Laser Therapy as a Preventive Approach for Oral Mucositis in Cancer Patients Undergoing Chemotherapy: The Potential Role of Superoxide Dismutase.

PURPOSE: Oral mucositis is a painful condition that occurs in patients who undergo chemotherapy. Due to the worsening of oral mucositis, the patient may progress to a worse clinical condition and interrupt antineoplastic treatment. There is little literature on low-power laser therapy in chemotherapy for other solid tumors. The purpose of this study was to investigate whether low-level laser therapy (LLLT) applied before chemotherapy could prevent oral mucositis in patients with solid tumors. METHODS: Laser therapy was applied at a frequency of 630nm, with a dose of 2J / cm2, for the prevention of oral mucositis induced by chemotherapy specifically for non-hematological tumors. Epidemiological data, total neutrophils, general side effects, development of oral mucositis and degree, and the performance of low-power laser therapy to prevent oral mucositis were collected. The involvement of oxidative stress was evaluated by the enzyme superoxide dismutase (SOD) through blood samples, before and after chemotherapy treatments. RESULTS: LLLT in the proposed protocol is efficient in reducing the development of oral mucositis (only at grade I/II) in patients under chemotherapy and able to reduce the severity of oral mucosal lesions, in patients who developed mucositis after the use of the laser for prevention. All individuals who underwent LLLT protocol did not show a significant reduction of SOD activity after the last chemotherapy cycle. CONCLUSIONS: The prophylactic laser therapy protocol proposed by the study, defined at a frequency of 630nm, a dose of 2J / cm2, demonstrated the ability to decrease the occurrence of oral mucositis in patients undergoing chemotherapy protocols to solid tumors. This effect could be related to preserved SOD activity, as it was observed that oral mucositis is related to leukopenia and reduced SOD activity and LLLT protocol prevented the decrease of SOD activity.

High-frequency transcutaneous electrical nerve stimulation reduces pain and cardio-respiratory parameters in an animal model of acute pain: participation of peripheral serotonin.

The objective of this study was to investigate the effect of high-frequency transcutaneous electrical nerve stimulation (HF-TENS) in antihyperalgesia, assessed through changes of sciatic nerve activity and its effects on cardiorespiratory parameters, using formalin-induced nociception in anesthetized rats. The animals were divided into formalin (FORM) and HF-TENS groups. All rats received injections of 5% formalin (50 µl, right hind-paw). The sciatic nerve activity and cardiopulmonary parameters (mean arterial pressure, heart rate, and respiratory frequency) were measured, and then the serum levels of serotonin (5-HT) were determined by an enzyme-linked immunosorbent assay kit. The formalin injection was able to increase the sciatic nerve activity, heart rate, and respiratory frequency. The treatment with HF-TENS significantly reduced the sciatic nerve activity and respiratory frequency 20 minutes after formalin injection and was able to increase serum 5-HT. Furthermore, when comparing the groups, reductions in the mean arterial pressure, heart rate, respiratory frequency, and sciatic nerve activity were shown at different times. Thus, we concluded that HF-TENS was capable of inducing analgesia, which was most likely related to increased serotonin release. Moreover, we demonstrated that TENS was able to block the adverse cardiovascular and respiratory changes induced by pain. Further neurophysiological studies are necessary to clarify the intrinsic mechanisms underlying HF-TENS-induced analgesia.

Raloxifene reduces blood pressure in hypertensive animals after ovarian hormone deprivation.

