Andrew Mitchell

Toddler: An Embryonic Signal That Promotes Cell Movement via Apelin Receptors

Introduction Embryogenesis is thought to be directed by a small number of signaling pathways with most if not all embryonic signals having been identified. However, the molecular control of some embryonic processes is still poorly understood. For example, it is unclear how cell migration is regulated during gastrulation, when mesodermal and endodermal germ layers form. The goal of our study was to identify and characterize previously unrecognized signals that regulate embryogenesis. Toddler promotes gastrulation movements via Apelin receptor signaling. Toddler is an essential, short, conserved embryonic signal that promotes cell migration during zebrafish gastrulation. The internalization movement highlighted by the colored cell tracks requires Toddler signaling. Toddler signals via the G-protein–coupled APJ/Apelin receptor and may be one of several uncharacterized embryonic signals. Methods To identify uncharacterized signaling molecules, we mined zebrafish genomic data sets for previously non-annotated translated open reading frames (ORFs). One such ORF encoded a putative signaling protein that we call Toddler (also known as Apela/Elabela/Ende). We analyzed expression, production, and secretion of Toddler using RNA in situ hybridization, mass spectrometry, and Toddler-GFP fusion proteins, respectively. We used transcription activator-like effector (TALE) nucleases to generate frame-shift mutations in the toddler gene. To complement loss-of-function analyses with gain-of-function studies, Toddler was misexpressed through mRNA or peptide injection. We characterized phenotypes using marker gene expression analysis and in vivo imaging, using confocal and lightsheet microscopy. Toddler mutants were rescued thorugh global or localized toddler production. The relationship between Toddler and APJ/Apelin receptors was studied through genetic interaction and receptor internalization experiments. Results We identified several hundred non-annotated candidate proteins, including more than 20 putative signaling proteins. We focused on the functional importance of the short, conserved, and secreted peptide Toddler. Loss or overproduction of Toddler reduced cell movements during zebrafish gastrulation; mesodermal and endodermal cells were slow to internalize and migrate. Both the local and ubiquitous expression of Toddler were able to rescue gastrulation movements in toddler mutants, suggesting that Toddler acts as a motogen, a signal that promotes cell migration. Toddler activates G-protein–coupled APJ/Apelin receptor signaling, as evidenced by Toddler-induced internalization of APJ/Apelin receptors and rescue of toddler mutants through expression of the known receptor agonist Apelin. Discussion These findings indicate that Toddler promotes cell movement during zebrafish gastrulation by activation of APJ/Apelin receptor signaling. Toddler does not seem to act as a chemo-attractant or -repellent, but rather as a global signal that promotes the movement of mesendodermal cells. Both loss and overproduction of Toddler reduce cell movement, revealing that Toddler levels need to be tightly regulated during gastrulation. The discovery of Toddler helps explain previous genetic studies that found a broader requirement for APJ/Apelin receptors than for Apelin. We propose that in these cases, Toddler—not Apelin—activates APJ/Apelin receptor signaling. Our genomics analysis identifying a large number of candidate proteins that function during embryogenesis suggests the existence of other previously uncharacterized embryonic signals. Applying similar genomic approaches to adult tissues might identify additional signals that regulate physiological and behavioral processes. It has been assumed that most, if not all, signals regulating early development have been identified. Contrary to this expectation, we identified 28 candidate signaling proteins expressed during zebrafish embryogenesis, including Toddler, a short, conserved, and secreted peptide. Both absence and overproduction of Toddler reduce the movement of mesendodermal cells during zebrafish gastrulation. Local and ubiquitous production of Toddler promote cell movement, suggesting that Toddler is neither an attractant nor a repellent but acts globally as a motogen. Toddler drives internalization of G protein–coupled APJ/Apelin receptors, and activation of APJ/Apelin signaling rescues toddler mutants. These results indicate that Toddler is an activator of APJ/Apelin receptor signaling, promotes gastrulation movements, and might be the first in a series of uncharacterized developmental signals. A conserved signal is identified that activates G protein–coupled receptors to promote zebrafish gastrulation. Toddler Welcome It has been assumed that most, if not all, major signals that control vertebrate embryogenesis have been identified. Using genomics, Pauli et al. (10.1126/science.1248636, published online 9 January) have now identified several new candidate signals expressed during early zebrafish development. One of these signals, Toddler, is a short, conserved, and secreted peptide that promotes the movement of cells during zebrafish gastrulation. Toddler signals through G protein–coupled receptors to drive internalization of the Apelin receptor, and activation of Apelin signaling can rescue toddler mutants.

