Intraoperative Protection of Pharyngeal Autonomic Nerves: Preventing Dysphagia After Anterior Cervical Decompression and Fusion Surgery.

OBJECTIVE: The study aims to investigate whether intraoperative protection of the pharyngeal autonomic nerve can effectively reduce the incidence of postoperative dysphagia following anterior cervical decompression and fusion surgery (ACDF). METHODS: A retrospective analysis was conducted on 130 cases that underwent ACDF from January 2018 to June 2022 at our hospital. Divided into nonautonomic neuroprotection (NANP) group and autonomic neuroprotection group based on whether receive protective measures for the pharyngeal autonomic nerve during surgery. General data were recorded and compared between the 2 groups. Postoperative outcomes were evaluated using Neck Disability Index, Japanese Orthopaedics Association (JOA) score, and JOA improvement rate. The incidence and severity of postoperative dysphagia were assessed using Bazaz dysphagia assessment criteria and swallowing-quality of life questionnaire. RESULTS: There were no significant differences in general data (P > 0.05). The average operation time and intraoperative blood loss also showed no significant differences (P > 0.05). Both groups showed significant improvements in Neck Disability Index and JOA scores at all follow-up time points compared to preoperative scores (P < 0.01). The incidence of postoperative dysphagia in the autonomic neuroprotection group was significantly lower than that in the NANP group at all follow-up time points (P < 0.05). Both group showed a significant reduction in scores 3 days postoperatively compared to preoperative scores (P < 0.01), and the NANP group also showed significant reductions in scores at 3 month and 1 year postoperative follow-up time points compared to preoperative scores (P < 0.01). CONCLUSIONS: The adoption of pharyngeal autonomic nerve protective measures during ACDF can effectively lower the probability of postoperative dysphagia.

The protective effect of nicotinamide riboside on mitochondrial function of retinal ganglion cell / 中国药师

Objective To explore the protective effect in a model of nicotinamide riboside(NR)against carbonyl cyanide m-chlorophenylhydrazone(CCCP)-induced oxidative stress in R28 cells.Methods 4 μmol/L CCCP was used to induce oxidative stress in R28 cells,and 400 nmol/L NR was used to intervene.The cell viability was quantified by CCK-8 assay.The apoptosis was detected by Annexin-V/PI double staining and flow cytometry.Western blotting was used to examine the levels of Cytochrome C,Caspase-3,and Caspase-9 to evaluate the apoptosis.Tetramethylrhodamine ethyl ester was used to detect the mitochondrial membrane potential(MMP),MitoSOX was used to detect the mitochondrial reactive oxygen species(mtROS)levels,and adenosine triphosphate(ATP)assay kit was used to assess ATP generation ability to evaluate mitochondrial function.Results After CCCP treatment of R28 cells,the cell viability decreased,the apoptotic protein levels and apoptosis rates increased,the MMP decreased,and the mtROS generation increased(P＜0.05).After NR pretreatment,the cell viability increased,the apoptotic protein levels and apoptosis rates decreased,the MMP increased,and the mtROS generation decreased(P＜0.05).Conclusion:NR enhances the cell viability,reduces the expression of apoptotic proteins,and ultimately reduces the apoptosis of retinal ganglion cell by inhibiting oxidative stress response and protecting mitochondrial function.

Mitigation of Paeoniae Radix Alba extracts on H2O2-induced oxidative damage in HepG2 cells and hyperglycemia in zebrafish, and identification of phytochemical constituents.

Paeoniae Radix Alba (PRA), as a Traditional Chinese Medicine, is widely used in Chinese cuisine due to high health-benefits and nutrition, but the effect of different polarity of solvents on the extraction of antioxidant and hypoglycemic constituents, as well as the major active compounds remain unclear. In this research, 40, 70, and 95% ethanol were firstly applied to extract the polyphenols from PRA, the extraction yields, total phenolics, and total flavonoids content, free radical scavenging ability, α-glucosidase inhibition ability, and anti-glycation ability of extracts were evaluated spectroscopically. The oxidative damage protection, hypoglycemic activity, and alleviation on peripheral nerve damage were evaluated by H2O2-induced HepG2 cells and hyperglycemic zebrafish models. UPLC-QTOF-MS/MS was used to identify the major chemical constituents. The results showed that 40, 70, and 95% ethanol exhibited insignificant difference on the extraction of phenolics and flavonoids from PRA. All extracts showed promising DPPH⋅ and ABTS⋅+ scavenging ability, α-glucosidase inhibition and anti-glycation ability. In addition, PRA extracts could restore the survival rate of HepG2 cells induced by H2O2, and alleviate the oxidative stress by reducing the content of MDA and increasing the levels of SOD, CAT, and GSH-Px. The 70% ethanol extract could also mitigate the blood glucose level and peripheral motor nerve damage of hyperglycemic zebrafish. Thirty-five compounds were identified from 70% ethanol extract, gallotannins, gallic acid and its derivatives, and paeoniflorin and its derivatives were the dominant bioactive compounds. Above results could provide important information for the value-added application of PRA in functional food and medicinal industry.

