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2.
Artículo en Inglés | MEDLINE | ID: mdl-37956468

RESUMEN

Janus kinase inhibitors (JAKi) are oral small molecules used in the treatment of a broad spectrum of autoimmune and myeloproliferative diseases. JAKi exhibit significant intra- and inter-individual pharmacokinetic variabilities, due to fluctuations in compliance with oral treatments and their metabolism essentially driven by cytochrome P450 enzymes. Intrinsically, JAKi have dose-response relationship and narrow therapeutic index: therapeutic drug monitoring (TDM) is expected to optimize and adapt their dosage regimen in order to resolve problems of efficacy and tolerance linked to dose and safety. A sensitive analytical method using multiplex high-performance liquid-chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) was developed and validated for the simultaneous quantification in plasma of the 6 major currently used JAKi, namely abrocitinib, baricitinib, fedratinib, ruxolitinib, tofacitinib, and upadacitinib. Plasma samples are subjected to protein precipitation with MeOH, using stable isotopically labelled internal standards. The separation of JAKi in supernatants diluted 1:1 with ultrapure H2O was performed using a C18 column Xselect HSS T3 2.5 µm, 2.1x150 mm using a mobile phase composed of formic acid (FA) 0.2% and acetonitrile (+FA 0.1%) in gradient mode. The analytical run time for the multiplex assay was 7 min. JAKi drugs were monitored by electrospray ionization in the positive mode followed by triple-stage quadrupole MS/MS analysis. The method was validated according to SFSTP and ICH guidelines over the clinically relevant concentration ranges (0.5-200 ng/mL for abrocitinib, baricitinib and upadacitinib; 1-400 ng/mL for tofacitinib; 0.5-400 ng/mL for ruxolitinib, and 10-800 ng/mL for fedratinib). This multiplex HPLC-MS/MS assay achieved good performances in term of trueness (91.1-113.5%), repeatability (3.0-9.9%), and intermediate precision (4.5-11.3%). We developed and validated a highly sensitive method for the multiplex quantification of the JAKi abrocitinib, baricitinib, fedratinib, ruxolitinib, tofacitinib, and upadacitinib in human plasma. The method will be applied for prospective clinical pharmacokinetic studies to determine whether TDM programs for JAKi based on residual drug concentrations can be recommended using disease-specific therapeutic ranges.


Asunto(s)
Inhibidores de las Cinasas Janus , Espectrometría de Masas en Tándem , Humanos , Cromatografía Líquida de Alta Presión/métodos , Espectrometría de Masas en Tándem/métodos , Estudios Prospectivos , Monitoreo de Drogas/métodos , Reproducibilidad de los Resultados
3.
Opt Lett ; 47(14): 3556-3559, 2022 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-35838729

RESUMEN

Quasiperiodicity is a form of spatial order that has been observed in quasicrystalline matter but not light. We construct a quasicrystalline surface out of a light emitting diode. Using a nanoscale waveguide as a microscope (NSOM), we directly image the light field at the surface of the diode. Here we show, using reciprocal space representations of the images, that the light field is quasiperiodic. We explain the structure of the light field with wave superposition. Periodic ordering is limited to at most six-fold symmetry. The light field exhibits 12-fold quasisymmetry, showing order while disproving periodicity. This demonstrates that a new class, consisting of projections from hyperspace, exists in the taxonomy of light ordering.

4.
Arch Cardiovasc Dis ; 115(3): 169-178, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35283039

RESUMEN

BACKGROUND: Previous studies have shown that pulmonary hypertension is a predictor of mortality in patients with systolic heart failure (SHF). Persistent pulmonary hypertension after a reactivity test is associated with a worse outcome after transplantation. Recent studies have shown the utility of different haemodynamic parameters. AIMS: To define best haemodynamic parameters for risk stratification in patients with advanced systolic heart failure. METHODS: We included 425 consecutive patients who underwent a right heart catheterization with an inotropic challenge if indicated. RESULTS: During a median (interquartile range) follow-up of 1.67 (0.49-4.49) years, there were 151 major cardiac events (126 cardiovascular deaths and 25 postoperative deaths after ventricular assist device implantation or heart transplantation). The most powerful independent predictors of major cardiac events were baseline right atrial pressure (RAP) (hazard ratio [HR]: 1.09, 95% confidence interval [CI]: 1.06-1.12; P<0.0001) and baseline pulmonary vascular resistance (PVR) (HR: 1.10; 95% CI: 1.03-1.17; P=0.002). After inotropic challenge, the only independent predictor was mean pulmonary arterial pressure (mPAP) (HR: 1.06; 95% CI: 1.03-1.09; P<0.0001). The combination of PVR (≤or>3 Wood units), RAP (30mmHg) was the best predictor of major events. CONCLUSION: We suggest using a simple algorithm based on baseline PVR, baseline RAP and mPAP after the inotropic challenge for the risk stratification of stable patients with advanced systolic heart failure.


