Realist analysis of qualitative data in health professions education research.

BACKGROUND: Qualitative realist analysis is gaining in popularity in health professions education research (HPER) as part of theory-driven program evaluation. Although realist approaches such as syntheses and evaluations typically advocate mixed methods, qualitative data dominate currently. Various forms of qualitative analysis have been articulated in HPER, yet realist analysis has not. Although realist analysis is interpretive, it moves beyond description to explain generative causation employing retroductive theorising. Ultimately, it attempts to build and/or 'test' (confirm, refute or refine) theory about how, why, for whom, when and to what extent programs work using the context-mechanism-outcome configuration (CMOC) heuristic. This paper aims to help readers better critique, conduct and report qualitative realist analysis. REALIST ANALYSIS METHODS: We describe four fundamentals of qualitative realist analysis: (1) simultaneous data collection/analysis; (2) retroductive theorising; (3) configurational analysis (involving iterative phases of identifying CMOCs, synthesising CMOCs into demi-regularities and translating demi-regularities into program theory); and (4) realist analysis quality (relevance, rigour, richness). Next, we provide a critical analysis of realist analyses employed in 15 HPER outputs-three evaluations and 12 syntheses. Finally, drawing on our understandings of realist literature and our experiences of conducting qualitative realist analysis (both evaluations and syntheses), we articulate three common analysis challenges (coding, consolidation and mapping) and strategies to mitigate these challenges (teamwork, reflexivity and consultation, use of data analysis software and graphical representations of program theory). CONCLUSIONS: Based on our critical analysis of the literature and realist analysis experiences, we encourage researchers, peer reviewers and readers to better understand qualitative realist analysis fundamentals. Realist analysts should draw on relevant realist reporting standards and literature on realist analysis to improve the quality and reporting of realist analysis. Through better understanding the common challenges and mitigation strategies for realist analysis, we can collectively improve the quality of realist analysis in HPER.

A roadmap to realist interviews in health professions education research: Recommendations based on a critical analysis.

CONTEXT: Realist evaluation is increasingly employed in health professions education research (HPER) because it can unpack the extent to which complex educational interventions work (or not), for whom under what circumstances and how. While realist evaluation is not wedded to particular methods, realist interviews are commonly the primary, if not only, data collection method in realist evaluations. While qualitative interviewing from an interpretivist standpoint has been well-articulated in the HPER literature, realist interviewing differs substantially. The former elicits participants' views and experiences of a topic of inquiry, whereas realist interviewing focuses on building, testing and/or refining programme theory. Therefore, this article aims to help readers better understand, conduct, report and critique realist interviews as part of realist evaluations. METHODS: In this paper, we describe what realist approaches are, what realist interviewing is and why realist interviewing matters. We outline five stages to realist interviewing (developing initial programme theory, realist sampling/samples, the interview itself, realist analysis and reporting realist interviews), drawing on two illustrative cases from our own realist evaluations employing interviewing to bring theory to life. We provide a critical analysis of 12 realist evaluations employing interviewing in the HPER literature. Alongside reporting standards, and our own realist interviewing experiences, this critical analysis of published articles serves to foreground our recommendations for realist interviewing. CONCLUSIONS: We encourage HPE researchers to consider realist interviews as part of realist evaluations of complex interventions. Our critical analysis reveals that realist interviews can provide unique insights into HPE, but authors now need to report their sampling approach, type of interviewing and interview questions more explicitly. Studies should also more explicitly draw on existing realist interviewing literature and follow reporting guidelines for realist evaluations. We hope this paper provides a useful roadmap to conducting, reporting and critically appraising realist interviews in HPER.

Unpacking economic programme theory for supervision training: Preliminary steps towards realist economic evaluation.

