Protocol for a mixed methods study investigating the impact of investment in housing, regeneration and neighbourhood renewal on the health and wellbeing of residents: the GoWell programme

Background

Childhood obesity is associated with the early development of diseases such as type 2 diabetes and cardiovascular disease. Unfortunately, to date, traditional methods of research have failed to identify effective prevention and treatment strategies, and large numbers of children and adolescents continue to be at high risk of developing weight-related disease.

Aim

To establish a unique 'biorepository' of data and biological samples from overweight and obese children, in order to investigate the complex 'gene × environment' interactions that govern disease risk.

Methods

The 'Childhood Overweight BioRepository of Australia' collects baseline environmental, clinical and anthropometric data, alongside storage of blood samples for genetic, metabolic and hormonal profiles. Opportunities for longitudinal data collection have also been incorporated into the study design. National and international harmonisation of data and sample collection will achieve required statistical power.

Results

Ethical approval in the parent site has been obtained and early data indicate a high response rate among eligible participants (71%) with a high level of compliance for comprehensive data collection (range 56% to 97% for individual study components). Multi-site ethical approval is now underway.

Conclusions

In time, it is anticipated that this comprehensive approach to data collection will allow early identification of individuals most susceptible to disease, as well as facilitating refinement of prevention and treatment programs.     

Self-Monitoring as a Mediator of Weight Loss in the SMART Randomized Clinical Trial

Background

Integral components of behavioral weight-loss treatment include self-monitoring of diet and physical activity along with feedback to participants regarding their behaviors. While providing feedback has been associated with weight loss, no studies have examined the impact of feedback frequency on weight loss or the mediating role of self-monitoring adherence in this relationship.

Purpose

This study examined the effect of participant feedback frequency on weight loss and determined if this effect was mediated by adherence to self-monitoring in a behavioral weight-loss trial conducted in the USA.

Method

Participants (N?=?210) were randomly assigned to one of three self-monitoring methods with either no-daily feedback messages or daily feedback messages: (1) paper diary (PD), no-daily feedback; (2) personal digital assistant (PDA), no-daily feedback; and (3) PDA, daily tailored feedback messages (PDA + FB). The Sobel test via bootstrapping examined the direct effect of feedback frequency on weight loss and the indirect effect through self-monitoring adherence.

Results

Receiving daily feedback messages significantly increased participants' self-monitoring adherence. A significant effect of feedback frequency on weight loss was noted; however, after adjusting for self-monitoring adherence, the effect of feedback frequency on weight loss was no longer significant. Feedback frequency had a significant indirect effect on weight loss through self-monitoring adherence.

Conclusion

Self-monitoring adherence mediated the effect of feedback frequency on weight loss. Increasing the frequency with which participants receive feedback could enhance self-monitoring adherence, a critical component of behavioral weight-loss treatment.     

Age-related differences in the availability of visual feedback during bimanual pinch

Purpose

Previous research has indicated that older adults have significantly lower accuracy in terms of force control than young adults. In addition, accuracy of force control is known to decrease in the absence of visual feedback. However, whether the effect of visual feedback on fine motor control is similar for young adults and older adults is not clear. The purpose of this study, therefore, was to examine the effect of visual feedback on bimanual pinch force control in older adults.

Methods

Thirty-one undergraduate students (age 19.7 ± 0.9 years) and 31 older adults (age 65.1 ± 8.1 years) participated in this study. After measuring finger-pinch maximal voluntary force (MVF), the participants were asked to maintain 10 % MVF as steadily as possible in two different conditions: with visual feedback (visual feedback condition; VF condition) and without visual feedback (no visual feedback condition; NVF condition).

Results

We found that older adults had significantly greater targeting error and force variability than young adults in the VF condition, but not in the NVF condition. In addition, older participants exhibited a significantly greater sum of power for the 0–4 and 4–8 Hz frequency bin than young adults (p < 0.05) in the VF condition, although there was no significant difference in the NVF condition.

Conclusions

These results suggest that older adults do not use visual information as effectively as younger adults to reduce force control error.     