Raloxifene is a selective oestrogen receptor modulator that has been approved for the prevention and treatment of osteoporosis in post-menopausal women. Studies have revealed several effects of raloxifene on the cardiovascular system, which might contribute to the blood pressure regulatory mechanisms, particularly in the systemic arterial hypertension. Therefore, the aim of this study was to investigate the effects of raloxifene on the blood pressure, renal excretion of water and Na(+) and plasma nitrite/nitrate levels in 2-kidney-1-clip (2K1C) hypertensive female rats. The groups were as follows: hypertensive (2K1C), hypertensive ovariectomized (2K1C + OVX) and hypertensive ovariectomized treated with raloxifene (2K1C + OVX + R). Seven days after the surgery that produced menopause, 2K1C hypertension was produced in anaesthetized animals. Seven days after the clip application, the rats were put into metabolic cages to allow for the measurement of water ingestion and diuresis, and raloxifene was administered (2 mg/kg/day i.p., for 7 more days). We found a large reduction (p < 0.01) in mean arterial pressure (197 ± 6 to 164 ± 2 mmHg), an increase in renal excretion of sodium and water (p < 0.05) and an increase in plasma levels of nitrite/nitrate in 2K1C + OVX + R animals, when compared with the 2K1C (23.4 ± 1 versus 14 ± 0.5 nmol/mL; p < 0.01, respectively). These findings suggest that raloxifene exerted its antihypertensive effect, at least in part, by improving the renal excretion of sodium and water.

Combined use of low level laser therapy and cyclooxygenase-2 selective inhibition on skin incisional wound reepithelialization in mice: a preclinical study.

BACKGROUND: Low level laser therapy and cyclooxygenase-2 (ICOX2) selective inhibitors have been widely used to modulate inflammatory response; however, their effect on wound reepithelialization are not well understood. OBJECTIVE: To evaluate the isolated and combined effects of low level laser therapy and ICOX2 in the reepithelization of skin incisional wounds in mice. METHODS: We induced a 1-cm wound on the back of each mouse, which were divided into four groups (N = 20): control, laser therapy, treated with celecoxib and combined therapy. The animals in the celecoxib and combined therapy groups were treated with celecoxib for 10 days before skin incision. The experimental wounds were irradiated with He-Ne low power laser (632nm, dose: 4J/cm2) in scanning for 12 seconds during three consecutive days in the laser therapy and combined therapy groups. The animals were sacrificed 3 days after surgery. Samples of the wounds were collected and stained (Masson's Trichrome) for histomorphometric analysis. RESULTS: Both the laser therapy group and the celecoxib group showed an increase in skin reepithelialization compared to the control group; however, the combined therapy group showed no differences. As for keratinization, the laser therapy and combined therapy groups showed a reduction in keratinocytes compared with the control group. CONCLUSION: The results show that the use of low level laser therapy and ICOX2 in isolation increases epithelial cells, but only low level laser therapy reduced skin keratinocytes. The combined treatment restores innate epithelialization and decreases keratinization in spite of accelerating wound contraction with improvement in the organization of the wound in the skin of mice.

Uso combinado da laserterapia de baixa potência e da inibição da ciclooxigenase-2 na reepitelização de ferida incisional em pele de camundongos: um estudo pré-clínico / Combined use of low level laser therapy and cyclooxygenase-2 selective inhibition on skin incisional wound reepithelialization in mice: a preclinical study

FUNDAMENTOS: A laserterapia de baixa potência e os inibidores seletivos da ciclooxigenase-2 (ICOX2) vem sendo muito utilizados para modular a resposta inflamatória, entretanto, os seus efeitos na reepitelização de feridas não são bem compreendidos. OBJETIVO: Avaliar os efeitos isolados e combinados da laserterapia de baixa potência e da ICOX2 na reepitelização de ferida incisional na pele de camundongos. MÉTODO: Foi induzida uma ferida de 1 cm no dorso de cada camundongo, que foram divididos em quatro grupos (N=20): Controle, Laserterapia, Tratados com celecoxib e Terapia conjugada. Os animais dos grupos celecoxib e Terapia conjugada foram tratados com celecoxib por 10 dias antes da incisão cutânea. As feridas experimentais foram irradiadas com laserterapia de baixa potência He-Ne (632nm, dose: 4J/cm2) em varredura, por 12 segundos durante três dias consecutivos nos grupos Laserterapia e Terapia conjugada. Os animais foram sacrificados no 3º dia de pós-operatório. Amostras das feridas foram coletadas e coradas (Tricromio de Masson) para análise histomorfométrica. RESULTADOS: Tanto o grupo Laserterapia, quanto o grupo celecoxib, mostrou aumento da reepitelização cutânea em relação ao grupo Controle, entretanto, o grupo Terapia conjugada não apresentou diferenças. Quanto à queratinização o grupo Laserterapia e Terapia conjugada apresentaram redução dos queratinócitos, comparados com o grupo Controle. CONCLUSÕES: Os resultados mostram que o uso da laserterapia de baixa potência e da ICOX2 isoladamente aumentam as células epiteliais, mas somente a laserterapia de baixa potência reduziu os queratinócitos cutâneos. O tratamento conjugado restabelece a reepitelização inata e dimunui a queratinização, embora ocorra uma acelerada contração da ferida com melhora na organização da ferida na pele de camundongos.

