Use of aerobic treadmill exercises on nerve regeneration after sciatic nerve injury in spontaneously hypertensive rats

Purpose: Various postoperative protocols have been proposed to improve outcomes and accelerate nerve regeneration. Recently, the use of physical exercise in a post-surgical neurorraphy procedure has shown good results when started early. We experimentally investigated the hypothesis that post-operative exercise speeds up results and improves clinical and morphologic parameters. Methods: Isogenic rats were randomly divided into four groups: 1 SHAM; 2 SHAM submitted to the exercise protocol (EP); 3 Grafting of the sciatic nerve; and 4 Grafting of the sciatic nerve associated with the EP. The EP was based on aerobic activities with a treadmill, with a progressive increase in time and intensity during 6 weeks. The results were evaluated by the sciatic functional index (SFI), morphometric and morphologic analysis of nerve distal to the lesion, and the number of spinal cord motor neurons, positive to the marker Fluoro-Gold (FG), captured retrogradely through neurorraphy. Results: Functional analysis (SFI) did not show a statistical difference between the group grafted with (­50.94) and without exercise (-65.79) after 90 days. The motoneurons count (Spinal cord histology) also showed no diference between these groups (834.5 × 833 respectively). Although functionally there is no difference between these groups, morphometric study showed a greater density (53.62) and larger fibers (7.762) in GRAFT group. When comparing both operated groups with both SHAM groups, all values were much lower. Conclusions: The experimental model that this aerobic treadmill exercises protocol did not modify nerve regeneration after sciatic nerve injury and repair with nerve graft.

Study on the mechanisms of Suaeda rigida polysaccharides on the heart inhibition and skeletal muscle promotion in the frog / [Estudo sobre os mecanismos dos polissacarídeos de Suaeda rigida na inibição do coração e promoção da musculatura esquelética no sapo]

The objectives of this study were to investigate the effects of different concentrations of Suaeda rigida polysaccharides (SRPs) on the physiological characteristics of the frog heart and gastrocnemius muscle, compare their similarities and differences, and analyze the mechanisms. CaCl2 and acetylcholine (Ach) were selected respectively to be co-incubated with the high concentration SRPs to observe the effects on the heart contraction of frog. The effects of different concentrations of the SRPs on the activities of acetylcholinesterase (A-CHE), Na+-K+-ATPase and Ca2+-Mg2+-ATPase in the isolated frog heart were detected by UV-Vis spectrophotometry. The gastrocnemius muscle was immersed in the high concentration of SRPs for 10 min, and the systolic indexes were recorded. The effects of SRPs on the Ach content and A-CHE activity at the sciatic nerve-gastrocnemius junction were determined by UV-Vis spectrophotometry and enzyme-linked immunosorbent assay (ELISA). The results showed that the SRPs had significant inhibitory effects on the contractile amplitude of isolated heart and the contractile amplitude induced by CaCl2 and Ach, respectively (P<0.01). The activity of Ca2+-Mg2+-ATPase was significantly promoted, and the activity of A-CHE was significantly inhibited (P<0.01). The contraction amplitude, contraction rate, relaxation rate of gastrocnemius muscle and the Ach content at the junction of sciatic nerve-gastrocnemius muscle were significantly increased (P<0.01), and the activity of A-CHE at the junction was significantly inhibited (P<0.01) by the SRPs. All the results suggested that the SRPs could inhibit the contraction of heart and promote the contraction and relaxation of skeletal muscle. The mechanism was related to blocking the fast INa channel, inhibiting the ICa-L and activating the M receptors of myocardial membrane and then inhibiting external Ca2+ influx, increasing Ca2+-Mg2+-ATPase activity, decreasing a-che activity.

