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result(s) for
"Goudarzi, Houman"
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Developmental Exposures to Perfluoroalkyl Substances (PFASs): An Update of Associated Health Outcomes
by
Goudarzi, Houman
,
Liew, Zeyan
,
Oulhote, Youssef
in
Biomedical and Life Sciences
,
Biomedicine
,
Birth weight
2018
Purpose of Review
We reviewed and summarized the epidemiological evidence for the influence that pre- and postnatal exposures to perfluoroalkyl substances (PFASs) may have on health outcomes in offspring, with a particular focus on birth outcomes and postnatal growth, immunomodulatory effects and neurodevelopment.
Recent Findings
PFASs are persistent organic pollutants that have been widely produced and used in a range of commercial products since the 1950s. Human exposures to PFASs are nearly ubiquitous globally, but studies that addressed potential health effects of PFASs have only begun to accumulate in recent years. Animal studies suggest adverse effects resulting from developmental encompasses prenatal exposures to PFASs. In humans, the developing fetus is exposed to PFASs via active or passive placenta transfer, while newborns might be exposed via breastfeeding or PFAS in the home environment.
Summary
Overall, epidemiological findings are consistent and suggest possible associations with fetal and postnatal growth and immune function, while the findings on neurodevelopmental endpoints to date are rather inconclusive. Methodological challenges and future directions for PFASs-focused research are discussed.
Journal Article
Impact of the Covid-19 pandemic and ensuing online teaching on pre-clinical medical education
by
Goudarzi, Houman
,
Onozawa, Masahiro
,
Takahashi, Makoto
in
COVID-19
,
COVID-19 pandemic
,
Data Analysis
2024
Background
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.
Methods
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.
Results
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.
Conclusions
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.
Journal Article
Associations among perfluorooctanesulfonic/perfluorooctanoic acid levels, nuclear receptor gene polymorphisms, and lipid levels in pregnant women in the Hokkaido study
2021
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
10
scale) decreased palmitic, palmitoleic, and oleic acid levels (log
10
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
int
= 0.004 to 0.017). In conclusion, the interactions between maternal PFOS levels and
PPARGC1A
or
PPARD
may modify maternal FA levels.
Journal Article
Effects of prenatal perfluoroalkyl acid exposure on cord blood IGF2/H19 methylation and ponderal index: The Hokkaido Study
by
Goudarzi, Houman
,
Araki, Atsuko
,
Itoh, Sachiko
in
631/337/176/1988
,
692/308/2779/174
,
704/172/169/895
2017
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.
Journal Article
Clustering of students in pre-clinical medical education and identification of academic performance profiles: does online education work for all medical students?
by
Goudarzi, Houman
,
Onozawa, Masahiro
,
Ito, Yoichi M.
in
Academic achievement
,
Academic performance
,
Academic Performance - statistics & numerical data
2026
Introduction
Unlike variable-centered analysis, person-centered analysis facilitates the development of more personalized learning. In this study, we investigated the predictors of academic performance in pre-clinical education using variable-centered analysis and identified academic performance profiles using person-centered analysis (cluster analysis).
Methods
A total of 321 second-year medical students from our medical English course at Hokkaido University participated in this study between 2019 and 2021. For variable-centered analysis, we assessed the predictors of academic performance (final exam score) using multivariable regression analysis. We performed cluster analysis using Ward’s minimum variance hierarchical clustering method for person-centered analysis. Nine variables, identical to those used in the variable-centered analysis, were selected and standardized for this analysis.
Results
Online education, female sex, baseline reading skills, and medical terminology predicted academic performance in the variable-centered analysis; however, cluster analysis identified four subgroups with different academic performances. Cluster 1 had the highest proportion of male and in-person education and the lowest academic performance. Cluster 2, with a high male ratio and low baseline skills, had poor academic performance, whereas most students had online/combined education. Clusters 3 and 4 had the highest online/combined education (Cluster 4: online> combined), and female students with the highest performance.
Discussion
Online education was the main predictor of academic performance using traditional analysis; however, cluster analysis captured a subgroup of students with online education but lacking better academic performance. The current person-centered analysis contributes novel insights into the nuanced interplay of educational formats, gender, and skills, offering implications for optimizing medical education strategies in the future.
