Characterization of a conserved rhoptry-associated leucine zipper-like protein in the malaria parasite Plasmodium falciparum

One of the key processes in the pathobiology of the malaria parasite is the invasion and subsequent modification of the human erythrocyte. In this complex process, an unknown number of parasite proteins are involved, some of which are leading vaccine candidates. The majority of the proteins that play pivotal roles in invasion are either stored in the apical secretory organelles or located on the surface of the merozoite, the invasive stage of the parasite. Using transcriptional and structural features of these known proteins, we performed a genomewide search that identified 49 hypothetical proteins with a high probability of being located on the surface of the merozoite or in the secretory organelles. Of these candidates, we characterized a novel leucine zipper-like protein in Plasmodium falciparum that is conserved in Plasmodium spp. This protein is expressed in late blood stages and localizes to the rhoptries of the parasite. We demonstrate that this Plasmodium sp.-specific protein has a high degree of conservation within field isolates and that it is refractory to gene knockout attempts and thus might play an important role in invasion.

You don't have other teachers to bounce ideas off : report from SiMERR Victoria

Companion volume to the SiMMER National Survey.

Healthy minds for country youth : help-seeking for depression among rural adolescents

Objective: To assess depression recognition, barriers to accessing help from health professionals and potential sources of help for depression among rural adolescents.

Design: Cross-sectional survey.

Setting: Two rural secondary schools in south-east South Australia.

Participants: Seventy-four secondary school students aged 14 to 16 years.

Main outcome measure(s): Depression recognition was measured using a depression vignette. Helpfulness of professionals, barriers to seeking help and help-seeking behaviours for depression were assessed by self-report questionnaire.

Results: Depression was identified in the vignette by 73% (n = 54) of participants. Participants indicated that it would be more helpful for the vignette character to see other health professionals (98.6%, 95% CI, 92.0–100.0%) than a doctor (82.4%, 72.1–89.6%). Barriers to seeking help from doctors and other health professionals were categorised into logistical and personal barriers. Participants agreed more strongly to personal (mean = 2.86) than logistical barriers (mean = 2.67, P < 0.05) for seeing a doctor. Boys and girls responded differently overall, and to personal barriers to seeing an other health professional. Sources of help were divided into three categories: formal, informal and external. Informal sources of help (mean = 4.02) were identified as more helpful than both formal (mean = 3.66) and external sources (mean = 3.72, P < 0.001). Gender differences were observed within and between the three sources of help categories.

Conclusions: Recognising symptoms of depression was demonstrated in this study. Helpfulness of professionals, barriers to seeking help and potential sources of help for depression were identified. More work is required for improving depression literacy and providing effective interventions specifically for rural adolescents.

From rural beginnings to statewide roll-out : evaluation of facilitator training for a group-based diabetes prevention program

Objective: To evaluate the approach used to train facilitators for a large-scale group-based diabetes prevention program developed from a rural implementation research project.

Participants: Orientation day was attended by 224 health professionals; 188 submitted the self-learning task; 175 achieved the satisfactory standard for the self-learning task and attended the workshop; 156 completed the pre- and post-training questionnaires.

Main outcome measures: Two pre- and post-training scales were developed to assess knowledge and confidence in group-based diabetes prevention program facilitation. Principal component analysis found four factors for measuring training effectiveness: knowledge of diabetes prevention, knowledge of group facilitation, confidence to facilitate a group to improve health literacy and confidence in diabetes prevention program facilitation. Self-learning task scores, training discontinuation rates and satisfaction scores were also assessed.

Results: There was significant improvement in all four knowledge and confidence factors from pre- to post-training (P < 0.001). The self-learning task mean test score was 88.7/100 (SD = 7.7), and mean assignment score was 72.8/100 (SD = 16.1). Satisfaction with training scores were positive and 'previous training' interacted with 'change in knowledge of diabetes prevention program facilitation' but not with change in 'confidence to facilitate.'

Conclusions: The training program was effective when analysed by change in facilitator knowledge and confidence and the positive mean satisfaction score. Learning task scores suggest tasks were manageable and the requirement contributed to facilitator self-selection. Improvement in confidence scores in facilitating a group-based diabetes prevention program, irrespective of previous training and experience, show that program-specific skill development activities are necessary in curriculum design.

