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Biomedical subjects

G Nicoletti

Publications and source records attributed to G Nicoletti.

At least 271 records · Page 15Linked to original sources
PubMedDate not supplied

Aztreonam versus gentamicin for short-term prophylaxis in biliary and gastric surgery.

Short-term antibiotic prophylaxis was studied in 80 patients undergoing biliary or gastric surgery. The patients were randomized to receive 1 g of aztreonam or 80 mg of gentamicin intravenously 30 minutes before surgery and 8 and 16 hours after surgery. Of samples taken from the abdominal cavity for bacteriologic study, 53% were culture positive. Wound infections developed in two (4.5%) of 44 patients receiving aztreonam and in seven (19.4%) of 36 patients treated with gentamicin. Staphylococcus epidermidis and Enterobacter species were isolated from sites of wound infection in the aztreonam group; Escherichia coli (two isolates), Pseudomonas aeruginosa (two isolates), Enterobacter species, Klebsiella species, Enterococcus faecalis, and Aeromonas hydrophila were isolated from the gentamicin group. Our data indicate that aztreonam is safe and effective for the prevention of infections following biliary and gastric surgery.

Adult↗
PubMedDate not supplied

In vitro activity of piperacillin/tazobactam against 615 Pseudomonas aeruginosa strains isolated in intensive care units.

From May 1996 to September 1997, 615 Pseudomonas aeruginosa strains isolated from patients in intensive care units collected from different Italian laboratories were studied. The susceptibility of piperacillin/tazobactam, in comparison with other antipseudomonal antibiotics, to their NCCLS breakpoints was evaluated: amikacin 79. 6%, carbenicillin 67.0%, ceftazidime 73.4%, ciprofloxacin 55.8%, imipenem 64.1%, piperacillin 88.1%, piperacillin/tazobactam 92.4% and ticarcillin/clavulanic acid 69.0%. Seventy-three strains were selected because of their resistance to piperacillin and the mechanisms underlying such a resistance were investigated. Isoelectric focusing and hydrolysis assays revealed the presence of 15 plasmid-mediated beta-lactamases. Chromosomal beta-lactamase derepression was demonstrated in 34 isolates. The remaining 24 piperacillin-resistant strains did not produce beta-lactamases and an 'intrinsic mechanism' of resistance was inferred. The piperacillin/tazobactam combination restored resistance in 25 piperacillin strains. Nine of these were derepressed for chromosomal beta-lactamase, 8 showed impermeability and 8 showed plasmid enzymes.

Drug Therapy, Combination↗
PubMedDate not supplied

In vitro activity of cefpirome against beta-lactamase-inducible and stably derepressed Enterobacteriaceae.

Most members of the Enterobacteriaceae and Pseudomonas aeruginosa possess an inducible chromosomal class I beta-lactamase. Bacterial strains which produce high levels of beta-lactamase constitutively can be isolated from infections; these derepressed mutants are responsible for resistance to third-generation cephalosporins and ureidopenicillins. Minimum inhibitory concentrations of cefpirome, a fourth-generation cephalosporin, and other beta-lactam antibiotics were determined for a series of mutants of Citrobacter freundii, Enterobacter cloacae, Morganella morganii, Proteus vulgaris and Serratia marcescens with inducible stably derepressed or basal expression of chromosomal class I beta-lactamases. All the antibiotics tested were almost equally active against beta-lactamase-inducible organisms and their basal mutants. Imipenem and cefpirome showed better activity against derepressed mutants than third-generation cephalosporins and ureidopenicillins.

Anti-Bacterial Agents↗
PubMedDate not supplied

Clinical isolate of a Xanthomonas maltophilia strain producing L-1-deficient and L-2-inducible beta-lactamases.

Xanthomonas maltophilia produces two inducible beta-lactamases, L-1 and L-2, and resists the antimicrobial activity of beta-lactam antibiotics including carbapenems. L-1 has carbapenemase activity and L-2 is a cephalosporinase. It has been suggested that these beta-lactamases share regulatory components. We isolated a recent clinical X. maltophilia strain susceptible to carbapenems and resistant to almost all the other beta-lactam antibiotics tested. beta-Lactamase induction with cefotaxime showed that the clinical isolate had low-level expression of L-1 beta-lactamase but remained inducible for L-2 enzyme. The possible relationship of this enzyme to carbapenem sensitivity is considered.

Anti-Bacterial Agents↗
PubMedDate not supplied

Cefetamet pivoxil: comparable evaluation with other orally available antibiotics against selected species of respiratory pathogens.

