29 research outputs found
Experimental trials and theoretical background about foaming, slag refractory interaction and feasibility of crude magnesium carbonate injection as foaming agent and its use for EAF refractory protection
A theoretical overview about the slag structure, their compatibility with the refractories and their foaming behaviorhas been realized. Such a theoretical background is the basis for the performed experimental trials focused onthe use of crude MgCO3 injected within the slag. This raw material can develop the gaseous phases (CO2) neededfor the slag foaming and it can provide the MgO useful to make the slag compatible with the refractories. Theexperimentation has been performed through the injection of different specific quantities of MgCO3 and theobtained results pointed out a significant decrease of refractory wear, a saving of the specific electric energy, adecrease of the lime injection and of the anthracite powder needed to induce the foaming effect
Experimental trials and theoretical background about foaming, slag refractory interaction and feasibility of crude magnesium carbonate injection as foaming agent and its use for EAF refractory protection
A theoretical overview about the slag structure, their compatibility with the refractories and their foaming behaviorhas been realized. Such a theoretical background is the basis for the performed experimental trials focused onthe use of crude MgCO3 injected within the slag. This raw material can develop the gaseous phases (CO2) neededfor the slag foaming and it can provide the MgO useful to make the slag compatible with the refractories. Theexperimentation has been performed through the injection of different specific quantities of MgCO3 and theobtained results pointed out a significant decrease of refractory wear, a saving of the specific electric energy, adecrease of the lime injection and of the anthracite powder needed to induce the foaming effect
Evaluation of high-dose daptomycin for therapy of experimental Staphylococcus aureus foreign body infection
BACKGROUND: Daptomycin is a novel cyclic lipopeptide whose bactericidal activity is not affected by current antibiotic resistance mechanisms displayed by S. aureus clinical isolates. This study reports the therapeutic activity of high-dose daptomycin compared to standard regimens of oxacillin and vancomycin in a difficult-to-treat, rat tissue cage model of experimental therapy of chronic S. aureus foreign body infection. METHODS: The methicillin-susceptible S. aureus (MSSA) strain I20 is a clinical isolate from catheter-related sepsis. MICs, MBCs, and time-kill curves of each antibiotic were evaluated as recommended by NCCLS, including supplementation with physiological levels (50 mg/L) of Ca(2+ )for daptomycin. Two weeks after local infection of subcutaneously implanted tissue cages with MSSA I20, each animal received (i.p.) twice-daily doses of daptomycin, oxacillin, or vancomycin for 7 days, or was left untreated. The reductions of CFU counts in each treatment group were analysed by ANOVA and Newman-Keuls multiple comparisons procedures. RESULTS: The MICs and MBCs of daptomycin, oxacillin, or vancomycin for MSSA strain I20 were 0.5 and 1, 0.5 and 1, or 1 and 2 mg/L, respectively. In vitro elimination of strain I20 was more rapid with 8 mg/L of daptomycin compared to oxacillin or vancomycin. Twice-daily administered daptomycin (30 mg/kg), oxacillin (200 mg/kg), or vancomycin (50 mg/kg vancomycin) yielded bactericidal antibiotic levels in infected cage fluids throughout therapy. Before therapy, mean (± SEM) viable counts of strain I20 were 6.68 ± 0.10 log(10 )CFU/mL of cage fluid (n = 74). After 7 days of therapy, the mean (± SEM) reduction in viable counts of MSSA I20 was 2.62 (± 0.30) log(10 )CFU/mL in cages (n = 18) of daptomycin-treated rats, exceeding by >2-fold (P < 0.01) the viable count reductions of 0.92 (± 0.23; n = 19) and 0.96 (± 0.24; n = 18) log(10 )CFU/mL in cages of oxacillin-treated and vancomycin-treated rats, respectively. Viable counts in cage fluids of untreated animals increased by 0.48 (± 0.24; n = 19) log(10 )CFU/mL. CONCLUSION: The improved efficacy of the twice-daily regimen of daptomycin (30 mg/kg) compared to oxacillin (200 mg/kg) or vancomycin (50 mg/kg) may result from optimisation of its pharmacokinetic and bactericidal properties in infected cage fluids
Toxicity and cosmetic outcome of hypofractionated whole-breast radiotherapy: predictive clinical and dosimetric factors
Comparison of sparfloxacin, temafloxacin, and ciprofloxacin for prophylaxis and treatment of experimental foreign-body infection by methicillin-resistant Staphylococcus aureus.
