Measurement of apixaban concentrations in different human biological fluids by UHPLC-MS/MS. Clinical pharmacokinetic application in a subject with chronic kidney disease and nonvalvular atrial fibrillation on haemodialysis.

BACKGROUND: Apixaban's technical sheet does not recommend its use in clinical practice for patients with chronic kidney disease undergoing haemodialysis. However, recent studies indicate that apixaban could be a safe oral anticoagulant in these kinds of patients who do not present valvular atrial fibrillation. We developed and validated ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) procedures for measuring apixaban concentrations in plasma, dialysate liquid, and urine. MATERIAL AND METHODS: Simple protein precipitation was implemented to prepare samples. Chromatographic separations were achieved on an Acquity®-UPLC®-BEHTM (2.1x100 mm id, 1.7 µm) reverse-phase C18 column using a water/acetonitrile non-linear gradient containing 0.1 % formic acid at a 0.4 mL/min flow rate. Apixaban and its internal standard (apixaban-d3) were detected by electrospray ionisation mass spectrometry in positive and multiple reaction monitoring modes, using transitions of 460.3 â†’ 199.0/443.2 and 463.3 â†’ 202.0, respectively. RESULTS: No significant interferences and carry-overs were observed. Precisions, absolute relative biases, normalised-matrix factors, and normalised recoveries were ≤ 12.2%, ≤8.0%, 94.3-105.1%, and 93.9-105.4%, respectively. Linearity was observed between 5 and 500 µg/L for plasma/dialysate liquid and 5-1000 µg/L for urine. CONCLUSIONS: The validated UHPLC-MS/MS procedures could help support a pharmacokinetic study in non-valvular atrial fibrillation subjects with chronic kidney disease undergoing haemodialysis and apixaban-based anticoagulant therapy.

RENEB biodosimetry intercomparison analyzing translocations by FISH.

PURPOSE: In the framework of RENEB, several biodosimetry exercises were conducted analyzing different endpoints. Among them, the analysis of translocations is considered the most useful method for retrospective biodosimetry due to the relative stability of their frequency with post irradiation time. The aim of this study was to harmonize the accuracy of translocation-based biodosimetry within the RENEB consortium. MATERIALS AND METHODS: An initial telescoring exercise analyzing FISH metaphase images was done to harmonize chromosome aberration descriptions. Then two blind intercomparison exercises (IE) were performed, by sending irradiated blood samples to each partner. Samples were cultured and stained by each partner using their standard protocol and translocation frequency was used to produce dose estimates. RESULTS: The coefficient of variation in the 1st IE (CV = 0.34) was higher than in the 2nd IE (CV = 0.16 and 0.23 in the two samples analyzed), for the genomic frequency of total translocations. Z-score analysis revealed that eight out of 10 and 17 out of 20 dose estimates were satisfactory in the 1st and 2nd IE, respectively. CONCLUSIONS: The results obtained indicate that, despite the problems identified in few partners, which can be corrected, the RENEB consortium is able to carry out retrospective biodosimetry analyzing the frequency of translocations by FISH.

Comparison of methods to quantify histone H2AX phosphorylation and its usefulness for prediction of radiosensitivity.

PURPOSE: The number of radio-induced double-strand breaks is correlated with the number of histone gamma-H2AX (γ-H2AX) foci. For this reason, foci quantification is a useful tool to measure radiation-induced DNA damage and the number of foci has been suggested as a predictive biomarker of radiosensitivity. The aim of the present study was to evaluate the reproducibility of different microscopic methodologies and flow cytometry analysis to score γ-H2AX induction, and its suitability to distinguish a radiosensitive (RS) cell line from a radioresistant (RR) one. MATERIALS AND METHODS: γ-H2AX analyses were performed by semi-automated and automated microscopic methods and by flow cytometry before and after irradiation in two human lymphoblastoid cell lines and in lymphocytes from three healthy donors. RESULTS: Reproducible results were obtained by all the methodologies tested, although not all showed the same sensitivity. The RS cell line always showed higher foci counts and higher levels of immunofluorescence intensity after irradiation than the RR cell line. CONCLUSIONS: Our results suggest that microscopic methodologies with z-stage capacity give the most accurate results after 1 Gy irradiation. However, for high doses of ionizing radiation, flow cytometry gives reliable results. Further studies will be necessary to determine the usefulness of γ-H2AX analysis to predict adverse side reactions in radiotherapy patients.

Evaluación y tratamiento ambulatorio de la acumulación compulsiva en un paciente con patología del espectro psicótico / Evaluation and outpatient treatment of compulsive hoarding in a patient with psychotic spectrum disorder

Introducción: los pacientes con acumulación compulsiva primaria tienden a presentar escasa adherencia y respuesta al tratamiento conductual ambulatorio, desconociéndose el papel que la patología comórbida del espectro psicótico pudiera ejercer en su abordaje terapéutico. Así mismo, la valoración de su gravedad y evolución clínica suele hallarse limitada a autoinformes. Caso clínico: se expone el caso de un varón de mediana edad, con antecedentes de acumulación compulsiva de 30 años de evolución, que desarrolló posteriormente un trastorno esquizoafectivo. Tras la implementación de psicoterapia conductual monitorizada en el domicilio por la pareja, se objetivó una remisión parcial de la acumulación compulsiva al cabo de 12 meses de tratamiento ambulatorio. Conclusiones: el uso de fotografías constituye una herramienta evaluativa que permite determinar con mayor precisión el diagnóstico clínico y la evolución de los sujetos con acumulación compulsiva. La presencia de sintomatología negativa comórbida debe estimular la supervisión de las pautas psicoterapéuticas en el propio domicilio del paciente (AU)

Introduction: patients with primary compulsive hoarding normally have a poor adherence and response to outpatient behavioral treatment, not knowing the role that comorbid psychotic spectrum psychopathology could exercise in its therapeutic approach. Likewise, the assessment of its severity and clinical course is usually limited to self-reports. Case report: we describe the case of a middle-aged male with a 30 years evolution of compulsive hoarding, which subsequently developed schizoaffective disorder. After implementing behavioral therapy monitored at home by the couple, a partial remission of compulsive hoarding was obtained during 12 months of outpatient treatment. Discussion: the use of photographs is an assessment tool for determining more accurately the clinical diagnosis and the evolution of patients with compulsive hoarding. The presence of comorbid negative symptoms should stimulate psychotherapeutic supervision in patient’s home (AU)