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Find video protocols related to scientific articles indexed in Pubmed.
Acute effects of noise exposure on 24-h ambulatory blood pressure in hypertensive adults.
J. Hypertens.
PUBLISHED: 11-08-2014
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Noise exposure is associated with elevated blood pressure, but the effects on susceptible workers have not been reported. This repeated-measure study investigated the effects of noise exposure on 24-h ambulatory blood pressure among hypertensive, pre-hypertensive, and normotensive adults.
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Inhibiting ACAT1/SOAT1 in Microglia Stimulates Autophagy-Mediated Lysosomal Proteolysis and Increases A?1-42 Clearance.
J. Neurosci.
PUBLISHED: 10-24-2014
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Acyl-CoA:cholesterol acyltransferase 1 (ACAT1) is a resident endoplasmic reticulum enzyme that prevents the buildup of cholesterol in membranes by converting it to cholesterol esters. Blocking ACAT1 pharmacologically or by Acat1 gene knock-out (KO) decreases amyloidopathy in mouse models for Alzheimer's disease. However, the beneficial actions of ACAT1 blockage to treat Alzheimer's disease remained not well understood. Microglia play essential roles in the proteolytic clearance of amyloid ? (A?) peptides. Here we show that Acat1 gene KO in mouse increases phagocytic uptake of oligomeric A?1-42 and stimulates lysosomal A?1-42 degradation in cultured microglia and in vivo. Additional results show that Acat1 gene KO or a specific ACAT1 inhibitor K604 stimulates autophagosome formation and transcription factor EB-mediated lysosomal proteolysis. Surprisingly, the effect of ACAT1 blockage does not alter mTOR signaling or endoplasmic reticulum stress response but can be modulated by agents that disrupt cholesterol biosynthesis. To our knowledge, our current study provides the first example that a small molecule (K604) can promote autophagy in an mTOR-independent manner to activate the coordinated lysosomal expression and regulation network. Autophagy is needed to degrade misfolded proteins/peptides. Our results implicate that blocking ACAT1 may provide a new way to benefit multiple neurodegenerative diseases.
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Operation of emergency operating centers during mass casualty incidents in taiwan: a disaster management perspective.
Disaster Med Public Health Prep
PUBLISHED: 09-15-2014
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On April 27, 2011, a train derailed and crashed in Taiwan, causing a mass casualty incident (MCI) that was similar to a previous event and with similar consequences. In both disasters, the emergency operating centers (EOCs) could not effectively integrate associated agencies to deal with the incident. The coordination and utilization of resources were inefficient, which caused difficulty in command structure operation and casualty evacuation.
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Therapeutic effect of dynamic interpersonal group psychotherapy for taiwanese patients with depressive disorder.
Int J Group Psychother
PUBLISHED: 09-05-2014
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This study investigated the therapeutic effects of dynamic interpersonal group psychotherapy (DIGP) for the depressed in Taiwan. A 16-session DIGP was held weekly, and participants were evaluated with the Hamilton Depression Rating Scale, Taiwanese Depression Questionnaire, and World Health Organization Quality of Life-BREF before and after DIGP. Compared with control group, the patients treated with DIGP showed significant improvement in severity of their depression, especially in the somatic subscale and quality of life regarding psychological health. We found that focusing on repairing interpersonal interaction in DIGP would improve the social interaction problems of Chinese with depressive disorder.
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Physicochemical and biological characterization of single-walled and double-walled carbon nanotubes in biological media.
J. Hazard. Mater.
PUBLISHED: 08-10-2014
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To study the toxicity of nanoparticles under relevant conditions, it is important to reproducibly disperse nanoparticles in biological media in in vitro and in vivo studies. Here, single-walled nanotubes (SWNTs) and double-walled nanotubes (DWNTs) were physicochemically and biologically characterized when dispersed in phosphate-buffered saline (PBS) and bovine serum albumin (BSA). BSA-SWNT/DWNT interaction resulted in a reduction of aggregation and an increase in particle stabilization. Based on the protein sequence coverage and protein binding results, DWNTs exhibited higher protein binding than SWNTs. SWNT and DWNT suspensions in the presence of BSA increased interleukin-6 (IL-6) levels and reduced tumor necrosis factor-alpha (TNF-?) levels in A549 cells as compared to corresponding samples in the absence of BSA. We next determined the effects of SWNTs and DWNTs on pulmonary protein modification using bronchoalveolar lavage fluid (BALF) as a surrogate collected form BALB/c mice. The BALF proteins bound to SWNTs (13 proteins) and DWNTs (11 proteins), suggesting that these proteins were associated with blood coagulation pathways. Lastly, we demonstrated the importance of physicochemical and biological alterations of SWNTs and DWNTs when dispersed in biological media, since protein binding may result in the misinterpretation of in vitro results and the activation of protein-regulated biological responses.
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Mobile phone use and health symptoms in children.
J. Formos. Med. Assoc.
PUBLISHED: 08-09-2014
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To investigate the mobile phone (MP) use for talking in relation to health symptoms among 2042 children aged 11-15 years in Taiwan.
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0274?Occupational noise exposure and the prevalence of hyperglycemia.
Occup Environ Med
PUBLISHED: 07-15-2014
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This cross-sectional study aimed to investigate the association between occupational noise exposure and the prevalence of hyperglycemia among workers.
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0240?Acute effects of occupational noise exposure on 24-hour ambulatory cardiac parameters in workers.
Occup Environ Med
PUBLISHED: 07-15-2014
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Exposure to noise has been associated with cardiovascular disease, but the mechanism related to cardiac activity is unknown. This repeated-measure study aimed to investigate effects of occupational noise exposure on 24-hour ambulatory cardiac parameters among aviation industry workers.
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General anesthesia in the pediatric population.
Curr Opin Ophthalmol
PUBLISHED: 07-04-2014
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This article reviews the pertinent perioperative, intraoperative, and short- and long-term postoperative risks associated with general anesthesia in children undergoing ocular surgery.
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Acyl-CoA:cholesterol acyltransferases (ACATs/SOATs): Enzymes with multiple sterols as substrates and as activators.
J. Steroid Biochem. Mol. Biol.
PUBLISHED: 06-05-2014
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Cholesterol is essential to the growth and viability of cells. The metabolites of cholesterol include: steroids, oxysterols, and bile acids, all of which play important physiological functions. Cholesterol and its metabolites have been implicated in the pathogenesis of multiple human diseases, including: atherosclerosis, cancer, neurodegenerative diseases, and diabetes. Thus, understanding how cells maintain the homeostasis of cholesterol and its metabolites is an important area of study. Acyl-coenzyme A:cholesterol acyltransferases (ACATs, also abbreviated as SOATs) converts cholesterol to cholesteryl esters and play key roles in the regulation of cellular cholesterol homeostasis. ACATs are most unusual enzymes because (i) they metabolize diverse substrates including both sterols and certain steroids; (ii) they contain two different binding sites for steroidal molecules. In mammals, there are two ACAT genes that encode two different enzymes, ACAT1 and ACAT2. Both are allosteric enzymes that can be activated by a variety of sterols. In addition to cholesterol, other sterols that possess the 3-beta OH at C-3, including PREG, oxysterols (such as 24(S)-hydroxycholesterol and 27-hydroxycholesterol, etc.), and various plant sterols, could all be ACAT substrates. All sterols that possess the iso-octyl side chain including cholesterol, oxysterols, various plant sterols could all be activators of ACAT. PREG can only be an ACAT substrate because it lacks the iso-octyl side chain required to be an ACAT activator. The unnatural cholesterol analogs epi-cholesterol (with 3-alpha OH in steroid ring B) and ent-cholesterol (the mirror image of cholesterol) contain the iso-octyl side chain but do not have the 3-beta OH at C-3. Thus, they can only serve as activators and cannot serve as substrates. Thus, within the ACAT holoenzyme, there are site(s) that bind sterol as substrate and site(s) that bind sterol as activator; these sites are distinct from each other. These features form the basis to further pursue ACAT structure-function analysis, and can be explored to develop novel allosteric ACAT inhibitors for therapeutic purposes. This article is part of a Special Issue entitled 'Steroid/Sterol signaling'.
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The epigenetic drug 5-azacytidine interferes with cholesterol and lipid metabolism.
J. Biol. Chem.
PUBLISHED: 05-22-2014
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DNA methylation and histone acetylation inhibitors are widely used to study the role of epigenetic marks in the regulation of gene expression. In addition, several of these molecules are being tested in clinical trials or already in use in the clinic. Antimetabolites, such as the DNA-hypomethylating agent 5-azacytidine (5-AzaC), have been shown to lower malignant progression to acute myeloid leukemia and to prolong survival in patients with myelodysplastic syndromes. Here we examined the effects of DNA methylation inhibitors on the expression of lipid biosynthetic and uptake genes. Our data demonstrate that, independently of DNA methylation, 5-AzaC selectively and very potently reduces expression of key genes involved in cholesterol and lipid metabolism (e.g. PCSK9, HMGCR, and FASN) in all tested cell lines and in vivo in mouse liver. Treatment with 5-AzaC disturbed subcellular cholesterol homeostasis, thereby impeding activation of sterol regulatory element-binding proteins (key regulators of lipid metabolism). Through inhibition of UMP synthase, 5-AzaC also strongly induced expression of 1-acylglycerol-3-phosphate O-acyltransferase 9 (AGPAT9) and promoted triacylglycerol synthesis and cytosolic lipid droplet formation. Remarkably, complete reversal was obtained by the co-addition of either UMP or cytidine. Therefore, this study provides the first evidence that inhibition of the de novo pyrimidine synthesis by 5-AzaC disturbs cholesterol and lipid homeostasis, probably through the glycerolipid biosynthesis pathway, which may contribute mechanistically to its beneficial cytostatic properties.