Health sector decentralization and local decision-making: Decision space, institutional capacities and accountability in Pakistan

Health sector decentralization has been widely adopted to improve delivery of health services. While many argue that institutional capacities and mechanisms of accountability required to transform decentralized decision-making into improvements in local health systems are lacking, few empirical studies exist which measure or relate together these concepts. Based on research instruments administered to a sample of 91 health sector decision-makers in 17 districts of Pakistan, this study analyzes relationships between three dimensions of decentralization: decentralized authority (referred to as decision space), institutional capacities, and accountability to local officials. Composite quantitative indicators of these three dimensions were constructed within four broad health functions (strategic and operational planning, budgeting, human resources management, and service organization/delivery) and on an overall/cross-function basis. Three main findings emerged. First, district-level respondents report varying degrees of each dimension despite being under a single decentralization regime and facing similar rules across provinces. Second, within dimensions of decentralization-particularly decision space and capacities-synergies exist between levels reported by respondents in one function and those reported in other functions (statistically significant coefficients of correlation ranging from ρ=0.22 to ρ=0.43). Third, synergies exist across dimensions of decentralization, particularly in terms of an overall indicator of institutional capacities (significantly correlated with both overall decision space (ρ=0.39) and accountability (ρ=0.23)). This study demonstrates that decentralization is a varied experience-with some district-level officials making greater use of decision space than others and that those who do so also tend to have more capacity to make decisions and are held more accountable to elected local officials for such choices. These findings suggest that Pakistans decentralization policy should focus on synergies among dimensions of decentralization to encouraging more use of de jure decision space, work toward more uniform institutional capacity, and encourage greater accountability to local elected officials.

Global Fund investments in human resources for health: innovation and missed opportunities for health systems strengthening

BACKGROUNDnSince the early 2000s, there have been large increases in donor financing of human resources for health (HRH), yet few studies have examined their effects on health systems.nnnOBJECTIVEnTo determine the scope and impact of investments in HRH by the Global Fund to Fight AIDS, Tuberculosis and Malaria (Global Fund), the largest investor in HRH outside national governments.nnnMETHODSnWe used mixed research methodology to analyse budget allocations and expenditures for HRH, including training, for 138 countries receiving money from the Global Fund during funding rounds 1-7. From these aggregate figures, we then identified 27 countries with the largest funding for human resources and training and examined all HRH-related performance indicators tracked in Global Fund grant reports. We used the results of these quantitative analyses to select six countries with substantial funding and varied characteristics-representing different regions and income levels for further in-depth study: Bangladesh (South and West Asia, low income), Ethiopia (Eastern Africa, low income), Honduras (Latin America, lower-middle income), Indonesia (South and West Asia, lower-middle income), Malawi (Southern Africa, low income) and Ukraine (Eastern Europe and Central Asia, upper-middle income). We used qualitative methods to gather information in each of the six countries through 159 interviews with key informants from 83 organizations. Using comparative case-study analysis, we examined Global Funds interactions with other donors, as well as its HRH support and co-ordination within national health systems.nnnRESULTSnAround US

Decentralisation, Governance and Health-System Performance: ‘Where You Stand Depends on Where You Sit’

1.4 billion (23% of total US

Health worker densities and immunization coverage in Turkey: a panel data analysis

5.1 billion) of grant funding was allocated to HRH by the 138 Global Fund recipient countries. In funding rounds 1-7, the six countries we studied in detail were awarded a total of 47 grants amounting to US

Improving Health System Performance in a Decentralized Health System: Capacity Building in Pakistan

1.2 billion and HRH budgets of US

Does social capital enhance health and well-being? Evidence from rural China.

276 million, of which approximately half were invested in disease-focused in-service and short-term training activities. Countries employed a variety of mechanisms including salary top-ups, performance incentives, extra compensation and contracting of workers for part-time work, to pay health workers using Global Fund financing. Global Fund support for training and salary support was not co-ordinated with national strategic plans and there were major deficiencies in the data collected by the Global Fund to track HRH financing and to provide meaningful assessments of health system performance.nnnCONCLUSIONnThe narrow disease focus and lack of co-ordination with national governments call into question the efficiency of funding and sustainability of Global Fund investments in HRH and their effectiveness in strengthening recipient countries health systems. The lessons that emerge from this analysis can be used by both the Global Fund and other donors to improve co-ordination of investments and the effectiveness of programmes in recipient countries.