Using Audience Response Technology to provide formative feedback on pharmacology performance for non-medical prescribing students - a preliminary evaluation

Background

The use of anonymous audience response technology (ART) to actively engage students in classroom learning has been evaluated positively across multiple settings. To date, however, there has been no empirical evaluation of the use of individualised ART handsets and formative feedback of ART scores. The present study investigates student perceptions of such a system and the relationship between formative feedback results and exam performance.

Methods

Four successive cohorts of Non-Medical Prescribing students (n=107) had access to the individualised ART system and three of these groups (n=72) completed a questionnaire about their perceptions of using ART. Semi-structured interviews were carried out with a purposive sample of seven students who achieved a range of scores on the formative feedback. Using data from all four cohorts of students, the relationship between mean ART scores and summative pharmacology exam score was examined using a non-parametric correlation.

Results

Questionnaire and interview data suggested that the use of ART enhanced the classroom environment, motivated students and promoted learning. Questionnaire data demonstrated that students found the formative feedback helpful for identifying their learning needs (95.6%), guiding their independent study (86.8%), and as a revision tool (88.3%). Interviewees particularly valued the objectivity of the individualised feedback which helped them to self-manage their learning. Interviewees’ initial anxiety about revealing their level of pharmacology knowledge to the lecturer and to themselves reduced over time as students focused on the learning benefits associated with the feedback.A significant positive correlation was found between students’ formative feedback scores and their summative pharmacology exam scores (Spearman’s rho = 0.71, N=107, p<.01).

Conclusions

Despite initial anxiety about the use of individualised ART units, students rated the helpfulness of the individualised handsets and personalised formative feedback highly. The significant correlation between ART response scores and student exam scores suggests that formative feedback can provide students with a useful reference point in terms of their level of exam-readiness.

     

Colitis generates remote antinociception in rats: the role of the l-arginine/NO/cGMP/PKG/KATP pathway and involvement of cannabinoid and opioid systems

Objective and design

The aim of this study was to investigate the possible involvement of the NO/cGMP/PKG/K _ATP ⁺ pathway, cannabinoids and opioids in remote antinociception associated with 2,4,6-trinitrobenzene sulph onic acid (TNBS)-induced colitis.

Methods

TNBS-induced colitis was induced by intracolonic administration of 20 mg of TNBS in 50 % ethanol. After induction, carrageenan (500 μg/paw) or prostaglandin (PG) E₂ (100 ng/paw) was injected in the rat’s plantar surface and hypersensitivity was evaluated by the electronic von Frey test. Rats were pre-treated with l-Noarg one hour before carrageenan injection. l-Arginine was given 10 min before l-Noarg injections. ODQ, KT 5823, glibenclamide (Glib), naloxone and AM 251 or AM 630 were administered 30 min prior to carrageenan or PGE₂ treatments.

Results

Colitis induction by TNBS reduced PGE₂ or carrageenan-induced hypersensitivity. Antinociception produced by TNBS-induced colitis was reversed significantly (P < 0.05) by l-Noarg, ODQ, KT 5823, glibenclamide, naloxone, AM251 and AM630 treatments.

Conclusions

TNBS-induced colitis causes antinociception in the rat paw. This disorder appears to be mediated by activation of the NO/cGMP/PKG/K_ATP pathway, endocannabinoids and endogenous opioids. This information may contribute to a better understanding of peripheral neurological dysfunctions occurring in Crohn’s disease.     

The Relationship Between Maternal Fear of Hypoglycaemia and Adherence in Children with Type-1 Diabetes

Background

Regular blood glucose monitoring is important for children with type-1 diabetes; however, the relationship between maternal fear of hypoglycaemia and glycaemic control is not well understood.

Purpose

The relationship between maternal beliefs about diabetes, concerns about glycaemic control and adherence to recommended blood glucose levels in young children with type-1 diabetes were examined in this study.

Method

Seventy-one mothers with children under 13 were recruited, and a prospective design was used. Demographics, maternal self-reported hypoglycaemic fear and illness perceptions were measured at baseline. Self-report daily blood sugar levels were recorded over 1 week, and glycosylated haemoglobin (HbA_1c) blood glucose levels were collected at baseline and 3 months later.

Results

High maternal fears of hypoglycaemia were predictive of suboptimal daily glycaemic control (elevated blood glucose levels), irrespective of illness duration or age at diagnosis.

