RESUMEN
RAF kinases are highly conserved serine/threonine kinases, and among the three RAF isoforms (ARAF, BRAF, and CRAF), the pathophysiological relevance of ARAF is not well defined. Here, we show that patients with lung cancer exhibit low expression of ARAF, which is associated with lymph node metastasis and poor patient survival. We uncover that depletion of ARAF promotes anchorage-independent growth and metastasis through activation of AKT signaling in a subset of lung cancer cells. We identified that loss of ARAF was associated with an increase in ERBB3 expression in a kinase-independent manner. ARAF suppressed the promoter activity of ERBB3, and reconstitution of ARAF in ARAF-depleted cells led to the reversal of enhanced ERBB3-AKT signaling. Furthermore, ARAF inhibited neuregulin 1 (hNRG1)-mediated AKT activation through controlling ERBB3 expression via the transcription factor KLF5. Our results disclose a critical dual role for ARAF kinase in the negative regulation of ERBB3-AKT signaling, thereby suppressing tumor metastasis.
Asunto(s)
Neoplasias Pulmonares , Quinasas raf , Humanos , Neoplasias Pulmonares/genética , Proteínas Serina-Treonina Quinasas , Receptor ErbB-3/genética , Receptor ErbB-3/metabolismo , Transducción de Señal , Quinasas raf/metabolismoRESUMEN
Nasal polyposis often is characterized by a persistent inflammation of the sinonasal mucosa, disease recurrence after medical or surgical intervention, and asthma comorbidity. Dysregulated complement activation may contribute to immunologic alterations and disease. To date, there is only scattered knowledge on the source and regulation of the central complement factors in the pathogenesis of nasal polyps. Here, we aim to study complement signatures, especially the C3-C3aR axis, and focus on cellular sources and targets in nasal polyps. Expression of complement factors, including C3, C5, and the anaphylatoxin receptors, was analyzed in nasal polyp tissue samples, the corresponding inferior turbinates, and healthy controls using transcriptomic methods and protein measurements. Distinct patterns of complement expression were found in nasal polyps compared to controls, characterized by an increased C3 activation and an increase in C3aR-bearing cells. In contrast, no difference was shown for epithelial-dependent C3 production. Besides low intracellular C3-expression levels for lymphocytes in general, we could identify an enlarged B lymphocyte population in nasal polyps displaying high amounts of intracellular C3. Our data suggest a prominent role for the C3-C3aR-axis in nasal polyps and, for the first time, describe a B cell population containing high levels of intracellular C3, suggesting a new role of B cells in the maintenance of the inflammation by complement.
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Linfocitos B/inmunología , Complemento C3/inmunología , Pólipos Nasales/inmunología , Femenino , Humanos , Inflamación/inmunología , Masculino , Persona de Mediana Edad , Mucosa Nasal/inmunología , Receptores Acoplados a Proteínas G/inmunología , Transcriptoma/inmunologíaRESUMEN
The mycotoxin zearalenone (ZEN) is produced by many plant pathogenic Fusarium species. It is well known for its estrogenic activity in humans and animals, but whether ZEN has a role in plant-pathogen interaction and which process it is targeting in planta was so far unclear. We found that treatment of Arabidopsis thaliana seedlings with ZEN induced transcription of the AtHSP90.1 gene. This heat shock protein (HSP) plays an important role in plant-pathogen interaction, assisting in stability and functionality of various disease resistance gene products. Inhibition of HSP90 ATPase activity impairs functionality. Because HSP90 inhibitors are known to induce HSP90 gene expression and due to the structural similarity with the known HSP90 inhibitor radicicol (RAD), we tested whether ZEN and its phase I metabolites α- and ß-zearalenol are also HSP90 ATPase inhibitors. Indeed, AtHSP90.1 and wheat TaHSP90-2 were inhibited by ZEN and ß-zearalenol, while α-zearalenol was almost inactive. Plants can efficiently glycosylate ZEN and α/ß-zearalenol. We therefore tested whether glucosylation has an effect on the inhibitory activity of these metabolites. Expression of the A. thaliana glucosyltransferase UGT73C6 conferred RAD resistance to a sensitive yeast strain. Glucosylation of RAD, ZEN, and α/ß-zearalenol abolished the in vitro inhibitory activity with recombinant HSP90 purified from Escherichia coli. In conclusion, the mycotoxin ZEN has a very prominent target in plants, HSP90, but it can be inactivated by glycosylation. This may explain why there is little evidence for a virulence function of ZEN in host plants.
