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1.
Science ; 382(6674): eadg8940, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-38033071

RESUMEN

The origins of maize were the topic of vigorous debate for nearly a century, but neither the current genetic model nor earlier archaeological models account for the totality of available data, and recent work has highlighted the potential contribution of a wild relative, Zea mays ssp. mexicana. Our population genetic analysis reveals that the origin of modern maize can be traced to an admixture between ancient maize and Zea mays ssp. mexicana in the highlands of Mexico some 4000 years after domestication began. We show that variation in admixture is a key component of maize diversity, both at individual loci and for additive genetic variation underlying agronomic traits. Our results clarify the origin of modern maize and raise new questions about the anthropogenic mechanisms underlying dispersal throughout the Americas.


Asunto(s)
Productos Agrícolas , Domesticación , Hibridación Genética , Zea mays , México , Fenotipo , Zea mays/genética , Variación Genética , Productos Agrícolas/genética
2.
Electron. j. biotechnol ; Electron. j. biotechnol;50: 29-36, Mar. 2021. tab, graf
Artículo en Inglés | LILACS | ID: biblio-1292313

RESUMEN

BACKGROUND: Lignocellulose is considered a renewable organic material, but the industrial production of biofuel from lignocellulose is challenging because of the lack of highly active hydrolytic enzymes. The guts of herbivores contain many symbiotic microorganisms that have evolved to hydrolyze plant lignocellulose. Chinese bamboo rats mainly consume high-fiber foods, indicating that some members of the intestinal tract microbiota digest lignocellulose, providing these rats with the energy required for growth. RESULTS: Here, we used metagenomics to analyze the diversity and functions of the gut microbiota in Chinese bamboo rats. We identified abundant populations of lignocellulose-degrading bacteria, whose main functions involved carbohydrate, amino acid, and nucleic acid metabolism. We also found 587 carbohydrate-active enzyme genes belonging to different families, including 7 carbohydrate esterase families and 21 glycoside hydrolase families. The glycoside hydrolase 3, glycoside hydrolase 1, glycoside hydrolase 43, carbohydrate esterase 4, carbohydrate esterase 1, and carbohydrate esterase 3 families demonstrated outstanding performance. CONCLUSIONS: The microbes and enzymes identified in our study expand the existing arsenal of proficient degraders and enzymes for lignocellulosic biofuel production. This study also describes a powerful approach for targeting gut microbes and enzymes in numerous industries.


Asunto(s)
Animales , Ratas , Ciego/enzimología , Enzimas/metabolismo , Lignina/metabolismo , Ciego/microbiología , Celulosa/metabolismo , Bacteroidetes , Biocombustibles , Metagenómica , Firmicutes , Microbioma Gastrointestinal
3.
Mol Pharmacol ; 96(5): 629-640, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31515284

RESUMEN

The ATP-binding cassette transporter P-glycoprotein (P-gp) is known to limit both brain penetration and oral bioavailability of many chemotherapy drugs. Although US Food and Drug Administration guidelines require that potential interactions of investigational drugs with P-gp be explored, often this information does not enter the literature. In response, we developed a high-throughput screen to identify substrates of P-gp from a series of chemical libraries, testing a total of 10,804 compounds, most of which have known mechanisms of action. We used the CellTiter-Glo viability assay to test library compounds against parental KB-3-1 human cervical adenocarcinoma cells and the colchicine-selected subline KB-8-5-11 that overexpresses P-gp. KB-8-5-11 cells were also tested in the presence of a P-gp inhibitor (tariquidar) to assess reversibility of transporter-mediated resistance. Of the tested compounds, a total of 90 P-gp substrates were identified, including 55 newly identified compounds. Substrates were confirmed using an orthogonal killing assay against human embryonic kidney-293 cells overexpressing P-gp. We confirmed that AT7159 (cyclin-dependent kinase inhibitor), AT9283, (Janus kinase 2/3 inhibitor), ispinesib (kinesin spindle protein inhibitor), gedatolisib (PKI-587, phosphoinositide 3-kinase/mammalian target of rampamycin inhibitor), GSK-690693 (AKT inhibitor), and KW-2478 (heat-shock protein 90 inhibitor) were substrates. In addition, we assessed direct ATPase stimulation. ABCG2 was also found to confer high levels of resistance to AT9283, GSK-690693, and gedatolisib, whereas ispinesib, AT7519, and KW-2478 were weaker substrates. Combinations of P-gp substrates and inhibitors were assessed to demonstrate on-target synergistic cell killing. These data identified compounds whose oral bioavailability or brain penetration may be affected by P-gp. SIGNIFICANCE STATEMENT: The ATP-binding cassette transporter P-glycoprotein (P-gp) is known to be expressed at barrier sites, where it acts to limit oral bioavailability and brain penetration of substrates. In order to identify novel compounds that are transported by P-gp, we developed a high-throughput screen using the KB-3-1 cancer cell line and its colchicine-selected subline KB-8-5-11. We screened the Mechanism Interrogation Plate (MIPE) library, the National Center for Advancing Translational Science (NCATS) pharmaceutical collection (NPC), the NCATS Pharmacologically Active Chemical Toolbox (NPACT), and a kinase inhibitor library comprising 977 compounds, for a total of 10,804 compounds. Of the 10,804 compounds screened, a total of 90 substrates were identified of which 55 were novel. P-gp expression may adversely affect the oral bioavailability or brain penetration of these compounds.


Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2/metabolismo , Citotoxinas/metabolismo , Ensayos Analíticos de Alto Rendimiento/métodos , Proteínas de Neoplasias/metabolismo , Subfamilia B de Transportador de Casetes de Unión a ATP/metabolismo , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/química , Antineoplásicos/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacología , Citotoxinas/química , Citotoxinas/farmacología , Relación Dosis-Respuesta a Droga , Células HEK293 , Células HeLa , Humanos , Especificidad por Sustrato/efectos de los fármacos , Especificidad por Sustrato/fisiología
4.
Acta Cir Bras ; 33(7): 577-587, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30110059

RESUMEN

PURPOSE: To investigate changes in the plasma concentrations of cardiac troponin I (CTnI), thromboxane A2 (TXA2), prostaglandin I2 (PGI2) and endothelin-1 (ET-1) in rabbits with massive pulmonary embolism (AMPE) and the impact of nitric oxide inhalation (NOI) on these indices. METHODS: A total of 30 Japanese rabbits were used to construct an MPE model and were divided into 3 groups equally (n=10), including an EXP group (undergoing modeling alone), an NOI group (receiving NOI 2 h post-modeling) and a CON group (receiving intravenous physiological saline). RESULTS: In the model group, plasma concentration of CTnI peaked at 16 h following modeling (0.46±0.10 µg/ml) and significantly decreased following NOI. Plasma levels of TXB2, PGI2 and ET-1 peaked at 12, 16 and 8 h following modeling, respectively, and significantly decreased at different time points (0, 2, 4, 8, 12, 16, 20 and 24 h) following NOI. A significant correlation was observed between the peak plasma CTnI concentration and peak TXB2, 6-keto prostaglandin F1α and ET-1 concentrations in the model and NOI groups. CONCLUSION: Increases in plasma TXA2, PGI2 and ET-1 levels causes myocardial damage in a rabbit model of AMPE; however, NOI effectively down regulates the plasma concentration of these molecules to produce a myocardial-protective effect.


Asunto(s)
Broncodilatadores/farmacología , Endotelina-1/sangre , Epoprostenol/sangre , Óxido Nítrico/farmacología , Embolia Pulmonar/sangre , Embolia Pulmonar/tratamiento farmacológico , Tromboxano A2/sangre , Troponina I/sangre , Enfermedad Aguda , Administración por Inhalación , Animales , Regulación hacia Abajo , Ensayo de Inmunoadsorción Enzimática , Femenino , Masculino , Embolia Pulmonar/patología , Conejos , Distribución Aleatoria , Valores de Referencia , Reproducibilidad de los Resultados , Factores de Tiempo , Resultado del Tratamiento
5.
Acta cir. bras ; Acta cir. bras;33(7): 577-587, July 2018. tab, graf
Artículo en Inglés | LILACS | ID: biblio-949362