Analysis of the effect of neuroendoscopy-assisted microscopy in the treatment of Large (Koos grade IV) vestibular schwannoma.

Introduction: This article aimed to investigate the effects of the endoscopic-assisted microsurgery technique on the resection of large (Koos grade IV) vestibular schwannoma (VS) and provide a prognosis analysis of the patients. Methods: A retrospective analysis of the use of the endoscopic-assisted microsurgery technique in 16 cases of large vestibular schwannoma surgery was carried out. Intraoperative nerve electrophysiological monitoring was conducted to explore the effect of neuroendoscopy on the resection of internal auditory canal tumors, protection of the facial nerve, and minimizing postoperative complications. Results: Tumors were completely removed in all 16 cases, and the facial nerve was anatomically preserved in 14 cases (87.5%). There was no postoperative cerebrospinal fluid leakage and no intracranial infection complications occurred.Following the House-Brackmann (H-B) grading system, post-operative facial nerve function was grade I in 5 cases, grade II in 6 cases, grade III in 3 cases, and grade V in 2 cases. As a result, the preservation rate of facial nerve function (H-B grade I-II) was 68.8%. All 16 patients were followed up for 3 to 24 months, and no tumor recurrence was found on enhanced MRI. Discussion: Using the endoscopic-assisted microsurgery technique in the retrosigmoid approach has many advantages over the microscopic-only approach. When compared to the microscopy-only approach, the endoscope can provide a wide-angle surgical field superior to that of a microscope in areas such as the internal auditory canal in the resection of large VS, minimize iatrogenic injuries, ensure complete removal of internal auditory canal tumors, and well as reducing postoperative complications such as cerebrospinal fluid leakage and the loss of facial and auditory nerve functions.

Research advances in neuroprotective role of sigma-1 receptor in retina / 中华实验眼科杂志

Retinal degenerative diseases are a major contributor to visual impairment worldwide, and research related to retinal degenerative diseases is increasingly becoming a hot topic.The sigma-1 receptor is a 223-amino-acid endoplasmic reticulum transmembrane protein, and its gene sequence is highly conserved throughout mammals.Sigma-1 receptors are widely distributed in various tissues and organs.Numerous studies have proved the protective role of sigma-1 receptors in retinal pathological processes, including anti-oxidative stress, anti-inflammatory response, and anti-apoptosis.In addition, sigma-1 receptors have potential therapeutic roles in retinal diseases, especially diabetic retinopathy, retinitis pigmentosa and glaucomatous neuropathy.In this paper, the molecular mechanisms of sigma-1 receptor-mediated retinal neuroprotection and its application in the treatment of retinal diseases were reviewed.

Neuroprotection in Glaucoma: Basic Aspects and Clinical Relevance.

Glaucoma is a neurodegenerative disease that affects primarily the retinal ganglion cells (RGCs). Increased intraocular pressure (IOP) is one of the major risk factors for glaucoma. The mainstay of current glaucoma therapy is limited to lowering IOP; however, controlling IOP in certain patients can be futile in slowing disease progression. The understanding of potential biomolecular processes that occur in glaucomatous degeneration allows for the development of glaucoma treatments that modulate the death of RGCs. Neuroprotection is the modification of RGCs and the microenvironment of neurons to promote neuron survival and function. Numerous studies have revealed effective neuroprotection modalities in animal models of glaucoma; nevertheless, clinical translation remains a major challenge. In this review, we select the most clinically relevant treatment strategies, summarize preclinical and clinical data as well as recent therapeutic advances in IOP-independent neuroprotection research, and discuss the feasibility and hurdles of each therapeutic approach based on possible pathogenic mechanisms. We also summarize the potential therapeutic mechanisms of various agents in neuroprotection related to glutamate excitotoxicity.

