Improved Recovery of Complete Spinal Cord Transection by a Plasma-Modified Fibrillar Scaffold.

Complete spinal cord injury causes an irreversible disruption in the central nervous system, leading to motor, sensory, and autonomic function loss, and a secondary injury that constitutes a physical barrier preventing tissue repair. Tissue engineering scaffolds are presented as a permissive platform for cell migration and the reconnection of spared tissue. Iodine-doped plasma pyrrole polymer (pPPy-I), a neuroprotective material, was applied to polylactic acid (PLA) fibers and implanted in a rat complete spinal cord transection injury model to evaluate whether the resulting composite implants provided structural and functional recovery, using magnetic resonance (MR) imaging, diffusion tensor imaging and tractography, magnetic resonance spectroscopy, locomotion analysis, histology, and immunofluorescence. In vivo, MR studies evidenced a tissue response to the implant, demonstrating that the fibrillar composite scaffold moderated the structural effects of secondary damage by providing mechanical stability to the lesion core, tissue reconstruction, and significant motor recovery. Histologic analyses demonstrated that the composite scaffold provided a permissive environment for cell attachment and neural tissue guidance over the fibers, reducing cyst formation. These results supply evidence that pPPy-I enhanced the properties of PLA fibrillar scaffolds as a promising treatment for spinal cord injury recovery.

The Estrogen Receptor Alpha Regulates the Sex-dependent Expression and Pronociceptive Role of Bestrophin-1 in Neuropathic Rats.

Bestrophin-1, a calcium-activated chloride channel (CaCC), is involved in neuropathic pain; however, it is unclear whether it has a dimorphic role in female and male neuropathic rats. This study investigated if 17ß-estradiol and estrogen receptor alpha (ERα) activation regulate bestrophin-1 activity and expression in neuropathic rats. Neuropathic pain was induced by L5-spinal nerve transection (SNT). Intrathecal administration of CaCCinh-A01 (.1-1 µg), a CaCC blocker, reversed tactile allodynia induced by SNT in female but not male rats. In contrast, T16Ainh-A01, a selective anoctamin-1 blocker, had an equal antiallodynic effect in both sexes. SNT increased bestrophin-1 protein expression in injured L5 dorsal root ganglia (DRG) in female rats but decreased bestrophin-1 protein in L5 DRG in male rats. Ovariectomy prevented the antiallodynic effect of CaCCinh-A01, but 17ß-estradiol replacement restored it. The effect of CaCCinh-A01 was prevented by intrathecal administration of MPP, a selective ERα antagonist, in rats with and without prior hormonal manipulation. In female rats with neuropathy, ovariectomy prevented the increase in bestrophin-1 and ERα protein expression, while 17ß-estradiol replacement allowed for an increase in both proteins in L5 DRG. Furthermore, ERα antagonism (with MPP) prevented the increase in bestrophin-1 and ERα protein expression. Finally, ERα activation with PPT, an ERα selective activator, induced the antiallodynic effect of CaCCinh-A01 in neuropathic male rats and prevented the reduction in bestrophin-1 protein expression in L5 DRG. In summary, data suggest ERα activation is necessary for bestrophin-1's pronociceptive action to maintain neuropathic pain in female rats. PERSPECTIVE: The mechanisms involved in neuropathic pain differ between male and female animals. Our data suggest that ERα is necessary for expression and function of bestrophin-1 in neuropathic female but not male rats. Data support the idea that a therapeutic approach to relieving neuropathic pain must be based on patient's gender.

A precise approach to robotic intracorporeal rectal transection and hand-sewn purse-string anastomosis for low anterior resection.

This study presents a new technique for robotic-assisted intracorporeal rectal transection and hand-sewn anastomosis for low anterior resection that overcomes some limitations of conventional techniques. By integrating the advantages of the robotic platform, ensuring standardized exposure during rectal transection, and emphasizing the importance of avoiding complications associated with staple crossings, this innovation has the potential to significantly improve outcomes and reduce costs for patients with lower rectal tumors.

