Book Review: Pilgrims of Dialogue

A review of Pilgrims of Dialogue edited by A. Pushparajan

Dynamics of testicular germ cell apoptosis in normal mice and transgenic mice overexpressing rat androgen-binding protein

The number and type of testicular germ cells undergoing apoptosis in different age groups of mice (from 7 to 360 days of age) was determined and compared in age-matched wild type (WT) control and in a transgenic (TG) mice homozygous to rat androgen binding protein (ABP) using flow cytometry. Flow cytometric quantification revealed that the total number of germ cells undergoing apoptosis did not differ significantly in WT and TG mice up to Day 14. From Day 21 to Day 60, the number of germ cells undergoing apoptosis was consistently higher in TG than in WT mice. Starting from Day 90, the number of germ cells undergoing apoptosis in TG mice was lower than controls until Day 360. In 21–60 days old TG mice, spermatogonia, S-Phase cells, and primary spermatocytes are the cell types undergoing apoptosis at significantly greater numbers than those in WT mice. However, starting from day 60, the total number of spermatids undergoing apoptosis was significantly lower in TG mice than in age-matched WT controls. TdT-mediated dUTP-biotin nick end labeling (TUNEL) in testicular sections from TG mice of 21 and 30 days of age confirmed the presence of increased numbers of apoptotic germ cells compared to their age matched controls. These data indicate that the continuous presence of greater than physiological concentrations of ABP in the mouse testis has a biphasic effect on the frequency of apoptosis in germ cells. The initial pre-pubertal increase in testicular germ cell apoptosis may result from direct or indirect actions of ABP and is likely to determine the subsequent life-death balance of germ cell populations in TG mice, whereas the subsequent reduction may result from maturation depletion. A wave of apoptosis during the pre-pubertal period is required for normal spermatogenesis to develop, and our data indicate that this apoptotic wave may be regulated by ABP and/or androgens

The Genetics of Inherited Cholestatic Disorders in Neonates and Infants: Evolving Challenges

Many inherited conditions cause cholestasis in the neonate or infant. Next-generation sequencing methods can facilitate a prompt diagnosis in some of these cases; application of these methods in patients with liver diseases of unknown cause has also uncovered novel gene-disease associations and improved our understanding of physiological bile secretion and flow. By helping to define the molecular basis of certain cholestatic disorders, these methods have also identified new targets for therapy as well patient subgroups more likely to benefit from specific therapies. At the same time, sequencing methods have presented new diagnostic challenges, such as the interpretation of single heterozygous genetic variants. This article discusses those challenges in the context of neonatal and infantile cholestasis, focusing on difficulties in predicting variant pathogenicity, the possibility of other causal variants not identified by the genetic screen used, and phenotypic variability among patients with variants in the same genes. A prospective, observational study performed between 2010–2013, which sequenced six important genes (ATP8B1, ABCB11, ABCB4, NPC1, NPC2 and SLC25A13) in an international cohort of 222 patients with infantile liver disease, is given as an example of potential benefits and challenges that clinicians could face having received a complex genetic result. Further studies including large cohorts of patients with paediatric liver disease are needed to clarify the spectrum of phenotypes associated with, as well as appropriate clinical response to, single heterozygous variants in cholestasis-associated genes

Complex expression dynamics and robustness in C. elegans insulin networks

Gene families expand by gene duplication and resulting paralogs diverge through mutation. Functional diversification can include neo-functionalization as well as sub-functionalization of ancestral functions. In addition, redundancy in which multiple genes fulfill overlapping functions is often maintained. Here, we use the family of 40 Caenorhabditis elegans insulins to gain insight into the balance between specificity and redundancy. The insulin/insulin-like growth factor (IIS) pathway comprises a single receptor, DAF-2. To date, no single insulin-like peptide recapitulates all DAF-2-associated phenotypes, likely due to redundancy between insulin-like genes. To provide a first-level annotation of potential patterns of redundancy, we comprehensively delineate the spatiotemporal and conditional expression of all 40 insulins in living animals. We observe extensive dynamics in expression that can explain the lack of simple patterns of pair-wise redundancy. We propose a model in which gene families evolve to attain differential alliances in different tissues and in response to a range of environmental stresses

BRG1 and BRM function antagonistically with c-MYC in adult cardiomyocytes to regulate conduction and contractility

