Protective effect of procyanidin B2 on hydrogen peroxide (H2O2)-induced oxidative damage in MCF-7 cells

Tan Jia-qi,Li Peng-cheng,Li Qian,Tang Jin-tian,Xue Hong-kun 한국응용생명화학회 2020 Applied Biological Chemistry (Appl Biol Chem) Vol.63 No.5

The aim of this study is to assess the cytoprotection and potential molecular mechanisms of procyanidin B2 ( PCB2) on hydrogen peroxide ( H2O2)-induced oxidative damage in MCF-7 cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to determine the viability of MCF-7 cell exposure to H2O2 or PCB2. We measured the antioxidant properties of PCB2 by determining the activities of SOD, GSH-Px, LDH and MDA levels, and evaluated apoptosis and intracellular reactive oxygen species (ROS) levels. The related proteins expression levels were monitored by Western blot. MCF-7 cells induced with H2O2 had a remarkable decrease in cell viability that was suppressed when it was interfered with PCB2 (0.1–10.0 μM). PCB2 interference memorably and dose-dependently inhibited H2O2- induced LDH leakage, ROS and MDA overproduction, while PCB2 markedly increased H2O2- induced the activities of SOD and GSH-Px. Eventually, H2O2 prominently down-regulated the ratio of Bcl-2/Bax and the relative proteins expression levels of Nrf2, GCLC, NQO1 and HO-1, and up-regulated the relative proteins expression levels of cytochrome c, caspase-3 and Keap1. However, the relative expression levels of these proteins were reversed in PCB2- interfered MCF-7 cells. This study implied that protective effect of PCB2 on H2O2- induced oxidative damage in MCF-7 cells might be related to inhibition of mitochondria-dependent apoptosis, activation of Keap1/Nrf2/HO-1 signaling pathway and improvement of the antioxidant enzymes activities.

淺朝鮮半島변文述略

담가건 ( Jia Jian Tan ) 한국중국산문학회 2015 중국산문연구집간 Vol.5 No.-

Korean Peninsula lies to the east of China. In its history, significant anthologies like Parallel Prose of Koreans(Dong Ren Zhi Wen Si Liu), Anthology of Korean Prose(Dong Wen Xuan) and so on to a large extent reflect the achievements of parallel prose. As early as 470s, a few of parallel prose written by Baekje civil officials were still in existence. Since then, eminent figures came forth with large numbers, and over a thousand year, parallel prose can be found in the collected works of literati in large quantities. The achievements of Ancient Korean parallel prose embody the affiliation shared by Chinese and Korean culture traditions. Furthermore, these works enjoy multiple document value out of their extensive concern for politics, diplomacy, learning and aesthetic.

Alternating Hemiplegia of Childhood in a Person of Malay Ethnicity with Diffusion Tensor Imaging Abnormalities

Ai Huey Tan,Tien Lee Ong,Norlisah Ramli,Li Kuo Tan,Jia Lun Lim,Mohamad Addin Azhan,Azlina Ahmad Annuar,Khairul Azmi Ibrahim,Zariah Abdul-Aziz,Laurie J. Ozelius,Allison Brashear,Shen-Yang LIM 대한파킨슨병및이상운동질환학회 2019 Journal Of Movement Disorders Vol.12 No.2

Alternating hemiplegia of childhood (AHC) is a rare neurodevelopmentaldisorder with an incidence of one per million,characterized by paroxysmal alternating hemiplegia, eye movementabnormalities, dystonia, and epilepsy.1 In 2012, mutationsin the ATP1A3 gene encoding the Na+-K+-ATPase α3 subunit(originally discovered in rapid-onset dystonia-parkinsonism)were identified as the cause for AHC.1,2 However, the diagnosisof AHC is still often delayed or missed. We report a case of AHCdiagnosed in adulthood; to our knowledge, this is the first reportin a person of Malay ethnicity.

