Avaliação experimental dos efeitos do anestésico local ropivacaína em nervos ciáticos

This study was undertaken to investigate the effects of ropivacaine after intrafascicular injection into the sciatic nerves of albino rabbits. Twenty adult albine rabbits were used, following sedation with intramuscular ketamine (50 mg/kg) for nerve exposure by lateral incision. We considered three experimental groups: Group I:sciatic nerve control; Group II: intrafascicular injection with 0.2 mL of physiologic saline solution in the left nerves and intrafascicular injection with 0.2 mL of local anesthetic ropivacaine into the rigth nerves. The specimens were colected at 48 h after drugs administration; Group III. intrafascicular injection with 0.2 mL of physiologic saline solution in the left nerves and intrafascicular injection with 0.2 mL of local anesthetic ropivacaine in the rigth nerves. The specimens were colected at 7 days after drugs administration. The sciatic nerves were removed from these animals and fixed in Karnowisky solution for 24 hours. After partial dehydration up to 95% ethanol, they were embedded in historesin (Leica). The tissue was then sectioned at 1-2μm. Sections were stained with haematoxylin-eosin (HE); toluidine blue (TB) or picrosirius-haematoxylin (PSH). Comparing with control group the histological evidence of inflammatory reaction (migration of macrophagic cells and eosinophils-appeared soon after injection, with intense proliferation of perineurial cells. The results show that after 7 days of intrafascicular injection there was a severe fibrosis and an increase on perineurial vascularization. In group 2 the inflammatory reaction was noted near the local of the injection. Furthermore in this experiment we observed an increase on the number of epineurial lipoblasts and adipocytes. This study demonstrated that the toxic effects of ropivacaine are transient. In many cases there was an initial fascicular recover and axonal regeneration after 7 days of the injection.

Estudo comparativo experimental da injeção perineural do álcool benzílico 0,75% e do álcool etílico absoluto nos nervos palmares de eqüinos

The clinical and histopathological effects of two alcoholic neurolytics were studied in horses. Normal horses were shod with a designed shoe adaptted with 5 screws to produce solar pain. After gait and lameness score analysis, the palmar nerve of 5 horses was injected with 5 ml of 0,75% benzyl alcohol (Group A) and 5 horses were injected with 5 ml of absolute ethyl alcohol (Group B). The animals were submitted to regular lameness evaluation and solar sensibility tests during next six months. The solar sensitivity returned 5 months latter in the group injected with benzyl alcohol 0,75%, while in the group injected with absolute ethyl alcohol, the sole was still desensitized 6 months latter. The histopathological findings showed that the nerve injected with benzyl alcohol 0,75%, resulted in axonotmesis, characterized by axonal nerve degeneration, with possibilities for the nerve conduction recovery. The perineural injection of ethyl alcohol absolute, resulted in neurotmesis with difficult nerve regeneration. It was concluded that chemical neurolysis with alcohol is an option for temporary or permanent nerve blocks in horses.

Neurorrafia do ramo bucal dorsal do nervo facial em coelhos com proteção de segmento intestinal alógeno

18 rabbits, New Zealand, males, adults were used for clinical and histological evaluation of repair dorsal buccal branch of facial nerve after 15, 30 and 60 days postoperatively (PO). The animals were divided into two groups for transection and 10-0 nylon monofilament epineural suture of buccal branch. In animals in Group I, the nerve was coated with protection of jejunum allograft preserved in glycerin 98% and in group II was applied epineural suture. Both groups occurred the return of movement of the upper lip from the eighth week. There was infiltrated cellular and giant cells with fibrosis unsystematic and collagen fibers of the allograft jejunum joing to the connective tissue. At 15 and 30 days of PO, the distal nerve stumps of both groups were found with degeneration wallerian and in 60 days, regenerated fibers. The repair of the dorsal buccal branch of facial nerve with the allograft wasn't significantly different between the control rabbits as to the assessment of histological and functional recovery.

Fator de crescimento nervoso em cola de fibrina no reparo término-lateral de nervos em ratos

Purpose: To determine the effects of end-to-side nerve repair performed only with fibrin glue containing nerve growth in rats. Methods: Seventy two Wistar rats were divided into six equal groups: group A was not submitted to nerve section; group B was submitted to nerve fibular section only. The others groups had the nerve fibular sectioned and then repaired in the lateral surface of an intact tibial nerve, with different procedures: group C: ETS with sutures; group D: ETS with sutures and NGF; group E: ETS with FG only; group F: ETS with FG containing NGF. The motor function was accompanied and the tibial muscle mass, the number and diameter of muscular fibers and regenerated axons were measured. Results: All the analyzed variables did not show any differences among the four operated groups (p>0.05), which were statistically superior to group B (p<0.05), but inferior to group A (p>0.05). Conclusion: The end-to-side nerve repair presented the same recovery pattern, independent from the repair used, showing that the addition of nerve growth factor in fibrin glue was not enough for the results potentiating.

