Numerous studies have indicated a protective effect of male circumcision against acquisition of human immunodeficiency virus (HIV)-1. We investigated mechanisms responsible for the possible increased HIV-1 susceptibility of human foreskin. Foreskins from eight pediatric and six adult patients with (n = 3) and without (n = 11) histories of sexually transmitted disease were evaluated. Six cervical biopsies from HIV-1-seronegative women were included as controls. CD4(+) T cells, macrophages, and Langerhans' cells (LCs) were quantified using image analysis. Cells expressing HIV-1 co-receptors CCR5 and CXCR4 were quantified using immunofluorescence and image analysis. Foreskin biopsies were infected ex vivo in organotypic culture with HIV-1. HIV-1 DNA copies in foreskin and cervical mucosal tissue were compared and the infected cell phenotype was determined. Foreskin mucosa contained higher mean proportions of CD4(+) T cells (22.4%), macrophages (2.4%), and LCs (11.5%) in adults than in children (4.9%, 0.3%, and 6.2%, respectively) or in cervical mucosa (6.2%, 1.4%, and 1.5%, respectively). The highest proportions of CD4(+) T cells and LCs occurred in patients with a history of infection. Foreskin immune cells expressed predominantly the CCR5 HIV-1 co-receptor. Adult foreskin mucosa had greater susceptibility to infection with HIV(bal) than cervical mucosa or the external surface of foreskin tissue. Circumcision likely reduces risk of HIV-1 acquisition in men by decreasing HIV-1 target cells.
Computer enhanced visual learning is a novel method that enhances resident learning by breaking a core procedure into discrete steps and providing a platform for constructive feedback. Computer enhanced visual learning, which is a checklist tool, complies with Accreditation Council for Graduate Medical Education documentation requirements. Computer enhanced visual learning has wide applicability among surgical specialties.
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