scholarly journals Morphological changes of the nerve after restorative treatment using electric welding technology (experimental study)

2019 ◽  
Vol 27 (1) ◽  
pp. 91-98
Author(s):  
V. Yu. Molotkovets
Keyword(s):  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Morphological Changes ◽  
Distal Segment ◽  
Male Rats ◽  
Simultaneous Formation ◽  
Electric Welding ◽  
Restorative Treatment ◽  
Recovery Processes ◽  
Complete Alignment

Objective – to study morphological features regenerative nerve neuroma after a complete intersection and restorative surgery with the use of electric welding technology.Materials and methods. The experimental model of operative intervention on injured peripheral nerve by immediate nerve stump’s epineurium welding and partial hindlimb immobilization was developed. The study was performed on 66 white, non-breeding male rats aged 5–7 months with a body weight of 350–450 g of vivarium breeding in Institute of Neurosurgery named after acad. A.P. Romodanov NAMS of Ukraine. Animals were divided into four experimental groups: 1 – surgical animals that included access to the sciatic nerve and its full intersection (n = 21), 2 – animals that were surgically intervened, which included access to the sciatic nerve, its intersection and the restoration of anatomical integrity by the application of an epineural suture (n = 18), 3 – animals that were operated surgically, which included access to the sciatic nerve, its intersection and the restoration of anatomical integrity by electric welding of the epineurium of the ends (n = 21), 4 – sham group, who were given access to the transverse nerve without its intersection (n = 6). In the experimental group of electric welding, the operation was performed using the apparatus EKWZ-300, «Patonmed» in the automatic mode dA2, with variable high-frequency (440 kHz) modulated current up to 0,3 A, the voltage at the 34 V pincer shield, the duration of the rectangular exposure pulse 0.8 s. Formated 5–6 electric weld point connections along the perimeter of the intersection with a complete alignment of the ends. The neurohistological method of study was used to study the morphological picture of the peripheral nerve in the region of the regenerative neurology and the distal segment in 1 and 3 months after surgical intervention. Results. It was established that simultaneous use of the technique of welded epineural joint of parts and partial immobilization of the limb in the postoperative period leads to uniform maturation of the neuro-connective tissue and its more complete neuroticisation.Conclusions. Recovery processes in the injured peripheral nerve occur better with the simultaneous formation of an immediate welded epineural joint of the ends and partial immobilization of the limb.

scholarly journals Morphological changes in the sciatic nerve in experimental modeling of contusion injury of the spinal cord in rats

2021 ◽  
Vol 18 (3) ◽  
pp. 36-42
Author(s):  
N. V. Kubrak ◽  
T. N. Varsegova ◽  
S. O. Ryabykh
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Morphological Changes ◽  
Female Rats ◽  
Nerve Tissue ◽  
Motor Deficit ◽  
Cord Injury ◽  
Contusion Injury

Objective. To analyze morphological and morphometric changes in the sciatic nerve of rats after the spinal cord injury.Material and Methods. The Т9 moderately severe contusion injury of the spinal cord was simulated in 12 Wistar female rats. Functions of the pelvic limbs were assessed according to the standardized BBB scale. The animals were withdrawn from the experiment after nine and 13 weeks. Epoxy semi-thin (1 µm) sections were used to study sciatic nerve at the light-optical level.Results. Significant recovery of pelvic limb functions was observed within four weeks after surgery, the plateau was achieved by Week 5 (9.5 ± 0.28 points according to the BBB scale), the deterioration in the motor activity was observed by Week 9 (8.67 ± 0.33), its recovery was achieved by Week 13 of the experiment (9.5 ± 0.87). After 9 and 13 weeks, reactive-destructive changes were detected in the sciatic nerve in 9 % and 8 % of nerve conductors, an increase in the number density of myelin fibers by 28 % and 27 % (p < 0.05) and myelin-free fibers by 20 % and 49 % (p < 0.05), and a decrease in axon diameters by 8 % and 10 % (p < 0.05), respectively.Conclusions. The morphological and morphometric changes in the sciatic nerve revealed after the spinal cord injury in the form of destruction of a part of the fibers, axonal atrophy and a decrease in the proportion of large fibers negatively affect its conductive properties. The leveling of peripheral nerve damage, possibly, will accelerate the regression of the motor deficit caused by the spinal cord injury; therefore, it is necessary to develop a set of preventive measures aimed at preventing the reorganization of the peripheral nerve tissue.

