Global DNA and p53 region-specific hypomethylation in human colonic cells is induced by folate depletion and reversed by folate supplementation.

There is increasing evidence to suggest that reduced folate status may be a causative factor in carcinogenesis, particularly colorectal carcinogenesis. Folate is essential for the synthesis of S-adenosylmethionine, the methyl donor required for all methylation reactions in the cell, including the methylation of DNA. Global DNA hypomethylation appears to be an early, and consistent, molecular event in carcinogenesis. We have examined the effects of folate depletion on human-derived cultured colon carcinoma cells using 2 novel modifications to the Comet (single cell gel electrophoresis) assay to detect global DNA hypomethylation and gene region–specific DNA hypomethylation. Colon cells cultured in folate-free medium for 14 d showed a significant increase in global DNA hypomethylation compared with cells grown in medium containing 3µmol/L folic acid. This was also true at a gene level, with folate-deprived cells showing significantly more DNA hypomethylation in the region of the p53 gene. In both cases, the effects of folate depletion were completely reversed by the reintroduction of folic acid to the cells. These results confirm that decreased folate levels are capable of inducing DNA hypomethylation in colon cells and particularly in the region of the p53 gene, suggesting that a more optimal folate status in vivo may normalize any DNA hypomethylation, offering potential protective effects against carcinogenesis. This study also introduces 2 novel functional biomarkers of DNA hypomethylation and demonstrates their suitability to detect folate depletion–induced molecular changes.

Changes in sedentary behavior among adolescent girls: a 2.5-Year prospective cohort study

Purpose: To describe longitudinal changes in leisure-time sedentary behavior among girls, during early to mid-adolescence. Methods: A 2.5-year prospective cohort study, comprising 5 data collections, 6 months apart, between 2000 and 2002. Girls aged 12–15 years (n = 200) from 8 high schools located in Sydney, Australia, self-reported the usual time spent each week in a comprehensive range of sedentary behaviors.  Results: Retention rate for the study was 82%. Girls aged 12.8 years spent approximately 45% of their discretionary time in sedentary behavior, which increased to 63% at age 14.9 years. Watching TV, videos, and playing video games (small screen recreation; SSR) was the most popular sedentary pastime, accounting for 33% of time spent in sedentariness, followed by homework and reading (25%). Sedentary behavior increased 1.4 and 3.3 hours on week and weekend days, respectively. On weekdays, increased time was spent on hobbies (27 min/day) and on weekend days, increased time was spent sitting around talking with friends (60 min/day), computer use (37 min/day), and television viewing (34 min/day). Conclusions: Among girls, the transition between early and mid-adolescence was accompanied by a significant increase in leisure-time sedentary behavior. Interventions to reduce sedentariness among adolescent girls are best to focus on weekend behaviors. Studies seeking to examine the association between inactivity and the development of chronic health problems need to examine a diverse range of activities that comprehensively measure sedentariness. This information will provide a better understanding of inactivity patterns among adolescent girls.

Peripheral proinflammatory markers associated with ketamine response in a preclinical model of antidepressant-resistance

© 2015 Elsevier B.V. Ketamine, N-methyl- d-aspartate (NMDA) receptor antagonist and anti-inflammatory agent, has rapid therapeutic effects in a subset of patients with more intractable forms of depression. Irregular proinflammatory cytokine and acute-reactive protein levels have been reported in clinical and preclinical depression research. We explored the association between the rapid antidepressant-like effects of ketamine and peripheral proinflammatory profile in a model of antidepressant-resistance. Male Wistar rats were pre-treated with ACTH-(1-24) 100. μg/d or saline (0.9%) for 14. d. Antidepressant-like effects were assessed with the forced swim test (FST). Ketamine (10. mg/kg) significantly reduced immobility duration in saline-pretreated control animals. In contrast, a divergent response was observed in ACTH-pretreated antidepressant resistant animals, with 50% responders and 50% non-responders. Plasma samples were analyzed via enzyme-linked immunosorbent assay (ELISA) for interleukin 6 (IL-6), tumour necrosis factor alpha (TNFα) and C-reactive protein (CRP). Levels of CRP and TNFα differentiated ketamine responders and non-responders.