BACKGROUND: Low level laser therapy and cyclooxygenase-2 (ICOX2) selective inhibitors have been widely used to modulate inflammatory response; however, their effect on wound reepithelialization are not well understood. OBJECTIVE: To evaluate the isolated and combined effects of low level laser therapy and ICOX2 in the reepithelization of skin incisional wounds in mice. METHODS: We induced a 1-cm wound on the back of each mouse, which were divided into four groups (N = 20): control, laser therapy, treated with celecoxib and combined therapy. The animals in the celecoxib and combined therapy groups were treated with celecoxib for 10 days before skin incision. The experimental wounds were irradiated with He-Ne low power laser (632nm, dose: 4J/cm2) in scanning for 12 seconds during three consecutive days in the laser therapy and combined therapy groups. The animals were sacrificed 3 days after surgery. Samples of the wounds were collected and stained (Masson's Trichrome) for histomorphometric analysis. RESULTS: Both the laser therapy group and the celecoxib group showed an increase in skin reepithelialization compared to the control group; however, the combined therapy group showed no differences. As for keratinization, the laser therapy and combined therapy groups showed a reduction in keratinocytes compared with the control group. CONCLUSION: The results show that the use of low level laser therapy and ICOX2 in isolation increases epithelial cells, but only low level laser therapy reduced skin keratinocytes. The combined treatment restores innate epithelialization and decreases keratinization in spite of accelerating wound contraction with improvement in the organization of the wound in the skin of mice.

Diferenças de gênero no limiar sensitivo para estimulação elétrica nervosa em adultos jovens / Gender differences in the sensitive threshold to electrical nerve stimulation in young adults

OBJETIVO: Investigar diferenças de gênero no limiar neuronal sensitivo (LNS) para estimulação elétrica nervosa transcutânea (TENS) entre adultos jovens, e os presumíveis efeitos da termoterapia prévia. MÉTODOS: Foram divididos por gênero, 30 estudantes jovens sadios (15 homens e 15 mulheres entre 6/11 ciclo estral) com 22±2 anos de idade. TENS foi aplicada simultaneamente nos joelhos direito e esquerdo dos sujeitos com frequência de 20 Hz e duração de pulso 230µs. A amplitude da corrente elétrica (mǺ) foi aumentada gradativamente para registro do limiar de percepção (LS) e tolerância (LT), antes/após termoterapia. O aquecimento no joelho-D foi realizado por luz infravermelha (250 W) à 0≈70 cm perpendicularmente, e o resfriamento do joelho-E por compressa de gelo, ambos realizados durante 15 minutos. A temperatura tecidual foi registrada por termometria digital. Os dados foram analisados e diferenças estabelecidas em p<0.05. RESULTADOS: A temperatura tecidual após termoterapia foi diferente (p<0.05) entre gêneros. No LS basal para TENS não houve diferenças entre gêneros, porém, a termoterapia alteou o LS em ambos os sexos. O LT basal foi menor (p<0.05) em mulheres, entretanto, após a termoterapia aumentou (p<0.05) em ambos os sexos. CONCLUSÃO: Os LNS para TENS são gênero-termo-dependentes em jovens sadios.

OBJECTIVE: To investigate gender differences in neuronal sensory threshold (NS) for transcutaneous electrical nerve stimulation (TENS) among young adults, and the probable effects of thermotherapy. METHODS: 30 young healthy students (15 men and 15 women) with 22±2 years old were divided by gender. TENS was applied in both right and left knees of subjects with a frequency of 20 Hz and pulse duration of 230µs. The amplitude of the electric current (mǺ) was gradually increased to record the perception threshold (ST) and tolerance threshold (TT), before/after thermotherapy. The warm R-knee was performed by infrared light (250W) ≈70cm perpendicular, and cooling L-knee with icepack, both carried out for 15 minutes. The tissue temperature was recorded by digital thermometry. The data were analyzed and differences established at p<0.05.RESULTS: The tissue temperature after heat treatments was different (p≤0.05) between genders. The basal ST for TENS was not different between genders, however, thermotherapy raised the NS in both men and women. At the baseline TT was lower (p ≤0.05) in women, however, after thermotherapy it increased (p≤0.05) in both sexes. CONCLUSION: Neuronal sensory threshold for TENS is gender- thermo-dependent in healthy young adults

Alterações morfofuncionais musculares em resposta ao alongamento passivo em modelo animal de imobilização prolongada de membro posterior / Muscle morphological changes in response to passive stretching in an animal model of prolonged immobilization of hind limb

INTRODUÇÃO: O alongamento passivo ou estático (EAL) é frequentemente utilizado em programas de reabilitação e na área desportiva; porém, as alterações morfofuncionais ocorridas ainda não estão bem claras, principalmente após imobilização prolongada. OBJETIVOS: Examinar as alterações morfofuncionais musculares produzidas em resposta a três semanas de exercícios de EAL em um modelo animal de imobilização prolongada de membro posterior (MP) em posição encurtada. MÉTODOS: Foram utilizados 32 ratos Wistar divididos em quatro grupos (n = 8, em cada): A - grupo controle (CONT), B - grupo imobilizado por 21 dias (IMOB), C - grupo remobilizado por 21 dias (LIVRE), D - grupo alongados por 21 dias (ALONG). Foram comparadas as variações morfofuncionais entre grupos experimentais. As variáveis foram: peso corporal e muscular, comprimento muscular e ósseo, número de miofibrilas e quantidade de colágeno, determinadas através de histomorfometria muscular por contraste de cor. RESULTADOS: A IMOB do bíceps femoral em posição encurtada produziu uma importante hipotrofia com hiperplasia muscular compensatória, além do aumento (p < 0,05) na deposição de colágeno no perimísio e intramuscular de ratos. A remobilização livre ou o alongamento passivo reduziram significativamente (p < 0,05) estas alterações morfofuncionais observados no grupo IMOB. CONCLUSÃO: Através desses resultados, pode-se concluir que tanto o EAL quanto a remobilização livre promovem a restauração das alterações morfofuncionais no bíceps femoral esquerdo induzida pela imobilização prolongada, embora somente o EAL foi capaz de reduzir a relação entre colágeno/músculo.

BACKGROUND: Passive or static stretching (ALMP) is often used in rehabilitation programs and in sports; however, the morphological changes occurred are not very clear, especially after prolonged immobilization. AIMS:This study aimed to examine the muscle morphological and functional changes produced in response to three weeks of ALMP in an animal model of prolonged immobilization of hind limb (HL) in the short range. METHODS: For this purpose, 32 rats (Wistar) were used and divided in 4 groups (n = 8 each): A- control group (CONT), B - immobilized group for 21 days (IMMOB), C - remobilized group for 21 days (FREE), D - elongated group for 21 days (ELONG). The variables evaluated were body weight and muscle mass, muscle and bone length, number of myofibrils and quantity of collagen, determined by histomorphometry muscle by color contrast. The morphological variations between all the experimental groups were compared. RESULTS: The IMMOB of the femoral biceps in shortened position produced important muscular atrophy with compensatory hyperplasia, and increase (p <0.05) in collagen deposition in the perimysium and intramuscular of rats. The free remobilization and the passive stretching reduced significantly (p <0.05) these morphological changes observed in group IMMOB. CONCLUSIONS: Based on these results, it was concluded that both passive stretch and free remobilization promote restoration of the morphological changes induced by prolonged immobilization in the left femoral biceps of rats; however only passive stretching was able to reduce the correlation between collagen/muscle.