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.

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.

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.

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.

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.

Infrared low-level diode laser on inflammatory process modulation in mice: pro- and anti-inflammatory cytokines.

To evaluate the modulation of proinflammatory (interleukin-6, IL-6; tumor necrosis factor-α, TNF-α; and interferon-γ, IFN-γ) and anti-inflammatory cytokines (transforming growth factor-ß1, TGF-ß1) in the inflammation processes in vivo with low-level laser action, 50 isogenic mice were randomly distributed into three groups: control (no surgical procedure, n = 10), sham (surgical procedure with three standard cutaneous incisions, followed by an abdominal muscle incision and suture, n = 20), and laser (same procedure followed by laser exposure, n = 20). The sham group was divided into three subgroups: sham I (euthanasia and evaluation, 36 h after surgical procedure), sham II (euthanasia and evaluation, 60 h after surgical procedure), and sham III (euthanasia and evaluation, 84 h after surgical procedure). The laser group was also divided in three subgroups: laser I (a single laser session, 12 h after surgery), laser II (two laser sessions, 12 and 36 h after surgery), and laser III (three laser sessions, 12, 36, and 60 h after surgery). All animals in the laser groups received three points per session of continuous infrared laser (wavelength of 780 nm, power of 20 mW, fluency of 10 J/cm(2), exposure time of 20 s per point, and energy of 0.4 J). After euthanasia, spleen mononuclear cells were isolated and cultured for 48 h. Concentrations of IL-6, TNF-α, IFN-γ, and TGF-ß1 were obtained by enzyme-linked immunosorbent assay method. There was a significant difference between the IL-6 and TNF-α concentrations in the 60-and 84-h evaluations when the laser and sham groups were compared to the control group (p < 0.05), except for laser II in the TNF-α analysis (p > 0.05). The IFN-γ concentration analysis showed a significant difference only in sham II when compared to the control group (p < 0.05). Thus, there was a modulatory effect of TNF-α and IFN-γ in the laser group, particularly in the 60-h postoperative evaluation. There was no significant difference between the laser, sham, and control groups for TGF-ß1 analysis (p > 0.05). The low-level laser application decreased the TNF-α and IFN-γ release in vivo of spleen mononuclear cells in mice, especially after two exposure sessions. However, there was no modulation of the IL-6 and TGF-ß1 release.

Infrared low-level diode laser on serum chemokine MCP-1 modulation in mice.

The effect of the low-level laser therapy (LLLT) in the modulation of cells related to inflammatory processes has been widely studied, with different parameters. The objective was to investigate the immediate and cumulative effect of infrared LLLT on chemokine monocyte chemotactic protein-1 (MCP-1) modulation in mice. Fifty-two isogenic mice were distributed in seven groups: control (n = 10, no surgical procedure), laser I (n = 7, surgical procedure and a single LLLT exposure 12 h after the surgery), laser II (n = 7, surgery followed by two LLLT exposures, 12 and 36 h after surgery), and laser III (n = 7, surgery followed by three LLLT exposures, 12, 36, and 60 h after surgery). For each group, a sham group (n = 21) underwent surgery without laser application. The animals in the laser groups received an infrared diode continuous laser exposure (AsGaAl, 780 nm wavelength, power of 20 mW, energy density of 10 J/cm(2), spot size of 0,04 cm(2)) on three points (20 s per point), and a final energy of 0.4 J. The animals were sacrificed 36 h (laser I and sham I groups), 60 h (laser II and sham II), and 84 h (laser III and sham III groups) after surgery. The MCP-1 concentrations were measured by cytometric bead array. There was no significant difference between the three periods in the sham group (p = 0.3). There was a lower concentration of MCP-1 in the laser III group compared to the laser I group (p = 0.05). The infrared LLLT showed a cumulative effect in the modulation of chemokine MCP-1 concentration. Three LLLT exposures were necessary to achieve the MCP-1 modulation.

Low-level laser irradiation, cyclooxygenase-2 (COX-2) expression and necrosis of random skin flaps in rats.