INTRODUCTION: Cost studies are increasingly popular given resource constraints. While scholars stress the context-dependent nature of cost, and the importance of theory, cost studies remain context-blind and atheoretical. However, realist economic evaluation (REE) privileges context and the testing/refinement of economic programme theory. This preliminary REE serves to test and refine economic programme theory for supervision training programmes of different durations to better inform future programme design/implementation. METHODS: Our preliminary REE unpacked how short (half-day) and extended (12 week) supervision training programmes in Victoria, Australia, produced costs and outcomes. We employed mixed methods: qualitative realist and quantitative cost methods. Economically optimised programme models were developed guided by identified cost-sensitive mechanisms and contexts. RESULTS: As part of identified context-mechanism-outcome configurations (CMOCs) for both training programmes, we found a wider diversity of positive outcomes but greater costs for the extended programme (11 outcomes; AU$3069/learner) compared with the short programme (7 outcomes; $385/learner). We identified four shared cost-sensitive mechanisms for both programmes (training duration, learner protected time, learner engagement, and facilitator competence) and one shared cost-sensitive context (learners' supervisory experience). We developed two economically optimised programme models: (1) short programme for experienced supervisors facilitated by senior educators ($406/learner); and (2) extended programme for inexperienced supervisors facilitated by junior educators ($2104/learner). DISCUSSION: Our initial economic programme theory was somewhat supported, refuted and refined. Results were partly consistent with previous research, but also extended it through unpacking cost-sensitive mechanisms and contexts. Although our preliminary REE fills a pressing gap in the methodology literature, conducting REE was challenging given our desire to integrate economic and realist analyses fully, and remain faithful to realist principles. Attention to training duration and experience levels of the facilitator-learner dyad may help to balance the cost and outcomes of training programmes.

Balancing the effectiveness and cost of online education: A preliminary realist economic evaluation.

PURPOSE: While online learning for faculty development has grown substantially over recent decades, it has been further accelerated in the face of the worldwide pandemic. The effectiveness of online learning has been repeatedly established through systematic reviews and meta-analyses, yet questions remain about its cost-effectiveness. This study evaluates how synchronous online supervision training workshops and their cost-effectiveness might work, and in what contexts. METHODS: We conducted preliminary realist economic evaluation including qualitative (13 realist interviews), and quantitative approaches (cost Ingredients method). We developed a cost-optimised model based on identified costs and cost-sensitive mechanisms. RESULTS: We identified 14 recurring patterns (so-called demi-regularities) illustrating multiple online workshop outcomes (e.g. satisfaction, engagement, knowledge), generated by various mechanisms (e.g. online technology, mixed pedagogies involving didactic and active/experiential learning, peer learning), and triggered by two contexts (supervisor experience levels, and workplace location). Each workshop cost $302.92 per learner, but the optimised model including senior facilitators cost $305.70. CONCLUSIONS: Our initial realist program theories were largely supported and refined. Although findings were largely concordant with previous literature, we illustrate how online workshop costs compare favourably with face-to-face alternatives. We encourage program developers to consider synchronous online learning for faculty development especially for remote learners, and in resource-constrained environments.

The effect of preparation strategies, qualification and professional background on clinical nurse educator confidence.

AIMS: To describe how clinical nurse educators (CliNEs) in Vietnam are prepared for their role; to identify which preparation strategies assist development of confidence in clinical teaching; and to measure the effect of educational qualifications and professional background on perceived confidence levels. BACKGROUND: The quality of clinical teaching can directly affect the quality of the student learning experience. The role of the clinical educator is complex and dynamic and requires a period of adjustment for successful role transition to occur. Planned orientation and specific preparation programmes assist transition and reduce anxiety for new CliNEs. There is, however, a lack of clear evidence to identify the form this preparation should take or which strategies are likely to facilitate the development of role confidence. DESIGN: Descriptive survey study. METHODS: Cross-sectional surveys were used to collect data from 334 CliNEs during January-March 2015. RESULTS: Eight preparation methods commonly used in Vietnam were identified. There was a small yet significant association between preparation and CliNEs' perceived confidence. Formal preparation methods, and postgraduate qualifications and years of clinical teaching experience were linked to increased confidence in clinical teaching. Conversely, informal mentorship was found to hinder confidence development. CONCLUSIONS: This study identifies several preparation strategies that significantly enhance clinical educator confidence and readiness for their complex role. These preparation strategies drawn from the Vietnamese context, provide important examples for the wider nursing community to consider.