RESUMEN

Abstract Purpose: To investigate changes in the plasma concentrations of cardiac troponin I (CTnI), thromboxane A2 (TXA2), prostaglandin I2 (PGI2) and endothelin-1 (ET-1) in rabbits with massive pulmonary embolism (AMPE) and the impact of nitric oxide inhalation (NOI) on these indices. Methods: A total of 30 Japanese rabbits were used to construct an MPE model and were divided into 3 groups equally (n=10), including an EXP group (undergoing modeling alone), an NOI group (receiving NOI 2 h post-modeling) and a CON group (receiving intravenous physiological saline). Results: In the model group, plasma concentration of CTnI peaked at 16 h following modeling (0.46±0.10 µg/ml) and significantly decreased following NOI. Plasma levels of TXB2, PGI2 and ET-1 peaked at 12, 16 and 8 h following modeling, respectively, and significantly decreased at different time points (0, 2, 4, 8, 12, 16, 20 and 24 h) following NOI. A significant correlation was observed between the peak plasma CTnI concentration and peak TXB2, 6-keto prostaglandin F1α and ET-1 concentrations in the model and NOI groups. Conclusion: Increases in plasma TXA2, PGI2 and ET-1 levels causes myocardial damage in a rabbit model of AMPE; however, NOI effectively down regulates the plasma concentration of these molecules to produce a myocardial-protective effect.


Asunto(s)
Animales , Masculino , Femenino , Conejos , Embolia Pulmonar/tratamiento farmacológico , Embolia Pulmonar/sangre , Tromboxano A2/sangre , Broncodilatadores/farmacología , Epoprostenol/sangre , Endotelina-1/sangre , Troponina I/sangre , Óxido Nítrico/farmacología , Embolia Pulmonar/patología , Valores de Referencia , Factores de Tiempo , Administración por Inhalación , Ensayo de Inmunoadsorción Enzimática , Distribución Aleatoria , Regulación hacia Abajo , Enfermedad Aguda , Reproducibilidad de los Resultados , Resultado del Tratamiento
6.
Acta cir. bras. ; 33(7): 577-587, jul. 2018. ilus, tab, graf
Artículo en Inglés | VETINDEX | ID: vti-18364

RESUMEN

Purpose: To investigate changes in the plasma concentrations of cardiac troponin I (CTnI), thromboxane A2 (TXA2), prostaglandin I2 (PGI2) and endothelin-1 (ET-1) in rabbits with massive pulmonary embolism (AMPE) and the impact of nitric oxide inhalation (NOI) on these indices. Methods: A total of 30 Japanese rabbits were used to construct an MPE model and were divided into 3 groups equally (n=10), including an EXP group (undergoing modeling alone), an NOI group (receiving NOI 2 h post-modeling) and a CON group (receiving intravenous physiological saline). Results: In the model group, plasma concentration of CTnI peaked at 16 h following modeling (0.46±0.10 µg/ml) and significantly decreased following NOI. Plasma levels of TXB2, PGI2 and ET-1 peaked at 12, 16 and 8 h following modeling, respectively, and significantly decreased at different time points (0, 2, 4, 8, 12, 16, 20 and 24 h) following NOI. A significant correlation was observed between the peak plasma CTnI concentration and peak TXB2, 6-keto prostaglandin F1 and ET-1 concentrations in the model and NOI groups. Conclusion: Increases in plasma TXA2, PGI2 and ET-1 levels causes myocardial damage in a rabbit model of AMPE; however, NOI effectively down regulates the plasma concentration of these molecules to produce a myocardial-protective effect.(AU)


Asunto(s)
Animales , Conejos , Óxido Nítrico/farmacología , Óxido Nítrico/uso terapéutico , Embolia Pulmonar/terapia , Troponina I/análisis , Tromboxano A2/análisis , Dinoprostona/análisis , Endotelina-1/análisis , Administración por Inhalación , Modelos Animales de Enfermedad
7.
J Pharmacol Toxicol Methods ; 94(Pt 1): 14-18, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29630936

RESUMEN

INTRODUCTION: Vaginal route is often used in topical antifungal formulations. Vaginal permeability assays are generally performed as in vitro tests. METHOD: An in vivo vaginal permeability assay was developed using female rabbits. Fenticonazole permeability was evaluated by assessing fenticonazole bioavailability in plasma by liquid chromatography coupled to tandem mass spectrometry (LC-MS-MS). Toxicity was monitored histopathologically after 8 consecutive days of antifungal treatment (20 mg/animal). RESULTS: The method of quantification was linear with a lower limit of quantification (LLOQ) of (0.1 ng/mL). The area-under-the-curves (AUC) of fenticonazole on day 1 and 8 of treatment were 280.3 ±â€¯86.1 ng/mL ∗ h and 805.7 ±â€¯252.4 ng/mL ∗ h, respectively. The calculated systemic bioavailability was 12.73% ±â€¯0.14%. No signs of toxicity were observed both macroscopically and histologically after 8 days fenticonazole treatment. DISCUSSION: The plasma levels of fenticonazole observed in rabbits are similar to that observed in human. Rabbit vagina may be a suitable model to evaluate vaginal antifungal formulations.


