Hieu Nguyen

The Seroprevalence and Seroincidence of Enterovirus71 Infection in Infants and Children in Ho Chi Minh City, Viet Nam

Enterovirus 71 (EV71)-associated hand, foot and mouth disease has emerged as a serious public health problem in South East Asia over the last decade. To better understand the prevalence of EV71 infection, we determined EV71 seroprevalence and seroincidence amongst healthy infants and children in Ho Chi Minh City, Viet Nam. In a cohort of 200 newborns, 55% of cord blood samples contained EV71 neutralizing antibodies and these decayed to undetectable levels by 6 months of age in 98% of infants. The EV71 neutralizing antibody seroconversion rate was 5.6% in the first year and 14% in the second year of life. In children 5–15 yrs of age, seroprevalence of EV71 neutralizing antibodies was 84% and in cord blood it was 55%. Taken together, these data suggest EV71 force of infection is high and highlights the need for more research into its epidemiology and pathogenesis in high disease burden countries.

Rationale design methodology and sample characteristics for the Vietnam pre-conceptual micronutrient supplementation trial (PRECONCEPT): a randomized controlled study.

BackgroundLow birth weight and maternal anemia remain intractable problems in many developing countries. The adequacy of the current strategy of providing iron-folic acid (IFA) supplements only during pregnancy has been questioned given many women enter pregnancy with poor iron stores, the substantial micronutrient demand by maternal and fetal tissues, and programmatic issues related to timing and coverage of prenatal care. Weekly IFA supplementation for women of reproductive age (WRA) improves iron status and reduces the burden of anemia in the short term, but few studies have evaluated subsequent pregnancy and birth outcomes.The Preconcept trial aims to determine whether pre-pregnancy weekly IFA or multiple micronutrient (MM) supplementation will improve birth outcomes and maternal and infant iron status compared to the current practice of prenatal IFA supplementation only. This paper provides an overview of study design, methodology and sample characteristics from baseline survey data and key lessons learned.Methods/designWe have recruited 5011 WRA in a double-blind stratified randomized controlled trial in rural Vietnam and randomly assigned them to receive weekly supplements containing either: 1) 2800 μg folic acid 2) 60 mg iron and 2800 μg folic acid or 3) MM. Women who become pregnant receive daily IFA, and are being followed through pregnancy, delivery, and up to three months post-partum. Study outcomes include birth outcomes and maternal and infant iron status. Data are being collected on household characteristics, maternal diet and mental health, anthropometry, infant feeding practices, morbidity and compliance.DiscussionThe study is timely and responds to the WHO Global Expert Consultation which identified the need to evaluate the long term benefits of weekly IFA and MM supplementation in WRA. Findings will generate new information to help guide policy and programs designed to reduce the burden of anemia in women and children and improve maternal and child health outcomes in resource poor settings.Trial registrationNCT01665378

A Novel Telomerase Activator Suppresses Lung Damage in a Murine Model of Idiopathic Pulmonary Fibrosis

The emergence of diseases associated with telomere dysfunction, including AIDS, aplastic anemia and pulmonary fibrosis, has bolstered interest in telomerase activators. We report identification of a new small molecule activator, GRN510, with activity ex vivo and in vivo. Using a novel mouse model, we tested the potential of GRN510 to limit fibrosis induced by bleomycin in mTERT heterozygous mice. Treatment with GRN510 at 10 mg/kg/day activated telomerase 2–4 fold both in hematopoietic progenitors ex vivo and in bone marrow and lung tissue in vivo, respectively. Telomerase activation was countered by co-treatment with Imetelstat (GRN163L), a potent telomerase inhibitor. In this model of bleomycin-induced fibrosis, treatment with GRN510 suppressed the development of fibrosis and accumulation of senescent cells in the lung via a mechanism dependent upon telomerase activation. Treatment of small airway epithelial cells (SAEC) or lung fibroblasts ex vivo with GRN510 revealed telomerase activating and replicative lifespan promoting effects only in the SAEC, suggesting that the mechanism accounting for the protective effects of GRN510 against induced lung fibrosis involves specific types of lung cells. Together, these results support the use of small molecule activators of telomerase in therapies to treat idiopathic pulmonary fibrosis.