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Road traffic noise frequency and prevalent hypertension in Taichung, Taiwan: a cross-sectional study.
Environ Health
PUBLISHED: 04-16-2014
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Epidemiological studies have reported the association between hypertension and exposure to road traffic noise, but the association between noise frequency characteristics is not clear. This study investigated the association between exposure to different frequency components of road traffic noise and the prevalence of hypertension in central Taiwan.
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Inhibition of cancer cell migration and invasion through suppressing the Wnt1-mediating signal pathway by G-quadruplex structure stabilizers.
J. Biol. Chem.
PUBLISHED: 04-08-2014
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WNT1 encodes a multifunctional signaling glycoprotein that is highly expressed in several malignant tumors. Patients with Wnt1-positive cancer are usually related to advanced metastasis. Here, we found that a stretch of G-rich sequences located at the WNT1 promoter region is capable of forming G-quadruplex structures. The addition of G-quadruplex structure stabilizers, BMVC and BMVC4, raises the melting temperature of the oligonucleotide formed by the WNT1 promoter G-rich sequences. Significantly, the expression of WNT1 was repressed by BMVC or BMVC4 in a G-quadruplex-dependent manner, suggesting that they can be used to modulate WNT1 expression. The role of G-quadruplex stabilizers on Wnt1-mediated cancer migration and invasion was further analyzed. The protein levels of ?-catenin, a mediator of the Wnt-mediated signaling pathway, and the downstream targets MMP7 and survivin were down-regulated upon BMVC or BMVC4 treatments. Moreover, the migration and invasion activities of cancer cells were inhibited by BMVC and BMVC4, and the inhibitory effects can be reversed by WNT1-overexpression. Thus the Wnt1 expression and its downstream signaling pathways can be regulated through the G-quadruplex sequences located at its promoter region. These findings provide a novel approach for future drug development to inhibit migration and invasion of cancer cells.
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Genetic variants in microRNAs and microRNA target sites predict biochemical recurrence after radical prostatectomy in localized prostate cancer.
Int. J. Cancer
PUBLISHED: 03-12-2014
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Recent evidence indicates that microRNAs might participate in prostate cancer initiation, progression and treatment response. Germline variations in microRNAs might alter target gene expression and modify the efficacy of prostate cancer therapy. To determine whether genetic variants in microRNAs and microRNA target sites are associated with the risk of biochemical recurrence (BCR) after radical prostatectomy (RP). We retrospectively studied two independent cohorts composed of 320 Asian and 526 Caucasian men with pathologically organ-confined prostate cancer who had a median follow-up of 54.7 and 88.8 months after RP, respectively. Patients were systematically genotyped for 64 single-nucleotide polymorphisms (SNPs) in microRNAs and microRNA target sites, and their prognostic significance on BCR was assessed by Kaplan-Meier analysis and Cox regression model. After adjusting for known clinicopathologic risk factors, two SNPs (MIR605 rs2043556 and CDON rs3737336) remained associated with BCR. The numbers of risk alleles showed a cumulative effect on BCR [perallele hazard ratio (HR) 1.60, 95% confidence interval (CI) 1.16-2.21, p for trend?=?0.005] in Asian cohort, and the risk was replicated in Caucasian cohort (HR 1.55, 95% CI 1.15-2.08, p for trend?=?0.004) and in combined analysis (HR 1.57, 95% CI 1.26-1.96, p for trend <0.001). Results warrant replication in larger cohorts. This is the first study demonstrating that SNPs in microRNAs and microRNA target sites can be predictive biomarkers for BCR after RP.
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Beta blocker treatment of infantile conjunctival hemangiomas--observations from 2 cases.
J AAPOS
PUBLISHED: 02-27-2014
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Infantile conjunctival hemangiomas are rare lesions in comparison to cutaneous and orbital capillary hemangiomas. They generally present several weeks following birth as a red stromal mass. Recent reports of cutaneous and orbital infantile hemangiomas involuting in response to oral or topical beta blocker treatment suggest that infantile conjunctival hemangiomas could respond similarly. We report 2 cases of presumed infantile hemangiomas of the conjunctiva. One, associated with cutaneous hemangiomas, did not respond to oral propranolol; the other was isolated and resolved with topical timolol.
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Enhanced resistive switching memory characteristics and mechanism using a Ti nanolayer at the W/TaOx interface.
Nanoscale Res Lett
PUBLISHED: 02-21-2014
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Enhanced resistive memory characteristics with 10,000 consecutive direct current switching cycles, long read pulse endurance of >105 cycles, and good data retention of >104 s with a good resistance ratio of >102 at 85°C are obtained using a Ti nanolayer to form a W/TiOx/TaOx/W structure under a low current operation of 80 ?A, while few switching cycles are observed for W/TaOx/W structure under a higher current compliance >300 ?A. The low resistance state decreases with increasing current compliances from 10 to 100 ?A, and the device could be operated at a low RESET current of 23 ?A. A small device size of 150?×?150 nm2 is observed by transmission electron microscopy. The presence of oxygen-deficient TaOx nanofilament in a W/TiOx/TaOx/W structure after switching is investigated by Auger electron spectroscopy. Oxygen ion (negative charge) migration is found to lead to filament formation/rupture, and it is controlled by Ti nanolayer at the W/TaOx interface. Conducting nanofilament diameter is estimated to be 3 nm by a new method, indicating a high memory density of approximately equal to 100 Tbit/in.2.
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Time-dependent pH sensing phenomena using CdSe/ZnS quantum dots in EIS structure.
Nanoscale Res Lett
PUBLISHED: 02-20-2014
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Time-dependent pH sensing phenomena of the core-shell CdSe/ZnS quantum dot (QD) sensors in EIS (electrolyte insulator semiconductor) structure have been investigated for the first time. The quantum dots are immobilized by chaperonin GroEL protein, which are observed by both atomic force microscope and scanning electron microscope. The diameter of one QD is approximately 6.5 nm. The QDs are not oxidized over a long time and core-shell CdSe/ZnS are confirmed by X-ray photon spectroscopy. The sensors are studied for sensing of hydrogen ions concentration in different buffer solutions at broad pH range of 2 to 12. The QD sensors show improved sensitivity (38 to 55 mV/pH) as compared to bare SiO2 sensor (36 to 23 mV/pH) with time period of 0 to 24 months, owing to the reduction of defects in the QDs. Therefore, the differential sensitivity of the QD sensors with respect to the bare SiO2 sensors is improved from 2 to 32 mV/pH for the time period of 0 to 24 months. After 24 months, the sensitivity of the QD sensors is close to ideal Nernstian response with good linearity of 99.96%. Stability and repeatability of the QD sensors show low drift (10 mV for 10 cycles) as well as small hysteresis characteristics (<10 mV). This QD sensor is very useful for future human disease diagnostics.
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Secretin: historical perspective and current status.
Pancreas
PUBLISHED: 02-13-2014
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This review describes the history of secretin discovery, identification, purification, and structural determination; cloning of secretin and its receptor; synthetic secretin; and highly specific and sensitive radioimmunoassay to define the characteristic physiological role on postprandial pancreatic fluid and bicarbonate secretion, which requires robust potentiation by cholecystokinin. Secretin plays a key role in the negative and positive regulatory mechanisms of exocrine pancreatic secretion. Secretin-releasing peptides were discovered in duodenal acid perfusates of both rat and dog and in canine pancreatic juice. The release and action of secretin and secretin-releasing peptides are in part mediated via vagovagal reflex mechanism involving afferent sensory neurons in proximal intestine and efferent cholinergic neurons in the pancreas. Besides acetylcholine, many neurotransmitters or neuromodulators influence release and action of secretin. The action of secretin in the pancreas depends on insulin, which also suppresses local release of somatostatin and pancreatic polypeptide. Thus, release and action of secretin are mediated via neurohormonal interaction. Clinical conditions with hypersecretinemia and hyposecretinemia are discussed. Synthetic human secretin is used for studies of exocrine pancreatic secretion, secretin-enhanced magnetic resonance cholangiopancreatography combined with exocrine pancreatic function test and diagnosis of gastrinoma syndrome. Therapeutic use of secretin is considered for the relief of severe pain in chronic pancreatitis.
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Leaf-derived cecidomyiid galls are sinks in Machilus thunbergii (Lauraceae) leaves.
Physiol Plant
PUBLISHED: 02-06-2014
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Three relevant hypotheses - nutrition, environment and the enemies hypothesis - often invoked to explore source and sink relationships between galls and their host plants are still under dispute. In this research, chlorophyll fluorescence, gas exchange capacity, stomatal conductance, total carbon and nitrogen, total soluble sugars and starches, and scanning and transmission electron microscopy of two types of galls were used to investigate source-sink relationships. Compared with host leaves, these galls demonstrated slightly lower chlorophyll fluorescence; however, gas exchange capacity and stomatal conductance were not detected at all. Scanning electron micrographs demonstrated that the abaxial epidermis of host leaves contain normal amounts of stomata, whereas no stomata were observed on the exterior and interior surfaces of both types of galls. In addition, gall inner surfaces were covered with many kinds of fungal hyphae. Gall total carbon (C) and nitrogen (N) levels were lower but the C/N ratio was higher in galls than host leaves. Both types of galls accumulated higher total soluble sugars and starches than host leaves. Transmission electron micrographs also revealed that both types of galls contain plastoglobuli and giant starch granules during gall development. Results strongly indicate that leaf-derived cecidomyiid galls are sinks in Machilus thunbergii leaves. However, it is perplexing how larvae cycle and balance CO2 and O2 in gall growth chambers without stomata.