Development of the Large-Scale Synthesis of Tetrahydropyran Glycine, a Precursor to the HCV NS5A Inhibitor BMS-986097.

An efficient large-scale synthesis of acid 1, a penultimate precursor to the HCV NS5A inhibitor BMS-986097, along with the final API step are described. Three routes were devised for the synthesis of 1 at the various stages of the program. The third generation route, the one that proved scalable and is the main subject of this paper, features a one-step Michael addition of t-butyl 2-((diphenylmethylene)amino)acetate (24) to (E)-benzyl 4-(1-hydroxycyclopropyl)but-2-enoate (28) followed by cyclization and chiral separation to form 27c, the core skeleton of cap piece 1. The epimerization and chiral resolution of 27c followed by further synthetic manipulations involving the carbamate formation, lactone reduction and cyclization, afforded cyclopropyl pyran 1. A detailed study of diphenylmethane deprotection via acid hydrolysis as well as a key lactone to tetrahydropyran conversion, in order to avoid a side reaction that afforded an alternative cyclization product, are discussed. This synthesis was applied to the preparation of more than 100 g of the final API BMS-986097 for toxicology studies.

Development and validation of an instrument to measure nurse educator perceived confidence in clinical teaching.

Teaching nursing in clinical environments is considered complex and multi-faceted. Little is known about the role of the clinical nurse educator, specifically the challenges related to transition from clinician, or in some cases, from newly-graduated nurse to that of clinical nurse educator, as occurs in developing countries. Confidence in the clinical educator role has been associated with successful transition and the development of role competence. There is currently no valid and reliable instrument to measure clinical nurse educator confidence. This study was conducted to develop and psychometrically test an instrument to measure perceived confidence among clinical nurse educators. A multi-phase, multi-setting survey design was used. A total of 468 surveys were distributed, and 363 were returned. Data were analyzed using exploratory and confirmatory factor analyses. The instrument was successfully tested and modified in phase 1, and factorial validity was subsequently confirmed in phase 2. There was strong evidence of internal consistency, reliability, content, and convergent validity of the Clinical Nurse Educator Skill Acquisition Assessment instrument. The resulting instrument is applicable in similar contexts due to its rigorous development and validation process.

Chemical genetics strategy identifies an HCV NS5A inhibitor with a potent clinical effect.

The worldwide prevalence of chronic hepatitis C virus (HCV) infection is estimated to be approaching 200 million people. Current therapy relies upon a combination of pegylated interferon-alpha and ribavirin, a poorly tolerated regimen typically associated with less than 50% sustained virological response rate in those infected with genotype 1 virus. The development of direct-acting antiviral agents to treat HCV has focused predominantly on inhibitors of the viral enzymes NS3 protease and the RNA-dependent RNA polymerase NS5B. Here we describe the profile of BMS-790052, a small molecule inhibitor of the HCV NS5A protein that exhibits picomolar half-maximum effective concentrations (EC(50)) towards replicons expressing a broad range of HCV genotypes and the JFH-1 genotype 2a infectious virus in cell culture. In a phase I clinical trial in patients chronically infected with HCV, administration of a single 100-mg dose of BMS-790052 was associated with a 3.3 log(10) reduction in mean viral load measured 24 h post-dose that was sustained for an additional 120 h in two patients infected with genotype 1b virus. Genotypic analysis of samples taken at baseline, 24 and 144 h post-dose revealed that the major HCV variants observed had substitutions at amino-acid positions identified using the in vitro replicon system. These results provide the first clinical validation of an inhibitor of HCV NS5A, a protein with no known enzymatic function, as an approach to the suppression of virus replication that offers potential as part of a therapeutic regimen based on combinations of HCV inhibitors.

Australian radiographer roles in the emergency department; evidence of regulatory compliance to improve patient safety - A narrative review.