The prophylactic and therapeutic activities of three broad-spectrum fluoroquinolones were evaluated in two different experimental models of foreign-body infections caused by methicillin-resistant Staphylococcus aureus (MRSA) susceptible to quinolones. In a guinea pig model of prophylaxis, subcutaneously implanted tissue cages were infected at a > 90% rate by 10(2) CFU of MRSA in control animals. A single dose of 50 mg of ciprofloxacin per kg of body weight administered intraperitoneally 3 h before bacterial challenge was less effective than an equivalent regimen of either sparfloxacin or temafloxacin in decreasing the rate of experimental infection in tissue cages challenged with increasing inocula of MRSA. In a rat model evaluating the therapy of chronic tissue cage infection caused by MRSA, the efficacy of a 7-day high-dose (50-mg/kg twice-daily) regimen of sparfloxacin, temafloxacin, or ciprofloxacin was compared to that of vancomycin (50 mg/kg twice daily). Active levels of sparfloxacin, temfloxacin, or ciprofloxacin were continuously present in tissue cage fluid during therapy, exceeding their MBCs for MRSA by 6- to 20-fold. Either temafloxacin, sparfloxacin, or vancomycin was significantly (P < 0.01) more active than ciprofloxacin in decreasing the viable counts of MRSA in tissue cage fluids. The different activities of ciprofloxacin compared with those of the other two quinolones against chronic tissue cage infections caused by MRSA did not involve the selective emergence of quinolone-resistant mutants. Temafloxacin and ciprofloxacin, which showed the most prominent differences in their in vivo activities, however, exhibited similar bactericidal properties and pharmacokinetic parameters in the rat model. In conclusion, both temafloxacin and sparfloxacin were significantly more active than ciprofloxacin for the prophylaxis or treatment of experimental foreign-body infections caused by a quinolone-susceptible strain of MRSA
Experimental trials and theoretical background about foaming, slag refractory interaction and feasibility of crude magnesium carbonate injection as foaming agent and its use for EAF refractory protection
A theoretical overview about the slag structure, their compatibility with the refractories and their foaming behaviorhas been realized. Such a theoretical background is the basis for the performed experimental trials focused onthe use of crude MgCO3 injected within the slag. This raw material can develop the gaseous phases (CO2) neededfor the slag foaming and it can provide the MgO useful to make the slag compatible with the refractories. Theexperimentation has been performed through the injection of different specific quantities of MgCO3 and theobtained results pointed out a significant decrease of refractory wear, a saving of the specific electric energy, adecrease of the lime injection and of the anthracite powder needed to induce the foaming effect
PO-0868: A method to define isodose-based structures in Dose Painting treatment of GBM in Tomotherapy
EP-1041: Acute and late toxicity with hypofractionated radiation therapy for early breast cancer compared to conventional RT
The effectiveness of desensitization versus rechallenge treatment in HIV-positive patients with previous hypersensitivity to TMP-SMX: a randomized multicentric study
Our study was undertaken to evaluate if desensitization treatment is more effective than rechallenge in preventing hypersensitivity reactions in HIV-positive patients with previous allergic reactions to TMP-SMX; the secondary aim was to evaluate the frequency of reactions to TMP alone. This was a randomized, multicentre open study. Patients with previous documented hypersensitivity to TMP-SMX who required primary or secondary PCP prophylaxis were enrolled; subjects who had previously had serious adverse reactions to TMP-SMX were excluded. All eligible patients assumed 200 mg TMP for 14 days and in case of no reactions were randomized for desensitization or rechallenge with TMP-SMX. The patients were then followed up by periodical visits for six months. Seventy-three patients were enrolled; 14 subjects (19%) presented reactions on TMP alone during the pre-enrollment phase. The remaining 59 subjects were randomly assigned to the two treatment groups: 34 carried out desensitization (group 1) and 25 rechallenge (group 2) with TMP-SMX. Seven patients in group 1 (20.5%) and seven in group 2 (28%) showed hypersensitivity reactions during treatment; this difference was not statistically significant. No serious reaction occurred in either group. This study showed the comparable effectiveness of the desensitization procedure and rechallenge in patients with a previous, not serious, allergic reaction to TMP-SMX