Photobiomodulation effect in tumoral necrosis factor-alpha(TNF-α) on the viability of random skin flap in rats.

The aim of this study was to investigate the effect of red laser (660 nm) photobiomodulation (PBM) with different energies on tumor necrosis factor-alpha(TNF-α) expression for random skin flap viability in rats. Twenty-four Wistar rats were divided into three groups: sham group (SG), PBM laser group with an energy dose of 0.29 J (0.29G), and PBM laser group with an energy dose of 7.30 J (7.30G). A cranially based dorsal skin flap measuring 10 × 4 cm was raised and a plastic barrier was placed between the flap and its bed. PBM was applied in 3 timepoints: in the immediate postoperative period, in the 1st and in the 2nd postoperative days; the animals were euthanized on the 7th postoperative day. The assessments included: TNF-α expression of 3 different flap areas (proximal, medial and distal), by immunohistochemistry; percentage of skin flap necrosis area, by the paper template method. The statistical analysis was performed through the Kruskal-Wallis and Mann-Whitney tests, the level of significance adopted was 5% (p < 0.05). TNF-α expression was significantly lower for 7.30G in the proximal area, reduced for SG in the medial point, and larger for 7.30G in the distal area. The percentage of flap necrosis area was significantly reduced for 7.30G. Higher energy doses are more efficacious than lower energy doses for modulating TNF-α expression. PBM with an energy dose of 7.30 J was effective in reducing the expression of TNF-α and increase skin flap viability.

The Role of Dimethoate and UV-B on Skin of Wistar Rats.

BACKGROUND/AIM: The pesticide dimethoate (O-dimethyl-S- Nmethylcarbamoylmethyl phosphorodithioate) is able to induce severe acute toxicity in living organisms. The aim of this study was to evaluate the effects of ultraviolet radiation, alone or combined with exposure to dimethoate, on the rat skin. MATERIALS AND METHODS: A total of 38 Wistar female rats (Rattus norvegicus albinus), were distributed into four groups: A (n=9) control group, B (n=10) exposed to ultraviolet-B radiation (UV-B), C (n=10) exposed to UV-B followed by application of dimethoate (UV-B+AGRO) and group D (n=9) exposed to dimethoate (AGRO). Histological examination of the tissues, as well as immunohistochemistry for cleaved caspase 3, Ki-67 and COX-2 expression were performed to all groups. RESULTS: Animals submitted to UV-B exhibited hyperkeratosis with moderate cell atypia. Regarding exposure to UV-B+AGRO, the animals presented hyperkeratosis and atrophy, whereas in animals exposed to AGRO, only atrophy was noticed. The immunohistochemical results on skin revealed that UVB, AGRO and UVB+AGRO decreased cleaved caspase 3 and Ki-67 expression when compared to the control group (p<0.05). COX-2 expression decreased to UVB or AGRO groups compared to controls (p<0.05). CONCLUSION: UV-B or AGRO exposure is able to induce histopathological changes and altered expression of cleaved caspase-3 and Ki-67 in rat skin, thus being categorized as a risk condition for skin carcinogenesis.

Photobiomodulation of Matrix Metalloproteinases in Rat Calcaneal Tendons.

Objective: The main objective was to verify the modulatory effects of MMP-1, MMP-3, and MMP-13 levels on the partially injured calcaneal tendons of rat exposure to photobiomodulation. Background: Photobiomodulation has been shown to have anti-inflammatory and regenerative effects on tendon injuries. However, there is still uncertainty regarding the beneficial effects in matrix metalloproteinase (MMP) levels, especially MMP-1, -3, and -13. Materials and methods: Sixty-five male Wistar rats were used. Sixty were submitted to a direct trauma on the calcaneal tendons and were randomly distributed into the following six groups: LASER 1, 3, and 7 (10 partially injured calcaneal tendons in each group treated with photobiomodulation for 1, 3, and 7 days, respectively) and Sham 1, 3, and 7 (same injury, with simulated photobiomodulation). The remaining five animals were allocated to the normal group (no injury or treatment procedure). The 780 nm low-level laser was applied with 70 mW of mean power and 17.5 J/cm2 of fluency for 10 sec, once a day. The tendons were surgically removed and analyzed for MMP-1, MMP-3, and MMP-13 through immunohistochemistry. Results: MMP-3 levels remained close to normal in all experimental groups (p > 0.05); however, reductions (p < 0.05) in MMP-1 and MMP-13 levels were detected in the groups submitted to one, three, and seven low level laser therapy applications. Conclusions: The photobiomodulation protocol was able to reduce MMP-1 and MMP-13 levels in injured calcaneal tendons.

