Australian dental policy reform and the use of dental therapists and hygienists

Oral diseases including dental caries and periodontal disease are among the most prevalent and costly diseases in Australia today. Around 5.4% of Australia’s health dollar is spent on dental services totalling around $2.6 billion, 84% of which are delivered through the private sector (AIHW 2001). The other 16% is spent providing public sector services in varied and inadequate ways. While disease rates among school children have declined significantly in the past 20 years the gains made among children are not flowing on to adult dentitions and our aging population will place increasing demands on an inadequate system into the future (AHMAC 2001). Around 50% of adults do not received regular care and this has implications for widening health inequalities as the greatest burden falls on lower income groups (AIHW DSRU 2001). The National Competition Policy agenda has initiated, Australia-wide, reviews of dental legislation applying to delivery of services by dentists, dental specialists, dental therapists and hygienists and dental technicians and prosthetists. The review of the Victorian Dentists Act 1972, was completed first in 1999, followed by the other Australian states with Queensland, the ACT and the Northern Territory still developing legislation. One of the objectives of the new Victorian Act is to ‘…promote access to dental care’. This study has grown out of the need to know more about how dental therapists and hygienists might be utilised to achieve this and the legislative frameworks that could enable such roles. This study used qualitative methods to explore dental health policy making associated with strategies that may increase access to dental care using dental therapists and hygienists. The study used a multiple case study design to critically examine the dental policy development process around the Review of the Dentists Act 1972 in Victoria; to assess legislative and regulatory dental policy reforms in other states in Australia and to conduct a comparative analysis of dental health policy as it relates to dental auxiliary practice internationally. Data collection has involved (I) semi-structured interviews with key participants and stakeholders in the policy development processes in Victoria, interstate and overseas, and (ii) analysis of documentary data sources. The study has taken a grounded theory approach whereby theoretical issues that emerged from the Victorian case study were further developed and challenged in the subsequent interstate and international case studies. A component of this study has required the development of indicators in regulatory models for dental hygienists and therapists that will increase access to dental care for the community. These indicators have been used to analyse regulation reform and the likely impacts in each setting. Despite evidence of need, evidence of the effectiveness and efficiency of dental therapists and hygienists, and the National Competition Policy agenda of increasing efficiency, the legislation reviews have mostly produces only minor changes. Results show that almost all Australian states have regulated dental therapists and hygienists in more prescriptive ways than they do dentists. The study has found that dental policy making is still dominated by the views of private practice dentists under elitist models that largely protect dentist authority, autonomy and sovereignty. The influence of dentist professional dominance has meant that governments have been reluctant to make sweeping changes. The study has demonstrated alternative models of regulation for dental therapists and hygienists, which would allow wider utilisation of their skills, more effective use of public sector funding, increased access to services and a grater focus on preventive care. In the light of theses outcomes, there is a need to continue to advocate for changes that will increase the public health focus of oral health care.

Origins of inflated responsibility in obsessive compulsive disorder

The pivotal role of inflated responsibility beliefs in the maintenance and treatment of obsessive-compulsive disorder (OCD) has been clearly demonstrated (Rachman, 1993; Salkovskis, 1998; Shafran, 1997; van Oppen & Arntz, 1994). Yet little is known about the origins of these beliefs, their contribution to a sense of inflated responsibility or the symptoms of OCD, or the contribution of personality to inflated responsibility and to OCD, The aims of this thesis were to investigate a model of the inter-relationships among the personality dimensions of neuroticism and psychoticism, inflated responsibility and OCD, and the origins of inflated responsibility to inflated responsibility and to OCD. In order to achieve these aims, a scale was developed to assess the origins of inflated responsibility based upon the five pathways proposed by Salkovskis, Shafran, Rachman, and Freeston (1999) and the additional domains of guilt, vigilance and thought-action fusion (Shafran, Thordarson, & Rachman, 1996; Shafran, Watkins & Charman, 1996; Tallis, 1994). Eighty-four participants with OCD (age M = 43.36) and 74 control participants (age M =37.14) volunteered to participate in the two studies of this thesis. The aim of Study 1 was to develop and validate a measure of the Origins of Inflated Responsibility (OIR). The results of the first study yielded a 25-ttem scale, the Origins of Inflated Responsibility Questionnaire (OIRQ) with five independent factors: responsibility, strictness, protection from responsibility, critical incidents, and peer blame which demonstrated both internal reliability and temporal stability over a 2-week period. In Study 2, participants also completed the Responsibility Attitudes Scale (Salkovskis, Wroe, Gledhill, Morrison, Forrester, Richards, ct al. (2000) (a measure of inflated responsibility), the Padua Inventory (Sanavio, 1988) (to measure of the symptoms of OCD)y and the Eysenck Personality Inventory-Revised (Eysenck & Eysenck, 1991). Multivariatc Analysis of Variance revealed that the OCD group scored higher on all variables than the control group except for strictness where the groups were not different, and psychoticism where the OCD group scored lower. A series of Multiple Regression analyses revealed that both group and the OIR contributed to inflated responsibility (R2 = .56). When all variables, OIR, inflated responsibility and neuroticism were entered as predictors of OCD, 60% of the variance in OCD was explained however, 49% of the variance was shared by the independent variables suggesting the presence of some underlying construct. Structural Equation Modelling, where all the constructs in the model were examined simultaneously, revealed that neuroticism contributed to the OIR, inflated responsibility and OCD. The OIR were also significant predictors of inflated responsibility and indirectly through inflated responsibility predictive of OCD. The OIR also directly predicted OCD and when the total effects are considered, their contribution was greater than the total effect for inflated responsibility alone. The results of these studies provide good support for the origins of inflated responsibility proposed by Salkovskis et al. (1999), as measured by the OIRQ developed for use in the current thesis. The results also support the contribution of inflated responsibility and neuroticism, as well as the OIR, to OCD, The large amount of variance shared by the OIR, inflated responsibility and neuroticism suggest that there might be some underlying construct, perhaps of a biopsychosocial nature, that requires further investigation for its role in the onset and maintenance of OCD. The clinical relevance of these findings is discussed in terms of early prevention strategies and interventions.

