A simple and sensitive high-performance liquid chromatographic method for the determination of vinflunine and 4-O-deacetylvinflunine from human blood

Vinflunine (VFL) is the first bifluorinated tubulin-targeted agent obtained through a semi synthetic process using superacidic chemistry. Pharmacologic models evidenced a high degree of activity from several cancer lines. The intravenous formulation of VFL (Javlor, Pierre Fabre Medicament, Boulogne, France) is registered for bladder cancer and is undergoing Phase III trials for nonsmall cell lung and breast cancer. To support most of the pharmacokinetic studies in humans, a sensitive high-performance liquid chromatography bioanalytical method coupled with ultraviolet detection was developed and validated for the simultaneous quantification of VFL and its active metabolite 4-O-deacetylvinflunine. The two compounds, together with 17-bromovinorelbine, used as an internal standard, were extracted from blood (1 mL) by a liquid-liquid process under basic conditions using diethyl ether. The organic phase was then back-extracted with HCl 0.1 mol/L. Analysis was performed through a cyano column and detection was set at 268 nm. Total analysis run time was less than 15 minutes. The assay was sensitive for the two compounds to at least 2 ng/mL and calibration curves were linear up to 200 ng/mL. The between-run imprecision and the mean inaccuracy were lower than 7% and 8.3%, respectively. Blood samples were stable when stored at -70°C over 24 months. The long-term reproducibility and the suitability of this analytical method were demonstrated through the analysis of about 6000 biologic samples during the clinical development of intravenous VFL. This method is adequately sensitive to monitor the blood concentrations observed at the recommended dose defined in a clinical setting.     

Bacterial biofilm: structure,function, and antimicrobial resistance

Biofilms are microbial communities attached to surfaces and encased in an extracellular matrix of microbial origin. They represent the predominant form of microbial life. Biofilms are everywhere and can develop on virtually every natural and man‐made surface. Biofilms are also ubiquitous in both normal and pathogenic human processes. Biofilm formation has been demonstrated for numerous pathogens and is clearly one of the main strategies for bacterial survival in a variety of sites within the human body. In almost all instances, the biofilm lifestyle helps bacteria survive and persist within the environment. This review discusses the fundamental biology of microbial biofilm and how biofilms impact the pathogenesis of human infections. The different mechanisms involved in the reduced antimicrobial susceptibility of microorganisms in pathogenic biofilms are discussed in detail in this review. Possible approaches that could be explored in the search for new anti‐biofilm strategies to eradicate medically relevant biofilms are also presented.     

Two intrauterine rescue transfusions in treatment of severe fetomaternal hemorrhage in the early third trimester

When massive fetomaternal hemorrhage is diagnosed in the early third trimester of pregnancy, serial fetal intravascular transfusion may be an alternative to immediate delivery.     

Refractoriness to platelet transfusion in acute myeloid leukemia correlated with the optical density of anti-platelet factor 4/heparin antibodies

A small number of reports have described cases of heparin-induced thrombocytopenia complicating hematological disorders with impaired platelet production. We describe the case of a 66-year-old woman with acute myeloid leukemia who exhibited unexplained refractoriness to platelet transfusion, while receiving heparin flushes, and was found to have anti-platelet factor 4 (PF4)/heparin antibodies with high optical density (OD) values (>2 units) detected by an enzyme-linked immunosorbent assay. After cessation of heparin flushes, her refractoriness to platelet transfusion resolved. We retrospectively confirmed that the OD values for anti-PF4/heparin antibodies declined gradually; refractoriness to platelet transfusion resolved when the OD values fell below 1.0 units. Given the absence of any other evident explanation for this phenomenon, and the correlation between the OD values for anti-PF4/heparin antibodies and the efficacy of platelet transfusions, we conclude that the patient’s refractoriness to platelet transfusion was most likely caused by anti-PF4/heparin antibodies that had platelet-activating properties.     

Association of walking speed in late midlife with mortality: results from the Whitehall II cohort study

Slow walking speed is associated with increased mortality in the elderly, but it is unknown whether a similar association is present in late midlife. Our aim was to examine walking speed in late midlife as a predictor of mortality, as well as factors that may explain this association. Data are drawn from the Whitehall II longitudinal cohort study of British civil servants. The analyses are based on 6,266 participants (29% women; mean age?=?61 years, SD?=?6) for whom “walking speed at usual pace” was measured over 8 ft (2.44 m) at baseline. Participants were followed for all-cause and cause-specific mortalities during a mean of 6.4 (SD?=?0.8) years. During this period, 227 participants died. Participants in the bottom sex-specific third of walking speed (men, <1.26 m/s; women, <1.09 m/s) had an increased risk of death compared to those in the middle and top thirds (age- and sex-adjusted hazard ratio?=?1.89, 95% confidence interval (CI)?=?1.45–2.46), with no evidence of effect modification by age or sex (interactions, P?≥?0.40). The association between walking speed and mortality was partially explained by baseline inflammatory markers (percentage reduction of the association 22.8%), height and body mass index (16.6%), chronic diseases (14.0%), and health behaviors (13.4%). Together these and other baseline factors (socioeconomic status, cardiovascular risk factors, cognitive function) explained 48.5% of the association (adjusted hazard ratio?=?1.39, 95% CI?=?1.04–1.84). In conclusion, walking speed measured in late midlife seems to be an important marker of mortality risk; multiple factors, in particular inflammatory markers, partially explain this association.     

