How does aqueous solubility of organic reactant affect a water-promoted reaction?

It was widely reported that under the "on water" condition, various water-promoted organic reactions can proceed with very high speed. Thus, it is considered that the aqueous solubility of reactant is not an important issue in these reactions. Three types of water-promoted organic reactions were investigated in the current study to distinguish whether the reaction rate of an aqueous reaction was affected by the aqueous solubilities of the reactants. The results showed that, for a Diels-Alder reaction which was fast under the neat conditions, the aqueous solubilities of reactants had little influence on the reaction. However, for the reactions which proceeded slowly under the neat conditions, such as [2σ+2σ+2π] cycloaddition reactions and epoxide aminolysis reactions, the reactants with good aqueous solubilities proceeded fast in water. Poorly aqueous soluble reactants reacted slowly or did not react under the "on water" condition, and an appropriate amount of organic cosolvent was needed to make the reaction become efficient. This evidence suggested that for these two types of reactions, the dissolution of the reactants in water was required.

PSMC2 knockdown inhibits the progression of oral squamous cell carcinoma by promoting apoptosis via PI3K/Akt pathway.

Proteasome 26S subunit, ATPase 2 (PSMC2) is a recently identified gene which is potentially associated with human carcinogenesis. However, the effects of PSMC2 on oral squamous cell carcinoma (OSCC) is still unclear. Here, we investigated PSMC2 expression in OSCC tissues and explored its effects on the biological behaviors of OSCC cells. PSMC2 expression was evaluated by immunohistochemistry in a tissue microarray containing 60 OSCC tissues and 9 normal tissues. PSMC2 was knocked down through lentivirus infection in OSCC cell lines. MTT, colony formation, flow cytometry, transwell, and scratch assays were performed to detect effects of PSMC2 knockdown on phenotypes of OSCC cells. Human apoptosis antibody array was used to screen potential downstream of PSMC2 in OSCC. Finally, the effects of PSMC2 knockdown on tumor growth were assessed in a tumor xenograft model using BALB/c nude mice. PSMC2 expression was significantly upregulated in OSCC tissues compared with normal tissues and correlated with poor prognosis. PSMC2 knockdown significantly suppressed cell proliferation, migration, but promoted apoptosis of OSCC cells. Additionally, we confirmed that PSMC2 knockdown can increase the expression of pro-apoptotic proteins. Furthermore, we found that PSMC2 knockdown downregulated expression of p100, p-Akt, CDK6, and upregulated of MAPK9. Xenograft experiments revealed that PSMC2 knockdown can suppress OSCC tumor growth and promote apoptosis. This study demonstrated that PSMC2 plays a critical role in OSCC progression through affecting pro-apoptotic protein expression and apoptosis pathways. It indicated that targeting PSMC2 might be a promising strategy for OSCC treatment.

Comparison Between Modified Lateral Arm Free Flap and Traditional Lateral Arm Free Flap for the Reconstruction of Oral and Maxillofacial Soft Tissue Defects.

Objective: The traditional lateral arm free flap (tLAFF) has the disadvantages of short vascular pedicle, small vascular diameter, and non-perforator flap. We used a new method to prepare modified LAFF (mLAFF) and evaluate its application value in the repair of oral and maxillofacial soft tissue defects. Methods: The anatomical features of the flap were recorded and compared between the tLAFF group and the mLAFF group. All the flaps in the modified group were perforator flaps. Statistical analysis was performed on the data using ANOVA on SPSS 22.0 statistical software package. Results: Forty-five mLAFFs were prepared as eccentric design rotation repair perforated flap, or multi-lobed or chimeric perforator flaps. Compared with the tLAFF, the vascular pedicle length of the mLAFF was increased, and the outer diameter of the anastomosis was thickened. The damage to the donor site was less. The difference was statistically significant. Conclusion: The mLAFF can effectively lengthen the vascular pedicle length and increase the anastomosis diameter. Perforator LAFFs in the repair of oral and maxillofacial defects have good application value.