Cefetamet pivoxil, the prodrug ester of cefetamet, is a new third-generation cephalosporin with a broad spectrum of activity. The in vitro activity of cefetamet was superior to that of cefaclor, ceftibuten, amoxicillin plus clavulanic acid, and amoxicillin alone when tested against 403 strains of freshly isolated upper and lower respiratory tract pathogens. Cefetamet killed 100% Haemophilus influenzae and H. parainfluenzae, including beta-lactamase-producing strains, at < or = 0.25 mg/l, Streptococcus pyogenes and S. pneumoniae at < or = 0.5 mg/l, S. agalactiae at < or = 0.1 mg/l, and streptococci at < or = 2.0 mg/l. Moreover, at < or = 4 mg/l (breaking point), cefetamet was also highly effective against Escherichia coli (94%), Klebsiella pneumoniae (92%), K. oxytoca (91%) and, at 1 mg/l, against Moraxella catarrhalis (90%), including beta-lactamase-producing strains. Furthermore, time-killing analyses at 4 x MIC demonstrated that cefetamet was bactericidal against beta-lactamase-producing H. influenzae, M. catarrhalis, and K. pneumoniae within 6 h and S. pneumoniae within 4 h. Hydrolysis studies confirmed cefetamet's stability to TEM1 and SHV1, the most common enterobacterial beta-lactamases.

Administration, Oral↗
PubMedDate not supplied

Comparative in vitro activity of cefodizime and other antibiotics against pathogens recently isolated in Italy.

In the present study we tested the susceptibility to cefodizime on 1,985 selected nosocomial pathogens isolated in five laboratories. Moreover, we evaluated the epidemiology of the resistance of the tested strains to cefodizime and to other antibiotics clinically available in Italy. The susceptibility to cefodizime was determined with both MIC (microdilution method) and the agar diffusion method (Kirby-Bauer). The Kirby-Bauer method was used to compare the antibiotics. Cefodizime was equivalent in activity to ceftazidime and ceftriaxone and was more active than piperacillin and amoxicillin + clavulanic acid. The activity of gentamicin (where tested) was generally comparable to that of cefodizime; ciprofloxacin had lower percentages of resistance against some species of Enterobacteriaceae and staphylococci.

Bacteria↗
PubMedDate not supplied

In vitro activity of biapenem against recent gram-negative and gram-positive clinical isolates.

The in vitro activity of biapenem, a new carbapenem, against 535 clinical recent isolates was compared with those of other antibiotics. Biapenem showed broad-spectrum activity against gram-negative and gram-positive clinical isolates. The new carbapenem was more active than imipenem against members of the family Enterobacteriaceae with MIC90S ranging from 0.12 to 2 mg/l and from 0.25 to 4 mg/l, respectively. Moreover it was 2-fold more active than imipenem against Pseudomonas aeruginosa (MIC90, 8 and 16 mg/l, respectively). Taken together, these results indicate that biapenem shares the favorable in vitro activity properties of imipenem and merits further study in the treatment of infections caused by a wide range of pathogens.

Gram-Negative Bacteria↗
PubMedDate not supplied

[Microbiological characteristics of coastal waters in the district of Catania].

The Authors examined bacteriological characteristics of the coast waters in the district of Catania. Contrary to initial expectations, the conditions of the coast of Catania, can be regarded more than satisfactory as regards sea-bathing, especially if these data are compared with those noticed from other Authors in different italian seaside resorts.

Bathing Beaches↗
PubMedDate not supplied

[Use of dermo-adipose grafts in facial morphology restoration in cases of progressive partial lipodystrophy].

Two cases of partial progressive lipodystrophy syndrome with extensive soft tissue atrophy of the face and of the upper part of the trunk, with kidney and blood alteration, are presented. On the basis of the psysical examination and pathological history of the patients, blood and instrumental tests have been performed in both cases. The diagnosis of partial progressive lipodystrophy syndrome has been made and a surgical treatment with dermal fat graft from the inguinal region was proposed to the patients after several information and was performed to improve the facial contour. After a follow up of 18 months a resorption of 50% of dermal fat graft was found according to surgeons' expectations with a good esthetic improvement of the face.

Adipose Tissue↗
PubMedDate not supplied

Ly-6A/E gene is widely expressed among transformed nonhematopoietic cells. Autocrine modulation by interferon.

Expression of the Ly-6A/E gene by transformed cells was investigated in 14 cell cultures of C57BL/6 and BALB/c mouse origin derived from spontaneous or chemically-induced non-hematopoietic tumours and from cells transformed by SV40 virus. Histologic types included carcinomas, sarcomas and a melanoma. Thirteen out of 14 cell cultures expressed membrane Ly-6A/E antigens; only the B16-A melanoma was negative, but it expressed Ly-6A/E after incubation with IFN-gamma. The effect of in vitro permanence was studied on early (< 10) and late (> 20) passages of B16-A melanoma and MN/MCA1 fibrosarcoma. Late passage B16-A cells were Ly-6A/E-negative and refractory to induction of Ly-6A/E (but not of H-2 antigens) by IFN-alpha, IFN-beta, or IFN-gamma; MN/MCA1 maintained a high expression of Ly-6A/E, but no increase was induced by IFNs. It was found that both early and late in vitro passages of MN/MCA1 actively produced IFN-alpha/beta. The analysis of cells of fibroblastic origin revealed a significant correlation between IFN release in the culture medium and Ly-6A/E levels. Culture of fibrosarcoma cells in the presence of an anti-IFN-alpha/beta serum reduced Ly-6A/E expression, thus indicating the existence of an autocrine loop.

