ABSTRACT
The bioactive sphingolipid metabolite sphingosine 1-phosphate (S1P), recently was reported to induce apoptosis of some cancer cells and neurons, although it generally known to exert mitogenic and antiapoptotic effects. In this study, we investigated the effects of S1P on the cell growth, melanogenesis, and apoptosis of cultured B16 mouse melanoma cells. In results, S1P was found to induce apoptosis in B16 melanoma cells in a dose- and time-dependent manner, but exerted minimal effects on melanogenesis. Although receptors of sphingosine 1-phosphate (endothelial differentiation gene 1 [Edg]/S1P1, Edg5/S1P2, Edg3/S1P3) were expressed in B16 melanoma cells, they were shown not to be associated with S1P-induced apoptosis. In addition, pertussis toxin did not block the apoptotic effects of S1P on B16 melanoma cells. S1P induced caspase-3 activation and the extracellular signal-regulated kinase (ERK) activation. Interestingly, the ERK pathway inhibitor, UO126, reversed the apoptotic effects of S1P on B16 melanoma cells. These results suggest that S1P induced apoptosis of B16 melanoma cells via an Edg receptor-independent, pertussis toxin-insensitive pathway, and appears to be associated with the ERK and caspase-3 activation.
Subject(s)
Mice , Animals , Sphingosine/administration & dosage , Signal Transduction/drug effects , Melanoma/enzymology , Lysophospholipids/administration & dosage , Extracellular Signal-Regulated MAP Kinases/metabolism , Enzyme Activation/drug effects , Cell Line , Caspase 3/metabolism , Apoptosis/drug effectsABSTRACT
BACKGROUND: There have been only a few electron microscopic studies after laser treatment of pigmented skin lesions. OBJECTIVE: The purpose was to investigate the pathologic, immunohistochemical, and electron microscopic changes following Q-switched alexandrite laser treatment of pigmented skin lesions. METHODS: Three patients with acquired bilateral nevus of Ota-like macules, and 2 patients with cafeau lait macule were irradiated with Q-switched alexandrite laser. Forty biopsies were taken before and immediately after laser treatment. Hematoxylin-eosin, Fontana-Masson, and gp100 staining were performed for the evaluation of the histopathologic and immunohistochemical findings of the specimens. Electron microscopic findings were also evaluated. RESULTS: Histopathologically, suprabasilar separations were observed immediately after laser treatment. Vacuolar alterations of pigment-containing cells were frequently found in the epidermis and/or in the dermis. Fontana-Masson and gp100 staining positivity changed to negative or decreased in the epidermis immediately after laser treatment, while they changed to negative in the dermis. Ultrastructurally, epidermal pigment-containing cells frequently showed severe vacuolar changes in the cytoplasm, pyknotic nuclei, and vacuolated and/or fragmented melanosomes immediately after laser treatment. Dermal melanocytes frequently revealed vacuolated and/or fragmented melanosomes immediately after laser treatment. CONCLUSION: Histopathologic, immunohistochemical, and electron microscopic examination of pigmented skin lesions immediately after Q-switched alexandrite laser treatment demonstrated vacuolated or fragmented melanosomes and vacuolar alteration of pigment-containing cells in the epidermis and/or in the dermis, which suggested selective photothermolysis of melanosomes.
Subject(s)
Humans , Biopsy , Cytoplasm , Dermis , Epidermis , Lasers, Solid-State , Melanocytes , Melanosomes , Nevus , SkinABSTRACT
A 62-year-old farmer was admitted to our department because of second degree chemical burns of both buttocks ten days following accidental contact with Gramoxone, a weed killer. He was treated with oral antibiotics and cold compresses and discharged after the burned area were reepithelialized. Laboratory findings were within normal limits for three weeks. Although lung fibrosis, hepatic and renal failure can be caused by repeated absorption of paraquat (Gramoxone) through injuried skin, systemic absorption through normal skin has not been reported. During the four month follow up period there were no systemic problems nor recurrence of skin lesions. We report herein a case of chemical burns induced by Gramoxone, which is probably an occupational dermatosis of farmers handling weed killers.
Subject(s)
Humans , Middle Aged , Absorption , Anti-Bacterial Agents , Burns , Burns, Chemical , Buttocks , Fibrosis , Follow-Up Studies , Lung , Paraquat , Recurrence , Renal Insufficiency , Skin , Skin DiseasesABSTRACT
Using atomic absorption spectrometry Pb, Cd, Cu, Zn and Fe were measured in sweat and Pb, Cd, Cu and Zn, in blood. The subjects were 22 healthy males, aged between 23-44. Sweating was induced with an environmental room (1 hour at 46C dry bulb and 36C wet bulb). Sweat samples were obtained from the left arm by the armbag technique. The sweat volume was 23.3+7.3ml(n= 22). The concentrations, in ug/ml, of trace elements in sweat were : lead, 0.18+0.17(n=22); cadmium, 0.006+0.006(n=22); copper, 0.37+0.66(n=10); zinc, 0.63+0.5(n=10); and iron, 0.22+0.12(n=10). The concentrations, in ug/ml, of trace elements in blood were : lead, 0.28+0.15(n=20); cadmium, 0.005+0.007 (n=20); copper,0.69+0.22(n=20); and zinc,5.61+0.86(n=20). These results clearly showed the significance of sweating as a route of excretion of trace element.