Protective effects and mechanism of puerarin targeting PI3K/Akt signal pathway on neurological diseases.

Neurological diseases impose a tremendous and increasing burden on global health, and there is currently no curative agent. Puerarin, a natural isoflavone extracted from the dried root of Pueraria montana var. Lobata (Willd.) Sanjappa and Predeep, is an active ingredient with anti-inflammatory, antioxidant, anti-apoptotic, and autophagy-regulating effects. It has great potential in the treatment of neurological and other diseases. Phosphatidylinositol 3-kinases/protein kinase B (PI3K/Akt) signal pathway is a crucial signal transduction mechanism that regulates biological processes such as cell regeneration, apoptosis, and cognitive memory in the central nervous system, and is closely related to the pathogenesis of nervous system diseases. Accumulating evidence suggests that the excellent neuroprotective effect of puerarin may be related to the regulation of the PI3K/Akt signal pathway. Here, we summarized the main biological functions and neuroprotective effects of puerarin via activating PI3K/Akt signal pathway in neurological diseases. This paper illustrates that puerarin, as a neuroprotective agent, can protect nerve cells and delay the progression of neurological diseases through the PI3K/Akt signal pathway.

Advances in the roles and mechanisms of lignans against Alzheimer's disease.

Background: Alzheimer's disease (AD) is a serious neurodegenerative disease associated with the memory and cognitive impairment. The occurrence of AD is due to the accumulation of amyloid ß-protein (Aß) plaques and neurofibrillary tangles (NFTs) in the brain tissue as well as the hyperphosphorylation of Tau protein in neurons, doing harm to the human health and even leading people to death. The development of neuroprotective drugs with small side effects and good efficacy is focused by scientists all over the world. Natural drugs extracted from herbs or plants have become the preferred resources for new candidate drugs. Lignans were reported to effectively protect nerve cells and alleviate memory impairment, suggesting that they might be a prosperous class of compounds in treating AD. Objective: To explore the roles and mechanisms of lignans in the treatment of neurological diseases, providing proofs for the development of lignans as novel anti-AD drugs. Methods: Relevant literature was extracted and retrieved from the databases including China National Knowledge Infrastructure (CNKI), Elsevier, Science Direct, PubMed, SpringerLink, and Web of Science, taking lignan, anti-inflammatory, antioxidant, apoptosis, nerve regeneration, nerve protection as keywords. The functions and mechanisms of lignans against AD were summerized. Results: Lignans were found to have the effects of regulating vascular disorders, anti-infection, anti-inflammation, anti-oxidation, anti-apoptosis, antagonizing NMDA receptor, suppressing AChE activity, improving gut microbiota, so as to strengthening nerve protection. Among them, dibenzocyclooctene lignans were most widely reported and might be the most prosperous category in the develpment of anti-AD drugs. Conclusion: Lignans displayed versatile roles and mechanisms in preventing the progression of AD in in vitro and in vivo models, supplying potential candidates for the treatment of nerrodegenerative diseases.

Erythropoietin in Optic Neuropathies: Current Future Strategies for Optic Nerve Protection and Repair.

Erythropoietin (EPO) is known as a hormone for erythropoiesis in response to anemia and hypoxia. However, the effect of EPO is not only limited to hematopoietic tissue. Several studies have highlighted the neuroprotective function of EPO in extra-hematopoietic tissues, especially the retina. EPO could interact with its heterodimer receptor (EPOR/ßcR) to exert its anti-apoptosis, anti-inflammation and anti-oxidation effects in preventing retinal ganglion cells death through different intracellular signaling pathways. In this review, we summarized the available pre-clinical studies of EPO in treating glaucomatous optic neuropathy, optic neuritis, non-arteritic anterior ischemic optic neuropathy and traumatic optic neuropathy. In addition, we explore the future strategies of EPO for optic nerve protection and repair, including advances in EPO derivates, and EPO deliveries. These strategies will lead to a new chapter in the treatment of optic neuropathy.

Epicardial access complications during electrophysiology procedures.

