Reproducibility of protected specimen brush and bronchoalveolar lavage conserved at 4 degrees C for 48 hours

OBJECTIVE: Protected specimen brush (PSB) and bronchoalveolar lavage (BAL) are proposed in combination to optimize antimicrobial treatment. Nevertheless, they are only validated for immediate laboratory processing. This study was therefore conducted to determine whether 48 h conservation at a mere 4 degrees C enables good culture reproducibility for both PSB and BAL. DESIGN AND SETTING: Prospective study, evaluation of a conservation procedure for PSB and BAL, from February 1994 to February 1995, in the 12 bed ICU of a general hospital (938 beds). SAMPLES: Ninety-nine PSB and 86 BAL samples, obtained from 100 bronchoscopic procedures, were analyzed. Thresholds were 10(3) and 10(4) cfu/ml for PSB and BAL, respectively. MEASUREMENTS AND RESULTS: Qualitative comparison between the immediate and 48 h procedures were, for PSB, specificity 100%, sensitivity 78%, positive predictive value 100%, negative predictive value 84% and overall accuracy 90%; and for BAL: 100%, 89%, 100%, 89% and 94%. Lowered 10(2) and 10(3) cfu/ml thresholds at the 48 h procedure for PSB and BAL reduce the false negatives from 10 to 3 and 5 to 1, respectively. Microorganism results were comparable for PSB and BAL ( r = 0.63 and 0.67), especially for the most resistant strains: Staphylococcus, Enterobacteriaceae and Pseudomonas. However, there was a decrease in the Neisseria and Haemophilus group ( p < 0.01). CONCLUSION: There is a good culture reproducibility for both PSB and BAL after 48 h conservation at 4 degrees C, especially with lowered thresholds; this technique is therefore appropriate for routine use.     

Steady-state plasma and intrapulmonary concentrations of piperacillin/tazobactam 4 g/0.5 g administered to critically ill patients with severe nosocomial pneumonia

Objective To determine the steady-state plasma and epithelial lining fluid (ELF) concentrations of piperacillin/tazobactam (P/T) administered to critically ill patients with severe bacterial pneumonia.Design Prospective, open-label study.Setting An intensive care unit and research ward in a university hospital.Patients Ten adult patients with severe nosocomial bacterial pneumonia on mechanical ventilation.Interventions All subjects received a 30-min intravenous infusion of P/T 4 g/0.5 g every 8 h. The steady-state plasma and ELF concentrations of P/T were determined by high-performance liquid chromatography.Measurements and main results The mean±SD steady-state plasma trough, peak, and intermediate concentrations were 8.5±4.6 µg/ml, 55.9±21.6 µg/ml, and 24.0±13.8 µg/ml for piperacillin, and 2.1±1.0 µg/ml, 4.8±2.1 µg/ml, and 2.4±1.2 µg/ml for tazobactam, respectively. The mean±SD steady-state intermediate ELF concentrations were 13.6±9.4 µg/ml for piperacillin and 2.1±1.1 µg/ml for tazobactam, respectively, showing a mean percentage penetration of piperacillin and tazobactam into ELF of 56.8% and 91.3 %, respectively, with a P/T ratio of 6.5:1.Conclusion Our results show that during the treatment of severe nosocomial pneumonia, a regimen of P/T 4 g/0.5 g every 8 h might provide insufficient concentrations into lung tissue to exceed the MIC of many causative pathogens. This suggests that higher doses of P/T should be administered in order to maximize the antibiotic concentration at the site of infection, or that a second antimicrobial agent should be used in association.     

Drug selection in French university hospitals: analysis of formularies for nine competitive pharmacological classes

AIM

To give a panorama of the selectivity and agreement of French university hospitals'' drug formularies (HDF) for nine competitive classes.

METHODS

All university hospitals were asked to send their HDF and selection criteria as of January 2009 for nine competitive pharmacological classes (proton pump inhibitors, serotonin antagonists, low molecular weight heparins, erythropoietins, angiotensin converting enzyme inhibitors, angiotensin II receptor antagonists, statins, α-adrenoreceptor antagonists and selective serotonin re-uptake inhibitors). Selectivity of HDF was estimated by the percentage of drug entities selected by the hospital within the pharmacological class. Agreement between hospitals was assessed with modified kappa coefficients for multi-raters.

RESULTS

Twenty-one out of the 29 hospitals agreed to participate. These hospitals selected between 34% and 63% of the drug entities available for the nine classes, which represented 18 to 35 agents. Regarding the nature of chosen drug entities, the overall level of agreement was ‘fair’ and varied with pharmacological classes. Selection criteria were sent by only 12 hospitals. The technical component was the most important element in all hospitals. The weight of the economic component varied between 20% and 40% in the tender''s grade.