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Structural basis of sodium-potassium exchange of a human telomeric DNA quadruplex without topological conversion.
Nucleic Acids Res.
PUBLISHED: 01-29-2014
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Understanding the mechanism of Na(+)/K(+)-dependent spectral conversion of human telomeric G-quadruplex (G4) sequences has been limited not only because of the structural polymorphism but also the lack of sufficient structural information at different stages along the conversion process for one given oligonucleotide. In this work, we have determined the topology of the Na(+) form of Tel23 G4, which is the same hybrid form as the K(+) form of Tel23 G4 despite the distinct spectral patterns in their respective nuclear magnetic resonance (NMR) and circular dichroism spectra. The spectral difference, particularly the well-resolved imino proton NMR signals, allows us to monitor the structural conversion from Na(+) form to K(+) form during Na(+)/K(+) exchange. Time-resolved NMR experiments of hydrogen-deuterium exchange and hybridization clearly exclude involvement of the global unfolding for the fast Na(+)/K(+) spectral conversion. In addition, the K(+) titration monitored by NMR reveals that the Na(+)/K(+) exchange in Tel23 G4 is a two-step process. The addition of K(+) significantly stabilizes the unfolding kinetics of Tel23 G4. These results offer a possible explanation of rapid spectral conversion of Na(+)/K(+) exchange and insight into the mechanism of Na(+)/K(+) structural conversion in human telomeric G4s.
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Tip of iceberg: when unusual vision complaints with a normal examination prompt a closer look.
Clin Case Rep
PUBLISHED: 01-23-2014
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Nonorganic vision loss (NOVL) is a relatively common condition in pediatric patients. Prompt diagnosis can prevent costly, time-consuming, and frustrating workups. It is valuable for general practitioners and specialists alike to include NOVL in their differential when evaluating patients with visual complaints that are inconsistent with normal examination findings.
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Unfolding kinetics of human telomeric G-quadruplexes studied by NMR spectroscopy.
J Phys Chem B
PUBLISHED: 01-17-2014
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Characterization of the unfolding kinetics of G-quadruplexes (G4s) is the key to a better understanding of the biological function of G4s and is important for biomedical research and material design. Of interest is that slight variations of human telomeric sequences can form different types of G4 structures. In general, there is a correlation between unfolding kinetics and thermal stability. Here we examined this correlation by first systematic analysis of the unfolding kinetics of a variety of telomeric G4 structures using the real-time imino proton NMR spectra of DNA hybridization and hydrogen-deuterium exchange (HDX). We then measured the melting temperature (Tm) and determined the Gibbs free energy (?G) of these G4 structures using differential scanning calorimetry (DSC). Our results showed that both Tm and ?G are slightly structure-dependent, except the Tm of the parallel G4 structure is ?10 °C higher than that of nonparallel G4 structures. The hybridization results showed that the decay times of different imino proton signals for each telomeric G4 structure are quite similar, which are also consistent with the time constant of the central G-tetrad obtained from HDX measurements. It is suggested that global unfolding is the rate-determining step for HDX, and each real-time imino proton NMR measurement can provide the intrinsic unfolding rate constant. The key finding is that the unfolding times of these various G4 structures are quite different and show no correlation between thermal stability and unfolding kinetics. Our results raised an issue that the folding and unfolding kinetics is more relevant for better understanding of biological function of G4 structures.
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Lipid droplet pattern and nondroplet-like structure in two fat mutants of Caenorhabditis elegans revealed by coherent anti-Stokes Raman scattering microscopy.
J Biomed Opt
PUBLISHED: 01-15-2014
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Lipid is an important energy source and essential component for plasma and organelle membranes in all kinds of cells. Coherent anti-Stokes Raman scattering (CARS) microscopy is a label-free and nonlinear optical technique that can be used to monitor the lipid distribution in live organisms. Here, we utilize CARS microscopy to investigate the pattern of lipid droplets in two live Caenorhabditis elegans mutants (fat-2 and fat-3). The CARS images showed a striking decrease in the size, number, and content of lipid droplets in the fat-2 mutant but a slight difference in the fat-3 mutant as compared with the wild-type worm. Moreover, a nondroplet-like structure with enhanced CARS signal was detected for the first time in the uterus of fat-2 and fat-3 mutants. In addition, transgenic fat-2 mutant expressing a GFP fusion protein of vitellogenin-2 (a yolk lipoprotein) revealed that the enhanced CARS signal colocalized with the GFP signal, which suggests that the nondroplet-like structure is primarily due to the accumulation of yolk lipoproteins. Together, this study implies that CARS microscopy is a potential tool to study the distribution of yolk lipoproteins, in addition to lipid droplets, in live animals.
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Anesthesia considerations in pediatric glaucoma management.
Curr Opin Ophthalmol
PUBLISHED: 01-11-2014
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This article reviews the potentially adverse neurodevelopmental effects of early exposure to general anesthesia and examines a changing paradigm in the management of pediatric glaucoma.
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Acyl-coenzyme A:cholesterol acyltransferase 1 - significance of single-nucleotide polymorphism at residue 526 and the role of Pro347 near the fifth transmembrane domain.
FEBS J.
PUBLISHED: 01-10-2014
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Acyl-coenzyme A:cholesterol acyltransferases (ACATs), which are members of the membrane-bound O-acyltransferase family, catalyze the conversion of cholesterol to cholesteryl esters. Mammals have two isoenzymes: ACAT1 and ACAT2. Both enzymes are drug targets for treating human diseases. ACAT1 is present in various cell types. It contains nine transmembrane domains (TMDs), with the active site His460 located within TMD7, and the active site Asn421 located within the fourth large cytoplasmic loop. In human ACAT1, a single-nucleotide polymorphism exists for residue 526: the codon is either CAG for Gln, or CGG for Arg. Gln526/Arg526 is present within the C-terminal loop. Its biochemical significance is unknown. In addition, within the C-terminal half of ACAT1, numerous residues conserved with those of ACAT2 are present; the functions of these conserved residues are largely unknown. Here, we performed single-substitution mutagenesis experiments to investigate the roles of individual residues present in the C-terminal loop, including Gln526/Arg526, and the eight conserved Pro residues located near/in various TMDs. The results show that the enzyme activity of ACAT1 with Gln526 is less active than that of ACAT1 with Arg526 by 40%. In addition, several residues in the C-terminal loop are important for maintaining proper ACAT1 protein stability. Other results show that Pro347 plays an important role in modulating enzyme catalysis. Overall, our results imply that the CAG/CGG polymorphism can be utilized to perform ACAT1 activity/human disease susceptibility studies, and that Pro347 located near TMD5 plays an important role in modulating enzyme catalysis.
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BMVC test, an improved fluorescence assay for detection of malignant pleural effusions.
Cancer Med
PUBLISHED: 01-10-2014
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The diagnosis of malignant pleural effusions is an important issue in the management of malignancy patients. Generally, cytologic examination is a routine diagnostic technique. However, morphological interpretation of cytology is sometimes inconclusive. Here an ancillary method named BMVC test is developed for rapid detection of malignant pleural effusion to improve the diagnostic accuracy at low cost. A simple assay kit is designed to collect living cells from clinical pleural effusion and a fluorescence probe, 3,6-Bis(1-methyl-4-vinylpyridinium) carbazole diiodide (BMVC), is used to illuminate malignant cells. The fluorescence intensity is quantitatively analyzed by ImageJ program. This method yields digital numbers for the test results without any grey zone or ambiguities in the current cytology tests due to intra-observer and inter-observer variability. Comparing with results from double-blind cytologic examination, this simple test gives a good discrimination between malignant and benign specimens with sensitivity of 89.4% (42/47) and specificity of 93.3% (56/60) for diagnosis of malignant pleural effusion. BMVC test provides accurate results in a short time period, and the digital output could assist cytologic examination to become more objective and clear-cut. This is a convenient ancillary tool for detection of malignant pleural effusions.
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Genetic variations in TP53 binding sites are predictors of clinical outcomes in prostate cancer patients.
Arch. Toxicol.
PUBLISHED: 01-09-2014
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Since the tumor protein p53 (TP53), a transcription factor, plays a crucial role in prostate cancer development and progression, we hypothesized that sequence variants in TP53 binding sites might affect clinical outcomes in patients with prostate cancer. We systematically evaluated 41 single nucleotide polymorphisms (SNPs) within genome-wide predicted TP53 binding sites in a cohort of 1,024 prostate cancer patients. The associations of these SNPs with prostate cancer characteristics and clinical outcomes after radical prostatectomy for localized disease and after androgen-deprivation therapy (ADT) for advanced disease were assessed by Kaplan-Meier analysis and Cox regression model. ARAP2 rs1444377 and TRPS1 rs722740 were associated with advanced stage prostate cancer. FRK rs171866 remained as a significant predictor for disease progression; DAB2 rs268091 and EXOC4 rs1149558 remained as significant predictors for prostate cancer-specific mortality (PCSM); and EXOC4 rs1149558 remained as a significant predictor for all-cause mortality after ADT in multivariate models that included clinicopathologic predictors. In addition, the numbers of protective genotypes at DAB2 rs268091 and EXOC4 rs1149558 showed a cumulative effect on PCSM (P for trend = 0.002). Our results suggested that SNPs within TP53 binding sites might be valuable biomarkers for prostate cancer outcome prediction.
