Effects of ganglioside G(M1) and erythropoietin on spinal cord lesions in rats: functional and histological evaluations

OBJECTIVE: To evaluate the functional and histological effects of ganglioside G(M1) and erythropoietin after experimental spinal cord contusion injury. METHODS: Fifty male Wistar rats underwent experimental spinal cord lesioning using an NYU-Impactor device and were randomly divided into the following groups, which received treatment intraperitoneally. The G(M1) group received ganglioside G(M1) (30 mg/kg); the erythropoietin group received erythropoietin (1000 IU/kg); the combined group received both drugs; and the saline group received saline (0.9%) as a control. A fifth group was the laminectomy group, in which the animals were subjected to laminectomy alone, without spinal lesioning or treatment. The animals were evaluated according to the Basso, Beattie and Bresnahan (BBB) scale, motor evoked potential recordings and, after euthanasia, histological analysis of spinal cord tissue. RESULTS: The erythropoietin group had higher BBB scores than the G(M1) group. The combined group had the highest BBB scores, and the saline group had the lowest BBB scores. No significant difference in latency was observed between the three groups that underwent spinal cord lesioning and intervention. However, the combined group showed a significantly higher signal amplitude than the other treatment groups or the saline group (

Evaluation of the effect of intrathecal GM1 in 24, 48, and 72 hours after acute spinal cord injury in rats

Objective: The aim of this study was to evaluate the best timing and feasibility of intrathecal application of sodium monosialoganglioside (GM1) after spinal cord contusion in Wistar rats as an experimental model. Methods: Forty Wistar rats were submitted to contusion spinal cord injury after laminectomy. The animals were randomized and divided into four groups: Group 1 – Intrathecal application of GM1 24 hours after contusion; Group 2 – Intrathecal application of GM1 48 hours after contusion; Group 3 – intrathecal application of GM1 72 hours after contusion; Group 4 – Sham, with laminectomy and intrathecal application of 0.5 mL of 0.9% saline solution, without contusion. The recovery of locomotor function was evaluated at seven different moments by the Basso, Beattie, and Bresnahan (BBB) test. They were also assessed by the horizontal ladder, with sensory-motor behavioral assessment criteria, pre-and postoperatively. Results: This experimental study showed better functional scores in the group submitted to the application of GM1, with statistically significant results, showing a mean increase when evaluated on known motor tests like the horizontal ladder and BBB, at all times of evaluation (p < 0.05), especially in group 2 (48 hours after spinal cord injury). Also, fewer mistakes and slips over the horizontal ladder were observed, and many points were achieved at the BBB scale analysis. Conclusion: The study demonstrated that the intrathecal application of GM1 after spinal cord contusion in Wistar rats is feasible. The application 48 hours after the injury presented the best functional results

Biomechanical comparison of the four-strand cruciate and Strickland techniques in animal tendons

OBJECTIVE: The objective of this study was to compare two four-strand techniques: the traditional Strickland and cruciate techniques. METHODS: Thirty-eight Achilles tendons were removed from 19 rabbits and were assigned to two groups based on suture technique (Group 1, Strickland suture; Group 2, cruciate repair). The sutured tendons were subjected to constant progressive distraction using a universal testing machine (Kratos®). Based on data from the instrument, which were synchronized with the visualized gap at the suture site and at the time of suture rupture, the following data were obtained: maximum load to rupture, maximum deformation or gap, time elapsed until failure, and stiffness. RESULTS: In the statistical analysis, the data were parametric and unpaired, and by Kolmogorov-Smirnov test, the sample distribution was normal. By Student's t-test, there was no significant difference in any of the data: the cruciate repair sutures had slightly better mean stiffness, and the Strickland sutures had longer time-elapsed suture ruptures and higher average maximum deformation. CONCLUSIONS: The cruciate and Strickland techniques for flexor tendon sutures have similar mechanical characteristics in vitro

Structured evaluation of a comprehensive microsurgical training program

OBJECTIVES: This study proposed a structured microsurgical training program and evaluated it with the assistance of a large sample of surgeons. METHODS: The practical course comprised 16 sessions of approximately 4 hours each. This included two sessions for suturing rubber gloves and two sessions for suturing arteries, veins, and nerves in chicken thighs. The other sessions were performed on the femoral vessels of rats: 5 sessions for end-to-end arterial anastomosis, 5 for end-to-end venous anastomosis, 1 for arterial grafting, and 1 for end-to-side anastomosis. We conducted a structured assessment of the microsurgical skills in each training session. RESULTS: In this study, 89 surgeons were evaluated. The mean scores for the different procedures were as follows: glove suturing, 33.3±0.59; chicken nerve end-to-end anastomosis, 40.3±0.49; chicken artery suturing, 40.9±0.36; chicken vein suturing, 42.3±0.36; graft interposition, 44.8±0.7; and end-to-side anastomosis, 43.7±0.63 (p<0.05 for all). The chicken thigh suturing scores were significantly higher than the rubber gloves suturing scores (p<0.01). There were no differences between scores of the rat artery and chicken thigh suturing procedures (p=0.24). The rat venous anastomosis scores were higher than the rat arterial anastomosis scores (p=0.02), as were graft interposition scores when compared with end-to-end venous anastomosis scores. The end-to-side anastomosis scores did not differ significantly from the grafting scores (p=0.85). The most common errors were inadequate knotting technique and suture rupture due to inadequate technique (both n=88 [98.9%]). CONCLUSION: We propose a 16-step, progressive microsurgical training program to learn the basic microsurgical techniques comprehensively and reliably. The program was evaluated in a large sample of trainees, and it demonstrated the adequacy of the training sequence and results