DISCUSSION

Large variations were seen in the number and nature of drugs selected by university hospitals which can be attributable to two successive decision-making processes (evaluation by the Drug and Therapeutics Committee followed by the purchasing process).     

Effect of Cyclosporine and Rifampin on the Pharmacokinetics of Macitentan, a Tissue-Targeting Dual Endothelin Receptor Antagonist

Macitentan is a dual endothelin receptor antagonist under phase 3 investigation in pulmonary arterial hypertension. We investigated the effect of cyclosporine (Cs) and rifampin on the pharmacokinetics of macitentan and its metabolites ACT-132577 and ACT-373898 in healthy male subjects. In addition, in vitro studies were performed to investigate interactions between macitentan and its active metabolite ACT-132577 with human organic anion-transporting polypeptides (OATPs). The clinical study (AC-055-111) was conducted as a two-part, one-sequence, crossover study. Ten subjects in each part received multiple-dose macitentan followed by multiple-dose co-administration of Cs (part A) or rifampin (part B). In the presence of Cs, steady-state area under the plasma concentration-time profiles during a dose interval (AUC(τ)) for macitentan and ACT-373898 increased 10% and 7%, respectively, and decreased 3% for ACT-132577. Steady-state AUC(τ) of macitentan and ACT-373898 in the presence of rifampin decreased 79% and 64%, respectively. For ACT-132577, no relevant difference in AUC(τ) between the two treatments was observed. Macitentan co-administered with Cs or rifampin was well tolerated. The complementary in vitro studies demonstrated no marked differences in uptake rates of macitentan and ACT-132577 between the wild-type and OATP over-expressing cells over the concentration range tested. Concomitant treatment with Cs did not have any clinically relevant effect on the exposure to macitentan or its metabolites, at steady-state. Concomitant treatment with rifampin reduced significantly the exposure to macitentan and its metabolite ACT-373898 at steady-state but did not affect the exposure to the active metabolite ACT-132577 to a clinically relevant extent.     

Microarray Analysis of Somatostatin Receptor 5-Regulated Gene Expression Profiles in Murine Pancreas

Background  We previously demonstrated that somatostatin receptor type 5 (SSTR5) gene ablation results in alterations in insulin secretion and glucose metabolism, accompanied by morphologic alterations in the islets of Langerhans. The underlying mechanism(s) by which SSTR5 exerts its cellular functions remain(s) unknown. We hypothesized that SSTR5 mediates the inhibitory effect of somatostatin (SST) on insulin secretion and islet proliferation by regulating a specific set of pancreatic genes. Methods  To identify SSTR5-regulated pancreatic genes, gene expression microarray analysis was performed on the whole pancreas of 1- and 3-month-old wild-type (WT) and SSTR5 knockout (SSTR5 ^−/−) male mice. Real-time RT-PCR and immunofluorescence were performed to validate selected differentially expressed genes. Results  A set of 143 probes were identified to be differentially expressed in the pancreas of 1-month-old SSTR5 ^−/− mice, 72 of which were downregulated and 71 upregulated. At 3 months of age, SSTR5 gene ablation resulted in downregulation of a set of 30 probes and upregulation of a set of 37 probes. Among these differentially expressed genes, there were 15 and 5 genes that were upregulated and downregulated, respectively, in mice at both 1 and 3 months of age. Three genes, PAP/INGAP, ANG, and TDE1, were selected to be validated by real-time RT-PCR and immunofluorescence. Conclusions  A specific set of genes linked to a wide range of cellular functions such as islet proliferation, apoptosis, angiogenesis, and tumorigenesis were either upregulated or downregulated in SSTR5-deficient male mice compared with their expression in wild-type mice. Therefore, these genes are potential SSTR5-regulated genes during normal pancreatic development and functional maintenance. This work was presented at the Molecular Surgeon Symposium on Personalized Genomic Medicine and Surgery, Baylor College of Medicine, Houston, TX, USA, 12 April 2008. The symposium was supported by a grant from the National Institutes of Health (R13 CA132572 to Changyi Chen).     

IFIH1-GCA-KCNH7 locus is not associated with genetic susceptibility to multiple sclerosis in French patients

A recent investigation reported, for the first time, an association between variants in the IFIH1-GCA-KCNH7 locus and multiple sclerosis (MS). We sought to replicate this genetic association in MS with a new independent MS cohort composed of French Caucasian MS trio families. The two most significant IFIH1 single nucleotide polymorphisms, rs1990760 and rs2068330, reported as involved in MS susceptibility, were genotyped in 591 French Caucasian MS trio families, and analyzed using the transmission/disequilibrium test. No association with MS was found (rs1990760, P=0.45 and rs2068330, P=0.27). Similarly, no significant association was detected after stratification for HLA-DRB1^*1501 carriers. Reasons that may explain this discrepancy between the original report and our study are discussed.