Direct microscopic examination of potassium hydroxide (KOH)-prepared specimens is the simplest, cheapest method used for the diagnosis of mycotic infections of the skin. However, KOH preparations have been reported to have 5-15% of false-negative results, possibly because of the low visibility of scant, scattered fungal material of the nail scrapings and because the detection of fungal elements depends on the skill of the observer [Arch Dermatol133 (1997) 1317; Clin Microbiol Rev8 (1995) 240]. We compared two different KOH-based staining methods in order to obtain reliable results in shorter time than expected for cultures. A total of 124 patients with suspect diagnosis of dermatomycosis or onychomycosis were enrolled. Two scrapings from the same lesion of each patient were stained with KOH-Chlorazole and KOH-Acridine Orange (AO), respectively; cultural examination of the same specimen was considered as diagnostic gold standard. The two methods showed neither significantly different sensitivity nor specificity; however, for onychomycoses, we observed a slightly higher sensitivity for KOH-Chlorazole and a higher specificity for KOH-AO. We suggest the use of both techniques in order to improve detection of fungal infection, especially for onychomycoses.

In the present study, we determined the incidence of dermatophyte species causing superficial mycoses among outpatients referred to the Department of Dermatology of the "La Sapienza" University of Rome between 2002 and 2004. Of the 3160 subjects studied, 1275 (40.3%) were positive for fungal infection, but only 252 (19.7%) of these had infections caused by dermatophytes. The dermatophyte most frequently isolated was Microsporum canis. Our epidemiological data were compared with those obtained previously by other authors in the same geographic area. For the first time we described an inversion of the T. rubrum/T. mentagrophytes ratio, the latter being more frequently encountered. We also observed the emergence of M. audouinii.

Insulin-like-factor-binding-protein 3 (IGFBP-3) is known to modulate the activity of insulin-like growth factors (IGFs) besides having a number of IGF-independent effects on cell growth and survival. IGFBP-3 has been reported to decrease significantly in the blood serum of patients affected by certain cancers. In the present work, we have evaluated the levels of IGFBP-3 in the blood serum and tissues of patients affected by cutaneous melanoma, showing that loss of IGFBP-3 from both is strongly correlated with disease progression and reduced survival. In vitro treatment with IGFBP-3 of human and murine metastatic melanoma cell lines specifically inhibited the cells' migratory and invasive behaviour, inducing up-regulation of melanocytic differentiation markers such as tyrosinase activity and melanin content. A molecular analysis of the cellular pathways transducing the effect of IGFBP-3 implicated the Akt-GSK3β axis. Moreover, administration of IGFBP-3 in vivo to SCID mice inoculated with human metastatic melanoma cells strongly reduced or completely inhibited tumor growth. In summary, IGFBP-3 appears to exert a specific inhibitory effect on melanoma growth and dissemination, suggesting that it may qualify as a useful therapeutic agent in melanomas and perhaps other cancers, at the least as a valid adjuvant therapy during treatment with conventional anti-tumoral drugs.

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