Asunto(s)
Insuficiencia Cardíaca Sistólica , Insuficiencia Cardíaca , Hipertensión Pulmonar , Cateterismo Cardíaco/efectos adversos , Insuficiencia Cardíaca Sistólica/diagnóstico , Insuficiencia Cardíaca Sistólica/terapia , Hemodinámica , Humanos , Estudios Retrospectivos , Medición de Riesgo
5.
J Cell Sci ; 135(5)2022 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-34981808

RESUMEN

High-density lipoproteins (HDLs) prevent cell death induced by a variety of cytotoxic drugs. The underlying mechanisms are however still poorly understood. Here, we present evidence that HDLs efficiently protect cells against thapsigargin (TG), a sarco/endoplasmic reticulum (ER) Ca2+-ATPase (SERCA) inhibitor, by extracting the drug from cells. Drug efflux could also be triggered to some extent by low-density lipoproteins and serum. HDLs did not reverse the non-lethal mild ER stress response induced by low TG concentrations or by SERCA knockdown, but HDLs inhibited the toxic SERCA-independent effects mediated by high TG concentrations. HDLs could extract other lipophilic compounds, but not hydrophilic substances. This work shows that HDLs utilize their capacity of loading themselves with lipophilic compounds, akin to their ability to extract cellular cholesterol, to reduce the cell content of hydrophobic drugs. This can be beneficial if lipophilic xenobiotics are toxic but may be detrimental to the therapeutic benefit of lipophilic drugs such as glibenclamide.


Asunto(s)
Lipoproteínas HDL , Preparaciones Farmacéuticas , Calcio/metabolismo , Retículo Endoplásmico/metabolismo , Estrés del Retículo Endoplásmico , ATPasas Transportadoras de Calcio del Retículo Sarcoplásmico/genética , Tapsigargina/farmacología
7.
Pharmacol Res Perspect ; 8(1): e00558, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31990440

RESUMEN

A pilot study was conducted aiming at specifying sultiame's pharmacokinetic profile, completed by in vitro assays evaluating the intraerythrocytic transfer of sultiame and by a pharmacokinetic model assessing its distribution. Single oral doses of sultiame (Ospolot® 50, 100, and 200 mg) were administered in open-label to four healthy volunteers. Serial plasma, whole blood, and urine samples were collected. A spiking experiment was also performed to characterize sultiame's exchanges between plasma and erythrocytes in vitro. Pharmacokinetic parameters were evaluated using standard noncompartmental calculations and nonlinear mixed-effect modeling. The plasma maximal concentrations (Cmax ) showed striking nonlinear disposition of sultiame, with a 10-fold increase while doses were doubled. Conversely, whole blood Cmax increased less than dose proportionally while staying much higher than in plasma. Quick uptake of sultiame into erythrocytes observed in vivo was confirmed in vitro, with minimal efflux. A two-compartment model with first-order absorption, incorporating a saturable ligand to receptor binding, described the data remarkably well, indicating apparent plasma clearance of 10.0 L/h (BSV: 29%) and distribution volume of 64.8 L; saturable uptake into an intracellular compartment of 3.3 L with a maximum binding capacity of 111 mg accounted for nonlinearities observed in plasma and whole blood concentrations. Pharmacokinetic characteristics of sultiame are reported, including estimates of clearance and volume of distribution that were so far unpublished. The noticeable nonlinearity in sultiame disposition should be taken into account for the design of future studies and the interpretation of therapeutic drug monitoring results.


