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Find video protocols related to scientific articles indexed in Pubmed.
CD44 variant isoforms expressed by breast cancer cells are functional E--selectin ligands under flow conditions.
Am. J. Physiol., Cell Physiol.
PUBLISHED: 10-24-2014
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AAdhesion of circulating tumor cells to vascular endothelium is mediated by specialized molecules that are functional under shear forces exerted by hematogenous flow. Endothelial E-selectin binding to glycoforms of CD44 mediates shear-resistant cell adhesion in numerous physiologic and pathologic conditions. However, this pathway is poorly understood in breast cancer and is the focus of the present investigation. All breast cancer cell lines used in this study strongly expressed CD44. In particular, BT-20 cells expressed CD44s and multiple CD44v isoforms, whereas MDA-MB-231 cells predominantly expressed CD44s but weakly expressed CD44v isoforms. CD44 expressed by BT-20 cells, but not MDA-MB-231 cells, possessed E-selectin ligand activity as detected by Western blotting and antigen capture assays. Importantly, CD44 expressed by intact BT-20 cells were functional E-selectin ligands - regulating cell rolling and adhesion under physiological flow conditions, as found by shRNA targeted silencing of CD44. Antigen capture assays strongly suggested that BT-20 cell CD44v isoforms possess greater shear-resistant E-selectin ligand activity than CD44s. Surprisingly, CD44 was not recognized by the HECA-452 mAb, which detects sialofucosylated epitopes traditionally expressed by selectin ligands, suggesting that BT-20 cells express a novel glycoform of CD44v as an E-selectin ligand. The activity of this glycoform was predominantly attributed to N-linked glycans. Furthermore, expression of CD44v as an E-selectin ligand correlated with high levels of fucosyltransferase (FT)-3 and FT-6 and epithelial, rather than mesenchymal, cell phenotype. Altogether, these data demonstrate that expression of CD44 as a functional E-selectin ligand may be important in breast cancer metastasis.
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TERT promoter mutations and gene amplification: Promoting TERT expression in Merkel cell carcinoma.
Oncotarget
PUBLISHED: 10-11-2014
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Telomerase activation through the induction of its catalytic component TERT is essential in carcinogenesis. The regulatory mechanism and clinical significance underlying cancer-specific TERT expression have been extensively investigated in various human malignancies, but little is known about these in Merkel cell carcinoma (MCC), an aggressive neuroendocrine skin tumor. Here we addressed these issues by determining TERT promoter mutations, gene amplification, mRNA expression and association with clinical variables in MCC. TERT mRNA was expressed in 6/6 MCC cell lines and 41 of 43 tumors derived from 35 MCC patients. Telomerase activity was detectable in all 6 cell lines and 11 tumors analyzed. TERT promoter mutations were identified in 1/6 cell lines and 4/35 (11.4%) MCC cases. The mutation exhibited UV signature and occurred in sun-exposed areas. Increased TERT gene copy numbers were observed in 1/6 cell lines and 11/14 (79%) tumors, and highly correlated with its mRNA expression (r = 0.7419, P = 0.0024). Shorter overall survival was significantly associated with higher TERT mRNA levels in MCC patients (P = 0.032). Collectively, TERT expression and telomerase activity is widespread in MCC, and may be attributable to TERT promoter mutations and gene amplification. Higher TERT expression predicts poor patient outcomes.
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Stereoselective bioaccumulation and metabolite formation of triadimefon in Tubifex tubifex.
Environ. Sci. Technol.
