Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 37
Filtrar
Más filtros











Intervalo de año de publicación
1.
Mater Today Bio ; 8: 100083, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33294837

RESUMEN

The fast and non-invasive detection of odors and volatile organic compounds (VOCs) by gas sensors and electronic noses is a growing field of interest, mostly due to a large scope of potential applications. Additional drivers for the expansion of the field include the development of alternative and sustainable sensing materials. The discovery that isolated cross-linked polymeric structures of suberin spontaneously self-assemble as a film inspired us to develop new sensing composite materials consisting of suberin and a liquid crystal (LC). Due to their stimuli-responsive and optically active nature, liquid crystals are interesting probes in gas sensing. Herein, we report the isolation and the chemical characterization of two suberin types (from cork and from potato peels) resorting to analyses of gas chromatography-mass spectrometry (GC-MS), solution nuclear magnetic resonance (NMR), and X-ray photoelectron spectroscopy (XPS). The collected data highlighted their compositional and structural differences. Cork suberin showed a higher proportion of longer aliphatic constituents and is more esterified than potato suberin. Accordingly, when casted it formed films with larger surface irregularities and a higher C/O ratio. When either type of suberin was combined with the liquid crystal 5CB, the ensuing hybrid materials showed distinctive morphological and sensing properties towards a set of 12 VOCs (comprising heptane, hexane, chloroform, toluene, dichlormethane, diethylether, ethyl acetate, acetonitrile, acetone, ethanol, methanol, and acetic acid). The optical responses generated by the materials are reversible and reproducible, showing stability for 3 weeks. The individual VOC-sensing responses of the two hybrid materials are discussed taking as basis the chemistry of each suberin type. A support vector machines (SVM) algorithm based on the features of the optical responses was implemented to assess the VOC identification ability of the materials, revealing that the two distinct suberin-based sensors complement each other, since they selectively identify distinct VOCs or VOC groups. It is expected that such new environmentally-friendly gas sensing materials derived from natural diversity can be combined in arrays to enlarge selectivity and sensing capacity.

2.
Mater Today Bio ; 5: 100039, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32211605

RESUMEN

Suberin, a plant polyester, consists of polyfunctional long-chain fatty acids and glycerol and is an intriguing candidate as a novel antimicrobial material. We purified suberin from cork using ionic-liquid catalysis during which the glycerol bonds that ensure the polymeric nature of suberin remained intact or were only partially cleaved-yielding the closest to a native configuration reported to date. The chemistry of suberin, both in situ (in cryogenically ground cork) and ex situ (ionic-liquid extracted), was elucidated using high-resolution one- and two-dimensional solution-state NMR analyses. Centrifugation was used to isolate suberin particles of distinct densities and their monomeric composition, assembly, and bactericidal effect, inter alia, were assessed. Analysis of the molecular structure of suberin revealed the relative abundance of linear aliphatic vs. acylglycerol esters, comprising all acylglycerol configurations and the amounts of total carbonyls (C[bond, double bond]O), free acid end groups (COOH), OH aliphatics, and OH aromatics. Suberin centrifuged fractions revealed generic physiochemical properties and monomeric composition â€‹and self-assemble into polygonal structures that display distinct degrees of compactness when lyophilized. Suberin particles-suberinsomes-display bactericidal activity against major human pathogenic bacteria. Fingerprinting the multifunctionality of complex (plant) polyesters such as suberin allows for the identification of novel polymer assemblies with significant value-added properties.

3.
Curr Cancer Drug Targets ; 18(3): 222-230, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-28460619

RESUMEN

Cancer is a global health issue that impairs the life quality of patients and origins thousands of deaths annually worldwide. Six-transmembrane epithelial antigen of the prostate (STEAP1) was identified to be overexpressed in several types of cancers, namely in prostate cancer (PCa). Considering its secondary structure, associated with its location in the cell membrane, has been suggested a role in intercellular communication between tumour cells. Taking into account its high specificity and overexpression in human cancers, STEAP1 is nowadays a promising candidate to be imposed as a therapeutic target. Several strategies have been developed during the last few years for targeting STEAP1, including antibody-drug conjugates, monoclonal antibodies (mAbs), DNA vaccines and small noncoding RNAs (ncRNAs). This review presents the current knowledge about STEAP1 protein expression in human tissues, its biochemical properties and targeting strategies with the purpose to evaluate its potential as therapeutic agent for cancer.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Antineoplásicos/uso terapéutico , Neoplasias/tratamiento farmacológico , Oxidorreductasas/antagonistas & inhibidores , Animales , Antígenos de Neoplasias/inmunología , Humanos , Neoplasias/inmunología , Neoplasias/metabolismo , Oxidorreductasas/inmunología , Transporte de Proteínas
4.
Anim Genet ; 46(4): 452-6, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26153924

