Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Más filtros











Base de datos
Intervalo de año de publicación
1.
Ultrasound Obstet Gynecol ; 55(4): 516-522, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-30989734

RESUMEN

OBJECTIVE: EXTrauterine Environment for Neonatal Development (EXTEND) is a system to support ongoing fetal growth and organ development in an extrauterine environment, utilizing a pumpless low-resistance oxygenator circuit. The aim of this study was to evaluate hemodynamics and cardiac function in fetal sheep sustained on the EXTEND system. METHODS: This was a prospective study of fetal sheep supported for a minimum of 3 weeks on EXTEND. Hemodynamic parameters were assessed weekly and included heart rate, mean arterial pressure (MAP), Doppler-echocardiography-derived cardiac output (CO), pulsatility indices (PIs) of the fetal middle cerebral artery (MCA), umbilical artery (UA) and ductus venosus and cardiac function, as assessed by speckle-tracking-derived global longitudinal strain and strain rate in the right (RV) and left (LV) ventricles. Parameters were compared at 0 days and 1, 2 and 3 weeks following placement on EXTEND. RESULTS: Of 10 fetal sheep enrolled, seven survived for 3 weeks and were included in the analysis. Median gestational age at cannulation was 107 (range, 95-109) days. Heart rate decreased and MAP increased significantly, but within acceptable ranges, during the study period. The quantities and relative ratios of right and left CO remained stable within the anticipated physiological range throughout the study period. Vascular tracings and PIs appeared to be similar to those seen normally in the natural in-utero state, with MCA-PI being higher than UA-PI. UA tracings demonstrated maintained abundant diastolic flow despite the absence of placental circulation. In both the RV and LV, strain decreased significantly at 1 and 2 weeks relative to baseline but returned to baseline values by week 3. CONCLUSIONS: The EXTEND mechanical support system replicates natural physiology and creates a stable and sustainable cardiovascular construct that supports growth over a 3-week period. However, there is a period of depressed contractility within the first week with subsequent improvement by week 3. This may reflect a period of physiological accommodation that warrants further investigation. This study lays the foundation for further exploration as the EXTEND system moves towards human application. © 2019 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.


Asunto(s)
Cardiotocografía/métodos , Ecocardiografía Doppler/métodos , Oxigenación por Membrana Extracorpórea , Corazón Fetal/diagnóstico por imagen , Feto/diagnóstico por imagen , Animales , Animales Recién Nacidos/embriología , Animales Recién Nacidos/crecimiento & desarrollo , Gasto Cardíaco , Femenino , Desarrollo Fetal/fisiología , Corazón Fetal/embriología , Corazón Fetal/crecimiento & desarrollo , Feto/embriología , Feto/fisiopatología , Ventrículos Cardíacos/diagnóstico por imagen , Hemodinámica , Arteria Cerebral Media/embriología , Embarazo , Estudios Prospectivos , Flujo Pulsátil , Ovinos , Factores de Tiempo , Arterias Umbilicales/embriología
2.
Int J Oncol ; 37(1): 5-14, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20514391

RESUMEN

Humans around the globe probably discovered natural remedies against disease and cancer by trial and error over the millennia. Biomolecular archaeological analyses of ancient organics, especially plants dissolved or decocted as fermented beverages, have begun to reveal the preliterate histories of traditional pharmacopeias, which often date back thousands of years earlier than ancient textual, ethnohistorical, and ethnological evidence. In this new approach to drug discovery, two case studies from ancient Egypt and China illustrate how ancient medicines can be reconstructed from chemical and archaeological data and their active compounds delimited for testing their anticancer and other medicinal effects. Specifically, isoscopoletin from Artemisia argyi, artemisinin from Artemisia annua, and the latter's more easily assimilated semi-synthetic derivative, artesunate, showed the greatest activity in vitro against lung and colon cancers. In vivo tests of these compounds previously unscreened against lung and pancreatic cancers are planned for the future.


