Amelanotic subungual melanoma and chilblains.

A female patient in her 50s presented with blue discolouration of several toes and with single nail dystrophy affecting the little toenail. The nail changes were considered to be secondary to poor circulation and chilblains, which led to delay in the diagnosis of amelanotic subungual melanoma.

Hanging on by a thread: a rare case of secondary pseudoainhum.

Pseudoainhum is a rare and poorly characterised phenomenon involving autoamputation of a digit associated with an identifiable or related disease process. We describe the case of a 19-year-old man with long-standing neurodisability, sensorineural hearing loss and severe keratoderma, presenting with painless rapidly-progressing autoamputation of his left little toe. Genetic analysis thus far has been inconclusive. The toe appeared to be hanging on by a thread, with no clinical signs of infection. Radiographs showed lysis with complete resorption of the proximal phalynx. Routine blood tests found an isolated neutropenia with normal C reactive protein and biochemistry. We report an unusual case of a young adult with a history of chronic neurological and dermatological problems presenting with secondary pseudoainhum and provide a valuable addition to the limited literature describing this rare condition.

Inhibition of TCR-mediated shedding of L-selectin (CD62L) on human and mouse CD4+ T cells by metalloproteinase inhibition: analysis of the regulation of Th1/Th2 function.

The generation of a productive primary immune response is dependent on the ability of naïve T lymphocytes to recirculate through peripheral lymph organs to encounter specific antigen. The process of naïve CD4(+) T cell entry into lymph nodes correlates with cell surface expression of L-selectin (CD62L), which mediates early tethering and rolling events to endothelium prior to entry. Here, we demonstrate that surface expression of CD62L enhances CD4(+) T cell activation in vitro. The synthetic hydroxamate metalloproteinase inhibitor (BB-3103), specifically inhibits activation-induced shedding of CD62L from CD4(+) T cells by TCR cross-linking and lowers proliferation in part by reducing rapid tyrosine phosphorylation of zeta-associated protein 70 kDa (ZAP-70) and by increasing cytosolic free Ca(2+) concentration mobilization. BB-3103 also inhibited the proliferative response of both murine CD4(+) Th1 and Th2 subsets in vitro but the inhibitory effects were sustained only in Th2-type cells. Similarly, BB-3103 mediated prolonged inhibition of allergen-dependent peripheral T cell proliferation in atopic dermatitis patients but not in healthy controls. Analysis of CD62L expression on murine CD4(+) T cell subsets revealed that surface expression was maintained on Th1 cells but not Th2 cells. The differential effects of BB-3103 on primed effector CD4(+) T cells may provide new insights into generating therapeutic agents capable of redressing the Th2/Th1 imbalance in allergic diseases.