Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
J Ovarian Res ; 17(1): 63, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38491534

RESUMEN

BACKGROUND: Artificial Intelligence entails the application of computer algorithms to the huge and heterogeneous amount of morphodynamic data produced by Time-Lapse Technology. In this context, Machine Learning (ML) methods were developed in order to assist embryologists with automatized and objective predictive models able to standardize human embryo assessment. In this study, we aimed at developing a novel ML-based strategy to identify relevant patterns associated with the prediction of blastocyst development stage on day 5. METHODS: We retrospectively analysed the morphokinetics of 575 embryos obtained from 80 women who underwent IVF at our Unit. Embryo morphokinetics was registered using the Geri plus® time-lapse system. Overall, 30 clinical, morphological and morphokinetic variables related to women and embryos were recorded and combined. Some embryos reached the expanded blastocyst stage on day 5 (BL Group, n = 210), some others did not (nBL Group, n = 365). RESULTS: The novel EmbryoMLSelection framework was developed following four-steps: Feature Selection, Rules Extraction, Rules Selection and Rules Evaluation. Six rules composed by a combination of 8 variables were finally selected, and provided a predictive power described by an AUC of 0.84 and an accuracy of 81%. CONCLUSIONS: We provided herein a new feature-signature able to identify with an high performance embryos with the best developmental competence to reach the expanded blastocyst stage on day 5. Clear and clinically relevant cut-offs were identified for each considered variable, providing an objective tool for early embryo developmental assessment.


Asunto(s)
Inteligencia Artificial , Desarrollo Embrionario , Femenino , Humanos , Estudios Retrospectivos , Blastocisto , Aprendizaje Automático , Técnicas de Cultivo de Embriones/métodos , Imagen de Lapso de Tiempo/métodos
2.
Biol Reprod ; 100(6): 1521-1535, 2019 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-30939201

RESUMEN

Breast cancer patients under 40 years of age who are candidate to chemotherapy with alkylating drugs may undergo controlled ovarian stimulation (COS) with recombinant human follicle-stimulating hormone (rhFSH) in order to get fertility preservation by mature oocyte cryostorage. The direct effect(s) of exogenous rhFSH on the chemosensitivity of breast cancer is currently unknown. To clarify this issue, we incubated four different breast cancer cell lines with rhFSH (10 IU/L, 24 h) and then we exposed them to doxorubicin (DOX) or cyclophosphamide (CPA). The effect(s) of rhFSH on human breast cancer cells treated with DOX or CPA was measured in terms of (1) cell viability, (2) cytotoxicity, (3) multidrug resistance (MDR) genes and proteins expression and activities, and (4) hypoxia-inducible factor 1-alpha (HIF-1α) activation. Pretreatment with rhFSH significantly increased the viability of breast cancer cells after treatment with DOX or CPA, and reduced the lactate dehydrogenase leakage and reactive oxygen species production. Moreover, after preincubation with rhFSH, the MDR proteins (Pgp, MPR1, and BCRP) expression and activity resulted upregulated and the HIF-1α pathway activated. In addition, the use of a widely used HIF-1α inhibitor, the 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole (YC-1), prevented the rhFSH effect on the onset of MDR. Taken together, these observations suggest that a short exposure to rhFSH induces chemoresistance to DOX and CPA in human breast cancer cells via HIF-1α activation.


Asunto(s)
Neoplasias de la Mama/patología , Resistencia a Antineoplásicos/efectos de los fármacos , Hormona Folículo Estimulante/farmacología , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , Ciclofosfamida/farmacología , Doxorrubicina/farmacología , Doxorrubicina/uso terapéutico , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Células MCF-7 , Unión Proteica/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Proteínas Recombinantes/farmacología , Activación Transcripcional/efectos de los fármacos
3.
J Biomed Mater Res A ; 99(2): 295-306, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21858918

RESUMEN

Phosphate-based glasses with different amounts of titanium dioxide (TiO(2)), having the following molar composition 50P(2)O(5)-30CaO-9Na(2)O-3SiO(2)-3MgO-(5-x)K(2)O-xTiO(2), (where x = 0, 2.5, 5 mol %), were synthesised and characterized in terms of solubility (according to ISO 10993-14), and in vitro biocompatibility using human MG-63 osteoblast cells. Dissolution tests were carried out in Tris-HCl (pH 7.4) to simulate the physiological pH and in citric acid (pH 3.0) to simulate an acidic environment. The weight loss decreased with increasing TiO(2) content, a process further enhanced in acidic medium. TiO(2) reduced the pH changes usually caused by the dissolution products released. Cellular tests showed that all the glasses studied (0-5 mol % TiO(2)) and TiCl(4), used to investigate the biocompatibility of titanium ions, did not produce cytotoxic effects on human MG-63 osteoblasts for up to 5 days in culture. On the basis of these results, we suggest that TiO(2)-containing phosphate glasses could be promising substrates for bone tissue engineering applications.


