Harmful Effect of Indoor Formaldehyde on Atopic Dermatitis in Children: A Longitudinal Study

PurposeEvidence supporting a link between indoor formaldehyde exposure and atopic dermatitis (AD) in humans is limited. The purpose of this longitudinal study was to investigate whether AD symptoms in children could be affected by indoor formaldehyde levels in ordinary households.MethodsFifty-five children with moderate-to-severe AD aged under 18 years were enrolled as a panel. They were followed up from February 2019 through February 2020. Indoor formaldehyde levels of patients'' houses and their AD symptoms were repeatedly measured on a daily basis. The generalized linear mixed model was utilized for statistical analysis. Subdivision analysis was performed by stratifying patients by sex, body mass index, presence of parental allergy, and indoor environments including mold/dampness, temperature, and relative humidity (RH).ResultsA total of 4,789 person-days of AD symptom data were collected. The average concentration of formaldehyde was 13.6 ± 16.4 ppb, with the highest value found in spring (18.1 ± 20.6 ppb). Higher levels of formaldehyde were observed when there was parental smoking, increased indoor temperature over 25.5°C, or RH over 60% (P < 0.0001). When the effect size was compared between each season after controlling for ambient particulate matter, temperature, and RH, an increase in 10 ppb of formaldehyde increased AD symptoms by 79.2% (95% confidence interval [CI], 19.6–168.4) in spring and by 39.9% (95% CI, 14.3–71.2) in summer. AD symptoms in children aged 6−18 years appeared to increase significantly, whereas there was no significant increase in children under 6 years. When indoor temperature was over 25.5°C, an increase in formaldehyde by 10 ppb increased AD symptoms by 17.8% (95% CI, 3.9–33.6).ConclusionsIndoor formaldehyde can exacerbate AD symptom in children with moderate-to-severe AD, particularly in spring and summer, even at allowable levels. Thus, minimizing exposure to indoor formaldehyde may be needed for the proper management of AD in children.     

支气管肺发育不良的CT表现

目的 观察支气管肺发育不良患儿胸部CT表现。方法 收集经临床确诊的支气管肺发育不良患儿42例,根据胎龄和吸入氧浓度分为轻、中、重度,均接受64层螺旋CT扫描及薄层重建,回顾性分析所有患儿的胸部CT表现。结果 胸部CT多表现为囊泡影(27/42,64.29%),双肺透光度减低、呈广泛或局部磨玻璃样改变(26/42,61.90%),条片状致密影(23/42,54.76%)及条索状、网格状、蜂窝状(16/42,38.10%);胸膜增厚4例,胸腔积液2例。囊泡影发生于双肺上下叶者15例(15/27,55.56%),其中10例发生于右肺中叶;仅发生于肺下叶者8例;仅发生于肺上叶者3例(3/27,11.11%);发生于双肺下叶及右肺中叶者1例。轻、中、重度支气管肺发育不良患儿中,囊泡影检出率分别为53.33%(8/15)、57.14%(8/14)、84.62%(11/13),差异无统计学意义(P=0.094);累及肺叶数(中位数)分别为1.0、1.5、4.0,差异有统计学意义(P<0.05)。结论 支气管肺发育不良常见的CT征象为囊泡影、局部或广泛磨玻璃影、致密影、条索状、网格状、蜂窝状影。囊泡影可发生于双肺,以肺下叶居多,胸膜下多见;囊泡影累及肺叶数越多,提示患儿临床表现越严重。     

Urinary excretion of frameshift mutagens in rats caused by passive smoking

Summary Several male Wistar rats were individually placed in a chamber resembling a room provided with minimal air flow. They were exposed separately to the main- and sidestream smoke of a commerical brand of cigarettes smoked by a smoking machine. Exposure to both sidestream and mainstream smoke of at least two cigarettes resulted in significant excretions of frameshift mutagens in urine within 24h, detected by the bacterial microtiter fluctuation test with Salmonella typhimurium TA1 538. Doubling exposure to the mainstream smoke resulted in similar quantitative mutagenic activities. Doubling exposure to the side-stream smoke resulted in reduced water intake by the animals and thus toxic effects of the urine concentrates on the test bacteria.     

