Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
2.
Gynecol Oncol ; 165(3): 637-641, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35393217

RESUMEN

INTRODUCTION: Since 2010, the network of rare malignant tumors of the ovary (TMRG) was developed to optimize the management of patients, also allowing a histological second opinion of rare ovarian tumors. The aim of this work was to study the contribution of second opinion to improve histological diagnostic accuracy on ovarian rare malignant tumors included in the TMRG database. MATERIAL AND METHODS: Histological data of patients diagnosed with a rare ovarian tumor included in TMRG network over a one-year period (2018) were collected. Initial diagnoses were compared with second opinion from national gynecological pathologist experts. The modalities of histological second opinion requests were studied, as well as the histological characteristics of the tumors. The discordances were classified as minor (if the modification of histological diagnosis did not change patient management) and major (if the patient management can be modified). RESULTS: Of 1185 included patients, 937 matched the inclusion criteria. Full concordance between primary diagnosis and expert second opinion was reached in 611 cases (65,3%), minor discordance was seen in 114 (12,2%) and major discordance in 209 (22,3%) of cases. In systematic review requested by the network, 26% (n = 137) of cases were reported with a change in histological diagnosis, while the change concerned 44% (n = 186) of cases for a second opinion spontaneously requested by the initial pathologist. The discrepancies concerned all categories of ovarian tumors, with a majority of mucinous tumors (43% of major discordances), followed by stromal and sex-cord tumors (13.8% of major discordances) and clear cell tumors (12,4% of major discordances). CONCLUSION: This analysis confirms the diagnostic difficulty of ovarian tumors, due to their rarity and morphological heterogeneity. French pathologists are aware of these difficulties and spontaneously refer ovarian tumors with unusual histology for a second opinion and collaborate with rare tumor networks for systematic review.


Asunto(s)
Neoplasias Ováricas , Tumores de los Cordones Sexuales y Estroma de las Gónadas , Femenino , Humanos , Neoplasias Ováricas/diagnóstico , Neoplasias Ováricas/patología , Derivación y Consulta
3.
Mol Cell Biol ; 33(24): 5005-20, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24144980

RESUMEN

X chromosome inactivation is a remarkable example of chromosome-wide gene silencing and facultative heterochromatin formation. Numerous histone posttranslational modifications, including H3K9me2 and H3K27me3, accompany this process, although our understanding of the enzymes that lay down these marks and the factors that bind to them is still incomplete. Here we identify Cdyl, a chromodomain-containing transcriptional corepressor, as a new chromatin-associated protein partner of the inactive X chromosome (Xi). Using mouse embryonic stem cell lines with mutated histone methyltransferase activities, we show that Cdyl relies on H3K9me2 for its general association with chromatin in vivo. For its association with Xi, Cdyl requires the process of differentiation and the presence of H3K9me2 and H3K27me3, which both become chromosomally enriched following Xist RNA coating. We further show that the removal of the PRC2 component Eed and subsequent loss of H3K27me3 lead to a reduction of both Cdyl and H3K9me2 enrichment on inactive Xi. Finally, we show that Cdyl associates with the H3K9 histone methyltransferase G9a and the MGA protein, both of which are also found on Xi. We propose that the combination of H3K9me2 and H3K27me3 recruits Cdyl to Xi, and this, in turn, may facilitate propagation of the H3K9me2 mark by anchoring G9a.


Asunto(s)
Células Madre Embrionarias/fisiología , Histonas/metabolismo , Proteínas/metabolismo , Inactivación del Cromosoma X , Cromosoma X/metabolismo , Animales , Diferenciación Celular , Núcleo Celular/metabolismo , Proteínas Co-Represoras , Epigénesis Genética , Femenino , Regulación del Desarrollo de la Expresión Génica , Células HEK293 , Histona Acetiltransferasas , N-Metiltransferasa de Histona-Lisina/metabolismo , Humanos , Hidroliasas , Metilación , Ratones , Complejo Represivo Polycomb 1/metabolismo , Isoformas de Proteínas/metabolismo , Procesamiento Proteico-Postraduccional , Estabilidad Proteica , Tretinoina/fisiología , Cromosoma X/genética
4.
Ann Dermatol Venereol ; 140(5): 382-5, 2013 May.
Artículo en Francés | MEDLINE | ID: mdl-23663712

RESUMEN

BACKGROUND: Localized myxoedema is a rare dermopathy in patients with Graves' disease. The pretibial area is the most commonly affected region but herein we present a case of myxoedema of the big toe. PATIENTS AND METHODS: A 44-year-old male with Graves' disease ongoing for seven years presented bilateral ophthalmopathy and myxoedema of the big toes. The myxoedema was treated successfully with intralesional steroids. DISCUSSION: The physiopathology of myxoedema involves fibroblast activation and glycosaminoglycan production. This activation could result from stimulation of TSH receptors at their surface by TSH receptor antibodies (TRAK) or from an inflammatory process. The pretibial topography may be related to the high frequency in this area of microtrauma, with modulation of the cytokine microenvironment. CONCLUSION: The atypical localization seems to correlate with a Koebner phenomenon. Treatment of Graves' disease is generally insufficient to resolve the cutaneous problems. Topical corticosteroid therapy generally results in rapid improvement of recent lesions.