Asunto(s)
Eritrocitos/química , Tiazinas/sangre , Tiazinas/farmacocinética , Administración Oral , Adulto , Área Bajo la Curva , Voluntarios Sanos , Humanos , Masculino , Tasa de Depuración Metabólica , Uso Fuera de lo Indicado , Proyectos Piloto , Tiazinas/administración & dosificación , Orina/química , Adulto Joven
8.
J Pediatric Infect Dis Soc ; 9(1): 96-99, 2020 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-31183500

RESUMEN

Little information on the efficacy and pharmacokinetics of letermovir among immunocompromised children is currently available. We describe here the use of letermovir in a 2-year-old immunocompromised child with ganciclovir-resistant cytomegalovirus disease who required extracorporeal membrane oxygenation. Detailed information on therapeutic-drug-monitoring measures and dosage adjustments for letermovir is provided.


Asunto(s)
Acetatos/administración & dosificación , Antivirales/administración & dosificación , Infecciones por Citomegalovirus/tratamiento farmacológico , Citomegalovirus , Monitoreo de Drogas/métodos , Huésped Inmunocomprometido , Neumonía Viral/tratamiento farmacológico , Quinazolinas/administración & dosificación , Acetatos/farmacocinética , Acetatos/uso terapéutico , Antivirales/farmacocinética , Antivirales/uso terapéutico , Preescolar , Ensayos de Uso Compasivo , Citomegalovirus/genética , Citomegalovirus/aislamiento & purificación , Infecciones por Citomegalovirus/inmunología , Infecciones por Citomegalovirus/virología , ADN Viral/sangre , Relación Dosis-Respuesta a Droga , Oxigenación por Membrana Extracorpórea/efectos adversos , Resultado Fatal , Femenino , Ganciclovir/uso terapéutico , Hepatitis Viral Humana/tratamiento farmacológico , Hepatitis Viral Humana/inmunología , Humanos , Infecciones Oportunistas/tratamiento farmacológico , Neumonía Viral/inmunología , Neumonía Viral/virología , Reacción en Cadena de la Polimerasa , Quinazolinas/farmacocinética , Quinazolinas/uso terapéutico , Insuficiencia del Tratamiento , Carga Viral
9.
Nanoscale ; 11(40): 18837-18844, 2019 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-31595913

RESUMEN

In this paper, we propose a hybrid quantum dot (QD)/solar cell configuration to improve performance of interdigitated back contact (IBC) silicon solar cells, resulting in 39.5% relative boost in the short-circuit current (JSC) through efficient utilisation of resonant energy transfer (RET) and luminescent downshifting (LDS). A uniform layer of CdSe1-xSx/ZnS quantum dots is deposited onto the AlOx surface passivation layer of the IBC solar cell. QD hybridization is found to cause a broadband improvement in the solar cell external quantum efficiency. Enhancement over the QD absorption wavelength range is shown to result from LDS. This is confirmed by significant boosts in the solar cell internal quantum efficiency (IQE) due to the presence of QDs. Enhancement over the red and near-infrared spectral range is shown to result from the anti-reflection properties of the QD layer coating. A study on the effect of QD layer thickness on solar cell performance was performed and an optimised QD layer thickness was determined. Time-resolved photoluminescence (TRPL) spectroscopy was used to investigate the photoluminescence dynamics of the QD layer as a function of AlOx spacer layer thickness. RET can be evoked between the QD and Si layers for very thin AlOx spacer layers, with RET efficiencies of up to 15%. In the conventional LDS architecture, down-converters are deposited on the surface of an optimised anti-reflection layer, providing relatively narrowband enhancement, whereas the QDs in our hybrid architecture provide optical enhancement over the broadband wavelength range, by simultaneously utilising LDS, RET-mediated carrier injection, and antireflection effects, resulting in up to 40% improvement in the power conversion efficiency (PCE). Low-cost synthesis of QDs and simple device integration provide a cost-effective solution for boosting solar cell performance.

10.
Open Forum Infect Dis ; 6(4): ofz130, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31008142

RESUMEN

Cardiac implantable electronic device-related infection is clinically challenging. Curative treatment commonly includes system removal. A case caused by Granulicatella adiacens occurred in a 32-year-old woman. Clinical course, literature review, and biofilm investigations enabled successful antibiotic management without system removal.

