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.

Correlates of screening mammography for Italian and Anglo-Australian women

The first aim of the research was to determine the applicability of certain variables from the Health Belief Model (HBM), the Theory of Reasoned Action (TRA), the risk dimensions from the Psychometric Paradigm, the Common-Sense Model of Illness Representations and the Locus of Control to Italian women’s beliefs and behaviours in relation to screening mammography. These models have predominantly been derived and evaluated with English-speaking persons. The study used quantitative and qualitative methods to enable explanation of research-driven and participant-driven issues. The second aim was to include Italian women in health behaviour research and to contrast the Italian sample with the Anglo-Australian sample to determine if differences exist in relation to their beliefs. In Australia many studies in health behaviour research do not include women whose first language is not English. The third aim was to evaluate the Anti-Cancer Council of Victoria’s (ACCV) Community Language Program (CLP) by: (a) identifying the strengths and weaknesses of the program as seen by the participants; and (b) assessing the impact of the program on women’s knowledge and beliefs about breast cancer, early detection of breast cancer, self-reported and intended breast screening behaviours. The CLP is an information service that uses women’s first language to convey information to women whose first language is not English. The CLP was designed to increase knowledge about breast and cervical cancer. The research used a pre-test-intervention-post-test design with 174 Italian-born and 138 Anglo-Australian women aged 40 years and over. Interviews for the Italian sample were conducted in Italian. The intervention was an information session that related to breast health and screening mammography. Demographic variables were collected in the Pre-Test only. Qualitative open-ended questions that related specifically to the information session were collected in the Post-Test phase of the study. Direct logistic regression was used with the participants’ beliefs and behaviours to identify the relevant variables for language (Italian speaking and English-speaking), attendance to an information session, mammography screening and breast self-examination (BSE) behaviour. Pre- and Post-Test comparisons were conducted using chi-square tests for the non-parametric data and paired sample t-tests for the parametric data. Differences were found between the Italian and Anglo-Australian women in relation to their beliefs about breast cancer screening. The Italian women were: (1) more likely to state that medical experts understood the causes of breast cancer; (2) more likely to feel that they had less control over their personal risk of getting breast cancer; (3) more likely to be upset and frightened by thinking about breast cancer; (4) less likely to perceive breast cancer as serious; (4) more likely to only do what their doctor told them to do; and (5) less likely to agree that there were times when a person has cancer and they don’t know it. A pattern emerged for the Italian and Anglo-Australian women from the logistic regression analyses. The Italian women were much more likely to comply with medical authority and advice. The Anglo-Australian women were more likely to feel that they had some control over their health. Specifically, the risk variable ‘dread’ was more applicable to the Italian women’s behaviour and internal locus of control variable was more relevant to the Anglo-Australian women. The qualitative responses also differed for the two samples. The Italian women’s comments were more general, less specific, and more limited than that of the Anglo-Australian women. The Italian women talked about learning how to do BSE whereas the Anglo-Australian women said that attending the session had reminded them to do BSE more regularly. The key findings and contributions of the present research were numerous. The focus on one cultural group ensured comprehensive analyses, as did the inclusion of an adequate sample size to enable the use of multivariate statistics. Separating the Italian and Anglo-Australian samples in the analyses provided theoretical implications that would have been overlooked if the two groups were combined. The use of both qualitative and quantitative data capitalised on the strengths of both techniques. The inclusion of an Anglo-Australian group highlighted key theoretical findings, differences between the two groups and unique contributions made by both samples during the collection of the qualitative data. The use of a pre-test-intervention-post-test design emphasised the reticence of the Italian sample to participate and talk about breast cancer and confirmed and validated the consistency of the responses across the two interviews for both samples. The inclusion of non-cued responses allowed the researcher to identify the key salient issues relevant to the two groups. The limitations of the present research were the lack of many women who were not screening and reliance on self-report responses, although few differences were observed between the Pre- and Post-Test comparisons. The theoretical contribution of the HBM and the TRA variables was minimal in relation to screening mammography or attendance at the CLP. The applicability of these health behaviour theories may be less relevant for women today as they clearly knew the benefits of and the seriousness of breast cancer screening. The present research identified the applicability of the risk variables to the Italian women and the relevance of the locus of control variables to the Anglo-Australian women. Thus, clear cultural differences occurred between the two groups. The inclusion of the illness representations was advantageous as the responses highlighted ideas and personal theories salient to the women not identified by the HBM. The use of the illness representations and the qualitative responses further confirmed the relevance of the risk variables to the Italian women and the locus of control variables to the Anglo-Australian women. Attendance at the CLP did not influence the women to attend for mammography screening. Behavioural changes did not occur between the Pre- and Post-Test interviews. Small incremental changes as defined by the TTM and the stages of change may have occurred. Key practical implications for the CLP were identified. Improving the recruitment methods to gain a higher proportion of women who do not screen is imperative for the CLP promoters. The majority of the Italian and Anglo-Australian women who attended the information sessions were women who screen. The fact that Italian women do not like talking or thinking about cancer presents a challenge to promoters of the CLP. The key theoretical finding that Italian women dread breast cancer but comply with their doctor provides clear strategies to improve attendance at mammography screening. In addition, the inclusion of lay health advisors may be one way of increasing attendance to the CLP by including Italian women already attending screening and likely to have attended a CLP session. The present research identified the key finding that improving Anglo-Australian attendance at an information session is related to debunking the myth surrounding familial risk of breast cancer and encouraging the Anglo-Australian women to take more control of their health. Improving attendance for Italian women is related to reducing the fear and dread of breast cancer and building on the compliance pattern with medical authority. Therefore, providing an information session in the target language is insufficient to attract non-screeners to the session and then to screen for breast cancer. Suggestions for future research in relation to screening mammography were to include variables from more than one theory or model, namely the risk, locus of control and illness representations. The inclusion of non-cued responses to identify salient beliefs is advantageous. In addition, it is imperative to describe the profile of the cultural sample in detail, include detailed descriptions of the translation process and be aware of the tendency of Italian women to acquiesce with medical authority.

