GUSTAVO BISPO DOS SANTOS

(Fonte: Lattes)
Índice h a partir de 2011
7
Lattes
Projetos de Pesquisa
Unidades Organizacionais
Instituto de Ortopedia e Traumatologia, Hospital das Clínicas, Faculdade de Medicina
LIM/41 - Laboratório de Investigação Médica do Sistema Músculoesquelético, Hospital das Clínicas, Faculdade de Medicina

Filtros

Limpar filtros

Configurações

Resultados de Busca

Agora exibindo 1 - 10 de 24
  • article 21 Citação(ões) na Scopus
    Effects of estrogen on functional and neurological recovery after spinal cord injury: An experimental study with rats
    (2015) LETAIF, Olavo Biraghi; CRISTANTE, Alexandre Fogaca; BARROS FILHO, Tarcisio Eloy Pessoa de; FERREIRA, Ricardo; SANTOS, Gustavo Bispo dos; ROCHA, Ivan Dias da; MARCON, Raphael Martus
    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.
  • article 3 Citação(ões) na Scopus
    Effect of neurotrophic factor, MDP, on rats' nerve regeneration
    (2011) FORNAZARI, A. A.; REZENDE, M. R. de; MATTAR JR., R.; TAIRA, R. I.; SANTOS, G. B. dos; PAULOS, R. G.
    Our objective was to determine the immune-modulating effects of the neurotrophic factor N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP) on median nerve regeneration in rats. We used male Wistar rats (120-140 days of age, weighing 250-332 g) and compared the results of three different techniques of nerve repair: 1) epineural neurorrhaphy using sutures alone (group S - 10 rats), 2) epineural neurorrhaphy using sutures plus fibrin tissue adhesive (FTA; group SF - 20 rats), and 3) sutures plus FTA, with MDP added to the FTA (group SFM - 20 rats). Functional assessments using the grasp test were performed weekly for 12 weeks to identify recovery of flexor muscle function in the fingers secondary to median nerve regeneration. Histological analysis was also utilized. The total number and diameter of myelinated fibers were determined in each proximal and distal nerve segment. Two indices, reported as percentage, were calculated from these parameters, namely, the regeneration index and the diameter change index. By the 8th week, superiority of group SFM over group S became apparent in the grasping test (P = 0.005). By the 12th week, rats that had received MDP were superior in the grasping test compared to both group S (P < 0.001) and group SF (P = 0.001). Moreover, group SF was better in the grasping test than group S (P = 0.014). However, no significant differences between groups were identified by histological analysis. In the present study, rats that had received MDP obtained better function, in the absence of any significant histological differences.
  • article 2 Citação(ões) na Scopus
    Evaluation of the Use of Nerve Allograft Preserved in Glycerol
    (2021) NAKAMOTO, Joao Carlos; WATAYA, Erick Yoshio; NAKAMOTO, Hugo Alberto; SANTOS, Gustavo Bispo; RIBARIC, Ivan; HERRERA, Ana K. A.; FARIA, Jose C. M.
    Background: We aimed to evaluate the use of nerve allograft preserved in glycerol. We compared the efficiency of glycerol-preserved allografts with autogenous nerve grafting, cryopreserved grafts, and detergent-processed grafts in the axonal regeneration. Secondarily, we evaluated the effectiveness of each preservation method in maintaining the extracellular matrix free of cellular components. Methods: This was a prospective experimental, longitudinal, unblinded, nonrandomized, controlled animal model study. Three different allograft preservation techniques for the repair of sciatic nerve injuries were compared, including cold preservation, glycerol preservation, and detergent preservation. Functional assessment was performed, and histomorphometric analyses were further performed, which enabled the allograft structure evaluation and an estimation of the nerve regeneration efficacy based on the myelinated axons count and on their diameters. Results: After the 14(th) week, all groups were already balanced and similar (P = 0.265): all groups present near-zero SFIs, thus confirming their efficiency in promoting nerve regeneration. In the histomorphometric evaluations, all groups were equivalent, presenting a similar efficiency in nerve regeneration (P = 0.716 and P = 0.577, respectively). Similarly, histomorphometric evaluations showed a reduction in the number of axons and in their diameters, but none of them effectively eliminated all cellular debris. Comparing the groups with each other, the groups preserved in glycerol and detergent solution were similar, both presenting better results than the cooled group. Conclusion: By evaluating the presence of cell debris after the treatment using glycerol, it was found to be similar to the treatment using detergent and significantly better than the cold-preservation treatment.
