1.Antimicrobial and sealant properties of nanohydroxyapatite as endodontic sealer
Chinese Journal of Tissue Engineering Research 2014;(21):3350-3354
BACKGROUND:Depending on different pH values, nanohydroxyapatite materials have different purities, whether root canal sealers formed by which exert effects on antimicrobial resistance, root canal closure and apical histocompatibility has no reports.
OBJECTIVE:To compare the antimicrobial and sealant properties of nanohydroxyapatite materials with different pH, nanohydroxyapatite-composite and traditional root canal sealants.
METHODS:We detected the antimicrobial action of nanohydroxyapatite with pH 8, 9, 10, Vitapex and AH-Plus root canal sealants with and without addition of ornidazole against three microbial strains namely Enterococcus faecalis, Candida albicans and Staphylococcus aureus using agar diffusion method. And we also analyzed the endodontic microleakage of six root canal sealants by determining the apical reservoir glucose concentration using Glucose Oxidase Method.
RESULTS AND CONCLUSION:Pure nanohydroxyapatite with different pH did not show antimicrobial properties. Addition of ornidazole to nanohydroxyapatite showed greater inhibitory action against Enterococcus faecalis, lesser in Staphylococcus aureus, fol owed by Candida albicans. Vitapex root canal sealer had inhibitory effects only against Staphylococcus aureus. AH-Plus, itself, had antimicrobial activity against al the three strains, but the antimicrobial activity decreased after addition of ornidazole. Nanohydroxyapatite, as a root canal sealant, was superior to zinc oxide eugenol and Vitapex, but inferior to AH-Plus. Addition of ornidazole to nanohydroxyapatite for a short period showed no impact on sealant properties of the material.
2.Ion-pairing HPLC methods to determine EDTA and DTPA in small molecule and biological pharmaceutical formulations$
Wang George ; Tomasella P. Frank
Journal of Pharmaceutical Analysis 2016;6(3):150-156
Ion-pairing high-performance liquid chromatography–ultraviolet (HPLC–UV) methods were developed to determine two commonly used chelating agents, ethylenediaminetetraacetic acid (EDTA) in Abilifys (a small molecule drug with aripiprazole as the active pharmaceutical ingredient) oral solution and die-thylenetriaminepentaacetic acid (DTPA) in Yervoys (a monoclonal antibody drug with ipilimumab as the active pharmaceutical ingredient) intravenous formulation. Since the analytes, EDTA and DTPA, do not contain chromophores, transition metal ions (Cu2 t , Fe3 t ) which generate highly stable metallocom-plexes with the chelating agents were added into the sample preparation to enhance UV detection. The use of metallocomplexes with ion-pairing chromatography provides the ability to achieve the desired sensitivity and selectivity in the development of the method. Specifically, the sample preparation in-volving metallocomplex formation allowed sensitive UV detection. Copper was utilized for the de-termination of EDTA and iron was utilized for the determination of DTPA. In the case of EDTA, a gradient mobile phase separated the components of the formulation from the analyte. In the method for DTPA, the active drug substance, ipilimumab, was eluted in the void. In addition, the optimization of the concentration of the ion-pairing reagent was discussed as a means of enhancing the retention of the aminopolycarboxylic acids (APCAs) including EDTA and DTPA and the specificity of the method. The analytical method development was designed based on the chromatographic properties of the analytes, the nature of the sample matrix and the intended purpose of the method. Validation data were presented for the two methods. Finally, both methods were successfully utilized in determining the fate of the chelates.
