Engineering the cellulolytic bacterium, Clostridium thermocellum, to co-utilize hemicellulose.

Consolidated bioprocessing (CBP) of lignocellulosic biomass holds promise to realize economic production of second-generation biofuels/chemicals, and Clostridium thermocellum is a leading candidate for CBP due to it being one of the fastest degraders of crystalline cellulose and lignocellulosic biomass. However, CBP by C. thermocellum is approached with co-cultures, because C. thermocellum does not utilize hemicellulose. When compared with a single-species fermentation, the co-culture system introduces unnecessary process complexity that may compromise process robustness. In this study, we engineered C. thermocellum to co-utilize hemicellulose without the need for co-culture. By evolving our previously engineered xylose-utilizing strain in xylose, an evolved clonal isolate (KJC19-9) was obtained and showed improved specific growth rate on xylose by ∼3-fold and displayed comparable growth to a minimally engineered strain grown on the bacteria's naturally preferred substrate, cellobiose. To enable full xylan deconstruction to xylose, we recombinantly expressed three different ß-xylosidase enzymes originating from Thermoanaerobacterium saccharolyticum into KJC19-9 and demonstrated growth on xylan with one of the enzymes. This recombinant strain was capable of co-utilizing cellulose and xylan simultaneously, and we integrated the ß-xylosidase gene into the KJC19-9 genome, creating the KJCBXint strain. The strain, KJC19-9, consumed monomeric xylose but accumulated xylobiose when grown on pretreated corn stover, whereas the final KJCBXint strain showed significantly greater deconstruction of xylan and xylobiose. This is the first reported C. thermocellum strain capable of degrading and assimilating hemicellulose polysaccharide while retaining its cellulolytic capabilities, unlocking significant potential for CBP in advancing the bioeconomy.

Towards standardised and valid anthropometric indicators of nutritional status in middle childhood and adolescence.

Recognition of the importance of nutrition during middle childhood (age 5-9 years) and adolescence (age 10-19 years) is increasing, particularly in the context of global food insecurity and rising overweight and obesity rates. Until now, policy makers have been slow to respond to rapidly changing patterns of malnutrition across these age groups. One barrier has been a scarcity of consistent and regular nutrition surveillance systems for these age groups. What should be measured, and how best to operationalise anthropometric indicators that have been the cornerstone of nutrition surveillance in younger children and in adults, has been the topic of ongoing debate. Even with consensus on the importance of a given anthropometric indicator, difficulties arise in interpreting trends over time and between countries owing to the use of different terminologies, reference data, and cutoff points. In this Viewpoint we highlight the need to revisit anthropometric indicators across middle childhood and adolescence, a process that will require WHO and UNICEF coordination, the engagement of national implementors and policy makers, and partnership with research communities and donors.

Global, regional, and national trends in under-5 mortality between 1990 and 2019 with scenario-based projections until 2030: a systematic analysis by the UN Inter-agency Group for Child Mortality Estimation.