Conclusion

The results suggest that mothers who worry most about hypoglycaemia compensate by maintaining their child’s blood glucose levels above recommended levels. Elevated blood glucose levels have important consequences for long-term health, and further research could explore ways to target maternal fear of hypoglycaemia.     

Family medicine graduates' perceptions of intimidation, harassment, and discrimination during residency training

Background

The role of deliberate practice in medical students' development from novice to expert was examined for preclinical skill training.

Methods

Students in years 1-3 completed 34 Likert type items, adapted from a questionnaire about the use of deliberate practice in cognitive learning. Exploratory factor analysis and reliability analysis were used to validate the questionnaire. Analysis of variance examined differences between years and regression analysis the relationship between deliberate practice and skill test results.

Results

875 students participated (90%). Factor analysis yielded four factors: planning, concentration/dedication, repetition/revision, study style/self reflection. Student scores on 'Planning' increased over time, score on sub-scale 'repetition/revision' decreased. Student results on the clinical skill test correlated positively with scores on subscales 'planning' and 'concentration/dedication' in years 1 and 3, and with scores on subscale 'repetition/revision' in year 1.

Conclusions

The positive effects on test results suggest that the role of deliberate practice in medical education merits further study. The cross-sectional design is a limitation, the large representative sample a strength of the study. The vanishing effect of repetition/revision may be attributable to inadequate feedback. Deliberate practice advocates sustained practice to address weaknesses, identified by (self-)assessment and stimulated by feedback. Further studies should use a longitudinal prospective design and extend the scope to expertise development during residency and beyond.     

In Vivo β-Adrenergic Receptor Responsiveness: Ethnic Differences in the Relationship with Symptoms of Depression and Fatigue

Background

Depressive symptoms and fatigue frequently overlap in clinical samples and the general population. The link of depressive symptoms and fatigue with increased risk of cardiovascular disease has been partly explained by shared biological mechanisms including sympathetic overactivity. Prolonged sympathetic overactivity downregulates the responsiveness of the β-adrenergic receptor (β-AR), a receptor that mediates several end-organ sympathetic responses.

Purpose

The authors studied whether depression and fatigue are related to reduced β-AR responsiveness within the human body (in vivo) in an ethnically diverse sample of African and Caucasian Americans.

Methods

The chronotropic₂₅ dose (CD₂₅) was used to determine in vivo β-AR responsiveness in 93 healthy participants. Psychometric measures included the Center of Epidemiological Studies-Depression Scale and the Multidimensional Fatigue Symptom Inventory.

Results

Hierarchical regression analyses (adjusted for age, gender, body mass index, blood pressure, smoking, and ethnicity) revealed that mental fatigue was significantly related to reduced β-AR responsiveness (i.e., higher CD₂₅ values) in the whole sample. Moderation analyses indicated significant ethnicity × depression/fatigue interactions. Depressive symptoms, total fatigue, emotional fatigue, mental fatigue, and physical fatigue were related to reduced β-AR responsiveness in Caucasian American but not in African Americans.

Conclusions

Our findings suggest that symptoms of depression and fatigue are related to decreased in vivo β-AR responsiveness in Caucasian Americans. The lack of this association in African Americans highlights the importance for considering ethnicity as a potential moderator in research focusing on associations between psychological variables and cardiovascular function.     

The effect of an even-pacing strategy on exercise tolerance in well-trained cyclists

Purpose

Previous research has suggested that the optimal pacing strategy for self-paced exercise lasting >4 min is a uniform distribution of work, but this posit is not well established for prolonged endurance events. This study examined the utility of even pacing during 20 km cycling time trials (TTs).

Methods

Fifteen well-trained male cyclists ( $\dot{V}$ O₂max = 4.80 ± 0.38 L min^?1) completed three best effort self-paced (SP) simulated 20 km TTs, followed by two even-paced trials. In one even-paced trial, participants cycled to exhaustion (EP_tlim) at a fixed intensity equivalent to their best SP performance. In the other EP trial, participants were instructed to maintain this target intensity for a distance of 20 km, but the actual intensity was free to vary depending on the effort and cadence of the cyclist (EP-maintained). Cardiorespiratory, blood lactate and perceptual (RPE and affect) measures were assessed throughout.