3.Roles of ERK and cPLA2α in biphasic regulation of renal proximal Na+-HCO3-transport by angiotensin Ⅱ
Yuehong LI ; Seki GEORGE ; Mei WANG
Chinese Journal of Nephrology 2008;24(10):751-758
Objective To clarify the signaling mechanisms underlying angiotensin Ⅱ biphasic regulation of renal proximal Na+-HCO3- transport. Methods Different concentration Ang Ⅱ to the responses of Na+-HCO3- cotransporter (NBC) activity in isolated proximal tubules, with or without ATR, MAPK, cPLA2α, P450 blockade was compared in wild-type and Ang Ⅱ type 1a receptor (AT1aR)-deficient mice. The phospholipase of ERK was examined by Western blotting. AT1aR mRNA was examined by RT-PCR from kidney proximal tubules. Results (1)In isolated wild-type mouse, renal proximal tubules showed biphasic effects of Ang Ⅱ on NBC activity. Low concentration Ang Ⅱ (10-10 mol/L) increased NBC activity, but high concentration Ang Ⅱ (10-6 mol/L) decreased NBC activity. Olmcsartan (AT1 antagonist) blocked both stimnlatory and inhibitory effects of Ang Ⅱ on NBC activity, but PD98059 (mitogen-activated protein kinase inhibitor) blocked only the stimulatory effect of low concentration Ang Ⅱ ( 10-10 mol/L). (2)In AT1aR-deficient mice, only the stimulatory effect by high concentration of Ang Ⅱ (10-6 mol/L) was observed, which was blocked by olmesartan and PD98059. (3)In wild-type mice, pharmacological blockade of cPLA2 or P450 converted the inhibition effect by high concentration Ang Ⅱ (10-6 mol/L) to the stimulation, which was blocked by olmesanan and PD98059. These results indicated that the extracellular sigual-regulated kinase (ERK) activation via AT1 mediated only the stimulatory effect of Ang Ⅱ, while the cPLA2α/P450 activation via AT1 mediated the inhibitory effect of Ang Ⅱ independently of ERK. The analysis of ERK phosphorylation by Ang Ⅱ also supported a view that the cPLA2α/P450 pathway worked to suppress the ERK activation. Conclusions Ang Ⅱ activates ERK and cPLA2α with different concentration dependency via AT1. The balance between ERK and cPLA2α activities determines the final responses to Ang Ⅱ in intact proximal tubules.
4.A family cluster of nitrite poisoning, Suzhou City, Jiangsu Province, China, 2013
Wang Ruiping ; Teng Chen-gang ; Zhang Ning ; Zhang Jun ; Conway George
Western Pacific Surveillance and Response 2013;4(3):33-36
Background:In April 2013, a hospital in Suzhou City notified authorities of a patient with nitrite poisoning with two other family members who had similar toxic symptoms five days prior. We investigated the event to identify the cause, source and possible route of contamination.Methods:A case was defined as any person living in the Yang Shan Hua Yuan community who had been diagnosed with cyanoderma and food poisoning symptoms from 15 to 25 April 2013. Active case finding was conducted by interviewing community residents and reviewing medical records from local clinics; information was then retrospectively collected on the patient’s food history, cooking procedures and food sources.Results:We identified three nitrite poisoning cases, one male and two females, from the same family. The time between dinner and onset of illness was less than an a hour. A retrospective survey showed that a substance presumed to be sugar mixed with asparagus on 17 April and with stir-fried asparagus on 21 April was the suspected contaminant. The presumed sugar came from a clean-up of a neighbouring rental house. Nitrite was detected in a vomitus sample, the sugar substance and two leftover food samples.Conclusion:This family cluster of nitrite poisoning resulted from the mistaken use of nitrite as sugar to cook dishes. We recommend that sodium nitrite be dyed a bright colour to prevent such a mistake and that health departments strengthen food hygiene education to alert people about the danger of eating unidentified food from an unknown source.
5.Proliferation of retinal pigment epithelial cells induced by (R,R)-XY-10 and (S,S)-XY-10 and their action mechanisms
Yu-Wen, CHENG ; Yu-Liang, WANG ; Yi-Hua, ZHANG ; Si-Xun, PENG ; George C Y CHIOU
International Eye Science 2009;9(9):1641-1645
AIM: To investigate the mechanism of proliferation effect induced by (R,R)-XY-10 and (S,S)-XY-10 on retinal pigmented epithelial cells(ARPE-19).METHODS: Human retinal pigmented epithelial cells(ARPE-19) and human umbilical vein endothelial cells (HUVECs) were used to investigate the effect of (R,R)-XY-10 and (S,S)-XY-10 on cell growth,and their mechanisms of proliferative action by using ERK、 AKT、PI3K、Protein kinase C (PKC)and Nitric oxide synthase (NOS) inhibitors.RESULTS: (R,R)-XY-10 and (S,S)-XY-10 dose-dependently increased ARPE-19 cell proliferation,but not on HUVECs. When treated with proliferative inhibitors,H7(5μmol/L)、hypericin(20μmol/L)、PD98059(2μmol/L)、LY294002(50μmol/L)、SH-5 (10μmol/L) and L-NAME (100μmol/L),the proliferative effect was reduced by H7、hypericin、PD98059 and LY294002,but not by SH-5 and L-NAME.CONCLUSION: (R,R)-XY-10 and (S,S)-XY-10 can induce cell proliferation through MAPK and PI3K dependent pathway. KEYWORDS: age-related macular degeneration; (R,R)-XY-10; (S,S)-XY-10; ARPE-19 cells; human umbilical vein endothelial cells; proliferation
