Patterning with clocks and genetic cascades: Segmentation and regionalization of vertebrate versus insect body plans

Oscillatory and sequential processes have been implicated in the spatial patterning of many embryonic tissues. For example, molecular clocks delimit segmental boundaries in vertebrates and insects and mediate lateral root formation in plants, whereas sequential gene activities are involved in the specification of regional identities of insect neuroblasts, vertebrate neural tube, vertebrate limb, and insect and vertebrate body axes. These processes take place in various tissues and organisms, and, hence, raise the question of what common themes and strategies they share. In this article, we review 2 processes that rely on the spatial regulation of periodic and sequential gene activities: segmentation and regionalization of the anterior-posterior (AP) axis of animal body plans. We study these processes in species that belong to 2 different phyla: vertebrates and insects. By contrasting 2 different processes (segmentation and regionalization) in species that belong to 2 distantly related phyla (arthropods and vertebrates), we elucidate the deep logic of patterning by oscillatory and sequential gene activities. Furthermore, in some of these organisms (e.g., the fruit fly Drosophila), a mode of AP patterning has evolved that seems not to overtly rely on oscillations or sequential gene activities, providing an opportunity to study the evolution of pattern formation mechanisms.

Developmental chronodisruption alters placental signaling in mice

Chronodisruption has been largely overlooked as a developmental exposure. The placenta, a conduit between the maternal and fetal environments, may relay circadian cues to the fetus. We have previously shown that developmental chronodisruption causes visual impairment and increased retinal microglial and macrophage marker expression. Here, we investigated the impacts of environmental chronodisruption on fetal and placental outcomes in a C57BL/6J mouse (Mus musculus) model. Developmental chronodisruption had no effect on embryo count, placental weight, or fetal sex ratio. When measured with RNAseq, mice exposed to developmental chronodisruption (CD) had differential placental expression of several transcripts including Serpinf1, which encodes pigment epithelium-derived factor (PEDF). Immunofluorescence of microglia/macrophage markers, Iba1 and CD11b, also revealed significant upregulation of immune cell markers in CD-exposed placenta. Our results suggest that in utero chronodisruption enhances placental immune cell expression, potentially programming a pro-inflammatory tissue environment.

The effects of evidence-based expert testimony on perceptions of child sexual abuse involving recantation

Child sexual abuse (CSA) cases involving recantation invoke concerns about children’s reliability. Expert testimony can help explain the complexities of these cases. Experts have historically relied on Child Sexual Abuse Accommodation Syndrome (CSAAS), yet this is not science-based. In a CSA case involving recantation, how would evidence-based testimony affect perceptions of child credibility when compared to CSAAS? Across 2 studies, we test the effects of expert testimony based on evidence-based science, nonscientific evidence, and experience-based evidence on outcomes in CSA cases involving recantation. Evidence-based testimony led to higher perceptions of credibility and scientific rigor of the evidence when compared to CSAAS testimony. Evidence-based testimony also led to more guilty verdicts when compared to the control. In sum, jurors had some ability to detect evidence strength, such that evidence-based expert testimony was superior to CSAAS testimony in many respects, and consistently superior to experience-based testimony in these cases.

Using food network analysis to understand meal patterns in pregnant women with high and low diet quality

BACKGROUND

Little is known about how meal-specific food intake contributes to overall diet quality during pregnancy, which is related to numerous maternal and child health outcomes. Food networks are probabilistic graphs using partial correlations to identify relationships among food groups in dietary intake data, and can be analyzed at the meal level. This study investigated food networks across meals in pregnant women and explored differences by overall diet quality classification.

METHODS

Women were asked to complete three 24-h dietary recalls throughout pregnancy (n = 365) within a prospective cohort study in the US. Pregnancy diet quality was evaluated using the Healthy Eating Index-2015 (HEI, range 0-100), calculated across pregnancy. Networks from 40 food groups were derived for women in the highest and lowest HEI tertiles at each participant-labeled meal (i.e., breakfast, lunch, dinner, snacks) using Gaussian graphical models. Network composition was qualitatively compared across meals and between HEI tertiles.

RESULTS

In both HEI tertiles, breakfast food combinations comprised ready-to-eat cereals with milk, quick breads with sweets (e.g., pancakes with syrup), and bread with cheese and meat. Vegetables were consumed at breakfast among women in the high HEI tertile only. Combinations at lunch and dinner were more varied, including vegetables with oils (e.g., salads) in the high tertile and sugary foods with nuts, fruits, and milk in the low tertile at lunch; and cooked grains with fats (e.g., pasta with oil) in the high tertile and potatoes with vegetables and meat in the low tertile at dinner. Fried potatoes, sugar-sweetened beverages, and sandwiches were consumed together at all main meals in the low tertile only. Foods were consumed individually at snacks in both tertiles; the most commonly consumed food were fruits in the high HEI tertile and cakes & cookies in the low tertile.

CONCLUSIONS

In this cohort of pregnant women, food network analysis indicated that food combinations differed by meal and between HEI tertiles. Meal-specific patterns that differed between diet quality tertiles suggest potential targets to improve food choices at meals; the impact of meal-based dietary modifications on intake of correlated foods and on overall diet quality should be investigated in simulations and intervention studies.

TRIAL REGISTRATION

PEAS was registered with number NCT02217462 in Clinicaltrials.gov on August 13, 2014.

Induction of a chromatin boundary in vivo upon insertion of a TAD border

Mammalian genomes are partitioned into sub-megabase to megabase-sized units of preferential interactions called topologically associating domains or TADs, which are likely important for the proper implementation of gene regulatory processes. These domains provide structural scaffolds for distant cis regulatory elements to interact with their target genes within the three-dimensional nuclear space and architectural proteins such as CTCF as well as the cohesin complex participate in the formation of the boundaries between them. However, the importance of the genomic context in providing a given DNA sequence the capacity to act as a boundary element remains to be fully investigated. To address this question, we randomly relocated a topological boundary functionally associated with the mouse HoxD gene cluster and show that it can indeed act similarly outside its initial genomic context. In particular, the relocated DNA segment recruited the required architectural proteins and induced a significant depletion of contacts between genomic regions located across the integration site. The host chromatin landscape was re-organized, with the splitting of the TAD wherein the boundary had integrated. These results provide evidence that topological boundaries can function independently of their site of origin, under physiological conditions during mouse development.

