The biomaterial, chitin, was used to create a nerve regeneration chamber for bridging healing experiment of sciatic nerve of rats having a defect of 12mm. The crude Schwann cells were introduced into the chambers in one group and the other group had no crude Schwann cells in the chamber and the results of the two groups were compared with those having the nerve defects bridged with skeletal muscles. The specimens were observed by macroscopic, microdissection. electrophysiologic testing, HRP retrograde labelling, histologic and electron microscopic examinations at 4, 8, and 12 weeks after the operation. The results showed that atthe 8th week, the regenerating nerve fibers from the cephalad ends had united with the fibers of the caudal ends of the divided nerves either the crude Schwanneclls were introduced or not, but the morphology of the regenerating nerve, the way of regeneration and the recovery of the function of the extremities were far superior in the group that no cruds Schwann cells had been introduced than those with crude Schwann cell introduced and those bridged by skeletal muscles.
Schwanns cell (SC) was isolated from sciatic nerve of adult rat with Wallerine degeneration. After culture, SC-serum free culture media (SCSFCM) was obtained. By ultrafiltration with PM-10 Amicon Membrane, electrophoresis with DiscPAGE,and electrical wash-out with Biotrap apparatus, D-band protein was isolated from the SC-SFCM. The D-band protein in the concentration of 25ng/ml could affect the survival of the spinal anterior horn neuron in vitro, prominently and itsactivity was not changed after being frozen. The molecular weight of the protein ranged from 43 to 67 Kd. The D-band protein might be a neurotrophic substancedifferent from the known SCderived neurotrophic factors (NTF). Its concentration with biological activity was high enough to be detected. The advantages of MTT in assessment of NTF activity were also discussed.
Objective To investigate the clinical features, treatment methods, and prognostic influence factors of patients with malignant peripheral nerve sheath tumor (MPNST). MethodsA retrospective analysis was conducted on 96 MPNST patients treated between January 1, 2015 and December 31, 2021. There were 46 males and 50 females, aged between 15 and 87 years (mean, 48.2 years). The tumors were located in the trunk in 50 cases, extremities in 39 cases, and head and neck in 7 cases. The maximum tumor diameter was <5 cm in 49 cases, ≥5 cm in 32 cases, with 15 cases missing data. Tumor depth was deep in 77 cases and superficial in 19 cases. The Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) histological grading was G1 in 9 cases, G2 in 12 cases, and G3 in 34 cases, with 41 cases missing data. There were 37 recurrent MPNST cases, 32 cases with neurofibromatosis type 1 (NF1), and 26 cases in stage Ⅳ. Postoperative adjuvant radiotherapy was administered to 25 patients, perioperative chemotherapy to 45 patients, and anlotinib-targeted therapy to 30 patients. R0 resection was achieved in 73 cases. Patients were divided into groups based on the presence or absence of NF1, and baseline data between the two groups were compared. Kaplan-Meier curves were generated to assess disease-free survival (DFS) and overall survival (OS) based on various factors (age, gender, presence of NF1, recurrent MPNST, stage Ⅳ MPNST, FNCLCC grade, R0 resection, tumor location, tumor size, tumor depth, perioperative chemotherapy, postoperative adjuvant radiotherapy, and anlotinib-targeted therapy), and differences between survival curves were analyzed using the Log-Rank test. Multivariate COX proportional hazards regression was used to identify independent prognostic factors for MPNST. Results Patients with NF1 had a significantly higher proportion of superficial tumors and lower FNCLCC grade compared to those without NF1 (P<0.05); no significant difference was found for other variables (P<0.05). Kaplan-Meier analysis showed that recurrent MPNST, stage Ⅳ MPNST, FNCLCC grade, R0 resection, perioperative chemotherapy, and anlotinib-targeted therapy were factors influencing 1-year DFS (P<0.05), while stage Ⅳ MPNST, FNCLCC grade, and perioperative chemotherapy were factors affecting 3-year OS (P<0.05). Multivariate COX proportional hazards regression analysis revealed that recurrent MPNST and high-grade FNCLCC (G3) were independent prognostic factors for 1-year DFS (P<0.05), while stage Ⅳ MPNST, superficial tumor depth, age over 60 years, postoperative adjuvant radiotherapy, and anlotinib-targeted therapy were independent prognostic factors for 3-year OS (P<0.05). Conclusion MPNST patients with NF1 tend to have more superficial tumors and lower FNCLCC grades. FNCLCC grade, R0 resection, and adjuvant therapies, including radiotherapy and anlotinib-targeted therapy, are closely associated with MPNST prognosis. Complete surgical resection should be prioritized in clinical management, along with adjuvant treatments such as radiotherapy and targeted therapy of anlotinib to improve patient outcomes.