Animals↗
PubMedDate not supplied

[The etiology of bacterial respiratory infections in adulthood].

Upper and lower respiratory tract infections are the most frequently reported pathologies both in children and in adults. In particular, the most common clinical pictures are otitis media, principally chronic, and acute and chronic sinusitis. The microbiology of otitis media, which has been investigated thoroughly in the last year, confirmed a bacterial origin in 90% of the cases (while the incidence of the viral form is low). The etiologic agents responsible for chronic infections are Gram-negative bacteria, staphylococci and anaerobic bacteria, while in the acute forms, which are rare in adults but frequent in children, the responsible pathogens are principally Haemophilus influenzae, Streptococcus pyogenes and Branhamella catarrhalis. Among the etiologic agents of chronic sinusitis, which, from a clinical point of view, is the most frequently observed, there are staphylococci, Streptococcus pyogenes and many anaerobic bacteria. As regards lower respiratory tract infections, chronic bronchitis is the most frequent pathology in adults. But, in this case, the etiologic agents are more difficult to identify. Analysing the above-mentioned clinical pictures and their relevant etiologic agents, among the different therapeutic proposals, one of the most innovative and recent is represented by azithromycin. Azithromycin is the first of a new class of macrolides termed "Azalides" which shows particular microbiological and pharmacokinetic characteristics. As compared to other macrolides, it has an higher distribution volume, a longer half-life, a deeper intracellular penetration and a wider spectrum of action. It is rapidly concentrated in leukocytes PMN, monocytes, macrophages and fibroblasts and slowly released by these cells to the infected tissues. Azithromycin concentrations in tissues and sites of infection can be increased by the phagocyte uptake.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Merkel cell carcinoma of the head and neck region: report of two cases.

Two cases of Merkel cell carcinoma (MCC) of the head and neck region are reported in order to stress their diversity in morphological, immunohistochemical and clinical findings. The remarkable variability of MCC has been analyzed, particularly in relation to the differential diagnosis and prognostic implications.

Aged↗
PubMedDate not supplied

[A rare case of isolated aspergilloma of the sphenoid sinus].

The authors report an interesting case of an isolated pathology of the sphenoid sinus (more precisely, in this case a mycotic infection of this paranasal sinus), up to a few years ago an extremely rare disease and still today an exceptional entity in the clinical practice of an otolaryngologist. The investigations carried out indicated that the infection was caused by Aspergillus candidus, a fungus which only rarely becomes pathogenic in man. The paper reports the main anamnestic data as well as the clinical and instrumental assessment of the disease. It furthermore describes the surgical procedure employed, the relative reports obtained and supplies data concerning the microbiological tests carried out on the material removed and the histological pattern observed. The surgery had an excellent outcome: the patient was cured and showed no sign of recurrence of the disease. The discussion briefly presents the clinical picture created in man by Aspergillus and stresses the rarity of the disease, noting that, including the case in question, only 23 reports, documented with histological and microscopic data, have been made in literature. The AA affirm that to their knowledge this particular case of sphenoid sinusitis caused by Aspergillus candidus [correction of Candida] is the first ever to be reported and in conclusion underline the extreme care necessary in dealing with this pathology and in making a "quoad vitam" prognosis.

Aspergillosis↗
PubMedDate not supplied

[The H2-antagonist therapy withdrawal syndrome: the possible role of hyperprolactinemia].

Patients previously treated with H2-receptor blocking agents (cimetidine or ranitidine) exhibited a complex neurobehavioral and gastroenteric syndrome, including anxiety, insomnia, anorexia, growing thin, irritability, tachycardia, diarrhoea, nausea, vomiting, abdominal pain, headache, vertigo. These symptoms were dramatically reduced by administration of cimetidine or ranitidine, and reappeared with a new suspension of the therapy. The withdrawal syndrome from H2-receptor antagonists was reversed by treatment with domperidone (10 mg three times per day), a potent hyperprolactinaemic drug which does not cross the blood brain barrier. These results suggest that the drop in prolactin levels that occurs when cimetidine or ranitidine are suspended may contribute to the development of the withdrawal syndrome.

Adult↗
PubMedDate not supplied

Metastatic ability and differentiative properties of a new cell line of human embryonal rhabdomyosarcoma (CCA).

A new cell line (CCA) was established from a human embryonal rhabdomyosarcoma. It showed an "early" myogenic differentiation pattern: vimentin expression was found in 100% of cells, desmin in about 40% and myosin of the embryonic isoform in about 5%. Class I HLA expression on CCA cells was undeterctable but was greatly increased by in vitro treatment with human recombinant interferon-gamma and only marginally increased by human recombinant tumour necrosis factor-alfa. CCA cell line was tumorigenic in nude mice after either subcutaneous or intramuscular injection; macroscopic spontaneous metastases were not detected. The ability to induce metastatic nodules in the lungs was found when CCA cells were injected intravenously in cyclophosphamide-pretreated nude mice and, at low frequency, in untreated nude mice.

Animals↗