IntroductionInterleukin-1 (IL-1) and tumor necrosis factor-α (TNF-α) are up-regulated in injured and osteoarthritic knee joints. IL-1 and TNF-α inhibit integrative meniscal repair; however, the mechanisms by which this inhibition occurs are not fully understood. Transforming growth factor-β1 (TGF-β1) increases meniscal cell proliferation and accumulation, and enhances integrative meniscal repair. An improved understanding of the mechanisms modulating meniscal cell proliferation and migration will help to improve approaches for enhancing intrinsic or tissue-engineered repair of the meniscus. The goal of this study was to examine the hypothesis that IL-1 and TNF-α suppress, while TGF-β1 enhances, cellular proliferation and migration in cell and tissue models of meniscal repair.MethodsA micro-wound assay was used to assess meniscal cell migration and proliferation in response to the following treatments for 0, 24, or 48 hours: 0 to 10 ng/mL IL-1, TNF-α, or TGF-β1, in the presence or absence of 10% serum. Proliferated and total cells were fluorescently labeled and imaged using confocal laser scanning microscopy and the number of proliferated, migrated, and total cells was determined in the micro-wound and edges of each image. Meniscal cell proliferation was also assessed throughout meniscal repair model explants treated with 0 or 10 ng/mL IL-1, TNF-α, or TGF-β1 for 14 days. At the end of the culture period, biomechanical testing and histological analyses were also performed. Statistical differences were assessed using an ANOVA and Newman-Keuls post hoc test.ResultsIL-1 and TNF-α decreased cell proliferation in both cell and tissue models of meniscal repair. In the presence of serum, TGF-β1 increased outer zone cell proliferation in the micro-wound and in the cross section of meniscal repair model explants. Both IL-1 and TNF-α decreased the integrative shear strength of repair and extracellular matrix deposition in the meniscal repair model system, while TGF-β1 had no effect on either measure.ConclusionsMeniscal cell proliferation in vivo may be diminished following joint injury due to the up-regulation of inflammatory cytokines, thereby limiting native cellular repair of meniscal lesions. Therefore, therapies that can promote meniscal cell proliferation have promise to enhance meniscal repair and improve tissue engineering strategies.
Background: Patient portals are online applications that typically allow users to interact with providers using secure messaging. Portal messaging use and content has not been studied in pediatric surgical specialties. Materials and Methods: We obtained all message threads initiated by pediatric patients/ caregivers and sent to pediatric surgical providers through the Vanderbilt University Medical Center patient portal from June 1 to December 31, 2014. We collected patient demographics and providers' surgical specialties. We determined the number of message threads and individual messages sent by patients/caregivers and providers by specialty. Message content was analyzed by semantic types using a validated consumer health taxonomy. Results: Most threads were about male (176, 60.3%), white (239, 81.8%), non-Hispanic (278, 95.2%) patients with median age of 6 years (range: 0-21). A total of 292 message threads containing 1679 individual messages were sent with mean 5.8 (SD 5.0) messages per thread. Messages were sent more frequently regarding younger patients (p = 0.001). Physicians directly
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