 nM [3H]naloxone by zipeprol vs morphine on the rat brain homogenate fractions. A second group was carried out on the longitudinal muscle of guinea-pig ileum, using the field stimulation technique, either in the absence or in the presence of naloxone 1 x 10(-5)M or in the absence or in the presence of yohimbine 1 x 10(-5)M. Further investigations concerning the pharmacological and the biochemical characterization of the mechanisms involved in abuse liability were carried out by means of the in vitro inhibition of ACh response on the guinea-pig ileum preparation. The results indicate zipeprol as a moderate opioid agonist, which also shows a direct anticholinergic effect, independent of presynaptic alpha 2 interaction.

Acetylcholine↗
PubMedDate not supplied

Osteoblast responses to collagen-PVA bioartificial polymers in vitro: the effects of cross-linking method and collagen content.

A range of 'bioartificial' collagen/poly(vinyl alcohol) blends have been produced, cast as films and cross-linked using either glutaraldehyde or a dehydrothermal treatment (DHT). Films were used as substrates for the culture of osteoblast-like cells. The attachment, adhesion and proliferative responses of these cells to the range of films were examined using proliferation assays, light, electron and confocal microscopy. There was an inverse relationship between collagen content of gluataraldehyde cross-linked films and the extent of cell proliferation on them. A cytotoxicity assay demonstrated no toxic effect related to increasing collagen content. The greatest differences in cell responses observed were associated with the choice of cross-linking method. Films cross-linked with glutaraldehyde showed variation related to collagen content in cell adhesion, proliferation and morphology. Such differences were not apparent with the DHT cross-linked films. Collagen/PVA 'bioartificial' films can be dehydrothermally cross-linked to increase biological stability and reduce water solubility. The method of cross-linking employed is the greater influence in determining osteoblast compatibility with these materials. The DHT cross-linking method is a preferable alternative to the use of glutaraldehyde. Collagen/PVA bioartificial films cross-linked by the DHT method have shown potential for biocompatibility with osteoblasts.

Biocompatible Materials↗
PubMedDate not supplied

Crohn disease of the small bowel: spiral CT evaluation after oral hyperhydration with isotonic solution.

PURPOSE: Our aim was to evaluate the accuracy of spiral CT study of small-bowel Crohn disease with use of oral hyperhydration with isoosmotic solution. METHOD: We prospectively analyzed 33 consecutive patients and 10 control subjects with spiral CT after oral administration of 2,000 ml of polyethylene glycol electrolyte-balanced solution. The CT diagnoses were compared with the results of conventional radiologic oral barium examination (33 cases), ileum colonoscopy (8 cases), and surgery (4 cases). RESULTS: The final diagnoses were Crohn disease (14 cases), no small-bowel disease (16 cases), cancer of ileocecal valve (1 case), carcinosis of mesenteric root (1 case), and intestinal lymphangiectasia (1 case). In the control group, no abnormalities of the small bowel were found. The sensitivity of spiral CT was 85.7%, specificity 100%, positive predictive value 100%, negative predictive value 90%, and diagnostic accuracy 93.9%. CONCLUSION: Our method allowed adequate distension of the small bowel for spiral CT studies, thus resulting in a safe and effective alternative to small-bowel spiral CT enema, which can be used in patients that refuse the nasojejunal balloon catheter.

Adolescent↗
PubMedDate not supplied

Multidetector CT of the small bowel: evaluation after oral hyperhydration with isotonic solution.

PURPOSE: The aim of our study was to assess the diagnostic capabilities of multidetector CT in the evaluation of the small bowel in different pathological conditions, with the use of oral hyperhydration with isotonic solution. MATERIALS AND METHODS: The study retrospectively evaluated 106 patients who underwent multidetector CT of the small bowel. Four groups were considered on the basis of the clinical findings: group A (48 cases), with suspected or certain chronic inflammatory disease of the small bowel; group B (16 cases), with suspected neoplastic lesion of the small bowel; group C (17 cases), patients affected by malabsorption; group D (25 cases), others: 13 cases with non-specific abdominal pain, 4 cases with occult bleeding, 8 cases affected by fever of unknown origin. Thirteen patients had previously undergone surgical intestinal resection. In all cases the CT examination was performed after the oral administration of 2000 mL polyethylene glycol electrolyte balanced solution; before the scan, N-butyl scopolamine or glucagon were administered intravenously to obtain rapid inhibition of bowel peristalsis. All multidetector CT scans were acquired at baseline and 50 seconds after the I.V. administration of 110-130 ml high-concentration non-ionic iodinated contrast medium. The images were subsequently processed on a dedicated workstation (Advantage Windows 4.0, GE Medical Systems) to obtain multiplanar reconstruction (MPR). We considered the following CT findings: fold distribution, wall thickening and stratification and contrast enhancement, extraparietal involvement and abnormalities of the abdominal organs. The CT diagnoses were compared with the clinical and laboratory findings (86 cases) and with the results of barium follow-through (55 cases), ileo-colonoscopy (45 cases) or surgery (28 cases). RESULTS: CT examination allowed the correct diagnosis in 86/106 cases (89%); 20 patients were not included in the study because of a poor (11 cases) or absent (9 cases) small bowel loop distension. The final diagnoses in the 86 patients were: Crohn's disease of the small bowel (38 cases), Crohn's disease of the duodenum (1 case), granulomatous colitis (3 cases), malabsorption (8 cases), neoplastic lesion (4 cases), post-radiation conglomeration of ileal loops (1 case), intestinal lymphangiectasia (1 case), ulceration of the last ileal loop (1 case). In 29 cases no abnormalities of the small bowel were found. Spiral CT yielded 52 true positive cases, 5 false negative cases, 2 false positive cases, and 27 true negative RESULTS: The sensitivity of the technique was 91%, specificity 93% and diagnostic accuracy 92%. CONCLUSIONS: Multidetector CT of the small bowel performed after oral hyperhydration with isosmotic solution, proved to be an accurate and thorough technique. It can be considered a safe and effective alternative to conventional radiographic studies and to small bowel spiral CT enema in patients that refuse the nasojejunal balloon catheter or the administration of methylcellulose.

Journal Article↗