Analysis of low-level laser transmission at wavelengths 660, 830 and 904 nm in biological tissue samples.

BACKGROUND: In recent decades, low-level laser therapy (LLLT) has occupied a prominent position and has been studied in various fields of knowledge, and your effects have been widely observed in studies about numerous tissues, such as tendons, peripheral nerves, cutaneous tissue, bone, and muscle, in different fields of knowledge. PURPOSE: To analyze the power transmitted by low-level laser therapy (LLLT) to different tissue samples by using distinct wavelengths. METHODS: Skin samples of rat (n = 7, 1.17-1.63 mm) and pig (n = 10; 1.20-2.30 mm); pig fat (n = 10; 2.71-14.01 mm) and pig muscle (n = 10; 1.91-8.91 mm) were analyzed and interposed between the emitter and the power analyzer sensor. All the samples were irradiated sequentially three times, at five equidistant points and average power levels of 35.34(±1.03), 32.40(±0.70), and 42.32(±0.82) mW, for the wavelengths 660, 830, and 904 nm, respectively. Transmitted radiation was measured with a power analyzer connected to a laser emitter. Statistical analysis was performed with a Shapiro-Wilk test followed by ANOVA with Tukey's post hoc test, with a significance level of 5%. RESULTS: The transmitted power of LLLT on skin, fat, and muscle of tissues decreases with the increase of thicknesses, presenting minor attenuation on rat skin, pig fat, and pig muscle for 904 nm. The pig skin has the slight attenuation for 830 nm. CONCLUSION: The LLLT should be applied after considering the transmission loss taking place in different anatomical structures, following the Beer-Lambert law and attenuation coefficient presented for more practical application in many fields.

Red and infrared laser therapy inhibits in vitro growth of major bacterial species that commonly colonize skin ulcers.

Low-level laser therapy (LLLT) is used in chronic wounds due to its healing effects. However, bacterial species may colonize these wounds and the optimal parameters for effective bacterial inhibition are not clear. The aim of this study was to analyze the effect of LLLT on bacterial growth in vitro. Bacterial strains including Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa were suspended in saline solution at a concentration of 10(3) cells/ml and exposed to laser irradiation at wavelengths of 660, 830, and 904 nm at fluences of 0 (control), 3, 6, 12, 18, and 24 J/cm(2). An aliquot of the irradiated suspension was spread on the surface of petri plates and incubated at 37 °C for quantification of colony-forming unit after 24, 48, and 72 h. Laser irradiation inhibited the growth of S. aureus at all wavelengths and fluences higher than 12 J/cm(2), showing a strong correlation between increase in fluence and bacterial inhibition. However, for P. aeruginosa, LLLT inhibited growth at all wavelengths only at a fluence of 24 J/cm(2). E. coli had similar growth inhibition at a wavelength of 830 nm at fluences of 3, 6, 12, and 24 J/cm(2). At wavelengths of 660 and 904 nm, growth inhibition was only observed at fluences of 12 and 18 J/cm(2), respectively. LLLT inhibited bacterial growth at all wavelengths, for a maximum of 72 h after irradiation, indicating a correlation between bacterial species, fluence, and wavelength.

The forearm positioning changes electromyographic activity of upper limb muscles and handgrip strength in the task of pushing a load cart.

The aim of the present study was to analyse the electromyographic activity of the upper limb muscles as well as the handgrip strength during the activity of pushing a load cart. Eighteen healthy male right-handed volunteers (21.50 ± 2.77 years old) took part in the study. Electrodes were placed on upper trapezius fibres, brachial biceps, brachial triceps, and extensors and flexors of wrist and fingers. The original handle of the load cart was replaced by two handgrip systems mounted on load cells, thus allowing the handgrip strength to be measured according to the wrist position variation, that is, wrists in neutral position with pronated forearm (WN-PF) or in ulnar deviation with forearm in neutral position (WUD-NF). The signals generated by the load cells during manoeuvre of the load cart and the electromyographic signals were simultaneously captured. Signal processing was performed by using a specific routine developed for analysis of root mean square (RMS) and median frequency (MF). Greater handgrip strength occurred in WN-PF position. In maximal isometric contraction, the RMS of the flexors and extensors showed greater electromyographic activity in WN-PF (intra-muscles) and extensors position (inter-muscles). Decreased handgrip strength in the latter stages of the circuit, with variation of the RMS and MF of all muscles tested. One can conclude that electromyographic activity and handgrip strength are both affected during the phases of an elliptical displacement of the load cart.

Blue Laser Inhibits Bacterial Growth of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa.

OBJECTIVE: The purpose of this study was to analyze the influence of blue laser on bacterial growth of the main species that usually colonize cutaneous ulcers, as well as its effect over time following irradiation. BACKGROUND DATA: The use of blue laser has been described as an adjuvant therapeutic method to inhibit bacterial growth, but there is no consensus about the best parameters to be used. METHODS: Strains of Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, and Escherichia coli ATCC 25922 were suspended in saline solution at a concentration of 1.5×10(3) colony forming units (CFU)/mL. Next, 300 µL of this suspension was transferred to a microtitulation plate and exposed to a single blue laser irradiation (450 nm) at fluences of 0 (control), 3, 6, 12, 18, and 24 J/cm(2). Each suspension was spread over the surface of a Petri plate before being incubated at 37°C, and counts of CFU were determined after 24 and 48 h. RESULTS: Blue laser inhibited the growth of S. aureus and P. aeruginosa at fluences >6 J/cm(2). On the other hand, E. coli was inhibited at all fluences tested, except at 24 J/cm(2). CONCLUSIONS: Blue laser light was capable of inhibiting bacterial growth at low fluences over time, thus presenting no time-dependent effect.

