Prenatal ethanol exposure impairs the conduction delay at the atrioventricular junction in the looping heart.

The etiology of ethanol-related congenital heart defects has been the focus of much study, but most research has concentrated on cellular and molecular mechanisms. We have shown with optical coherence tomography (OCT) that ethanol exposure led to increased retrograde flow and smaller atrioventricular (AV) cushions compared with controls. Since AV cushions play a role in patterning the conduction delay at the atrioventricular junction (AVJ), this study aims to investigate whether ethanol exposure alters the AVJ conduction in early looping hearts and whether this alteration is related to the decreased cushion size. Quail embryos were exposed to a single dose of ethanol at gastrulation, and Hamburger-Hamilton stage 19-20 hearts were dissected for imaging. Cardiac conduction was measured using an optical mapping microscope and we imaged the endocardial cushions using OCT. Our results showed that, compared with controls, ethanol-exposed embryos exhibited abnormally fast AVJ conduction and reduced cushion size. However, this increased conduction velocity (CV) did not strictly correlate with decreased cushion volume and thickness. By matching the CV map to the cushion-size map along the inflow heart tube, we found that the slowest conduction location was consistently at the atrial side of the AVJ, which had the thinner cushions, not at the thickest cushion location at the ventricular side as expected. Our findings reveal regional differences in the AVJ myocardium even at this early stage in heart development. These findings reveal the early steps leading to the heterogeneity and complexity of conduction at the mature AVJ, a site where arrhythmias can be initiated.NEW & NOTEWORTHY To the best of our knowledge, this is the first study investigating the impact of ethanol exposure on the early cardiac conduction system. Our results showed that ethanol-exposed embryos exhibited abnormally fast atrioventricular conduction. In addition, our findings, in CV measurements and endocardial cushion thickness, reveal regional differences in the AVJ myocardium even at this early stage in heart development, suggesting that the differentiation and maturation at this site are complex and warrant further studies.

Glutathione Protects the Developing Heart from Defects and Global DNA Hypomethylation Induced by Prenatal Alcohol Exposure.

BACKGROUND: Fetal alcohol spectrum disorder (FASD) is caused by prenatal alcohol exposure (PAE), the intake of ethanol (C2 H5 OH) during pregnancy. Features of FASD cover a range of structural and functional defects including congenital heart defects (CHDs). Folic acid and choline, contributors of methyl groups to one-carbon metabolism (OCM), prevent CHDs in humans. Using our avian model of FASD, we have previously reported that betaine, another methyl donor downstream of choline, prevents CHDs. The CHD preventions are substantial but incomplete. Ethanol causes oxidative stress as well as depleting methyl groups for OCM to support DNA methylation and other epigenetic alterations. To identify more compounds that can safely and effectively prevent CHDs and other effects of PAE, we tested glutathione (GSH), a compound that regulates OCM and is known as a "master antioxidant." METHODS/RESULTS: Quail embryos injected with a single dose of ethanol at gastrulation exhibited congenital defects including CHDs similar to those identified in FASD individuals. GSH injected simultaneously with ethanol not only prevented CHDs, but also improved survival and prevented other PAE-induced defects. Assays of hearts at 8 days (HH stage 34) of quail development, when the heart normally has developed 4-chambers, showed that this single dose of PAE reduced global DNA methylation. GSH supplementation concurrent with PAE normalized global DNA methylation levels. The same assays performed on quail hearts at 3 days (HH stage 19-20) of development, showed no difference in global DNA methylation between controls, ethanol-treated, GSH alone, and GSH plus ethanol-treated cohorts. CONCLUSIONS: GSH supplementation shows promise to inhibit effects of PAE by improving survival, reducing the incidence of morphological defects including CHDs, and preventing global hypomethylation of DNA in heart tissues.

Elevation through reflection: closing the circle to improve librarianship.

Reflective practice is a strategy promoted as a way to improve professional performance and to develop expertise. Intentional reflection on work situations can lead to improved understanding of a specific situation, identify strategies for similar situations in the future, and uncover assumptions that hinder service to patrons. Research has identified lack of knowledge to be a barrier to health sciences librarians engaging in reflective practice. This article introduces the use of intentional reflection at work: what it is, how it helps, and how it can be applied in librarianship. It also provides practical advice on how to choose a format, how to use a model to guide reflection, and how to incorporate it into work.

