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1.
Environ Res ; 170: 406-415, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30623888

RESUMEN

Bisphenol A (BPA) is a high-production-volume chemical with endocrine disrupting properties commonly used as color developer in thermal paper. Concerns about the potential hazards of human BPA exposure have led to the increasing utilization of alternatives such as bisphenol S (BPS) and bisphenol F (BPF). This study was designed to assess: (i) BPA, BPS, and BPF concentrations in 112 thermal paper receipts from Brazil, France, and Spain by liquid chromatography coupled to mass spectrometry (LC-MS); and (ii) hormone-like activities of these receipts using two receptor-specific bioassays, the E-Screen for (anti-)estrogenicity and PALM luciferase assay for (anti-)androgenicity. BPA was present in 95.3% of receipts from Spain, 90.9% of those from Brazil, and 51.1% of those from France at concentrations up to 20.27 mg/g of paper. Only two samples from Brazil, two from Spain, and ten from France had a BPS concentration ranging from 6.46 to 13.29 mg/g; no BPA or BPS was detected in 27.7% of French samples. No BPF was detected in any receipt. Estrogenic activity was observed in all samples from Brazil and Spain and in 74.5% of those from France. Anti-androgenic activity was observed in > 90% of samples from Brazil and Spain and in 53.2% of those from France. Only 25.5% of French samples were negative for both estrogenic and anti-androgenic activity. Estrogenic and anti-androgenic activities per gram of paper were up to 1.411 µM estradiol (E2) equivalent units (E2eq) and up to 359.5 mM procymidone equivalent units (Proceq), respectively. BPA but not BPS concentrations were positively correlated with both estrogenic and anti-androgenic activities. BPA still dominates the thermal paper market in Brazil and Spain, and BPS appears to be one of the main alternatives in France. There is an urgent need to evaluate the safety of alternatives proposed to replace BPA as developer in thermal printing. The large proportion of samples with hormonal activity calls for the adoption of preventive measures.


Asunto(s)
Compuestos de Bencidrilo/análisis , Papel , Fenoles/análisis , Sulfonas/análisis , Brasil , Monitoreo del Ambiente , Estrógenos , Francia , Humanos , España
3.
PLoS One ; 13(2): e0192894, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29462174

RESUMEN

Blood is a fluid connective tissue of human body, where it plays vital functions for the nutrition, defense and well-being of the organism. When circulating in peripheral districts, it is exposed to some physical stresses coming from outside the human body, as electromagnetic fields (EMFs) which can cross the skin. Such fields may interact with biomolecules possibly inducing non thermal-mediated biological effects at the cellular level. In this study, the occurrence of biochemical/biological modifications in human peripheral blood lympho-monocytes exposed in a reverberation chamber for times ranging from 1 to 20 h to EMFs at 1.8 GHz frequency and 200 V/m electric field strength was investigated. Morphological analysis of adherent cells unveiled, in some of these, appearance of an enlarged and deformed shape after EMFs exposure. Raman spectra of the nuclear compartment of cells exposed to EMFs revealed the onset of biochemical modifications, mainly consisting in the reduction of the DNA backbone-linked vibrational modes. Respirometric measurements of mitochondrial activity in intact lympho-monocytes resulted in increase of the resting oxygen consumption rate after 20 h of exposure, which was coupled to a significant increase of the FoF1-ATP synthase-related oxygen consumption. Notably, at lower time-intervals of EMFs exposure (i.e. 5 and 12 h) a large increase of the proton leak-related respiration was observed which, however, recovered at control levels after 20 h exposure. Confocal microscopy analysis of the mitochondrial membrane potential supported the respiratory activities whereas no significant variations in the mitochondrial mass/morphology was observed in EMFs-exposed lympho-monocytes. Finally, altered redox homeostasis was shown in EMFs-exposed lympho-monocytes, which progressed differently in nucleated cellular subsets. This results suggest the occurrence of adaptive mechanisms put in action, likely via redox signaling, to compensate for early impairments of the oxidative phosphorylation system caused by exposure to EMFs. Overall the data presented warn for health safety of people involved in long-term exposure to electromagnetic fields, although further studies are required to pinpoint the leukocyte cellular subset(s) selectively targeted by the EMFs action and the mechanisms by which it is achieved.


