Objective To observe the delaying effect of neural stem cell (NSC) transplantation on denervated muscle atrophy after peri pheral nerve injury, and to investigate its mechanism. Methods NSCs were separated from the spinal cords of green fluorescent protein (GFP) transgenic rats aged 12-14 days mechanically and were cultured and induced to differentiate in vitro. Thirty-two F344 rats, aged 2 months and weighed (180 ± 20) g, were randomized into two groups (n=16 per group). The animal models of denervated musculus triceps surae were establ ished by transecting right tibial nerve and commom peroneal nerve 1.5 cm above the knee joints. In the experimental and the control group, 5 μL of GFP-NSCsuspension and 5 μL of culture supernatant were injected into the distal stump of the tibial nerve, respectivel. The generalcondition of rats after operation was observed. At 4 and 12 weeks postoperatively, the wet weight of right musculus tricepssurae was measured, the HE staining, the Mallory trichrome staining and the postsynaptic membrane staining were adopted for the histological observation. Meanwhile, the section area of gastrocnemius fiber and the area of postsynaptic membrane were detected by image analysis software and statistical analysis. Results The wounds in both groups of animals healed by first intension, no ulcer occurred in the right hind l imbs. At 4 and 12 weeks postoperatively, the wet weight of right musculus triceps surae was (0.849 ± 0.064) g and (0.596 ± 0.047) g in the experimental group, respectively, and was (0.651 ± 0.040) g and (0.298 ± 0.016) g in the control group, respectively, showing a significant difference (P lt; 0.05). The fiber section area of the gastrocnemius was 72.55% ± 8.12% and 58.96% ± 6.07% in the experimental group, respectively, and was 50.23% ± 4.76% and 33.63% ± 4.41% in the control group, respectively. There were significant differences between them (P lt; 0.05). Mallory trichrome staining of muscle notified that there was more collagen fiber hyperplasia of denervated gastrocnemius in the control group than that in the experimental group at 4 and 12 weeks postoperatively. After 12 weeks of operation, the area of postsynaptic membrane in the experimental group was (137.29 ± 29.14) μm2, which doubled that in the control group as (61.03 ± 11.38) μm2 and was closer to that in normal postsynaptic membrane as (198.63 ± 23.11) μm2, showing significant differences (P lt; 0.05). Conclusion The transplantation in vivo of allogenic embryonic spinal cord NSCs is capable of delaying denervated muscle atrophy and maintaining the normal appearance of postsynaptic membrane, providing a new approach to prevent and treat the denervated muscle atrophy cl inically.
Objective To recover the loss of the shoulder and elbow function after superior trunks injury of brachial plexus through multi ple nerves branch transfer simultaneously near the nerve entering points of reci pient nerves. Methods Four male patients (aged 21-39 years) with superior trunks injury of brachial plexus were treated from February to September 2007. All cases were injured in the traffic accident, left side in 1 case and right side in 3 cases, resulting in the loss of shoulder abduction, shoulder extorsion, shoulder l ift and elbow flexion, and the increase of muscle strength of shoulder shrug, elbow extension and finger flexion to above or equal to 4th grade. Patients were hospital ized 3-11 months afterinjury. Electromyography showed that the functions of accessory nerve, ulnar nerve and the branch to long head of tricepsbrachii were good, but the function of median nerve was injured partially. The following multiple donor nerves transfer were performed under general anaesthesia, namely from posterior approach accessory nerve to suprascapular nerve, from triceps to axillary nerve, from the partial branch of ulnar nerve to the biceps and/or brachial is muscular branch of musculocutaneous nerve. Results All incisions healed by first intention. One case suffered postoperative numbness on the ulnar side of hand and was symptomatically rel ieved after expectant treatment, while 3 cases had no manifestation of the motor and sensory functional injury related to donor nerve. All patients were followed up for 7-12 months. All patients regained the shoulder abduction and the elbow flexion 3-4 months after operation and electromyography showed that there was the regenerative potential in 3 recipient muscles. The shoulder abduction, elbow flexion and the muscle strength of the patients was 30-65°, 90-120° and 3-4 grade, respectively, 6-7 months after operation. Twelve months after operation, the first patient’s shoulder abduction, external rotation, superduction and elbow flexion almost returned to normal, and his shape of triangular muscle and biceps muscle were nearly normal. Conclusion Adopting donor nerves with similar functions to conduct the multiple donor nerves transfer in cord level has the advantages of l ittle functional loss at the donor sites, and fast and sound functional recovery at the reci pient sites. It is especially suitable for the superior trunks injury patient with delayed treatment and for the patient with the great risk in supraclavicular exploration, providing a new approach for treating superior trunks injury of brachial plexus.