Problematic smartphone use and the quantity and quality of peer engagement among adolescents: A longitudinal study

Problematic smartphone use (PSU) has recently attracted a lot of attention, especially among adolescents. The knowledge about the role peer engagement might play in the development of PSU is still limited. We aimed to investigate the bidirectional relationships between PSU, the quantity of online (i.e., passive and active social media messaging on smartphone) and offline peer engagement (i.e., intensity of face-to-face meeting with friends) and the quality of peer engagement (i.e., perceived competence in close friendships) among adolescents. Data from a three-wave longitudinal study among 2100 Dutch high school students (56.7% boys) was used. Cross-lagged models indicated that: (1) perceived competence in close friendships at T1 negatively predicted PSU at T2 and PSU at T2 negatively predicted perceived competence in close friendships at T3; (2) there were positive and reciprocal cross-lagged correlations between PSU and passive social media messaging on smartphone; (3) there were positive and reciprocal cross-lagged correlations between intensity of face-to-face meeting with friends and active social media messaging on smartphone. This implies that adolescents who perceive a low competence in close friendships and/or intensively check their smartphone for messages from their peers may be particularly vulnerable to developing problematic smartphone use over time

Breast cancer risk reduction:is it feasible to initiate a randomised controlled trial of a lifestyle intervention programme (ActWell) within a national breast screening programme?

BackgroundBreast cancer is the most commonly diagnosed cancer and the second cause of cancer deaths amongst women in the UK. The incidence of the disease is increasing and is highest in women from least deprived areas. It is estimated that around 42% of the disease in post-menopausal women could be prevented by increased physical activity and reductions in alcohol intake and body fatness. Breast cancer control endeavours focus on national screening programmes but these do not include communications or interventions for risk reductionThis study aimed to assess the feasibility of delivery, indicative effects and acceptability of a lifestyle intervention programme initiated within the NHS Scottish Breast Screening Programme (NHSSBSP).MethodsA 1:1 randomised controlled trial (RCT) of the 3 month ActWell programme (focussing on body weight, physical activity and alcohol) versus usual care conducted in two NHSSBSP sites between June 2013 and January 2014. Feasibility assessments included recruitment, retention, and fidelity to protocol. Indicative outcomes were measured at baseline and 3 month follow-up (body weight, waist circumference, eating and alcohol habits and physical activity. At study end, a questionnaire assessed participant satisfaction and qualitative interviews elicited women¿s, coaches and radiographers¿ experiences. Statistical analysis used Chi squared tests for comparisons in proportions and paired t tests for comparisons of means. Linear regression analyses were performed, adjusted for baseline values, with group allocation as a fixed effectResultsA pre-set recruitment target of 80 women was achieved within 12 weeks and 65 (81%) participants (29 intervention, 36 control) completed 3 month assessments. Mean age was 58¿±¿5.6 years, mean BMI was 29.2¿±¿7.0 kg/m2 and many (44%) reported a family history of breast cancer.The primary analysis (baseline body weight adjusted) showed a significant between group difference favouring the intervention group of 2.04 kg (95%CI ¿3.24 kg to ¿0.85 kg). Significant, favourable between group differences were also detected for BMI, waist circumference, physical activity and sitting time. Women rated the programme highly and 70% said they would recommend it to others.ConclusionsRecruitment, retention, indicative results and participant acceptability support the development of a definitive RCT to measure long term effects.Trial registrationThe trial was registered with Current Controlled Trials (ISRCTN56223933)

Cytological and transcript analyses reveal fat and lazy persister-like bacilli in tuberculous sputum

As nonreplicating tubercle bacilli are tolerant to the cidal action of antibiotics and resistant to multiple stresses, identification of this persister-like population of tubercle bacilli in sputum presents exciting and tractable new opportunities to investigate both responses to chemotherapy and the transmission of tuberculosis

Anti-cancer effects and mechanism of actions of aspirin analogues in the treatment of glioma cancer

INTRODUCTION: In the past 25 years only modest advancements in glioma treatment have been made, with patient prognosis and median survival time following diagnosis only increasing from 3 to 7 months. A substantial body of clinical and preclinical evidence has suggested a role for aspirin in the treatment of cancer with multiple mechanisms of action proposed including COX 2 inhibition, down regulation of EGFR expression, and NF-κB signaling affecting Bcl-2 expression. However, with serious side effects such as stroke and gastrointestinal bleeding, aspirin analogues with improved potency and side effect profiles are being developed. METHOD: Effects on cell viability following 24 hr incubation of four aspirin derivatives (PN508, 517, 526 and 529) were compared to cisplatin, aspirin and di-aspirin in four glioma cell lines (U87 MG, SVG P12, GOS – 3, and 1321N1), using the PrestoBlue assay, establishing IC50 and examining the time course of drug effects. RESULTS: All compounds were found to decrease cell viability in a concentration and time dependant manner. Significantly, the analogue PN517 (IC50 2mM) showed approximately a twofold increase in potency when compared to aspirin (3.7mM) and cisplatin (4.3mM) in U87 cells, with similar increased potency in SVG P12 cells. Other analogues demonstrated similar potency to aspirin and cisplatin. CONCLUSION: These results support the further development and characterization of novel NSAID derivatives for the treatment of glioma

