Investigation of the Neuro-Regenerative Effects of Bioresonance and Magnetotherapy in Sciatic Nerve Damage-Induced Rats / Investigación de los Efectos Neurorregenerativos de Biorresonancia y Magnetoterapia en Ratas Inducidas por Daño del Nervio Ciático

SUMMARY: Peripheral nerve damage is a significant clinical problem that can lead to severe complications in patients. Regarding the regeneration of peripheral nerves, it is crucial to use experimental animals' nerves and use different evaluation methods. Epineural or perineural suturing is the gold standard in treating sciatic nerve injury, but nerve repair is often unsuccessful. This study aimed to investigate the neuroregenerative effects of magnetotherapy and bioresonance in experimental animals with sciatic nerve damage. In this study, 24 female Wistar rats were divided into 7 groups (n=6) as follows: Group 1 (Control), Group 2 (Axonotmesis control), Group 3 (Anastomosis control), Group 4 (Axonotmesis + magnetotherapy), Group 5 (Anastomosis + magnetotherapy), Group 6 (Axonotmesis + bioresonance), Group 7 (Anastomosis + bioresonance). Magnetotherapy and bioresonance treatments were applied for 12 weeks. Behavioural tests and EMG tests were performed at the end of the 12th week. Then the rats were sacrificed, and a histopathological evaluation was made. The statistical significance level was taken as 5 % in the calculations, and the SPSS (IBM SPSS for Windows, ver.21) statistical package program was used for the calculations. Statistically significant results were obtained in animal behaviour tests, EMG, and pathology groups treated with magnetotherapy. There was no statistically significant difference in the groups treated with bioresonance treatment compared to the control groups. Muscle activity and nerve repair occurred in experimental animals with acute peripheral nerve damage due to 12 weeks of magnetotherapy, and further studies should support these results.

El daño a los nervios periféricos es un problema clínico importante que puede conducir a complicaciones graves en los pacientes. En cuanto a la regeneración de los nervios periféricos, es crucial utilizar los nervios de los animales de experimentación y diferentes métodos de evaluación. La sutura epineural o perineural es el gold estándar en el tratamiento de lesiones del nervio ciático, pero la reparación del nervio a menudo no tiene éxito. Este estudio tuvo como objetivo investigar los efectos neuroregenerativos de la magnetoterapia y la biorresonancia en animales de experimentación con daño del nervio ciático. En el estudio, 24 ratas hembras Wistar se dividieron en 7 grupos (n=6) de la siguiente manera: Grupo 1 (Control), Grupo 2 (Control de axonotmesis), Grupo 3 (Control de anastomosis), Grupo 4 (Axonotmesis + magnetoterapia), Grupo 5 (Anastomosis + magnetoterapia), Grupo 6 (Axonotmesis + biorresonancia), Grupo 7 (Anastomosis + biorresonancia). Se aplicaron durante 12 semanas tratamientos de magnetoterapia y biorresonancia. Las pruebas de comportamiento y las pruebas de EMG se realizaron al final de la semana 12. Luego se sacrificaron las ratas y se realizó una evaluación histopatológica. El nivel de significación estadística se tomó como 5 % en los cálculos, y se utilizó el programa de paquete estadístico SPSS (IBM SPSS para Windows, ver.21). Se obtuvieron resultados estadísticamente significativos en pruebas de comportamiento animal, EMG y grupos de patología tratados con magnetoterapia. No hubo diferencia estadísticamente significativa en los grupos con tratamiento de biorresonancia en comparación con los grupos controles. La actividad muscular y la reparación nerviosa, se produjeron en animales de experimentación con daño nervioso periférico agudo, debido a 12 semanas de magnetoterapia.Estudios adicionales deberían respaldar estos resultados.

Effect of folic acid coated-crosslinked urethane-doped polyester elastomer nerve conduit on promoting the repair of long distance peripheral nerve injury in rats / 中国修复重建外科杂志