6.Anticancer potential of metabolic compounds from marine actinomycetes isolated from Lagos Lagoon sediment
Davies-Bolorunduro Flora OLABISI ; Adeleye Adeyemi ISAAC ; Akinleye Olushola MOSHOOD ; George-Peng WANG
Journal of Pharmaceutical Analysis 2019;9(3):201-208
Thirty-two actinomycetes strains were isolated from sediment samples from 12 different sites at Lagos Lagoon and identified using standard physiological and biochemical procedures as well as 16S rDNA gene sequence analysis. Secondary metabolites were extracted from the strains and their anticancer activity on the K562 (Human acute myelocytic leukemia), HeLa (cervical carcinoma), AGS (Human gastric), MCF-7 (breast adenocarcinoma) and HL-60 (Human acute promyelocytic leukemia) cell lines was determined. The metabolic extracts exhibited cytotoxicity with IC50 values ranging from 0.030 mg/mL to 4.4 mg/mL. The Streptomyces bingchenggensis ULS14 extract was cytotoxic against all the cell lines tested. The bioactivity-guided extraction and purification of the metabolic extracts from this strain yielded two purified anticancer compounds: ULDF4 and ULDF5. The structures of the extracted compounds were determined using spectroscopic analyses, including electrospray ionization mass spectrophotometer and nuclear magnetic resonance (1 Dimensional and 2 Dimensional), and were shown to be structurally similar to staurosporine and kigamicin. The IC50 of ULDF4 and ULDF5 against the HeLa cell line was 0.034 μg/mL and 0.075 μg/mL, respectively. This study is the first to reveal the anticancer potential of actinomycetes from Lagos Lagoon, which could be exploited for therapeutic purposes.
7.Surface Modification of Intraocular Lenses.
Qi HUANG ; George Pak-Man CHENG ; Kin CHIU ; Gui-Qin WANG ;
Chinese Medical Journal 2016;129(2):206-214
OBJECTIVEThis paper aimed to review the current literature on the surface modification of intraocular lenses (IOLs).
DATA SOURCESAll articles about surface modification of IOLs published up to 2015 were identified through a literature search on both PubMed and ScienceDirect.
STUDY SELECTIONThe articles on the surface modification of IOLs were included, but those on design modification and surface coating were excluded.
RESULTSTechnology of surface modification included plasma, ion beam, layer-by-layer self-assembly, ultraviolet radiation, and ozone. The main molecules introduced into IOLs surface were poly (ethylene glycol), polyhedral oligomeric silsesquioxane, 2-methacryloyloxyethyl phosphorylcholine, TiO 2 , heparin, F-heparin, titanium, titanium nitride, vinyl pyrrolidone, and inhibitors of cytokines. The surface modification either resulted in a more hydrophobic lens, a more hydrophilic lens, or a lens with a hydrophilic anterior and hydrophobic posterior surface. Advances in research regarding surface modification of IOLs had led to a better biocompatibility in both in vitro and animal experiments.
CONCLUSIONThe surface modification is an efficient, convenient, economic and promising method to improve the biocompatibility of IOLs.
Animals ; Heparin ; chemistry ; Humans ; Hydrophobic and Hydrophilic Interactions ; Lenses, Intraocular ; Methacrylates ; chemistry ; Ozone ; chemistry ; Phosphorylcholine ; analogs & derivatives ; chemistry ; Ultraviolet Rays
8.Insights into battles between Mycobacterium tuberculosis and macrophages.
Guanghua XU ; Jing WANG ; George Fu GAO ; Cui Hua LIU
Protein & Cell 2014;5(10):728-736
As the first line of immune defense for Mycobacterium tuberculosis (Mtb), macrophages also provide a major habitat for Mtb to reside in the host for years. The battles between Mtb and macrophages have been constant since ancient times. Triggered upon Mtb infection, multiple cellular pathways in macrophages are activated to initiate a tailored immune response toward the invading pathogen and regulate the cellular fates of the host as well. Toll-like receptors (TLRs) expressed on macrophages can recognize pathogen-associated-molecular patterns (PAMPs) on Mtb and mediate the production of immune-regulatory cytokines such as tumor necrosis factor (TNF) and type I Interferons (IFNs). In addition, Vitamin D receptor (VDR) and Vitamin D-1-hydroxylase are up-regulated in Mtb-infected macrophages, by which Vitamin D participates in innate immune responses. The signaling pathways that involve TNF, type I IFNs and Vitamin D are inter-connected, which play critical roles in the regulation of necroptosis, apoptosis, and autophagy of the infected macrophages. This review article summarizes current knowledge about the interactions between Mtb and macrophages, focusing on cellular fates of the Mtb-infected macrophages and the regulatory molecules and cellular pathways involved in those processes.