scholarly journals Role of bone marrow derived pluripotent stem cells in peripheral nerve repair in adult rats: A morphometric evaluation

2015 ◽  
Vol 6 (02) ◽  
pp. 152-159 ◽  
Author(s):  
Nilesh S. Kurwale ◽  
Vaishali Suri ◽  
Arati Srivastava ◽  
Ashish Suri ◽  
Sujata Mohanti ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Fibrin Sealant ◽  
Male Rats ◽  
Control Group ◽  
Albino Rats ◽  
Repair Site ◽  
Significant Difference ◽  
Distal Site

ABSTRACT Objectives: Semi-quantitative and quantitative assessment of the effect of bone marrow-derived mononuclear cells (BM-MNC) on early and late phase of nerve regeneration in rat sciatic nerve model. Materials and Methods: Sciatic nerve transection and repair was performed in 50 inbred female Wistar albino rats divided equally in two groups. In the test group the gap was filled with BM-MNCs obtained from the two male rats and fibrin sealant, while in the control group only fibrin sealant was used. Sciatic nerve was harvested at 15 days and at 60 days interval. Parameters of regeneration were assessed at anastomosis (G), intermediate distal (C), and distal site (A). Semi-quantitative (histopathological) and quantitative (morphometric) parameters were analyzed. Results: At 15 days there was a statistically significant difference found in mean axon diameter, mean nerve thickness and myelin thickness at the repair site (P < 0.05). However, in the distal areas, the axons were sparse and myelin rings were very thin in both the groups. At 60 days, the difference in above-mentioned parameters was statistically significant at the distal most sites. FISH assay confirmed the presence of Y chromosome, confirming the presence of BM-MNCs from the male rats. Conclusions: Transplanting BM-MNC S at the site of peripheral nerve injury leads to significantly better recovery. These differences were evident at the repair site and at the intermediate distal site at 15 days and at the distal most sites at 60 days. With practically no ethical issue regarding their isolation and application, they can be easily used for clinical trials.

Facilitated migration of cells from a transected peripheral nerve over collagen fibers: in vivo observations

1989 ◽  
Vol 47 ◽  
pp. 888-889
Author(s):  
Arthur J. Wasserman ◽  
Azam Rizvi ◽  
George Zazanis ◽  
Frederick H. Silver
Keyword(s):  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Collagen Gel ◽  
Collagen Fibers ◽  
Control Group ◽  
Guide Tube ◽  
Sprague Dawley ◽  
Silicone Tube ◽  
Thin Sections

In cases of peripheral nerve damage the gap between proximal and distal stumps can be closed by suturing the ends together, using a nerve graft, or by nerve tubulization. Suturing allows regeneration but does not prevent formation of painful neuromas which adhere to adjacent tissues. Autografts are not reported to be as good as tubulization and require a second surgical site with additional risks and complications. Tubulization involves implanting a nerve guide tube that will provide a stable environment for axon proliferation while simultaneously preventing formation of fibrous scar tissue. Supplementing tubes with a collagen gel or collagen plus extracellular matrix factors is reported to increase axon proliferation when compared to controls. But there is no information regarding the use of collagen fibers to guide nerve cell migration through a tube. This communication reports ultrastructural observations on rat sciatic nerve regeneration through a silicone nerve stent containing crosslinked collagen fibers.Collagen fibers were prepared as described previously. The fibers were threaded through a silicone tube to form a central plug. One cm segments of sciatic nerve were excised from Sprague Dawley rats. A control group of rats received a silicone tube implant without collagen while an experimental group received the silicone tube containing a collagen fiber plug. At 4 and 6 weeks postoperatively, the implants were removed and fixed in 2.5% glutaraldehyde buffered by 0.1 M cacodylate containing 1.5 mM CaCl2 and balanced by 0.1 M sucrose. The explants were post-fixed in 1% OSO4, block stained in 1% uranyl acetate, dehydrated and embedded in Epon. Axons were counted on montages prepared at a total magnification of 1700x. Montages were viewed through a dissecting microscope. Thin sections were sampled from the proximal, middle and distal regions of regenerating sciatic plugs.

