Nanomolar Levels Of Pahs In Extracts From Urban Air Induce Mapk Signaling In Hepg2 Cells.

Polycyclic aromatic hydrocarbons (PAHs) are common environmental pollutants that occur naturally in complex mixtures. Many of the adverse health effects of PAHs including cancer are linked to the activation of intracellular stress response signaling. This study has investigated intracellular MAPK signaling in response to PAHs in extracts from urban air collected in Stockholm, Sweden and Limeira, Brazil, in comparison to BP in HepG2 cells. Nanomolar concentrations of PAHs in the extracts induced activation of MEK4 signaling with down-stream increased gene expression of several important stress response mediators. Involvement of the MEK4/JNK pathway was confirmed using siRNA and an inhibitor of JNK signaling resulting in significantly reduced MAPK signaling transactivated by the AP-1 transcription factors ATF2 and c-Jun. ATF2 was also identified as a sensitive stress responsive protein with activation observed at extract concentrations equivalent to 0.1 nM BP. We show that exposure to low levels of environmental PAH mixtures more strongly activates these signaling pathways compared to BP alone suggesting effects due to interactions. Taken together, this is the first study showing the involvement of MEK4/JNK/AP-1 pathway in regulating the intracellular stress response after exposure to nanomolar levels of PAHs in environmental mixtures.

Prevalence And Treatment Of Hypertension In Urban And Riverside Areas In Porto Velho, The Brazilian Amazon.

Abstract Introduction: Hypertension (HTN) is a preventable cause of cardiovascular morbidity and mortality. To compare the prevalence, awareness, treatment, and control of HTN among urban and riverside populations in Porto Velho, Amazon region. We conducted a cross-sectional study between July and December 2013 based on a household survey of individuals aged 35-80 years. Interviews by using a standardized questionnaire, and blood pressure (BP), weight, height, and waist circumference measurements were performed. HTN was defined when individuals reported having the disease, received antihypertensive medications, or had a systolic BP ≥ 140 mm Hg or diastolic BP ≥ 90 mm Hg. Awareness was based on self-reports and the use of antihypertensive medications. Control was defined as a BP ≤ 140/90 mm Hg. Among the 1410 participants, 750 (53.19%) had HTN and 473 (63.06%) had diagnosis awareness, of whom 404 (85.41%) received pharmacological treatment but with low control rate. The prevalence and treatment rates were higher in the urban areas (55.48% vs. 48.87% [p = 0.02] and 61.25% vs. 52.30% [p < 0.01], respectively). HTN awareness was higher in the riverside area (61.05% vs. 67.36% ; p < 0.01), but the control rates showed no statistically significant difference (22.11% vs. 23.43% ; p = 0.69). HTN prevalence was higher in the urban population than in the riverside population. Of the hypertensive individuals in both areas, <25% had controlled HTN. Comprehensive public health measures are needed to improve the prevention and treatment of systemic arterial HTN and prevent other cardiovascular diseases.

Obstacle Crossing With Dual Tasking Is A Danger For Individuals With Alzheimer's Disease And For Healthy Older People.

The aim of this study was to analyze the effects of dual tasking on obstacle crossing during walking by individuals with Alzheimer's disease (AD) and by healthy older people. Thirty four elderly individuals (16 healthy subjects and 18 individuals with AD) were recruited to participate in this study. Three AD individuals and one control participant were excluded due to exclusion criteria. The participants were instructed to walk barefoot at their own speed along an 8 m long pathway. Each participant performed five trials for each condition (unobstructed walking, unobstructed walking with dual tasking, and obstacle crossing during walking with dual tasking). The trials were completely randomized for each participant. The mid-pathway stride was measured in the unobstructed walking trials and the stride that occurred during the obstacle avoidance was measured in the trials that involved obstacle crossing. The behavior of the healthy elderly subjects and individuals with AD was similar for obstacle crossing during walking with dual tasking. Both groups used the posture first strategy to prioritize stability and showed decreased attention to executive tasking while walking. Additionally, AD had a strong influence on the modifications that are made by the elderly while walking under different walking conditions.

Seed rain in areas with and without bamboo dominance within an urban fragment of the Atlantic Forest

Understanding the flow of diaspores is fundamental for determining plant population dynamics in a particular habitat, and a lack of seeds is a limiting factor in forest regeneration, especially in isolated forest fragments. Bamboo dominance affects forest structure and dynamics by suppressing or delaying the recruitment of and colonization by tree species as well as by inhibiting the survival and growth of adult trees. The goal of the present study was to determine whether dominance of the bamboo species Aulonemia aristulata (Döll) McClure in the forest understory influences species abundance and composition. We examined the seed rain at two noncontiguous sites (1.5 km apart) within an urban forest fragment, with and without bamboo dominance (BD+ and BD- areas, respectively). Sixty seed traps (0.5 m², with a 1-mm mesh) were set in the BD+ and BD- areas, and the seed rain was sampled from January to December 2007. Diaspores were classified according to dispersal syndrome, growth form and functional type of the species to which they belonged. There were significant differences between the two areas in terms of seed density, species diversity and dispersal syndrome. The BD+ area showed greater seed density and species diversity. In both areas, seed distribution was limited primarily by impaired dispersal. Bamboo dominance and low tree density resulted in fewer propagules in the seed rain. Our results suggest that low availability of seeds in the rain does not promote the maintenance of a degraded state, characterized by the presence of bamboo.