Central regulation of energy balance in Psammomys obesus

This body of work focussed on the central regulation of energy balance in a polygenic animal model of obesity and type II diabetes, the Israeli Sand Rat. These studies investigated the role of a number of hypothalamic neuropeptides in the development of obesity, and highlighted the complex nature of this disease.

Doxycycline-inducible expression of SPARC/osteonectin/BM40 in MDA-MB-231 human breast cancer cells results in growth inhibition

SPARC (secreted protein acidic and rich in cysteine)/BM40/Osteonectin is a matricellular protein with multiple effects on cell behaviour. In vitro, its major known functions are anti-adhesive and anti-proliferative, and it is associated with tissue remodelling and cancer in vivo. SPARC is overexpressed in many cancers, including breast cancer, and the effects of SPARC seem to be cell type-specific. To study the effects of SPARC on breast cancer, we transfected SPARC into the MDA-MB-231 BAG, human breast cancer cell line using the Tet-On inducible system. By western analysis, we found low background levels in the MDA-MB-231 BAG and clone X parental cells, and prominent induction of SPARC protein expression after doxycycline treatment in SPARC transfected clones X5, X21, X24 and X75. Induction of SPARC expression did not affect cell morphology or adhesiveness to collagens type I and IV, but it slowed the rate of proliferation in adherent cultures. Cell cycle analysis showed that SPARC slowed the progression to S phase. Doxycycline induction of SPARC also slowed the rate of monolayer wound closure in the cultured wound healing assay. Thymidine inhibition of proliferation abrogated this effect, confirming that it was due to anti-proliferation rather than inhibition of migration. Consistent with this, we were unable to detect any differences in migration and Matrigel outgrowth analysis of doxycycline-stimulated cells. We conclude that SPARC is inhibitory to human breast cancer cell proliferation, and does not stimulate migration, in contrast to its stimulatory effects reported for melanoma (proliferation and migration) and glioma (migration) cells. Similar growth repression by SPARC has been reported for ovarian cancer cells, and this may be a common feature among carcinoma.

Maternal prenatal mental health and placental 11β-HSD2 gene expression: initial findings from the mercy pregnancy and emotional wellbeing study

High intrauterine cortisol exposure can inhibit fetal growth and have programming effects for the child's subsequent stress reactivity. Placental 11beta-hydroxysteroid dehydrogenase (11β-HSD2) limits the amount of maternal cortisol transferred to the fetus. However, the relationship between maternal psychopathology and 11β-HSD2 remains poorly defined. This study examined the effect of maternal depressive disorder, antidepressant use and symptoms of depression and anxiety in pregnancy on placental 11β-HSD2 gene (HSD11B2) expression. Drawing on data from the Mercy Pregnancy and Emotional Wellbeing Study, placental HSD11B2 expression was compared among 33 pregnant women, who were selected based on membership of three groups; depressed (untreated), taking antidepressants and controls. Furthermore, associations between placental HSD11B2 and scores on the State-Trait Anxiety Inventory (STAI) and Edinburgh Postnatal Depression Scale (EPDS) during 12-18 and 28-34 weeks gestation were examined. Findings revealed negative correlations between HSD11B2 and both the EPDS and STAI (r = -0.11 to -0.28), with associations being particularly prominent during late gestation. Depressed and antidepressant exposed groups also displayed markedly lower placental HSD11B2 expression levels than controls. These findings suggest that maternal depression and anxiety may impact on fetal programming by down-regulating HSD11B2, and antidepressant treatment alone is unlikely to protect against this effect.

Developing effective advertising self-regulation in Australia: reflections on the old and new systems

The regulation of advertising is a controversial and difficult process. Over the past three decades, two attempts have been made in Australia to produce more acceptable ads. This paper reviews these systems using a macro framework for analysis which contextualises advertising in society. The systems have the fundamental process of handling complaints about advertising in common, however there are advantages and disadvantages of each and these are discussed. Important insights for the development of regulation of advertising are presented together with critical implications for the future of the industry.

Don't worry, be active : positive affect and habitual physical activity

Objective: The aim of ths study was to examine the association between habitual physical activity and positive and negative affect.

Method: This cross-sectional study included 276 women aged 20 +, from the Geelong Osteoporosis Study. Habitual physical activity and other lifestyle exposures were assessed by questionnaire, concurrent with anthropometric assessments. Physical activity was categorized as very active, moderately active or sedentary. Positive and negative affect scores were derived from the validated 20 item Positive and Negative Affect Schedule (PANAS) self-report and were categorized into tertiles.

Results: There was a pattern of lower positive affect scores for lower levels of physical activity. With very active as the reference category, the odds for having a positive affect score in the highest tertile were sequentially lower for those who were moderately active (OR = 0.53, 95%CI 0.28–1.01) and sedentary (OR = 0.28, 95%CI 0.10–0.75). Associations were sustained after adjusting for body mass index and polypharmacy (OR = 0.50, 95%CI 0.26–0.96 and OR = 0.25, 95%CI 0.09–0.72, respectively). These associations were not explained by age, negative affect score or other exposures. No association was detected between physical activity and negative affect scores.

