Bioaugmented soil aquifer treatment for P-nitrophenol removal in wastewater unique for cold regions.

P-nitrophenol (PNP) is a toxic and recalcitrant organic pollutant and a usual intermediate in the production of fine chemicals, which has posed a significant threat to subsurface environment safety. Soil aquifer treatment (SAT) is a promising method to remove and remediate contamination in vadose zone with low cost and high efficiency. However, there are still research gaps for the treatment of recalcitrant contaminants by SAT in cold regions, such as un-robust indigenous microbes and low temperature constraint in vadose zone. The bioaugmentation technology was first introduced into SAT in order to enhance the removal ability of PNP by SAT operated in cold regions in this study. A high-efficiency PNP-degrading bacterium was successfully isolated, which can efficiently degrade PNP below 200 mg L-1 with a degradation rate above 99% at 15 °C close to the real subsurface temperature in cold regions, and added into SAT for bioaugmentation. The feasibility of bioaugmented SAT and associated PNP removal process were investigated by laboratory sand columns, along with effects of the SAT operative parameters (namely PNP loading concentration, flow rate and soil saturation level of SAT). Within the range of PNP loading stresses tested (1-200 mg L-1), PNP removal efficiency was optimal at constant flow rate of 219 mL d-1 in unsaturated operating condition of SAT under 15 °C among all the investigated experimental conditions. Longer hydraulic residence time increased the PNP removal rate, although the accumulated mass removed reduced and the removal efficiencies remained constant in unsaturated operating condition of SAT. It is found from the comparison between the PNP removals via both unsaturated and saturated columns that slight difference only in the removal rate of PNP was observed and the highly efficient bioaugmented SAT can completely degrade PNP of 10 mg L-1 within 5 wetting/drying cycles under both scenarios.

Activation of imidazoline I-2B receptors by allantoin to increase glucose uptake into C2C12 cells.

Allantoin, an active principle of the yam, belongs to the group of guanidinium derivatives and has been reported to lower plasma glucose in diabetic animals. Recent evidence indicates that activation of the imidazoline I(2B) receptor (I(2B)R) by guanidinium derivatives also increases glucose uptake; however, the effect of allantoin on I(2B)R is still unknown. Glucose uptake into cultured C2C12 cells was determined using 2-[¹4C]-deoxy-D-glucose as a tracer. The changes in 5'-AMP-activated protein kinase (AMPK) expression were also identified by Western blotting analysis. The allantoin-induced glucose uptake action was dose-dependently blocked by BU224, a specific I2R antagonist, in C2C12 cells. Moreover, AMPK phosphorylation by allantoin was found to be dose-dependently increased in C2C12 cells using AICAR treatment as a reference. In addition, both actions of allantoin, the increases in glucose uptake and AMPK phosphorylation, were dose-dependently attenuated by amiloride in C2C12 cells. Moreover, compound C at concentrations sufficient to inhibit AMPK blocked the allantoin-induced glucose uptake and AMPK phosphorylation. Thus, we suggest that allantoin can activate I(2B)R to increase glucose uptake into cells, and propose I(2B)R as a new target for diabetic therapy.

Dynamic progression of an intraperitoneal xenograft model of human ovarian cancer and its potential for preclinical trials.

This study was conducted to establish a feasible intraperitoneal xenograft model in nude mice which mimicked the dynamic progression of human ovarian cancer and to explore its potential for preclinical trials. A human ovarian tumor line SKOV3 was originally injected s.c. to develop tumors; then the tumors were harvested and minced into small particles for i.p. inoculation in three groups of nude mice which would be monitored consecutively. The intraperitoneal carcinomatosis and relevant organs were collected for histopathological dynamic comparison and CA125 immunohistochemical staining 7, 21 and 49 days after inoculation. An additional experiment with cisplatin sensitivity test was performed and tumor tissues were observed for apoptosis-Hoechst assay. The intraperitoneal carcinomatosis had a rapid progression which resulted in extensive dissemination on the peritoneal surfaces and invasion into abdominal lymph nodes, livers, pancreas and spleen. Tumor tissues revealed similar morphological features of primary tumor from which SKOV3 derived and part of in vivo tumor mass was positive for CA125. Cisplatin could significantly inhibit the intraperitoneal carcinomatosis growth. This model may provide a valuable platform to study the biological properties of ovarian cancer as well as to test new therapeutic strategies in preclinical trials.