Asunto(s)
Dermatosis del Pie/patología , Enfermedad de Graves/patología , Mixedema/patología , Dedos del Pie/patología , Adulto , Biopsia , Carbimazol/uso terapéutico , Descompresión Quirúrgica , Fibroblastos/metabolismo , Fibroblastos/patología , Dermatosis del Pie/tratamiento farmacológico , Dermatosis del Pie/etiología , Dermatosis del Pie/fisiopatología , Glicosaminoglicanos/análisis , Glicosaminoglicanos/metabolismo , Enfermedad de Graves/complicaciones , Enfermedad de Graves/tratamiento farmacológico , Enfermedad de Graves/fisiopatología , Enfermedad de Graves/cirugía , Oftalmopatía de Graves/etiología , Oftalmopatía de Graves/cirugía , Terapia de Reemplazo de Hormonas , Humanos , Inmunoglobulinas Estimulantes de la Tiroides/inmunología , Inmunosupresores/administración & dosificación , Inmunosupresores/uso terapéutico , Inyecciones Intralesiones , Masculino , Metimazol/uso terapéutico , Mixedema/tratamiento farmacológico , Mixedema/etiología , Mixedema/fisiopatología , Receptores de Tirotropina/inmunología , Receptores de Tirotropina/fisiología , Tiroidectomía , Tiroxina/uso terapéutico , Triamcinolona/administración & dosificación , Triamcinolona/uso terapéutico
5.
J Microsc ; 242(1): 70-85, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21128940

RESUMEN

The conventional approach for microscopic 3D cellular imaging is based on axial through-stack image series which has some significant limitations such as anisotropic resolution and axial aberration. To overcome these drawbacks, we have recently introduced an alternative approach based on micro-rotation image series. Unfortunately, this new technique suffers from a huge burden of computation that makes its use quite difficult for current applications. To address these problems we propose a new imaging strategy called bi-protocol, which consists of coupling micro-rotation acquisition and conventional z-stack acquisition. We experimentally prove bi-protocol 3D reconstruction produces similar quality to that of pure micro-rotation, but offers the advantage of reduced computation burden because it uses the z-stack volume to accelerate the registration of the micro-rotation images.


Asunto(s)
Imagenología Tridimensional/métodos , Microscopía Confocal , Algoritmos , Línea Celular Tumoral , Humanos , Procesamiento de Imagen Asistido por Computador , Reproducibilidad de los Resultados , Rotación
6.
J Microsc ; 233(3): 404-16, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19250461

RESUMEN

Recently, micro-rotation confocal microscopy has enabled the acquisition of a sequence of micro-rotated images of nonadherent living cells obtained during a partially controlled rotation movement of the cell through the focal plane. Although we are now able to estimate the three-dimensional position of every optical section with respect to the cell frame, the reconstruction of the cell from the positioned micro-rotated images remains a last task that this paper addresses. This is not strictly an interpolation problem since a micro-rotated image is a convoluted two-dimensional map of a three-dimensional reality. It is rather a 'reconstruction from projection' problem where the term projection is associated to the PSF of the deconvolution process. Micro-rotation microscopy has a specific difficulty. It does not yield a complete coverage of the volume. In this paper, experiments illustrate the ability of the classical EM algorithm to deconvolve efficiently cell volume despite of the incomplete coverage. This cell reconstruction method is compared to a kernel-based method of interpolation, which does not take account explicitly the point-spread-function (PSF). It is also compared to the standard volume obtained from a conventional z-stack. Our results suggest that deconvolution of micro-rotation image series opens some exciting new avenues for further analysis, ultimately laying the way towards establishing an enhanced resolution 3D light microscopy.


Asunto(s)
Procesamiento de Imagen Asistido por Computador/métodos , Microscopía Confocal/métodos , Rotación , Algoritmos , Adhesión Celular , Línea Celular Tumoral , Núcleo Celular/ultraestructura , Humanos , Aumento de la Imagen , Laminas/ultraestructura
7.
Langmuir ; 25(3): 1393-402, 2009 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-19138076

RESUMEN

A simple phenomenological model that describes capillary condensation and evaporation of pure fluids confined in cylindrical mesopores is presented. Following the work of Celestini (Celestini, F. Phys. Lett. A 1997, 228, 84), the free energy density of the system is derived using interfacial tensions and a corrective term that accounts for the interaction coupling between the vapor/adsorbed liquid and the adsorbed liquid/adsorbent interfaces. This corrective term is shown to be consistent with the Gibbs adsorption isotherm and assessed by standard adsorption tests. This model reveals that capillary condensation and evaporation are metastable and equilibrium processes, respectively, hence exhibiting the existence of a hysteresis loop inadsorption/desorption isotherm that is well-known in experiment. We extend the phenomenological model of Celestini to give a quantitative description of adsorption on the pore wall and hysteresis width evolution with temperature and confinement. Direct quantitative comparison is made with experimental data for confined argon. Used as a characterizing tool, this integrated model allows in a single fit of an experimental adsorption/desorption isotherm assessing essential characterization data such as the specific surface area, pore volume, and mean pore size.