BACKGROUND: The Sustainable Development Goals (SDGs), set in 2015 by the UN General Assembly, call for all countries to reach an under-5 mortality rate (U5MR) of at least as low as 25 deaths per 1000 livebirths and a neonatal mortality rate (NMR) of at least as low as 12 deaths per 1000 livebirths by 2030. We estimated levels and trends in under-5 mortality for 195 countries from 1990 to 2019, and conducted scenario-based projections of the U5MR and NMR from 2020 to 2030 to assess country progress in, and potential for, reaching SDG targets on child survival and the potential under-5 and neonatal deaths over the next decade. METHODS: Levels and trends in under-5 mortality are based on the UN Inter-agency Group for Child Mortality Estimation (UN IGME) database on under-5 mortality, which contains around 18 000 country-year datapoints for 195 countries-nearly 10 000 of those datapoints since 1990. The database includes nationally representative mortality data from vital registration systems, sample registration systems, population censuses, and household surveys. As with previous sets of national UN IGME estimates, a Bayesian B-spline bias-reduction model (B3) that considers the systematic biases associated with the different data source types was fitted to these data to generate estimates of under-5 (age 0-4 years) mortality with uncertainty intervals for 1990-2019 for all countries. Levels and trends in the neonatal mortality rate (0-27 days) are modelled separately as the log ratio of the neonatal mortality rate to the under-5 mortality rate using a Bayesian model. Estimated mortality rates are combined with livebirths data to calculate the number of under-5 and neonatal deaths. To assess the regional and global burden of under-5 deaths in the present decade and progress towards SDG targets, we constructed several scenario-based projections of under-5 mortality from 2020 to 2030 and estimated national, regional, and global under-5 mortality trends up to 2030 for each scenario. FINDINGS: The global U5MR decreased by 59% (90% uncertainty interval [UI] 56-61) from 93·0 (91·7-94·5) deaths per 1000 livebirths in 1990 to 37·7 (36·1-40·8) in 2019, while the annual number of global under-5 deaths declined from 12·5 (12·3-12·7) million in 1990 to 5·2 (5·0-5·6) million in 2019-a 58% (55-60) reduction. The global NMR decreased by 52% (90% UI 48-55) from 36·6 (35·6-37·8) deaths per 1000 livebirths in 1990, to 17·5 (16·6-19·0) in 2019, and the annual number of global neonatal deaths declined from 5·0 (4·9-5·2) million in 1990, to 2·4 (2·3-2·7) million in 2019, a 51% (47-54) reduction. As of 2019, 122 of 195 countries have achieved the SDG U5MR target, and 20 countries are on track to achieve the target by 2030, while 53 will need to accelerate progress to meet the target by 2030. 116 countries have reached the SDG NMR target with 16 on track, leaving 63 at risk of missing the target. If current trends continue, 48·1 million under-5 deaths are projected to occur between 2020 and 2030, almost half of them projected to occur during the neonatal period. If all countries met the SDG target on under-5 mortality, 11 million under-5 deaths could be averted between 2020 and 2030. INTERPRETATION: As a result of effective global health initiatives, millions of child deaths have been prevented since 1990. However, the task of ending all preventable child deaths is not done and millions more deaths could be averted by meeting international targets. Geographical and economic variation demonstrate the possibility of even lower mortality rates for children under age 5 years and point to the regions and countries with highest mortality rates and in greatest need of resources and action. FUNDING: Bill & Melinda Gates Foundation, US Agency for International Development.

Global, regional, and national estimates and trends in stillbirths from 2000 to 2019: a systematic assessment.

BACKGROUND: Stillbirths are a major public health issue and a sensitive marker of the quality of care around pregnancy and birth. The UN Global Strategy for Women's, Children's and Adolescents' Health (2016-30) and the Every Newborn Action Plan (led by UNICEF and WHO) call for an end to preventable stillbirths. A first step to prevent stillbirths is obtaining standardised measurement of stillbirth rates across countries. We estimated stillbirth rates and their trends for 195 countries from 2000 to 2019 and assessed progress over time. METHODS: For a systematic assessment, we created a dataset of 2833 country-year datapoints from 171 countries relevant to stillbirth rates, including data from registration and health information systems, household-based surveys, and population-based studies. After data quality assessment and exclusions, we used 1531 datapoints to estimate country-specific stillbirth rates for 195 countries from 2000 to 2019 using a Bayesian hierarchical temporal sparse regression model, according to a definition of stillbirth of at least 28 weeks' gestational age. Our model combined covariates with a temporal smoothing process such that estimates were informed by data for country-periods with high quality data, while being based on covariates for country-periods with little or no data on stillbirth rates. Bias and additional uncertainty associated with observations based on alternative stillbirth definitions and source types, and observations that were subject to non-sampling errors, were included in the model. We compared the estimated stillbirth rates and trends to previously reported mortality estimates in children younger than 5 years. FINDINGS: Globally in 2019, an estimated 2·0 million babies (90% uncertainty interval [UI] 1·9-2·2) were stillborn at 28 weeks or more of gestation, with a global stillbirth rate of 13·9 stillbirths (90% UI 13·5-15·4) per 1000 total births. Stillbirth rates in 2019 varied widely across regions, from 22·8 stillbirths (19·8-27·7) per 1000 total births in west and central Africa to 2·9 (2·7-3·0) in western Europe. After west and central Africa, eastern and southern Africa and south Asia had the second and third highest stillbirth rates in 2019. The global annual rate of reduction in stillbirth rate was estimated at 2·3% (90% UI 1·7-2·7) from 2000 to 2019, which was lower than the 2·9% (2·5-3·2) annual rate of reduction in neonatal mortality rate (for neonates aged <28 days) and the 4·3% (3·8-4·7) annual rate of reduction in mortality rate among children aged 1-59 months during the same period. Based on the lower bound of the 90% UIs, 114 countries had an estimated decrease in stillbirth rate since 2000, with four countries having a decrease of at least 50·0%, 28 having a decrease of 25·0-49·9%, 50 having a decrease of 10·0-24·9%, and 32 having a decrease of less than 10·0%. For the remaining 81 countries, we found no decrease in stillbirth rate since 2000. Of these countries, 34 were in sub-Saharan Africa, 16 were in east Asia and the Pacific, and 15 were in Latin America and the Caribbean. INTERPRETATION: Progress in reducing the rate of stillbirths has been slow compared with decreases in the mortality rate of children younger than 5 years. Accelerated improvements are most needed in the regions and countries with high stillbirth rates, particularly in sub-Saharan Africa. Future prevention of stillbirths needs increased efforts to raise public awareness, improve data collection, assess progress, and understand public health priorities locally, all of which require investment. FUNDING: Bill & Melinda Gates Foundation and the UK Foreign, Commonwealth and Development Office.

