Results of plasma radiative compression investigation in the PF-24 device operated with D2, Ar and (100%-x)D2+x%Ar mixtures obtained using the 5-phase Lee model code.

The article presents new results for plasma radiative compression in high-current discharges in the z-pinch configuration. The results are based on the 113 discharges performed in the plasma-focus PF-24 device operated with D2, Ar and (100%-x)D2+xAr mixtures, with Ar pressure fractions x ≈ 3-60% (mole fractions). The constant initial total pressure is about 2.9 mbar and the constant initial pressure of Ar is 1.2 mbar. Each experimental discharge was simulated individually using the 5-phase Lee model code to carry out the fitting procedure of the total discharge current waveform. The results from these 113 computed discharges fitted to the corresponding 113 experimental discharges show that the increase of the effective atomic number of the gas mixture increases the probability of occurrence of plasma radiative compression phenomenon. Relatively weak radiative compression was found for part of the discharges in 15-60% range of Ar mole fractions and in Ar, while the stronger radiative compression occurred for part of discharges in Ar only. This is because there was too little total x-ray line radiation emission during the equilibrium pinch lifetime related to the very small amount of swept up mass and the low current flow through pinched plasma, represented by the decreasing values of model parameters as the Ar mole fraction increases. The results show that the main pinch parameters influencing the occurrence and strength of radiative compression are: total x-ray line emission yield, effective atomic number, initial pinch radius, initial pinch ion number density and initial pinch ion/electron temperature.

Clinical evaluation of serological IgG antibody response on the Abbott Architect for established SARS-CoV-2 infection.

OBJECTIVE: This study aimed to evaluate the diagnostic performance of the Abbott Architect SARS-CoV-2 IgG assay in COVID-19 patients. METHODS: Residual sera from 177 symptomatic SARS-CoV-2-positive patients and 163 non-COVID-19 patients were tested for antibody with the Abbott SARS-CoV-2 IgG assay (Abbott Diagnostics, Chicago, USA). Clinical records for COVID-19 patients were reviewed to determine the time from onset of clinical illness to testing. RESULTS: Specificity of the assay was 100.0% (95%CI: 97.1-100.0%). The clinical sensitivity of the assay varied depending on time from onset of symptoms, increasing with longer periods from the onset of clinical illness. The clinical sensitivity at ≤6 days was 8.6% (7/81; 95%CI: 3.8-17.5%), at 7-13 days 43.6% (17/39; 95%CI: 28.2-60.2%), at 14-20 days 84.0% (21/25; 95%CI: 63.1-94.7%), and at ≥21 days 84.4% (27/32; 95%CI: 66.5-94.1%). Clinical sensitivity was higher in the ≥14-day group compared to <14 days. There were no differences between the 14-20-day and ≥21-days groups; the combined clinical sensitivity for these groups (≥14 days) was 84.2% (49/57; 71.6-92.1%). CONCLUSION: The Abbott SARS-CoV-2 IgG test has high specificity. Clinical sensitivity was limited in the early stages of disease but improved from 14 days after the onset of clinical symptoms.

Caries Risk Prediction Models in a Medical Health Care Setting.