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Enhanced resistive switching memory characteristics and mechanism using a Ti nanolayer at the W/TaO x interface.
Nanoscale Res Lett
PUBLISHED: 01-01-2014
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Enhanced resistive memory characteristics with 10,000 consecutive direct current switching cycles, long read pulse endurance of >10(5) cycles, and good data retention of >10(4) s with a good resistance ratio of >10(2) at 85°C are obtained using a Ti nanolayer to form a W/TiO x /TaO x /W structure under a low current operation of 80 ?A, while few switching cycles are observed for W/TaO x /W structure under a higher current compliance >300 ?A. The low resistance state decreases with increasing current compliances from 10 to 100 ?A, and the device could be operated at a low RESET current of 23 ?A. A small device size of 150?×?150 nm(2) is observed by transmission electron microscopy. The presence of oxygen-deficient TaO x nanofilament in a W/TiO x /TaO x /W structure after switching is investigated by Auger electron spectroscopy. Oxygen ion (negative charge) migration is found to lead to filament formation/rupture, and it is controlled by Ti nanolayer at the W/TaO x interface. Conducting nanofilament diameter is estimated to be 3 nm by a new method, indicating a high memory density of approximately equal to 100 Tbit/in.(2).
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Detection of cell carcinogenic transformation by a quadruplex DNA binding fluorescent probe.
PLoS ONE
PUBLISHED: 01-01-2014
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Cancer can be easily treated when found early. A probe capable of detecting cell transformation may increase the success rate of early diagnosis of cancer. In this report we have tested the ability of a fluorescent, quadruplex DNA binding probe, 3,6-bis(1-methyl-4- vinylpyridinium) carbazole diiodide (BMVC), to detect cell transformation in vitro. BMVC was applied to living cells in several different models of cell transformation, and the fluorescence signals of BMVC were measured. The degrees of cell transformation in these models were characterized by alterations in cellular morphological phenotype and subcellular organization. When BMVC probes were applied, the number of BMVC-positive cells increased in accordance with the degree of transformation. BMVC was capable of significantly detecting formation of foci, increased cellular motility, cell proliferation, cell apoptosis, anchorage-independent growth, and increased invasiveness of transformed cells. These results demonstrate the ability of BMVC probes to detect cell transformation and indicate that BMVC is of promise for use as a probe in early cancer detection.
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Variant GADL1 and Response to Lithium Therapy in Bipolar I Disorder.
N. Engl. J. Med.
PUBLISHED: 12-25-2013
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Background Lithium has been a first-line choice for maintenance treatment of bipolar disorders to prevent relapse of mania and depression, but many patients do not have a response to lithium treatment. Methods We selected subgroups from a sample of 1761 patients of Han Chinese descent with bipolar I disorder who were recruited by the Taiwan Bipolar Consortium. We assessed their response to lithium treatment using the Alda scale and performed a genomewide association study on samples from one subgroup of 294 patients with bipolar I disorder who were receiving lithium treatment. We then tested the single-nucleotide polymorphisms (SNPs) that showed the strongest association with a response to lithium for association in a replication sample of 100 patients and tested them further in a follow-up sample of 24 patients. We sequenced the exons, exon-intron boundaries, and part of the promoter of the gene encoding glutamate decarboxylase-like protein 1 (GADL1) in 94 patients who had a response to lithium and in 94 patients who did not have a response in the genomewide association sample. Results Two SNPs in high linkage disequilibrium, rs17026688 and rs17026651, that are located in the introns of GADL1 showed the strongest associations in the genomewide association study (P=5.50×10(-37) and P=2.52×10(-37), respectively) and in the replication sample of 100 patients (P=9.19×10(-15) for each SNP). These two SNPs had a sensitivity of 93% for predicting a response to lithium and differentiated between patients with a good response and those with a poor response in the follow-up cohort. Resequencing of GADL1 revealed a novel variant, IVS8+48delG, which lies in intron 8 of the gene, is in complete linkage disequilibrium with rs17026688 and is predicted to affect splicing. Conclusions Genetic variations in GADL1 are associated with the response to lithium maintenance treatment for bipolar I disorder in patients of Han Chinese descent. (Funded by Academia Sinica and others.).
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Bromoform Activation. TiCl4-Mg-Promoted CHBr2(-) and CBr3(-) Transfer to a Variety of Aldehydes and Ketones.
Org. Lett.
PUBLISHED: 11-05-2013
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TiCl4-Mg can mediate addition of CHBr3 to a variety of aldehydes and ketones to form dibromomethyl carbinols and also be used to effect CBr3 transfer to carbonyl groups to form tribromomethyl carbinols. The successful application of TiCl4-Mg-promoted coupling of CHBr3 with various carbonyl compounds, especially in the case of highly enolizable ketones such as 2-indanone and ?-tetralone, highlights the extraordinary reactivity and selectivity and the weakly basic nature of this system.
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A specific cholesterol metabolic pathway is established in a subset of HCCs for tumor growth.
J Mol Cell Biol
PUBLISHED: 10-26-2013
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The liver plays a central role in cholesterol homeostasis. It exclusively receives and metabolizes oxysterols, which are important metabolites of cholesterol and are more cytotoxic than free cholesterol, from all extrahepatic tissues. Hepatocellular carcinomas (HCCs) impair certain liver functions and cause pathological alterations in many processes including cholesterol metabolism. However, the link between an altered cholesterol metabolism and HCC development is unclear. Human ACAT2 is abundantly expressed in intestine and fetal liver. Our previous studies have shown that ACAT2 is induced in certain HCC tissues. Here, by investigating tissue samples from HCC patients and HCC cell lines, we report that a specific cholesterol metabolic pathway, involving induction of ACAT2 and esterification of excess oxysterols for secretion to avoid cytotoxicity, is established in a subset of HCCs for tumor growth. Inhibiting ACAT2 leads to the intracellular accumulation of unesterified oxysterols and suppresses the growth of both HCC cell lines and their xenograft tumors. Further mechanistic studies reveal that HCC-linked promoter hypomethylation is essential for the induction of ACAT2 gene expression. We postulate that specifically blocking this HCC-established cholesterol metabolic pathway may have potential therapeutic applications for HCC patients.
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In-cell optical imaging of exogenous G-quadruplex DNA by fluorogenic ligands.
Nucleic Acids Res.
PUBLISHED: 09-11-2013
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Guanine-rich oligonucleotides (GROs) are promising therapeutic candidate for cancer treatment and other biomedical application. We have introduced a G-quadruplex (G4) ligand, 3,6-bis(1-methyl-4-vinylpyridinium) carbazole diiodide, to monitor the cellular uptake of naked GROs and map their intracellular localizations in living cells by using confocal microscopy. The GROs that form parallel G4 structures, such as PU22, T40214 and AS1411, are detected mainly in the lysosome of CL1-0 lung cancer cells after incubation for 2 h. On the contrary, the GROs that form non-parallel G4 structures, such as human telomeres (HT23) and thrombin binding aptamer (TBA), are rarely detected in the lysosome, but found mainly in the mitochondria. Moreover, the fluorescence resonant energy transfer studies of fluorophore-labeled GROs show that the parallel G4 structures can be retained in CL1-0 cells, whereas the non-parallel G4 structures are likely distorted in CL1-0 cells after cellular uptake. Of interest is that the distorted G4 structure of HT23 from the non-parallel G4 structure can reform to a probable parallel G4 structure induced by a G4 ligand in CL1-0 living cells. These findings are valuable to the design and rationale behind the possible targeted drug delivery to specific cellular organelles using GROs.
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Chemical principles for the design of a novel fluorescent probe with high cancer-targeting selectivity and sensitivity.
Integr Biol (Camb)
PUBLISHED: 08-24-2013
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Understanding of principles governing selective and sensitive cancer targeting is critical for development of chemicals for cancer diagnostics and treatment. We determined the underlying mechanisms of how a novel fluorescent small organic molecule, 3,6-bis(1-methyl-4-vinylpyridinium)carbazole diiodide (BMVC), selectively labels cancer cells but not normal cells. We show that BMVC is retained in the lysosomes of normal cells. In cancer cells, BMVC escapes lysosomal retention and localizes to the mitochondria or to the nucleus, where DNA-binding dramatically increases BMVC fluorescence intensity, allowing it to light up only cancer cells. Structure-function analyses of BMVC derivatives show that hydrogen-bonding capacity is a key determinant of lysosomal retention in normal cells, whereas lipophilicity directs these derivatives to the mitochondria or the nucleus in cancer cells. In addition, drug-resistant cancer cells preferentially retain BMVC in their lysosomes compared to drug-sensitive cancer cells, and BMVC can be released from drug-resistant lysosomes using lysosomotropic agents. Our results further our understanding of how properties of cellular organelles differ between normal and cancer cells, which can be exploited for diagnostic and/or therapeutic use. We also provide physiochemical design principles for selective targeting of small molecules to different organelles. Moreover, our results suggest that agents which can increase lysosomal membrane permeability may re-sensitize drug-resistant cancer cells to chemotherapeutic agents.
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Acat1 gene ablation in mice increases hematopoietic progenitor cell proliferation in bone marrow and causes leukocytosis.
Arterioscler. Thromb. Vasc. Biol.
PUBLISHED: 07-11-2013
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To investigate the role of acyl-CoA:cholesterol acyltransferase 1 (ACAT1) in hematopoiesis.
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Fluorescent probe for visualizing guanine-quadruplex DNA by fluorescence lifetime imaging microscopy.
