OBJECTIVE In order to provide the scientific basis to find out a practical and effective method to evaluate the degree of muscle atrophy and a better method of prevention and treatment of skeletal muscle atrophy. METHODS Forty-two adult Spray-Dawley rats were used and the model of denervated gastrocnemius muscle was established by cutting off the tibial nerve. The muscle wet weight, diameter and cross section area of myocyte were measured. The motor end-plate, fibrillation potential amplitude and frequency of denervated skeletal muscle were observed. RESULTS The muscle wet weight rapidly reduced within 4 weeks. Afterwards, it maintained about 30 per cent of normal value, and the diameter and cross section area of myocyte progressively reduced. The motor end-plate slightly changed within 4 weeks, but its degeneration accelerated in 6 weeks and disappeared after 16 weeks. The fibrillation potential amplitude was maximum at 2 weeks and it progressively reduced after 12 weeks of muscle denervation. The changes of amplitude and frequency were consistent with the degeneration of end-plate. CONCLUSION The muscle wet weight, diameter and cross section area of myocyte, fibrillation potential amplitude and frequency could be considered as the morphological and electrophysiological indexes of muscle atrophy degree. It’s suggested that the repairing operation of peripheral nerve should be performed before the disappearance of motor end-plate.
In order to introduce a novel reversed digital artery island flap, it was used in 13 cases involving 17 digital skin defects since 1993, in which digital skin defects were covered by a reversed digital artery island flap, a comparative study was made between the flaps with or without a palmar digital vein. The results showed that the 17 island flaps were all survived, and during the early stage after operation, the incidence of venous crisis in the flaps without palmar digital vein was 87.5% (7/8) while that in the flaps with the vein was only 11.1% (1/9), so, it was concluded that the reversed digital artery island flap containing a palmar digital vein could obviously reduce the incidence of venous crisis and improve the survival of the flap.
To observe the effect of percutaneous electrical stimulation on peripheral nerve regeneration, a model was created on the sciatic nerves of 56 rats from either sectioned and followed by direct anastomosis or clamping of the nerve. The indices, such as conducting velocity of nerve, maximal induced action potential of muscle, growth speed of nerve, rateof axon crossing anastomosis site, number of muscular fiber on transverse area and weight of muscle by autocontrol were compared. In this study, 36 rats were divided into two groups, 24 rats in Group 1 and 12 rats in Group 2. In Gourp 1, both sciatic nerves were sectioned and was anastomozed 4 weeks later. One side of the nerve was stimulated with percutaneous electric current, the other side was served as control. In Group 2, both sides of nerves were clamped and the electical stimulationwas carried out on one side. The parameters of the electric current were 2～5HZ, 0.4m/s, 24～48V. The electrophysiological and histomorphological features were observed 1 to 6 weeks after operation. The results showed that in the stimulatedside, the indices were all superior to that of the control side. This suggestedthat electrical stimulation could promote peripheral nerve regeneration.
OBJECTIVE To explore the regularity of the change of S-100 protein in degenerative nerve after different pathological brachial plexus injuries. METHODS Eighty SD rats were randomly divided into two groups, right C5, C6 preganglionic injury, and postganglionic injury. The distribution and content of S-100 protein in distal degenerative nerve were detected after 1, 2, 3 and 6 months of injury by immunohistochemical methods. RESULTS The S-100 protein was mainly distributed along the axons. The S-100 protein positive axons of each time interval decreased after operation, with significant difference from normal nerves (P lt; 0.01). There was no statistically significant difference among 1, 2, 3 and 6 months group (P gt; 0.05). The S-100 protein stain of postganglionic group was negative. CONCLUSION In preganglionic injury, the functional expression of Schwann’s cells in the distal stump keeps at a certain level and for a certain period. Since Schwann’s cell has inductive effect on nerve regeneration, it suggests that the distal nerve stump in preganglionic injury can be used as nerve grafts.
OBJECTIVE Using electrophysiological method to evaluate the severity of incomplete obstetric paralysis brachial plexus injuries, and establish an electrophysiological criteria for selection of operative procedure in the treatment of cases of late stage. METHODS Neurolysis was performed in 16 patients, and during the operation, the neuroma at the upper trunk was discovered. The electrophysiological study was carried out before and during operation to evaluate the conducting function of neuroma. In the follow-up the operative result was analysed by Mallet test. RESULTS The preoperative study showed that the compound muscular active potential (CMAP) amplitude of supraspinatus deltoid and biceps were decreased more than 60% in comparison with that of the healthy side. After external neurolysis of the neuroma, by stimulation of the proximal and distal ends of the neuroma the average decrease of CMAP amplitude of the above three muscles was 37.45% +/- 20.97%, 47.85% +/- 26.23%, 47.05% +/- 21.23%, respectively and no significant improvement was observed in the shoulder and elbow function in all of the 16 cases. CONCLUSION When the preoperative electrophysiological study found that the CMAP amplitude decreased more than 60% in comparison with that of the healthy side, transposition of nerve or nerve grafting was indicated.
our patients with brachial plexus root arulsion, who had undergone various nerve operationswith no functional recovery of the limb, were treated with transfer of sternocledomastoid muscle toreconstruct the function of elbow fleaion. The sternocleidomastoid muscle was datached from itsincertions and was lengthened by fascia lata graft from the thigh , and then , was transferred under theclavicle to the radiai shaft just distal to the radial tuberosity. After the recostruction, The potient...