Four decades of measuring stillbirths and neonatal deaths in Demographic and Health Surveys: historical review.

BACKGROUND: Worldwide, an estimated 5.1 million stillbirths and neonatal deaths occur annually, 98% in low- and middle-income countries. Limited coverage of civil and vital registration systems necessitates reliance on women's retrospective reporting in household surveys for data on these deaths. The predominant platform, Demographic and Health Surveys (DHS), has evolved over the last 35 years and differs by country, yet no previous study has described these differences and the effects of these changes on stillbirth and neonatal death measurement. METHODS: We undertook a review of DHS model questionnaires, protocols and methodological reports from DHS-I to DHS-VII, focusing on the collection of information on stillbirth and neonatal deaths describing differences in approaches, questionnaires and geographic reach up to December 9, 2019. We analysed the resultant data, applied previously used data quality criteria including ratios of stillbirth rate (SBR) to neonatal mortality rate (NMR) and early NMR (ENMR) to NMR, comparing by country, over time and by DHS module. RESULTS: DHS has conducted >320 surveys in 90 countries since 1984. Two types of maternity history have been used: full birth history (FBH) and full pregnancy history (FPH). A FBH collecting information only on live births has been included in all model questionnaires to date, with data on stillbirths collected through a reproductive calendar (DHS II-VI) or using additional questions on non-live births (DHS-VII). FPH collecting information on all pregnancies including live births, miscarriages, abortions and stillbirths has been used in 17 countries. We found no evidence of variation in stillbirth data quality assessed by SBR:NMR over time for FBH surveys with reproductive calendar, some variation for surveys with FBH in DHS-VII and most variation among the surveys conducted with a FPH. ENMR:NMR ratio increased over time, which may reflect changes in data quality or real epidemiological change. CONCLUSION: DHS remains the major data source for pregnancy outcomes worldwide. Although the DHS model questionnaire has evolved over the last three and half decades, more robust evidence is required concerning optimal methods to obtain accurate data on stillbirths and neonatal deaths through household surveys and also to develop and test standardised data quality criteria.

Transcriptomic analysis of a Clostridium thermocellum strain engineered to utilize xylose: responses to xylose versus cellobiose feeding.

Clostridium (Ruminiclostridium) thermocellum is recognized for its ability to ferment cellulosic biomass directly, but it cannot naturally grow on xylose. Recently, C. thermocellum (KJC335) was engineered to utilize xylose through expressing a heterologous xylose catabolizing pathway. Here, we compared KJC335's transcriptomic responses to xylose versus cellobiose as the primary carbon source and assessed how the bacteria adapted to utilize xylose. Our analyses revealed 417 differentially expressed genes (DEGs) with log2 fold change (FC) >|1| and 106 highly DEGs (log2 FC >|2|). Among the DEGs, two putative sugar transporters, cbpC and cbpD, were up-regulated, suggesting their contribution to xylose transport and assimilation. Moreover, the up-regulation of specific transketolase genes (tktAB) suggests the importance of this enzyme for xylose metabolism. Results also showed remarkable up-regulation of chemotaxis and motility associated genes responding to xylose feeding, as well as widely varying gene expression in those encoding cellulosomal enzymes. For the down-regulated genes, several were categorized in gene ontology terms oxidation-reduction processes, ATP binding and ATPase activity, and integral components of the membrane. This study informs potentially critical, enabling mechanisms to realize the conceptually attractive Next-Generation Consolidated BioProcessing approach where a single species is sufficient for the co-fermentation of cellulose and hemicellulose.