RESUMEN
Library preparation for whole-exome sequencing is a critical step serving the enrichment of the regions of interest. For Ion Proton, there are only two exome library preparation methods available, AmpliSeq and SureSelect. Although of major interest, a comparison of the two methods is hitherto missing in the literature. Here, we systematically evaluate the performance of AmpliSeq and SureSelect and present an improved variant calling pipeline. We used 12 in-house DNA samples with genome-wide and exome microarray data and a commercially available reference DNA (NA12878) for evaluation. Both methods had a high concordance (>97%) with microarray genotypes and, when validating against NA12878, a sensitivity and positive predictive values of >93% and >80%, respectively. Application of our variant calling pipeline decreased the number of false positive variants dramatically by 90% and resulted in positive predictive value of 97%. This improvement is highly relevant in research as well as clinical setting.
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A 67-year-old man was adrenalectomized due to a tumor measuring 100 mm. Specimens revealed an inflammation with slight fibrosis and moderate infiltrates of lymphocytes and plasmacytes with immunoreactivity for IgG and IgG4 resulting in the diagnosis of an active IgG4-associated adrenalitis. To our knowledge, this is the first reported active adrenalitis of this type. It should be the precursor lesion of the adrenal calcifying fibrous tumor that was reported once before.
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Enfermedades de las Glándulas Suprarrenales/patología , Granuloma de Células Plasmáticas/patología , Enfermedad Relacionada con Inmunoglobulina G4/patología , Anciano , Humanos , Inmunoglobulina G , MasculinoRESUMEN
BACKGROUND: In a small group of patients, we have previously shown that a combination of electrophysiological tests was able to distinguish functional (psychogenic) tremor and organic tremor with excellent sensitivity and specificity. OBJECTIVES: This study aims to validate an electrophysiological test battery as a tool to diagnose patients with functional tremor with a "laboratory-supported" level of certainty. METHODS: For this prospective data collection study, we recruited 38 new patients with functional tremor (mean age 37.9 ± 24.5 years; mean disease duration 5.9 ± 9.0 years) and 73 new patients with organic tremor (mean age 55.4 ± 25.4 years; mean disease duration 15.8 ± 17.7 years). Tremor was recorded at rest, posture (with and without loading), action, while performing tapping tasks (1, 3, and 5 Hz), and while performing ballistic movements with the less-affected hand. Electrophysiological tests were performed by raters blinded to the clinical diagnosis. We calculated a sum score for all performed tests (maximum of 10 points) and used a previously suggested cut-off score of 3 points for a diagnosis of laboratory-supported functional tremor. RESULTS: We demonstrated good interrater reliability and test-retest reliability. Patients with functional tremor had a higher average score on the test battery when compared with patients with organic tremor (3.6 ± 1.4 points vs 1.0 ± 0.8 points; P < .001), and the predefined cut-off score for laboratory-supported functional tremor yielded a test sensitivity of 89.5% and a specificity of 95.9%. CONCLUSION: We now propose this test battery as the basis of laboratory-supported criteria for the diagnosis of functional tremor, and we encourage its use in clinical and research practice.
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Acelerometría/métodos , Electromiografía/métodos , Examen Neurológico/métodos , Trastornos Psicofisiológicos/diagnóstico , Temblor/diagnóstico , Acelerometría/normas , Adulto , Anciano , Electromiografía/normas , Medicina Basada en la Evidencia , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Examen Neurológico/normas , Trastornos Psicofisiológicos/fisiopatología , Reproducibilidad de los Resultados , Método Simple Ciego , Temblor/fisiopatologíaRESUMEN
BACKGROUND: Previous case series suggested a link between Klinefelter syndrome (KS) and essential tremor (ET) or an ET-like syndrome. METHODS: We investigated three KS-patients with tremor including tremor-analyzes and discuss our data in context to findings from a literature review. The clinical outcome after deep brain stimulation (DBS) is also reviewed. RESULTS: Tremor in KS is predominantly a postural and kinetic tremor that resembles ET. Our patients were further characterized by absent family history for tremor in first degree relatives, lack of subjective alcohol responsiveness inquired by history, and tremor onset in childhood. One of our patients and two cases from literature improved after DBS of the ventral intermediate nucleus (VIM) of the thalamus. CONCLUSIONS: Tremor in KS shares several features with ET. If other characteristics such as family history, alcohol responsiveness, and age at tremor onset may serve as discriminating factors from ET, needs to be further investigated. First observations suggest that VIM-DBS may be efficacious.