Regulation of insulin signalling by exercise in skeletal muscle

Regular physical activity improves insulin action and is an effective therapy for the treatment and prevention of type 2 diabetes. However, little is known of the mechanisms by which exercise improves insulin action in muscle. These studies investigate the actions of a single bout of exercise and short-term endurance training on insulin signalling. Twenty-four hours following the completion of a single bout of endurance exercise insulin action improved, although greater enhancement of insulin action was demonstrated following the completion of endurance training, implying that cumulative bouts of exercise substantially increase insulin action above that seen from the residual effects of an acute bout of prior exercise. No alteration in the abundance and phosphorylation of proximal members of the insulin-signalling cascade in skeletal muscle, including the insulin receptor and IRS-1 were found. A major finding however, was the significant increase in the serine phosphorylation of a known downstream signalling protein, Akt (1.5 fold, p ≤0.05) following an acute bout of exercise and exercise training. This was matched by the observed increase in protein abundance of SHPTP2 (1.6 fold, p ≤0.05) a protein tyrosine phosphatase, in the cytosolic fraction of skeletal muscle following endurance exercise. These data suggest a small positive role for SHPTP2 on insulin stimulated glucose transport consistent with transgenic mice models. Further studies were aimed at examining the gene expression following a single bout of either resistance or endurance exercise. There were significant transient increases in IRS-2 mRNA concentration in the few hours following a single bout of both endurance and resistance exercise. IRS-2 protein abundance was also observed to significantly increase 24-hours following a single bout of endurance exercise indicating transcriptional regulation of IRS-2 following muscular contraction. One final component of this PhD project was to examine a second novel insulin-signalling pathway via c-Cbl tyrosine phosphorylation that has recently been shown to be essential for insulin stimulated glucose uptake in adipocytes. No evidence was found for the tyrosine phosphorylation of c-Cbl in the skeletal muscle of Zucker rats despite demonstrating significant phosphorylation of the insulin receptor and Akt by insulin treatment and successfully immunoprecipitating c-Cbl protein. Surprisingly, there was a small but significant increase in c-Cbl protein expression following insulin-stimulation, however c-Cbl tyrosine phosphorylation does not appear to be associated with insulin or exercise-mediated glucose transport in skeletal muscle.