PROTECTIVE EFFECT OF SOME SALTS 2-AMINOETHANESULFONIC ACID IN AN EXPERIMENTAL MODEL OF DEGENERATIVE SPINAL CORD INJURY

2020 ◽  
pp. 41-47
Author(s):  
Semeleva E.V. ◽  
Blinova E.V. ◽  
Zaborovsky A.V. ◽  
Vasilkina O.V. ◽  
Shukurov A.S.
Keyword(s):  
Spinal Cord ◽  
Morphological Changes ◽  
Male Rats ◽  
Zinc Salt ◽  
Control Group ◽  
Morphological Studies ◽  
Cord Injury ◽  
The Central Nervous System ◽  
Acid Compound ◽  
Lateral Sclerosis

In this work, we studied the pharmacological activity of zinc and magnesium salts of 2-aminoethanesulfonic acid in white non-linear male rats with amyotrophic lateral sclerosis, which was modeled by neurotoxicantsimplication into the pelvic part of spinal cord. After the reproduction of the pathology in animals, the indices of motor activity were recorded in the Rotarod test, and morphological studies of spinal cord sections stained according to Nisl in the Belshovsky modification were carried out. It was shown that the magnesium salt of 2-aminoethanesulfonic acid (compound LHT-317) to a greater extent reduces the development of motor disorders in experimental animals compared with the control group on the 4th day of observation. The course of intravenous administration of the studied compounds of 2-aminoethanesulfonic acid did not inhibit morphological changes in the spinal cord that develop in degenerative-dystrophic pathology of the central nervous system: connections. Moreover, if, against the background of treatment with zinc salt, the total area of motor zones in animals of the experimental group exceeded that of control rats, then the number of motoneurons did not differ from the control.

Changes in Crossed Spinal Reflexes After Peripheral Nerve Injury and Repair

2002 ◽  
Vol 87 (4) ◽  
pp. 1763-1771 ◽  
Author(s):  
Antoni Valero-Cabré ◽  
Xavier Navarro
Keyword(s):  
Sciatic Nerve ◽  
Action Potential ◽  
Peripheral Nerve ◽  
Nerve Injury ◽  
Peripheral Nerve Injury ◽  
Tibialis Anterior ◽  
Tibial Nerve ◽  
Spinal Reflexes ◽  
Injury And Repair

We investigated the changes induced in crossed extensor reflex responses after peripheral nerve injury and repair in the rat. Adults rats were submitted to non repaired sciatic nerve crush (CRH, n = 9), section repaired by either aligned epineurial suture (CS, n = 11) or silicone tube (SIL4, n = 13), and 8 mm resection repaired by tubulization (SIL8, n = 12). To assess reinnervation, the sciatic nerve was stimulated proximal to the injury site, and the evoked compound muscle action potential (M and H waves) from tibialis anterior and plantar muscles and nerve action potential (CNAP) from the tibial nerve and the 4th digital nerve were recorded at monthly intervals for 3 mo postoperation. Nociceptive reinnervation to the hindpaw was also assessed by plantar algesimetry. Crossed extensor reflexes were evoked by stimulation of the tibial nerve at the ankle and recorded from the contralateral tibialis anterior muscle. Reinnervation of the hindpaw increased progressively with time during the 3 mo after lesion. The degree of muscle and sensory target reinnervation was dependent on the severity of the injury and the nerve gap created. The crossed extensor reflex consisted of three bursts of activity (C1, C2, and C3) of gradually longer latency, lower amplitude, and higher threshold in control rats. During follow-up after sciatic nerve injury, all animals in the operated groups showed recovery of components C1 and C2 and of the reflex H wave, whereas component C3 was detected in a significantly lower proportion of animals in groups with tube repair. The maximal amplitude of components C1 and C2 recovered to values higher than preoperative values, reaching final levels between 150 and 245% at the end of the follow-up in groups CRH, CS, and SIL4. When reflex amplitude was normalized by the CNAP amplitude of the regenerated tibial nerve, components C1 (300–400%) and C2 (150–350%) showed highly increased responses, while C3 was similar to baseline levels. In conclusion, reflexes mediated by myelinated sensory afferents showed, after nerve injuries, a higher degree of facilitation than those mediated by unmyelinated fibers. These changes tended to decline toward baseline values with progressive reinnervation but still remained significant 3 mo after injury.