Review of rural and regional alcohol research in Australia

INTRODUCTION: Alcohol is the most commonly used drug within Australia. Recently, there have been indications that there is a greater incidence of high-risk drinking within rural populations as compared with their urban counterparts. High-risk drinking is associated with numerous conditions, such as diabetes, heart attack and cancer, as well as acute harms such as assault, suicide and road accidents. The objective of this article is to review the current research and relevant data pertaining to alcohol use and alcohol-related harms within rural Australia. METHODS: This paper is a systematic review of 16 databases, including PubMed, PsycINFO and Google Scholar. RESULTS: Overall, 18 studies describing alcohol consumption or alcohol-related harms were found. Approximately half of these studies were large-scale national population surveys, which were therefore limited in their representativeness of specific regional and rural towns. Most studies examining alcohol consumption used self-report data collection, meaning that interpretation of results needs to be tentative. There is a consistent pattern of higher rates of alcohol consumption and consequent harm within regional and rural Australia than in urban areas. CONCLUSIONS: There is emerging research examining alcohol consumption and alcohol-related harms within regional and rural Australia. All studies show that these populations experience disproportionate harm because of alcohol consumption. The causes and mechanism for this have not been investigated, and a program of research is required to understand how and why rural populations experience disproportionate levels of alcohol-related harm and ultimately, what interventions will be most effective in reducing alcohol-related harms.

Improving the quality of diabetes care in general practice

Objective: The evidence treatment gap for patients with type 2 diabetes.
Design: A summary of convenience sample of seven general practices.
Setting: Metropolitan and rural Victoria, Australia.
Participants: 561 patients of general practices (75% from rural general practices).
Main outcome measures: Demographic data, duration of diabetes, diabetes complications, HbA1c and lipid levels, blood pressure and score on PHQ-9.
Results: Patients with depression show more severe, progressive and intensively treated diabetes. The prevalence of depression in diabetes is about twice that of the general population.
Conclusion: Australian guidelines for diabetes should recommend screening for depression.

Implementation of diabetes prevention programs in rural areas : Montana and south-eastern Australia compared

Objective: To identify the key elements that enabled the Greater Green Triangle Diabetes Prevention Project (GGT DPP) and the Montana Cardiovascular Disease and Diabetes Prevention (CDDP) programs successful establishment and implementation in rural areas, as well as identifying specific challenges or barriers for implementation in rural communities.
Methods: Focus groups were held with the facilitators who delivered the GGT DPP in Australia and the Montana CDDP programs in the USA. Interview questions covered the facilitators’ experiences with recruitment, establishing the program, the components and influence of rurality on the program, barriers and challenges to delivering the program, attributes of successful participants, and the influence of community resources and partnerships on the programs.
Results: Four main themes emerged from the focus groups: establishing and implementing the diabetes prevention program in the community; strategies for recruitment and retention of participants; what works in lifestyle intervention programs; and rural-centred issues.
Conclusions: The results from this study have assisted in determining the factors that contribute to developing, establishing and implementing successful diabetes prevention programs in two rural areas. Recommendations to increase the likelihood of success of programs in rural communities include: securing funding early for the program; establishing support from community leaders and developing positive relationships with health care providers; creating a professional team with passion for the program; encouraging participants to celebrate their small and big successes; and developing procedures for providing post-intervention support to help participants maintain their success.

Young mothers’ lived experiences prior to becoming pregnant in rural Victoria : a phenomenological study

Objective: To explore the lived experiences and social context prior to becoming pregnant, of women who became mothers during adolescence in rural Victoria.
Design: Qualitative interpretive phenomenological study using semistructured interviews.
Setting: Rural community in North East Victoria, Australia.
Participants: Four rural women who gave birth to a child between the ages of 15 and 19.
Results: Five themes emerged from the data as being essential to the participants’ experiences prior to pregnancy. These included feeling isolated; life change: transition into adulthood; support and understanding in sexual relationships; feeling dissatisfied; and overcoming adversity. Participants’ provided practical recommendations to improve life for young people in rural areas through reflecting on their own experiences.
Conclusion: These findings highlight the complex nature of rural young women’s experiences leading up to pregnancy and suggest that early motherhood might be largely reflective of the social environment in which one lives prior to pregnancy. Providing somewhere safe to go, organised and appropriate social activities and increasing access to health services were identified as being pertinent to improving experiences for rural young people prior to pregnancy. Health professionals should consider the importance of supporting young women through non-judgemental, approachable and accessible services.

Sequence requirements for the export of the Plasmodium falciparum Maurer's clefts protein REX2

A short motif termed Plasmodium export element (PEXEL) or vacuolar targeting signal (VTS) characterizes Plasmodium proteins exported into the host cell. These proteins mediate host cell modifications essential for parasite survival and virulence. However, several PEXEL-negative exported proteins indicate that the currently predicted malaria exportome is not complete and it is unknown whether and how these proteins relate to PEXEL-positive export. Here we show that the N-terminal 10 amino acids of the PEXEL-negative exported protein REX2 (ring-exported protein 2) are necessary for its targeting and that a single-point mutation in this region abolishes export. Furthermore we show that the REX2 transmembrane domain is also essential for export and that together with the N-terminal region it is sufficient to promote export of another protein. An N-terminal region and the transmembrane domain of the unrelated PEXEL-negative exported protein SBP1 (skeleton-binding protein 1) can functionally replace the corresponding regions in REX2, suggesting that these sequence features are also present in other PEXEL-negative exported proteins. Similar to PEXEL proteins we find that REX2 is processed, but in contrast, detect no evidence for N-terminal acetylation.