OBJECTIVES: Using a narrative approach, this paper aims to determine the extent of Australian radiographers' regulatory compliance to improve patient safety when performing appendicular X-ray and non-contrast brain computed tomography (CT) in the Emergency Department (ED). KEY FINDINGS: A narrative review explored relevant literature and key regulatory policy. Ten documents were identified, three main themes were developed related to the radiographer roles in X-ray request justification, dose optimisation and preliminary image evaluation (PIE). Radiographers were equally aware of justification and optimisation pre and post the introduction of a Medical Code of Practice. The collective PIE accuracy of radiographers remained unaffected by changes in mode of PIE delivery and regulatory factors but varied based on the anatomical region. CONCLUSION: While current Australian regulations mandate radiographer request justification, dose optimisation and PIE, the degree of compliance by Australian radiographers remains uncertain. Current literature provides evidence that radiographers can improve patient care and safety through justification, optimisation, and PIE delivery. Change in workplace practice, supported by key stakeholders including radiologists, is essential to integrate radiographers' functions into routine ED clinical practice. Further research is required to audit radiographers' regulatory compliance to improve patient safety. IMPLICATIONS FOR PRACTICE: Patient safety in ED can be improved with timely and accurate diagnosis provided by radiographers. Radiographers have a professional obligation to adhere to the capabilities and standards for safe medical radiation practice defined by Australian regulations. Therefore, radiographers must justify the X-ray request, optimise the radiation dose where appropriate and communicate urgent or unexpected findings to the referrer.

HCV NS5A replication complex inhibitors. Part 5: discovery of potent and pan-genotypic glycinamide cap derivatives.

The isoquinolinamide series of HCV NS5A inhibitors exemplified by compounds 2b and 2c provided the first dual genotype-1a/1b (GT-1a/1b) inhibitor class that demonstrated a significant improvement in potency toward GT-1a replicons compared to that of the initial program lead, stilbene 2a. Structure-activity relationship (SAR) studies that uncovered an alternate phenylglycine-based cap series that exhibit further improvements in virology profile, along with some insights into the pharmacophoric elements associated with the GT-1a potency, are described.

HCV NS5A replication complex inhibitors. Part 3: discovery of potent analogs with distinct core topologies.

In a recent disclosure, we described the discovery of dimeric, prolinamide-based NS5A replication complex inhibitors exhibiting excellent potency towards an HCV genotype 1b replicon. That disclosure dealt with the SAR exploration of the peripheral region of our lead chemotype, and herein is described the SAR uncovered from a complementary effort that focused on the central core region. From this effort, the contribution of the core region to the overall topology of the pharmacophore, primarily vector orientation and planarity, was determined, with a set of analogs exhibiting <10 nM EC(50) in a genotype 1b replicon assay.

A snapshot of Australian primary health care nursing workforce characteristics and reasons they work in these settings: A longitudinal retrospective study.

AIM: This article aimed to provide a snapshot of demographics and professional characteristics of nursing and midwifery workforce in Australian primary health care (PHC) settings during 2015-2019 and factors that influenced their decisions to work in PHC. DESIGN: Longitudinal retrospective survey. METHODS: Longitudinal data that were collected from a descriptive workforce survey were retrieved retrospectively. After collation and cleaning, data from 7066 participants were analysed using descriptive and inferential statistics in SPSS version 27.0. RESULTS: The majority of the participants were female, aged between 45 and 64 years old and working in general practice. There was a small yet steady increase in the number of participants in the 25-34 age group and a downward trend in the percentage of postgraduate study completion among participants. While factors perceived most/least important to their decision to work in PHC were consistent during 2015-2019, these factors differed among different age groups and postgraduate qualification holders. This study's findings are both novel and supported by previous research. It is necessary to tailor recruitment and retention strategies to nurses/midwives' age groups and qualifications to attract and retain highly skilled and qualified nursing and midwifery workforce in PHC settings.

HCV NS5A replication complex inhibitors. Part 2: investigation of stilbene prolinamides.