A Mutagenic Screen Identifies a TonB-Dependent Receptor Required for the Lanthanide Metal Switch in the Type I Methanotroph "Methylotuvimicrobium buryatense" 5GB1C.

Several of the metabolic enzymes in methanotrophic bacteria rely on metals for both their expression and their catalysis. The MxaFI methanol dehydrogenase enzyme complex uses calcium as a cofactor to oxidize methanol, while the alternative methanol dehydrogenase XoxF uses lanthanide metals such as lanthanum and cerium for the same function. Lanthanide metals, abundant in the earth's crust, strongly repress the transcription of mxaF yet activate the transcription of xoxF This regulatory program, called the "lanthanide switch," is central to methylotrophic metabolism, but only some of its components are known. To uncover additional components of the lanthanide switch, we developed a chemical mutagenesis system in the type I gammaproteobacterial methanotroph "Methylotuvimicrobium buryatense" 5GB1C and designed a selection system for mutants unable to repress the mxaF promoter in the presence of lanthanum. Whole-genome resequencing for multiple lanthanide switch mutants identified several unique point mutations in a single gene encoding a TonB-dependent receptor, which we have named LanA. The LanA TonB-dependent receptor is absolutely required for the lanthanide switch and controls the expression of a small set of genes. While mutation of the lanA gene does not affect the amount of cell-associated lanthanum, it is essential for growth in the absence of the MxaF methanol dehydrogenase, suggesting that LanA is involved in lanthanum uptake to supply the XoxF methanol dehydrogenase with its critical metal ion cofactor. The discovery of this novel component of the lanthanide regulatory system highlights the complexity of this circuit and suggests that further components are likely involved.IMPORTANCE Lanthanide metals, or rare earth elements, are abundant in nature and used heavily in technological devices. Biological interactions with lanthanides are just beginning to be unraveled. Until very recently, microbial mechanisms of lanthanide metal interaction and uptake were unknown. The TonB-dependent receptor LanA is the first lanthanum receptor identified in a methanotroph. Sequence homology searches with known metal transporters and regulators could not be used to identify LanA or other lanthanide metal switch components, and this method for mutagenesis and selection was required to identify the receptor. This work advances the knowledge of microbe-metal interactions in environmental niches that impact atmospheric methane levels and are thus relevant to climate change.

Pharmacotherapy of BPD: Current status & future perspectives.

Bronchopulmonary dysplasia (BPD) is a disease exclusive to prematurity and has changed in its definition since Northway first described it in 1967. There have been countless clinical trials evaluating the efficacy of drugs in the treatment and prevention of BPD in human subjects, and an even larger number of animal studies. Despite these, only a handful of drugs are used at the bedside today, primarily due to the lack of consistent efficacy seen in clinical trials or due to reports of adverse effects. This review summarizes the list of the most commonly used drugs and emerging new therapies which target BPD and BPD-related pulmonary hypertension (BPD-PH), including those which have shown promise in human trials but are not yet used routinely.

The truth project paper one-how did victims and survivors experience participation? Addressing epistemic relational inequality in the field of child sexual abuse.

The last 30 years has seen an exponential increase in Historical Institutional Abuse Inquiries. One feature of these has been to place adult survivor voices at the center of Inquiry work, meaning that child abuse victims and survivors are engaging with Inquiries, sharing their experiences, with this participation often presented as empowering and healing. This initiative challenges long held beliefs that child sexual abuse survivors are unreliable witnesses, which has led to epistemic injustice and a hermeneutical lacunae in survivor testimony. However to date there has been limited research on what survivors say about their experiences of participation. The Truth Project was one area of work of the Independent Inquiry into Child Sexual Abuse in England and Wales. It invited survivors of Child Sexual Abuse to share their experiences including the impacts of abuse and their recommendations for change. The Truth Project concluded in 2021 and heard from more than 6,000 victims of child sexual abuse. The evaluation of the Trauma Informed Approach designed to support survivors through their engagement with the project was a mixed methods, two phase methodology. A total of 66 survey responses were received. Follow-up interviews were conducted with seven survey respondents. The Trauma Informed Approach was found to be predominantly helpful in attending to victim needs and minimizing harm. However, a small number of participants reported harmful effects post-session. The positive impacts reported about taking part in the Truth Project as a one-off engagement challenges beliefs that survivors of child sexual abuse cannot safely talk about their experiences. It also provides evidence of the central role survivors should have in designing services for trauma victims. This study contributes to the epistemic justice literature which emphasizes the central role of relational ethics in the politics of knowing, and the importance of developing a testimonial sensibility when listening to marginalized groups.