J Biomed Opt
PUBLISHED: 07-11-2013
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The importance of guanine-quadruplex (G4) is not only in protecting the ends of chromosomes for human telomeres but also in regulating gene expression for several gene promoters. However, the existence of G4 structures in living cells is still in debate. A fluorescent probe, 3,6-bis(1-methyl-2-vinylpyridinium) carbazole diiodide (o-BMVC), for differentiating G4 structures from duplexes is characterized. o-BMVC has a large contrast in fluorescence decay time, binding affinity, and fluorescent intensity between G4 structures and duplexes, which makes it a good candidate for probing G4 DNA structures. The fluorescence decay time of o-BMVC upon interaction with G4 structures of telomeric G-rich sequences is ?2.8??ns and that of interaction with the duplex structure of a calf thymus is ?1.2??ns. By analyzing its fluorescence decay time and histogram, we were able to detect one G4 out of 1000 duplexes in vitro. Furthermore, by using fluorescence lifetime imaging microscopy, we demonstrated an innovative methodology for visualizing the localization of G4 structures as well as mapping the localization of different G4 structures in living cells.
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Differentiation between dysplastic nodule and early-stage hepatocellular carcinoma: The utility of conventional MR imaging.
World J. Gastroenterol.
PUBLISHED: 06-22-2013
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To elucidate the variety of ways early-stage hepatocellular carcinoma (HCC) can appear on magnetic resonance (MR) imaging by analyzing T1-weighted, T2-weighted, and gadolinium-enhanced dynamic studies.
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Automated quantitative analysis of lipid accumulation and hydrolysis in living macrophages with label-free imaging.
Anal Bioanal Chem
PUBLISHED: 05-14-2013
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The accumulation of lipids in macrophages is a key factor that promotes the formation of atherosclerotic lesions. Several methods such as biochemical assays and neutral lipid staining have been used for the detection of lipids in cells. However, a method for real-time quantitative assessment of the lipid content in living macrophages has yet to be shown, particularly for its kinetic process with drugs, due to the lack of suitable tools for non-invasive chemical detection. Here we demonstrate label-free real-time monitoring of lipid droplets (LDs) in living macrophages by using coherent anti-Stokes Raman scattering (CARS) microscopy. In addition, we have established an automated image analysis method based on maximum entropy thresholding (MET) to quantify the cellular lipid content. The result of CARS image analysis shows a good correlation (R(2) > 0.9) with the measurement of biochemical assay. Using this method, we monitored the processes of lipid accumulation and hydrolysis in macrophages. We further characterized the effect of a lipid hydrolysis inhibitor (diethylumbelliferyl phosphate, DEUP) and determined the kinetic parameters such as the inhibition constant, K(i). Our work demonstrates that the automated quantitative analysis method is useful for the studies of cellular lipid metabolism and has potential for preclinical high-throughput screening of therapeutic agents related to atherosclerosis and lipid-associated disorders.
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Biomass torrefaction characteristics in inert and oxidative atmospheres at various superficial velocities.
Bioresour. Technol.
PUBLISHED: 05-10-2013
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The reaction characteristics of four biomass materials (i.e. oil palm fiber, coconut fiber, eucalyptus, and Cryptomeria japonica) with non-oxidative and oxidative torrefaction at various superficial velocities are investigated where nitrogen and air are used as carrier gases. Three torrefaction temperatures of 250, 300, and 350 °C are considered. At a given temperature, the solid yield of biomass is not affected by N2 superficial velocity, revealing that the thermal degradation is controlled by heat and mass transfer in biomass. Increasing air superficial velocity decreases the solid yield, especially in oil palm fiber and coconut fiber, implying that the torrefaction reaction of biomass is dominated by surface oxidation. There exists an upper limit of air superficial velocity in the decrement of solid yield, suggesting that beyond this limit the thermal degradation of biomass is no longer governed by surface oxidation, but rather is controlled by internal mass transport.
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Impact of interleukin-10 gene polymorphisms on survival in patients with colorectal cancer.
J. Korean Med. Sci.
PUBLISHED: 04-12-2013
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Chronic inflammation is thought to be the leading cause of colorectal cancer, and interleukin-10 (IL10) has been identified as a potent immunomodulatory cytokine that regulates inflammatory responses in the gastrointestinal tract. Although several single nucleotide polymorphisms (SNPs) in IL10 have been associated with the risk of colorectal cancer, their prognostic significance has not been determined. Two hundred and eighty-two colorectal cancer patients were genotyped for two candidate cancer-associated SNPs in IL10. The associations of these SNPs with distant metastasis-free survival and overall survival were evaluated by Kaplan-Meier analysis and Cox regression model. The minor homozygote GG genotype of IL10 rs3021094 was significantly associated with a 3.30-fold higher risk of death compared with the TT+TG genotypes (P=0.011). The patients with IL10 rs3021094 GG genotype also had a poorer overall survival in Kaplan-Meier analysis (log-rank P=0.007) and in multivariate Cox regression model (P=0.044) adjusting for age, gender, carcinoembryonic antigen levels, tumor differentiation, stage, lymphovascular invasion, and perineural invasion. In conclusion, our results suggest that IL10 rs3021094 might be a valuable prognostic biomarker for colorectal cancer patients.
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Paradoxical thinning of the retinal nerve fiber layer after reversal of cupping: A case report of primary infantile glaucoma.
Indian J Ophthalmol
PUBLISHED: 04-04-2013
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The circumpapillary retinal nerve fiber layer (RNFL) thickness was assessed by spectral domain optical coherent tomography (SD-OCT) before and after surgical reduction of intraocular pressure in an eye with primary infantile glaucoma. In this case, a postoperative reduction of cupping and a subsequent increase in neuroretinal rim area is associated with a paradoxical thinning of the RNFL. This is the first-known characterization of cupping reversal using SD-OCT.
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Continuous production of high-purity fructooligosaccharides and ethanol by immobilized Aspergillus japonicus and Pichia heimii.
Bioprocess Biosyst Eng
PUBLISHED: 03-27-2013
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High-purity fructooligosaccharides (FOS) were produced from sucrose by an innovative process incorporating immobilized Aspergillus japonicus and Pichia heimii cells. Intracellular FTase of A. japonicus converted sucrose into FOS and glucose, and P. heimii fermented glucose mainly into ethanol. The continuous production of FOS was carried out using a tanks-in-series bioreactor consisting of three stirred tanks. When a solution composed of 1 g L(-1) yeast extract and 300 g L(-1) sucrose was fed continuously to the bioreactor at a dilution rate of 0.1 h(-1), FOS at a purity of up to 98.2 % could be achieved and the value-added byproduct ethanol at 79.6 g L(-1) was also obtained. One gram of sucrose yielded 0.62 g FOS and 0.27 g ethanol. This immobilized dual-cell system was effective for continuous production of high-purity FOS and ethanol for as long as 10 days.
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Occupational noise exposure and incident hypertension in men: a prospective cohort study.
Am. J. Epidemiol.
PUBLISHED: 03-06-2013
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The associations between occupational noise exposure and hypertension remain controversial because of the differences in study designs, exposure assessments, and confounding controls. This prospective study investigated the relationship between noise exposure and the 10-year risk of hypertension. A cohort of 578 male workers in Taiwan was followed from 1998 to 2008. All subjects were divided into high-, intermediate-, and low-exposure groups on the basis of noise exposure assessment. Cox regression models were used to estimate the relative risks of hypertension after adjustment for potential confounders. During the 7,805 person-years of follow-up, 141 hypertension cases were identified. Significant increases of 3.2 (95% confidence interval (CI): 0.2, 6.2) mm Hg in systolic blood pressure and 2.5 (95% CI: 0.1, 4.8) mm Hg in diastolic blood pressure between the baseline and follow-up measurements were observed in the high-exposure group. Participants exposed to ?85 A-weighted decibels (dBA) had a 1.93-fold (95% CI: 1.15, 3.22) risk of hypertension compared with those exposed to <80 dBA. There was a significant exposure-response pattern (P = 0.016) between the risk of hypertension and the stratum of noise exposure. Prolonged exposure to noise levels ?85 dBA may increase males systolic and diastolic blood pressure levels. This association may translate into a higher incidence of hypertension.
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Surgical management in primary congenital glaucoma: four debates.
J Ophthalmol
PUBLISHED: 02-28-2013
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Primary congenital glaucoma is a worldwide diagnostic and therapeutic challenge. Although medical management is often a temporizing measure, early surgical intervention is the definitive treatment. As the abundance of surgical treatment options continues to expand, the authors will compare and contrast the available options and attempt to provide a consensus on surgical management.
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Marfan syndrome caused by a novel FBN1 mutation with associated pigmentary glaucoma.
Am. J. Med. Genet. A
PUBLISHED: 02-26-2013
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Mutations in fibrillin-1 (FBN1) cause a wide spectrum of disorders, including Marfan syndrome, which have in common defects in fibrillin-1 microfibrils. Ectopia lentis and myopia are frequently observed ocular manifestations of Marfan syndrome. Glaucoma is also associated with Marfan syndrome, though the form of glaucoma has not been well-characterized. In this report, ocular examination of a patient diagnosed with Marfan syndrome based on family history and aortic dilatation was performed, including measurement of facility of aqueous humor outflow by tonography. The patient did not have ectopia lentis at the age of 42 years. Based on optic nerve appearance, reduced outflow facility, elevated IOP with open angles and clear signs of pigment dispersion, the patient was diagnosed with pigmentary glaucoma. The patient was heterozygous for a novel truncating mutation in FBN1, p.Leu72Ter. Histology of normal human eyes revealed abundant expression of elastic fibers and fibrillin-1 in aqueous humor outflow structures. This is the first report of a patient with Marfan syndrome that is caused by a confirmed FBN1 mutation with associated pigmentary glaucoma. In addition to identifying a novel mutation of FBN1 and broadening the spectrum of associated ocular phenotypes in Marfan syndrome, our findings suggest that pigmentary glaucoma may involve defects in fibrillin-1 microfibrils.