N-terminal protein acetylation by NatB modulates the levels of Nmnats, the NAD+ biosynthetic enzymes in Saccharomyces cerevisiae.

NAD+ is an essential metabolite participating in cellular biochemical processes and signaling. The regulation and interconnection among multiple NAD+ biosynthesis pathways are incompletely understood. Yeast (Saccharomyces cerevisiae) cells lacking the N-terminal (Nt) protein acetyltransferase complex NatB exhibit an approximate 50% reduction in NAD+ levels and aberrant metabolism of NAD+ precursors, changes that are associated with a decrease in nicotinamide mononucleotide adenylyltransferase (Nmnat) protein levels. Here, we show that this decrease in NAD+ and Nmnat protein levels is specifically due to the absence of Nt-acetylation of Nmnat (Nma1 and Nma2) proteins and not of other NatB substrates. Nt-acetylation critically regulates protein degradation by the N-end rule pathways, suggesting that the absence of Nt-acetylation may alter Nmnat protein stability. Interestingly, the rate of protein turnover (t½) of non-Nt-acetylated Nmnats did not significantly differ from those of Nt-acetylated Nmnats. Accordingly, deletion or depletion of the N-end rule pathway ubiquitin E3 ligases in NatB mutants did not restore NAD+ levels. Next, we examined whether the status of Nt-acetylation would affect the translation of Nmnats, finding that the absence of Nt-acetylation does not significantly alter the polysome formation rate on Nmnat mRNAs. However, we observed that NatB mutants have significantly reduced Nmnat protein maturation. Our findings indicate that the reduced Nmnat levels in NatB mutants are mainly due to inefficient protein maturation. Nmnat activities are essential for all NAD+ biosynthesis routes, and understanding the regulation of Nmnat protein homeostasis may improve our understanding of the molecular basis and regulation of NAD+ metabolism.

NAD+ Metabolism and Regulation: Lessons From Yeast.

Nicotinamide adenine dinucleotide (NAD+) is an essential metabolite involved in various cellular processes. The cellular NAD+ pool is maintained by three biosynthesis pathways, which are largely conserved from bacteria to human. NAD+ metabolism is an emerging therapeutic target for several human disorders including diabetes, cancer, and neuron degeneration. Factors regulating NAD+ homeostasis have remained incompletely understood due to the dynamic nature and complexity of NAD+ metabolism. Recent studies using the genetically tractable budding yeast Saccharomyces cerevisiae have identified novel NAD+ homeostasis factors. These findings help provide a molecular basis for how may NAD+ and NAD+ homeostasis factors contribute to the maintenance and regulation of cellular function. Here we summarize major NAD+ biosynthesis pathways, selected cellular processes that closely connect with and contribute to NAD+ homeostasis, and regulation of NAD+ metabolism by nutrient-sensing signaling pathways. We also extend the discussions to include possible implications of NAD+ homeostasis factors in human disorders. Understanding the cross-regulation and interconnections of NAD+ precursors and associated cellular pathways will help elucidate the mechanisms of the complex regulation of NAD+ homeostasis. These studies may also contribute to the development of effective NAD+-based therapeutic strategies specific for different types of NAD+ deficiency related disorders.

Regulation and Maturation of the Shewanella oneidensis Sulfite Reductase SirA.

Shewanella oneidensis, a metal reducer and facultative anaerobe, expresses a large number of c-type cytochromes, many of which function as anaerobic reductases. All of these proteins contain the typical heme-binding motif CXXCH and require the Ccm proteins for maturation. Two c-type cytochrome reductases also possess atypical heme-binding sites, the NrfA nitrite reductase (CXXCK) and the SirA sulfite reductase (CX12NKGCH). S. oneidensis MR-1 encodes two cytochrome c synthetases (CcmF and SirE) and two apocytochrome c chaperones (CcmI and SirG). SirE located in the sir gene cluster is required for the maturation of SirA, but not NrfA. Here we show that maturation of SirA requires the combined function of the two apocytochrome c chaperones CcmI and SirG. Loss of either protein resulted in decreased sulfite reductase. Furthermore, SirA was not detected in a mutant that lacked both chaperones, perhaps due to misfolding or instability. These results suggest that CcmI interacts with SirEFG during SirA maturation, and with CcmF during maturation of NrfA. Additionally, we show that CRP regulates expression of sirA via the newly identified transcriptional regulatory protein, SirR.