PUBLISHED: 05-29-2014
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Triadimefon, a chiral fungicide, could be metabolized to triadimenol which has two chiral centers. In this work, Tubifex tubifex was exposed to triadimefon through the aqueous and soil phase to explore the relative importance of the routes of uptake. Bioaccumulation of triadimefon in tubifex was detected in both treatments, and the kinetics of the accumulation processes were significantly different in these two experiments. In spiked water treatment, (S)-triadimefon was preferentially accumulated over the (R)-triadimefon, whereas the enantioselective bioaccumulation was not detected in the spiked soil microenvironment. Simultaneously, four stereoisomers of triadimenol were also found in the tubifex tissue. Although the amount of these stereoisomers were different from each other with relatively more accumulation of the most fungi-toxic stereoisomer (1S,2R), the abundance ratios in the two exposure treatments were similar at the same sampling, following the order (1S,2S) > (1R,2S) > (1R,2R) > (1S,2R). The bioaccumulation factor was calculated for parent compound triadimefon and metabolite enrichment factor for metabolite. The results showed that both uptake routes, epidermal contact in the aqueous phase and ingestion of solid particles in soil, were important to the bioaccumulation of the triadimefon and triadimenol in tubifex.
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Enhancement of anammox activity by addition of compatible solutes at high salinity conditions.
Bioresour. Technol.
PUBLISHED: 04-29-2014
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The enhancement effect of compatible solutes on anammox activity under salinity stress was investigated. Glycine betaine (GB) was the most effective in alleviating salt toxicity, although all the compatible solutes (GB, trehalose and ectoine) were found to be valid. Acclimation potential of anammox biomass under salinity of 30 g/L increased significantly with GB addition. The recovery time in the reactor with GB addition (RB) (49 days) accompanied by a more stable stoichiometric ratio was 2.65 times shorter than in the control reactor (RC) (130 days). After 49 days, the extracellular polymeric substances and the tetrazolium chloride-dehydrogenase activity were 217.9 mg/g VSS and 38.7 ?g TF/g VSS/h in RB, 1.86 times lower and 3.17 times higher than the levels in RC, respectively. RB possessed evident superiority in the aspects of microbial population proportion. And thus, compatible solutes addition was regarded as one of the feasible solution to counteract saline inhibition on anammox.
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TERT promoter mutations in renal cell carcinomas and upper tract urothelial carcinomas.
Oncotarget
PUBLISHED: 04-19-2014
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TERT promoter mutations are identified in many malignancies including bladder cancer (BC) and upper tract urothelial carcinoma (UTUC). In contrast, no mutations were found in renal cell carcinoma (RCC) as reported in a recent study. Because the mutant TERT promoter in urine DNA was recently tested as a marker for BC, it is important to ascertain whether these mutations are truly absent in RCCs. Here we determined TERT promoter mutations in 109 patients with RCC and 14 patients with UTUC. The mutations were found in 9/96 (9.3%) clear cell RCC (ccRCC) tumors and 1/8 (13%) chromophobe RCC tumors. Among ccRCC patients, the mutation was correlated with the advanced stages and metastasis, and higher TERT expression. Among UTUCs, the mutation was detected in tumors from 3/5 (60%) patients with renal pelvic cancer and 1/9 (11%) patients with ureter cancer. The mutation was also detected in 1 of 4 urine samples from patients with mutation+ UTUC. Collectively, TERT promoter mutations do occur in RCCs and are associated with aggressive disease. The mutation is more frequent in renal pelvic cancer. Thus, the mutant TERT promoter found in urine may come from not only BC, but also RCC or UTUC.
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TERT promoter mutation as an early genetic event activating telomerase in follicular thyroid adenoma (FTA) and atypical FTA.
Cancer
PUBLISHED: 03-31-2014
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The telomerase reverse transcriptase (TERT) promoter mutations C228T and C250T have been found in many malignancies, including in thyroid carcinomas. However, it is unclear how early these mutations occur in thyroid tumorigenesis.
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Spectrum-effect relationships between UPLC fingerprints and bioactivities of crude secondary roots of Aconitum carmichaelii Debeaux (Fuzi) and its three processed products on mitochondrial growth coupled with canonical correlation analysis.