INTRODUCTION: Percutaneous epicardial access (EA) was first described more than two decades ago. Since its initial introduction, indications for its utilization in the field of electrophysiology have expanded dramatically. DISCUSSION: Epicardial mapping and ablation in patients with ventricular tachycardia is routinely performed in tertiary electrophysiology centers around the world. Although limited by lack of randomized controlled trials, epicardial ablation for atrial fibrillation has been suggested as a conjunctive strategy in patients who have failed an initial endocardial catheter ablation attempt, and it is necessary for placement of some left atrial appendage occlusion devices as well. An accurate understanding of the cardiac anatomy is crucial to avoid complications such as inadvertent right ventricular puncture, injury to the coronary arteries, abdominal viscera, phrenic nerves, and esophagus during both EA and catheter ablation. CONCLUSION: The aim of this review is to provide a comprehensive overview of the cardiac anatomy, technical aspects to optimize the safety of epicardial puncture, recognize and avoid potential complications.

PI3K/AKT Signal Pathway: A Target of Natural Products in the Prevention and Treatment of Alzheimer's Disease and Parkinson's Disease.

Alzheimer's disease (AD) and Parkinson's disease (PD) are two typical neurodegenerative diseases that increased with aging. With the emergence of aging population, the health problem and economic burden caused by the two diseases also increase. Phosphatidylinositol 3-kinases/protein kinase B (PI3K/AKT) signaling pathway regulates signal transduction and biological processes such as cell proliferation, apoptosis and metabolism. According to reports, it regulates neurotoxicity and mediates the survival of neurons through different substrates such as forkhead box protein Os (FoxOs), glycogen synthase kinase-3ß (GSK-3ß), and caspase-9. Accumulating evidences indicate that some natural products can play a neuroprotective role by activating PI3K/AKT pathway, providing an effective resource for the discovery of potential therapeutic drugs. This article reviews the relationship between AKT signaling pathway and AD and PD, and discusses the potential natural products based on the PI3K/AKT signaling pathway to treat two diseases in recent years, hoping to provide guidance and reference for this field. Further development of Chinese herbal medicine is needed to treat these two diseases.

Lymph node dissection and key technical points in 4K laparoscopic radical resection of mid-distal sigmoid colon cancer / 中华消化外科杂志

Colon cancer is a commonly malignant tumor with high morbidity and mortality in China, which seriously threatens human health and lives. Surgery plays a key role in the treatment of colorectal cancer so far. The sigmoid colon is the predilection site of colon cancer. Laparoscopic surgery has been gradually applied in radical operation of sigmoid colon cancer. 4K laparoscopy belongs to a kind of high-imaging technology, of which the information volume is more than 4 times that of conventional high-definition televisions. It can improve the operator's sense of control on the surgical field of view. Combined with team practical experience, the author introduces and interprets the excision extent and operative procedures in radical resection of mid-distal sigmoid colon cancer from the perspective of the 4K laparoscopy.

Prophylactic nimodipine treatment improves hearing outcome after vestibular schwannoma surgery in men: a subgroup analysis of a randomized multicenter phase III trial.

A 2016 published randomized multicenter phase III trial of prophylactic nimodipine treatment in vestibular schwannoma surgery showed only a tendency for higher hearing preservation rates in the treatment group. Gender was not included in statistical analysis at that time. A retrospective analysis of the trial considering gender, preoperative hearing, and nimodipine treatment was performed. The treatment group received parenteral nimodipine from the day before surgery until the seventh postoperative day. The control group was not treated prophylactically. Cochlear nerve function was determined by pure-tone audiometry with speech discrimination preoperatively, during in-patient care, and 1 year after surgery and classified according to the Gardner-Robertson grading scale (GR). Logistic regression analysis showed a statistically significant effect for higher hearing preservation rates (pre- and postoperative GR 1-4) in 40 men comparing the treatment (n = 21) and the control (n = 19) groups (p = 0.028), but not in 54 women comparing 27 women in both groups (p = 0.077). The results were also statistically significant for preservation of postoperative hearing with pre- and postoperative GR 1-3 (p = 0.024). There were no differences in tumor sizes between the treatment and the control groups in men, whereas statistically significant larger tumors were observed in the female treatment group compared with the female control group. Prophylactic nimodipine is safe, and an effect for hearing preservation in 40 men with preoperative hearing ability of GR 1-4 was shown in this retrospective investigation. The imbalance in tumor size with larger tumors in females of the treatment group may falsely suggest a gender-related effect. Further investigations are recommended to clarify whether gender has impact on nimodipine's efficacy.