"Every Newborn-INDEPTH" (EN-INDEPTH) study protocol for a randomised comparison of household survey modules for measuring stillbirths and neonatal deaths in five Health and Demographic Surveillance sites.

BACKGROUND: Under-five and maternal mortality were halved in the Millennium Development Goals (MDG) era, with slower reductions for 2.6 million neonatal deaths and 2.6 million stillbirths. The Every Newborn Action Plan aims to accelerate progress towards national targets, and includes an ambitious Measurement Improvement Roadmap. Population-based household surveys, notably Demographic and Health Surveys (DHS) and Multiple Indicator Cluster Surveys, are major sources of population-level data on child mortality in countries with weaker civil registration and vital statistics systems, where over two-thirds of global child deaths occur. To estimate neonatal/child mortality and pregnancy outcomes (stillbirths, miscarriages, birthweight, gestational age) the most common direct methods are: (1) the standard DHS-7 with Full Birth History with additional questions on pregnancy losses in the past 5 years (FBH+) or (2) a Full Pregnancy History (FPH). No direct comparison of these two methods has been undertaken, although descriptive analyses suggest that the FBH+ may underestimate mortality rates particularly for stillbirths. METHODS: This is the protocol paper for the Every Newborn-INDEPTH study (INDEPTH Network, International Network for the Demographic Evaluation of Populations and their Health Every Newborn, Every Newborn Action Plan), aiming to undertake a randomised comparison of FBH+ and FPH to measure pregnancy outcomes in a household survey in five selected INDEPTH Network sites in Africa and South Asia (Bandim in urban and rural Guinea-Bissau; Dabat in Ethiopia; IgangaMayuge in Uganda; Kintampo in Ghana; Matlab in Bangladesh). The survey will reach >68 000 pregnancies to assess if there is ≥15% difference in stillbirth rates. Additional questions will capture birthweight, gestational age, birth/death certification, termination of pregnancy and fertility intentions. The World Bank's Survey Solutions platform will be tailored for data collection, including recording paradata to evaluate timing. A mixed methods assessment of barriers and enablers to reporting of pregnancy and adverse pregnancy outcomes will be undertaken. CONCLUSIONS: This large-scale study is the first randomised comparison of these two methods to capture pregnancy outcomes. Results are expected to inform the evidence base for survey methodology, especially in DHS, regarding capture of stillbirths and other outcomes, notably neonatal deaths, abortions (spontaneous and induced), birthweight and gestational age. In addition, this study will inform strategies to improve health and demographic surveillance capture of neonatal/child mortality and pregnancy outcomes.

Global Contraceptive Failure Rates: Who Is Most at Risk?

Contraceptive failure is a major contributor to unintended pregnancy worldwide. DHS retrospective calendars, which are the most widely used data source for estimating contraceptive failure in low-income countries, vary in quality across countries and surveys. We identified surveys with the most reliable calendar data and analyzed 105,322 episodes of contraceptive use from 15 DHSs conducted between 1992 and 2014. We estimate contraceptive method-specific 12-month failure rates. We also examined how failure rates vary by age, education, socioeconomic status, contraceptive intention, residence, and marital status using multilevel piecewise exponential hazard models. Our failure rate estimates are significantly lower than results from the United States and slightly higher than previous studies that included more DHS surveys, including some with lower-quality data. We estimate age-specific global contraceptive failure rates and find strong, consistent age patterns with the youngest users experiencing failure rates up to ten times higher than older women for certain methods. Failure also varies by socioeconomic status, with the poorest, and youngest, women at highest risk of experiencing unintended pregnancy due to failure.

The copper-sensing transcription factor Mac1, the histone deacetylase Hst1, and nicotinic acid regulate de novo NAD+ biosynthesis in budding yeast.