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Common variants in IGF1 pathway genes and clinical outcomes after radical prostatectomy.
Ann. Surg. Oncol.
PUBLISHED: 02-10-2013
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Insulin-like growth factor-1 (IGF1) pathway plays a critical role in malignant transformation, and epidemiology studies have also shown that single nucleotide polymorphisms (SNPs) in IGF1 pathway genes are associated with prostate cancer risk. However, the clinical significance of these SNPs on prostate cancer aggressiveness and prognosis after radical prostatectomy (RP) has not been determined.
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Genetic variants in nuclear factor-kappa B binding sites are associated with clinical outcomes in prostate cancer patients.
Eur. J. Cancer
PUBLISHED: 02-08-2013
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Nuclear factor-kappa B (NF-?B) transcription factors have been suggested to be involved in prostate cancer progression. Activated NF-?B translocates to the nucleus, binds to NF-?B binding sites and regulates target gene expression, leading to the given physiological response. It was hypothesised that the sequence variants in NF-?B binding sites might affect prostate cancer progression. We systematically evaluated 15 single-nucleotide polymorphisms (SNPs) within NF-?B binding sites those were predicted using a genome-wide database in a cohort of 1024 prostate cancer patients. Associations of these SNPs with prostate cancer characteristics and clinical outcomes after radical prostatectomy (RP) for localised disease, and after androgen-deprivation therapy (ADT) for advanced disease were assessed by Kaplan-Meier analysis and Cox regression model. We found that PSMD7 rs2387084 and MYCN rs1429409 were significantly related to earlier onset of prostate cancer and advanced clinical stage, respectively. No SNPs were significantly associated with disease recurrence after RP. Four and three SNPs were notably associated with prostate cancer-specific mortality (PCSM) and all-cause mortality (ACM), respectively, after ADT. LSAMP rs13088089, CCL17 rs223899, PSMD7 rs2387084 and MON1B rs284924 remained the significant predictors for PCSM whilst PSMD7 rs2387084 remained a significant predictor for ACM in multivariate models including clinical predictors. Moreover, we also noted that there were strong effects of the combined genotype on PCSM and patients with a greater number of unfavourable genotypes had a shorter time to PCSM during ADT (P for trend<0.001). It was concluded that SNPs inside NF-?B binding sites might be useful to improve outcome prediction in prostate cancer patients.
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Acat1 knockdown gene therapy decreases amyloid-? in a mouse model of Alzheimers disease.
Mol. Ther.
PUBLISHED: 02-01-2013
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Both genetic inactivation and pharmacological inhibition of the cholesteryl ester synthetic enzyme acyl-CoA:cholesterol acyltransferase 1 (ACAT1) have shown benefit in mouse models of Alzheimers disease (AD). In this study, we aimed to test the potential therapeutic applications of adeno-associated virus (AAV)-mediated Acat1 gene knockdown in AD mice. We constructed recombinant AAVs expressing artificial microRNA (miRNA) sequences, which targeted Acat1 for knockdown. We demonstrated that our AAVs could infect cultured mouse neurons and glia and effectively knockdown ACAT activity in vitro. We next delivered the AAVs to mouse brains neurosurgically, and demonstrated that Acat1-targeting AAVs could express viral proteins and effectively diminish ACAT activity in vivo, without inducing appreciable inflammation. We delivered the AAVs to the brains of 10-month-old AD mice and analyzed the effects on the AD phenotype at 12 months of age. Acat1-targeting AAV delivered to the brains of AD mice decreased the levels of brain amyloid-? and full-length human amyloid precursor protein (hAPP), to levels similar to complete genetic ablation of Acat1. This study provides support for the potential therapeutic use of Acat1 knockdown gene therapy in AD.
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Molecular markers in sex hormone pathway genes associated with the efficacy of androgen-deprivation therapy for prostate cancer.
PLoS ONE
PUBLISHED: 01-24-2013
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Although most advanced prostate cancer patients respond to androgen-deprivation therapy (ADT), the efficacy is widely variable. We investigated whether the host genetic variations in sex hormone pathway genes are associated with the efficacy of ADT. A cohort of 645 patients with advanced prostate cancer treated with ADT was genotyped for 18 polymorphisms across 12 key genes involved in androgen and estrogen metabolism. We found that after adjusting for known risk factors in multivariate Cox regression models, AKR1C3 rs12529 and AR-CAG repeat length remained significantly associated with prostate cancer-specific mortality (PCSM) after ADT (P ? 0.041). Furthermore, individuals carrying two unfavorable genotypes at these loci presented a 13.7-fold increased risk of PCSM compared with individuals carrying zero (P<0.001). Our results identify two candidate molecular markers in key genes of androgen and estrogen pathways associated with PCSM after ADT, establishing the role of pharmacogenomics in this therapy.
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The cytosolic adaptor AP-1A is essential for the trafficking and function of Niemann-Pick type C proteins.
Traffic
PUBLISHED: 01-16-2013
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Niemann-Pick type C (NPC) disease is a fatal neurodegenerative disorder characterized by over-accumulation of low-density lipoprotein-derived cholesterol and glycosphingolipids in late endosomes/lysosomes (LE/L) throughout the body. Human mutations in either NPC1 or NPC2 genes have been directly associated with impaired cholesterol efflux from LE/L. Independent from its role in cholesterol homeostasis and its NPC2 partner, NPC1 was unexpectedly identified as a critical player controlling intracellular entry of filoviruses such as Ebola. In this study, a yeast three-hybrid system revealed that the NPC1 cytoplasmic tail directly interacts with the clathrin adaptor protein AP-1 via its acidic/di-leucine motif. Consequently, a nonfunctional AP-1A cytosolic complex resulted in a typical NPC-like phenotype mainly due to a direct impairment of NPC1 trafficking to LE/L and a partial secretion of NPC2. Furthermore, the mislocalization of NPC1 was not due to cholesterol accumulation in LE/L, as it was not rescued upon treatment with M?-cyclodextrin, which almost completely eliminated intracellular free cholesterol. Our cumulative data demonstrate that the cytosolic clathrin adaptor AP-1A is essential for the lysosomal targeting and function of NPC1 and NPC2.
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High prevalence but low awareness of hepatitis C virus infection among heroin users who received methadone maintenance therapy in Taiwan.
Addict Behav
PUBLISHED: 01-10-2013
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This study investigates the prevalence and correlates of hepatitis C virus (HCV) infections among heroin dependent individuals who received methadone maintenance therapy in Taiwan. Also, we investigate users awareness of HCV.
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Assaying the binding strength of G-quadruplex ligands using single-molecule TPM experiments.
Anal. Biochem.
PUBLISHED: 01-10-2013
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G-quadruplexes are stable secondary structures formed by Hoogsteen base pairing of guanine-rich single-stranded DNA sequences in the presence of monovalent cations (Na(+) or K(+)). Folded G-quadruplex (G4) structures in human telomeres have been proposed as a potential target for cancer therapy. In this study, we used single-molecule tethered particle motion (TPM) experiments to assay the binding strength of possible G4 ligands. We found that individual single-stranded DNA molecules containing the human telomeric sequence d[AGGG(TTAGGG)3] fluctuated between the folded and the unfolded states in a 10 mM Na(+) solution at 37 °C. The durations of folded and unfolded states were single-exponentially distributed, and in return the folding and unfolding rate constants were 1.68 ± 0.01 and 1.63 ± 0.03 (s(-1)), respectively. In the presence of G4 ligands, such as TMPyP4, DODCI, BMVC, and BMVPA, the unfolding rate constant decreased appreciably. In addition, combining the Cu(2+)-induced G4 unfolding and TPM assay, we showed that BMVC and TMPyP4 are better G4 stabilizers than DODCI. The capability of monitoring the fluctuation between the folded and the unfolded state of G4 DNA in real time allows the determination of both kinetic and thermodynamic parameters in a single measurement and offers a simple way to assay binding strength under various conditions.
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Common genetic variants in Wnt signaling pathway genes as potential prognostic biomarkers for colorectal cancer.
PLoS ONE
PUBLISHED: 01-07-2013
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Compelling evidence has implicated the Wnt signaling pathway in the pathogenesis of colorectal cancer. We assessed the use of tag single nucleotide polymorphisms (tSNPs) in adenomatous polyposis coli (APC)/?-catenin (CTNNB1) genes to predict outcomes in patients with colorectal cancer. We selected and genotyped 10 tSNP to predict common variants across entire APC and CTNNB1 genes in 282 colorectal cancer patients. The associations of these tSNPs with distant metastasis-free survival and overall survival were evaluated by Kaplan-Meier analysis, Cox regression model, and survival tree analysis. The 5-year overall survival rate was 68.3%. Survival tree analysis identified a higher-order genetic interaction profile consisting of the APC rs565453, CTNNB1 2293303, and APC rs1816769 that was significantly associated with overall survival. The 5-year survival overall rates were 89.2%, 66.1%, and 58.8% for the low-, medium-, and high-risk genetic profiles, respectively (log-rank P?=?0.001). After adjusting for possible confounders, including age, gender, carcinoembryonic antigen levels, tumor differentiation, stage, lymphovascular invasion, perineural invasion, and lymph node involvement, the genetic interaction profile remained significant. None of the studied SNPs were individually associated with distant metastasis-free survival and overall survival. Our results suggest that the genetic interaction profile among Wnt pathway SNPs might potentially increase the prognostic value in outcome prediction for colorectal cancer.