Asunto(s)
Antifúngicos/administración & dosificación , Antifúngicos/efectos adversos , Imidazoles/administración & dosificación , Imidazoles/efectos adversos , Vagina/metabolismo , Administración Intravaginal , Animales , Antifúngicos/sangre , Área Bajo la Curva , Disponibilidad Biológica , Cromatografía Liquida/métodos , Femenino , Imidazoles/sangre , Permeabilidad , Conejos , Espectrometría de Masas en Tándem/métodos
8.
Nat Commun ; 8(1): 1874, 2017 11 30.
Artículo en Inglés | MEDLINE | ID: mdl-29187731

RESUMEN

Maize was domesticated from lowland teosinte (Zea mays ssp. parviglumis), but the contribution of highland teosinte (Zea mays ssp. mexicana, hereafter mexicana) to modern maize is not clear. Here, two genomes for Mo17 (a modern maize inbred) and mexicana are assembled using a meta-assembly strategy after sequencing of 10 lines derived from a maize-teosinte cross. Comparative analyses reveal a high level of diversity between Mo17, B73, and mexicana, including three Mb-size structural rearrangements. The maize spontaneous mutation rate is estimated to be 2.17 × 10-8 ~3.87 × 10-8 per site per generation with a nonrandom distribution across the genome. A higher deleterious mutation rate is observed in the pericentromeric regions, and might be caused by differences in recombination frequency. Over 10% of the maize genome shows evidence of introgression from the mexicana genome, suggesting that mexicana contributed to maize adaptation and improvement. Our data offer a rich resource for constructing the pan-genome of Zea mays and genetic improvement of modern maize varieties.


Asunto(s)
Evolución Molecular , Genoma de Planta/genética , Zea mays/genética , Haplotipos
9.
Ann Hepatol ; 14(1): 108-17, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25536648

RESUMEN

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is correlated with obesity, but specific therapeutic interventions are lacking. Adiponectin is an adipokine with anti-inflammatory activity and is considered a hepatic protector. We aimed to investigate effects of a low-fat diet on the hepatic expression of adiponectin and its receptors in rats with NAFLD. MATERIALS AND METHODS: Sixteen male SD rats were fed a high-fat diet for 8 weeks (HFD1 group) or 16 weeks (HFD2 group) to induce NAFLD, and these rats were compared with rats on a normal diet for 8 weeks (NC1 group) or 16 weeks (NC2 group). Another group of 8 rats was fed an HFD for 8 weeks and then switched to a low-fat diet (DIET group) until the 16th week. The expression of hepatic adiponectin and its receptors was detected by western blotting, immunohistochemistry and RT-qPCR. RESULTS: The NAFLD activity score (NAS) in the HFD groups increased from 3.2 ± 0.45 (8th week) to 6.2 ± 0.84 (16th week) (P < 0.001), reflecting the progression in the NAFLD histology. In contrast to the HFD2 group, the low-fat diet ameliorated the steatosis, ballooning degeneration and inflammation. Dietary intervention augmented the expression of adiponectin and its receptors, which was down-regulated in the HFD2 group. CONCLUSIONS: The NAFLD rat model was successfully developed by feeding the animals a high-fat diet. Adiponectin may play a role in the pathogenesis of NAFLD, especially in the progression from steatosis to NASH. The low-fat diet alleviated the histological lesions associated with NAFLD by up-regulating the expression of adiponectin and its receptors.