J Ethnopharmacol
PUBLISHED: 03-03-2014
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Ethnopharmacological relevance: The crude secondary roots of Aconitum carmichaelii Debeaux (Fuzi), together with its processed products, including Yanfuzi, Heishunpian and Paofupian, are commonly applied in clinic using for thousands of years, such as collapse, syncope, rheumatic fever, painful joints and various tumors. Aim of the study: To explore the different effects of Fuzi and its processed products on energy metabolism, with mitochondria as the model with the aim of guiding the clinical use of Fuzi and its products. fingerprints of Fuzi, Yanfuzi, Heishunpian and Paofupian were established by Ultra-high Performance Liquid Chromatography (UPLC) and effects of Fuzi and its processed products on rat's liver?s mitochondrial metabolism were studied by microcalorimetry. Spectrum-effect relationships between UPLC fingerprints and energy metabolism of mitochondria were investigated using canonical correlation analysis (CCA). Results: Because of their inherent differences in chemical compositions, the main activities of energy metabolism of mitochondria were different among Fuzi and its processed products. The potential bioactivity sequence of the tested products was Fuzi>Heishunpian>Paofupian>Yanfuzi. Results of CCA showed that compounds mesaconitine, benzoylaconitine, and benzoylhypacoitine might be the principal active components. Conclusion: Altogether, this work provides a general model of combination of UPLC and microcalorimetry to study the spectrum-effect relationships of Fuzi and its processed products which can offer some references for detecting principal components of traditional Chinese medicine on bioactivity to mitochondrial growth.
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The impact of exogenous DNA on the structure of sperm of olive flounder (Paralichthys olivaceus).
Anim. Reprod. Sci.
PUBLISHED: 02-13-2014
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Sperm-mediated gene transfer (SMGT) is a promising transgenic technology that relies on the capability of sperm to internalize exogenous DNA. In marine fish, however, the interaction between sperm and exogenous DNA appears to be deficient. Here, we demonstrated significant DNase activity in the seminal plasma of the olive flounder. When incubated with naked-DNA, the spermatozoa lost their structural integrity, including the head, mitochondria and flagellum, in an incubation time-dependent manner. However, internalization of a liposome-DNA complex resulted in the structural integrity of the spermatozoa being maintained, even when using incubation times of up to 50min. We concluded that in the olive flounder, SMGT is possible by integrating liposome-DNA complexes, rather than naked-DNA alone, into the sperm. In brief, removal of the seminal plasma and packaging the exogenous DNA were necessary for successful SMGT in the olive flounder.
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Resveratrol inhibits the TRIF-dependent pathway by upregulating sterile alpha and armadillo motif protein, contributing to anti-inflammatory effects after respiratory syncytial virus infection.
J. Virol.
PUBLISHED: 01-29-2014
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Respiratory syncytial virus (RSV) is the most important cause of lower respiratory tract infection in young children and the leading cause of infant hospitalization worldwide. Uncontrolled response to RSV is mediated by a toll-like receptor (TLR)-mediated immune response. Resveratrol possesses anti-RSV activity and is an inhibitor of the TRIF/TBK1/IRF-3 complex. We hypothesize that resveratrol inhibits the TRIF-dependent pathway through upregulation of SARM post-RSV infection. BALB/c mice were infected with RSV and were injected with resveratrol 1 h postinoculation. SARM short interfering RNA was administered to RSV-infected and resveratrol-treated mice. Lung function was measured by whole-body plethysmography, lung histopathology was examined, and lymphocytes in bronchoalveolar lavage fluid were quantified. SARM and TRIF protein expression were detected in the lung by Western blot analyses. The expression of gamma interferon in bronchoalveolar lavage fluid (BALF) was evaluated by enzyme-linked immunosorbent assay (ELISA). SARM expression was reduced and TRIF expression was increased after infection with RSV. Resveratrol increased SARM expression and decreased TRIF expression after RSV infection. SARM knockdown in resveratrol-treated mice enhanced gamma interferon production, RSV-induced airway inflammation, and airway hyperresponsiveness (AHR). Resveratrol decreased TRIF expression and prevented the RSV-mediated reduction of SARM expression. Resveratrol-mediated inhibition of the TRIF-dependent pathway may be dependent on SARM expression.