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Síndrome de Klinefelter/complicaciones , Síndrome de Klinefelter/diagnóstico , Temblor/complicaciones , Temblor/diagnóstico , Adulto , Humanos , Síndrome de Klinefelter/genética , Masculino , Persona de Mediana Edad , Temblor/genética , Adulto JovenRESUMEN
Signals from pharmacovigilance studies indicate that women are at higher risk for adverse drug reactions (ADRs) due to diuretics. Despite the long-term use of torasemide, there are few studies investigating gender differences of torasemide pharmacokinetics in the hospital setting. Therefore, torasemide pharmacokinetics were investigated in 90 patients (45 women, 45 men) during steady-state conditions. Torasemide elimination was significantly reduced in women compared with men (eg, body-weight-normalized area under the concentration-time curve: 42.1 +/- 20.4 vs 30.9 +/- 10.3 kg.h/L; P < .001). Among the investigated genetic factors [SLC22A11(OAT4), SLCO1B1(OATP1B1), CYP2C9], only the SLCO1B1c.521T>C polymorphism had a significant influence on torasemide pharmacokinetics. Using cell lines expressing OATP1B1, the authors identified torasemide as OATP1B1 substrate (K(m) = 6.2 microM) with a significant reduction of uptake by the 521C-variant. Taken together, gender differences in torasemide pharmacokinetics are likely to contribute to a higher rate of ADRs in women, which has, for example, been observed in a German Pharmacovigilance Project with 66% of hospitalizations due to torasemide ADRs occurring in women.
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Diuréticos/farmacocinética , Transportadores de Anión Orgánico/genética , Sulfonamidas/farmacocinética , Línea Celular , Diuréticos/administración & dosificación , Diuréticos/efectos adversos , Femenino , Insuficiencia Cardíaca/tratamiento farmacológico , Humanos , Hipertensión/tratamiento farmacológico , Transportador 1 de Anión Orgánico Específico del Hígado , Masculino , Mutagénesis Sitio-Dirigida , Transportadores de Anión Orgánico/metabolismo , Polimorfismo Genético , Factores Sexuales , Sulfonamidas/administración & dosificación , Sulfonamidas/efectos adversos , TorasemidaRESUMEN
Products derived from roots of Leuzea carthamoides (Maral root) are being promoted as dietary supplements with anti-aging, adaptogenic and anabolic activity, without much scientific evidence. We investigated the effects of a lipophilic Leuzea root extract and the major phytoecdysteroid, 20-hydroxyecdysone, in human breast adenocarcinoma MCF-7 cells. Cell proliferation was inhibited by the extract (IC50 = 30 microg/mL) but not by 20-hydroxyecdysone. Genome-wide expression profiling using Affymetrix HG U133 Plus 2.0 microarrays was carried out to analyse effects at the transcriptional level. 241 genes appeared to be differentially expressed after Leuzea treatment, more than after treatment with either 17beta-estradiol or tamoxifen. Transcripts linked to cell cycle regulation and DNA replication were highly over-represented and regulated in an anti-proliferative manner. Genes involved in apoptosis were regulated in a pro-apoptotic manner. Expression levels of several oxidoreductase transcripts were strongly induced, most prominent CYP1A1, known to be regulated via the aryl hydrocarbon receptor pathway. An XRE-dependent reporter gene assay confirmed the AhR-agonistic activity of the Leuzea root extract, whereas 20-hydroxyecdysone was not active. Leuzea extract also inhibited 5alpha-reductase, type II. While the extract significantly modulates cellular activities, the phytoecdysteroids, are most likely not the active principles of L. carthamoides.