OBJECTIVE@#To investigate the effect of folic acid coated-crosslinked urethane-doped polyester elastomer (fCUPE) nerve conduit in repairing long distance peripheral nerve injury.@*METHODS@#Thirty-six 3-month-old male Sprague Dawley rats weighing 180-220 g were randomly assigned to 3 groups, each consisting of 12 rats: CUPE nerve conduit transplantation group (group A), fCUPE nerve conduit transplantation group (group B), and autologous nerve transplantation group (group C), the contralateral healthy limb of group C served as the control group (group D). A 20-mm-long sciatic nerve defect model was established in rats, and corresponding materials were used to repair the nerve defect according to the group. The sciatic function index (SFI) of groups A-C was calculated using the Bain formula at 1, 2, and 3 months after operation. The nerve conduction velocity (NCV) of the affected side in groups A-D was assessed using neuroelectrophysiological techniques. At 3 months after operation, the regenerated nerve tissue was collected from groups A-C for S-100 immunohistochemical staining and Schwann cell count in groups A and B to compare the level of nerve repair and regeneration in each group.@*RESULTS@#At 3 months after operation, the nerve conduits in all groups partially degraded. There was no significant adhesion between the nerve and the conduit and the surrounding tissues, the conduit was well connected with the distal and proximal nerves, and the nerve-like tissues in the conduit could be observed when the nerve conduit stents were cut off. SFI in group A was significantly higher than that in group C at each time point after operation and was significantly higher than that in group B at 2 and 3 months after operation ( P<0.05). There was no significant difference in SFI between groups B and C at each time point after operation ( P>0.05). NCV in group A was significantly slower than that in the other 3 groups at each time point after operation ( P<0.05). The NCV of groups B and C were slower than that of group D, but the difference was significant only at 1 month after operation ( P<0.05). There was no significant difference between groups B and C at each time point after operation ( P>0.05). Immunohistochemical staining showed that the nerve tissue of group A had an abnormal cavo-like structure, light tissue staining, and many non-Schwann cells. In group B, a large quantity of normal neural structures was observed, the staining was deeper than that in group A, and the distribution of dedifferentiated Schwann cells was obvious. In group C, the nerve bundles were arranged neatly, and the tissue staining was the deepest. The number of Schwann cells in group B was (727.50±57.60) cells/mm 2, which was significantly more than that in group A [(298.33±153.12) cells/mm 2] ( t=6.139, P<0.001).@*CONCLUSION@#The fCUPE nerve conduit is effective in repairing long-distance sciatic nerve defects and is comparable to autologous nerve grafts. It has the potential to be used as a substitute material for peripheral nerve defect transplantation.

Comparison of the Nerve Regeneration Capacity and Characteristics between Sciatic Nerve Crush and Transection Injury Models in Rats / 生物医学与环境科学（英文）

OBJECTIVE@#To provide useful information for selecting the most appropriate peripheral nerve injury model for different research purposes in nerve injury and repair studies, and to compare nerve regeneration capacity and characteristics between them.@*METHODS@#Sixty adult SD rats were randomly divided into two groups and underwent crush injury alone (group A, n = 30) or transection injury followed by surgical repair (group B, n = 30) of the right hind paw. Each group was subjected to the CatWalk test, gastrocnemius muscle evaluation, pain threshold measurement, electrophysiological examination, retrograde neuronal labeling, and quantification of nerve regeneration before and 7, 14, 21, and 28 days after injury.@*RESULTS@#Gait analysis showed that the recovery speed in group A was significantly faster than that in group B at 14 days. At 21 days, the compound muscle action potential of the gastrocnemius muscle in group A was significantly higher than that in group B, and the number of labeled motor neurons in group B was lower than that in group A. The number of new myelin sheaths and the g-ratio were higher in group A than in group B. There was a 7-day time difference in the regeneration rate between the two injury groups.@*CONCLUSION@#The regeneration of nerve fibers was rapid after crush nerve injury, whereas the transection injury was relatively slow, which provides some ideas for the selection of clinical research models.

Transcriptome Analysis of Schwann Cells at Various Stages of Myelination Implicates Chromatin Regulator Sin3A in Control of Myelination Identity / 神经科学通报·英文版

Enhancing remyelination after injury is of utmost importance for optimizing the recovery of nerve function. While the formation of myelin by Schwann cells (SCs) is critical for the function of the peripheral nervous system, the temporal dynamics and regulatory mechanisms that control the progress of the SC lineage through myelination require further elucidation. Here, using in vitro co-culture models, gene expression profiling of laser capture-microdissected SCs at various stages of myelination, and multilevel bioinformatic analysis, we demonstrated that SCs exhibit three distinct transcriptional characteristics during myelination: the immature, promyelinating, and myelinating states. We showed that suppressor interacting 3a (Sin3A) and 16 other transcription factors and chromatin regulators play important roles in the progress of myelination. Sin3A knockdown in the sciatic nerve or specifically in SCs reduced or delayed the myelination of regenerating axons in a rat crushed sciatic nerve model, while overexpression of Sin3A greatly promoted the remyelination of axons. Further, in vitro experiments revealed that Sin3A silencing inhibited SC migration and differentiation at the promyelination stage and promoted SC proliferation at the immature stage. In addition, SC differentiation and maturation may be regulated by the Sin3A/histone deacetylase2 (HDAC2) complex functionally cooperating with Sox10, as demonstrated by rescue assays. Together, these results complement the recent genome and proteome analyses of SCs during peripheral nerve myelin formation. The results also reveal a key role of Sin3A-dependent chromatin organization in promoting myelinogenic programs and SC differentiation to control peripheral myelination and repair. These findings may inform new treatments for enhancing remyelination and nerve regeneration.