Effect of low power laser in biomodulation of cultured osteoblastic cells of Wistar rats1.

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.

Photobiomodulation of matrix metalloproteinases in rat calcaneal tendons

Objective: The main objective was to verify the modulatory effects of MMP-1, MMP-3, and MMP-13 levels on the partially injured calcaneal tendons of rat exposure to photobiomodulation. Background: Photobiomodulation has been shown to have anti-inflammatory and regenerative effects on tendon injuries. However, there is still uncertainty regarding the beneficial effects in matrix metalloproteinase (MMP) levels, especially MMP-1, -3, and -13. Materials and methods: Sixty-five male Wistar rats were used. Sixty were submitted to a direct trauma on the calcaneal tendons and were randomly distributed into the following six groups: LASER 1, 3, and 7 (10 partially injured calcaneal tendons in each group treated with photobiomodulation for 1, 3, and 7 days, respectively) and Sham 1, 3, and 7 (same injury, with simulated photobiomodulation). The remaining five animals were allocated to the normal group (no injury or treatment procedure). The 780?nm low-level laser was applied with 70?mW of mean power and 17.5 J/cm2 of fluency for 10 sec, once a day. The tendons were surgically removed and analyzed for MMP-1, MMP-3, and MMP-13 through immunohistochemistry. Results: MMP-3 levels remained close to normal in all experimental groups (p > 0.05); however, reductions (p < 0.05) in MMP-1 and MMP-13 levels were detected in the groups submitted to one, three, and seven low level laser therapy applications. Conclusions: The photobiomodulation protocol was able to reduce MMP-1 and MMP-13 levels in injured calcaneal tendons.

Photobiomodulation of matrix metalloproteinases in rat calcaneal tendons

Objective: The main objective was to verify the modulatory effects of MMP-1, MMP-3, and MMP-13 levels on the partially injured calcaneal tendons of rat exposure to photobiomodulation. Background: Photobiomodulation has been shown to have anti-inflammatory and regenerative effects on tendon injuries. However, there is still uncertainty regarding the beneficial effects in matrix metalloproteinase (MMP) levels, especially MMP-1, -3, and -13. Materials and methods: Sixty-five male Wistar rats were used. Sixty were submitted to a direct trauma on the calcaneal tendons and were randomly distributed into the following six groups: LASER 1, 3, and 7 (10 partially injured calcaneal tendons in each group treated with photobiomodulation for 1, 3, and 7 days, respectively) and Sham 1, 3, and 7 (same injury, with simulated photobiomodulation). The remaining five animals were allocated to the normal group (no injury or treatment procedure). The 780?nm low-level laser was applied with 70?mW of mean power and 17.5 J/cm2 of fluency for 10 sec, once a day. The tendons were surgically removed and analyzed for MMP-1, MMP-3, and MMP-13 through immunohistochemistry. Results: MMP-3 levels remained close to normal in all experimental groups (p > 0.05); however, reductions (p < 0.05) in MMP-1 and MMP-13 levels were detected in the groups submitted to one, three, and seven low level laser therapy applications. Conclusions: The photobiomodulation protocol was able to reduce MMP-1 and MMP-13 levels in injured calcaneal tendons.

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

Abstract 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

Dosimetry of a Carbon Dioxide Laser for Black Tattoo Removal in a Rat Model.