11.
Malar J ; 18(1): 139, 2019 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-30999915

RESUMEN

BACKGROUND: The World Health Organization (WHO) recommends combinations of an artemisinin derivative plus an anti-malarial drug of longer half-life as treatment options for uncomplicated Plasmodium falciparum infections. In Africa, artesunate-mefloquine (ASMQ) is an infrequently used artemisinin-based combination therapy (ACT) because of perceived poor tolerance to mefloquine. However, the WHO has recommended reconsideration of the use of ASMQ in Africa. In this large clinical study, the pharmacokinetics (PK) of a fixed dose combination of ASMQ was investigated in an African paediatric population to support dosing recommendations used in Southeast Asia and South America. METHODS: Among the 472 paediatric patients aged 6-59 months from six African centres included in the large clinical trial, a subset of 50 Kenyan children underwent intensive sampling to develop AS, its metabolite dihydroartemisinin (DHA) and MQ PK models. The final MQ PK model was validated using sparse data collected in the remaining participants (NONMEM®). The doses were one or two tablets containing 25/55 mg AS/MQ administered once a day for 3 days according to patients' age. A sensitive LC-MS/MS method was used to quantify AS, DHA and MQ concentrations in plasma. An attempt was made to investigate the relationship between the absence/presence of malaria recrudescence and MQ area under the curve (AUC) using logistic regression. RESULTS: AS/DHA concentration-time profiles were best described using a one-compartment model for both compounds with irreversible AS conversion into DHA. AS/DHA PK were characterized by a significant degree of variability. Body weight affected DHA PK parameters. MQ PK was characterized by a two-compartment model and a large degree of variability. Allometric scaling of MQ clearances and volumes of distribution was used to depict the relationship between MQ PK and body weight. No association was found between the model predicted AUC and appearance of recrudescence. CONCLUSIONS: The population pharmacokinetic models developed for both AS/DHA and MQ showed a large variability in drug exposure in the investigated African paediatric population. The largest contributor to this variability was body weight, which is accommodated for by the ASMQ fixed dose combination (FDC) dosing recommendation. Besides body weight considerations, there is no indication that the dosage should be modified in children with malaria compared to adults. Trial registration Pan African Clinical Trials Registry PACTR201202000278282 registration date 2011/02/16.


Asunto(s)
Antimaláricos/farmacología , Artesunato/farmacología , Malaria Falciparum/tratamiento farmacológico , Mefloquina/farmacología , Antimaláricos/farmacocinética , Artesunato/farmacocinética , Preescolar , Relación Dosis-Respuesta a Droga , Combinación de Medicamentos , Femenino , Humanos , Lactante , Kenia , Masculino , Mefloquina/farmacocinética , Estudios Prospectivos , Recurrencia
12.
Nat Commun ; 9(1): 4848, 2018 11 19.
Artículo en Inglés | MEDLINE | ID: mdl-30451843

RESUMEN

X-linked myotubular myopathy (XLMTM, also known as XLCNM) is a severe congenital muscular disorder due to mutations in the myotubularin gene, MTM1. It is characterized by generalized hypotonia, leading to neonatal death of most patients. No specific treatment exists. Here, we show that tamoxifen, a well-known drug used against breast cancer, rescues the phenotype of Mtm1-deficient mice. Tamoxifen increases lifespan several-fold while improving overall motor function and preventing disease progression including lower limb paralysis. Tamoxifen corrects functional, histological and molecular hallmarks of XLMTM, with improved force output, myonuclei positioning, myofibrillar structure, triad number, and excitation-contraction coupling. Tamoxifen normalizes the expression level of the XLMTM disease modifiers DNM2 and PI3KC2B, likely contributing to the phenotypic rescue. Our findings demonstrate that tamoxifen is a promising candidate for clinical evaluation in XLMTM patients.


Asunto(s)
Actividad Motora/efectos de los fármacos , Músculo Esquelético/efectos de los fármacos , Miopatías Estructurales Congénitas/tratamiento farmacológico , Sustancias Protectoras/farmacología , Proteínas Tirosina Fosfatasas no Receptoras/genética , Tamoxifeno/farmacología , Animales , Fosfatidilinositol 3-Quinasas Clase II/genética , Fosfatidilinositol 3-Quinasas Clase II/metabolismo , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Dinamina II/genética , Dinamina II/metabolismo , Estimulación Eléctrica , Acoplamiento Excitación-Contracción/efectos de los fármacos , Femenino , Expresión Génica/efectos de los fármacos , Genes Letales , Humanos , Longevidad/efectos de los fármacos , Masculino , Ratones , Ratones Noqueados , Músculo Esquelético/metabolismo , Músculo Esquelético/patología , Miofibrillas/efectos de los fármacos , Miofibrillas/metabolismo , Miofibrillas/ultraestructura , Miopatías Estructurales Congénitas/genética , Miopatías Estructurales Congénitas/metabolismo , Miopatías Estructurales Congénitas/patología , Proteínas Tirosina Fosfatasas no Receptoras/deficiencia
13.
Artículo en Inglés | MEDLINE | ID: mdl-30344511