Indomethacin attenuates mechanical allodynia during the organization but not the maintenance of the peripheral neuropathic pain induced by nervus ischiadicus chronic constriction injury

The neurochemical mechanisms underlying neuropathic pain (NP) are related to peripheral and central sensitization caused by the release of inflammatory mediators in the peripheral damaged tissue and ectopic discharges from the injured nerve, leading to a hyperexcitable state of spinal dorsal horn neurons. The aim of this work was to clarify the role played by cyclooxygenase (COX) in the lesioned peripheral nerve in the development and maintenance of NP by evaluating at which moment the non-steroidal anti-inflammatory drug indomethacin, a non-selective COX inhibitor, attenuated mechanical allodynia after placing one loose ligature around the nervus ischiadicus, an adaptation of Bennett and Xie's model in rodents. NP was induced in male Wistar rats by subjecting them to chronic constriction injury (CCI) of the nervus ischiadicus, placing one loose ligature around the peripheral nerve, and a sham surgery (without CCI) was used as control. Indomethacin (2 mg/kg) or vehicle was intraperitoneally and acutely administered in each group of rats and at different time windows (1, 2, 4, 7, 14, 21, and 28 days) after the CCI or sham surgical procedures, followed by von Frey's test for 30 min. The data showed that indomethacin decreased the mechanical allodynia threshold of rats on the first, second, and fourth days after CCI (P<0.05). These findings suggested that inflammatory mechanisms are involved in the induction of NP and that COX-1 and COX-2 are involved in the induction but not in the maintenance of NP.

Impairment induction by axotomy in motor functional and histological anterior horn of spinal cord structure / Inducción del deterioro por axotomía en la estructura motora funcional e histológica del asta anterior de la médula espinal

We have surveyed the motor changes in rats subjected to sciatic nerve axotomy. The rats were divided into two groups, each one consisting of ten animals, which underwent the following intervention: The first group (control): healthy rats without any injuries and experimental group: rats with injured sciatic nerve without treatment. at 12 weeks, the L4 and L5 spinal cord segments were removed. We evaluated nerve function using muscle electromyography (EMG) activity and sciatic function index (SFI) simultaneously with histological spinal cord analyses by stereological methods at 12 week. After nerve injury presented gross locomotor deficits at week 12. We also found that the volume of the anterior horn of spinal cord and total number of motor neurons were decreased after nerve axotomy (p<0.05). In conjunction, these results indicate that peripheral nerve injuries have more severe consequences on hind limb motor output.

En este estudio se examinaron los cambios motores en ratas sometidas a axotomía del nervio ciático. Las ratas se dividieron en dos grupos diez animales. El primer grupo (control) eran ratas sanas sin lesiones, y el grupo experimental consistió en ratas con nervio ciático lesionado sin tratamiento. A las 12 semanas, los segmentos de la médula espinal L4 y L5 fueron removidos. Se evaluó la función nerviosa mediante electromiografía muscular (EMG) y el índice de función ciática (IFC), simultáneamente con análisis histológicos de la médula espinal mediante métodos estereológicos. A las 12 semanas de la lesión nerviosa presentó déficit locomotor grueso. Además, se observó que el volumen del asta anterior y el número total de neuronas motoras disminuyeron después de la axotomía nerviosa (P <0,05). En conjunto, estos resultados indican que las lesiones de los nervios periféricos determinan graves consecuencias de la función motora de los miembros posteriores.

Tenotomy of the Gluteus Maximus in Total Hip Arthroplasty with Prevention of Sciatic Nerve Injury / Tenotomia do glúteo máximo em artroplastia total do quadril como prevenção de lesão do nervo ciático

Abstract The authors report a single case of complex primary hip total arthroplasty in a 34-yearold female patient with a 5.5 cm lower limb dysmetria, in whom a maximum gluteus tenotomy was performed in order to prevent sciatic nerve injury. The surgery was performed under electroneurophysiological monitoring of the fibular and tibial branches of the sciatic nerve, collecting pretenotomy, posttenotomy, and postarthroplasty reduction data. The findings demonstrate that the maximum gluteus tenotomy improved the motor response of the fibular component of the sciatic nerve.

Resumo Os autores relatam um único caso de artroplastia total de quadril primária complexa em uma paciente do sexo feminino de 34 anos, com dismetria de membros inferiores de 5,5 cm, na qual foi feita tenotomia do glúteo máximo a fim de prevenir lesão do nervo ciático. Tal cirurgia foi feita sob monitoração eletroneurofisiológica dos ramos fibular e tibial do nervo ciático. Foramcoletados dados pré-tenotomia, pós-tenotomia e pós-redução artroplástica. Os achados demonstram que a tenotomia do glúteo máximo melhorou a reposta motora do componente fibular do nervo ciático.

Involvement of adenosine A1 receptor in electroacupuncture-mediated inhibition of astrocyte activation during neuropathic pain / Envolvimento do receptor de adenosina A1 na inibição da ativação de astrócitos mediada por eletroacupuntura durante a dor neuropática

ABSTRACT Neuropathic pain is a chronic pain condition caused by damage or dysfunction of the central or peripheral nervous system. Electroacupuncture (EA) has an antinociceptive effect on neuropathic pain, which is partially due to inhibiting astrocyte activation in the spinal cord. We found that an intrathecal injection of 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), a selective adenosine A1 receptor antagonist, reversed the antinociceptive effects of EA in a chronic constriction injury-induced neuropathic pain model. The expression of GFAP in L4-L6 spinal cord was significantly upgraded, while DPCPX suppressed the effect of the EA-mediating inhibition of astrocyte activation, as well as wiping out the EA-induced suppression of cytokine content (TNF-α). These results indicated that the adenosine A1 receptor is involved in EA actions during neuropathic pain through suppressing astrocyte activation as well as TNF-α upregulation of EA, giving enlightenment to the mechanisms of acupuncture analgesia and development of therapeutic targets for neuropathic pain.