Evaluation of coagulation assays versus LC-MS/MS for determinations of dabigatran concentrations in plasma

Background

Dabigatran is an oral direct thrombin inhibitor for which routine laboratory monitoring is currently not recommended. However, there are situations in which measurements of the drug and its effect are desirable. We therefore compared and validated different coagulation methods for assessments of dabigatran in clinical samples in relation to measurements of plasma dabigatran, without the purpose of establishing effective and safe concentrations of dabigatran in plasma.

Methods

Samples were obtained from 70 atrial fibrillation patients treated with dabigatran etexilate. Plasma concentrations were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and were compared with coagulation methods Hemoclot thrombin inhibitors (HTI) and Ecarin clotting assay (ECA), as well as with prothrombin time-international normalized ratio (PT-INR) and activated partial thromboplastin time (aPTT).

Results

A wide range of dabigatran concentrations was determined by LC-MS/MS (<0.5–586 ng/mL). Correlations between LC-MS/MS results and estimated concentrations were excellent for both HTI and ECA overall (r²?=?0.97 and 0.96 respectively, p?<?0.0001), but the precision and variability of these assays were not fully satisfactory in the low range of dabigatran plasma concentrations, in which ECA performed better than HTI. aPTT performed poorly, and was normal (<40 s) even with dabigatran levels of 60 ng/mL. PT-INR was normal even at supratherapeutic dabigatran concentrations.

Conclusion

LC-MS/MS is the gold standard for measurements of dabigatran in plasma. Alternatively, either HTI or ECA assays may be used, but neither of these assays is dependable when monitoring low levels or to infer total absence of dabigatran. The aPTT assay is relatively insensitive to dabigatran, and normal aPTT results may be observed even with therapeutic dabigatran concentrations.     

FDG PET during radiochemotherapy is predictive of outcome at 1 year in non-small-cell lung cancer patients: a prospective multicentre study (RTEP2)

Purpose

To assess prospectively the prognostic value of FDG PET/CT during curative-intent radiotherapy (RT) with or without concomitant chemotherapy in patients with non-small-cell lung cancer (NSCLC).

Methods

Patients with histological proof of invasive localized NSCLC and evaluable tumour, and who were candidates for curative-intent radiochemotherapy (RCT) or RT were preincluded after providing written informed consent. Definitive inclusion was conditional upon significant FDG uptake before RT (PET₁). All included patients had a FDG PET/CT scan during RT (PET₂, mean dose 43 Gy) and were evaluated by FDG PET/CT at 3 months and 1 year after RT. The main endpoint was death (from whatever cause) or tumour progression at 1 year.

Results

Of 77 patients preincluded, 52 were evaluable. Among the evaluable patients, 77 % received RT with induction chemotherapy and 73 % RT with concomitant chemotherapy. At 1 year, 40 patients (77 %) had died or had tumour progression. No statistically significant association was found between stage (IIIB vs. other), histology (squamous cell carcinoma vs. other), induction or concomitant chemotherapy, and death/tumour progression at 1 year. The SUV_max in the PET₂ scan was the single variable predictive of death or tumour progression at 1 year (odds ratio 1.97, 95 % CI 1.25 – 3.09, p?=?0.003) in multivariate analysis. The area under the receiver operating characteristic curve was 0.85 (95 % CI 0.73 – 0.94, p?<?10^?4). A SUV_max value of 5.3 in the PET₂ scan yielded a sensitivity of 70 % and a specificity of 92 % for predicting tumour progression or death at 1 year.

Conclusion

This prospective multicentre study demonstrated the prognostic value in terms of disease-free survival of SUV_max assessed during the 5th week of curative-intent RT or RCT in NSCLC patients (NCT01261598; RTEP2 study).     

Near point-of-care administration by the attending physician of the rapid influenza antigen detection immunochromatography test and the fully automated respiratory virus nucleic acid test: contribution to patient management

Rapid influenza antigen detection tests (RIADTs) using immunochromatography are the most readily available tools for the diagnosis and management of influenza. This study was designed to assess whether near point-of-care administration by primary care physicians of the RIADT and a fully automated respiratory virus nucleic acid test (Verigene Respiratory Virus Plus®; RV+) would contribute to improved patient management. When viral culture and RT-PCR/bi-directional sequencing were used as the gold standard, sensitivities and specificities for RIADT and RV+ were 58.3% and 90.9%, and 97.2% and 100%, respectively. Within 12 hours from onset of fever, sensitivities were 44.4% and 94.4%, respectively, for RIADT and RV+. In clinical situations where a higher-sensitivity test is needed, such as during pre-admission evaluations, for testing of hospital employees during the prodromal phase of infection, during the therapeutic decision-making process, and during outbreaks, we suggest that patients testing negative by the RIADT can be reassessed with the RV+ test to achieve maximal diagnostic accuracy.