Cellular versus acellular matrix devices in the treatment of diabetic foot ulcers: Interim results of a comparative efficacy randomized controlled trial.

Healing of diabetic foot ulcers is a major challenge. Despite adhering to optimal standard of care (SOC), less than 30% of wounds heal after 20 weeks. Advanced cellular tissue-based products have shown better healing over SOC, albeit with great cost and modest improvement. We hypothesized no difference in healing effected by either cellular (Dermagraft), noncellular (Oasis) devices, relative to SOC in treating diabetic foot ulcer in a randomized controlled trial. The primary and secondary outcomes were the percentage of subjects that achieved complete wound closure by study endpoint (12 weeks of treatment) and study completion, respectively. During the 2-week screening phase with SOC, subjects with 40% change in ulcer size were excluded. After randomization, 56 patients entered an active treatment phase (8 weeks) followed by a maintenance phase (4-week SOC), with endpoint at visit 15, and 4 monthly follow-up visits. There was equal distribution of demographic data (p>.05) and no difference in initial wound characteristics (p>.05) between all groups. No differences were observed in complete wound closure by 12 and 28 weeks of treatment, nor were there any difference in percentage area reduction from treatment weeks 1 to 12 and from treatment weeks 1 to 28 between the groups. Each of the treatment arms showed statistically significant reduction in wound area from treatment weeks 1 to 28 (p<.05). This exploratory analysis suggests that the outcomes of treatment with either Dermagraft or Oasis matrix are comparable. We have completed enrollment, and the final data analysis is underway to make definitive conclusions.

Does class attendance matter? Results from a second-year medical school dermatology cohort study.

BACKGROUND: Little is known about the impacts of class attendance and learning preferences on academic performance in dermatology. OBJECTIVES: This study was designed to examine the effects of medical student class attendance and learning preferences on students' academic performance in an introductory dermatology course. METHODS: A total of 101 second-year medical students enrolled in a required introductory dermatology course were surveyed regarding their learning preferences. Records of class attendance and scores on the final examination were reviewed. RESULTS: The most frequently cited reason for attending classes was social expectation (96%), whereas the least cited was learning well in a classroom-type setting (65%). The top reasons cited by students for not attending classes were availability of lectures online (35%), preference for individual study outside the classroom setting (26%), and the inconvenience of traveling to class (24%). Multivariate analysis found no statistically significant relationship between class attendance and performance on the final examination (estimate -0.074, standard error 0.12; P = 0.54) after adjusting for sex, age, Medical College Admission Test (MCAT) score, having children at home, and reason for attending class. Those who prefer to learn by watching online videos scored significantly higher on the final examination (prefer online videos: 87 ± 5.5; neutral: 86 ± 5.9; do not prefer online videos: 82 ± 2.6 [P = 0.049]). CONCLUSIONS: Class attendance was not associated with improved academic performance in a dermatology course. Those who preferred to learn by watching online videos demonstrated a higher level of performance than those who did not prefer to learn this way.

Epithelialization in Wound Healing: A Comprehensive Review.

Significance: Keratinocytes, a major cellular component of the epidermis, are responsible for restoring the epidermis after injury through a process termed epithelialization. This review will focus on the pivotal role of keratinocytes in epithelialization, including cellular processes and mechanisms of their regulation during re-epithelialization, and their cross talk with other cell types participating in wound healing. Recent Advances: Discoveries in epidermal stem cells, keratinocyte immune function, and the role of the epidermis as an independent neuroendocrine organ will be reviewed. Novel mechanisms of gene expression regulation important for re-epithelialization, including microRNAs and histone modifications, will also be discussed. Critical Issues: Epithelialization is an essential component of wound healing used as a defining parameter of a successful wound closure. A wound cannot be considered healed in the absence of re-epithelialization. The epithelialization process is impaired in all types of chronic wounds. Future Directions: A comprehensive understanding of the epithelialization process will ultimately lead to the development of novel therapeutic approaches to promote wound closure.

Catecholamine stress alters neutrophil trafficking and impairs wound healing by ß2-adrenergic receptor-mediated upregulation of IL-6.

Stress-induced hormones can alter the inflammatory response to tissue injury; however, the precise mechanism by which epinephrine influences inflammatory response and wound healing is not well defined. Here we demonstrate that epinephrine alters the neutrophil (polymorphonuclear leukocyte (PMN))-dependent inflammatory response to a cutaneous wound. Using noninvasive real-time imaging of genetically tagged PMNs in a murine skin wound, chronic, epinephrine-mediated stress was modeled by sustained delivery of epinephrine. Prolonged systemic exposure of epinephrine resulted in persistent PMN trafficking to the wound site via an IL-6-mediated mechanism, and this in turn impaired wound repair. Further, we demonstrate that ß2-adrenergic receptor-dependent activation of proinflammatory macrophages is critical for epinephrine-mediated IL-6 production. This study expands our current understanding of stress hormone-mediated impairment of wound healing and provides an important mechanistic link to explain how epinephrine stress exacerbates inflammation via increased number and lifetime of PMNs.