Inhibition of xanthine oxidase activity by gnaphalium affine extract.

OBJECTIVE: To evaluate the inhibitory effect of Gnaphalium affine extracts on xanthine oxidase (XO) activity in vitro and to analyze the mechanism of this effect. METHODS: In this in vitro study, Kinetic measurements were performed in 4 different inhibitor concentrations and 5 different xanthine concentrations (60, 100, 200, 300, 400 Μmol/L). Dixon and Lineweaver-Burk plot analysis were used to determine Ki values and the inhibition mode for the compounds isolated from Gnaphalium affine extract. RESULTS: Four potent xanthine oxidase inhibitors were found in 95% ethanolic (v/v) Gnaphalium affine extract. Among them, the flavone Eupatilin exhibited the strongest inhibitory effect on XO with a inhibition constant (Ki) of 0.37 Μmol/L, lower than the Ki of allopurinol (4.56 mol/L), a known synthetic XO inhibitor. Apigenin (Ki of 0.56 Μmol/L, a proportion of 0.0053‰ in Gnaphalium affine), luteolin (Ki of 2.63 Μmol/L, 0.0032‰ in Gnaphalium affine) and 5-hydroxy-6,7,3',4'-tetramethoxyflavone (Ki of 3.15 Μmol/L, 0.0043‰ in Gnaphalium affine) also contributed to the inhibitory effect of Gnaphalium affine extract on XO activity. CONCLUSIONS: These results suggest that the use of Gnaphalium affine in the treatment of gout could be attributed to its inhibitory effect on XO. This study provides a rational basis for the traditional use of Gnaphalium affine against gout.

JAK/STAT3 Signaling Activation Related to Distinct Clinicopathologic Features in Systemic ALK - Anaplastic Large Cell Lymphomas : New Insights into Their Heterogeneity.

Systemic anaplastic lymphoma kinase (ALK)-negative anaplastic large cell lymphoma (ALCL) is a group of heterogenous CD30 + T-cell non-Hodgkin lymphomas. Previous studies have highlighted the importance of JAK/STAT3 signaling activation in the molecular pathogenesis of ALK - ALCLs. In the present study, we aimed to establish a potential relationship between JAK/STAT3 signaling activation and clinicopathologic features in ALK - ALCLs, and further recognize the heterogenous nature of these neoplasms. Immunohistochemistry staining of the phosphorylated-STAT3 (p-STAT3) and dual-specificity protein phosphatase 22 ( DUSP22 ) gene rearrangement analysis were performed. Forty-five cases of ALK - ALCL were divided into 3 groups, including 9 DUSP22 -rearranged ALCLs, 21 p-STAT3 + double-negative (DN) ALCLs (both ALK and DUSP22 rearrangement negative), and 15 p-STAT3 - DN-ALCLs. Morphologically, p-STAT3 + DN-ALCLs exhibited sheet-like neoplastic cells and sometimes showed large pleomorphic cells scattered in a lymphocyte-rich background more frequently than those in other ALK - ALCLs subtypes. Phenotypically, the p-STAT3 + DN-ALCLs frequently expressed cytotoxic molecules, epithelial membrane antigen, and programmed death-ligand 1, whereas CD3 and CD5 expression was not observed. Clinically, patients with p-STAT3 + DN-ALCLs had a better prognosis than those with p-STAT3 - DN-ALCLs. These observations suggest that p-STAT3 + DN-ALCLs represent a distinct subtype of ALK - ALCLs. Identifying ALK - ALCL subtypes by using p-STAT3 staining and DUSP22 rearrangement is a promising approach that may contribute to risk stratification and better treatment decisions in the future clinical practice.

The distributions of particulate heavy metals and its indication to the transfer of sediments in the Changjiang Estuary and Hangzhou Bay, China.

Particulate heavy metals (Cu, Pb, Cd) were measured following intensive sampling in June and October 1994 at 70 stations in the Changjiang Estuary and Hangzhou Bay, China. In the study area, particulate Cu and Pb have a similar level that is higher than the concentration of particulate Cd. Cu, Pb and Cd concentrations in suspended sediments are higher than those in bed load. In the middle of Hangzhou Bay, heavy metal concentrations in suspended sediments and bed load are similar. This may be the result of the frequent exchange between them, which is due to the strong dynamic condition. A negative relationship was observed between concentrations of heavy metals in bed load and bulk density. Fine-grained sediments were the main carriers of heavy metals. Sedimentary dynamics dominate the fate of heavy metals in these sites. The distributions of metals (especially Cu) in suspended sediments can indicate the transfer of sediments in this area.