Rationale The contractile dysfunction that underlies heart failure involves perturbations in multiple biological processes ranging from metabolism to electrophysiology. Yet the epigenetic mechanisms that are altered in this disease state have not been elucidated. SWI/SNF chromatin-remodeling complexes are plausible candidates based on mouse knockout studies demonstrating a combined requirement for the BRG1 and BRM catalytic subunits in adult cardiomyocytes. Brg1/Brm double mutants exhibit metabolic and mitochondrial defects and are not viable although their cause of death has not been ascertained. Objective To determine the cause of death of Brg1/Brm double-mutant mice, to test the hypothesis that BRG1 and BRM are required for cardiac contractility, and to identify relevant downstream target genes. Methods and results A tamoxifen-inducible gene-targeting strategy utilizing αMHC-Cre-ERT was implemented to delete both SWI/SNF catalytic subunits in adult cardiomyocytes. Brg1/Brm double-mutant mice were monitored by echocardiography and electrocardiography, and they underwent rapidly progressive ventricular dysfunction including conduction defects and arrhythmias that culminated in heart failure and death within 3 weeks. Mechanistically, BRG1/BRM repressed c-Myc expression, and enforced expression of a DOX-inducible c-MYC trangene in mouse cardiomyocytes phenocopied the ventricular conduction defects observed in Brg1/Brm double mutants. BRG1/BRM and c-MYC had opposite effects on the expression of cardiac conduction genes, and the directionality was consistent with their respective loss- and gain-of-function phenotypes. To support the clinical relevance of this mechanism, BRG1/BRM occupancy was diminished at the same target genes in human heart failure cases compared to controls, and this correlated with increased c-MYC expression and decreased CX43 and SCN5A expression. Conclusion BRG1/BRM and c-MYC have an antagonistic relationship regulating the expression of cardiac conduction genes that maintain contractility, which is reminiscent of their antagonistic roles as a tumor suppressor and oncogene in cancer

Arduous implementation: Does the Normalisation Process Model explain why it's so difficult to embed decision support technologies for patients in routine clinical practice

Background: decision support technologies (DSTs, also known as decision aids) help patients and professionals take part in collaborative decision-making processes. Trials have shown favorable impacts on patient knowledge, satisfaction, decisional conflict and confidence. However, they have not become routinely embedded in health care settings. Few studies have approached this issue using a theoretical framework. We explained problems of implementing DSTs using the Normalization Process Model, a conceptual model that focuses attention on how complex interventions become routinely embedded in practice.Methods: the Normalization Process Model was used as the basis of conceptual analysis of the outcomes of previous primary research and reviews. Using a virtual working environment we applied the model and its main concepts to examine: the 'workability' of DSTs in professional-patient interactions; how DSTs affect knowledge relations between their users; how DSTs impact on users' skills and performance; and the impact of DSTs on the allocation of organizational resources.Results: conceptual analysis using the Normalization Process Model provided insight on implementation problems for DSTs in routine settings. Current research focuses mainly on the interactional workability of these technologies, but factors related to divisions of labor and health care, and the organizational contexts in which DSTs are used, are poorly described and understood.Conclusion: the model successfully provided a framework for helping to identify factors that promote and inhibit the implementation of DSTs in healthcare and gave us insights into factors influencing the introduction of new technologies into contexts where negotiations are characterized by asymmetries of power and knowledge. Future research and development on the deployment of DSTs needs to take a more holistic approach and give emphasis to the structural conditions and social norms in which these technologies are enacte

Family-led rehabilitation after stroke in India: a randomised controlled trial

Background: Most people with stroke in India have no access to organised rehabilitation services. The effectiveness of training family members to provide stroke rehabilitation is uncertain. Our primary objective was to determine whether family-led stroke rehabilitation, initiated in hospital and continued at home, would be superior to usual care, in a low resource setting. Methods: The Family-led Rehabilitation after Stroke in India (ATTEND) trial was a prospectively randomised open trial with blinded endpoints (PROBE) conducted across 14 hospitals in India. Patients (and their caregivers) were randomised to intervention or usual care by site Coordinators, using a secure web-based system, with minimisation by site and stroke severity. The intervention group received additional structured rehabilitation training, commenced in hospital and continued at home for up to 2 months. The primary outcome was death or dependency, defined by scores 3 to 6 on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]) as assessed by blinded observers at six months. Secondary outcomes included any serious adverse event, hospital length of stay, activities of daily living, health-related quality of life, anxiety and depression, and caregiver strain. All analyses were intention to treat. Registration: Clinical Trials Registry-India (CTRI/2013/04/003557); Australian New Zealand Clinical Trials Registry (ACTRN12613000078752); and Universal Trial Number (U1111-1138-6707) Findings: A total of 1,250 patients were randomised (623 intervention and 627 control) between 13 January 2014 and 12 February 2016. At six months, 285 of 607 (47·0%) participants in the intervention group were dead or dependent compared to 287 of 605 (47·4%) in the control group (odds ratio 0·98; 95% confidence Interval 0·78 to 1·23, P = 0·87). No significant differences were observed in any of the secondary or safety outcomes. Interpretation: Family-led rehabilitation did not reduce death or dependency after stroke