Apps for IMproving FITness and increasing physical activity among young people: the AIMFIT pragmatic randomized controlled trial

BACKGROUND: Given the global prevalence of insufficient physical activity (PA), effective interventions that attenuate age-related decline in PA levels are needed. Mobile phone interventions that positively affect health (mHealth) show promise; however, their impact on PA levels and fitness in young people is unclear and little is known about what makes a good mHealth app. OBJECTIVE: The aim was to determine the effects of two commercially available smartphone apps (Zombies, Run and Get Running) on cardiorespiratory fitness and PA levels in insufficiently active healthy young people. A second aim was to identify the features of the app design that may contribute to improved fitness and PA levels. METHODS: Apps for IMproving FITness (AIMFIT) was a 3-arm, parallel, randomized controlled trial conducted in Auckland, New Zealand. Participants were recruited through advertisements in electronic mailing lists, local newspapers, flyers posted in community locations, and presentations at schools. Eligible young people aged 14-17 years were allocated at random to 1 of 3 conditions: (1) use of an immersive app (Zombies, Run), (2) use of a nonimmersive app (Get Running), or (3) usual behavior (control). Both smartphone apps consisted of a fully automated 8-week training program designed to improve fitness and ability to run 5 km; however, the immersive app featured a game-themed design and narrative. Intention-to-treat analysis was performed using data collected face-to-face at baseline and 8 weeks, and all regression models were adjusted for baseline outcome value and gender. The primary outcome was cardiorespiratory fitness, objectively assessed as time to complete the 1-mile run/walk test at 8 weeks. Secondary outcomes were PA levels (accelerometry and self-reported), enjoyment, psychological need satisfaction, self-efficacy, and acceptability and usability of the apps. RESULTS: A total of 51 participants were randomized to the immersive app intervention (n=17), nonimmersive app intervention (n=16), or the control group (n=18). The mean age of participants was 15.7 (SD 1.2) years; participants were mostly NZ Europeans (61%, 31/51) and 57% (29/51) were female. Overall retention rate was 96% (49/51). There was no significant intervention effect on the primary outcome using either of the apps. Compared to the control, time to complete the fitness test was -28.4 seconds shorter (95% CI -66.5 to 9.82, P=.20) for the immersive app group and -24.7 seconds (95% CI -63.5 to 14.2, P=.32) for the nonimmersive app group. No significant intervention effects were found for secondary outcomes. CONCLUSIONS: Although apps have the ability to increase reach at a low cost, our pragmatic approach using readily available commercial apps as a stand-alone instrument did not have a significant effect on fitness. However, interest in future use of PA apps is promising and highlights a potentially important role of these tools in a multifaceted approach to increase fitness, promote PA, and consequently reduce the adverse health outcomes associated with insufficient activity.

Evaluation of weaning strategies for intensively reared Australian fish, Murray cod, Maccullochella peelii peelii

The Australian Murray cod supports a growing national industry. However, with regard to the process of weaning fry, there is a lack of information and optimal procedures need to be developed. The aim of the present investigation was to test the biological and economic efficacy of different weaning strategies for Murray cod. Three weaning strategies were tested on triplicate groups of fish: (1) only Artemia for 5 d, 7 d on Artemia plus starter diet, and 14 d on dry diet only; (2) 12 d on Artemia plus starter diet and 14 d on dry diet only; and (3) directly to dry diet for the entire experimental period. No significant differences were recorded in the growth and feed efficiency, while significantly higher mortality (38.4 ± 0.35%) was recorded in fish weaned directly onto dry diet. Fish subjected to the first 5 d on Artemia only showed a growth reduction during this period, which was compensated by a phase of enhanced growth during the dry-diet phase. No significant differences were noted in the proximate composition of fish under the different treatments. The economic evaluation suggested that the treatment with the simultaneous supply of Artemia and starter diet is preferable.