Asunto(s)
Adiponectina/genética , Dieta con Restricción de Grasas , Dieta Alta en Grasa , Hígado/metabolismo , Enfermedad del Hígado Graso no Alcohólico/genética , ARN Mensajero/metabolismo , Receptores de Adiponectina/genética , Adiponectina/metabolismo , Alanina Transaminasa/sangre , Animales , Aspartato Aminotransferasas/sangre , Hígado/patología , Masculino , Enfermedad del Hígado Graso no Alcohólico/dietoterapia , Enfermedad del Hígado Graso no Alcohólico/patología , Ratas , Receptores de Adiponectina/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
10.
Adv Drug Deliv Rev ; 81: 104-16, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25239236

RESUMEN

One of the most fascinating discoveries in molecular oncology has been that cancer represents a disease in which genetic alterations in protein-coding, but also in non-coding genes complement each other. MicroRNAs (miRNAs) are a type of non-coding RNA (ncRNA) transcripts that can regulate gene expression primarily by disrupting messenger RNA (mRNA) translation and/or stability, or alternatively by modulating the transcription of target mRNAs. For the last decade, miRNAs have shown to be pivotal characters of every single one of the cancer hallmarks. Profiling studies have proven the significance of identifying over-expressed miRNAs (oncomiRs) causative of the activation of oncogenic pathways that lead to malignancy. Due to their crucial role in cancer, it has become a challenge to develop efficient miRNA-inhibiting strategies such as antagomiRs, locked nucleic acids or antisense oligonucleotides. However, to this date, the accessible delivery agents and their pharmacokinetic/pharmacodynamic properties are not ideal. Thus there is an urgent, unmet need to develop miRNA-based inhibitory therapeutics. Herein we present a novel therapeutic strategy that is only at the tip of the iceberg: the use of small molecule inhibitors to target specific miRNAs (SMIRs). Furthermore we describe several high-throughput techniques to screen for SMIRs both in vitro and in silico. Finally we take you through the journey that has led to discovering the handful of SMIRs that have been validated to this date.


Asunto(s)
MicroARNs/genética , Neoplasias/terapia , Oligonucleótidos/administración & dosificación , Animales , Simulación por Computador , Regulación Neoplásica de la Expresión Génica/genética , Ensayos Analíticos de Alto Rendimiento , Humanos , MicroARNs/antagonistas & inhibidores , Neoplasias/genética , Oligonucleótidos Antisentido/administración & dosificación
11.
Artículo en Inglés | MEDLINE | ID: mdl-24705538

RESUMEN

A simple, selective and sensitive method based on high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) has been developed for the determination of dapaconazole in human plasma using tioconazole as internal standard. The drugs were extracted from plasma by liquid-liquid extraction with ether/hexane (80/20, v/v). The chromatography separation was performed on a Genesis(®) C18 reversed phase analytical column 4µm (100×2.1mm i.d.) with a mobile phase of methanol/acetonitrile/water (80/10/10, v/v/v)+ammonium acetate (0.5mM). Dapaconazole was quantified using a mass spectrometer with an electrospray source in the ESI positive mode (ES+) configured for multiple reaction monitoring (MRM) to monitor the transitions 415.1>159.2 and 387.0>131.0 for dapaconazole and tioconazole, respectively. The method had a chromatography run time of 3.8min and a linear calibration curve over the range 0.2-100ng/mL (r=0.9998). The lower limit of quantification (LLOQ) was 0.2ng/mL. The precision and accuracy values of the assay were within ±10%. The stability tests indicate no significant degradation under the conditions of the experiment. This method was used for a phase I study of topical administration of dapaconazole tosylate in healthy human male volunteers.


Asunto(s)
Antifúngicos/sangre , Cromatografía Líquida de Alta Presión/métodos , Imidazoles/sangre , Monitoreo de Drogas/métodos , Humanos , Límite de Detección , Masculino , Espectrometría de Masas en Tándem/métodos
12.
Genet Mol Res ; 12(3): 2771-8, 2013 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-23979902

RESUMEN

Patterning of the limb anterior-posterior axes depends on several signals that derive from the three signaling centers of the limb bud. These signals interact to constitute a complex and ordered network that critically contributes to the development of limb buds. Preaxial polydactyly in mouse is predominantly caused by ectopic expression of the zone of polarizing activity or Sonic hedgehog in the anterior region of the limb bud. In this study, we describe an N-ethyl-N-nitrosourea-induced polydactylous mouse (Alx4m1Yzcm) with an extra digit on the anterior aspect of one or two hinddigits. The mutation was mapped to chromosome 2, between markers D2Mit45 and D2Mit184. The Alx4 gene was identified as a potential candidate gene in this location. Sequence analysis of the Alx4 gene for polydactylous heterozygotes revealed an A/T transversion mutation that resulted in substitution of a lysine codon with a stop (nonsense) codon at position 145. Alx4m1Yzcm homozygous mice exhibited multiple abnormalities, including extensive preaxial polydactyly of all four limbs (up to seven digits) and the formation of omphalocele.


