Synthesis of Quercetin-Acid Esters and Its Reduction of H2 O2 -Triggered PC12 Cells Damage by Down-Regulating ROS.

Quercetin is a kind of polyphenolic flavonoid compounds which has perfect antioxidant properties. However, quercetin is not available in many situations due to its poor bioavailability. In this work, the QAEs with better solubility and even stronger antioxidant properties were synthesized, through the esterification between quercetin and the chlorinated cinnamic acid or its derivatives, whose chlorination were achieved by using SOCl2 . The protective effects of the QAEs were evaluated by the H2 O2 -induced apoptosis experiment in rat adrenal pheochromocytoma cells (PC12 cells) and its ability to remove ROS generated by oxidative stress. Compared with the original quercetin group, the QAEs groups showed much improved cell viability and capability of removing ROS, which means their higher bioavailability than the parent.

A multiple combined method for rebalancing medical data with class imbalances.

Most classification algorithms assume that classes are in a balanced state. However, datasets with class imbalances are everywhere. The classes of actual medical datasets are imbalanced, severely impacting identification models and even sacrificing the classification accuracy of the minority class, even though it is the most influential and representative. The medical field has irreversible characteristics. Its tolerance rate for misjudgment is relatively low, and errors may cause irreparable harm to patients. Therefore, this study proposes a multiple combined method to rebalance medical data featuring class imbalances. The combined methods include (1) resampling methods (synthetic minority oversampling technique [SMOTE] and undersampling [US]), (2) particle swarm optimization (PSO), and (3) MetaCost. This study conducted two experiments with nine medical datasets to verify and compare the proposed method with the listing methods. A decision tree is used to generate decision rules for easy understanding of the research results. The results show that (1) the proposed method with ensemble learning can improve the area under a receiver operating characteristic curve (AUC), recall, precision, and F1 metrics; (2) MetaCost can increase sensitivity; (3) SMOTE can effectively enhance AUC; (4) US can improve sensitivity, F1, and misclassification costs in data with a high-class imbalance ratio; and (5) PSO-based attribute selection can increase sensitivity and reduce data dimension. Finally, we suggest that the dataset with an imbalanced ratio >9 must use the US results to make the decision. As the imbalanced ratio is < 9, the decision-maker can simultaneously consider the results of SMOTE and US to identify the best decision.

A feasible tool to detect mRNA expression of matrix metalloproteinases and their tissue inhibitors in human Tenon's capsule.

PURPOSE: To determine the mRNA expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in human specimens of Tenon's capsule. METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) with specific primers for MMP-1, MMP-2, MMP-9, TIMP-1 and TIMP-2 was performed on tissue specimens obtained from patients with cataract, rhegmatogenous retinal detachment, glaucoma, or diabetes mellitus. RESULTS: Glyceraldehyde phosphate dehydrogenase (GAPDH) mRNA transcripts were detected in 26 (76.5%) of 34 specimens, with almost the same amount of expression in each of these samples. Messenger RNA expression of one or more of the MMPs/TIMPs could also be detected in all of these 26 samples, but not in any sample without GAPDH expression. MMP-2, TIMP-1 and TIMP-2 were detected in 25 (96.2%) of the 26 samples with GAPDH expression, while MMP-1 and MMP-9 were detected with a lower percentage (34.6 and 19.2%, respectively). CONCLUSION: The feasibility of RT- PCR with GAPDH as an internal standard to determine mRNA transcripts of the MMPs and TIMPs in the subconjunctival Tenon's capsule was demonstrated.