Zebrafish cardiac repolarization does not functionally depend on the expression of the hERG1b-like transcript.

Zebrafish provide a translational model of human cardiac function. Their similar cardiac electrophysiology enables screening of human cardiac repolarization disorders, drug arrhythmogenicity, and novel antiarrhythmic therapeutics. However, while zebrafish cardiac repolarization is driven by delayed rectifier potassium channel current (IKr), the relative role of alternate channel transcripts is uncertain. While human ether-a-go-go-related-gene-1a (hERG1a) is the dominant transcript in humans, expression of the functionally distinct alternate transcript, hERG1b, modifies the electrophysiological and pharmacologic IKr phenotype. Studies of zebrafish IKr are frequently translated without consideration for the presence and impact of hERG1b in humans. Here, we performed phylogenetic analyses of all available KCNH genes from Actinopterygii (ray-finned fishes). Our findings confirmed zebrafish cardiac zkcnh6a as the paralog of human hERG1a (hKCNH2a), but also revealed evidence of a hERG1b (hKCNH2b)-like N-terminally truncated gene, zkcnh6b, in zebrafish. zkcnh6b is a teleost-specific variant that resulted from the 3R genome duplication. qRT-PCR showed dominant expression of zkcnh6a in zebrafish atrial and ventricular tissue, with low levels of zkcnh6b. Functional evaluation of zkcnh6b in a heterologous system showed no discernable function under the conditions tested, and no influence on zkcnh6a function during the zebrafish ventricular action potential. Our findings provide the first descriptions of the zkcnh6b gene, and show that, unlike in humans, zebrafish cardiac repolarization does not rely upon co-assembly of zERG1a/zERG1b. Given that hERG1b modifies IKr function and drug binding in humans, our findings highlight the need for consideration when translating hERG variant effects and toxicological screens in zebrafish, which lack a functional hERG1b-equivalent gene.

Tracking development assistance for health from India to low- and middle-income countries, 2009-2020.

BACKGROUND: Development assistance for health (DAH) is an important source of financing for health for many low-income and some middle-income countries. Most DAH has predominantly been contributed by high-income countries. However, in the context of economic progress and changing global priorities, DAH contributions from countries of the Global South such as India have gained importance. In this paper, we estimate DAH contributed by India between 2009 and 2020. METHODS: We leveraged data from budgetary documents, databases, and financial reports of the Ministry of External Affairs and multilateral organizations to estimate DAH contributions. The proportions of development assistance that go towards health in major recipient countries were estimated and reported by recipient country and year. RESULTS: Between 2009 and 2020, DAH contributed by India to bilateral and multilateral partners totaled $206.0 million. South Asian countries including Bangladesh, Bhutan, Nepal, Sri Lanka, and Myanmar received the most DAH from India. DAH contributed relative to DAH received ranged from 1.42% in 2009 to 5.26% in 2018, the latest year with country-level data. Health focus areas prioritized by India included technical training and innovation, health care infrastructure support, and supply of medications and medical equipment. CONCLUSION: India is an important development partner to many countries-particularly to those in the South Asian region. India's DAH allocation strategy prioritizes contributions toward neighboring countries in the South Asia region in several health focus areas. Detailed project-level data are needed to estimate DAH contributions from India with greater precision and accuracy.

CRISPR-Cas9-mediated Precise Knock-in Edits in Zebrafish Hearts.

Clustered regularly interspaced short palindromic repeats (CRISPR) in animal models enable precise genetic manipulation for the study of physiological phenomena. Zebrafish have been used as an effective genetic model to study numerous questions related to heritable disease, development, and toxicology at the whole-organ and -organism level. Due to the well-annotated and mapped zebrafish genome, numerous tools for gene editing have been developed. However, the efficacy of generating and ease of detecting precise knock-in edits using CRISPR is a limiting factor. Described here is a CRISPR-Cas9-based knock-in approach with the simple detection of precise edits in a gene responsible for cardiac repolarization and associated with the electrical disorder, Long QT Syndrome (LQTS). This two-single-guide RNA (sgRNA) approach excises and replaces the target sequence and links a genetically encoded reporter gene. The utility of this approach is demonstrated by describing non-invasive phenotypic measurements of cardiac electrical function in wild-type and gene-edited zebrafish larvae. This approach enables the efficient study of disease-associated variants in a whole organism. Furthermore, this strategy offers possibilities for the insertion of exogenous sequences of choice, such as reporter genes, orthologs, or gene editors.

Spinal mobility in radiographic axial spondyloarthritis: criterion concurrent validity of classic and novel measurements.