Fracturing the façade : exploring the impact of childhood sexual abuse

Examination of previous empirical literature illustrates how researchers have concentrated on documenting the impact of childhood sexual abuse (CSA) on the later psychological functioning of survivors, through comparisons with those who have not had such a history. Only more recently has there been a focus on assessing the relationship between aspects of the abuse and specific psychological difficulties. This thesis investigated the relationships between CSA characteristics and women’s later psychological adjustment. The role of attributions, coping methods, parenting competency and marital satisfaction were also investigated. Qualitative data on perception of benefit and general reflections of participants were used to explore participants’ self-esteem, locus of control, decisions relating to parenting, disclosure experiences, and attributions in relation to their abuse, including the search for meaning. Recruitment through newspapers and counselling services led to 118 women volunteering to complete a questionnaire evaluating the characteristics of their CSA and their current psychological adjustment. Of this group, 33 subsequently volunteered to participate in a telephone interview that explored in greater depth issues related to the long-term impact of their CSA. Both quantitative and qualitative analyses were conducted on the data. The women reported a high prevalence of dysfunction in their families of origin. Abuse had generally commenced by middle childhood, and lasted for a number of years and often involved a number of perpetrators. Perpetrators were most likely to be intrafamilial, with stepfathers being over-represented. Sexual activities generally involved physical contact, with participation often induced by the use of coercion. Participants demonstrated significant difficulties in psychological adjustment, but attributions regarding the abuse improved over time. Some concerns were expressed regarding parenting competency, and avoidant coping methods were favoured. In general, participants were satisfied with their current marital relationship. Significant associations were found between coping methods, attributional style, beliefs and various psychological adjustment measures. Participants, in general, demonstrated low self-esteem and displayed an external locus of control. As a consequence of their experience of CSA, many participants reported they had decided not to have children. For those who did have children, CSA was almost universally seen as having had an impact on their parenting. Disclosure of CSA was usually delayed for a number of years, with poor outcomes generally resulting from disclosure when it occurred. Women with current partners rated them as very caring and not controlling. Participants were generally still searching for meaning in their abuse, despite many having accepted it. Survivors outlined an extensive range of long-term effects of CSA, and nominated a number of strategies that would assist in reducing these effects. The results of the study indicated that there are a number of characteristics associated with CSA which signal a higher risk of difficulties in psychological adjustment. Concerns of survivors regarding parenting were confirmed according to those who undertook this role. Unfortunately, concerns expressed by survivors that disclosure of their CSA would have had negative consequences was usually the case when they did finally disclose. However, the accessing of social and family support appeared to have an important role in changing the attributions of survivors regarding their CSA. Furthermore, change of attributions in relation to abuse may provide the key to resilience in survivors against the negative impact of CSA on later psychological adjustment.

Energetics of interlimb coordination

While the traditional dependent variables of motor skill learning are accuracy and consistency of movement outcome, there has been increasing interest in aspects of motor performance that are described as reflecting the ‘energetics’ of motor behaviour. One defining characteristic of skilled motor performance is the ability to complete the task with minimum energy expenditure (Sparrow & Newell, 1998). A further consideration is that movements also have costs in terms of cognitive ‘effort’ or ‘energy’. The present project extends previous work on energy expenditure and motor skill learning within a coordination dynamics framework. From the dynamic pattern perspective, a coordination pattern lowest on the 11KB model potential curve (Haken, Kelso & Bunz, 1985) is more stable and least energy is required to maintain pattern stability (Temprado, Zanone, Monno & Laurent, 1999). Two experiments investigated the learning of stable and unstable coordination patterns with high metabolic energy demand. An experimental task was devised by positioning two cycle ergometers side-by-side, placing one foot on each, with the pedals free to move independently at any metronome-paced relative phase, Experiment 1 investigated practice-related changes to oxygen consumption, heart rate, relative phase, reaction time and muscle activation (EMG) as participants practiced anti-phase, in-phase and 90°-phase cycling. Across six practice trials metabolic energy cost reduced and AE and VE of relative phase declined. The trend in the metabolic and reaction time data and percent co-contraction of muscles was for the in-phase cycling to demonstrate the highest values, anti-phase the lowest and 90°-phase cycling in-between. It was found that anti- and in-phase cycling were both kinematically stable but anti-phase coordination revealed significantly lower metabolic energy cost. It was, therefore, postulated that of two equally stable coordination patterns, that associated with lower metabolic energy expenditure would constitute a stronger attractor. Experiment 2 was designed to determine whether a lower or higher energy-demanding coordination pattern was a stronger attractor by scanning the attractor layout at thirty-degree intervals from 0° to 330°. The initial attractor layout revealed that in-phase was most stable and accurate, but the remaining coordination patterns were attracted to the low energy cost anti-phase cycling. In Experiment 2 only 90°- phase cycling was practiced with a post-test attractor layout scan revealing that 90°-phase and its symmetrical partner 270°-phase had become attractors of other coordination patterns. Consistent with Experiment 1, practicing 90°-phase cycling revealed a decline in AE and VE and a reduction in metabolic and cognitive cost. Practicing 90°-phase cycling did not, however, destabilise the in-phase or anti-phase coordination patterns either kinematically or energetically. In summary, the findings suggest that metabolic and mental energy can be considered different representations of a ‘global’ energy expenditure or ‘energetic’ phenomenon underlying human coordination. The hypothesis that preferred coordination patterns emerge as stable, low-energy solutions to the problem of inter-and intra-limb coordination is supported here in showing that the low-energy minimum of coordination dynamics is also an energetic minimum.

Prostate cancer : Anglo-Australian heterosexual perspectives

Prostate cancer is one of the most prominent diseases in men’s health. It is inherently 'male', given the exclusivity of the prostate gland to men’s bodies and its physiological connection to testosterone and male sexuality. The biomedical complexities of prostate cancer continue to be unravelled and researched and are often connected to identifying causes, the virtues of screening and treatment modalities. However, despite the biological male 'sex' link, most of the prostate cancer research is not connected with research on gender relations, men and masculinities. The net outcome is that men’s lives and illness experiences are absent in much of the prostate cancer research. This PhD thesis Prostate cancer: Anglo-Australian heterosexual perspectives, is an ethnographic study of thirty-five Anglo-Australian men diagnosed with prostate cancer. Participants shared their experiences of living with prostate cancer in the context of health promotion, health services and in relation to their sexuality and intimate relationships. Through participant photographic novella and in-depth semi-structured interviews, rich cultural insights are provided. A social constructionist gender analysis is used in this research that shows how the social constructions of masculinity interconnect and occasionally collide with prostate cancer throughout the illness trajectory.