Motor Recovery and Synaptic Preservation after Ventral Root Avulsion and Repair with a Fibrin Sealant Derived from Snake Venom

Background:Ventral root avulsion is an experimental model of proximal axonal injury at the central/peripheral nervous system interface that results in paralysis and poor clinical outcome after restorative surgery. Root reimplantation may decrease neuronal degeneration in such cases. We describe the use of a snake venom-derived fibrin sealant during surgical reconnection of avulsed roots at the spinal cord surface. The present work investigates the effects of this fibrin sealant on functional recovery, neuronal survival, synaptic plasticity, and glial reaction in the spinal motoneuron microenvironment after ventral root reimplantation.Methodology/Principal Findings:Female Lewis rats (7 weeks old) were subjected to VRA and root replantation. The animals were divided into two groups: 1) avulsion only and 2) replanted roots with fibrin sealant derived from snake venom. Post-surgical motor performance was evaluated using the CatWalk system twice a week for 12 weeks. The rats were sacrificed 12 weeks after surgery, and their lumbar intumescences were processed for motoneuron counting and immunohistochemistry (GFAP, Iba-1 and synaptophysin antisera). Array based qRT-PCR was used to evaluate gene regulation of several neurotrophic factors and receptors as well as inflammatory related molecules. The results indicated that the root reimplantation with fibrin sealant enhanced motor recovery, preserved the synaptic covering of the motoneurons and improved neuronal survival. The replanted group did not show significant changes in microglial response compared to VRA-only. However, the astroglial reaction was significantly reduced in this group.Conclusions/Significance:In conclusion, the present data suggest that the repair of avulsed roots with snake venom fibrin glue at the exact point of detachment results in neuroprotection and preservation of the synaptic network at the microenvironment of the lesioned motoneurons. Also such procedure reduced the astroglial reaction and increased mRNA levels to neurotrophins and anti-inflammatory cytokines that may in turn, contribute to improving recovery of motor function. © 2013 Barbizan et al.

Efeito da catuama e do bilobalide na regeneração nervosa perifírica de ratos submetidos à secção do nervo isquático

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Dessensibilização dos nervos palmares em eqüinos: estudo comparativo experimental do álcool benzílico 0,75% e álcool etílico absoluto (95,5% PA)

Pós-graduação em Medicina Veterinária - FMVZ

Efeito da estimulação do músculo tibial cranial após neurorrafia término-lateral do nervo fibular em ratos

Pós-graduação em Bases Gerais da Cirurgia - FMB

Enxerto venoso ao avesso e normal, com ou sem preenchimento de músculo, em regeneração nervosa de ratos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Implante de tubo de silicone com e sem colágeno na regeneração de nervos de eqüinos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A Catuama e o bilobalide na regeneração nervosa periférica de ratos submetidos à secção do nervo isquiático

The Catuama((R)) is composed of four Brazilian plants extracts (Paullinia cupana, Trichilia catigua, Ptychopetalum olacoides e Zingiber officinale). The Catuama((R)) is known as having neuroprotector, anti-inflammatory, antioxidant and antidepressant effects. Bilobalide, extracted from leaves of Ginkgo biloba, is known by its neuroprotective effect in the central and peripheral nervous systems. The present study evaluates the effect of Catuama((R)) and bilobalide on peripheral nerve regeneration in rats following a sciatic nerve section. Sciatic nerve of forty adult rats was transected with a 10-mm gap and the proximal and distal nerve stumps were fixed in a silicone tube filled with liquid collagen. The animals were divided into four groups: the control group (A), two groups treated with Catuama((R)) by gavage along 28 days after the surgery in different doses of 100 (B) and 400mg. kg(-1) (C) and the group using 200 mu M bilobalide (D) associated with the liquid collagen in the silicone tube. Evaluations were done by a walk test on the first, fifth and tenth week after the surgery. Electrophysiological stimulation and quantitative and qualitative histological analyses of the sciatic nerve and gastrocnemius muscle were also performed on the tenth week after the surgery. All groups showed good regeneration but no statistical difference was found between treatments and control groups (P > 0.05).

Low-intensity laser therapy effect on the recovery of traumatic spinal cord injury

Scientific advances have been made to optimize the healing process in spinal cord injury. Studies have been developed to obtain effective treatments in controlling the secondary injury that occurs after spinal cord injury, which substantially changes the prognosis. Low-intensity laser therapy (LILT) has been applied in neuroscience due to its anti-inflammatory effects on biological tissue in the repairing process. Few studies have been made associating LILT to the spinal cord injury. The objective of this study was to investigate the effect of the LILT (GaAlAs laser-780 nm) on the locomotor functional recovery, histomorphometric, and histopathological changes of the spinal cord after moderate traumatic injury in rats (spinal cord injury at T9 and T10). Thirty-one adult Wistar rats were used, which were divided into seven groups: control without surgery (n = 3), control surgery (n = 3), laser 6 h after surgery (n = 5), laser 48 h after surgery (n = 5), medullar lesion (n = 5) without phototherapy, medullar lesion + laser 6 h after surgery (n = 5), and medullar lesion + laser 48 h after surgery (n = 5). The assessment of the motor function was performed using Basso, Beattie, and Bresnahan (BBB) scale and adapted Sciatic Functional Index (aSFI). The assessment of urinary dysfunction was clinically performed. After 21 days postoperative, the animals were euthanized for histological and histomorphometric analysis of the spinal cord. The results showed faster motor evolution in rats with spinal contusion treated with LILT, maintenance of the effectiveness of the urinary system, and preservation of nerve tissue in the lesion area, with a notorious inflammation control and increased number of nerve cells and connections. In conclusion, positive effects on spinal cord recovery after moderate traumatic spinal cord injury were shown after LILT.

Efeitos do FK-506 na regeneração de nervos após neurorrafia láteo-terminal: estudo em ratos

Pós-graduação em Bases Gerais da Cirurgia - FMB

Análise do exercício físico e eletroestimulção do músculo tibial cranial após neurorrafia término-lateral do nervo fibular em ratos

Pós-graduação em Bases Gerais da Cirurgia - FMB

Células-tronco na neurorrafia látero-terminal: estudo experimental em ratos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)