RESUMO A dor neuropática é uma condição de dor crônica causada por dano ou disfunção do sistema nervoso central ou periférico. A eletroacupuntura (EA) tem um efeito antinociceptivo durante a dor neuropática, que é parcialmente devido à inibição da ativação de astrócitos na medula espinhal. Descobrimos que a injeção intratecal de 8-ciclopentil-1,3-dipropilxantina (DPCPX), um antagonista seletivo do receptor de adenosina A1, reverteu os efeitos antinociceptivos da EA no modelo de dor neuropática induzida por lesão por constrição crônica (CCI). A expressão da GFAP na medula espinal L4-L6 foi significativamente melhorada, enquanto a DPCPX suprimiu o efeito da inibição mediadora da EA na ativação de astrócitos, bem como eliminou a supressão induzida pela EA do conteúdo de citocina (TNF-α). Esses resultados indicam que o receptor de adenosina A1 está envolvido nas ações da EA durante a dor neuropática, suprimindo a ativação astrocitária, bem como o aumento da TNF-α na EA, fornecendo esclarecimentos sobre os mecanismos de analgesia da acupuntura e o desenvolvimento de alvos terapêuticos para dor neuropática.

Effect of Sciatic Nerve Transection on acetylcholinesterase activity in spinal cord and skeletal muscles of the bullfrog Lithobates catesbeianus / Efeito da Secção do Nervo Isquiático sobre a atividade da acetilcolinesterase em medula espinal e músculos esqueléticos da rã-touro Lithobates catesbeianus

Abstract Sciatic nerve transection (SNT), a model for studying neuropathic pain, mimics the clinical symptoms of "phantom limb", a pain condition that arises in humans after amputation or transverse spinal lesions. In some vertebrate tissues, this condition decreases acetylcholinesterase (AChE) activity, the enzyme responsible for fast hydrolysis of released acetylcholine in cholinergic synapses. In spinal cord of frog Rana pipiens, this enzyme's activity was not significantly changed in the first days following ventral root transection, another model for studying neuropathic pain. An answerable question is whether SNT decreases AChE activity in spinal cord of frog Lithobates catesbeianus, a species that has been used as a model for studying SNT-induced neuropathic pain. Since each animal model has been created with a specific methodology, and the findings tend to vary widely with slight changes in the method used to induce pain, our study assessed AChE activity 3 and 10 days after complete SNT in lumbosacral spinal cord of adult male bullfrog Lithobates catesbeianus. Because there are time scale differences of motor endplate maturation in rat skeletal muscles, our study also measured the AChE activity in bullfrog tibial posticus (a postural muscle) and gastrocnemius (a typical skeletal muscle that is frequently used to study the motor system) muscles. AChE activity did not show significant changes 3 and 10 days following SNT in spinal cord. Also, no significant change occurred in AChE activity in tibial posticus and gastrocnemius muscles at day 3. However, a significant decrease was found at day 10, with reductions of 18% and 20% in tibial posticus and gastrocnemius, respectively. At present we cannot explain this change in AChE activity. While temporally different, the direction of the change was similar to that described for rats. This similarity indicates that bullfrog is a valid model for investigating AChE activity following SNT.

Resumo A transecção do nervo isquiático (SNT), um modelo para estudar dor neuropática, simula os sintomas clínicos do "membro fantasma", uma condição dolorosa que ocorre nos humanos após amputação ou secção completa da medula espinal. Essa condição muda a atividade da acetilcolinesterase (AChE), a enzima responsável pela rápida hidrólise da acetilcolina liberada nas sinapses colinérgicas, em alguns tecidos de vertebrados. Em medula espinal de rã Rana pipiens, a atividade da AChE não foi significativamente alterada nos primeiros dias após a secção da raiz ventral, outro modelo para o estudo da dor neuropática. Uma questão ainda não respondida é se a SNT diminui a atividade da AChE na medula espinal de rã Lithobates catesbeianus, uma espécie que vem sendo usada como modelo em estudos da dor neuropática induzida por SNT. Como cada modelo animal é criado a partir de metodologia específica, e seus resultados tendem a variar com pequenas mudanças na metodologia de indução da dor, o presente estudo avaliou a atividade da AChE em medula espinal lombossacral de rã-touro Lithobates catesbeianus, adultos, machos, 3 e 10 dias após a completa SNT. Como há diferenças temporais na maturação de placas motoras em músculos esqueléticos de ratos, nosso estudo ainda demonstrou, na rã-touro, os efeitos da SNT sobre a atividade da AChE nos músculos esqueléticos tibial posticus, um músculo postural, e gastrocnêmio, um músculo frequentemente usado em estudos do sistema motor. A atividade da AChE não mudou significativamente na medula espinal aos 3 e 10 dias após a SNT. Nos músculos, a atividade não alterou significativamente aos 3 dias após a lesão, mas reduziu de forma significativa aos 10 dias após a SNT. Aos 10 dias, a diminuição foi 18% no músculo tibial posticus e 20% no gastrocnêmio. No momento, nós não temos explicação para essa mudança na atividade da AChE. Embora temporalmente diferente, o sentido da mudança é similar ao que é descrito em ratos. Esta similaridade torna a rã-touro um modelo válido para se estudar questões ainda não respondidas da SNT sobre a AChE.

