[Research on the establishment of standard limits for perfluorooctanoic acid and perfluorooctane sulfonate in the "Standards for Drinking Water Quality（GB5749-2022）"in China].

Perfluorinated compounds, especially Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), are widely detected in water environments in China. Considering the potential health risks of drinking water exposure routes, PFOA and PFOS have been added to the water quality reference index of the newly issued "Standards for Drinking Water Quality (GB5749-2022)", with limit values of 40 and 80 ng/L, respectively. This study analyzed and discussed the relevant technical contents for determining the limits of the hygiene standard, including the environmental existence level and exposure status of PFOA and PFOS, health effects, derivation of safety reference values, and determination of hygiene standard limits. It also proposed prospects for the future direction of formulating drinking water standards.

The quantification of ADAMTS expression in an animal model of cerebral ischemia using real-time PCR.

BACKGROUND: ADAMTS1 and ADAMTS8 are proteases involved in extracellular matrix proteolysis and antiangiogenesis, but little is known about their expression and function in cerebral ischemia. We investigated the changes in ADAMTS1 and ADAMTS8 in a rat model of permanent middle cerebral artery occlusion (pMCAO). The expressions of glyseraldehyde-3-phosphate dehydrogenase (GAPDH), beta-actin, cyclophilin, and RPL13A were examined in order to validate the appropriate housekeeping genes for a long duration after inducing cerebral ischemia. METHODS: Male Sprague-Dawley rats were subjected to pMCAO, and ischemic penumbra was collected at 2, 24 h, 3, 7, and 21 days after inducing ischemia, ADAMTS1, ADAMTS8, and the four housekeeping genes were quantified using real-time polymerase chain reaction (PCR). RESULTS: The expression of beta-actin increased up to 21 days, and that of GAPDH decreased at 24 h after pMCAO, with no statistically significant changes in RPL13A and cyclophilin being detected. ADAMTS1 mRNA increased at 2 h after pMCAO, peaked at 24 h, and remained at a high level until 21 days. The expression of ADAMTS8 mRNA decreased at 2 and 24 h after pMCAO, followed by a slight increase at 3 days, and then decreased again at 7 days. CONCLUSION: The results suggest that RPL13A and cyclophilin are two appropriate housekeeping genes for the rat pMCAO model up to 21 days. ADAMTS1 mRNA levels increased, but ADAMTS8 decreased after pMCAO. Our data provide new insight into the mechanism of brain ischemia and self-repair after injury.