The truth project- paper two- using staff training and consultation to inculcate a testimonial sensibility in non-specialist staff teams working with survivors of child sexual abuse.

This paper explores how trauma informed training and consultation for non-specialist staff at the Independent Inquiry into Child Sexual Abuse in England and Wales enabled them to work with survivors of non-recent child sexual abuse in the Truth Project and other areas of the Inquiry. The paper draws on data gathered from 32 semi-structured interviews with a range of Inquiry staff, including civil servants, legal professionals, senior operational managers, and researchers. The interview questions mapped on to the trauma informed principles embedded in the Inquiry and considered the efficacy and implementation of this training for engaging with survivors' voices, working with challenging testimonies and materials, and contributing to epistemic change. Findings included all staff having an awareness of what it meant to be trauma informed in an Inquiry context, talking about the principles in terms of value-based positions. Staff described an awareness of needing to attend to the idiosyncratic experiences of the individual survivor, and there was recognition that previous damage to survivor trust, through institutional failure, meant that demonstrating trustworthiness was a central task. Staff talked about the impacts of participation on some survivors, and the impacts it had on them to be exposed to trauma-related materials. There was acknowledgment of the limitations of the trauma informed approach but also recognition of the wider applications of this learning for other areas of their personal and professional lives. There is some support for the therapeutic culture developed at the Inquiry leading to what Fricker refers to as a testimonial sensibility, a quality of listening necessary for the establishment of epistemic justice. The discussion focuses on how this way of working can be applied to other public service settings and how epistemic justice concepts can be included in more traditional trauma informed care models to encourage an ethic of listening that has political and social, in addition to therapeutic, outcomes.

Segmentation of beating embryonic heart structures from 4-D OCT images using deep learning.

Optical coherence tomography (OCT) has been used to investigate heart development because of its capability to image both structure and function of beating embryonic hearts. Cardiac structure segmentation is a prerequisite for the quantification of embryonic heart motion and function using OCT. Since manual segmentation is time-consuming and labor-intensive, an automatic method is needed to facilitate high-throughput studies. The purpose of this study is to develop an image-processing pipeline to facilitate the segmentation of beating embryonic heart structures from a 4-D OCT dataset. Sequential OCT images were obtained at multiple planes of a beating quail embryonic heart and reassembled to a 4-D dataset using image-based retrospective gating. Multiple image volumes at different time points were selected as key-volumes, and their cardiac structures including myocardium, cardiac jelly, and lumen, were manually labeled. Registration-based data augmentation was used to synthesize additional labeled image volumes by learning transformations between key-volumes and other unlabeled volumes. The synthesized labeled images were then used to train a fully convolutional network (U-Net) for heart structure segmentation. The proposed deep learning-based pipeline achieved high segmentation accuracy with only two labeled image volumes and reduced the time cost of segmenting one 4-D OCT dataset from a week to two hours. Using this method, one could carry out cohort studies that quantify complex cardiac motion and function in developing hearts.

Real-World Sarilumab Use and Rule Testing to Predict Treatment Response in Patients with Rheumatoid Arthritis: Findings from the RISE Registry.