Asunto(s)
Codón sin Sentido , Hernia Umbilical/genética , Proteínas de Homeodominio/genética , Polidactilia/genética , Animales , Cromosomas de los Mamíferos/genética , Etilnitrosourea/toxicidad , Sitios Genéticos , Heterocigoto , Ratones , Ratones Endogámicos C57BL , Mutagénesis , Teratogénesis/genética
14.
Biomed Chromatogr ; 26(1): 129-36, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21432861

RESUMEN

A rapid, sensitive and specific method to quantify cyproheptadine in human plasma using amitriptyline as the internal standard (IS) is described. The analyte and the IS were extracted from plasma by liquid-liquid extraction using a diethyl-ether/dichloromethane (70/30; v/v) solvent. After removing and drying the organic phase, the extracts were reconstituted with a fixed volume of acetonitrile/water (50/50 v/v)+0.1% of acetic acid. The extracts were analyzed by high performance liquid chromatography coupled to electrospray tandem mass spectrometry (LC-MS/MS). Chromatography was performed isocratically using an Alltech Prevail C18 5 µm analytical column, (150 mm x 4.6 mm I.D.). The method had a chromatographic run time of 4 min and a linear calibration curve ranging from 0.05 to 10 ng/mL (r2 > 0.99). The limit of quantification was 0.05 ng/mL. This HPLC/MS/MS procedure was used to assess the bioequivalence of cyproheptadine in two cyproheptadine + cobamamide (4 mg + 1 mg) tablet formulations (Cobactin® [cyproheptadine + cobamamide] test formulation supplied from Zambon Laboratórios Farmacêuticos Ltda. and Cobavital® from Solvay Farma (standard reference formulation)). A single 4 mg + 1 mg [cyproheptadine + cobamamide] dose of each formulation was administered to healthy volunteers. The study was conducted using an open, randomized, two-period crossover design with a 1-week washout interval. Since the 90% CI for Cmax and AUCs ratios were all within the 80-125% bioequivalence limit proposed by the US Food and Drug Administration, it was concluded that the cyproheptadine test formulation (Cobactin®) is bioequivalent to the Cobavital® formulation for both the rate and the extent of absorption of cyproheptadine.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Ciproheptadina/sangre , Ciproheptadina/farmacocinética , Espectrometría de Masa por Ionización de Electrospray/métodos , Espectrometría de Masas en Tándem/métodos , Administración Oral , Adolescente , Adulto , Área Bajo la Curva , Estudios Cruzados , Ciproheptadina/administración & dosificación , Combinación de Medicamentos , Estabilidad de Medicamentos , Femenino , Humanos , Límite de Detección , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Comprimidos , Equivalencia Terapéutica
15.
J Chromatogr B Analyt Technol Biomed Life Sci ; 879(24): 2361-8, 2011 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-21763220

RESUMEN

A rapid, sensitive and specific method for quantifying ciprofibrate in human plasma using bezafibrate as the internal standard (IS) is described. The sample was acidified prior extraction with formic acid (88%). The analyte and the IS were extracted from plasma by liquid-liquid extraction using an organic solvent (diethyl ether/dichloromethane 70/30 (v/v)). The extracts were analyzed by high performance liquid chromatography coupled with electrospray tandem mass spectrometry (HPLC-MS/MS). Chromatography was performed using Genesis C18 4 µm analytical column (4.6 × 150 mm i.d.) and a mobile phase consisting of acetonitrile/water (70/30, v/v) and 1mM acetic acid. The method had a chromatographic run time of 3.4 min and a linear calibration curve over the range 0.1-60 µg/mL (r>0.99). The limit of quantification was 0.1 µg/mL. The intra- and interday accuracy and precision values of the assay were less than 13.5%. The stability tests indicated no significant degradation. The recovery of ciprofibrate was 81.2%, 73.3% and 76.2% for the 0.3, 5.0 and 48.0 ng/mL standard concentrations, respectively. For ciprofibrate, the optimized parameters of the declustering potential, collision energy and collision exit potential were -51 V, -16 eV and -5 V, respectively. The method was also validated without the use of the internal standard. This HPLC-MS/MS procedure was used to assess the bioequivalence of two ciprofibrate 100mg tablet formulations in healthy volunteers of both sexes. The following pharmacokinetic parameters were obtained from the ciprofibrate plasma concentration vs. time curves: AUC(last), AUC(0-168 h), C(max) and T(max). The geometric mean with corresponding 90% confidence interval (CI) for test/reference percent ratios were 93.80% (90% CI=88.16-99.79%) for C(max,) 98.31% (90% CI=94.91-101.83%) for AUC(last) and 97.67% (90% CI=94.45-101.01%) for AUC(0-168 h). Since the 90% CI for AUC(last), AUC(0-168 h) and C(max) ratios were within the 80-125% interval proposed by the US FDA, it was concluded that ciprofibrate (Lipless 100mg tablet) formulation manufactured by Biolab Sanus Farmacêutica Ltda. is bioequivalent to the Oroxadin (100 mg tablet) formulation for both the rate and the extent of absorption.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Ácidos Fíbricos/farmacocinética , Espectrometría de Masa por Ionización de Electrospray/métodos , Adolescente , Adulto , Femenino , Ácidos Fíbricos/sangre , Humanos , Masculino , Persona de Mediana Edad , Espectrometría de Masas en Tándem/métodos , Adulto Joven
16.
Arzneimittelforschung ; 60(7): 440-4, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20712134

