[Analysis of the Effect of Temperature on the Microbial Flora Structure During the Nitrite Oxidation Process Using 16S rRNA High-throughput Sequencing].

In order to further understand the influence of high temperature shock on the microbial community structure of activated sludge during the process of nitrite oxidation, the enriched nitrifying activated sludge under different NO-N concentration was taken as the research object in this study. 16S rRNA high-throughput sequencing technology was used to analyze the changes in the microbial community abundance and structural characteristics of activated sludge by changing the environmental temperature. The results of high-throughput sequencing showed that microorganisms were more likely to grow at 25℃, and the diversity of the microbial community in the activated sludge was the most abundant.

Expression of stem cell factor in gastrointestinal stromal tumors: Implications for proliferation and imatinib resistance.

KIT autophosphorylation caused by mutation of KIT is considered to be a critical mechanism for the oncogenesis of gastrointestinal stromal tumors (GISTs). However, little is known regarding whether stem cell factor (SCF), the KIT ligand, is able to induce the proliferation of GIST cells by activating the wild-type KIT receptor in GISTs. Imatinib, a tyrosine kinase inhibitor, has been demonstrated to be effective as treatment for the majority of GISTs.

Stem cell factor-mediated wild-type KIT receptor activation is critical for gastrointestinal stromal tumor cell growth.

Aim: To clarify the biological role of stem cell factor (SCF)-mediated wild-type KIT receptor activation in gastrointestinal stromal tumor (GIST) growth.

Methods: The co-expression of wild-type KIT receptor and SCF was evaluated in 51 GIST samples using mutation analysis and immunohistochemistry, and the results were correlated with clinicopathological parameters, including the mitotic count, proliferative index (Ki-67 immunohistochemical staining), mitotic index (phospho-histone H3 immunohistochemical staining) and apoptotic index (terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling). Using primary cultured GIST cells, the effect of SCF-mediated wild-type KIT receptor activation was determined by western blotting, methyl thiazolyl tetrazolium (MTT), and apoptosis assays.

[Transforming effect of PDGFRA gene mutant on the cell function in gastrointestinal stromal tumor].

Objective: To explore the effect of malignant transformation of the L839P, a new mutation site of the PDGFRA gene, on the pathogenesis of gastrointestinal stromal tumors.

Methods: All recombinant plasmids were stably transfected into CHO cells by liposomes. Western blotting was used to detect the expression of PDGFRA protein.

Crystal structure of Natratoxin, a novel snake secreted phospholipaseA2 neurotoxin from Naja atra venom inhibiting A-type K+ currents.

Snake secreted phospholipasesA2 (sPLA2s) are widely used as pharmacological tools to investigate their role in diverse pathophysiological processes. Some members of snake venom sPLA2s have been found to block voltage-activated K(+) channels (K(v) channels). However, most studies involved in their effects on ion channels were indirectly performed on motor nerve terminals while few studies were directly done on native neurons.