•Allergies and infectious diseases were assessed using longitudinal data until age 7.•Eleven maternal plasma PFAS levels were measured.•Longer carbon-chain (more than C8) PFAS was associated with ...allergies and infectious diseases.•Effects of prenatal PFAS exposure remained on allergies and infectious diseases until 7 y.•Increased risk of pneumonia and RSV were found among the children without any siblings.
Per- and polyfluoroalkyl substances (PFAS) are widely used bio-accumulative chemicals in many industrial and household products. Experimental studies reported that exposure to PFAS results in immunotoxicity. We have previously reported that prenatal exposure to PFAS decreased the risk of allergies, while it increased the risk of infectious diseases at ages 2 and 4 years. However, it remains unclear whether the adverse effects of PFAS on allergies and infectious diseases continue until a reliable age of diagnosing allergies. This study aimed at investigating the effects of prenatal exposure to PFAS on the prevalence of allergies and infectious diseases in children up to age 7, from the Hokkaido Study.
Among mother-child pairs enrolled in the Hokkaido study and followed up until the age of 7 years, 2689 participants with maternal PFAS, 1st trimester of pregnancy and 7-year-old questionnaire survey data were included in this study. Eleven PFAS in the 3rd-trimester plasma were measured using ultra-performance liquid chromatography coupled to triple quadrupole tandem mass spectrometry. Wheeze, rhino-conjunctivitis, and eczema were defined using the International Study of Asthma and Allergies on Childhood (ISAAC) questionnaire. History childhood infectious diseases diagnosed by a doctor was assessed by a mother-reported questionnaire at child’s age 7. The relative risk of childhood allergies was calculated by generalized estimating equation models. The odds ratio of an episode of infectious diseases was calculated by logistic regression analysis, adjusted for potential confounders.
The prevalence of various allergies and infectious diseases was: wheeze, 11.9%; rhino-conjunctivitis, 11.3%; eczema, 21.0%; chickenpox, 61.5%; otitis media, 55.7%; pneumonia, 30.6%; and respiratory syncytial virus infection, 16.8%. Prenatal exposure to perfluorooctanoic acid, perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnDA) was inversely associated with rhino-conjunctivitis, while that for perfluorooctanoate (PFOA), perfluorooctane sulfonate, PFUnDA, perfluorododecanoic acid (PFDoDA), and perfluorotridecanoic acid was inversely associated with eczema. For infectious diseases, PFDA and PFDoDA were associated with increased risk of pneumonia and PFOA was associated with increased risk of RSV infection among children not having any siblings (only-one-child).
Our results corroborate the hypothesis on immunosuppressive and immunomodulating effects of PFAS on allergies and infectious diseases in children. These effects observed previously at 2 and 4 years continued until the age of 7 years. However, additional studies assessing inflammatory biomarkers along with ISAAC questionnaires, doctor-diagnosed allergies, and longer follow-ups are necessary to better assess the effects of exposure to chemicals on human immune outcomes.
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic that has developed in late 2019 and 2020 is a serious threat to human health. With no vaccines or drugs approved for ...prevention and treatment until now, all efforts at drug design and/or clinical trials of already approved drugs are worthy and creditable. Using structure-based drug selection for identification of SARS-CoV-2 protease inhibitors, old drugs such as macrolides (MAC) were predicted to be effective for COVID-19. Lately, the anti-viral effects of macrolides have attracted considerable attention. Very recently, hydroxychloroquine in combination with azithromycin treatment was reported to be effective for COVID-19. We believe that treatments with macrolides alone or in combination with other drugs are promising and open the possibility of an international strategy to fight this emerging viral infection.
Major disruptions and changes in education have occurred worldwide as a result of the coronavirus disease (COVID-19) pandemic and the ensuing shift from in-person to online education. However, the ...effect of such changes on medical education, its magnitude, and the learning domains impacted by such rapid changes have not been adequately addressed, particularly with regard to objective assessment approaches.
Second-year medical students enrolled in our Medical English Course between 2019 and 2021 were recruited from Hokkaido University, Japan (N = 321) to participate in this study. We evaluated the potential impact of teaching styles on the academic performance of students before (2019; face-to-face) and during (2020; online; 2021; in-person and online) the pandemic. We examined the potential effect of three teaching styles--in-person (2019), online (2020), and a combination of these (2021) on the academic performance of medical students using: (i) subjective assessment of self-reported general English skills, including reading, writing, listening, and speaking; and (ii) objective assessment of medical terminology scores, evidence-based medicine (EBM) skills, and final written exam scores.