Critical care nurses' haemodynamic decision making

For cardiac surgical patients, the immediate 2-hour recovery period is distinguished by potentially life-threatening haemodynamic instability. To ensure optimum patient outcomes, nurses of varying levels of experience must make rapid and accurate decisions in response to episodes of haemodynamic instability. Decision complexity, nurses’ characteristics, and environmental characteristics, have each been found to influence nurses' decision making in some form. However, the effect of the interplay between these influences on decision outcomes has not been investigated. The aim of the research reported in this thesis was to explore variability in critical care nurses' haemodynamic decision making as a function of interplay between haemodynamic decision complexity, nurses' experience, and specific environmental characteristics by applying a naturalistic decision making design. Thirty-eight nurses were observed recovering patients in the immediate 2-hour period after cardiac surgery. A follow-up semi-structured interview was conducted. A naturalistic decision making approach was used. An organising framework for the goals of therapy related to maintaining haemodynamic stability after cardiac surgery was developed to assist the observation and analysis of practice. The three goals of therapy were the optimisation of cardiovascular performance, the promotion of haemostasia, and the reestablishment of normothermia. The research was conducted in two phases. Phase One explored issues related to observation as method, and identified emergent themes. Phase Two incorporated findings of Phase 1, investigating the variability in nurses' haemodynamic decision making in relation to the three goals of therapy. The findings showed that patients had a high acuity after cardiac surgery and suffered numerous episodes of haemodynamic instability during the immediate 2-hour recovery period. The quality of nurses' decision making in relation to the three goals of therapy was influenced by the experience of the nurse and social interactions with colleagues. Experienced nurses demonstrated decision making that reflected the ability to recognise subtle changes in haemodynamic cues, integrate complex combinations of cues, and respond rapidly to instability. The quality of inexperienced nurses' decision making varied according to the level and form of decision support as well as the complexity of the task. When assistance was provided by nursing colleagues during the reception and recovery of patients, the characteristics of team decision making were observed. Team decision making in this context was categorised as either integrated or non integrated. Team decision making influenced nurses' emotions and actions and decision making practices. Findings revealed nurses' experience affected interactions with other team members and their perceptions of assuming responsibility for complex patients. Interplay between decision complexity, nurses' experience, and the environment in which decisions were made influenced the quality of nurses' decision making and created an environment of team decision making, which, in turn, influenced nurses' emotional responses and practice outcomes. The observed variability in haemodynamic decision making has implications for nurse education, nursing practice, and system processes regarding patient allocation and clinical supervision.

Social control, self-control and psychosocial problems in adolescent males

‘Psychosocial problems’ are psychological problems that are regarded as resulting from the interaction between the adaptive capacities of individuals and the demands of their physical and social environments. Many different factors have been theoretically proposed, and empirically established, as predictors of a range of psychosocial problems in adolescents. However, a problem exists in that this literature appears to lack an integrative framework that has validity across the range of problems that are observed. The purpose of the current research is to propose and test a model that draws together three clusters of factors that are useful in predicting the incidence of adolescent psychosocial problems. These are family structural background factors, family functioning variables and control beliefs. Data were collected from 155 adolescent males aged between 12 and 19 by a single concurrent and retrospective self-report questionnaire. This included data about the respondent (age, involvements with mental health or juvenile justice agencies) and family structural background factors (days per week worked by mother/father, occupational status for mother/father, residential mobility, number of persons in the family home). The questionnaire also incorporated the Parental Bonding Instrument (Parker, Tupling & Brown, 1979) to quantify the levels of perceived parental care and overprotection, and an adaptation of the Parental Discipline Style Scale (Shaw & Scott, 1991), to assess punitive, love withdrawing and inductive discipline practices. In addition, the (Low) Self-control Scale (Grasmick, Tittle, Bursick & Arneklev, 1993) and the Locus of Control of Behaviour Scale (Craig, Franklin, & Andrews, 1984) were used to collect data concerning adolescents’ perceived behavioural self-control and locus of control. Finally, selected sub-scales of the Child Behavior Checklist Youth Self-Report (Achenbach, 1991b) were used to collect data on the incidence of social withdrawal, somatisation, anxiety and depression, aggression and delinquency among the respondents, and in aggregated form, the incidence of ‘total problems’ and internalising and externalising behaviours. Results indicated family structural background factors, family functioning variables and control beliefs possess limited predicted validity and that the usefulness of the proposed model varies between specific psychosocial problems. Family functioning variables were generally stronger predictors than family structural background factors, particularly for internalising behaviours. Of these, levels of parental care and overprotection were generally the strongest predictors. Perceived self-control and locus of control were also generally strong predictors, but were particularly powerful with respect to externalising behaviours. The strength of predictive relationships was observed to vary between specific internalising and externalising behaviours, suggesting that individual difference variables not assessed in the current research were differentially influential. Finally, the parental and individual characteristics that predicted maximal levels of adjustment (defined in terms of minimal levels of internalising and externalising behaviours) were explored and the correlates of various parenting style typologies (Parker et al., 1979) were investigated. These results strongly confirmed the importance of family functioning and control beliefs with respect to the prediction of internalising, externalising and well-adjusted behaviours. In all analyses, substantial proportions of the variance in the incidence of problem behaviours remain unexplained. The findings are examined in relation to previous research focused on (familial) social control and (individual) self-control with respect to psychosocial problems in adolescents. In addition, methodological considerations are discussed and the implications of the findings for clinical and community interventions to address problem behaviours, and for further study, are explored.