scholarly journals Effects of Taxol on Regeneration in a Rat Sciatic Nerve Transection Model

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Shih-Tien Hsu ◽  
Chun-Hsu Yao ◽  
Yuan-Man Hsu ◽  
Jia-Horng Lin ◽  
Yung-Hsiang Chen ◽  
...  
Keyword(s):  
Growth Factors ◽  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Nerve Regeneration ◽  
Nerve Transection ◽  
Cremophor El ◽  
Neuronal Connectivity ◽  
Sciatic Nerve Transection ◽  
Expression Levels ◽  
Nerve Growth Factors

Abstract Recent studies describe taxol as a candidate treatment for promoting central nerve regeneration. However, taxol has serious side effects including peripheral neurotoxicity, and little information is known about the effect of taxol on peripheral nerve regeneration. We investigated the effects of taxol on regeneration in a rat sciatic nerve transection model. Rats were divided into four groups (n = 10): normal saline (i.p.) as the control, Cremophor EL vehicle, and 2 or 6 mg/kg of taxol in the Cremophor EL solution (four times in day-2, 4, 6, and 8), respectively. We evaluated neuronal electrophysiology, animal behaviour, neuronal connectivity, macrophage infiltration, location and expression levels of calcitonin gene-related peptide (CGRP), and expression levels of both nerve growth factors and immunoregulatory factors. In the high-dose taxol group (6 mg/kg), neuronal electrophysiological function was significantly impaired. Licking latencies were significantly changed while motor coordination was unaffected. Neuronal connectivity, macrophage density, and expression levels of CGRP was dramatically reduced. Expression levels of nerve growth factors and immunoregulatory factors was also reduced, while it was increased in the low-dose taxol group (2 mg/kg). These results indicate that taxol can modulate local inflammatory conditions, impair nerve regeneration, and impede recovery of a severe peripheral nerve injury.

scholarly journals Magnetization Transfer Ratio of Peripheral Nerve and Skeletal Muscle

2021 ◽  
Author(s):  
Olivia Fösleitner ◽  
Véronique Schwehr ◽  
Tim Godel ◽  
Fabian Preisner ◽  
Philipp Bäumer ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Body Weight ◽  
Sciatic Nerve ◽  
Linear Regression ◽  
Peripheral Nerve ◽  
Regression Model ◽  
Multiple Linear Regression ◽  
Linear Regression Model ◽  
Magnetization Transfer ◽  
Multiple Linear Regression Model

Abstract Purpose To assess the correlation of peripheral nerve and skeletal muscle magnetization transfer ratio (MTR) with demographic variables. Methods In this study 59 healthy adults evenly distributed across 6 decades (mean age 50.5 years ±17.1, 29 women) underwent magnetization transfer imaging and high-resolution T2-weighted imaging of the sciatic nerve at 3 T. Mean sciatic nerve MTR as well as MTR of biceps femoris and vastus lateralis muscles were calculated based on manual segmentation on six representative slices. Correlations of MTR with age, body height, body weight, and body mass index (BMI) were expressed by Pearson coefficients. Best predictors for nerve and muscle MTR were determined using a multiple linear regression model with forward variable selection and fivefold cross-validation. Results Sciatic nerve MTR showed significant negative correlations with age (r = −0.47, p < 0.001), BMI (r = −0.44, p < 0.001), and body weight (r = −0.36, p = 0.006) but not with body height (p = 0.55). The multiple linear regression model determined age and BMI as best predictors for nerve MTR (R2 = 0.40). The MTR values were different between nerve and muscle tissue (p < 0.0001), but similar between muscles. Muscle MTR was associated with BMI (r = −0.46, p < 0.001 and r = −0.40, p = 0.002) and body weight (r = −0.36, p = 0.005 and r = −0.28, p = 0.035). The BMI was selected as best predictor for mean muscle MTR in the multiple linear regression model (R2 = 0.26). Conclusion Peripheral nerve MTR decreases with higher age and BMI. Studies that assess peripheral nerve MTR should consider age and BMI effects. Skeletal muscle MTR is primarily associated with BMI but overall less dependent on demographic variables.