INTRODUCTION: Clinical trial findings may not be generalizable to routine practice. This study evaluated sarilumab effectiveness in patients with rheumatoid arthritis (RA) and tested the real-world applicability of a response prediction rule, derived from trial data using machine learning (based on C-reactive protein [CRP] > 12.3 mg/l and seropositivity [anticyclic citrullinated peptide antibodies, ACPA +]). METHODS: Sarilumab initiators from the ACR-RISE Registry, with ≥ 1 prescription on/after its FDA approval (2017-2020), were divided into three cohorts based on progressively restrictive criteria: Cohort A (had active disease), Cohort B (met eligibility criteria of a phase 3 trial in RA patients with inadequate response/intolerance to tumor necrosis factor inhibitors [TNFi]), and Cohort C (characteristics matched to the phase 3 trial baseline). Mean changes in Clinical Disease Activity Index (CDAI) and Routine Assessment of Patient Index Data 3 (RAPID3) were evaluated at 6 and 12 months. In a separate cohort, predictive rule was tested based on CRP levels and seropositive status (ACPA and/or rheumatoid factor); patients were categorized into rule-positive (seropositive with CRP > 12.3 mg/l) and rule-negative groups to compare the odds of achieving CDAI low disease activity (LDA)/remission and minimal clinically important difference (MCID) over 24 weeks. RESULTS: Among sarilumab initiators (N = 2949), treatment effectiveness was noted across cohorts, with greater improvement noted for Cohort C at 6 and 12 months. Among the predictive rule cohort (N = 205), rule-positive (vs. rule-negative) patients were more likely to reach LDA (odds ratio: 1.5 [0.7, 3.2]) and MCID (1.1 [0.5, 2.4]). Sensitivity analyses (CRP > 5 mg/l) showed better response to sarilumab in rule-positive patients. CONCLUSIONS: In real-world setting, sarilumab demonstrated treatment effectiveness, with greater improvements in the most selective population, mirroring phase 3 TNFi-refractory and rule-positive RA patients. Seropositivity appeared a stronger driver for treatment response than CRP, although optimization of the rule in routine practice requires further data.

Rheumatoid arthritis (RA) is a condition that may cause joint damage, if untreated. Sarilumab is an advanced medication, approved for treating moderate-to-severe RA in patients not responding to initial standard medicines. Clinical trials have shown that sarilumab improves RA symptoms; however, some people do not respond. This is a common problem in RA treatment. Physicians measure proteins in people's blood (called biomarkers; e.g., anticyclic citrullinated peptide antibodies [ACPA], C-reactive protein [CRP], and rheumatoid factor [RF]) to predict a medicine's response. A previous study showed that people with positive blood tests for ACPA and CRP (> 12.3 mg/l) responded well to sarilumab; this study was based on machine learning (a branch of science using computers) and identified factors that could be linked to treatment benefits. The present study analyzed routine data of 2949 people from the ACR-RISE Registry and showed an improvement in RA symptoms after 6 and 12 months of sarilumab, with a greater improvement noted in patients previously treated with other medicines. Biomarkers were tested in 205 people to check whether they could predict treatment response in day-to-day life. People were called rule-positive if they tested positive for RF and/or ACPA with CRP > 12.3 mg/l, and otherwise rule-negative. After 24 weeks of treatment, rule-positive people had a greater chance of disease improvement than rule-negative people. These results showed the benefits of sarilumab in RA in routine care and suggested the usefulness of machine learning in identifying biomarkers that physicians can use to make treatment decisions.

Project EPIC (Early Palliative Care In COPD): A Formative and Summative Evaluation of the EPIC Telehealth Intervention.

