Effects of S1PR2 antagonist on blood pressure and angiogenesis imbalance in preeclampsia rats.

Preeclampsia (PE), a hypertensive multisystem disorder, can lead to increased maternal and fetal mortality and morbidity. Sphingosine­1­phosphate (S1P) plays various roles, depending on the cell type, by binding to S1P receptors (S1PR). The present study evaluated the changes of S1PRs and investigated the potential role of S1PRs in pregnancy­induced hypertension. PE rats were established by reduced uterine perfusion pressure. The involvement of S1PR2 was evaluated using JTE­013, a specific S1PR2 antagonist, in PE rats. After the treatment, inflammatory cytokines were evaluated using enzyme linked immunosorbent assay, and the expression of vascular endothelial growth factor (VEGF), inducible nitric oxide synthase (iNOS) activation and endothelial nitric oxide synthase (eNOS) were evaluated by reverse transcription­quantitative PCR and western blotting. Results showed that S1PR2, but not S1PR1 and S1PR3, was significantly increased in the serum and placenta tissues of PE rats. Notably, JTE­013 significantly decreased blood pressure, attenuated infiltration of inflammatory cells and decreased inflammation, as indicated by the decreased expression of inflammatory cytokines, including tumor necrosis factor­α, interleukin­1ß (IL­1ß) and IL­6, in placental tissues. Mechanistic studies demonstrated that JTE­013 significantly increased the expression of VEGF and decreased the expression of fms­like tyrosine kinase 1 in placental tissue. Furthermore, JTE­013 prevented iNOS activation and increased eNOS in placental tissue. In summary, the present study demonstrated that S1PR2 contributed to hypertension and angiogenesis imbalance in PE rats.

Radial basis function artificial neural network able to accurately predict disinfection by-product levels in tap water: Taking haloacetic acids as a case study.

Control of risks caused by disinfection by-products (DBPs) requires pre-knowledge of their levels in drinking water. In this study, a radial basis function (RBF) artificial neural network (ANN) was proposed to predict the concentrations of haloacetic acids (HAAs, one dominant class of DBPs) in actual distribution systems. To train and verify the RBF ANN, a total of 64 samples taken from a typical region (Jinhua region) in China were characterized in terms of water characteristics (dissolved organic carbon (DOC), ultraviolet absorbance at 254 nm (UVA254), NO2--N level, NH4+-N level, Br- and pH), temperature and the prevalent HAAs concentrations. Compared with multiple linear/log linear regression (MLR) models, predictions done by RBF ANNs showed rather higher regression coefficients and accuracies, indicating the high capability of RBF ANNs to depict complicated and non-linear relationships between HAAs formation and various factors. Meanwhile, it was found that, predictions of HAAs formation done by RBF ANNs were efficient and allowed to further improve the prediction accuracy. This is the first study to systematically explore feasibility of RBF ANNs in prediction of DBPs. Accurate predictions by RBF ANNs provided great potential application of DBPs monitoring in actual distribution system.

Overexpression of tyrosine kinase receptor B promotes metastasis of ovarian serous adenocarcinoma by lymphangiogenesis.

AIMS AND BACKGROUND: The aim of this study was to detect the expression features of tyrosine kinase receptor B (TrkB) and analyze the possible correlation between TrkB expression and lymph vessel density (LVD) in metastasis of ovarian serous adenocarcinoma. METHODS: An immunohistochemical method was used to evaluate TrkB expression in 139 ovarian tumor sections (103 primary ovarian serous adenocarcinomas and 36 serous adenomas) and investigate the correlation between TrkB expression and LVD, which was estimated by means of VEGFR-3 assessment. RESULTS: TrkB was significantly upregulated in serous adenocarcinomas and absent in serous adenomas. There was no association between TrkB expression and the histological grade of cancer cells. The expression of TrkB was correlated with surgicopathological stage and metastasis in serous adenocarcinomas. The level of TrkB was higher in advanced-stage than in early-stage disease. TrkB was overexpressed in metastatic lesions compared with the corresponding primary lesions. Furthermore, a positive correlation between TrkB expression and LVD in serous adenocarcinomas was observed. CONCLUSIONS: TrkB was overexpressed in ovarian serous adenocarcinomas and might be involved in cancer metastasis by associated lymphangiogenesis.