  • article
    Characterization of traumatic spinal cord injury model in relation to neuropathic pain in the rat
    (2019) BATISTA, Chary Marquez; MARIANO, Eric Domingos; ONUCHIC, Fernando; DALE, Camila Squarzoni; SANTOS, Gustavo Bispo dos; CRISTANTE, Alexandre Fogaca; OTOCH, Jose Pinhata; TEIXEIR, Manoel Jacobsen; MORGALLA, Matthias; LEPSKI, Guilherme
    Purpose/aim: Neuropathic pain following spinal cord injury (SCI) has a tremendous impact on patient's quality of life, and frequently is the most limiting aspect of the disease. In view of the severity of this condition and the absence of effective treatments, the establishment of a reliable animal model that reproduces neuropathic pain after injury is crucial for a better understanding of the pathophysiology and for the development of new therapeutic strategies. Thus, the objective of the present study was to standardize the traumatic SCI model in relation to neuropathic pain.Materials and methods: Wistar rats were submitted to SCI of mild intensity (pendulum height 12.5mm) or moderate intensity (pendulum height 25mm) using the New York University Impactor equipment. Behavioural assessment was performed during 8weeks. Thereafter, spinal cords were processed for immunohistochemistry.Results: The animals of the moderate injury group in comparison with mild injury had a greater motor function deficit, worse mechanical allodynia, and latter bladder recovery; moreover, histological analysis revealed more extensive lesions with lower neuronal population.Conclusions: Our study suggests that moderate SCI causes a progressive and long-lasting painful condition (at least 8weeks), in addition to motor impairment, and thus represents a reliable animal model for the study of chronic neuropathic pain after SCI.
  • article 1 Citação(ões) na Scopus
    Biomechanical comparison of the four-strand cruciate and Strickland techniques in animal tendons
    (2013) IAMAGUCHI, Raquel Bernardelli; VILLANI, William; REZENDE, Marcelo Rosa; WEI, Teng Hsiang; CHO, Alvaro B.; SANTOS, Gustavo Bispo dos; MATTAR JR., Rames
    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 (R)). 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.
  • article 5 Citação(ões) na Scopus
    Neuroprotective effect of epidural hypothermia after spinal cord lesion in rats
    (2014) BARBOSA, Marcello Oliveira; CRISTANTE, Alexandre Fogaca; SANTOS, Gustavo Bispo dos; FERREIRA, Ricardo; MARCON, Raphael Martus; BARROS FILHO, Tarcisio Eloy Pessoa de
    OBJECTIVES : To evaluate the neuroprotective effect of epidural hypothermia in rats subjected to experimental spinal cord lesion. METHODS: Wistar rats (n = 30) weighing 320-360 g were randomized to two groups (hypothermia and control) of 15 rats per group. A spinal cord lesion was induced by the standardized drop of a 10-g weight from a height of 2.5 cm, using the New York University Impactor, after laminectomy at the T9-10 level. Rats in the hypothermia group underwent epidural hypothermia for 20 minutes immediately after spinal cord injury. Motor function was assessed for six weeks using the Basso, Beattie and Bresnahan motor scores and the inclined plane test. At the end of the final week, the rats' neurological status was monitored by the motor evoked potential test and the results for the two groups were compared. RESULTS: Analysis of the Basso, Beattie and Bresnahan scores obtained during the six-week period indicated that there were no significant differences between the two groups. There was no significant difference between the groups in the inclined plane test scores during the six-week period. Furthermore, at the end of the study, the latency and amplitude values of the motor evoked potential test were not significantly different between the two groups. CONCLUSION: Hypothermia did not produce a neuroprotective effect when applied at the injury level and in the epidural space immediately after induction of a spinal cord contusion in Wistar rats.
  • article 2 Citação(ões) na Scopus
    Evaluation of the effects of erythropoietin and interleukin-6 in rats submitted to acute spinal cord injury
    (2019) BARROS, Alderico Girao Campos de; CRISTANTE, Alexandre Fogaca; SANTOS, Gustavo Bispo dos; NATALINO, Renato Jose Mendonca; FERREIRA, Ricardo Jose Rodriguez; BARROS-FILHO, Tarcisio Eloy Pessoa De
