IntroductionAs a result of drug sequestration and increased volume of distribution, the extracorporeal membrane oxygenation (ECMO) procedure might lead to a decrease in drug concentrations during a patient’s treatment. The aim of this study was to evaluate sedative, antibiotic and immunosuppressive drug loss in ECMO circuit using ex-vivo and in-vitro experiments.MethodsBlood concentrations of propofol, midazolam, cyclosporine and vancomycin were measured in an ex-vivo ECMO circuit primed with whole human blood, and compared to controls stored in polypropylene tubes. In vitro experiments were also conducted to further explore the role of temperature, oxygen exposure and polyvinylchloride surfaces on propofol loss in the ECMO circuit.ResultsPropofol concentration decreased rapidly; 70% of its baseline concentration was lost after only 30 minutes, and only 11% remained after five hours (P <0.001 for the comparison with control polypropylene tube propofol concentration). Further experiments demonstrated that oxygen exposure and contact with polyvinylchloride tubing were respectively responsible for 70% and 85% of propofol loss after 45 minutes. Midazolam concentration also rapidly decreased in the ECMO circuit, with only 54% and 11% of baseline concentration being detected at 30 minutes and 24 hours respectively (P = 0.01 versus control). Alternatively, cyclosporine concentration remained stable for the five first hours, then decreased to 78% and 73% of the baseline value after 24 hours and 48 hours, (P = 0.35 versus control). Lastly, vancomycin concentration remained stable in the ECMO circuit for the 48-hour experimental protocol.ConclusionsWe observed important losses of propofol and midazolam, while cyclosporine concentration decreased slowly and moderately, and vancomycin concentration remained unchanged in the ex-vivo ECMO circuit primed with whole human blood. These data might help intensive care unit physicians planning clinical trials with a final objective to better adapt doses of these drugs while treating critically ill ECMO patients.

IntroductionIt has been extensively reported that defective programmed cell death in B-cell chronic lymphocytic leukemia (B-CLL) is responsible for the relentless accumulation of malignant B cells in blood, bone marrow, and lymphoid organs and that it plays a key role in the pathogenesis of the disease. 1 However, the discrepancy between the in vivo resistance of leukemic cells to apoptosis and their high sensitivity to in vitro spontaneous or induced apoptosis remains unclear. Corticosteroids, 2 alkylating agents, 3 purine analogs, 4 irradiation, 5 methylxanthine derivatives, 6 interleukin-5 (IL-5) 7 and IL-10, 8 salicylates, 9 mitoxantrone, 10 ubiquitin proteasome inhibitors, 11 arsenic trioxyde, 12 colchicine, 13 hydroxychloroquine, 14 flavopiridol, 15 monoclonal antibodies such as CD20, 16 CD47, 17 and CD52, 16 immunoglobulin M (IgM), 16 and mitochondrial benzodiazepine receptor antagonist PK11195 18 were all successively demonstrated to elicit in vitro apoptosis in B-CLL cells. Clinical efficacy has been shown for most of them.Cyclic adenosine monophosphate (cAMP) is catabolized within cells to 5Ј AMP by 3Ј5Ј cAMP phosphodiesterases (PDEs). The PDE family includes 10 classes of enzymes that are differentially expressed in various cell types. Normal lymphocytes express at least cAMP-PDE3 and -PDE4. 19,20 Increases in cAMP levels induced growth arrest or cell death of malignant lymphoid cells. We and others 21,22 reported that PDE4 inhibitors induced the apoptosis of B-CLL cells. Sildenafil (Viagra; Pfizer, Paris, France) and vardenafil (a generous gift from Bayer, Puteaux, France) are known to be potent and specific inhibitors of PDE5A, expressed mainly in human vascular smooth muscle cells and platelets. 23 However, they also inhibit PDE6 in retina. 24 We here present evidence, following one clinical observation, that sildenafil and vardenafil are new inducers of apoptosis in B-CLL cells in vitro. This may be relevant for the development of therapeutic strategies to treat CLL. Patients, materials, and methods Patient samplesNineteen peripheral blood samples from 17 patients with CLL were studied after informed consent was obtained. According to the Binet classification, 15 patients had stage A disease, one (patient 14) had stage B disease, and one (patient 11) had stage C disease. Patients received no treatment for at least 6 months before the study. Cell culture conditions and reagentsPeripheral blood mononuclear cells (PBMCs) were isolated from patients with CLL by density-gradient centrifugation of heparinized blood using Lymphoprep (Nycomed, Olso, Norway). B cells were prepared from CLL PBMCs or tonsillar lymphocytes by one cycle of rosetting with S-(2 aminoethyl) isothiouronium bromide (Aldrich, Milwaukee, MN)-treated sheep red blood cells to deplete T cells. B-cell purity was shown to be greater than 98% by flow cytometry (FACScan; Becton Dickinson, Le-Pont-de-Claix, France). Cells were cultured in RPMI 1640 10% fetal calf serum (FCS) at 2 ϫ 10 6 /mL with or without PDE inhibitors at the indicated con...

