The aim of this study was to evaluate the effects of low-level laser therapy (LLLT) on bone formation, immunoexpression of osteogenic factors, and biomechanical properties in a tibial bone defect model in rats. Sixty male Wistar rats were distributed into bone defect control group (CG) and laser irradiated group (LG). Animals were euthanized on days 15, 30, and 45 post-injury. The histological and morphometric analysis showed that the treated animals presented no inflammatory infiltrate and a better tissue organization at 15 and 30 days postsurgery. Also, a higher amount of newly formed bone was observed at 15 days postsurgery. No statistically significant difference was observed in cyclooxygenase-2 immunoexpression among the groups at 15, 30, and 45 days in the immunohistochemical analysis. Considering RUNX-2, the immunoexpression was statistically higher in the LG compared to the CG at 45 days. BMP-9 immunoexpression was significantly higher in the LG in comparison to CG at day 30. However, there was no expressivity for this immunomarker, both in the CG and LG, at the day 45 postsurgery. No statistically significant difference was observed in the receptor activator of nuclear factor kappa-B ligand immunoexpression among the groups in all periods evaluated. No statistically significant difference among the groups was observed in the maximal load in any period of time. Our findings indicate that laser therapy improved bone healing by accelerating the development of newly formed bone and activating the osteogenic factors on tibial defects, but the biomechanical properties in LG were not improved.

Our findings suggest that Biosilicate presented osteogenic activity, accelerating bone repair. However, laser therapy was not able to enhance the bioactive properties of the Biosilicate.

No abstract

Vaspin and omentin are adipose tissue adipokines that have often been related to obesity and its comorbidities. The aim of this study was to investigate the behaviour of serum omentin and vaspin in models of type 2 diabetes. To do this, Wistar rats (~200 g) were randomly divided into two groups: a non-diabetic group (n = 6) and a diabetic group fed on a high-fat diet (n = 6) and a low dose of streptozotocin (Sigma ). All procedures were approved by the Brazilian Ethics Committee. Body weight (BW) and food intake were recorded daily. Tail blood glucose levels were assessed at the end of the diabetes induction period. The insulin tolerance test (ITT) was performed after the diabetes induction period (7 weeks). The serum and tissues (liver, pancreas, and retroperitoneal (RET), epididymal (EPI) and visceral (VIS) white adipose tissues) were immediately removed and weighed. Analyses of levels of insulin, omentin, vaspin, adiponectin and inflammatory cytokines IL-6, IL-8 (CXCL8), TNF-α and C-reactive protein (CRP) in serum were performed using the enzyme-linked immunosorbent assay (ELISA). Our results showed that IL-8 and CRP serum levels in the diabetic group were significantly higher than in the non-diabetic group. Vaspin and adiponectin values were lower for the diabetic group than for the non-diabetic group. Omentin, IL-6 and TNF-α values did not differ between the groups. Our results showed that both the metabolism of the adipose tissue and the secretion of adipokines may be affected in diabetic rats. Omentin showed no difference between the groups, although the vaspin values decreased in the diabetic group.

Objective: The aim of this study was to evaluate the effects of low level laser therapy (LLLT) on the degenerative process in the articular cartilage after an anterior cruciate ligament transection (ACLT) model in rats. Methods: Eighty male rats (Wistar) were divided into four groups: 1.) intact control group (CG), 2.) injured control group (ICG), 3.) injured laser-treated group at 10 J/cm 2 (L10) and 4.) injured laser-treated group at 50 J/cm 2 (L50). Animals were divided into 2 subgroups, with different periods of sacrifice (5 and 8 weeks post-surgery). The ACLT was used to induce osteoarthritis (OA) in the knees of the rats. LLLT started 2 weeks after the surgery and it was performed for 15 and 30 sessions, respectively using a 685-nm laser, at 10 and 50 J/cm 2 . Qualitative and semiquantitative histologic, morphometric and immunohistochemistry analyses were performed. Results: Initial signs of tissue degradation could be observed 5 weeks post-ACLT, evidenced by the decrease of proteoglycan concentration and increase in cartilage thickness of the ICG. After 8 weeks post-surgery, analysis showed a progression of the degenerative processes in the ICG revealed by the increased cellularity and higher TNF-α, IL1-β and MMP-13 immunoexpression. LLLT was able to modulate some of the aspects relating to the degradative process, such as biomodulation of the number of chondrocyte proliferation, prevention of proteoglycan loss, and decrease of MMP-13 immunoexpression. Conclusion: This study showed that the 685-nm laser irradiation, especially at 10 J/cm 2 , prevented features related to the articular degenerative process in the knees of rats. ZusammenfassungZiel: Das Ziel dieser Studie war es, die Effekte der LowLevel-Lasertherapie (LLLT) auf den degenerativen Prozess im Gelenkknorpel von Ratten nach vorderer Kreuzbanddurchtrennung zu evaluieren. Methoden: Achtzig männliche Wistar-Ratten wurden in vier Versuchsgruppen unterteilt: 1.) intakte Kontrollgruppe (CG), 2.) verletzte Kontrollgruppe (ICG), 3.) verletzte Laser-behandelte Gruppe bei 10 J/cm 2 (L10) und 4.) verletzte Laser-behandelte Gruppe bei 50 J/cm 2 (L50). Die Tiere wurden in zwei Untergruppen aufgeteilt und entweder 5 oder 8 Wochen nach der Operation eingeschläfert. Die vordere Kreuzbanddurchtrennung wurde verwendet, um in den Kniegelenken der Ratten Osteoarthritis (OA) zu induzieren. Die LLLT begann 2 Wochen nach der Operation und wurde für 15 bzw. 30 Sitzungen bei 10 und 50 J/cm 2 mit einem 685 nm-Laser durchgeführt. Qualitative und semi-quantitative histologische, morphometrische und immunhistochemische Analysen wurden durchgeführt. Ergebnisse: Erste Anzeichen von Gewebeabbau wurden 5 Wochen nach der vorderen Kreuzbanddurchtrennung beobachtet und durch die Abnahme der ProteoglycanKonzentration und die Erhöhung der Knorpeldicke in der verletzten Kontrollgruppe (ICG) belegt. Acht Wochen nach der Operation zeigte sich in der ICG ein Fortschreiten der degenerativen Prozesse durch eine erhöhte Zellularität und eine höhere TNF-α-, IL1-β-und MMP-13-Immunexpression....