Baoguo Jiang

Bone marrow stromal cells differentiated into functional Schwann cells in injured rats sciatic nerve.

Bone marrow stromal cells (MSCs) have been shown to differentiate into various lineage cells including neural cells in vitro and in vivo. We therefore examined whether MSCs can differentiate into Schwann cells in injured peripheral nerves. After cultured in vitro, PKH-67-labeled MSCs were injected into the mechanically injured rat sciatic nerves. Three weeks after injection, immunofluorescent examinations were carried out. MSCs had been incorporated around the injured nerves and differentiated into Schwann cells. MSCs had accumulated mainly in the epineurium around the injured nerve. The incorporated cells partially expressed GFAP, S-100, and P75. These results confirmed the possibility that MSCs have the ability to differentiate into Schwann cells, and that injection of MSCs into the injured peripheral nerve would help repair damaged nerve.

Accurate Determination of Isthmus of Lumbar Pedicle : A Morphometric Study using Reformatted Computed Tomographic Images

Study Design. Lumbar pedicle isthmus, the narrowest section of pedicle, was investigated. Objective. To determine the lumbar pedicle isthmus accurately and measure related parameters. Summary of Background Data. Accurate anatomic knowledge of pedicle parameters is critical for a successful transpedicular procedure. Many studies on lumbar pedicle dimensions have been conducted, yet less is known about how to obtain these data and their veracity. In fact, the narrowest section is present in the pedicle, i.e., the isthmus of the pedicle. This is the bottleneck of the pedicle; to determine and measure it could illustrate the true morphologic characteristics of the lumbar pedicle. Methods. Ultra high-speed spiral CT scan of lumbar spine was performed in 41 patients of Chinese origin. After reformation of the original images, isthmus and transverse plane of pedicle axis were determined. Eleven dimensions of isthmus plane and three dimensions of transverse plane were calculated using software. Results. Pedicle endosteal width and height in female patients who were over the age of 50 were greater than those of female patients younger than 50 years old. The isthmus endosteal width from L1 to L5 was 5.2, 6.0, 7.5, 7.5, and 8.7 mm and 4.0, 4.1, 5.4, 5.7, and 7.1 mm, respectively, in men and women. Isthmus inclination inclined to midline with less than 10° above L3 but increased in L4 and 30° in L5. Conclusions. An objective narrowest section, the pedicle isthmus, exists in lumbar pedicle axis. The parameters of isthmus, especially isthmus endosteal width, show the morphologic characteristics of the lumbar pedicle and are the most important data provided for transpedicular procedures. The small pedicles of female patients over the age of 50 also show certain primary osteoporosis. Isthmus inclination puts the pedicle in a more complicated space position. A better understanding of the complicated structure of the pedicle isthmus guarantees success in transpedicular procedures.

Lumbricus extract promotes the regeneration of injured peripheral nerve in rats

BACKGROUND Earthworms regenerate amputated parts of their body if the nervous system is intact. Lumbricus is one traditional Chinese medicine (TCM), which has been used in China to promote nerve function for hundreds of years. AIM OF THE STUDY To investigate the beneficial effect of lumbricus extract on peripheral nerve regeneration in rats. MATERIALS AND METHODS Nerve function was surgically impaired in Sprague-Dawley (SD) rats by clamping of the left sciatic nerve. The sham-operated group (surgery but no sciatic nerve clamping), control group, and treatment group were treated with 2 ml 0.9% NaCl, 0.9% NaCl, and lumbricus extract (1g/ml), respectively. Treatments were administered once daily after the operation for 6 weeks. During this period, motor function was monitored by walking track analysis, conduction function of injured sciatic nerve was monitored by electrophysiology, and regeneration of myelinated nerve was assessed by immunohistochemistry. RESULTS (1) For nerve function index value, treatment group is higher than control group. (2) For conduction velocity of injured sciatic nerve, treatment group is higher than control group at week 3 and 6. (3) For the number of regenerated myelinated nerve fibers, treatment group is higher than control group at week 2 and 6. CONCLUSIONS Lumbricus extract appears to enhance sciatic nerve regeneration and function recovery following injury, suggesting the clinical potential of lumbricus extract on the treatment of peripheral nerve injury in humans.

Effect of Calcar Screw Use in Surgical Neck Fractures of the Proximal Humerus With Unstable Medial Support: A Biomechanical Study.