During development, enhancer sequences tightly regulate the spatio-temporal expression of target genes often located hundreds of kilobases away. This complex process is made possible by the folding of chromatin into domains, which are separated from one another by specific genomic regions referred to as boundaries. In order to understand whether such boundary sequences require their particular genomic contexts to achieve their isolating effect, we analyzed the impact of introducing one such boundary, taken from the HoxD locus, into a distinct topological domain. We show that this ectopic boundary splits the host domain into two sub-domains and affects the expression levels of a neighboring gene. We conclude that this sequence can work independently from its genomic context and thus carries all the information necessary to act as a boundary element.

Destination shapes antibiotic resistance gene acquisitions, abundance increases, and diversity changes in Dutch travelers

BACKGROUND

Antimicrobial-resistant bacteria and their antimicrobial resistance (AMR) genes can spread by hitchhiking in human guts. International travel can exacerbate this public health threat when travelers acquire AMR genes endemic to their destinations and bring them back to their home countries. Prior studies have demonstrated travel-related acquisition of specific opportunistic pathogens and AMR genes, but the extent and magnitude of travel's effects on the gut resistome remain largely unknown.

METHODS

Using whole metagenomic shotgun sequencing, functional metagenomics, and Dirichlet multinomial mixture models, we investigated the abundance, diversity, function, resistome architecture, and context of AMR genes in the fecal microbiomes of 190 Dutch individuals, before and after travel to diverse international locations.

RESULTS

Travel markedly increased the abundance and α-diversity of AMR genes in the travelers' gut resistome, and we determined that 56 unique AMR genes showed significant acquisition following international travel. These acquisition events were biased towards AMR genes with efflux, inactivation, and target replacement resistance mechanisms. Travel-induced shaping of the gut resistome had distinct correlations with geographical destination, so individuals returning to The Netherlands from the same destination country were more likely to have similar resistome features. Finally, we identified and detailed specific acquisition events of high-risk, mobile genetic element-associated AMR genes including qnr fluoroquinolone resistance genes, blaCTX-M family extended-spectrum β-lactamases, and the plasmid-borne mcr-1 colistin resistance gene.

CONCLUSIONS

Our results show that travel shapes the architecture of the human gut resistome and results in AMR gene acquisition against a variety of antimicrobial drug classes. These broad acquisitions highlight the putative risks that international travel poses to public health by gut resistome perturbation and the global spread of locally endemic AMR genes.

White matter microstructure associations with episodic memory in adults with Down syndrome: a tract-based spatial statistics study

BACKGROUND

Nearly all persons with Down syndrome will show pathology of Alzheimer's disease in their 40s. There is a critical need for studies to identify early biomarkers of these various pathological changes of Alzheimer's disease in the Down syndrome population and understand the relationship of these biomarkers to cognitive symptoms in order to inform clinical trials. Although Alzheimer's disease is often considered a disease of gray matter, white matter degeneration has been documented during the preclinical stage of Alzheimer's disease. The current study examined the association between diffusion tensor imaging (DTI) measures of white matter microstructure and episodic memory performance in 52 adults with Down syndrome.

METHODS

Seventy (N = 70) participants (M = 40.13, SD = 7.77 years) received baseline scans as part of the Neurodegeneration in Aging Down Syndrome (NiAD) study at two imaging facilities (36 at the University of Wisconsin-Madison [UW-Madison] and 34 at the University of Pittsburgh Medical Center [UPMC]). All participants had genetically confirmed trisomy 21. Fifty-two (N = 52) participants remained after QC. The DTI measures, fractional anisotropy (FA) and mean diffusivity (MD), were calculated for each participant. A combined measure of episodic memory was generated by summing the z-scores of (1) Free and Cued Recall test and (2) Rivermead Behavioural Memory Test for Children Picture Recognition. The DTI data were projected onto a population-derived FA skeleton and tract-based spatial statistics analysis was conducted using the FSL tool PALM to calculate Pearson's r values between FA and MD with episodic memory.

RESULTS

A positive correlation of episodic memory with FA and a negative correlation of episodic memory and MD in the major association white matter tracts were observed. Results were significant (p < 0.05) after correction for chronological age, imaging site, and premorbid cognitive ability.

CONCLUSION

These findings suggest that white matter degeneration may be implicated in early episodic memory declines prior to the onset of dementia in adults with Down syndrome. Further, our findings suggest a coupling of episodic memory and white matter microstructure independent of chronological age.

Associations of firearm dealer openings with firearm self-harm deaths and injuries: A differences-in-differences analysis

BACKGROUND

Firearm dealer density is correlated with firearm interpersonal violence, but no quasi-experimental studies have assessed whether changes in dealer density lead to changes in firearm self-harm injuries and deaths. We assessed whether openings of firearm dealers are associated with short-term changes in local firearm self-harm injury rates.

METHODS

We identified 718 openings of firearm dealers in California using licensing data, 2014-2016. We defined exposure regions based on aggregations of zip codes defined by proximity to firearm dealer openings and matched each opening to four control regions on time and determinants of firearm injury. We applied a differences-in-differences approach to compare rates of firearm self-harm, in the month before and after each opening, in places with and without openings.

RESULTS

Firearm dealer openings were not associated with acute, local changes in firearm self-harm relative to places without openings (ratio of rate ratio: 0.90 [95% CI:0.68-1.19]). Results were robust to numerous sensitivity and secondary analyses.

CONCLUSION

We found no associations of firearm dealer openings with acute, localized firearm self-harm deaths and injuries. Our focus on acute, local effects; broad availability of dealers and firearms; durability of firearms; or strong confounding-control may explain these null findings.

Comparison of levonorgestrel level and creamatocrit in milk following immediate versus delayed postpartum placement of the levonorgestrel IUD

BACKGROUND

Breastfeeding and postpartum contraception critically influence infant and maternal health outcomes. In this pilot study, we explore the effects of timing and duration of postpartum levonorgestrel exposure on milk lipid and levonorgestrel content to establish baseline data for future research.

