Arginine metabolism in soft tissue sarcoma.

BACKGROUND: L-Arginine (L-Arg) is a conditionally essential amino acid for humans, which is the substrate for both arginase (ARG) and the inducible form of nitric oxide synthase (iNOS) enzymes. Whether L-Arg metabolism has detrimental or beneficial influence on the tumor growth depends on local up regulation of the NOS or ARG pathways at the tumor site. OBJECTIVE: To evaluate the expression profile of ARG and iNOS in various histological subtypes of soft tissue sarcomas (STSs). METHODS: A series of 81 adult STSs were tested for ARG1, ARG2 and iNOS expression by immunohistochemical analysis. RESULTS: ARG1, ARG2 and iNOS expression was found in tumor cells of all cases of STSs except dermatofibrosarcoma protuberans (DFSP) in a cytoplasmic pattern. However, there was no significant correlation found between ARG, iNOS expression and histopathological parameters. Conversely, the majority of DFSP were devoid of ARG and iNOS expression, while only two cases showed focal and weak expression. CONCLUSIONS: Overexpression of L-Arg-metabolizing enzymes ARG and iNOS in tumor cells of all of the STS cases except DFSP may have a role in mediating the biological processes which characterize STSs. New knowledge of the regulation of arginine metabolism in tumor tissues is key to designing sound therapeutic means to effectively prevent tumorigenesis. Further studies are needed to clarify the absence of ARG and iNOS staining in DFSP.

Are lifetime prevalence of impetigo, molluscum and herpes infection really increased in children having atopic dermatitis?

BACKGROUND: Cutaneous infections such as impetigo contagiosum (IC), molluscum contagiosum (MC) and herpes virus infection (HI) appear to be associated with atopic dermatitis (AD), but there are no reports of concrete epidemiological evidence. OBJECTIVE: We evaluated the association of childhood AD with these infections by conducting a population-based cross-sectional study. METHODS: Enrolled in this study were 1117 children aged 0-6 years old attending nursery schools in Ishigaki City, Okinawa Prefecture, Japan. Physical examination was performed by dermatologists, and a questionnaire was completed on each child's history of allergic diseases including AD, asthma, allergic rhinitis and egg allergy, and that of skin infections including IC, MC and HI, as well as familial history of AD. RESULTS: In 913 children (AD; 132), a history of IC, MC or HI was observed in 45.1%, 19.7%, and 2.5%, respectively. Multiple logistic regression analysis revealed that the odds of having a history of IC were 1.8 times higher in AD children than in non-AD children. Meanwhile, a history of MC was significantly correlated to the male gender, but not to a personal history of AD. As for HI, we found no correlated factors in this study. CONCLUSIONS: The lifetime prevalence of IC was indeed higher in young children with a history of AD.