Use of the parenteral antibiotic Ertapenem as short term prophylaxis in bariatric surgery: a pharmaco-kinetic-pharmacodynamic study in class III obese female patients

BACKGROUND

The objective of this study was to determine the pharmacokinetics-pharmacodynamics (PK/PD) of Ertapenem in extremely obese female patients (Body Mass Index [BMI] ≥ 40 kg/m²) undergoing bariatric surgery.

METHODS

Ten patients received 1 g intravenous Ertapenem 0.5 h prior to surgery as short term prophylaxis. Serum Ertapenem concentrations were determined at baseline, at the end of infusion (30 minutes), then at 1, 2, 4, 8, 12 and 24 hours postinfusion. In patients in whom a liver biopsy was necessitated by clinical need, Ertapenem liver concentrations were determined through intraoperative biopsies at 1 and 2 h postadministration. Peritoneal Ertapenem concentrations were determined in drainage fluid samples collected during the 4-8, 8-12, and 12-24 h intervals after Ertapenem administration. A Monte Carlo simulation was performed to estimate the probability of achieving free drug levels above the minimum inhibitory concentration (fT>MIC) for at least 20% and 40% of the dosing interval as PK/PD targets.

RESULTS

Peak drug concentration and 24-h area under the concentration-time curve (AUC) were found to be 191.9 ± 37.4 mg/L and 574.3 ± 110.5 mg·h/L, respectively. Ertapenem liver/serum concentration ratios were 6% at 1 h and 5% at 2 h. Drug concentrations in peritoneal fluid were 28.2 ± 6.4 mg/L at 4-8h, declined to 15.2 ± 5.9 at 8-12h and fell further to 4.79 ± 0.2 mg/L at 12-24 h post-administration. The probability to reach the desired PK/PD targets were never reached at any MICs >0.25 µg/mL with a 90% probability.

CONCLUSION

Our data suggest that in extremely obese female patients, the standard dose of 1 g i.v. Ertapenem as short term prophylaxis may not provide optimal clinical levels of free drug for prevention of surgical site infections.

Treatment options for methicillin-resistant Staphylococcus aureus (MRSA) infection: Where are we now?

Methicillin-resistant Staphylococcus aureus (MRSA) infection continues to be a substantial global problem with significant associated morbidity and mortality. This review summarises the discussions that took place at the 4th MRSA Consensus Conference in relation to the current treatment options for serious MRSA infections and how to optimise whichever therapy is embarked upon. It highlights the many challenges faced by both the laboratory and clinicians in the diagnosis and treatment of MRSA infections.

Direct observation of OH formation from stabilised Criegee intermediates

The first direct observation of OH radicals from syn-CH₃CHOO Criegee intermediates decomposition suggests it affects tropospheric chemistry and ambient OH measurements.

Clinical Efficacy and Tolerability of Caspofungin in a Renal Transplant Patient withAspergillus flavusLung Infection: Case Report

Organ transplant recipients are at increased risk for severe invasive aspergillosis, and amphotericin deoxycholate has been the standard treatment for many years. Currently, however, lipid formulations are preferred due to their few side effects. Also, a number of new antifungal drugs have been developed including new azoles and echinocandins. Caspofungin is the first of the echinocandin derivatives patented to treat patients with invasive aspergillosis who are refractory or intolerant to other therapies. A renal transplant patient on immunosuppressive treatment with chronic hepatitis B virus infection was admitted with fever, hemophthisis and lung consolidation, diagnosed to be probably caused by Aspergillus flavus. The patient developed cholestatic hepatitis most likely related to itraconazole. Clinical failure and in vitro itraconazole resistance of the isolate was also documented while the patient was receiving itraconazole at a reduced dosage. Caspofungin was administered once a day as ambulatory treatment and was well tolerated. Clinical improvement was observed after 6 weeks of treatment and no hepatic toxicity was documented. Caspofungin seems to be a potentially useful antifungal agent in renal transplant patients with invasive aspergillosis. Further evaluation of the efficacy of caspofungin is needed.

Another patient with 12q13 microduplication

Interstitial duplication of the long arm of chromosome 12 is a rare cytogenetic condition. While several reports describe distal 12q duplication, only one case report of homogeneous, non-mosaic interstitial 12q13 duplication has been documented to date. The authors of that observation proposed that the associated phenotype represented a phenocopy of Wolf-Hirschhorn syndrome [Dallapiccola et al., 2009]. Only a few other recorded patients with deletion 12q13 → 12q21 involved mosaicism. We describe a new patient with homogeneous 12q13 duplication in a 6-year-old girl who, in early infancy, presented with dysmorphic features suggesting Wolf-Hirschhorn syndrome. What is potentially significant about this patient is that her facial phenotype evolved with age, suggesting a different gestalt in older patients.