CONTEXT: Early, concurrent palliative care interventions in chronic obstructive pulmonary disease (COPD) are limited. Project EPIC (Early Palliative Care In COPD) is a multiphase mixed methods study working to fill this gap. OBJECTIVES: To conduct a formative and summative evaluation of EPIC, a telephonic nurse coach-led early palliative care intervention for COPD adapted from the ENABLE© intervention in cancer. METHODS: Phase I Formative Evaluation: Patients with moderate-to-very-severe COPD, family caregivers, and pulmonary and palliative care clinicians rated the acceptability and feasibility of EPIC (≥4 out of five on a Likert-scale survey). Phase II Summative Evaluation: Patients and family caregivers in Phase I participated in a pilot of the three month EPIC prototype to evaluate intervention and data collection feasibility (≥70% completion) and to seek qualitative feedback. RESULTS: Phase I Formative Evaluation: Patients (n=10), family caregivers (n=10), pulmonary clinicians (n=6), and palliative care clinicians (n=6) found EPIC acceptable and feasible to support adaptation, while priority early palliative care needs in COPD from our prior research mapped well to the EPIC prototype. Phase II Summative Evaluation: Patients (n=5; ages 49-72, 40% moderate COPD, 40% Black) and their family caregivers (n=5; ages 51-73, 40% Black) completed 100% of EPIC prototype components, including weekly telephone sessions, a one month follow-up call, Advance Directive, palliative care clinic attendance, and 95% of monthly phone data collection sessions. Feedback from participants about EPIC was all positive. CONCLUSION: EPIC was acceptable and feasible in patients with COPD and their family caregivers. Larger feasibility and effectiveness trials are warranted.

The neuroscience of spirituality, religion, and mental health: A systematic review and synthesis.

Prior research highlights the importance of spirituality/religion (S/R) as it relates to several aspects of mental health and clinical interventions. This research has been expanded to include the concurrent examination of neurobiological correlates of S/R to elucidate potential biological mechanisms. However, the majority of neurobiological research on S/R has neglected mental health, and the relationship across all three of these domains (S/R, mental health, and neurobiology) remains unclear. This study systematically reviewed research concurrently examining S/R, mental health, and neurobiology, and rated the methodological quality of included studies. Eighteen identified studies were then included in an integrated literature review and discussion, regarding the neurobiological correlates of S/R as it pertains to depression, anxiety, alcohol/substance misuse, and psychosis. The majority of studies demonstrated moderate to high methodological quality. Findings highlight the need for additional studies in this area as well as research that includes validated assessment of S/R.

Automated endocardial cushion segmentation and cellularization quantification in developing hearts using optical coherence tomography.

Of all congenital heart defects (CHDs), anomalies in heart valves and septa are among the most common and contribute about fifty percent to the total burden of CHDs. Progenitors to heart valves and septa are endocardial cushions formed in looping hearts through a multi-step process that includes localized expansion of cardiac jelly, endothelial-to-mesenchymal transition, cell migration and proliferation. To characterize the development of endocardial cushions, previous studies manually measured cushion size or cushion cell density from images obtained using histology, immunohistochemistry, or optical coherence tomography (OCT). Manual methods are time-consuming and labor-intensive, impeding their applications in cohort studies that require large sample sizes. This study presents an automated strategy to rapidly characterize the anatomy of endocardial cushions from OCT images. A two-step deep learning technique was used to detect the location of the heart and segment endocardial cushions. The acellular and cellular cushion regions were then segregated by K-means clustering. The proposed method can quantify cushion development by measuring the cushion volume and cellularized fraction, and also map 3D spatial organization of the acellular and cellular cushion regions. The application of this method to study the developing looping hearts allowed us to discover a spatial asymmetry of the acellular cardiac jelly in endocardial cushions during these critical stages, which has not been reported before.

A Computational Framework for Identifying Promoter Sequences in Nonmodel Organisms Using RNA-seq Data Sets.

Engineering microorganisms into biological factories that convert renewable feedstocks into valuable materials is a major goal of synthetic biology; however, for many nonmodel organisms, we do not yet have the genetic tools, such as suites of strong promoters, necessary to effectively engineer them. In this work, we developed a computational framework that can leverage standard RNA-seq data sets to identify sets of constitutive, strongly expressed genes and predict strong promoter signals within their upstream regions. The framework was applied to a diverse collection of RNA-seq data measured for the methanotroph Methylotuvimicrobium buryatense 5GB1 and identified 25 genes that were constitutively, strongly expressed across 12 experimental conditions. For each gene, the framework predicted short (27-30 nucleotide) sequences as candidate promoters and derived -35 and -10 consensus promoter motifs (TTGACA and TATAAT, respectively) for strong expression in M. buryatense. This consensus closely matches the canonical E. coli sigma-70 motif and was found to be enriched in promoter regions of the genome. A subset of promoter predictions was experimentally validated in a XylE reporter assay, including the consensus promoter, which showed high expression. The pmoC, pqqA, and ssrA promoter predictions were additionally screened in an experiment that scrambled the -35 and -10 signal sequences, confirming that transcription initiation was disrupted when these specific regions of the predicted sequence were altered. These results indicate that the computational framework can make biologically meaningful promoter predictions and identify key pieces of regulatory systems that can serve as foundational tools for engineering diverse microorganisms for biomolecule production.

