Respiratory Health Effects of Exposure to Ambient Particulate Matter and Bioaerosols.

Researchers have been studying the respiratory health effects of ambient air pollution for more than 70 years. While air pollution as a whole can include gaseous, solid, and liquid constituents, this article focuses only on the solid and liquid fractions, termed particulate matter (PM). Although PM may contain anthropogenic, geogenic, and/or biogenic fractions, in this article, particles that originate from microbial, fungal, animal, or plant sources are distinguished from PM as bioaerosols.

Cardiopulmonary Health Effects of Airborne Particulate Matter: Correlating Animal Toxicology to Human Epidemiology.

The effects of particulate matter (PM) on cardiopulmonary health have been studied extensively over the past three decades. Particulate matter is the primary criteria air pollutant most commonly associated with adverse health effects on the cardiovascular and respiratory systems. The mechanisms by which PM exerts its effects are thought to be due to a variety of factors which may include, but are not limited to, concentration, duration of exposure, and age of exposed persons.

Correction to: The AHR represses nucleotide excision repair and apoptosis and contributes to UV-induced skin carcinogenesis.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Toxicokinetic Interaction between Hepatic Disposition and Pulmonary Bioactivation of Inhaled Naphthalene Studied Using -Null and CYP2A13/2F1-Humanized Mice with Deficient Hepatic Cytochrome P450 Activity.

Previous studies using -null (lacking all genes of the , , , , and subfamilies), CYP2A13/2F1-humanized, and liver--null (LCN) mice showed that although hepatic cytochrome P450 (P450) enzymes are essential for systemic clearance of inhaled naphthalene (a possible human carcinogen), both hepatic and extrahepatic P450 enzymes may contribute to naphthalene-induced lung toxicity via bioactivation. Herein, we aimed to further understand the toxicokinetics of inhaled naphthalene in order to provide a basis for predicting the effects of variations in rates of xenobiotic disposition on the extent of target tissue bioactivation. We assessed the impact of a hepatic deficit in naphthalene metabolism on the toxicokinetics of inhaled naphthalene using newly generated -null-and-LCN and CYP2A13/2F1-humanized-and-LCN mice.

Neuroprotective activation of astrocytes by methylmercury exposure in the inferior colliculus.

Methylmercury (MeHg) is well known to induce auditory disorders such as dysarthria. When we performed a global analysis on the brains of mice exposed to MeHg by magnetic resonance imaging, an increase in the T1 signal in the inferior colliculus (IC), which is localized in the auditory pathway, was observed. Therefore, the purpose of this study is to examine the pathophysiology and auditory dysfunction induced by MeHg, focusing on the IC.

Inflammatory marker and aryl hydrocarbon receptor-dependent responses in human macrophages exposed to emissions from biodiesel fuels.

Biodiesel or renewable diesel fuels are alternative fuels produced from vegetable oil and animal tallow that are being considered to help reduce the use of petroleum-based fuels and emissions of air pollutants including greenhouse gases. Here, we analyzed the gene expression of inflammatory marker responses and the cytochrome P450 1A1 (CYP1A1) enzyme after exposure to diesel and biodiesel emission samples generated from an in-use heavy-duty diesel vehicle. Particulate emission samples from petroleum-based California Air Resource Board (CARB)-certified ultralow sulfur diesel (CARB ULSD), biodiesel, and renewable hydro-treated diesel all induced inflammatory markers such as cyclooxygenase-2 (COX)-2 and interleukin (IL)-8 in human U937-derived macrophages and the expression of the xenobiotic metabolizing enzyme CYP1A1.

Age-Dependent Translocation of Gold Nanoparticles across the Air-Blood Barrier.

Do immature lungs have air-blood barriers that are more permeable to inhaled nanoparticles than those of fully developed mature lungs? Data supporting this notion and explaining the underlying mechanisms do not exist as far as we know. Using a rat model of postnatal lung development, here the data exactly supporting this notion, that is, significantly more gold nanoparticles (NPs) cross from the air space of the lungs to the rest of the body in neonates than in adults, are presented. Moreover, in neonates the translocation of gold NPs is not size dependent, whereas in adult animals smaller NPs cross the air-blood lung barrier much more efficiently than larger NPs.

