Evaluation of sensory function and recovery after replantation of fingertips at ZoneⅠin children

Sensory function is the most significant criterion when evaluating the prognosis of replanted fingers. Current clinical research has focused on surgical techniques and indications for finger replantation; however, few studies have focused on recovery of finger sensory function af- ter replantation. This study retrospectively assessed data of eight patients who had undergone nine Zone I replantations of the fingertips in the First Affiliated Hospital of Sun Yat-sen University of China from July 2014 to January 2016. Variations in the extent of damage, with the residual vessels or nerves in some fingers being too short or even missing, prevented tension-free suture repair in some patients. Thus, re- pair of four of the nine fingertips included arteriovenous anastomosis, the remaining five undergoing arterial anastomosis during replanta- tion of the amputated fingers. Three patients underwent nerve repair, whereas the remaining six cases did not. Fingertip replantations were successful in all eight patients. Compared with the patients without vascular anastomosis, no obvious atrophy was visible in the fingertips of patients who did undergo vascular anastomosis during replantation and their sensory function did recover. Fingertip replantation pro- vides good sensory function and cosmetic outcomes when good artery and vein anastomoses have been created, even when digital nerves have not been repaired.

Analysis of transcriptome sequencing of sciatic nerves in Sprague-Dawley rats of different ages

An aging-induced decrease in Schwann cell viability can affect regeneration following peripheral nerve injury in mammals. It is therefore necessary to investigate possible age-related changes in gene expression that may affect the biological function of peripheral nerves. Ten 1-week-old and ten 12-month-old healthy male Sprague-Dawley rats were divided into young（1 week old） and adult（12 months old） groups according to their ages. mRNA expression in the sciatic nerve was compared between young and adult rats using next-generation sequencing（NGS） and bioinformatics（n = 4/group）. The 18 groups of differentially expressed mRNA（DEmRNAs） were also tested by quantitative reverse transcription polymerase chain reaction（n = 6/group）. Results revealed that（1） compared with young rats, adult rats had 3608 groups of DEmRNAs. Of these, 2684 were groups of upregulated genes, and 924 were groups of downregulated genes. Their functions mainly involved cell viability, proliferation, differentiation, regeneration, and myelination.（2） The gene with the most obvious increase of all DEmRNAs in adult rats was Thrsp（log2 FC = 9.01, P 〈 0.05）, and the gene with the most obvious reduction was Col2 a1（log2 FC = -8.89, P 〈 0.05）.（3） Gene Ontology analysis showed that DEmRNAs were mainly concentrated in oligosaccharide binding, nucleotide-binding oligomerization domain containing one signaling pathway, and peptide-transporting ATPase activity.（4） Analysis using the Kyoto Encyclopedia of Genes and Genomes showed that, with increased age, DEmRNAs were mainly enriched in steroid biosynthesis, Staphylococcus aureus infection, and graft-versus-host disease.（5） Spearman＇s correlation coefficient method for evaluating NGS accuracy showed that the NGS results and quantitative reverse transcription polymerase chain reaction results were positively correlated（rs = 0.74, P 〈 0.05）. These findings confirm a difference in sciatic nerve gene expression between adult and young rats, suggesting that, in peripheral nerves, cells and the microenvironment change with age, thus influencing the function and repair of peripheral nerves.

Various changes in cryopreserved acellular nerve allografts at-80°C

The experimental design evaluated histological,mechanical,and biological properties of allogeneic decellularized nerves after cryopreservation in a multi-angle,multi-directional manner to provide evidence for long-term preservation.Acellular nerve allografts from human and rats were cryopreserved in a cryoprotectant（10% fetal bovine serum,10% dimethyl sulfoxide,and 5% sucrose in RPMI1640 medium） at-80°C for 1 year,followed by thawing at 40°C or 37°C for 8 minutes.The breaking force of acellular nerve allografts was measured using a tensile test.Cell survival was determined using L-929 cell suspensions.Acellular nerve allografts were transplanted into a rat model with loss of a 15-mm segment of the left sciatic nerve.Immunohistochemistry staining was used to measure neurofilament 200 expression.Hematoxylin-eosin staining was utilized to detect relative muscle area in gastrocnemius muscle.Electron microscopy was applied to observe changes in allograft ultrastructure.There was no obvious change in morphological appearance or ultrastructure,breaking force,or cytotoxicity of human acellular nerve allografts after cryopreservation at-80°C.Moreover,there was no remarkable change in neurofilament 200 expression,myelin sheath thickness,or muscle atrophy when fresh or cryopreserved rat acellular nerve allografts were applied to repair nerve injury in rats.These results suggest that cryopreservation can greatly extend the storage duration of acellular nerve tissue allografts without concomitant alteration of the physiochemical and biological properties of the engineered tissue to be used for transplantation.

Three-dimensional scanning technique in the congenital microtia reconstruction with tissue expander

To solve the problems of the color,texture mismatch and lack of sensory after skin graft,Brent applied tissue expansion technique in microtia reconstruction in 1980.More recently,several groups from China and Korea reported their successful experiences of soft tissue expansion technique in microtia reconstruction with excellent results and low complication rate.[1]One of the critical questions is whether there is enough skin or not after the expansion.Unfortunately,this question may only be answered by an empirical judgment from the experienced surgeons.In this article,the authors introduced the preliminary results of a new objective and quantitative measuring system by using three-dimensional(3D)surface scanning technique to help the surgeons in microtia reconstruction with tissue expansion technique.