METHODS

This sub-study recruited a balanced convenience sample from 259 participants enrolled in a parent randomized controlled trial comparing immediate to delayed (4-8 weeks) postpartum levonorgestrel IUD placement. All planned to breastfeed, self-selected for sub-study participation, and provided the first sample at 4-8 weeks postpartum (before IUD placement for the delayed group) and the second four weeks later. We used the Wilcoxon rank sum (inter-group) and signed rank (intra-group) tests to compare milk lipid content (creamatocrit) and levonorgestrel levels between groups and time points.

RESULTS

We recruited 15 participants from the immediate group and 17 from the delayed group with 10 and 12, respectively, providing both early and late samples. Initially, median levonorgestrel concentration of the immediate group (n = 10) (32.5 pg/mL, IQR: 24.8, 59.4) exceeded that of the delayed group (n = 12) (17.5 pg/mL, IQR: 0.0, 25.8) (p = 0.01). Four weeks later, the values aligned: 26.2 pg/mL (IQR: 20.3, 37.3) vs. 28.0 pg/mL (IQR: 25.2, 40.8). Creamatocrits were similar between both groups and timepoints.

CONCLUSIONS

Immediate postpartum levonorgestrel IUD placement results in steady, low levels of levonorgestrel in milk without apparent effects on lipid content. These findings provide initial support for the safety of immediate postpartum levonorgestrel IUD initiation, though the study was not powered to detect noninferiority between groups.

TRIAL REGISTRATION

This randomized controlled trial was registered with ClinicalTrials.gov (Registry No. NCT01990703) on November 21, 2013.

Efficient multiplexed genome engineering with a polycistronic tRNA and CRISPR guide-RNA reveals an important role of detonator in reproduction of Drosophila melanogaster

Genome association studies in human and genetic studies in mouse implicated members of the transmembrane protein 132 (TMEM132) family in multiple conditions including panic disorder, hearing loss, limb and kidney malformation. However, the presence of five TMEM132 paralogs in mammalian genomes makes it extremely challenging to reveal the full requirement for these proteins in vivo. In contrast, there is only one TMEM132 homolog, detonator (dtn), in the genome of fruit fly Drosophila melanogaster, enabling straightforward research into its in vivo function. In the current study, we generate multiple loss-of-function dtn mutant fly strains through a polycistronic tRNA-gRNA approach, and show that most embryos lacking both maternal and paternal dtn fail to hatch into larvae, indicating an essential role of dtn in Drosophila reproduction.

Association of parity with birthweight and neonatal death in five sites: The Global Network's Maternal Newborn Health Registry study

BACKGROUND

Nulliparity has been associated with lower birth weight (BW) and other adverse pregnancy outcomes, with most of the data coming from high-income countries. In this study, we examined birth weight for gestational age z-scores and neonatal (28-day) mortality in a large prospective cohort of women dated by first trimester ultrasound from multiple sites in low and middle-income countries.

METHODS

Pregnant women were recruited during the first trimester of pregnancy and followed through 6 weeks postpartum from Maternal Newborn Health Registry (MNHR) sites in the Democratic Republic of Congo (DRC), Guatemala, Belagavi and Nagpur, India, and Pakistan from 2017 and 2018. Data related to the pregnancy and its outcomes were collected prospectively. First trimester ultrasound was used for determination of gestational age; (BW) was obtained in grams within 48 h of delivery and later transformed to weight for age z-scores (WAZ) adjusted for gestational age using the INTERGROWTH-21st standards.

RESULTS

15,121 women were eligible and included. Infants of nulliparous women had lower mean BWs (males: 2676 gr, females: 2587 gr, total: 2634 gr) and gestational age adjusted weight for age z-scores (males: - 0.73, females: - 0.77, total: - 0.75,) than women with one or more previous pregnancies. The largest differences were between zero and one previous pregnancies among female infants. The associations of parity with BW and z-scores remained even after adjustment for maternal age, maternal height, maternal education, antenatal care visits, hypertensive disorders, and socioeconomic status. Nulliparous women also had a significantly higher < 28-day neonatal mortality rate (27.7 per 1,000 live births) than parous women (17.2 and 20.7 for parity of 1-3 and ≥ 4 respectively). Risk of preterm birth was higher among women with ≥ 4 previous pregnancies (15.5%) compared to 11.3% for the nulliparous group and 11.8% for women with one to three previous pregnancies (p = 0.0072).

CONCLUSIONS

In this large sample from diverse settings, nulliparity was independently associated with both lower BW and WAZ scores as well as higher neonatal mortality compared to multiparity.

Cesarean birth in the Global Network for Women's and Children's Health Research: trends in utilization, risk factors, and subgroups with high cesarean birth rates

BACKGROUND

The objectives of this analysis were to document trends in and risk factors associated with the cesarean birth rate in low- and middle-income country sites participating in the Global Network for Women's and Children's Health Research (Global Network).

METHODS

This is a secondary analysis of a prospective, population-based study of home and facility births conducted in the Global Network sites.

RESULTS

Cesarean birth rates increased uniformly across all sites between 2010 and 2018. Across all sites in multivariable analyses, women younger than age twenty had a reduced risk of cesarean birth (RR 0.9 [0.9, 0.9]) and women over 35 had an increased risk of cesarean birth (RR 1.1 [1.1, 1.1]) compared to women aged 20 to 35. Compared to women with a parity of three or more, less parous women had an increased risk of cesarean (RR 1.2 or greater [1.2, 1.4]). Four or more antenatal visits (RR 1.2 [1.2, 1.3]), multiple pregnancy (RR 1.3 [1.3, 1.4]), abnormal progress in labor (RR 1.1 [1.0, 1.1]), antepartum hemorrhage (RR 2.3 [2.0, 2.7]), and hypertensive disease (RR 1.6 [1.5, 1.7]) were all associated with an increased risk of cesarean birth, p < 0.001. For multiparous women with a history of prior cesarean birth, rates of vaginal birth after cesarean were about 20% in the Latin American and Southeast Asian sites and about 84% at the sub-Saharan African sites. In the African sites, proportions of cesarean birth in the study were highest among women without a prior cesarean and a single, cephalic, term pregnancy. In the non-African sites, groups with the greatest proportion of cesarean births were nulliparous women with a single, cephalic, term pregnancy and all multiparous women with at least one previous uterine scar with a term, cephalic pregnancy.