Measuring dimensions of social capital: Evidence from surveys in poor communities in Nicaragua

Advocates of local government often argue that when decentralisation is accompanied by adequate mechanisms of accountability, particularly those responsive to local preferences, improved service delivery will result. From the perspective of the health sector, the appropriate degree of decentralisation and the necessary mechanisms of accountability depend upon the achievement of health system goals. Drawing on evidence from six countries (Bolivia, Chile, India, Pakistan, Philippines, Uganda), this article comes to the conclusion that a balance between centralisation of some functions and decentralisation of others, along with improved mechanisms of accountability, is needed to achieve health system objectives.

Assessing financing, education, management and policy context for strategic planning of human resources for health.

BackgroundIncreased immunization coverage is an important step towards fulfilling the Millennium Development Goal of reducing childhood mortality. Recent cross-sectional and cross-national research has indicated that physician, nurse and midwife densities may positively influence immunization coverage. However, little is known about relationships between densities of human resources for health (HRH) and vaccination coverage within developing countries and over time. The present study examines HRH densities and coverage of the Expanded Programme on Immunization (EPI) in Turkey during the period 2000 to 2006.MethodsThe study is based on provincial-level data on HRH densities, vaccination coverage and provincial socioeconomic and demographic characteristics published by the Turkish government. Panel data regression methodologies (random and fixed effects models) are used to analyse the data.ResultsThree main findings emerge: (1) combined physician, nurse/midwife and health officer density is significantly associated with vaccination rates – independent of provincial female illiteracy, GDP per capita and land area – although the association was initially positive and turned negative over time; (2) HRH-vaccination rate relationships differ by cadre of health worker, with physician and health officers exhibiting significant relationships that mirror those for aggregate density, while nurse/midwife densities are not consistently significant; (3) HRH densities bear stronger relationships with vaccination coverage among more rural provinces, compared to those with higher population densities.ConclusionWe find evidence of relationships between HRH densities and vaccination rates even at Turkeys relatively elevated levels of each. At the same time, variations in results between different empirical models suggest that this relationship is complex, affected by other factors that occurred during the study period, and warrants further investigation to verify our findings. We hypothesize that the introduction of certain health-sector policies governing terms of HRH employment affected incentives to provide vaccinations and therefore relationships between HRH densities and vaccination rates. National-level changes experienced during the study period – such as a severe financial crisis – may also have affected and/or been associated with the HRH-vaccination rate link. While our findings therefore suggest that the size of a health workforce may be associated with service provision at a relatively elevated level of development, they also indicate that focusing on per capita levels of HRH may be of limited value in understanding performance in service provision. In both Turkey and elsewhere, further investigation is needed to corroborate our results as well as gain deeper understanding into relationships between health worker densities and service provision.

Healthcare utilisation in rural Andhra Pradesh

Abstract—Key policy questions on decentralization in health relate to whether and in which ways health sector decentralization can improve health outcomes. Focusing on a maternal, neonatal, and child health program in Pakistan, this study examines relationships between three dimensions of decentralization: the degree of local decision-making choice (“decision space”), individual and institutional capacities, and local accountability. Additionally, these relationships are examined at two points in time to assess whether “capacity building” interventions, as well as any changes in decision space, are related to improvements in health sector performance as measured by improved administrative processes and indicators of health coverage in important primary care services. The study is based on surveys administered in 2006 and 2009 to local health sector decision-makers in 15 districts in Pakistan—ten of which received capacity-building assistance from the US government–funded maternal and child health project (PAIMAN), and five control districts not receiving capacity-building interventions. Findings indicate that while local authorities in both districts reported using wider decision space by 2009, institutional capacities in PAIMAN districts improved to a higher degree than in comparison districts. Officials in neither set of districts reported significant changes in their accountability to local elected officials, although those districts with more decision space and institutional capacities mobilized greater local support for health programs. Extending findings from an earlier study focused on similar questions, there were strong synergies among the dimensions of decentralization for different health sector functions, as well as some evidence of associations between stronger institutional capacities/wider decision-space and improvements in health coverage and in better administration of the health system. Findings suggest that targeted capacity-building activities at the district level may contribute to improved decision-making abilities and, in turn, improved health system performance.