In-person education significantly improved listening and speaking skills in 2019 (p < 0.001). This trend was observed for writing skills in an online course in 2020 (p = 0.001). With the combined teaching method, students reported significant improvements in all four English skills. In our objective assessments, medical terminology improved significantly post-test versus pre-test for all three teaching styles, and we found that the online course did not adversely affect the gain in medical terminology knowledge during the course. Additionally, we did not find any significant differences across the three applied teaching styles regarding EBM skill levels. It is noteworthy that the students taking online courses had a significantly higher final exam score (mean ± SD; 82.8 ± 8.2) than in in-person (78.6 ± 8.8) and combined (79.7 ± 12.1) teaching styles.
In our study, the online/combined courses showed better academic outcomes compared to the face-to-face course in the preclinical clerkship. Although the current results need to be replicated on a larger scale, online/combined courses can continue and evolve in the post-pandemic education of medical students. Medical schools and institutions should consider incorporating such courses, especially combined courses, into their curricula in the future to improve the effectiveness, accessibility, and flexibility of medical education.
Prenatal exposure to perfluoroalkyl acids (PFAAs) influences fetal growth and long-term health. However, whether PFAAs affect offspring DNA methylation patterns to influence health outcomes is yet to ...be evaluated. Here, we assessed effect of prenatal PFAA exposure on cord blood insulin-like growth factor 2 (IGF2), H19, and long interspersed element 1 (LINE1) methylation and its associations with birth size. Mother-child pairs (N=177) from the Hokkaido Study on Environment and Children's Health were included in the study. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) levels in maternal serum were measured by liquid chromatography-tandem mass spectrometry. IGF2, H19, and LINE1 methylation in cord blood DNA was determined by pyrosequencing. After full adjustment in multiple linear regression models, IGF2 methylation showed a significant negative association with log-unit increase in PFOA (partial regression coefficient=-0.73; 95% confidence interval: -1.44 to -0.02). Mediation analysis suggested that reduced IGF2 methylation explained ~21% of the observed association between PFOA exposure and reduced ponderal index of the infant at birth. These results indicated that the effects of prenatal PFOA exposure could be mediated through DNA methylation. Further study will be required to determine the potential for long-term adverse health effects of reduced IGF2 methylation induced by PFOA exposure.
There is growing data on T helper 2 (Th2) biomarker determinants in adult populations. However, the determinants and typical range of these biomarkers have not been well studied in general ...populations of children. Therefore, we assessed the determinants and typical range of three Th2 biomarkers, including blood eosinophils, FeNO, and serum total IgE in 9-11-year-old children in a prospective birth cohort.
We examined the pre- and postnatal factors associated with Th2 biomarkers using multivariable logistic regression analysis (n = 428) and extended the results to the original cohort (n = 17,009) using inverse probability weighting. We also measured typical Th2 biomarker distribution in all examined children and healthy participants without allergic diseases (n = 180).
At age 9–11, wheeze (odds ratio (OR) 7.63), rhinitis (OR 3.14), and eczema (OR 2.46) were significantly associated with increased blood eosinophils. All three allergic conditions were associated with FeNO and total serum IgE, but the ORs were smaller than those for blood eosinophils. Secondhand smoking was inversely associated with the blood eosinophils (OR, 0.38). Similar results were found in the original cohort. Male sex and prenatal factors (maternal smoking and parental history of allergies) were not independent predictors of high Th2 levels.
In addition to wheezing and rhinitis, eczema and secondhand smoke exposure are independent factors for Th2 biomarker interpretation in children. Furthermore, the typical values and cutoff values of blood eosinophils in adults may not be applicable to children.
The effect of interactions between perfluorooctanesulfonic (PFOS)/perfluorooctanoic acid (PFOA) levels and nuclear receptor genotypes on fatty acid (FA) levels, including those of triglycerides, is ...not clear understood. Therefore, in the present study, we aimed to analyse the association of PFOS/PFOA levels and single-nucleotide polymorphisms (SNPs) in nuclear receptors with FA levels in pregnant women. We analysed 504 mothers in a birth cohort between 2002 and 2005 in Japan. Serum PFOS/PFOA and FA levels were measured using liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry. Maternal genotypes in PPARA (rs1800234; rs135561), PPARG (rs3856806), PPARGC1A (rs2970847; rs8192678), PPARD (rs1053049; rs2267668), CAR (rs2307424; rs2501873), LXRA (rs2279238) and LXRB (rs1405655; rs2303044; rs4802703) were analysed. When gene-environment interaction was considered, PFOS exposure (log
scale) decreased palmitic, palmitoleic, and oleic acid levels (log
scale), with the observed β in the range of - 0.452 to - 0.244; PPARGC1A (rs8192678) and PPARD (rs1053049; rs2267668) genotypes decreased triglyceride, palmitic, palmitoleic, and oleic acid levels, with the observed β in the range of - 0.266 to - 0.176. Interactions between PFOS exposure and SNPs were significant for palmitic acid (P
= 0.004 to 0.017). In conclusion, the interactions between maternal PFOS levels and PPARGC1A or PPARD may modify maternal FA levels.