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Adenocarcinoma/metabolismo , Neoplasias de la Mama/metabolismo , Leuzea/química , Extractos Vegetales/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Femenino , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Genoma , Humanos , Extractos Vegetales/química , Raíces de Plantas/químicaRESUMEN
BACKGROUND: Torasemide is frequently used for the treatment of hypertension and heart failure. However, the determinants of torasemide pharmacokinetics in patients during steady-state conditions are largely unknown. We therefore explored the impact of genetic polymorphisms of cytochrome P450 (CYP) 2C9 (CYP2C9) and organic anion transporting polypeptide (OATP) 1B1 (SLCO1B1), gender, and the effects of losartan and irbesartan comedication on the interindividual variability of steady-state pharmacokinetics of torasemide. PATIENTS AND METHODS: Twenty-four patients receiving stable medication with torasemide 10 mg once daily and with an indication for additional angiotensin II receptor blocker (ARB) treatment to control hypertension or to treat heart failure were selected. Blood samples were taken before torasemide administration and 0.5, 1, 2, 4, 8, 12 and 24 hours after administration. After this first study period, patients received either irbesartan 150 mg (five female and seven male patients aged 69+/-8 years) or losartan 100 mg (two female and ten male patients aged 61+/-8 years) once daily. After 3 days of ARB medication, eight blood samples were again collected at the timepoints indicated above. The patients' long-term medications, which did not include known CYP2C9 inhibitors, were maintained at a constant dose during the study. All patients were genotyped for CYP2C9 (*1/*1 [n=15]; *1/*2 [n = 4]; *1/*3 [n=5]) as well as for SLCO1B1 (c.521TT [n=13]; c.521TC [n=11]). RESULTS: Factorial ANOVA revealed an independent impact of the CYP2C9 genotype (dose-normalized area under the plasma concentration-time curve during the 24-hour dosing interval at steady state [AUC(24,ss)/D]: *1/*1 375.5+/-151.4 microg x h/L/mg vs *1/*3 548.5+/-271.6 microg x h/L/mg, p=0.001), the SLCO1B1 genotype (AUC(24,ss)/D: TT 352.3+/-114 microg x h/L/mg vs TC 487.6+/-218.4 microg x h/L/mg, p<0.05) and gender (AUC(24,ss)/D: males 359.5+/-72.2 microg x h/L/mg vs females 547.3+/-284 microg x h/L/mg, p<0.01) on disposition of torasemide. Coadministration of irbesartan caused a 13% increase in the AUC(24,ss)/D of torasemide (p=0.002), whereas losartan had no effect. CONCLUSION: This study shows that the CYP2C9*3 and SLCO1B1 c.521TC genotype and female gender are significant and independent predictors of the pharmacokinetics of torasemide. Coadministration of irbesartan yields moderate but significant increases in the torasemide plasma concentration and elimination half-life.
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Bloqueadores del Receptor Tipo 1 de Angiotensina II/efectos adversos , Bloqueadores del Receptor Tipo 1 de Angiotensina II/farmacocinética , Antihipertensivos/farmacocinética , Sulfonamidas/farmacocinética , Anciano , Análisis de Varianza , Área Bajo la Curva , Hidrocarburo de Aril Hidroxilasas/genética , Hidrocarburo de Aril Hidroxilasas/metabolismo , Calibración , Cromatografía Líquida de Alta Presión , Citocromo P-450 CYP2C9 , Relación Dosis-Respuesta a Droga , Interacciones Farmacológicas , Femenino , Genotipo , Semivida , Humanos , Transportador 1 de Anión Orgánico Específico del Hígado , Masculino , Transportadores de Anión Orgánico/genética , Transportadores de Anión Orgánico/metabolismo , Farmacogenética , Caracteres Sexuales , TorasemidaRESUMEN