RESUMEN

Post-translational modifications (PTMs) of sarcomeric proteins could participate to left ventricular (LV) remodeling and contractile dysfunction leading in advanced heart failure (HF) with altered ejection fraction. Using an experimental rat model of HF (ligation of left coronary artery) and phosphoproteomic analysis, we identified an increase of desmin phosphorylation and a decrease of desmin O-N-acetylglucosaminylation (O-GlcNAcylation). We aim to characterize interplay between phosphorylation and O-GlcNAcylation for desmin in primary cultures of cardiomyocyte by specific O-GlcNAcase (OGA) inhibition with thiamet G and silencing O-GlcNAc transferase (OGT) and, in perfused heart perfused with thiamet G in sham- and HF-rats. In each model, we found an efficiency of O-GlcNAcylation modulation characterized by the levels of O-GlcNAcylated proteins and OGT expression (for silencing experiments in cells). In perfused heart, we found an improvement of cardiac function under OGA inhibition. But none of the treatments either in in vitro or ex vivo cardiac models, induced a modulation of desmin, phosphorylated and O-GlcNAcylated desmin expression, despite the presence of O-GlcNAc moities in cardiac desmin. Our data suggests no interplay between phosphorylation and O-GlcNAcylation of desmin in HF post-myocardial infarction. The future requires finding the targets in heart involved in cardiac improvement under thiamet G treatment.

14.
J Pharm Biomed Anal ; 159: 341-347, 2018 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-30025299

RESUMEN

The use of DNA aptamers in biosensors for the quantification of pharmaceuticals in the clinics would help to overcome the limitations of antibody-based detection for small molecules. The interest for such systems is proven by the ever-increasing number of aptamer-based solutions for analytics proposed in the literature as proof-of-concept demonstrators. Despite such diversity, these platforms often lack a comparative assessment of their performances against the current standard of practice in the clinics when using real samples. We employed an aptamer against tobramycin discovered in our laboratory to quantify through surface plasmon resonance the concentration of the antibiotic in clinical samples obtained from patients treated with tobramycin and undergoing therapeutic drug monitoring. We then compared the performances of our detection strategy against the current standard of practice. Our results show how, using adequate calibration and matrix complexity reduction, DNA aptamer-based direct assays can assess clinically relevant concentrations of small molecules in patient serum and with good correlation to current standards used in the clinics.


Asunto(s)
Aptámeros de Nucleótidos/sangre , Monitoreo de Drogas/normas , Tobramicina/sangre , Antibacterianos/sangre , Monitoreo de Drogas/métodos , Humanos , Resonancia por Plasmón de Superficie
15.
Front Microbiol ; 9: 919, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29867830

RESUMEN

The rate of invasive group B Streptococcus (GBS) infections is steadily increasing, particularly in older persons and in adults with diabetes and other comorbidities. This population includes persons with a foreign body (e.g., who have undergone arthroplasty). In a rat tissue cage model, we evaluated the efficacy of adjunctive gentamicin (GEN) administered systemically (5 mg/kg body weight) every 24 h, or locally (12.5 mg/L tissue cage concentration) every 24 or 72 h, in combination with penicillin (PEN) administered systemically (250,000 IU/kg body weight three times per day). The efficacy was evaluated on two different sessile forms of GBS: transition (i.e., in between planktonic and biofilm) and biofilm. After 3 days of treatment, the mean bacterial load reduction of transition-form GBS was greater in all PEN-GEN combination groups than in the PEN monotherapy group (P ≤ 0.03). The 6-day regimen decreased the bacterial load significantly in comparison to the 3-day regimen, irrespective of growth form and adjunctive GEN (P < 0.01). After 6 days of treatment, the mean reduction in transition-form GBS was greater with PEN plus GEN administered locally every 24 h than with PEN monotherapy (P = 0.03). These results were not confirmed with biofilm GBS. The difference in mean bacterial load reduction between all PEN-GEN and PEN monotherapy groups was <100 CFU/mL. Hence, synergy criteria were not fulfilled. Adjunctive systemic GEN consists of potential side effects and showed poor efficacy in this study. Combining systemic PEN and local GEN has a potential application in the treatment of streptococcal implant-associated infections.