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Production of ACAT1 56-kDa isoform in human cells via trans-splicing involving the ampicillin resistance gene.
Cell Res.
PUBLISHED: 01-03-2013
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Trans-splicing, a process involving the cleavage and joining of two separate transcripts, can expand the transcriptome and proteome in eukaryotes. Chimeric RNAs generated by trans-splicing are increasingly described in literatures. The widespread presence of antibiotic resistance genes in natural environments and human intestines is becoming an important challenge for public health. Certain antibiotic resistance genes, such as ampicillin resistance gene (Amp(r)), are frequently used in recombinant plasmids. Until now, trans-splicing involving recombinant plasmid-derived exogenous transcripts and endogenous cellular RNAs has not been reported. Acyl-CoA:cholesterol acyltransferase 1 (ACAT1) is a key enzyme involved in cellular cholesterol homeostasis. The 4.3-kb human ACAT1 chimeric mRNA can produce 50-kDa and 56-kDa isoforms with different enzymatic activities. Here, we show that human ACAT1 56-kDa isoform is produced from an mRNA species generated through the trans-splicing of an exogenous transcript encoded by the antisense strand of Amp(r) (asAmp) present in common Amp(r)-plasmids and the 4.3-kb endogenous ACAT1 chimeric mRNA, which is presumably processed through a prior event of interchromosomal trans-splicing. Strikingly, DNA fragments containing the asAmp with an upstream recombined cryptic promoter and the corresponding exogenous asAmp transcripts have been detected in human cells. Our findings shed lights on the mechanism of human ACAT1 56-kDa isoform production, reveal an exogenous-endogenous trans-splicing system, in which recombinant plasmid-derived exogenous transcripts are linked with endogenous cellular RNAs in human cells, and suggest that exogenous DNA might affect human gene expression at both DNA and RNA levels.
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Genetic polymorphisms of matrix metalloproteinases and clinical outcomes in colorectal cancer patients.
Int J Med Sci
PUBLISHED: 01-01-2013
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Colorectal cancer metastasis is a multistep process involving degradation of extracellular matrix components by proteolytic enzymes. Among them, matrix metalloproteinases (MMPs) are the principal degrading enzymes and their expressions/activities are also correlated with survival. Much research has showed the associations between genetic polymorphisms in MMPs and risk of colorectal cancer; however, their prognostic significance has not been well determined.
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Androgen receptor (AR) physiological roles in male and female reproductive systems: lessons learned from AR-knockout mice lacking AR in selective cells.
Biol. Reprod.
PUBLISHED: 01-01-2013
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Androgens/androgen receptor (AR) signaling is involved primarily in the development of male-specific phenotypes during embryogenesis, spermatogenesis, sexual behavior, and fertility during adult life. However, this signaling has also been shown to play an important role in development of female reproductive organs and their functions, such as ovarian folliculogenesis, embryonic implantation, and uterine and breast development. The establishment of the testicular feminization (Tfm) mouse model exploiting the X-linked Tfm mutation in mice has been a good in vivo tool for studying the human complete androgen insensitivity syndrome, but this mouse may not be the perfect in vivo model. Mouse models with various cell-specific AR knockout (ARKO) might allow us to study AR roles in individual types of cells in these male and female reproductive systems, although discrepancies are found in results between labs, probably due to using various Cre mice and/or knocking out AR in different AR domains. Nevertheless, no doubt exists that the continuous development of these ARKO mouse models and careful studies will provide information useful for understanding AR roles in reproductive systems of humans and may help us to develop more effective and more specific therapeutic approaches for reproductive system-related diseases.
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Axenfeld-Rieger syndrome: new perspectives.
Br J Ophthalmol
PUBLISHED: 12-23-2011
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Axenfeld-Rieger syndrome is a genetic disease affecting multiple organ systems. In the eye, this condition manifests with varying degrees of anterior segment dysgenesis and carries a high risk of glaucoma. Other associated systemic issues include cardiovascular outflow tract malformations, craniofacial abnormalities and pituitary abnormalities, which can result in severe endocrinological sequelae. Recent advances in molecular genetics have identified two major genes, PITX2 and FOXC1, demonstrating a wide spectrum of mutations, which aids in the molecular diagnosis of the disease, although evidence exists to implicate other loci in this condition. The management of individuals affected by Axenfeld-Rieger syndrome requires a multidisciplinary approach and would include dedicated surveillance and management of glaucoma, sensorineural hearing loss, and cardiac, endocrinological, craniofacial and orthopaedic abnormalities.
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Gene-environment interaction between angiotensinogen and chronic exposure to occupational noise contribute to hypertension.
Occup Environ Med
PUBLISHED: 11-22-2011
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Previous studies on the effects of angiotensinogen (AGT) gene polymorphisms and chronic exposure to occupational noise on the risk of hypertension have mainly been cross-sectional or prevalent case-control studies, where temporality constitutes problems. The present study was to assess longitudinally both independent and joint effects of AGT gene polymorphisms and chronic exposure to occupational noise on occurrence of hypertension.
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A novel mouse model of Niemann-Pick type C disease carrying a D1005G-Npc1 mutation comparable to commonly observed human mutations.
Hum. Mol. Genet.
PUBLISHED: 11-02-2011
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We have identified a point mutation in Npc1 that creates a novel mouse model (Npc1(nmf164)) of Niemann-Pick type C1 (NPC) disease: a single nucleotide change (A to G at cDNA bp 3163) that results in an aspartate to glycine change at position 1005 (D1005G). This change is in the cysteine-rich luminal loop of the NPC1 protein and is highly similar to commonly occurring human mutations. Genetic and molecular biological analyses, including sequencing the Npc1(spm) allele and identifying a truncating mutation, confirm that the mutation in Npc1(nmf164) mice is distinct from those in other existing mouse models of NPC disease (Npc1(nih), Npc1(spm)). Analyses of lifespan, body and spleen weight, gait and other motor activities, as well as acoustic startle responses all reveal a more slowly developing phenotype in Npc1(nmf164) mutant mice than in mice with the null mutations (Npc1(nih), Npc1(spm)). Although Npc1 mRNA levels appear relatively normal, Npc1(nmf164) brain and liver display dramatic reductions in Npc1 protein, as well as abnormal cholesterol metabolism and altered glycolipid expression. Furthermore, histological analyses of liver, spleen, hippocampus, cortex and cerebellum reveal abnormal cholesterol accumulation, glial activation and Purkinje cell loss at a slower rate than in the Npc1(nih) mouse model. Magnetic resonance imaging studies also reveal significantly less demyelination/dysmyelination than in the null alleles. Thus, although prior mouse models may correspond to the severe infantile onset forms of NPC disease, Npc1(nmf164) mice offer many advantages as a model for the late-onset, more slowly progressing forms of NPC disease that comprise the large majority of human cases.
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Selective photodynamic therapy based on aggregation-induced emission enhancement of fluorescent organic nanoparticles.
Biomaterials
PUBLISHED: 09-23-2011
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Three binary molecule conjugates were designed and synthesized by conjugating a chromophore (3, 6-bis-(1-methyl-4-vinylpyridinium)-carbazole diiodide, BMVC) to mono-, bis- and trishydroxyl photosensitizers, respectively. BMVC plays the role of cancer cells recognizer; AIEE (aggregation-induced emission enhancement) generator and FRET (Fluorescence Resonance Energy Transfer) donor. The self assembling properties of these binary conjugates result in different degrees of AIEE and then achieve the formations of FONs (fluorescent organic nanoparticles), which present efficient FRET and singlet oxygen generations. Biologically, FONs-photosensitizers from these compounds were much more phototoxicities to cancer cell than to normal cell without significant dark toxicity. In addition, their intracellular fluorescent colors switching upon photo-excitation are expected to be used for further cell death biomarker applications. This improved photodynamic activity might be due to the aggregation of compounds in the cell that form FONs which can promote PDT (photodynamic therapy) and are observed in cancer cell but not normal cell.
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Vitamin D receptor gene variants and clinical outcomes after androgen-deprivation therapy for prostate cancer.
World J Urol
PUBLISHED: 09-19-2011
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Molecular epidemiology studies have shown that vitamin D receptor (VDR) gene polymorphisms are associated with prostate cancer risk. However, the prognostic value of these polymorphisms on clinical outcomes in prostate cancer patients receiving androgen-deprivation therapy (ADT) has not been determined.
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Comprehensive assessment of host responses to ionizing radiation by nuclear factor-?B bioluminescence imaging-guided transcriptomic analysis.