Os objetivos deste estudo foram investigar os efeitos de diferentes concentrações de Suaeda rigida polissacarídeos (SRPs) sobre as características fisiológicas do coração de rã e do músculo gastrocnêmio, comparar suas semelhanças e diferenças, e analisar os mecanismos. CaCl2 e acetilcolina (Ach) foram selecionados respectivamente para serem co-incubados com os SRPs de alta concentração para observar os efeitos sobre a contração do coração de rã. Os efeitos das diferentes concentrações dos SRPs sobre as atividades da acetilcolinesterase (A-CHE), Na+-K+-ATPase e Ca2+-Mg2+-ATPase no coração isolado de rã foram detectados pela espectrofotometria UV-Vis. O músculo gastrocnêmio foi imerso na alta concentração de SRP por 10 min, e os índices sistólicos foram registrados. Os efeitos das SRPs no conteúdo de Ach e na atividade de A-CHE na junção nervo-gastrocnêmio ciático foram determinados pela espectrofotometria UV-Vis e pelo ensaio de imunoabsorção enzimática (ELISA). Os resultados mostraram que os SRPs tiveram efeitos inibidores significativos sobre a amplitude contrátil do coração isolado e a amplitude contrátil induzida por CaCl2 e Ach, respectivamente (P<0,01). A atividade do Ca2+-Mg2+-ATPase foi significativamente promovida e a atividade do A-CHE foi significativamente inibida (P<0,01). A amplitude de contração, a taxa de contração, a taxa de relaxamento do músculo gastrocnêmio e o conteúdo de Ach na junção do músculo nervo ciático-gastrocnêmio foram significativamente aumentados (P<0,01), e a atividade do A-CHE na junção foi significativamente inibida (P<0,01) pelas SRPs. Todos os resultados sugeriram que os SRPs poderiam inibir a contração do coração e promover a contração e o relaxamento do músculo esquelético. O mecanismo estava relacionado ao bloqueio do canal INa rápido, inibindo a ICa-L e ativando os receptores M da membrana miocárdica e depois inibindo o influxo externo de Ca2+, aumentando a atividade de Ca2+-Mg2+-ATPase, diminuindo a atividade a-che.

Criteria for assessing peripheral nerve injury: behavioral and functional assessment in non-operated Wistar rats

Purpose To evaluate the normality pattern in functional tests of peripheral nerves. Methods Sixty female and sixty male Wistar rats were submitted to vibrissae movement and nictitating reflex for facial nerve; grooming test and grasping test for brachial plexus; and walking tracking test and horizontal ladder test for lumbar plexus. The tests were performed separately, with an interval of seven days between each. Results All animals showed the best score in vibrissae movement, nictitating reflex, grooming test, and horizontal ladder test. The best score was acquired for the first time in more than 90% of animals. The mean of strength on the grasping test was 133.46±12.08g for the right and 121.74±8.73g for the left anterior paw. There was a difference between the right and left sides. There was no difference between the groups according to sex. There is no statistical difference comparing all functional indexes between sex, independent of the side analyzed. The peroneal functional index showed higher levels than the sciatic and tibial functional index on both sides and sex. Conclusions The behavioral and functional assessment of peripheral nerve regeneration are low-cost, easy to perform, and reliable tests. However, they need to be performed by experienced researchers to avoid misinterpretation.(AU)

Stem cells in end-to-side neurorrhaphy: experimental study in rats

Purpose: To evaluate the influence of mesenchymal stem cells from adipose tissue in the end-to-side neurorrhaphy, focusing in the nerve regeneration and the muscle reinnervation in acute trauma. Methods: 140 animals were randomly divided in seven groups: control, denervated, end-to-side neurorrhaphy between distal stump of common peroneal nerve and tibial nerve (ESN), ESN wrapped in fascia, ESN wrapped in fascia and platelet gel, ESN wrapped in platelet gel, ESN wrapped in fascia and platelet gel within stem cells (without culture) removed from the adipose tissue. Mass measurements of the animal and of cranial tibial muscles, electromyography, walking track analysis tests and histological examinations of the nerves and muscles after 180 days was performed. Results: In the groups where the ESN was performed, the results were always better when compared to the denervated group, showing reinnervation in all ESN groups. The most sensitive methods were walking track and histological analysis. Only the group with stem cells showed values similar to the control group, as well as the functional indices of peroneal nerve and the number of nerve fibers in the peroneal nerve. Conclusions: Stem cells were effective in ESN according with the functional index of the peroneal nerve, evaluated by walking track analysis and the number of nerve fibers in the peroneal nerve.(AU)

Avaliação radiográfica da profundidade do sulco troclear e diâmetro patelar em cães / Radiographic assessment of the depth of the troclear groove and patellar diameter in dogs

Background: Patellar luxation is an alteration of bone development for which the indicated treatment is surgery. Failure to correct it may result in clinical worsening. The most commonly used surgical approach is the transposition of the tibial crest with trochleoplasty, which aims to accommodate 50% of the patella in the trochlea. The femoral groove and trochlea can be evaluated radiographically by tangential projection, tomography, or ultrasonography; however, all these methodologies have limitations. The objective of this study was to evaluate the depth of the trochlear groove in three regions and to compare it with the patellar diameter on simple mediolateral radiographic images. Materials, Methods & Results: Fifty non-paired pelvic limbs of adult dogs of a specific breed, weighing less than 40 kg and without orthopedic changes, were used. In the mediolateral radiographic projection, three evaluators measured the femoral trochlear sulcus at three different points and the patellar diameter. After imaging examinations, all limbs were skeletonized, and the trochlea and patella were measured with a digital caliper in the same regions as that of the radiographic measurements. All post-skeletonization calculations were performed by an evaluator. The highest mean radiographic and ex vivo trochlear depth was 3.4 ± 1.2 mm and 2.7 ± 0.8 mm, respectively. The lowest mean radiographic and ex vivo patellar diameter was 7.7 ± 1.7 mm and 7.9 ± 1.6 mm, respectively. The average relationship between the trochlear depth and patellar diameter was less than 50% in all animals, with the highest radiographically determined ratio being 44.15% and that determined ex vivo as 34.17%. The mean patellar diameter calculated radiographically was similar among the animals. Discussion: Radiographic images made it possible to assess the patella and bone surface regions of the femoral condyles. A wide arthrotomy...