Asunto(s)
Campos Electromagnéticos/efectos adversos , Linfocitos/metabolismo , Linfocitos/efectos de la radiación , Monocitos/metabolismo , Monocitos/efectos de la radiación , Teléfono Celular , Citrato (si)-Sintasa/metabolismo , Complejo IV de Transporte de Electrones/metabolismo , Humanos , Linfocitos/patología , Microscopía Confocal , Mitocondrias/metabolismo , Mitocondrias/efectos de la radiación , Monocitos/patología , Especies Reactivas de Oxígeno/metabolismo , Espectrometría Raman , Factores de Tiempo
4.
Br J Pharmacol ; 169(8): 1652-71, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23714011

RESUMEN

UNLABELLED: Adult haematopoietic stem/progenitor cells (HSPCs) constitute the lifespan reserve for the generation of all the cellular lineages in the blood. Although massive progress in identifying the cluster of master genes controlling self-renewal and multipotency has been achieved in the past decade, some aspects of the physiology of HSPCs still need to be clarified. In particular, there is growing interest in the metabolic profile of HSPCs in view of their emerging role as determinants of cell fate. Indeed, stem cells and progenitors have distinct metabolic profiles, and the transition from stem to progenitor cell corresponds to a critical metabolic change, from glycolysis to oxidative phosphorylation. In this review, we summarize evidence, reported in the literature and provided by our group, highlighting the peculiar ability of HSPCs to adapt their mitochondrial oxidative/bioenergetic metabolism to survive in the hypoxic microenvironment of the endoblastic niche and to exploit redox signalling in controlling the balance between quiescence versus active cycling and differentiation. Especial prominence is given to the interplay between hypoxia inducible factor-1, globins and NADPH oxidases in managing the mitochondrial dioxygen-related metabolism and biogenesis in HSPCs under different ambient conditions. A mechanistic model is proposed whereby 'mitochondrial differentiation' is a prerequisite in uncommitted stem cells, paving the way for growth/differentiation factor-dependent processes. Advancing the understanding of stem cell metabolism will, hopefully, help to (i) improve efforts to maintain, expand and manipulate HSPCs ex vivo and realize their potential therapeutic benefits in regenerative medicine; (ii) reprogramme somatic cells to generate stem cells; and (iii) eliminate, selectively, malignant stem cells. LINKED ARTICLES: This article is part of a themed section on Emerging Therapeutic Aspects in Oncology. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2013.169.issue-8.


Asunto(s)
Células Madre Adultas/citología , Células Madre Adultas/metabolismo , Mitocondrias/metabolismo , Adulto , Diferenciación Celular , Linaje de la Célula , Metabolismo Energético , Glucólisis , Humanos , Modelos Biológicos , Oxidación-Reducción , Fosforilación Oxidativa
5.
J Microsc ; 229(Pt 3): 517-24, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18331504

RESUMEN

The aim of this study was to characterize the local distribution and organization of the plasma membrane NADPH-oxidase (NOX) in human haematopoietic stem cell (HSC) by means of the fluorescence scanning near-field optical microscopy approach. The presence of NOX in haematopoietic stem cells is thought to have a functional role as O(2) sensor and/or as low-level reactive oxygen species (ROS) producer to be used as redox messenger for controlling cell growth and differentiation. Given the harmful potential of ROS, a fine-tuning of NOX activity is needed. The high resolution imaging of haematopoietic stem cell membrane obtained in this study combined with the immunodetection of NOX indicates for this the occurrence of a cluster-organized structure. These membrane 'rafts'-like micro-compartments may constitute localized protein aggregates whereby the assembly/activation of the NOX components are functionally integrated with upstream factors constituting signal-transduction platforms.