Despite development of new technologies for caries control, tooth decay in primary teeth remains a major global health problem. Caries risk assessment (CRA) models for toddlers and preschoolers are rare. Among them, almost all models use dental factors (e.g., past caries experience) to predict future caries risk, with limited clinical/community applicability owing to relatively uncommon dental visits compared to frequent medical visits during the first year of life. The objective of this study was to construct and evaluate risk prediction models using information easily accessible to medical practitioners to forecast caries at 2 and 3 y of age. Data were obtained from the Growing Up in Singapore Towards Healthy Outcomes (GUSTO) mother-offspring cohort. Caries was diagnosed using modified International Caries Detection and Assessment System criteria. Risk prediction models were constructed using multivariable logistic regression coupled with receiver operating characteristic analyses. Imputation was performed using multiple imputation by chained equations to assess effect of missing data. Caries rates at ages 2 y (n = 535) and 3 y (n = 721) were 17.8% and 42.9%, respectively. Risk prediction models predicting overall caries risk at 2 and 3 y demonstrated area under the curve (AUC) (95% confidence interval) of 0.81 (0.75-0.87) and 0.79 (0.74-0.84), respectively, while those predicting moderate to extensive lesions showed 0.91 (0.85-0.97) and 0.79 (0.73-0.85), respectively. Postimputation results showed reduced AUC of 0.75 (0.74-0.81) and 0.71 (0.67-0.75) at years 2 and 3, respectively, for overall caries risk, while AUC was 0.84 (0.76-0.92) and 0.75 (0.70-0.80), respectively, for moderate to extensive caries. Addition of anterior caries significantly increased AUC in all year 3 models with or without imputation (all P < 0.05). Significant predictors/protectors were identified, including ethnicity, prenatal tobacco smoke exposure, history of allergies before 12 mo, history of chronic maternal illness, maternal brushing frequency, childbearing age, and so on. Integrating oral-general health care using medical CRA models may be promising in screening caries-susceptible infants/toddlers, especially when medical professionals are trained to "lift the lip" to identify anterior caries lesions.

High prevalence and incidence of tuberculosis in people living with the HIV in Mandalay, Myanmar, 2011-2017.

SETTING: Two human immunodeficiency virus (HIV) clinics providing antiretroviral therapy (ART), Mandalay, Myanmar. OBJECTIVE: To assess prevalent TB at enrolment, incident TB during follow-up and associated risk factors in adult people living with HIV (PLHIV) between 2011 and 2017. DESIGN: Cohort study using secondary data. RESULTS: Of 11 777 PLHIV, 2911 (25%) had prevalent TB at or within 6 weeks of enrolment. Independent risk factors for prevalent TB were being male or single/widowed, daily alcohol consumption, CD4 count 200 cells/µl and anaemia. During 6 years follow-up in 8866 PLHIV with no prevalent TB, the rate of new TB was 2.9 per 100 person-years (95%CI 2.6-3.1). Cumulative TB incidence was 9.6%, with 370 (72%) of 517 new TB cases occurring in the first year. Independent risk factors for incident TB were being male and anaemia. Incident TB was highest in the first year of ART, in PLHIV with CD4 counts 200 cells/µl and those not receiving isoniazid preventive therapy (IPT). Incident TB declined with time on ART and rising CD4 counts. CONCLUSION: Prevalent and incident TB were high in PLHIV in the Mandalay clinics. Consideration should be given to earlier TB diagnosis using more sensitive diagnostic tools, effective ART and scaling up IPT.

Childhood TB in Myanmar: trends in notification, profile and treatment outcomes in the private sector.

SETTING: Myanmar National Tuberculosis (TB) programme (NTP). OBJECTIVE: To describe 1) the trends in childhood TB (aged ⩾ 14 years) notification from 2014 to 2017 and quantify the private sector contribution to this notification; and 2) the profile and treatment outcomes of childhood TB managed in the private sector in 2016. STUDY DESIGN: This was an observational study involving the review of routine records and reports of the NTP public-private mix (PPM) projects managed by the Myanmar Medical Association and Population Service International. RESULTS: The total number of childhood TB notified has declined from 36 314 in 2014 to 28 723 in 2017 (average annual decline = 2607 cases per year). The private sector contribution to the notification remained between 17% and 19%. Of the 5616 childhood TB cases diagnosed and treated under the two PPM projects in 2016, 99% were clinically diagnosed and 5459 (97.7%) had successful treatment outcomes. Children aged ⩾10 years, males, those with bacteriologically confirmed TB, those treated in the regions or states of Mandalay, Chin and Shan had a higher risk of an unfavourable outcome (lost to follow-up, death, move to second-line treatment and not evaluated). CONCLUSION: Childhood TB notification is showing a declining trend. One of five notified childhood TB cases was diagnosed and treated in the private sector, where the successful treatment rate was high.

Rifampicin-resistant tuberculosis patients in Myanmar in 2016: how many are lost on the path to treatment?

