Esclarecimiento del mecanismo de acción de la dotarizina como agente antimigrañoso

Tesis doctoral inédita leida en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Farmacología y Terapéutica. Fecha de lectura: 25 de Julio de 200

Improvement and validation of a high-performance liquid chromatography in tandem mass spectrometry method for monitoring of omeprazole in Plasma

Omeprazole (OME) is a proton pump inhibitor (PPI) with 58% bioavailability after single oral dose, presenting large inter-individual variations and significant drug-drug interactions. A simple and rapid liquid chromatography in tandem with mass spectrometry (LC/MS-MS) with solid phase extraction (SPE) and isotope-labelled internal standard (IS) method was developed to monitor the plasma levels of OME for application in pharmacokinetics and drug-drug interactions studies. OME and its IS (OME-D3), were eluted with Zorbax extend C-18 rapid resolution (4.6 mm x 50 mm, 3.5 μm) at 25ºC, under isocratic conditions through a mobile phase consisting of 1 mM ammonium acetate, pH 8.5 (55%), and acetonitrile (ACN, 45%). The flow rate was 0.8 mL/min and the run time of chromatogram was 1.2 min. OME was detected and quantified by LC-MS/MS with positive electrospray ionization (ESI) that operates in multiple-reaction monitoring (MRM) mode. The method was linear in the range of 1.5- 2000 ng/mL for OME. The validation assays of accuracy and precision, matrix effect, extraction recovery and stability of the samples for OME did not deviate more than 20% for the lower limit of quantification (LLOQ) and no more than 15% for other quality controls (QCs), according to regulatory agencies.This work was also supported by FIS No. PI052124 and CA12/00122 to ARN and FPU12/02220 to AW

Foliar Architecture and caulinar morpho-anatomy of Zuccagnia Punctata (Fabaceae). Histolocalization of bioactive compounds

Zuccagnia punctata Cav. (Fabaceae, Caesalpinioideae), comúnmente denominada jarilla macho, es una especie endémica de Argentina, característica de la flora xerófila de la Provincia Biogeográfica del Monte. Resulta una especie de interés medicinal ya que sus partes aéreas, usadas en medicina popular, presentan actividad antioxi- dante, antiulcerosa, antifúngica y antimicrobiana frente a bacterias patógenas humanas mul- tiresistentes. Dado que se registran escasos estudios morfológicos y anatómicos de esta promisoria especie, el objetivo del presente trabajo es realizar la descripción de sus partes aéreas apuntando a una histolocalización de los tejidos encargados de la síntesis de compues- tos bioactivos. Se realizaron técnicas de anatomía vegetal y pruebas histoquímicas. Z. punc- tata presenta hojas pseudo-paripinnadas, folíolos nanófilos subopuestos, acuminados, de base redondeada y márgenes enteros. Venación de tipo pinnada camptódroma broquidódroma con vena primaria masiva, estructura anatómica claramente adaptada a ambientes xerófitos, fo- líolo isolateral, anfistomático, con aparato estomático ciclocítico, células epidérmicas de pa- redes rectas, cutícula gruesa, tricomas glandulares capitados ubicados en criptas de ambas superficies epidérmicas y tricomas eglandulares unicelulares o bicelulares uniseriados articu- lados en el margen foliar. El nervio medio está formado por un único haz colateral cerrado con casquete de esclerénquima a nivel de floema. El tallo presenta una eustela con fuerte de- sarrollo de fibras durante el crecimiento secundario. Tanto en tallo como en hoja se observan idioblastos con drusas a nivel del mesofilo y floema. La tinción específica con vainillín sulfúrico revela que tanto el mesofilo como los tricomas glandulares se hallan comprometidos en la producción de compuestos fenólicos y terpénicos.Fil: Mercado, Maria Ines. Fundación Miguel Lillo; ArgentinaFil: Ruiz, Ana I.. Fundación Miguel Lillo; ArgentinaFil: Zampini, Iris Catiana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Quimica del Noroeste; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Nuño, Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Quimica del Noroeste; ArgentinaFil: Cuello, Ana Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Quimica del Noroeste; ArgentinaFil: Isla, Maria Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Quimica del Noroeste; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Ponessa, Graciela I.. Fundación Miguel Lillo; Argentin

CALHM1 and its polymorphism P86L differentially control Ca²⁺ homeostasis, mitogen-activated protein kinase signaling, and cell vulnerability upon exposure to amyloid β