Family food environments as determinants of children's eating : implications for obesity prevention

The prevalence of childhood obesity is escalating rapidly and it considered to be a major public health problem. Diet is a recognised precursor of fatness, and current evidence supports the premise that in Westernised countries, the dietary intakes of children are likely to be important in obesity genesis. However, we have a relatively poor understanding of the environments in which a child’s eating is learnt and maintained. Much of the existing work in this area is based on small-scale or experimental studies, or has been derived from homogeneous populations within the USA. Despite these limitations, there is evidence that aspects of the child’s family environment are likely to be important in determining obesity risk in children. This thesis examines the impact of the family food environment on a child’s eating through two related studies. The first study, titled the Children and Family Eating (CAFÉ) study comprised three phases. Phase one involved qualitative interviews with 17 parents of 5-6 year-old children to explore parental perceptions regarding those factors in a child’s environment believed to influence the development of their child’s eating habits. These interviews were used to inform the development of quantitative measures of the family food environment. The second phase involved the development of a Food Frequency Questionnaire (FFQ) to assess dietary intake in 5-6 year-olds. The FFQ was informed by analysis of 1995 Australian National Nutrition Survey data. In the final phase the relationships between dietary intakes of 5-6 year-old children, and potential predictors of dietary intake were examined in a cross-sectional study of 560 families. Predictors included measures of: parental perceptions of the adequacy of their child’s diet; food availability and accessibility; child-feeding; the opportunities for parental modelling of food intake; a child’s television exposure; maternal Body Mass Index; and maternal education. Analysis of the CAFÉ data provides unique information regarding the relationships between a child’s family food environment and their food consumption. Models developed for a range of dietary outcomes considered to be predictive of increased risk for obesity, including total energy and fat intakes, vegetable variety, vegetable consumption, and high-energy (non-dairy) fluid consumption, explained between 11 and 20 percent of the variance in dietary intake. Two aspects of the family food environment, parental perception of a child’s dietary adequacy, and the total minutes of television viewed per day, were frequently found to be predictive of dietary outcomes likely to promote fatness in these children. The second study, titled the Parent Education and Support (PEAS) Feeding Intervention Study, was a prospective pre/post non-randomised intervention trial that assessed the impact of a feeding intervention to 240 first-time mothers of one-year-old children. This intervention focused on one aspect of the family food environment, child-feeding, which has been proposed as influential in the development of obesogenic eating behaviours. In this study, Maternal and Child Health Nurses (MCHNs), using a ‘Division of Responsibility’ model of feeding, taught parents to provide nutritious food at regular intervals and to let children decide if to eat and how much to eat. Thus parents were encourages to food their child without exerting pressure, or employing coercion or rewards (controlling behaviours). The aim was to influence parental attitudes and beliefs regarding child-feeding. Through the use of these feeding techniques, this intervention also aimed to increase the variety of fruits and vegetables a child consumed by teaching parents to persist with offering these foods, over the year of the intervention, in non-emotive environments. Fruits and vegetables were chosen in this intervention because they are likely to be protective in the development of obesity. Analysis of the PEAS data suggests that this low-level feeding intervention, delivered through existing Maternal and Child Health services, was modestly effective in changing parental attitudes and beliefs regarding the feeding of young children. Further, the validity of fruits offered to intervention group children increased. This thesis expands the existing knowledge base by providing a comprehensive analysis of the relative impact of aspects of the family environment on dietary intakes of 5-6 year-olds. Further, the analysis of a feeding intervention in first-time parents provides important insights regarding the potential to influence child-feeding and the impact this may have on the promotion of eating behaviours protective against obesity.