Asunto(s)
Membrana Celular/enzimología , Membrana Celular/ultraestructura , Células Madre Hematopoyéticas/enzimología , Células Madre Hematopoyéticas/ultraestructura , NADPH Oxidasas/análisis , Células Madre Hematopoyéticas/citología , Humanos , Inmunohistoquímica , Microscopía Confocal , Microscopía Fluorescente , Microscopía de Sonda de Barrido , NADPH Oxidasas/química
7.
Antioxid Redox Signal ; 8(3-4): 495-502, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16677093

RESUMEN

A study is presented of the effect of the cAMP cascade on oxygen metabolism in mammalian cell cultures. Serum-starvation of the cell cultures resulted in depression of the forward NADH-ubiquinone oxidoreductase activity of complex I, decreased content of glutathione, and enhancement of the cellular level of H2O2. Depressed transcription of cytosolic Cu/Zn-SOD 1, mitochondrial glutathione peroxidase and catalase was also observed. Activation of the cAMP cascade reversed the depression of the activity of complex I and the accumulation of H2O2. The effect of cAMP involved the cAMP-dependent protein kinase.


Asunto(s)
AMP Cíclico/metabolismo , Radicales Libres , Oxígeno/química , Animales , Catalasa/química , Proteínas Quinasas Dependientes de AMP Cíclico/química , Citosol/enzimología , Fibroblastos/metabolismo , Glutatión Peroxidasa/química , Humanos , Peróxido de Hidrógeno/farmacología , Ratones , Ratones Endogámicos BALB C , Células 3T3 NIH , Especies Reactivas de Oxígeno , Superóxido Dismutasa/química
8.
Phys Med Biol ; 50(10): 2241-8, 2005 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-15876664

RESUMEN

The compound probability density function (pdf) is investigated for the ability of its parameters to classify masses in ultrasonic B scan breast images. Results of 198 images (29 malignant and 70 benign cases and two images per case) are reported and compared to the classification performance reported by us earlier in this journal. A new parameter, the speckle factor, calculated from the parameters of the compound pdf was explored to separate benign and malignant masses. The receiver operating characteristic curve for the parameter resulted in an A(z) value of 0.852. This parameter was combined with one of the parameters from our previous work, namely the ratio of the K distribution parameter at the site and away from the site. This combined parameter resulted in an A(z) value of 0.955. In conclusion, the parameters of the K distribution and the compound pdf may be useful in the classification of breast masses. These parameters can be calculated in an automated fashion. It should be possible to combine the results of the ultrasonic image analysis with those of traditional mammography, thereby increasing the accuracy of breast cancer diagnosis.


Asunto(s)
Algoritmos , Inteligencia Artificial , Neoplasias de la Mama/diagnóstico por imagen , Interpretación de Imagen Asistida por Computador/métodos , Modelos Biológicos , Neoplasias de la Mama/clasificación , Análisis por Conglomerados , Femenino , Humanos , Modelos Estadísticos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Distribuciones Estadísticas , Ultrasonografía
9.
Ultrasound Med Biol ; 28(10): 1295-300, 2002 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12467856

RESUMEN

Classification of masses in ultrasonic B-mode images of the breast tissue using "normalized" parameters of the Nakagami distribution was recently investigated. The technique, however, did not yield performances that were comparable to those of an experienced radiologist, and utilized only a single image for tissue characterization. Because radiologists commonly use two to four images of a mass for characterization, a similar procedure is developed here. A simple summation of the normalized Nakagami parameters from two different images of a mass is utilized for classification as benign or malignant. The performance of the normalized Nakagami parameters before and after the summation has been carried out through a receiver operating characteristic (ROC) study. The bootstrap procedure has been utilized to compute the mean and SD of the ROC area, A(z), obtained for each parameter. It has been observed that combining normalized Nakagami parameters from two images of the mass may help to improve classification performance over that from utilizing the parameters of just a single image. The performance of this automated parameter-based approach appears to match that of a trained radiologist.