Objective: To determine the optimal parameters of power, energy, and time for the application of a carbon dioxide laser for Tribal Black ink tattoo removal. Background data: The use of antiquated techniques to remove tattoos demonstrates the difficulty of making advances in this field. Studies by the American Society for Dermatologic Surgery have shown that 5% of the global population has at least one tattoo on the body, with 10% of them wanting a tattoo to be removed. Laser removal has been studied and improved as a less invasive and safer method of surgical removal; however, the ideal dosimetry is not yet established. Materials and methods: Thirty-three male Wistar rats were anesthetized and tattooed in the dorsal region in a quadrangular manner. The rats were distributed under low/null luminosity for 4 months into three equal and random groups for the application of the laser, namely, G1 (P = 0.6 W, Et = 0.9 J), G2 (P = 0.8 W, Et = 1, 2 J), and G3 (P = 1 W, Et = 1.5 J), with the application time standardized to 0.15 sec with 10 passes per application. The procedure was repeated at intervals of 4 weeks until 10 cycles of laser application were completed. The images were studied using the ImageJ program and histological analysis and subjected to the one-way ANOVA test for Tukey's multiple comparison post-test. Results: We observed a significant difference between groups 1 and 3 and between groups 2 and 3. Conclusions: The laser with the parameters of P = 1 W, Et = 1.5 J, and t = 0.15 sec yields better Tribal Black ink removal results.

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.

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

Abstract 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.

Low-Level Laser Therapy (780 nm) on VEGF Modulation at Partially Injured Achilles Tendon.

OBJECTIVE: The aim of this study was to analyze the modulatory effects of near infrared (780 nm) low-level laser therapy (LLLT) on the presence of the vascular endothelial growth factor (VEGF) in the partially injured Achilles tendons of rats. BACKGROUND: LLLT stimulates the healing process for Achilles tendon injuries, although the extent of the modulatory effect of LLLT on the VEGF levels found in the injured tendons remains unclear. METHODS: Sixty-five male Wistar rats were distributed in the following seven groups: LASER 1, 3, and 7 (10 partially injured Achilles tendons in each group, which were treated with LLLT for 1, 3, and 7 days, respectively); Sham 1, 3, and 7 (same injury, with simulated LLLT); Control group containing the five remaining animals and in which no procedures were performed. LLLT was applied once a day for 10 sec, with a mean power of 70 mW and fluency of 17.5 J/cm(2). After euthanasia, all of the Achilles tendons were surgically removed and the VEGF levels were analyzed using immunohistochemistry. RESULTS: The VEGF levels remained close to normal (p > 0.05) when comparing the experimental groups (LASER and Sham: 1, 3, and 7) with the Control group. CONCLUSION: LLLT did not stimulate the expression of VEGF in the treated Achilles tendons.

Evaluation of different laser wavelengths on ablation lesion and residual thermal injury in intervertebral discs of the lumbar spine.

Laser discectomy or nucleotomy is an increasingly important method for less invasive procedures of column, but the ideal kind of laser is still not established. As the wavelength is an important parameter for water absorption, this study was performed to investigate the action of the laser emission in the near infrared (808 to 1908 nm) region in the context of surgical procedures for percutaneous intervertebral disc decompression (nucleotomy). Forty intervertebral discs from pigs lumbar spines were irradiated with laser (λ = 808, 980, 1470 and 1908 nm), 1-s on/off time cycles, for 120 cycles and 10 W of power (808, 980, and 1470 nm) or 240 cycles and 5 W of power (1908 nm), with total power of 1200 J, and subjected to microscopic evaluation through hematoxylin-eosin (HE) staining in order to measure the ablation lesions and the residual thermal injury. Ten other discs were not irradiated and worked as controls. The ablation lesions were measured (in mm) at 1.08 ± 1.25, 1.70 ± 0.63, 2.23 ± 1.02, 1.37 ± 0.39, and 0.94 ± 0.41 (median ± SD) for the control, 808, 980, 1470, and 1908 nm groups, respectively. The difference between 1908 nm and all the other groups was statistically significant (p < 0.05). The residual thermal injury was less evident in 1908 nm laser and sharper in 980 nm laser wavelengths. The laser at a wavelength of 1908 nm was considered the most efficient for the vaporization of the nucleus pulposus, followed by the laser wavelengths of 1470, 808, and 980 nm, and proved to be useful for laser nucleotomy procedure.

Morphological and functional response to injury to the external urethral sphincter - similarities and differences between male and female rats.