16.
Shock ; 49(6): 675-681, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29757923

RESUMEN

Ischemic heart disease remains the leading cause of morbidity and mortality in the Western world. Artesunate is the WHO-recommended drug of choice for complicated malaria (with organ failure). The administration of high doses of artesunate is safe in healthy volunteers (up to 8 mg/kg i.v.) and patients with severe malaria (2.4 mg/kg i.v.). We investigated the effects of artesunate (1 mg/kg) or its active metabolite dihydroartemisinin (DHA; 0.1 mg/kg) in a model of transient myocardial ischemia/reperfusion (I/R) and evaluated the mechanism of action of the observed cardioprotective effects of artesunate and DHA. We report here for the first time that the administration of artesunate at the onset of reperfusion attenuates the myocardial injury associated with I/R. The observed beneficial effects of artesunate are associated with activation of the PI3K/Akt/ERK 1/2 (RISK) pathway, activation of endothelial nitric oxide synthase, inhibition of glycogen synthase kinase-3ß, inhibition of nuclear factor kappa B, and activation of the STAT3 (SAFE) pathway. In conclusion, as artesunate has an excellent safety profile, the above data should stimulate clinical trials in patients with acute coronary syndromes.


Asunto(s)
Antimaláricos/farmacología , Artesunato/farmacología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Infarto del Miocardio/tratamiento farmacológico , Miocardio/metabolismo , Animales , Antimaláricos/farmacocinética , Artesunato/farmacocinética , Modelos Animales de Enfermedad , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Masculino , Infarto del Miocardio/metabolismo , Infarto del Miocardio/patología , Miocardio/patología , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas , Ratas Wistar , Factor de Transcripción STAT3/metabolismo
17.
J Pharm Biomed Anal ; 154: 263-277, 2018 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-29579633

RESUMEN

In epidemiological studies, antimalarials measurements in blood represent the best available marker of drugs exposure at population level, an important driver for the emergence of drug resistance. We have developed a liquid chromatography-tandem mass spectrometry method (LC-MS/MS) for the simultaneous quantification of 7 frequently used antimalarials (amodiaquine, chloroquine, quinine, sulfadoxine, pyrimethamine, mefloquine, lumefantrine) and 2 active metabolites (N-desethyl-amodiaquine, desbutyl-lumefantrine) in 10-µl dried blood spots (DBS). This sampling approach is suitable for field studies wherein blood samples processing, transportation and storage are problematic. Sample preparation included extraction from a 3 mm-disk punched out of the DBS with 100-µl of methanol + 1% formic acid containing deuterated internal standards for all drugs. Good performances were achieved in terms of trueness (-12.1 to +11.1%), precision (1.4-15.0%) and sensitivity, with lower limits of quantification comprised between 2 ng/ml (sulfadoxine) and 20 ng/ml (chloroquine, quinine, pyrimethamine, mefloquine, lumefantrine and desbutyl-lumefantrine). All analytes were stable in DBS kept for 24 h at room temperature and at 37 °C. The developed assay was applied within the frame of a pharmacokinetic study including 16 healthy volunteers who received a single dose of artemether-lumefantrine. Lumefantrine concentrations in plasma and in DBS were highly correlated (R = 0.97) at all time points, confirming the assumption that lumefantrine concentrations determined in DBS confidently reflect blood concentrations. The blood/plasma ratio of 0.56 obtained using the Bland-Altman approach (and corresponding to the slope of the linear regression) is in line with very low penetration of lumefantrine into red blood cells. This sensitive multiplex LC-MS/MS assay enabling the simultaneous analysis of antimalarials in DBS is suitable for epidemiological studies in field conditions.


Asunto(s)
Antimaláricos/sangre , Cromatografía Liquida/métodos , Pruebas con Sangre Seca/métodos , Plasma/química , Espectrometría de Masas en Tándem/métodos , Antimaláricos/farmacocinética , Arteméter , Artemisininas/sangre , Artemisininas/farmacocinética , Etanolaminas/sangre , Etanolaminas/farmacocinética , Fluorenos/sangre , Fluorenos/farmacocinética , Humanos , Lumefantrina , Reproducibilidad de los Resultados , Temperatura
18.
Artículo en Inglés | MEDLINE | ID: mdl-29544202