FoxO1 Links Insulin Resistance to Proinflammatory Cytokine IL-1β Production in Macrophages

© 2009 by the American Diabetes Association.[Objetives]: Macrophages play an important role in the pathogenesis of insulin resistance via the production of proinflammatory cytokines. Our goal is to decipher the molecular linkage between proinflammatory cytokine production and insulin resistance in macrophages.[Research design and methods]: We determined cytokine profiles in cultured macrophages and identified interleukin (IL)-1 gene as a potential target of FoxO1, a key transcription factor that mediates insulin action on gene expression. We studied the mechanism by which FoxO1 mediates insulin-dependent regulation of IL-1 expression in cultured macrophages and correlated FoxO1 activity in peritoneal macrophages with IL-1 production profiles in mice with low-grade inflammation or insulin resistance.[Results]: FoxO1 selectively promoted IL-1 production in cultured macrophages. This effect correlated with the ability of FoxO1 to bind and enhance IL-1 promoter activity. Mutations of the FoxO1 binding site within the IL-1 promoter abolished FoxO1 induction of IL-1 expression. Macrophages from insulinresistant obese db/db mice or lipopolysaccharide-inflicted mice were associated with increased FoxO1 production, correlating with elevated levels of IL-1 mRNA in macrophages and IL-1 protein in plasma. In nonstimulated macrophages, FoxO1 remained inert with benign effects on IL-1 expression. In response to inflammatory stimuli, FoxO1 activity was augmented because of an impaired ability of insulin to phosphorylate FoxO1 and promote its nuclear exclusion. This effect along with nuclear factor-B acted to stimulate IL-1 production in activated macrophages.[Conclusions]: FoxO1 signaling through nuclear factor-B plays an important role in coupling proinflammatory cytokine production to insulin resistance in obesity and diabetesThis study was supported in part by American Diabetes Association and National Health Institute Grant DK-066301. No potential conflicts of interest relevant to this article were reported.Peer reviewe

Ser649 and Ser650 Are the Major Determinants of Protein Kinase A-Mediated Activation of Human Hormone-Sensitive Lipase against Lipid Substrates

BACKGROUND: Hormone-sensitive lipase (HSL) is a key enzyme in the mobilization of fatty acids from stored triacylglycerols. Its activity is regulated by reversible protein phosphorylation. In rat HSL Ser563, Ser659 and Ser660 have been shown to be phosphorylated by protein kinase A (PKA) in vitro as well as in vivo. METHODOLOGY/PRINCIPAL FINDINGS: In this study we employed site-directed mutagenesis, in vitro phosphorylation and mass spectrometry to show that in vitro phosphorylation of human HSL by PKA occurs primarily on Ser649 and Ser650 (Ser659 and Ser660 in rat HSL). The wild type enzyme and four mutants were expressed in C-terminally His-tagged form in Sf9 insect cells and purified to homogeneity. HSL variants in which Ser552 and/or Ser554 were mutated to Ala or Glu retained both lipolytic and non-lipolytic activity and were phosphorylated by PKA and activated to a similar extent as the wild type enzyme. (32)P-labeling studies revealed that the bulk of the phosphorylation was on the Ser649/Ser650 site, with only a minor phosphorylation of Ser552 and Ser554. MS/MS analysis demonstrated that the peptide containing Ser649 and Ser650 was primarily phosphorylated on Ser650. The mutant lacking all four serines had severely reduced lipolytic activity, but a lesser reduction in non-lipolytic activity, had S(0.5) values for p-nitrophenol butyrate and triolein comparable to those of wild type HSL and was not phosphorylated by PKA. PKA phosphorylation of the wild type enzyme resulted in an increase in both the maximum turnover and S(0,5) using the TO substrate. CONCLUSIONS: Our results demonstrate that PKA activates human HSL against lipid substrates in vitro primarily through phosphorylation of Ser649 and Ser650. In addition the results suggest that Ser649 and Ser650 are located in the vicinity of a lipid binding region and that PKA phosphorylation controls the accessibility of this region

Circulating short-chain fatty acids are positively associated with adiposity measures in chinese adults