Assessing cultural and linquistic appropriateness of the Rose Angina questionnaire in three ethnic groups

Introduction. Meeting the needs of migrant groups in Europe requires cross-culturally valid questionnaires, a substantial challenge to researchers. The Rose Angina Questionnaire (RAQ) is an important measure of coronary heart disease prevalence. It consists of seven items that collectively yield a diagnosis of angina. It has been shown to perform inconsistently across some ethnic groups in Britain. This study aimed to assess the need for modifying the RAQ for cross-culturally valid use in the three main ethnic groups in Scotland.

Methods. Interviews were carried out with Pakistani Punjabi speakers (n=26), Chinese Cantonese speakers (n=29) and European-origin English speakers (n=25). Bilingual project workers interviewed participants and provided translation and commentary to the English-speaking researcher. Participants were asked about general and cardiovascular health beliefs and behaviours, and about attitudes to pain and chest pain. They were also asked to comment on their understanding of an existing version of the RAQ in their language.

Results. No dominant themes in the cultural construction of health, pain or cardiovascular knowledge emerged that may significantly influence RAQ response between language groups. Problems were encountered with the Punjabi and Cantonese translations of the RAQ. For example, the translation for “chest” was interpreted by some Pakistani and fewer Chinese women to mean “breasts”. “Walking uphill” was translated in Chinese as “walking the hill”, without stipulation of the direction, so that some Cantonese speakers interpreted the question as meaning walking downhill. In addition, many Chinese interpreted RAQ items to be referring to breathlessness rather than chest pain due to ambiguous wording.

Conclusion. Existing Punjabi and Cantonese versions of the RAQ should be modified before being used in multi-ethnic surveys. Current versions are unlikely to be yielding data that is comparable across groups. Other language versions also require similar investigation to study the cardiovascular health of Europe’s migrant groups.