ObjectiveTo summarize the applications of Schwann cells (SCs), stem cells, and genetically modified cells (GMCs) in repair of peripheral nerve defects. MethodsThe literature of original experimental study and clinical research related with SCs, stem cells, and GMCs was reviewed and analyzed. ResultsSCs play a key role in repair of peripheral nerve defects; the stem cells can be induced to differentiate into SCs, which can be implanted into nerve conduits to promote the repair of peripheral nerve defect; genetically modified technology can enhance the function of SCs and different stem cells, which has been regarded as a new option for tissue engineered nerve. ConclusionAlthough great progress has been made in tissue engineered nerve recently, mostly limited to the experimental stage. The research of seed cells in application of tissue engineered nerve need be studied deeply.
Objective To review systematically whether there is enough existing evidence that methylcobalamin is effective and safe in the treatment of the patients with diabetic peripheral neuropathy.Methods A Cochrane systematic review of all relevant randomized or quasi-randomized controlled trials of methycobalamin for diabetic peripheral neuropathy was performed. Clinical trials were searched from Cochrane Controlled Trials Register (Issue 4, 2003), MEDLINE (January 1966 to January 2004), EMBASE (January 1980 to January 2004), the Chinese Biological Medicine Database (1978 to January 2004), the Chinese Science and Technology Journal Full-text Database (1989 to January 2004) and references of all included trials. The selection of studies, data extraction and assessment of methodological quality were performed independently by two reviewers. The following outcomes were assessed: effectiveness of clinical signs and symptoms, sensory nerve and motor nerve conduction velocities and serious adverse events of methylcobalamin. Results Thirty randomized clinical trials including 1 949 patients met the inclusion criteria. The quality of the most included trials was of low level. The "funnel plot" of the comparison of thirteen studies of methylcobalamin with other B Vitamins studies showed symmetry, which indicated less possible publication bias and the result was partly reliable, but it could not indicate the whole publication biases. The results of meta-analysis indicated that methylcobalamin showed significantly positive effects on the improvement of the signs and symptoms of peripheral neuropathy, and the effects were better than the other vitamin B agents. The increase of some nerves conduction velocities by methylcobalamin was better than by the other vitamin B. No serious adverse events were observed during the treatment period.Conclusions Methylcobalamin appears to be a safe and effective treatment on diabetic peripheral neuropathy. However, the evidence is not b because of the low quality of most trials. Rigorously designed, randomized, double-blinded, placebo-controlled trials of methylcobalamin for diabetic peripheral neuropathy are needed to further assess the effect.
OBJECTIVE Following the delayed repair of peripheral nerve injury, the cell number of anterior horn of the spinal cord and its ultrastructural changes, motorneuron and its electrophysiological changes were investigated. METHODS In 16 rabbits the common peroneal nerves of both sides being transected one year later were divided into four groups randomly: the degeneration group and regeneration of 1, 3 and 5 months groups. Another 4 rabbits were used for control. All transected common peroneal nerves underwent epineural suture except for the degeneration group the electrophysiological examination was carried out at 1, 3 and 5 months postoperatively. Retrograde labelling of the anterior horn cells was demonstrated and the cells were observed under light and electronmicroscope. RESULTS 1. The number of labelled anterior horn cell in the spinal cord was 45% of the normal population after denervation for one year (P lt; 0.01). The number of labelled cells increased steadily from 48% to 57% and 68% of normal values at 1, 3 and 5 months following delayed nerve repair (P lt; 0.01). 2. The ultrastructure of the anterior horn cells of the recover gradually after repair. 3. With the progress of regeneration the latency become shortened, the conduction velocity was increased, the amplitude of action potential was increased. CONCLUSION Following delayed repair of injury of peripheral nerve, the morphology of anterior horn cells of spinal cord and electrophysiological display all revealed evidence of regeneration, thus the late repair of injury of peripheral nerve was valid.
