Biomedical subjects

Jian-Guang Xu

Publications and source records attributed to Jian-Guang Xu.

8 recordsLinked to original sources

PubMed2007

Contralateral C7 transfer for the treatment of brachial plexus root avulsions in children - a report of 12 cases.

PURPOSE: To retrospectively determine the risks and benefits of contralateral C7 nerve root transfer in infants and children. METHODS: In 12 infants and children with brachial plexus root avulsions from birth injury or other trauma, the common trunk of the contralateral C7 root was transferred to the trunk, division, cord, or nerve branch(es) on the affected side with 2 different types of interposition grafts. The surgery was performed in 1 stage for 5 patients and in 2 stages for 7 patients. RESULTS: Patients were followed up for a mean of 42 months, with a minimum of 21 months. Noteworthy function (> or = M2+, modified British Medical Research Council grading system) was gained in 10 of 12 patients and sensory function (> or = S3, British Medical Research Council grading system) was gained in all patients. Improvements in strength and sensation were accompanied by little synchronous motion and sensibility changes in the donor limb in 7 children, to whom the repaired nerves were those innervating the shoulder and/or elbow or both the musculocutaneous and median nerves. In addition to slight damage to the sensory function of the median nerve, 2 infants also had temporarily reduced shoulder abduction on the healthy side. CONCLUSIONS: For contralateral C7 transfer in infants and children with brachial plexus root avulsions, the deficit created by the procedure is minimal and motor and sensory function is gained. Transfer of the contralateral C7 root to different nerves for a child may improve the quality of functional recovery. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic, Level IV.

Brachial Plexus Neuropathies↗

PubMed2006

The non-steroidal anti-inflammatory drug, diclofenac, inhibits Na(+) current in rat myoblasts.

The inhibitory effect of diclofenac, a non-steroidal anti-inflammatory drug (NSAID), on the voltage-gated inward Na+ current (I(Na)) in cultured rat myoblasts was investigated using the whole-cell voltage-clamp technique. At concentrations of 10 nM-100 microM, diclofenac produced a dose-dependent and reversible inhibition of I(Na) with an IC50 of 8.51 microM, without modulating the fast activation and inactivation process. The inhibitory effect of diclofenac took place at resting channels and increased with more depolarizing holding potential. In addition to inhibiting the Na+ current amplitude, diclofenac significantly modulated the steady-state inactivation properties of the Na+ channels, but did not alter the steady-state activation. The steady-state inactivation curve was significantly shifted towards the hyperpolarizing potential in the presence of diclofenac. Furthermore, diclofenac treatment resulted in a fairly slow recovery from inactivation of the Na+ channel. The inhibitory effect of diclofenac was enhanced by repetitive pulses and was inflected by changing frequency; the blocking effect at higher frequency was significantly greater than at lower frequency. Both intracellular and extracellular application of diclofenac could inhibit I(Na), indicating that diclofenac may exert its channel inhibitory action both inside and outside the channel sites. Our data directly demonstrate that diclofenac can inhibit the inward Na+ channels in rat myoblasts. Some different inhibitory mechanisms from that in neuronal Na+ channels are discussed.

Animals↗

PubMed2006

Proteomic analysis of the cerebrospinal fluid of patients with lumbar disk herniation.

To better understand the pathophysiologic mechanisms underlying spinal nerve root injury induced by lumbar disk herniation (LDH), comparative proteomic analysis of cerebrospinal fluid (CSF) between patients with LDH (the experiment group) and the otherwise healthy patients who had had implants removed from healed fractures in the lower limbs (the control group) was carried out using 2-DE followed by LC-IT-MS and database searching. Image analysis of silver-stained 2-DE gels revealed that 15 protein spots showed significant differential expression between the two groups of CSF samples (p < 0.05). After searching the database we found that in CSF of LDH patients, the expression of cystatin C, apolipoprotein A-IV, vitamin D-binding protein, neurofilament triplet L protein, IgG, tetranectin, and hemoglobin were elevated. However, ProSAAS, prostagladin D2 synthase, creatine kinase B, superoxide dismutase 1 and peroxiredoxin 2 were decreased. The subsequent ELISA measured the concentration of tetranectin, vitamin D-binding protein and cystatin C and confirmed the results of proteomic analysis. These identified proteins are involved in the pathophysiological process of spinal nerve root injury caused by herniated lumbar disk. The functional implications of the alterations in the levels of these proteins are discussed in this paper.

Adult↗

PubMed2005

Comparative clinic study on vascularized and nonvascularized full-length phrenic nerve transfer.

In order to understand whether the vascularizing procedure has any clinical value in nerve transfer and grafting, we compared nonvascularized and vascularized full-length phrenic never transfers in patients with a brachial plexus injury. Full-length phrenic nerve transfer to the musculocutaneous nerve had been conducted by the technique of video-assisted thoracic surgery in 15 patients. Three kinds of procedures were carried out. The first involved retaining the initial point of the phrenic nerve and dissecting the full-length distal nerve. The second involved keeping the cervical segment and isolating the thoracic segment of the phrenic nerve. The last involved vascularized phrenic nerve transfer. All these phrenic nerves were sutured to musculocutaneous nerves. After 28-35 months, the results of electrophysiology and function of the biceps brachii muscle were compared. All three procedures had no significant differences and led to the same functional recovery of the biceps brachii muscle after at least 28 months of follow-up. In conclusion, the vascularizing procedure had little clinical value, not only in full-length phrenic nerve transfer, but also in nerve grafting irrespective of the length of the gap, when the recipient bed had normal vascularity.

