Effect of electrophysical resources on healing of neurotendinous injury in an experimental model of type I diabetes and kidney disease

Purpose: To evaluate and describe the effect of electrophysical resources laser therapy (LLLT), intravascular laser blood irradiation (ILIB), and cryotherapy on the healing process of neurotendinous injury, as well as possible systemic changes, in the experimental model of type 1 diabetes associated with kidney injury. Methods: The animals were randomized into four groups: G1) healthy control with untreated injury; G2) healthy control with injury and treatment; G3) disease control with untreated lesion; G4) disease with injury and treatment. Furthermore, the treated groups were divided into three, according to the type of treatment. All animals were induced to neurotendinous injury and treated according to the therapeutic protocols. Healing and inflammation were analyzed by semiquantitative histopathological study. Results: It was observed in sick animals treated with cryotherapy and ILIB reduction of inflammatory exudate, presence of fibroblasts and organization of collagen, when compared to the effects of LLLT. Moreover, there was reduction in glycemic levels in the group treated with ILIB. Conclusions: Cryotherapy promoted reduction in inflammatory exudate and organization of collagen fibers, in addition to the absence of signs of tissue necrosis, in the groups treated with and without the disease. ILIB therapy showed the same findings associated with significant reduction in glycemic levels in the group of diseased animals. The application of LLLT showed increased inflammatory exudate, low organization of collagen fibers and low sign of tissue degeneration and necrosis. This study in a model of associated diseases (diabetes and kidney disease) whose effects of electrophysical resources studied after neurotendinous injury allows us to verify histopathological variables suggestive of patients with the same comorbidities.

Effect of low-level laser therapy on the membrane induced by the Masquelet technique at an orthotopic site in rabbits

ABSTRACT Purpose: To evaluate the low-level laser therapy (LLLT) on the membrane induced by the Masquelet technique in rabbits. Methods: Twelve Norfolk rabbits at approximately 3 months of age were used. A 1-cm segmental defect was induced in both radii, which were filled with polymethylmethacrylate cylinder. LLLT was used postoperatively in the bone defect of one of the forelimbs every 48 hours for 15 days. Six rabbits were euthanatized on third and sixth postoperative weeks. Results: In both forelimbs, radiographs showed new bone growth from radius cut ends on the third postoperative week and more advanced stage on the sixth postoperative week. Ultrasound showed induced membrane one week after the surgery. Histologically, there were no significant differences in the semi-quantitative score of inflammation intensity, total number of blood vessels, bone metaplasia, and collagen. The average thicknesses were 2,050.17 and 1,451.96 μm for control membranes and 2,724.26 and 2,081.03 μm for irradiated membranes, respectively, on third and sixth postoperative weeks. Vascular endothelial growth factor A (VEGF-A) and platelet derived growth factor (PDGF) expression were present in the induced membranes of control and irradiated forelimbs, but there was no significant difference. Conclusions: Based on assessment methods, it was not possible to demonstrate the effect of LLLT on the induced membrane.

Effect of low intensity photobiomodulation associated with norbixin-based poly (hydroxybutyrate) membrane on post-tenotomy tendon repair: in vivo study

Purpose: To evaluate the in vivo response of photobiomodulation therapy associated with norbixin-based poly(hydroxybutyrate) membrane (PHB) in tenotomized calcaneal tendon. Methods: Thirty rats were randomly allocated to six groups (n=5 each): LED groups (L1, L2 and L3) and membrane + LED groups (ML1, ML2 and ML3). The right calcaneal tendons of all animals were sectioned transversely and were irradiated with LED daily, one hour after surgery every 24 hours, until the day of euthanasia. At the end of the experiments the tendons were removed for histological analysis. Results: The histological analysis showed a significant reduction in inflammatory cells in the ML1, ML2 and ML3 groups (p=0.0056, p=0.0018 and p 0.0001, respectively) compared to those in the LED group. There was greater proliferation of fibroblasts in the ML1 (p 0.0001) and L3 (p 0.0001) groups. A higher concentration of type I collagen was also observed in the ML1 group (p=0.0043) replacing type III collagen. Conclusion: Photobiomodulation in association with norbixin-based PHB membrane led to control of the inflammatory process. However, it did not favor fibroblast proliferation and did not optimize type I collagen formation in the expected stage of the repair process.(AU)

Effect of low power laser in biomodulation of cultured osteoblastic cells of Wistar rats