Conclusions: This study reports that higher positive affect scores, encompassing emotions such as interest, excitement, enthusiasm and alertness, are associated with higher levels of habitual physical activity. These observations warrant further investigations into possible mechanistic interplay between neurobiological and psychosocial factors that underpin this association.

Concepts and factors influencing independent learning in IS higher education

The concepts of independent learning (IL), self-directed learning (SDL) and self-regulated learning (SRL) have been widely used in relation to students’ learning success. Often, these terms are interrelated and used interchangeably in the literature with regards to students’ learning process. The purpose of this paper is (1) to promote conceptual clarity by having clear definitions of SRL, SDL and IL and (2) to provide a review of research related to the development of students’ SRL at higher education particularly in the context of Information Systems studies. The findings from the literature reveal that mastering the process self-regulation progressively leads to self-directed and independent learning. The literature review on SRL reveals that students’ academic self-regulation is influenced by their personal processes such as cognitive knowledge and motivational beliefs and also external processes such as lecturers and instructions in higher education.

Human neuronal cells : epigenetic aspects

Histone acetyltransferases (HATs) and histone deacetylases (HDACs) promote histone posttranslational modifications, which lead to an epigenetic alteration in gene expression. Aberrant regulation of HATs and HDACs in neuronal cells results in pathological consequences such as neurodegeneration. Alzheimer's disease is the most common neurodegenerative disease of the brain, which has devastating effects on patients and loved ones. The use of pan-HDAC inhibitors has shown great therapeutic promise in ameliorating neurodegenerative ailments. Recent evidence has emerged suggesting that certain deacetylases mediate neurotoxicity, whereas others provide neuroprotection. Therefore, the inhibition of certain isoforms to alleviate neurodegenerative manifestations has now become the focus of studies. In this review, we aimed to discuss and summarize some of the most recent and promising findings of HAT and HDAC functions in neurodegenerative diseases.

Healthy weight regulation and eating disorder prevention in high school students: a universal and targeted web-based intervention

Background: Given the rising rates of obesity in children and adolescents, developing evidence-based weight loss or weight maintenance interventions that can be widely disseminated, well implemented, and are highly scalable is a public health necessity. Such interventions should ensure that adolescents establish healthy weight regulation practices while also reducing eating disorder risk.

Objective: This study describes an online program, StayingFit, which has two tracks for universal and targeted delivery and was designed to enhance healthy living skills, encourage healthy weight regulation, and improve weight/shape concerns among high school adolescents.

Methods: Ninth grade students in two high schools in the San Francisco Bay area and in St Louis were invited to participate. Students who were overweight (body mass index [BMI] >85th percentile) were offered the weight management track of StayingFit; students who were normal weight were offered the healthy habits track. The 12-session program included a monitored discussion group and interactive self-monitoring logs. Measures completed pre- and post-intervention included self-report height and weight, used to calculate BMI percentile for age and sex and standardized BMI (zBMI), Youth Risk Behavior Survey (YRBS) nutrition data, the Weight Concerns Scale, and the Center for Epidemiological Studies Depression Scale.

Results: A total of 336 students provided informed consent and were included in the analyses. The racial breakdown of the sample was as follows: 46.7% (157/336) multiracial/other, 31.0% (104/336) Caucasian, 16.7% (56/336) African American, and 5.7% (19/336) did not specify; 43.5% (146/336) of students identified as Hispanic/Latino. BMI percentile and zBMI significantly decreased among students in the weight management track. BMI percentile and zBMI did not significantly change among students in the healthy habits track, demonstrating that these students maintained their weight. Weight/shape concerns significantly decreased among participants in both tracks who had elevated weight/shape concerns at baseline. Fruit and vegetable consumption increased for both tracks. Physical activity increased among participants in the weight management track, while soda consumption and television time decreased.

Conclusions: Results suggest that an Internet-based, universally delivered, targeted intervention may support healthy weight regulation, improve weight/shape concerns among participants with eating disorders risk, and increase physical activity in high school students. Tailored content and interactive features to encourage behavior change may lead to sustainable improvements in adolescent health.

Dissecting ADAMTS proteoglycanase biology in development and disease

 This research was focused upon members of the ADAMTS family of 'proteinases', proteins that have enzymatic activity. Their dysregulation can cause developmental defects and disease. This thesis describes the expression and regulation of ADAMTS15, as well as new developmental functions and inhibition of ADAMTS5 in arthritis.