SETTING: Regional tuberculosis (TB) centres of the Yangon and Mandalay Regions of Myanmar, which account for 65% of all notified rifampicin-resistant tuberculosis (RR-TB) cases countrywide. OBJECTIVE: To determine 1) initial loss to follow-up (LTFU), 2) treatment delay, and 3) factors associated with initial LTFU and treatment delay among RR-TB patients residing in the Yangon and Mandalay regions diagnosed using Xpert® during January-August 2016. DESIGN: This was a retrospective cohort study. Each diagnosed patient was tracked in the drug-resistant TB treatment registers of the Yangon and Mandalay regional treatment centres for January-December 2016 using patient name, age, sex, township and date of diagnosis. If the diagnosed patient was not found in the treatment register by 31 December 2016, he/she was considered 'initial LTFU'. RESULTS: Of the 1037 RR-TB patients diagnosed, 310 (30%) experienced initial LTFU, which was significantly higher among patients aged 55 years and among those diagnosed in the Mandalay Region. A treatment delay of >1 month was observed in 440 (70%) patients (median delay 41 days). Delay was uniformly high across patient subgroups, and was not associated with any factor. CONCLUSION: Initial LTFU and treatment delays among RR-TB patients were high. Future studies using qualitative research methods are needed to ascertain the reasons for this observation.

Child, Maternal and Demographic Factors Influencing Caregiver-Reported Autistic Trait Symptomatology in Toddlers.

Current research on children's autistic traits in the general population relies predominantly on caregiver-report, yet the extent to which individual, caregiver or demographic characteristics are associated with informants' ratings has not been sufficiently explored. In this study, caregivers of 396 Singaporean two-year-olds from a birth cohort study completed the Quantitative Checklist for Autism in Toddlers. Children's gender, cognitive functioning and birth order, maternal age, and ethnic group membership were not significant predictors of caregiver-reported autistic traits. Poorer child language development and higher maternal depressive symptoms significantly predicted more social-communicative autistic traits, while lower maternal education predicted more behavioural autistic traits. Children's language and informants' educational level and depressive symptomatology may need to be considered in caregiver-reports of autistic traits.

How many sputum samples should be examined during follow-up of tuberculosis patients in Myanmar: two or one?

Setting: Ten selected microscopy centres in Sagaing Region, Myanmar, functioning under an external quality assurance system with no reported major errors. Objective: To assess the pattern of serial sputum results (NN, both smear-negative; NP, first smear-negative and second smear-positive; PN, first smear-positive and second smear-negative; and PP, both smear-positive) among follow-up sputum microscopy examinations of tuberculosis (TB) patients (end of intensive phase, mid-continuation phase and end of treatment) conducted from 1 November 2017 to 15 April 2018. Design: Cross-sectional study using secondary data (laboratory registers). Results: Of 2001 examinations, 94 (4.7%) were smear-positive: 66 PP (3.3%), 12 PN (0.6%) and 16 NP (0.8%); 75% of NP results were scanty. The proportion of NP results was 0.8% (95%CI 0.5-1.3), i.e., 125 smears (95%CI 77-200) were required to detect one additional smear-positive result in the second sample. Of the 16 NP results (15 patients), 14 were tested using Xpert® MTB/RIF and none had rifampicin resistance. During the continuation phase of treatment, 13 became smear-negative, one remained smear-positive and one had unknown follow-up smear status. Conclusion: The benefit of the second sputum sample for monitoring anti-tuberculosis treatment was negligible. Given the favourable resource implications (reduced laboratory workload and costs), we recommend changing the policy from two sputum smears to one during follow-up sputum examinations of TB patients.