Biportal endoscopic spine surgery (BESS): considering merits and pitfalls.

The biportal endoscopic spine surgery allow us to use conventional spine surgical instruments in the endoscopic procedure like open surgery. And protection of the neural structures with assistant retractor make this procedure safer than the uniportal endoscopic spine surgery. The authors present a novel technique in treating degenerative spinal diseases in variable access angle different from the conventional uniportal endoscopic spine surgeries. The main objective of this report is presenting two approaches for central and extraforaminal stenosis using an assistant retractor. Both central and foraminal stenosis were well decompressed and a migrated disc fragment was removed successfully with this minimal endoscopic procedure without major complications in these cases.

Advances of anti-glaucoma Chinese herb monomers / 国际眼科杂志(Guoji Yanke Zazhi)

@#Glaucoma is an eye disease characterized by progressiveretinal nerve damage and impaired vision, which is the top one irreversible blinding eye disease. The pathologic intraocular pressure elevation is its key risk. At present, the clinical medicine with intraocular pressure reducing and retinal nerve protection effects focused on symptomatic therapy with unsatisfied effects. Chinese herb monomers have advantages of both Chinese herbs and chemical drugs. Chinese herbs and Chinese herb monomers have favorable effects on glaucoma therapy, especially on retinal nerve protection, which provides a vast room for new drug development. The paper summarized applications and mechanism of representative anti-glaucoma Chinese herbal formulas, Chinese herbs and especially Chinese herb monomers, which would provide references for clinical therapy and new drug development for glaucoma.

Mastering the art of epicardial access in cardiac electrophysiology.

Access to the epicardial space is fundamental to several cardiac procedures. While traditional indications include catheter ablation of ventricular arrhythmias and accessory pathways, novel indications include left atrial appendage occlusion, esophageal protection, mapping and ablation during atrial fibrillation procedures, implantation of epicardial pacing leads, and phrenic nerve displacement to facilitate safe ablation of atrial and ventricular arrhythmias. Accessing the epicardial space safely is a major challenge requiring intimate knowledge of cardiac anatomy, extensive training, and expertise. Over the past years, multiple technological advances have led to significant improvements in epicardial access success and safety. Important examples of such advances include CO2 insufflation through the coronary sinus or the right atrial appendage, pressure sensor needle, computed tomography, cardiac magnetic resonance, and electroanatomic mapping-guided epicardial access. In addition, we provide special maneuvers to minimize inadvertent right ventricular perforation.

Clinical study of Xingnaojing combined with butylphthalide in treatment of vascular dementia / 中国中西医结合急救杂志

Objective To observe the clinical efficacy of Xingnaojing combined with butylphthalide in the treatment of vascular dementia (VD). Methods One hundred and twenty VD patients admitted to First People's Hospital of Tongxiang from August 1st 2014 to December 1st 2017 were enrolled, all the patients were given routine treatment according to their disease conditions, 53 cases were treated by intravenous drip of butylphthalide and sodium chloride injection (100 mL containing butylphthalide 25 mg and sodium chloride 0.9 g), 100 mL once, 2 times each day (single-use group); another 67 patients were treated with Xingnaojing 20 mL added into 200 mL glucose solution intravenous drip, once a day, on the basis of the treatment in the single-use group (combined group), and both groups were treated for 4 weeks. The changes of mini-mental state examination (MMSE) and activity of daily life (ADL) scores, clinical efficacy and adverse reactions were observed before and after treatment in the two groups. Results The MMSE and ADL scores in both groups were higher after treatment than those before treatment, and the MMSE and ADL scores in the combined group were significantly higher than those in the single-use group (MMSE scores: 26.77±1.30 vs. 25.64±2.81, ADL: 74.77±3.30 vs. 59.23±4.21, both P < 0.05); the clinical efficacy of the combined group was significantly higher than that of the single-use group [97.0% (65/67) vs. 81.1% (43/53), P < 0.05], however, there was no significant difference in the incidence of adverse reactions between the combined group and the single-use group [7.5% (5/67) vs. 7.6% (4/53), P > 0.05 ]. Conclusions After treatment of VD with the combination of Xingnaojing and butylphthalide, the cognitive function and daily living ability of the patients are improved to some extent, the combined treatment is more effective than the single application of butylphthalide, and no obvious adverse reaction occurs during the therapeutic course.