Trial for reducing weight retention in new mums: a randomised controlled trial evaluating a low intensity, postpartum weight management programme

BACKGROUND: Failure to return to pregnancy weight by 6 months postpartum is associated with long-term obesity, as well as adverse health outcomes. This research evaluated a postpartum weight management programme for women with a body mass index (BMI) > 25 kg m(-2) that combined behaviour change principles and a low-intensity delivery format with postpartum nutrition information. METHODS: Women were randomised at 24-28 weeks to control (supported care; SC) or intervention (enhanced care; EC) groups, stratified by BMI cohort. At 36 weeks of gestation, SC women received a 'nutrition for breastfeeding' resource and EC women received a nutrition assessment and goal-setting session about post-natal nutrition, plus a 6-month correspondence intervention requiring return of self-monitoring sheets. Weight change, anthropometry, diet, physical activity, breastfeeding, fasting glucose and insulin measures were assessed at 6 weeks and 6 months postpartum. RESULTS: Seventy-seven percent (40 EC and 41 SC) of the 105 women approached were recruited; 36 EC and 35 SC women received a programme and 66.7% and 48.6% completed the study, respectively. No significant differences were observed between any outcomes. Median [interquartile range (IQR)] weight change was EC: -1.1 (9.5) kg versus SC: -1.1 (7.5) kg (6 weeks to 6 months) and EC: +1.0 (8.7) kg versus SC: +2.3 (9) kg (prepregnancy to 6 months). Intervention women breastfed for half a month longer than control women (180 versus 164 days; P = 0.10). An average of 2.3 out of six activity sheets per participant was returned. CONCLUSIONS: Despite low intervention engagement, the high retention rate suggests this remains an area of interest to women. Future strategies must facilitate women's engagement, be individually tailored, and include features that support behaviour change to decrease women's risk of chronic health issues.

Body image and strategies to lose weight and increase muscle among boys and girls

This study examined factors that influence body image and strategies to either lose weight or increase muscle among children. Participants were 237 boys and 270 girls. Body mass index (BMI), body dissatisfaction, cognitions and behaviors to both lose weight and increase muscles, as well as self-esteem and positive and negative affect, were evaluated. Self-esteem was associated with body satisfaction, positive affect predicted strategies to lose weight and increase muscles, and negative affect predicted body dissatisfaction and cognitions to lose weight and increase muscles. Boys were more likely to focus on changing muscles. Respondents with higher BMIs were more focused on losing weight but not muscle. The discussion focuses on health risk behaviors related to eating and exercise among children.

Do logbooks influence recall of physical activity in validation studies?

Purpose: To examine whether physical activity logbooks influence estimates of validity of 7-d recall physical activity questionnaires. Methods: A  convenience sample of 551 adults aged 18–75 yr wore an MTI  accelerometer for seven consecutive days and were then randomly administered two of four 7-d recall physical activity questionnaires that varied in length and format (Active Australia Survey (AAS), long and short  International Physical Activity Questionnaires (IPAQ-L and IPAQ-S), and Behavioral Risk Factor Surveillance System (BRFSS)). A subsample of 75% concurrently completed a physical activity logbook. Results: Correlations (rho) between self-reported and measured duration of moderate- and vigorous-intensity activity and total activity were similar among participants who received a logbook and those who did not for each of the four instruments. There was also no interaction between assessment method (survey, accelerometer) and the assignment of a logbook. For the IPAQ-L, however, variability in the difference between accelerometer data and responses to the vigorous items was smaller among those assigned a logbook (F = 4.128, df = 260, P = 0.043). Overall, there were no differences in percent agreement or kappa for participation in sufficient levels of physical activity according to receipt of a logbook for any of the surveys. Conclusion: The process of self-monitoring through completion of a logbook does not appear to influence estimates of validity for brief or long questionnaires with global questions. Whereas the magnitude of error in accuracy of recall of particular types of activity may be reduced by completion of a logbook that is similar in structure to the survey being validated, this does not appear to influence overall estimates of validity.

Reducing latent deprivation during unemployment: the role of meaningful leisure activity

The aim of this study was to investigate the role of meaningful leisure activity in reducing latent deprivation during unemployment. Samples of unemployed (N=201) and employed (N=128) participants were asked to rate their levels of latent deprivation using the Access to Categories of Experience Scale. They were also asked to complete the Profile of Mood States depression subscale, Adult Self-Perception Profile, Meaningful Leisure Activities Questionnaire, and to rate the frequency with which they engaged in social and solitary leisure activities. Results indicate that unemployed participants engaged in social leisure activities less frequently than employed participants and solitary leisure activities more frequently; and they reported higher perceived latent deprivation, higher depressive affect and lower self-esteem. Overall, these findings suggest that participation in leisure activities that are meaningful, rather than simply frequent, may be a constructive and readily achievable coping response during unemployment.

Expectancy model of disordered eating : a longitudinal study

This thesis proposes a new model of disordered eating and tests it using a longitudinal design. The Expectancy Model of Disordered Eating maintains that dieting and binge eating can best be explained as a predisposition towards avoidance coping which is triggered by outcome expectancies and negative affect or low self-esteem.