Inside-out and standard vein grafts associated with platelet-rich plasma (PRP) in sciatic nerve repair. A histomorphometric study

Abstract Purpose: To evaluated the tubulization technique with standard and inside-out vein, filled or not with platelet-rich plasma (PRP), in sciatic nerve repair. Methods: Seventy male Wistar rats were randomly divided into five groups: IOVNF (Inside-Out Vein with No Filling); IOVPRP (Inside-Out Vein filled with PRP); SVNF (Standard Vein with No Filling); SVPRP (Standard Vein filled with PRP); Sham (Control). The left external jugular vein was used as graft in a 10 mm nervous gap. Results: In the morphological analysis of all groups, myelinated nerve fibers with evident myelin sheath, neoformation of the epineurium and perineurium, organization of intraneural fascicles and blood vessels were observed. In the morphometry of the distal stump fibers, SVPRP group had the highest means regarding fiber diameter (3.63±0.42 μm), axon diameter (2.37±0.31 μm) and myelin sheath area (11.70±0.84 μm2). IOVPRP group had the highest means regarding axon area (4.39±1.16 μm2) and myelin sheath thickness (0.80±0.19 μm). As for values of the fiber area, IOVNF group shows highest means (15.54±0.67 μm2), but are still lower than the values of the Sham group. Conclusion: The graft filled with platelet-rich plasma, with use standard (SVPRP) or inside-out vein (IOVPRP), promoted the improvement in axonal regeneration on sciatic nerve injury.

Comparative study between standard and inside-out vein graft techniques on sciatic nerve repair of rats. Muscular and functional analysis

Abstract Purpose: To compare the functional result of standart vein grafts and inside-out vein graft technique on sciatic nerve repair. Methods: We used 24 male Wistar rats divided into 4 groups: control group (CG), standard vein graft group (SVG), Inside-out vein graft group (IOVG) and denervated Group (DG). SVG, IOVG and DG underwent total section of the sciatic nerve, SVG and IOVG however underwent nerve repair surgery using a graft with normal jugular vein and inside-out jugular vein, respectively. Histological analysis of the soleus and Extensor Digitorum Longus (EDL), and Sciatic Functional Index were used to compare the results after 6 weeks. Results: Both grafts acted favorably in muscle recovery and improved functionality; They were similar in all parameters, however, in more points SVG achieved similar to the CG, in the other hand IOVG more times was similar to DG. Fact that makes the graft with normal vein the most viable option between the two options. Conclusion: Both types of grafts acted beneficially wherein the graft normal vein has proved to be the best option

Effect of ozone and methylprednisolone treatment following crush type sciatic nerve injury

ABSTRACT PURPOSE: To assess and compare the histopathological effects of ozone therapy and/or methylprednisolone (MPS) treatment on regeneration after crush type sciatic nerve injury. METHODS: Forty Sprague-Dawley male rats were randomly allocated into four groups. Four groups received the following regimens intraperitoneally every day for 14 days after formation of crush type injury on sciatic nerve: Group I: ozone (20mcg/ml); Group II: methylprednisolone (2mg/kg); Group III: ozone (20 mcg/ml) and methylprednisolone (2mg/kg); Group IV: isotonic saline (0.9%). The histomorphological evaluation was made after biopsies were obtained from the sites of injury. RESULTS: Significant differences were noted between groups in terms of degeneration (p=0.019), nerve sheath cell atrophy (p=0.012), intraneural inflammatory cellular infiltration (p=0.002), perineural granulation tissue formation (p=0.019), perineural vascular proliferation (p=0.004), perineural inflammatory cellular infiltration (p<0.001) and inflammation in peripheral tissue (p=0.006). Degeneration was remarkably low in Group III, while no change in nerve sheath cell was noted in Group II. CONCLUSION: The combined use of methylprednisolone and ozone treatment can have beneficial effects for regeneration after crush type nerve injury.

Mobilização neural aplicada em diferentes locais sobre a compressão do nervo isquiático de ratos Wistar / Neural mobilization applied at different sites on the sciatic nerve compression in Wistar rats

Introdução: a mobilização neural é uma técnica que visa restituir a função do sistema nervoso, contudo há ainda desconhecimento sobre o local mais apropriado. Objetivos: avaliar os efeitos da mobilização neural no tratamento da compressão do nervo isquiático de ratos Wistar, e comparar os diferentes locais de aplicação. Métodos: 24 ratos Wistar foram submetidos à compressão do nervo isquiático direito, e separados em quatro grupos: lesão (GL), mobilização neural no lesionado (GPD), mobilização neural no membro contralateral (GPE) e mobilização neural no membro ipsilateral a lesão (GEP). Foram realizadas avaliações funcionais pelo tempo de elevação da pata (TEP) e dolorímetro digital de Von Frey, após a última avaliação, o nervo isquiático foi seccionado para análise histológica. Resultados: houve diferença entre o GL (23,54) e GPE (23,98) na avaliação do TEP (p=0,028), na avaliação nociceptiva e histológica não houve diferenças significativas (p>0,05). Conclusão: a mobilização neural no membro contralateral foi prejudicial, enquanto o tratamento no membro acometido e no membro ipsilateral não apresentou diferença significativa.

