No abstract

Cartilage defects have a limited ability to self-heal. Stem cell treatment is a promising approach; however, replicative senescence is a challenge to acquiring large-quantity and high-quality stem cells for cartilage regeneration. Synovium-derived stem cells (SDSCs) are a tissue-specific stem cell for cartilage regeneration. Our recent findings suggest that decellularized stem cell matrix (DSCM) can rejuvenate expanded SDSCs in cell proliferation and chondrogenic potential. In this study, we were investigating (1) whether transforming growth factor (TGF)-β1 and TGF-β3 played a similar role in chondrogenic induction of SDSCs after expansion on either DSCM or plastic flasks (plastic), and (2) whether DSCM-expanded SDSCs had an enhanced capacity in repairing partial-thickness cartilage defects in a minipig model. SDSCs were isolated from synovium in two 3-month-old pigs and DSCM was prepared using SDSCs. Passage 2 SDSCs were expanded on either DSCM or plastic for one passage. The expanded cells were evaluated for cell morphology, chondrogenic capacity, and related mechanisms. TGF-β1 and TGF-β3 were compared for their role in chondrogenesis of SDSCs after expansion on either DSCM or plastic. The chondrogenic induction medium without TGF-β served as a control. In 13 minipigs, we intraarticularly injected DSCM- or plastic-expanded SDSCs or saline into knee partial-thickness cartilage defects and assessed their repair using histology and immunohistochemistry. We found DSCM-expanded SDSCs were small, had a fibroblast-like shape, and grew quickly in a three-dimensional format with concomitant up-regulation of phosphocyclin D1 and TGF-β receptor II. Plastic-expanded SDSCs exhibited higher mRNA levels of chondrogenic markers when incubated with TGF-β3, while DSCM-expanded SDSCs displayed comparable chondrogenic potential when treated with either TGF-β isotype. In the minipig model, DSCM-expanded SDSCs were better than plastic-expanded SDSCs in enhancing collagen II and sulfated glycosaminoglycan expression in repair of partial-thickness cartilage defects, but both groups were superior to the saline control group. Our observations suggested that DSCM is a promising cell expansion system that can promote cell proliferation and enhance expanded cell chondrogenic potential in vitro and in vivo. Our approach could lead to a tissue-specific cell expansion system providing large-quantity and high-quality stem cells for the treatment of cartilage defects.

Selected Issues in Sport-Related Concussion (SRC|Mild Traumatic Brain Injury) for the Team Physician: A Consensus Statement is title 22 in a series of annual consensus documents written for the practicing team physician. This document provides an overview of selected medical issues important to team physicians who are responsible for athletes with sports-related concussion (SRC). This statement was developed by the Team Physician Consensus Conference (TPCC), an annual project-based alliance of six major professional associations. The goal of this TPCC statement is to assist the team physician in providing optimal medical care for the athlete with SRC.

Selected Issues in Sport-Related Concussion (SRC | Mild Traumatic Brain Injury) for the Team Physician: A Consensus Statement is title 22 in a series of annual consensus articles written for the practicing team physician. This document provides an overview of select medical issues important to team physicians who are responsible for athletes with sports-related concussion (SRC). This statement was developed by the Team Physician Consensus Conference (TPCC), an annual project-based alliance of six major professional associations. The goal of this TPCC statement is to assist the team physician in providing optimal medical care for the athlete with SRC.

ObjectiveFeasibility study to investigate the acceptability of different-sized placebo tablets in children aged 4–12 years.Design and settingClinical Research Facilities, inpatient wards and outpatient clinics within a Regional Paediatric Hospital and/or District General Hospital. Healthy children and National Health Service (NHS) patients were asked to swallow three placebo tablets: 6 mm, 8 mm and 10 mm, smallest to largest. The researcher observed children’s facial expressions and behaviours on swallowing and measured the volume of water consumed. Participants completed a questionnaire about the overall acceptability; including swallowability, taste and volume of water consumed. For analysis, participants were stratified by age: 4–8 years and 9–12 years.ResultsThe feasibility study led to an estimated recruitment rate of 0.8% for NHS inpatients and 211 healthy children over a 1-year period. In total, 55 participants were recruited, 30 to the younger group, of which 77% had never taken a tablet before. 84% of the 25 older children had previously taken a tablet. All participants attempted to swallow the smallest sized tablet. The children aged 4–8 years found the larger tablets easier to swallow, however the older children found little difference between the tablet sizes. The younger children required more water to swallow each tablet size compared with the older children where an increasing volume of water was consumed as tablet size increased. Taste was rated highly for both age groups. The 8 mm tablets were deemed the most acceptable tablet size by all participants.ConclusionTablets are potentially an acceptable formulation for children aged 4–12 years. Most children aged 4–8 years who attempted to swallow tablets successfully did so. Recruitment of NHS inpatients to medicine acceptability studies is challenging, however, recruitment of children of staff proved an effective strategy. Valuable lessons have been learnt from this feasibility study which will inform the design of a larger definitive trial.