Asunto(s)
Algoritmos , Neoplasias de la Mama/diagnóstico por imagen , Ultrasonografía Mamaria , Neoplasias de la Mama/clasificación , Diagnóstico Diferencial , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Curva ROC , Sensibilidad y Especificidad
10.
Med Phys ; 29(9): 1968-73, 2002 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12349916

RESUMEN

Frequency compounding was recently investigated for computer aided classification of masses in ultrasonic B-mode images as benign or malignant. The classification was performed using the normalized parameters of the Nakagami distribution at a single region of interest at the site of the mass. A combination of normalized Nakagami parameters from two different images of a mass was undertaken to improve the performance of classification. Receiver operating characteristic (ROC) analysis showed that such an approach resulted in an area of 0.83 under the ROC curve. The aim of the work described in this paper is to see whether a feature describing the characteristic of the boundary can be extracted and combined with the Nakagami parameter to further improve the performance of classification. The combination of the features has been performed using a weighted summation. Results indicate a 10% improvement in specificity at a sensitivity of 96% after combining the information at the site and at the boundary. Moreover, the technique requires minimal clinical intervention and has a performance that reaches that of the trained radiologist. It is hence suggested that this technique may be utilized in practice to characterize breast masses.


Asunto(s)
Neoplasias de la Mama/clasificación , Neoplasias de la Mama/diagnóstico por imagen , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Ultrasonografía Mamaria/métodos , Humanos , Modelos Biológicos , Modelos Estadísticos , Control de Calidad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
11.
Artículo en Inglés | MEDLINE | ID: mdl-12046943

RESUMEN

The parameters of the Nakagami distribution have been utilized in the past to classify lesions in breast tissue as benign or malignant. To avoid the effect of operatorgain settings on the parameters of the Nakagami distribution, normalized parameters were utilized for the classification. The normalized parameter was defined as the ratio of the parameter at the site of the lesion to its average value over several regions away from the site. This technique, however, was very time consuming. In this paper, the application of frequency diversity and compounding is explored to achieve this normalization. Lesions are classified using these normalized parameters at the site. A receiver operating characteristic (ROC) analysis of the parameters of the Nakagami distribution has been conducted before and after compounding on a data set of 60 benign and 65 malignant lesions. The ROC results indicate that this technique can reasonably classify lesions in breast tissue as benign or malignant.


Asunto(s)
Neoplasias de la Mama/clasificación , Neoplasias de la Mama/diagnóstico por imagen , Interpretación de Imagen Asistida por Computador/métodos , Modelos Estadísticos , Biopsia , Neoplasias de la Mama/patología , Humanos , Aumento de la Imagen/métodos , Curva ROC , Dispersión de Radiación , Sensibilidad y Especificidad , Ultrasonografía
12.
Ultrasound Med Biol ; 27(11): 1505-14, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11750750

RESUMEN

This paper presents performance comparisons between breast tumor classifiers based on parameters from a conventional texture analysis (CTA) and the generalized spectrum (GS). The computations of GS-based parameters from radiofrequency (RF) ultrasonic scans and their relationship to underlying scatterer properties are described. Clinical experiments demonstrate classifier performances using 22 benign and 24 malignant breast mass regions taken from 40 patients. Linear classifiers based on parameters from the front edge, back edge and interior tumor regions are examined. Results show significantly better performances for GS-based classifiers, with improvements in empirical receiver operating characteristic (ROC) areas of greater than 10%. The ROC curves show GS-based classifiers achieving a 90% sensitivity level at 50% specificity when applied to the back-edge tumor regions, an 80% sensitivity level at 65% specificity when applied to the front-edge tumor regions, and a 100% sensitivity level at 45% specificity when applied to the interior tumor regions.


Asunto(s)
Neoplasias de la Mama/clasificación , Neoplasias de la Mama/diagnóstico por imagen , Interpretación de Imagen Asistida por Computador/métodos , Ultrasonografía Mamaria/métodos , Diagnóstico Diferencial , Femenino , Humanos , Curva ROC , Sensibilidad y Especificidad
13.
Magn Reson Imaging Clin N Am ; 9(2): 393-408, vii-viii, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11493428

RESUMEN

There are two reasons for radiologic evaluation of the augmented breast. Because women with implants are at the same risk for breast cancer as other women, imaging is performed to screen for cancer or to work up clinical abnormalities. Additionally, imaging allows assessment of implant integrity. The various methods for imaging implants and breast tissue in the augmented patient are discussed. Imaging findings suggestive of silicone gel implant rupture are presented.


