Fibrin Glue Acutely Blocks Distal Muscle Contraction after Confirmed Polyethylene Glycol Nerve Fusion: An Animal Study.

Background: Polyethylene glycol (PEG) is a synthetic, biodegradable, and hyperosmotic material promising in the treatment of acute peripheral nerve injuries. Our team set out to investigate the impact of fibrin glue upon PEG fusion in a rat model. Methods: Eighteen rats underwent sciatic nerve transection and PEG fusion. Electrophysiologic testing was performed to measure nerve function and distal muscle twitch. Fibrin glue was applied and testing repeated. Due to preliminary findings, fibrin glue was applied to an uncut nerve in five rodents and testing was conducted before and after glue application. Mann-Whitney U tests were used to compare median values between outcome measures. A Shapiro-Wilk test was used to determine normality of data for each comparison, significance set at a P value less than 0.05. Results: PEG fusion was confirmed in 13 nerves with no significant change in amplitude (P = 0.054), latency (P = 0.114), or conduction velocity (P = 0.114). Stimulation of nerves following PEG fusion produced distal muscle contraction in 100% of nerves. Following application of fibrin glue, there was a significant reduction in latency (P = 0.023), amplitude (P < 0.001), and conduction velocity (P = 0.023). Stimulation of the nerve after application of fibrin glue did not produce distal muscle twitch. Five uncut nerves with fibrin glue application blocked distal muscle contraction following stimulation. Conclusions: Our data suggest that fibrin glue alters the nerve's function. The immediate confirmation of PEG fusion via distal muscle twitch is blocked with application fibrin glue in this experimental model. Survival and functional outcome studies are necessary to understand if this has implications on the long-term functional outcomes.

Towards optimised extracellular vesicle proteomics from cerebrospinal fluid.

The proteomic profile of extracellular vesicles (EVs) from cerebrospinal fluid (CSF) can reveal novel biomarkers for diseases of the brain. Here, we validate an ultrafiltration combined with size-exclusion chromatography (UF-SEC) method for isolation of EVs from canine CSF and probe the effect of starting volume on the EV proteomics profile. First, we performed a literature review of CSF EV articles to define the current state of art, discovering a need for basic characterisation of CSF EVs. Secondly, we isolated EVs from CSF by UF-SEC and characterised the SEC fractions by protein amount, particle count, transmission electron microscopy, and immunoblotting. Data are presented as mean ± standard deviation. Using proteomics, SEC fractions 3-5 were compared and enrichment of EV markers in fraction 3 was detected, whereas fractions 4-5 contained more apolipoproteins. Lastly, we compared starting volumes of pooled CSF (6 ml, 3 ml, 1 ml, and 0.5 ml) to evaluate the effect on the proteomic profile. Even with a 0.5 ml starting volume, 743 ± 77 or 345 ± 88 proteins were identified depending on whether 'matches between runs' was active in MaxQuant. The results confirm that UF-SEC effectively isolates CSF EVs and that EV proteomic analysis can be performed from 0.5 ml of canine CSF.

Reliability and validity of two versions of the upper extremity functional index.

