El nevus displásico (ND), factor de riesgo de melanoma maligno (MM), ha sido fuente de controversia en diferentes sentidos desde su descripción, desde el nombre asignado, los criterios clínicos e histológicos que la caracterizan hasta la gradación de los mismos en tres grados de atipia: leve, moderado y severo. Se ha evaluado en primer lugar si el grado de atipia de los ND tiene alguna relación con el riesgo de padecer melanoma mediante un estudio de datos clínicos y en segundo lugar, buscar un marcador que permita realizar una clasificación del grado de atipia de los nevus displásicos basada en criterios objetivos mediante el estudio de la expresión del marcador de proliferación Ki-67 y el marcador de migración ChAT (Acetil-colina transferasa).En la primera parte del estudio se revisaron los informes de 20.275 nevus recibidos entre 1989 y 1996, constatándose que 6.275 eran ND que pertenecían a 4.481 pacientes. Los pacientes fueron clasificados con respecto a su lesión con mayor grado de atipia y se revisó sus datos clínicos con respecto a la historia de melanoma. Se calculó la Odds Ratio (OR) como medida de asociación entre los grados de atipia de los ND e historia de melanoma. En la segunda parte del estudio se realizó estudio inmunohistoquímico con doble marcaje para HMB-45 y Ki-67 en 36 ND con atipia leve, 36 ND con atipia moderada, 36 ND con atipia severa, 18 nevus melanocíticos benignos (NMB) y 18 MM in-situ, evaluándose la proporción de células melanocíticas de la unión dermo-epidérmica positivas para Ki-67. Así mismo se realizó estudio inmunohistoquímico para ChAT en 30 ND con atipia leve, 30 con atipia moderada y 30 con atipia severa.Los resultados pusieron de manifiesto que 2.504 pacientes presentaban ND con atipia leve como nevus con mayor grado de atipia, 1.657 ND con atipia moderada y 320 ND con atipia severa. La revisión de sus datos clínicos puso de manifiesto que 142 pacientes del grupo de atipia leve, 133 pacientes del grupo con atipia moderada y 63 pacientes del grupo con atipia severa tenían historia de melanoma (c2= 59,89; p<0,001). El estudio de la asociación del grado de atipia con historia de melanoma dio como resultado una OR de 4,08 (2.91-5,7) para los ND con atipia severa versus ND con atipia leve, 2,81 (2-3,95) para los ND con atipia severa vs ND con atipia moderada y 1,45 (1,13-1,87) para ND con atipia moderada vs leve. El estudio inmunohistoquímico con doble marcaje con HMB-45 y Ki-67 mostraron diferencias significativas entre ND vs NMB vs MM (p<0,0001) y entre ND con atipia severa vs ND con atipia leve y moderada (p<0,0003). No se observaron diferencias significativas en el estudio mediante ChAT.En conclusión, la gradación de la atipia citológica de los ND se correlaciona con el riesgo de presentar historia de melanoma y el estudio del índice de proliferación Ki-67 puede ser de ayuda para diferenciar entre NMB, ND y MM, así como para distinguir entre ND con alto y bajo grado de atipia (leve y moderada). / Classification of the different aspects of dysplastic nevus (DN), a risk factor of malignant melanoma (MM), has been source of controversy from its decription, its assigned name and clinical and histological criteria, by which it is chacarcterized, to the ranking of the same into three grades of atypia: mild, moderate, and severe. In the first place, through a study of clinical data, it has been assessed if the grade of DN atypia has some relationship to the risk of suffering from MM; and, in the second place, through studies of the proliferation marker Ki-67 and the ChAT migration marker (acetyl choline transferase), a marker has been searched for, which will allow the classification of the grade of atypia for DN, based on objective criteria. In the first part of the study, reports on 20,275 nevi received between 1989 and 1996 were examined, verifiying that 6,275 of them were DN belonging to 4,481 patients. The patients were classified with respect to their lesions, having the greatest grade of atypia, and their clinical data was also examined, with respect to their history of melanoma. The Odds Ratio (OR) was calculated as a measure of association between the grades of DN aypia and the history of melanoma. In the second part of the study, an immunohistochemical study was conducted, with double staining for HMB-45 and Ki-67 on 36 DN with mild atypia, 36 DN with moderate atypia, 36 DN with severe atypia,18 BMN and 18 MM in-situ, evaluating the proportion of melanocytic cells in the dermo-epidermic junction, showing positive for Ki-67. In this way, an immunohistochemical study was also carried out for ChAT in 30 DN with mild atypia, 