Standardization of a spinal cord lesion model and neurologic evaluation using mice

OBJECTIVE: To standardize a spinal cord lesion mouse model. METHODS: Thirty BALB/c mice were divided into five groups: four experimental groups and one control group (sham). The experimental groups were subjected to spinal cord lesion by a weight drop from different heights after laminectomy whereas the sham group only underwent laminectomy. Mice were observed for six weeks, and functional behavior scales were applied. The mice were then euthanized, and histological investigations were performed to confirm and score spinal cord lesion. The findings were evaluated to prove whether the method of administering spinal cord lesion was effective and different among the groups. Additionally, we correlated the results of the functional scales with the results from the histology evaluations to identify which scale is more reliable. RESULTS: One mouse presented autophagia, and six mice died during the experiment. Because four of the mice that died were in Group 5, Group 5 was excluded from the study. All the functional scales assessed proved to be significantly different from each other, and mice presented functional evolution during the experiment. Spinal cord lesion was confirmed by histology, and the results showed a high correlation between the Basso, Beattie, Bresnahan Locomotor Rating Scale and the Basso Mouse Scale. The mouse function scale showed a moderate to high correlation with the histological findings, and the horizontal ladder test had a high correlation with neurologic degeneration but no correlation with the other histological parameters evaluated. CONCLUSION: This spinal cord lesion mouse model proved to be effective and reliable with exception of lesions caused by a 10-g drop from 50 mm, which resulted in unacceptable mortality. The Basso, Beattie, Bresnahan Locomotor Rating Scale and Basso Mouse Scale are the most reliable functional assessments, and but the horizontal ladder test is not recommended

Effects of ganglioside GM1 and erythropoietin on spinal cord injury in mice: Functional and immunohistochemical assessments

Objectives: To evaluate the functional and immunohistochemical effects of ganglioside GM1 and erythropoietin following experimental spinal cord injury. Methods: Thirty-two male BALB/c mice were subjected to experimental spinal cord injury using the NYU Impactor device and were randomly divided into the following groups: GM1 group, receiving standard ganglioside GM1 (30 mg/kg); erythropoietin group, receiving erythropoietin (1000 IU/kg); combination group, receiving both drugs; and control group, receiving saline (0.9%). Animals were evaluated according to the Basso Mouse Scale (BMS) and Hindlimb Mouse Function Score (MFS). After euthanasia, the immunohistochemistry of the medullary tissue of mice was analyzed. All animals received intraperitoneal treatment. Results: The GM1 group had higher BMS and MFS scores at the end of the experiment when compared to all other groups. The combination group had higher BMS and MFS scores than the erythropoietin and control groups. The erythropoietin group had higher BMS and MFS scores than the control group. Immunohistochemical tissue analysis showed a significant difference among groups. There was a significant increase in myelinated axons and in the myelinated axon length in the erythropoietin group when compared to the other intervention groups (p < 0.01). Conclusions: Erythropoietin and GM1 have therapeutic effects on axonal regeneration in mice subjected to experimental spinal cord injury, and administration of GM1 alone had the highest scores on the BMS and MFS scales

Effects of estrogen on functional and neurological recovery after spinal cord injury: An experimental study with rats

OBJECTIVES:To evaluate the functional and histological effects of estrogen as a neuroprotective agent after a standard experimentally induced spinal cord lesion.METHODS:In this experimental study, 20 male Wistar rats were divided into two groups: one group with rats undergoing spinal cord injury (SCI) at T10 and receiving estrogen therapy with 17-beta estradiol (4mg/kg) immediately following the injury and after the placement of skin sutures and a control group with rats only subjected to SCI. A moderate standard experimentally induced SCI was produced using a computerized device that dropped a weight on the rat's spine from a height of 12.5 mm. Functional recovery was verified with the Basso, Beattie and Bresnahan scale on the 2nd, 7th, 14th, 21st, 28th, 35th and 42nd days after injury and by quantifying the motor-evoked potential on the 42nd day after injury. Histopathological evaluation of the SCI area was performed after euthanasia on the 42nd day.RESULTS:The experimental group showed a significantly greater functional improvement from the 28th to the 42nd day of observation compared to the control group. The experimental group showed statistically significant improvements in the motor-evoked potential compared with the control group. The results of pathological histomorphometry evaluations showed a better neurological recovery in the experimental group, with respect to the proportion and diameter of the quantified nerve fibers.CONCLUSIONS:Estrogen administration provided benefits in neurological and functional motor recovery in rats with SCI beginning at the 28th day after injury