Exercise, muscle glycogen and insulin action

The aim of this thesis was to investigate the influence of muscle glycogen concentration on whole body insulin stimulated glucose uptake in humans and to examine the potential signalling mechanisms responsible for enhanced insulin action in the post exercise period. Untrained male subjects were conditioned to achieve a range of muscle glycogen concentrations via acute exercise or a combination of exercise and diet. The influence of muscle glycogen content on whole body insulin stimulated glucose uptake was determined via hyperinsulinaemic / euglycaemic clamps conducted at rest, 30 min after exercise or 24 hours after exercise. Muscle glycogen content did not influence insulin mediated glucose disposal either 30 min or 24 hrs after exercise when compared with basal. Conventional insulin signalling to muscle glucose uptake and signalling through the p38 MAPK cascade was also largely unaltered by glycogen concentration. Muscle glycogen synthesis was significantly increased in heavily but not moderately glycogen depleted muscle 30 min after exercise. Enhanced muscle glycogen synthesis occurred in line with a significant increase in insulin stimulated GSK-3 serine phosphorylation. This finding suggests that enhanced insulin sensitivity of muscle glycogen synthesis following glycogen depleting exercise may be mediated via a pathway involving alterations in insulin stimulated GSK-3 phosphorylation. In summary, whilst glycogen influences insulin mediated GSK-3 phosphorylation and glycogen synthesis, the findings of the present series of investigations suggest that the role of muscle glycogen in the process of insulin stimulated glucose uptake may not be as important as previously theorised.

When the whole 'bloke' thing starts to crumble : men's access to chronic illness (arthritis) self management programs

This thesis explores the issue of men's access to chronic illness self management programs from a social constructionist perspective. A combination of research methodologies was used; a quantitative analysis to confirm gender differences in levels and patterns of service use; a qualitative analysis to gain an increased understanding of the factors affecting men's access; and a trial to test the application of the research findings. The clients and services of Arthritis Victoria were chosen as the setting for this research. The quantitative analyses were conducted on contingency tables and odds ratios and confirmed that men were under-represented as service users. The analyses also identified gender differences in patterns of service use. The qualitative analysis was based on a series of in-depth, semi-structured interviews. It was undertaken from a grounded theory approach to allow for the development of theoretical explanations grounded in the data. It was found that men's decisions to access chronic illness self management programs were strongly influenced by dominant social constructions of masculinity which constrained help-seeking and health management behaviour. However, the restrictive influence of hegemonic masculinity was progressively undermined by the increasing severity of the chronic condition until a crisis point was reached in terms of the severity of the condition or its impact on lifestyle. This resulted in a reformulation or rejection of hegemonic masculinity. The described conceptual framework was consistent for men from diverse social groupings, although it appeared less prominent in both younger and older men, suggesting that dominant social constructions of masculinity have the greatest influence on health decisions during the middle stage of adulthood when work and family obligations are greatest. The thesis findings informed the development of some guiding principles for reviewing the structure and delivery of chronic illness self management services for men. The guiding principles will have direct application in the planning of Arthritis Victoria programs, and implications for other chronic illness self management programs in Australia, and also in Western countries with a similar health and sociocultural setting to Australia.