Contexte : Dix centres de microscopie sélectionnés de la région de Sagaing, Myanmar, fonctionnant avec un système d'assurance de qualité externe sans erreurs majeures rapportées.Objectif : Evaluer les profils de séries de résultats de crachats (NN, deux frottis négatifs ; NP, premier frottis négatif et deuxième frottis positif ; PN, premier frottis positif et deuxième frottis négatif ; et PP, deux frottis positifs) parmi les examens de suivi de microscopie de crachats de patients TB (à la fin de la phase intensive, au milieu de la phase de continuation et à la fin du traitement) réalisés du 1e novembre 2017 au 15 avril 2018.Schéma : Etude transversale grâce à des données secondaires (registres de laboratoire).Résultats : Sur 2001 examens, 94 (4,7%) ont eu un frottis positif : 66 (3,3%) PP ; 12 (0,6%) PN ; 16 (0,8%) NP ; 75% des NP avaient de rares bacilles. La proportion de NP a été de 0,8% (IC95% 0,5­1,3), impliquant qu'il a fallu 125 frottis (IC95% 77­200) pour détecter un frottis positif supplémentaire dans un deuxième échantillon. Sur les 16 NP (15 patients), 14 ont été testés par Xpert® MTB/RIF et aucun n'a eu de résistance à la rifampicine. Lors de la continuation du traitement, 13 sont devenus à frottis négatif, un patient est resté à frottis positif et un autre a eu un frottis de suivi « indéterminé ¼.Conclusion : Le bénéfice du deuxième échantillon de crachats pour le suivi du traitement antituberculeux a été négligeable. Devant les implications favorables en termes de ressources (charge de travail et coûts réduits pour le laboratoire), nous recommandons de modifier la politique de deux frottis de crachats à un seul lors du suivi de patients TB par examens des crachats.

Marco de Referencia: Diez centros de microscopia escogidos en la región de Sagaing de Birmania, que funcionan con un sistema externo de garantía de la calidad y no notifican errores importantes.Objetivos: Evaluar el perfil de los resultados seriados del esputo (NN, ambas baciloscopias negativas; NP, primera baciloscopia negativa y segunda positiva; PN, primera baciloscopia positiva y segunda negativa; y PP, ambas baciloscopias positivas) en las baciloscopias de esputo de seguimiento de los pacientes con tuberculosis (TB) (al final de la fase intensiva, en medio de la fase de continuación y al final del tratamiento), realizadas del 1° de noviembre del 2017 al 15 de abril del 2018.Métodom: Fue este un estudio transversal que utilizó datos secundarios (los registros de laboratorio).Resultados: De las 2001 baciloscopias realizadas, 94 (4,7%) fueron positivas, a saber: 66 (3,3%) PP; 12 (0,6%) PN; 16 (0,8%) NP; 75% de los resultados NP se notificaron como 'escasos bacilos'. La proporción de resultados NP fue 0,8% (IC95% 0,5­1,3), lo cual indica que se precisaron 125 baciloscopias a fin de detectar una baciloscopia positiva adicional en la segunda muestra (IC95% 77­200). De los 16 casos NP (15 pacientes), 14 se examinaron mediante la prueba Xpert® MTB/RIF y ninguno exhibió resistencia a rifampicina. Durante la fase de continuación del tratamiento, en 13 casos la baciloscopia se hizo negativa, uno permaneció positivo y en otro caso el resultado de la baciloscopia de seguimiento era 'desconocido'.Conclusión: La utilidad de una segunda muestra de esputo en la supervisión del tratamiento antituberculoso fue insignificante. Teniendo en cuenta sus repercusiones económicas favorables (disminución de la carga de trabajo y los costos de laboratorio), se recomienda cambiar la norma de practicar dos muestras de esputo por una sola muestra, durante las baciloscopias de seguimiento de los pacientes con TB.

Modifiable risk factors in the first 1000 days for subsequent risk of childhood overweight in an Asian cohort: significance of parental overweight status.