PURPOSE: To examine the reliability, validity, and sensitivity to change of the 20-item version and the Rasch-refined 15-item version of the Upper Extremity Functional Index (UEFI-20 and UEFI-15, respectively) and to determine the impact of arm dominance on the positive minimal clinically important difference (pMCID). METHODS: Adults with upper-extremity (UE) dysfunction completed the UEFI-20, Upper Extremity Functional Scale (UEFS), Pain Limitation Scale, and Pain Intensity Scale at their initial physiotherapy assessment (Time 1); 24-48 hours later (Time 2); and 3 weeks into treatment or at discharge, whichever came first (Time 3). Demographics, including working status, were obtained at Time 1. Global ratings of change (GRC) were provided by the treating physiotherapist and patient at Time 3. The UEFI-15 was calculated from relevant items in the UEFI-20. The intra-class correlation coefficient (ICC) and minimal detectable change (MDC) quantified test-retest reliability (Time 1-Time 2). Cross-sectional convergent validity was determined by the association (Pearson's r) between Time 1 measures of function and pain. Known-groups validity was evaluated with a one-way ANOVA across three levels of working status. Longitudinal validity was determined by the association (Pearson's r) between function and pain change scores (Time 1-Time 3). Receiver operating characteristic (ROC) curves estimated the pMCID using Time 1-Time 3 change scores and average patient/therapist GRC. RESULTS: Reliability for the UEFI-20 and UEFI-15 was the same (ICC=0.94 for both measures). MDC values were 9.4/80 for the UEFI-20 and 8.8/100 for the UEFI-15. Cross-sectional, known-groups, and longitudinal validity were confirmed for both UEFI measures. pMCID values were 8/80 for the UEFI-20 and 6.7/100 for the UEFI-15; pMCID was higher for people whose non-dominant arm was affected. CONCLUSIONS: Both UEFI measures show acceptable reliability and validity. Arm dominance affects pMCID. The UEFI-15 is recommended because it measures only one dimension: UE function.

Objectif : Étudier la fiabilité, la validité et la sensibilité au changement des versions à 20 questions et à 15 questions raffinées par Rasch de l'Indice fonctionnel des membres supérieurs (IFMS-20 et IFMS-15, respectivement) et déterminer l'effet du bras dominant sur la différence minimale positive cliniquement importante (pDMCI). Méthodes : Les adultes ayant une dysfonction des membres supérieurs (MS) ont répondu au questionnaire IFMS-20, aux questionnaires de l'Échelle fonctionnelle des membres supérieurs (EFMS), de l'Échelle de limitation de la douleur et de l'Échelle de l'intensité de la douleur au cours de leurs premières évaluations en physiothérapie (moment 1); de 24 à 48 heures plus tard (moment 2) et 3 semaines après le début du traitement ou le congé, selon l'échéance la plus rapprochée (moment 3). On a réuni des données démographiques, y compris sur leur état de travailleur, au cours du moment 1. Le physiothérapeute traitant et le patient ont fourni des évolutions globales du changement (EGC) au moment 3. On a calculé le résultat du questionnaire IFMS-15 à partir de questions pertinentes contenues dans la version IFMS-20. Le coefficient de corrélation intracatégorie (CCI) et le changement détectable minimal (CDM) ont quantifié la fiabilité de test­retest (moment 1­moment 2). La validité convergente transversale a été déterminée par le lien (r de Pearson) entre les mesures de fonction et de douleur prises au moment 1. On a évalué la validité des groupes connus au moyen d'une analyse bidirectionnelle des écarts (ANOVA) entre trois niveaux d'état de fonctionnement. La validité longitudinale a été déterminée en fonction du lien (r de Pearson) entre les scores de changement de la fonction et de la douleur (moment 1­moment 3). Des courbes des caractéristiques opérationnelles du récepteur (COR) ont estimé la pDMCI à partir des scores de changement entre le moment 1 et le moment 3 et les EGC moyennes patient/thérapeute. Résultats : La fiabilité des questionnaires IFMS-20 et IFMS-15 a été la même (CCI=0,94 pour les deux mesures). Les valeurs du CDM se sont établies à 9,4/80 pour le questionnaire IFMS-20 et à 8,8/100 pour le questionnaire IFMS-15. La validité transversale, de groupes connus et longitudinale a été confirmée pour les deux mesures de l'IFMS. Les valeurs de la pDMCI s'établissaient à 8/80 pour le questionnaire IFMS-20 et à 6,7/100 pour le questionnaire IFMS-15; la pDMCI était plus élevée chez les personnes dont le bras non dominant était atteint. Conclusions : Les deux mesures de l'IFMS montrent une fiabilité et une validité acceptables. Le bras dominant a un effet sur la pDMCI. On recommande le questionnaire IFMS-15 parce qu'il mesure une dimension seulement: la fonction des membres supérieurs.