Objectives: To evaluate the effect of calcar screw use in proximal humeral fractures with unstable medial support treated with locked plates. Methods: Standard osteotomies were performed in 36 cadaveric humeri to create a surgical neck fracture proximal humeral model. For static testing, 12 pairs of humeri were divided into 4 groups: normal alignment and varus deformity groups with and without 5-mm medial deficiencies. Calcar screw function was measured in each group by axial, shear, and torsion stiffness tests. Another 6 pairs of humeri with 5-mm medial deficiencies were subjected to cyclic loading tests in the normal alignment model with and without calcar screw application. Results: Calcar screws improved rotational stability in the normal alignment (P = 0.007) and varus (P = 0.002) groups. Calcar screws improved static and cyclic axial (P = 0.004) and shear (P = 0.017) stability in the normal alignment group with medial deficiency. In specimens with normal alignment and intact medial cortex, calcar screws provided no advantage in axial (P = 0.535) or shear (P = 0.537) stiffness. Calcar screws did not provide sufficient axial (P = 0.782) or shear (P = 0.772) stability to avoid reduction loss in humeri with varus malreduction. Conclusions: In humeri with normal alignment, calcar screws can provide additional stability even when a medial deficiency exists. The use of calcar screws in humeri with varus deformity showed no biomechanical superiority.

Electrical Stimulation Promotes Regeneration of Defective Peripheral Nerves after Delayed Repair Intervals Lasting under One Month

Background Electrical stimulation (ES) has been proven to be an effective means of enhancing the speed and accuracy of nerve regeneration. However, these results were recorded when the procedure was performed almost immediately after nerve injury. In clinical settings, most patients cannot be treated immediately. Some patients with serious trauma or contaminated wounds need to wait for nerve repair surgery. Delays in nerve repair have been shown to be associated with poorer results than immediate surgery. It is not clear whether electrical stimulation still has any effect on nerve regeneration after enough time has elapsed. Methods A delayed nerve repair model in which the rats received delayed nerve repair after 1 day, 1 week, 1 month, and 2 months was designed. At each point in time, the nerve stumps of half the rats were bridged with an absorbable conduit and the rats were given 1 h of weak electrical stimulation. The other half was not treated. In order to analyze the morphological and molecular differences among these groups, 6 ES rats and 6 sham ES rats per point in time were killed 5 days after surgery. The other rats in each group were allowed to recover for 6 weeks before the final functional test and tissue observation. Results The amounts of myelinated fibers in the distal nerve stumps decreased as the delay in repair increased for both ES rats and sham ES rats. In the 1-day-delay and 1-week-delay groups, there were more fibers in ES rats than in sham ES rats. And the compound muscle action potential (CMAP) and motor nerve conduction velocity (MNCV) results were better for ES rats in these two groups. In order to analyze the mechanisms underlying these differences, Masson staining was performed on the distal nerves and quantitative PCR on the spinal cords. Results showed that, after delays in repair of 1 month and 2 months, there was more collagen tissue hyperplasia in the distal nerve in all rats. The brain-derived neurotrophic factor (BDNF) and trkB expression levels in the spinal cords of ES rats were higher than in sham ES rats. However, these differences decreased as the delay in repair increased. Conclusions Electrical stimulation does not continue to promote nerve regeneration after long delays in nerve repair. The effective interval for nerve regeneration after delayed repair was found to be less than 1 month. The mechanism seemed to be related to the expression of nerve growth factors and regeneration environment in the distal nerves.

Biodegradable Conduit Small Gap Tubulization for Peripheral Nerve Mutilation: A Substitute for Traditional Epineurial Neurorrhaphy

Nerve regeneration and re-innervation are usually difficult after peripheral nerve injury. Epineurium neurorrhaphy to recover the nerve continuity is the traditional choice of peripheral nerve mutilation without nerve defects, whereas the functional recovery remains quite unsatisfactory. Based on previous research in SD rats and Rhesus Monkeys, a multiple centers clinical trial about biodegradable conduit small gap tubulization for peripheral nerve mutilation to substitute traditional epineurial neurorrhaphy was carried out. Herein, the authors reviewed the literature that focused on peripheral nerve injury and possible clinical application, and confirmed the clinical possibilities of biodegradable conduit small gap tubulization to substitute traditional epineurial neurorrhaphy for peripheral nerve mutilation. The biodegradable conduit small gap tubulization to substitute traditional epineurial neurorrhaphy for peripheral nerve mutilation may be a revolutionary innovation in peripheral nerve injury and repair field.