Prenatal Particulate Matter/Tobacco Smoke Increases Infants' Respiratory Infections: COCOA Study

Purpose

To investigate whether prenatal exposure to indoor fine particulate matter (PM_2.5) and environmental tobacco smoke (ETS) affects susceptibility to respiratory tract infections (RTIs) in infancy, to compare their effects between prenatal and postnatal exposure, and to determine whether genetic factors modify these environmental effects.

Methods

The study population consisted of 307 birth cohort infants. A diagnosis of RTIs was based on parental report of a physician''s diagnosis. Indoor PM_2.5 and ETS levels were measured during pregnancy and infancy. TaqMan was used for genotyping of nuclear factor erythroid 2-related factor (Nrf2) (rs6726395), glutathione-S-transferase-pi (GSTP) 1 (rs1695), and glutathione-S-transferase-mu (GSTM) 1. Microarrays were used for genome-wide methylation analysis.

Results

Prenatal exposure to indoor PM_2.5 increased the susceptibility of lower RTIs (LRTIs) in infancy (adjusted odds ratio [aOR]=2.11). In terms of combined exposure to both indoor PM_2.5 and ETS, prenatal exposure to both pollutants increased susceptibility to LRTIs (aOR=6.56); however, this association was not found for postnatal exposure. The Nrf2 GG (aOR=23.69), GSTM1 null (aOR=8.18), and GSTP1 AG or GG (aOR=7.37) genotypes increased the combined LRTIs-promoting effects of prenatal exposure to the 2 indoor pollutants. Such effects of prenatal indoor PM_2.5 and ETS exposure were not found for upper RTIs.

Conclusions

Prenatal exposure to both indoor PM_2.5 and ETS may increase susceptibility to LRTIs. This effect can be modified by polymorphisms in reactive oxygen species-related genes.     

阿奇霉素在吸烟支气管哮喘患者治疗中的作用

目的 探讨阿奇霉素在吸烟支气管哮喘患者中的治疗作用. 方法 选取80例吸烟的支气管哮喘未控制患者随机分为阿奇霉素组与对照组,阿奇霉素组以阿奇霉素联合布地奈德福莫特罗治疗,对照组以布地奈德福莫特罗治疗.观察两组治疗4周及12周后的肺功能变化情况、症状改善情况及呼出气一氧化氮水平. 结果 对照组治疗4周及12周后,患者的哮喘测试评分、肺功能指标与呼出气一氧化氮水平较治疗前均无统计学差异;阿奇霉素组的各项指标在治疗12周后均较治疗前明显好转,且两组间比较差异有统计学意义. 两组均未出现严重不良事件. 结论 阿奇霉素联合吸入布地奈德福莫特罗治疗吸烟的支气管哮喘患者安全有效.     

Health impacts of bushfire smoke exposure in Australia

Smoke exposure from bushfires, such as those experienced in Australia during 2019–2020, can reach levels up to 10 times those deemed hazardous. Short‐term and extended exposure to high levels of air pollution can be associated with adverse health effects, although the most recent fires have brought into sharp focus that several important knowledge gaps remain. In this article, we briefly identify and discuss the existing Australian evidence base and make suggestions for future research.     

Evaluation method for the cytotoxicity of cigarette smoke by in vitro whole smoke exposure

An in vitro whole smoke (WS) exposure method was established to evaluate the toxicological effects of fresh cigarette smoke using the VITROCELL^® system associated with the neutral red uptake (NRU) cytotoxicity assay. The VITROCELL^® system is a newly representative culture and exposure system for in vitro studies of gases or complex mixtures. The impacts of two factors on cytotoxicity measurements of cigarette smoke were investigated using this WS exposure system. The factors include synthetic air exposure and optimal time to perform the NRU assay after smoke exposure. Results showed that synthetic air exposure used in the system did not significantly alter cell survival; 24 h after smoke exposure appeared to be an optimal time-point to assess the cytotoxicity of cigarette smoke. A clear dose–response relationship between smoke exposure and cell viability was demonstrated using this system, and the evaluation method was sensitive to distinguish the differences in smoke-induced cytotoxic effects from different cigarettes. In addition, we tried converting the values of EC₅₀ from WS exposure testing into the values in unit used in total particulate matter (TPM) testing for a purpose of comparison, and the data indicate that the cytotoxicity of smoke measured by WS exposure is greater than that measured by TPM exposure.