Insights from research on cross-cultural validation of health-related questionnaires : the role of bilingual project workers and lay participants

This article discusses the recruitment and training of bilingual project workers and their role in data gathering; the level of comprehension of the interviewees with regard to the nature of the task and its alien nature; the contribution of social customs and expectations; the vagaries of language; the researchers' level of comprehension of data collected across a range of languages; the feelings of loss of control by the researchers over the research process; and issues of communication with bilingual project workers. The authors draw on two studies designed to assess the adequacy of questionnaire translations from English into four ethnic minority languages: Cantonese, Punjabi, Urdu and Sylheti. Bilingual project workers were recruited to carry out interviews and focus groups with the lay communities and to feed back results in English to the researchers. The authors conclude that researchers should be aware of the influence of social and contextual factors when carrying out research with ethnic minority participants mediated by bilingual project workers.

Assessing the intake of obesity-related foods and beverages in young children: comparison of a simple population survey with 24 hr-recall

Background: With an increasing focus on obesity prevention there is a need for simple, valid tools to assess dietary indicators that may be the targets of  intervention programs. The objective of this study was to determine the relative  validity of previous day dietary intake using a newly developed parent-proxy  questionnaire (EPAQ) for two to five year old children.

Methods: A convenience sample of participants (n = 90) recruited through preschools and the community in Geelong, Australia provided dietary data for their child via EPAQ and interviewer administered 24-hour dietary recall (24 hr-recall). Comparison of mean food and beverage group servings between the  EPAQ and 24 hr-recall was conducted and Spearman rank correlations were computed to examine the association between the two methods.

Results: Mean servings of food/beverage groups were comparable between methods for all groups except water, and significant correlations were found between the servings of food and beverages using the EPAQ and 24-hr recall methods (ranging from 0.57 to 0.88).

Conclusion: The EPAQ is a simple and useful population-level tool for  estimating the intake of obesity-related foods and beverages in children aged two to five years. When compared with 24-hour recall data, the EPAQ produced an acceptable level of relative validity and this short survey has application for population monitoring and the evaluation of population-based obesity prevention interventions for young children.

Biopsychosocial factors related to Australian and Fijian adolescent body image distortion

The thesis study was a cross-cultural comparison of the biopsychosocial predictors of body image perception and ideals among 294 Australian and 101 Fijian adolescents. The results demonstrated similarities across cultural groups, but parents, peers and the media were stronger influences for Fijians. These findings have implications for body image intervention programs.The portfolio presented a thorough review of the evidence for the cognitive behavioural therapy (CBT) treatment option for adolescents with major depressive disorder (MDD). Four case studies are presented.

Health-related beliefs, explanations and actions of older Anglo-Celtic-Australians

This thesis was an exploration of the health-related understandings and experiences of older Anglo-Celtic-Australians from a disadvantaged metropolitan locality. New insights were gained about the relationship between disadvantage and poor health outcomes; particularly the impact of limited self-care practices in combination with difficulties relating to the health care professionals.

"We've got a problem!" women and prenatal diagnosis

This feminist qualitative research addresses the lack of women's voices in the ethical debates surrounding prenatal diagnosis (PD). The conclusions reached challenge current ethical debates around PD programmes which, through the exclusion of groups intimately affected by PD, remain partial and inadequate.

Are safety-related features of the road environment associated with smaller declines in physical activity among youth?

This study examined how objective measures of the local road environment related to safety were associated with change in physical activity (including active transport) among youth. Few longitudinal studies have examined the impact of the road environment on physical activity among children/adolescents in their neighborhoods. Participants were children aged 8–9 years (n=170) and adolescents aged 13–15 years (n=276) in 2004. Data were collected in 2004 and 2006 during followup of participants recruited initially in 2001 from 19 primary schools in Melbourne, Australia. Walking/cycling to local destinations was parent-reported for children and self-reported by adolescents. Moderate-to-vigorous physical activity (MVPA) during nonschool hours was recorded using accelerometers. Road environment features in each participant’s neighborhood (area within 800 m radius of their home) were measured objectively using a Geographical Information System. Linear regression analyses examined associations between road features and changes in active transport (AT) and MVPA over 2 years. Children’s AT increased but MVPA levels decreased in both age groups; on average, younger girls recorded the greatest declines. The number of traffic/pedestrian lights was associated with ΔAT among younger girls (B=0.45, p=0.004). The total length of walking tracks (in meters) was associated with ΔAT among younger girls (B=0.0016, p=0.015) and adolescent girls (B=0.0016, p=0.002). For adolescent boys, intersection density was associated with ΔAT (B=0.03, p=0.030). Slow points were associated with ΔMVPA among younger boys before school (B=1.55, p=0.021), while speed humps were associated with ΔMVPA among adolescent boys after school (B=0.23, p=0.015). There were many associations for adolescent girls: for example, the total length of local roads (B=0.49, p=0.005), intersection density (B=0.05, p=0.036), and number of speed humps (B=0.33, p=0.020) were associated with ΔMVPA during nonschool hours. Safety-related aspects of the built environment are conducive to physical activity among youth and may help stem age-related declines in physical activity. Passive road safety interventions may promote AT and physical activity among less active girls, in particular.