Asunto(s)
Antineoplásicos Fitogénicos/aislamiento & purificación , Antineoplásicos Fitogénicos/farmacología , Bebidas , Extractos Vegetales/química , Arqueología , Bebidas/análisis , China , Descubrimiento de Drogas/historia , Descubrimiento de Drogas/métodos , Antiguo Egipto , Fermentación/fisiología , Historia de la Medicina , Historia Antigua , Humanos , Extractos Vegetales/farmacología
3.
Mol Ecol ; 15(12): 3707-14, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17032268

RESUMEN

The domestication of the Eurasian grape (Vitis vinifera ssp. sativa) from its wild ancestor (Vitis vinifera ssp. sylvestris) has long been claimed to have occurred in Transcaucasia where its greatest genetic diversity is found and where very early archaeological evidence, including grape pips and artefacts of a 'wine culture', have been excavated. Whether from Transcaucasia or the nearby Taurus or Zagros Mountains, it is hypothesized that this wine culture spread southwards and eventually westwards around the Mediterranean basin, together with the transplantation of cultivated grape cuttings. However, the existence of morphological differentiation between cultivars from eastern and western ends of the modern distribution of the Eurasian grape suggests the existence of different genetic contribution from local sylvestris populations or multilocal selection and domestication of sylvestris genotypes. To tackle this issue, we analysed chlorotype variation and distribution in 1201 samples of sylvestris and sativa genotypes from the whole area of the species' distribution and studied their genetic relationships. The results suggest the existence of at least two important origins for the cultivated germplasm, one in the Near East and another in the western Mediterranean region, the latter of which gave rise to many of the current Western European cultivars. Indeed, over 70% of the Iberian Peninsula cultivars display chlorotypes that are only compatible with their having derived from western sylvestris populations.


Asunto(s)
ADN de Cloroplastos/química , Polimorfismo Genético , Vitis/clasificación , Europa (Continente) , Genotipo , Región Mediterránea , Repeticiones de Microsatélite , Medio Oriente , Filogenia , Vitis/genética
4.
Cancer Res ; 55(14): 2998-3002, 1995 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-7606717

RESUMEN

Germline mutations of the BRCA1 tumor suppressor gene on chromosome 17q are involved in a significant fraction of hereditary breast and ovarian cancers. Allelic deletions that include the BRCA1 locus are common in breast and ovarian cancers, implying that somatic mutations of this gene may play an important role in the more common sporadic forms of these tumors as well. The recent cloning of BRCA1 allows direct testing of this hypothesis. A combination of single strand conformation and sequencing analyses was used to examine the 22 coding exons and intronic splice donor and acceptor regions of BRCA1 for mutations in 115 unselected cases of epithelial ovarian carcinoma. Seven mutations were identified, all of which were present in the germlines of patients with remarkable family or medical histories of breast and/or ovarian cancer. Eighty-nine of these tumors were examined for loss of heterozygosity in the BRCA1 region of chromosome 17q, and 67% of the tumors studied exhibited allelic deletions that included this region. These data are consistent with the hypothesis that BRCA1 mutations are involved in the etiology of hereditary ovarian carcinomas but occur rarely in sporadic tumors, and that the frequent allelic loss on chromosome 17q in this cancer type reflects the involvement of an additional tumor suppressor gene(s).


Asunto(s)
Mutación de Línea Germinal , Proteínas de Neoplasias/genética , Neoplasias Ováricas/genética , Factores de Transcripción/genética , Adulto , Anciano , Alelos , Proteína BRCA1 , Secuencia de Bases , Neoplasias de la Mama/genética , Análisis Mutacional de ADN , ADN de Neoplasias/genética , Exones , Femenino , Mutación del Sistema de Lectura , Eliminación de Gen , Genes Relacionados con las Neoplasias/genética , Humanos , Intrones , Persona de Mediana Edad , Datos de Secuencia Molecular , Polimorfismo Conformacional Retorcido-Simple
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA