Machine Learning-Based Identification of Diagnostic Biomarkers for Korean Male Sarcopenia Through Integrative DNA Methylation and Methylation Risk Score: From the Korean Genomic Epidemiology Study (KoGES).

BACKGROUND: Sarcopenia, characterized by a progressive decline in muscle mass, strength, and function, is primarily attributable to aging. DNA methylation, influenced by both genetic predispositions and environmental exposures, plays a significant role in sarcopenia occurrence. This study employed machine learning (ML) methods to identify differentially methylated probes (DMPs) capable of diagnosing sarcopenia in middle-aged individuals. We also investigated the relationship between muscle strength, muscle mass, age, and sarcopenia risk as reflected in methylation profiles. METHODS: Data from 509 male participants in the urban cohort of the Korean Genome Epidemiology Study_Health Examinee study were categorized into quartile groups based on the sarcopenia criteria for appendicular skeletal muscle index (ASMI) and handgrip strength (HG). To identify diagnostic biomarkers for sarcopenia, we used recursive feature elimination with cross validation (RFECV), to pinpoint DMPs significantly associated with sarcopenia. An ensemble model, leveraging majority voting, was utilized for evaluation. Furthermore, a methylation risk score (MRS) was calculated, and its correlation with muscle strength, function, and age was assessed using likelihood ratio analysis and multinomial logistic regression. RESULTS: Participants were classified into two groups based on quartile thresholds: sarcopenia (n = 37) with ASMI and HG in the lowest quartile, and normal ranges (n = 48) in the highest. In total, 238 DMPs were identified and eight probes were selected using RFECV. These DMPs were used to build an ensemble model with robust diagnostic capabilities for sarcopenia, as evidenced by an area under the receiver operating characteristic curve of 0.94. Based on eight probes, the MRS was calculated and then validated by analyzing age, HG, and ASMI among the control group (n = 424). Age was positively correlated with high MRS (coefficient, 1.2494; odds ratio [OR], 3.4882), whereas ASMI and HG were negatively correlated with high MRS (ASMI coefficient, -0.4275; OR, 0.6521; HG coefficient, -0.3116; OR, 0.7323). CONCLUSION: Overall, this study identified key epigenetic markers of sarcopenia in Korean males and developed a ML model with high diagnostic accuracy for sarcopenia. The MRS also revealed significant correlations between these markers and age, HG, and ASMI. These findings suggest that both diagnostic models and the MRS can play an important role in managing sarcopenia in middle-aged populations.

Effects of Exercise on Physical Function and Quality of Life in Prostate Cancer Patients Receiving Androgen Deprivation Therapy: High-Intensity Interval Training versus Moderate-Intensity Continuous Training.

INTRODUCTION: We assessed the effects of exercise on the physical function and health quality of life (hQoL) in prostate cancer patients underwent androgen deprivation therapy (ADT). Additionally, the effects of high-intensity interval training (HIIT) on the physical function and hQoL in these patients were compared with those of moderate-intensity continuous training (MICT). METHODS: Seventeen prostate cancer patients who underwent ADT were prospectively allocated to either HIIT (n = 9) or MICT (n = 8). In these patients, physical function and hQoL were measured before and after 12 weeks of exercise and 3-6 months after the exercise program, respectively. RESULTS: Although the whole-body total mass significantly increased after the exercise program, it was equivalent regardless of the exercise methods. After the exercise program, muscle strength and endurance improved and tended to be maintained until 3-6 months later. Improvement in muscle endurance was more prominent after HIIT, and that in muscle strength was more prominent after MICT. Performance in the senior fitness test improved after the exercise program, and HIIT was more effective for lower and upper muscle endurance and flexibility, although MICT was more effective for the others. The hQoL significantly improved 3-6 months after the exercise program. CONCLUSION: The 12-week exercise program has a positive effect on the physical function and hQoL in prostate cancer patients who underwent ADT. In these patients, compared with MICT, HIIT may be a better option for improving muscle endurance, which is thought to be significant for preventing falls and fractures in elderly patients.

Corrigendum to "Physical activity in the era of climate change and COVID-19 pandemic: Results from the South Korea's 2022 Report Card on physical activity for children and adolescents" [J Exercise Sci Fitness 21(1) (2023) 26-33].

[This corrects the article DOI: 10.1016/j.jesf.2022.10.014.].

Physical activity in the era of climate change and COVID-19 pandemic: Results from the South Korea's 2022 Report Card on physical activity for children and adolescents.

Background: With intensifying air pollutant levels and the COVID-19 pandemic, physical inactivity of South Korean children and adolescents may be threatened. Therefore, monitoring and surveillance of physical activity (PA) and relevant indicators are important for policy making pertaining to health promotion. Report Card is a third comprehensive evaluation of PA-related behaviors among and the sources of influence for South Korean children and adolescents. Purpose: To provide the outcome of the South Korea's 2022 Report Card on PA for children and adolescents. Methods: Based on a variety of sources including national surveys collected pre- and during-COVID-19 and information collected from government webpages, 11 indicators were graded by a committee of experts informed by the best available evidence. Data from during-COVID-19 were available for Overall PA, Sedentary Behavior, and Sleep and considered together in generating the overall grades. Results: Grades were assigned to behavioral indicators (Overall PA: D-; Active Transportation: B+; Sedentary Behavior: D; Sleep: F) and sources of Influence (Family and Peers: C-; School: A; Community and Environment: B-; Government: A). Organized Sport and PA, Active Play, and Physical Fitness could not be graded due to the lack of data. The results largely indicated that children and adolescents show unfavorable behavioral grades even with favorable grades observed for the sources of influence indicators. Trivial differences were observed pre- and during-pandemic for Overall PA (≥60 min of MVPA for ≥4 d/wk: 20.8% vs 19.9%) and Sleep (met age-specific recommendation: 14.1% vs 15.0%); however, a marked increase in Sedentary Behavior was observed (≤2 h/d screen time: 28.8% vs 20.1%). A stark weekday vs weekend difference was observed in sleep duration. In terms of PA related sources of influence, high accessibility to PA facilities (81.1%) and high satisfaction of neighborhood public transit (74.6%) and safety (80.7%) were well reflected in our Active Transportation grade (B+). Nonetheless, perception of green environments including outdoor air quality (44.0%), noise (39.6%) and green space (56.5%) showed lower scores, suggesting that new barriers to active lifestyles are emerging for South Korean children and adolescents. Gender differences were also observed for overall PA (≥60 min of MVPA for ≥4 d/wk: 29.1% for boys vs 11.3% for girls) and sleep (met age-specific recommendations: 17.3% for boys vs 11.4% for girls), but not for sedentary behavior (≤2 h/d screen time: 26.4% for boys and 24.9% for girls). Conclusions: Government and school policies/programs and the built environment are, in general, conducive to physically active lifestyles for South Korean children and adolescents; however, behavioural indicators received poor grades except for Active Transportation. A thorough evaluation of policies/programs at government, local, and school levels is needed to ensure that the efforts to have PA-enhancing infrastructure and systems are actually being translated into the behavior of children and adolescents in South Korea. Furthermore, improving PA surveillance, monitoring, and advocacy to ultimately establish healthy lifestyle patterns among children and adolescents is a top priority.

Differences in salient beliefs associated with voluntary exercise training among South Korean firefighters before and after COVID-19.

BACKGROUND: Participating in voluntary exercise training is important to meet occupational requirements as well as firefighters' health and safety. The purpose of this study is to identify salient beliefs associated with voluntary exercise training among firefighters in the pandemic era by comparing outcomes with those from a previous elicitation study, which was carried out before the COVID-19 outbreak. METHODS: A total of 57 firefighters are recruited to participate in an elicitation study. Participants are requested to respond to six open-ended questions related to voluntary exercise training. Content analysis is used to create categories that combine similar factors in each belief. Beliefs mentioned by more than 30% of participants are used for comparison with the results of the previous research. RESULTS: "Improves my physical ability" (n = 44) and "cause injury" (n = 17) are identified as behavioral beliefs in the present study, whereas "makes me tired" and "takes too much time" were also elicited in Lee's study. Normative beliefs are "family members" (n = 45) and "colleagues" (n = 27) and these results are consistent with those in Lee's study. "Lack of time" (n = 28), "exercise facilities" (n = 19), and "COVID-19" (n = 19) are elicited as control beliefs in the present study, whereas "physical condition" (n = 21) and "exercise partners" (n = 14) were elicited as other control beliefs, and "COVID-19" was not mentioned in Lee's study. CONCLUSION: This study can contribute valuable information about salient beliefs associated with exercise training behavior among firefighters, particularly under pandemic conditions. Future researchers should develop tailored exercise training programs for firefighters based on current elicited beliefs.

The Potential Roles of Myokines in Adipose Tissue Metabolism with Exercise and Cold Exposure.

Exercise and cold exposure are two stimuli that have been suggested as solely effective to modulate adipose tissue metabolism and improve metabolic health in obese populations. The two primary organs involved in energy metabolism during exercise and/or cold exposure are skeletal muscle and adipose tissue. Adipose tissue can be divided mainly into two types: white adipose tissue (WAT), which primarily stores energy, and brown adipose tissue (BAT), known as the primary source of thermogenesis. The exercise-stimulated release of myokines allows for crosstalk between skeletal muscle and adipose tissue, partially mediating the beneficial effects of exercise. Cold exposure is another trigger for the regulation of myokine secretions, thus increasing adipose tissue metabolism, especially via activation of BAT. Therefore, this has generated the hypothesis that exercise in conjunction with cold exposure might be the optimal regimen to regulate myokine profiles and gain more beneficial health effects. However, to date, human experimental data regarding different exercise (frequency, type, time and intensity) and cold exposure (temperature, time and frequency) patterns are scarce. In this review, we will summarize the current human clinical trials investigating the regulation of myokines induced by exercise combined with cold exposure, to elaborate on the roles of myokines in mediating adipose tissue metabolism.

The effect of fibroblast growth factor receptor inhibition on resistance exercise training-induced adaptation of bone and muscle quality in mice.

Aging in mammals, including humans, is accompanied by loss of bone and muscular function and mass, characterized by osteoporosis and sarcopenia. Although resistance exercise training (RET) is considered an effective intervention, its effect is blunted in some elderly individuals. Fibroblast growth factor (FGF) and its receptor, FGFR, can modulate bone and muscle quality during aging and physical performance. To elucidate this possibility, the FGFR inhibitor NVP-BGJ398 was administrated to C57BL/6n mice for 8 weeks with or without RET. Treatment with NVP-BGJ398 decreased grip strength, muscular endurance, running capacity and bone quality in the mice. FGFR inhibition elevated bone resorption and relevant gene expression, indicating altered bone formation and resorption. RET attenuated tibial bone resorption, accompanied by changes in the expression of relevant genes. However, RET did not overcome the detrimental effect of NVP-BGJ398 on muscular function. Taken together, these findings provide evidence that FGFR signaling may have a potential role in the maintenance of physical performance and quality of bone and muscles.

Effects of exercise on AKT/PGC1-α/FOXO3a pathway and muscle atrophy in cisplatin-administered rat skeletal muscle.

Cisplatin has been reported to cause side effects such as muscle wasting in humans and rodents. The physiological mechanisms involved in preventing muscle wasting, such as the regulation of AKT, PGC1-α, and autophagy-related factor FOXO3a by MuRF 1 and Atrogin-1, remain unclear following different types of exercise and in various skeletal muscle types. Eight-week-old male Wistar rats (n = 34) were assigned to one of four groups: control (CON, n = 6), cisplatin injection (1 mg/kg) without exercise (CC, n = 8), cisplatin (1 mg/kg) + resistance exercise (CRE, n = 9) group, and cisplatin (1 mg/kg) + aerobic exercise (CAE, n = 11). The CRE group performed progressive ladder exercise (starting with 10% of body weight on a 1-m ladder with 2-cm-interval grids, at 85°) for 8 weeks. The CAE group exercised by treadmill running (20 m/min for 60 min daily, 4 times/week) for 8 weeks. Compared with the CC group, the levels of the autophagy-related factors BNIP3, Beclin 1, LC3-II/I ratio, p62, and FOXO3a in the gastrocnemius and soleus muscles were significantly decreased in the CRE and CAE groups. The CRE and CAE groups further showed significantly decreased MuRF 1 and Atrogin-1 levels and increased phosphorylation of AKT, FOXO3a, and PGC1-α. These results suggest that both ladder and aerobic exercise directly affected muscle wasting by modulating the AKT/PGC1-α/FOXO3a signaling pathways regardless of the skeletal muscle type.

The effect of Qigong-based therapy on patients with Parkinson's disease: a systematic review and meta-analysis.

OBJECTIVE: This study was to evaluate the effects of Qigong on clinical motor symptoms, walking ability, and balance of patients with Parkinson's disease. DATA SOURCES: Seven electronic databases (MEDLINE, Web of Science, CINAHL, SportDiscus, Scopus, China National Knowledge Infrastructure, and Wanfang Database) were searched from inception to June 28, 2020. METHODS: Two reviewers independently selected and extracted the data from studies with randomized controlled trial, and effect sizes were calculated by employing random-effect models with 95% confidential interval (CI). We used Physiotherapy Evidence Database scale to evaluate the quality of included studies. RESULTS: A total of seven studies with 325 participants (180 males and 145 females) were included in this meta-analysis. Results of this meta-analysis showed that Qigong had significantly positive effects on motor symptoms (SMD = 0.59, 95% CI [0.24, 0.93]), walking ability (SMD = 0.78, 95% CI [0.10, 1.47]), and balance (SMD = 0.72, 95% CI [0.23, 1.20]) in patients with Parkinson's disease. Subgroup analysis showed Qigong exercise had significant difference on improving motor symptoms and walking ability compared to passive control (P < 0.01), and no significant difference compared to active control. Subgroup analysis of Qigong exercise revealed a significant difference on balance compared to both active and passive control (P < 0.05). In addition, meta-regression result indicated that the effect of Qigong exercise on motor symptoms was influenced by age. CONCLUSION: The findings from current meta-analysis supported Qigong exercise as a beneficial alternative therapy may contribute to increasing motor function, walking ability, and balance for patients with Parkinson's disease.

Results from South Korea's 2018 Report Card on physical activity for children and youth.

BACKGROUND/OBJECTIVE: South Korea's 2018 Report Card on Physical Activity for Children and Youth is the second comprehensive evaluation of physical activity and the sources of influence based on the 10 core indicators provided by the Active Healthy Kids Global Alliance. It will serve as an advocacy tool to promote physical activity among children and youth. METHODS: Three national surveillance data (i.e., 2017 Korea Youth Risk Behavior Web-based Survey, 2016 Korea National Health and Nutrition Examination Survey, 2016 Physical Activity Promotion System) were used as main sources to evaluate the indicators. Descriptive statistics were performed to obtain prevalence estimates of physical activity-related indicators. In addition, expert opinions as well as the most recently available published or unpublished relevant sources were synthesized. RESULTS: South Korea's 2018 Report Card, compared to the 2016 Report Card, showed favourable changes in the Active Transportation (B+), Organized Sports Participation (C), Sedentary Behaviours (D), and School (D+) indicators, while unfavourable changes were shown in Overall Physical Activity (F) and Government (D). Physical Fitness was graded as D+. In parallel with the 2016 Report Card, Active Play, Family and Peers, and Community and Environment remain ungraded due to insufficient data. CONCLUSIONS: Successes as well as gaps and research needs were identified in the 2018 Report Card. Though some indicators have shown improvement, most children and youth continue to be insufficiently physically active with overall poor grades (Average of D+). To achieve substantial improvement in all grades in future Report Cards, more institutional and governmental support and investment is needed to promote physical activity. Furthermore, effort should be made to generate data pertaining to the indicators that were ungraded.

The association of low muscle mass with soluble receptor for advanced glycation end products (sRAGE): The Korean Sarcopenic Obesity Study (KSOS).

BACKGROUND: Advanced glycation end products (AGEs) are accumulated with aging in various tissues of humans. The soluble receptor for AGEs (sRAGE) exerts a protective role against the development of aging-related chronic disorders by neutralizing the action of AGEs. We investigated the implication of sRAGE on low muscle mass in Asian men and women. METHODS: This cross-sectional study included a 390-participant, nondiabetic subcohort recruited within the framework of the Korean Sarcopenic Obesity Study, an ongoing prospective cohort study. Low muscle mass was defined based on the distribution of appendicular skeletal muscle mass divided by body mass index, as proposed by the Foundation for the National Institutes Sarcopenia Project. RESULTS: Serum sRAGE levels were significantly lower in participants with low muscle mass than in participants without low muscle mass (0.76 [0.60-1.00] ng/mL vs 0.87 [0.67-1.15] ng/mL, P = .005). In age- and sex-adjusted correlation analyses, appendicular skeletal muscle mass divided by body mass index was associated with sRAGE (r = 0.109, P = .037). Furthermore, decreased circulating levels of sRAGE are independently associated with low muscle mass (odds ratio = 0.254, P = .002) after adjusting for confounding factors, including insulin resistance and inflammatory markers. CONCLUSIONS: The present study shows that a low circulating level of sRAGE may be an independent risk factor for the presence of low muscle mass.

Ankle Arthritis Combined With Chronic Instability of the Syndesmosis After Ankle Fracture With Syndesmotic Injury: A Case Report.

Syndesmotic injuries associated with ankle fractures are commonly treated with reduction and fixation using a transfixing screw. On rare occasions, however, progression to chronic instability of the syndesmosis is observed. Several surgical techniques have been applied in such cases but usually without a report on the results. We report a case of chronic syndesmotic instability and ankle joint osteoarthritis after ankle fracture-dislocation in a 21-year-old male patient who underwent distal tibiofibular arthrodesis. During the relatively long 4-year, 1-month follow-up period, the pain and activity improved from the patient's preoperative condition. Radiographs demonstrated cessation of arthritic changes in the ankle that had initially displayed joint space narrowing. Our findings suggest distal tibiofibular arthrodesis as an option to consider for the treatment of young and active patients with arthritic changes in the ankle joint with concomitant chronic instability of the syndesmosis.

Effects of exercise-induced apelin levels on skeletal muscle and their capillarization in type 2 diabetic rats.

INTRODUCTION: Exercise-induced apelin as a myokine is believed to play a role in the improvement of type 2 diabetes mellitus (T2DM) and capillarization. In this study, we evaluated the association between exercise-induced apelin and muscle capillarization. METHODS: Zucker rats underwent a treadmill exercise program. Body composition, muscle strength, muscle size, muscle capillarization, and insulin resistance (homeostatic model assessment [HOMA-IR]) were measured. Apelin levels of skeletal muscle and plasma were then analyzed. RESULTS: Exercise improved body composition (P < 0.05), HOMA-IR (P < 0.05), and grip strength (P < 0.001). In the soleus, the fiber size of T2DM was decreased (P < 0.001), but it increased in fiber size and capillarization after exercise (P < 0.001) occurred. We identified an increase in plasma apelin (P < 0.05) and a decrease in soleus apelin (P < 0.01), as well as an association between soleus apelin and angiogenesis (P < 0.01). DISCUSSION: A role for exercise-induced apelin in improving metabolism indicates the possibility of a new drug target for the treatment of metabolic diseases and repairing skeletal muscle damage. Muscle Nerve 56: 1155-1163, 2017.

Combined Low-Intensity Exercise and Ascorbic Acid Attenuates Kainic Acid-Induced Seizure and Oxidative Stress in Mice.

Physical exercise and vitamins such as ascorbic acid (ASC) have been recognized as an effective strategy in neuroprotection and neurorehabilitatioin. However, there is a need to find an efficient treatment regimen that includes ASC and low-intensity exercise to diminish the risk of overtraining and nutritional treatment by attenuating oxidative stress. In the present study, we investigated the combined effect of low-intensity physical exercise (EX) and ASC on kainic acid (KA)-induced seizure activity and oxidative stress in mice. The mice were randomly assigned into groups as follows: "KA only" (n = 11), "ASC + KA" (n = 11), "Ex + KA" (n = 11), "ASC + Ex + KA" (n = 11). In the present study, low intensity of swimming training period lasted 8 weeks and consisted of 30-min sessions daily (three times per week) without tail weighting. Although no preventive effect of low-intensity exercise or ASC on KA seizure occurrence was evident, there was a decrease of seizure activity, seizure development (latency to first seizures), and mortality in "ASC + Ex + KA" compared to "ASC + KA", "Ex + KA", and "KA only" group. In addition, a preventive synergistic coordination of low-intensity exercise and ASC was evident in glutathione peroxidase and superoxide dismutase activity compared to separate treatment. These results suggest that low-intensity exercise and ASC treatment have preventive effects on seizure activity and development with alternation of oxidative status.

Effect of resistance ladder training on sparc expression in skeletal muscle of hindlimb immobilized rats.

INTRODUCTION: Secreted protein acidic and rich in cysteine (SPARC) is associated with skeletal muscle atrophy. Here we examined possibility that resistance training could regulate SPARC expression in muscle atrophy in an immobilized hindlimb model. METHODS: Sprague-Dawley rats underwent resistance ladder training and hindlimb immobilization. Cross sectional area and grip strength were measured. SPARC protein levels in the plantaris and soleus, and serum after exercise and immobilization were then analyzed. RESULTS: Resistance training decreased body weight (P < 0.001) and increased muscle quality (P < 0.001). In the plantaris, muscle atrophy (31.82%) and up-regulated SPARC expression (P < 0.05) after immobilization were alleviated by resistance training. CONCLUSIONS: Resistance training led to suppression of SPARC expression in the plantaris and showed a pretraining effect in atrophied rat muscle. Thus, SPARC may play a pivotal role in muscle homeostasis. Muscle Nerve 53: 951-957, 2016.

Effect of Preoperative Stress Radiographic Findings on Radiographic and Clinical Outcomes of the Modified Broström Procedure for Chronic Ankle Instability.

The purpose of the present study is to evaluate whether findings of instability on preoperative stress radiographs of patients with chronic ankle instability affects the radiographic and clinical outcomes after a modified Broström procedure. A total of 45 consecutive patients (45 ankles) who had undergone the modified Broström procedure for unilateral ankle joint instability and were followed up for ≥2 years were selected. The patients were classified into 2 groups according to the results of the preoperative stress radiographs: 1 group with positive findings (35 [77.8%] patients; stress-positive group) and 1 group with negative findings (10 [22.2%] patients; stress-negative group). The radiographic and clinical outcomes were compared between the 2 groups. The mean preoperative talar tilt measured on the stress radiograph was 14.4° ± 4.2° and 4.8° ± 2.6° in the stress-positive and stress-negative groups, respectively, a statistically significant difference. Postoperative talar tilt improved in both groups, with a mean final talar tilt of 5.4° ± 3.4° in the stress-positive group (p < .001) and 3.0° ± 1.5° in the stress-negative group (p = .038). The average American Orthopaedic Foot and Ankle Society ankle-hindfoot score in the stress-positive and stress-negative groups improved from 65.1 ± 14.6 to 90.0 ± 6.3 (p < .001) and 72.5 ± 9.3 to 92.6 ± 7.8 (p = .007), respectively. The mean postoperative satisfaction rate was 83.9 ± 11.9 and 85.0 ± 11.8 in the 2 groups. No statistically significant differences were seen in the preoperative and postoperative American Orthopaedic Foot and Ankle Society ankle-hindfoot scores or in postoperative satisfaction rates between the 2 groups.

Serum HBV surface antigen positivity is associated with low prevalence of metabolic syndrome in Korean adult men.

BACKGROUND: Metabolic syndrome has clinical implications for chronic liver disease, but the relationship between chronic hepatitis B and metabolic syndrome remains unclear. The aim of this study was to determine whether hepatitis B surface antigen (HBsAg) positivity is associated with metabolic syndrome. METHODS: Data were obtained from the Third Korean National Health and Nutrition Examination Survey (KNHANES). Participant sera were tested for HBsAg. Metabolic syndrome was defined according to the modified National Cholesterol Education Program Adult Treatment Panel III guidelines for Koreans. RESULTS: Of the 5108 participants, 209 (4.1%) tested positive for HBsAg, and 1364 (26.7%) were diagnosed with metabolic syndrome. The prevalence of metabolic syndrome was 23.4% in HBsAg-positive men, 31.5% in HBsAg-negative men, 18.6% in HBsAg-positive women, and 23.7% in HBsAg-negative women. After adjusting for multiple factors, male participants who tested positive for serum HBsAg had an odds ratio of 0.612 (95% confidence interval [CI] 0.375-0.998) for metabolic syndrome and an odds ratio of 0.631 (95% CI 0.404-0.986) for elevated triglycerides. Women who tested positive for serum HBsAg had an odds ratio of 0.343 (95% CI 0.170-0.693) for elevated triglycerides. CONCLUSIONS: Positive results for serum HBsAg are inversely associated with metabolic syndrome in men and with elevated triglycerides in men and women. This suggests that elevated triglycerides may contribute to the inverse association between HBsAg and metabolic syndrome.

