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Biomedical subjects

P Valentini

Publications and source records attributed to P Valentini.

At least 73 records · Page 4Linked to original sources
PubMed1985

Effects of pirenzepine on plasma insulin, glucagon and pancreatic polypeptide levels in normal man.

The secretion of various pancreatic hormones (insulin, glucagon and pancreatic polypeptide) is affected to a different extent by the cholinergic system. In 7 healthy subjects the effects of treatment for 1 week with pirenzepine, an anticholinergic drug selective for muscarinic receptors, on basal secretion of these hormones and on that induced by i.v. glucose (IVGTT) and arginine were evaluated. The drug did not reduce basal levels of insulin and glucagon whereas it caused an appreciable reduction in basal pancreatic polypeptide (PP). The responses of insulin and blood glucose to IVGTT and to arginine were not changed by treatment, nor was that of plasma glucagon to arginine. The infusion of arginine did induce an increase in PP level, which reached a statistically significant maximum at 90 min. This response was not particularly different after administration of pirenzepine. Thus, the results confirm the finding that arginine stimulates PP secretion in vivo and that pirenzepine reduces the basal level of the hormone, whereas it did not appear to affect the response to arginine. The findings exclude any direct action of the drug on insulin or glucagon secretion or on glucose metabolism in general.

Adult↗
PubMed1983

Long-term treatment and follow-up studies with pirenzepine in duodenal ulcer: a double-blind study.

Pirenzepine, a new antimuscarinic drug which selectively binds to gastric mucosal muscarinic receptors, has been found to be as effective as cimetidine in promoting the healing of duodenal ulcer. Since recurrence is the major clinical problem in duodenal ulcer, the authors have performed a double-blind randomized study to evaluate the relapse rates during a follow-up period of six months after healing with pirenzepine. Fifty patients were admitted to the trial and randomly allocated to placebo (group C) or pirenzepine (50 mg daily, group A, and 100 mg daily, group B). Forty-four patients completed the trial. During the six months treatment 9 patients had relapses. No significant difference was found between three groups. No side-effects were observed. The 6-month treatment with 50 mg or 100 mg of pirenzepine was well tolerated and without side-effects. The relapse rate during the six months after healing was very low and no significant difference was found between relapse rates in the three treatment groups. These results suggest that seasonal treatment with pirenzepine will prevent duodenal ulcer relapses, increase patient compliance and reduce the social cost of peptic ulcer disease. Additional studies over 12 months of treatment should be undertaken to verify our findings.

Benzodiazepinones↗
PubMed1982

Effect of pirenzepine on L--amino acids stimulated gastric acid secretion and serum gastrin levels in peptic ulcer disease in men.

This report tests in men the effect of Pirenzepine on L-Amino acids stimulated gastric secretion and serum gastrin levels in order to evaluate the true antimuscarinic selective properties of this drug. Since L-Amino acids given intravenously stimulate gastric acid secretion by a mechanism of action selective on the cholinergic receptors of the gastric parietal cells, not mediated through the vagus nerve, gastrin or other gut hormones. Pirenzepine should be an L-Amino acids antagonist as far as the gastric acid secretion is concerned. By confirming this presumed antagonism between Pirenzepine and L-Amino acids given intravenously, this report points out in men the selective antimuscarinic effect of this anti ulcer drug on the high affinity muscarinic receptors of the gastric parietal cells. Finally a decrease in gastrin serum levels was observed after the i.v. administration of Pirenzepine and this could be explained by a possible effect of blockade of this drug on the cholinergic receptors of the antral G cells, but these data need further experimental confirm. Attention is then paid to the different mechanism of action between Pirenzepine, H2 receptors antagonist drugs and other anti ulcer drugs on healing gastric or duodenal peptic ulcers.

Amino Acids↗
PubMed1979

[Drug resistance of Shigella strains isolated in Central Italy during 1969-1976 (author's transl)].

Only ninety-three strains of Shigella, eightyseven of which have been identified as S. sonnei and six as S. flexneri were collected during 1969-1976 at the Pathogen Enterobacteria Centre of Pisa in Central Italy, as evidence of an epidemiological situation marked by a rare occurrence of syndromes related to these organisms. The collected strains were tested with disks of nine antibacterial drugs in common use: the survey detected sensitivity of all the strains to cephaloridine, ampicillin, carbenicillin, kanamycin and gentamicin, whereas a fair percentage of resistance appeared to streptomycin, tetracycline, chloramphenicol and cotrimoxazole. Both within multiresistant strains and those characterized by single resistances (forty-three of them in all), were present strains capable of transferring different drug resistance patterns to E. coli K-12, as evidence of being under extrachromosomial genetic control.

Anti-Bacterial Agents↗
PubMedDate not supplied

Cholestatic jaundice in infectious mononucleosis.

Jaundice is a less frequent sign in infectious mononucleosis, more often caused by hemolysis, rarely by hepatocytes damage. In subjects with erythrocyte plasmatic membrane defects such as spherocytosis, any infection could increase hemolysis. The authors describe the case of a young spherocytosis patient in whom Epstein-Barr virus caused an intense cholestatic jaundice and they discuss the possible damage mechanisms according to the recent studies on cholestasis pathogenesis.

Child↗
PubMedDate not supplied

Childhood glomerulonephritis associated with varicella and streptococcal infection.