Food consumption patterns and associated factors among Vietnamese women of reproductive age

Background and objectivesAdequate nutrient intakes among women of reproductive age (WRA) are important determinants of maternal, neonatal and child health outcomes. However, data on dietary intake for WRA in Vietnam are lacking. This paper aimed to examine the adequacy and determinants of energy and macronutrient intakes among WRA enrolled in a study of preconceptual micronutrient supplementation (PRECONCEPT) being conducted in 20 rural communes in Thai Nguyen province, Vietnam.MethodsDietary intakes were determined for 4983 WRA who participated in the baseline survey using a previously validated 107-item (semi-quantitative) food-frequency questionnaire that was administered by trained field workers. Multivariate linear and logistic regression analyses were used to examine factors associated with energy and macronutrient intakes.ResultsA disproportionate number of energy came from starches, primarily rice. Carbohydrate, fat and protein constituted 65.6%, 19.5% and 14.8% of total energy, respectively. Fat intake was below recommended levels in 56.5% of respondents, but carbohydrate intakes were above recommended level in 54.6%. Only 0.1% and 5.2% of WRA achieved adequate intake of n-3 and n-6 long-chain polyunsaturated fatty acids, respectively. Multivariate linear regression revealed that low education, low socioeconomic status, and food insecurity were significant predictors of reduced total energy intake, reduced energy from protein and fat, and greater energy from carbohydrates. Logistic regression confirmed that inadequate macronutrient intake was more common among the poor, food insecure, and less educated.ConclusionsImbalanced dietary intakes among underprivileged women reflect lack of dietary diversity. Nutrition programs should be linked with social development, poverty reduction, education programs and behavior change counseling in order to improve the nutritional status of WRA in Vietnam.

Micronutrient Intakes among Women of Reproductive Age in Vietnam

Background Micronutrient deficiencies are a public health concern worldwide negatively affecting maternal and child health outcomes. The primary underlying causes of micronutrient deficiencies are insufficient intake and poor bioavailability of micronutrients. However, reliable data on micronutrient intakes are sparse. The objectives of this study were to identify the key local food sources providing the majority of micronutrients and assess the adequacy and determinants of micronutrient intakes. Methods The study used data from a survey of 4,983 rural women of reproductive age (WRA) participating in a preconception micronutrient supplementation trial in Vietnam. Micronutrient intakes were assessed using a validated 107-item semi-quantitative food-frequency questionnaire. Multivariate linear and logistic regression analyses were used to examine the association between socioeconomic status and micronutrient intakes. Results Starchy staples were the main source of iron and zinc (37% and 54%, respectively) with only a small proportion from meat (10% and 18%, respectively). The primary source of folate and vitamin A were vegetables; vitamin B12 came from meat and eggs. The proportion of the population with intakes below the estimated average requirement was 25% for iron, 16% for zinc, 54% for folate, 64% for vitamin B12 and 27% for vitamin A. Socioeconomic status was the main determinant of micronutrient intakes. WRA in the highest quintile consumed 26% more iron, 19% more zinc, 36% more folate, 82% more vitamin B12 and 47% more vitamin A compared to those in the lowest quintile. Women in the upper quintiles of SES were more likely to obtain nutrients from more nutritious and higher bioavailable foods than those in the lowest quintile. Conclusions Underprivileged women were at increased risk for insufficient micronutrient intakes due to poor diet quality. Targeted efforts to promote the consumption of local nutrient rich foods along with educational programs and social development are needed.

The relative influence of maternal nutritional status before and during pregnancy on birth outcomes in Vietnam

OBJECTIVE This study aimed to: (1) examine the role of multiple measures of prepregnancy nutritional status (weight, height, body composition) on birth outcomes (low birth weight (LBW), small for gestational age (SGA), preterm, birth weight, birth length, infant head circumference and mid-upper arm circumference (MUAC)); (2) assess relative influence of maternal nutritional status before and during (gestational weight gain) pregnancy on birth outcomes. STUDY DESIGN We used prospective data on maternal body size and composition collected from women who participated in a randomized controlled trial evaluating the impact of preconceptional micronutrient supplements (PRECONCEPT) on birth outcomes in Thai Nguyen province, Vietnam (n=1436). Anthropometric measurements were obtained before conception through delivery by trained health workers. The relationship between prepregnancy nutritional status indicators, gestational weight gain (GWG) and birth outcomes were examined using generalized linear models, adjusting for potential confounding factors. RESULTS Maternal prepregnancy weight (PPW) was the strongest anthropometric indicator predicting infant birth size. A 1 standard deviation (SD) increase in PPW (5.4kg) was associated with a 283g (95%CI: 279-286) increase in birthweight. A similar and independent association was observed with birthweight for an increase of 1 SD in gestational weight gain (4kg) (250g; 95% CI: 245-255). Women with a PPW <43kg or who gained <8kg during their pregnancy were more likely to give birth to a SGA (OR 2.9: 95%CI 1.9-4.5, OR 3.3: 95%CI 2.2-5.1) or LBW infant (OR 3.1: 95%CI 1.5-6.2, OR 3.4: 95%CI 1.6-7.2), respectively. CONCLUSIONS These findings indicate that clinical care and programs aimed at improving birth outcomes will have the greatest impact if they address maternal nutrition both before and during pregnancy. Women with a PPW <43kg or a GWG <8kg are at greatest risk for poor birth outcomes in this setting. Preconception counseling and clinical care to obtain a healthy weight prior to pregnancy along with routine obstetric care on gestational weight gain is critical to improve birth outcomes. TRIAL REGISTRATION NCT01665378 (https://clinicaltrials.gov/show/NCT01665378).