Enhanced external counterpulsation (EECP) is a noninvasive counterpulsation technique that reduces angina and improves exercise capacity in patients with coronary artery disease. Diastolic coronary perfusion is augmented by pneumatic compression of 3 sets of cuffs wrapped around the lower extremities. Although central hemodynamic changes are well investigated, almost no data exist about the changes of peripheral circulation during EECP. In this study, 12 patients with angina and angiographic evidence of coronary artery disease were treated for 1 hour with EECP. In these patients, peripheral artery disease was excluded by duplex sonography. The patients rested 1 hour before EECP in supine position, and they remained in that position for 1 hour after the procedure. Changes of flow volumes and flow pattern of the posterior tibial artery and the brachial artery were measured by sonography at the end of all 3 periods. Furthermore, we measured the concentration of circulating prostanoids at these 3 time points. Averaged flow volume of the posterior tibial artery decreased to 69% +/- 23% (P < .05) during EECP and increased to 133% +/- 34% (P < .05) of baseline 1 hour after the procedure. In contrast, the averaged flow volume of the brachial artery increased by 9% +/- 4% (P < .05) during EECP and returned to baseline values after EECP. The flow pattern of the posterior tibial artery showed a second early diastolic antegrade flow caused by the cuff inflation and a reverse end-diastolic flow after the deflation of the cuffs. These flow changes caused an increase of the pulsatility index by Gosling (397% during EECP), returning to baseline values in the recovery period. Plasma concentrations of circulating prostanoids showed no significant change during EECP. Thus, pedal flow volume decreased to approximately two thirds of baseline during EECP followed by reactive hyperemia even 1 hour after the procedure; however, this decreased perfusion triggered no change of the prostacyclin/thromboxane ratio and was well tolerated by all investigated patients. The observed 4-fold increase of the peripheral pulsatility index supports the thesis of increase of shear-stress-related improvement of endothelial function during EECP.
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Angina de Pecho/terapia , Enfermedad de la Arteria Coronaria/terapia , Contrapulsación/métodos , Pierna/irrigación sanguínea , Angina de Pecho/diagnóstico por imagen , Angina de Pecho/fisiopatología , Velocidad del Flujo Sanguíneo , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/fisiopatología , Femenino , Humanos , Pierna/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Posición Supina , Ultrasonografía Doppler DúplexRESUMEN
The aim of this study was to determine the analgesic effect of acetaminophen compared to a combination of both caffeine and acetaminophen or caffeine alone using tonic and phasic pain stimulation. Twenty-four subjects were treated orally with 1000 mg acetaminophen, 130 mg caffeine, and a combination of both in a 4-way crossover, double-blind, placebo-controlled study. Pharmacokinetics and analgesic effects were assessed by means of an experimental pain model based on pain-related cortical potentials after phasic stimulation of the nasal mucosa with CO(2) and based on pain ratings after tonic stimulation with dry air. Analgesic effects of acetaminophen and acetaminophen plus caffeine but not caffeine alone caused a significant reduction of pain-related cortical potentials beginning 30 minutes after medication. The combination demonstrated an enhanced effect throughout the observation time up to 3 hours. Caffeine accelerated acetaminophen absorption, indicated by enhanced early AUCs. Significant analgesic effects of the combination on tonic pain ratings were found throughout the observation time as compared to acetaminophen and placebo. In this study, caffeine enhanced and prolonged the analgesic activity of acetaminophen.
