Follistatin protein enhances satellite cell counts in reinnervated muscle

Background Muscle recovery following peripheral nerve repair is sup-optimal. Follistatin (FST), a potent muscle stimulant, enhances muscle size and satellite cell counts following reinnervation when administered as recombinant FST DNA via viral vectors. Local administration of recombinant FST protein, if effective, would be more clinically translatable but has yet to be investigated following muscle reinnervation. Objective  The aim of this study is to assess the effect of direct delivery of recombinant FST protein on muscle recovery following muscle reinnervation. Materials and Methods  In total, 72 Sprague-Dawley rats underwent temporary (3 or 6 months) denervation or sham denervation. After reinnervation, rats received FST protein (isoform FS-288) or sham treatment via a subcutaneous osmotic pump delivery system. Outcome measures included muscle force, muscle histomorphology, and FST protein quantification. Results  Follistatin treatment resulted in smaller muscles after 3 months denervation ( p  = 0.019) and reduced force after 3 months sham denervation ( p  < 0.001). Conversely, after 6 months of denervation, FST treatment trended toward increased force output ( p  = 0.066). Follistatin increased satellite cell counts after denervation ( p  < 0.001) but reduced satellite cell counts after sham denervation ( p  = 0.037). Conclusion  Follistatin had mixed effects on muscle weight and force. Direct FST protein delivery enhanced satellite cell counts following reinnervation. The positive effect on the satellite cell population is intriguing and warrants further investigation

Neurotrophic effects of perfluorocarbon emulsion gel: a pilot study

Abstract Background Positive neurotrophic effects of hyperbaric oxygen treatment may be more easily achieved by applying a Perflourocarbon (PFC) emulsion gel to the repair site. PFCs are halogen substituted carbon oils with unique oxygen transport potentials that are capable of increasing oxygen availability in local tissues. The purpose of this study was to determine if the application of a PFC emulsion to a repaired nerve would improve recovery. Materials and methods The left tibial nerve of 21 immature female Sprague-Dawley rats was transected, immediately repaired, and then circumferentially coated with PFC gel (Group A, n = 7), PFC-less gel (Group B, n = 7), or nothing (suture only, Group C, n = 7). At eight weeks post surgery, electrophysiological testing and histological and morphological analysis was performed. Results No statistically significant differences between experimental groups were found for muscle size and weight, axon counts, or nerve conduction velocity. Group A had a significantly smaller G-ratio than Groups B and C (p Conclusion Overall results do not indicate a functional benefit associated with application of a PFC emulsion gel to rodent tibial nerve repairs. A positive effect on myelination was seen.</p

A novel method of removal of a broken drill bit in the femoral medullary canal during internal fixation of a type C distal femoral fracture: a case report

【Abstract】 Breakage of surgical instruments and implants during operative procedures is not uncommon in any surgical discipline. The need for removal and the out-come of leaving the broken instruments and implants in the surgical area have not been described in detail. Few studies have suggested removal if they are lying loosely in the tis-sues or joint, close to neurovascular structures. Challenges and the amount of time spent in the retrieval of broken in-struments and implants are well known among surgeons, so most choose to leave them in situ. We reported a novel method of retrieval of a broken drill bit in the femoral medul-lary canal during internal fixation of a type C distal femoral fracture. Key words: Fracture fixation, internal; Femoral fractures; Surgical instrument

Effects of nandrolone on recovery after neurotization of chronically denervated muscle in a rat model.

OBJECT: Suboptimal recovery following repair of major peripheral nerves has been partially attributed to denervation atrophy. Administration of anabolic steroids in conjunction with neurotization may improve functional recovery of chronically denervated muscle. The purpose of this study was to evaluate the effect of the administration of nandrolone on muscle recovery following prolonged denervation in a rat model. METHODS: Eight groups of female Sprague-Dawley rats (15 rats per group, 120 in all) were divided into 3- or 6-month denervated hind limb and sham surgery groups and, then, nandrolone treatment groups and sham treatment groups. Evaluation of treatment effects included nerve conduction, force of contraction, comparative morphology, histology (of muscle fibers), protein electrophoresis (for muscle fiber grouping), and immunohistochemical evaluation. RESULTS: Although a positive trend was noted, neither reinnervated nor normal muscle showed a statistically significant increase in peak muscle force following nandrolone treatment. Indirect measures, including muscle mass (weight and diameter), muscle cell size, muscle fiber type, and satellite cell counts, all failed to support significant anabolic effect. CONCLUSIONS: There does not seem to be a functional benefit from nandrolone treatment following reinnervation of either mild or moderately atrophic muscle (related to prolonged denervation) in a rodent model

The quorum sensing molecule <i>N</i>-acyl homoserine lactone produced by <i>Acinetobacter baumannii</i> displays antibacterial and anticancer properties

<p>Secretory <i>N</i>-acyl homoserine lactones (AHLs) mediate quorum sensing (QS) in bacteria. AHLs are shown to be inhibitory for an unrelated group of bacteria and might mimic host signalling elements, thereby subverting the regulatory events in host cells. This study investigated the AHL produced by <i>Acinetobacter baumannii</i> and analysed its effect on other bacterial species and mammalian cells. Chemically characterized AHL had an m/z value of 325 with a molecular formula C₁₈H₃₁NO₄ and showed its inhibitory potential against <i>Staphylococcus aureus</i>. Molecular docking studies identified D-alanine-D-alanine synthetase A, a cell wall synthesizing enzyme of <i>S. aureus</i> having a strong binding affinity towards AHL. Electron microscopy showed the disruption and sloughing off of the <i>S. aureus</i> cell wall when treated with AHL. <i>In vitro</i> experiments revealed that this bacteriostatic AHL showed time-dependent activity and induced apoptosis in cancer cell lines. This compound could be a potential structural backbone for constructing new AHL analogues against <i>S. aureus</i>. The findings emphasize the need to re-evaluate all previously characterized AHLs for any additional new biological functions other than QS.</p