A Formative Evaluation of Patient and Family Caregiver Perspectives on Early Palliative Care in Chronic Obstructive Pulmonary Disease across Disease Severity.

Rationale: Little direction exists on how to integrate early palliative care in chronic obstructive pulmonary disease (COPD).Objectives: We sought to identify patient and family caregiver early palliative care needs across stages of COPD severity.Methods: As part of the Medical Research Council Framework developmental phase for intervention development, we conducted a formative evaluation of patients with moderate to very severe COPD (forced expiratory volume in 1 s [FEV1]/FVC < 70% and FEV1 < 80%-predicted) and their family caregivers. Validated surveys on quality of life, anxiety and depressive symptoms, and social isolation quantified symptom severity. Semi-structured interviews were analyzed for major themes on early palliative care and needs in patients and family caregivers and across COPD severity stages.Results: Patients (n = 10) were a mean (±SD) age of 60.4 (±7.5) years, 50% African American, and 70% male, with 30% having moderate COPD, 30% severe COPD, and 40% very severe COPD. Family caregivers (n = 10) were a mean age of 58.3 (±8.7) years, 40% African American, and 10% male. Overall, 30% (n = 6) of participants had poor quality of life, 45% (n = 9) had moderate-severe anxiety symptoms, 25% (n = 5) had moderate-severe depressive symptoms, and 40% (n = 8) reported social isolation. Only 30% had heard of palliative care, and most participants had misconceptions that palliative care was end-of-life care. All participants responded positively to a standardized description of early palliative care and were receptive to its integration as early as moderate stage. Five broad themes of early palliative care needs emerged: 1) coping with COPD; 2) emotional symptoms; 3) respiratory symptoms; 4) illness understanding; and 5) prognostic awareness. Coping with COPD and emotional symptoms were commonly shared early palliative care needs. Patients with very severe COPD and their family caregivers prioritized illness understanding and prognostic awareness compared with those with moderate-severe COPD.Conclusions: Patients with moderate to very severe COPD and their family caregivers found early palliative care acceptable and felt it should be integrated before end-stage. Of the five broad themes of early palliative care needs, coping with COPD and emotional symptoms were the highest priority, followed by respiratory symptoms, illness understanding, and prognostic awareness.

Diagnostic and Therapeutic Management of Nasal Airway Obstruction: Advances in Diagnosis and Treatment.

IMPORTANCE: Nasal airway obstruction (NAO) is a common complaint in the otolaryngologist's office and can have a negative influence on quality of life (QOL). Existing diagnostic methods have improved, but little consensus exists on optimal tools. Furthermore, although surgical techniques for nasal obstruction continue to be developed, effective outcome measurement is lacking. An update of recent advances in diagnostic and therapeutic management of NAO is warranted. OBJECTIVE: To review advances in diagnosis and treatment of NAO from the last 5 years. EVIDENCE REVIEW: PubMed, Embase, CINAHL, the Cochrane Library, LILACS, Web of Science, and Guideline.gov were searched with the terms nasal obstruction and nasal blockage and their permutations from July 26, 2012, through October 23, 2017. Studies were included if they evaluated NAO using a subjective and an objective technique, and in the case of intervention-based studies, the Nasal Obstruction Symptom Evaluation (NOSE) scale and an objective technique. Exclusion criteria consisted of animal studies; patients younger than 14 years; nasal foreign bodies; nasal masses including polyps; choanal atresia; sinus disease; obstructive sleep apnea or sleep-disordered breathing; allergic rhinitis; and studies not specific to nasal obstruction. FINDINGS: The initial search resulted in 942 articles. After independent screening by 2 investigators, 46 unique articles remained, including 2 randomized clinical trials, 3 systematic reviews, 3 meta-analyses, and 39 nonrandomized cohort studies (including a combined systematic review and meta-analysis). An aggregate of approximately 32 000 patients were reviewed (including meta-analyses). Of the subjective measures available for NAO, the NOSE scale is outstanding with regard to disease-specific validation and correlation with symptoms. No currently available objective measure can be considered a criterion standard. Structural measures of flow, pressure, and volume appear to be necessary but insufficient to assess NAO. Therefore, novel variables and techniques must continue to be explored in search of an ideal instrument to aid in assessment of surgical outcomes. CONCLUSIONS AND RELEVANCE: Nasal airway obstruction is a clinical diagnosis with considerable effects on QOL. An adequate diagnosis begins with a focused history and physical examination and requires a patient QOL measure such as the NOSE scale. Objective measures should be adjunctive and require further validation for widespread adoption. These results are limited by minimal high-quality evidence among studies and the risk of bias in observational studies. LEVEL OF EVIDENCE: NA.