Bloqueios dos nervos ciático e femoral guiado por neuroestimulador em Chinchilla lanigera submetida a osteossíntese de tíbia / Nerve stimulator-guided ciatic and femoral nerve block during tibial osteosynthesis in Chinchilla lanigera

Background: Nociceptive stimulation in orthopedic surgery requires effective pain management to ensure trans andpostoperative patient comfort. Several techniques can be used for this, and multimodal analgesia protocols such as guidedlocoregional blocks provide a balanced effect, as they enable the use of low-dose anesthetics and offer rapid recovery. Thebenefits of specific nerve blocks in domestic animals are well known; however, there are few reports that have ascertainedtheir safety in wild species. This report is aimed at describing the successful use of neurolocalizer-guided sciatic andfemoral nerve blocks during tibial osteosyntheses in a chinchilla.Case: A 9-month-old chinchilla weighing 0.56 kg was referred for surgery for proximal and mid-diaphyseal tibia fracturesresulting from trauma. Following preanesthetic evaluation, the animal received intramuscular dexmedetomidine (15 µgkg1) as preanesthetic medication. Sedation was apparent after 15 min and was verified by a decreased activity, the animalallowing manipulation, absence of the eyelid and righting reflexes, and limb movement after clamping removal of limbafter clamping. After achieving sedation, anesthesia was induced and maintained with sevoflurane (FiO2 = 1.0), suppliedthrough a nasoral mask. Sciatic and femoral nerve blocks were performed with the aid of a neurostimulator. A needle wasinserted into the femoral triangle, cranial to the femoral artery, and into the depression between the sciatic tuberosity andthe greater femoral trochanter. The neurostimulator was set at a pulse frequency of 1 Hz, pulse duration of 0.1 ms andinitial current of 0.6 mA. The needle was advanced toward the nerves until muscle contractions were observed, and thecurrent was gradually reduced until contractions were manifested at a minimum current...

Bloqueios dos nervos ciático e femoral guiado por neuroestimulador em Chinchilla lanigera submetida a osteossíntese de tíbia / Nerve stimulator-guided ciatic and femoral nerve block during tibial osteosynthesis in Chinchilla lanigera

Background: Nociceptive stimulation in orthopedic surgery requires effective pain management to ensure trans andpostoperative patient comfort. Several techniques can be used for this, and multimodal analgesia protocols such as guidedlocoregional blocks provide a balanced effect, as they enable the use of low-dose anesthetics and offer rapid recovery. Thebenefits of specific nerve blocks in domestic animals are well known; however, there are few reports that have ascertainedtheir safety in wild species. This report is aimed at describing the successful use of neurolocalizer-guided sciatic andfemoral nerve blocks during tibial osteosyntheses in a chinchilla.Case: A 9-month-old chinchilla weighing 0.56 kg was referred for surgery for proximal and mid-diaphyseal tibia fracturesresulting from trauma. Following preanesthetic evaluation, the animal received intramuscular dexmedetomidine (15 µgkg1) as preanesthetic medication. Sedation was apparent after 15 min and was verified by a decreased activity, the animalallowing manipulation, absence of the eyelid and righting reflexes, and limb movement after clamping removal of limbafter clamping. After achieving sedation, anesthesia was induced and maintained with sevoflurane (FiO2 = 1.0), suppliedthrough a nasoral mask. Sciatic and femoral nerve blocks were performed with the aid of a neurostimulator. A needle wasinserted into the femoral triangle, cranial to the femoral artery, and into the depression between the sciatic tuberosity andthe greater femoral trochanter. The neurostimulator was set at a pulse frequency of 1 Hz, pulse duration of 0.1 ms andinitial current of 0.6 mA. The needle was advanced toward the nerves until muscle contractions were observed, and thecurrent was gradually reduced until contractions were manifested at a minimum current...(AU)

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

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 enzymes 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.[...](AU)

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 neuroptípica. 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.[...](AU)

