Biomedical subjects

Giovanni Russo

Publications and source records attributed to Giovanni Russo.

6 recordsLinked to original sources

PubMed2003

Molecular alterations of VanA element in vancomycin-resistant enterococci isolated during a survey of colonized patients in an Italian intensive care unit.

To screen for vancomycin-resistant enterococci (VRE) colonization in hospitalized patients and to study molecular evolution and alterations of Tn1546-like elements in VRE among potentially at-risk patients, a 3-year surveillance protocol in an Intensive Care Unit was performed. A total of 397 patients were screened in the period June, 1997-June, 2000, and VRE were isolated from rectal swabs taken at admission, weekly, and when clinically indicated. The susceptibility of the enterococci was determined by the disk diffusion and broth dilution methods. The presence of vancomycin-resistance genes (vanA, vanB, and vanC) was assessed by polymerase chain reaction (PCR); genetic clonality of isolates was assessed by pulsed-field gel electrophoresis (PFGE); Tn1546 types were obtained by restriction fragment length polymorphism (RFLP) analysis of Tn1546 PCR fragments. Thirty-four strains, 31 identified as Enterococcus faecium and 3 strains as E. faecalis, were isolated from 12 of the 397 patients (3.0%); all strains were VanA as assessed by PCR and were resistant to the other antibiotics tested and showed high-level resistance to aminoglycosides. Enterococci isolated during the study period showed that different genetic backgrounds of strains, determined by PFGE combined with RFLP of Tn1546, are present in all the strains isolated in the study. PFGE type B was predominant in 1998 and 1999, and insertion sequence movements were found to have a role in the evolution of VanA resistance elements found in all strains. This study demonstrates that single patients may be colonized by closely related VRE with several PFGE types containing a wide variety of VanA elements. Moreover, isolates with identical PFGE types may contain different VanA elements reflecting rearrangements mediated by insertion sequences in VRE strains during their stay in the gastrointestinal tract.

Adolescent↗

PubMed2002

Synthesis of building blocks of human milk oligosaccharides. Fucosylated derivatives of the lacto- and neolacto-series.

The synthesis of protected fucosylated derivatives of a Galbeta(1-->3)GlcNAc and of lactosamine Galbeta(1-->4)GlcNAc building blocks contained in human milk oligosaccharides is described. Both chemical and enzymatic methods have been exploited for selective protection of the disaccharide. Fucosylation of the appropriate derivatives allowed an easy and relatively short access to different products from common precursors.

Carbohydrate Conformation↗

PubMed2002

Human milk oligosaccharides: an enzymatic protection step simplifies the synthesis of 3'- and 6'-O-sialyllactose and their analogues.

We describe a chemo-enzymatic synthesis of 3'- and 6'-O-sialyllactose, two trisaccharides occurring in the 'acidic fraction' of the human milk oligosaccharides and endowed with potential antiadhesive activity. The key step is the highly regioselective 6'-O-acylation of benzyllactoside, which gave access to suitably protected lactose building blocks to be used as acceptors in the sialylation reaction. Moreover, the synthesis of the carboxymethyl and sulfo analogues of the title compounds is reported.

Acylation↗

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↗

PubMed2002

Prophylactic abciximab in elective coronary stenting: results of a randomized trial.

BACKGROUND: The use of abciximab (c7E3 Fab; ReoPro , Eli Lilly & Company, Indianapolis, Indiana) during percutaneous coronary intervention (PCI) decreases the incidence of early (30-day) and late (6-month to 1 year) adverse cardiac ischemic events. In a high-risk population, abciximab also reduced the need for target lesion revascularization. PCI of lesions with complex morphology, particularly long lesions, is associated with more complicated outcomes. The use of multiple and/or long intracoronary stents to cover long coronary lesions may lower the incidence of acute or subacute occlusion, but is still limited by a high late restenosis rate. We characterized patients undergoing elective implantation of long or multiple overlapping coronary stents and determined the impact of abciximab administration on clinical and angiographic outcomes. METHODS AND RESULTS: In a prospective, single-center randomized trial, a total of 107 patients undergoing elective implantation of long or multiple overlapping coronary stents were randomly assigned to receive either standard-dose heparin (n = 53) or abciximab plus low-dose heparin (n = 54). The use of abciximab was not associated with an increased incidence of bleeding or vascular complications compared to standard heparin regimen (3.7% versus 3.8%, respectively; p = NS). A 68% reduction in composite in-hospital cardiac events (i.e., death, myocardial infarction, urgent revascularization) was observed in the abciximab group (3.7% versus 11.5%, p = 0.1). At 6-month follow-up, a 48% reduction of target lesion revascularization (11% versus 21%; p = 0.1) and a decrease in binary angiographic restenosis were observed for abciximab-treated patients (17% versus 34%; p < 0.05). CONCLUSION: The peri-procedural use of abciximab during implantation of long or multiple overlapping coronary stents is safe and effective, as it does not increase bleeding or vascular complications compared to standard heparin anticoagulation and reduces the incidence of in-hospital adverse cardiac events; moreover, abciximab improves 6-month clinical and angiographic outcomes in such a complex setting.

Abciximab↗

PubMed2002

[Two consecutive cases of myocardial infarction among young women in reproductive age and without risk factors].

Coronary artery disease does not occur in all the patients with acute myocardial infarction. Coronary artery diseases occurs in 97% of cases; in the other 3% of cases, myocardial infarction is caused by coronary spasm (40%, intracoronary thrombosis (60%) due to platelet hyperreactivity, peripartum thrombophilia or use of oral contraceptives. Myocardial infarction in young women is an infrequent event. Spontaneous coronary artery dissection is a rare cause of acute myocardial infarction that typically occurs during the peripartum period. A few cases of myocardial infarction in premenopausal women with no risk factors for coronary artery disease and normal coronary arteries have been reported. We describe 2 consecutive cases of acute myocardial infarction occurred in young, premenopausal women, without risk factors for cardiovascular diseases.

Adult↗