BACKGROUND/OBJECTIVE: Many studies have identified early-life risk factors for subsequent childhood overweight/obesity, but few have evaluated how they combine to influence risk of childhood overweight/obesity. We examined associations, individually and in combination, of potentially modifiable risk factors in the first 1000 days after conception with childhood adiposity and risk of overweight/obesity in an Asian cohort. METHODS: Six risk factors were examined: maternal pre-pregnancy overweight/obesity (body mass index (BMI) ⩾25 kg m-2), paternal overweight/obesity at 24 months post delivery, maternal excessive gestational weight gain, raised maternal fasting glucose during pregnancy (⩾5.1 mmol l-1), breastfeeding duration <4 months and early introduction of solid foods (<4 months). Associations between number of risk factors and adiposity measures (BMI, waist-to-height ratio (WHtR), sum of skinfolds (SSFs), fat mass index (FMI) and overweight/obesity) at 48 months were assessed using multivariable regression models. RESULTS: Of 858 children followed up at 48 months, 172 (19%) had none, 274 (32%) had 1, 244 (29%) had 2, 126 (15%) had 3 and 42 (5%) had ⩾4 risk factors. Adjusting for confounders, significant graded positive associations were observed between number of risk factors and adiposity outcomes at 48 months. Compared with children with no risk factors, those with four or more risk factors had s.d. unit increases of 0.78 (95% confidence interval 0.41-1.15) for BMI, 0.79 (0.41-1.16) for WHtR, 0.46 (0.06-0.83) for SSF and 0.67 (0.07-1.27) for FMI. The adjusted relative risk of overweight/obesity in children with four or more risk factors was 11.1(2.5-49.1) compared with children with no risk factors. Children exposed to maternal pre-pregnancy (11.8(9.8-13.8)%) or paternal overweight status (10.6(9.6-11.6)%) had the largest individual predicted probability of child overweight/obesity. CONCLUSIONS: Early-life risk factors added cumulatively to increase childhood adiposity and risk of overweight/obesity. Early-life and preconception intervention programmes may be more effective in preventing overweight/obesity if they concurrently address these multiple modifiable risk factors.

Management of concurrent thoracic and abdominal aortic aneurysms.

Concurrent thoracic and abdominal aortic aneurysm is uncommon. It remains a formidable surgical challenge to vascular surgeons, as decision to treat in staged or simultaneous setting still debatable. We present, here, a case of a 62-year-old-man with asymptomatic concurrent thoracic and abdominal aortic aneurysms, which was successfully treated with two-stage hybrid endovascular repair. The aim of this case report is to discuss the treatment options available, possible associated complications and measures to prevent them.

Identification of Caries Risk Determinants in Toddlers: Results of the GUSTO Birth Cohort Study.

The aim of this study was to identify risk determinants leading to early childhood caries (ECC) and visible plaque (VP) in toddlers. Data for mother-child pairs participating in the Growing Up in Singapore towards Healthy Outcomes (GUSTO) birth cohort were collected from pregnancy to toddlerhood. Oral examinations were performed in 543 children during their clinic visit at 24 months to detect ECC and VP. Following logistic regression, ECC and VP were jointly regressed as primary and secondary outcomes, respectively, using the bivariate probit model. The ECC prevalence was 17.8% at 2 years of age, with 7.3% of children having a VP score >1. ECC was associated with nighttime breastfeeding (3 weeks) and biological factors, including Indian ethnicity (lower ECC rate), higher maternal childbearing age and existing health conditions, maternal plasma folate <6 ng/mL, child BMI, and the plaque index, while VP was associated with psychobehavioral factors, including the frequency of dental visits, brushing frequency, lower parental perceived importance of baby teeth, and weaning onto solids. Interestingly, although a higher frequency of dental visits and toothbrushing were associated with lower plaque accumulation, they were associated with increased ECC risk, suggesting that these established caries-risk factors may be a consequence rather than the cause of ECC. In conclusion, Indian toddlers may be less susceptible to ECC, compared to Chinese and Malay toddlers. The study also highlights a problem-driven utilization pattern of dental services (care sought for treatment) in Singapore, in contrast to the prevention-driven approach (care sought to prevent disease) in Western countries.

Postnatal height and adiposity gain, childhood blood pressure and prehypertension risk in an Asian birth cohort.