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Enantioselective determination of triazole fungicide epoxiconazole bioaccumulation in tubifex based on HPLC-MS/MS.
J. Agric. Food Chem.
PUBLISHED: 01-09-2014
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In this study, the enantioselective bioaccumulation of epoxiconazole enantiomers in tubifex (Oligochaeta, Tubificida) was investigated in two uptake pathways. A sensitive and rapid chiral method was developed for the determination of epoxiconazole enantiomers in tubifex and soil based on high-performance liquid chromatography coupled with triple-quadrupole mass spectrometry (HPLC-MS/MS). In the spiked-water or spiked-soil treatments, enantioselective bioaccumulation of epoxiconazole in tubifex was obersved. For spiked-water treatment, (-)-epoxiconazole accumulated in tubifex to a greater extent than (+)-epoxiconazole, leading to enrichments with a composition (-) > (+). However, for spiked-soil treatment, the enantioselectivity in tubifex was reversed with a preferential accumulation of (+)-epoxiconazole. Calculated accumulation factors (AFs) indicated that epoxiconazole in spiked-water treatment had higher bioaccumulation potential than that in spiked-soil treatment. The results from the spiked-soil treatment also revealed that the dissipation of epoxiconazole in soil was enantioselective, and tubifex has positive effects on epoxiconazole diffusion from soil to overlying water.
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The activating TERT promoter mutation C228T is recurrent in subsets of adrenal tumors.
Endocr. Relat. Cancer
PUBLISHED: 01-01-2014
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The telomerase reverse transcriptase gene (TERT) encodes the reverse transcriptase component of the telomerase complex, which is essential for telomere stabilization and cell immortalization. Recent studies have demonstrated a transcriptional activation role for the TERT promoter mutations C228T and C250T in many human cancers, as well as a role in aggressive disease with potential clinical applications. Although telomerase activation is known in adrenal tumors, the underlying mechanisms are not established. We assessed C228T and C250T TERT mutations by direct Sanger sequencing in tumors of the adrenal gland, and further evaluated potential associations with clinical parameters and telomerase activation. A total of 199 tumors were evaluated, including 34 adrenocortical carcinomas (ACC), 47 adrenocortical adenomas (ACA), 105 pheochromocytomas (PCC; ten malignant and 95 benign), and 13 abdominal paragangliomas (PGL; nine malignant and four benign). TERT expression levels were determined by quantitative RT-PCR. The C228T mutation was detected in 4/34 ACCs (12%), but not in any ACA (P=0.028). C228T was also observed in one benign PCC and in one metastatic PGL. The C250T mutation was not observed in any case. In the ACC and PGL groups, TERT mutation-positive cases exhibited TERT expression, indicating telomerase activation; however, since expression was also revealed in TERT WT cases, this could denote additional mechanisms of TERT activation. To conclude, the TERT promoter mutation C228T is a recurrent event associated with TERT expression in ACCs, but rarely occurs in PGL and PCC. The involvement of the TERT gene in ACC represents a novel mutated gene in this entity.
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Promoter polymorphism in the serotonin transporter (5-HTT) gene is significantly associated with leukocyte telomere length in Han Chinese.