AIMS: The objective of this study was to evaluate the similarities and differences of the urethral morphological and functional changes following external urethral sphincter EUS injury in male and female rats. METHODS: 30 female and 30 male age-matched Wistar rats were used in the experiments. Half of them underwent electrocauterization of the surrounding tissues lateral to the urethra at the level of the (EUS) and the others, a sham operation. At 2, 6, and 16 weeks after surgeries they underwent anesthetized cystometry, measurement of leak point pressure (LPP) and their urethras were harvested for morphological analyses. RESULTS: There were no differences in cystometric parameters between sex-time-matched animals, ensuring normal bladder function in the manipulated animals. The mean LPP in male and female rats was lower compared with sham animals. Age-time-matched sham operated male rats exhibited a higher LPP compared with female rats. The reduction in LPP comparing electrocauterized and sham time-matched animals was more pronounced in male rats than in female rats. Electrocauterization produced urethral collagen deposition and nerve damage in both male and female animals. Muscle atrophy and disruption also occurred, being more evident in female rats. CONCLUSIONS: The urethras of male and female rats exhibited a similar morphological and functional response to electrocauterization. The time-course evaluation revealed that the male animal model is as reliable, reproducible and long-lasting as the female model. Intact males had a higher LPP than female rats and the nerve injury led to a more drastic impairment of this mechanism.

Real time echo-guided endolaser for thermal ablation without perivenous tumescence / Endolaser ecoguiado em tempo real para termoablação sem intumescência perivenosa

There is no consensus in the medical literature on the ideal procedure for endovenous laser application. Objective To assess the safety and efficacy of real time echo-guided endovenous laser for thermal ablation of great saphenous vein (GSV) incompetence, without perivenous tumescence. Methods Thirty-four limbs of patients with CEAP clinical scores of 2 to 6 and bilateral incompetence of the saphenofemoral junction (SFJ) and GSV, confirmed by Echo-Doppler, underwent endovenous laser therapy and were followed for 1 year. Laser ablation was performed using a 600 µ bare optical fiber introduced endovenously close to the malleolus along the full extent of the GSV in an anterograde direction, using a standardized echo-Doppler-guided AND? 15 watt continuous mode 980 nm diode laser with real-time monitoring of thermal ablation of the whole target vein. Adverse effects and complications were recorded. Results Hyperesthesia, cellulitis, and fibrous cord, all transitory, developed in 2.9% of the 34 limbs treated; 8.8% developed hypoesthesia in the perimalleolar region, which was transitory and had no clinical consequences; there were no cases of deep venous thrombosis. Immediate occlusion was achieved in 100% of the 34 saphenous veins that underwent photocoagulation, although one exhibited recanalization without reflux at 1-month follow-up. After 6 months and 1 year, occlusion was 100% according to echo-Doppler findings. Conclusions Real-time echo-guided 980 nm endovenous laser ablation without perivenous tumescence provided controlled thermal ablation with safe, effective, immediate and medium-term GSV occlusion and can therefore be recommended as a method for the treatment of chronic venous disease.

Não há consenso na literatura médica sobre qual técnica é a ideal para aplicação do endolaser. Objetivos Avaliar a segurança e a eficácia do endolaser ecoguiado em tempo real para termoablação da veia safena magna (VSM) insuficiente, sem intumescência perivenosa. Métodos Trinta e quatro membros de pacientes em estágio clínico CEAP 2 a 6, com incompetência bilateral da junção safeno-femoral e da VSM, confirmada por eco-Doppler, foram submetidos à terapia por endolaser e acompanhados por um período de um ano. A aplicação foi feita por meio de fibra condutora de 600 µ, introduzida por via endovenosa, ao nível da região perimaleolar por toda VSM, sentido anterógrado, utilizando laser diodo com 15 w de potência e 980 nm de comprimento de onda, no modo contínuo, guiado por eco-Doppler, e forma padronizada para monitoração em tempo real da termoablação de toda a veia-alvo. Foram anotados os efeitos adversos e as complicações. Resultados Dos 34 membros tratados, 2,9% apresentaram hiperestesia, celulite e cordão fibroso, todos transitórios; em 8,8%, constatou-se hipoestesia perimaleolar, transitória e sem repercussão clínica; não houve relato de trombose venosa profunda. Das 34 safenas fotocoaguladas, houve 100% de oclusão imediata, uma recanalização sem refluxo no controle de um mês e 100% de oclusão após seis meses e um ano, mostrado pelo eco-Doppler. Conclusões Ablação utilizando endolaser 980 nm, ecoguiado em tempo real, sem intumescência perivenosa, promoveu fotocoagulação suficientemente controlada, com oclusão imediata e em médio prazo da VSM, de forma segura e eficaz, e configura-se como método terapêutico recomendável para o tratamento da doença venosa crônica.