8.
J Med Virol ; 73(2): 262-8, 2004 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15122802

RESUMEN

Since human papillomavirus (HPV) is the central causal factor in cervical cancer, understanding the epidemiology of this infection constitutes an important step towards development of strategies for prevention. Six hundred and fifty seven cervical samples were tested for HPV using PCR with consensus primers (MY09/MY11), by genotyping (restriction and sequencing analyses) and by cervical cytology, from women who attended a Health Examination Center of the French social security. Women with no cervical smear as well as women with cytological abnormalities within the last 3 years were recruited. HPV DNA was detected in 7.3% of the women (5.3% for high-risk, 2.4% for low-risk, and 0.5% for unknown risk types) including 6 (0.9%) mixed infections. Fifteen different genotypes were detected, of which genotypes 16 (22.2%), 58 (13.0%), 18 (11.1%), 30 (9.2%), and 33 (9.2%) were the most prevalent. In age group 17-25 years, we found the highest frequencies for both any (22.1%) and high-risk (14.7%) HPV, and prevalences gradually decreased with age. 5.2% of low-grade squamous intraepithelial lesion, 0.3% of high-grade squamous intraepithelial lesion, and 1.2% of atypical squamous cells of undetermined significance were found. The frequencies of high risk and all HPV types were significantly higher in squamous intraepithelial lesions than in those with normal and reactive/reparative changes (P < 0.0001). The prevalence of high-risk HPV in the atypical squamous cells of undetermined significance/low-grade squamous intraepithelial lesion group (28.6%) was significantly higher than in the normal and reactive/reparative changes groups (3.4%) (P < 0.0001). HPV detection was associated with younger age, single marital and non-pregnant status (P < 0.0001), premenopausal status (P = 0.0004), and contraception (P = 0.0008). Marital status (OR 4.5; 95% CI = 2.3-9.0) and tobacco consumption (OR 3.0; 95% CI = 1.6-5.7) were predictive independent factors of HPV infection. The French system of Health Examination Centers might be of interest for following women regularly, especially those with a low socioeconomic status.


Asunto(s)
Cuello del Útero/patología , Cuello del Útero/virología , Papillomaviridae/genética , Papillomaviridae/aislamiento & purificación , Infecciones por Papillomavirus/epidemiología , Adolescente , Adulto , Factores de Edad , Anciano , Anticoncepción , Dermatoglifia del ADN , ADN Viral/análisis , ADN Viral/química , ADN Viral/aislamiento & purificación , Femenino , Francia/epidemiología , Genotipo , Humanos , Estado Civil , Ciclo Menstrual , Persona de Mediana Edad , Neoplasias de Células Escamosas/patología , Neoplasias de Células Escamosas/virología , Polimorfismo de Longitud del Fragmento de Restricción , Embarazo , Factores de Riesgo , Análisis de Secuencia de ADN , Fumar , Displasia del Cuello del Útero/patología , Displasia del Cuello del Útero/virología
9.
Dev Biol ; 240(2): 361-76, 2001 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-11784069

RESUMEN

The role of scabrous (sca) in the evenly spaced bristle pattern of Drosophila is explored. Loss-of-function of sca results in development of an excess of bristles. Segregation of alternately spaced bristle precursors and epidermal cells from a group of equipotential cells relies on lateral inhibition mediated by Notch and Delta (Dl). In this process, presumptive bristle precursors inhibit the neural fate of neighbouring cells, causing them to adopt the epidermal fate. We show that Dl, a membrane-bound ligand for Notch, can inhibit adjacent cells, in direct contact with the precursor, in the absence of Sca. In contrast, inhibition of cells not adjacent to the precursor requires, in addition, Sca, a secreted molecule with a fibrinogen-related domain. Over-expression of Sca in a wild-type background, leads to increased spacing between bristles, suggesting that the range of signalling has been increased. scabrous acts nonautonomously, and we present evidence that, during bristle precursor segregation, Sca is required to maintain the normal adhesive properties of epithelial cells. The possible effects of such changes on the range of signalling are discussed. We also show that the sensory organ precursors extend numerous fine cytoplasmic extensions bearing Dl molecules, and speculate on a possible role for these structures during signalling.


Asunto(s)
Proteínas de Drosophila , Drosophila/crecimiento & desarrollo , Drosophila/fisiología , Glicoproteínas/fisiología , Proteínas de Insectos/fisiología , Animales , Animales Modificados Genéticamente , Tipificación del Cuerpo/fisiología , Cadherinas/fisiología , Adhesión Celular/fisiología , Drosophila/citología , Drosophila/genética , Células Epiteliales/fisiología , Femenino , Regulación del Desarrollo de la Expresión Génica , Genes de Insecto , Glicoproteínas/genética , Proteínas de Insectos/genética , Péptidos y Proteínas de Señalización Intracelular , Masculino , Proteínas de la Membrana/genética , Proteínas de la Membrana/fisiología , Microscopía Electrónica , Mutación , Fenotipo , Receptores Notch , Transducción de Señal/fisiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...