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Acetaminofén/farmacocinética , Acetaminofén/uso terapéutico , Analgésicos no Narcóticos/farmacocinética , Analgésicos no Narcóticos/uso terapéutico , Cafeína/farmacología , Estimulantes del Sistema Nervioso Central/farmacología , Dolor/tratamiento farmacológico , Adolescente , Adulto , Área Bajo la Curva , Estudios Cruzados , Método Doble Ciego , Sinergismo Farmacológico , Femenino , Humanos , Absorción Intestinal , Masculino , Persona de Mediana Edad , SolubilidadAsunto(s)
Antagonistas Adrenérgicos beta/metabolismo , Citocromo P-450 CYP2D6/metabolismo , Antagonistas Adrenérgicos beta/efectos adversos , Antagonistas Adrenérgicos beta/farmacocinética , Anciano , Anciano de 80 o más Años , Bradicardia/inducido químicamente , Relación Dosis-Respuesta a Droga , Femenino , Alemania , Hospitalización/estadística & datos numéricos , Humanos , Hipotensión/inducido químicamente , Estudios Longitudinales , Masculino , Metoprolol/efectos adversos , Metoprolol/metabolismo , Metoprolol/farmacocinética , Persona de Mediana Edad , Factores Sexuales , Síncope/inducido químicamenteRESUMEN
Transporter proteins such as P-glycoprotein are major determinants of intracellular drug concentrations. Moreover, inhibition or induction of transporters is an important mechanism underlying drug interactions in humans. However, very little is known whether beta-adrenoceptor antagonists are substrates and/or inhibitors of P-glycoprotein. Therefore, we investigated the P-glycoprotein-mediated transport of propranolol, metoprolol, bisoprolol, carvedilol and sotalol in P-glycoprotein-expressing Caco-2 monolayers and inhibition of P-glycoprotein-mediated digoxin transport by the beta-adrenoceptor antagonists. A significant inhibition of polarized, basal to apical drug transport by the P-glycoprotein inhibitor PSC-833 was observed for bisoprolol (0.5 and 5 microm) and carvedilol (0.5 microm). Moreover, propranolol and carvedilol inhibited P-glycoprotein-mediated digoxin transport with IC(50) values of 24.8 and 0.16 microm, respectively, whereas metoprolol and sotalol had no effect. Bisoprolol significantly inhibited directional digoxin transport at 50 and 250 microm by 31% and 44%, respectively. Taken together, P-glycoprotein is likely to be one determinant of bisoprolol and carvedilol disposition in humans. In addition, the beta-adrenoceptor antagonists propranolol and carvedilol significantly inhibit P-glycoprotein function thereby possibly contributing to drug interactions in humans (e.g. digoxin-carvedilol and cyclosporine-carvedilol).
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Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/antagonistas & inhibidores , Antagonistas Adrenérgicos beta/farmacología , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Antagonistas Adrenérgicos beta/metabolismo , Bisoprolol/metabolismo , Bisoprolol/farmacología , Células CACO-2 , Carbazoles/metabolismo , Carbazoles/farmacología , Carvedilol , Ciclosporinas/farmacología , Digoxina/metabolismo , Relación Dosis-Respuesta a Droga , Interacciones Farmacológicas , Humanos , Propanolaminas/metabolismo , Propanolaminas/farmacología , Propranolol/metabolismo , Propranolol/farmacología , Factores de TiempoRESUMEN
During an investigation of the possible pharmacokinetic interactions of cyclooxygenase-2 (COX-2) inhibitors with metoprolol, we observed that rofecoxib caused a significant reduction in heart rate in young healthy volunteers. The effect of valdecoxib did not reach significance. When these drugs were given together with metoprolol, the effect was continued. The latter effect could not be related to pharmacokinetic interactions. In the light of experimental results claiming a cardioprotective effect of possibly COX-2-derived prostaglandins and clinical observations hinting at an increased risk of sudden cardiovascular death in conjunction with the long-term use of selective cyclooxygenase inhibitors, our results may help to increase awareness and to suggest investigation of the impact of coxibs on heart function.
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Inhibidores de la Ciclooxigenasa/farmacología , Frecuencia Cardíaca/efectos de los fármacos , Antagonistas Adrenérgicos beta/farmacología , Combinación de Medicamentos , Interacciones Farmacológicas , Electrocardiografía Ambulatoria , Corazón/efectos de los fármacos , Corazón/fisiología , Frecuencia Cardíaca/fisiología , Humanos , Isoxazoles/farmacología , Masculino , Metoprolol/farmacología , Pirimidinas/farmacología , Valores de Referencia , Sulfadimetoxina/farmacología , Sulfonamidas/farmacologíaRESUMEN
AIM: Diclofenac-K has been recently launched at low oral doses in different countries for over-the-counter use. However, given the considerable first-pass metabolism of diclofenac, the degree of absorption of diclofenac-K at low doses remained to be determined. The aim of this study was to determine the bioavailability of low-dose diclofenac-K. METHODS: A randomized, three-way, cross-over study was performed in 10 subjects. Each received diclofenac-K, 22.5 mg via short-term i.v. infusion and orally at single doses of 12.5 mg and 25 mg. RESULTS: Mean (+/- SD) times to maximal plasma concentration (t(max)) of diclofenac were 0.48 +/- 0.28 h (12.5 mg) and 0.93 +/- 0.96 h (25 mg). The absolute bioavailability of diclofenac-K after oral administration did not differ significantly in the 12.5-mg and 25-mg dose group (63.1 +/- 12.6%vs. 65.1 +/- 19.4%, respectively). The 90% confidence intervals for the AUC(infinity) and AUC(t) ratios for the two oral regimes were 82.6, 103.4% (point estimate 92.4%) and 86.2, 112.9% (point estimate 98.6%), respectively. These values were within the acceptance criteria for bioequivalence (80-125%). CONCLUSIONS: Our data indicate that diclofenac-K is rapidly and well absorbed at low dose, and are consistent with a rapid onset of action of the drug. Abbreviations AUC, area under plasma concentration-time curve; C(max), peak plasma concentration; CI, confidence interval; COX, cyclooxygenase; D, dose; F, absolute bioavailability; t(max), time to reach C(max).
