Presentación clínica de pigmentación melánica fisiológica / Clinical presentation of physiologic melanin pigmentation

Las pigmentaciones de la cavidad oral son comunes, éstas pueden representar diversas entidades clínicas, desde cambios fisiológicos hasta cambios malignos. Las pigmentaciones en la encía se conocen como pigmentaciones melánicas o melanosis gingival; en la encía se observan como tinciones oscuras ocasionadas por la acumulación de melanina en la zona. Éstas se consideran comunes, pueden representar variación normal en la pigmentación de melanina de la mucosa oral, hasta representar procesos malignos. En general, las personas de piel más oscura presentan frecuentemente mayor pigmentación de melanina oral que las personas de piel clara. Las variaciones en la pigmentación fisiológica oral están determinadas genéticamente a menos que estén asociadas con alguna enfermedad subyacente (AU)

Pigmentation of the oral cavity is common, it can represent diverse clinical entities, from physiological changes to malignant changes. Gum pigmentations are known as melanic pigmentations or gingival melanosis, and are observed as dark stains caused by the accumulation of melanin in the localized area. These are considered common, they can represent normal variation in melanin pigmentation of the oral mucosa, or malignant processes. In general, people with darker skin often exhibit greater pigmentation of oral melanin than people with fair skin. Variations in oral physiological pigmentation are genetically determined unless they are associated with some underlying disease (AU)

Aparición de melanina como pigmento protector en el encéfalo de xenopus laevis para protegerlo de los efectos de la radiación ultravioleta / Emerging melanin protective pigment in the brain of xenopus laevis to protect from the effects of uv radiation

Con el fin de proteger al organismo de condiciones estresantes, tales como cambios de osmolaridad y de temperatura, además de actuar como pantalla protectora en contra de los rayos ultravioleta (UV). Se ha observado que ciertos anfibios han desarrollado pigmentación en su encéfalo como una posible protección ante el aumento de la radiación UV, causada por el daño en la capa de ozono, la cual estaría alterando al ecosistema. En este trabajo se describe la presencia de pigmentación en el encèfalo de X. laevis durante el desarrollo larvario y su posible función protectora frente a la radiación UV. Para ello, se recolectaron individuos de diferentes estados larvarios, los que fueron obtenidos de distintas localidades de la región de Valparaíso (V región, Chile), para ser procesados con el método corriente H-E y el método de Lillie. En los análisis se pudo evidenciar que la pigmentación correspondía a melanina, que se encontraría en la membrana denominada leptomeninge, la cual recubre al encéfalo y estaría actuando como un filtro protector para evitar daños a nivel del desarrollo en el sistema nervioso de estos anuros. En suma, los rayos UV como agentes deletéreos estarían estimulando la producción de eumelanina en la leptomeninge de estos anfibios, para proteger parte del SNC (encéfalo), como al individuo en sí de posibles alteraciones teratogénicas y/o mutagénicas.

It has been observed that certain amphibians have developed pigmentation in brain as a possible increased protection against UV radiation, caused by damage to the ozone layer, which would alter the ecosystem. In this paper we describe the presence of pigment in the brain of X. laevis during larval development and possible protective function against UV radiation. To do this, we collected individuals at various larval stages, which were obtained from different locations in Valparaiso (V Region, Chile), to be processed with HE and the method of Lillie. In the analysis it was evident that pigmentation corresponded to melanin, which would be in the membrane called leptomeninges, which covers the brain and would be acting as a protective filter to prevent damage to the level of development in the nervous system of these frogs. In addition, UV rays would be deleterious agents stimulating production of eumelanin in the leptomeninges of these amphibians, to protect the CNS (brain), and the individual itself of potential teratogenic or mutagenic alterations.

Microglia, major player in the brain inflammation: their roles in the pathogenesis of Parkinson's disease

Inflammation, a self-defensive reaction against various pathogenic stimuli, may become harmful self-damaging process. Increasing evidence has linked chronic inflammation to a number of neurodegenerative disorders including Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis. In the central nervous system, microglia, the resident innate immune cells play major role in the inflammatory process. Although they form the first line of defense for the neural parenchyma, uncontrolled activation of microglia may directly toxic to neurons by releasing various substances such as inflammatory cytokines (IL-1beta, TNF-alpha, IL-6), NO, PGE

Treatment of gingival pigmentation: a case series.

A smile expresses a feeling of joy, success, sensuality, affection and courtesy, and reveals self confidence and kindness. The harmony of the smile is determined not only by the shape, the position and the color of the teeth but also by the gingival tissues. Gingival health and appearance are essential components of an attractive smile. Gingival pigmentation results from melanin granules, which are produced by melanoblasts. The degree of pigmentation depends on melanoblastic activity. Although melanin pigmentation of the gingiva is completely benign and does not present a medical problem, complaints of 'black gums' are common particularly in patients having a very high smile line (gummy smile). For depigmentation of gingiva different treatment modalities have been reported like- Bur abrasion, scraping, partial thickness flap, cryotherapy, electrosurgery and laser. In the present case series bur abrasion, scraping, partial thickness flap (epithelial excision) cryotherapy and electrosurgery have been tried for depigmentation, which are simple, effective and yield good results, along with good patient satisfaction. The problems encountered with some of these techniques have also been discussed.

El color del pelo como marcador cutáneo / Hair color as \"cutaneous marker\"

Se hace una revisión de los cambios de color del pelo así como de sus mecanismos fisiopatogénicos. Se mencionan las causas genéticas y adquiridas, así como metabólicas e inmunológicas, por fármacos y ambientales

Tratamiento de la melanosis del tejido gingival por la técnica de mucoabrasión / Treatment of melanosis of the gingival tissue by the muco-abrassion technique

Se realizaron 54 tratamientos de eliminación melánica fisiológica gingival; 10 pacientes mostraron repigmentación clínica leve al término de un año del tratamiento. Ocho de estos individuos resultaron ser fumadores crónicos. El método mucoabrasivo es una técnica quirúrgica sencilla sin grandes riesgos; se trató la región anterosuperior e inferior debido a que es el área de la sonrisa y afecta estética y psicológicamente.

Histopathology of vitiligo

A total of twenty one patients with vitiligo was studied, shave biopsies were taken both from early lesion [stage I] and late lesions [stage II] of depigmentation. Haematoxilin Eosin and Fontana stains were carried out on all sections. Melanin pigment was found in the basal layer of the epidermis in stage I with either very slight reduction or partial absence while there was almost complete absence of melanin in stage II of the disease. The histopathology showed marked inflammatory response mainly lymphocytic perivascular infiltrate in the dermis with epidermal invasion. These changes were more intense in stage I. Also there was perifollicular lymphocytic infiltrate with invasion into the follicular wall