OBJECTIVE: There have been hypotheses that early life adiposity gain may influence blood pressure (BP) later in life. We examined associations between timing of height, body mass index (BMI) and adiposity gains in early life with BP at 48 months in an Asian pregnancy-birth cohort. METHODS: In 719 children, velocities for height, BMI and abdominal circumference (AC) were calculated at five intervals [0-3, 3-12, 12-24, 24-36 and 36-48 months]. Triceps (TS) and subscapular skinfold (SS) velocities were calculated between 0-18, 18-36 and 36-48 months. Systolic (SBP) and diastolic blood pressure (DBP) was measured at 48 months. Growth velocities at later periods were adjusted for growth velocities in preceding intervals, as well as measurements at birth. RESULTS: After adjusting for confounders and child height at BP measurement, each unit z-score gain in BMI, AC, TS and SS velocities at 36-48 months were associated with 2.3 (95% CI:1.6, 3.1), 2.1 (1.3, 2.8), 1.4 (0.6, 2.2) and 1.8 (1, 2.6) mmHg higher SBP respectively, and 0.9 (0.4, 1.4), 0.9 (0.4, 1.3), 0.6 (0.1, 1.1) and 0.8 (0.3, 1.3) mmHg higher DBP respectively. BMI and adiposity velocities (AC, TS or SS) at various intervals in the first 36 months however, were not associated with BP. Faster BMI, AC, TS and SS velocities, but not height, at 36-48 months were associated with 0.22 (0.15, 0.29), 0.17 (0.10, 0.24), 0.11 (0.04, 0.19) and 0.15 (0.08, 0.23) units higher SBP z-score respectively, and OR=1.46 (95% CI: 1.13-1.90), 1.49 (1.17-1.92), 1.45 (1.09-1.92) and 1.43 (1.09, 1.88) times higher risk of prehypertension/hypertension respectively at 48 months. CONCLUSIONS: Our results indicated that faster BMI and adiposity (AC, TS or SS) velocities only at the preceding interval before 48 months (36-48 months), but not at earlier intervals in the first 36 months, are predictive of BP and prehypertension/hypertension at 48 months.

The contribution of recently identified adult BMI risk loci to paediatric obesity in a Singaporean Chinese childhood dataset.

INTRODUCTION: Recent genome-wide association studies have identified 103 adult obesity risk loci; however, it is unclear if these findings are relevant to East-Asian childhood body mass index (BMI) levels. METHODS AND RESULTS: We evaluated for paediatric obesity associations at these risk loci utilizing genome-wide data from Chinese childhood subjects in the Singapore Cohort study Of the Risk factors for Myopia study (N = 1006). A weighted gene-risk score of all adult obesity risk loci in the Singapore Cohort study Of the Risk factors for Myopia study showed strong associations with BMI at age 9 (p-value = 3.40 × 10-12 ) and 4-year average BMI (age 9 to 12, p-value = 6.67 × 10-8 ). Directionally consistent nominal associations for 15 index single nucleotide polymorphisms (SNPs) (p-value < 0.05) were observed. Pathway analysis with genes from these 15 replicating loci revealed over-representation for the G-protein-coupled receptor (GPCR)-mediated integration of entero-endocrine signalling pathway exemplified by L-cell (adjusted p-value = 0.018). Evaluations of birth weight to modify the effects of BMI risk SNPs in paediatric obesity did not reveal significant interactions, and these SNPs were generally not associated with birth weight. CONCLUSIONS: At least some common adult BMI risk variants predispose to paediatric obesity risk in East-Asians.

Tobacco smoke exposure and respiratory morbidity in young children.