Sciatic nerve injection palsy in a dog: electrodiagnostic testing and microsurgical treatment

Background: Iatrogenic damage to the ischiatic nerve is considered uncommon and may cause dysfunction with variable clinical signs dependent on type and severity of injury. Due to important role of this nerve in locomotion and weightbearing limb, a poor prognosis for recovery may be observed in many cases. Electromyography analysis may suggest the neuroanatomic localization, diagnosis information, and severity of lesion to determine better therapeutic intervention. Therefore, the aim of this report is to describe the possible cause, diagnosis and treatment of a postinjection ischiatic nerve injury in a dog with complete recovery.Case: A 3-year-old neutered male dachshund dog was referred to the Veterinary Hospital due to inability to weight support in the right hind limb after diminazene diaceturate intramuscular injection. The gait evaluation showed dropped-hock and knuckling into the digits of the right hind limb and neurologic examination revealed moderate muscle atrophy below to femorotibial joint of the right hind limb with sensory analgesia (superficial and deep) on the lateral, dorsal, and plantar surfaces, absent patellar reflex, and proprioceptive deficit. Electrophysiologic testing was done under general anesthesia in a 2-channel Nicolet Compass Meridian apparatus. Absence of compound muscle action potentials after right fibular and tibial nerve stimulations, and abnormal spontaneous activity in cranial tibial, gastrocnemius and deep digital extensor muscles were observed. A diagnosis of moderate/severe axonotmesis of sciatic nerve was achieved. Under microscope magnification, all adherent adjacent tissue and epineural sheat were removed. Due this, a small epineural window was created. On neurological examination performed 30 days after surgery, complete recovery of sensitivity of the right hind limb, and normal proprioception were observed. The muscle atrophy was also noted to have improved.[...]

Sciatic nerve injection palsy in a dog: electrodiagnostic testing and microsurgical treatment

Background: Iatrogenic damage to the ischiatic nerve is considered uncommon and may cause dysfunction with variable clinical signs dependent on type and severity of injury. Due to important role of this nerve in locomotion and weightbearing limb, a poor prognosis for recovery may be observed in many cases. Electromyography analysis may suggest the neuroanatomic localization, diagnosis information, and severity of lesion to determine better therapeutic intervention. Therefore, the aim of this report is to describe the possible cause, diagnosis and treatment of a postinjection ischiatic nerve injury in a dog with complete recovery.Case: A 3-year-old neutered male dachshund dog was referred to the Veterinary Hospital due to inability to weight support in the right hind limb after diminazene diaceturate intramuscular injection. The gait evaluation showed dropped-hock and knuckling into the digits of the right hind limb and neurologic examination revealed moderate muscle atrophy below to femorotibial joint of the right hind limb with sensory analgesia (superficial and deep) on the lateral, dorsal, and plantar surfaces, absent patellar reflex, and proprioceptive deficit. Electrophysiologic testing was done under general anesthesia in a 2-channel Nicolet Compass Meridian apparatus. Absence of compound muscle action potentials after right fibular and tibial nerve stimulations, and abnormal spontaneous activity in cranial tibial, gastrocnemius and deep digital extensor muscles were observed. A diagnosis of moderate/severe axonotmesis of sciatic nerve was achieved. Under microscope magnification, all adherent adjacent tissue and epineural sheat were removed. Due this, a small epineural window was created. On neurological examination performed 30 days after surgery, complete recovery of sensitivity of the right hind limb, and normal proprioception were observed. The muscle atrophy was also noted to have improved.[...](AU)

Mapeamento comparativo de nervos periféricos em caninos e bovinos / Comparative mapping of peripheral nerves in dogs and cattle

O estudo dos dados anatômicos é fundamental para possibilitar ao médico veterinário o reconhecimento de pequenas estruturas, como os nervos nos animais, oferecendo subsídio para construção do conhecimento do profissional principalmente em técnicas anestésicas e cirúrgicas. Para investigar e mapear os nervos do plexo braquial (nervo radial, nervo musculocutâneo, nervo ulnar, nervo mediano), nervo isquiático, nervo tibial, nervo femoral e os nervos para bloqueio paravertebral, foram utilizados um cadáver canino adulto, de peso aproximado de 8kg, e um cadáver de bezerro Holandês, de peso aproximado de 40kg. O mapeamento dos nervos é de grande importância, já que conhecer bem essas estruturas permite ao veterinário um bom desenvolvimento de suas atividades profissionais a fim de exercer funções mais complexas durante a anestesia e cirurgia veterinária, uma vez que, identificados os pontos de referência anatômicos, é possível trabalhar com mais clareza nas técnicas de bloqueios dos nervos periféricos.(AU)

