Search results for "Depigmentation"

Evaluation of genetic melanoma vaccines in cdk4-mutant mice provides evidence for immunological tolerance against authochthonous melanomas in the skin

2005

We evaluated the efficacy of a candidate melanoma vaccine approach in mice genetically prone to develop melanoma due to the introduction of an oncogenic mutation (R24C) in the germline sequence of the cyclin-dependent kinase 4 (cdk4), a protein critically involved in cell cycle regulation. Melanomas were induced in cdk4-mutant mice by chemical carcinogenesis and UVB irradiation. A genetic prime-boost strategy targeting the clinically relevant differentiation antigen tyrosinase-related protein 2 (TRP2) was performed which was able to stimulate a melanocyte-specific cellular immune response associated with localized autoimmune vitiligo-like depigmentation. However, significant destruction of …

2014

Purpose The removal of excessive melanin pigments that obscure ocular tissue morphology is important to address scientific questions and for differential diagnosis of ocular tumours based on histology. Thus, the goal of the present study was to establish an effective and fast melanin bleaching method for paraffin and frozen mouse and human ocular tissues. Methods Paraffin-embedded and frozen ocular specimens from mice and human donors were subjected to bleaching employing two methods. The first employed potassium permanganate (KMnO4) with oxalic acid, and the second 10% hydrogen peroxide (H2O2). To determine optimal bleaching conditions, depigmentation was carried out at various incubation …

Progressive depigmentation of a melanocytic lesion: a dermoscopic challenge for melanoma diagnosis.

2013

Baicalin and berberine ultradeformable vesicles as potential adjuvant in vitiligo therapy.

2018

0.5-1% of the world's population is affected by vitiligo, a disease characterized by a gradual depigmentation of the skin. Baicalin and berberine are natural compounds with beneficial activities, such as antioxidant, anti-inflammatory and proliferative effects. These polyphenols could be useful for the treatment of vitiligo symptoms, and their efficacy can be improved by loading in suitable carriers. The aim of this work was to formulate and characterize baicalin or berberine loaded ultradeformable vesicles, and demonstrate their potential as adjuvants in the treatment of vitiligo. The vesicles were produced using a previously reported simple, scalable method. Their morphology, size distrib…

Descriptive Dermoscopic Study of Depigmentation in Melanocytic Nevi Without a Visible Halo

2011

Background and objectives: There are few cases described in the literature in which depigmentation of melanocytic nevi occurs without the appearance of halos. The aim of this study was to analyze the correlation between clinical and dermoscopic findings and to assess the usefulness of dermoscopy to identify possible markers of complete regression in melanocytic lesions. Materials and methods: A prospective, observational, descriptive study of 77 melanocytic lesions in 52 patients was undertaken over a 5-year period. Melanocytic lesions from patients who underwent periodic follow-up in the digital dermoscopy unit were analyzed if they had exhibited partial or total, permanent depigmentation …

Znaczenie roślinnych i syntetycznych składników aktywnych we wspomaganiu procesu depigmentacji skóry

2021

Melanogenesis is a process catalyzed by tyrosinase enzyme leading to synthesis of two types of pigment in the skin: black-brown eumelanin and red-yellow pheomelanin. Pheomelanin is synthesized in the second stage of melanosome maturation, while eumelanin-synthesizing melanosomes are inactive. The black-brown pigment is produced in the third stage of melanosome development. The last, fourth stage of melanosome maturation is characterized by low tyrosinase activity, which reflects the low pigment production in the skin. The process of skin pigment production (melanogenesis) is mainly regulated by solar radiation, hormones and other endo- and exogenous factors. Over- stimulated melanogenesis l…