OBJECTIVE: Secondhand smoke exposure is a potentially preventable cause of significant respiratory morbidity in young children. Our study aimed to quantify respiratory morbidity in young children exposed to secondhand smoke to identify potentially modifiable factors. MATERIALS AND METHODS: This study was embedded in a prospective birth cohort study of pregnant women and their children from fetal life onwards in Singapore (Growing Up in Singapore Towards healthy Outcomes, or GUSTO). Data on prenatal, antenatal and postnatal active and secondhand tobacco smoke exposure were obtained by an investigator-administered questionnaire for the periods before pregnancy, at 26-28 weeks' gestation and 24 months after delivery. Data on respiratory morbidity (wheezing episodes, croupy cough, nebuliser use, snoring) and other morbidity (fever, hospitalisation, ear infection) of the child was collected at week 3 and at months 3, 6, 9, 12, 15, 18 and 24 after delivery. Information on parental atopy and potential confounders such as socioeconomic status and maternal educational level were also obtained. Statistical analysis of the data was performed to quantify any significant differences in incidence of respiratory morbidity in children exposed to tobacco smoke in utero and postdelivery, compared with those in smoke-free environments. RESULTS: Women who smoked regularly prior to pregnancy comprised 12.5% (n=155) of the study population; this number fell to 2.3% (n=29) during pregnancy. Mothers exposed to secondhand smoke in the household before pregnancy comprised 35.7% of the study population (n=441) and 31.5% (n=389) were exposed during pregnancy. Postnatally, the prevalence of secondhand tobacco smoke exposure from birth to 2 years of age was 29% (n=359). Participants of Malay ethnicity (p<0.001), mothers with no or primary level education (p<0.001) and mothers with low socioeconomic status (p<0.001) had the highest exposure to tobacco smoke. Offspring secondhand smoke exposure at home by 12 months and by 24 months of age was associated with an increase in hospital admissions due to respiratory disease (RR 1.89, 95% CI 1.02 to 3.50, p=0.04 by 12 months and RR 1.64, 95% CI 1.05 to 2.55, p=0.03 by 24 months) as well as all-cause hospitalisation (RR 1.57, 95% CI 1.14 to 2.17, p=0.01 by 12 months and RR 1.49, 95% CI 1.17 to 1.90, p=0.001 by 24 months), adjusting for parental atopy and child atopic dermatitis. Participants exposed to secondhand smoke by 12 months postdelivery had a significantly increased risk of having at least one wheezing episode (RR 1.71, 95% CI 1.38 to 2.11, p<0.001). CONCLUSIONS: Secondhand smoke exposure during the prenatal and postnatal periods is associated with increased respiratory morbidity in children. Opportunistic screening and targeted smoking cessation counselling for parents at child hospital admissions and well-child outpatient visits, as well as preconception smoking cessation counselling for future pregnancies, may be beneficial to protect the child from negative health impacts.

MC3R gene polymorphisms are associated with early childhood adiposity gain and infant appetite in an Asian population.

BACKGROUND: Polymorphic variants within human melanocortin-3 receptor gene (MC3R) gene have been associated with obesity. However, its influence on infancy and early childhood adiposity has not been reported before. OBJECTIVES: We assessed associations between genotype at polymorphic sites within MC3R with early childhood adiposity and interaction with early childhood appetitive traits. METHODS: We studied 1090 singletons in an Asian mother-offspring cohort genotyped for MC3R and in a subgroup (n = 422) who had completed Child Eating Behaviour Questionnaires (CEBQ) at 12 months. Children were followed from birth to 48 months, and up to 10 measurements of body mass index and five measures of triceps and subscapular skin-folds were obtained. RESULTS: Independent of potential confounders, each additional MC3R minor allele copy was associated with greater body mass index standard deviation score [B{95% confidence interval}: 0.004 units/month {0.001,0.007}; p = 0.007], triceps [0.009 mm/month {0.001,0.02}; p = 0.021] and subscapular skin-fold [0.008 mm/month {0.002,0.01}; p = 0.011] gain velocity in the first 48 months. Each additional MC3R minor allele copy was also associated with increased odds of overweight [odds ratio {95% confidence interval}: 1.48{1.17-1.88}] and obesity [1.58{1.10-2.28}] in the first 48 months. Every additional copy of MC3R minor allele was positively associated with 'slowness-in-eating' appetitive trait [0.24{0.06,0.39}, p = 0.006]; however, the relationship between 'slowness-in-eating' with adiposity gain was not statistically significant. CONCLUSIONS: Our findings support the role of MC3R genetic variants in adiposity gain during early childhood.

Maternal sensitivity, infant limbic structure volume and functional connectivity: a preliminary study.

