Is natural experiment a cure? Re-examining the long-term health effects of China's 1959–1961 famine

Abstract Health behavior researchers should refocus and retool as it becomes increasingly clear that the challenges of the COVID-19 pandemic surpass the direct effects of COVID-19 and include unique, drastic, and ubiquitous consequences for health behavior. The circumstances of the pandemic have created a natural experiment, allowing researchers focusing on a wide range of health behaviors and populations with the opportunity to use previously collected and future data to study: (a) changes in health behavior prepandemic and postpandemic, (b) health behavior prevalence and needs amidst the pandemic, and (c) the effects of the pandemic on short- and long-term health behavior. Our field is particularly challenged as we attempt to consider biopsychosocial, political, and environmental factors that affect health and health behavior. These realities, while daunting, should call us to action to refocus and retool our research, prevention, and intervention efforts

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Long-Term Exposure to Nanosized TiO2 Triggers Stress Responses and Cell Death Pathways in Pulmonary Epithelial Cells

International Journal of Molecular Sciences ◽

10.3390/ijms22105349 ◽

2021 ◽

Vol 22 (10) ◽

pp. 5349

Author(s):

Mayes Alswady-Hoff ◽

Johanna Samulin Erdem ◽

Santosh Phuyal ◽

Oskar Knittelfelder ◽

Animesh Sharma ◽

...

Keyword(s):

Cell Death ◽

Epithelial Cells ◽

Health Effects ◽

Stress Responses ◽

Cell Stress ◽

Lipid Classes ◽

Long Term Effects ◽

Cell Death Pathways ◽

Pulmonary Epithelial Cells

There is little in vitro data available on long-term effects of TiO2 exposure. Such data are important for improving the understanding of underlying mechanisms of adverse health effects of TiO2. Here, we exposed pulmonary epithelial cells to two doses (0.96 and 1.92 µg/cm2) of TiO2 for 13 weeks and effects on cell cycle and cell death mechanisms, i.e., apoptosis and autophagy were determined after 4, 8 and 13 weeks of exposure. Changes in telomere length, cellular protein levels and lipid classes were also analyzed at 13 weeks of exposure. We observed that the TiO2 exposure increased the fraction of cells in G1-phase and reduced the fraction of cells in G2-phase, which was accompanied by an increase in the fraction of late apoptotic/necrotic cells. This corresponded with an induced expression of key apoptotic proteins i.e., BAD and BAX, and an accumulation of several lipid classes involved in cellular stress and apoptosis. These findings were further supported by quantitative proteome profiling data showing an increase in proteins involved in cell stress and genomic maintenance pathways following TiO2 exposure. Altogether, we suggest that cell stress response and cell death pathways may be important molecular events in long-term health effects of TiO2.

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