Results

Nine out of fifteen cyclists failed the EP_tlim task, completing 51–83 % (10.3–15.3 km) of the work done in their SP trial. Failure as a result of even pacing was associated with a faster rise in blood lactate, attainment of a higher relative intensity during SP and a moderate fast starting strategy. This failure was independent of the nature of the even-paced task.

Conclusion

By adopting an uneven, parabolic distribution of work, cyclists in this study were able to achieve an average intensity during self-paced exercise in excess of their maximum sustainable power output. A subsequent matched even-paced bout resulted in cumulative metabolic stress that could not be managed by moment-to-moment changes in power output. These results challenge the notion that strict even pacing is optimal for endurance time trial events.     

Gender-Specific Associations of Perceived Stress and Coping Strategies with C-Reactive Protein in Middle-Aged and Older Men and Women

Background

Perceived stress and coping strategies may influence the risk of cardiovascular disease through their possible association with inflammation, but data remain controversial for perceived stress or scanty for coping strategies.

Purpose

We examined the associations of perceived stress and coping strategies with serum high-sensitivity C-reactive protein (CRP) in a Japanese general population.

Methods

This cross-sectional study included 2,971 men and 4,902 women aged 40–69 years who were enrolled between 2005 and 2007. Subjects with possible inflammation-related disease, CRP levels ≥3,000 ng/mL, or currently used analgesics or lipid-lowering drugs were excluded. Analyses were performed by gender with adjustment for lifestyle, socioeconomic, and psychosocial factors.

Results

Unexpectedly, elevated perceived stress was significantly associated with lower CRP levels in men (P _trend?P _trend?=?0.90) after adjustment for age and covariates. Among five items of coping strategies evaluated, “disengagement” showed a significant inverse association with CRP in men only (P _trend?=?0.027). In addition, a possible interaction between “emotional support seeking” and perceived stress on CRP was detected in men (P _interaction?=?0.021); “emotional support seeking” was associated with lower CRP at the high stress level only (P _trend?=?0.028).

Conclusions

Both perceived stress and coping strategies may be associated with systemic inflammation in Japanese men, yet caution must be exercised before accepting the stress–inflammation–disease pathway.     

Transformational Teaching and Adolescent Physical Activity: Multilevel and Mediational Effects

Background

Regular physical activity is associated with a range of physical and psychological health benefits. In North America the majority of adolescents are insufficiently active.

Purpose

The purpose of this study was to examine the prospective relationship between adolescents' perceptions of transformational leadership displayed by their school physical education teachers and their own physical activity behaviors, both with respect to within-class physical activity (WCPA) and also leisure time physical activity (LTPA).

Method

The study used a prospective observational design. Using multilevel structural equation modeling (MSEM), we examined the extent to which adolescents' affective attitudes mediated the effects of teachers' behaviors on adolescents' physical activity responses. Two thousand nine hundred and forty-eight adolescents (M _age?=?14.33, SD?=?1.00, N _female?=?1,641, 55.7 %) from 133 Grade 8–10 classes in British Columbia (Canada) provided ratings of their physical education teachers' behaviors midway through the school year. Two months later, students completed measures of affective attitudes, WCPA, and LTPA.

Results

The results indicated that adolescents' perceptions of transformational teaching explained significant variance in both WCPA and LTPA, and these effects were fully mediated by adolescents' affective attitudes (total indirect effect: b?=?0.581, p?<?0.001).

Conclusion

The findings suggest that transformational leadership behaviors displayed by physical education teachers may be an important source of adolescent enjoyment of physical education as well as health-enhancing physical activity involvement within school and outside of school.     

Effect of exercise intensity on post-exercise oxygen consumption and heart rate recovery

Purpose

There is some evidence that measures of acute post-exercise recovery are sensitive to the homeostatic stress of the preceding exercise and these measurements warrant further investigation as possible markers of training load. The current study investigated which of four different measures of metabolic and autonomic recovery was most sensitive to changes in exercise intensity.

Methods

Thirty-eight moderately trained runners completed 20-min bouts of treadmill exercise at 60, 70 and 80 % of maximal oxygen uptake (VO_2max) and four different recovery measurements were determined: the magnitude of excess post-exercise oxygen consumption (EPOC_MAG), the time constant of the oxygen consumption recovery curve (EPOCτ), heart rate recovery within 1 min (HRR_60s) and the time constant of the heart rate recovery curve (HRRτ) .