Impact of adrenal hormones, reproductive aging, and major depression on memory circuitry decline in early midlife.

Dehydroepiandrosterone-sulfate (DHEAS) is an adrenal androgen that is, in part, aromatized to estradiol. It continues to be produced after menopause and provides estrogenicity after depletion of ovarian hormones. Estradiol depletion contributes to memory circuitry changes over menopause, including changes in hippocampal (HIPP) and dorsolateral- and ventrolateral-prefrontal cortex (DLPFC; VLPFC) function.

Suppressive effects of levetiracetam on neuroinflammation and phagocytic microglia: A comparative study of levetiracetam, valproate and carbamazepine.

We previously reported that treatment with levetiracetam (LEV) after status epilepticus (SE) termination by diazepam (DZP) prevents the development of spontaneous recurrent seizures. LEV suppresses increased expression levels of proinflammatory mediators during epileptogenesis after SE, but how LEV acts in neuroinflammatory processes is not yet known. In this study, we examined the effects of LEV on neuroinflammation and phagocytic microglia in vivo and in vitro and compared the effects of LEV with those of representative antiepileptic drugs valproate (VPA) and carbamazepine (CBZ).

Retinoid X receptor-mediated neuroprotection via CYP19 upregulation and subsequent increases in estradiol synthesis.

Increasing evidence has shown that one of the major neurosteroids, estradiol, has potent neuroprotective actions. We have reported that estradiol synthesis was enhanced when retinoic acid was added into rat hippocampal slice culture. In this study, we investigated the effects of a potent retinoid X receptor (RXR) agonist, bexarotene, on estrogen synthesis and neuroprotective action in hippocampal slices.

Role of NF-kB RelB in Aryl Hydrocarbon Receptor-Mediated Ligand Specific Effects.

Here, we investigate the role of RelB in the regulation of genes which were identified to be induced in an aryl hydrocarbon receptor (AhR)-dependent manner and critically involved in regulation of immune responses. We analyzed the expression of genes of the AhR gene battery, cytokines, and immune regulatory enzymes in bone marrow-derived macrophages (BMM) and thymus of B6 wildtype (wt) mice and RelB knockout (RelB) mice after treatment with various AhR ligands. The 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced expression of indoleamine 2,3-dioxygenase 1 (IDO1) and IDO2 was significantly repressed in thymus of RelB mice but not in BMM derived from RelB mice.

Interleukin 33 Expression Induced by Aryl Hydrocarbon Receptor in Macrophages.

Polycyclic aromatic hydrocarbons (PAHs) contained in airborne particulate matter have been identified as a contributing factor for inflammation in the respiratory tract. Recently, interleukin-33 (IL-33) is strongly suggested to be associated with airway inflammation. Aryl hydrocarbon receptor (AhR) is a receptor for PAHs to regulate several metabolic enzymes, but the relationships between AhR and airway inflammation are still unclear.

A Protective Role of Aryl Hydrocarbon Receptor Repressor in Inflammation and Tumor Growth.

The aryl hydrocarbon receptor (AhR) is known for mediating the toxicity of environmental pollutants such as dioxins and numerous dioxin-like compounds, and is associated with the promotion of various malignancies, including lymphoma. The aryl hydrocarbon receptor repressor (AhRR), a ligand-independent, transcriptionally inactive AhR-like protein is known to repress AhR signaling through its ability to compete with the AhR for dimerization with the AhR nuclear translocator (ARNT). While AhRR effectively blocks AhR signaling, several aspects of the mechanism of AhRR's functions are poorly understood, including suppression of inflammatory responses and its putative role as a tumor suppressor.

Association of Increased Serum S100B Levels With High School Football Subconcussive Head Impacts.

Astrocyte-enriched marker, S100B, shows promise for gauging the severity of acute brain trauma, and understanding subconcussive effects will advance its utility in tracking real-time acute brain damage. The aim of the study was to investigate whether serum S100B elevations were associated with frequency and magnitude of subconcussive head impacts in adolescents. This prospective cohort study of 17 high-school football players consisted of the following 12 time points: pre-season baseline, 5 in-season pre-post games, and post-season.