NADH (NAD+) is an essential metabolite involved in various cellular biochemical processes. The regulation of NAD+ metabolism is incompletely understood. Here, using budding yeast (Saccharomyces cerevisiae), we established an NAD+ intermediate-specific genetic system to identify factors that regulate the de novo branch of NAD+ biosynthesis. We found that a mutant strain (mac1Δ) lacking Mac1, a copper-sensing transcription factor that activates copper transport genes during copper deprivation, exhibits increases in quinolinic acid (QA) production and NAD+ levels. Similar phenotypes were also observed in the hst1Δ strain, deficient in the NAD+-dependent histone deacetylase Hst1, which inhibits de novo NAD+ synthesis by repressing BNA gene expression when NAD+ is abundant. Interestingly, the mac1Δ and hst1Δ mutants shared a similar NAD+ metabolism-related gene expression profile, and deleting either MAC1 or HST1 de-repressed the BNA genes. ChIP experiments with the BNA2 promoter indicated that Mac1 works with Hst1-containing repressor complexes to silence BNA expression. The connection of Mac1 and BNA expression suggested that copper stress affects de novo NAD+ synthesis, and we show that copper stress induces both BNA expression and QA production. Moreover, nicotinic acid inhibited de novo NAD+ synthesis through Hst1-mediated BNA repression, hindered the reuptake of extracellular QA, and thereby reduced de novo NAD+ synthesis. In summary, we have identified and characterized novel NAD+ homeostasis factors. These findings will expand our understanding of the molecular basis and regulation of NAD+ metabolism.

Prevalence thresholds for wasting, overweight and stunting in children under 5 years.

OBJECTIVE: Prevalence ranges to classify levels of wasting and stunting have been used since the 1990s for global monitoring of malnutrition. Recent developments prompted a re-examination of existing ranges and development of new ones for childhood overweight. The present paper reports from the WHO-UNICEF Technical Expert Advisory Group on Nutrition Monitoring. DESIGN: Thresholds were developed in relation to sd of the normative WHO Child Growth Standards. The international definition of 'normal' (2 sd below/above the WHO standards median) defines the first threshold, which includes 2·3 % of the area under the normalized distribution. Multipliers of this 'very low' level (rounded to 2·5 %) set the basis to establish subsequent thresholds. Country groupings using the thresholds were produced using the most recent set of national surveys. SETTING: One hundred and thirty-four countries. SUBJECTS: Children under 5 years. RESULTS: For wasting and overweight, thresholds are: 'very low' (≈6 times 2·5 %). For stunting, thresholds are: 'very low' (≈12 times 2·5 %). CONCLUSIONS: The proposed thresholds minimize changes and keep coherence across anthropometric indicators. They can be used for descriptive purposes to map countries according to severity levels; by donors and global actors to identify priority countries for action; and by governments to trigger action and target programmes aimed at achieving 'low' or 'very low' levels. Harmonized terminology will help avoid confusion and promote appropriate interventions.

A functional link between NAD+ homeostasis and N-terminal protein acetylation in Saccharomyces cerevisiae.

Nicotinamide adenine dinucleotide (NAD+) is an essential metabolite participating in cellular redox chemistry and signaling, and the complex regulation of NAD+ metabolism is not yet fully understood. To investigate this, we established a NAD+-intermediate specific reporter system to identify factors required for salvage of metabolically linked nicotinamide (NAM) and nicotinic acid (NA). Mutants lacking components of the NatB complex, NAT3 and MDM20, appeared as hits in this screen. NatB is an Nα-terminal acetyltransferase responsible for acetylation of the N terminus of specific Met-retained peptides. In NatB mutants, increased NA/NAM levels were concomitant with decreased NAD+ We identified the vacuolar pool of nicotinamide riboside (NR) as the source of this increased NA/NAM. This NR pool is increased by nitrogen starvation, suggesting NAD+ and related metabolites may be trafficked to the vacuole for recycling. Supporting this, increased NA/NAM release in NatB mutants was abolished by deleting the autophagy protein ATG14 We next examined Tpm1 (tropomyosin), whose function is regulated by NatB-mediated acetylation, and Tpm1 overexpression (TPM1-oe) was shown to restore some NatB mutant defects. Interestingly, although TPM1-oe largely suppressed NA/NAM release in NatB mutants, it did not restore NAD+ levels. We showed that decreased nicotinamide mononucleotide adenylyltransferase (Nma1/Nma2) levels probably caused the NAD+ defects, and NMA1-oe was sufficient to restore NAD+ NatB-mediated N-terminal acetylation of Nma1 and Nma2 appears essential for maintaining NAD+ levels. In summary, our results support a connection between NatB-mediated protein acetylation and NAD+ homeostasis. Our findings may contribute to understanding the molecular basis and regulation of NAD+ metabolism.