Reduced exercise tolerance in CHF may be related to factors other than impaired skeletal muscle oxidative capacity

Background : We sought to determine whether skeletal muscle oxidative capacity, fiber type proportions, and fiber size, capillary density or muscle mass might explain the impaired exercise tolerance in chronic heart failure (CHF). Previous studies are equivocal regarding the maladaptations that occur in the skeletal muscle of patients with CHF and their role in the observed exercise intolerance.

Methods and results : Total body O₂ uptake (VO_2peak) was determined in 14 CHF patients and 8 healthy sedentary similar-age controls. Muscle samples were analyzed for mitochondrial adenosine triphosphate (ATP) production rate (MAPR), oxidative and glycolytic enzyme activity, fiber size and type, and capillary density. CHF patients demonstrated a lower VO_2peak (15.1±1.1 versus 28.1±2.3 mL·kg⁻¹·min⁻¹, P<.001) and capillary to fiber ratio (1.09±0.05 versus 1.40±0.04; P<.001) when compared with controls. However, there was no difference in capillary density (capillaries per square millimeter) across any of the fiber types. Measurements of MAPR and oxidative enzyme activity suggested no difference in muscle oxidative capacity between the groups.

Conclusions : Neither reductions in muscle oxidative capacity nor capillary density appear to be the cause of exercise limitation in this cohort of patients. Therefore, we hypothesize that the low VO_2peak observed in CHF patients may be the result of fiber atrophy and possibly impaired activation of oxidative phosphorylation.

Identifying co-regulating microrna groups

Background: Current miRNA target prediction tools have the common problem that their false positive rate is high. This renders identification of co-regulating groups of miRNAs and target genes unreliable. In this study, we describe a procedure to identify highly probable co-regulating miRNAs and the corresponding co-regulated gene groups. Our procedure involves a sequence of statistical tests: (1) identify genes that are highly probable miRNA targets; (2) determine for each such gene, the minimum number of miRNAs that co-regulate it with high probability; (3) find, for each such gene, the combination of the determined minimum size of miRNAs that co-regulate it with the lowest p-value; and (4) discover for each such combination of miRNAs, the group of genes that are co-regulated by these miRNAs with the lowest p-value computed based on GO term annotations of the genes.
Results: Our method identifies 4, 3 and 2-term miRNA groups that co-regulate gene groups of size at least 3 in human. Our result suggests some interesting hypothesis on the functional role of several miRNAs through a "guilt by association" reasoning. For example, miR-130, miR-19 and miR-101 are known neurodegenerative diseases associated miRNAs. Our 3-term miRNA table shows that miR-130/19/101 form a co-regulating group of rank 22 (p-value =1.16 × 10^-2). Since miR-144 is co-regulating with miR-130, miR-19 and miR-101 of rank 4 (p-value = 1.16 × 10^-2) in our 4-term miRNA table, this suggests hsa-miR-144 may be neurodegenerative diseases related miRNA. Conclusions: This work identifies highly probable co-regulating miRNAs, which are refined from the prediction by computational tools using (1) signal-to-noise ratio to get high accurate regulating miRNAs for every gene, and (2) Gene Ontology to obtain functional related co-regulating miRNA groups. Our result has partly been supported by biological experiments. Based on prediction by TargetScanS, we found highly probable target gene groups in the Supplementary Information. This result might help biologists to find small set of miRNAs for genes of interest rather than huge amount of miRNA set.