Phospholipase activity in human mesenteric ischaemia and infarction

Currently, diagnostic tests for mesenteric ischaemia and infarction are inadequate due to poor sensitivity and specificity. In addition, many potential markers appear too late to be clinically useful. At present, definitive diagnosis can only be made at the time of surgery, which is not ideal as surgery is often to be avoided in critically ill and elderly patients. A clinically useful, minimally invasive test is likely to decrease the currently very high mortality rate and allow monitoring of 'at risk' patients during their hospital stay. A two-dimensional electrophoresis based proteomic approach was undertaken to assess plasma protein differences between patients with surgically confirmed bowel infarction and control Intensive Care patients. The major protein differences were found to be members or variants of acute phase proteins. Serum amyloid A showed the largest difference between the two patient groups, and this protein was investigated in greater depth. An analysis was performed to compare the diagnostic ability of several commonly used indicators of critical illness and bowel infarction with serum amyloid A and phospholipase A2. Although none of the variables were ideal for clinical use, plasma phospholipase A2 activity showed the best discriminatory power, as determined by Receiver Operating Characteristic curves. From a review of the literature, phospholipase AI (PLA2) appeared to be increased in the bowel as a result of ischaemia and infarction. In one patient, matched tissues were obtained, and PLA2 activity was found to be significantly higher in infarcted bowel tissue compared to ischaemic bowel tissue. PLA2 activity was significantly greater in bowel lumen than tissue, suggesting that the protein was being released, and may enter the circulation. PLA2 activity was increased in the plasma of bowel infarction patients compared with control patients, though the difference was not significant. The phospholipase activity exhibited a number of similarities to typical phospholipase A2 proteins, but also showed a number of inconsistent characteristics. For this reason, we wished to identify the protein responsible for the increased phospholipase activity in infarcted human bowel. The PLA2 activity in human bowel could not be abolished by immunoprecipitation of the PLA2 isoforms IIA (well described in bowel) and V (a closely related isoform). To investigate these proteins, a native urea protein gel devised for snake venom phospholipase A2 was modified for use with mammalian phospholipase AI. The modified gel was used to show that the protein with phospholipase activity from infarcted gut was different from normal gut PLA2 and type IIA PLA2. A number of extensions were devised for these native gels and were found to be useful both in this investigation and for venom investigations. Protein purification was undertaken to identify the protein responsible for the increased phospholipase activity in infarcted bowel. Protein was purified from infarcted human bowel using a number of techniques that exploited unusual characteristics of the protein. The purification techniques each retained the native activity of the protein and the purification could therefore be monitored with a phospholipid hydrolysis assay at each stage. The protein identified by mass spectrometry was an excellent match for cyclophilin B, an inflammatory protein that had previously been identified in rat bowel at the mRNA level (Hasel et al, 1991, Kainer & Doris, 2000). As the purification progress had been monitored throughout with a phospholipid hydrolysis assay, cyclophilin B was an unexpected identification, as it is not known to have phospholipase activity. Cyclophilin B was removed from the highly purified samples via immunoprecipitation and this process abolished all phospholipase activity. The addition of cyclosporin A, (the pharmaceutical ligand of cyclophilin B), did not effect the phospholipase activity. Cyclophilin B protein was found in normal and infarcted human bowel using Western blotting. Cyclophilin B protein also appeared to be present in the bowel lumen and plasma of several patients with bowel infarction, but not in control patients. Immunohistochemistry confirmed the ubiquitous nature of cyclophilin B that had been reported by other groups. This project has investigated the use of two dimensional gel electrophoresis based proteomics to identify proteins present in the plasma of patients with confirmed bowel infarction and control intensive care patients. The major protein classes observed were members of the acute phase proteins, which highlights the need for pre-fractionation of plasma to identify lower abundance, disease associated proteins. A series of potential plasma markers were compared using Receiver Operating Characteristic Curves. Although no ideal marker was clear from this analysis, phospholipase activity appeared to warrant further investigation. Phospholipase activity was investigated in human infarcted bowel. Protein purification identified cyclophilin B as a bowel protein that showed unusual phospholipid hydrolysing activity. Cyclophilin B is a ubiquitous protein in intestinal cell types in both normal and infarcted tissue. There appears to be release of cyclophilin B into bowel lumen and plasma under conditions of mesenteric ischaemia and infarction.

Identification and characterisation of novel genes involved in skeletal muscle hypertrophy

There is mounting evidence in support of the view that skeletal muscle hypertrophy results from the complex and coordinated interaction of numerous signalling pathways. Well characterised components integral to skeletal muscle adaptation include the transcriptional activity of the members of the myogenic regulatory factors, numerous secreted peptide growth factors, and the regenerative potential of satellite cells. Whilst studies investigating isolated components or pathways have enhanced our current understanding of skeletal muscle hypertrophy, our knowledge of how all of these components react in concert to a common stimulus remains limited. The broad aim of this thesis was to identify and characterise novel genes involved in skeletal muscle hypertrophy. We have created a customised human skeletal muscle specific microarray which contains ∼11,000 cDNA clones derived from a normalised human skeletal muscle cDNA library as well as 270 genes with known functional roles in human skeletal muscle. The first aspect of this thesis describes the production of the microarray and evaluates the robustness and reproducibility of this analytical technique. Study one aimed to use this microarray in the identification of genes that are differentially expressed during the forced differentiation of human rhabdomyosarcoma cells, an in vitro model of skeletal muscle development. Firstly using this unique model of aberrant myogenic differentiation we aimed to identify genes with previously unidentified roles in myogenesis. Secondly, the data from this study permitted the examination of the performance of the microarray in detecting differential gene expression in a biological system. We identified several new genes with potential roles in the myogenic arrest of rhabdomyosarcoma and further characterised the expression of muscle specific genes in rhabdomyosarcoma differentiation. In study two, the molecular responses of cell cycle regulators, muscle regulatory factors, and atrophy related genes were mapped in response to a single bout of resistance exercise in human skeletal muscle. We demonstrated an increased expression of MyoD, myogenin and p21, whilst the expression of myostatin was decreased. The results of this study contribute to the existing body of knowledge on the molecular regulation skeletal muscle to a hypertrophic stimulus. In study three, the muscle samples collected in study two were analysed using the human skeletal muscle specific microarray for the identification of novel genes with potential roles in the hypertrophic process. The analysis uncovered four interesting genes (TXNIP, MLP, ASB5, FLJ 38973) that have not previously been examined in human skeletal muscle in response to resistance exercise. The functions of these genes and their potential roles in skeletal muscle are discussed. In study four, the four genes identified in study three were examined in human primary skeletal muscle cell cultures during myogenic differentiation. Human primary skeletal muscle cells were derived from the vastus lateralis muscle of 8 healthy volunteers (6 males and 2 females). Cell cultures were differentiated using serum withdrawal and serum withdrawal combined with IGF-1 supplementation. Markers of the cell proliferation, cell cycle arrest and myogenic differentiation were examined to assess the effectiveness of the differentiation stimulus. Additionally, the expressions of TXNIP, MLP, ASB5 and FLJ 38973 measured in an attempt to characterise further their roles in skeletal muscle. The expression of TXNIP changed markedly in response to both differentiation stimuli, whilst the expression of the remaining genes were not altered. Therefore it was suggested that expression of these genes might be responsive to the mechanical strain or contraction induced by the resistance exercise. In order to examine whether these novel genes responded specifically to resistance type exercise, their expression was examined following a single bout of endurance exercise. The expression of TXNIP, MLP, and FLJ 38973 remained unchanged whilst ASB5 increased 30 min following the cessation of the exercise.

