Comparison of acute physiological effects between alternating current and pulsed current electrical muscle stimulation

Electrical muscle stimulation (EMS) is widely used in rehabilitation and sport training, and alternating current and pulsed current EMS are commonly used. However, no systematic comparison between alternating and pulsed current EMS has been made in the previous studies. The main aim of this research was to compare acute physiological responses between the alternating and pulsed current EMS. The secondary purpose of the research was to investigate further muscle damage induced by EMS-evoked isometric contractions. Three experimental studies were conducted in the thesis project together with literature review about EMS

Effects of Acute Eccentric Exercise on Appetite-Related Hormones and Food Preferences in Men

Eccentric exercise has been suggested to improve muscle atrophy, muscle function, and insulin sensitivity. The aim of this study was to examine the effect of acute eccentric exercise on appetite-related hormones, food preferences, and food intake. Fourteen moderately active men were recruited to participate in this study (age 24.2 ± 5.5 years; BMI 23.4 ± 3.3 kg/m2; VO2max 48.9 ± 3.1 ml/kg/min). Three different conditions were implemented; no exercise, flat running “inclination 0” and downhill running “inclination –12%.” Appetite-related hormones, subjective appetite sensations, food preference and reward, and ad libitum food intake were measured at pre-, immediately post-, and 24 h post exercise.There were no significant median changes in total ghrelin or pancreatic peptide concentrations between conditions. There were also no median differences in subjective appetite ratings or energy intake between conditions, but the median change in explicit liking of sweet versus savory foods differed significantly between pre-exercise and 24 h post exercise (p = .013). Post-hoc analysis observed a significant difference in the pre-exercise to 24 h post exercise change between front running and downhill running (p = .023), and indicated greater liking of savory foods over sweet foods in downhill running than front running. However, no further differences were seen between conditions for the remaining food preference parameters, suggesting there were no systematic trends in these data. In conclusion, there was no effect of front and downhill running on eating behavior as compared to a nonexercise control condition, but these data need to be replicated in a larger and more heterogeneous sample

Biodistribution and in Vivo Activities of Tumor-Associated Macrophage-Targeting Nanoparticles Incorporated with Doxorubicin

Tumor-associated macrophages (TAMs) are increasingly considered a viable target for tumor imaging and therapy. Previously, we reported that innovative surface-functionalization of nanoparticles may help target them to TAMs. In this report, using poly(lactic-co-glycolic) acid (PLGA) nanoparticles incorporated with doxorubicin (DOX) (DOX-NPs), we studied the effect of surface-modification of the nanoparticles with mannose and/or acid-sensitive sheddable polyethylene glycol (PEG) on the biodistribution of DOX and the uptake of DOX by TAMs in tumor-bearing mice. We demonstrated that surface-modification of the DOX-NPs with both mannose and acid-sensitive sheddable PEG significantly increased the accumulation of DOX in tumors, enhanced the uptake of the DOX by TAMs, but decreased the distribution of DOX in mononuclear phagocyte system (MPS), such as liver. We also confirmed that the acid-sensitive sheddable PEGylated, mannose-modified DOX-nanoparticles (DOX-AS-M-NPs) targeted TAMs because depletion of TAMs in tumor-bearing mice significantly decreased the accumulation of DOX in tumor tissues. Furthermore, in a B16-F10 tumor-bearing mouse model, we showed that the DOX-AS-M-NPs were significantly more effective than free DOX in controlling tumor growth but had only minimum effect on the macrophage population in mouse liver and spleen. The AS-M-NPs are promising in targeting cytotoxic or macrophage-modulating agents into tumors to improve tumor therapy

Effect of nanoparticle size on their distribution and retention in chronic inflammation sites

Abstract Nanomedicines are increasingly researched and used for the treatment of chronic inflammatory diseases. Herein, the effect of the size of nanoparticles on their distribution and retention in chronic inflammatory sites, as compared to healthy tissues, was studied in a mouse model with chronic inflammation in one of the hind footpads. Using PEGylated gold nanoparticles of 2, 10, 100, and 200 nm, we found that although the smaller nanoparticles of 2 and 10 nm showed greater distribution and slower clearance in the inflamed footpad than the relatively larger nanoparticles of 100 and 200 nm, the larger nanoparticles of 100 and 200 nm were more selectively distributed in the inflamed hind footpad than in the healthy hind footpad in the same mouse. Based on these findings, we prepared protein nanoparticles of 100–200 nm with albumin, IgG antibody, or anti-TNF-α monoclonal antibody (mAb). The nanoparticles can release proteins in response to high redox activity and/or low pH, conditions seen in chronic inflammation sites. We then showed that upon intravenous injection, those stimuli-responsive protein nanoparticles distributed more selectively in the inflamed footpad than free proteins and remained longer in the inflamed footpad than similar protein nanoparticles that are not sensitive to high redox activity or low pH. These findings support the feasibility of increasing the selectivity of nanomedicines and protein therapeutics to chronic inflammation sites and prolonging their retention at the sites by innovative nanoparticle engineering. Graphical Abstrac