Effect of low-level laser therapy on bone repair: a randomized controlled experimental study.

The aim of this study was to investigate the effect of low-level laser therapy (LLLT) on bone repair in femoral fractures. Sixty adult Wistar rats were randomly assigned into one of two groups: group A (ostectomy + LLLT) or group B (ostectomy + sham laser). An experimental model of complete bone fracture was surgically created by removing a 2-mm fragment from the middle third of the femoral shaft. Data were analyzed on days 8, 13, and 18 after the fracture (subgroups 1, 2, and 3). Samples were assessed for changes in inflammatory infiltration; trabecular bone matrix, periosteal, and new bone formations; and changes in the expression of particular osteogenic-related proteins (osteocalcin, osteopontin, and osteonectin). Microscopic analysis revealed a significant decrease in inflammatory infiltration, intense trabecular bone matrix and periosteal formation, and an increase in newly formed bone after laser irradiation. We also found an increase in the expression of bone matrix proteins with LLLT, with a significant difference measured for osteocalcin in the LLLT group at day 8 (p = 0.007). We show that LLLT plays an important role in augmenting bone tissue formation, which is relevant to fracture healing. LLLT may therefore be indicated as an adjunct therapeutic tool in clinical practice for the treatment or recovery of nonunion injuries.

Low-level laser therapy in IL-1ß, COX-2, and PGE2 modulation in partially injured Achilles tendon.

This study evaluated IL-1ß, COX-2, and PGE2 modulation in partially injured Achilles tendons treated with low-level laser therapy (LLLT). Sixty-five male Wistar rats were used. Sixty were submitted to a direct injury on Achilles tendon and then distributed into six groups: LASER 1 (a single LLLT application), LASER 3 (three LLLT applications), and LASER 7 (seven LLLT applications) and Sham 1, 3, and 7 (the same injury but LLLT applications were simulated). The five remaining animals were allocated at control group (no procedure performed). LLLT (780 nm) was applied with 70 mW of mean power and 17.5 J/cm(2) of fluency for 10 s, once a day. The tendons were surgically removed and assessed immunohistochemically for IL-1ß, COX-2, and PGE2. In comparisons with control (IL-1ß: 100.5 ± 92.5 / COX-2: 180.1 ± 97.1 / PGE2: 187.8 ± 128.8) IL-1ß exhibited (mean ± SD) near-normal level (p > 0.05) at LASER 3 (142.0 ± 162.4). COX-2 and PGE2 exhibited near-normal levels (p > 0.05) at LASER 3 (COX-2: 176.9 ± 75.4 / PGE2: 297.2 ± 259.6) and LASER 7 (COX-2: 259.2 ± 190.4 / PGE2: 587.1 ± 409.7). LLLT decreased Achilles tendon's inflammatory process.

Low-level laser therapy on tissue repair of partially injured achilles tendon in rats.

OBJECTIVE: The aim of this study was to assess the alignment and type of collagen (I and III) in partially injured Achilles tendons of rats treated with low-level laser therapy (LLLT). BACKGROUND: Achilles tendons present high indices of injury and their regeneration process may take a long time. LLLT has been used to accelerate and enhance injured Achilles tendon repair. METHODS: Sixty-five male Wistar rats were distributed into seven groups: LASER 1, 3, and 7 (the rat's Achilles tendons were partially injured and submitted to treatment for 1, 3, or 7 days, respectively); a Sham group 1, 3, and 7 for each of LASER group (same injury, but the LLLT was only simulated), and five remaining animals were allocated to the control group (no procedures were performed). The 780 nm LLLT was applied once a day, with 70 mW of mean power, fluence of 17.5 J/cm(2) for 10 sec. After the rats were euthanized, the tendons were surgically removed and assessed by birefringence technique (collagen alignment) and picrosirius red (collagen I and III). RESULTS: Sham versus LASER analysis did not show differences (p>0.05) for collagen alignment. The collagen composition (median) was significantly different (p<0.05) for LASER 3 (I: 16.5; III: 83.5) versus Sham 3 (I: 12.5; III: 87.5) and LASER 7 (I: 20.2; III: 79.8) versus Sham 7 (I: 10.2; III: 89.8). LASER groups exhibited a higher percentage of type I collagen and a lower percentage of type III collagen. CONCLUSIONS: LLLT stimulated collagen I proliferation, improving the injured Achilles tendons' healing process.

