STUDIES OF MOLECULAR CHANGES IN INTERVERTEBRAL DISC DEGENERATION IN ANIMAL MODEL.

OBJECTIVE: To evaluate the structural and molecular changes in the extracellular matrix (ECM) during the process of intervertebral disc degeneration, using animal model. METHODS: Wistar rats underwent intervertebral disc degeneration through 20-gauge needle puncture, and 360° rotation applied for 30 sec, representing the degenerated group, while control group was not submitted to this procedure. Histological parameters and expression of extracellular matrix molecules were evaluated in the 15(th) and 28(th) days after degenerative induction. RESULTS: Fifteen days after the induction of intervertebral disc degeneration, significant changes were observed, such as reduction in the expression metalloprotease-9 (MMP9) and interleukins (IL-6 and IL-10). There was a significant increase in the expression of vascular endothelial growth factor (VEGF) and caspase-3. However, different alterations in the ECM were observed at 28 days, the level of collagen I, metalloprotease-2 (MMP2) and caspase-3 were enhanced. Furthermore, expression of heparanase isoforms (HPSE1 and HPSE2) mRNA were increased in the degenerative intervertebral disc. CONCLUSION: The different profiles of ECM molecules observed during the intervertebral disc degeneration suggest that molecular processes such as ECM remodeling, neovascularization, apoptosis and inflammation occur. Experimental Study.

STUDIES OF MOLECULAR CHANGES IN INTERVERTEBRAL DISC DEGENERATION IN ANIMAL MODEL

ABSTRACT Objective: To evaluate the structural and molecular changes in the extracellular matrix (ECM) during the process of intervertebral disc degeneration, using animal model. Methods: Wistar rats underwent intervertebral disc degeneration through 20-gauge needle puncture, and 360° rotation applied for 30 sec, representing the degenerated group, while control group was not submitted to this procedure. Histological parameters and expression of extracellular matrix molecules were evaluated in the 15th and 28th days after degenerative induction. Results: Fifteen days after the induction of intervertebral disc degeneration, significant changes were observed, such as reduction in the expression metalloprotease-9 (MMP9) and interleukins (IL-6 and IL-10). There was a significant increase in the expression of vascular endothelial growth factor (VEGF) and caspase-3. However, different alterations in the ECM were observed at 28 days, the level of collagen I, metalloprotease-2 (MMP2) and caspase-3 were enhanced. Furthermore, expression of heparanase isoforms (HPSE1 and HPSE2) mRNA were increased in the degenerative intervertebral disc. Conclusion: The different profiles of ECM molecules observed during the intervertebral disc degeneration suggest that molecular processes such as ECM remodeling, neovascularization, apoptosis and inflammation occur. Experimental Study.

Pancreatic islet allograft in spleen with immunosuppression with cyclosporine. Experimental model in dogs.

PURPOSE: To study the functional behavior of the allograft with immunosuppression of pancreatic islets in the spleen. METHODS: Five groups of 10 Mongrel dogs were used: Group A (control) underwent biochemical tests; Group B underwent total pancreatectomy; Group C underwent total pancreatectomy and pancreatic islet autotransplant in the spleen; Group D underwent pancreatic islet allograft in the spleen without immunosuppressive therapy; Group E underwent pancreatic islet allograft in the spleen and immunosuppression with cyclosporine. All of the animals with grafts received pancreatic islets prepared by the mechanical-enzymatic method - stationary collagenase digestion and purification with dextran discontinuous density gradient, implanted in the spleen. RESULTS: The animals with autotransplant and those with allografts with immunosuppression that became normoglycemic showed altered results of intravenous tolerance glucose (p < 0.001) and peripheral and splenic vein plasmatic insulin levels were significantly lower (p < 0.001) in animals that had allografts with immunosuppression than in those with just autotransplants. CONCLUSIONS: In the animals with immunosuppression with cyclosporine subjected to allograft of pancreatic islets prepared with the mechanical-enzymatic preparation method (stationary collagenase digestion and purification with dextran discontinuous density gradient), the production of insulin is decreased and the response to intravenous glucose is altered.

Comparison of uniatrial and biatrial radiofrequency ablation procedures in atrial fibrillation: initial results.