30 with moderate atypia and 30 with severe atypia.Results made clear that 2,504 patients presented DN with mild atypia as the highest presenting grade of atypia, 1,657 DN presented with moderate atypia, and 320 presented DN with severe grade of atypia. The review of the clinical data made clear that there were 142 patients in the group having mild atypia, 133 having moderate atypia, and 63 with sever atypia, who all had personal histories of MM (c2= 59,89; p<0,001). The study of the association of the grade of atypia with the history of MM gave as its result an OR of 4.08 (2.91-5.7) for the DN with severe atypia: DN with mild atypia; 2.81 (2-3.95) for the DN with severe atypia: DN with moderate atypia; and 1.45 (1.13-1.87) for DN with moderate atypia : DN with mild atypia. The immunohistochemical study with double staining for HMB-45 and Ki-67 showed significant differences between DN:BMN:MM (p<0.0001) and between DN with severe atypia : DN with mild and moderate atypia (p<0.0003). No significant differences were observed in the study using ChAT. In conclusion, the ranking of the cytological atypia of DN is correlated to the risk of presenting a history of melanoma, and the study of the proliferation rate of Ki-67 can help in the differentiation between BMN, DN, and MM, such as between DN with severe and mild+moderate atypia.

La incidencia del melanoma cutáneo va en aumento en un gran número de países. El diagnóstico precoz es muy importante, ya que el tratamiento más eficaz para el melanoma es la escisión tumoral.La biopsia del ganglio centinela (BGC) es una técnica bien establecida y una herramienta útil para el estadiaje y manejo de pacientes con melanoma maligno cutáneo. La BGC, introducida por Morton y colaboradores, es un procedimiento implantado en múltiples centros, permitiendo el estadiaje anatomopatológico de los ganglios linfáticos regionales.El ganglio centinela (GC) presenta metástasis de melanoma en el 20% de los pacientes con esta patología. En nuestro estudio, la biopsia de ganglio centinela fue positiva en catorce pacientes (28%).Sin embargo, la selección de pacientes para la realización de la biopsia de ganglio centinela y la linfadenectomía selectiva en caso de BGC positiva son temas controvertidos.Recientemente, el Comité Americano sobre Cáncer (AJCC) ha modificado los criterios de estadiaje de los pacientes con melanoma y recomienda la biopsia de ganglio centinela en la mayoría, dado que las metástasis ganglionares microscópicas representan el principal factor predictivo de la supervivencia.Por este motivo, en esta tesis se han recogido las diferentes variables que se han ido identificando en la literatura como predictivas de la supervivencia y de la afectación metastásica de los ganglios linfáticos regionales de esta neoplasia, en un intento de conocer su capacidad de predecir la afectación metastásica en el ganglio centinela. El objetivo de este estudio es desarrollar un modelo pronóstico, basado en datos clínicos del paciente y en características histológicas e inmunohistoquímicas del melanoma primario para evaluar la probabilidad de micrometástasis en GC en estos pacientes. Para ello, esta tesis incluye 50 pacientes sometidos a biopsia de ganglio centinela entre Enero de 1.999 y Agosto de 2.005. Las variables clínicas analizadas han sido la edad, el sexo y la localización del melanoma primario.La evaluación histológica del tumor primario ha incluido características histopatológicas como: Índice de Breslow, nivel de invasión de Clark, fase de crecimiento, tipo de melanoma, índice mitósico, ulceración, invasión vascular angiolinfática, inflamación linfocitaria peritumoral, signos de regresión, neurotropismo, microsatelitosis, afectación anexial y restos de nevus.La expresión de marcadores de diferenciación melanocítica (HMB45, Melan A) y de marcadores de progresión (ki67, p53, p16) se han determinado por técnicas inmunohistoquímicas.El examen histológico del ganglio centinela se ha realizado tras tinción de hematoxilina-eosina e inmunohistoquímica (HMB45).El análisis estadístico ha demostrado que el Índice de Breslow (P=0,019), el índice mitósico (P=0,033) y el porcentaje de ki67 (P=0,022) son factores predictivos independientes de la presencia de metástasis en ganglio centinela. Nuestros datos apoyan la relevancia conocida del espesor de Breslow como el principal factor a considerar en la selección de los pacientes para la realización de la BGC.La utilización de la BGC en pacientes con melanomas delgados (Índice de Breslow ? 