CONCLUSION

Cesarean birth rates continue to rise within the Global Network. The proportions of cesarean birth are higher among women with no history of cesarean birth in the African sites and among women with primary elective cesarean, primary cesarean after induction, and repeat cesarean in the non-African sites.

Associations between legal performance-enhancing substance use and future cardiovascular disease risk factors in young adults: A prospective cohort study

BACKGROUND

Legal performance-enhancing substances (PES), such as creatine, are commonly used by adolescents and young adults. As PES are mostly unregulated by the US Food and Drug Administration, there has been limited empirical attention devoted to examining their long-term safety and health outcomes. Preliminary studies have demonstrated associations between PES use and severe medical events, including hospitalizations and death. PES could be linked to cardiovascular disease (CVD), the most common cause of mortality in the US, by altering the myocardium, vasculature, or metabolism. The objective of this study was to examine prospective associations between the use of legal PES in young adulthood and CVD risk factors at seven-year follow-up.

MATERIALS AND METHODS

Nationally representative longitudinal cohort data from the National Longitudinal Study of Adolescent to Adult Health, Waves III (2001-2002) and IV (2008), were analyzed. Regression models determined the prospective association between the use of legal PES (e.g. creatine monohydrate) and CVD risk factors (e.g. body mass index, diabetes, hypertension, hyperlipidemia), adjusting for relevant covariates.

RESULTS

Among the diverse sample of 11,996 male and female participants, no significant differences by PES use in body mass index, diabetes, hypertension, or hyperlipidemia were noted at Wave III. In unadjusted comparisons, legal PES users (versus non-users) were more likely to be White, be male, be college educated, drink alcohol, and engage in weightlifting, exercise, individual sports, team sports, and other strength training. There were no significant prospective associations between legal PES use at Wave III and body mass index, hemoglobin A1c, systolic and diastolic blood pressure, and cholesterol (total, HDL, LDL, triglycerides) deciles at seven-year follow-up (Wave IV), adjusting for demographics, health behaviors, and Wave III CVD risk factors. Similarly, there were no significant prospective associations between legal PES use and diabetes, hypertension, or hyperlipidemia based on objective measures or self-reported medications and diagnoses, adjusting for demographics, health behaviors, and Wave III CVD risk.

CONCLUSIONS

We do not find evidence for a prospective association between legal PES use and CVD risk factors in young adults over seven years of follow-up, including BMI, diabetes, hypertension, or hyperlipidemia. It should be noted that legal PES use was operationalized dichotomously and as one broad category, which did not account for frequency, amount, or duration of use. Given the lack of regulation and clinical trials data, observational studies can provide much needed data to inform the safety and long-term health associations of legal PES use and, in turn, inform clinical guidance and policy.

A small-molecule screen reveals novel modulators of MeCP2 and X-chromosome inactivation maintenance

BACKGROUND

Rett syndrome (RTT) is a neurodevelopmental disorder caused by mutations in the X-linked methyl-CpG binding protein 2 (MeCP2) gene. While MeCP2 mutations are lethal in most males, females survive birth but show severe neurological defects. Because X-chromosome inactivation (XCI) is a random process, approximately 50% of the cells silence the wild-type (WT) copy of the MeCP2 gene. Thus, reactivating the silent WT copy of MeCP2 could provide therapeutic intervention for RTT.

METHODS

Toward this goal, we screened ~ 28,000 small-molecule compounds from several libraries using a MeCP2-luciferase reporter cell line and cortical neurons from a MeCP2-EGFP mouse model. We used gain/increase of luminescence or fluorescence as a readout of MeCP2 reactivation and tested the efficacy of these drugs under different drug regimens, conditions, and cellular contexts.

RESULTS

We identified inhibitors of the JAK/STAT pathway as XCI-reactivating agents, both by in vitro and ex vivo assays. In particular, we show that AG-490, a Janus Kinase 2 (JAK2) kinase inhibitor, and Jaki, a pan JAK/STAT inhibitor, are capable of reactivating MeCP2 from the inactive X chromosome, in different cellular contexts.

CONCLUSIONS

Our results suggest that inhibition of the JAK/STAT pathway is a new potential pathway to reinstate MeCP2 gene expression as an efficient RTT treatment.

Predisaster predictors of posttraumatic stress symptom trajectories: An analysis of low-income women in the aftermath of Hurricane Katrina

Exposure to disasters is associated with a range of posttraumatic stress symptom (PTSS) trajectories. However, few studies have tracked PTSS for more than a decade postdisaster, and none to our knowledge has explored the role of predisaster resources and vulnerabilities in shaping the likelihood of trajectory membership. The current study included participants from the Resilience in Survivors of Katrina Study (N = 885). Participants were originally part of a community college intervention study and were assessed prior to the hurricane (6–21 months predisaster), and approximately 1 year, 4 years, and 12 years postdisaster. Latent class growth analysis identified PTSS trajectories. Perceived social support, probable mental illness, and physical health conditions or problems–all assessed predisaster–were examined as predictors of trajectory membership at the univariate level and in multivariable models without and with adjustment for disaster exposure. Three PTSS trajectories were detected: Moderate-Decreasing (69.3%), High-Decreasing (23.1%), and High-Stable (7.6%). In the multivariable predictive model without adjustment for disaster exposure, probable predisaster mental illness was significantly associated with greater odds of the High-Decreasing and High-Stable trajectories, and physical health conditions or problems with greater odds of the High-Decreasing trajectory, relative to the Moderate-Decreasing trajectory. However, when disaster exposure was adjusted, only the association between predisaster mental illness and the odds of the High-Stable trajectory remained statistically significant. Lower predisaster perceived social support was significantly associated with membership in the High-Decreasing trajectory, relative to the Moderate-Decreasing, at the univariate level, but not in either multivariable model. Whereas predisaster mental illness confers risk for chronic postdisaster PTSS, other impacts of predisaster resources and vulnerabilities on elevated PTSS trajectories do not go beyond those of disaster exposure. The results support disaster preparedness efforts targeting those with mental and physical health conditions, and postdisaster mental health services addressing preexisting vulnerabilities in addition to disaster-related PTSS.