Validity and reliability of the Arabic sedentary behavior questionnaire among university students aged between 18–30 years old

Abstract Purpose The study aimed to test the validity and reliability of the Arabic version of the sedentary behavior questionnaire (SBQ). Methods A total of 624 university students (273 males; 351 females, mean age = 20.8 years) were recruited from Taibah University, Madinah, Saudi Arabia. For criterion and constructive validity (n = 352), the Arabic SBQ was compared with total sitting time from the International Physical Activity Questionnaire-short form (IPAQ-SF) and the International Physical Activity Questionnaire-long form (IPAQ-LF). For concurrent validity, the English and Arabic SBQ versions were given concurrently to bilingual university students (n = 122) once. For test–retest reliability, the Arabic SBQ was given twice to participants (n = 150) at a one-week interval. Results Sitting time of IPAQ-SF (7th question: sitting time on weekdays) and IPAQ-LF (21st question: sitting time on weekdays and 22nd question: sitting time on weekends) correlated significantly with total sitting time/week of the Arabic SBQ (r = 0.29, p = 0.003; r = 0.14, p = 0.02, respectively). Motorized transportation measured with the IPAQ-LF correlated significantly with time spent driving in a car, bus, or train from the Arabic SBQ on weekdays and weekends (r = 0.53, p < 0.001; r = 0.44 p < 0.001, respectively). The total sitting time of the Arabic SBQ was inversely correlated with BMI (r = -0.18, p = 0.001). The correlations between the Arabic and the English SBQ versions ranged from 0.25–0.96; p < 0.001 on weekdays and 0.50–0.90; p < 0.001 on weekends. Moderate to good reliability was also found between test and retest for all SBQ items and total score during weekdays (0.72 to 0.8), and weekends (0.64 to 0.87), with exception of the 7th item "play musical instrument", ICC = 0.46). Mean difference of test–retest of the Arabic SBQ was not significantly different from zero for the total sitting time of the Arabic SBQ (t = -0.715, P = 0.476). Conclusion The Arabic SBQ had satisfactory levels of reliability, with total sitting time of the Arabic SBQ correlating significantly with sitting times derived from IPAQ-SF, IPAQ-LF, and the English SBQ versions. Hence, the Arabic SBQ can be used as a tool to measure sedentary behavior among adult Arabs aged between 18 to 30 years old in future epidemiologic and clinical practice

The prevalence of sedentary behavior among university students in Saudi Arabia

Abstract Background A considerable body of research has demonstrated that reducing sitting time benefits health. Therefore, the current study aimed to explore the prevalence of sedentary behavior (SB) and its patterns. Methods A total of 6975 university students (49.1% female) were chosen randomly to participate in a face-to-face interview. The original English version of the sedentary behavior questionnaire (SBQ) was previously translated into Arabic. Then, the validated Arabic version of the SBQ was used to assess SB. The Arabic SBQ included 9 types of SB (watching television, playing computer/video games, sitting while listening to music, sitting and talking on the phone, doing paperwork or office work, sitting and reading, playing a musical instrument, doing arts and crafts, and sitting and driving/riding in a car, bus or train) on weekdays and weekends. Results SBQ indicated that the total time of SB was considerably high (478.75 ± 256.60 and 535.86 ± 316.53 (min/day) during weekdays and weekends, respectively). On average, participants spent the most time during the day doing office/paperwork (item number 4) during weekdays (112.47 ± 111.11 min/day) and weekends (122.05 ± 113.49 min/day), followed by sitting time in transportation (item number 9) during weekdays (78.95 ± 83.25 min/day) and weekends (92.84 ± 100.19 min/day). The average total sitting time of the SBQ was 495.09 ± 247.38 (min/day) and 58.4% of the participants reported a high amount of sitting time (≥ 7 hours/day). Independent t-test showed significant differences (P ≤ 0.05) between males and females in all types of SB except with doing office/paperwork (item number 4). The results also showed that male students have a longer daily sitting time (521.73 ± 236.53 min/day) than females (467.38 ± 255.28 min/day). Finally, 64.1% of the males reported a high amount of sitting time (≥ 7 hours/day) compared to females (52.3%). Conclusion In conclusion, the total mean length of SB in minutes per day for male and female university students was considerably high. About 58% of the population appeared to spend ≥7 h/day sedentary. Male university students are likelier to sit longer than female students. Our findings also indicated that SB and physical activity interventions are needed to raise awareness of the importance of adopting an active lifestyle and reducing sitting time