1,0 mm) no se realiza de manera rutinaria. Aunque en el presente trabajo ninguna variable estudiada ayuda a predecir la presencia de metástasis de melanoma en GC en el subgrupo de melanomas delgados, consideramos que se han de continuar investigando diferentes factores de riesgo que puedan predecir la positividad del ganglio centinela en este grupo. Si bien nuestro estudio no ha demostrado una asociación de las otras variables analizadas con el resultado de la biopsia de ganglio centinela, el reducido tamaño muestral de este trabajo puede contribuir a que alguna asociación detectada no haya alcanzado la significación estadística, requiriéndose de la replicación del mismo con mayor número de casos. / Melanoma incidence is rising worlwide. Early diagnosis is very important, as the most effective treatment for melanoma still consists of excision of the tumor before onset of the metastatic phase.Sentinel lymph node biopsy is a well-established technique and a precise tool for staging and managing patients with cutaneous malignant melanoma. Introduced by Morton and colleagues, the sentinel lymph node biopsy procedure is now widely available, and marked enhances our ability to pathologically stage the regional nodes.The sentinel node is the site of metastatic melanoma in approximately 20% of melanoma patients. In our study, sentinel node biopsy was positive for tumor in fourteen patients (28%). It is customary to perform a complete dissection of the regional lymph nodes if tumor is present in the sentinel node. But, the selection of patients for sentinel lymph node biopsy and selective lymphadenectomy for histologically positive sentinel lymph nodes are areas of debate. The American Joint Committee on Cancer has recently modified staging criteria for primary melanoma patients and recommends sentinel lymph node biopsy in many, because microscopic nodal metastasis represents the most important factor predicting survival.Because sentinel node status is the most important prognostic factor for melanoma, this analysis was performed to determine if sentinel lymph node dissection status can be predicted using other prognostic factors. The objective of this study is to develop a prognostic model, based on clinical and primary tumor histological and immunohistochemical characteristics, to estimate the probability of micrometastasis in the sentinel lymph node in patients with malignant melanoma.To correlated pathological features in melanoma with sentinel node metastasis this study includes and reviews patients submitted to sentinel node biopsy between January 1999 and August 2005.A total of 50 patients are evaluated in the statistical analysis. Reported clinical, histological and immunohistochemical features are assessed for predictive value by univariate and multivariate logistic regression.Clinical attributes recorded include age, sex and location of the primary melanoma.Histological evaluation of the primary tumor include histopathologic characteristics, some of then are historically been associated with an increased risk of recurrence and mortality like: Breslow thickness, Clark's level of invasion, growth phase, type of melanoma, mitotic rate, ulceration, angiolymphatic invasion, tumor infiltrating lymphocytes, regression, neurotropism, microsatellites, anexial involvement and pre-existing nevus.Expression of melanocytic differentiation markers (HMB45, Melan A), and melanoma progression markers (ki67, p53, p16) were assessed by immunohistochemistry.Histological examination of sentinel node consisted of hematoxylin-eosin and immunohistochemical staining (HMB45).Statistical analysis shows that Breslow thickness (P=0,019), mitotic rate (P=0,033) and ki67 (P=0,022) are found to be independently predictive of the presence of sentinel node metastasis. Our data supports the known relevance of Breslow thickness as the main factor considered in the selection of patients to be submitted to SLN biopsy.Although the use of this technique (sentinel node biopsy) in patients with thin melanomas (Breslow thickness ? 1,0 mm) is not rutine, risk factors that may predict sentinel lymph node positivity in this patient population are under investigation. Although the present study is unable to identify predictors of metastatic involvement in patients with thin melanoma, efforts to identify predictors of SN tumor involvement should continue.The published data are not sufficient to demonstrate a correlation between the other indicators included and a positive sentinel lymph node biopsy, but the cohort size (small sample size) may lack the statistical power to demonstrate subtle associations. So, the predictive value of some variables for positivity needs to be validated in other populations of melanoma patients.