BACKGROUND: Limitations in spinal mobility are a characteristic feature of Axial Spondyloarthritis. Current clinical measurements of spinal mobility have shown low criterion-concurrent validity. This study sought to evaluate criterion-concurrent validity for a clinically feasible measurement method of measuring spine mobility using tri-axial accelerometers. METHODS: Fifteen radiographic-Spondyloarthritis patients were recruited for this study. Two postural reference radiographs, followed by three trials in forward, left and right lateral bending were taken. For all trials, three measurements were collected: tape (Original Schober's, Modified Schober's, Modified-Modified Schober's, Lateral Spinal Flexion Test and Domjan Test), followed immediately by synchronized radiograph and accelerometer measurements at end range of forward and bilateral lateral flexion. The criterion-concurrent validity of all measurement methods was compared to the radiographic measures using Pearson's correlation coefficients. A Bland-Altman analysis was conducted to assess agreement. RESULTS: In forward bending, the accelerometer method (r = 0.590, p = 0.010) had a stronger correlation to the radiographic measures than all tape measures. In lateral bending, the Lateral Spinal Flexion tape measure (r = 0.743, p = 0.001) correlated stronger than the accelerometer method (r = 0.556, p = 0.016). The Domjan test of bilateral bending (r = 0.708, p = 0.002) had a stronger correlation to the radiographic measure than the accelerometer method. CONCLUSIONS: Accelerometer measures demonstrated superior criterion-concurrent validity compared to current tape measures of spinal mobility in forward bending. While a moderate correlation exists between accelerometer and radiographs in lateral bending, the Lateral Spinal Flexion Test and Domjan Test were found to have the best criterion-concurrent validity of all tests examined in this study.

Factors associated with the disbursements of development assistance for health in low-income and middle-income countries, 2002-2017.

INTRODUCTION: In 2017, development assistance for health (DAH) comprised 5.3% of total health spending in low-income countries. Despite the key role DAH plays in global health-spending, little is known about the characteristics of assistance that may be associated with committed assistance that is actually disbursed. In this analysis, we examine associations between these characteristics and disbursement of committed assistance. METHODS: We extracted data from the Creditor Reporting System of the Organization for Economic Co-operation and Development, Institute for Health Metrics and Evaluation, and the WHO National Health Accounts database. Factors examined were off-budget assistance, administrative assistance, publicly sourced assistance and assistance to health systems strengthening. Recipient-country characteristics examined were perceived level of corruption, civil fragility and gross domestic product per capita (GDPpc). We used linear regression methods for panel of data to assess the proportion of committed aid that was disbursed for a given country-year, for each data source. RESULTS: Factors that were associated with a higher disbursement rates include off-budget aid (p<0.001), lower administrative expenses (p<0.01), lower perceived corruption in recipient country (p<0.001), lower fragility in recipient country (p<0.05) and higher GDPpc (p<0.05). CONCLUSION: Substantial gaps remain between commitments and disbursements. Characteristics of assistance (administrative, publicly sourced) and indicators of government transparency and fragility are also important drivers associated with disbursement of DAH. There remains a continued need for better aid flow reporting standards and clarity around aid types for better measurement of DAH.

Utility of Zebrafish Models of Acquired and Inherited Long QT Syndrome.

Long-QT Syndrome (LQTS) is a cardiac electrical disorder, distinguished by irregular heart rates and sudden death. Accounting for ∼40% of cases, LQTS Type 2 (LQTS2), is caused by defects in the Kv11.1 (hERG) potassium channel that is critical for cardiac repolarization. Drug block of hERG channels or dysfunctional channel variants can result in acquired or inherited LQTS2, respectively, which are typified by delayed repolarization and predisposition to lethal arrhythmia. As such, there is significant interest in clear identification of drugs and channel variants that produce clinically meaningful perturbation of hERG channel function. While toxicological screening of hERG channels, and phenotypic assessment of inherited channel variants in heterologous systems is now commonplace, affordable, efficient, and insightful whole organ models for acquired and inherited LQTS2 are lacking. Recent work has shown that zebrafish provide a viable in vivo or whole organ model of cardiac electrophysiology. Characterization of cardiac ion currents and toxicological screening work in intact embryos, as well as adult whole hearts, has demonstrated the utility of the zebrafish model to contribute to the development of therapeutics that lack hERG-blocking off-target effects. Moreover, forward and reverse genetic approaches show zebrafish as a tractable model in which LQTS2 can be studied. With the development of new tools and technologies, zebrafish lines carrying precise channel variants associated with LQTS2 have recently begun to be generated and explored. In this review, we discuss the present knowledge and questions raised related to the use of zebrafish as models of acquired and inherited LQTS2. We focus discussion, in particular, on developments in precise gene-editing approaches in zebrafish to create whole heart inherited LQTS2 models and evidence that zebrafish hearts can be used to study arrhythmogenicity and to identify potential anti-arrhythmic compounds.