RESUMEN

In the course of human migrations, domestic animals often have been translocated to islands with the aim of assuring food availability. These founder events are expected to leave a genetic footprint that may be recognised nowadays. Herewith, we have examined the mitochondrial diversity of goat populations living in the Canarian and Balearic archipelagos. Median-joining network analysis produced very distinct network topologies for these two populations. Indeed, a majority of Canarian goats shared a single ancestral haplotype that segregated in all sampled islands, suggesting a single founder effect followed by a stepping-stone pattern of diffusion. This haplotype also was present in samples collected from archaeological assemblies at Gran Canaria and Lanzarote, making evident its widespread distribution in ancient times. In stark contrast, goats from Majorca and Ibiza did not share any mitochondrial haplotypes, indicating the occurrence of two independent founder events. Furthermore, in Majorcan goats, we detected the segregation of the mitochondrial G haplogroup that has only been identified in goats from Egypt, Iran and Turkey. This finding suggests the translocation of Asian and/or African goats to Majorca, possibly as a consequence of the Phoenician and Carthaginian colonisations of this island.


Asunto(s)
ADN Mitocondrial/genética , Efecto Fundador , Genética de Población , Cabras/genética , Animales , Animales Domésticos/genética , Pool de Genes , Flujo Genético , Haplotipos , Islas , Datos de Secuencia Molecular , Análisis de Secuencia de ADN , España
7.
Actas urol. esp ; 32(10): 1035-1036, nov.-dic. 2008. ilus
Artículo en Es | IBECS | ID: ibc-69621

RESUMEN

El quiste de Tarlov o quiste perineural son lesiones de las raíces nerviosas localizadas a nivel de la región sacra y de etiología incierta. La mayoría de estos quistes permanecen asintomáticos y carecen de relevancia clínica. Los quistes sintomáticos son infrecuentes y los síntomas más habituales son el dolor y las radiculopatías. Nosotros presentamos el caso de una mujer de 53 años con un quiste de Tarlov sintomático ( síndrome de frecuencia y urgencia miccional) que tras el tratamiento quirúrgico presenta una mejoría clínica importante (AU)


Tarlov cysts or perineural cyst are lesions of the nerve roots located at the sacral level and uncertain etiology. Most of these cysts remain asymptomatic with no clinical relevance. The symptomatic cysts are uncommon and the usual symptoms are pain or radiculopathy. We report the case of a 53 year old woman with a symptomatic cyst (with a history of frequency and urgency syndrom), that disappears after surgery (AU)


Asunto(s)
Humanos , Femenino , Persona de Mediana Edad , Quistes Aracnoideos/complicaciones , Quistes Aracnoideos/diagnóstico , Radiculopatía/complicaciones , Radiculopatía/diagnóstico , Urografía/métodos , Laminectomía/métodos , Factores de Riesgo , Quistes Aracnoideos , Urografía/normas , Urografía/tendencias , Urografía , Calidad de Vida
10.
Arch. esp. urol. (Ed. impr.) ; 61(4): 544-546, mayo 2008. ilus
Artículo en Es | IBECS | ID: ibc-64503

RESUMEN

Objetivo: Presentar un nuevo caso de melanoma localizado en el glande. Métodos/Resultados: Presentamos en este artículo el caso de un paciente diagnosticado y tratado en nuestro servicio, describiendo su forma de presentación así como su manejo terapéutico. Conclusiones: El melanoma de localización peneana es una forma infrecuente de presentación de este tipo de tumores cutáneos. Hacemos especial hincapié en su diagnóstico, presentación clínica y manejo terapéutico, ya que se trata de una neoplasia que requiere un diagnóstico y tratamiento precoces debido a su pronta diseminación metastásica (AU)


Objective: To report one case of melanoma of the glans penis. Methods/Results: We present the case of a patient diagnosed and treated in our department describing diagnosis and therapeutic management. Conclusions: Melanoma of the penis is an uncommon presentation form of this kind of cutaneous tumor. We especially emphasize its diagnosis, clinical presentation and therapeutic management due to its prompt metastatic dissemination requiring early diagnosis and treatment (AU)