Time-dependent proregenerative effects of exogenous melatonin on the transected sciatic nerve / Efectos proregenerativos dependientes del tiempo de la melatonina exógena en el nervio ciático seccionado

SUMMARY: Microsurgical procedures are the treatment of choice of peripheral nerve injuries, but often fail to reach full functional recovery. Melatonin has neuroprotective actions and might be used as a possible proregenerative pharmacological support. Therefore, the aim of this study was to analyze the time-dependence of the neuroprotective effect of melatonin on the overall fascicular structures of both ends of the transected nerve. Sciatic nerve transection was performed in 34 adult male Wistar rats divided in four groups: two vehicle groups (N=7) treated intraperitoneally for 7 (V7) or 21 (V21) consecutive days with vehicle (5 % ethanol in Ringer solution) and two melatonin groups (N=10) administered intraperitoneally 30 mg/kg of melatonin for 7 (M7) or 21 (M21) consecutive days. At the end of the experiment, proximal stump neuroma and distal stump fibroma were excised and processed for qualitative and quantitative histological analysis. Intrafascicular neural structures were better preserved and the collagen deposition was reduced in the melatonin treated groups than in the vehicle groups. Myelin sheath regeneration observed through its thickness measurement was statistically significantly (p<0,05) more pronounced in the M21 (1,23±0,18 µm) vs. V21 group (0,98±0,13 µm). The mean volume density of the endoneurium was lower in both melatonin treated groups in comparison to the matching vehicle treated groups. Although not statistically different, the endoneural tube diameter was larger in both melatonin groups vs. vehicle groups, and the effect of melatonin was more pronounced after 21 days (24,97 % increase) vs. 7 days of melatonin treatment (18,8 % increase). Melatonin exerts a time-dependent proregenerative effect on nerve fibers in the proximal stump and an anti-scarring effect in both stumps.

Los procedimientos microquirúrgicos son el tratamiento de elección de las lesiones de los nervios periféricos, pero a menudo no logran una recuperación funcional completa. La melatonina tiene acciones neuroprotectoras y podría ser utilizada como un posible apoyo farmacológico proregenerativo. Por lo tanto, el objetivo de este estudio fue analizar la dependencia del tiempo del efecto neuroprotector de la melatonina sobre las estructuras fasciculares generales de ambos extremos del nervio seccionado. La sección del nervio ciático se realizó en 34 ratas Wistar macho adultas divididas en cuatro grupos: dos grupos de vehículo (N=7) tratados por vía intraperitoneal durante 7 (V7) o 21 (V21) días consecutivos con vehículo (5 % de etanol en solución Ringer) y dos grupos grupos de melatonina (N=10) a los que se les administró por vía intraperitoneal 30 mg/kg de melatonina durante 7 (M7) o 21 (M21) días consecutivos. Al final del experimento, se extirparon y procesaron el neuroma del muñón proximal y el fibroma del muñón distal del nervio para un análisis histológico cualitativo y cuantitativo. Las estructuras neurales intrafasciculares se conservaron mejor y el depósito de colágeno se redujo en los grupos tratados con melatonina respecto a los grupos con vehículo. La regeneración de la vaina de mielina observada a través de la medición de su espesor fue estadísticamente significativa (p<0,05) más pronunciada en el grupo M21 (1,23±0,18 µm) vs V21 (0,98±0,13 µm). La densidad de volumen media del endoneuro fue menor en ambos grupos tratados con melatonina en comparación con los grupos tratados con vehículo equivalente. Aunque no fue estadísticamente diferente, el diámetro del tubo endoneural fue mayor en ambos grupos de melatonina frente a los grupos de vehículo, y el efecto de la melatonina fue más pronunciado después de 21 días (aumento del 24,97 %) frente a los 7 días de tratamiento con melatonina (18,8 % de aumento). La melatonina ejerce un efecto proregenerativo dependiente del tiempo sobre las fibras nerviosas del muñón proximal y un efecto anticicatricial en ambos muñones.