Adult↗

PubMed2005

Pulmonary function after complete unilateral phrenic nerve transection.

OBJECT: The status of pulmonary function following phrenic nerve transfer surgery is still largely unknown because of the high degree of variability in the accessory phrenic nerve that may be involved. In the present study, pulmonary functions were assessed in patients before and after full-length phrenic nerve transfer surgery, in whom the phrenic nerve was severed at a location just before its entry into the diaphragm. METHODS: Fifteen patients (average age 27.4 years) with complete brachial plexus palsy underwent full-length phrenic nerve transfer. The phrenic nerve was harvested from the thoracic cavity by means of video-assisted thoracic surgery and then transferred to the musculocutaneous nerve. Postoperative pulmonary functions were retrospectively analyzed. Patients underwent follow-up evaluation for 42 to 48 months; four patients were eventually lost to follow up. Although no patient experienced pulmonary problems following the surgery, all sustained varying degrees of diaphragmatic paralysis and elevation (for 1-1.5 intercostal spaces) on the surgically treated side as seen on chest x-ray films. Pulmonary functional parameters, including vital capacity, vital capacity in percentage of predicted values, residual volume, total lung capacity, forced vital capacity, and forced expiratory volume in 1 second, recovered to preoperative levels by 1 year postsurgery. In contrast, the postoperative maximal inspiratory pressure value was significantly decreased compared with the predicted values (average decrease approximately 20%) in all of the patients, even at 4 years after the surgery. CONCLUSIONS: In young patients with healthy lung function, unilateral phrenic nerve transection surgery can cause unilateral diaphragmatic paralysis and reduce the inspiration muscle force; however, most pulmonary function parameters gradually recover to preoperative levels within 1 year.

Adolescent↗

PubMed2004

Comparative experimental study on treatment outcome of nerve transfer, using selective C7 nerve root vs. phrenic nerve.

The treatment outcome of nerve transfer using the C7 nerve root or phrenic nerve was compared in a rat experiment. One hundred and twenty SD rats were divided into two groups, one undergoing phrenic nerve transfer to the musculocutaneous nerve, and the other partial ipsilateral C7 (anteriolateral fascicles of the anterior division) to the musculocutaneous nerve. Neurotization outcomes of the two groups were evaluated by comparing the electrophysiologic, histologic, and myophysiologic changes of the biceps muscle. No significant differences were found between parameters from the phrenic nerve transfer group and those from the ipsilateral C7 nerve transfer group. This indicates that the treatment outcome of selective ipsilateral C7 transfer is comparable to that of phrenic nerve transfer. It is the surgery of choice in treating brachial plexus upper-trunk avulsion accompanied by phrenic nerve injury.

Animals↗

PubMed2004

Electrophysiologic study of influence on C7 innervated muscles after transection of different C7 fascicles.

An experimental study was conducted to observe the electrophysiologic changes in C7 innervated muscles following transection of different fascicles of C7 nerve root in the brachial plexus with already transected C5 and C6. Twenty-four Sprague-Dawley rats were randomized into groups A, B, and C. C5 and C6 transection, C5, C6, and partial C7 (anteriolateral fascicles of the anterior division) transection, and C5, C6, and C7 transection were done in group A, B, and C, respectively. One month postoperatively, compound muscle action potentials of the latissimus dorsi, triceps, and extensor digitorum communis were recorded. Decreased amplitude and a prolonged latent period were seen in all three muscles of group C. No obvious changes, however, were found in groups A and B. This suggests that when the upper trunk of the brachial plexus is injured, partial transection of C7 does not obviously impair C7 innervated muscle function. Selective ipsilateral C7 transfer is safe for the treatment of upper-trunk avulsion.

Action Potentials↗

PubMed2002

Full-length phrenic nerve transfer by means of video-assisted thoracic surgery in treating brachial plexus avulsion injury.

Phrenic nerve transfer has been widely used in treating brachial plexus avulsion injury. However, the present method crosses the thoracic part of the phrenic nerve, and nerve graft is needed, resulting in a long period of regeneration and partly irreversible muscle atrophy. We present our early experience of using video-assisted thoracic surgery to harvest a full length of phrenic nerve for transfer. Fifteen patients (mean age, 28 years) were treated. The thoracic part of the phrenic nerve was freed by means of video-assisted thoracic surgery and taken out of the thoracic cavity, and a full-length phrenic nerve was transferred to the musculocutaneous nerve to recover elbow flexion. The patients were followed. Another 29 patients with long-term follow-up who underwent traditional cervical phrenic nerve to musculocutaneous nerve transfer in our institute between 1994 and 1997 were selected. The period of newborn potential appearing in the biceps and the period for biceps to achieve M3 between two groups were compared. The operation was safe and no complications occurred. The additional length of phrenic nerve was 12.3 +/- 4.5 cm. Eleven patients received sufficient follow-up. Eight patients achieved biceps recovery to M3 (elbow flexion against gravity), and mean time was 198.8 +/- 36.0 days, much earlier than that of the traditional method (p < 0.01). Pulmonary function recovered to the preoperative level 9 months after operation. This new method is safe and minimally invasive. The result of full-length phrenic nerve transfer is much better than that of the traditional method. It obviously shortens the time required for nerve reinnervation, and offers a promising method for patients who have had a long interval from injury to operation and for forearm muscle reconstruction by phrenic nerve transferred to the median nerve or combined with free-muscle transfer.

Adolescent↗