Animals
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Apoptosis
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Autophagy
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Humans
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Interferon Type I
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metabolism
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Macrophages
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immunology
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metabolism
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Mycobacterium tuberculosis
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physiology
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Receptors, Calcitriol
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metabolism
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Steroid Hydroxylases
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metabolism
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Toll-Like Receptors
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metabolism
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Tuberculosis
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immunology
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metabolism
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pathology
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Tumor Necrosis Factors
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metabolism
9.Interaction of Hsp40 with influenza virus M2 protein: implications for PKR signaling pathway.
Zhenhong GUAN ; Di LIU ; Shuofu MI ; Jie ZHANG ; Qinong YE ; Ming WANG ; George F GAO ; Jinghua YAN
Protein & Cell 2010;1(10):944-955
Influenza virus contains three integral membrane proteins: haemagglutinin, neuraminidase, and matrix protein (M1 and M2). Among them, M2 protein functions as an ion channel, important for virus uncoating in endosomes of virus-infected cells and essential for virus replication. In an effort to explore potential new functions of M2 in the virus life cycle, we used yeast two-hybrid system to search for M2-associated cellular proteins. One of the positive clones was identified as human Hsp40/Hdj1, a DnaJ/Hsp40 family protein. Here, we report that both BM2 (M2 of influenza B virus) and A/M2 (M2 of influenza A virus) interacted with Hsp40 in vitro and in vivo. The region of M2-Hsp40 interaction has been mapped to the CTD1 domain of Hsp40. Hsp40 has been reported to be a regulator of PKR signaling pathway by interacting with p58(IPK) that is a cellular inhibitor of PKR. PKR is a crucial component of the host defense response against virus infection. We therefore attempted to understand the relationship among M2, Hsp40 and p58(IPK) by further experimentation. The results demonstrated that both A/M2 and BM2 are able to bind to p58(IPK) in vitro and in vivo and enhance PKR autophosphorylation probably via forming a stable complex with Hsp40 and P58(IPK), and consequently induce cell death. These results suggest that influenza virus M2 protein is involved in p58(IPK) mediated PKR regulation during influenza virus infection, therefore affecting infected-cell life cycle and virus replication.
HSP40 Heat-Shock Proteins
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genetics
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metabolism
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Humans
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Orthomyxoviridae
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genetics
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metabolism
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Phosphorylation
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Protein Binding
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genetics
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Signal Transduction
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genetics
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Two-Hybrid System Techniques
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Viral Matrix Proteins
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metabolism
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Virus Replication
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genetics
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Virus Uncoating
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eIF-2 Kinase
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metabolism
10.Comparative genomic hybridization of esophageal squamous cell carcinoma and gastric cardia adenocarcinoma in high-incidence region of esophageal carcinoma, Linzhou Henan.
Yan-ru QIN ; Li-dong WANG ; Dora KWONG ; Xin-yuan GUAN ; Ze-hao ZHUANG ; Zong-min FAN ; Ji-ye AN ; George TSAO
Chinese Journal of Medical Genetics 2004;21(6):625-628
OBJECTIVETo characterize the profiles of chromosome imbalance in esophageal squamous cell carcinoma (SCC) and gastric cardia adenocarcinoma (GCA) from the high incidence area in Henan.
METHODSChromosomal aberrations of 37 samples of SCC and 30 GCA were analyzed by comparative genomic hybridization comparative genomic hybridization (CGH).
RESULTSIt was found that the most frequently detected gains were on chromosome arm 8q (78%), and followed by 3q, 5p, 6q and 7p. The most frequent loss was found on 3p (57%), and followed by 8p, 9q and 11q in SCC. For GCA, the most frequent gain was found on chromosome arm 20q (43%), and followed by 6q, 8q and 6p. The most frequent loss was on the chromosome 17p (57%), and followed by 19p, 1p and 4p.
CONCLUSIONThe present findings demonstrate that gains of 8q, 3q and 5p, and losses of 3p, 8p, and 9q are characteristic profile of chromosome imbalance in SCC, and the gains of 20q, 6q and losses of 17p, 19p and 1p are characteristic profile of chromosome imbalance in GCA, which provide important theoretic information for identifying and cloning novel SCC/GCA-related genes.
Adenocarcinoma ; genetics ; Carcinoma, Squamous Cell ; epidemiology ; genetics ; Cardia ; Chromosomes, Human, Pair 17 ; Chromosomes, Human, Pair 20 ; Chromosomes, Human, Pair 3 ; Chromosomes, Human, Pair 8 ; DNA, Neoplasm ; genetics ; Esophageal Neoplasms ; epidemiology ; genetics ; Gene Amplification ; Gene Deletion ; Humans ; Nucleic Acid Hybridization ; methods ; Stomach Neoplasms ; epidemiology ; genetics