Melanin granule model for heating of tissue by laser

1994 ◽  
Author(s):  
Charles R. Thompson
Keyword(s):  
Melanin Granule

scholarly journals Electron Microscope Observations of the Melanocyte of the Human Epidermis

1959 ◽  
Vol 6 (1) ◽  
pp. 41-44 ◽  
Author(s):  
Arwyn Charles ◽  
John T. Ingram
Keyword(s):  
Electron Microscope ◽  
Local Anaesthesia ◽  
Human Epidermis ◽  
Melanin Granule ◽  
Cytoplasmic Matrix ◽  
Pigment Granules ◽  
Human Biopsy

Using standard osmium fixation and methacrylate embedding techniques, a study has been made of the melanocyte of human biopsy skin removed under general and local anaesthesia. Melanogenesis was easily observable in the melanocytes, but immature pigment granules were rarely seen in the Malpighian cells. The passage of melanin from melanocyte to Malpighian cell—cytocrine secretion—is thought to have been observed. Phagocytes near the dermal-epidermal junction seem to have their pigment granules in vacuoles, rather than surrounded directly by the cytoplasmic matrix as in the melanocytes. This, together with the failure to observe "effete" melanocytes, prompts the suggestion that the phagocytes are melanocytes which have migrated from the epidermis into the dermis. A melanin granule is shown with alternating dark and lighter transverse striations, concerning which structure little can at present be said.

Melanin granule model for laser-induced thermal damage in the retina

1996 ◽  
Vol 58 (3) ◽  
pp. 513-553 ◽  
Author(s):  
C. R. Thompson ◽  
B. S. Gerstman ◽  
S. L. Jacques ◽  
M. E. Rogers
Keyword(s):  
Thermal Damage ◽  
Melanin Granule

scholarly journals Melanin granule model for laser-induced thermal damage in the retina

1996 ◽  
Vol 58 (4) ◽  
pp. 809-810 ◽  
Author(s):  
C. R. Thompson ◽  
B. S Gerstman ◽  
S. L. Jacques ◽  
M. E. Rogers
Keyword(s):  
Thermal Damage ◽  
Melanin Granule

scholarly journals Interaction of Melanin with Metal Ions Modulates Their Cytotoxic Potential

2021 ◽  
Author(s):  
Tadeusz Sarna ◽  
Harold M. Swartz ◽  
Andrzej Zadlo
Keyword(s):  
Metal Ions ◽  
Biological Function ◽  
Melanin Granule ◽  
Redox Activation ◽  
Redox Active ◽  
Active Metal ◽  
Physicochemical Methods ◽  
Catalyzed Reactions ◽  
Enzyme Catalyzed Reactions ◽  
Redox Active Metal

AbstractMelanin is one the most common biological pigments. In humans, specialized cells called melanocytes synthesize the pigment from tyrosine and 3,4-dihydroxyphenylalanine via enzyme-catalyzed reactions and spontaneous processes. The formed melanin granule consists of nanoaggregates of oligomers containing different monomers. Although the main biological function of melanin is protection against damage from solar radiation, melanin may also be involved in protection against oxidative stress. In the latter function, sequestration of redox-active metal ions and scavenging of reactive oxygen species are of importance. The paper reviews basic physicochemical properties of melanin responsible for binding of metal ions and discusses specific conditions that may induce cytotoxicity of metal ions such as iron and copper by facilitating their redox activation and release from melanin. While the value of EPR spectroscopy and other EPR-related techniques for the study of melanin is emphasized, the concomitant use of other physicochemical methods is the most efficient approach.

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