Skin flaps are still a matter of concern among surgeons, as failures can occur leading to flap necrosis. However, low-level laser irradiation has been reported as an effective tool to improve the viability of ischemic flaps, yet its mechanisms of action remain unclear. We investigated the effect of low-level laser irradiation on the viability of random skin flaps in rats and determined COX-2 expression in the flap pedicle. The study animals comprised 24 EPM-1 Wistar rats which were randomly allocated into three equal groups. A cranially based dorsal random skin flap measuring 10 × 4 cm was created in all the animals. In one group, laser irradiation was simulated (sham group), and in the other two groups the animals were irradiated at 12 points with 0.29 J at 20 mW (energy density 10.36 J/cm(2), irradiance 0.71 W/cm(2)), or with 7.3 J at 100 mW (energy density 260.7 J/cm(2), irradiance 3.57 W/cm(2)). These procedures were applied to the cranial half of the flap immediately after surgery and were repeated on days 2 and 5 after surgery. The percentage necrotic area was determined on day 7 after surgery by the paper template method. The immunohistochemical expression of COX-2 in the samples was given scores from 0 to 3. The necrotic area was smaller in group irradiated at 7.3 J compared to sham-treated group and to the group irradiated at 0.29 J (P < 0.05); there was no difference between the sham-treated group and group irradiated at 0.29 J. COX-2 expression was lower in the group irradiated at 7.3 J than in the sham-treated group and the group irradiated at 0.29 J (P < 0.001). Low-level laser therapy was effective in decreasing random skin flap necrosis in rats using a laser energy of 7.30 J per point. Laser irradiation also decreased the expression of COX-2 in the flap pedicle.

Single session to infrared low level diode laser on TNF-alpha and IL-6 cytokines release by mononuclear spleen cells in mice: a pilot study.

BACKGROUND AND OBJECTIVE: The results of low-level infrared laser (LLL) systemic action on inflammatory modulation process, specifically diminishing pro-inflammatory and producing anti-inflammatory cytokines are extremely controversial in the literature. More studies are necessary to clarify the biomodulation process. The main objective was to investigate the effect of a single session of an AsGaAl laser on spleen cells interleukin-6 (IL-6) and tumor necrosis factor - alpha (TNF-alpha) release, in vivo, in mice. STUDY DESIGN/MATERIALS AND METHODS: In a pilot study, 18 isogenic mice were distributed in three groups: control (no surgical procedure, n = 6), sham (surgical procedure with three standard cutaneous incisions, followed by abdominal muscle incision followed by suture, n = 6) and LLL (same procedure followed by a single LLL exposure 12 hours after the procedure, n = 6). The animals in the LLL group received a single infrared continuous laser session (780 nm wavelength, power of 20 mW, energy density of 10 J/cm(2)) on three points (20 seconds per point), and final energy of 0.4 J. All animals of the sham and LLL groups were sacrificed 36 hours after surgical procedure; the spleen mononuclear cells were isolated and cultivated for 48 hours. The IL-6 and TNF-alpha were measured by the ELISA method. RESULTS: IL-6 and TNF-alpha concentrations released by the mononuclear cells showed significant differences between the control and sham group (P < 0.07). However, there were no differences between the control and LLL group and between the sham and LLL groups (P > 0.07). CONCLUSION: The single session of infrared LLL showed a tendency of decreasing the IL-6 and TNF-alpha release by mononuclear spleen cells in mice after application, although there was not a significant difference between the sham and LLL group. Conclusions regarding effectiveness of a single session procedure cannot be made due to the low statistical power of this pilot study.

Effects of low-level laser therapy on collagen expression and neutrophil infiltrate in 5-fluorouracil-induced oral mucositis in hamsters.

BACKGROUND AND OBJECTIVES: Several studies have suggested that low-level laser therapy (LLLT) can ameliorate oral mucositis; however, the mechanisms involved are not well understood. The aim of this study was to investigate the mechanisms of action of LLLT on chemotherapy-induced oral mucositis, as related to effects on collagen expression and inflammation. MATERIALS AND METHODS: A hamster cheek pouch model of oral mucositis was used with all animals receiving intraperitoneal 5-fluorouracil, followed by surface irritation. Animals were randomly allocated into three groups, and treated with an InGaAIP diode laser at a wavelength of 660 nm and output power of 35 or 100 mW laser, or no laser. Clinical severity of mucositis was assessed at four time-points by a blinded examiner. Buccal pouch tissue was harvested from a subgroup of animals in each group at four time-points. Collagen was qualitatively and quantitatively evaluated after picrosirius staining. The density of the neutrophil infiltrate was also scored. RESULTS: Peak clinical severity of mucositis was reduced in the 35 mW laser group as compared to the 100 mW and control groups. The reduced peak clinical severity of mucositis in the 35 mW laser group was accompanied by a decrease in the number of neutrophils and an increase in the proportion of mature collagen as compared to the other two groups. The total quantity of collagen was significantly higher in the control (no laser) group at the day 11 time-point, as compared to the 35 mW laser group, consistent with a more prolonged inflammatory response in the control group. CONCLUSION: This study supports two mechanisms of action for LLLT in reducing mucositis severity. The increase in collagen organization in response to the 35 mW laser indicates that LLLT promotes wound healing. In addition, LLLT also appears to have an anti-inflammatory effect, as evidenced by the reduction in neutrophil infiltrate.

Cyclooxygenase-2 and vascular endothelial growth factor expression in 5-fluorouracil-induced oral mucositis in hamsters: evaluation of two low-intensity laser protocols.

