scholarly journals A Strange Mosaic-Like Skin Pigmentation in a 2-Year-Old Child

2021 ◽  
pp. e2021135
Author(s):  
Linda Tognetti ◽  
Davide Cosetti ◽  
Pietro Rubegni
Keyword(s):  
Author(s):  
Raul I. Garcia ◽  
Evelyn A. Flynn ◽  
George Szabo

Skin pigmentation in mammals involves the interaction of epidermal melanocytes and keratinocytes in the structural and functional unit known as the Epidermal Melanin Unit. Melanocytes(M) synthesize melanin within specialized membrane-bound organelles, the melanosome or pigment granule. These are subsequently transferred by way of M dendrites to keratinocytes(K) by a mechanism still to be clearly defined. Three different, though not necessarily mutually exclusive, mechanisms of melanosome transfer have been proposed: cytophagocytosis by K of M dendrite tips containing melanosomes, direct injection of melanosomes into the K cytoplasm through a cell-to-cell pore or communicating channel formed by localized fusion of M and K cell membranes, release of melanosomes into the extracellular space(ECS) by exocytosis followed by K uptake using conventional phagocytosis. Variability in methods of transfer has been noted both in vivo and in vitro and there is evidence in support of each transfer mechanism. We Have previously studied M-K interactions in vitro using time-lapse cinemicrography and in vivo at the ultrastructural level using lanthanum tracer and freeze-fracture.


JAMA ◽  
1965 ◽  
Vol 194 (6) ◽  
pp. 670-672 ◽  
Author(s):  
A. S. Zelickson
Keyword(s):  

2020 ◽  
Vol 19 (7) ◽  
pp. 712-717 ◽  
Author(s):  
Hawasatu Dumbuya ◽  
Pearl Grimes ◽  
Stephen Lynch ◽  
Kalli Ji ◽  
Manisha Brahmachary ◽  
...  

2020 ◽  
Vol 27 ◽  
Author(s):  
Mohammad Kashif Iqubal ◽  
Aiswarya Chaudhuri ◽  
Ashif Iqubal ◽  
Sadaf Saleem ◽  
Madan Mohan Gupta ◽  
...  

: At present, skin cancer is a widespread malignancy in human beings. Among diverse population types, Caucasian populations are much more prone in comparison to darker skin populations due to the comparative lack of skin pigmentation. Skin cancer is divided into malignant and non-melanoma skin cancer, which is additionally categorized as basal and squamous cell carcinoma. The exposure to ultraviolet radiation, chemical carcinogen (polycyclic aromatic hydrocarbons, arsenic, tar, etc.), and viruses (herpes virus, human papillomavirus, and human T-cell leukemia virus type-1) are major contributing factors of skin cancer. There are distinct pathways available through which skin cancer develops, such as the JAKSTAT pathway, Akt pathway, MAPKs signaling pathway, Wnt signaling pathway, to name a few. Currently, several targeted treatments are available, such as monoclonal antibodies, which have dramatically changed the line of treatment of this disease but possess major therapeutic limitations. Thus, recently many phytochemicals have been evaluated either alone or in combination with the existing synthetic drugs to overcome their limitations and have found to play a promising role in the prevention and treatment. In this review, complete tracery of skin cancer, starting from the signaling pathways involved, newer developed drugs with their targets and limitations along with the emerging role of natural products alone or in combination as potent anticancer agents and their molecular mechanism involved has been discussed. Apart from this, various nanocargos have also been mentioned here, which can play a significant role in the management and treatment of different types of skin cancer.


Nutrients ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1071
Author(s):  
Toshihiko Shoji ◽  
Saeko Masumoto ◽  
Nina Moriichi ◽  
Yasuyuki Ohtake ◽  
Tomomasa Kanda

This clinical study was performed to evaluate the effects of continuous apple polyphenol (AP) administration on facial skin conditions and pigmentation induced by ultraviolet (UV) irradiation in healthy women participants. Participants (n = 65, age 20–39 years) were randomized to receive tablets containing AP (300 or 600 mg/day) or placebo in a double-blinded, placebo-controlled clinical trial. Continuous administration of AP for 12 weeks significantly prevented UV irradiation induced skin pigmentation (erythema value, melanin value, L value), although a dose-dependent relationship was not clearly observed. In contrast, no significant differences were detected between the groups with regard to water content and trans-epidermal water loss. Our study demonstrated that APs and their major active compounds, procyanidins, have several health benefits. Here, we report that continuous administration of AP for 12 weeks alleviated UV irradiation induced skin pigmentation, when compared with placebo, in healthy women.


2020 ◽  
Vol 21 (24) ◽  
pp. 9769
Author(s):  
Saaya Koike ◽  
Kenshi Yamasaki

The epidermis is located in the outermost layer of the living body and is the place where external stimuli such as ultraviolet rays and microorganisms first come into contact. Melanocytes and melanin play a wide range of roles such as adsorption of metals, thermoregulation, and protection from foreign enemies by camouflage. Pigmentary disorders are observed in diseases associated with immunodeficiency such as Griscelli syndrome, indicating molecular sharing between immune systems and the machineries of pigment formation. Melanocytes express functional toll-like receptors (TLRs), and innate immune stimulation via TLRs affects melanin synthesis and melanosome transport to modulate skin pigmentation. TLR2 enhances melanogenetic gene expression to augment melanogenesis. In contrast, TLR3 increases melanosome transport to transfer to keratinocytes through Rab27A, the responsible molecule of Griscelli syndrome. TLR4 and TLR9 enhance tyrosinase expression and melanogenesis through p38 MAPK (mitogen-activated protein kinase) and NFκB signaling pathway, respectively. TLR7 suppresses microphthalmia-associated transcription factor (MITF), and MITF reduction leads to melanocyte apoptosis. Accumulating knowledge of the TLRs function of melanocytes has enlightened the link between melanogenesis and innate immune system.


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