Familiality of Gender Nonconformity Among Homosexual Men

We examined whether recalled childhood gender nonconformity and self-reported adult gender nonconformity is familial, using data from 1154 families selected for having at least two homosexual brothers. Specifically, we examined the extent to which homosexual men's variation in gender nonconformity runs in families by examining pairs of genetic brothers who were both homosexual (N = 672-697 full sibling concordant pairs). We also examined similarity between homosexual and heterosexual brothers (N = 79-82 full sibling discordant pairs). Consistent with past studies, concordant pairs yielded modest positive correlations consistent with moderate genetic and/or familial environmental effects on gender nonconformity. Unlike results of smaller past studies, discordant pairs also yielded modest positive, though nonsignificant, correlations. Our results support the feasibility of supplementing genetic studies of male sexual orientation with analyses of gender nonconformity variation.

Excess crossovers impede faithful meiotic chromosome segregation in C. elegans

During meiosis, diploid organisms reduce their chromosome number by half to generate haploid gametes. This process depends on the repair of double strand DNA breaks as crossover recombination events between homologous chromosomes, which hold homologs together to ensure their proper segregation to opposite spindle poles during the first meiotic division. Although most organisms are limited in the number of crossovers between homologs by a phenomenon called crossover interference, the consequences of excess interfering crossovers on meiotic chromosome segregation are not well known. Here we show that extra interfering crossovers lead to a range of meiotic defects and we uncover mechanisms that counteract these errors. Using chromosomes that exhibit a high frequency of supernumerary crossovers in Caenorhabditis elegans, we find that essential chromosomal structures are mispatterned in the presence of multiple crossovers, subjecting chromosomes to improper spindle forces and leading to defects in metaphase alignment. Additionally, the chromosomes with extra interfering crossovers often exhibited segregation defects in anaphase I, with a high incidence of chromatin bridges that sometimes created a tether between the chromosome and the first polar body. However, these anaphase I bridges were often able to resolve in a LEM-3 nuclease dependent manner, and chromosome tethers that persisted were frequently resolved during Meiosis II by a second mechanism that preferentially segregates the tethered sister chromatid into the polar body. Altogether these findings demonstrate that excess interfering crossovers can severely impact chromosome patterning and segregation, highlighting the importance of limiting the number of recombination events between homologous chromosomes for the proper execution of meiosis.

Ecological factors associated with suicide mortality among non-Hispanic whites

BACKGROUND

In this paper, we examine the ecological factors associated with death rates from suicide in the United States in 1999 and 2017, a period when suicide mortality increased in the United States. We focus on Non-Hispanic Whites, who experienced the largest increase in suicide mortality. We ask whether variation in suicide mortality among commuting zones can be explained by measures of the social and economic environment and access to lethal means used to kill oneself in one's area of residence.

METHODS

We use vital statistics data on deaths and Census Bureau population estimates and define area of residence as one of 704 commuting zones. We estimate separate models for men and women at ages 20-64 and 65 and above. We measure economic environment by percent of the workforce in manufacturing and the unemployment rate and social environment by marital status, educational attainment, and religious participation. We use gun sellers and opioid prescriptions as measures of access to lethal means.

RESULTS

We find that the strongest contextual predictors of higher suicide mortality are lower rates of manufacturing employment and higher rates of opiate prescriptions for all age/sex groups, increased gun accessibility for men, and religious participation for older people.

CONCLUSIONS

Socioeconomic characteristic and access to lethal means explain much of the variation in suicide mortality rates across commuting zones, but do not account for the pervasive national-level increase in suicide mortality between 1999 and 2017.

Cortisol profiles and clinical severity in MECP2 duplication syndrome

BACKGROUND

MECP2 duplication syndrome (MDS) is a rare X-linked genomic disorder primarily affecting males which is caused by interstitial chromosomal duplications at Xq28 encompassing the MECP2 gene. Core clinical features of MDS include choreiform movements, progressive spasticity, recurrent respiratory infections, developmental delays in the first 6 months of life, hypotonia, vasomotor disturbances, constipation, drooling, and bruxism. Prior studies suggest that HPA axis activity may be altered in MDS and measures of HPA axis activity may offer insight into disease severity.

METHODS

To ascertain whether cortisol profiles are a potential biomarker of clinical severity, diurnal profiles of cortisol and the cortisol awakening response were examined from saliva samples in 31 participants with MDS (ages 2-24 years), and 27 of these samples were usable. Documentation of a positive diagnostic test for MECP2 duplication was required for entry into the study. Samples were collected on each of two consecutive weekdays at four time points during the day: immediately after waking, 30 min after waking, between 3 and 4 PM, and in the evening before bedtime. Correlations with duplication size, clinical severity, sleep problems, and behavior were also examined.

RESULTS

Results revealed that a majority of participants with MDS exhibit a declining cortisol awakening response (n = 17). A declining CAR was significantly associated with increased clinical severity scores (r = - .508; p = .03), larger duplication size, waking later, and an increased number of hospitalizations for infections.

CONCLUSIONS

Future mechanistic studies will have to determine whether the declining CAR in MDS is attributable to problems with "flip-flop switching" of regional brain activation (involving the suprachiasmatic nucleus and the hippocampus, and the HPA axis) that is responsible for the switch from reduced to increased adrenal sensitivity. Taken together, results suggest the possibility that cortisol profiles could potentially be a biomarker of clinical severity and utilized for the purposes of patient stratification for future clinical trials in MDS.

