Record-setting algal bloom in Lake Erie caused by agricultural and meteorological trends consistent with expected future conditions.

In 2011, Lake Erie experienced the largest harmful algal bloom in its recorded history, with a peak intensity over three times greater than any previously observed bloom. Here we show that long-term trends in agricultural practices are consistent with increasing phosphorus loading to the western basin of the lake, and that these trends, coupled with meteorological conditions in spring 2011, produced record-breaking nutrient loads. An extended period of weak lake circulation then led to abnormally long residence times that incubated the bloom, and warm and quiescent conditions after bloom onset allowed algae to remain near the top of the water column and prevented flushing of nutrients from the system. We further find that all of these factors are consistent with expected future conditions. If a scientifically guided management plan to mitigate these impacts is not implemented, we can therefore expect this bloom to be a harbinger of future blooms in Lake Erie.

Effects of omega-3 fatty acids on progestin stimulation of invasive properties in breast cancer.

Clinical studies have shown that progestins increase breast cancer risk in hormone replacement therapy, while we and others have previously reported that progestins stimulate invasive properties in progesterone receptor (PR)-rich human breast cancer cell lines. Based on others' reports that omega-3 fatty acids inhibit metastatic properties of breast cancer, we have reviewed the literature for possible connections between omega-3 fatty-acid-driven pathways and progestin-stimulated pathways in an attempt to suggest theoretical mechanisms for possible omega-3 fatty acid inhibition of progestin stimulation of breast cancer invasion. We also present some data suggesting that fatty acids regulate progestin stimulation of invasive properties in PR-rich T47D human breast cancer cells, and that an appropriate concentration of the omega-3 fatty acid eicosapentaenoic acid inhibits progestin stimulation of invasive properties. It is hoped that focus on the inter-relationship between pathways by which omega-3 fatty acids inhibit and progestins stimulate breast cancer invasive properties will lead to further in vitro, in vivo, and clinical studies testing the hypothesis that omega-3 fatty acids can inhibit progestin stimulation of invasive properties in breast cancer, and ameliorate harmful effects of progestins which occur in combined progestin-estrogen hormone replacement therapy.

Prevention of cadmium accumulation in retinal pigment epithelium with manganese and zinc.

Age-related macular degeneration (AMD) is a leading cause of irreversible blindness in the elderly. Risk factors include old age, female gender, obesity, smoking, low dietary intakes of antioxidants and increased exposure to the toxic metal cadmium (Cd(2+)). Supplementation with high-dose zinc (80 mg) provides some protection, but the mechanism(s) underlying such protection has not been fully elucidated. The present study had a focus on the human retinal pigment epithelial (RPE) cell line ARPE-19 in an attempt to demonstrate a reduction in intracellular Cd(2+) effect associated with heme oxygenase-1 (HO-1) expression by co-exposure with zinc (Zn(2+)) or manganese (Mn(2+)), which is known to be a more potent inhibitor of Cd(2+) uptake than Zn(2+). Our results indicated that co-exposure of 10 microM Cd(2+) with 5 microM Mn(2+) reduced the intracellular Cd(2+) effect by 50-60%, possibly by limiting the amounts of Cd(2+) entering cells through Mn(2+) transporter protein (ZIP8). A similar reduction in a Cd(2+) effect was achieved by co-exposure with 20 microM Zn(2+) while co-exposure with 5 and 10 microM Zn(2+) ions was ineffective. Mn(2+) ions as low as 2.5 microM were found to cause an increase in HO-1 mRNA expression levels in ARPE-19 cells, demonstrating for the first time that Mn(2+) is an inducer of HO-1. Mn(2+) ions at 1 microM induced HO-1 mRNA expression in the HEK293 human embryonic kidney cells. In contrast, Zn(2+) in 5, 10 or 20 microM concentrations did not induce expression of HO-1 in ARPE-19 cells or any other cells tested. These data suggest the superiority of Mn(2+) over Zn(2+) in preventing Cd(2+) uptake and accumulation in RPE to toxic levels. Further, induction of HO-1 by Mn(2+) could provide RPE with some resistance to enhanced oxidative stress arising from Cd(2+) accumulation in RPE as HO-1 is one of the frontline cellular antioxidant defense mechanisms.

Public health risks from heavy metals and metalloids present in traditional Chinese medicines.

Out of 247 traditional Chinese medicines (TCM) investigated, a proportion were contaminated with arsenic (5-15%), lead (approximately 5%), and mercury (approximately 65%). Some preparations exceeded the tolerable daily intake (TDI) for males and females for arsenic (4 and 5 products, respectively), lead (1 and 2 products), and mercury (5 and 7 products). These exceedances were as high as 2760-fold, which posed a potential danger to public health. As many users are known to self-prescribe, there is a substantial risk of poisoning from the consumption of these contaminated TCM.