Systematic review: total knee arthroplasty (TKA) in patients with pigmented villonodular synovitis (PVNS)

( Yi Chuen Tan ),( Jia Yin Tan ),( Konstantinos Tsitskaris ) 대한슬관절학회 2021 대한슬관절학회지 Vol.33 No.-

Background: To determine the functional outcomes, complications and revision rates following total knee arthroplasty (TKA) in patients with pigmented villonodular synovitis (PVNS). Materials and methods: We conducted a systematic review of the literature. Five studies with a total of 552 TKAs were included for analysis. The methodological quality of the articles was evaluated using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) scale. Functional outcomes, complications and revision rates were assessed. The mean age was 61 years (range 33-94 years) and the mean follow-up period was 61.1 months (range 0.2-35 years). Results: All the studies reported improvement in knee function following TKA. Post-operative stiffness was the most frequently reported complication, affecting 32.7% (n = 32) of patients in our review. Symptomatic recurrence of PVNS, component loosening, tibial-component fracture, instability and periprosthetic infection were the main factors leading to the need for revision TKA. Conclusion: The findings of this review support the use of TKA to alleviate the functional limitations and pain due to knee degeneration in patients with PVNS. The operating surgeon should be aware of the increased risk of postoperative stiffness, as well as a potentially higher risk of infection. Implant survival should also be considered inferior to the one expected for the general population undergoing TKA.

Ginseng improves cognitive deficit via the RAGE/NF-κB pathway in advanced glycation end product-induced rats

Tan, Xiaobin,Gu, Junfei,Zhao, Bingjie,Wang, Shuyuan,Yuan, Jiarui,Wang, Chunfei,Chen, Juan,Liu, Jiping,Feng, Liang,Jia, Xiaobin The Korean Society of Ginseng 2015 Journal of Ginseng Research Vol.39 No.2

Background: Ginseng, the root of Panax ginseng (PG), is used widely as a herbal medicine to prevent and treat various diseases. Panax ginseng has pharmacological effects on neurodegenerative diseases such as Alzheimer's disease (AD). The present study evaluated the neuroprotective effects of PG and its possible neuroprotective mechanisms in advanced glycation end product (AGE)-induced AD in a rat model. Methods: Advanced glycation end products were injected bilaterally into the CA3 region of the rats' brains. The Morris water maze test and step-down type passive avoidance test were performed to evaluate their memory and cognitive abilities. The oxidation indexes in the hippocampus were detected. Immunohistochemistry was conducted to visualize the receptors for advanced glycation end products (RAGEs) and nuclear factor-kappa-light-chain-enhancer of activated B cell (NF-${\kappa}B$). Results: Behavioral results showed that PG (1 g/kg, 0.5 g/kg, and 0.25 g/kg) significantly shortened the escape latency, remarkably increased the number of crossing times, significantly decreased the number of errors, and prolonged the latency in rats with AGE-induced AD. Panax ginseng also significantly reduced the malondialdehyde level, increased the glutathione content, and increased superoxide dismutase activity in the hippocampus. Panax ginseng significantly decreased the expression of RAGE and NF-${\kappa}B$. The blockade of anti-RAGE antibody could significantly reduce AGE-induced impairments and regulate these expressions. Conclusion: Our results demonstrated that PG significantly inhibits AGE-induced memory impairment and attenuates Alzheimer-like pathophysiological changes. These neuroprotective effects of PG may be associated with the RAGE/NF-${\kappa}B$ pathway. Our results provided the experimental basis for applying PG in preventing and treating AD.

Sound absorption coefficient measurement and analysis of bio-composite micro perforated panel (BC-MPP)

Tan Wei Hong,Faridah Wahab,Lee Jia Jian,Siti Hajar Ishak 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.7

The sound absorption performance of bio-composite micro-perforated panel (BC-MPP) made from composite polypropylene (PP) filled rice husk (PP/RH), and coconut coir (PP/CC) is presented. The sound absorption coefficient (SAC) of BC-MPP was obtained via the impedance tube two-microphone method, and the investigation was according to types of fillers, filler compositions, perforation ratio, and the air gap size. It was found that the SAC of BCMPP PP/RH provides a higher SAC value than BC-MPP PP/CC. Furthermore, the SAC peak was observed to shift to the lower frequency spectrum when there was an increment in filler content, the distance between the perforation, and the air gap size. The SAC value from the simulation also shows a good agreement with the experimental result.

