Purinergic receptors are part of a signalling system for proliferation and differentiation in distinct cell lineages in human anagen hair follicles

We investigated the expression of P2X5, P2X7, P2Y1 and P2Y2 receptor subtypes in adult human anagen hair follicles and in relation to markers of proliferation [proliferating cell nuclear antigen (PCNA) and Ki-67], keratinocyte differentiation (involucrin) and apoptosis (anticaspase-3). Using immunohistochemistry, we showed that P2X5, P2Y1 and P2Y2 receptors were expressed in spatially distinct zones of the anagen hair follicle: P2Y1 receptors in the outer root sheath and bulb, P2X5 receptors in the inner and outer root sheaths and medulla and P2Y2 receptors in living cells at the edge of the cortex/medulla. P2X7 receptors were not expressed. Colocalisation experiments suggested different functional roles for these receptors: P2Y1 receptors were associated with bulb and outer root sheath keratinocyte proliferation, P2X5 receptors were associated with differentiation of cells of the medulla and inner root sheaths and P2Y2 receptors were associated with early differentiated cells in the cortex/medulla that contribute to the formation of the hair shaft. The therapeutic potential of purinergic agonists and antagonists for controlling hair growth is discussed

Should the nail plate be replaced or discarded after nail bed repair in children? Nail bed INJury Analysis (NINJA) randomised controlled trial: a health economic and statistical analysis plan

BACKGROUND:Nail bed trauma is one of the most common surgically treated paediatric hand injuries in the UK. Despite surgeons generally expressing a preference to replace the nail plate after repairing the nail bed, there is limited evidence to support this practice. We describe a statistical and health economic analysis plan (SHEAP) for the Nail bed INJury Analysis (NINJA) randomised controlled trial. METHODS/DESIGN:NINJA is a multicentre, pragmatic, superiority, parallel group randomised controlled trial of the treatment of nail bed injury in participants 16 years old or younger. The study aims to evaluate the efficacy and cost-effectiveness of replacing the nail plate compared to discarding it following the repair of a nail bed injury. Surgical site infection at 7-10 days post-randomisation and cosmetic appearance of the nail are the co-primary outcomes for NINJA. Surgical site infection at 7-10 days post-randomisation will be evaluated using a logistic regression model adjusting for site as the sole stratification factor and allowing for intra-site correlation. Cosmetic appearance will be assessed via the newly developed Oxford Finger Nail Appearance Score and will be evaluated by use of a Mann-Whitney U test. An ordinal logistic regression model will also be used to assess the Oxford Finger Nail Appearance Score, adjusting for site and allowing for intra-site correlation. Secondary outcomes are measured at 7-10 days and 4 months and include the EQ-5D-Y questionnaire, pain at first dressing change, cost-effectiveness, late surgical site infection, and participant/parent satisfaction with nail healing. Missing primary outcome data will be summarised by treatment arm and investigated through a sensitivity analysis. Full details of the planned methods of analysis and descriptive statistics are described in this paper. The NINJA study protocol has been published previously. DISCUSSION:The planned analysis strategy for the NINJA trial has been set out here to reduce the risk of reporting bias and data-driven analysis. Any deviations from the SHEAP described in this paper will be detailed and justified fully in the final report of the trial. TRIAL REGISTRATION:ISRCTN, ISRCTN44551796 . Registered on 23 April 2018

The Oxford Finger Nail Appearance Score - a new scoring system for fingernail deformity following paediatric finger tip trauma

Fingernail deformity is common, yet current methods used to define cosmetic appearance following trauma are mainly descriptive. In order to quantify the cosmetic appearance of the fingernail, we developed the Oxford Fingernail Appearance Score using a three stage iterative process. The score has five cosmetic components marked as binary outcomes composed of nail shape, nail adherence, eponychial appearance, nail surface appearance and presence of a split. In the first stage, two assessors independently assessed 25 photographs of fingernails taken at a minimum of four months following paediatric nail bed repair and compared them to the corresponding contralateral uninjured finger. Following refinement in the score, ten different assessors scored a further 62 photographs of fingernails taken after paediatric nail bed repair. Assessors completed each of the five components, and the overall component score was calculated by statisticians post-hoc, taking the ideal appearance of each component as 1 ("identical to opposite" for nail shape, eponychium and surface, "complete" for adherence, "absent" for split) and all the non-ideal appearances as 0. Assessors effectively scored the photographs' integer values between 0 (least optimal appearance) and 5 (most optimal appearance). Refinements in the scoring system resulted in an improvement in a weighted kappa statistic of 0.36 (95% CI:0.09,0.68) in the initial score to 0.52 (95% CI: 0.42, 0.61). The Oxford Fingernail Appearance Score is a user-friendly and reliable scoring system which has application in a clinical trial setting