GOAL OF WORK: The aim of this study was to investigate the mechanisms whereby low-intensity laser therapy may affect the severity of oral mucositis. MATERIALS AND METHODS: A hamster cheek pouch model of oral mucositis was used with all animals receiving intraperitoneal 5-fluorouracil followed by surface irritation. Animals were randomly allocated into three groups and treated with a 35 mW laser, 100 mW laser, or no laser. Clinical severity of mucositis was assessed at four time-points by a blinded examiner. Buccal pouch tissue was harvested from a subgroup of animals in each group at four time-points. This tissue was used for immunohistochemistry for cyclooxygenase-2 (COX-2), vascular endothelial growth factor (VEGF), and factor VIII (marker of microvessel density) and the resulting staining was quantified. MAIN RESULTS: Peak severity of mucositis was reduced in the 35 mW laser group as compared to the 100 mW laser and control groups. This reduced peak clinical severity of mucositis in the 35 mW laser group was accompanied by a significantly lower level of COX-2 staining. The 100 mW laser did not have an effect on the severity of clinical mucositis, but was associated with a decrease in VEGF levels at the later time-points, as compared to the other groups. There was no clear relationship of VEGF levels or microvessel density to clinical mucositis severity. CONCLUSION: The tissue response to laser therapy appears to vary by dose. Low-intensity laser therapy appears to reduce the severity of mucositis, at least in part, by reducing COX-2 levels and associated inhibition of the inflammatory response.

A study of actinic cheilitis treatment by two low-morbidity CO2 laser vaporization one-pass protocols.

Therapeutic approaches to chronic actinic cheilitis focus on the removal or destruction of diseased epithelium. The CO(2) laser has become an important therapeutic alternative, achieving clinical resolution in around 90% of patients. Although many laser physical parameters have been reported, some are known for their low potential for scar induction without compromising the success of the results. The aim of this clinicohistological study was to compare the therapeutic responses to two low-morbidity protocols involving a single laser pass. A total of 40 patients with chronic multicentric and microscopically proven disease were randomly submitted to two conservative CO(2) laser protocols using a bilateral comparative model. The degree of histological atypia of the epithelium was determined in 26 patients both pre- and postoperatively for both protocols. Other histological phenomena were assessed in addition to this central analysis parameter. Clinical recurrence occurred in 12.5% of patients for each protocol, together with a significant reduction in the degree of epithelial atypia (p < 0.001), which was occasionally complete. However, no difference was found between the protocols (p > 0.05). Using these morphological parameters it was not possible to determine whether postoperative epithelial atypias in part of the sample were reactive or residual in nature. A few patients may show minor postoperative lesions. Due to their potential to achieve clinical and importantly microscopic resolution, the studied protocols may be used for mild through moderate dysplastic epithelium and clinically diffuse disease.

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.

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.

A new method for hemorrhoid surgery: experimental model of diode laser application in monkeys.

OBJECTIVE: Detailed here is an experimental model in monkeys of a new approach to treat hemorrhoids using a diode laser. BACKGROUND DATA: Hemorrhoids are a common source of pain and suffering. Endovascular laser therapy for variceal veins is a method that potentially could be used in the treatment of hemorrhoids. There is currently no such method described in the literature. MATERIALS AND METHODS: Hemorrhoids were induced in monkeys by ligation of the inferior hemorrhoidal vein, similar to their cause in humans. After the piles were identified, laser fibers were introduced into them, and they were irradiated with laser energy (810 nm at 1-2 W in 1-sec pulses of 1-2 J each, for a total fluency of 4-10 J). RESULTS: The piles were completely reduced, and histological examination performed 10 d post-surgery showed reduction of the dilated vessels and complete healing. The laser energy was not delivered directly into the veins, but instead to the surrounding submucosal interstitial tissue, effectively reducing the hemorrhoids. CONCLUSION: The diode laser energy delivered into the hemorrhoids led to their complete resolution. Further clinical trials using this protocol must be carried out to determine its applicability to human hemorrhoids.

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.

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.

Hemorrhoids: an experimental model in monkeys.

PURPOSE: Hemorrhoids are a matter of concern due to a painful outcome. We describe a simple, easy and reliable experimental model to produce hemorrhoids in monkeys. METHODS: 14 monkeys (Cebus apella) were used. After general anesthesia, hemorrhoids were induced by ligation of the inferior hemorrhoidal vein, which is very alike to humans. The vein was located through a perianal incision, dissected and ligated with a 3-0 vicryl. The skin was sutured with a 4-0 catgut thread. Animals were kept in appropriate cages and evaluated daily. RESULTS: Nine days later there were hemorrhoidal piles in the anus in fifty percent (50%) of the animals. Outcome was unremarkable. There was no bleeding and all animals showed no signs of pain or suffering. CONCLUSION: This is an affordable and reliable experimental model to induce hemorrhoids for experimental studies.

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.