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Antiinflamatorios no Esteroideos/farmacocinética , Inhibidores de la Ciclooxigenasa/farmacocinética , Diclofenaco/farmacocinética , Adulto , Antiinflamatorios no Esteroideos/administración & dosificación , Área Bajo la Curva , Disponibilidad Biológica , Cromatografía Líquida de Alta Presión , Estudios Cruzados , Inhibidores de la Ciclooxigenasa/administración & dosificación , Diclofenaco/administración & dosificación , Femenino , Humanos , MasculinoRESUMEN
A practicable and selective liquid chromatography-mass spectrometry assay for the determination of two cyclooxygenase-2 inhibitors, etoricoxib and valdecoxib, in human plasma is presented. The analytical technique is based on reversed-phase high-performance liquid chromatography (HPLC) coupled to atmospheric pressure chemical ionisation (APCI) mass spectrometry (Finnigan Mat LCQ ion trap). Mass analysis was performed in the positive ion mode. The ion trap was operated in the tandem MS mode (MS2) and the transitions of etoricoxib (m/z 359.2 --> 280.3) and valdecoxib (m/z 315.1 --> 235.1) were followed by selected reaction monitoring. Retention times of etoricoxib and valdecoxib were 1.05 and 1.08 min, respectively. The method was validated over a linear range 10-2500 and 5-1000 microg/L using the other substrate as internal standard. After validation, the method was used to study the pharmacokinetic pro fi le of etoricoxib or valdecoxib in a healthy volunteer after administration of a single oral dose (valdecoxib, 20 mg; etoricoxib, 90 mg). The presented method was suf fi cient to cover more than 90% of the area under the plasma concentration time curve.
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Cromatografía Líquida de Alta Presión/métodos , Inhibidores de la Ciclooxigenasa/sangre , Isoxazoles/sangre , Espectrometría de Masas/métodos , Piridinas/sangre , Sulfonamidas/sangre , Sulfonas/sangre , Etoricoxib , Humanos , Isoxazoles/administración & dosificación , Isoxazoles/farmacocinética , Masculino , Piridinas/administración & dosificación , Piridinas/farmacocinética , Sensibilidad y Especificidad , Sulfonamidas/administración & dosificación , Sulfonamidas/farmacocinética , Sulfonas/administración & dosificación , Sulfonas/farmacocinéticaRESUMEN
On average, metoprolol plasma concentration is doubled after an amiodarone loading dose (1.2 g/day over a period of 6 days). However, the individual amount of this drug interaction depends on the CYP2D6 genotype.