Functional analysis of the leading malaria vaccine candidate AMA-1 reveals an essential role for the cytoplasmic domain in the invasion process

A key process in the lifecycle of the malaria parasite Plasmodium falciparum is the fast invasion of human erythrocytes. Entry into the host cell requires the apical membrane antigen 1 (AMA-1), a type I transmembrane protein located in the micronemes of the merozoite. Although AMA-1 is evolving into the leading blood-stage malaria vaccine candidate, its precise role in invasion is still unclear. We investigate AMA-1 function using live video microscopy in the absence and presence of an AMA-1 inhibitory peptide. This data reveals a crucial function of AMA-1 during the primary contact period upstream of the entry process at around the time of moving junction formation. We generate a Plasmodium falciparum cell line that expresses a functional GFP-tagged AMA-1. This allows the visualization of the dynamics of AMA-1 in live parasites. We functionally validate the ectopically expressed AMA-1 by establishing a complementation assay based on strain-specific inhibition. This method provides the basis for the functional analysis of essential genes that are refractory to any genetic manipulation. Using the complementation assay, we show that the cytoplasmic domain of AMA-1 is not required for correct trafficking and surface translocation but is essential for AMA-1 function. Although this function can be mimicked by the highly conserved cytoplasmic domains of P. vivax and P. berghei, the exchange with the heterologous domain of the microneme protein EBA-175 or the rhoptry protein Rh2b leads to a loss of function. We identify several residues in the cytoplasmic tail that are essential for AMA-1 function. We validate this data using additional transgenic parasite lines expressing AMA-1 mutants with TY1 epitopes. We show that the cytoplasmic domain of AMA-1 is phosphorylated. Mutational analysis suggests an important role for the phosphorylation in the invasion process, which might translate into novel therapeutic strategies.

Transcriptional profiling of growth perturbations of the human malaria parasite Plasmodium falciparum

Functions have yet to be defined for the majority of genes of Plasmodium falciparum, the agent responsible for the most serious form of human malaria. Here we report changes in P. falciparum gene expression induced by 20 compounds that inhibit growth of the schizont stage of the intraerythrocytic development cycle. In contrast with previous studies, which reported only minimal changes in response to chemically induced perturbations of P. falciparum growth, we find that ~59% of its coding genes display over three-fold changes in expression in response to at least one of the chemicals we tested. We use this compendium for guilt-by-association prediction of protein function using an interaction network constructed from gene co-expression, sequence homology, domain-domain and yeast two-hybrid data. The subcellular localizations of 31 of 42 proteins linked with merozoite invasion is consistent with their role in this process, a key target for malaria control. Our network may facilitate identification of novel antimalarial drugs and vaccines.

Repulsive interaction between coplanar cracks in the double–cantilever geometry

Experiments on thin mica sheets are used to demonstrate that coplanar cracks in double-cantilever beam specimens do not universally attract each other, as conventionally portrayed, but, at long range, actually repel. An elasticity analysis explains the repulsion in terms of a compression zone, 0.35 times the beam half-thickness ahead of the crack tip, generated by bending moments from the cantilever arms on the remaining specimen section.

Potential of pharmacists to help reduce the burden of poorly managed cardiovascular risk

Introduction: Rural areas require better use of existing health professionals to ensure capacity to deliver improved cardiovascular outcomes. Community pharmacists (CPs) are accessible to most communities and can potentially undertake expanded roles in prevention of cardiovascular disease (CVD).

Objective: This study aims to establish frequency of contact with general practitioners (GPs) and CPs by patients at high risk of CVD or with inadequately controlled CVD risk factors.

Design, setting and participants: Population survey using randomly selected individuals from the Wimmera region electoral roll and incorporating a physical health check and self-administered health questionnaire. Overall, 1500 were invited to participate.

Results: The participation rate was 51% when ineligible individuals were excluded. Nine out of 10 participants visited one or both types of practitioner in the previous 12 months. Substantially more participants visited GPs compared with CPs (88.5% versus 66.8%). With the exception of excess alcohol intake, the median number of opportunities to intervene for every inadequately controlled CVD risk factor and among high risk patient groups at least doubled for the professions combined when compared with GP visits alone.

Conclusion: Opportunities exist to intervene more frequently with target groups by engaging CPs more effectively but would require a significant attitude shift towards CPs. Mechanisms for greater pharmacist integration into primary care teams should be investigated.