Bestrophin-1 Participates in Neuropathic Pain Induced by Spinal Nerve Transection but not Spinal Nerve Ligation.

Previous studies have reported that L5/L6 spinal nerve ligation (SNL), but not L5 spinal nerve transection (SNT), enhances anoctamin-1 in injured and uninjured dorsal root ganglia (DRG) of rats suggesting some differences in function of the type of nerve injury. The role of bestrophin-1 in these conditions is unknown. The aim of this study was to investigate the role of bestrophin-1 in rats subjected to L5 SNT and L5/L6 SNL. SNT up-regulated bestrophin-1 protein expression in injured L5 and uninjured L4 DRG at day 7, whereas it enhanced GAP43 mainly in injured, but also in uninjured DRG. In contrast, SNL enhanced GAP43 at day 1 and 7, while bestrophin-1 expression increased only at day 1 after nerve injury. Accordingly, intrathecal injection of the bestrophin-1 blocker CaCCinh-A01 (1-10 µg) reverted SNT- or SNL-induced tactile allodynia in a concentration-dependent manner. Intrathecal injection of CaCCinh-A01 (10 µg) prevented SNT-induced upregulation of bestrophin-1 and GAP43 at day 7. In contrast, CaCCinh-A01 did not affect SNL-induced up-regulation of GAP43 nor bestrophin-1. Bestrophin-1 was mainly expressed in small- and medium-size neurons in naïve rats, while SNT increased bestrophin-1 immunoreactivity in CGRP+, but not in IB4+ neuronal cells in DRG. Intrathecal injection of bestrophin-1 plasmid (pCMVBest) induced tactile allodynia and increased bestrophin-1 expression in DRG and spinal cord in naïve rats. CaCCinh-A01 reversed bestrophin-1 overexpression-induced tactile allodynia and restored bestrophin-1 expression. Our data suggest that bestrophin-1 plays a relevant role in neuropathic pain induced by SNT, but not by SNL. PERSPECTIVE: SNT, but not SNL, up-regulates bestrophin-1 and GAP43 protein expression in injured L5 and uninjured L4 DRG. SNT increases bestrophin-1 immunoreactivity in CGRP+ neurons in DRG. Bestrophin-1 overexpression induces allodynia. CaCCinh-A01 reduces allodynia and restores bestrophin-1 expression. Our data suggest bestrophin-1 is differentially regulated depending on the neuropathic pain model.

The efficacy of corticosteroid after facial nerve neurorrhaphy: a systematic review and meta-analysis of randomized controlled trial.

OBJECTIVES: The benefit of corticosteroids following facial nerve neurorrhaphy in the setting of complete transection is questionable. This systematic review and meta-analysis aimed to evaluate corticosteroid efficacy on facial nerve regeneration and functional recovery after complete disruption and neurorrhaphy. METHODS: Randomized controlled trials on both human and animal models from Ovid MEDLINE and Ovid EMBASE studying corticosteroid efficacy in complete facial nerve disruption followed by neurorrhaphy were included. Data were extracted and pooled for meta-analysis. The outcomes were evaluated from electrophysiology, histology, and functional recovery. However, no randomized controlled trial in human was performed. Possibly, performing human trials with histopathology may not be feasible in clinical setting. RESULTS: Six animal studies (248 participants) met inclusion criteria. Electrophysiologic outcomes revealed no differences in latency (Standardized Mean Difference (SMD) = -1.97, 95% CI -7.38 to 3.44, p = 0.47) and amplitude (SMD = 0.37, 95% CI -0.44 to 1.18, p = 0.37) between systemic corticosteroids and controls. When analysis compared topical corticosteroid and control, the results provided no differences in latency (Mean Difference (MD) = 0.10, 95% CI -0.04 to 0.24, p = 0.16) and amplitude (SMD = 0.01, 95% CI -0.08 to 0.10, p = 0.81). In histologic outcomes, the results showed no differences in axon diameter (MD = 0.13, 95% CI -0.15 to 0.41, p = 0.37) between systemic corticosteroid and control; however, the result in myelin thickness (MD = 0.06, 95% CI 0.04 to 0.08, p < 0.05) favored control group. When comparing systemic corticosteroid with control in eye blinking, the results favored control (MD = 1.33, 95% CI 0.60 to 2.06, p =  0.0004). CONCLUSIONS: This evidence did not show potential benefits of systemic or topical corticosteroid deliveries after facial nerve neurorrhaphy in complete transection when evaluating electrophysiologic, histologic, and functional recovery outcomes in animal models.