Journal Article
Hokkaido birth cohort study on environment and children’s health: cohort profile 2021
2021
Background The Hokkaido Study on Environment and Children’s Health is an ongoing study consisting of two birth cohorts of different population sizes: the Sapporo cohort and the Hokkaido cohort. Our primary objectives are to (1) examine the effects that low-level environmental chemical exposures have on birth outcomes, including birth defects and growth retardation; (2) follow the development of allergies, infectious diseases, and neurobehavioral developmental disorders, as well as perform a longitudinal observation of child development; (3) identify high-risk groups based on genetic susceptibility to environmental chemicals; and (4) identify the additive effects of various chemicals, including tobacco. Methods The purpose of this report is to provide an update on the progress of the Hokkaido Study, summarize recent results, and suggest future directions. In particular, this report provides the latest details from questionnaire surveys, face-to-face examinations, and a collection of biological specimens from children and measurements of their chemical exposures. Results The latest findings indicate different risk factors of parental characteristics on birth outcomes and the mediating effect between socioeconomic status and children that are small for the gestational age. Maternal serum folate was not associated with birth defects. Prenatal chemical exposure and smoking were associated with birth size and growth, as well as cord blood biomarkers, such as adiponectin, leptin, thyroid, and reproductive hormones. We also found significant associations between the chemical levels and neuro development, asthma, and allergies. Conclusions Chemical exposure to children can occur both before and after birth. Longer follow-up for children is crucial in birth cohort studies to reinforce the Developmental Origins of Health and Disease hypothesis. In contrast, considering shifts in the exposure levels due to regulation is also essential, which may also change the association to health outcomes. This study found that individual susceptibility to adverse health effects depends on the genotype. Epigenome modification of DNA methylation was also discovered, indicating the necessity of examining molecular biology perspectives. International collaborations can add a new dimension to the current knowledge and provide novel discoveries in the future.
Journal Article
Future career plans of medical students and the COVID‐19 pandemic: Time to recover?
by
Goudarzi, Houman
,
Onozawa, Masahiro
,
Takahashi, Makoto
in
Career development planning
,
Conflicts of interest
,
Coronaviruses
2023
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.
Journal Article
The Hokkaido Birth Cohort Study on Environment and Children’s Health: cohort profile—updated 2017
2017
The Hokkaido Study on Environment and Children’s Health is an ongoing study consisting of two birth cohorts of different population sizes: the Sapporo cohort and the Hokkaido cohort. Our primary study goals are (1) to examine the effects of low-level environmental chemical exposures on birth outcomes, including birth defects and growth retardation; (2) to follow the development of allergies, infectious diseases, and neurobehavioral developmental disorders and perform a longitudinal observation of child development; (3) to identify high-risk groups based on genetic susceptibility to environmental chemicals; and (4) to identify the additive effects of various chemicals, including tobacco smoking. The purpose of this report is to update the progress of the Hokkaido Study, to summarize the recent results, and to suggest future directions. In particular, this report provides the basic characteristics of the cohort populations, discusses the population remaining in the cohorts and those who were lost to follow-up at birth, and introduces the newly added follow-up studies and case-cohort study design. In the Sapporo cohort of 514 enrolled pregnant women, various specimens, including maternal and cord blood, maternal hair, and breast milk, were collected for the assessment of exposures to dioxins, polychlorinated biphenyls, organochlorine pesticides, perfluoroalkyl substances, phthalates, bisphenol A, and methylmercury. As follow-ups, face-to-face neurobehavioral developmental tests were conducted at several different ages. In the Hokkaido cohort of 20,926 enrolled pregnant women, the prevalence of complicated pregnancies and birth outcomes, such as miscarriage, stillbirth, low birth weight, preterm birth, and small for gestational age were examined. The levels of exposure to environmental chemicals were relatively low in these study populations compared to those reported previously. We also studied environmental chemical exposure in association with health outcomes, including birth size, neonatal hormone levels, neurobehavioral development, asthma, allergies, and infectious diseases. In addition, genetic and epigenetic analyses were conducted. The results of this study demonstrate the effects of environmental chemical exposures on genetically susceptible populations and on DNA methylation. Further study and continuous follow-up are necessary to elucidate the combined effects of chemical exposure on health outcomes.
