No abstract

Background: In diabetic foot infection, causative pathogens differ in Western population as compared with Asian population. The aim of this study is to analyze microbiological data with respect to diabetic foot infection in Korea to help the choice adequate empirical antibiotics. Methods: We enrolled 745 patients with diabetic foot infection, who were admitted to diabetic wound center of the Korea University Guro Hospital between January 2011 and December 2015. Deep tissue and/or bone biopsy cultures were taken during surgical debridement in the operating room and microbiological analysis was performed. Results: Out of the 745 patients, 613 patients (82.2%) had isolated causative organisms and 832 microbial isolates were identified. Gram-positive aerobic bacteria were isolated in 57.5%, followed by Gram-negative aerobic bacteria (40.0%), anaerobes (1.4%), and fungus (1.1%). MRSA found most frequently identified (13.7%) in Gram-positive aerobes and Pseudomonas found most frequently identified (9.4%) in Gram-negative aerobes. Conclusion: Microbiologic analysis in Korea differs from the reports from Western population. We propose the need of our own guidelines based on microbiology of Korea for better treatment.

Ultraviolet (UV) irradiation affects neuronal structures of the skin and accelerates skin aging. Cytokine cascades in keratinocytes after UV irradiation may result in a paracrine inhibitory effect on nerve cells. The purpose of the present study was to determine the direct effect of cytokines induced by UV radiation on nerve cells in terms of neuronal senescence. Our group performed a preliminary study to determine cytokines induced in UV-irradiated keratinocytes. Among 40 cytokines studied, granulocyte–macrophage colony-stimulating factor (GM-CSF) was increased 4-fold in inflammation antibody array. The GM-CSF was added to cultured human neuroblastoma cells. To evaluate the effect of cellular senescence, the authors performed real-time polymerase chain reaction (RT-PCR), western blot, immunocytochemical, and phase-contrast microscopic evaluations. Expression levels of matrix metallopeptidase-9 (MMP-9), nuclear factor kappa-light-chain-enhancer of activated B cells 1 (NF-κB1), inducible nitric oxide synthase (iNOS), and interleukin β1 (IL-β1) were assessed by RT-PCR. Expression levels of AAP and beta-site amyloid precursor protein cleaving enzyme 1 (BACE1) related to formation of beta-amyloid were evaluated by western blot analysis. Expression levels of MMP-9, NF-κB1, iNOS, and IL-β1 after treatment with GM-CSF were significantly higher than those in the control group. Enhanced expression of AAP and BACE1 was also observed in the treatment group. Thus, GM-CSF might have a provocative effect on nerve cells in terms of neuronal senescence.