Gangliosides in human uveal melanoma metastatic process.

The inability of current therapy to prevent metastases arising from uveal melanoma often results in patient mortality. With the goal of developing a treatment for metastasis, gangliosides were studied as potential tumor-associated antigens. Our report describes the production of a metastatic liver variant (MH) from a human uveal melanoma cell line (SP6.5). Cells were injected into nude mouse spleens and liver metastases collected 2 months later. After 21 days of in vitro subculture, the cells were re-injected into normal nude mice spleen; 10 cycles (MH10) were performed. Gangliosides were extracted, purified, chromatographed on HPTLC plates and sprayed with a resorcinol-HCl reagent, the sialic acid spots being quantified by densitometry. Gangliosides were analyzed in each metastatic liver variant and compared with the SP6.5 s.c. tumor. The results showed a significant increase in GM3 and a significant decrease in GD3 and GD2 in the last metastatic variants obtained (MH5, MH8, MH9 and MH1O) compared with the primary s.c. tumor, SP6.5. Such evolution in the ganglioside pattern was maintained throughout the progression of the different liver variants. Our results indicate that precursor ganglioside GM3 and gangliosides GD3 and GD2 could be associated with neoplastic evolution of malignancy of human uveal melanoma in nude mice.

Effect of pre-enucleation radiotherapy on the viability of human choroidal melanoma cells.

Using standard tissue culture techniques we cultured cells from 12 large choroidal melanomas to assess the capacity of pre-enucleation radiotherapy to decrease the viability of melanoma cells. Specimens from the six melanomas that received 40 Gy given in 20 daily fractions did not grow in tissue culture. Specimens from the six nonirradiated tumours did grow, with a mean in-vitro doubling time of 39.6 hours. The results show that the applied regimen of pre-enucleation radiotherapy decreased the viability of choroidal melanoma cells. Further study is needed to determine the correlation between the in-vitro characteristics of irradiated and nonirradiated choroidal melanomas.

[Retinopathy due to canthazanthine: 2. Predisposing factors]. / La rétinopathie à la canthaxanthine: 2. Facteurs prédisposants.

A retrospective study of 14 cases of retinopathy due to canthaxanthine, a carotenoid recently used as a skin-tanning agent, revealed that several clinical factors were associated with an increased susceptibility to retinal deposits: focal epitheliopathy, ocular hypertension and, possibly, the concurrent use of beta-carotene. Age has already been established as such a factor.

[Canthaxanthine retinopathy: 1. Clinical study in 51 consumers]. / La rétinopathie à la canthaxanthine: 1. Etude clinique de 51 consommateurs.

Canthaxanthine, a non-provitamin A carotenoid, has been marketed in Canada since March 1979 as a skin-tanning agent. Fifty-one individuals who ingested from 3.6 to 66 g of the drug within a 24-month period were ophthalmologically evaluated. Six of them had deposits in the ocular fundus that appeared to be related to ingestion of the substance, but no functional impairment could be detected.

[Maculopathy with golden particles]. / Maculopathie en paillettes d'or.

This article describes two patients with a bilateral maculopathy due to the presence of numerous glistening yellow particles located mainly around the edge of the macular pit. This picture has apparently not been reported before. Further studies are needed to confirm a possibly toxic origin.