RESUMEN

OBJECTIVE: To assess the comparative bioavailability of two formulations (16 mg tablet) of betahistine (CAS 5579-84-0) in healthy volunteers of both sexes. METHODS: The study was conducted using an open, randomized, two-period crossover design with a 1-week washout interval. Plasma samples were obtained for up to 36 h post dose. Plasma 2-pyridylacetic acid concentrations were analyzed by liquid chromatography coupled with tandem mass spectrometry (LC-MS-MS) with positive ion electrospray ionization using multiple reaction monitoring (MRM). From the 2-pyridylacetic acid plasma concentration vs. time curves, the following pharmacokinetic parameters were obtained for AUCIast and Cmax. RESULTS: The limit of quantification was 4 ng/mL for plasma 2-pyridylacetic acid analysis. The geometric mean and 90% confidence interval (CI) of test/reference percent ratios were: 98.94% (92.21%-106.16%) for Cmax, 95.42% (91.74%-99.25%) for AUClast. CONCLUSION: Since the 90% CI for Cmax and AUCs ratios were all within the 80-125% interval proposed by the US Food and Drug Administration Agency, it was concluded that the test formulation is bioequivalent to the reference for both the rate and the extent of absorption.


Asunto(s)
Betahistina/farmacocinética , Comprimidos , Acetatos/sangre , Acetatos/farmacocinética , Adolescente , Adulto , Área Bajo la Curva , Betahistina/administración & dosificación , Betahistina/sangre , Disponibilidad Biológica , Femenino , Semivida , Humanos , Masculino , Persona de Mediana Edad , Piridinas/sangre , Piridinas/farmacocinética , Valores de Referencia , Vasodilatadores/administración & dosificación , Vasodilatadores/sangre , Vasodilatadores/farmacocinética
17.
Rev. bras. cardiol. invasiva ; 18(2): 185-192, jun. 2010.
Artículo en Portugués | LILACS | ID: lil-559925

RESUMEN

Introdução: Atorvastatina 80 mg é recomendada a pacientes portadores de doença coronária para redução de eventos cardiovasculares, havendo controvérsia sobre as interações farmacocinéticas entre doses elevadas das estatinas e uso concomitante de clopidogrel, por compartilharem a mesma via de biotransformação. Este estudo avaliou os efeitos da terapia combinada atorvastatina/clopidogrel na farmacocinética da estatina e função plaquetária em pacientes com doença coronária estável, sob uso crônico e efetivo de estatina. Método: Os pacientes foram admitidos quatro vezes para internação (V1 a V4) em leito-dia. Sete dias (D) antes da primeira internação a estatina em uso foi suspensa. A seguir, receberam atorvastatina 80 mg (D1 a D22) e clopidogrel 75 mg/dia (D8 a D29). Em todas as V foram obtidas amostras de sangue em jejum para dosagens lipídicas, avaliação da função plaquetária (técnica da placa e cone) e quantificação dos níveis plasmáticos de atorvastatina (cromatografia líquida e espectrometria de massa). Resultados: A suspensão por uma semana da estatina modificou o perfil lipídico (P < 0,05 vs. basal), ocorrendo rápida melhora de todas as frações lipídicas após atorvastatina 80 mg (P < 0,005; V1 > V2, V3 e V4). A adesão plaquetária foi menor com clopidogrel isolado (P = 0,003; V4 < V1, V2 e V3), enquanto para a agregação houve menor valor com tratamento combinado atorvastatina/clopidogrel ou clopidogrel isolado comparado aos demais períodos (P < 0,0001; V3 e V4 < V1 e V2). O clopidogrel não modificou as concentrações de atorvastatina. Conclusão: Atorvastatina em alta dose não afetou as meias respostas plaquetárias ao clopidogrel; entretanto, curto período de suspensão da estatina piorou o perfil lipídico e a função plaquetária.