BACKGROUND: Atrial fibrillation (AF) is the most commonly sustained cardiac rhythm disturbance. Surgical ablation techniques were developed involving the left atrium only and modifications of the maze procedure in ablating both atria. OBJECTIVE: The aim of this study was to compare, in patients with permanent AF, the efficacy of uniatrial versus biatrial radiofrequency ablation procedure in the treatment of chronic atrial fibrillation in patients with associated cardiac disease. METHOD: Between September 2003 and May 2009, 30 patients were submitted to the radiofrequency ablation procedure for AF associated with concomitant cardiac surgery; 15 patients underwent a uniatrial procedure, and 15 patients underwent biatrial ablation. The mean age was 47.73 ± 9.85 years, and 53.4% were men. The average followup time was 12.16 ± 10.89 months for the uniatrial group and 7.0 ± 4.0 months for the biatrial group. RESULTS: Neither hospital mortality nor complications related to radiofrequency ablation were was registered. At the time of hospital discharge, 9 patients (60%) were in a state of sinus rhythm in both groups. However, patients undergoing biatrial ablation (range 73.3% versus 46.7%) demonstrated complete freedom from atrial fibrillation at all times. CONCLUSION: Biatrial ablation surgical procedures were more effective in controlling atrial fibrillation than procedures limited to the left atrium.

Pancreatic islet allograft in spleen with immunossuppression with cyclosporine. Experimental model in dogs / Alotransplante de ilhotas pancreáticas no baço com imunossupressão com ciclosporina. Modelo experimental em cães

PURPOSE: To study the functional behavior of the allograft with immunosuppression of pancreatic islets in the spleen. METHODS: Five groups of 10 Mongrel dogs were used: Group A (control) underwent biochemical tests; Group B underwent total pancreatectomy; Group C underwent total pancreatectomy and pancreatic islet autotransplant in the spleen; Group D underwent pancreatic islet allograft in the spleen without immunosuppressive therapy; Group E underwent pancreatic islet allograft in the spleen and immunosuppression with cyclosporine. All of the animals with grafts received pancreatic islets prepared by the mechanical-enzymatic method - stationary collagenase digestion and purification with dextran discontinuous density gradient, implanted in the spleen. RESULTS: The animals with autotransplant and those with allografts with immunosuppression that became normoglycemic showed altered results of intravenous tolerance glucose (p < 0.001) and peripheral and splenic vein plasmatic insulin levels were significantly lower (p < 0.001) in animals that had allografts with immunosuppression than in those with just autotransplants. CONCLUSIONS: In the animals with immunosupression with cyclosporine subjected to allograft of pancreatic islets prepared with the mechanical-enzymatic preparation method (stationary collagenase digestion and purification with dextran discontinuous density gradient), the production of insulin is decreased and the response to intravenous glucose is altered.

OBJETIVO: Avaliar o comportamento funcional do alotransplante com imunossupressão de ilhotas pancreáticas no baço. MÉTODOS: Foram utilizados cinco grupos de 10 cães mestiços: grupo A (controle) submetido aos exames bioquímicos; grupo B, submetido à pancreatectomia total; grupo C (autotransplante) submetido à pancreatectomia total e autotransplantação de ilhotas pancreáticas no baço; grupo D, submetido à alotransplantação de ilhotas pancreáticas no baço sem terapia imunossupressiva; grupo E, submetido à alotransplantação de ilhotas no baço e imunossupressão com ciclosporina. Todos os animais transplantados receberam ilhotas pancreáticas isoladas pelo método mecânico-enzimático, digestão estacionária com colagenase e purificação com gradiente de densidade descontínua de dextran e foram implantadas no baço. RESULTADOS: Animais autotransplantados e alotransplantados com imunossupressão que se tornaram normoglicêmicos apresentaram testes de tolerância à glicose intravenosa alterados (p<0,001) e o nível de insulina plasmática periférica e na veia esplênica foram significantemente menores (p<0,001) nos animais alotransplantados com imunossupressão em relação aos autotransplantados. CONCLUSÃO: Nos animais submetidos ao alotransplante de ilhotas pancreáticas com imunossupressão com ciclosporina e preparadas pelo método mecânico-enzimático, digestão estacionária com colagenase e purificação com gradiente de densidade descontínua de dextran, a produção de insulina está diminuída e a resposta à sobrecarga de glicose intravenosa alterada.