Knowledge of animal anatomy is essential for the veterinarian to identify small structures such as nerves, thus providing a solid background for the professional especially for surgical and anesthetic techniques. To investigate and map the nerves of the brachial plexus (radial, musculocutaneous, ulnar, median), sciatic, tibial, femoral and the nerves for paravertebral blocking in bovine, embalmed specimens were used. One adult male dog weighing approximately 8kg and one 40kg male calf were used. Nerve mapping is fundamental due to its interdisciplinary nature, thus providing the veterinarian with a major improvement in his/her professional activities which permits allows one to perform complex tasks in anesthesia and veterinary surgery. Knowledge ofanatomical reference points increases clarity and precision in techniques involving peripheral nerve blocks.(AU)

Mapeamento comparativo de nervos periféricos em caninos e bovinos / Comparative mapping of peripheral nerves in dogs and cattle

O estudo dos dados anatômicos é fundamental para possibilitar ao médico veterinário o reconhecimento de pequenas estruturas, como os nervos nos animais, oferecendo subsídio para construção do conhecimento do profissional principalmente em técnicas anestésicas e cirúrgicas. Para investigar e mapear os nervos do plexo braquial (nervo radial, nervo musculocutâneo, nervo ulnar, nervo mediano), nervo isquiático, nervo tibial, nervo femoral e os nervos para bloqueio paravertebral, foram utilizados um cadáver canino adulto, de peso aproximado de 8kg, e um cadáver de bezerro Holandês, de peso aproximado de 40kg. O mapeamento dos nervos é de grande importância, já que conhecer bem essas estruturas permite ao veterinário um bom desenvolvimento de suas atividades profissionais a fim de exercer funções mais complexas durante a anestesia e cirurgia veterinária, uma vez que, identificados os pontos de referência anatômicos, é possível trabalhar com mais clareza nas técnicas de bloqueios dos nervos periféricos.(AU)

Knowledge of animal anatomy is essential for the veterinarian to identify small structures such as nerves, thus providing a solid background for the professional especially for surgical and anesthetic techniques. To investigate and map the nerves of the brachial plexus (radial, musculocutaneous, ulnar, median), sciatic, tibial, femoral and the nerves for paravertebral blocking in bovine, embalmed specimens were used. One adult male dog weighing approximately 8kg and one 40kg male calf were used. Nerve mapping is fundamental due to its interdisciplinary nature, thus providing the veterinarian with a major improvement in his/her professional activities which permits allows one to perform complex tasks in anesthesia and veterinary surgery. Knowledge ofanatomical reference points increases clarity and precision in techniques involving peripheral nerve blocks.(AU)

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

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.(AU)

Effect of Sciatic Nerve Transection on acetylcholinesterase activity in spinal cord and skeletal muscles of the bullfrog 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 enzymes 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.

Effect of Sciatic Nerve Transection on acetylcholinesterase activity in spinal cord and skeletal muscles of the bullfrog 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 enzymes 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.

End-to-side versus end-to-end neurorrhaphy at the peroneal nerve in rats

Purpose: To evaluate three different kinds of neurorrhaphy of the peroneal nerve. Methods: Eigthy rats were divided into 5 groups. Control: nerve had no intervention. End-to-end (EE): nerve was cut and elongated with a nerve graft with two end-to-end neurorrhaphies. End-to-side (ES): nerve was cut and sutured to the graft with at the lateral side of the nerve. Side-to-end (SE): the nerve was cut and sutured to the graft with end-to-end neurorrhaphy. Denervated: nerve was cut and both endings were buried into the muscle. The evaluation was done by walking track analysis, electrophysiology, body mass, cranial tibial muscle mass, nerve and muscle fibers morphometry. Results: The EE, ES and SE have the same potential of reinnervation. Conclusion: There is no functional or histological difference between these different types of neurorrhaphy.(AU)

Tibial and fibular nerves evaluation using intraoperative electromyography in rats

PURPOSE:To evaluate a new model of intraoperative electromyographic (EMG) assessment of the tibial and fibular nerves, and its respectives motor units in rats.METHODS:Eight Wistar rats underwent intraoperative EMG on both hind limbs at two different moments: week 0 and week 12. Supramaximal electrical stimulation applied on sciatic nerve, and compound muscle action potential recorded on the gastrocnemius muscle (GM) and the extensor digitorum longus muscle (EDLM) through electrodes at specifics points. Motor function assessment was performaced through Walking Track Test.RESULTS:Exposing the muscles and nerves for examination did not alter tibial (p=0.918) or fibular (p=0.877) function between the evaluation moments. Electromyography of the GM, innervated by the tibial nerve, revealed similar amplitude (p=0.069) and latency (p=0.256) at week 0 and at 12 weeks, creating a standard of normality. Meanwhile, electromyography of the EDLM, innervated by the fibular nerve, showed significant differences between the amplitudes (p=0.003) and latencies (p=0.021) at the two different moments of observation.CONCLUSION:Intraoperative electromyography determined and quantified gastrocnemius muscle motor unit integrity, innervated by tibial nerve. Although this study was not useful to, objectively, assess extensor digitorum longus muscle motor unit, innervated by fibular nerve.(AU)