Purpose:To analyze aspects of the biomodulating effect of light in biological tissues, bone cells from surgical explants of the femur of rats were irradiated with low intensity laser.Methods:Bone cells were cultured and irradiated with LASER light (GaAlAs). Growth, cell viability, mineralized matrix formation, total protein dosage, immunostimulatory properties, cytochemical analysis, gene expression of bone proteins were examined using live cell imaging and cell counting by colorimetric assay. The gene expression of: alkaline phosphatase (ALP), type 1 collagen, osteocalcin and osteopontin through the real-time polymerase chain reaction.Results:At 8 days, the viability of the irradiated culture was 82.3% and 72.4% in non-irradiated cells. At 18 days, the cellular viability (with laser) was 77.42% and 47.62% without laser. At 8 days, the total protein concentration was 21.622 mg / mol in the irradiated group and 16, 604 mg / mol in the non-irradiated group and at 18 days the concentration was 37.25 mg / mol in the irradiated group and 24, 95 mg / mol in the non-irradiated group.Conclusion:The laser interfered in the histochemical reaction, cell viability, matrix mineralization, and maintained the cellular expression of proteins.(AU)

Influence of low-level laser irradiation on osteocalcin protein and gene expression in bone tissue1

Purpose: To evaluate osteocalcin gene and protein expression in vitro and in an in vivo model of ostectomy. Methods: Twenty Wistar rats were assigned into two groups A (n=10, laser) and B (n=10, control). Ostectomy was performed in the femur diaphysis; the twenty fragments removed, composed in vitro groups named as in vivo (A and B) and cultivated in CO2 atmosphere for thirteen days. Low-level laser irradiation was performed in groups A (in vivo and in vitro) by an GaAlAs device (λ=808 nm, dose of 2J/cm2, power of 200mW, power density of 0.2W/cm2, total energy of 1.25J, spot diameter of 0.02mm) for 5 seconds, at one point, daily. It was performed immunocytochemistry assays in vivo and in vitro groups. In vitro groups were also submitted to RNA extraction, cDNA synthesis and gene expression by quantitative PCR. Statistical analysis was realized with p<0.05. Results: Immunocytochemistry scores showed no significant differences between control and laser groups either in vivo and in vitro. Gene expression also showed no statistical differences. Conclusion: Low-level laser irradiation did not alter osteocalcin protein and gene expression in vivo and in vitro in the studied period but it may have been expressed them in an earlier period.(AU)

The effects of photobiomodulation therapy on Staphylococcus aureus infected surgical wounds in diabetic rats. A microbiological, histopathological, and biomechanical study

PURPOSE:To evaluate the effects of photobiomodulation therapy (PBMT) at 685 nm on diabetic wound healing in rats suffering from bacterial infection induced by Staphylococcus aureus (S. aureus).METHODS:Thirty streptozotocin-induced diabetic rats were allocated into two groups: control and PBMT. A 4-cm full-thickness linear-incision was made on the dorsal midline and was contaminated with S. aureus. The wounds in the PBMT group were irradiated daily for 5 consecutive days, starting 3 days after the induction and always in the mornings.RESULTS:The result revealed that PBMT resulted in a significant decrease in S. aureus CFU in the PBMT group in comparison to the control group (P<0.05). The length of wounds, in the 2nd and 3rd weeks, in the PBMT group were significantly shorter compared to the control group (P<0.05). PBMT caused a significant increase in the histological parameters in comparison to the control group (P<0.05). Moreover, PBMT significantly increased the breaking strength of the surgical scars produced in the skin of the PBMT group when compared to the control group (P<0.05).CONCLUSION:Photobiomodulation therapy may be useful in the management of wound infection through a significant bacterial growth inhibition and an acceleration of wound healing process.(AU)

The effects of low level laser therapy on Staphylococcus aureus infected third-degree burns in diabetic rats

PURPOSE:To characterize the effects of low-level laser (LLL) on third-degreeburn wounds which were infected with Staphylococcus aureus (S. aureus) in diabetic rats.METHODS:Thirty streptozotocin-induced diabetic rats were divided into two groups: the control and the LLL groups. Third-degree burns were induced using a heated metal rod, and then, were contaminated with S. aureus. The wounds in the LLL group were irradiated with a LLL (685nm) daily for five consecutive days, starting three days after the induction. The wound area was measured at 3, 5, 8, 14 and 21 days after burning. At the end of trial, the skin samples were harvested.RESULTS:Reduction in wound areas in the LLL and control groups were significantly different only on the 21st day (p<0.05). The mean bacterial numbers in the LLL group were significantly lower (p<0.05) than those in the control group.The number of macrophages, new blood vessels, fibroblast, and elevated collagen deposition in the LLL group significantly increased compared to the control group (p<0.05).The mean breaking strength of scars in the control group was significantly lower (p<0.05) than that of the LLL group.CONCLUSION:The low-level laser improved the healing of S. aureus third-degree burn infections in diabetic rats.(AU)