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 investigate the different influence of the expression levels of the epidermal growth factor (EGF) and the keratinocyte growth factor (KGF) after the unilateral phrenectomy in piglets. Methods Thirty-six piglets were divided into 3 groups according to their ages during the operation (10 d,30 d,50 d). In each group, 6 piglets underwent the left cervical phrenectomy and 6 piglets were used as the shamoperation controls. The expression levels of EGF and KGF were determined by the real time quantitative RT-PCR at 2 weeks after operation.Results The melting curves of RTPCR showed that there was a single peark at the temperature of 80.0, 84.5 and 89.0℃ of EGF,KGF and GAPDH, respectively. In the experimental group, the expression levels of EGF were 3.53±0.36 and 1.73±0.29, and the expression levels of KGF were 4.71±0.42 and 2.77±0.29 in thepiglets undergiong the operation at their ages of 10 d and 30 d.Compared with the control group,the expression levels of EGF (4.60±0.41，2.18±0.24) and KGF(6.05±0.42，3.58±0.31) showed that there was a significant decrease postoperatively in the piglets undergoing the operation at their ages of 10 d and 30 d（P＜0.05）. However, there was no significant change in the piglets undergoing the operation at their ages of 50 d（P＞0.05）. The expression levels of EGF and KGF were significantly decreased with the lung development of the piglets（P＜0.05）. Conclusion The unilateral phrenectomy performed in the piglets younger than 30 d may cause abnormity of the EGF and KGF expression levels. The piglets older than 50 d may not cause a significant influence.
Objective To investigate the sensation of the fingers innervated by the brachial plexus roots and provide the theoretic basis for diagnosis of a brachial plexus injury. Methods From June 2003 to January 2005，10 patients (8 males, 2 females; age,18-47 years) with complete brachial plexus avulsion were involved in this study, who underwent thecontralateral C7 nerve root transfer. The latency and amplitude of the sensory nerve actiopotential(SNAP) were record at the C5 T1 nerve roots when stimulation was given at the fingers.Results When the thumb and the index finger were stimulated and SNAP was recorded at all the roots of the brachial plexus in all the patients, we found that there was a higher amplitude and a shorter latency at the C5-7 roots than at the C8 and T1 roots(P＜0.05). When the middle finger was stimulated and SNAP was recorded at the C7,8 and T1 roots, we found that there was the highest amplitude and the shortest laency at the C7 root(P＜0.01). When the ring finger was stimulated and SNAP was recorded at the C7,8and T1 roots, we found that there was a higher amplitude and a shorter latency at the C8 and T1 roots than at the C7 root(P＜0.01). When the little finger was stimulated and SNAP was recorded at the C7,8and T1 roots, we found that there was the highest amplitude and the shortest latency at the T1 root(P＜0.01). ConclusionThe sense of the thumband the index finger is mainly nnervated by the C5-7 roots, the middle finger sense is mainly innervated by the C7 root, the ring finger sense is mainly innervated by the C8 and T1 roots, and the little finger sense is mainly innervated by the T1 root.
Objective To review the recent development of extraplexal neurotization as a treatment for brachial plexus injuries. Methods Relevant literature was extensively reviewed.The new development, the advantages and disadvantages of extraplexal neurotization were comprehensively evaluated and analyzed. Results After many years of clinical research, great improvement in treatment of brachial plexus injuries was achieved. There were more donor nerves and better use of every donor nerve was made.Conclusion Extraplexal neurotization is an effective treatment for brachial plexus injuries.