Epidemiological studies suggest a positive association between obesity and fecal short-chain fatty acids (SCFAs) produced by microbial fermentation of dietary carbohydrates, while animal models suggest increased energy harvest through colonic SCFA production in obesity. However, there is a lack of human population-based studies with dietary intake data, plasma SCFAs, gut microbial, and anthropometric data. In 490 Chinese adults aged 30–68 years, we examined the associations between key plasma SCFAs (butyrate/isobutyrate, isovalerate, and valerate measured by non-targeted plasma metabolomics) with body mass index (BMI) using multivariable-adjusted linear regression. We then assessed whether overweight (BMI ≥ 24 kg/m2 ) modified the association between dietary-precursors of SCFAs (insoluble fiber, total carbohydrates, and high-fiber foods) with plasma SCFAs. In a sub-sample (n = 209) with gut metagenome data, we examined the association between gut microbial SCFA-producers with BMI. We found positive associations between butyrate/isobutyrate and BMI (p-value < 0.05). The associations between insoluble fiber and butyrate/isobutyrate differed by overweight (p-value < 0.10). There was no statistical evidence for an association between microbial SCFA-producers and BMI. In sum, plasma SCFAs were positively associated with BMI and that the colonic fermentation of fiber may differ for adults with versus without overweight

Gut Microbiota and Host Plasma Metabolites in Association with Blood Pressure in Chinese Adults

Animal studies have revealed gut microbial and metabolic pathways of blood pressure (BP) regulation, yet few epidemiological studies have collected microbiota and metabolomics data in the same individuals. In a population-based, Chinese cohort who did not report antihypertension medication use (30-69 years, 54% women), thus minimizing BP treatment effects, we examined multivariable-adjusted (eg, diet, physical activity, smoking, kidney function), cross-sectional associations between measures of gut microbiota (16S rRNA [ribosomal ribonucleic acid], N=1003), and plasma metabolome (liquid chromatography-mass spectrometry, N=434) with systolic (SBP, mean [SD]=126.0 [17.4] mm Hg) and diastolic BP (DBP [80.7 (10.7) mm Hg]). We found that the overall microbial community assessed by principal coordinate analysis varied by SBP and DBP (permutational multivariate ANOVA P<0.05). To account for strong correlations across metabolites, we first examined metabolite patterns derived from principal component analysis and found that a lipid pattern was positively associated with SBP (linear regression coefficient [95% CI] per 1 SD pattern score: 2.23 [0.72-3.74] mm Hg) and DBP (1.72 [0.81-2.63] mm Hg). Among 1104 individual metabolites, 34 and 39 metabolites were positively associated with SBP and DBP (false discovery rate-adjusted linear model P<0.05), respectively, including linoleate, palmitate, dihomolinolenate, 8 sphingomyelins, 4 acyl-carnitines, and 2 phosphatidylinositols. Subsequent pathway analysis showed that metabolic pathways of long-chain saturated acylcarnitine, phosphatidylinositol, and sphingomyelins were associated with SBP and DBP (false discovery rate-adjusted Fisher exact test P<0.05). Our results suggest potential roles of microbiota and metabolites in BP regulation to be followed up in prospective and clinical studies

Associations of sodium and potassium consumption with the gut microbiota and host metabolites in a population-based study in Chinese adults

Background: There is increasing evidence that sodium consumption alters the gut microbiota and host metabolome in murine models and small studies in humans. However, there is a lack of population-based studies that capture large variations in sodium consumption as well as potassium consumption. Objective: We examined the associations of energy-adjusted dietary sodium (milligrams/kilocalorie), potassium, and sodium-to-potassium (Na/K) ratio with the microbiota and plasma metabolome in a well-characterized Chinese cohort with habitual excessive sodium and deficient potassium consumption. Methods: We estimated dietary intakes from 3 consecutive validated 24-h recalls and household inventories. In 2833 adults (18-80 y old, 51.2% females), we analyzed microbial (genus-level 16S ribosomal RNA) between-person diversity, using distance-based redundancy analysis (dbRDA), and within-person diversity and taxa abundance using linear regression, accounting for geographic variation in both. In a subsample (n = 392), we analyzed the overall metabolome (dbRDA) and individual metabolites (linear regression). P values for specific taxa and metabolites were false discovery rate adjusted (q-value). Results: Sodium, potassium, and Na/K ratio were associated with microbial between-person diversity (dbRDA P < 0.01) and several specific taxa with large geographic variation, including pathogenic Staphylococcus and Moraxellaceae, and SCFA-producing Phascolarctobacterium and Lachnospiraceae (q-value < 0.05). For example, sodium and Na/K ratio were positively associated with Staphylococcus and Moraxellaceae in Liaoning, whereas potassium was positively associated with 2 genera from Lachnospiraceae in Shanghai. Additionally, sodium, potassium, and Na/K ratio were associated with the overall metabolome (dbRDA P ≤ 0.01) and several individual metabolites, including butyrate/isobutyrate and gut-derived phenolics such as 1,2,3-benzenetriol sulfate, which was negatively associated with sodium in Guizhou (q-value < 0.05). Conclusions: Our findings suggest that sodium and potassium consumption is associated with taxa and metabolites that have been implicated in cardiometabolic health, providing insights into the potential roles of gut microbiota and host metabolites in the pathogenesis of sodium- and potassium-associated diseases. More studies are needed to confirm our results