PLoS ONE
PUBLISHED: 01-01-2014
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The serotonin transporter gene (5-HTT)-linked polymorphic region (5-HTTLPR) plays an important role in modulating mood and behavior by regulating 5-HTT expression and thereby controlling the concentration of serotonin (5-HT) in brain synapses: The homozygous shorter allele (S/S) in 5-HTTLPR results in lower 5-HTT expression coupled with stronger psycho-pathological reactions to stressful experiences compared to the homozygous long (L/L) and heterozygous (S/L) alleles. Psychological insults and mood disorders have been shown to cause accelerated telomere shortening, a marker of biological aging, however, it is currently unclear whether the allelic variants of 5-HTTLPR affect telomere length (TL) in the healthy population without mood disorders. In the present study, we determined the relationship between TL and the 5-HTTLPR variants in healthy Han Chinese. The 5-HTTLPR genotyping and leukocyte TL analysis of 280 young female Han Chinese freshmen showed a significantly shorter TL in 149 of them carrying the 5-HTTLPR S/S version compared to those (131) with the L/S or L/S plus L/L genotypes (mean ± SD, 0.533±0.241 for S/S vs 0.607±0.312 for L/S, P ?=? 0.034; or vs 0.604±0.313 for L/S plus L/L, P ?=? 0.038). Similar results were achieved in the other cohort including 220 adult healthy individuals of different age, gender and profession (0.691±0.168 for S/S vs 0.729±0.211 for L/S, P ?=? 0.046, or vs 0.725±0.213 for L/S plus L/L, P ?=? 0.039). Taken together, shorter leukocyte TL is significantly associated with the 5-HTTLPR S/S allelic variant, which may be implicated in psychological stress-related health problems.
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Long-term resveratrol treatment prevents ovariectomy-induced osteopenia in rats without hyperplastic effects on the uterus.
Br. J. Nutr.
PUBLISHED: 09-30-2013
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Resveratrol (Res), a polyphenol that is abundant in many medicinal plants and is a selective oestrogen receptor modulator, exhibits multiple biological activities. In the present study, we determined whether Res prevents oestrogen deficiency-induced osteopenia and whether Res administration decreases pathological changes in the endometrium and lumen of the uterus compared with oestradiol replacement therapy (ERT). A total of sixty 3-4-month-old female Wistar rats were randomly divided into a sham-operated group (Sham) and five ovariectomy (OVX) subgroups, i.e. OVX rats as a control group (OVX); OVX rats receiving oestradiol valerate (ERT, 0·8 mg/kg); and OVX rats receiving Res 20, 40 and 80 mg/kg. Daily oral administration was initiated at week 2 after OVX for 12 weeks. A dose-response difference was observed in the effects of Res on bone mineral density (BMD) and trabecular microarchitecture. Only at the highest dose, bone loss was almost equivalent to that observed in the ERT group. The dose-response effects of Res on the biochemical parameters (alkaline phosphatase, IL-6, TNF-? and transforming growth factor-?1 concentrations in the serum as well as urinary Ca and P excretion) and the expressions of receptor activator of nuclear factor ?B ligand (RANKL) and the RANKL:osteoprotegerin protein ratio in the femur were also observed. Furthermore, the thickening of the endometrium and the infiltration of lymphocytes were prevented in all the three Res-treated groups compared with the ERT group. In conclusion, Res treatment not only improves BMD and trabecular microarchitecture but also does not affect the uterus and Res might be a potential remedy for the treatment of postmenopausal osteoporosis.
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Enantioselective Bioaccumulation and Dissipation of Soil-Associated Metalaxyl Enantiomers in Tubifex.
Chirality
PUBLISHED: 08-19-2013
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Many pesticides are chiral compounds and stereochemistry is an important factor for any reaction of chiral structures in biological systems. In this study, experiment about bioaccumulation of the two metalaxyl enantiomers in Tubifex (Oligochaeta, Tubificida) was conducted in laboratory aquatic ecosystems. Terrestrial soil spiked with two dose levels of metalaxyl was employed as the artificial bottom substrate. A method of determination of metalaxyl enantiomers in tubifex tissue, soil and overlying water were developed by HPLC. During a 14-day exposure, concentrations of metalaxyl in tubifex increased with the of soil concentration, however, the enantioselective bioaccumulation was only detected at high-dose exposure group, with the preferential accumulation of (-)-(R)-metalaxyl. The bioturbation activity of tubifex decreased water clarity and released soil-associated metalaxyl to overlying water. In those experiments where tubifex was exposed to metalaxyl from soil, pore water and overlying water, each route contributed to the total body burden, and our results indicated the pore water and soil are the primary exposure routes for high-dose exposure concentration treatment. Chirality 00:000-000, 2013. © 2013 Wiley Periodicals, Inc.