Results

Despite significant differences in exercise parameters at each exercise intensity, only EPOC_MAG showed significantly slower recovery with each increase in exercise intensity at the group level and in the majority of individuals. EPOCτ was significantly slower at 70 and 80 % of VO_2max vs. 60 % VO_2max and HRRτ was only significantly slower when comparing the 80 vs. 60 % VO_2max exercise bouts. In contrast, HRR_60s reflected faster recovery at 70 and 80 % of VO_2max than at 60 % VO_2max.

Conclusion

Of the four recovery measurements investigated, EPOC_MAG was the most sensitive to changes in exercise intensity and shows potential to reflect changes in the homeostatic stress of exercise at the group and individual level. Determining EPOC_MAG may help to interpret the homeostatic stress of laboratory-based research trials or training sessions.     

The First US Domestic Report of Disseminated Mycobacterium avium Complex and Anti-Interferon-γ Autoantibodies

Introduction

Anti-interferon-γ (IFNγ) autoantibodies have been associated with disseminated mycobacterial infections, mostly in patients from Southeast Asia.

Purpose

We studied an American-born, Caucasian female with M. avium complex infection of the subglottic mucosa and brain for underlying etiologies of infection.

Methods

Plasma was screened for anticytokine autoantibodies using a Luminex-based approach. The ability of patient plasma to block IFNγ-induced STAT1 phosphorylation in normal blood cells was evaluated by flow cytometry with intracellular staining. Plasma inhibition of IFNγ production and IFNγ-induced cytokines in normal and patient blood cells washed of autologous plasma was also evaluated.

Results

Patient plasma contained high-titer IgG anti-IFNγ autoantibodies, primarily of the IgG₁ subclass. Patient but not control plasma prevented IFNγ-induced STAT1 phosphorylation and expression of the IFNγ-inducible cytokines tumor necrosis factor (TNF) α and interleukin (IL)-12 in normal blood cells. Patient blood cells washed free of autologous plasma demonstrated normal IFNγ production and response.

Conclusions

Disseminated nontuberculous mycobacterial infections should always prompt immune evaluation. This first case of disseminated nontuberculous mycobacterial infection and anti-IFNγ autoantibodies in an American-born Caucasian suggests that anti-cytokine autoantibodies are not racially or regionally restricted.     

Differences in Weight Loss Across Different BMI Classes:A Meta-analysis of the Effects of Interventions with Diet and Exercise

Background

Lifestyle interventions are effective for weight loss and are recommended for persons with a body mass index (BMI) of 25–40 kg m^?2. However, this group is very heterogeneous, which could influence outcomes from lifestyle interventions.

Purpose

In this systematic review, differences in 1-year weight change and percentage weight change after lifestyle interventions were investigated for participants varying in initial BMI using meta-analyses.

Method

Twenty-two interventions with healthy Caucasian adults, a mean BMI between 25 and 40 kg m^?2, a dietary as well as a physical activity component aiming at weight loss, and at least five contact sessions guided by a professional health care provider were selected from a systematic search in the MEDLINE database. Participants in each intervention were divided into one of the three BMI classes: overweight (BMI of 25–29.99 kg m^?2), class-I obesity (BMI of 30–34.99 kg m^?2), and class-II obesity (BMI of 35–39.99 kg m^?2). Differences in weight change and percentage weight change were analyzed and compared among different BMI classes within the same intervention by calculating standardized mean differences.

Results

Overweight participants lost 1.1 kg less (p?p?Conclusion Average weight change during lifestyle interventions only differs to a small extent among people with BMI between 25 and 40 kg m^?2. This implies that these interventions are equally appropriate for these BMI classes.     

Beliefs About Expectations Moderate the Influence of Expectations on Pain Perception

Background

Expectations congruently influence, or bias, pain perception. Recent social psychological research reveals that individuals differ in the extent to which they believe in expectation biases and that individuals who believe in expectation biases may adjust for this bias in their perceptions and reactions. That is, idiosyncratic beliefs about expectations can moderate the influence of expectations on experience.

Purpose

Prior research has not examined whether idiosyncratic beliefs about expectations can alter the degree to which one's expectations influence pain perception. Using a laboratory pain stimulus, we examined the possibility that beliefs about expectation biases alter pain responses following both pain- and placebo-analgesic expectations.