Las metástasis, diseminación y crecimiento de las células tumorales en órganos distantes, representan el aspecto más peligroso y devastador en el melanoma de úvea. A pesar de los avances en el diagnóstico, técnicas quirúrgicas y terapias adyuvantes, la aparición de metástasis sigue siendo la principal causa de muerte en los pacientes con melanoma de úvea. Hasta un 50% de los pacientes morirán a los 10 años del diagnóstico inicial debido a la aparición de metástasis, principalmente en el hígado. A lo largo de las últimas décadas se han identificado varios parámetros pronósticos metastásicos, clínicos e histopatológicos. Actualmente, las principales líneas de investigaciones se centran en el análisis de las alteraciones genéticas y moleculares que puedan estar asociadas al desarrollo de metástasis en melanoma de úvea y permitan establecer de forma precoz los genotipos-fenotipos más agresivos así como desarrollar nuevas alternativas terapéuticas.Las quimiocinas constituyen un grupo de moléculas de bajo peso molecular con propiedades quimioatrayentes implicadas en un gran número de procesos fisiológicos y patológicos. Se ha visto que en un gran número de neoplasias existe un entramado de quimiocinas y sus receptores cuya producción, expresión y señalización se encuentra alterada. La quimiocina CXCL12, también llamada stromal-derived factor-1(SDF-1), y su receptor transmembrana CXCR4 son un ejemplo de ello. La interacción entre ambas proteínas desencadena diversas funciones biológicas dentro del proceso cancerígeno, tanto a nivel del tumor primario como en la cascada metastásica. Su presencia ha demostrado ser imprescindible para la proliferación y supervivencia celular, la angiogénesis, la adhesión e invasión tumoral y la migración selectiva hacia el hígado de las células metastásicas en un gran número de neoplasias, relacionándose su expresión con una mayor malignidad tumoral y una menor supervivencia de los pacientes.En la presente estudio, se examinará por primera vez la expresión de CXCR4 y CXCL12 en especimenes de melanomas malignos de úvea sugiriendo la posibilidad de que, al igual que en otras neoplasias, las células melanocíticas malignas estén utilizando la unión quimiocina-receptor para promover el crecimiento tumoral local así como estimular la formación de focos metastáticos a distancia. Para ello, también se intentará establecer una correlación del grado de expresión de CXCR4 y CXCL12 con la aparición de metástasis y la supervivencia de los pacientes. Y por último se analizará la relación existente entre la expresión de CXCR4 y CXCL12 y otras variables clínicopatológicas de mal pronóstico conocidas como son la edad, sexo, tipo celular, presencia de círculos vasculares cerrados e infiltración linfocitaria tumoral.