Varicella is a usually benign disease of childhood and its complications are uncommon in immunocompetent children. In recent years we have witnessed the increasing virulence of group A beta-haemolytic streptococci (GABHS). In particular, in 1993, 50% of new cases of invasive GABHS disease were associated with varicella infection and all were suppurative complications. Because also a non suppurative complication of varicella as glomerulonephritis associated with GABHS infection, has been published in only one case, we feel that it could be of interest to describe this condition in two other cases we have observed.

Chickenpox↗
PubMedDate not supplied

Low-dose ARA-C and 1(OH) D3 administration in acute non lymphoid leukemia: pilot study.

BACKGROUND AND METHODS: Vitamin D3 metabolites have been shown to be able to induce monocytic differentiation both in vitro and in vivo. In this paper we report the preliminary results of an uncontrolled clinical trial where low doses of ARA-C and 1(OH)D3 were administered to patients affected by acute non lymphoid leukemia. The achievement of complete or partial remission was recorded. Morphological and cytochemical studies were performed in order to control the blastic populations under therapy. Immunocytochemical studies were also performed in some patients in order to detect the presence of 1,25(OH)2D3 receptors in the blast population. Seventeen percent reached complete remission and 45% reached only a partial remission. RESULTS AND CONCLUSIONS: The results are in line with those showing that low doses of ARA-C are an effective treatment in this type of leukemia. In some cases (7/11), a monocytic/monoblastic shift was detected. The demonstration of 1,25(OH)2D3 receptors in some blasts is also reported. Thus it is possible to suggest that the vitamin D metabolite displays "in vivo" the differentiating activity already shown "in vitro".

Adult↗
PubMedDate not supplied

Synergistic effects of alpha interferon and 1,25 dihydroxyvitamin D3: preliminary evidence suggesting that interferon induces expression of the vitamin receptor.

BACKGROUND: To active metabolite of vitamin D3-1,25(OH)2D3-is a well-known differentiation inducer. The addition of this metabolite to sensitive cell cultures inhibits proliferation and induces monocytic-macrophagic differentiation. Alpha interferon may also inhibit proliferation and increase the expression of some surface antigens in some neoplastic cells. In the present report, we describe the synergistic activity of these two drugs on U-937 and on cultured cells from a leukemic patient. METHODS: Proliferation was studied by 3H-thymidine incorporation; differentiation markers were evaluated immunologically by monoclonal antibodies and by cytochemical tests. Phagocytosis and NBT reduction test were also performed in order to confirm the differentiating properties of these drugs. Finally, the expression of the 1,25(OH)2D3 receptor was evaluated by immunochemical methods. RESULTS: After culturing these cells for 72 hours in the presence of 1,25(OH)2D3, cell proliferation was reduced and the expression of some phenotypic and functional markers suggested monocytic-macrophagic differentiation. Alpha interferon and 1,25(OH)2D3 synergistically inhibit the proliferation of U-937 cells. Alpha interferon increased the expression of the 1,25(OH)2D3 receptor in U-937 cells. CONCLUSIONS: The reported results confirm the synergistic activity of INF and 1,25(OH)2D3 on cell proliferation in monoblastic cells. The possible role of the increased expression of the vitamin receptor in cells cultured in the presence of INF is discussed.

Calcitriol↗
PubMedDate not supplied

[Stationary and migratory avifauna as reservoirs of Salmonella, Yersinia and Campylobacter].

Domestic and wild animals have been always considered very important as reservoir of agents of human infections. Particularly birds, because of their great mobility from a continent to another or within the limits of the same ecosystem may transfer pathogenic micro-organisms. The present survey was undertaken in order to evaluate the presence of Campylobacter, Yersinia and Salmonella in migratory and permanent birds. During the period October 1986 to March 1988 intestinal loops were collected from a total of 217 birds representing 17 different species shot, during hunting seasons, in the inland of Versilia in the district of Lucca. Each sample was divided into three parts and examined for the presence of Campylobacter, Yersinia and Salmonella. Campylobacter was isolated from 74 of the 217 birds examined (34.10%). Yersinia was recovered from 26 birds (11.98%), while only 8 birds (3.68%) harboured Salmonella. Most of the samples carried only one of the three bacterial genera investigated while 9 harboured at the same time Yersinia and Campylobacter, 1 Salmonella and Campylobacter, and 1 Salmonella, Yersinia and Campylobacter. Campylobacter spp.: On the ground of Lior's biotyping scheme, the 74 strains, isolated from 16 of the 17 species of birds examined, have assigned to three biochemically different species. C. coli was the most commonly isolated followed by C. jejuni and C. laridis. Of the 54 isolates of C. coli 30 belonged to biotype I and 24 to biotype II. 19 C. jejuni organisms were differentiated into 5 belonging to biotype I and 14 to biotype II. The only C. laridis isolated belonged to biotype I. Yersinia spp.: 37 strains belonging to the genus Yersinia were isolated from 26 birds. In 10 samples different types of Yersinia were identified. Most of the strains could be ascribed to Yersinia enterocolitica (28 strains), 3 to Yersinia frederiksenii, 3 to Yersinia intermedia and 1 to Yersinia pseudotuberculosis. 2 strains were identified as atypical Yersinia. Salmonella spp.: 8 strains belonging to the genus Salmonella were isolated from 3 different species of birds. The isolates were identified as Salmonella typhi-murium (7 strains) and Salmonella blockley (1 strain). Salmonella has been isolated from 8 birds, six of which were pheasants shot during the same day in the same area and probably coming from the same breeding. In fact, in Tuscany, pheasants are bred and then set free in many hunting areas.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