Reaching the 'first 90': Gaps in coverage of HIV testing among people living with HIV in 16 African countries.

BACKGROUND: UNAIDS has recently proposed a set of three ambitious targets that, if achieved, are predicted to end the AIDS epidemic by 2030. The targets, known as 90-90-90, call for 90% of people living with HIV (PLHIV) to know their status, 90% of PLHIV to receive antiretroviral therapy, and 90% of those on antiretroviral therapy to achieve viral suppression by the year 2020. We examine the first of these targets, focusing on sub-Saharan Africa, the region of the world most affected by HIV, to measure the proportion of PLHIV estimated to know their HIV status, and to identify background and behavioral characteristics significantly associated with gaps in ever testing among PLHIV. METHODS AND FINDINGS: We analyze cross-sectional population-based data from the Demographic and Health Surveys (DHS) and AIDS Indicator Surveys (AIS) fielded since 2010 in 16 sub-Saharan African countries where voluntary serological testing was recently conducted: Burkina Faso, Cameroon, Chad, Cote d'Ivoire, Ethiopia, Gabon, Lesotho, Malawi, Namibia, Rwanda, Sierra Leone, Tanzania, Togo, Uganda, Zambia, and Zimbabwe. Survey response rates averaged 95.0% (range 89.3-99.5%), while consent to serotesting averaged 94.9% (range 88.7-99.6%). This study, which includes more than 14,000 respondents living with HIV, finds that 69% of PLHIV in the average study country have ever been tested for HIV (range 34-95%). Based on timing of the last test and on ART coverage, we estimate that 54% of PLHIV in the average country are aware of their status (range 26-84%). Adjusted logistic regression finds that men (median adjusted odds ratio [AOR] = 0.38), adults with less than primary education (median AOR = 0.31), and adolescents (median AOR = 0.32) are consistently less likely to have ever been tested for HIV than women, adults with secondary and above education, and adults age 30-39, respectively. In most countries unadjusted logistic regression also finds significant gaps in testing among the poorest groups and those reporting never having had sex. CONCLUSION: The fact that an average of 54% of PLHIV in these 16 countries are estimated to know their status reflects encouraging progress. However, not only is this average far short of the 90% target set by UNAIDS for 2020, but it also implies that in the average study country nearly one-half of PLHIV are unable to access lifesaving care and treatment because they are unaware that they are HIV-positive. Several gaps in HIV testing coverage exist, particularly among adolescents, the least educated, and men. While the need to target demographic groups at greatest risk of HIV continues, additional interventions focused on reaching men and on reaching socially vulnerable populations such as adolescents, the poorest, and the least educated are essential.

Typical-use contraceptive failure rates in 43 countries with Demographic and Health Survey data: summary of a detailed report.

BACKGROUND: While most unintended pregnancies occur because couples do not use contraception, contraceptive failure is also an important underlying cause. However, few recent studies outside of the United States have estimated contraceptive failure rates, and most such studies have been restricted to married women, to a limited number of countries and to 12-month failure rate estimates. METHODS: Using self-reported data from 43 countries with Demographic and Health Survey data, we estimated typical-use contraceptive failure rates for seven contraceptive methods at 12, 24 and 36months of use. We provide a median estimate for each method across 43 countries overall, in seven subregions and in individual countries. We assess differences by various demographic and socioeconomic characteristics. Estimates are not corrected for potential errors in retrospective reporting contraceptive use or potential underreporting of abortion, which may vary by country and subgroups within countries. RESULTS: Across all included countries, reported 12-month typical-use failure rates were lowest for users of longer-acting methods such as implants (0.6 failures per 100 episodes of use), intrauterine devices (1.4) and injectables (1.7); intermediate for users of short-term resupply methods such as oral contraceptive pills (5.5) and male condoms (5.4); and highest for users of traditional methods such as withdrawal (13.4) or periodic abstinence (13.9), a group largely using calendar rhythm. CONCLUSIONS: Our findings help us to highlight those methods, subregions and population groups that may be in need of particular attention for improvements in policies and programs to address higher contraceptive failure rates.