Feature extraction of segmented skin lesions is a pivotal step for implementing accurate decision support systems. Existing feature sets combine many ad-hoc calculations and are unable to easily provide intuitive diagnostic reasoning. This thesis presents the design and evaluation of a set of features for objectively detecting melanoma in an intuitive and accurate manner. We call these "high-level intuitive features" (HLIFs). The current clinical standard for detecting melanoma, the deadliest form of skin cancer, is visual inspection of the skin's surface. A widely adopted rule for detecting melanoma is the "ABCD" rule, whereby the doctor identifies the presence of Asymmetry, Border irregularity, Colour patterns, and Diameter. The adoption of specialized medical devices for this cause is extremely slow due to the added temporal and financial burden. Therefore, recent research efforts have focused on detection support systems that analyse images acquired with standard consumer-grade camera images of skin lesions. The central benefit of these systems is the provision of technology with low barriers to adoption. Recently proposed skin lesion feature sets have been large sets of low-level features attempting to model the widely adopted ABCD criteria of melanoma. These result in high-dimensional feature spaces, which are computationally expensive and sparse due to the lack of available clinical data. It is difficult to convey diagnostic rationale using these feature sets due to their inherent ad-hoc mathematical nature. This thesis presents and applies a generic framework for designing HLIFs for decision support systems relying on intuitive observations. By definition, a HLIF is designed explicitly to model a human-observable characteristic such that the feature score can be intuited by the user. Thus, along with the classification label, visual rationale can be provided to further support the prediction. This thesis applies the HLIF framework to design 10 HLIFs for skin cancer detection, following the ABCD rule. That is, HLIFs modeling asymmetry, border irregularity, and colour patterns are presented. This thesis evaluates the effectiveness of HLIFs in a standard classification setting. Using publicly-available images obtained in unconstrained environments, the set of HLIFs is compared with and against a recently published low-level feature set. Since the focus is on evaluating the features, illumination correction and manually-defined segmentations are used, along with a linear classification scheme. The promising results indicate that HLIFs capture more relevant information than low-level features, and that concatenating the HLIFs to the low-level feature set results in improved accuracy metrics. Visual intuitive information is provided to indicate the ability of providing intuitive diagnostic reasoning to the user.

DE LA TESIS:Se trata de un estudio observacional no controlado, de 120 pacientes afectos de melanoma uveal, tratados todos ellos con braquiterapia con semillas de Yodo-125, a los que se les ha efectuado un seguimiento desde el punto de vista oftalmológico, durante al menos un año. El objetivo principal de la tesis fue determinar los factores que influyen en la evolución de la agudeza visual tras la aplicación de dicho tratamiento, y la descripción de un modelo matemático que pueda explicar la evolución de dicha variable clínica oftalmológica.Tras la finalización del estudio, se observó que la pérdida de agudeza visual de forma significativa está en relación con las variables: dosis administrada en la mácula, dosis administrada en el cristalino y tiempo de seguimiento tras el tratamiento. Esta relación se concreta en la fórmula siguiente:AV final= Av basal+Tiempo+Dosis Mácula+Dosis mácula*Tiempo

No description available.

Melanoma is a cancer of the pigment producing cells, melanocytes, and is the most serious type of skin cancer. Cancer is a condition in which one type of cell grows without limit in a disorganized fashion, disrupting and replacing normal tissues and their functions. Normal melanocytes reside in the outer layer of the skin and produce a brown pigment called melanin, which is responsible for skin color. Melanoma occurs when melanocytes become cancerous, grow, and invade other tissues. Pro-opiomelanocortin (POMC) is a precursor polypeptide of 241 amino acids and the prohormone of various neuropeptide, including corticotropin (ACTH), £\-melanocyte-stimulating hormone (£\-MSH), and £]-endorphin (£]-EP). Recently, we demonstrated that systemic POMC overexpression potently suppresses the growth and metastasis of B16-F10 melanoma in vitro and in vivo. However, despite potent inhibition of tumor proliferation