Muscle Performance Changes with Age in Active Women

The purpose of this study was to examine age-related differences in muscle performance in women divided into young (YW, 20–39 years, n = 29) middle-aged (MAW, 40–59 years, n = 33), and older (OW, ≥60 years, n = 40) age groups. Methods: Hand grip strength, vertical jump performance, and knee extensor (KE) strength (0 deg/s, 60 deg/s, and 240 deg/s), speed of movement (SoM; at 1 Nm, 20%, 40%, and 60% isometric strength), and endurance (30-repetition test at 60 degs/s and 240 deg/s) were assessed. Computed tomography-acquired muscle cross-sectional area (mCSA) was measured and included to determine specific strength (KE strength/mCSA). Results: Hand grip strength was similar across groups, while jump performance declined with age (YW and MAW \u3e OW, p \u3c 0.001). KE strength declined significantly with age (all conditions p \u3c 0.01), while specific strength was similar across groups. SoM was significantly higher for YW and MAW compared to OW (both p \u3c 0.01). An age × velocity interaction revealed YW KE endurance was similar between conditions, whereas MAW and OW displayed significantly better endurance during the 60 deg/s condition. OW displayed impaired KE endurance at 240 deg/s (vs. YW and MAW, p \u3c 0.01) but improved at 60 deg/s (vs. YW, p \u3c 0.01). Dynamic torque decline increased with age (YW \u3c OW, p = 0.03) and was associated with intramuscular adipose tissue (r = 0.21, p = 0.04). Conclusions: Performance declines were most evident among OW, but few performance deficits had emerged in MAW. Interestingly, strength declines disappeared after normalizing to mCSA and endurance appears to be velocity-dependent

Efficacy of lisdexamfetamine dimesylate in children with attention-deficit/hyperactivity disorder previously treated with methylphenidate: a post hoc analysis

<p>Abstract</p> <p>Background</p> <p>Attention-deficit/hyperactivity disorder (ADHD) is a common neurobehavioral psychiatric disorder that afflicts children, with a reported prevalence of 2.4% to 19.8% worldwide. Stimulants (methylphenidate [MPH] and amphetamine) are considered first-line ADHD pharmacotherapy. MPH is a catecholamine reuptake inhibitor, whereas amphetamines have additional presynaptic activity. Although MPH and amphetamine can effectively manage ADHD symptoms in most pediatric patients, many still fail to respond optimally to either. After administration, the prodrug stimulant lisdexamfetamine dimesylate (LDX) is converted to l-lysine and therapeutically active d-amphetamine in the blood. The objective of this study was to evaluate the clinical efficacy of LDX in children with ADHD who remained symptomatic (ie, nonremitters; ADHD Rating Scale IV [ADHD-RS-IV] total score > 18) on MPH therapy prior to enrollment in a 4-week placebo-controlled LDX trial, compared with the overall population.</p> <p>Methods</p> <p>In this post hoc analysis of data from a multicenter, randomized, double-blind, forced-dose titration study, we evaluated the clinical efficacy of LDX in children aged 6-12 years with and without prior MPH treatment at screening. ADHD symptoms were assessed using the ADHD-RS-IV scale, Conners' Parent Rating Scale-Revised short form (CPRS-R), and Clinical Global Impressions-Improvement scale, at screening, baseline, and endpoint. ADHD-RS-IV total and CPRS-R ADHD Index scores were summarized as mean (SD). Clinical response for the subgroup analysis was defined as a ≥ 30% reduction from baseline in ADHD-RS-IV score and a CGI-I score of 1 or 2. Dunnett test was used to compare change from baseline in all groups. Number needed to treat to achieve one clinical responder or one symptomatic remitter was calculated as the reciprocal of the difference in their proportions on active treatment and placebo at endpoint.</p> <p>Results</p> <p>Of 290 randomized participants enrolled, 28 received MPH therapy at screening, of which 26 remained symptomatic (ADHD-RS-IV > 18). ADHD-RS-IV total scores, changes from baseline, clinical responsiveness, and rates of symptomatic remission in this subgroup were comparable to the overall population. The safety and tolerability profiles for LDX were comparable to other stimulants currently available.</p> <p>Conclusion</p> <p>In this analysis, children with significant clinical ADHD symptoms despite MPH treatment improved during treatment with LDX and experienced similar improvements in their symptoms as the overall study population.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00556296">NCT00556296</a></p

Why do you drink caffeine? The development of the Motives for Caffeine Consumption Questionnaire (MCCQ) and its relationship with gender, age and the types of caffeinated beverages

Caffeine is the most popular psychoactive substance that is consumed worldwide. As motives influence behavior, investigation of the motivational background of caffeine consumption should help provide a better understanding of the popularity of caffeinated products. The present study aimed (i) to explore and operationalize the motives of caffeine consumption and (ii) to reveal possible differences in the motives regarding gender, age and the type of caffeinated products consumed. Motives for caffeine consumption were collected from regular caffeine consumers (N = 26) and were informed by a review of the relevant literature. Following this, a cross-sectional study was conducted on a convenience sample of Hungarian university students and working adults (N = 598). The participants completed the Motives for Caffeine Consumption Questionnaire and the Caffeine Consumption Questionnaire. Six motivational factors were identified: Alertness, Habit, Mood, Social, Taste and Symptom Management. Women had higher scores on Habit, Social, Taste and Symptom Management. Younger participants had higher scores on Alertness than the older group, and the older group had higher scores on Habit and Symptom Management. Five types of caffeine users were identified. Those who consumed (i) coffee, (ii) tea, (iii) energy drinks, (iv) coffee and tea and (v) mixed drinks. Several differences between the five groups were revealed across all motives except for Taste. The present study developed a robust psychometric instrument for assessing caffeine consumption motives. The factors varied in importance in relation to gender, age and caffeine consumption habits

Differential Pharmacological Actions of Methadone and Buprenorphine in Human Embryonic Kidney 293 Cells Coexpressing Human μ-Opioid and Opioid Receptor-Like 1 Receptors

Methadone and buprenorphine are used in maintenance therapy for heroin addicts. In this study, we compared their effects on adenylate cyclase (AC) activity in human embryonic kidney (HEK) 293 cells stably overexpressing human μ-opioid receptor (MOR) and nociceptin/opioid receptor-like 1 receptor (ORL1) simultaneously. After acute exposure, methadone inhibited AC activity; however, buprenorphine induced compromised AC inhibition. When naloxone was introduced after 30 min incubation with methadone, the AC activity was enhanced. This was not observed in the case of buprenorphine. Enhancement of the AC activity was more significant when the incubation lasted for 4 h, and prolonged exposure to buprenorphine elevated the AC activity as well. The removal of methadone and buprenorphine by washing also obtained similar AC superactivation as that revealed by naloxone challenge. The study demonstrated that methadone and buprenorphine exert initially different yet eventually convergent adaptive changes of AC activity in cells coexpressing human MOR and ORL1 receptors