Metabolism and Lung Toxicity of Inhaled Naphthalene: Effects of Postnatal Age and Sex.

Human exposure to naphthalene (NA), an acute lung toxicant and possible human carcinogen, is primarily through inhalation. Acute lung toxicity and carcinogenesis are thought to be related because the target sites for both are similar. To understand susceptibility of the developing lung to cytotoxicity of inhaled NA, we exposed neonatal (7 days), juvenile (3 weeks), and adult mice to 5 or 10 ppm NA vapor for 4 h.

Impacts of weather, work rate, hydration, and clothing in heat-related illness in California farmworkers.

Background: The primary aim of this study was to investigate the effects of work rate, hydration status, and clothing on core body temperature (CBT) on California farmworkers.

Methods: Two hundred and eighty-seven farmworkers were recruited in Summer 2015, with 259 participants having sufficient data for analysis. We collected CBT, ambient temperature, work rate, body weight loss, and clothing worn by each participant throughout the work day and demographic data from a questionnaire.

Alveolar macrophage reaction to PM of hazy day in vitro: Evaluation methods and mitochondrial screening to determine mechanisms of biological effect.

Hazy weather in China has recently become a major public health concern due to high levels of atmospheric fine particulate matter (PM) with a large amount of polycyclic aromatic hydrocarbon (PAHs). In this study, the mass concentration of PAHs in hazy PM in urban Taiyuan city, China was determined and toxicities of different dosage of the hazy PM on rat alveolar macrophages (AMs) were examined. It was found that the hazy PM, bounded with many species of PAHs (CHR, BbF, BaP, BaA, and etc.

Workplace health promotion and safety in state and territorial health departments in the United States: a national mixed-methods study of activity, capacity, and growth opportunities.

Background: State and Territorial Health Departments (SHDs) have a unique role in protecting and promoting workers' health. This mixed-methods study presents the first systematic investigation of SHDs' activities and capacity in both Occupational Safety and Health (OSH) and Workplace Health Promotion (WHP) in the United States (US).

Methods: National survey of OSH and WHP practitioners from each of 56 SHDs, followed by in-depth interviews with a subset of survey respondents.

Age-dependent pulmonary reactivity to house dust mite allergen: a model of adult-onset asthma?

Asthma is a heterogeneous disease differentiated by factors like allergen sensitivity, inflammation, sex, and age at onset. The mouse model is widely used to study the early-life development of allergic asthma. However, age-dependent allergen responses later in life remain relatively understudied and lack a widely accepted model.

Allergen Sensitization and Asthma Outcomes among World Trade Center Rescue and Recovery Workers.

A large number of World Trade Center (WTC) rescue and recovery workers are affected by asthma. While physical and mental health comorbidities have been associated with poor asthma control in this population, the potential role of allergen sensitization is unknown. This study examined the association of indoor sensitization and exposure as a risk factor for increased asthma morbidity in WTC workers.

Reduction in FSH Throughout the Menstrual Cycle After Omega-3 Fatty Acid Supplementation in Young Normal Weight but not Obese Women.

Dietary fish oil restores ovarian function in subfertile rats, which is thought to be associated with decreased transcription of follicle-stimulating hormone (FSH) β-subunit. We have previously demonstrated a reduction in early follicular serum FSH levels in normal weight but not obese women after treatment with omega-3 polyunsaturated fatty acids (PUFA). Herein, we report the effect of supplementation with omega-3 PUFA on urinary reproductive hormones across the whole menstrual cycle.

Exposure to Secondhand Smoke and Arrhythmogenic Cardiac Alternans in a Mouse Model.

Background: Epidemiological evidence suggests that a majority of deaths attributed to secondhand smoke (SHS) exposure are cardiovascular related. However, to our knowledge, the impact of SHS on cardiac electrophysiology, [Formula: see text] handling, and arrhythmia risk has not been studied.

Objectives: The purpose of this study was to investigate the impact of an environmentally relevant concentration of SHS on cardiac electrophysiology and indicators of arrhythmia.