Asunto(s)
Implantes de Mama , Imagen por Resonancia Magnética/métodos , Neoplasias de la Mama/diagnóstico , Femenino , Geles , Humanos , Mamografía , Falla de Prótesis , Sensibilidad y Especificidad , Siliconas , Ultrasonografía Mamaria
14.
Artículo en Inglés | MEDLINE | ID: mdl-11477787

RESUMEN

We propose a new model for the RF ultrasound echo, namely the power-law shot-noise process. Based on this model, the in-phase and quadrature components of the echo are shown to exhibit 1/f beta-type spectral behavior, in a sense that is defined in the paper. The envelope also exhibits this type of spectral behavior, but with a different exponent. This result explains the experimental observations by other researchers of the power-law trend of the RF echo spectrum. Although the shot-noise model has been used in the past for modeling the RF echo, this is the first time that a power-law impulse response filter is used and that the resulting 1/f beta-type spectral behavior of the RF echo has been investigated. The model parameters are linked to tissue characteristics, such as scatterer density and attenuation; thus, they have the potential to be used as tissue characterization features. The validity of the proposed model is tested based on a database of 100 clinical ultrasound images of the breast.


Asunto(s)
Modelos Teóricos , Ondas de Radio , Ultrasonografía/estadística & datos numéricos , Ingeniería Biomédica , Simulación por Computador , Bases de Datos Factuales , Femenino , Humanos , Método de Montecarlo , Ultrasonografía Mamaria/estadística & datos numéricos
15.
Eur J Clin Invest ; 31(7): 628-38, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11454019

RESUMEN

Cryoglobulins are cold-precipitable immunoglobulins associated with a number of infectious, autoimmune and neoplastic disorders. Their appearance along with rheumatoid factor (RF) can be considered a normal event in the clearance of immune complexes and rarely produces any symptoms. The association between hepatitis C virus (HCV) and mixed cryoglobulinemia (MC) has been rendered evident since the recognition of serological markers of HCV infection. There is thus every reason to suppose that direct or indirect involvement of B cells on the part of the HCV results in their persistent stimulation, clonal expansion and release of molecules with RF activity. The formation of RF/IgG immune complexes is the key pathogenetic mechanism. The close correlation between HCV infection and MC also throws new light on the interpretation of autoimmune phenomena in the course of viral infection and on the close link between autoimmune diseases and lymphoproliferative disorders. The higher risk of non-Hodgkin's lymphoma (NHL) displayed by HCV positive subjects, especially in the Mediterranean basin, suggests that the HCV's chronic lymphoproliferative drive may progress towards frank lymphoid neoplasia. The presence of MC does not represent an in situ or 'occult' NHL, because recent evidences indicate that none of the clones interpreted as predominant displays the molecular features of a true neoplastic process. The cryoglobulinemic syndrome is probably the consequence of pathogenic noxae that act upon the immune system of a host in which regulation of the peripheral T cell response appears to be in some way altered.


Asunto(s)
Crioglobulinemia/diagnóstico , Crioglobulinemia/etiología , Crioglobulinas/análisis , Hepatitis C/complicaciones , Trastornos Linfoproliferativos/etiología , Crioglobulinemia/terapia , Humanos , Linfoma no Hodgkin/etiología , Síndrome , Vasculitis
16.
J Immunol ; 167(1): 21-9, 2001 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-11418627