RESUMEN

A sensitive and selective method of high performance liquid chromatography (HPLC) coupled to tandem mass spectrometry (MS/MS) has been developed for the simultaneous quantification of six anticancer protein kinase inhibitors (PKIs), dabrafenib, trametinib, vemurafenib, cobimetinib, pazopanib, regorafenib, and two active metabolites (regorafenib-M2 and regorafenib-M5) in human plasma. Plasma protein precipitation with methanol enables the sample extraction of 100 µL aliquot of plasma. Analytes are detected by electrospray triple-stage quadrupole mass spectrometry and quantified using the calibration curves with stable isotope-labeled internal standards. The method was validated based on FDA recommendations, including assessment of extraction yield (74-104%), matrix effects, analytical recovery (94-104%) with low variability (<15%). The method is sensitive (lower limits of quantification within 1 to 200 ng/mL), accurate (intra- and inter-assay bias: -0.3% to +12.7%, and -3.2% to +6.3%, respectively) and precise (intra- and inter-assay CVs within 0.7-7.3% and 2.5-8.0%, respectively) over the clinically relevant concentration range (upper limits of quantification 500 to 100,000 ng/mL). This method is applied in our laboratory for both clinical research programs and routine therapeutic drug monitoring service of PKIs.


Asunto(s)
Antineoplásicos/sangre , Cromatografía Líquida de Alta Presión/métodos , Espectrometría de Masas en Tándem/métodos , Administración Oral , Antineoplásicos/administración & dosificación , Antineoplásicos/química , Antineoplásicos/farmacocinética , Azetidinas/administración & dosificación , Azetidinas/sangre , Azetidinas/química , Azetidinas/farmacocinética , Niño , Humanos , Imidazoles/administración & dosificación , Imidazoles/sangre , Imidazoles/química , Imidazoles/farmacocinética , Indazoles , Indoles/administración & dosificación , Indoles/sangre , Indoles/química , Indoles/farmacocinética , Límite de Detección , Modelos Lineales , Oximas/administración & dosificación , Oximas/sangre , Oximas/química , Oximas/farmacocinética , Compuestos de Fenilurea/administración & dosificación , Compuestos de Fenilurea/sangre , Compuestos de Fenilurea/química , Compuestos de Fenilurea/farmacocinética , Piperidinas/administración & dosificación , Piperidinas/sangre , Piperidinas/química , Piperidinas/farmacocinética , Piridinas/administración & dosificación , Piridinas/sangre , Piridinas/química , Piridinas/farmacocinética , Piridonas/administración & dosificación , Piridonas/sangre , Piridonas/química , Piridonas/farmacocinética , Pirimidinas/administración & dosificación , Pirimidinas/sangre , Pirimidinas/química , Pirimidinas/farmacocinética , Pirimidinonas/administración & dosificación , Pirimidinonas/sangre , Pirimidinonas/química , Pirimidinonas/farmacocinética , Reproducibilidad de los Resultados
19.
Front Microbiol ; 7: 1604, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27790201

RESUMEN

Background: The timing of infection is closely determined in controlled human malaria infection (CHMI) studies, and as such they provide a unique opportunity to dissect changes in immunological responses before and after a single infection. The first Kenyan Challenge Study (KCS) (Pan African Clinical Trial Registry: PACTR20121100033272) was performed in 2013 with the aim of establishing the CHMI model in Kenya. This study used aseptic, cryopreserved, attenuated Plasmodium falciparum sporozoites administered by needle and syringe (PfSPZ Challenge) and was the first to evaluate parasite dynamics post-CHMI in individuals with varying degrees of prior exposure to malaria. Methods: We describe detailed serological and functional immunological responses pre- and post-CHMI for participants in the KCS and compare these with those from malaria-naïve UK volunteers who also underwent CHMI (VAC049) (ClinicalTrials.gov NCT01465048) using PfSPZ Challenge. We assessed antibody responses to three key blood-stage merozoite antigens [merozoite surface protein 1 (MSP1), apical membrane protein 1 (AMA1), and reticulocyte-binding protein homolog 5 (RH5)] and functional activity using two candidate measures of anti-merozoite immunity; the growth inhibition activity (GIA) assay and the antibody-dependent respiratory burst activity (ADRB) assay. Results:Clear serological differences were observed pre- and post-CHMI by ELISA between malaria-naïve UK volunteers in VAC049, and Kenyan volunteers who had prior malaria exposure. Antibodies to AMA1 and schizont extract correlated with parasite multiplication rate (PMR) post-CHMI in KCS. Serum from volunteer 110 in KCS, who demonstrated a dramatically reduced PMR in vivo, had no in vitro GIA prior to CHMI but the highest level of ADRB activity. A significant difference in ADRB activity was seen between KCS volunteers with minimal and definite prior exposure to malaria and significant increases were seen in ADRB activity post-CHMI in Kenyan volunteers. Quinine and atovaquone/proguanil, previously assumed to be removed by IgG purification, were identified as likely giving rise to aberrantly high in vitro GIA results. Conclusions: The ADRB activity assay is a promising functional assay that warrants further investigation as a measure of prior exposure to malaria and predictor of control of parasite growth. The CHMI model can be used to evaluate potential measures of naturally-acquired immunity to malaria.