Background: Atorvastatin 80 mg is recommended in patientswith coronary artery disease to reduce cardiovascular events, however, there is controversy regarding the pharmacokinetic interactions between high doses of statins and the concomitant use of clopidogrel, since they share the same biotransformation pathway. This study evaluated theeffects of the atorvastatin/clopidogrel combination therapy on the pharmacokinetics of statins and on platelet function of patients with stable coronary artery disease receivingchronic statins. Method: Patients were admitted four times (V1 to V4) to a day-clinic. Statin was discontinued sevendays (D) before the first admission. Patients then received atorvastatin 80 mg (D1 to D22) and clopidogrel 75 mg/day (D8 to D29). Fasting blood samples were obtained at all time points for lipid measurements, platelet function tests (cone and plate technique), and quantification of atorvastatin plasma levels (liquid chromatography and mass spectrometry). Results: The discontinuation of statins for one weekchanged the lipid profile (P < 0.05 vs. baseline), with an early improvement of all lipid parameters after the administration of atorvastatin 80 mg (P < 0.005; V1 > V2, V3 and V4). Platelet adhesion was lower with clopidogrel alone (P = 0.003; V4 < V1, V2 and V3), whereas platelet aggregation values were lower following the atorvastatin/clopidogrel combination therapy or clopidogrel alone when compared to the other time points (P < 0.0001; V3 and V4 < V1 and V2). The use of clopidogrel did not affect atorvastatin serum levels. Conclusion: High-dose atorvastatin did not affectplatelet responses to clopidogrel, however the short-term statindiscontinuation worsened the lipid profile and platelet function.


Asunto(s)
Humanos , Masculino , Femenino , LDL-Colesterol/sangre , Enfermedades Cardiovasculares/tratamiento farmacológico
18.
Arq. bras. endocrinol. metab ; Arq. bras. endocrinol. metab;47(6): 711-715, dez. 2003. tab
Artículo en Inglés | LILACS | ID: lil-356035

RESUMEN

PURPOSES: To estimate plasma 1,5-anhydroglucitol (AG) in diabetic (DM) and non-DM patients in a Chinese population, and to compare it with fructosamine, glycosylated hemoglobin (HbA1c), and fasting glucose (FG) levels. METHODS: Case-control study on the significance of AG conducted in a medical center of southern Taiwan, including356 patients (300 non-DM and 56 type 2 DM). Plasma AG, fructosamine, HbA1c and FG were measured on the second day of admission and only those with normal values (except glucose) were enrolled. Glycemic markers of the non-DM patients were examined only once whereas DM patients were sequentially sampled over 3 months. RESULTS: Mean plasma AG levels were lower in DM than in non-DM patients (4.02+/-2.96 vs 26.68+/-11.33µg/ml, P<0.001), and lower in non-DM females than males (22.90+/-9.51 vs 29.45+/-11.7µg/ml, P<0.05). AG showed a good correlation with FG. Mean plasma AG were inversely correlated with FG, fructosamine and HbA1c in DM patients and worked as well as other glycemic markers in detecting short-term changes in glycemic control. AG levels of DM patients demonstrated no difference with or without smoking, hypertension, micro- and macro-vascular complications. CONCLUSIONS: We recommend clinical application of plasma AG in long-standing DM patients for short-term detection and monitoring glycemic condition.


Asunto(s)
Humanos , Masculino , Femenino , Persona de Mediana Edad , Desoxiglucosa , Diabetes Mellitus Tipo 2 , Glucemia , Estudios de Casos y Controles , Fructosamina , Hemoglobina Glucada
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