ObjectiveTo summarize the research progress of autologous vein nerve conduit for the repair of peripheral nerve defect. MethodsThe recent domestic and foreign literature concerning autologous vein nerve conduit for repair of peripheral nerve defect was analyzed and summarized. ResultsA large number of basic researches and clinical applications show that the effect of autologous venous nerve conduit is close to that of autologous nerve transplantation in repairing short nerve defect, especially the compound nerve conduit has a variety of autologous nerve tissue, cells, and growth factors, etc. ConclusionAutologous vein nerve conduit for repair of non-nerve defect can be a good supplement of autologous nerve graft, improvement of autologous venous catheter to repair peripheral nerve defect is the research direction in the future.
To observe the change of morphology and neuropeptide in the spinal neurons in order to clarify the functional state after injury of peripheral nerves is especially in the late stage. Sciatic nerves were cut with their proximal segments in the preparation of a model of peripheral nerve injury. Combination of horseradish peroxidase retrograde tracing immunohistochemistry and computer image analysis the changes in the morphometry of the perikarya of ventral horn neurons of the spinal cord, the quantitative changes of substance P (SP). Calcitonin gene-related peptide (CGRP) in dorsal horn and CGRP and choline acetyransferase (CHAT) in ventral horn of the spinal cord were examed. The results showd: (1) At the 3rd week after injury, swollen perikarya of the ventral horn neurons were observed, subseauently the swelling of perikarya was decreased tile the 6th week the neurons recovered to their normal size. At the 12th week the neurons were generally stable in their size, shortening of the dendrites was seen in 27% of the neurons. (2) The dendrites of the neurons progressively contracted till at the 12th week 53% of them were degenerated. The results of the 24th week were similar to the that at the 12th week. (3) CGRP in the ventral horn of the spinal cord was elevated to the highest point after 1 week of injury, that lasting for 4 weeks and 8 weeks later, the lever of CGRP returned to normal. From 20th to 24th week, there was no obvious changes of CHAT in the ventral horn of the spinal cord during observation. (4) SP went to the lowest point in the dorsal horn during 2-6 weeks, then recovered slowly, and beiny normal again after 16 weeks, however, CGRP was changed slightly. The results indicated that although a series of degenerating changes occurred in the neurons of the spinal cord during the late peripheral nerve injury, but the functional activity of the central meurons still was maintained at a certain level.
Objective To analyze the diagnostic value of shear wave elastography (SWE) combined with vascular endothelial growth factor B (VEGF-B) and hemoglobin A1c (HbA1c) in early diabetic peripheral neuropathy (DPN). Methods A total of 100 patients with type 2 diabetes mellitus (T2DM) admitted to Mianyang Central Hospital between October 2020 and October 2023 were selected and divided into a T2DM with DPN group (n=31) and a T2DM without DPN group (n=69) based on the presence or absence of DPN. Additionally, 50 healthy individuals from the same hospital’s health examination center were included as a healthy control group. The basic clinical characteristics, mean elasticity (Emean) values of the left and right median and tibial nerves, serum VEGF-B, and HbA1c levels were compared among the three groups. The diagnostic efficacy of SWE, VEGF-B, and HbA1c for DPN was evaluated using receiver operating characteristic (ROC) curves, and Pearson correlation analysis was performed to assess the relationships between median/tibial nerve Emean and VEGF-B/HbA1c. Results The Emean values of the left and right median nerves, Emean values of the left and right tibial nerves, serum VEGF-B, and HbA1c levels in the T2DM with DPN group were significantly higher than those in the T2DM without DPN group and the healthy control group (P<0.05). The Emean values of the left and right median and tibial nerves, Emean values of the left and right tibial nerves, and HbA1c level in the T2DM without DPN group were significantly higher than those in the healthy control group (P<0.05), while no significant difference was observed in serum VEGF-B level between the T2DM without DPN group and the healthy control group (P>0.05). The area under the ROC curve for the combined diagnosis of DPN using SWE, VEGF-B, and HbA1c was 0.859 [95% confidence interval (0.828, 0.955)]. The sensitivity of the combined diagnosis (93.72%) was significantly higher than that of individual diagnoses (78.82%, 75.39%, and 71.05%, respectively; P<0.05), while the specificity (88.64%) showed no significant difference compared to individual diagnoses (80.18%, 78.96%, and 82.88%, respectively; P>0.05). Positive correlations were observed between median/tibial nerve Emean and VEGF-B/HbA1c levels (r=0.428, 0.395, 0.416, and 0.416, respectively; P<0.05). Conclusions Elevated median/tibial nerve Emean, serum VEGF-B, and HbA1c levels are closely associated with DPN. The combination of SWE, VEGF-B, and HbA1c improves diagnostic sensitivity for DPN, demonstrating significant clinical value.