University of Macau

About: University of Macau is a education organization based out in Macao, Macau, China. It is known for research contribution in the topics: Computer science & Population. The organization has 6636 authors who have published 18324 publications receiving 327384 citations. The organization is also known as: UM & UMAC.

Ethanolic extract of fructus Alpinia oxyphylla protects against 6-hydroxydopamine-induced damage of PC12 cells in vitro and dopaminergic neurons in zebrafish

Abstract: In an attempt to understand the neuroprotective effect of Fructus Alpinia oxyphylla (AOE) and to elucidate its underlying mechanism of action, the ethanolic extract of AOE was investigated using zebrafish and PC12 cell models. AOE prevented and restored 6-hydroxydopamine (6-OHDA)-induced dopaminergic (DA) neuron degeneration and attenuated a deficit of locomotor activity in a zebrafish (Danio rerio) model of Parkinson’s disease (PD). Treatment with AOE increased the viability of 6-OHDA-treated PC12 cells in vitro in a dose-dependent manner by attenuating cellular apoptosis. However, protocatechuic acid (PCA) and chrysin, two known polyphenol components of AOE, could not reproduce the neuroprotective activity of AOE in the PD zebrafish or PC12 cell models. A mechanistic study found that the protective effect of AOE against 6-OHDA-induced neuronal injury involved anti-inflammatory action (down-regulation of gene expression of IL-1β and TNF-α) and anti-oxidative action (inhibition of NO production and iNOS expression in PC12 cells). Moreover, the PI3K-AKT pathway might be part of the mechanism of neuroprotection of AOE. The results of this research are expected to provide a scientific rationale for the use of AOE in the treatment of PD. However, it is important that the active components that contribute to the neuroprotective action of AOE are identified and characterized.

Prevalence of suicide attempt in individuals with major depressive disorder: a meta-analysis of observational surveys.

Abstract: BackgroundSuicide attempt (SA), which is one of the strongest predictors of completed suicide, is common in major depressive disorder (MDD) but its prevalence across epidemiological studies has been mixed. The aim of this comprehensive meta-analysis was to examine the pooled prevalence of SA in individuals with MDD.MethodsA systematic literature search was conducted in PubMed, Embase, PsycINFO, Web of Science and Cochrane Library from their commencement date until 27 December 2017. Original studies containing data on prevalence of SA in individuals with MDD were analyzed.ResultsIn all, 65 studies with a total of 27 340 individuals with MDD were included. Using the random effects model, the pooled lifetime prevalence of SA was 31% [95% confidence interval (CI) 27–34%], 1-year prevalence was 8% (95% CI 3–14%) and 1-month prevalence was 24% (95% CI 15–34%). Subgroup analyses revealed that the lifetime prevalence of SA was significantly associated with the patient setting, study region and income level, while the 1-month prevalence of SA was associated with only the patient setting.ConclusionThis meta-analysis confirmed that SA was common in individuals with MDD across the world. Careful screening and appropriate interventions should be implemented for SA in the MDD population.

Wideband Stub-Loaded Slotline Antennas Under Multi-Mode Resonance Operation

Abstract: A novel center-fed wideband slotline antenna is proposed using the multi-mode resonance concept. By symmetrically introducing one or two pairs of slot stubs along the slotline resonator near the nulls of electric field distribution of the second odd-order mode, two modes are excited in a single slotline radiator. With the help of these stubs, the second odd-order mode can be gradually merged with its first counterpart, resulting in a wideband radiation characteristic with two resonances. Prototype antennas are then designed and fabricated to experimentally validate the principle and design approach. It is shown that the operation fractional bandwidth of the proposed slotline antenna could be effectively increased to 31.5% while keeping an inherent narrow slot structure.

Oridonin Induces Apoptosis, Inhibits Migration and Invasion on Highly-Metastatic Human Breast Cancer Cells

Abstract: Oridonin, a natural tetracycline diterpenoid isolated from Chinese herb Rabdosia rubescens, has been reported to be a potent cytotoxic agent against a wide variety of tumors. However, its effect on highly metastatic breast cancer cells has not been addressed. In this study, we investigated the effects of oridonin on growth, migration and invasion of highly-metastatic human breast cancer cells. Our results showed that oridonin induced potent growth inhibition on human breast cancer cells MCF-7 and MDA-MB-231 in a time- and dose-dependent manner. According to the flow cytometric analysis, oridonin suppressed MCF-7 cell growth by cell cycle arrest at the G2/M phase and caused accumulation of MDA-MB-231 cells in the Sub-G1 phase. The induced apoptotic effect of oridonin was further confirmed by a morphologic characteristics assay and TUNEL assay. Oridonin triggered the reduction of Bcl-2/Bax ratio, caspase-8, NF-κB (p65), IKKα, IKKβ, phospho-mTOR, and increased expression level of cleaved PARP, Fas and PPARγ in a time-dependent manner. Immunofluorescent analysis showed that γH2AX-containing nuclear foci were significant in oridonin-treated MDA-MB-231 cells. Meanwhile, oridonin significantly suppressed MDA-MB-231 cell migration and invasion, decreased MMP-2/MMP-9 activation and inhibited the expression of Integrin β1 and FAK. In conclusion, oridonin inhibited the growth and induced apoptosis in breast cancer cells, which might be related to DNA damage and activation of intrinsic or extrinsic apoptotic pathways. Moreover, oridonin also inhibited tumor invasion and metastasis in vitro possibly via decreasing the expression of MMPs and regulating the Integrin β1/FAK pathway in MDA-MB-231 cells.