AVALIAÇÃO COMPARATIVA DE DIFERENTES MÉTODOS DE PROTEÇÃO AOS TECIDOS PRÓXIMOS AO JOELHO DURANTE OSTEOTOMIA PARA NIVELAMENTO DO PLATÔ TIBIAL (TPLO). ESTUDO EX-VIVO EM CÃES

Objetivou-se comparar a eficácia de oito diferentes métodos de proteção à artéria poplítea, fíbula e nervos tibial e fibular após osteotomia da TPLO. Foram utilizados 40 cadáveres (80 joelhos) caninos com massa corpórea de 25,9±3,7Kg, distribuídos igualmente em oito grupos experimentais. No primeiro grupo (G1) utilizou-se a compressa cirúrgica, posicionada na face craniolateral da tíbia proximal. No G2 a compressa foi alocada na face caudolateral da tíbia proximal. No G3, a compressa foi aplicada na face craniolateral, porém sendo tracionada até sua visibilização na face caudal da tíbia. O afastador cirúrgico I e II foram utilizados nos grupos G4/G5 e G7\G8, respectivamente. No G4 e G7, o afastador foi utilizado na craniolateral e no G5 e G8, na face caudolateral. No grupo G6, a osteotomia foi realizada de forma parcial na cortical trans e completada, de forma manual, por aplicação de pressão digital. As avaliações foram realizadas por meio de comparação radiográfica pré e pós osteotomia, assim como por meio de dissecação anatômica de forma cega por 4 avaliadores experientes para classificação das possíveis lesões em 3 graus. Encontrou-se uma incidência total de lesões de 20%, sendo 13,8% das lesões grau 2 e 6,2% de lesões grau 3. Das lesões grau 2, 81,8% e 60% das lesões grau 3 foram identificadas quando se utilizou os métodos de proteção. Apesar da maior incidência de lesão quando se utilizou os métodos de proteção, tal diferença não foi significativa (p>5%). Os métodos de proteção que foram utilizados no sentido cranial para caudal foram os que apresentaram piores resultados e o afastador tipo II no sentido caudal para cranial o que menos prejudicou as estruturas avaliadas, porém tal comportamento também não foi significativo. Pelas condições do estudo, conclui-se que o uso dos métodos de proteção adotados não traz benefícios de proteção à artéria poplítea, fíbula e nervos tibial e fibular durante a TPLO.

The propose of the study was to compare the effectiveness of eight different methods of protection of the popliteal artery, fibula, tibial and fibular nerves after TPLO osteotomy. 40 canine corpses (80 knees) with body weight 25,9±3,7Kg were separated in eight experimental groups. In the first group, denominated G1 was used a surgical sponge in the craniolateral aspect of the proximal tibial. In G2 the surgical sponge was allocated in the caudolateral aspect of the proximal tibial. In G3, the surgical sponge was applied in the craniolateral aspect, but it was pushed through caudally to the tibia until it being visible in the operative field. The special retractors I and II developed by the team for this purpose were used in groups G4\G5 and G7\G8, respectively. In G4 and G7, the retractor was used in the craniolateral direction and in G5 and G8, in the caudolateral aspect of the proximal tibial. In G6, the trans cortex osteotomy was partially performed and completed with digital pression. The evaluations were performed through radiographic comparison before and after osteotomy and by dissection of the structures adjacent to the osteotomy line. The images were prepared and sent to 4 evaluators for damage graduation in 3 degrees. A 20% of total incidence of injuries was found with 13,8% of grade 2 injuries and 6,2% of grade 3 injuries. Of grade 2 injuries, 81,8% and 60% of grade 3 injuries were identified when protective methods were used. Despite the higher incidence of injury when protective methods were used, this difference was not significant (p>0,05). The protection methods that were used in the cranial to caudal direction were the ones that showed the worst results and the type II retractor in the caudal to cranial direction was the one which least harmed the evaluated structures, but this behavior was also not significant. Due to the conditions of the study, it is concluded that the use of these methods does not bring benefits to the popliteal artery, fibula and tibial and fibular nerve protection during TPLO.