scholarly journals SUR1, newly expressed in astrocytes, mediates neuropathic pain in a mouse model of peripheral nerve injury

2021 ◽  
Vol 17 ◽  
pp. 174480692110066
Author(s):  
Orest Tsymbalyuk ◽  
Volodymyr Gerzanich ◽  
Aaida Mumtaz ◽  
Sanketh Andhavarapu ◽  
Svetlana Ivanova ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Neuropathic Pain ◽  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Dorsal Horn ◽  
Nerve Injury ◽  
Peripheral Nerve Injury ◽  
Thermal Sensitivity ◽  
Gradual Improvement ◽  
Pain Behaviors

Background Neuropathic pain following peripheral nerve injury (PNI) is linked to neuroinflammation in the spinal cord marked by astrocyte activation and upregulation of interleukin 6 (IL -6 ), chemokine (C-C motif) ligand 2 (CCL2) and chemokine (C-X-C motif) ligand 1 (CXCL1), with inhibition of each individually being beneficial in pain models. Methods Wild type (WT) mice and mice with global or pGfap-cre- or pGFAP-cre/ERT2-driven Abcc8/SUR1 deletion or global Trpm4 deletion underwent unilateral sciatic nerve cuffing. WT mice received prophylactic (starting on post-operative day [pod]-0) or therapeutic (starting on pod-21) administration of the SUR1 antagonist, glibenclamide (10 µg IP) daily. We measured mechanical and thermal sensitivity using von Frey filaments and an automated Hargreaves method. Spinal cord tissues were evaluated for SUR1-TRPM4, IL-6, CCL2 and CXCL1. Results Sciatic nerve cuffing in WT mice resulted in pain behaviors (mechanical allodynia, thermal hyperalgesia) and newly upregulated SUR1-TRPM4 in dorsal horn astrocytes. Global and pGfap-cre-driven Abcc8 deletion and global Trpm4 deletion prevented development of pain behaviors. In mice with Abcc8 deletion regulated by pGFAP-cre/ERT2, after pain behaviors were established, delayed silencing of Abcc8 by tamoxifen resulted in gradual improvement over the next 14 days. After PNI, leakage of the blood-spinal barrier allowed entry of glibenclamide into the affected dorsal horn. Daily repeated administration of glibenclamide, both prophylactically and after allodynia was established, prevented or reduced allodynia. The salutary effects of glibenclamide on pain behaviors correlated with reduced expression of IL-6, CCL2 and CXCL1 by dorsal horn astrocytes. Conclusion SUR1-TRPM4 may represent a novel non-addicting target for neuropathic pain.

scholarly journals IL-17F depletion accelerates chitosan conduit guided peripheral nerve regeneration

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Feixiang Chen ◽  
Weihuang Liu ◽  
Qiang Zhang ◽  
Ping Wu ◽  
Ao Xiao ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Nerve Regeneration ◽  
Knockout Mice ◽  
Inflammatory Markers ◽  
Nerve Repair ◽  
Peripheral Nerve Regeneration ◽  
Wild Type ◽  
Anti Inflammatory

