Adriana Pertille

Evaluation of muscle regeneration in aged animals after treatment with low-level laser therapy

BACKGROUND The aging process and its associated morphophysiological changes trigger a reduction in the regenerative ability of the satellite cells, a reduction of vascular tissue and an increase in the production of fibroblasts, developing a cellular environment unfavorable for muscle regeneration. OBJECTIVE The aim of this study was to evaluate the effect of low-level laser therapy on the muscle regeneration of old experimental rat models after contusion. METHOD A total of 25 old rats,18 months old, were divided into three groups: control group (CT) without treatment; injury group (IN) with muscle contusion and without treatment and laser group (LA) with contusion and low-level laser therapy, 830 nm, 30 mW e 4 J/cm². The no invasive contusion was induced in the Tibialis Anterior muscle and the samples were collected after 7 and 21 treatment sessions. The muscle was evaluated by Light Microscopy and Immunoblotting. RESULTS After 21 days of treatment there was a significant reduction in the areas of inflammation/regeneration of the LA 21 group compared to IN 21 group. The cross-sectional area of the fibers in regeneration was not statistically different between the groups. Molecular analysis showed that the content of MyoD was statistically reduced in the IN 21 group compared to the CT group. The Myogenin content was increased in the IN 21 group compared to the CT group. Ultimately, the content of TGF-β1 on the IN 21 group was higher when compared to the CT group. CONCLUSION Considering the parameters used, the laser therapy demonstrated to be effective for muscle regeneration in old rats, however only through its anti-inflammatory effect.

Low-Level Laser Therapy (LLLT) in Dystrophin-Deficient Muscle Cells: Effects on Regeneration Capacity, Inflammation Response and Oxidative Stress

The present study evaluated low-level laser therapy (LLLT) effects on some physiological pathways that may lead to muscle damage or regeneration capacity in dystrophin-deficient muscle cells of mdx mice, the experimental model of Duchenne muscular dystrophy (DMD). Primary cultures of mdx skeletal muscle cells were irradiated only one time with laser and analyzed after 24 and 48 hours. The LLLT parameter used was 830 nm wavelengths at 5 J/cm² fluence. The following groups were set up: Ctrl (untreated C57BL/10 primary muscle cells), mdx (untreated mdx primary muscle cells), mdx LA 24 (mdx primary muscle cells - LLLT irradiated and analyzed after 24 h), and mdx LA 48 (mdx primary muscle cells - LLLT irradiated and analyzed after 48 h). The mdx LA 24 and mdx LA 48 groups showed significant increase in cell proliferation, higher diameter in muscle cells and decreased MyoD levels compared to the mdx group. The mdx LA 48 group showed significant increase in Myosin Heavy Chain levels compared to the untreated mdx and mdx LA 24 groups. The mdx LA 24 and mdx LA 48 groups showed significant increase in [Ca2+]i. The mdx group showed significant increase in H2O2 production and 4-HNE levels compared to the Ctrl group and LLLT treatment reduced this increase. GSH levels and GPx, GR and SOD activities increased in the mdx group. Laser treatment reduced the GSH levels and GR and SOD activities in dystrophic muscle cells. The mdx group showed significant increase in the TNF-α and NF-κB levels, which in turn was reduced by the LLLT treatment. Together, these results suggest that the laser treatment improved regenerative capacity and decreased inflammatory response and oxidative stress in dystrophic muscle cells, indicating that LLLT could be a helpful alternative therapy to be associated with other treatment for dystrophinopathies.

Immediate Effects of Bilateral Grade III Mobilization of the Talocrural Joint on the Balance of Elderly Women

OBJECTIVE The purpose of this study was to evaluate the immediate effects of a single treatment session of bilateral grade III mobilization of the talocrural joint on the balance of elderly women. METHODS Thirty-two elderly women (age, 65-80 years) with low physical activity levels completed balance evaluation using baropodometry, the Functional Reach Test and the Timed Up and Go Test, and plantar flexion and dorsiflexion range of motion (ROM), before and immediately after the mobilization (n = 16) or sham (n = 16). Each subject was submitted to a total of twelve 30-second grade III mobilizations, 6 for each ankle, in a single treatment session. RESULTS No significant difference was found for intragroup and intergroup comparisons in the balance of elderly women during the following evaluations: Functional Reach Test (P = .851), Timed Up and Go Test (P = .653), anteroposterior oscillation with eyes opened (P = .333) and with eyes closed (P = .652), and mediolateral oscillation with eyes opened (P = .486) and with eyes closed (P = .602). In addition, no significant difference was observed in right (P = .881) and left (P = .060) plantar flexion ROM and in right (P = .540) and left (P = .341) dorsiflexion ROM. CONCLUSION The results of this study suggest that a single session of bilateral grade III mobilization of the talocrural joint does not immediately improve balance and ROM in elderly women with low physical activity levels.

Prior swimming exercise favors muscle recovery in adult female rats after joint immobilization.

[Purpose] To evaluate the efficacy of pre-exercise on immobilization and subsequent recovery of white gastrocnemius (WG) and soleus (SOL) muscles of female rats. [Subjects and Methods] Thirty, 8-month-old, female Wistar rats were randomly and evenly allocated to six groups: sedentary (S); immobilized sedentary (IS); immobilized/rehabilitated sedentary (IRS); trained (T); immobilized trained (IT); and immobilized/rehabilitated trained (IRT). For four months, T, IT and IRT group animals performed swimming exercise (three sessions per week, 60 minutes per session), while S, IS and IRS groups animals remained housed in cages. After this period, the left hindlimb of the animals from the IS, IRS, IT and IRT groups was immobilized for five days, with the ankle at 90°. After removal of the orthosis, animals from the IRS and IRT groups followed a rehabilitation program based on swimming (five sessions per week, 60 minutes per session) for two weeks. [Results] Immobilization significantly reduced the cross-sectional area of the white gastrocnemius muscle; no changes were observed in the soleus muscles of the trained animals. Transforming growth factor-β1 protein levels were similar among the trained groups. [Conclusion] Prior swimming prevents hypotrophy of the soleus muscle after immobilization, and protein levels reflected the adaptive capacity of the skeletal muscle.

Translation of the short version of the Smartphone Addiction Scale into Brazilian Portuguese: cross-cultural adaptation and testing of measurement properties

BACKGROUND Smartphone use has been constantly increasing. Smartphone addiction can lead to changes in the emotional state and musculoskeletal system of users. To identify smartphone addicts, the Smartphone Addiction Scale-Short Version was developed; however, this scale has not been translated into Brazilian Portuguese and tested for its measurement properties. OBJECTIVE To translate and cross-culturally adapt the Smartphone Addiction Scale-Short Version into Brazilian Portuguese; to assess the internal consistency, reliability and construct validity of the scale among university students. METHODS The cross-cultural adaptation was performed following the guidelines for cross-cultural adaptation of self-report measures, and data were collected via online surveys administered to 59 university students over 18 years of age for test-retest. To test the measurement properties of the final version of the Smartphone Addiction Scale-Short Version, a convenience sample including 130 university students was used. RESULTS The Smartphone Addiction Scale-Short Version showed good reliability for test-retest scores (ICC3,1=0.82; 95% CI=0.70-0.89) and good internal consistency considering all 10 items (Cronbachs alpha=0.95). The construct validity was calculated comparing the Smartphone Addiction Scale-Short Version score to data from a questionnaire prepared by the authors of this study, including frequency per day (r=0.35; p<0.001), leisure time on the smartphone (r=0.33; p<0.001), and time working on the smartphone (r=0.18; p=0.04) that were significantly positively associated with higher Smartphone Addiction Scale-Short Version scores. The results show a high prevalence of smartphone addiction among university students (33.1%). CONCLUSION It can be concluded that the Brazilian Portuguese version of the Smartphone Addiction Scale-Short Version is a reliable and valid tool for screening smartphone addiction in university students.