Abdominal muscle strength is related to the quality of life among older adults with lumbar osteoarthritis.

The aim of the present study was to determine the association between abdominal muscle strength and quality of life among older adults with lumbar osteoarthritis. A blind, cross-sectional study was conducted involving 40 older adults: 20 with lumbar osteoarthritis (12 women and 8 men, mean age of 65.90 ± 4.80 years) and 20 controls (14 women and 6 men, mean age of 67.90 ± 4.60 years). The volunteers were submitted to an abdominal muscle strength test. Quality of life was evaluated using the SF-36 questionnaire. Both abdominal muscle strength and quality of life scores were significantly lower in the group with lumbar osteoarthritis in comparison to the controls (p < 0.05). Moreover, significant and positive associations were found between abdominal muscle strength and the subscales of the SF-36 questionnaire (p < 0.05, 0.421 ≥ rs ≤ 0.694). Based on the present findings, older adults with lumbar osteoarthritis with greater abdominal muscle strength have a better quality of life.

Polarized currents inhibit in vitro growth of bacteria colonizing cutaneous ulcers.

Infections caused by Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli are among the microorganisms that often lead to infection in pressure ulcers. Polarized current has emerged as a possible intervention to limit bacterial proliferation. We analyzed the effect of fixed diphasic - Bernard (FD-B) and high voltage monophasic pulsed (HVMP) currents on bacteria S. aureus ATCC 25923 (Gram +), P. aeruginosa ATCC 27853 (Gram -), and E. coli ATCC 25922 (Gram -). After the bacterial strains were activated the bacteria were suspended in physiological solution (0.9%) and the concentration adjusted to 1.5 × 10(3) CFU/mL. The cultures were stimulated with FD-B current at (3, 6, and 9 mA, 100 Hz, 15 and 30 minutes) and HVMP (32, 64, and 95 V, 100 Hz, 30 and 60 min) while monitoring the pH and temperature. After the stimulation, the suspensions were plated and incubated for 24 hours at 37°C. Then the counts were made of colony forming units (CFU). Data were submitted to normality Shapiro-Wilk test followed by nonparametric ANOVA test and post hoc Tukey test with p < 0.05. There was a decrease in the CFU for the two currents, but the most effective reduction was in FD-B. The temperature remained constant and the pH measured alkaline at the negative pole and acid at the positive pole during stimulation. The application of FD-B and HVMP currents promoted inhibition of bacterial proliferation when stimulated in vitro, acting as an adjuvant resource in the healing process.

Avaliação da eficácia das medidas preventivas do linfedema secundário ao tratamento cirúrgico do câncer de mama / Association of the lymphedema appearance with the acomplishment of the prophylactic measures

O linfedema é um problema quantitativo entre o fluxo linfático produzido e a capacidade de transporte. O risco está associado a esvaziamento e radioterapia axilar; idade; número de linfonodos dissecados e positivos; nível de retirada dos linfonodos; obesidade; extensão da técnica cirúrgica e infecção. Medidas preventivas são adotadas rotineiramente no pós-operatório, na orientação dessas pacientes. Entretanto, não há comprovação científica, questionando-se então, a eficácia dessas medidas na sua prevenção. Objetivo: objetivou-se neste estudo analisar a associação do aparecimento do finfedema com o cumprimento das medidas preventivas. Métodos: foram utilizadas 50 mulheres, tendo realizado cirurgia por câncer de mama há pelo menos 1 ano. As pacientes responderam a um questionário a fim de conhecer se as medidas preventivas geralmente orientadas no pós-operatório, como não tirar a cutícula, raspar ou depilar a axila, expor braço ao sol; tirar sangue; tomar injeção vacina ou medir a pressão; carregar peso; usar luvas paras lavar louças, roupas ou mexer no jardim; não se ferir, queimar; não fazer atividades com peso e não ser picada por insetos, eram seguidas. Resultados/conclusão: os resultados demonstraram estatisticamente que as variáveis analisadas não se relacionam com o aparecimento do linfedema.

The lymphedema is a quantitative problem between the produced lymphatic flow and the capacity of transportation. The risk is associated with to the axillary dissection and armpit radiotherapy, age, number of dissected lymphonodes and positive ones, level of withdrawal, obesity, extension of surgical technique and infection. prophylactic measures routinely adopted on the post operation, due to the necessity of information from these patients. However there’s no scientific affirmative, so it’s questioned the efficacy of these prevention measures. Objective: It was objectified on this study to analyse the association of the lymphedema appearance with the accomplishment of the prophylactic measures. Methods: There were used 50 women, that went through the breast cancer surgery at, at least 1 (one) year. The referred patients answered a questionnaire with the purpose of knowing if the prophylactic measures generally oriented in the post operative as not to go to the manicure, shave or wax the armpit, expose the arm to the sunlight, blood withdrawal,have shots, vaccines, or measure the blood pressure on the surgically treated arm, lift weight, use gloves to do the dishes, do the laundry and to do yard work, not to injure yourself, or not to burn yourself, not to do activities with heavy weight, and not to be bitten by bugs were followed. Results/Conclusion: The results show statistically that the analyzed variables aren’t related to the appearance of the lymphedema