Induction of neoplastic cells in rat skin.

PURPOSE: To investigate the induction of neoplastic lesions under the action of ultraviolet B radiation (UVR-B) and dimethyl benzanthracene (DMBA). METHODS: Forty Wistar rats were assigned to four groups (ten animals each), according to the procedure: group A received UVR-B irradiation, group B received topic DMBA, group C, UVR-B+DMBA and group D as control, observed for ten weeks. In the tenth week they went through a skin biopsy and histopathological study. The average thickness of the epidermis was calculated and evaluated statistically. RESULTS: Macroscopic lesions in group B were more of inflammatory kind compared to group A. Group C presented more injuries with neoplastic features than the others (p<0.01). Histologically there was a significant increase in thickness of the epidermis of all groups compared to control, however the greatest thickness measures occurred in Group C (p<0.01). CONCLUSIONS: The population exposed to ultraviolet B radiation is subject to suffer skin lesions that can develop into cancer. The association with hydrocarbons as the dimethyl benzanthracene increases the possibility of malignancy. May not be clinically evident determine when a solar keratosis ends and when a CEC begins. For this reason, histological study associated with health education prompting the early and irreversible injury prevention is necessary.

Induction of neoplastic cells in rat skin

To investigate the induction of neoplastic lesions under the action of ultraviolet B radiation (UVR-B) and dimethyl benzanthracene (DMBA). METHODS: Forty Wistar rats were assigned to four groups (ten animals each), according to the procedure: group A received UVR-B irradiation, group B received topic DMBA, group C, UVR-B+DMBA and group D as control, observed for ten weeks. In the tenth week they went through a skin biopsy and histopathological study. The average thickness of the epidermis was calculated and evaluated statistically. RESULTS: Macroscopic lesions in group B were more of inflammatory kind compared to group A. Group C presented more injuries with neoplastic features than the others (p<0.01). Histologically there was a significant increase in thickness of the epidermis of all groups compared to control, however the greatest thickness measures occurred in Group C (p<0.01). CONCLUSIONS: The population exposed to ultraviolet B radiation is subject to suffer skin lesions that can develop into cancer. The association with hydrocarbons as the dimethyl benzanthracene increases the possibility of malignancy. May not be clinically evident determine when a solar keratosis ends and when a CEC begins. For this reason, histological study associated with health education prompting the early and irreversible injury prevention is necessary.

Cutaneous changes in rats induced by chronic skin exposure to ultraviolet radiation and organophosphate pesticide.

PURPOSE: To study the possible potentiation of the carcinogenic effects of ultraviolet radiation associated with an organophosphate pesticide. METHODS: Forty Wistar rats were assigned into four groups (n=10 each) randomized according to the procedures: group A received only UVR-B radiation; group B, UVR-B for eight weeks followed by a seven week period of pesticide exposure; group C, UVR-B + pesticide concomitantly: group D, only pesticide application. At the end of the fifth, tenth and fifteenth weeks the animals were photographed. Skin biopsy and histopathological study with Hematoxylin-Eosin were done on the fifteenth week. Statistical analysis with Fisher's and Sign (unilateral) tests, 5% value for significance. RESULTS: Macroscopic lesions in the group A evolved from the erythema to erythema + desquamation. The groups B and C, with the association of two carcinogens, and group D presented evolution to keratosis, with higher incidence in group D. The histology showed a significant increase in the severity of injuries when the UVR-B and the pesticide were applied simultaneously, leading to cellular atypia. CONCLUSIONS: Concurrent association of UVR-B to organophosphate pesticide produced more severe lesions microscopically, although this has not been so apparent macroscopically. In daily practice the clinical evaluation should be complemented with laboratory evaluation.