Biomedical subjects

E Bertazzoni Minelli

Publications and source records attributed to E Bertazzoni Minelli.

12 recordsLinked to original sources

PubMed2003

Release of gentamicin and vancomycin from temporary human hip spacers in two-stage revision of infected arthroplasty.

AIM: Evaluation of the delivery of gentamicin and vancomycin from polymethylmethacrylate (PMMA) spacers before and after implantation for the treatment of total hip replacement infections. METHODS: Twenty industrially produced spacers containing gentamicin (1.9%) were utilized. Vancomycin (2.5%) mixed with PMMA cement was used to fill holes drilled in the cement of 14 of the 20 spacers immediately before implantation. The spacers were removed from 20 patients 3-6 months after implantation and then immersed in phosphate buffer at 37 degrees C for 10 days. Antibiotic concentrations were determined by fluorescence polarization immunoassay. RESULTS: Gentamicin and vancomycin were still present in all the spacers removed from the patients. The release of gentamicin alone and in combination with vancomycin was in the range 0.05%-0.4% of the initial amount present, whereas the release of vancomycin was in the range 0.8%-3.3%. The release kinetics showed a similar pattern for both drugs. After a high initial release of drug, a reduced, but constant, elution was observed over the next few days. CONCLUSIONS: The delivery of gentamicin and vancomycin from PMMA cement was high initially, with sustained release over several months. Incorporation of vancomycin into the surface of the spacers permitted spacers to be prepared with multiple antibiotics present and without adversely affecting the release kinetics of the agents. The gentamicin-vancomycin combination shows potential for the treatment of infection following total hip replacement in specific patients.

Aged↗

PubMed2002

Release of antibiotics from polymethylmethacrylate cement.

The increase in resistance rates to antibiotics of bacteria isolated from infected hip joints, particularly staphylococci, prompted us to investigate the usefulness of antibiotic combinations such as gentamicin plus vancomycin. Cylinder test specimens of polymethylmethacrylate (PMMA) cement (Cemex, Tecres) containing gentamicin alone, vancomycin alone and both drugs in combination, were studied. The antibiotic concentrations were determined using a microbiological method and fluorescence polarization immunoassay (FPIA). The release of gentamicin alone, vancomycin alone and in combination from PMMA cement was prompt. The combination revealed synergistic antimicrobial activity against Escherichia coli and Enterococcus faecalis. FPIA showed that gentamicin and vancomycin delivery rates from PMMA cement were different. Gentamicin alone and in combination with vancomycin presented similar release rates from PMMA cement (1.50%). Vancomycin release from PMMA cylinders impregnated with the combination was lower (0.51%) than that from cylinders with vancomycin alone (1.16%). Vancomycin showed a 34.1% loss of microbiological activity at 37 degrees C after 10 days of incubation; the reduction corresponded to 15.0% when measured by FPIA. Results obtained with test specimens are indicative for the preparation of antibiotic-impregnated cements for different human prostheses.

Anti-Bacterial Agents↗

PubMed1998

The intestinal ecosystem in chronic functional constipation.

Chronic functional constipation is common in infants, and the bacterial composition of stools in this condition is not known. The study aims were to: (i) investigate the composition of the intestinal ecosystem in chronic functional constipation; (ii) establish whether the addition of the water-holding agent calcium polycarbophil to the diet induces an improvement in constipation; and (iii) determine the composition of the intestinal ecosystem after the use of this agent. In total, 42 children (20F, 22M; mean age: 8.6 +/- 2.9 y) were studied. Twenty-eight children with functional chronic constipation without anatomical disorders were treated double-blind in random sequence for 1 month with an oral preparation of calcium polycarbophil (0.62 g/twice daily) or placebo. Intestinal flora composition was evaluated by standard microbiological methods and biochemical assays on faecal samples collected before and after treatment. Fourteen healthy children were studied as controls. The results show that (i) the constipated children presented a significant increase in clostridia and bifidobacteria in faeces compared to healthy subjects--different species of clostridia and enterobacteriaceae were frequently isolated; no generalized overgrowth was observed; Clostridia outnumbered bacteroides and E. coli mean counts by 2-3log, while bacteroides and E. coli counts were similar (5-6 log10/g fresh faeces); these intestinal disturbances could be defined as a dysbiosis, i.e. a quantitative alteration in the relative proportions of certain intestinal bacterial species. (ii) Clinical resolution of constipation was achieved only in 43% of treated children and an improvement in 21% (one bowel movement every 2 d). (iii) Calcium polycarbophil treatment induced no significant changes in the composition of the intestinal ecosystem, nor in blood chemistry parameters.

Acrylic Resins↗

PubMed1996

Pefloxacin penetration into human necrotic pancreatic tissue.

Antibiotic prophylaxis may be useful in acute necrotising pancreatis, a disease associated with a considerable incidence of infectious complications. The aim of this study was to assess pefloxacin penetration into necrotic pancreatic tissue during human necrotic pancreatitis. Ten patients (mean age 53.2 +/- 17.4 years) with severe acute pancreatitis (mean Ranson score 4.3) were studied. Pefloxacin was administered at a dose of 400 mg bd every 12 h by i.v. infusion (bolus, 15 min). Intraoperative samples of necrotic pancreatic tissue and blood were collected simultaneously 1, 2, 4.5, 6, 8.5 or 10 h after the last pefloxacin administration in patients treated for 1, 3, 4, 7, 8, 17 or 20 days. Drug concentrations were determined by the microbiological agar-well diffusion method (Escherichia coli Kp 05124 as test micro-organism in Isosensitest Agar). Levels in serum ranged from 2.0 to 9.0 mg/L (at 2 and 6 h, respectively), in necrotic pancreatic tissue from 2.0 to 29.0 micrograms/g depending on different sampling time. Maximum tissue peak concentrations appeared between 4 and 6 h. The necrotic pancreatic tissue/serum concentration ratio ranged from 0.9 to 5.1, values depending on tissue sample collection. Therapeutic concentrations (20.6 micrograms/g) above the MIC of potentially pathogenic enteric microorganisms were still present in necrotic pancreatic tissue 10 h after the last drug administration. Pefloxacin appeared to concentrate in necrotic pancreatic tissue, without appreciable accumulation after multiple-dose administration. The pefloxacin concentrations in necrotic pancreatic tissue showed high variability, depending on the degree of necrosis, inflammation and sample vascularization. Our results provided evidence of good, prompt penetration of pefloxacin into necrotic pancreatic tissue. Pefloxacin seems to exhibit favourable pharmacokinetic and pharmacodynamic properties for pancreatic infections.

Anti-Infective Agents↗

PubMed1989