The long-term effects of a family based economic empowerment intervention (Suubi+Adherence) on suppression of HIV viral loads among adolescents living with HIV in southern Uganda: Findings from 5-year cluster randomized trial

BACKGROUND

The rapid scale-up of HIV therapy across Africa has failed to adequately engage adolescents living with HIV (ALWHIV). Retention and viral suppression for this group (ALWHIV) is 50% lower than for adults. Indeed, on the African continent, HIV remains the single leading cause of mortality among adolescents. Strategies tailored to the unqiue developmental and social vulnerabilities of this group are urgently needed to enhance successful treatment.

METHODS

We carried out a five-year longitudinal cluster randomized trial (ClinicalTrials.gov ID: NCT01790373) with adolescents living with HIV (ALWHIV) ages 10 to 16 years clustered at health care clinics to test the effect of a family economic empowerment (EE) intervention on viral suppression in five districuts in Uganda. In total, 39 accredited health care clinics from study districts with existing procedures tailored to adolescent adherence were eligible to participate in the trial. We used data from 288 youth with detectable HIV viral loads (VL) at baseline (158 -intervention group from 20 clinics, 130 -non-intervention group from 19 clinics). The primary end point was undetectable plasma HIV RNA levels, defined as < 40 copies/ml. We used Kaplan-Meier (KM) analysis and Cox proportional hazard models to estimate intervention effects.

FINDINGS

The Kaplan-Meier (KM) analysis indicated that an incidence of undetectable VL (0.254) was significantly higher in the intervention condition compared to 0.173 (in non-intervention arm) translated into incidence rate ratio of 1.468 (CI: 1.064-2.038), p = 0.008. Cox regression results showed that along with the family-based EE intervention (adj. HR = 1.446, CI: 1.073-1.949, p = 0.015), higher number of medications per day had significant positive effects on the viral suppression (adj.HR = 1.852, CI: 1.275-2.690, p = 0.001).

INTERPRETATION

A family economic empowerment intervention improved treatment success for ALWHIV in Uganda. Analyses of cost effectiveness and scalability are needed to advance incorporation of this intervention into routine practice in low and middle-income countries.

Network analyses to quantify effects of host movement in multilevel disease transmission models using foot and mouth disease in Cameroon as a case study

The dynamics of infectious diseases are greatly influenced by the movement of both susceptible and infected hosts. To accurately represent disease dynamics among a mobile host population, detailed movement models have been coupled with disease transmission models. However, a number of different host movement models have been proposed, each with their own set of assumptions and results that differ from the other models. Here, we compare two movement models coupled to the same disease transmission model using network analyses. This application of network analysis allows us to evaluate the fit and accuracy of the movement model in a multilevel modeling framework with more detail than established statistical modeling fitting methods. We used data that detailed mobile pastoralists’ movements as input for 100 stochastic simulations of a Spatio-Temporal Movement (STM) model and 100 stochastic simulations of an Individual Movement Model (IMM). Both models represent dynamic movement and subsequent contacts. We generated networks in which nodes represent camps and edges represent the distance between camps. We simulated pathogen transmission over these networks and tested five network metrics–strength, betweenness centrality, three-step reach, density, and transitivity–to determine which could predict disease simulation outcomes and thereby be used to correlate model simulation results with disease transmission simulations. We found that strength, network density, and three-step reach of movement model results correlated with the final epidemic size of outbreak simulations. Betweenness centrality only weakly correlated for the IMM model. Transitivity only weakly correlated for the STM model and time-varying IMM model metrics. We conclude that movement models coupled with disease transmission models can affect disease transmission results and should be carefully considered and vetted when modeling pathogen spread in mobile host populations. Strength, network density, and three-step reach can be used to evaluate movement models before disease simulations to predict final outbreak sizes. These findings can contribute to the analysis of multilevel models across systems.

Epidemics of infectious disease vary geographically and vary through time. A large part of this variation is caused by movement of individuals who are susceptible to the disease or infected with the disease. To study how movement affects epidemics, researchers often combine movement models with transmission models. However, multiple movement models have been proposed, and their effect on infectious disease model output is not well understood. Here, we combine two different movement models that we developed to represent mobile pastoralists in the Far North Region, Cameroon, with the same disease transmission model. We use network metrics to test how different movement models can affect the output of the disease transmission model. We found that three metrics could be applied to movement model output in order to predict epidemic model output. We conclude that movement models coupled with disease transmission models can affect disease transmission results and should be carefully considered and vetted when modeling epidemics.

Protecting children's health in a calorie-surplus context: Household structure and child growth in the United States

Studies from the social and health sciences have tended to view the household as the locus of access to and distribution of care, resources, monitoring and modeling for children's wellbeing. Obesity may present a special case for the study of investments in children, being a component of health for which more of certain inputs may not lead to better outcomes. We expanded on common measures of household structure in the child health literature by considering co-residence and relatedness of parents, grandparents, other relatives, and other children. Data were from a longitudinal sample of 6,700 children participating in the Early Childhood Longitudinal Study Kindergarten Class of 1998-99 (ECLS-K), the largest U.S. national dataset with measures of child anthropometrics and household structure at seven time-points over nine years. We used lagged survey-adjusted regressions to estimate associations between household structure and subsequent changes in children's weight between ages 5 and 14 years in terms of BMI gain and incident obesity. Adjusting for household structure more thoroughly, children living in households with two parents rather than one parent did not experience advantages in terms of less excess weight gain or lower incidence of obesity during elementary and middle school. Children living with a grandmother gained more weight than children not living with a grandmother. Living with siblings and with non-related adults was associated with less weight gain. These findings corroborate a scenario in which, for health problems associated with caloric surplus, classic household factors have more complex associations with child wellbeing.

Factors affecting the psychosocial well-being of orphan and separated children in five low- and middle-income countries: Which is more important, quality of care or care setting?