Journal Article
Effects of obesity on CC16 and their potential role in overweight/obese asthma
2022
Introduction
Club cell secretory protein-16 (CC16) is a major anti-inflammatory protein expressed in the airway; however, the potential role of CC16 on overweight/obese asthma has not been assessed. In this study, we examined whether obesity reduces airway/circulatory CC16 levels using experimental and epidemiological studies. Then, we explored the mediatory role of CC16 in the relationship of overweight/obesity with clinical asthma measures.
Methods
Circulating CC16 levels were assessed by ELISA in three independent human populations, including two groups of healthy and general populations and asthma patients. The percentage of cells expressing club markers in obese vs. non-obese mice and human airways was determined by immunohistochemistry. A causal mediation analysis was conducted to determine whether circulatory CC16 acted as a mediator between overweight/obesity and clinical asthma measures.
Results
BMI was significantly and monotonously associated with reduced circulating CC16 levels in all populations. The percentage of CC16-expressing cells was reduced in the small airways of both mice and humans with obesity. Finally, mediation analysis revealed significant contributions of circulatory CC16 in the association between BMI and clinical asthma measures; 21.8% of its total effect in BMI’s association with airway hyperresponsiveness of healthy subjects (p = 0.09), 26.4% with asthma severity (p = 0.030), and 23% with the required dose of inhaled corticosteroid (p = 0.042). In logistic regression analysis, 1-SD decrease in serum CC16 levels of asthma patients was associated with 87% increased odds for high dose ICS requirement (p < 0.001).
Conclusions
We demonstrate that airway/circulating CC16, which is inversely associated with BMI, may mediate development and severity in overweight/obese asthma.
Journal Article
Spatial, temporal, and demographic patterns in prevalence of smoking tobacco use and attributable disease burden in 204 countries and territories, 1990–2019: a systematic analysis from the Global Burden of Disease Study 2019
2021
Ending the global tobacco epidemic is a defining challenge in global health. Timely and comprehensive estimates of the prevalence of smoking tobacco use and attributable disease burden are needed to guide tobacco control efforts nationally and globally.
We estimated the prevalence of smoking tobacco use and attributable disease burden for 204 countries and territories, by age and sex, from 1990 to 2019 as part of the Global Burden of Diseases, Injuries, and Risk Factors Study. We modelled multiple smoking-related indicators from 3625 nationally representative surveys. We completed systematic reviews and did Bayesian meta-regressions for 36 causally linked health outcomes to estimate non-linear dose-response risk curves for current and former smokers. We used a direct estimation approach to estimate attributable burden, providing more comprehensive estimates of the health effects of smoking than previously available.
Globally in 2019, 1·14 billion (95% uncertainty interval 1·13–1·16) individuals were current smokers, who consumed 7·41 trillion (7·11–7·74) cigarette-equivalents of tobacco in 2019. Although prevalence of smoking had decreased significantly since 1990 among both males (27·5% [26·5–28·5] reduction) and females (37·7% [35·4–39·9] reduction) aged 15 years and older, population growth has led to a significant increase in the total number of smokers from 0·99 billion (0·98–1·00) in 1990. Globally in 2019, smoking tobacco use accounted for 7·69 million (7·16–8·20) deaths and 200 million (185–214) disability-adjusted life-years, and was the leading risk factor for death among males (20·2% [19·3–21·1] of male deaths). 6·68 million [86·9%] of 7·69 million deaths attributable to smoking tobacco use were among current smokers.
In the absence of intervention, the annual toll of 7·69 million deaths and 200 million disability-adjusted life-years attributable to smoking will increase over the coming decades. Substantial progress in reducing the prevalence of smoking tobacco use has been observed in countries from all regions and at all stages of development, but a large implementation gap remains for tobacco control. Countries have a clear and urgent opportunity to pass strong, evidence-based policies to accelerate reductions in the prevalence of smoking and reap massive health benefits for their citizens.
Bloomberg Philanthropies and the Bill & Melinda Gates Foundation.
Journal Article