Hye Rim Suh

Immediate therapeutic effect of interferential current therapy on spasticity, balance, and gait function in chronic stroke patients: a randomized control trial:

Objective: To determine whether a single trial of interferential current therapy (ICT) can immediately alleviate spasticity and improve balance and gait performance in patients with chronic stroke. Design: Randomized, placebo-controlled clinical trial. Setting: Inpatient rehabilitation in a local center. Subjects: A total of 42 adult patients with chronic stroke with plantar flexor spasticity of the lower limb. Intervention: The ICT group received a single 60-minute ICT stimulation of the gastrocnemius in conjunction with air-pump massage. In the placebo-ICT group, electrodes were placed and air-pump massage performed without electrical stimulation. Main measures: After a single ICT application, spasticity was measured immediately using the Modified Ashworth Scale (MAS), and balance and functional gait performance were assessed using the following clinical tools: Functional Reach Test (FRT), Berg Balance Scale (BBS), Timed Up and Go Test (TUG), and 10-m Walk Test (10MWT). Results: Gastrocnemius spasticity significantly decreased in the ICT group than in the placebo-ICT group (MAS: ICT vs placebo-ICT: 1.55±0.76 vs 0.40±0.50). The ICT group showed significantly greater improvement in balance and gait abilities than the placebo-ICT group (FRT: 2.62±1.21 vs 0.61±1.34, BBS: 1.75±1.52 vs 0.40±0.88, TUG: 6.07±6.11 vs 1.68±2.39, 10MWT: 7.02±7.02 vs 1.96±3.13). Spasticity correlated significantly with balance and gait abilities (P < 0.05). Conclusion: A single trial of ICT is a useful intervention for immediately improving spasticity, balance, and gait abilities in chronic stroke patients, but not for long-term effects. Further study on the effects of repeated ICT is needed.

The contribution of activated peripheral kappa opioid receptors (kORs) in the inflamed knee joint to anti-nociception.

The systemic administration of opioids can be used for their strong analgesic effect. However, extensive activation of opioid receptors (ORs) beyond the targeted tissue can cause dysphoria, pruritus, and constipation. Therefore, selective activation of peripheral ORs present in the afferent fibers of the targeted tissue can be considered a superior strategy in opioid analgesia to avoid potential adverse effects. The purpose of this study was to clarify the role of peripheral kappa opioid receptors (kORs) in arthritic pain for the possible use of peripheral ORs as a target in anti-nociceptive therapy. We administered U50488 or nor-BNI/DIPPA, a selective agonist or antagonist of kOR, respectively into arthritic rat knee joints induced using 1% carrageenan. After the injection of U50488 or U50488 with nor-BNI or DIPPA into the inflamed knee joint, we evaluated nociceptive behavior as indicated by reduced weight-bearing on the ipsilateral limbs of the rat and recorded the activity of mechanosensitive afferents (MSA). In the inflamed knee joint, the intra-articular application of 1μM, 10nM, or 0.1nM U50488 resulted in a significant reduction in nociceptive behavior. In addition, 1μM and 10nM U50488 decreased MSA activity. However, in a non-inflamed knee joint, 1μM U50488 had no effect on MSA activity. Additionally, intra-articular pretreatment with 20μM nor-BNI or 10μM DIPPA significantly blocked the inhibitory effects of 1μM U50488 on nociceptive behavior and MSA activity in the inflamed knee joint. These results implicate that peripheral kORs can contribute to anti-nociceptive processing in an inflamed knee joint.

The effects of Chamaecyparis obtusa essential oil on pain-related behavior and expression of pro-inflammatory cytokines in carrageenan-induced arthritis in rats

Chamaecyparis obtusa essential oil (COE) has been widely used to treat allergic diseases and was suggested to exert anti-inflammatory, antioxidant, and antimicrobial effects. This study evaluated the effects of COE on pain-related behavior and pro-inflammatory cytokines in rats with carrageenan (CGN)-induced arthritis. Reduced dynamic weight load on inflamed joint in voluntarily walking rats was used as the behavior test for arthritic pain; 10% COE-treated group was significantly attenuated pain (6–8 h post-CGN injection) compared to VEH (mineral oil)-treated group. In addition, the protein levels of interleukin (IL)-1β, tumor necrosis factor-α, IL-6 (6–8 h), and cyclooxygenase (COX)-2 (8 h) within the synovial membrane, as well as IL-1β, COX-2 (6–8 h), and IL-6 (5–7 h) within the meniscus, of 10% COE-treated group were significantly reduced. The current results implicate that COE has anti-inflammatory and anti-nociceptive effects on arthritis in rats. Graphical abstract Chamaecyparis obtusa have inhibitory effects on pain and inflammation in acute arthritis in rats.

Apoptotic changes in a full-lengthened immobilization model of rat soleus muscle: Apoptotic changes in a full-lengthened immobilization

Introduction: Lengthened immobilization may prevent muscle shortening, and help maintain normal muscle length. However, its apoptotic effects remain unclear. We evaluated the effects of long‐term immobilization on apoptotic proteins. Methods: Rat soleus muscles were immobilized by casting in a neutral (NEUT) or lengthened (LENG) position for 21 days. We evaluated dynamic weight load and muscle atrophy following the 21‐day period using hematoxylin and eosin staining. We measured Bax (pro‐apoptotic Bcl‐2 family member), MyoD (myogenic differentiation factor D), MYH (myosin heavy chain), and cleaved poly(ADP‐ribose)polymerase levels and examined apoptotic nucleus expression. Results: Decreased dynamic weight load and muscle atrophy changes were observed in LENG. Both NEUT and LENG showed significantly reduced levels of MYH. LENG showed a significant increase in Bax and MyoD expression as well as in the number of apoptotic nuclei. Conclusions: Long‐term lengthened immobilization may increase apoptotic changes and decrease muscle formation proteins in muscle. Muscle Nerve 59:263–269, 2019

The ratio of medial and lateral hamstring muscle thickness does not correlate with the lateral tibial rotation angle in the standing position in healthy young adults

[Purpose] To investigate the relationship between the lateral tibial rotation angle during knee joint flexion and the medial and lateral hamstring muscle thickness ratio during knee joint extension while resting, doing nothing, in upright standing position. The lateral tibial torsion is an important factor of orthopedic knee joint diseases as well as other weight bearing joint diseases such as osteoarthritis, meniscus syndrome, anterior cruciate ligament rupture, etc. [Subjects and Methods] Thirty healthy young adults participated in this study. The thickness of the medial and lateral hamstrings was measured using ultrasonographic imaging technique during knee extension in a resting position. The angle of tibial rotation was measured with 2D motion analysis during knee flexion in a half kneeling position. Pearson’s correlation coefficient was used to test the relationship. [Results] There is no significant relationship between the angle of lateral tibial rotation and the ratio of hamstring muscle thickness. [Conclusion] These results demonstrate that lateral tibial rotation is not affected by hamstrings during rest in a standing position.