Perfluorinated chemicals (PFCs) are ubiquitous and persistent pollutants widely detected in blood samples of animals and humans across the globe. Although animal studies have shown the potential ...neurotoxicity of PFCs, there are few epidemiological studies regarding neurological effects of PFCs in humans, and those studies have had inconclusive results. In this study, we conducted a hospital-based prospective birth cohort study between 2002 and 2005 (n=514) to examine the associations between prenatal perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) exposures and the neurodevelopment of infants at 6 (n=173) and 18 (n=133) months of age. Using the second edition of the Bayley Scales of Infant Development (BSID II), the Mental and Psychomotor Developmental Indices (MDI and PDI, respectively) were assessed. PFOS and PFOA were measured in maternal serum samples by liquid chromatography–tandem mass spectrometry. After controlling for confounders, prenatal PFOA concentrations were associated with the MDI of female (but not male) infants at 6months of age (β=−0.296; 95% confidence interval (CI): −11.96, −0.682). Furthermore, females born to mothers with prenatal concentrations of PFOA in the fourth quartile had MDI scores −5.05 (95% CI: −10.66 to 0.55) lower than females born to mothers with concentrations of PFOA in the first quartile (p for trend=0.045). However, PFOA concentrations were not significantly associated with neurodevelopmental indices at 18months of age. In addition, we did not observe any significant association between PFOS concentrations and neurodevelopmental outcomes in early infancy. In conclusion, our results suggest that prenatal PFOA exposure may affect female mental scales of neurodevelopment at 6months of age. Further studies with larger sample sizes and longer observation periods are required to clarify sex difference of the neurodevelopmental effects.
The dose–response relationship between the quartiles of PFOA and reduced MDI scores among female (A) and male (B) infants at 6months of age. Display omitted
•The association of prenatal exposure to PFCs with neurodevelopment were assessed.•Neurodevelopment was evaluated at 6 and 18 months of age using the Bayley Scales of Infant Development.•PFOA was negatively associated with mental developmental indices among 6-month female infants.
•Prenatal exposure to PFNA and PFDA was inversely associated with birth size.•PFTrDA exposure was associated with decreased birth weight of only female infants.•Prenatal exposure to other PFAS showed ...no associations with birth size.
Prenatal maternal exposure to perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) has been reportedly associated with decreased birth weight. Although a majority of epidemiological studies concerning perfluoroalkyl substances (PFAS) have focused on PFOS and PFOA, epidemiological studies of PFAS with longer carbon chains are scarce. In this study, we investigated whether prenatal maternal exposure to 11 PFAS, in particular those with longer carbon chains, is associated with fetal growth.
The study included 1985 mother-infant pairs (inclusive of preterm and post-term infants), who enrolled in a large-scale, prospective birth cohort study in any of the 37 hospitals in Hokkaido, Japan between 2003 and 2009. The concentration of 11 PFAS was measured in maternal plasma collected during the third trimester of pregnancy, using ultra-performance liquid chromatography in combination with triple quadrupole mass spectrometry. Associations between the measured PFAS values and weight, length, and head circumference of all newborns at birth were examined using multiple regression analyses with adjustment for potential confounders based on data collected from medical records, questionnaires, and those for maternal plasma samples.
Of the 11 PFAS analyzed, prenatal perfluorononanoic acid (PFNA) per log10-unit: regression coefficient (β) = −96.2 g, 95% confidence intervals (95% CI), −165.3 to −27.1 and perfluorodecanoic acid (PFDA) (β = −72.2 g, 95% CI, −138.1 to −6.3) concentrations were inversely associated with birth weight. Furthermore, PFNA concentrations were inversely associated with birth length (per Log10 unit: β = −0.48 cm, 95% CI; − 0.86 to −0.11). Maternal perfluorotridecanoic acid (PFTrDA) exposure showed a significant inverse association with birth weight only for female infants (per Log10 unit: β = −99.8 g, 95% CI, − 193.7 to −6.0) (P for interaction = 0.04).
Our findings suggest that prenatal, maternal exposure to PFAS with longer carbon chains tends to be inversely associated with birth size of newborn infants, which may indicate that these commercially used compounds have an adverse effect on fetal growth.
In 2019 and before the COVID‐19 pandemic, about 68% of our medical students in Japan wished to engage in academic activities abroad. However, in 2020 and during the pandemic, this percentage fell to ...35%. We found a significant increase in the number of students wishing to go abroad for studies/training in 2021 than in 2020, taking the percentage to the prepandemic level in 2019.
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