Comparison of short- with long-term regeneration results after digital nerve reconstruction with musclein-vein conduits

Muscle-in-vein conduits are used alternatively to nerve grafts for bridging nerve defects. The purpose of this study was to examine short- and long-term regeneration results after digital nerve reconstruction with muscle-in-vein conduits. Static and moving two-point discriminations and Semmes-Weinstein Monofilaments were used to evaluate sensory recovery 6–12 months and 14–35 months after repair of digital nerves with muscle-in-vein in 7 cases. Both follow-ups were performed after clinical signs of progressing regeneration disappeared. In 4 of 7 cases, a further recovery of both two-point discriminations and in another case of only the static two-point discrimination of 1–3 mm could be found between the short-term and long-term follow-up examination. Moreover, a late recovery of both two-point discriminations was demonstrated in another case. Four of 7 cases showed a sensory improvement by one Semmes-Weinstein Monofilaments. This pilot study suggests that sensory recovery still takes place even when clinical signs of progressing regeneration disappear.

Telemedicine and digital management in repair and regeneration after nerve injury and in nervous system diseases

To the editor, We read with interest the article, ＂Facilitating transparency in spinal cord injury studies using data standards and ontol- ogles＂ by Professor Vance E Lemmon, University of Miami, USA （Lemmon et al., 2014） and would like to add to the discussion on digital management in spinal cord injury. We have analyzed the advancements in the treatment of spinal cord injury, traumatic brain jury. Encouraging outcomes injury and peripheral nerve in- have been achieved in the area of regulating axon growth in vivo and in vitro. However, such a large amount of information neither provides in-depth insight for other scholars nor provides detailed therapeutic nrotocols for clinical studies.

Activation of the Melanocortin-4 receptor signaling byα-MSH stimulates nervedependent mouse digit regeneration

Background:Expression of Mc4r in peripheral organs indicates it has broader roles in organ homeostasis and regeneration.However,the expression and function of Mc4r in the mouse limb and digit has not been fully investigated.Our previous work showed that Mc4r−/−mice fail to regenerate the digit,but whether activation of MC4R signaling could rescue digit regeneration,or stimulate proximal digit regeneration is not clear.Results:We analyzed the expression dynamics of Mc4r in the embryonic and postnatal mouse limb and digit using the Mc4r-gfp mice.We found that Mc4r-GFP is mainly expressed in the limb nerves,and in the limb muscles that are undergoing secondary myogenesis.Expression of Mc4r-GFP in the adult mouse digit is restricted to the nail matrix.We also examined the effect ofα-MSH on mouse digit regeneration.We found that administration ofα-MSH in the Mc4r+/−mice rescue the delayed regeneration of distal digit tip.α-MSH could rescue distal digit regeneration in denervated hindlimbs.In addition,α-MSH could stimulate regeneration of the proximally amputated digit,which is non-regenerative.Conclusions:Mc4r expression in the mouse limb and digit is closely related to nerve tissues,andα-MSH/MC4R signaling has a neurotrophic role in mouse digit tip regeneration.