Introduction: neural mobilization is a technique that aims to restore the function of the nervous system, yet there still lack of knowledge about the most appropriate place. Objectives: to evaluate the effects of neural mobilization in the treatment of sciatic nerve compression Wistar rats, and compare the different application sites. Methods: 24 Wistar rats were right sciatic nerve compression, and separated into four groups: injury (GL), neural mobilization in the injured (GPD), neural mobilization in the contralateral limb (GPE) and neural mobilization in the ipsilateral limb injury (GEP). Functional assessments were performed at paw elevation time (TEP) and digital Von Frey dolorimeter after the last evaluation, the sciatic nerve was sectioned for histological analysis. Results: there was a difference between the GL (23.54) and GPE (23.98) in the evaluation of the TEP (p=0.028), in nociceptive and histological evaluation no significant differences (p>0.05). Conclusion: the neural mobilization held in the contralateral limb was harmful, while treating the affected and ipsilateral limb showed no significant difference.

Osseointegration of hydroxyapatite implants in rat tibial defects with sciatic nerve injury / Oseointegración de implantes de hidroxiapatita en defectos tibiales de ratas con lesión del nervio ciático

Bone metabolism is influenced by different factors and muscle activity acts as a stimulator of bone plasticity. Conditions such as nerve injuries can compromise bone physiology due to muscle inactivity. Preview studies have shown that nerve damage reduces P substance and calcitonin gene-related peptides, also known as neuropeptides that may have a key role on bone healing. Therefore, this study evaluated the osseointegration of hydroxyapatite implants in tibial defects of rats submitted to unilateral sciatic nerve section. Twelve Wistar rats were divided into two groups (G1 and G2). In G1, the sciatic nerve was left intact and in G2 the left sciatic nerve was completely sectioned. An experimental tibial bone defect was then created in both groups and filled with hydroxyapatite granules. The animals were sacrificed 2 months after implantation and samples were submitted to macroscopic inspection and histological analysis. Good radiopacity of the hydroxyapatite granules and radiographic definition of the bone defect were noted. Histologic analysis revealed formation of new bone adjacent to the hydroxyapatite granules in G1 and, to a lesser extent, in G2 in which the proliferation of connective tissue predominated at the implant site. The formation of new bone stimulated by hydroxyapatite in bone defects can be expected even in animals with limb paralysis due to nerve injury; however, bone formation occurs at a slower speed in these animals and the volume of newly formed bone is lower.

El metabolismo óseo está influenciado por diferentes factores y la actividad muscular como un estimulador de la plasticidad ósea. Condiciones tales como lesiones nerviosas pueden comprometer la fisiología ósea debido a la inactividad muscular. Estudios previos han demostrado que el daño nervioso reduce la sustancia P y el péptido relacionado con el gen de la calcitonina, también conocidos como neuropéptidos que pueden tener un papel clave en la cicatrización ósea. Este estudio evaluó la oseointegración de los implantes de hidroxiapatita en defectos tibiales de ratas sometidas a la sección del nervio ciático unilateralmente. Doce ratas Wistar se dividieron en dos grupos (G1 y G2). En G1, el nervio ciático se dejó intacto y en el G2 el nervio ciático izquierdo fue completamente seccionado. Un defecto óseo tibial fue creado experimentalmente en ambos grupos y se rellenó con gránulos de hidroxiapatita. Los animales se sacrificaron 2 meses después de la implantación y las muestras fueron sometidas a inspección macroscópica y el análisis histológico. Se observó buena radiopacidad de los gránulos de hidroxiapatita y definición radiográfica del defecto óseo. El análisis histológico reveló neoformación ósea adyacente a los gránulos de hidroxiapatita en G1 y, en menor medida en G2, donde la proliferación de tejido conectivo predominó en el sitio de implante. La neoformación ósea estimulada por hidroxiapatita en defectos óseos se puede esperar incluso en animales con parálisis de los miembros producto de una lesión nerviosa; sin embargo, la formación de hueso se produce a menor velocidad en estos animales y su volumen es menor.

Analisis comparativo del número de neurofilamentos en nervios isquiáticos de rata sometidos a neuropraxia tratadas con láser de baja intensidad y ultrasonido terapéutico / Comparative analysis of the number of neurofilaments in rat sciatic nerve undergoing neuropraxia treated by low-level laser and therapeutic ultrasound