Neither Preconceptional Weekly Multiple Micronutrient nor Iron–Folic Acid Supplements Affect Birth Size and Gestational Age Compared with a Folic Acid Supplement Alone in Rural Vietnamese Women: A Randomized Controlled Trial

BACKGROUND Maternal nutritional status before and during early pregnancy plays a critical role in fetal growth and development. The benefits of periconception folic acid (FA) supplementation in the prevention of neural tube defects is well recognized, but the evidence for preconception micronutrient interventions for improving pregnancy outcomes is limited. OBJECTIVE This study aimed to evaluate whether preconception supplementation with weekly iron and folic acid (IFA) or multiple micronutrients (MMs) improves birth outcomes compared with FA alone. METHODS We recruited 5011 women of reproductive age in a double-blind, randomized controlled trial in Vietnam and provided weekly supplements containing either 2800 μg FA, 60 mg Fe and 2800 μg FA (IFA), or the same amount of FA and iron plus other MMs until they conceived (n = 1813). All pregnant women received daily IFA through delivery, and were followed up for birth outcomes, including birth weight, gestational age, preterm delivery and small for gestational age (SGA). Group comparisons were done with the use of ANOVA or chi-square tests for both intention-to-treat (n = 1599) and per-protocol analyses (women consumed supplements ≥26 wk before conception; n = 824). Effect modification by baseline underweight or anemia status was tested with the use of generalized linear models. RESULTS The mean age of the women was 26 y, 30% were underweight, and <10% were nulliparous. The groups were similar for most baseline characteristics. The mean ± SD duration of the preconception intervention was 33 ± 25 wk and compliance was high (>90%). Infants born to the 3 groups of women did not differ (P ≥ 0.05) on mean ± SD birth weight (3076.8 ± 444.5 g) or gestational age (39.2 ± 2.0 wk), or prevalence of SGA (12%), low birth weight (5%) and preterm delivery (10%). There were no significant differences in women who consumed supplements ≥26 wk before conception or by baseline underweight or anemia. CONCLUSION Weekly supplementation with MMs or IFA before conception did not affect birth outcomes compared with FA in rural Vietnamese women. The trial was registered at clinicaltrials.gov as NCT01665378.

Luminal fluid of epididymis and vas deferens contributes to sperm chromatin fragmentation

STUDY QUESTION Do the luminal fluids of the epididymis and the vas deferens contribute to sperm chromatin fragmentation (SCF) in mice? SUMMARY ANSWER The luminal fluids of both organs are required for activating SCF in mice, but the vas deferens luminal fluid does this more efficiently than that of the epididymis. WHAT IS KNOWN ALREADY Mice sperm have the ability to degrade their DNA in an apoptotic-like fashion when treated with divalent cations in a process termed SCF. SCF has two steps: the induction of reversible double-strand DNA breaks at the nuclear matrix attachment sites, followed by the irreversible degradation of DNA by nuclease. Single stranded DNA breaks accompany SCF. STUDY DESIGN, SIZE, DURATION Luminal fluids from two reproductive organs of the mouse (B6D2F1 strain), the epididymis and vas deferens, were extracted and tested for SCF activation with divalent cations using four different combinations of the sperm and the surrounding luminal fluids: (i) in situ--sperm were kept in their luminal fluid and activated directly; (ii) reconstituted--sperm were centrifuged and resuspended in their luminal fluid before SCF activation; (iii) mixed--sperm were centrifuged and resuspended in the luminal fluid of the other organ; (iv) no luminal fluid--sperm were centrifuged and reconstituted in buffer. All four experiments were performed without (controls) and with divalent cations (resulting in SCF). For each experimental condition, two different mice were used and the analyses averaged. PARTICIPANTS/MATERIALS, SETTING, METHODS DNA damage by SCF was analyzed by three different methods, the sperm chromatin structure assay (SCSA), terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling (TUNEL) analysis and field inversion gel electrophoresis. MAIN RESULTS AND THE ROLE OF CHANCE In all three assays that we used, the vas deferens luminal fluid was much more efficient in stimulating SCF in the sperm from either source than that of the epididymis (P < 0.0001). Vas deferens sperm were capable of initiating lower levels of SCF in the absence of luminal fluid (P < 0.0001). LIMITATIONS, REASONS FOR CAUTION Analyses were performed in only one species, the mouse, but we used three separate assays in our analysis. WIDER IMPLICATIONS OF THE FINDINGS The data suggest that the luminal fluid of the male reproductive tract interacts with sperm during their transit providing a mechanism to degrade the DNA. We hypothesize that this is part of an apoptotic-like mechanism that allows the reproductive tract to eliminate defective sperm. The SCF model also allowed us to identify differences in the types of DNA lesions that the three tests can identify, providing important background information for the use of these tests clinically.