Mechanisms underlying the profound parental effects on cognitive, emotional and social development in humans remain poorly understood. Studies with nonhuman models suggest variations in parental care affect the limbic system, influential to learning, autobiography and emotional regulation. In some research, nonoptimal care relates to decreases in neurogenesis, although other work suggests early-postnatal social adversity accelerates the maturation of limbic structures associated with emotional learning. We explored whether maternal sensitivity predicts human limbic system development and functional connectivity patterns in a small sample of human infants. When infants were 6 months of age, 20 mother-infant dyads attended a laboratory-based observational session and the infants underwent neuroimaging at the same age. After considering age at imaging, household income and postnatal maternal anxiety, regression analyses demonstrated significant indirect associations between maternal sensitivity and bilateral hippocampal volume at six months, with the majority of associations between sensitivity and the amygdala demonstrating similar indirect, but not significant results. Moreover, functional analyses revealed direct associations between maternal sensitivity and connectivity between the hippocampus and areas important for emotional regulation and socio-emotional functioning. Sensitivity additionally predicted indirect associations between limbic structures and regions related to autobiographical memory. Our volumetric results are consistent with research indicating accelerated limbic development in response to early social adversity, and in combination with our functional results, if replicated in a larger sample, may suggest that subtle, but important, variations in maternal care influence neuroanatomical trajectories important to future cognitive and emotional functioning.

The psychometric properties of the Quantitative-Checklist for Autism in Toddlers (Q-CHAT) as a measure of autistic traits in a community sample of Singaporean infants and toddlers.

BACKGROUND: There is growing research evidence that subclinical autistic traits are elevated in relatives of individuals with autism spectrum disorder (ASD), continuously distributed in the general population and likely to share common etiology with ASD. A number of measures have been developed to assess autistic traits quantitatively in unselected samples. So far, the Quantitative-Checklist for Autism in Toddlers (Q-CHAT) is one of very few measures developed for use with toddlers as young as 18 months, but little is known about its measurement properties and factor structure. METHODS: The present study examined internal consistency, factor structure, test-retest stability, and convergent validity of the Q-CHAT in a sample of toddlers in Singapore whose caregivers completed the Q-CHAT at 18 (n = 368) and 24 months (n = 396). RESULTS: Three factors were derived accounting for 38.1 % of the variance: social/communication traits, non-social/behavioral traits, and a speech/language factor. Internal consistency was suboptimal for the total and speech/language scores, but acceptable for the social/communication and non-social/behavioral factor scores. Scores were generally stable between 18 and 24 months. Convergent validity was found with the Pervasive Developmental Disorders subscale of the Child Behavior Checklist (CBCL) completed by caregivers when their children were 24 months. Q-CHAT total scores in this sample were higher than those reported in other unselected samples from the UK. CONCLUSIONS: The Q-CHAT was found to have a three-factor structure, acceptable internal consistency for its two main factor scores (social/communication and non-social/behavioral), normally distributed scores in an unselected sample, and similar structure and measurement properties as those reported in other published studies. Findings are discussed in relation to existing literature and future directions for the validation of the Q-CHAT.

Prenatal maternal depression alters amygdala functional connectivity in 6-month-old infants.

Prenatal maternal depression is associated with alterations in the neonatal amygdala microstructure, shedding light on the timing for the influence of prenatal maternal depression on the brain structure of the offspring. This study aimed to examine the association between prenatal maternal depressive symptomatology and infant amygdala functional connectivity and to thus establish the neural functional basis for the transgenerational transmission of vulnerability for affective disorders during prenatal development. Twenty-four infants were included in this study with both structural magnetic resonance imaging (MRI) and resting-state functional MRI (fMRI) at 6 months of age. Maternal depression was assessed at 26 weeks of gestation and 3 months after delivery using the Edinburgh Postnatal Depression Scale. Linear regression was used to identify the amygdala functional networks and to examine the associations between prenatal maternal depressive symptoms and amygdala functional connectivity. Our results showed that at 6 months of age, the amygdala is functionally connected to widespread brain regions, forming the emotional regulation, sensory and perceptual, and emotional memory networks. After controlling for postnatal maternal depressive symptoms, infants born to mothers with higher prenatal maternal depressive symptoms showed greater functional connectivity of the amygdala with the left temporal cortex and insula, as well as the bilateral anterior cingulate, medial orbitofrontal and ventromedial prefrontal cortices, which are largely consistent with patterns of connectivity observed in adolescents and adults with major depressive disorder. Our study provides novel evidence that prenatal maternal depressive symptomatology alters the amygdala's functional connectivity in early postnatal life, which reveals that the neuroimaging correlates of the familial transmission of phenotypes associated with maternal mood are apparent in infants at 6 months of age.