As millions of children continue to live without parental care in under-resourced societies in low- and middle-income countries (LMICs), it is important for policymakers and practitioners to understand the specific characteristics within different care settings and the extent to which they are associated with outcomes of orphan and separated children (OSC). This study was designed to (1) examine if the psychosocial well-being of OSC in under-resourced societies in LMICs is more dependent on the availability of certain components of quality of care rather than the care setting itself (i.e. the residential care-based or community family-based setting), and (2) identify the relative significance of certain components of quality of care that are associated with a child's psychosocial well-being across different OSC care settings. This study drew from 36-month follow-up data from the Positive Outcomes for Orphans (POFO) Study and used a sample population of 2,013 (923 institution- and 1,090 community-based) OSC among six diverse study sites across five LMICs: Cambodia, India (Hyderabad and Nagaland), Kenya, Tanzania, and Ethiopia. Analyses showed that all four components of quality of care significantly predicted child psychosocial well-being. Child psychosocial well-being across "high" and "low" levels of quality of care showed negligible differences between residential- and community-based care settings, suggesting the important factor in child well-being is quality of care rather than setting of care. Practical and policy implications and future research are discussed.

Prenatal exposure to phthalates and autism spectrum disorder in the MARBLES study

BACKGROUND

Evidence from experimental and observational studies suggests that prenatal phthalate exposures may be associated with autism spectrum disorder (ASD). We examined whether prenatal phthalate exposures were associated with an increased risk of ASD.

METHODS

We quantified 14 metabolites of eight phthalates in 636 multiple maternal urine samples collected during 2nd and 3rd trimesters of pregnancy from 201 mother-child pairs in MARBLES (Markers of Autism Risk in Babies - Learning Early Signs), a high-risk ASD longitudinal cohort. At 3 years old, children were clinically assessed for ASD and classified into three diagnostic categories: ASD (n = 46), non-typical development (Non-TD, n = 55), and typical development (TD, n = 100). We used multinomial logistic regression to evaluate the association of phthalate metabolite concentrations with ASD and Non-TD.

RESULTS

Most associations of phthalate biomarkers with both ASD and Non-TD were null, with the exception that monoethyl phthalate (MEP) was significantly associated with an increased risk of Non-TD (per 2.72-fold relative increase in concentration: Relative risk ratio (RRR) = 1.38; 95% confidence interval (CI): 1.01, 1.90). When stratified by prenatal vitamin use during the first month of pregnancy, among mothers who took vitamins, ASD risk was inversely associated with mono-isobutyl phthalate (MiBP, RRR = 0.44; 95% CI: 0.21, 0.88), mono(3-carboxypropyl) phthalate (MCPP, RRR = 0.41; 95% CI: 0.20, 0.83) and mono-carboxyisooctyl phthalate (MCOP, RRR = 0.49; 95% CI: 0.27, 0.88), but among mothers who did not take prenatal vitamins, Non-TD risk was positively associated with MCPP (RRR = 5.09; 95% CI: 2.05, 12.6), MCOP (RRR = 1.86; 95% CI: 1.01, 3.39), and mono-carboxyisononyl phthalate (MCNP, RRR = 3.67; 95% CI: 1.80, 7.48). When stratified by sex, among boys, MEP, monobenzyl phthalate, MCPP, MCNP, and sum of di(2-ethylhexyl) phthalate metabolites (ΣDEHP) were positively associated with Non-TD risk, but associations with ASD were null. Among girls, associations with both ASD and Non-TD were null.

CONCLUSIONS

Our study showed that phthalate exposures in mid- to late pregnancy were not associated with ASD in children from this high-risk ASD cohort. Further studies should be conducted in the general population without high-risk genes to confirm our findings.

Apolipoprotein E, cognitive function, and cognitive decline among older Taiwanese adults

Apolipoprotein E (APOE) genotype is believed to play a role in the onset of dementia, though less is known about its relationship with non-pathogenic age-related cognitive decline. We assessed whether APOE was a risk factor for cognitive decline among older Taiwanese adults using nationally representative data. General cognition was measured longitudinally over eleven years; domain-specific cognitive assessments of working memory, declarative learning and three aspects of attention (executive function, alerting, and orientation) were performed once. Having at least one risky APOE allele was associated with more rapid longitudinal cognitive decline compared to those with no risky alleles. Some evidence from the cross-sectional analysis of domain-specific cognitive assessments suggested that APOE genotype may be more closely associated with working memory and declarative learning than with attention. Most genetic studies of cognition include only populations of European descent; extension is crucial. This study confirmed the association between APOE genotype and the rate of cognitive decline in a predominantly Han Chinese population. Additional studies on diverse populations are warranted.

Agreement between medical records and self-reports: Implications for transgender health research

A key priority of transgender health research is the evaluation of long-term effects of gender affirmation treatment. Thus, accurate assessment of treatment receipt is critical. The data for this analysis came from an electronic medical records (EMR) based cohort of transgender individuals. A subset of cohort members were also asked to complete a self-administered survey. Information from the EMR was compared with survey responses to assess the extent of agreement regarding transmasculine (TM)/transfeminine (TF) status, hormone therapy receipt, and type of surgery performed. Logistic regression models were used to assess whether participant characteristics were associated with disagreement between data sources. Agreement between EMR and survey-derived information was high regarding TM/TF status (99%) and hormone therapy receipt (97%). Lower agreement was observed for chest reconstruction surgery (72%) and genital reconstruction surgery (84%). Using survey responses as the "gold standard", both chest and genital reconstruction surgeries had high specificity (95 and 93%, respectively), but the corresponding sensitivities were low (49 and 68%, respectively). A lower proportion of TM had concordant results for chest reconstruction surgery (64% versus 79% for TF) while genital reconstruction surgery concordance was lower among TF (79% versus 89% for TM). For both surgery types, agreement was highest among the youngest participants. Our findings offer assurance that EMR-based data appropriately classify cohort participants with respect to their TM/TF status or hormone therapy receipt. However, current EMR data may not capture the complete history of gender affirmation surgeries. This information is useful in future studies of outcomes related to gender affirming therapy.