Treadmill Exercise Attenuates Retinal Oxidative Stress in Naturally-Aged Mice: An Immunohistochemical Study.

In the retina, a number of degenerative diseases, including glaucoma, diabetic retinopathy, and age-related macular degeneration, may occur as a result of aging. Oxidative damage is believed to contribute to the pathogenesis of aging as well as to age-related retinal disease. Although physiological exercise has been shown to reduce oxidative stress in rats and mice, it is not known whether it has a similar effect in retinal tissues. The aim of this study was to evaluate retinal oxidative stress in naturally-aged mice. In addition, we evaluated the effects of aerobic training on retinal oxidative stress by immunohistochemically evaluating oxidative stress markers. A group of twelve-week-old male mice were not exercised (young control). Two groups of twenty-two-month-old male mice were created: an old control group and a treadmill exercise group. The old control group mice were not exercised. The treadmill exercise group mice ran on a treadmill (5 to 12 m/min, 30 to 60 min/day, 3 days/week for 12 weeks). The retinal thickness and number of cells in the ganglion cell layer of the naturally-aged mice were reduced compared to those in the young control mice. However, treadmill exercise reversed these morphological changes in the retinas. We evaluated retinal expression of carboxymethyllysine (CML), 8-hydroxy-2'-deoxyguanosine (8-OHdG) and nitrotyrosine. The retinas from the aged mice showed increased CML, 8-OHdG, and nitrotyrosine immunostaining intensities compared to young control mice. The exercise group exhibited significantly lower CML levels and nitro-oxidative stress than the old control group. These results suggest that regular exercise can reduce retinal oxidative stress and that physiological exercise may be distinctly advantageous in reducing retinal oxidative stress.

Use of Ilizarov External Fixation Without Soft Tissue Release to Correct Severe, Rigid Equinus Deformity.

The purpose of the present retrospective study was to report the correction of severe, rigid equinus deformities using an Ilizarov external fixator alone, without adjunctive open procedures. Ten feet in 10 patients with rigid equinus deformities were enrolled and underwent gradual correction using an Ilizarov external fixator alone, without additional open procedures. The range of ankle joint motion was measured preoperatively and at the last follow-up visit. The radiographic outcome was assessed using the lateral tibiotalar angle on ankle radiographs taken preoperatively, immediately after removal of the Ilizarov fixator, and at the last follow-up visit. The mean duration of external fixator treatment was 40.1 ± 13.5 days. The preoperative mean ankle range of motion was -55.5° ± 22.2° of dorsiflexion and 63.0° ± 20.8° of plantarflexion. At the last follow-up visit, the mean dorsiflexion had increased to -2.5° ± 6.8° and the mean plantarflexion had decreased to 30.5° ± 12.6°. The mean lateral tibiotalar angle was 152.9° ± 19.7° preoperatively, 103.9° ± 9.4° immediately after removal of the Ilizarov external fixator, and 113.9° ± 11.6° at the last follow-up visit. Immediately after fixator removal, all the patients had clinical correction of their deformity to a plantigrade foot using the Ilizarov external fixator alone, with a mean correction of 49.0° ± 17.4°. Some recurrence was noted at the last follow-up examination, with a final mean correction of 39.0° ± 18.0°. The present study has demonstrated successful correction of severe, rigid equinus deformity with the use of an Ilizarov external fixator without the need for adjunctive soft tissue procedures. This method can be effective for patients with a high risk of complications after open procedures owing to their poor soft tissue envelope.