In a previous disclosure,(1) we reported the dimerization of an iminothiazolidinone to form 1, a contributor to the observed inhibition of HCV genotype 1b replicon activity. The dimer was isolated via bioassay-guided fractionation experiments and shown to be a potent inhibitor of genotype 1b HCV replication for which resistance mapped to the NS5A protein. The elements responsible for governing HCV inhibitory activity were successfully captured in the structurally simplified stilbene prolinamide 2. We describe herein the early SAR and profiling associated with stilbene prolinamides that culminated in the identification of analogs with PK properties sufficient to warrant continued commitment to this chemotype. These studies represent the key initial steps toward the discovery of daclatasvir (BMS-790052), a compound that has demonstrated clinical proof-of-concept for inhibiting the NS5A replication complex in the treatment of HCV infection.

The effectiveness of extended-duration supervision training for nurses and allied health professionals: A realist evaluation.

BACKGROUND: Training helps maintain high-quality supervision and its associated benefits (e.g. reduced burnout, improved care). While studies have previously evaluated extended-duration supervision training programmes, none have treated these as complex interventions so have not employed realist approaches. OBJECTIVES: Building on a previous realist synthesis, this evaluation tests and develops programme theory for extended-duration supervision training to answer the question: to what extent does the supervision training programme work, for whom, under what circumstances and why? DESIGN: We conducted a realist evaluation of a novel state-wide Victorian 3-month supervision training programme including one or two 3.5-h workshops followed by weekly reflexive longitudinal audio diaries (LADs) for up to 12 weeks. METHODS: Realist evaluation data comprised 25 entrance interviews with nurses and allied health professionals, 176 LADs (and 29 written diaries), and 23 exit interviews. We employed team-based realist analysis to identify context-mechanism-outcome configurations (CMOCs) to test and develop programme theory. RESULTS: We refined four recurring CMOCs from the realist synthesis programme theory, found insufficient evidence for two, and established five new recurring CMOCs. We identified multiple positive outcomes from our extended-duration supervision training programme (e.g. improved supervisor practices) through various mechanisms relating to pedagogy (e.g. weekly reflexivity), supervisors (e.g. engagement), and workplaces (e.g. enabling supervision cultures). Some negative outcomes were reported (e.g. decreased engagement) through various mechanisms (e.g. suboptimal training design). Such mechanisms were thought to come about by diverse contexts including supervisors (e.g. inexperienced/experienced), professions (nursing/allied health), and organisations (supervision-enabled/non-enabled cultures). CONCLUSIONS: Our findings extend the realist synthesis programme theory by highlighting various contexts triggering outcome-generating mechanisms. Programme outcomes are maximised through ongoing supervisor reflexivity paying attention to facilitator-supervisor relationships, as well as protected time for supervisors to translate learning into practice.

What Really Matters for Supervision Training Workshops? A Realist Evaluation.

PURPOSE: Supervision training supports health care supervisors to perform their essential functions. Realist evaluations are increasingly popular for evaluating complex educational interventions, but no such evaluations exist appraising supervision workshops. Building on an earlier realist synthesis of supervision training, the authors evaluated whether supervision workshops work, for whom and under what circumstances, and why. METHOD: The authors conducted a 2-stage realist evaluation during 2018-2019 to refine and develop program theory. The intervention involved half-day, face-to-face supervision workshops as part of an Australian state-wide government-funded program for health care and human services supervisors. Data collection involved realist interviews with 10 workshop developers (stage 1) and 43 supervisors (stage 2). The authors employed team-based data analysis using realist logic to refine and develop program theory by identifying contexts, mechanisms, outcomes, and context-mechanism-outcome configurations. RESULTS: Despite their brevity, the supervision workshops had many reported benefits for supervisors (e.g., improved satisfaction) through various perceived mechanisms pertaining to pedagogy (e.g., mixed pedagogies), workshops (e.g., optimal duration), and individuals (e.g., supervisor engagement). However, they also yielded negative reported outcomes (e.g., suboptimal knowledge gains) brought about by assorted perceived mechanisms related to pedagogy (e.g., suboptimal peer learning), workshops (e.g., content irrelevance), and individuals (e.g., suboptimal facilitator competence). Such mechanisms were thought to be triggered by diverse contexts including supervisors' levels of experience, sector, and workplace supervision cultures. CONCLUSIONS: While the findings partly support the realist synthesis of supervision training and previous realist evaluations of faculty development, this realist evaluation extends this literature considerably. Health care educators should employ mixed pedagogies (e.g., didactic teaching, peer learning), relevant content, optimal workshop duration, and competent/engaging facilitators. Educators also need to tailor workshops according to supervisors' contexts including the sectors and supervision cultures in which supervision is practiced, and supervisors' levels of experience (e.g., experienced supervisors appreciated workshop brevity).