Methods

Participants' beliefs about expectation biases were measured. Next, participants were randomly assigned to receive either a pain expectation or a placebo-analgesia expectation prior to a cold-pressor task. After the task, participants rated their pain.

Results

Beliefs about expectation biases significantly influenced pain reports. Specifically, pain reports were more influenced by provided expectations the less participants believed in expectation biases (i.e., pain expectations resulted in more pain than analgesia expectations).

Conclusions

Beliefs about the expectation bias are an important and under-examined predictor of pain and placebo analgesia.     

Evaluation of the physician quality improvement initiative: the expected and unexpected opportunities

Background

The Physician Quality Improvement Initiative (PQII) uses a well-established multi-source feedback program, and incorporates an additional facilitated feedback review with their department chief. The purpose of this mixed methods study was to examine the value of the PQII by eliciting feedback from various stakeholders.

Methods

All participants and department chiefs (n?=?45) were invited to provide feedback on the project implementation and outcomes via survey and/or an interview. The survey consisted of 12 questions focused on the value of the PQII, it’s influence on practice and the promotion of quality improvement and accountability.

Results

A total of 5 chiefs and 12 physician participants completed semi structured interviews. Participants found the PQII process, report and review session helpful, self-affirming or an opportunity for self-reflection, and an opportunity to engage their leaders about their practice. Chiefs indicated the sessions strengthened their understanding, ability to communicate and engage physicians about their practice, best practices, quality improvement and accountability.Thirty participants (66.7 %) completed the survey; of the responders 75.9, 89.7, 86.7 % found patient, co-worker, and physician colleague feedback valuable, respectively. A total of 67.9 % valued their facilitated review with their chief and 55.2 % indicated they were contemplating change due to their feedback. Participants believed the PQII promoted quality improvement (27/30, 90.0 %), and accountability (28/30, 93.3 %).

Conclusions

The PQII provides an opportunity for physician development, affirmation and reflection, but also a structure to further departmental quality improvement, best practices, and finally, an opportunity to enhance communication, accountability and relationships between the organization, department chiefs and their staff.

     

Maturity-Associated Variation in Physical Activity and Health-Related Quality of Life in British Adolescent Girls: Moderating Effects of Peer Acceptance

Background

Using a Biocultural Model of Maturity-Associated Variance in physical activity (PA) as a conceptual framework, the main and interactive effects of biological maturity status and perceived peer acceptance on PA and health-related quality of life (HRQoL) in adolescent girls were examined.

Methods

Three hundred forty-two female British students in years 7 to 9 (13.2?±?0.83 years) participated in the study. All participants completed the PA Questionnaire for Adolescents and KIDSCREEN-10, a measure of HRQoL. Self-reported perceptions of peer acceptance were measured by items from the National Longitudinal Study of Adolescent Health. Maturity status was estimated as the percentage of predicted adult (mature) height attained at the time of observation.

Results

Analysis of covariance suggested an influence of peer acceptance on maturity-associated differences in PA, but not on HRQoL. Girls early and “on time” in maturation with higher perceptions of peer acceptance reported greater involvement in PA than girls early and “on time” in maturation with lower perceptions of peer acceptance. A reverse association was observed for late-maturing girls.

Conclusions

Peer acceptance is an important moderator of maturity-associated variation in PA.     

Central and peripheral adjustments during high-intensity exercise following cold water immersion

Purpose

We investigated the acute effects of cold water immersion (CWI) or passive recovery (PAS) on physiological responses during high-intensity interval training (HIIT).

Methods

In a crossover design, 14 cyclists completed 2 HIIT sessions (HIIT1 and HIIT2) separated by 30 min. Between HIIT sessions, they stood in cold water (10 °C) up to their umbilicus, or at room temperature (27 °C) for 5 min. The natural logarithm of square-root of mean squared differences of successive R–R intervals (ln rMSSD) was assessed pre- and post-HIIT1 and HIIT2. Stroke volume (SV), cardiac output ( $ \dot{Q} $ ), O₂ uptake ( $ \dot{V} $ O₂), total muscle hemoglobin (t _Hb) and oxygenation of the vastus lateralis were recorded (using near infrared spectroscopy); heart rate, $ \dot{Q} $ , and $ \dot{V} $ O₂ on-kinetics (i.e., mean response time, MRT), muscle de-oxygenation rate, and anaerobic contribution to exercise were calculated for HIIT1 and HIIT2.