The efficacy of corticosteroid after facial nerve neurorrhaphy: a systematic review and meta-analysis of randomized controlled trial

Abstract Objectives: The benefit of corticosteroids following facial nerve neurorrhaphy in the setting of complete transection is questionable. This systematic review and meta-analysis aimed to evaluate corticosteroid efficacy on facial nerve regeneration and functional recovery after complete disruption and neurorrhaphy. Methods: Randomized controlled trials on both human and animal models from Ovid MEDLINE and Ovid EMBASE studying corticosteroid efficacy in complete facial nerve disruption followed by neurorrhaphy were included. Data were extracted and pooled for meta-analysis. The outcomes were evaluated from electrophysiology, histology, and functional recovery. However, no randomized controlled trial in human was performed. Possibly, performing human trials with histopathology may not be feasible in clinical setting. Results: Six animal studies (248 participants) met inclusion criteria. Electrophysiologic outcomes revealed no differences in latency (Standardized Mean Difference (SMD) = −1.97, 95% CI −7.38 to 3.44, p = 0.47) and amplitude (SMD = 0.37, 95% CI −0.44 to 1.18, p = 0.37) between systemic corticosteroids and controls. When analysis compared topical corticosteroid and control, the results provided no differences in latency (Mean Difference (MD)=0.10, 95% CI −0.04 to 0.24, p = 0.16) and amplitude (SMD = 0.01, 95% CI −0.08 to 0.10, p = 0.81). In histologic outcomes, the results showed no differences in axon diameter (MD = 0.13, 95% CI −0.15 to 0.41, p = 0.37) between systemic corticosteroid and control; however, the result in myelin thickness (MD = 0.06, 95% CI 0.04 to 0.08, p < 0.05) favored control group. When comparing systemic corticosteroid with control in eye blinking, the results favored control (MD= 1.33, 95% CI 0.60 to 2.06, p = 0.0004). Conclusions: This evidence did not show potential benefits of systemic or topical corticosteroid deliveries after facial nerve neurorrhaphy in complete transection when evaluating electrophysiologic, histologic, and functional recovery outcomes in animal models.

Endovascular repair of aortobronchial fistula three decades after open repair of traumatic aortic transection: A case report and 3-year follow-up.

A rare and lethal vascular condition is the communication of the thoracic aorta and tracheobronchial tree. Typically, the development occurs after open or endovascular aortic repair that has been complicated by infection and usually presents with hemoptysis as the heralding event, which can lead to massive hemorrhage. Computed tomography angiography remains the diagnostic imaging modality of choice. Medical management will be futile, with the need for expedited operative intervention via open, endovascular, or hybrid open and endovascular repair.

Distal pancreatectomy: experience in a National Hospital.

AIMS: To compare the short-term outcomes of patients undergoing open DP (ODP) and laparoscopic DP (LDP); and to analyze the association between the section site of the pancreas and pancreatic fistula. MATERIALS AND METHODS: Clinical, perioperative, and histopathologic data of patients who underwent ODP and LDP between 2009 and 2019 were retrospectively analyzed. RESULTS: 70 patients were included. 39 (56%) underwent ODP and 31 (44%) underwent LDP. The tumor size in ODP group was 70mm and in LDP group was 45mm (p = 0,032) Blood loss was lower in LDP group (229mL versus 498mL) (p = 0,001). Operative time, spleen preservation, B/C pancreatic fistula, major morbidity, reoperation, and length of hospital stay, were similar in both groups. There was no postoperative mortality. No differences were found in B/C pancreatic fistula rate regarding to pancreatic transection site. CONCLUSIONS: LDP is a safe procedure, with perioperative outcomes similar to ODP and with less blood loss. The pancreatic transection site did not influence post-operative pancreatic fistula rate.

OBJETIVOS: Comparar los resultados a corto plazo de pacientes intervenidos mediante pancreatectomía distal abierta (PDA) y laparoscópica (PDL); y analizar si el lugar de la sección del páncreas tiene relación con la formación de fístula pancreática. MATERIALES Y MÉTODOS: Serie retrospectiva y descriptiva de las PD realizadas, desde enero del 2009 a diciembre del 2019. Se compararon las características clínicas, perioperatorias e histopatológicas de pacientes con PDA y PDL. RESULTADOS: Se incluyeron 70 pacientes. Treinta y nueve casos (56%) con PDA y 31 casos (44%) con PDL. El tamaño tumoral promedio en la PDA fue de 70 mm y en la PDL 45 mm (p = 0.032). La pérdida sanguínea fue menor en la PDL (229 vs. 498 ml) (p = 0.001). No se encontró diferencia significativa en tiempo operatorio, porcentaje de preservación esplénica, fístula pancreática B/C, reoperación, morbilidad mayor y estancia hospitalaria. No hubo mortalidad postoperatoria. No hubo diferencias en la formación de fístula pancreática con respecto al lugar de sección del páncreas. CONCLUSIONES: La PDL es un procedimiento seguro, con resultados perioperatorios similares a la PDA y con menor pérdida sanguínea. El lugar de sección del páncreas no tuvo relación con la formación de fístula pancreática.

Surgical technique and considerations about transanal transection and single-stapled (TTSS) anastomosis: the search for a perfect anastomosis

The evaluation of preventivemeasures and risk factors for anastomotic leakage has been a constant concern among colorectal surgeons. In this context, the description of a new way to perform a colorectal, coloanal or ileoanal anastomosis, known as transanal transection and single-stapled (TTSS) anastomosis, deserves an appreciation of its qualities, and a discussion about its properties and technical details. In the present paper, the authors review themost recent efforts aiming to reduce anastomotic dehiscence, and describe the TTSS technique in a patient submitted to laparoscopic total proctocolectomy with ileal pouch-anal anastomosis for familial adenomatous polyposis. Surgical perception raises important advantages such as distal rectal transection under visualization, elimination of double-stapling lines (with cost-effectiveness and potential protection against suture dehiscence), elimination of dog ears, and the opportunity to be accomplished via a transanal approach after open, laparoscopic, or robotic colorectal resections. Future studies to confirm these supposed advantages are needed. (AU)

Laparoscopic Hepatectomy via Remote Mentoring From Jamaica to Trinidad.

Laparoscopic hepatectomy brings many physiologic advantages over open hepatectomy and adheres to all oncologic principles. It is currently considered the standard of care. However, these are technically difficult operations to perform. Consequently, the expertise may not be universally available for all patients to benefit from laparoscopic hepatectomy. We report a unique situation where remote mentoring was used to guide bariatric surgeons in Jamaica to complete a laparoscopic hepatectomy.

Effects of Nogo-A and its receptor on the repair of sciatic nerve injury in rats

Regeneration of injured peripheral nerves is an extremely complex process. Nogo-A (neurite outgrowth inhibitor-A) inhibits axonal regeneration by interacting with Nogo receptor in the myelin sheath of the central nervous system (CNS). The aim of this study was to investigate the effects of Nogo-A and its receptor on the repair of sciatic nerve injury in rats. Sprague-Dawley rats (n=96) were randomly divided into 4 groups: control group (control), sciatic nerve transection group (model), immediate repair group (immediate repair), and delayed repair group (delayed repair). The rats were euthanized 1 week and 6 weeks after operation. The injured end tissues of the spinal cord and sciatic nerve were obtained. The protein expressions of Nogo-A and Nogo-66 receptor (NgR) were detected by immunohistochemistry. The protein expressions of Nogo-A, NgR, and Ras homolog family member A (RhoA) were detected by western blot. At 1 week after operation, the pathological changes in the immediate repaired group were less, and the protein expressions of Nogo-A, NgR, and RhoA in the spinal cord and sciatic nerve tissues were decreased (P<0.05) compared with the model group. After 6 weeks, the pathological changes in the immediate repair group and the delayed repair group were alleviated and the protein expressions decreased (P<0.05). The situation of the immediate repair group was better than that of the delayed repair group. Our data suggest that the expression of Nogo-A and its receptor increased after sciatic nerve injury, indicating that Nogo-A and its receptor play an inhibitory role in the repair process of sciatic nerve injury in rats.