Asunto(s)
Materiales Biocompatibles/química , Vidrio/química , Fosfatos/química , Titanio/química , Materiales Biocompatibles/farmacología , Línea Celular , Humanos , Concentración de Iones de Hidrógeno , Ensayo de Materiales , Osteoblastos/citología , Osteoblastos/efectos de los fármacos , Fosfatos/farmacología , Solubilidad , Propiedades de Superficie , Titanio/farmacología
4.
Curr Med Chem ; 17(22): 2431-41, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20491635

RESUMEN

The behavior of fluoride ions in the human organism is a classic example of double-edged sword. On the one hand the daily supplementation with fluoride is undoubtedly an important preventing factor in protecting teeth from caries, and, as an important mitogenic stimulus for osteoblasts, it may enhance mineral deposition in bone, but on the other hand fluoride, above a threshold concentration, has been demonstrated to be toxic. We present here a brief review of fluoride metabolism and exposure, its use in caries prevention and its effects on bone, followed by an updating about the main hypotheses concerning its mechanism of action and toxicity. The effects of fluoride have been related mainly to its ability to evoke the activation of G proteins and the inhibition of phosphotyrosine phosphatases, leading to an intracellular increase of tyrosine phosphorylation and activation of the mitogen-activated protein kinase pathway, and its capacity to cause generation of reactive oxygen species. We present also a unifying hypothesis accounting for these apparently different effects, although the available experimental models and conditions are highly variable in the literature. A lot of experiments still need to be performed to clarify the positive and negative effects of fluoride. Finding the mechanisms accounting for fluoride toxicity is an important point: indeed, the use of fluoride has been proposed in the preparation of new biomaterials to be inserted in the bone, in order to improve their stable and safe integration.


Asunto(s)
Fluoruros/farmacología , Fluoruros/farmacocinética , Animales , Caries Dental/prevención & control , Relación Dosis-Respuesta a Droga , Fluoruros/efectos adversos , Fluoruros/metabolismo , Humanos
5.
Arterioscler Thromb Vasc Biol ; 23(12): 2215-21, 2003 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-14615391

RESUMEN

OBJECTIVE: In cultured human vascular smooth muscle cells, insulin increases cyclic GMP production by inducing nitric oxide (NO) synthesis. The aim of the present study was to determine whether in these cells the insulin-stimulated NO/cyclic GMP pathway plays a role in the regulation of glucose uptake. METHODS AND RESULTS: Glucose transport in human vascular smooth muscle cells was measured as uptake of 2-deoxy-d-[3H]glucose, cyclic GMP synthesis was checked by radioimmunoassay, and GLUT4 recruitment into the plasma membrane was determined by immunofluorescence. Insulin-stimulated glucose transport and GLUT4 recruitment were blocked by an inhibitor of NO synthesis and mimicked by NO-releasing drugs. Insulin- and NO-elicited glucose uptake were blocked by inhibitors of soluble guanylate cyclase and cyclic GMP-dependent protein kinase; furthermore, glucose transport was stimulated by an analog of cyclic GMP. CONCLUSIONS: Our results suggest that insulin-elicited glucose transport (and the corresponding GLUT4 recruitment into the plasma membrane) in human vascular smooth muscle cells is mediated by an increased synthesis of NO, which stimulates the production of cyclic GMP and the subsequent activation of a cyclic GMP-dependent protein kinase.


Asunto(s)
GMP Cíclico/metabolismo , Glucosa/metabolismo , Insulina/fisiología , Proteínas Musculares , Músculo Liso Vascular/fisiología , Óxido Nítrico/fisiología , Transducción de Señal/fisiología , Transporte Biológico , Membrana Celular/química , Membrana Celular/enzimología , Membrana Celular/metabolismo , Células Cultivadas , Proteínas Quinasas Dependientes de GMP Cíclico/metabolismo , Técnica del Anticuerpo Fluorescente , Transportador de Glucosa de Tipo 4 , Guanilato Ciclasa/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Proteínas de Transporte de Monosacáridos/inmunología , Proteínas de Transporte de Monosacáridos/metabolismo , Proteínas de Transporte de Monosacáridos/fisiología , Músculo Liso Vascular/química , Músculo Liso Vascular/citología , Músculo Liso Vascular/enzimología , Óxido Nítrico/biosíntesis
6.
Fertil Steril ; 76(3): 496-500, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11532471

RESUMEN

OBJECTIVE: To correlate the concentration of nitrite (the stable metabolite of nitric oxide) in seminal plasma with sperm number and motility, leukocytospermia, and sperm culture. DESIGN: Prospective study. SETTING: Academic research institution. PATIENT(S): Seventy normozoospermic or dyspermic men enrolled in an artificial insemination/in vitro fertilization program. INTERVENTION(S): Semen samples (n = 70) were checked for sperm concentration, total sperm count, sperm motility, seminal leukocyte concentration, and sperm culture; similarly, the concentration of nitrite in seminal plasma was measured by Griess reaction. MAIN OUTCOME MEASURE(S): Measurement of nitrite concentration in seminal plasma and its correlation with sperm concentration, total sperm count, sperm motility, leukocytospermia, and sperm culture. RESULT(S): The concentration of nitrite in seminal plasma does not correlate with sperm concentration, total sperm count, or with the proportion of immotile or rapid-forward motile spermatozoa. Moreover, the concentration of nitrite in seminal plasma is not significantly increased when sperm culture is positive, nor does it correlate with leukocyte concentration in semen. CONCLUSION(S): Our results do not support the hypothesis that in vivo nitric oxide synthesis affects sperm function; alternatively, our results could suggest that nitrite in the seminal plasma is not a sensitive marker of in vivo nitric oxide synthesis.


Asunto(s)
Leucocitos/citología , Nitritos/análisis , Oligospermia/fisiopatología , Semen/química , Semen/citología , Recuento de Espermatozoides , Motilidad Espermática , Espermatozoides/citología , Fertilización In Vitro , Bacterias Gramnegativas/aislamiento & purificación , Bacterias Grampositivas/aislamiento & purificación , Humanos , Inseminación Artificial , Masculino , Oligospermia/patología , Estudios Prospectivos , Análisis de Regresión , Semen/microbiología , Espermatozoides/fisiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...