Amaramalar Selvi Naicker

Neural‐differentiated mesenchymal stem cells incorporated into muscle stuffed vein scaffold forms a stable living nerve conduit

Autologous nerve grafts to bridge nerve gaps have donor site morbidity and possible neuroma formation resulting in development of various methods of bridging nerve gaps without using autologous nerve grafts. We have fabricated an acellular muscle stuffed vein seeded with differentiated mesenchymal stem cells (MSCs) as a substitute for nerve autografts. Human vein and muscle were both decellularized by liquid nitrogen immersion with subsequent hydrolysis in hydrochloric acid. Human MSCs were subjected to a series of treatments with a reducing agent, retinoic acid, and a combination of trophic factors. The differentiated MSCs were seeded on the surface of acellular muscle tissue and then stuffed into the vein. Our study showed that 35–75% of the cells expressed neural markers such as S100b, glial fibrillary acidic protein (GFAP), p75 NGF receptor, and Nestin after differentiation. Histological and ultra structural analyses of muscle stuffed veins showed attachment of cells onto the surface of the acellular muscle and penetration of the cells into the hydrolyzed fraction of muscle fibers. We implanted these muscle stuffed veins into athymic mice and at 8 weeks post‐implantation, the acellular muscle tissue had fully degraded and replaced with new matrix produced by the seeded cells. The vein was still intact and no inflammatory reactions were observed proving the biocompatibility and biodegradability of the conduit. In conclusion, we have successfully formed a stable living nerve conduit which may serve as a substitute for autologous nerves.

Olfactory ensheathing cells seeded muscle-stuffed vein as nerve conduit for peripheral nerve repair: a nerve conduction study.

We evaluated bridging of 15 mm nerve gap in rat sciatic nerve injury model with muscle-stuffed vein seeded with olfactory ensheathing cells as a substitute for nerve autograft. Neurophysiological recovery, as assessed by electrophysiological analysis was faster in the constructed biological nerve conduit compared to that of autograft.

Clinical evaluation of the anterior translation of glenohumeral joint using ultrasonography: an intra- and inter-rater reliability study.

OBJECTIVE The aim of this study was to investigate the intra- and inter-rater reliability of ultrasonography (US) to measure anterior translation of the humeral head (ATHH) among healthy subjects and patients with sacroiliac joint dysfunction. METHODS The study included a total of 22 shoulder joints from 11 subjects. Six subjects were healthy and 5 had sacroiliac joint dysfunction. Anterior translation of the humeral head was measured twice using US by two different investigators. Intraclass correlation coefficient (ICC3,1), standard error of measurements (SEMs), coefficient of variations (CVs) and Bland-Altman plot were used as analytical tests to investigate intra- and inter-rater reliability, amount of error and agreeability of the measurements between investigators. RESULTS Intraclass correlation coefficient was 0.94, showing a high level of intra-rater reliability of the first investigator with SEMs (0.01 cm) and CV (5.1%) in measuring ATHH. Intra-rater reliability of the second investigator was 0.84 with SEMs (0.03 cms) and CV (9.6%), indicating a high level of reliability. Inter-rater reliability was high, with an ICC value of 0.92 with SEMs (0.02 cms) and CV (5.9%). CONCLUSION The use of US as a measurement of ATHH has good levels of intra- and inter-rater reliability in clinical practice.

Human Bone Marrow-Derived MSCs Spontaneously Express Specific Schwann Cell Markers: Spontaneous Schwann Cell Marker Expression

In peripheral nerve injuries, Schwann cells (SC) play pivotal roles in regenerating damaged nerve. However, the use of SC in clinical cell‐based therapy is hampered due to its limited availability. In this study, we aim to evaluate the effectiveness of using an established induction protocol for human bone marrow derived‐MSC (hBM‐MSCs) transdifferentiation into a SC lineage. A relatively homogenous culture of hBM‐MSCs was first established after serial passaging (P3), with profiles conforming to the minimal criteria set by International Society for Cellular Therapy (ISCT). The cultures (n = 3) were then subjected to a series of induction media containing β‐mercaptoethanol, retinoic acid, and growth factors. Quantitative RT‐PCR, flow cytometry, and immunocytochemistry analyses were performed to quantify the expression of specific SC markers, that is, S100, GFAP, MPZ and p75 NGFR, in both undifferentiated and transdifferentiated hBM‐MSCs. Based on these analyses, all markers were expressed in undifferentiated hBM‐MSCs and MPZ expression (mRNA transcripts) was consistently detected before and after transdifferentiation across all samples. There was upregulation at the transcript level of more than twofolds for NGF, MPB, GDNF, p75 NGFR post‐transdifferentiation. This study highlights the existence of spontaneous expression of specific SC markers in cultured hBM‐MSCs, inter‐donor variability and that MSC transdifferentiation is a heterogenous process. These findings strongly oppose the use of a single marker to indicate SC fate. The heterogenous nature of MSC may influence the efficiency of SC transdifferentiation protocols. Therefore, there is an urgent need to re‐define the MSC subpopulations and revise the minimal criteria for MSC identification.