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)

Schwann Cell Precursor Transplant in a Rat Spinal Cord Injury Model.

BACKGROUND: Differentiation of mesenchymal stem cells into Schwann cell precursors could reverse established lesions and sequelae of medullary transection. OBJECTIVE: The objective of this study was to study the clinical response of mesenchymal stem cell transplantation with Schwann precursor cell transplantation in a rat spinal cord injury model, using motor function and histopathologic studies. MATERIALS AND METHODS: A total of 28 Sprague-Dawley rats were randomly divided among four groups (n = 7 in each): sham group, control group, mesenchymal stem cell transplant group, and Schwann cell precursor transplant group. The surgical procedure was a laminectomy with transection of the spinal cord at the T11 level in the transplant groups and the injury control group. After 1 week, the transplant groups received stem cells directly in the injury site. Hind limb motor function was assessed using the locomotive scale of Basso, Beattie, and Bresnahan. 1 month after transplantation, all specimens were sacrificed to make a histopathologic description of sections taken from the site of injury and where stem cells were transplanted. Mean scores of mobility were compared using analysis of variance (ANOVA) of one factor with 95% reliability between groups and ANOVA of repetitive measures to evaluate evolution in the same group. RESULTS: We observed that the control group had statistically greater mobility than the other groups (p < 0.0001) and that the group with spinal injury without treatment had the lowest mean mobility. The mobility score values from the Schwann cell precursor group were statistically higher than the group treated with mesenchymal stem cells (p < 0.0001). CONCLUSION: Schwann precursor cells had a greater effect on locomotive function than mesenchymal stem cells.

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.

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.

Evaluation of a biopsy technique of the epiphyseal plate radius of mules with angular deformity of surgical type: case study / Evaluación de una técnica de biopsia de la placa epifisaria del radio de mulares con deformidad angular de tipo quirúrgica: estudio de caso / Avaliação de uma técnica de biopsia da placa epifisária do rádio de muares com deformidade angular de tipo cirúrgico: estudo de caso

Background: eight mules with angular limb deformity (ALD) type carpus varus and carpus valgus were studied. Objetive: to evaluate a biopsy technique of the distal growth plate of the radius using a Jamshidi needle. Methods: thirteen limbs with ALD were biopsied immediately before undergoing corrective surgery. The site of biopsy depended on the severity of ALD and surgical technique. The samples were preserved and processed for histopathological study. Results: of all biopsies evaluated, only three were successfully obtained. Conclusions: the biopsy technique used was not efficient (23% success rate), however it allowed us to describe the physeal dysplasia in mules with ALD. Our findings agree with those previously described in horses.

Antecedentes: ocho mulares con deformidad angular (ALD) de tipo varus y valgus del carpo fueron estudiados. Objetivo: evaluar una técnica de biopsia para la placa de crecimiento distal del radio con la aguja Jamshidi. Métodos: se utilizaron 13 miembros con ALD; inmediatamente antes de la cirugía correctiva. El lugar de la biopsia varió con la severidad de la ALD y con la técnica quirúrgica. Las muestras fueron conservadas y tratadas para estudio histopatológico. Resultados: se obtuvieron solamente 3 muestras exitosas. Conclusiones: la técnica de biopsia utilizada fue poca eficiente (23%), pero permitió describir la presencia de displasia fisária en mulares con ALD. Los hallazgos coinciden con los descritos para equinos.