Asunto(s)
Humanos , Masculino , Persona de Mediana Edad , Melanoma/complicaciones , Melanoma/diagnóstico , Metástasis de la Neoplasia/diagnóstico , Metástasis de la Neoplasia/patología , Prostatectomía/métodos , Biopsia/métodos , Neoplasias del Pene/complicaciones , Inmunoterapia/métodos , Interferones/uso terapéutico , Escisión del Ganglio Linfático/métodos , Adenocarcinoma/complicaciones , Neoplasias del Pene/diagnóstico , Adenocarcinoma/diagnóstico , Neoplasias del Pene/patología , Pene/patología , Pene/cirugía , Pene
11.
Actas Urol Esp ; 32(10): 1035-6, 2008.
Artículo en Español | MEDLINE | ID: mdl-19143297

RESUMEN

Tarlov cysts or perineural cyst are lesions of the nerve roots located at the sacral level and uncertain aetiology. Most of these cysts remain asymptomatic with no clinical relevance. The symptomatic cysts are uncommon and the usual symptoms are pain or radiculopathy. We report the case of a 53-year-old woman witha symptomatic cyst (with a history of frequency and urgency syndrom), that disappears after surgery.


Asunto(s)
Quistes de Tarlov/complicaciones , Quistes de Tarlov/cirugía , Enfermedades de la Vejiga Urinaria/etiología , Enfermedades de la Vejiga Urinaria/cirugía , Trastornos Urinarios/etiología , Trastornos Urinarios/cirugía , Femenino , Humanos , Persona de Mediana Edad
14.
Drug Dev Ind Pharm ; 26(7): 785-90, 2000 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10872100

RESUMEN

The evaluation of the biopharmaceutical quality of omeprazole enteric-coated products (granules in capsules) with respect to its dissolution characteristics is not specifically regulated in any of the most common official pharmacopoeia. USP 23 includes a general monograph for enteric-coated products. This paper reports the evaluation of the medium pH effect on the dissolution rates of omeprazole from four omeprazole-containing products of different manufacturers. It is concluded that the USP 23 recommended dissolution procedure for enteric-coated products is not suitable due to the degradation of omeprazole under such conditions. Furthermore, the medium with pH 8.0 showed different dissolution rates not observed at pH 7.4, allowing discrimination between products of different manufacturers.


Asunto(s)
Antiulcerosos/administración & dosificación , Química Farmacéutica/métodos , Omeprazol/administración & dosificación , Administración Oral , Evaluación de Medicamentos/métodos , Estabilidad de Medicamentos , Concentración de Iones de Hidrógeno , Comprimidos Recubiertos
15.
Int J Pharm ; 182(1): 41-7, 1999 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-10332073

RESUMEN

Permeation of caffeine through human skin and artificial membranes (mounted in modified Franz type diffusion cells) was evaluated, either from saturated solutions or from commercially available topical formulations (all containing 3% caffeine). Data interpretation of the caffeine diffusion through human skin does not implicate transfer through pores despite caffeine being a relatively polar molecule. No correlation was found between transfer though the synthetic membranes (cellulose acetate impregnated with isopropyl myristate and silicone rubber soaked in isopropyl myristate) and that observed through skin. The synthetic membranes can be used for assessing product performance in quality assurance but will give little indication of its performance in vivo. The study investigated the percutaneous permeation of caffeine through human skin in order to obtain a mechanistic interpretation of its route of permeation. Synthetic membranes were also examined to determine if they could be used as models for human skin. Different commercial formulations investigated to determine the significance of enhancement strategies.


Asunto(s)
Cafeína/administración & dosificación , Estimulantes del Sistema Nervioso Central/administración & dosificación , Membranas Artificiales , Administración Tópica , Cafeína/química , Cafeína/farmacocinética , Celulosa/análogos & derivados , Estimulantes del Sistema Nervioso Central/química , Estimulantes del Sistema Nervioso Central/farmacocinética , Química Farmacéutica , Difusión , Humanos , Técnicas In Vitro , Cinética , Permeabilidad , Silicio , Piel/metabolismo , Absorción Cutánea , Solubilidad , Soluciones
16.
Eur J Pharm Sci ; 7(4): 311-5, 1999 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9971914

RESUMEN

Omeprazole, a proton pump inhibitor, effectively suppresses the gastric acid secretion in the parietal cells of the stomach. Several previously published papers focus on the pharmacokinetics of the drug and its interactions with physiological aspects or with other drugs. The increasing number of omeprazole containing products available in the market, raises questions of therapeutic equivalence and/or generic substitution. The bioequivalence evaluation between two or more formulations provides information about in vivo performance. In a favorable decision regarding bioequivalence, the products are considered to have a similar therapeutic efficacy when used under the same therapeutic conditions. This paper reports the design, results and some important aspects involved in a bioequivalence study between two solid oral formulations from different manufacturers. Some important findings were the high intra-subject variability observed for Cmax and the variability observed between subject profiles, probably caused by the multi-unit type of formulations studied.