Advances in Small Gap Sleeve Bridging Peripheral Nerve Injury

Abstract: Nerve regeneration and re-innervation are usually difficult after peripheral nerve injury. Epineurium neurorrhaphy to recover the nerve continuity was the traditional choice of peripheral nerve mutilation without nerve defects, whereas the functional recovery was not quite satisfactory. In this article, the authors review the literature focused on peripheral nerve injury research and possible clinical application, including introducing peripheral nerve selective regeneration theory, small gap sleeve bridging nerve methodepineurium neurorrhaphy, kinds of biological conduit, and microenvironment research between nerve stumps.

The Histological Analysis of Biological Conduit Sleeve Bridging Rhesus Monkey Median Nerve Injury with Small Gap

Based on the research on small gap bridging peripheral nerve injury in SD rats, we decided to investigate the histological analysis possibility of bridging peripheral nerve injury with small gap using a de-acetyl chitin conduit in primate. Median nerves of 8 rhesus monkeys were cut at 2 cm above the elbow, and the right sides were subjected to small gap (2 mm) bridging to repair the nerve with chitin conduit (conduit inner diameter 4 mm; length 10 mm); the left sides were subjected to traditionary epineurium suture. Histology detections were conducted after 6th month. The conduit was almost absorbed and the conduit cast contour disappeared after 6 months. The histological analysis displayed that the regenerated nerve fibers in conduit grew forward in fasciculation. The re-myelinated nerve axons number per unit area in the conduit group distal segment was higher than that of traditionary epineurium suture group. The biocompatibility of biological chitin conduit in primate rhesus monkeys was quite good. The regenerated nerve fibers in conduit grew forward in fasciculation. The histological analysis results of biological conduit in primate rhesus monkeys were better than the traditionary epineurium suture. The biological conduit can be used in primate rhesus monkeys to substitute the traditionary epineurium suture methods.

The Electrophysiology Analysis of Biological Conduit Sleeve Bridging Rhesus Monkey Median Nerve Injury with Small Gap

Based on the research on small gap bridging peripheral nerve injury in SD rats, we propose to investigate the possibility of bridging peripheral nerve injury with small gap using a de-acetyl chitin conduit in primates. The median nerves of 8 rhesus monkeys were cut at 2 cm above the elbow; the right sides were subjected to small gap (2 mm) bridging to repair the nerve with chitin conduit (conduit inner diameter 4 mm; length 10 mm); the left sides were subjected to traditionary epineurium suture. The electrophysiology analysis was conducted after the 3rd month and 6th month, respectively. The adhesions condition of biological conduit was only a little after the 15 3rd month; the conduit can remain cast contour; vessels can be seen on the conduit 16 surface and nerve intumescentia was not obvious. The adhesion and intumescentia condition can display better biocompatibilities than traditional suture methods. The motor nerve conduction velocity was only 1/2 of the control group. Although the motor nerve conduction velocity of the conduit group was a little higher than the epineurium suture group, there was no statistically significant difference (P>0.05) at the 3rd month (). The conduit cast contour disappeared after 6 months. The motor nerve conduction velocity was only 4/5 of the control group. The motor nerve conduction velocity of the conduit group was higher than the epineurium suture group; there were statistically significant differences (P<0.05) at 6 months. The nerve trunk conduction velocity of biological conduit was higher than the epineurium suture group at the 6th month, and there were statistically significant differences (P<0.05) (). The biocompatibility of the biological chitin conduit in primate rhesus monkeys was quite good. The electrophysiological results of biological conduit in primate rhesus monkeys were better than the traditional epineurium suture. The biological conduit can be used in primate rhesus monkeys to substitute for the traditional epineurium suture methods.

Belief rule-based inference for predicting trauma outcome

A RIMER methodology-based trauma outcome prediction model is developed.The RIMER-based prediction model is fine-tuned and validated using historical data.LR, SVM, and ANN models are developed and compared with the RIMER model.The RIMER model has the best prediction performance among the four models. A belief rule-based inference methodology using the evidential reasoning approach (RIMER) is employed in this study to construct a decision support tool that helps physicians predict in-hospital death and intensive care unit admission among trauma patients in emergency departments (EDs). This study contributes to the research community by developing and validating a RIMER-based decision tool for predicting trauma outcome. To compare the prediction performance of the RIMER model with those of models derived using commonly adopted methods, such as logistic regression analysis, support vector machine (SVM), and artificial neural network (ANN), several logistic regression models, SVM models, and ANN models are constructed using the same dataset. Five-fold cross-validation is employed to train and validate the prediction models constructed using four different methods. Results indicate that the RIMER model has the best prediction performance among the four models, and its performance can be improved after knowledge base training with historical data. The RIMER tool exhibits strong potential to help ED physicians to better triage trauma, optimally utilize hospital resources, and achieve better patient outcomes.