Evaluation of the effects of erythropoietin and interleukin-6 in rats submitted to acute spinal cord injury

OBJECTIVE: To evaluate the effects of interleukin-6 (IL-6) and erythropoietin (EPO) in experimental acute spinal cord injury (SCI) in rats. METHODS: Using standardized equipment, namely, a New York University (NYU) Impactor, a SCI was produced in 50 Wistar rats using a 10-g weight drop from a 12.5-mm height. The rats were divided into the following 5 groups of 10 animals each: ‘‘Group EPO’’, treated with erythropoietin only; ‘‘Group EPO + IL-6’’, treated with both substances; ‘‘Group IL-6’’, receiving IL-6 administration only; ‘‘Group Placebo’’, receiving a placebo solution; and ‘‘Group Sham’’, submitted to an incomplete procedure (only laminectomy, without SCI). All drugs and the placebo solution were administered intraperitoneally for three weeks. The animals were followed up for 42 days. Functional motor recovery was monitored by the Basso, Beattie, and Bresnahan (BBB) scale on days 2, 7, 14, 21, 28, 35 and 42. Motor-evoked potential tests were performed on the 42nd day. Histological analysis was performed after euthanasia. RESULTS: The group receiving EPO exhibited superior functional motor results on the BBB scale. IL-6 administration alone was not superior to the placebo treatment, and the IL-6 combination with EPO yielded worse results than did EPO alone. CONCLUSIONS: Using EPO after acute SCI in rats yielded benefits in functional recovery. The combination of EPO and IL-6 showed benefits, but with inferior results compared to those of isolated EPO; moreover, isolated use of IL-6 resulted in no benefit

Experimental study of histological changes in vascular loops according to the duration of the postoperative period: Application in reconstructive microsurgery

OBJECTIVES: To analyze the histological changes observed in venous grafts subjected to arterial blood flow as a function of the duration of the postoperative period to optimize their use in free flap reconstructions. METHOD: Twenty-five rats (7 females and 18 males) underwent surgery. Surgeries were performed on one animal per week. Five weeks after the first surgery, the same five animals were subjected to an additional surgery to assess the presence or absence of blood flow through the vascular loop, and samples were collected for histological analysis. This cycle was performed five times. RESULTS: Of the rats euthanized four to five weeks after the first surgery, no blood flow was observed through the graft in 80% of the cases. In the group euthanized three weeks after the first surgery, no blood flow was observed in 20% of the cases. In the groups euthanized one to two weeks after the first surgery, blood flow through the vascular loop was observed in all animals. Moreover, intimal proliferation tended to increase with the duration of the postoperative period. Two weeks after surgery, intimal proliferation increased slightly, whereas strong intimal proliferation was observed in all rats evaluated five weeks after surgery. CONCLUSION: Intimal proliferation was the most significant change noted in venous grafts as a function of the duration of the postoperative period and was directly correlated with graft occlusion. In cases in which vascular loops are required during free flap reconstruction, both procedures should preferably be performed during the same surgery

IDENTIFICAÇÃO DE OVOS DE HELMINTOS EM EQUINOS DE POLICIAMENTO E TERAPIA ASSISTIDA DA CIDADE DE SALVADOR/BA

The health and well-being of animals used in the police and assisted therapy service is linked to nutritional and preventive care. Routine preventions include control of intestinal parasites, The objective of this work was to identify the occurrence of gastrointestinal helminth eggs in horses in service horses in the Mounted Police Squadron / Salvador-BA. The methodology used was qualitative evaluation of 50 feces, analyzed by the Willis- Mollay fluctuation method adapted and quantitative egg count per gram (OPG). It was possible to observe that 86% (43/50) of the animals obtained were infected to a degree of mild to moderate by helminths of the Strongylidae families 32.55% (14/43), Trichostrongylidae 30.23% (13/43), Ascarididae 25.58% (11/43) and family Oxyuridae 11.62% (5/43).A saúde e bem-estar de animais utilizados no serviço de policiamento e terapia assistida estão diretamente ligados aos cuidados nutricionais e preventivos. Entre as prevenções de rotina está o controle de parasitoses gastrointestinais. O objetivo deste trabalho foi identificar a ocorrência de ovos de helmintos gastrointestinais em equinos de serviço, no Esquadrão de Polícia Montada em Salvador/BA. A metodologia empregada foi a avaliação qualitativa de 50 amostras de fezes, analisadas pelo método flutuação de Willis-Mollay adaptado, e quantitativa, de contagem de ovos por grama (OPG). Foi possível observar que 86% (43/50) dos animais avaliados encontravam-se infectados, em grau de leve a moderado, por helmintos das famílias Strongylidae 32,55% (14/ 43), Trichostrongylidae 30,23% (13/43), Ascarididae 25,58% (11/43) e fammília Oxyuridae 11,62% (5/43)