Four New Depsides Isolated from Salvia miltiorrhiza and Their Significant Nerve-Protective Activities.

By investigating of the roots of Salvia miltiorrhiza, which is one of the most widely used Chinese herbs, we used phytochemical methods successfully to obtain twelve depsides: four depsides (1⁻4) that were previously undescribed, along with eight known ones (5⁻12). Their structure characteristics were assessed by HR-ESIMS, CD, NMR (¹H, 13C, HSQC, HMBC) data analyses. These four newly isolated compounds (1⁻4), as well as the other eight compounds (5⁻12), show extraordinary protective effects on hydrogen peroxide-induced apoptosis in HS-SY5Y cells. Among them, depside 4 and depside 6 displayed more obviously protective effects than others.

Acupuncture through Baihui (DU20) to Qubin (GB7) mitigates neurological impairment after intracerebral hemorrhage.

Inflammation plays an important role in nerve defects caused by intracerebral hemorrhage. Repairing brain damage by inhibiting the macrophage-inducible C-type lectin/spleen tyrosine kinase (Mincle/Syk) signaling pathway is a potential new target for treating cerebral hemorrhage. In this study, we aimed to determine whether acupuncture through Baihui (DU20) to Qubin (GB7) is an effective treatment for intracerebral hemorrhage through the Mincle/Syk signaling pathway. An intracerebral hemorrhage rat model was established by autologous blood infusion into the caudate nucleus. Acupuncture through Baihui to Qubin was performed for 30 minutes, once every 12 hours, for a total of three times. Piceatannol (34.62 mg/kg), a Syk inhibitor, was intraperitoneally injected as a control. Modified neurological severity score was used to assess neurological function. Brain water content was measured. Immunohistochemistry and western blot assay were used to detect immunoreactivity and protein expression levels of Mincle, Syk, and CARD9. Real-time polymerase chain reaction was used to determine interleukin-1ß mRNA levels. Hematoxylin-eosin staining was performed to observe histopathological changes. Our results showed that acupuncture through Baihui to Qubin remarkably improved neurological function and brain water content, and inhibited immunoreactivity and expression of Mincle, Syk, CARD9, and interkeukin-1ß. Moreover, this effect was similar to piceatannol. These findings suggest that acupuncture through Baihui to Qubin can improve neurological impairment after cerebral hemorrhage by inhibiting the Mincle/Syk signaling pathway.

Perineurium-like sheath derived from long-term surviving mesenchymal stem cells confers nerve protection to the injured spinal cord.

The functional multipotency enables mesenchymal stem cells (MSCs) promising translational potentials in treating spinal cord injury (SCI). Yet the fate of MSCs grafted into the injured spinal cord has not been fully elucidated even in preclinical studies, rendering concerns of their safety and genuine efficacy. Here we used a rat spinal cord transection model to evaluate the cell fate of allograft bone marrow derived MSCs. With the application of immunosuppressant, donor cells, delivered by biocompatible scaffold, survived up to 8 weeks post-grafting. Discernible tubes formed by MSCs were observed beginning 2 weeks after transplantation and they dominated the morphological features of implanted MSCs at 8 weeks post-grafting. The results of immunocytochemistry and transmission electron microscopy displayed the formation of perineurium-like sheath by donor cells, which, in a manner comparable to the perineurium in peripheral nerve, enwrapped host myelins and axons. The MSC-derived perineurium-like sheath secreted a group of trophic factors and permissive extracellular matrix, and served as a physical and chemical barrier to insulate the inner nerve fibers from ambient oxidative insults by the secretion of soluble antioxidant, superoxide dismutase-3 (SOD3). As a result, many intact regenerating axons were preserved in the injury/graft site following the forming of perineurium-like sheath. A parallel study utilizing a good manufacturing practice (GMP) grade human umbilical cord-derived MSCs or allogenic MSCs in an acute contusive/compressive SCI model exhibited a similar perineurium-like sheath formed by surviving donor cells in rat spinal cord at 3 weeks post-grafting. The present study for the first time provides an unambiguous morphological evidence of perineurium-like sheath formed by transplanted MSCs and a novel therapeutic mechanism of MSCs in treating SCI.