Exercise as a vital sign: a preliminary pilot study in a chiropractic setting.

BACKGROUND: The association between physical inactivity and non-communicable disease risk has been well documented in recent literature. An exercise vital sign (EVS) is a measure that can routinely capture vital information about a patient's physical activity behaviour. The objective of this study is to understand if (1) patient exercise minutes per week (EMPW) are being recorded by chiropractic interns, and (2) whether these patients are exceeding, meeting or falling short of the current recommendations provided by the Canadian Physical Activity Guidelines (CPAG). METHODS: Electronic medical records obtained from two Canadian Memorial Chiropractic College (CMCC) teaching clinics for patients seen between August 01, 2015 and January 31, 2017 (N=273). EMPW, age, and gender were used to compare patient files relative to the CPAG. RESULTS: Overall, 86.4% of patient files had recorded data to the question of how many EMPW they perform. The majority (68.8%) of individuals appear to be meeting or exceeding the CPAG, leaving nearly one third (31.2%) of individuals failing to meet these guidelines. CONCLUSIONS: In this pilot study with two sports specialist clinicians an exercise vital sign had been integrated alongside traditional vital signs in order to identify issues of physical inactivity and improve opportunities for continued exercise counselling.

CONTEXTE: L'existence d'un lien entre inactivité physique et risque de maladie non transmissible est bien documentée dans la littérature récente. Exercise vital sign (EVS) est une mesure permettant d'obtenir de façon systématique des données sur l'activité physique d'un patient. Cette étude visait à savoir si 1) les minutes consacrées à l'exercice physique par semaine (MEPPS) sont consignées par les internes en chiropratique et si 2) ces patients suivent les recommandations actuelles énoncées dans les Lignes directrices canadiennes en matière d'activité physique (LDCAC). MÉTHODOLOGIE: Dossiers médicaux électroniques de patients vus entre le 1er août 2015 et le 31 janvier 2017 (n=273) provenant de deux cliniques d'enseignement affiliées au Canadian Memorial Chiropratique College (CMCC). Les MEPPS, l'âge et le sexe ont servi à comparer les dossiers de patients en tenant compte des LDCAC. RÉSULTATS: Dans l'ensemble, 86,4 % des dossiers de patients contenaient des données sur le nombre de MEPPS. Il semble que la majorité (68,8 %) des sujets respectaient les LDCAC ou allaient même au-delà, alors que presque le tiers (31,2 %) ne les respectaient pas. CONCLUSIONS: Dans cette étude pilote menée par deux cliniciens spécialistes de la médecine sportive, l'exercise vital sign et d'autres signes vitaux classiques ont servi à cerner les problèmes reliés à l'inactivité physique et à accroître les occasions de fournir des conseils en matière d'exercice continu.

Small changes in climate can profoundly alter the dynamics and ecosystem services of tropical crater lakes.

African tropical lakes provide vital ecosystem services including food and water to some of the fastest growing human populations, yet they are among the most understudied ecosystems in the world. The consequences of climate change and other stressors on the tropical lakes of Africa have been informed by long-term analyses, but these studies have largely focused on the massive Great Rift Valley lakes. Our objective was to evaluate how recent climate change has altered the functioning and services of smaller tropical lakes, which are far more abundant on the landscape. Based on a paired analysis of 20 years of high-resolution water column data and a paleolimnological record from a small crater lake in western Uganda, we present evidence that even a modest warming of the air (∼0.9°C increase over 20 years) and changes in the timing and intensity of rainfall can have significant consequences on the dynamics of this common tropical lake type. For example, we observed a significant nonlinear increase (R(2) adj  = 0.23, e.d.f. = 7, p<0.0001) in thermal stability over the past 20 years. This resulted in the expansion of anoxic waters and consequent deterioration of fish habitat and appears to have abated primary production; processes that may impair ecosystem services for a vulnerable human population. This study on a system representative of small tropical crater lakes highlights the far-reaching effects of global climatic change on tropical waters. Increased research efforts into tropical aquatic ecosystem health and the development of sound management practices are necessary in order to strengthen adaptive capabilities in tropical regions.