Multiple skin ulcers due to Serratia marcescens in a immunocompetent patient.

Serratia marcescens is a species of gram negative bacillus, classified as a member of the Enterobacteriaceae, mainly involved in opportunistic infections, particulary in the hospital environment. Cutaneous infections have rarely reported in literature and are predominantly observed in elderly or in immunocompromised patients. The clinical manifestations of skin infections include granulomatous lesions, necrotizing fasciitis, nodules, cellulitis, ulcers, dermal abscesses. Infections caused by S. marcescens may be difficult to treat because of resistance to a variety of antibiotics, including ampicillin and first and second generation cephalosporins. Aminoglycosides have good activity against S. marcescens, but resistant strains have also been described. We report a very intriguing case of S. marcescens infection, in an immunocompetent 18-year-old man, causing multiple rounded ulcers of varying sizes, along with few pustular lesions that both clinically and histopathologically mimic a pyoderma gangrenosum (PG). This is a non infectious neutrophilic skin disorder, characterized by painful and rapidly progressing skin ulceration. According to our experience, we would strongly recommend to perform cultures of multiple skin ulcers resembling PG, even in young healthy patients, to ensure correct diagnosis and treatment, since resistant to conventional antibiotics bacteria such as S. marcescens may be the cause of these lesions, like in the case here reported.

A case of lichen amyloidosus treated with acitretin.

Lichen amyloidosus is a cutaneous dermatosis clinically characterized by an hyperkeratotic brownish-grey papular eruption located on trunk and extremities, associated to severe pruritus. Histologically it is characterized by amyloid deposits in the papillary derma. Amyloid is an amorphous substance, probably derived by apoptotic keratinocites and other protein such as Apolipoprotein E. The exact pathogenesis of this deposition is not yet understood but some factors can act as favourable agents, such as pruritus. In fact this dermatosis is often associated to intensely pruritic conditions. Its treatment is very difficult but is important, because patients refer a bad quality of life. In literature have been described a lot of therapeutic options, often unefficacious. We describe herein the case of a 39-year old patient affected by Lichen amyloidosis, treated with acitretin a good improvement of cutaneous lesions and a complete resolution of pruritus after only three weeks of treatment. At actual follow-up of eight months the results are maintained.

Aurora-A and ch-TOG act in a common pathway in control of spindle pole integrity.

Mitotic spindle assembly is a highly regulated process, crucial to ensure the correct segregation of duplicated chromosomes in daughter cells and to avoid aneuploidy, a common feature of tumors. Among the most important spindle regulators is Aurora-A, a mitotic centrosomal kinase frequently overexpressed in tumors. Here, we investigated the role of Aurora-A in spindle pole organization in human cells. We show that RNA interference-mediated Aurora-A inactivation causes pericentriolar material fragmentation in prometaphase, yielding the formation of spindles with supernumerary poles. This fragmentation does not necessarily involve centrioles and requires microtubules (MTs). Aurora-A-depleted prometaphases mislocalize the MT-stabilizing protein colonic hepatic tumor-overexpressed gene (ch-TOG), which abnormally accumulates at spindle poles, as well as the mitotic centromere-associated kinesin (MCAK), the major functional antagonist of ch-TOG, which delocalizes from poles. ch-TOG is required for extrapole formation in prometaphases lacking Aurora-A, because co-depletion of Aurora-A and ch-TOG mitigates the fragmented pole phenotype. These results indicate a novel function of Aurora-A, the regulation of ch-TOG and MCAK localization, and highlight a common pathway involving the three factors in control of spindle pole integrity.