The role of nitrite and nitrate ions as photosensitizers in the phototransformation of phenolic compounds in seawater

Nitrite and nitrate are known to be involved in photochemical processes occurring in natural waters. In this study we have investigated the role played by these photosensitizers towards the transformation of xenobiotic organic matter in marine water, with the goal of assessing the typical transformation routes induced in seawater by irradiated nitrite/nitrate. For this purpose, phenol was chosen as model molecule. Phenol transformation was investigated under simulated solar radiation in the presence of nitrite (in the range of 1 × 10(-5)-1 × 10(-2)M) or nitrate ions, in pure water at pH 8, in artificial seawater (containing same dissolved salts as seawater but no organic matter), and in natural seawater. In all experiments, phenol degradation rate and formation of intermediates were assessed. As expected, phenol disappearance rate decreased with decreasing nitrite concentration and was slightly reduced by the presence of chloride. Other salts present in artificial seawater (e.g. HCO(3)(-), CO(3)(2-) and Br(-)) had a more marked effect on phenol transformation. Analysis of intermediates formed in the different matrices under study showed generation of hydroxyl-, nitro- and chloroderivatives of phenol, to a different extent depending on experimental conditions. 1,4-Benzoquinone prevailed in all cases, nitroderivatives were only formed with nitrite but were not detected in nitrate-spiked solutions. Competition was observed between halogenation and nitration of phenol, with variable outcome depending on nitrite concentration. The most likely reason is competition between nitrating and halogenating species for reaction with the phenoxyl radical. A kinetic model able to justify the occurrence of different intermediates under the adopted conditions is presented and discussed.

The reaction of Criegee intermediates with NO, RO2, and SO2, and their fate in the atmosphere

The reaction of Criegee intermediates (CI) with NO and RO(2) radicals is studied for the first time by theoretical methodologies; additionally, the reaction of CI with SO(2) molecules is re-examined. The reaction of CI with NO was found to be slow, with a distinct energy barrier. Their reaction with RO(2) radicals proceeds by the formation of a pre-reactive complex followed by addition of the RO(2) radical on the CI carbon over a submerged barrier, leading to a larger peroxy radical and opening the possibility for oligomer formation in agreement with experiment. The impact of singlet biradicals on the reaction of CI with SO(2) is examined, finding a different reaction mechanism compared to earlier work. For larger CI, the reaction with SO(2) at atmospheric pressures mainly yields thermalized sulfur-bearing secondary ozonides. The fate of the CI in the atmosphere is examined in detail, based on observed concentration of a multitude of coreactants in the atmosphere, and estimated rate coefficients available from literature data. The impact of SCI on tropospheric chemistry is discussed.

Microarray application in prenatal diagnosis: a position statement from the cytogenetics working group of the Italian Society of Human Genetics (SIGU), November 2011

A precise guideline establishing chromosomal microarray analysis (CMA) applications and platforms in the prenatal setting does not exist. The controversial question is whether CMA technologies can or should soon replace standard karyotyping in prenatal diagnostic practice. A review of the recent literature and survey of the knowledge and experience of all members of the Italian Society of Human Genetics (SIGU) Committee were carried out in order to propose recommendations for the use of CMA in prenatal testing. The analysis of datasets reported in the medical literature showed a considerable 6.4% incidence of pathogenic copy number variations (CNVs) in the group of pregnancies with sonographically detected fetal abnormalities and normal karyotype. The reported CNVs are likely to have a relevant role in terms of nosology for the fetus and in the assessment of reproductive risk for the couple. Estimation of the frequency of copy number variations of uncertain significance (VOUS) varied depending on the different CMA platforms used, ranging from 0-4%, obtained using targeted arrays, to 9-12%, obtained using high-resolution whole genome single nucleotide polymorphism (SNP) arrays. CMA analysis can be considered a second-tier diagnostic test to be used after standard karyotyping in selected groups of pregnancies, namely those with single (apparently isolated) or multiple ultrasound fetal abnormalities, those with chromosomal rearrangements, even if apparently balanced, and those with supernumerary marker chromosomes.