CONDUTO DE ORIENTAÇÃO NERVOSA FUNCIONALIZADO COM CÉLULAS ESTROMAIS MESENQUIMAIS MULTIPOTENTES PROMOVE A REGENERAÇÃO DO NERVO ISQUIÁTICO EM RATOS

As lesões traumáticas do sistema nervoso periférico (SNP) são altamente debilitantes, levando a déficits sensório-motores a longo prazo. A regeneração nervosa depende de um microambiente permissivo para o crescimento axonal, associado a presença de moléculas solúveis bioativas. Neste sentido, o uso das células estromais mesenquimais multipotentes derivadas do tecido adiposo (AdMSC) em combinação com condutos de orientação nervosa (NGC) poderiam acarretar estratégias promissoras para a regeneração nervosa. Ratos Wistar foram submetidos a lesão crítica do nervo isquiático (12 mm de gap) e divididos em grupos experimentais: Sham (abordagem do nervo isquiático sem alterações), GA (técnica de autoenxerto), GPCL (tubulação com NGC vazio), GPCL+MSCc (tubulação com NGC + 106 AdMSC de cão embebidas em biopolímero de fibrina) e GPCL+MSCr (tubulação com NGC + 106 AdMSC de rato embebidas em biopolímero de fibrina). Os NGC de policaprolactona (PCL) foram fabricados por impressão 3D. As AdMSC de cão foram caracterizadas in vitro e foi avaliado o potencial neuroregenerativo após a estimulação com INF-y (BDNF, GDNF, HGF e IL-10). Foram avaliados o índice de funcionalidade do nervo isquiático e tibial durante 12 semanas in vivo. A análise da marcha e a eletroneuromiografia foram avaliadas nas semanas 8 e 12. Foi realizada a morfometria post-mortem nas semanas 8 e 12 após o reparo nervoso. Trinta dias após a lesão nos grupos GPCL+MSCc e Sham, foram analisadas a expressão de fatores neurotróficos (BDNF, GDNF e o receptor p75NTR) e a reatividade das células de Schwann (S-100 e neurofilamento) pela imunofluorescencia, e a expressão gênica na medula espinhal (BDNF, GDNF, HGF, IL-6 e IL-10). A estimulação com INF-y aumentou a expressão gênica de BDNF, GDNF, HGF e IL-10 nas AdMSC de cão. Os grupos GPCL+MSCc e GPCL+MSCr apresentaram recuperação motora e eletrofisiológica quando comparados ao grupo GPCL em 8 e 12 semanas. Porém, os valores não foram superiores ao autoenxerto. Os achados foram relacionados a presença de fibras mielinizadas, maior expressão de BDNF, GDNF e P75NTR no nervo isquiático e a up-regulation de BDNF, GDNF e HGF na medula espinhal. Foi observada tendência a maior reatividade das células de Schwann e ramificação axonal no nervo isquiático. A combinação de NGC impressos em 3D e funcionalizados com AdMSC de cão e de rato mostraram efeitos neuroprotetores. A associação de AdMSC e biopolímero de fibrina suportaram o microambiente trófico e estimularam o estado pró-regenerativo na lesão crítica do nervo isquiático em ratos.

Peripheral nervous injuries (PNS) are highly debilitating, leading to long-term motor and sensory deficits. Nerve regeneration depends of the permissive microenvironment for axonal growth associated to bioactive molecules. In this sense, the use of multipotent mesenchymal stromal cells adipose tissue derived (AdMSC) in combination with nerve guidance conduits (NGC) could be promising strategies for nerve regeneration. Wistar rats were submitted to critical sciatic nerve injury (12 mm gap) and divided into experimental groups: Sham, GA (autograft), GPCL (empty NGC), GPCL + MSCc (NGC + 106 plus canine AdMSC embedded in fibrin biopolymer), GPCL + MSCr (NGC + 106 plus rat AdMSC embedded in fibrin biopolymer). Polycaprolactone (PCL) NGC was manufactured by 3D printing. In vitro, regenerative potential was evaluated after INF- stimulation (BDNF, GDNF, HGF and IL-10). In vivo, were measure the sciatic ant tibial functional index for 12 weeks. Gait analysis and electroneuromyography were performed at 8 and 12 weeks. Post-mortem, morphometric analysis was made at 8 and 12 weeks after nerve repair. Thirty days after lesion in the GPLC+MSCc and Sham, were evaluated the expression of neurotrophins (BDNF, GDNF and p75NTR receptor), Schwann cells reactivity by immunofluorescence (S-100 and neurofilament) and gene expression in the spinal cord (BDNF, GDNF, HGF, IL-6 and IL-10). The stimulation with INF- increased gene expression on canine AdMSC in vitro for BDNF, GDNF, HGF and IL-10. The groups GPCL+MSCc and GPCL+MSCr showed functional motor and electrophysiological motor recovery when compared with the GPCL group at 8 and 12 weeks. However, the values were not superior to GA group. These findings were related to presence of myelinated fibers, increased of neurotrophins expression BDNF, GDNF and p75NTR on sciatic nerve and up-regulation of the BDNF, GDNF and HGF in the spinal cord. A trend towards greater reactivity of Schwann cells and axonal branching in the sciatic nerve were observed. The combination of NGC 3D-printing and functionalized with canine and rat AdMSC showed neuroprotective effects. The association of canine or rat AdMSC and fibrin biopolymer support trophic microenvironment and stimulate a pro-regenerative state in severe sciatic nerve injury in rats.