Impact of Preconception Micronutrient Supplementation on Anemia and Iron Status during Pregnancy and Postpartum: A Randomized Controlled Trial in Rural Vietnam

Objective Preconception micronutrient interventions may be a promising approach to reduce anemia and iron deficiency during pregnancy, but currently we have limited data to inform policies. We evaluated whether providing additional pre-pregnancy weekly iron-folic acid (IFA) or multiple micronutrient (MM) supplements compared to only folic acid (FA) improves iron status and anemia during pregnancy and early postpartum. Methods We conducted a double blind randomized controlled trial in which 5011 Vietnamese women were provided with weekly supplements containing either only 2800 μg FA (control group), IFA (60 mg Fe and 2800 μg FA) or MM (15 micronutrients with similar amounts of IFA). All women who became pregnant (n = 1813) in each of the 3 groups received daily IFA (60 mg Fe and 400 μg FA) through delivery. Hematological indicators were assessed at baseline (pre-pregnancy), during pregnancy, 3 months post-partum, and in cord blood. Adjusted generalized linear models were applied to examine the impact of preconception supplementation on anemia and iron stores, using both intention to treat and per protocol analyses (women consumed supplements ≥ 26 weeks before conception). Results At baseline, 20% of women were anemic, but only 14% had low iron stores (ferritin <30 μg/L) and 3% had iron deficiency (ferritin <12 μg/L). The groups were balanced for baseline characteristics. Anemia prevalence increased during pregnancy and post-partum but was similar among intervention groups. In intention to treat analyses, prenatal ferritin was significantly higher among women receiving MM (geometric mean (μg/L) [95% CI]: 93.6 [89.3–98.2]) and IFA (91.9 [87.6–96.3]) compared to control (85.3 [81.5–89.2]). In per protocol analyses, women receiving MM or IFA had higher ferritin 3 months postpartum (MM 118.2 [109.3–127.8]), IFA 117.8 [108.7–127.7] vs control 101.5 [94.0–109.7]) and gave birth to infants with greater iron stores (MM 184.3 [176.1–192.9]), IFA 189.9 [181.6–198.3] vs control 175.1 [167.9–182.6]). Conclusion Preconception supplementation with MM or IFA resulted in modest increases in maternal and infant iron stores but did not impact anemia. Further research is needed to characterize the etiology of anemia in this population and identify effective interventions for reducing prenatal anemia. Trial Registration ClinicalTrials.Gov NCT01665378

ORC4 Surrounds Extruded Chromatin in Female Meiosis

Six proteins, ORC1–6, make up the origin recognition complex (ORC) that initiates licensing of DNA replication origins. We have previously reported that subunit ORC2 is localized between the separating maternal chromosomes at anaphase II just after fertilization and is present in zygotic pronuclei at G1. Here, we found that ORC1, 3, and 5 all localize between the chromosomes at anaphase II, but could not be detected in zygotic G1. ORC6 localized to the periphery of the nucleoli at all zygotic stages. We identified an unexpected potential role for ORC4 in polar body formation. We found that in both female meiotic divisions, ORC4 surrounds the set of chromosomes, as a sphere‐like structure, that will eventually be discarded in the polar bodies, but not the chromosomes that segregate into the oocyte. None of the other five ORC proteins are involved in this structure. In Zygotic G1, ORC4 surrounds the nuclei of the polar bodies, but was not detectable in the pronuclei. When the zygote entered mitosis ORC4 was only detected in the polar body. However, ORC4 appeared on both sets of separating chromosomes at telophase. At this point, the ORC4 that was in the polar body also migrated into the nuclei, suggesting that ORC4 or an associated protein is modified during the first embryonic cell cycle to allow it to bind DNA. Our results suggest that ORC4 may help identify the chromosomes that are destined to be expelled in the polar body, and may play a role in polar body extrusion. ORC4 surrounds the chromatin that will be extruded in the polar body in both female meiotic divisions, then makes a transition from the cytoplasm to the chromosomes at zygotic anaphase, suggesting multiple roles for this replication licensing protein. J. Cell. Biochem. 116: 778–786, 2015.