Es habitual que tras una compresión nerviosa se aplique terapia, ya sea, a través de laser de baja intensidad (LBI) o ultrasonido (US). El objetivo de este trabajo fue determinar la efectividad de dichos tratamientos para reparar el citoesqueleto neuronal evaluando la variación en el número de neurofilamentos. Se realizó un diseño experimental, en el cual se utilizaron 30 ratas que fueron separadas en 6 grupos: 1- control sano; 2- control lesionado; 3- irradiado con LBI 2J/cm2; 4- irradiado con LBI 10 J/cm2; 5- irradiado con US 0,5W/cm2 y 6- irradiado con US 1W/cm2. Con excepción del grupo 1 los especímenes fueron anestesiados y se les realizó la compresión del nervio isquiático derecho utilizando una presión de 40N durante 45 segundos. Veinticuatro horas después de la compresión se inició la irradiación con LBI y US, según protocolo. En nuestra investigación constatamos que el incremento en el número de neurofilamentos se relacionó con la dosis aplicada de LBI y US. El valor medio de neurofilamentos/0,25 mm2 obtenidos en cada grupo fue: 1 - 128; 2 - 100; 3 - 156; 4 - 140; 5 - 100; 6 - 148. La aplicación de LBI de y de US terapéutico aumenta el número de neurofilamentos en nervios isquiáticos de rata sometidos a neuropraxia, siendo el LBI más eficaz en comparación al US. Se agrega que estas terapias para inducir la regeneración del nervio lesionado se relacionan al tipo de protocolo utilizado, lo que demuestra la necesidad de establecer la adecuada dosis de irradiación con el propósito de obtener la mejor respuesta terapéutica.

Therapy by low-level laser (LLL) or ultrasound (US) are commonly used as treatment after nerve crush. The aim of this study was to determine the effectiveness of such treatments to repair the neuronal cytoskeleton evaluating the variation in the number of neurofilaments. For this an experimental design was performed, which involved 30 rats divided into 6 groups: 1 - control healthy; 2 - control injured; 3 - irradiated by LLL 2 J/cm2; 4 - irradiated by LLL 10 J/cm2; 5 - irradiated by US 0.5 W/cm2 and 6 - irradiated by US 1W/cm2. With the exception of group 1 all specimens were anesthetized and underwent right sciatic nerve compression using 40N pressure for 45 seconds. Twenty-four hours after compression irradiation was started by LLL and US according protocol. In our research we found that the increase in the number of neurofilaments was related to the applied dose of LLL and US. The average value of neurofilaments / 0.25 mm2 obtained in each group was: 1 - 128; 2-100; 3-156; 4-140; 5-100; 6-148. We concluded that the application of LLL and therapeutic US increases the number of neurofilaments in rat sciatic nerve undergoing neuropraxia, with LLL being more effective compared to the US. Furthermore we concluded that the effectiveness of therapies to induce regeneration of injured nerve is related to the type of protocol used, demonstrating the need to establish an adequate radiation dose with the purpose of obtaining the best therapeutic response, thus achieving successful treatment.

In Vivo Effects of Adipose-Derived Stem Cells in Inducing Neuronal Regeneration in Sprague-Dawley Rats Undergoing Nerve Defect Bridged with Polycaprolactone Nanotubes

There have been many attempts for regeneration of peripheral nerve injury. In this study, we examined the in vivo effects of non-differentiated and neuronal differentiated adipose-derived stem cells (ADSCs) in inducing the neuronal regeneration in the Sprague-Dawley (SD) rats undergoing nerve defect bridged with the PCL nanotubes. Then, we performed immunohistochemical and histopathologic examinations, as well as the electromyography, in three groups: the control group (14 sciatic nerves transplanted with the PCL nanotube scaffold), the experimental group I (14 sciatic nerves with the non-differentiated ADSCs at a density of 7x105 cells/0.1 mL) and the experimental group II (14 sciatic nerves with the neuronal differentiated ADSCs at 7x105 cells/0.1 mL). Six weeks postoperatively, the degree of the neuronal induction and that of immunoreactivity to nestin, MAP-2 and GFAP was significantly higher in the experimental group I and II as compared with the control group. In addition, the nerve conduction velocity (NCV) was significantly higher in the experimental group I and II as compared with the control group (P=0.021 and P=0.020, respectively). On the other hand, there was no significant difference in the NCV between the two experimental groups (P>0.05). Thus, our results will contribute to treating patients with peripheral nerve defects using PCL nanotubes with ADSCs.

Estudio comparativo entre dos intensidades de ultrasonido continuo en la reparación del nervio espinal lesionado por compresión / Comparative study between two intensities of continuous ultrasound in the repair of the spinal nerve injured by compression

El ultrasonido continuo fundamenta su efectividad en la energía térmica que genera, favoreciendo la reparación nerviosa. Es por esto que surge la interrogante de que si al aplicar diferentes intensidades de ultrasonido continuo sobre el nervio espinal lesionado, la respuesta reparativa será igual o distinta. Para ello se utilizaron 12 ratas de sexo masculino a las que se les aisló quirúrgicamente el nervio isquiático, el cual fue pinzado durante 45 segundos con una fuerza constante de 40N. La compresión se realizó a 10mm sobre la bifurcación, luego se desinfectó y suturó. Inmediatamente después de la operación las ratas fueron agrupadas de a 3: A) control sano, B) control lesionado, C) aplicación de ultrasonido terapéutico de 0,5w/cm2 y D) aplicación de ultrasonido terapéutico de 1w/cm2. El grupo A se utilizó como control sano y no recibió irradiación. Las ratas del grupo B fueron lesionadas y no recibieron irradiación y las del grupo C y D fueron lesionadas e irradiadas transcutáneamente en la región correspondiente al recorrido del nervio isquiático utilizando intensidades de 0,5w/cm2 y 1w/cm2, 3 MHZ de frecuencia, un cabezal de 0,5cm2, durante 1 minuto y 10 días consecutivos. 28 días post operatorio se extrajeron los nervios isquiáticos y fueron sometidos a técnicas de tinción de H-E y Van Gieson. Se realizó el diagnóstico histopatológico y la morfometría: se midió el Grosor del Perineuro, Perímetro del núcleo del Schwannocito, Perímetro del Axón Mielínicoy Perímetro de la Mielina. Los resultados revelan que el ultrasonido continuo es efectivo en la reparación del nervio espinal, siéndolo más con 1w/cm2 que con 0,5w/cm2.