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Effect of salinity on N2O production during shortcut biological nitrogen removal from landfill leachate.
J. Biosci. Bioeng.
PUBLISHED: 08-01-2013
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Three identical SBR adapted to different salinity were applied to investigate the characteristics of the treatment performance and N2O production [Formula: see text] during shortcut biological nitrogen removal from landfill leachate under various operating parameters. Increase of salinity might deteriorate the activity of the microorganisms leading to the increase of [Formula: see text] , however, the system could be gradually adapted to the inhibition and alleviate the detrimental effect to some extent. The system acclimated to high salinity provided better performance under high salinity shock and a lower possibility of [Formula: see text] , while a sudden decrease in salinity can cause a temporary increase in [Formula: see text] . High salinity strengthened the influence of high ammonia nitrogen concentration and low DO concentration on [Formula: see text] while the strengthening effect was unconspicuous at high DO concentration. The anoxic phase did not produce a significant amount of N2O even at the lowest C/N ratio of 0.5 and was less susceptible to salinity. Characterization of the biomass composition using fluorescence in situ hybridization analysis confirmed that the relative proportion of Nitrosomonas europaea was increased with the increase of the salinity, which may be an important factor for the strengthening effect of salinity on [Formula: see text] .
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Enantioselective bioaccumulation and degradation of sediment-associated metalaxyl enantiomers in Tubifex tubifex.
J. Agric. Food Chem.
PUBLISHED: 05-20-2013
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Knowledge about the enantioselective bioavailability of chiral pesticides in aquatic organisms facilitates more accurate interpretation of their environmental behaviors. In this study, the enantioselective bioaccumulation of metalaxyl enantiomers in Tubifex tubifex was detected in two uptake pathways. For the spike water treatment, a 16 day exposure experiment was employed and the enantiomer fractions (EFs) in tubifex tissue were maintained approximately at 0.47 during the experiment. For the spike sediment treatment, a 14 day bioaccumulation period indicated the concentrations of (-)-(R)-metalaxyl were higher than those of (+)-(S)-metalaxyl. Therefore, the bioaccumulation of metalaxyl in worms was enantioselective for these treatments. With the presence of tubifex, higher concentrations of metalaxyl in overlying water and lower concentrations in sediment were detected than in worm-free treatments. This means that tubifex has positive functions in metalaxyls diffusion from the sediment to overlying water and in the degradation of the sediment-associated metalaxyl.
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Determination of triazine herbicides in milk by cloud point extraction and high-performance liquid chromatography.
Food Chem
PUBLISHED: 05-01-2013
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High-performance liquid chromatography with UV detection was used to detect four triazines in milk. An efficient pretreatment method known as cloud point extraction (CPE) was proposed for extracting and preconcentrating analytes. The parameters of CPE including surfactant type and concentration, electrolyte, sample pH, incubation temperature and duration were investigated. Under optimal conditions, satisfying recoveries in the range of 70.5-96.9% were achieved for four triazines. The limits of detection ranged from 6.79 to 11.19?g L(-1). The linear range of quantitation for the four triazines was 50-2000?g L(-1), and the correlation coefficients of the calibration curves were all 0.9999. The results demonstrated that the proposed method was efficient and reliable for the determination of triazine herbicides in milk samples.
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EETs and CYP2J2 inhibit TNF-?-induced apoptosis in pulmonary artery endothelial cells and TGF-?1-induced migration in pulmonary artery smooth muscle cells.
Int. J. Mol. Med.