The effectiveness of partnership models in clinical nursing education - A scoping review.

OBJECTIVES: To examine the effectiveness of partnership models in clinical nursing education with regards to cost effectiveness; student employability, work-readiness, confidence, and competence; and stakeholders' satisfaction. DESIGN: Scoping review. DATA SOURCES: Research studies published in English were searched electronically through EbscoHost (CINAHL and ERIC), Scopus, Medline (via Ovid), ProQuest Central, and Web of Science databases. Criteria were developed to guide the selection of original studies published in English before 2019 for review. REVIEW METHODS: Arksey and Malley's framework (2005) and relevant enhancements guided the conduct of the review. An informal appraisal of selected studies was applied. RESULTS: Two theses and 31 articles with a variation in methodologies, methods, sample sizes, research populations and quality of evidence were included for review. Four themes were identified: (i) Description of partnership models in clinical education, (ii) length of model implementation prior to evaluation, (iii) positive qualitative findings, and (iv) quantitative findings limited by data collection periods and methods. CONCLUSIONS: Shared among the reviewed studies is stakeholder view of the positive impacts of partnership models on the clinical learning environment, and the increased level of support and individualised instruction for students. However, the use of not fully validated survey instruments and the lack of description about the implementation period before evaluation in many reviewed studies limit the interpretation of quantifiable effect of the partnership models. This review identifies a lack of attention on student employability, work-readiness, cost evaluation, patient perspective, and partnership models in low-income countries. Future research to address these knowledge gaps using high quality data collection methods and rigorous research design is warranted.

OsABCG9 Is an Important ABC Transporter of Cuticular Wax Deposition in Rice.

The importance of the cuticular layer in regulating a plant's water status and providing protection from environmental challenges has been recognized for a long time. The cuticular layer in plants restricts non-stomatal water loss and protects plants against damage from pathogen infection and UV radiation. Much genetic and biochemical research has been done about cutin and wax transportation in Arabidopsis thaliana, but little is known about it in rice. Here, we report that a rice ATP-binding cassette (ABC) transporter, OsABCG9, is essential for normal development during vegetative growth and could play a critical role in the transportation of epicuticular wax in rice. Rice phenotypes with mutated OsABCG9 exhibited growth retardation and sensitivity to low humidity. The total amount of cuticular wax on the leaves of the osabcg9-1 mutant diminished by 53% compared with the wild type, and wax crystals disappeared completely in osabcg9-2 mutant leaves. However, OsABCG9 does not seem to be involved in cutin transportation, even though its ortholog in Arabidopsis, AtABCG11, transports both wax and cutin. Furthermore, the osabcg9-1 mutant had increased leaf chlorophyll leaching and more severe drought susceptibility. This study provides new insights about differences between rice and A. thaliana in wax and cutin transportation associated with the ABCG family during evolution.

Measurement of cytokine mRNA expression in intestinal biopsies of cats with inflammatory enteropathy using quantitative real-time RT-PCR.