Fecal Calprotectin in Parkinson’s Disease and Multiple System Atrophy

Jia Wei Hor,Ai Huey Tan 대한파킨슨병및이상운동질환학회 2022 Journal Of Movement Disorders Vol.15 No.2

Converging evidence suggests that intestinal inflammation is involved in the pathogenesis of neurodegenerative diseases. Previous studies on fecal calprotectin in Parkinson’s disease (PD) were limited by small sample sizes, and literature regarding intestinal inflammation in multiple system atrophy (MSA) is very scarce. We investigated the levels of fecal calprotectin, a marker of intestinal inflammation, in PD and MSA.

Effect of 3.7 at% F doping on the atomic structure and reducibility of CeO2(111) surface: A first principles calculation

Jia Huiling,Hu Jinbao,Chen Hao,Wu Jinxiu,Tan Xin,Sun Shiyang 한국물리학회 2022 Current Applied Physics Vol.43 No.-

Density functional theory calculations was conducted to clarify effect of fluorination on the reducibility of CeO2 polishing powder. The atomic structure and O vacancy formation energy of F-doped CeO2(111) surface were systematically calculated, and electronic structure was also analyzed to understand the calculation results. It showed that the CeO1.963(111) surface needs absorb 7.853 eV to be reduced further, so it is difficult to generate the second O vacancy (V2). After fluorination, the first O vacancy (V1) in CeO1.926F0.037(111) surface caused adjacent atoms to move significantly, and O vacancy formation energy decreased to 2.913 eV, which promoted the formation of V2. Moreover, electronic structure calculation also showed that the interaction between O2p and Ce4f5d orbits was enhanced in reduced CeO1.963(111) surface, which hindered the formation of V2. The F2p orbit in CeO1.926F0.037(111) surface moved towards the low energy level, V1 made the reduced surface stable and promoted the formation of V2.

Enantioselective Synthesis of <i>anti</i>–<i>syn</i>-Trihalides and <i>anti</i>–<i>syn</i>–<i>anti</i>-Tetrahalides via Asymmetric β-Elimination

Tan, Yu,Luo, Shilong,Li, Dongmei,Zhang, Nan,Jia, Shiqi,Liu, Yidong,Qin, Wenling,Song, Choong Eui,Yan, Hailong American Chemical Society 2017 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.139 No.18

<P>Structural motifs containing contiguous halide bearing stereocenters are common in natural products as well as bioactive molecules. A few successful examples have been reported in the area of asymmetric vicinal dihalogenation of alkenes for accessing dihalogenated products; in this report, an alternative generation method of contiguous halide-bearing stereocenters alpha,beta,gamma,delta relative to carbonyl group in excellent enantioselectivity is proposed by utilizing a Song's oligoEG catalyst-catalyzed asymmetric beta-elimination. According to this methodology, a wide range of anti-syn-trihalides and anti-syn-anti-tetrahalides with high levels of enantioselectivity were synthesized. The synthetic utility of the contiguous halide-bearing stereocenters was demonstrated by several transformations. The results of high-resolution mass spectrometry indicated that the favorable interaction between catalyst and one of the enantiomers of racemic contiguously multihalogenated ketone contributed to the original enantioselectivity of dehydrohalogenation. A deuterium kinetic isotope effect experiment revealed that this beta-elimination reaction proceeds by the E2 mechanism. This strategy opens a new pathway for the asymmetric synthesis of contiguous halide bearing stereocenters of great complexity.</P>

Cervical Pneumatocele as Delayed Manifestation of Tracheal Injury after Thyroidectomy: Case Series and Literature Review

Jia Ern Leong,Wai Leong Kok,Yee Ling Tan,Balwinder Singh Mann,Sadhana Mahamad 대한갑상선-내분비외과학회 2021 The Koreran journal of Endocrine Surgery Vol.21 No.1

Delayed manifestation of surgical emphysema as cervical pneumatocele post thyroid surgery is rare and unexpected that which needs to be managed appropriately. Herein we report three cases of delayed tracheal injury presenting with persistent subcutaneous emphysema, without acute respiratory distress. All three cases were managed surgically. Possible risk factors were discussed alongside hypotheses on the mechanisms of delayed tracheal injury and recommendations to prevent such complications. The management algorithm was summarized after the literature review. While surgical management is definitive, the non-surgical approach can also be a reasonable option, but requires a longer hospital stay.