The continuous ultrasound bases its efficiency on the heat energy it generates, favoring the nervous repair. Therefore, the question arises whether the reparative response will be equal or different under varying intensities of continuous ultrasound application on the disabled spinal nerve. For the study we used 12 male rats; the ischiatic nerve was surgically isolated and compressed during 45 seconds with a constant force of 40N. The compression was realized at 10 mm on the bifurcation, and was subsequently disinfected and sutured. Immediately following the operation the rats were separated in groups of 3: A) Healthy control, B) Injured control, C) Application of therapeutic ultrasound of 0.5 w/cm2 and D) Application of therapeutic ultrasound of 1 w/cm2. Group A was used as healthy control and did not receive irradiation. The rats in group B were injured and did not receive irradiation and those of groups C and D were injured and were transcutaneously irradiated in the area corresponding to the ischiatic nerve using intensities of 0.5 w/cm2 and 1 w/cm2, 3 MHZ of frequency. We used a compress of 0.5 cm2, during 1 minute and for 10 consecutive days. 28 days post operative ischiatic nerves were removed and submitted to technologies of H.E and VG stain. Histopathological and morphometrical diagnosis was realized: Thickness of the Perineurium, schwannocyte perimeter, Myelin Axon and Myelin perimeters were measured. The results revealed that the continuous ultrasound is effective in the repair of the spinal nerve, more so with 1 w/cm2 than with 0.5 w/cm 2.

Effects of sciatic nerve transection on ultrastructure, NADPH-diaphorase reaction and serotonin-, tyrosine hydroxylase-, c-Fos-, glucose transporter 1- and 3-like immunoreactivities in frog dorsal root ganglion

Frogs have been used as an alternative model to study pain mechanisms. Since we did not find any reports on the effects of sciatic nerve transection (SNT) on the ultrastructure and pattern of metabolic substances in frog dorsal root ganglion (DRG) cells, in the present study, 18 adult male frogs (Rana catesbeiana) were divided into three experimental groups: naive (frogs not subjected to surgical manipulation), sham (frogs in which all surgical procedures to expose the sciatic nerve were used except transection of the nerve), and SNT (frogs in which the sciatic nerve was exposed and transected). After 3 days, the bilateral DRG of the sciatic nerve was collected and used for transmission electron microscopy. Immunohistochemistry was used to detect reactivity for glucose transporter (Glut) types 1 and 3, tyrosine hydroxylase, serotonin and c-Fos, as well as nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-diaphorase). SNT induced more mitochondria with vacuolation in neurons, satellite glial cells (SGCs) with more cytoplasmic extensions emerging from cell bodies, as well as more ribosomes, rough endoplasmic reticulum, intermediate filaments and mitochondria. c-Fos immunoreactivity was found in neuronal nuclei. More neurons and SGCs surrounded by tyrosine hydroxylase-like immunoreactivity were found. No change occurred in serotonin- and Glut1- and Glut3-like immunoreactivity. NADPH-diaphorase occurred in more neurons and SGCs. No sign of SGC proliferation was observed. Since the changes of frog DRG in response to nerve injury are similar to those of mammals, frogs should be a valid experimental model for the study of the effects of SNT, a condition that still has many unanswered questions.

An improved experimental model for peripheral neuropathy in rats

A modification of the Bennett and Xie chronic constriction injury model of peripheral painful neuropathy was developed in rats. Under tribromoethanol anesthesia, a single ligature with 100% cotton glace thread was placed around the right sciatic nerve proximal to its trifurcation. The change in the hind paw reflex threshold after mechanical stimulation observed with this modified model was compared to the change in threshold observed in rats subjected to the Bennett and Xie or the Kim and Chung spinal ligation models. The mechanical threshold was measured with an automated electronic von Frey apparatus 0, 2, 7, and 14 days after surgery, and this threshold was compared to that measured in sham rats. All injury models produced significant hyperalgesia in the operated hind limb. The modified model produced mean ± SD thresholds in g (19.98 ± 3.08, 14.98 ± 1.86, and 13.80 ± 1.00 at 2, 7, and 14 days after surgery, respectively) similar to those obtained with the spinal ligation model (20.03 ± 1.99, 13.46 ± 2.55, and 12.46 ± 2.38 at 2, 7, and 14 days after surgery, respectively), but less variable when compared to the Bennett and Xie model (21.20 ± 8.06, 18.61 ± 7.69, and 18.76 ± 6.46 at 2, 7, and 14 days after surgery, respectively). The modified method required less surgical skill than the spinal nerve ligation model.