Klf15 Is Critical for the Development and Differentiation of Drosophila Nephrocytes

Insect nephrocytes are highly endocytic scavenger cells that represent the only invertebrate model for the study of human kidney podocytes. Despite their importance, nephrocyte development is largely uncharacterised. This work tested whether the insect ortholog of mammalian Kidney Krüppel-Like Factor (Klf15), a transcription factor required for mammalian podocyte differentiation, was required for insect nephrocyte development. It was found that expression of Drosophila Klf15 (dKlf15, previously known as Bteb2) was restricted to the only two nephrocyte populations in Drosophila, the garland cells and pericardial nephrocytes. Loss of dKlf15 function led to attrition of both nephrocyte populations and sensitised larvae to the xenotoxin silver nitrate. Although pericardial nephrocytes in dKlf15 loss of function mutants were specified during embryogenesis, they failed to express the slit diaphragm gene sticks and stones and did not form slit diaphragms. Conditional silencing of dKlf15 in adults led to reduced surface expression of the endocytic receptor Amnionless and loss of in vivo scavenger function. Over-expression of dKlf15 increased nephrocyte numbers and rescued age-dependent decline in nephrocyte function. The data place dKlf15 upstream of sns and Amnionless in a nephrocyte-restricted differentiation pathway and suggest dKlf15 expression is both necessary and sufficient to sustain nephrocyte differentiation. These findings explain the physiological relevance of dKlf15 in Drosophila and imply that the role of KLF15 in human podocytes is evolutionarily conserve

Family-led rehabilitation in India (ATTEND)—Findings from the process evaluation of a randomized controlled trial

Background Training family carers to provide evidence-based rehabilitation to stroke patients could address the recognized deficiency of access to stroke rehabilitation in low-resource settings. However, our randomized controlled trial in India (ATTEND) found that this model of care was not superior to usual care alone. Aims This process evaluation aimed to better understand trial outcomes through assessing trial implementation and exploring patients’, carers’, and providers’ perspectives. Methods Our mixed methods study included process, healthcare use data and patient demographics from all sites; observations and semi-structured interviews with participants (22 patients, 22 carers, and 28 health providers) from six sampled sites. Results Intervention fidelity and adherence to the trial protocol was high across the 14 sites; however, early supported discharge (an intervention component) was not implemented. Within both randomized groups, some form of rehabilitation was widely accessed. ATTEND stroke coordinators provided counseling and perceived that sustaining patients’ motivation to continue with rehabilitation in the face of significant emotional and financial stress as a key challenge. The intervention was perceived as an acceptable community-based package with education as an important component in raising the poor awareness of stroke. Many participants viewed family-led rehabilitation as a necessary model of care for poor and rural populations who could not access rehabilitation. Conclusion Difficulty in sustaining patient and carer motivation for rehabilitation without ongoing support, and greater than anticipated access to routine rehabilitation may explain the lack of benefit in the trial. Nonetheless, family-led rehabilitation was seen as a concept worthy of further development

Protocol for process evaluation of a randomised controlled trial of family-led rehabilitation post stroke (ATTEND) in India

Introduction We are undertaking a randomised controlled trial (fAmily led rehabiliTaTion aftEr stroke in INDia, ATTEND) evaluating training a family carer to enable maximal rehabilitation of patients with stroke-related disability; as a potentially affordable, culturally acceptable and effective intervention for use in India. A process evaluation is needed to understand how and why this complex intervention may be effective, and to capture important barriers and facilitators to its implementation. We describe the protocol for our process evaluation to encourage the development of in-process evaluation methodology and transparency in reporting. Methods and analysis The realist and RE-AIM (Reach, Effectiveness, Adoption, Implementation and Maintenance) frameworks informed the design. Mixed methods include semistructured interviews with health providers, patients and their carers, analysis of quantitative process data describing fidelity and dose of intervention, observations of trial set up and implementation, and the analysis of the cost data from the patients and their families perspective and programme budgets. These qualitative and quantitative data will be analysed iteratively prior to knowing the quantitative outcomes of the trial, and then triangulated with the results from the primary outcome evaluation. Ethics and dissemination The process evaluation has received ethical approval for all sites in India. In low-income and middle-income countries, the available human capital can form an approach to reducing the evidence practice gap, compared with the high cost alternatives available in established market economies. This process evaluation will provide insights into how such a programme can be implemented in practice and brought to scale. Through local stakeholder engagement and dissemination of findings globally we hope to build on patient-centred, cost-effective and sustainable models of stroke rehabilitation. Trial registration number CTRI/2013/04/003557