AbstractPeripheral nerve injury is a serious health problem and repairing long nerve deficits remains a clinical challenge nowadays. Nerve guidance conduit (NGC) serves as the most promising alternative therapy strategy to autografts but its repairing efficiency needs improvement. In this study, we investigated whether modulating the immune microenvironment by Interleukin-17F (IL-17F) could promote NGC mediated peripheral nerve repair. Chitosan conduits were used to bridge sciatic nerve defect in IL-17F knockout mice and wild-type mice with autografts as controls. Our data revealed that IL-17F knockout mice had improved functional recovery and axonal regeneration of sciatic nerve bridged by chitosan conduits comparing to the wild-type mice. Notably, IL-17F knockout mice had enhanced anti-inflammatory macrophages in the NGC repairing microenvironment. In vitro data revealed that IL-17F knockout peritoneal and bone marrow derived macrophages had increased anti-inflammatory markers after treatment with the extracts from chitosan conduits, while higher pro-inflammatory markers were detected in the Raw264.7 macrophage cell line, wild-type peritoneal and bone marrow derived macrophages after the same treatment. The biased anti-inflammatory phenotype of macrophages by IL-17F knockout probably contributed to the improved chitosan conduit guided sciatic nerve regeneration. Additionally, IL-17F could enhance pro-inflammatory factors production in Raw264.7 cells and wild-type peritoneal macrophages. Altogether, IL-17F may partially mediate chitosan conduit induced pro-inflammatory polarization of macrophages during nerve repair. These results not only revealed a role of IL-17F in macrophage function, but also provided a unique and promising target, IL-17F, to modulate the microenvironment and enhance the peripheral nerve regeneration.

Transplantation of Schwann cells in a collagen tube for the repair of large, segmental peripheral nerve defects in rats

2013 ◽  
Vol 119 (3) ◽  
pp. 720-732 ◽  
Author(s):  
Yerko A. Berrocal ◽  
Vania W. Almeida ◽  
Ranjan Gupta ◽  
Allan D. Levi
Keyword(s):  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Schwann Cells ◽  
Nerve Injury ◽  
Peripheral Nerve Injury ◽  
Fluorescent Protein ◽  
Control Groups ◽  
Myelinated Axons ◽  
Segmental Nerve ◽  
Green Fluorescent

Object Segmental nerve defects pose a daunting clinical challenge, as peripheral nerve injury studies have established that there is a critical nerve gap length for which the distance cannot be successfully bridged with current techniques. Construction of a neural prosthesis filled with Schwann cells (SCs) could provide an alternative treatment to successfully repair these long segmental gaps in the peripheral nervous system. The object of this study was to evaluate the ability of autologous SCs to increase the length at which segmental nerve defects can be bridged using a collagen tube. Methods The authors studied the use of absorbable collagen conduits in combination with autologous SCs (200,000 cells/μl) to promote axonal growth across a critical size defect (13 mm) in the sciatic nerve of male Fischer rats. Control groups were treated with serum only–filled conduits of reversed sciatic nerve autografts. Animals were assessed for survival of the transplanted SCs as well as the quantity of myelinated axons in the proximal, middle, and distal portions of the channel. Results Schwann cell survival was confirmed at 4 and 16 weeks postsurgery by the presence of prelabeled green fluorescent protein–positive SCs within the regenerated cable. The addition of SCs to the nerve guide significantly enhanced the regeneration of myelinated axons from the nerve stump into the proximal (p < 0.001) and middle points (p < 0.01) of the tube at 4 weeks. The regeneration of myelinated axons at 16 weeks was significantly enhanced throughout the entire length of the nerve guide (p < 0.001) as compared with their number in a serum–only filled tube and was similar in number compared with the reversed autograft. Autotomy scores were significantly lower in the animals whose sciatic nerve was repaired with a collagen conduit either without (p < 0.01) or with SCs (p < 0.001) when compared with a reversed autograft. Conclusions The technique of adding SCs to a guidance channel significantly enhanced the gap distance that can be repaired after peripheral nerve injury with long segmental defects and holds promise in humans. Most importantly, this study represents some of the first essential steps in bringing autologous SC-based therapies to the domain of peripheral nerve injuries with long segmental defects.

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