The mutated form of the Ca2+ channel CALHM1 (Ca2+ homeostasis modulator 1), P86L-CALHM1, has been correlated with early onset of Alzheimer’s disease (AD). P86L-CALHM1 increases production of amyloid beta (Ab) upon extracellular Ca2+ removal and its subsequent addback. The aim of this study was to investigate the effect of the overexpression of CALHM1 and P86L-CALHM, upon Ab treatment, on the following: (i) the intracellular Ca2+ signal pathway; (ii) cell survival proteins ERK1/2 and Ca2+/cAMP response element binding (CREB); and (iii) cell vulnerability after treatment with Ab. Using aequorins to measure the effect of nuclear Ca2+ concentrations ([Ca2+]n) and cytosolic Ca2+ concentrations ([Ca2+]c) on Ca2+ entry conditions, we observed that baseline [Ca2+]n was higher in CALHM1 and P86L-CALHM1 cells than in control cells. Moreover, exposure to Ab affected [Ca2+]c levels in HeLa cells overexpressing CALHM1 and P86L-CALHM1 compared with control cells. Treatment with Ab elicited a significant decrease in the cell survival proteins p-ERK and p-CREB, an increase in the activity of caspases 3 and 7, and more frequent cell death by inducing early apoptosis in P86L-CALHM1- overexpressing cells than in CALHM1 or control cells. These results suggest that in the presence of Ab, P86L-CALHM1 shifts the balance between neurodegeneration and neuronal survival toward the stimulation of pro-cytotoxic pathways, thus potentially contributing to its deleterious effects in AD.This work was partly supported by the following grants: Ministerio de Economía y Competitividad, FPU Program, Refs. AP2009/0343 (AJMO) and AP2010/1219 (IB). ARN: FIS PI10/01426. MGL: Ministerio de Economía y Competitividad, Ref. SAF2012-23332. MFCA: Consolidación de grupos de investigación UAM-CAM 1004040047. We also thank Fundación Teófilo Hernando, Madrid, Spain, for their continued suppor

Noninvasive monitoring of serial changes in pulmonary vascular resistance and acute vasodilator testing using cardiac magnetic resonance

Objectives The study sought to evaluate the ability of cardiac magnetic resonance (CMR) to monitor acute and long-term changes in pulmonary vascular resistance (PVR) noninvasively. Background PVR monitoring during the follow-up of patients with pulmonary hypertension (PH) and the response to vasodilator testing require invasive right heart catheterization. Methods An experimental study in pigs was designed to evaluate the ability of CMR to monitor: 1) an acute increase in PVR generated by acute pulmonary embolization (n = 10); 2) serial changes in PVR in chronic PH (n = 22); and 3) changes in PVR during vasodilator testing in chronic PH (n = 10). CMR studies were performed with simultaneous hemodynamic assessment using a CMR-compatible Swan-Ganz catheter. Average flow velocity in the main pulmonary artery (PA) was quantified with phase contrast imaging. Pearson correlation and mixed model analysis were used to correlate changes in PVR with changes in CMR-quantified PA velocity. Additionally, PVR was estimated from CMR data (PA velocity and right ventricular ejection fraction) using a formula previously validated. Results Changes in PA velocity strongly and inversely correlated with acute increases in PVR induced by pulmonary embolization (r = –0.92), serial PVR fluctuations in chronic PH (r = –0.89), and acute reductions during vasodilator testing (r = –0.89, p ≤ 0.01 for all). CMR-estimated PVR showed adequate agreement with invasive PVR (mean bias –1.1 Wood units,; 95% confidence interval: –5.9 to 3.7) and changes in both indices correlated strongly (r = 0.86, p < 0.01). Conclusions CMR allows for noninvasive monitoring of acute and chronic changes in PVR in PH. This capability may be valuable in the evaluation and follow-up of patients with PH

Do specific antimicrobial stewardship interventions have an impact on carbapenem resistance in Gram-negative bacilli? A multicentre quasi-experimental ecological study: time-trend analysis and characterization of carbapenemases

CarbaPIRASOA team.[Background] Carbapenem-resistant Gram-negative bacilli (CR-GNB) are among the most threatening microorganisms worldwide and carbapenem use facilitates their spread. Antimicrobial stewardship programmes (ASPs) can help to optimize the use of antibiotics. This study evaluates the impact of a multifaceted educational ASP on carbapenem use and on the epidemiology of CR-GNB.[Methods] We conducted a quasi-experimental, time-series study in seven hospitals, from January 2014 to September 2018. The key intervention was composed of educational interviews promoting the appropriate use of carbapenems. The primary endpoints were carbapenem consumption and incidence density (ID) of CR-GNB. All non-duplicated CR-GNB clinical isolates were tested using phenotypic assays and PCR for the presence of carbapenemases. Joinpoint regression and interrupted time-series analyses were used to determine trends.[Results] A decrease in carbapenem consumption throughout the study period [average quarterly percentage change (AQPC) −1.5%, P < 0.001] and a −8.170 (−16.064 to −0.277) level change following the intervention were observed. The ID of CR-Acinetobacter baumannii decreased (AQPC −3.5%, P = 0.02) and the overall ID of CR-GNB remained stable (AQPC −0.4%, P = 0.52). CR-GNB, CR-Pseudomonas aeruginosa and CR-A. baumannii IDs per hospital correlated with the local consumption of carbapenems. The most prevalent carbapenem resistance mechanisms were OXA-23 for CR-A. baumannii (76.1%), OXA-48 for CR-Klebsiella pneumoniae (66%) and no carbapenemases for CR-P. aeruginosa (91.7%). The epidemiology of carbapenemases was heterogeneous throughout the study, especially for carbapenemase-producing Enterobacteriaceae.[Conclusions] In conclusion, a multifaceted, educational interview-based ASP targeting carbapenem prescribing reduced carbapenem use and the ID of CR-A. baumannii.This work was funded by the Spanish Infectious Diseases and Clinical Microbiology Society (SEIMC).Peer reviewe