PUBLISHED: 03-27-2013
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Cytochrome P450 epoxygenase-derived epoxyeicosatrienoic acids (EETs) have multiple biological functions in cardiovascular homeostasis. The antiin?ammatory, anti-migratory and pro-proliferative effects of EETs suggest a possible bene?cial role for EETs in the apoptosis, proliferation and migration of pulmonary vascular cells. In this study, we investigated the effects of exogenous EETs and cytochrome P450 2J2 (CYP2J2) overexpression on tumor necrosis factor-? (TNF-?)-induced pulmonary artery endothelial cell (PAEC) apoptosis, and transforming growth factor-?1 (TGF-?1)-induced pulmonary artery smooth muscle cell (PASMC) proliferation and migration. PAECs and PASMCs were cultured from porcine pulmonary arteries. Our findings indicated that EETs or CYP2J2 overexpression signi?cantly protected the PAECs from TNF-?-induced apoptosis, as evaluated by cell viability and flow cytometry. Two mechanisms were found to be involved in these important protective effects: firstly, EETs and CYP2J2 overexpression inhibited the decrease in the expression of the antiapoptotic proteins, Bcl-2 and Bcl-xL, as well as the increase in the expression of the pro-apoptotic protein, Bax, mediated by TNF-?; secondly, they activated the phosphoinositide 3-kinase (PI3K)/Akt and extracellular signal-regulated kinase (ERK) signaling pathways. We also found that 11,12-EET and 14,15-EET significantly inhibited TGF-?1-stimulated PASMC migration. However, EETs did not suppress TGF-?1-induced PASMC proliferation in vitro. These data may represent a novel approach to mitigate pulmonary vascular remodeling in diseases, such as pulmonary arterial hypertension.
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Preparation and characterization of biomass carbon-based solid acid catalyst for the esterification of oleic acid with methanol.
Bioresour. Technol.
PUBLISHED: 01-22-2013
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A solid acid catalyst, prepared by sulfonating carbonized corn straw, was proved to be an efficient and environmental benign catalyst for the esterification of oleic acid and methanol. Various synthetic parameters, such as carbonization temperature and time were systematically examined. It was found that the catalyst exhibited the highest acid density of 2.64 mmol/g by NaOH titration. A quantitative yield (98%) of ester was achieved, using the most active sulfonated catalyst at 333 K with a 7 wt.% catalyst/oleic acid ratio for 4h, at a 7:1 M ratio of methanol/oleic acid, while the commercial available Amberlyst-15 only gave 85% yield under the same reaction condition.
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Histone demethylase JMJD2B is required for tumor cell proliferation and survival and is overexpressed in gastric cancer.
Biochem. Biophys. Res. Commun.
PUBLISHED: 10-13-2011
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Epigenetic alterations such as aberrant expression of histone-modifying enzymes have been implicated in tumorigenesis. Jumonji domain containing 2B (JMJD2B) is a newly identified histone demethylase that regulates chromatin structure or gene expression by removing methyl residues from trimethylated lysine 9 on histone H3. Recent observations have shown oncogenic activity of JMJD2B. We explored the functional role of JMJD2B in cancer cell proliferation, survival and tumorigenesis, and determined its expression profile in gastric cancer. Knocking down JMJD2B expression by small interfering RNA (siRNA) in gastric and other cancer cells inhibited cell proliferation and/or induced apoptosis and elevated the expression of p53 and p21(CIP1) proteins. The enhanced p53 expression resulted from activation of the DNA damage response pathway. JMJD2B knockdown markedly suppressed xenograft tumor growth in vivo in mice. Moreover, JMJD2B expression was increased in primary gastric-cancer tissues of humans. Thus, JMJD2B is required for sustained proliferation and survival of tumor cells in vitro and in vivo, and its aberrant expression may contribute to the pathogenesis of gastric cancer.
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Reptin is required for the transcription of telomerase reverse transcriptase and over-expressed in gastric cancer.
Mol. Cancer
PUBLISHED: 05-30-2010
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Telomerase is activated in oncogenesis, which confers an immortal phenotype to cancer cells. The AAA + ATPase Reptin is required for telomerase biogenesis by maintaining telomerase RNA (hTER) stability and is aberrantly expressed in certain cancers. Given its role in chromatin remodeling and transcription regulation, we determined the effect of Reptin on the transcription of the telomerase reverse transcriptase (hTERT) gene, a key component of the telomerase complex and its expression in gastric cancer.
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A novel method for preparing quantum dot nanospheres with narrow size distribution.