Missed opportunities for family planning: an analysis of pregnancy risk and contraceptive method use among postpartum women in 21 low- and middle-income countries.

OBJECTIVES: To analyze data from recent Demographic and Health Surveys (DHS) conducted in 21 low- and middle-income countries (LMICs) to examine patterns of interpregnancy intervals, unmet need, pregnancy risk and family planning method use and method mix among women 0-23 months postpartum. STUDY DESIGN: Secondary analysis of postpartum women aged 15-49 years in 22 DHS surveys from 21 LMICs conducted between 2005 and 2012. We applied an adapted unmet need definition for postpartum women to look at prospective fertility preferences. We also constructed a new composite pregnancy risk indicator for postpartum women who have been sexually active since their last birth. RESULTS: In 9 of 22 surveys, 50% or more of nonfirst births occur at interpregnancy intervals that are too short. Overall prospective unmet need for family planning by postpartum women has not changed demonstrably since a 2001 analysis and is universally high: 61% of all postpartum women across the 21 countries have an unmet need for family planning. In 10 of 22 surveys, pregnancy risk rises steadily throughout the 2 years after birth. In the remaining 12 surveys, the risk of pregnancy peaks at 6-11 months after birth. Even when postpartum women are using family planning, they rely overwhelmingly on short-acting methods (51-96% in 21 of 22 surveys). CONCLUSION: Our approach of estimating pregnancy risk by postpartum timing confirms a high probability for pregnancies to be less than optimally spaced within 2 years of a prior birth and suggests that special consideration is needed to effectively reach this population with the right messages and services. IMPLICATIONS: Using recent, multicountry data for women within 2 years postpartum in LMICs, this paper updates existing estimates of high prospective unmet need for family planning and presents a new composite pregnancy risk analysis based on postpartum women's actual practices to demonstrate the magnitude of missed opportunities for programmatic intervention for the postpartum population.

Patterns and trends in adolescents' contraceptive use and discontinuation in developing countries and comparisons with adult women.

CONTEXT: The reproductive choices made by young women and men have an enormous impact on their health, schooling, employment prospects and overall transition to adulthood. As the largest cohort of young people in history enter their childbearing years, their reproductive behavior will determine the growth and size of the world's population for decades to come. METHODS: Demographic and Health Survey data from more than 40 countries were used to examine the proportions of 15-19-year-old women who are currently married or are unmarried but sexually active; their rates of contraceptive adoption, current use, discontinuation, method switching and contraceptive failure; trends in these indicators; and comparisons with older women. RESULTS: In many countries, the proportion of adolescent women using contraceptives increased substantially over the last two decades; prevalence among adolescents increased faster than among older women. Greater proportions of adolescents than of older women discontinued using a contraceptive method within a year or experienced contraceptive failure. CONCLUSIONS: Adolescent contraceptive use is growing, and compared with adult use, is characterized by shorter periods of consistent use with more contraceptive failure and more stopping for other reasons. Use through the reproductive years is likely to grow, fueled further by growth in the numbers of young people. An expanded demand for contraceptive supplies, services and information can be expected to challenge the preparedness, capacity and resources of existing family planning programs and providers.

Skilled care at birth in the developing world: progress to date and strategies for expanding coverage.

Skilled attendance at delivery is one of the key indicators to reflect progress toward the Millennium Development Goal of improving maternal health. This paper assesses global progress in the use of skilled attendants at delivery and identifies factors that could assist in achieving Millennium Development Goals for maternal health. National data covering a substantial proportion of all developing country births were used for the estimation of trends and key differentials in skilled assistance at delivery. Between 1990 and 2000, the percentage of births with a skilled attendant increased from 45% to 54% in developing countries, primarily as a result of an increasing use of doctors. A substantial proportion of antenatal care users do not deliver with a skilled attendant. Delivery care use among antenatal care users is highly correlated with wealth. Women aged 35 and above, who are at greatest risk of maternal death, are the least likely to receive professional delivery care. Births in mid-level facilities appear to be a strategy that has been overlooked. More effective strategies are needed to promote skilled attendance at birth during antenatal care, particularly among poor women. Specific interventions are also needed to encourage older and high parity mothers to seek professional care at delivery.