Antecedentes: oito muares com deformidade angular (ALD) de tipo varus e valgus do carpo foram estudados. Objetivo: avaliar uma técnica de biopsia para a placa de crescimento distal do rádio com a agulha de Jamshidi. Métodos: se utilizaram 13 membros com ALD, imediatamente antes da cirurgia corretiva. O lugar da biopsia dependeu da severidade de ALD e da técnica cirúrgica. As amostras foram conservadas e tratadas para estudo histopatológico. Resultados: três amostras foram obtidas com sucesso. Conclusões: a técnica de biópsia utilizada foi pouca eficiente (23%), mas permitiu descrever displasia fisária em ALD. Os achados concordam com os descritos em equinos.

Transplantation of muscle-derived stem cells plus biodegradable fibrin glue restores the urethral sphincter in a pudendal nerve-transected rat model

We investigated whether fibrin glue (FG) could promote urethral sphincter restoration in muscle-derived stem cell (MDSC)-based injection therapies in a pudendal nerve-transected (PNT) rat, which was used as a stress urinary incontinence (SUI) model. MDSCs were purified from the gastrocnemius muscles of 4-week-old inbred female SPF Wistar rats and labeled with green fluorescent protein. Animals were divided into five groups (N = 15): sham (S), PNT (D), PNT+FG injection (F), PNT+MDSC injection (M), and PNT+MDSC+FG injection (FM). Each group was subdivided into 1- and 4-week groups. One and 4 weeks after injection into the proximal urethra, leak point pressure (LPP) was measured to assess urethral resistance function. Histology and immunohistochemistry were performed 4 weeks after injection. LPP was increased significantly in FM and M animals after implantation compared to group D (P < 0.01), but was not different from group S. LPP was slightly higher in the FM group than in the M group but there was no significant difference between them at different times. Histological and immunohistochemical examination demonstrated increased numbers of surviving MDSCs (109 ± 19 vs 82 ± 11/hpf, P = 0.026), increased muscle/collagen ratio (0.40 ± 0.02 vs 0.34 ± 0.02, P = 0.044), as well as increased microvessel density (16.9 ± 0.6 vs 14.1 ± 0.4/hpf, P = 0.001) at the injection sites in FM compared to M animals. Fibrin glue may potentially improve the action of transplanted MDSCs to restore the histology and function of the urethral sphincter in a SUI rat model. Injection of MDSCs with fibrin glue may provide a novel cellular therapy method for SUI.

Participation of neuronal nitric oxide synthase in experimental neuropathic pain induced by sciatic nerve transection

Nerve injury leads to a neuropathic pain state that results from central sensitization. This phenomenom is mediated by NMDA receptors and may involve the production of nitric oxide (NO). In this study, we investigated the expression of the neuronal isoform of NO synthase (nNOS) in the spinal cord of 3-month-old male, Wistar rats after sciatic nerve transection (SNT). Our attention was focused on the dorsal part of L3-L5 segments receiving sensory inputs from the sciatic nerve. SNT resulted in the development of neuropathic pain symptoms confirmed by evaluating mechanical hyperalgesia (Randall and Selitto test) and allodynia (von Frey hair test). Control animals did not present any alteration (sham-animals). The selective inhibitor of nNOS, 7-nitroindazole (0.2 and 2 µg in 50 µL), blocked hyperalgesia and allodynia induced by SNT. Immunohistochemical analysis showed that nNOS was increased (48 percent by day 30) in the lumbar spinal cord after SNT. This increase was observed near the central canal (Rexed’s lamina X) and also in lamina I-IV of the dorsal horn. Real-time PCR results indicated an increase of nNOS mRNA detected from 1 to 30 days after SNT, with the highest increase observed 1 day after injury (1469 percent). Immunoblotting confirmed the increase of nNOS in the spinal cord between 1 and 15 days post-lesion (20 percent), reaching the greatest increase (60 percent) 30 days after surgery. The present findings demonstrate an increase of nNOS after peripheral nerve injury that may contribute to the increase of NO production observed after peripheral neuropathy.