RESUMEN

PCR DNA amplification of IgH genes was performed on liver biopsy samples of 42 unselected hepatitis C virus (HCV)-positive patients. Genotypic analysis and signal amplification by branched DNA were used to characterize and quantitate HCV RNA genomic sequences. Intraportal lymphoid follicle-like structures were isolated from surrounding hepatocytes by microdissection technique. IgH VDJ PCR products were cloned and sequenced. IgH VDJ gene rearrangements were detected in the liver of 26 (62%) patients. Unequivocal monoclonal or oligoclonal patterns of B cell expansions were found in 14 (33.3%) and 12 (28.6%) patients, respectively. Patients with intrahepatic B cell monoclonal expansions showed liver HCV RNA levels higher than those with oligoclonal or polyclonal features (1106.4 +/- 593.5 vs 677.3 +/- 424.3 vs 406.2 +/- 354.3 pg HCV RNA/g tissue; p = 0.048 and p = 0.001, respectively). Although a single dominant band was obtained with total DNA, characterization of DNA recovered from intraportal inflammatory aggregates resulted in the detection of multiple IgH VDJ gene rearrangements, pointing to an oligoclonal pattern of lymphoproliferation. Cloning and sequence analyses showed that B cell clonalities were differently distributed in adjacent portal tracts of the same liver area. In addition, HCV RNA genomic sequences could be consistently amplified from each of the portal inflammatory aggregates examined. These data support the concept that in chronic HCV infection the intrahepatic B cell repertoire is frequently clonally restricted and that HCV may have a direct role in sustaining in situ B cell proliferation.


Asunto(s)
Linfocitos B/inmunología , Hepatitis C Crónica/inmunología , Hígado/inmunología , Hígado/patología , Adulto , Anciano , Linfocitos B/patología , Linfocitos B/virología , Secuencia de Bases , Agregación Celular/inmunología , Diferenciación Celular/inmunología , Células Clonales , Clonación Molecular , Femenino , Mutación de Línea Germinal , Hepatitis C Crónica/patología , Hepatitis C Crónica/virología , Humanos , Recuento de Linfocitos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Sistema Porta/inmunología , Sistema Porta/patología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Carga Viral
17.
Artículo en Inglés | MEDLINE | ID: mdl-11370350

RESUMEN

In the first part of this work [16], a wavelet-based decomposition algorithm of the RF echo into its coherent and diffuse components was introduced. In this paper, the proposed algorithm is used to estimate structural parameters of the breast tissue such as the number and energy of coherent scatterers, the energy of the diffuse scatterers, and the correlation between them. Based on these individual parameters, breast tissue characterization is performed. The database used consists of 155 breast scans from 42 patients. The results are presented in terms of empirical receiver operating characteristics (ROC) curves. The results of this study are discussed in relation to the tissue microstructure. Individual estimated parameters are able to differentiate reliably between normal and fibroadenoma or fibrocystic or cancerous tissue (area under the ROC Az > 0.93). Also, the differentiation between malignant and benign (normal, fibrocystic, and fibroadenoma) tissue was possible (Az > 0.89).


Asunto(s)
Ultrasonografía Mamaria , Algoritmos , Ingeniería Biomédica , Neoplasias de la Mama/diagnóstico por imagen , Carcinoma Ductal de Mama/diagnóstico por imagen , Femenino , Fibroadenoma/diagnóstico por imagen , Enfermedad Fibroquística de la Mama/diagnóstico por imagen , Humanos , Curva ROC , Ondas de Radio , Dispersión de Radiación , Ultrasonografía Mamaria/estadística & datos numéricos
18.
Artículo en Inglés | MEDLINE | ID: mdl-11370371

RESUMEN

The Nakagami distribution was proposed recently for modeling the echo from tissue. In vivo breast data collected from patients with lesions were studied using this Nakagami model. Chi-square tests showed that the Nakagami distribution is a better fit to the envelope than the Rayleigh distribution. Two parameters, m (effective number) and alpha (effective cross section), associated with the Nakagami distribution were used for the classification of breast masses. Data from 52 patients with breast masses/lesions were used in the studies. Receiver operating characteristics (ROC) were calculated for the classification methods based on these two parameters. The results indicate that these parameters of the Nakagami distribution may be useful in classification of the breast abnormalities. The Nakagami distribution may be a reasonable means to characterize the backscattered echo from breast tissues toward a goal of an automated scheme for separating benign and malignant breast masses.


Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Ultrasonografía Mamaria/métodos , Acústica , Ingeniería Biomédica , Neoplasias de la Mama/clasificación , Distribución de Chi-Cuadrado , Diagnóstico por Computador , Diagnóstico Diferencial , Femenino , Humanos , Modelos Teóricos , Curva ROC , Dispersión de Radiación , Ultrasonografía Mamaria/estadística & datos numéricos
19.
Radiology ; 219(2): 495-7, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11323477

RESUMEN

A 53-year-old woman with right breast microcalcifications of intermediate concern underwent stereotactic directional vacuum-assisted biopsy with marking clip placement. Postbiopsy mammograms showed displacement of a few of the targeted microcalcifications adjacent to misplaced marker clips. Mammography following stereotactic breast biopsy is important to document the location and number of residual calcifications and to determine the adequacy and location of clip placement.


Asunto(s)
Biopsia , Enfermedades de la Mama/patología , Mama/patología , Calcinosis/patología , Mamografía , Biopsia/métodos , Enfermedades de la Mama/diagnóstico por imagen , Calcinosis/diagnóstico por imagen , Femenino , Humanos , Persona de Mediana Edad , Técnicas Estereotáxicas , Vacio
20.
Semin Liver Dis ; 20(2): 143-57, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10946420

RESUMEN

Like other hepatotropic viruses, hepatitis C virus (HCV) shares the property of inducing hepatocellular damage, possibly through induction of immune mechanisms that lead to hepatocellular necrosis. After infection of hepatocytes, and possibly other cells, humoral and cellular responses occur aimed at prevention of virus dissemination and elimination of infected cells. The early activated mechanisms include production of nonspecific and specific antibodies that represent the first-line of defense against invading foreign pathogens. As a consequence, circulating immune complexes are promptly formed, and antigen uptake and processing by specialized cells are enhanced. A major fraction of circulating immunoglobulins (Igs) are part of the spectrum of the so-called natural antibodies, which include anti-idiotypic antibodies and molecules with rheumatoid factor (RF) activity. They mainly belong to the IgM class, are polyclonal, and have no intrinsic pathogenetic potential. In 20-30% of HCV-infected patients, RFs share characteristics of high affinity molecules, are monoclonal in nature, and result in the production of cold-precipitating immune complexes and mixed cryoglobulinemia. It has been shown that anti-idiotypic antibodies and polyclonal and monoclonal RF molecules have the same cross-reactive idiotype, called WA, suggesting that their production is highly restricted. This strongly indicates that they arise from stimulation with the same antigen, likely HCV. It has also been speculated that B-1 (CD5+) and B-2 (CD5-) B-cell subsets, which use a limited number of VH germline genes, underlie the production of low-affinity polyclonal and high-affinity monoclonal antibodies, respectively. The persistent production of monoclonal RF molecules implies the existence of a further mechanism capable of restricting the reactivity and reflects a distinct selection of a cell population that can be maintained throughout life because they are continuously exposed to antigen pressure. Either polyclonal or monoclonal profiles of B-cell expansion are demonstrable in the liver of most HCV-infected patients. The occurrence of B-cell clonal expansion is strictly related to intrahepatic production of RF molecules, and this suggests that liver is a microenvironment, other than lymphoid tissue, in which a germinal centerlike reaction is induced. The frequent detection of oligoclonal B-cell expansion may, indeed, represent a key pathobiologic feature that sustains nonmalignant B-cell lymphoproliferation. The preferential expansion of one clone would in turn lead to a monoclonal pattern that could favor stochastic oncogenic events. It can be postulated that HCV is the stimulus not only for the apparent benign lymphoproliferative process underlying a wide spectrum of clinical features, but also for the progression to frank lymphoid malignancy in a subgroup of patients. Current data indicate a higher prevalence of overt B-cell non-Hodgkin's lymphoma in HCV-infected patients, especially in some geographic areas.


Asunto(s)
Autoinmunidad/inmunología , Crioglobulinemia/inmunología , Hepacivirus/inmunología , Hepatitis C/inmunología , Hígado/inmunología , Linfoma de Células B/inmunología , División Celular , Crioglobulinemia/fisiopatología , Hepatitis C/fisiopatología , Humanos , Hígado/citología , Linfoma de Células B/etiología , Factor Reumatoide/biosíntesis
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