Exploring optimistic and pessimistic attributions in depression-specific mood

Cognitive theories of depression include maladaptive thinking styles as depressive vulnerabilities. The hopelessness theory of depression (Abramson, Metalsky, & Alloy, 1989) particularly implicates stable and global attributions for negative events as influences upon depression. Positive event attributions are considered less influential, yet they have shown equal predictiveness to negative event attributions for depression-specific mood. Previous research has provided equivocal results largely because of cross-sectional design and modest psychometric properties of the measures. The present research aimed to: create a new instrument to measure optimistic and pessimistic attributions; test the relatedness of attributions for positive and negative events; and, clarify relationships of the scales with optimism and mood. Three studies were undertaken, all of which used structural equation modeling. Two cross-sectional studies, using 342 and 332 community participants respectively, developed and validated the Questionnaire of Explanatory Style (QES). A final longitudinal study with 250 community participants tested the predictive validity of the QES. Overall, six scales were developed, three of which were optimistic and three of which were negative. The scales were acceptable to community samples and had adequate psychometric properties. The optimistic scales were attributions for positive events and the negative scales were attributions for negative events rather than pessimistic scales. Cross-sectional results indicated that only one of the negative scales weakly directly predicted depression-specific mood, but all predicted general psychological distress. By contrast, the optimistic scales were more directly predictive of depression-specific mood, particularly the Positive Disposition scale. Longitudinal results indicated that two of the optimistic scales were the most important QES predictors of depression-specific mood two months later. The optimistic scale Positive Disposition appears most central to the prediction of both concurrent and subsequent depression-specific mood. The scale content represents explanations for positive events that are internal and stable characteristics. These may be construed as personal competencies to bring about positive outcomes. This scale is closely allied to measures of optimism. Findings affirm the importance of optimistic attributions to the understanding of depression-specific mood and provide a productive focus for therapeutic intervention and future research.

Preventing weight and muscle concerns among preadolescents

The high level of weight and shape concerns amongst preadolescent children has prompted interest in the development of prevention programs for this age group. In the 1990s weight and shape concerns were considered primarily an adolescent phenomenon. However, prevention programs which have been designed with adolescent and adult populations have been found to show limited success. Some researchers have argued that programs which target preadolescent children are more likely to be effective than programs that target adolescents, as by adolescence many attitudes and behaviours have become entrenched so they may be more difficult to modify. On the other hand, children's weight and shape concerns are believed to be more malleable and amenable to change. To date there have been limited controlled studies implementing prevention programs designed to reduce weight and shape concerns with preadolescent populations. The new study conducted as part of this thesis involves the development and implementation of the ‘Everybody’ s Different, Nobody Else Is Me’ preadolescent prevention program. The program was designed to address some of the methodological biases of past research and incorporate three risk factors, social comparisons, negative affect, and self-esteem, to reduce and/or prevent the development of weight and muscle concerns among children. These three risk factors have been found to be associated with weight and shape concerns of adolescents and adults, and there is also increasing evidence that they are important factors among children. Research also suggests that social comparisons, negative affect, and self-esteem are interrelated, which highlights the importance of targeting the variables in one program. The new five session prevention initiative was implemented with 156 grade four children. Both the treatment and control conditions consisted of 78 children. Preliminary evidence from the new prevention initiative indicated that the program reduced muscle bulk and exercise (ie. An over-emphasis on exercise to lose weight rather than health promotion), and negative affect in the long term as assessed by the six month follow-up. At the six month follow-up, children in both the treatment and control conditions reported reduced negative affect, dieting, and muscle bulk and exercise scores and increased positive affect. Consistent with short term follow-up results, boys reported greater muscle bulk and exercise scores than girls at the six month follow-up. Girls, in both conditions, were also found to report greater positive affect than boys. These findings are discussed in relation to past research, and suggestions for future prevention initiatives are highlighted.