Treadmill Exercise Alleviates Aging-induced Apoptosis in Rat Cardiac Myocytes

SummaryBackgroundThe incidence and prevalence of heart failure increases with age. Cardiomyocyte apoptosis contributes to the pathogenesis of heart failure. In the end-stage of human heart failure, increased cardiomyocyte apoptosis is observed. Exercise training is one of the nonpharmacological treatments for chronic heart failure.MethodsIn the present study, we investigated the effect of treadmill exercise on the aging-induced apoptosis within cardiac myocytes in relation to the expression of heat shock protein 70 (HSP70) using rats. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining and Western blotting for the expression of Bcl-2, Bax, HSP70, and phosphorylated p38 (p-p38) in the cardiac myocardium were conducted.ResultsAging induced apoptosis in the myocardium, which was confirmed by increased TUNEL-positive cells and the enhancement of Bax. Expression of HSP70 was suppressed and p-p38 expression was enhanced by aging. Treadmill exercise alleviated aging-induced apoptosis with enhancing HSP70 expression and suppressing p-p38 expression in the cardiac myocytes.ConclusionBased on the present results, it can be inferred that treadmill exercise can provide a cardioprotective effect on aging-induced apoptosis through the enhancement of HSP70 expression in the heart. Thus, regular exercise may be a useful strategy for preventing heart problems in the elderly

Anoikis Resistance: An Essential Prerequisite for Tumor Metastasis

Metastasis is a multistep process including dissociation of cancer cells from primary sites, survival in the vascular system, and proliferation in distant target organs. As a barrier to metastasis, cells normally undergo an apoptotic process known as “anoikis,” a form of cell death due to loss of contact with the extracellular matrix or neighboring cells. Cancer cells acquire anoikis resistance to survive after detachment from the primary sites and travel through the circulatory and lymphatic systems to disseminate throughout the body. Because recent technological advances enable us to detect rare circulating tumor cells, which are anoikis resistant, currently, anoikis resistance becomes a hot topic in cancer research. Detailed molecular and functional analyses of anoikis resistant cells may provide insight into the biology of cancer metastasis and identify novel therapeutic targets for prevention of cancer dissemination. This paper comprehensively describes recent investigations of the molecular and cellular mechanisms underlying anoikis and anoikis resistance in relation to intrinsic and extrinsic death signaling, epithelial-mesenchymal transition, growth factor receptors, energy metabolism, reactive oxygen species, membrane microdomains, and lipid rafts

Relationship between smartphone addiction and physical activity in Chinese international students in Korea

Background and Aims Excessive usage of smartphones may induce social problems, such as depression and impairment of social and emotional functioning. Moreover, its usage can impede physical activity, but the relationship between smartphone addiction and physical activity is obscure. Therefore, we examined the relationship and the impact of excessive smartphone use on physical activity. Methods This study collected data through the structured questionnaire consisting of general characteristics, the number and hours of smartphone usage, and the Smartphone Addiction Proneness Scale (SAPS) from 110 Chinese international students in Korea. The body composition and physical activity, such as the total daily number of steps and consumed calories, were measured. Results In this study, high-risk smartphone users showed less physical activity, such as the total number of steps taken and the average consumed calories per day. Moreover, their body composition, such as muscle mass and fat mass, was significantly different. Among these factors, the hours of smartphone use revealed the proportional relationship with smartphone addiction (β = 0.209, p = 0.026), while the average number of walking steps per day showed a significant reverse proportional tendency in participants with smartphone addiction (β = –0.883, p < 0.001). Conclusions Participants with smartphone addiction were less likely to walk for each day. Namely, smartphone addiction may negatively influence physical health by reducing the amount of physical activity, such as walking, resulting in an increase of fat mass and a decrease of muscle mass associated with adverse health consequences

VHF meteor radar at King Sejong Station, Antarctica

Since 2002, we have been observing the mesosphere and lower thermosphere (MLT) region over King Sejong Station (KSS; 62.22°S, 58.78°W), Antarctica, using various instruments such as the Spectral Airglow Temperature Imager (SATI), All Sky Camera (ASC) and VHF meteor radar. The meteor radar, installed in March 2007, continuously measures neutral winds in the altitude region 70–110 km and neutral temperature near the mesopause 24 h∙d-1, regardless of weather conditions. In this study, we present results of an analysis of the neutral wind data for gravity wave activity over the tip of the Antarctic Peninsula, where such activity is known to be very high. Also presented is temperature estimation from measurement of the decay times of meteor trails, which is compared with other temperature measurements from SATI and the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument onboard the Thermosphere Ionosphere Mesosphere Energy and Dynamics (TIMED) satellite