Anatomical aspects of the nerves of the leg and foot of the giant anteater (Myrmecophaga tridactyla, Linnaeus, 1758) / Aspectos anatômicos dos nervos da perna e pé do tamanduá-bandeira (Myrmecophaga tridactyla, Linnaeus, 1758)

Although distal stifle joint nerve distribution has been well established in domestic animals, this approach is scarcely reported in wild animals. Therefore, the aim of this study was to describe the nerves of the leg and foot of Myrmecophaga tridactyla with emphasis on their ramification, distribution, topography and territory of innervation. For this purpose, six adult cadavers fixed and preserved in 10% formalin solution were used. The nerves of the leg and foot of the M. tridactyla were the saphenous nerve (femoral nerve branch), fibular and tibial nerves and lateral sural cutaneous nerve (branches of the sciatic nerve) and caudal sural cutaneous nerve (tibial nerve branch). The saphenous nerve branches to the skin, the craniomedial surface of the leg, the medial surface of the tarsal and metatarsal regions and the dorsomedial surface of the digits I and II (100% of cases), III (50% of cases) and IV (25% of cases). The lateral sural cutaneous nerve innervates the skin of the craniolateral region of the knee and leg. The fibular nerve innervates the flexor and extensor muscles of the tarsal region of the digits and skin of the craniolateral surface of the leg and dorsolateral surface of the foot. The tibial nerve innervates the extensor muscles of the tarsal joint and flexor, adductor and abductor muscles of the digits and the skin of the plantar surface. The caudal sural cutaneous nerve innervates the skin of the caudal surface of the leg. The nerves responsible for the leg and foot innervation were the same as reported in domestic and wild animals, but with some differences, such as the more distal division of the common fibular nerve, the absence of dorsal metatarsal branches of the deep fibular nerve and a greater involvement of the saphenous nerve in the digital innervation with branches to the digits III and IV, in addition to digits I and II.(AU)

Apesar de bem estabelecida nos animais domésticos, a abordagem da distribuição nervosa distal do joelho é rara em animais selvagens. Portanto, o objetivo deste estudo foi descrever os nervos da perna e pé do Myrmecophaga tridactyla, com ênfase na sua ramificação, distribuição, topografia e território de inervação. Para tanto, foram utilizados seis cadáveres adultos, fixados e conservados em solução de formalina a 10%. A dissecação envolveu desde a formação dos nervos femoral e isquiático pelos ramos ventrais dos nervos espinhais lombares e sacrais até sua distribuição nos territórios propostos. Os nervos responsáveis pela inervação da perna e pé do M. tridactyla foram o N. safeno (ramo do N. femoral), os nervos fibular comum e tibial e o N. cutâneo lateral da sura (derivados do N. isquiático) e o N. cutâneo caudal da sura (ramo do N. tibial). O nervo safeno emite ramos cutâneos para a superfície craniomedial da perna, medial do tarso e metatarso e dorsomedial dos dedos I e II (100% dos casos), III (50% dos casos) e IV (25% dos casos). O nervo cutâneo lateral da sura inerva a região cutânea craniolateral do joelho e perna. O nervo fibular inerva os músculos flexores do tarso e extensores dos dedos e a região cutânea craniolateral da perna e dorsolateral do pé. O nervo tibial inerva os músculos extensores do tarso e flexores, adutores e abdutores dos dedos e região cutânea plantar. O nervo cutâneo caudal da sura inerva a pele da face caudal da perna. Pode-se concluir que os nervos responsáveis pela inervação da perna e pé foram os mesmos relatados em animais domésticos e selvagens, porém com algumas diferenças, como a divisão mais distal do nervo fibular comum, ausência de ramos metatarsianos dorsais do N. fibular profundo e uma maior participação do nervo safeno na inervação digital, contribuindo com ramos inclusive para os dedos III e IV, além dos dedos I e II.(AU)