A striking new species of Rhipidocladum (Poaceae: Bambusoideae: Bambuseae: Arthrostylidiinae) with single, terminal-spikelet synflorescences, endemic to Jalisco, Mexico

Background and aims – Rhipidocladum, a woody bamboo genus distributed from Mexico to Argentina, has raceme like synflorescences of multiple spikelets. Six of the 21 known species occur in Mexico. In this study, we present a full description, distribution map, illustrations, and photographs of an unusual new Rhipidocladum species endemic to Jalisco, Mexico. Additionally, we provide an updated key to the species of Rhipidocladum in Mexico. Material and methods – This study was based on fieldwork, literature, and herbarium specimens review. Specimens collected were analysed and photographed during fieldwork. The conservation assessment is based on spatial analyses, following the IUCN guidelines and criteria. Results – This is the first species in the genus Rhipidocladum that has synflorescences with only a single, terminal spikelet. Rhipidocladum singuliflorum occurs only in three localities in the municipality of Puerto Vallarta, Jalisco, Mexico. This species inhabits the canyon slopes of rivers in subdeciduous and tropical dry forests, at 6–150 m a.s.l. According to our IUCN assessment, this new species should be considered Critically Endangered

Data supporting the rat brain sample preparation and validation assays for simultaneous determination of 8 neurotransmitters and their metabolites using liquid chromatography–tandem mass spectrometry

The data presented in this article supports the rat brain sample preparation procedure previous to its injection into the liquid chromatography–tandem mass spectrometry (LC–MS/MS) system to monitor levels of adrenaline, noradrenaline, glutamic acid, γ-aminobutyric acid, dopamine, 5-hydroxytryptamine, 5-hydroxyindole acetic acid, and 3-methoxy-4-hydroxyphenylglycol. In addition, we describe the method validation assays (such as calibration curve, lower limit of quantification, precision and accuracy intra- and inter-day, selectivity, extraction recovery and matrix effect, stability, and carry-over effect) according to the United States Food and Drug Administration and European Medicine Agency to measure in one step different neurotransmitters and their metabolites. The data supplied in this article is related to the research study entitled: “Simultaneous determination of 8 neurotransmitters and their metabolite levels in rat brain using liquid chromatography in tandem with mass spectrometry: application to the murine Nrf2 model of depression” (Wojnicz et al. 2016) [1]

Effective phospholipids removing microelution-solid phase extraction LC-MS/MS method for simultaneous plasma quantification of aripiprazole and dehydro-aripiprazole: Application to human pharmacokinetic studies

A simple liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for simultaneous quantification of aripiprazole and its active metabolite, dehydro-aripiprazole, in human plasma. Stable isotopically labeled aripiprazole, aripiprazole-D8, has been used as the internal standard (IS) for both analytes. Only 200 μl of human plasma was needed for analyte extraction, using effective phospholipids-eliminating three-step microelution-solid-phase extraction (SPE, Oasis PRiME HLB 96-well μElution Plate). An ACE C18-PFP column was applied for chromatographic separation at 25 °C, protected by a 0.2-μm on-line filter. A combination of ammonium formate (5 mM)-acetonitrile (pH 4.0; 65:35, v/v) was used as mobile phase and the chromatogram was run under gradient conditions at a flow rate of 0.6 ml/min. Run time lasted 5 min, followed by a re-equilibration time of 3 min, to give a total run time of 8 min. Five μl of the sample was injected into the chromatographic system. Aripiprazole, dehydro-aripiprazole and IS were detected using the mode multiple reaction monitoring in the positive ionization mode. The method was linear in the concentration range of 0.18–110 ng/ml and 0.35–100 ng/ml for aripiprazole and dehydro-aripiprazole, respectively. Our method has been validated according to the recommendations of regulatory agencies through tests of precision, accuracy, recovery, matrix effect, stability, sensitivity, selectivity and carry-over. Our microelution-SPE method removes more than 99% of main plasma phospholipids compared to protein precipitation and was successfully applied to several bioequivalence studies.The authors wish to thank Instituto-Fundación Teófilo Hernando for its continued financial support. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 721236. This work was also supported by FPU12/02220 from MECD to AW.Peer reviewe