Fairness informs social decision making in infancy

The ability to reason about fairness plays a defining role in the development of morality. Thus, researchers have long been interested in understanding when and how a sensitivity to fairness first develops. Here, we examined infants’ ability to use fairness information in selecting social partners. Using a novel experimental paradigm that combined pre-recorded stimuli with an active behavioral measure, we tested whether infants preferred to socially engage with an individual they had previously seen behave fairly or unfairly. After viewing an individual distribute goods to third parties either equally (i.e., 3:3 distribution) or unequally (i.e., 5:1 distribution), both 13- and 17-month-old infants selectively chose to engage in a social interaction with (i.e., take a toy from) an individual who distributed resources equally. The use of a novel paradigm to assess infants’ fairness preferences demonstrates that infants’ previously established fairness preferences extend across different, more demanding paradigms, and may therefore be more enduring in nature. Together, these findings provide new insights into the nature of infants’ fairness representations, and fill in key gaps in the developmental timeline of infants’ ability to use fairness information in their consideration of potential social partners. In sum, these findings build on previous research by demonstrating that infants not only hold an expectation that resources should be distributed fairly, they also preferentially interact with those who have previously done so. The early-emerging ability to both reason about and use fairness information may play an influential role in the development of complex prosocial behaviors related to morality more broadly.

Combined evaluation of sexually transmitted infections in HIV-infected pregnant women and infant HIV transmission

Background

Sexually transmitted infections (STIs) including Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Treponema pallidum (TP), and cytomegalovirus (CMV) may lead to adverse pregnancy and infant outcomes. The role of combined maternal STIs in HIV mother-to-child transmission (MTCT) was evaluated in mother-infant pairs from NICHD HPTN 040.

Methodology

Urine samples from HIV-infected pregnant women during labor were tested by polymerase chain reaction (PCR) for CT, NG, and CMV. Infant HIV infection was determined by serial HIV DNA PCR testing. Maternal syphilis was tested by VDRL and confirmatory treponemal antibodies.

Results

A total of 899 mother-infant pairs were evaluated. Over 30% had at least one of the following infections (TP, CT, NG, and/or CMV) detected at the time of delivery. High rates of TP (8.7%), CT (17.8%), NG (4%), and CMV (6.3%) were observed. HIV MTCT was 9.1% (n = 82 infants). HIV MTCT was 12.5%, 10.3%, 11.1%, and 26.3% among infants born to women with CT, TP, NG or CMV respectively. Forty-two percent of HIV-infected infants were born to women with at least one of these 4 infections. Women with these infections were nearly twice as likely to have an HIV-infected infant (aOR 1.9, 95% CI 1.1–3.0), particularly those with 2 STIs (aOR 3.4, 95% CI 1.5–7.7). Individually, maternal CMV (aOR 4.4 1.5–13.0) and infant congenital CMV (OR 4.1, 95% CI 2.2–7.8) but not other STIs (TP, CT, or NG) were associated with an increased risk of HIV MTCT.

Conclusion

HIV-infected pregnant women identified during labor are at high risk for STIs. Co-infection with STIs including CMV nearly doubles HIV MTCT risk. CMV infection appears to confer the largest risk of HIV MTCT.

Trial registration

NCT00099359.

Fast food consumption and its associations with obesity and hypertension among children: results from the baseline data of the Childhood Obesity Study in China Mega-cities

BACKGROUND

China has seen rapid increase in obesity and hypertension prevalence and fast food consumption over the past decade. We examined status and risk factors for Western- and Chinese fast food consumption and their associations with health outcomes in Chinese children, and examined how maternal factors were associated with child health outcomes.

METHODS

Data of 1626 students aged 7-16 (11.6 ± 2.0) years and their parents in four mega-cities across China (Beijing, Shanghai, Nanjing, and Xi'an) were collected in the 2015 baseline survey of the Childhood Obesity Study in China Mega-cities. Weight, height, waist circumference, and blood pressure were measured. Food intake was assessed using questionnaire. Mixed models were used to examine the associations.

RESULTS

Among the children, 11.1% were obese, 19.7% were centrally obese, and 9.0% had hypertension. Obesity prevalence was much higher in boys than in girls (15.2% vs. 6.9% and 27.4% vs. 11.7%, respectively, both P < 0.001). About half (51.9% and 43.6%) of children consumed Western and Chinese fast food, respectively, over the past 3 months. Compared to those with college or above maternal education level, those with elementary school or below maternal education level were 49% more likely to consume Western fast food (odds ratio [OR] and 95% confidence interval [CI]: 1.49 [1.10-2.03]). Chinese fast food consumption rate increased by 12% with each year of increase in child's age (OR and 95% CI: 1.12 [1.02-1.23]). No significant associations between fast food consumption and health outcomes were detected. Adjusting for Western fast food consumption, children with lower maternal education were 71% and 43% more likely to have obesity and central obesity (ORs and 95% CIs: 1.71 [1.12-2.61] and 1.43 [1.00-2.03], respectively), and maternal body mass index was positively associated with child obesity, central obesity, and hypertension (ORs and 95% CIs: 1.11 [1.06-1.17], 1.12 [1.07-1.17], and 1.09 [1.03-1.15], respectively). Results were similar when Chinese fast food consumption was adjusted for.

CONCLUSIONS

The prevalence of fast food consumption, obesity and hypertension is high among children in major cities in China. Maternal factors affect child outcomes.

Decoding the infant mind: Multivariate pattern analysis (MVPA) using fNIRS

The MRI environment restricts the types of populations and tasks that can be studied by cognitive neuroscientists (e.g., young infants, face-to-face communication). FNIRS is a neuroimaging modality that records the same physiological signal as fMRI but without the constraints of MRI, and with better spatial localization than EEG. However, research in the fNIRS community largely lacks the analytic sophistication of analogous fMRI work, restricting the application of this imaging technology. The current paper presents a method of multivariate pattern analysis for fNIRS that allows the authors to decode the infant mind (a key fNIRS population). Specifically, multivariate pattern analysis (MVPA) employs a correlation-based decoding method where a group model is constructed for all infants except one; both average patterns (i.e., infant-level) and single trial patterns (i.e., trial-level) of activation are decoded. Between subjects decoding is a particularly difficult task, because each infant has their own somewhat idiosyncratic patterns of neural activation. The fact that our method succeeds at across-subject decoding demonstrates the presence of group-level multi-channel regularities across infants. The code for implementing these analyses has been made readily available online to facilitate the quick adoption of this method to advance the methodological tools available to the fNIRS researcher.