20.
Lasers Surg Med ; 47(10): 807-16, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26415084

RESUMEN

BACKGROUND: Low-dose, Visudyne®-mediated photodynamic therapy (photo-induction) was shown to selectively enhance tumor vessel transport causing increased uptake of systemically administered chemotherapy in various tumor types grown on rodent lungs. The present experiments explore the efficacy of photo-induced vessel modulation combined to intravenous (IV) liposomal cisplatin (Lipoplatin®) on rodent lung tumors and the feasibility/toxicity of this approach in porcine chest cavities. MATERIAL AND METHODS: Three groups of Fischer rats underwent orthotopic sarcoma (n = 14), mesothelioma (n = 14), or adenocarcinoma (n = 12) implantation on the left lung. Half of the animals of each group had photo-induction (0.0625 mg/kg Visudyne®, 10 J/cm(2) ) followed by IV administration of Lipoplatin® (5 mg/kg) and the other half received Lipoplatin® without photo-induction. Then, two groups of minipigs underwent intrapleural thoracoscopic (VATS) photo-induction (0.0625 mg/kg Visudyne®; 30 J/cm(2) hilum; 10 J/cm(2) apex/diaphragm) with in situ light dosimetry in combination with IV Lipoplatin® administration (5 mg/kg). Protocol I (n = 6) received Lipoplatin® immediately after light delivery and Protocol II (n = 9) 90 minutes before light delivery. Three additional animals received Lipoplatin® and VATS pleural biopsies but no photo-induction (controls). Lipoplatin® concentrations were analyzed in blood and tissues before and at regular intervals after photo-induction using inductively coupled plasma mass spectrometry. RESULTS: Photo-induction selectively increased Lipoplatin® uptake in all orthotopic tumors. It significantly increased the ratio of tumor to lung Lipoplatin® concentration in sarcoma (P = 0.0008) and adenocarcinoma (P = 0.01) but not in mesothelioma, compared to IV drug application alone. In minipigs, intrapleural photo-induction combined to systemic Lipoplatin® was well tolerated with no toxicity at 7 days for both treatment protocols. The pleural Lipoplatin® concentrations were not significantly different at 10 and 30 J/cm(2) locations but they were significantly higher in protocol I compared to II (2.37 ± 0.7 vs. 1.37 ± 0.7 ng/mg, P < 0.001). CONCLUSION: Visudyne®-mediated photo-induction selectively enhances the uptake of IV administered Lipoplatin® in rodent lung tumors. Intrapleural VATS photo-induction with identical treatment conditions combined to IV Lipoplatin chemotherapy is feasible and well tolerated in a porcine model. Lasers Surg. Med. 47:807-816, 2015. © 2015 Wiley Periodicals, Inc.


Asunto(s)
Antineoplásicos/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Cisplatino/uso terapéutico , Neoplasias Pulmonares/tratamiento farmacológico , Fotoquimioterapia/métodos , Fármacos Fotosensibilizantes/uso terapéutico , Porfirinas/uso terapéutico , Adenocarcinoma/tratamiento farmacológico , Animales , Antineoplásicos/farmacocinética , Línea Celular Tumoral , Cisplatino/farmacocinética , Esquema de Medicación , Estudios de Factibilidad , Masculino , Mesotelioma/tratamiento farmacológico , Trasplante de Neoplasias , Fármacos Fotosensibilizantes/farmacocinética , Porfirinas/farmacocinética , Ratas , Ratas Endogámicas F344 , Sarcoma/tratamiento farmacológico , Porcinos , Resultado del Tratamiento , Verteporfina
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