Asunto(s)
Antiulcerosos/administración & dosificación , Antiulcerosos/farmacología , Omeprazol/administración & dosificación , Omeprazol/farmacocinética , Adulto , Área Bajo la Curva , Estudios Cruzados , Femenino , Semivida , Humanos , Masculino , Modelos Biológicos , Comprimidos Recubiertos , Equivalencia Terapéutica
17.
J Pharm Biomed Anal ; 14(5): 617-22, 1996 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8738192

RESUMEN

An isocratic high-performance liquid chromatographic method is described for the quantitative analysis of low concentrations of apovincaminic acid (AVA) in blood plasma. AVA, interfering plasma components and primidone (used as the internal standard) were separated on a reversed-phase column of LiChrospher 60 RP-Select B (125 mm x 3 mm i.d.; 5 microns) (Merck). A UV-Vis detector was used at a wavelength of 254 nm. Each chromatographic separation was completed in 14 min and the results showed a relative recovery which varied between 95.9 and 116%, a good overall precision (relative standard deviation, 7.00%) and sensitivity over a linear range of 5.00-300 ng ml-1 (R = 0.999) for AVA in plasma. The method was applied to the analysis of plasma samples obtained from healthy subjects treated with one single oral dose of 20 mg of vinpocetine. The results indicate the method to be suitable for pharmacokinetic studies.


Asunto(s)
Vasodilatadores/sangre , Alcaloides de la Vinca/sangre , Administración Oral , Disponibilidad Biológica , Cromatografía Líquida de Alta Presión/métodos , Preparaciones de Acción Retardada , Humanos , Sensibilidad y Especificidad , Comprimidos , Vasodilatadores/farmacocinética , Alcaloides de la Vinca/farmacocinética
18.
Eur J Drug Metab Pharmacokinet ; 20(4): 275-9, 1995.
Artículo en Inglés | MEDLINE | ID: mdl-8983932

RESUMEN

The influence of an antacid on droxicam pharmacokinetics was investigated in 12 healthy male volunteers. A two way cross-over study was performed after the oral administration of 20 mg of droxicam (Ombolan capsules) and droxicam together with an antacid (Mucal powder). The plasma concentrations of piroxicam, the active moiety of droxicam, were determined by a high-performance liquid chromatographic method. The pharmacokinetic parameter values (mean +/- RSD) of piroxicam after administration of droxicam alone were: AUC0-->infinity = 125.5 +/- 25.1 micrograms.h/l, Cmax = 2.08 +/- 19.9 micrograms/l, tmax = 7.08 +/- 36.8 h and t1/2 = 46.3 +/- 27.0 h. Following administration of droxicam together with the antacid the values obtained for the same parameters were: AUC0-->infinity = 135.1 +/- 24.1 micrograms.h/l. Cmax = 1.85 +/- 23.9 micrograms/l, tmax = 8.17 +/- 34.9 h and t1/2 = 52.0 +/- 22.4 h. These results indicate that concurrent administration of the antacid does not significantly change the bioavailability and pharmacokinetics of droxicam.


Asunto(s)
Compuestos de Aluminio/farmacología , Antiácidos/farmacología , Antiinflamatorios no Esteroideos/farmacocinética , Compuestos de Magnesio/farmacología , Piroxicam/sangre , Piridinas/farmacocinética , Silicatos/farmacología , Administración Oral , Adulto , Análisis de Varianza , Antiinflamatorios no Esteroideos/administración & dosificación , Antiinflamatorios no Esteroideos/sangre , Disponibilidad Biológica , Estudios Cruzados , Humanos , Masculino , Piridinas/administración & dosificación , Piridinas/sangre
20.
Eur J Surg Oncol ; 20(5): 592-4, 1994 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7926067

RESUMEN

Solitary extramedullary plasmacytoma (EMP) of the rectum is an exceedingly rare entity. We report the fourth case of solitary EMP of the rectum and the first one treated by endoscopic polypectomy and radiotherapy. The patient showed no signs of local recurrence or dissemination of the disease after a 12-month follow-up. This case report is presented along with a review of the literature dealing with solitary plasmacytomas of the rectum.


Asunto(s)
Plasmacitoma/terapia , Proctoscopía , Neoplasias del Recto/terapia , Anciano , Anciano de 80 o más Años , Terapia Combinada , Femenino , Humanos , Plasmacitoma/radioterapia , Plasmacitoma/cirugía , Neoplasias del Recto/radioterapia , Neoplasias del Recto/cirugía
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA