Reliability and validity of the T-shirt test for the assessment of unsupported sitting in manual wheelchair users with spinal cord injury.

This study aimed to evaluate the validity and reliability of the T-shirt test (TST) in assessing sitting stability under three thigh support conditions and with timed outcomes derived in six ways among individuals with a spinal cord injury (SCI). The TST was performed five times under three thigh support conditions (85%, 55% and 25% of total thigh length) in two evaluations spaced between 7-14 days. For each thigh condition, six different outcomes were derived (average or best time from 2, 3, and 5 trial). All outcomes derivation showed excellent reliability on test day (intraclass correlation coefficient; ICC  ≥ 0.997) and excellent test-retest reliability (ICC ≥ 0.874) for each thigh support condition. The TST showed high inverse correlations with the Spinal Cord Independence Measure III (SCIM)-mobility score for all outcomes and support conditions (ρ≥-0.706), except for Best-5; moderate inverse correlations with total SCIM-total scores for most outcome derivations and support conditions (ρ≥-0.636); and a moderate inverse correlation with confidence and capacity domains of Wheelchair Skills Test-Questionnaire for most outcome derivation and support conditions (ρ≥-0.504). The TST could discriminate cervical from high and low thoracic levels of injuries under minimal thigh support condition. Overall, all the TST-derived outcomes and support conditions showed adequate validity and test-retest reliability, but Best-5 had inconsistency. Under the minimal thigh support condition, all outcome derivations except Best-3 could discriminate cervical from other injury-level groups. Although all outcome derivations and thigh support conditions provided reliable results, we recommend using the average of 3 trials under the maximal thigh support condition.

Clinical-Like Cryotherapy in Acute Knee Arthritis Protects Neuromuscular Junctions of Quadriceps and Reduces Joint Inflammation in Mice.

Rheumatoid arthritis is an autoimmune and inflammatory disease that affects synovial joint tissues and skeletal muscle. Clinical-like cryotherapy benefits signs of joint inflammation in knee osteoarthritis after 60 days of anterior cruciate ligament transection surgery. However, it is unknown whether it also benefits acute knee arthritis (e.g., reduces inflammatory process and protects neuromuscular junction [NMJ] and muscle fibers). We aimed to analyze the effects of clinical-like cryotherapy on NMJ and quadriceps muscle fibers in a model of acute knee arthritis. Twenty-four male C57BL/6 mice (20 to 25 g) were randomly allocated into three groups: control (mice with no intervention), antigen-induced arthritis (AIA; mice sensitized and immunized with intra-articular [i.a.] injection of methylated bovine serum albumin [mBSA]), and AIA+cryotherapy (mice sensitized, immunized with i.a. injection of mBSA, and submitted to a clinical-like cryotherapy protocol). Twenty-one days after sensitization, arthritis was induced in immunized mice via i.a. injection of mBSA (100 µg/joint). Two clinical-like cryotherapy sessions (crushed ice pack for 20 min) were applied two hours apart. The first session was applied immediately after i.a. injection of mBSA. The quadriceps was removed two hours after the second clinical-like cryotherapy session for morphological analysis of muscle fibers (cross-sectional area), frequency distribution of muscle fiber area (%), and NMJ (area, perimeter, and maximum diameter). Gene expressions of mRNA involved in NMJ signaling (γ-nAChR, α1-nAChR, ε-nAChR, Agrin-MusK-Rapsyn, α-dystrobrevin, and utrophin) and atrophy (muscle RING-finger protein-1 and Atrogin-1) pathways were analyzed. Inflammatory signs were assessed in knee joint (swelling, articular surface temperature, and neutrophil migration in synovial fluid). Regarding morphological analysis of muscle fibers, 180 to 270 and >270 µm2 classes were higher in the AIA+cryotherapy than the AIA group. Area, perimeter, and maximum diameter of NMJ also increased in the AIA+cryotherapy compared with the control group. Agrin mRNA expression increased in the AIA+cryotherapy compared with the control and AIA groups. In the atrophy pathway, Atrogin-1 increased compared with the control and AIA groups. The AIA+cryotherapy group reduced knee swelling and neutrophil migration compared with the AIA group. In conclusion, clinical-like cryotherapy increased Agrin expression, contributing to NMJ maintenance and increased Atrogin-1 expression, thus protecting NMJ and muscle fiber. Furthermore, clinical-like cryotherapy reduced inflammatory signs (swelling and neutrophil migration) of acute knee arthritis.

Clinical-like cryotherapy in acute knee arthritis of the knee improves inflammation signs, pain, joint swelling, and motor performance in mice.

To assess the effects of clinical-like cryotherapy on inflammatory signs (in vivo neutrophil migration, cytokines, and joint inflammation), pain, joint swelling, balance, and motor coordination in mice with knee arthritis. Young C57BL/6 mice were randomly divided into three groups (8 to 10 mice per group): Control group: mice with no intervention; antigen-induced arthritis (AIA) group: mice sensitized and immunized with intra-articular (i.a.) injection of methylated bovine serum albumin (mBSA); and AIA + cryotherapy group: mice sensitized, immunized with i.a. injection of mBSA, and submitted to a clinical-like cryotherapy protocol. After 21 days of sensitization, AIA and AIA + cryotherapy groups received i.a. injection of mBSA (100 µg/joint) to induce joint inflammation, and a clinical-like cryotherapy protocol was applied to AIA + cryotherapy group (crushed ice bag, two cryotherapy sessions of 20 min every two hours). Experimental analysis was conducted in the initial (immediately after i.a. injection of mBSA) and final periods (two hours after the second cryotherapy session). The number of synovial fluid neutrophils, cytokine levels, joint histology, pain, joint swelling, and motor performance were also analyzed. Our results showed that clinical-like cryotherapy in mice with acute knee arthritis reduced inflammatory signs, pain, and joint swelling, and improved balance and motor coordination.

Thirty days after anterior cruciate ligament transection is sufficient to induce signs of knee osteoarthritis in rats: pain, functional impairment, and synovial inflammation.

OBJECTIVE: To compare the unilateral signs of knee osteoarthritis (KOA) 30 and 60 days after anterior cruciate ligament transection (ACLT). Pain, gait function, synovial fluid inflammation, and histopathological changes in the synovial membrane were analyzed, as well as the interaction between the variables. MATERIALS AND METHODS: Male Wistar rats (n = 32; 219.2 ± 18.6 g) were randomly distributed into four groups of eight animals each. Two groups were submitted to unilateral ACLT surgery to induce KOA and analyzed after 30 (KOA30) and 60 days (KOA60). Two control groups (without surgery) were also assessed after the same time periods (C30 and C60). All the groups were evaluated before ACLT from the least to most stressful tests (skin temperature, mechanical response threshold, gait test, thermal response threshold, and joint swelling), as well as 30 and 60 days after surgery. After euthanasia, the synovial fluid and synovial membrane were collected. RESULTS: Thirty days after ACLT, KOA30 showed decrease paw print area and mechanical response threshold, higher joint swelling, skin temperature, leukocyte count, cytokine levels, and synovitis score. No differences were found between KOA30 and KOA60. CONCLUSION: Our data showed that 30 days after ACLT is sufficient to induce signs of KOA in rats, such as pain, functional impairment, and synovial inflammation, suggesting that a shorter time period can be used as an experimental model.

Energy Cost During the 6-Minute Walk Test and Its Relationship to Real-World Walking After Stroke: A Correlational, Cross-Sectional Pilot Study.

BACKGROUND: After experiencing stroke, individuals expend more energy walking than people who are healthy. However, among individuals who have experienced stroke, the correlation between the energy cost of walking, as measured by validated tests (such as the 6-minute walk test), and participation in walking, as measured by more sensitive tools (such as an ambulatory activity monitor), remains unknown. OBJECTIVE: The main objective of this study was to determine whether the energy cost of walking is correlated with participation in walking. DESIGN: This study was a correlational, cross-sectional pilot study. METHODS: Data from 23 participants who had experienced chronic stroke were analyzed. On the first day, data on oxygen uptake were collected using a portable metabolic system while participants walked during the 6-minute walk test. Then, the ambulatory activity monitor was placed on the participants' nonparetic ankle and removed 9 days later. The energy cost of walking was calculated by dividing the mean oxygen uptake recorded during the steady state by the walking speed. RESULTS: The energy cost of walking was correlated with the following: the number of steps (Spearman rank correlation coefficient [rs] = -0.59); the percentage of time spent in inactivity (rs = 0.48), low cadence (rs = 0.67), medium cadence (rs = -0.56), high cadence (rs = -0.65), and the percentages of steps taken at low cadence (rs = 0.65) and high cadence (rs = -0.64). LIMITATIONS: Individuals who were physically inactive, convenience sampling, and a small sample size were used in this study. CONCLUSIONS: Higher energy costs of walking were associated with fewer steps per day and lower cadence in real-world walking in individuals who had experienced stroke.

Ankle torque steadiness and gait speed after a single session of robot therapy in individuals with chronic hemiparesis: a pilot study.

Background: Anklebot therapy has proven to be effective in improving hemiparetic gait. However, neither ankle torque steadiness nor the relationship between changes in force control and functional tasks after therapy with Anklebot were described.Objective: To assess whether a single session of robotic therapy promotes short-term ankle adaptations that influence ankle torque steadiness and walking speed in individuals with chronic hemiparesis.Methods: A sample of participants who had residual hemiparesis deficits (hemiparesis group; n = 13) and age- and sex-matched healthy control participants (control group; n = 13). For sample characterization, balance, mobility, sensorimotor impairment, and daily living activities performance were measured.Results: Differences in functional tests were identified only when the control and hemiparesis groups (F = 29.1; p = .001) were compared during the 10-metre Walking Test. Regarding the pre- and post-robotic assistance session, no significant difference was observed for any comparison (p > .05), except for the steadiness test, as demonstrated by the standard deviation (F = 7.10; p = .01) and coefficient of variation (F = 6.20; p = .02). The hemiparesis group showed better torque steadiness during dorsiflexion post-robotic assistance therapy (p ≥ 0.02) when compared with pre-robotic assessment. Correlations were identified between steadiness and walking speed variables.Conclusion:  People with chronic hemiparesis presented short-term performance gains in torque steadiness, especially during dorsiflexion, after a single robotic therapy session. The robotic therapy did not influence the walking speed, although low to moderate correlations between torque steadiness variables and walking speed were observed.

Effects of mesenchymal stromal cells on motor function and collagen in the skeletal muscles of rats with type I diabetes.

The present study aimed to evaluate the effects of mesenchymal stromal cell (MSC) transplantation on motor function and collagen organization in the muscles of rats with type 1 diabetes mellitus. Male Wistar rats were randomly assigned to three groups: control (C), diabetic (DM) and diabetic treated with MSCs (DM-MSCs). Diabetes was induced by streptozotocin (50 µg/kg). Bone marrow cells were isolated from the tibia and femur. After 10 weeks of DM induction, the DM-MSC rats received four i.p. injections of MSCs (1 × 106). Ten weeks after MSC transplantation, motor performance was evaluated by the rotarod test and the anterior tibial (TA) muscles were collected for morphometric and quantification of collagen birefringence by polarizing microscopy analysis. Motor performance of the DM group was significantly reduced when compared to the C group and increased significantly in the DM + MSC group. The TA muscle mass was significantly reduced in the DM and DM + MSC groups compared to the C group. The connective tissue increased in the DM group compared to the C group and decreased in the DM + MSC group. The percentage collagen birefringence decreased significantly in the DM group when compared to the C group and increased in the DM + MSC group. Motor performance was positively correlated with collagen birefringence and negatively correlated with percentage of connective tissue. The results indicate that MSC transplantation improves both motor function and the collagen macromolecular organization in type 1 DM.

Different Error Size During Locomotor Adaptation Affects Transfer to Overground Walking Poststroke.

BACKGROUND: Studies in neurologically intact subjects suggest that the gradual presentation of small perturbations (errors) during learning results in better transfer of a newly learned walking pattern to overground walking. Whether the same result would be true after stroke is not known. OBJECTIVE: To determine whether introducing gradual perturbations, during locomotor learning using a split-belt treadmill influences learning the novel walking pattern or transfer to overground walking poststroke. METHODS: Twenty-six chronic stroke survivors participated and completed the following walking testing paradigm: baseline overground walking; baseline treadmill walking; split-belt treadmill/adaptation period (belts moving at different speeds); catch trial (belts at same speed); post overground walking. Subjects were randomly assigned to the Gradual group (gradual changes in treadmill belts speed during adaptation) or the Abrupt group (a single, large, abrupt change during adaptation). Step length asymmetry adaptation response on the treadmill and transfer of learning to overground walking was assessed. RESULTS: Step length asymmetry during the catch trial was the same between groups ( P = .195) confirming that both groups learned a similar amount. The magnitude of transfer to overground walking was greater in the Gradual than in the Abrupt group ( P = .041). CONCLUSIONS: The introduction of gradual perturbations (small errors), compared with abrupt (larger errors), during a locomotor adaptation task seems to improve transfer of the newly learned walking pattern to overground walking poststroke. However, given the limited magnitude of transfer, future studies should examine other factors that could impact locomotor learning and transfer poststroke.

Post-stroke BDNF Concentration Changes Following Physical Exercise: A Systematic Review.

Background: Research over the last two decades has highlighted the critical role of Brain-derived neurotrophic factor (BDNF) in brain neuroplasticity. Studies suggest that physical exercise may have a positive impact on the release of BDNF and therefore, brain plasticity. These results in animal and human studies have potential implications for the recovery from damage to the brain and for interventions that aim to facilitate neuroplasticity and, therefore, the rehabilitation process. Purpose: The aim of this study was to carry out a systematic review of the literature investigating how aerobic exercises and functional task training influence BDNF concentrations post-stroke in humans and animal models. Data Sources: Searches were conducted in PubMed (via National Library of Medicine), SCOPUS (Elsevier), CINAHL with Full Text (EBSCO), MEDLINE 1946-present with daily updates (Ovid) and Cochrane. Study Selection: All of the database searches were limited to the period from January, 2004 to May, 2017. Data Extraction: Two reviewers extracted study details and data. The methodological quality of the studies that used animal models was assessed using the ARRIVE Guidelines, and the study that evaluated human BDNF was assessed using the PEDro Scale. Data Synthesis: Twenty-one articles were included in this review. BDNF measurements were performed systemically (serum/plasma) or locally (central nervous system). Only one study evaluated human BDNF concentrations following physical exercise, while 20 studies were experimental studies using a stroke model in animals. A wide variation was observed in the training protocol between studies, although treadmill walking was the most common type of intervention among the studies. Studies were of variable quality: the studies that used animal models scored from 8/20 to 15/20 according to the ARRIVE Guidelines. The only study that evaluated human subjects scored 5/10 according to the PEDro scale and, which indicates a quality classified as "fair". Conclusions: The results of the current systematic review suggest that aerobic exercise promotes changes in central BDNF concentrations post-stroke. On the other hand, BDNF responses following functional exercises, such as reaching training and Constraint Induced Movement Therapy (CIMT), seem to be still controversial. Given the lack of studies evaluating post-stroke BDNF concentration following physical exercise in humans, these conclusions are based on animal work.

Intracerebellar microinjection of histaminergic compounds on locomotor and exploratory behaviors in mice.

The neural histaminergic system innervates the cerebellum, with a high density of fibers in the vermis and flocculus. The cerebellum participates in motor functions, but the role of the histaminergic system in this function is unclear. In the present study, we investigated the effects of intracerebellar histamine injections and H1, H2 and H3 receptor antagonist injections (chlorpheniramine, ranitidine, and thioperamide, respectively) and H4 receptor agonist (VUF-8430) on locomotor and exploratory behaviors in mice. The cerebellar vermis of male mice was implanted with guide cannula. After three days of recovery,the animals received microinjections of saline or histamine (experiment1), saline or chlorpheniramine (experiment 2), saline or ranitidine(experiment 3), saline or thioperamide (experiment 4), and saline or VUF-8430 (experiment 5) in different concentrations. Five minutes postinjection,the open field test was performed. The data were analyzed using one-way ANOVA and Duncan's post hoc test. The microinjections of histamine, ranitidine or thioperamide did not lead any behavioral effects at the used doses. In contrast, animals that received chlorpheniramine at the highest dose (0.16 nmol) and VUF-8430 at the highest dose (1.48 nmol)were more active in the open field apparatus, with an increase in the number of crossed quadrants, number of rearings and time spent in the central area of the arena, suggesting that chlorpheniramine and VUF-8430 modulates locomotor and exploratory behaviors in mice.

Electrical stimulation delays reinnervation in denervated rat muscle.

INTRODUCTION: It is not clear if electrical stimulation (ES) can affect muscle reinnervation. This study aimed to verify if ES affects neuromuscular recovery after nerve crush injury in rats. METHODS: Denervated muscles were electrically stimulated daily for 6 or 14 days. Neuromuscular performance and excitability, and muscle morphology were determined. Muscle trophism markers (atrogin-1, MuRF-1, and myoD), as well as neuromuscular junction (NMJ) organization (muscle-specific receptor tyrosine kinase [MuSK], cytoplasmic protein downstream of kinase-7 [Dok-7], nicotinic ACh receptor [nAChR], and neural cell adhesion molecule [N-CAM]) were assessed. RESULTS: ES impaired neuromuscular recovery at day 14 postdenervation. Muscle hypoexcitability was accentuated by ES at 6 and 14 days postdenervation. Although ES reduced the accumulation of atrogin-1, MuRF1, and myoD mRNAs, it increased muscle atrophy. Gene expression of MuSK, Dok-7, nAChR, and the content of N-CAM protein were altered by ES. DISCUSSION: ES can delay the reinnervation process by modulating factors related to NMJ stability and organization, and inducing dysfunction, hypoexcitability, and muscle atrophy. Muscle Nerve 56: E108-E118, 2017.

Intermittent stretching induces fibrosis in denervated rat muscle.

INTRODUCTION: Stretching (St) has been used for treating denervated muscles. However, its effectiveness and safety claims require further study. METHODS: Rats were divided into: (1) those with denervated (D) muscles, evaluated 7 or 15 days after sciatic nerve crush injury; (2) those with D muscles submitted to St during 7 or 15 days; and (3) those with normal muscles. Muscle fiber cross-sectional area, serial sarcomere number, sarcomere length, and connective tissue density were measured. MMP-2, MMP-9, TIMP-1, TGF-ß1, and myostatin mRNAs were determined by real-time polymerase chain reaction. MMP-2 and MMP-9 activity was evaluated by zymography. Collagen I was localized using immunofluorescence. RESULTS: St did not prevent muscle atrophy due to denervation, but it increased fibrosis and collagen I deposition at day 15. St also upregulated MMP-9 and TGF-ß1 gene expressions at day 7, and myostatin at day 15. CONCLUSIONS: Stretching denervated muscle does not prevent atrophy, but it increases fibrosis via temporal modulation of TGF-ß1/myostatin and MMP-9 cascades.

Effect of high-voltage electrical stimulation on the albumin and histamine serum concentrations, edema, and pain in acute joint inflammation of rats.

BACKGROUND: The mechanism by which high-voltage electrical stimulation (HVPC) acts on edema reduction is unknown. OBJECTIVE: To assess the effect of HVPC with negative polarity (-) applied to the ankle of rats with acute joint inflammation. METHOD: Sixty-four rats were divided into four groups (n=16): inflamed+HVPC(-), 0.03 mL application of ι-carrageenan (3%) to the tibiotarsal joint plus HVPC(-); inflamed+HVPC placebo, carrageenan application and HVPC placebo; normal+HVPC(-), HVPC application(-); and normal control, no intervention. The HVPC(-) 100 Hz at a submotor level was applied daily for 45 min on three consecutive days. The variables were pain, hind-foot volume, and serum histamine and albumin assessed before and during the 48 hours following inflammation. The variables were compared using the t test, one-way ANOVA, nested ANOVA for repeated measures, and the post hoc Bonferroni test. Analysis of covariance was applied to adjust the effects of HVPC(-) by measurements of pain, inflammation, albumin, and histamine at 24 h, and the final weight was compared to the other groups. The significance level was set at p<0.05. RESULTS: There were no differences between the inflamed+HVPC(-) and inflamed+HVPC placebo groups in terms of pain or edema (p>0.05). Albumin was reduced in the groups that received the intervention, but there was no differences between them. There was only a 24 hour increase in histamine with the normal+HVPC(-) (p=0.0001) and inflamed+HVPC placebo groups (p=0.01) compared to the normal control group. CONCLUSIONS: The results of the present study suggest that HVPC(-) with the parameters employed did not reduce pain or edema and did not change serum albumin or histamine levels,, which indicates the inability of this resource to have a positive effect when treating treat acute joint inflammation.

Effect of high-voltage electrical stimulation on the albumin and histamine serum concentrations, edema, and pain in acute joint inflammation of rats

BACKGROUND: The mechanism by which high-voltage electrical stimulation (HVPC) acts on edema reduction is unknown. OBJECTIVE: To assess the effect of HVPC with negative polarity (-) applied to the ankle of rats with acute joint inflammation. METHOD: Sixty-four rats were divided into four groups (n=16): inflamed+HVPC(-), 0.03 mL application of ι-carrageenan (3%) to the tibiotarsal joint plus HVPC(-); inflamed+HVPC placebo, carrageenan application and HVPC placebo; normal+HVPC(-), HVPC application(-); and normal control, no intervention. The HVPC(-) 100 Hz at a submotor level was applied daily for 45 min on three consecutive days. The variables were pain, hind-foot volume, and serum histamine and albumin assessed before and during the 48 hours following inflammation. The variables were compared using the t test, one-way ANOVA, nested ANOVA for repeated measures, and the post hoc Bonferroni test. Analysis of covariance was applied to adjust the effects of HVPC(-) by measurements of pain, inflammation, albumin, and histamine at 24 h, and the final weight was compared to the other groups. The significance level was set at p<0.05. RESULTS: There were no differences between the inflamed+HVPC(-) and inflamed+HVPC placebo groups in terms of pain or edema (p>0.05). Albumin was reduced in the groups that received the intervention, but there was no differences between them. There was only a 24 hour increase in histamine with the normal+HVPC(-) (p=0.0001) and inflamed+HVPC placebo groups (p=0.01) compared to the normal control group. CONCLUSIONS: The results of the present study suggest that HVPC(-) with the parameters employed did not reduce pain or edema and did not change serum albumin or histamine levels,, which indicates the inability of this resource to have a positive effect when treating treat acute joint inflammation. .

Neuromuscular electrical stimulation alters gene expression and delays quadriceps muscle atrophy of rats after anterior cruciate ligament transection.

INTRODUCTION: Neuromuscular electrical stimulation (NMES) is used to improve quadriceps mass after anterior cruciate ligament (ACL) injury. We studied the effect of NMES on mRNA levels of atrophy genes in the quadriceps muscle of rats after ACL transection. METHODS: mRNA levels of atrogin-1, MuRF-1, and myostatin were assessed by quantitative PCR and the polyubiquitinated proteins by Western blot at 1, 2, 3, 7, and 15 days postinjury. RESULTS: NMES minimized the accumulation of atrogenes and myostatin according to time period. NMES also prevented reduction in muscle mass in all muscles of the ACLES group at 3 days. CONCLUSIONS: Use of NMES decreased the accumulation of atrogenes and myostatin mRNA in the quadriceps muscles, inhibiting early atrophy at 3 days, although it did not prevent atrophy at 7 and 15 days after ACL transection. This study highlights the importance of therapeutic NMES interventions in the acute phase after ACL transection.

Scapular kinematics and muscle performance in a single case of Parsonage-Turner.

This study characterized the impairments of range of motion, three-dimensional scapulo-thoracic kinematics, isokinetic muscle performance and disability in a patient with Parsonage-Turner Syndrome. The patient had a history of 2.5-years of shoulder pain, and electroneurodiagnostic testing indicative of suprascapular neuropathy. The patient-rated Disabilities of the Arm, Shoulder and Hand (DASH) score was 33.3% (0 = no symptoms/disability), and reduced shoulder internal rotation, external rotation, and flexion as compared bilaterally. There were deficits in isokinetic muscle performance at slow and fast speeds during abduction, lateral and medial rotations as compared to the uninvolved side. Alterations in scapular kinematics were decreased posterior tilt, increased internal rotation, and increased upward rotation during arm elevation and lowering. This information can be used to assist clinicians in developing treatment programs to address the alterations caused by this neuralgic amyotrophy.

Effect of tibiotarsal joint inflammation on gene expression and cross-sectional area in rat soleus muscle.

BACKGROUND: Joint inflammation is a common clinical problem in patients treated by physical therapists. The hypothesis of this study is that joint inflammation induces molecular and structural changes in the soleus muscle, which is composed mainly of slow-twitch muscle fibers. OBJECTIVE: To study the effect of tibiotarsal joint inflammation on muscle fiber cross-sectional area (CSA), gene expression levels (atrogin-1, MuRF1, MyoD, myostatin, p38MAPK, NFκB, TNF-alpha), and TNF-alpha protein in the soleus muscle. METHOD: Wistar rats were randomly divided into 3 periods (2, 7 and 15 days) and assigned to 4 groups (control, sham, inflammation, and immobilization). RESULTS: In the inflammation group at 2 days, MuRF1 and p38MAPK expression had increased, and NFκB mRNA levels had decreased. At 7 days, myostatin expression had decreased. At 7 and 15 days, this group had muscle fiber CSA reduction. At 2 days, the immobilization group showed increased atrogin-1, MuRF1, NFκB, MyoD, and p38MAPK expressions and reduced muscle fiber CSA. At 7 and 15 days, myostatin mRNA levels had increased, and the CSA had decreased. The sham group showed increased p38MAPK and myostatin expressions at 2 and 7 days, respectively. No changes occurred in TNF-alpha gene or protein expression. CONCLUSION: Acute joint inflammation induces gene expression related to the proteolytic pathway without reduction in muscle fiber CSA. Chronic joint inflammation induced muscle atrophy without up-regulation of important genes belonging to the proteolytic pathway. Thus, muscle adaptation may differ according to the stage of joint inflammation, which suggests that the therapeutic modalities used by physical therapists at each stage should also be different.

Effect of low-level laser therapy (LLLT) on acute neural recovery and inflammation-related gene expression after crush injury in rat sciatic nerve.

BACKGROUND AND OBJECTIVES: Peripheral nerve function can be debilitated by different kinds of injury. Low-level laser therapy (LLLT) has been used successfully during rehabilitation to stimulate recovery. The aim of this study was to evaluate the effects of LLLT (660 nm, 60 J/cm(2) , 40 mW/cm(2) ) on acute sciatic nerve injury. MATERIALS AND METHODS: Thirty Wistar male rats were divided into three groups: (1) Normal, intact nerves; (2) I3d, crushed nerves evaluated on Day-3 post-injury; (3) I + L3d, crushed nerves submitted to two sessions of LLLT and investigated at 3 days post-injury. Sciatic nerves were removed and processed for gene expression analysis (real-time PCR) of the pro-inflammatory factors TWEAK, Fn14 and TNF-α and extracellular matrix remodeling and axonal growth markers, such as TIMP-1, MMP-2, and MMP-9. Zymography was used to determine levels of MMP-2 and MMP-9 activity and Western blotting was used to evaluate TNF-α protein content. Shapiro-Wilk and Levene's tests were applied to evaluate data normality and homogeneity, respectively. One-way ANOVA followed by Tukey test was used for statistical analysis with a significance level set at 5%. RESULTS: An increase in TNF-α protein level was found in I + L3 compared to Normal and I3d (P < 0.05). Zymography showed an increase in proMMP-9 activity, in both I3d and I + L3d groups (P < 0.05). The increase was more evident in I + L3d (P = 0.02 compared to I3d). Active-MMP-9 isoform activity was increased in I + L3d compared to Normal and I3d groups (P < 0.05). Furthermore, the activity of active-MMP-2 isoform was increased in I3d and I + L3 (P < 0.05). An increase in TIMP-1 expression was observed in both I3d and I + L3d groups (P < 0.05). CONCLUSIONS: The current study showed that LLLT increased MMPs activity, mainly MMP-9, and TNF-α protein level during the acute phase of nerve injury, modulating inflammation. Based on these results, it is recommended that LLLT should be started as soon as possible after peripheral nerve injury.

Quadriceps muscle atrophy after anterior cruciate ligament transection involves increased mRNA levels of atrogin-1, muscle ring finger 1, and myostatin.

OBJECTIVE: The aim of this study was to assess the mRNA levels of atrogin-1, muscle ring finger 1, and myostatin in rat quadriceps after anterior cruciate ligament (ACL) transection. DESIGN: Wistar rats were randomized into three different groups: ACL (surgery and ACL transection), sham (surgery without ACL transection), and control. Vastus medialis, rectus femoris, and vastus lateralis muscles were harvested at 1, 2, 3, 7, and 15 days after ACL transection. The mRNA levels of atrogin-1, muscle ring finger 1, and myostatin, as well as the ubiquitinated protein content, muscle mass, and cross-sectional area of the muscle fibers, were evaluated. RESULTS: Elevated levels of atrogin-1, muscle ring finger 1, and myostatin mRNA were detected in all tested muscles at most time points. The ubiquitinated protein content was increased at 3 days in the ACL and sham groups. The muscle mass of the ACL group was reduced at 3, 7, and 15 days (vastus lateralis and vastus medialis) and at 7 and 15 days (rectus femoris), whereas it was reduced in the sham group at 3 and 7 days (vastus lateralis and vastus medialis) and at 7 days (rectus femoris). The cross-sectional area of vastus medialis was reduced at 3, 7, and 15 days in the ACL group and at 3 and 7 days in the sham group. The cross-sectional area of the vastus lateralis was reduced at 7 and 15 days in the ACL group and at 7 days in the sham group. Whereas muscle mass and cross-sectional area recovery was noted in the sham group, no recovery was observed in the ACL group. CONCLUSIONS: Quadriceps atrophy after ACL transection involves increased levels of myostatin, atrogin-1, and muscle ring finger 1 mRNA and the accumulation of ubiquitinated protein.