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Amiodarona/farmacología , Antiarrítmicos/farmacología , Fibrilación Atrial/tratamiento farmacológico , Metoprolol/farmacocinética , Anciano , Alelos , Antiarrítmicos/farmacocinética , Fibrilación Atrial/sangre , Fibrilación Atrial/genética , Citocromo P-450 CYP2D6/genética , Interacciones Farmacológicas , Quimioterapia Combinada , Femenino , Genotipo , Humanos , MasculinoRESUMEN
PURPOSE: Several studies indicate that calcium channel blockers improve the clinical course of normal tension glaucoma (NTG), whereas the underlying mechanism is not fully investigated. Hemodynamic improvement and neuroprotective effects are discussed. In this study, we measured the hemodynamic effects of nimodipine on retinal circulation. PATIENTS AND METHODS: Sixteen patients with NTG and clinical signs of vasospastic hyperreactivity, such as suffering from extremely cold hands and feet, were consecutively selected out of the local glaucoma registry. Ten healthy age-matched volunteers were included as controls. Retinal capillary blood flow was measured by Scanning Laser Doppler Flowmetry in both eyes before and 90 +/- 10 minutes after a single oral dose of 30 mg nimodipine. RESULTS: Before administration of nimodipine, retinal capillary blood flow was significantly reduced in NTG patients compared with controls (262 +/- 80 vs. 487 +/- 164 AU, P < 0.001). Nimodipine increased retinal capillary blood flow in NTG patients by 91 +/- 73% (P < 0.001) to values of healthy controls (440 +/- 113 vs. 439 +/- 123 AU, P = 0.635). In controls, nimodipine did not show significant effects. CONCLUSIONS: In NTG patients with additional vasospastic symptoms, retinal capillary blood is significantly reduced in comparison with healthy controls. Single-dose nimodipine yields to a normalization of retinal circulation in NTG patients up to values of healthy controls 90 minutes after drug administration.
Asunto(s)
Bloqueadores de los Canales de Calcio/administración & dosificación , Glaucoma de Ángulo Abierto/tratamiento farmacológico , Nimodipina/administración & dosificación , Enfermedades de la Retina/tratamiento farmacológico , Vasos Retinianos/efectos de los fármacos , Circulación Sanguínea , Velocidad del Flujo Sanguíneo/efectos de los fármacos , Presión Sanguínea/efectos de los fármacos , Femenino , Glaucoma de Ángulo Abierto/fisiopatología , Humanos , Presión Intraocular/efectos de los fármacos , Flujometría por Láser-Doppler , Masculino , Persona de Mediana Edad , Disco Óptico/irrigación sanguínea , Flujo Sanguíneo Regional/efectos de los fármacos , Enfermedades de la Retina/fisiopatología , Vasos Retinianos/fisiopatología , Vasodilatación/efectos de los fármacosRESUMEN
PURPOSE: We investigated whether a short treatment with the cyclooxygenase-2 (COX-2) inhibitor celecoxib could modulate Ki67 antigen and the caspase cleavage product of keratin 18, recognized as a marker of early apoptosis. The activity of celecoxib on microvessel density (MVD) and angio-power Doppler sonography-derived indices of tumor vascularization was also assessed. Serum levels of squamous cell carcinoma antigen and the proliferative potential and subsets of peripheral T cells before and after celecoxib treatment were also analyzed. EXPERIMENTAL DESIGN: Tumor biopsy specimens from 14 patients with cervical cancer were obtained at baseline and after 10 days of celecoxib treatment (400 mg twice daily). Tumor and stroma COX-2 expression, Ki67, apoptosis, and MVD were assessed by immunohistochemistry, whereas prostaglandin E(2) levels were measured by RIA. RESULTS: At baseline, COX-2 integrated density values in tumor compartment ranged from 10.7 to 60.1 (median, 26.5) and were significantly higher than tumor COX-2 integrated density values after celecoxib treatment (range, 0.6-42.3; median, 12.6; P = 0.0043). The percentages of Ki67-positive tumor cells in pre-celecoxib cases ranged from 39.3 to 87.4 (median, 50.8) and were significantly higher than the percentage in the corresponding posttreatment samples (range, 27.7-83.8; median, 43.1; P = 0.0092). MVD values in pre-celecoxib biopsies ranged from 28.0 to 55.0 (median, 38.5) and were significantly higher than the corresponding values in posttreatment samples (range, 16.0-49.5; median; 27.6; P = 0.012). Also, prostaglandin E(2) levels showed a trend to be reduced after celecoxib treatment (range: 4.7-386.6 pg/mg wet tissue in pretreated cases versus 4.8-91.9 pg/mg wet tissue in posttreated cases (P = 0.092). CONCLUSIONS: In cervical cancer, celecoxib treatment decreases tumor COX-2 expression and markers of proliferation and neoangiogenesis, while being uneffective on stroma COX-2 levels, thus suggesting that selective COX-2 inhibitors may be a promising strategy not only for chemopreventive approaches but also for therapeutic approaches in this neoplasia.