Biomedical subjects

Giuseppe Nicoletti

Publications and source records attributed to Giuseppe Nicoletti.

23 records · Page 2Linked to original sources

PubMed2002

A large family with pure autosomal dominant hereditary spastic paraplegia from southern Italy mapping to chromosome 14q11.2-q24.3.

A large Italian pedigree from southern Italy with autosomal dominant uncomplicated spastic paraplegia is reported. The clinical picture was uniform and characterized by insidiously progressive lower extremity weakness and spasticity. The mean age at onset of symptoms was 8.3 years. Significant linkage to the SPG3 locus on chromosome 14 was detected. The authors also report their search for mutations in a gene located in the region and its exclusion as a candidate for SPG3.

Adult↗

PubMed2002

Prevalence of extended spectrum beta-lactamases among Enterobacteriaceae: an Italian survey.

The prevalence of extended-spectrum beta-lactamase (ESBL) production by consecutive non-repeated isolates of Enterobacteriaceae was determined over a 6-month period. A total of 8015 strains were isolated from ten Italian laboratories and 509 (6.3%) of these were designated ESBL producers from the results of a double-disk synergy test. Escherichia coli was the most isolated microrganism, followed by Klebsiella pneumoniae and Proteus mirabilis. Providencia stuartii (28.1%) was the most frequently isolated ESBL producer, followed by K. pneumoniae and Enterobacter aerogenes (20.5%). However, amongst all ESBL producers, K. pneumoniae (38.2%) was the most represented followed by P. mirabilis (25.7%). All the strains positive to DD tests were confirmed for the carriage of TEM and SHV genes using colony-blot hybridisation (CH). A total of 447 strains (88.0%) were CH-positive, of which 42.3% hybridised with the TEM-type probe, 30.1% with the SHV-type probe and 15.6% with both probes. In conclusion, our findings indicate that 6.3% of all Enterobacteriaceae tested produced ESBLs, 42.3% of which were TEM-derived enzymes. More than 20% of P. stuartii, K. pneumoniae and E. aerogenes harbour these enzymes. The double-disk test seems to be a useful test to identify ESBL producing strains.

Anti-Bacterial Agents↗

PubMed2002

Molecular characterization of extended-spectrum beta-lactamases produced by nosocomial isolates of Enterobacteriaceae from an Italian nationwide survey.

Extended-spectrum beta-lactamases (ESBLs) are widespread in hospital settings worldwide. The present investigation was undertaken to assess the distribution and prevalence of ESBLs belonging to the TEM and SHV families in 448 ESBL-producing clinical isolates of Enterobacteriaceae collected from 10 different Italian hospitals. The natures of TEM and SHV determinants were identified by direct sequencing of PCR-amplified genes. TEM-52 and SHV-12 were the most common variants, and they were found in most hospitals and in several different species. Other less frequent variants included TEM-5, TEM-12, TEM-15, TEM-19, TEM-20, TEM-24, TEM-26, TEM-43, TEM-60, TEM-72, TEM-87, SHV-2a, SHV-5, and SHV-11. Proteus mirabilis was the most common producer of TEM-type ESBLs, while Klebsiella pneumoniae was the most common producer of SHV-type ESBLs. The distribution of TEM- and SHV-type ESBL variants in Enterobacteriaceae from Italian hospitals exhibited notable differences from those from other geographical settings.

Cross Infection↗

PubMed2002

Recent developments in carbapenems.

Carbapenems are beta-lactam antibiotics characterised by the presence of a beta-lactam ring with a carbon instead of sulfone in the 4-position of the thyazolidinic moiety. The first carbapenem to be utilised in therapy was imipenem, the N-formimidoyl derivative of thienamycin. Imipenem is coadministered with cilastatin, an inhibitor of human renal dehydropeptidase I, as imipenem is hydrolysed by this enzyme. Meropenem was the first carbapenem with a 1-beta-methyl group and 2-thio pyrrolidinyl moiety, which renders this antibiotic stable to renal dehydropeptidase I. Other carbapenems for parenteral administration later discovered include biapenem, panipenem, ertapenem, lenapenem, E-1010, S-4661 and BMS-181139. Carbapenems which are orally administered include sanfetrinem, DZ-2640, CS-834 and GV-129606. Carbapenems have an ultra-broad spectrum of antibacterial activity and stability to almost all clinically relevant beta-lactamases. This differentiates them from all other currently available classes of beta-lactam antibiotics. However, Class B beta-lactamases, along with some rare Class A and D enzymes, are able to hydrolyse these antibiotics. Although Class B enzymes are generally chromosomally-encoded (isolated from Stenotrophomonas maltophilia, Aeromonas spp., Bacillus cereus, Bacteroides fragilis, Flavobacterium spp. and Legionella gormanii), plasmid-metallo-beta-lactamases now are appearing in B. fragilis, Pseudomonas aeruginosa, Acinetobacter baumannii and members of Enterobacteriaceae such as Serratia marcescens and Klebsiella pneumoniae. The number of these enzymes compared to the number of other beta-lactamase types is still low, however, it is likely that they will spread due to the increased selective pressure of carbapenem use. The very broad spectrum of antimicrobial activity associated with a good clinical efficacy and a favourable safety profile makes the carbapenems valuable as 'first-line' antibiotics in initial empirical therapy for the treatment of severe infections.

Bacterial Infections↗

PubMedDate not supplied

Body weight influences pharmacokinetics of levodopa in Parkinson's disease.

Changes in body weight may induce substantial variations in peripheral pharmacokinetics of drugs, but the relation between body weight and levodopa (LD) pharmacokinetics has never been investigated in Parkinson's disease. To address this issue, we conducted a pharmacokinetic study with 164 patients with sporadic Parkinson's disease. Patients underwent an oral acute LD test with 250 mg of LD, and pharmacokinetic variables were assessed at baseline and at 30, 60, 120, and 240 minutes after LD administration. Plasmatic-LD areas under the curve and body weight were significantly and inversely correlated as well as the elimination of the half-life of LD and body weight. In our sample, women were significantly lighter and had a significantly greater area under the curve than men. Moreover, a greater percentage of women showed LD peak-dose dyskinesias compared with men. Our findings suggest that lighter patients with Parkinson's disease probably receive a greater cumulative dosage of LD per kilogram of body weight during long-term treatment, because in clinical practice, LD is administered without any adjustment of the dose to body weight. This could explain gender differences for the development of LD-induced peak-dose dyskinesias observed during the course of the disease.

Aged↗