The effect of acute fenitrotion exposure on a variety of physiological indices, including avian aerobic metabolism during exercise and cold exposure

The effect of fenitrothion exposure on birds was examined by measuring aerobic metabolism, blood hemoglobin content, plasma cholinesterases, and body weight for up to 21 d postdose. Peak metabolic rate was measured in a flight chamber in three-dose groups of house sparrows (Passer domesticus; 100 mg/kg = high, 60 mg/kg = medium, 30 mg/kg = low) and one-dose groups of zebra finches (Taeniopygia guttata; 3 mg/kg) and king quails (Coturnix chinensis; 26 mg/kg). Aerobic metabolism was measured during 1 h of exposure to subfreezing thermal conditions in low-dose house sparrows and king quails (26 mg/kg). Fenitrothion had no effect on metabolic rate during cold exposure or on blood hemoglobin at any time. By contrast, aerobic performance during exercise in sparrows was reduced by 58% (high), 18% (medium), and 20% (low), respectively, 2 d postdose. House sparrows (high) had the longest recovery period for peak metabolic rate (21 d) and plasma cholinesterase activity (14 d). House sparrows (high) and treated king quails had significantly lower myoglobin at 48 h postdose, whereas myoglobin was invariant in zebra finches and house sparrows (medium and low). Cholinesterase was maximally inhibited at 6 h postdose, and had recovered within 24 h, in house sparrows (low), king quails, and zebra finches. Exercise peak metabolic rate in zebra finches and king quails was reduced by 23% at 2 d and 3 d, respectively, despite these birds being asymptomatic in both behavior and plasma cholinesterase activities.

Leptin resistance in a polygenic, hyperleptinemic animal model of obesity and NIDDM : Psammomys obesus

OBJECTIVE: To investigate the effects of leptin administration to Psammomys obesus, a polygenic animal model of obesity and type 2 diabetes mellitus.

DESIGN: Longitudinal intervention study utilising three separate leptin treatment protocols lasting 7-14 d.

MEASUREMENTS: Body weight and food intake were measured daily, body fat and muscle content were estimated by carcass analysis on completion of the study. Blood glucose, plasma insulin, leptin, triglycerides and cholesterol were measured at baseline and twice each week during the study.

RESULTS: Relatively high doses of leptin were required to significantly reduce food intake and body fat content in lean Psammomys obesus, but had no discernible effect on their obese littermates.

CONCLUSION: As a species, Psammomys obesus appear to be relatively insensitive to the effects of leptin administration, compared with other rodents. Obese Psammomys obesus are leptin resistant relative to their lean littermates.

Incorporation of group 14 elements into siloxane-bridged paracyclophanes cyclo-[p,p´-Me2SiC6H4EMe2C6H4SiMe2O]2 (E = C, Si, Ge, Sn)§

The bis(arylene silanes) p,p'-HMe₂SiC₆H₄EMe₂C₆H₄SiMe₂H (E = C (10), Si (11), Ge (12), Sn(13)) were prepared by the in situ Grignard reaction of p,p'-BrC₆H₄CMe₂C₆H₄Br, Mg turnings, and HSiMe₂Cl (for 10) and the Grignard reaction using p-HMe₂SiC₆H₄Br, Mg turnings, and Me₂ECl₂ (E = Si for 11, Ge for 12, Sn for 13). The oxidation of 10-13 using Pearlman's catalyst, Pd(OH)₂/C, in aqueous THF provided the bis(arylene silanols) p,p'-HOMe₂SiC₆H₄EMe₂C₆H₄SiMe₂OH (E = C (14), Si (15), Ge (16), Sn(17)). The HCl-catalyzed condensation of 14-17 in highly diluted solutions of acetone/water afforded the siloxane-bridged paracyclophanes cyclo-[p,p'-Me₂SiC₆H₄EMe₂C₆H₄SiMe₂O]₂ (6-9) that incorporate the group 14 elements E = C, Si, Ge, and Sn. Compounds 6-17 were investigated by multinuclear solution and solid-state NMR spectroscopy and 6 and 9 also by X-ray crystallography.