Purpose:To study the influence of HeNe laser irradiation on the collagen percentage in surgically-induced skin wounds in rats with and without alloxan-induced diabetes, by morphometric analysis of collagen fibers. Methods: 48 male Wistar rats were used, divided into groups: laser-treated diabetic (group 1); untreated diabetic (group 2); treated non-diabetic (group 3); and untreated non-diabetic (group 4). For groups 1 and 2, diabetes was induced by intravenous injection of alloxan (2,4,5,5, Sigma), into the dorsal vein of the penis, at a rate of 0.1 ml of solution per 100 g of body weight. A wound was made on the back of all the animals. Groups 1 and 3 were treated with HeNe laser (4 J/cm 2 ) for 60 s. One animal from each group was sacrificed on the 3 rd , 7 th and 14 th days after wounding. Samples were taken, embedded in paraffin, stained with hematoxylin-eosin and Masson's trichrome, and morphometrically analyzed using the Imagelab software. The percentages of collagen fibers were determined from the samples from the euthanasia animals. The data were treated statistically using analysis of variance (ANOVA) and the Student t and Kruskal-Wallis tests. The significance level was set at 0.05 or 5%. Results: The results obtained from the samples taken on the third, seventh and fourteenth days after wounding demonstrated that the laser-treated group presented a statistically significant (p<0.05) greater mean quantity of collagen fibers than in the non-treated group, both for diabetic rats (p = 0.0104) and for non-diabetic rats (p = 0.039). Conclusion: The low-power laser (632.8 nm) was shown to be capable of influencing the collagen percentage in skin wounds by increasing the mean quantity of collagen fibers, both for the diabetic and for the non-diabetic group. Key words: Laser Therapy, Low-Level. Wound Healing. Collagen. Rats. RESUMOObjetivo: Estudar, comparativamente, através de análises morfométricas das fibras colágenas, a influência da irradiação com laser HeNe no percentual de colágeno de lesões cutâneas induzidas em ratos diabéticos aloxânico e não diabéticos. Métodos: Foram utilizados 48 ratos Wistar, machos sendo estes divididos em grupos: Grupo 1 diabético tratado com laser, Grupo 2 diabético não-tratado, Grupo 3 não-diabético tratado e Grupo 4 não-diabéticos não-tratados. Nos grupos 1 e 2 diabetes foi induzido por injeção intravenosa (veia dorsal do pênis de Aloxana (2, 4, 5, 6 -Tetraoxypyrimidina; 5 -6 Dioxyuracila) SIGMA, 0.1ml de solução a cada 100 g. de peso corporal. Todos os animais foram submetidos a uma lesão no dorso e os Grupos 1 e 3, foram tratados com laser HeNe com dosagem de 4 J/cm 2 por 36 s. Um animal de cada grupo sofreu eutanásia no 3º, 7º e 14 dias após a lesão e retiradas as amostras que foram emblocadas em parafina, coradas com H.E., Tricrômico de Masson e a analisadas morfométricamente pelo software IMAGELAB . Os dados resultantes foram tratados estatisticamente pela análise de variância (ANOVA), e pelos testes t e Kruskal-Wallis fixou-se em 0,05 ou 5% (a £ 0,05) o nível ...

With the aim of accelerating the regenerative processes, the objective was to study the influence of gallium-aluminum-arsenide (GaAlAs) laser (660 nm) on functional and histomorphological recovery of the sciatic nerve in rats. The sciatic nerves of 12 Wistar rats were crushed divided into two groups: control and laser therapy. For the latter, GaAlAs laser was utilized (660 nm, 4 J/cm(2), 26.3 mW and 0.63 cm(2) beam), at three equidistant points on the lesion, for 20 days. Comparison of the sciatic functional index (SFI) showed that there was a significant difference only between the pre-lesion value of the laser therapy group and that after the 21st day in the control group. It was concluded that the parameters and methods utilized demonstrated positive results regarding the SFI over the time period evaluated.

PURPOSE: To investigate the effects of therapeutic ultrasound on the healing of tendon injuries in malnourished rats. METHODS: After the intended nutritional states had been attained, the animals (N=36) were distributed into three groups, named: G1(N=12), control group; G2(N=12), malnourished rats treated with 3 MHz ultrasound at an intensity of 0.5 W/cm²; and G3 (N=12), normal animals treated with 3 MHz at 0.5 W/cm². The injuries were induced by means of an operation to expose the heel tendon and crush it using Allis forceps. RESULTS: The data obtained relating to leukocyte counts, fibroblasts, vessel neoformation, fibrosis and collagen were subjected to statistical treatment using analysis of variance (ANOVA) and Student's t test. Results of p < 0.05 were obtained for fibrosis and collagen. CONCLUSION: The ultrasound was shown to be effective in repairing the tendon, even in malnourished animals whose healing process was retarded.

In this study, we aimed to analyze the effects of low-level laser therapy (LLLT; 660 nm) on levels of protein expression of inflammatory mediators after cutting Achilles tendon of rats. Thirty Wistar male rats underwent partial incisions of the left Achilles tendon, and were divided into three groups of 10 animals according to the time of euthanasia after injury: 6, 24 and 72 h. Each group was then divided into control group and LLLT group (treated with 100 mW, 3.57 W cm(-2), 0.028 cm(2), 214 J cm(-2), 6 J, 60 s, single point). In LLLT group, animals were treated once time per day until the time of euthanasia established for each group. The group treated with LLLT showed a significant reduction of IL-1β compared with control groups at three time points (6 h: P=0.0401; 24 h: P=0.0015; 72 h: P=0.0463). The analysis of IL-6 showed significant reduction only in the LLLT group at 72 h compared with control group (P=0.0179), whereas IL-10 showed a significant increase in the treated group compared with control group at three experimental times (6 h: P=0.0007; 24 h: P=0.0256; 72 h: P<0.0001). We conclude that LLLT is an important modulator of inflammatory cytokines release after injury in Achilles tendon.

PURPOSE:To investigate biomarkers of acute renal injury in Wistar rats, subjected to left renal ischemia for 10 minutes, and then compare reperfusion at 24 hours, and at 5, 7, 14 and 21 days after the procedure. METHODS:Eight female and male rats between 60 and 81 days old were used in the Central Animal Facility of the UFMS. Assessed biomarkers included urine protein, urea, creatinine, glucose, sodium, potassium, urine alkaline phosphatase and gamma-glutamyl transferase activities, and protein-to-creatinine ratio; and in serum: urea, creatinine, sodium and potassium, fractional excretion of sodium, potassium, urine flow and creatinine clearance. RESULTS:Greater variance was observed in the parameters at 24 hours and at five days (p<0.05) after reperfusion. On the 21 st day, these parameters approximated those obtained for the control group. CONCLUSIONS:Renal ischemia for 10 minutes was sufficient to raise urine levels of protein, glucose, fractional excretion of potassium, urea, creatinine clearance, urine activity of gamma-glutamyltransferase and alkaline phosphatase enzymes in the first 24 hours, up to five days after reperfusion, which may indicate risk of acute kidney injury, according to the RIFLE classification.