Results

ln rMSSD was likely higher [between-trial difference (90 % confidence interval) [+13.2 % (3.3; 24.0)] after CWI compared with PAS. CWI also likely increased SV [+5.9 % (?0.1; 12.1)], possibly increased $ \dot{Q} $ [+4.4 % (?1.0; 10.3)], possibly slowed $ \dot{Q} $ MRT [+18.3 % (?4.1; 46.0)], very likely slowed $ \dot{V} $ O₂ MRT [+16.5 % (5.8; 28.4)], and likely increased the anaerobic contribution to exercise [+9.7 % (?1.7; 22.5)].

Conclusion

CWI between HIIT slowed $ \dot{V} $ O₂ on-kinetics, leading to increased anaerobic contribution during HIIT2. This detrimental effect of CWI was likely related to peripheral adjustments, because the slowing of $ \dot{V} $ O₂ on-kinetics was twofold greater than that of central delivery of O₂ (i.e., $ \dot{Q} $ ). CWI has detrimental effects on high-intensity aerobic exercise performance that persist for ≥45 min.     

Weight Perception and Dietary Intake among Chinese Youth, 2004–2009

Background

Little is known on the extent of weight misperception and its relation with dietary intake among Chinese youth.

Purpose

The study aimed to investigate extent and correlates of weight misperception and its relation with dietary intake among Chinese youth.

Method

Data pertaining to Chinese youth, 6–17 years of age, from the 2004–2009 China Health and Nutrition Survey (N?=?3,923) were analyzed using STATA version 12.1. The heights and weights of the participants were measured by well-trained health workers at the participants' homes or a local clinic following the reference protocol recommended by the World Health Organization. The dietary intake data of the participants were collected on three consecutive days at both the household and individual levels.

Results

Of the children 6–11 years of age, 18.9 % were underweight and 15.3 % were overweight. Among the children 12–17 years of age, 18.3 % were underweight and 8.1 % were overweight. Less than 60 % of Chinese youth accurately estimated their weight status. Nutrition knowledge was positively related to a perception of being overweight (adjusted odds ratio [AOR]?=?1.98, p?=?.007) among children 12–17 years of age. A perception of being overweight was positively associated with fat and protein intake among children 6–11 years of age (p?<?.05).

Conclusions

A discrepancy exists between the actual and perceived weight status of Chinese youth. Efforts are needed in China to promote accurate weight perception, healthy weight, and eating behaviors.     

Vitamin E protects chondrocytes against hydrogen peroxide-induced oxidative stress in vitro

Objective and design

This study evaluated the effect of an antioxidant, Vitamin E, on cultured chondrocytes against H₂O₂-induced damage in vitro.

Material

Rat chondrocytes isolated from articular cartilage.

Treatment

Chondrocytes were pretreated with either 50 or 100 μM Vitamin E or serum-free medium for 24 h followed by their exposure to 200 μM H₂O₂ for 3 h. Chondrocytes without exposure to H₂O₂ served as control group.

Methods

The effect of Vitamin E pretreatment was evaluated by examining proteoglycan contents, nitrite levels, viability, apoptosis, and senescence of cultured chondrocytes.

Results

Proteoglycan contents increased in groups treated with Vitamin E. Semi-quantitative real-time PCR data also correlated with these results and demonstrated that Vitamin E up-regulated expression of Agc1, Col2a1, and PCNA genes along with down-regulation in the expression of Col1a1 and Casp3 genes. The differentiation index improved after Vitamin E pretreatment. Nitrite levels were reduced with a corresponding increase in cell viability. Reduction in apoptosis and senescence was also observed after Vitamin E pretreatment. Moreover, a dose-dependent effect of Vitamin E was seen. In contrast to 50 μM Vitamin E, 100 μM was more potent in inducing protection of chondrocytes from H₂O₂-induced oxidative damage.

Conclusion

Vitamin E reversed the oxidant-induced alterations in chondrocytes and may be a good option to pretreat chondrocytes before transplantation.