Primary melanoma of the skin and cutaneous melanomatous metastases: comparative histologic features and immunophenotypes.

Through careful clinicopathologic correlation, we identified 37 metastatic melanomas in the skin, all of which had intraepidermal components. These were compared with 43 microscopically similar primary melanomas with a predetermined panel of immunostains in general use in surgical pathology, including bcl-2 protein, mutant p53 protein, Ki-67 (MIB-1), proliferating cell nuclear antigen (PCNA), alpha-isoform actin, and CD117 (c-kit protein). There was no significant difference in bcl-2 or alpha-isoform actin staining patterns of primary vs secondary cutaneous melanomas.

The mouse model of amebic colitis reveals mouse strain susceptibility to infection and exacerbation of disease by CD4+ T cells.

Amebic colitis is an important worldwide parasitic disease for which there is not a well-established animal model. In this work we show that intracecal inoculation of Entamoeba histolytica trophozoites led to established infection in 60% of C3H mice, while C57BL/6 or BALB/c mice were resistant, including mice genetically deficient for IL-12, IFN-gamma, or inducible NO synthase. Infection was a chronic and nonhealing cecitis that pathologically mirrored human disease.