Increased regurgitant flow causes endocardial cushion defects in an avian embryonic model of congenital heart disease.

BACKGROUND: The relationship between changes in endocardial cushion and resultant congenital heart diseases (CHD) has yet to be established. It has been shown that increased regurgitant flow early in embryonic heart development leads to endocardial cushion defects, but it remains unclear how abnormal endocardial cushions during the looping stages might affect the fully septated heart. The goal of this study was to reproducibly alter blood flow in vivo and then quantify the resultant effects on morphology of endocardial cushions in the looping heart and on CHDs in the septated heart. METHODS: Optical pacing was applied to create regurgitant flow in embryonic hearts, and optical coherence tomography (OCT) was utilized to quantify regurgitation and morphology. Embryonic quail hearts were optically paced at 3 Hz (180 bpm, well above intrinsic rate 60-110 bpm) at stage 13 of development (3-4 weeks human) for 5 min. Pacing fatigued the heart and led to at least 1 h of increased regurgitant flow. Resultant morphological changes were quantified with OCT imaging at stage 19 (cardiac looping-4-5 weeks human) or stage 35 (4 chambered heart-8 weeks human). RESULTS: All paced embryos imaged at stage 19 displayed structural changes in cardiac cushions. The amount of regurgitant flow immediately after pacing was inversely correlated with cardiac cushion size 24-h post pacing (P value < .01). The embryos with the most regurgitant flow and smallest cushions after pacing had a decreased survival rate at 8 days (P < .05), indicating that those most severe endocardial cushion defects were lethal. Of the embryos that survived to stage 35, 17/18 exhibited CHDs including valve defects, ventricular septal defects, hypoplastic ventricles, and common AV canal. CONCLUSION: The data illustrate a strong inverse relationship in which regurgitant flow precedes abnormal and smaller cardiac cushions, resulting in the development of CHDs.

Alzheimer's disease skin fibroblasts selectively express a bradykinin signaling pathway mediating tau protein Ser phosphorylation.

Increased Ser phosphorylation of tau microtubule-associated protein in the brain is an early feature of Alzheimer's disease (AD) that precedes progression of the disease to frank neuronal disruption. We demonstrate that bradykinin (BK) B2 receptor activation leads to selective Ser phosphorylation of tau in skin fibroblasts from persons who have or will develop AD due to Presenilin 1 mutations or Trisomy 21, but not in skin fibroblasts from normal individuals at any age. The increased signal transduction in AD fibroblasts that culminates in tau Ser phosphorylation reflects modification of the G protein-coupled BK B2 receptors themselves. Both the BK B2 receptor modification and BK-mediated tau Ser phosphorylation are dependent on activation of protein kinase C and can be detected in fibroblasts from persons with Trisomy 21 two decades before the characteristic onset of AD. This dysregulated signaling cascade in AD may thus be expressed throughout life as an aberrant pathway in peripheral tissues more accessible than brain for molecular analysis. The sites of greatest BK B2 receptor expression in brain overlap with those areas displaying the earliest pathology in the course of AD, suggesting that BK receptor pathway dysfunction may be a molecular signature yielding information about the pathogenesis of AD.