and angiogenesis, B16-F10 melanoma still managed to survive after POMC gene therapy. The underlying survival mechanism of B16-F10 melanoma remains unclear. Microphthalmia-associated transcription factor (MITF) is a basic helix-loop-helix transcription factor that plays a key role not only in melanin synthesis, but also in melanocyte development and survival. Besides, MITF binds to the hypoxia-inducible factor-1£\ (HIF-1£\) promoter to stimulate its transcriptional activity. In this study, we investigate the influence of POMC gene delivery on the pro-survival MITF/HIF-1£\ pathway in B16-F10 melanoma cells. Quantitative RT-PCR and western blot analysis revealed that POMC gene delivery increased the MITF mRNA and protein level in B16-F10 melanoma cells. Besides, POMC gene delivery significantly enhanced the HIF-1£\-driven luciferase activities in melanoma cells. By transfection and puromycin selection, we generated and characterized a MITF-knockdown B16-F10 melanoma cells (MITF KD) stably expressing short hairpin RNA against MITF. The growth, invasion, and colonies formation of MITF-KD were similar to those of vector control. However, implantation of MITF-KD cells led to melanoma with significantly reduced tumor size compared with those in mice implanted with vector control cells. Histological analysis revealed a significant reduction of CD31-positive blood vessels in implantation of MITF-KD cells-treated tumors, which was accompanied with a decrease in Ki-67-positive proliferating cells and an increase in TUNEL-positive apoptotic cells. Moreover, POMC-mediated upregulation of MITF and HIF-1 £\ was significantly attenuated in MITF KD-B16-F10 cells. Acetylsalicylic acid (aspirin; ASA) is widely used as an analgesic/antipyretic drug. ASA exhibits a wide range of biological effects, including preventative effects against heart attack, stroke, and the development of some types of cancer. In our study, we found ASA enhanced cell proliferation. However, in invasion test, ASA had no effect on cell migration. POMC gene delivery elevated the mRNA and protein level of hemeoxygenase-1 (HO-1), a downstream effector of HIF-1£\ pathway and an enzyme catalyzing the converting reaction of heme to carbon monoxide, ion and biliverdine. Inhibition of HO-1 activities augmented the inhibitory effect of POMC gene delivery on proliferation, migration and anchorage-independent growth of B16-F10 melanoma cells. These studies indicated that activation of MITF/HIF-1£\/HO-1 indeed contributes to melanoma survival after POMC gene delivery.

An experienced dermatopathologist can reliably diagnose most cutaneous malignant melanomas based on well-established morphologic characteristics. However, in a minority of cases, traditional histopathologic evaluation and immunohistochemistry (IHC) are inadequate to confidently distinguish melanoma from benign melanocytic lesions such as Spitz nevi and dysplastic nevi. The advent of high-throughput gene expression array technology has resulted in the identification of hundreds of potential molecular diagnostic biomarkers, but no single chromosomal, DNA, RNA or protein marker has yet been shown to differentiate melanoma from nevus with sensitivity and specificity approaching 100%. We selected the protein products of 11 genesATP1B1, CYCLIN D1, DLX-1, HOXB13, LIF, MEIS2, MITF, MYC, PHACTR1, PTPRF and TWISTup-regulated in melanoma cell-culture and tissue-based expression arrays as candidate diagnostic biomarkers for preliminary investigation. Based on the results of our pilot studies, we proposed that increased expression of Phactr1 protein, as measured by IHC, could be used to differentiate malignant melanomas from nevi. We applied Phactr1 monoclonal antibody to a 480-core tissue microarray that included samples from 28 nevi and 62 primary melanomas. A simple scoring algorithm derived from this data distinguished primary melanoma from nevus in the training set with 92% sensitivity and 100% specificity. These data suggest that Phactr1 immunohistochemical staining is a potentially useful aid in the clinical diagnosis of primary cutaneous melanoma.

Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves 153-156). Also available on the Internet.

Thesis (M.S. in Applied Physics)--Naval Postgraduate School, December 2009. / Thesis Advisor(s): Karunasiri, Gamani. Second Reader: Smith, Craig. "December 2009." Description based on title screen as viewed on January 28, 2010. Author(s) subject terms: Zinc Selenide, photodetectors, ultraviolet, Schottky, responsivity, current-voltage, depletion region, bandgap, melanoma, dark current, forward biased, reverse biased. Includes bibliographical references (p. 39-40). Also available in print.