Vitamin D, obesity, and obesity-related chronic disease among ethnic minorities : a systematic review

Objective : To assess the association between 25-hydroxyvitamin D (25[OH]D) status and obesity, cardiovascular diseases (CVDs), the metabolic syndrome, and type 2 diabetes mellitus (T2DM) in ethnic minorities.

Methods : Databases searched were CINHAL with full text, Global Health, MEDLINE with full text, and PsycINFO from 1980 through 2010 (February). Studies were included if they 1) targeted immigrants from low- to high-income countries or ethnic minorities, 2) focused primarily on 25(OH)D and its relation to obesity, T2DM, and/or CVDs, and 3) were published in peer-reviewed journals. The influences of key confounders such as age, gender, and ethnicity on any observed relations were also assessed. Due to the heterogeneity of study characteristics, only a narrative synthesis was undertaken.

Results : Ethnic minorities had significantly higher rates of vitamin D insufficiency (25[OH]D <50 nmol/L; children 43.6–48.7% versus 10%; adults 30.3–53% versus 13.7–26%) than their white counterparts. None of the studies reported a prevalence of obesity stratified by ethnicity. There was evidence supporting links between vitamin D deficiency and obesity-related chronic diseases, with 14 of 14 studies reporting a statistically significant result with a measurement of obesity, four of five for T2DM, four of five for CVDs, and one of one for the metabolic syndrome. However, the strength of the association varied across ethnic groups depending on the index used to measure adiposity, T2DM, and CVDs. Because most of the included studies were cross-sectional and there were variations in outcome measurements, it was not possible to determine the relative contributions of obesity or vitamin D insufficiency to CVD risk and risk of T2DM or which is the initial driver It is possible both have a role to play.

Conclusion : Further research specific to migrant populations using randomized controlled trials are required to establish whether causal links between 25(OH)D and obesity-related chronic disease exist, and whether vitamin D supplementation could be valuable in the prevention or treatment of obesity-related diseases.

Care needs and functional status of older acute care patients

A growing number of older adults are admitted to hospitals, and information is needed on how age-related functional decline affects nursing care needs of this population. This study compared the functional status at admission and total nursing care needs of three age groups of older inpatients. A 12-month retrospective audit was performed on the records of 225 patients in a private metropolitan hospital. The three groups of patients were matched on diagnosis. Findings revealed that older patients were significantly more dependent, had greater total nursing care needs, and were less likely to be discharged to home, indicating that in addition to medical diagnoses, age-related differences of older patients’ functional status at admission and inpatient nursing care needs should be factored into staff workloads and funding of nursing care. The finding that significantly fewer of the older patients returned home must be considered when reviewing health care policy and services.

Socioeconomic variation in diet and activity-related behaviours of Australian children and adolescents aged 2–16 years

Background

Evidence for age-related variation in the relationship between obesity-related behaviours and socioeconomic position may assist in the targeting of dietary and physical activity interventions among children.
Objective

To investigate the relationship between different indicators of socioeconomic position and obesity-related behaviours across childhood and adolescence.
Methods

Data were from 4487 children aged 2 to 16 years participating in the cross-sectional 2007 Australian National Children's Nutrition and Physical Activity Survey. Socioeconomic position was defined by the highest education of the primary or secondary carer and parental income. Activity was assessed using recall methods with physical activity also assessed using pedometers. Intake of energy-dense drinks and snack foods, fruits and vegetables was assessed using 2 × 24-h dietary recalls.
Results

A socioeconomic gradient was evident for each dietary measure (although in age-specific analyses, not for energy-dense snacks in older children), as well as television viewing, but not physical activity. Whether each behaviour was most strongly related to parental income or education of the primary or secondary carer was age and sex dependent. The socioeconomic gradient was strongest for television viewing time and consumption of fruit and energy-dense drinks.
Conclusions

A strong socioeconomic gradient in eating behaviours and television viewing time was observed. Relationships for particular behaviours differed by age, sex and how socioeconomic position was defined. Socioeconomic indicators define different population groups and represent different components of socioeconomic position. These findings may provide insights into who should be targeted in preventive health efforts at different life stages.