    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.
  • article 8 Citação(ões) na Scopus
    Granulocyte Colony-Stimulating Factor Combined with Methylprednisolone Improves Functional Outcomes in Rats with Experimental Acute Spinal Cord Injury
    (2018) TEIXEIRA, William Gemio Jacobsen; CRISTANTE, Alexandre Fogaca; MARCON, Raphael Martus; BISPO, Gustavo; FERREIRA, Ricardo; BARROS-FILHO, Tarcisio Eloy Pessoa de
    OBJECTIVES: To evaluate the effects of combined treatment with granulocyte colony-stimulating factor (G-CSF) and methylprednisolone in rats subjected to experimental spinal cord injury. METHODS: Forty Wistar rats received a moderate spinal cord injury and were divided into four groups: control (no treatment); G-CSF (G-CSF at the time of injury and daily over the next five days); methylprednisolone (methylprednisolone for 24 h); and G-CSF/Methylprednisolone (methylprednisolone for 24 h and G-CSF at the time of injury and daily over the next five days). Functional evaluation was performed using the Basso, Beattie and Bresnahan score on days 2, 7, 14, 21, 28, 35 and 42 following injury. Motor-evoked potentials were evaluated. Histological examination of the spinal cord lesion was performed immediately after euthanasia on day 42. RESULTS: Eight animals were excluded (2 from each group) due to infection, a normal Basso, Beattie and Bresnahan score at their first evaluation, or autophagy, and 32 were evaluated. The combination of methylprednisolone and G-CSF promoted greater functional improvement than methylprednisolone or G-CSF alone (p < 0.001). This combination also exhibited a synergistic effect, with improvements in hyperemia and cellular infiltration at the injury site (p < 0.001). The groups displayed no neurophysiological differences (latency p=0.85; amplitude p=0.75). CONCLUSION: Methylprednisolone plus G-CSF promotes functional and histological improvements superior to those achieved by either of these drugs alone when treating spinal cord contusion injuries in rats. Combining the two drugs did have a synergistic effect.
  • article 6 Citação(ões) na Scopus
    Standardization of a spinal cord lesion model and neurologic evaluation using mice
    (2018) BORGES, Paulo Alvim; CRISTANTE, Alexandre Fogaca; BARROS-FILHO, Tarcisio Eloy Pessoa de; NATALINO, Renato Jose Mendonca; SANTOS, Gustavo Bispo dos; MARCON, Raphael Marcus
    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.
  • article 2 Citação(ões) na Scopus
    Standardization of an experimental model of intradural injection after spinal cord injury in rats
    (2021) LETAIF, Olavo B.; TAVARES-JUNIOR, Mauro C. M.; SANTOS, Gustavo B. dos; FERREIRA, Ricardo J. R.; MARCON, Raphael M.; CRISTANTE, Alexandre F.; BARROS-FILHO, Tarcisio E. P. de
    OBJECTIVES: The intrathecal route has not yet been thoroughly standardized and evaluated in an experimental model of spinal cord injury (SCI) in Wistar rats. The objective of this study was to standardize and evaluate the effect of intradural injection in this animal model. METHOD: The animals were divided into 6 groups: 1) laminectomy and intradural catheter; 2) laminectomy, intradural catheter and infusion; 3) only SCI; 4) SCI and intradural catheter; 5) SCI, intradural catheter and infusion; and 6) control (laminectomy only). Motor evaluations were performed using the Basso, Beattie and Bresnahan (BBB) scale and the horizontal ladder test; motor evoked potentials were measured for functional evaluation, and histological evaluation was performed as well. All experimental data underwent statistical analysis. RESULTS: Regarding motor evoked potentials, the groups with experimental SCI had worse results than those without, but neither dural puncture nor the injection of intrathecal solution aggravated the effects of isolated SCI. Regarding histology, adverse tissue effects were observed in animals with SCI. On average, the BBB scores had the same statistical behaviour as the horizontal ladder results, and at every evaluated timepoint, the groups without SCI presented scored significantly better than those with SCI (p<0.05). The difference in performance on motor tests between rats with and without experimental SCI persisted from the first to the last test. CONCLUSIONS: The present work standardizes the model of intradural injection in experimental SCI in rats. Intrathecal puncture and injection did not independently cause significant functional or histological changes.