Thirty-five representative samples of milk from either a highland area of France (Auvergne region) or a lowland area of France (Brittany region) were collected in spring and summer (grazing periods), and in winter (stabling period). The monoterpenes and sesquiterpenes extracted from the milk fat were semi-quantified by dynamic headspace-gas chromatography-mass spectrometry (DHS-GC-MS). Milk samples were classified by factorial discriminant analysis. Milk collected in the Auvergne highland area was richer in sesquiterpenes than that collected in the Brittany lowland area. All the samples were correctly classified according to their geographical origin irrespective of seasonal herd management pattern. These findings show that the assay of terpene compounds can provide useful fingerprints for the characterization of dairy produce according to geographical area and production conditions.

The prevalence of extensively drug-resistant tuberculosis (XDR-TB), defined as TB that is resistant to isoniazid, rifampin, fluoroquinolones, and aminoglycosides, is rising worldwide. The extent of Mycobacterium tuberculosis resistance to fluoroquinolones depends on the mutation in the DNA gyrase, the only target of fluoroquinolones. The MIC of moxifloxacin, the most active fluoroquinolone against M. tuberculosis, may be lower than its peak serum level for some ofloxacin-resistant strains of Mycobacterium tuberculosis. Therefore, if the MIC of moxifloxacin is lower than its peak serum level, it may be effective against XDR-TB. Our objective was to determine the efficacy of moxifloxacin in treating ofloxacin-resistant TB. We selected isogenic fluoroquinolone-resistant mutants of M. tuberculosis H37Rv in vivo. We infected Swiss mice with either wild-type H37Rv or one of three mutant strains with different MICs that are commonly seen in clinical practice. The MICs of the mutant strains ranged from below to above the peak moxifloxacin level seen in humans (3 g/ml). Each mouse was treated with one of four moxifloxacin doses for 1 month. Moxifloxacin was effective against mutant strain GyrB D500N, with the lowest MIC (0.5 g/ml), when the standard dose was doubled. Moxifloxacin reduced mortality in mice infected with mutant strain GyrA A90V with an intermediate MIC (2 g/ml). However, it had no impact on the mutant strain GyrA D94G with the highest MIC (4 g/ml). Our study underscores current WHO recommendations to use moxifloxacin when there is resistance to early-generation fluoroquinolones such as ofloxacin, restricting this recommendation to strains with moxifloxacin MICs of less than or equal to 2 g/ml.As the leading cause of death from curable infectious diseases worldwide, tuberculosis (TB) is a serious global health issue (15). The high rates of TB incidence and prevalence in developing countries have a considerable impact on population-level morbidity and mortality, particularly in settings where HIV incidence rates are high (43). Inappropriate administration of standard anti-TB drugs can lead to the emergence of bacilli that are resistant to one or more of these drugs.

Human multidrug resistance protein 2 (MRP2, encoded by ABCC2) is involved in active efflux of anionic drugs such as methotrexate. MRP2 is expressed on the luminal side of hepatocytes and renal proximal tubular cells, indicating an important role in drug elimination. We postulated that loss-of-function mutations in ABCC2, which are involved in the Dubin-Johnson syndrome, may be associated with impaired methotrexate elimination and an increased risk of toxicity. We studied the biological phenotype and ABCC2 coding sequence in a patient receiving a high-dose methotrexate infusion for large B-cell lymphoma and who had an unusual pharmacokinetic profile, mainly characterized by a three-fold reduction in the methotrexate elimination rate. This resulted in severe methotrexate over-dosing and reversible nephrotoxicity. An inversion of the urinary coproporphyrin isomer I/III ratio (a specific biological marker of the Dubin-Johnson syndrome) was observed in this patient. Genetic analysis of ABCC2 identified a heterozygous mutation replacing a highly conserved arginine by glycine in the cytoplasmic part of the second membrane-spanning domain (position 412 of MRP2), a region associated with substrate affinity. This genetic variant was not found in a control population. Functional analysis in transiently transfected Chinese hamster ovary cells revealed a loss of transport activity of the G412 MRP2 mutant protein. An ABCC2 mutation altering MRP2-mediated methotrexate transport and resulting in impaired drug elimination and subsequent renal toxicity was identified. Candidates for methotrexate therapy should be considered for MRP2 functional testing.

No abstract

No abstract

No abstract