Nanoscale
PUBLISHED: 01-14-2010
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Differently colored quantum dot (QD) nanoparticles are incorporated into bovine serum albumin (BSA) nanospheres by spray-drying followed by thermal denaturization, which is a rapid, highly efficient, large scale, and low cost method. Because the spray-dryer is equipped with an ultrasonic atomizer, most of the nanospheres are no more than 550 nm in diameter and a have narrow size distribution. Ultrathin sections (70 nm) of nanospheres are first prepared using a technique which is normally applied to cell sectioning. The section images show that the QD-BSA nanospheres are solid, and that the QDs are successfully dispersed inside the BSA nanospheres. The nanospheres emit bright fluorescence, and their fluorescence stabilities are not obviously changed compared with that of the QDs. This work provides a novel and simple method for preparing nanoscale spheres encapsulating differently colored QDs. We also present an ultrathin sectioning method for investigating the interior details of nanomaterials.
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Long-term resveratrol consumption protects ovariectomized rats chronically treated with D-galactose from developing memory decline without effects on the uterus.
Brain Res.
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Resveratrol (Res) displays potent anti-oxidant activity and is a selective estrogen receptor modulator. The aim of the present study is to investigate whether Res consumption protects ovariectomized (OVX) rats chronically treated with D-galactose (D-gal) from developing memory decline and whether Res administration decreases pathological changes in the endometrium and lumen of the uterus compared with estradiol replacement therapy. Rats were divided into 6 groups: 1) Sham control group; 2) OVX+D-gal 100mg/kg group (OVX+D-gal); 3-5) OVX, D-gal and Res 20, 40, 80 mg/kg treated groups; and 6) OVX, D-gal and estradiol valerate 0.8 mg/kg treated group (ET). Twelve weeks later, in a Morris water maze test, the OVX+D-gal rats exhibited a significant memory impairment compared with the Sham control rats, which was accompanied by decreased total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) activities and an increased thiobarbituric acid reactive substances (TBARS) level in the serum. In addition, the TBARS and protein carbonylation levels increased in the hippocampus. The beneficial roles of the 40 and 80 mg/kg Res treatments were manifested in the prevention of memory decline and markedly decreased oxidant stress indices. The disruption of the cristae in the mitochondria and the irregular nuclei and condensed chromatin in the pyramidal cells of the hippocampal CA1 region were also reduced after Res treatment. Furthermore, edema in the endometrium and lymphocyte infiltration was avoided in all three of the Res-treated groups compared with the ET group. These results suggest that Res is useful not only in protecting OVX+D-gal rats from developing memory decline by increasing the anti-oxidation but also in avoiding the effects on the uterus.
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Enantioselective bioaccumulation of soil-associated fipronil enantiomers in Tubifex tubifex.
J. Hazard. Mater.
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Enantioselective behavior of chiral pesticides in the aquatic environment has been a subject of growing interest. In this study, the enantioselective bioaccumulation of fipronil enantiomers in Tubifex tubifex (Oligochaeta, Tubificida) was detected in both spike-water and spike-soil systems, respectively. For the spike-water treatment, a 9-day exposure experiment was employed and the enantiomer fraction in tubifex tissue was maintained approximately at 0.58 during the experiment. In addition, a 14-day bioaccumulation period was chosen for the spike-soil treatment and a more significant deviation of enantiomer fraction from 0.5 in tubifex tissue was detected, with concentrations of the R-form higher than that of the S-form. Therefore, the bioaccumulation of fipronil was enantioselective in tubifex tissue for the two treatments and the magnitude of enantioselectivity may be influenced by different exposure conditions. For the spike-soil treatment, the concentrations of fipronil in verlying water and soil were also determined. With the presence of tubifex worms, higher concentrations of fipronil in overlying water and lower concentrations in soil were detected than that in the absence of tubifex treatment during the whole 14-day exposure period. This means that tubifex has positive functions in fipronils diffusion from soil to overlying water and in the degradation of the soil-associated fipronil.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.