Inflammatory bowel disease (IBD) is a common condition in cats characterised by infiltration of inflammatory cells into the intestinal mucosa. In this study, real-time reverse transcriptase polymerase chain reaction (RT-PCR) was used to quantify cytokine messenger RNA (mRNA) expression in intestinal biopsies from cats. Biopsies were collected from seven cats with chronic diarrhoea and histologically confirmed IBD, five cats with chronic diarrhoea due to non-IBD gastrointestinal (GI) disease, and nine clinically normal cats with or without subclinical inflammatory changes in small intestine. Real-time RT-PCR was developed for quantification of mRNA encoding interleukin (IL)-2, IL-4, IL-5, IL-6, IL-10, IL-12 (p35 and p40), IL-18, tumour necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma) and transforming growth factor-beta (TGF-beta). Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was used as a 'housekeeper' gene. All real-time PCR efficiencies were>90% (range 90.4-102%) with correlation coefficients >0.99 (range 0.998-1). The results of the study were analyzed on the basis of either clinical presentation or histopathological evidence of intestinal inflammation. The former analysis showed that mRNA encoding IL-10 and TGF-beta (immunoregulatory cytokines), and IL-6, IL-18, TNF-alpha and IL-12 p40 (Th1 and pro-inflammatory cytokines) was significantly higher in clinically normal cats and cats with IBD when compared to cats with other GI diseases. IL-5 mRNA was significantly higher in cats with IBD compared to clinically normal cats. IL-2 mRNA was significantly lower in cats with non-IBD GI disease than in clinically normal cats. Analysis on the basis of histopathological change revealed that cats with intestinal inflammation had significantly more transcription of genes encoding IL-6, IL-10, IL-12p40, TNF-alpha and TGF-beta than those with normal intestinal morphology. The results suggest that immune dysregulation plays a role in feline IBD and that IBD in cats has a complicated pathogenesis with both pro-inflammatory and immunoregulatory features.

A Systematic View of the MLO Family in Rice Suggests Their Novel Roles in Morphological Development, Diurnal Responses, the Light-Signaling Pathway, and Various Stress Responses.

The Mildew resistance Locus O (MLO) family is unique to plants, containing genes that were initially identified as a susceptibility factor to powdery mildew pathogens. However, little is known about the roles and functional diversity of this family in rice, a model crop plant. The rice genome has 12 potential MLO family members. To achieve systematic functional assignments, we performed a phylogenomic analysis by integrating meta-expression data obtained from public sources of microarray data and real-time expression data into a phylogenic tree. Subsequently, we identified 12 MLO genes with various tissue-preferred patterns, including leaf, root, pollen, and ubiquitous expression. This suggested their functional diversity for morphological agronomic traits. We also used these integrated transcriptome data within a phylogenetic context to estimate the functional redundancy or specificity among OsMLO family members. Here, OsMLO12 showed preferential expression in mature pollen; OsMLO4, in the root tips; OsMLO10, throughout the roots except at the tips; and OsMLO8, expression preferential to the leaves and trinucleate pollen. Of particular interest to us was the diurnal expression of OsMLO1, OsMLO3, and OsMLO8, which indicated that they are potentially significant in responses to environmental changes. In osdxr mutants that show defects in the light response, OsMLO1, OsMLO3, OsMLO8, and four calmodulin genes were down-regulated. This finding provides insight into the novel functions of MLO proteins associated with the light-responsive methylerythritol 4-phosphate pathway. In addition, abiotic stress meta-expression data and real-time expression analysis implied that four and five MLO genes in rice are associated with responses to heat and cold stress, respectively. Upregulation of OsMLO3 by Magnaporthe oryzae infection further suggested that this gene participates in the response to pathogens. Our analysis has produced fundamental information that will enhance future studies of the diverse developmental or physiological phenomena mediated by the MLO family in this model plant system.

HCV NS5A replication complex inhibitors. Part 4. Optimization for genotype 1a replicon inhibitory activity.

A series of symmetrical E-stilbene prolinamides that originated from the library-synthesized lead 3 was studied with respect to HCV genotype 1a (G-1a) and genotype 1b (G-1b) replicon inhibition and selectivity against BVDV and cytotoxicity. SAR emerging from an examination of the prolinamide cap region revealed 11 to be a selective HCV NS5A inhibitor exhibiting submicromolar potency against both G-1a and G-1b replicons. Additional structural refinements resulted in the identification of 30 as a potent, dual G-1a/1b HCV NS5A inhibitor.