PLoS ONE
PUBLISHED: 07-25-2011
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The aim of this study was to analyze the host responses to ionizing radiation by nuclear factor-?B (NF-?B) bioluminescence imaging-guided transcriptomic tool. Transgenic mice carrying the NF-?B-driven luciferase gene were exposed to a single dose of 8.5 Gy total-body irradiation. In vivo imaging showed that a maximal NF-?B-dependent bioluminescent intensity was observed at 3 h after irradiation and ex vivo imaging showed that liver, intestine, and brain displayed strong NF-?B activations. Microarray analysis of these organs showed that irradiation altered gene expression signatures in an organ-specific manner and several pathways associated with metabolism and immune system were significantly altered. Additionally, the upregulation of fatty acid binding protein 4, serum amyloid A2, and serum amyloid A3 genes, which participate in both inflammation and lipid metabolism, suggested that irradiation might affect the cross pathways of metabolism and inflammation. Moreover, the alteration of chemokine (CC-motif) ligand 5, chemokine (CC-motif) ligand 20, and Jagged 1 genes, which are involved in the inflammation and enterocyte proliferation, suggested that these genes might be involved in the radiation enteropathy. In conclusion, this report describes the comprehensive evaluation of host responses to ionizing radiation. Our findings provide the fundamental information about the in vivo NF-?B activity and transcriptomic pattern after irradiation. Moreover, novel targets involved in radiation injury are also suggested.
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Emulsified BMVC derivative induced filtration for G-quadruplex DNA structural separation.
Nucleic Acids Res.
PUBLISHED: 06-28-2011
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A novel method based on emulsion/filtration is introduced for G-quadruplex DNA structural separation. We first synthesized a lipophilic analogue of BMVC, 3,6-Bis(1-methyl-4-vinylpyridinium)-9-(12-bromododecyl) carbazole diiodide (BMVC-12C-Br), which can form an oil-in-water (o/w) phase emulsion. Due to the binding preferences of BMVC-12C-Br emulsion to some specific DNA structures, the large emulsion (?2?µm) bound DNA was separated from the small free DNA in the filtrate by a 0.22?µm pore size MCE membrane. This method is able to isolate the non-parallel G-quadruplexes from the parallel G-quadruplexes and the linear duplexes from both G-quadruplexes. In addition, this method allows us not only to determine the absence of the parallel G-quadruplexes of d(T(2)AG(3))(4) and the presence of the parallel G-quadruplexes of d(T(2)AG(3))(2) in K(+) solution, but also to verify structural conversion from antiparallel to parallel G-quadruplexes of d[AG(3)(T(2)AG(3))(3)] in K(+) solution under molecular PEG condition. Moreover, this emulsion can separate the non-parallel G-quadruplexes of d(G(3)CGCG(3)AGGAAG(5)CG(3)) monomer from the parallel G-quadruplexes of its dimer in K(+) solution. Together with NMR spectra, one can simplify the spectra for both the free DNA and the bound DNA to establish a spectrum-structure correlation for further structural analysis.
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A pre-operative approach of range of motion simulation and verification for femoroacetabular impingement.
Int J Med Robot
PUBLISHED: 04-07-2011
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BACKGROUND: Femoroacetabular impingement (FAI) is increasingly recognized as a potential cause of hip osteoarthritis. A system capable of pre-operatively simulating hip range of motion (ROM) by given surface models from either healthy or FAI diseased bone is desirable. METHODS: An impingement detection system using bounding sphere hierarchies was first developed. Both precision and accuracy of the impingement detection system were verified by a custom-designed phantom to imitate ball-and-socket hip movement. The impingement detection system was then implemented into the hip ROM simulation system to simulate the ROM of (1) healthy pelvis and femur, and (2) healthy pelvis and pathologic femur. The ROM simulation system was also verified by manipulating sawbones under the navigation of an optical tracking system. RESULTS: The impingement detection system achieved a distance error of 0.53 ± 0.06 mm and an angular error of 0.28 ± 0.03°. The impingement detection accuracies were 100%, 100%, and 96% in three different phantom orientations, respectively. The mean errors between simulated and verified ROM were 0.10 ± 1.39° for the healthy pelvis and femur group, and - 2.38 ± 3.49° for the healthy pelvis and pathologic femur group. CONCLUSION: The present study demonstrates a pre-operative approach to virtually simulate and predict the functional hip ROM based on the given bone models. The impingement detection and ROM simulation systems developed may also be used for other orthopedic applications. Copyright © 2011 John Wiley & Sons, Ltd.
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Significant associations of prostate cancer susceptibility variants with survival in patients treated with androgen-deprivation therapy.
Int. J. Cancer
PUBLISHED: 03-11-2011
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Androgen-deprivation therapy (ADT) is the most common therapy for advanced prostate cancer, but the prognosis significantly differs among individuals. In this study, we evaluated recently identified 19 prostate cancer susceptibility variants as prognostic predictors for the survival after ADT. A total of 601 prostate cancer patients treated with ADT were enrolled in this study cohort. The prognostic significance of the prostate cancer risk variants on disease progression, prostate cancer-specific mortality (PCSM) and all-cause mortality (ACM) after ADT were assessed by Kaplan-Meier analysis and Cox regression model. Two polymorphisms, rs16901979 and rs7931342, were significantly associated with PCSM (p = 0.005 for rs16901979 and p = 0.038 for rs7931342), and rs16901979 was also associated with ACM (p = 0.003) following ADT. Although the effect of rs7931342 was attenuated after controlling for other known clinical prognostic factors, rs16901979 remained a significant predictor for PCSM and ACM after ADT (p = 0.002). Moreover, the addition of the rs16901979 status in current clinical staging system further enhanced the risk prediction on PCSM and ACM particularly for the high-risk patients with distant metastasis (p < 0.017). In conclusion, this is the first study showing that prostate cancer risk variants, such as rs16901979, might improve outcome prediction following ADT, thus allowing identification of high-risk patients who might benefit from appropriate adjuvant therapy.
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Structural conversion of intramolecular and intermolecular G-quadruplexes of bcl2mid: the effect of potassium concentration and ion exchange.
J Phys Chem B
PUBLISHED: 02-22-2011
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The gel assay, circular dichroism, and differential scanning calorimetry results all demonstrate that a major monomer component of bcl2mid exists at low [K(+)] and an additional dimer component appears at high [K(+)]. This implies that bcl2mid is a good candidate for elucidating the mechanisms of structural conversion between different G-quadruplexes. We further discovered that the conversion between the monomer and dimer forms of bcl2mid does not occur at room temperature but is detected when heated above the melting point. In addition, the use of the lithium cation to keep the same ionic strength in a K(+) solution favors the formation of the bcl2mid dimer. We also found that the bcl2mid dimer is more stable than the monomer. However, after the bcl2mid monomer is formed in a K(+) solution, there is no appreciable structural conversion from the monomer to the dimer detected with addition of Li(+) at room temperature. Furthermore, the spectral changes of bcl2mid when transitioning from sodium form to potassium form take place upon K(+) titration. The absence of the dimer form for bcl2mid after the direct addition of 150 mM [K(+)] at room temperature suggests that the spectral changes are not due to rapid unfolding and refolding. In addition, this work reveals the conditions that would be useful for NMR studies of G-quadruplexes.
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Label-free imaging of Drosophila in vivo by coherent anti-Stokes Raman scattering and two-photon excitation autofluorescence microscopy.
J Biomed Opt
PUBLISHED: 02-02-2011
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Drosophila is one of the most valuable model organisms for studying genetics and developmental biology. The fat body in Drosophila, which is analogous to the liver and adipose tissue in human, stores lipids that act as an energy source during its development. At the early stages of metamorphosis, the fat body remodeling occurs involving the dissociation of the fat body into individual fat cells. Here we introduce a combination of coherent anti-Stokes Raman scattering (CARS) and two-photon excitation autofluorescence (TPE-F) microscopy to achieve label-free imaging of Drosophila in vivo at larval and pupal stages. The strong CARS signal from lipids allows direct imaging of the larval fat body and pupal fat cells. In addition, the use of TPE-F microscopy allows the observation of other internal organs in the larva and autofluorescent globules in fat cells. During the dissociation of the fat body, the findings of the degradation of lipid droplets and an increase in autofluorescent globules indicate the consumption of lipids and the recruitment of proteins in fat cells. Through in vivo imaging and direct monitoring, CARS microscopy may help elucidate how metamorphosis is regulated and study the lipid metabolism in Drosophila.
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High-frequency hearing loss, occupational noise exposure and hypertension: a cross-sectional study in male workers.
Environ Health
PUBLISHED: 01-20-2011
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The association between occupational noise exposure and hypertension is inconsistent because of an exposure bias caused by outer-ear measurements of noise levels among workers. This study used hearing loss values (HLVs) measured at 4 kHz and 6 kHz in both ears as a biomarker to investigate the chronic effects of noise exposure on hypertension in 790 aircraft-manufacturing workers.
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Pain induced by intensive light beam pulse stimulation of acupuncture point GB34 of lower extremities and its associated changes in EEGs.
Acupunct Electrother Res
PUBLISHED: 01-01-2011
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Pain perception and its EEG wave have been used to describe the bodys neural systemic response with respect to a given stimulation. Pain artificially induced by non-coherent intensive light (wavelength of 500nm-1200nm) impulse has not been studied yet. In this study this technique was applied to statistically correlate the brain activity under induced pain while particular acupuncture points (yanlingchuan of both feet, GB34) were stimulated by intensive light impulses. The brain electrophysiological signals or electroencephalogram (EEG) at F(p1), F(p2) were recorded. The data of brain waves showed a distinguishable raising slope in this study. Intensive light beam impulse with beam diameter of 10 mm and intensity of 14 joule/cm2 was applied to the acupuncture points. In order to quantify the pain effects, a pain intensity function was defined based on the induced pain activities related to the collected data. The pain intensity function and its equations were used to analyze the changing rate of pain with respect to stimulated intensity and pain momentum transport activity. The results showed that the area of the brain wave evoked by pain could be used as pain perception indicator. The raising slope at one brain side was relatively higher when the acupuncture point GB34 at the contralateral side was stimulated.
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