bluuebunny/crossref_metadata_2025_split huggingface dataset:
Apigenin, a chemopreventive bioflavonoid, induces AMP‐activated protein kinase activation in human keratinocytes
Authors: Tong Xin , Smith Kimberly A. , Pelling Jill C. 
Published: May 2011

AbstractAMP‐activated protein kinase (AMPK) is a cellular energy sensor that is conserved in eukaryotes. Although AMPK is traditionally thought to play a major role in the regulation of cellular lipid and protein metabolism, recent discoveries reveal that AMPK inhibits mammalian target of rapamycin (mTOR) signaling and connects with several tumor suppressors such as liver kinase B1 (LKB1), p53, and tuberous sclerosis complex 2 (TSC2), indicating that AMPK may be a potential target for cancer prevention and treatment. For the first time, we demonstrated that apigenin, a naturally occurring nonmutagenic flavonoid, induced AMPK activation in human keratinocytes (both cultured HaCaT cell line and primary normal human epidermal keratinocytes). Through experiments with over‐expression of constitutively active Akt and knockdown of LKB1 expression by siRNAs, we further found that the activation of AMPK by apigenin was not dependent on its inhibition of Akt, and was independent of the activation of upstream kinase LKB1. Instead, another upstream kinase of AMPK, calcium/calmodulin‐dependent protein kinase kinase‐β (CaMKKβ), was required for apigenin‐induced AMPK activation. We have demonstrated that knockdown of CaMKKβ expression by siRNA or inhibition of CaMKKβ activity by either CaMKK inhibitor STO‐609 or BAPTA‐AM (1,2‐bis(2‐aminophenoxy)ethane‐N,N,N′,N′‐tetraacetic acid acetoxymethyl ester; a chelator of intracellular Ca2+) prevented apigenin‐induced AMPK activation. Apigenin‐induced AMPK activation inhibited mTOR signaling and further induced autophagy in human keratinocytes. These results suggest that one of the mechanisms by which apigenin exerts its chemopreventive action may be through activation of AMPK and induction of autophagy in human keratinocytes. © 2011 Wiley Periodicals, Inc.
Association of a common genetic variant in prostate stem‐cell antigen with gastric cancer susceptibility in a Korean population
Authors: Song Hye‐Rim , Kim Hee Nam , Piao Jin‐Mei , Kweon Sun‐Seog , Choi Jin‐Su , Bae Woo‐Kyoun , Chung Ik Joo , Park Young‐Kyu , Kim Soo‐Hyun , Choi Yoo‐Duk , Shin Min‐Ho 
Published: May 2011

AbstractA recent genome wide association study (GWAS) indentified a significant association between rs2294008 (C > T) polymorphism in prostate stem‐cell antigen (PSCA) and increased risk of gastric cancer in Japanese and Korean populations. The aim of this study was to determine whether rs2294008 polymorphism is associated with risk of gastric cancer in a Korean population. We conducted a large‐scale case–control study of 3,245 gastric cancer patients and 1,700 controls. The frequencies of the CC, CT, and TT genotypes of rs2294008 polymorphism were 17.8%, 49.9%, and 32.3% in the gastric cancer patients; and 24.4%, 48.1%, and 27.5% in the controls, respectively. We found that the CT and TT genotypes were associated with a significantly increased risk of gastric cancer (ORCT = 1.50, 95% confidence intervals, 95% CI: 1.28–1.76; ORTT = 1.71, 95% CI: 1.43–2.04), compared with the CC genotype. Further, stratified by tumor location and histological type, the effect of the rs2294008 T allele was larger in cardia (ORTT = 2.62, 95% CI = 1.42–4.85) than non‐cardia (ORTT = 1.67, 95% CI = 1.40–2.00), in diffuse‐type (ORTT = 2.00, 95% CI: 1.55–2.59) than in intestinal‐type (ORTT = 1.51, 95% CI: 1.22–1.86). Our study showed that rs2294008 in the PSCA gene was associated with increased risks of gastric cancer in a Korean population, suggests that rs2294008 might play an important role in gastric carcinogenesis. © 2011 Wiley Periodicals, Inc.
Preparation and characterization of shellac‐coated anthocyanin pectin beads as dietary colonic delivery system
Authors: Oehme Anett , Valotis Anagnostis , Krammer Gerhard , Zimmermann Ingfried , Schreier Peter 
Published: May 2011

AbstractScope: Anthocyanins are connected with various biological activities. A promising way to enhance the availability of anthocyanins for in situ effects in the lower intestine is colon‐specific delivery.Methods and results: Shellac and shellac/hydroxypropyl methylcellulose (HPMC) coated anthocyanin amidated pectin beads as dietary colonic delivery systems were successfully prepared by ionotropic gelation and fluid bed Wurster coating with aqueous shellac solution. Release characteristics, studied in vitro and ex vivo using simulated gastric fluid (SGF), ileostomy fluid and colostomy fluid (CF) revealed a retardation of anthocyanins during simulated passage of stomach and ileum as well as the desired release of pigments in the colon. Coating level was identified as an important parameter. By addition of 5 or 15% of the water‐soluble polysaccharide HPMC to the shellac film, resistance in SGF was increased due to the plasticizer properties of the polymer. Incorporation of 15% HPMC (w/w based on shellac) into the shellac film additionally led to increased anthocyanin diffusivity and complete release as well as degradation of the formulation in CF.Conclusion: In the used in vitro and ex vivo model system mimicking the human intestinal transit, the potential of shellac and shellac/HPMC coated anthocyanin amidated pectin beads as dietary colon targeting systems was demonstrated.
Flavanols from green tea and phenolic acids from coffee: Critical quantitative evaluation of the pharmacokinetic data in humans after consumption of single doses of beverages
Authors: Williamson Gary , Dionisi Fabiola , Renouf Mathieu 
Published: May 2011

AbstractCoffee contains a complex mixture of chlorogenic acids, which are mainly ferulic and caffeic acids ester‐linked to quinic acid. Green tea contains flavanols, mainly (−)‐epigallocatechin gallate (EGCG), (−)‐epigallocatechin (EGC) and (−)‐epicatechin (EC). For healthy humans, we identified seven studies on green tea in liquid form and five on coffee beverage reporting single‐dose plasma pharmacokinetics. Weighted averages, based on the number of subjects, and elimination of outliers, allowed estimation of some pharmacokinetic parameters. After consumption of an “average” cup of green tea containing 112 mg of (−)‐epigallocatechin gallate, 51 mg of EGC and 15 mg of EC in 200 mL, the predicted Cmax values (total free and sulfate/glucuronide conjugates) in plasma are 125, 181 and 76 nM, respectively, together with 94 nM methyl‐EGC and 51 nM methyl‐EC (standard deviation <20%). After consumption of an “average” cup of coffee (160 mg total chlorogenic acids (0.46 mmol)/200 mL), predicted Cmax values of caffeic, ferulic, isoferulic, dihydrocaffeic and dihydroferulic acids are 114, 96, 50, 384 and 594 nM, respectively (too few studies to calculate standard deviation). Most studies report a very low amount of intact chlorogenic acids in plasma, with one exception. More studies on absorption of chlorogenic acids from coffee are required, including dose–response studies.
Body composition and hormonal effects following exposure to mycotoxin deoxynivalenol in the high‐fat diet‐induced obese mouse
Authors: Kobayashi‐Hattori Kazuo , Amuzie Chidozie J. , Flannery Brenna M. , Pestka James J. 
Published: May 2011

AbstractScope: To characterize the effects of ingesting the common foodborne mycotoxin deoxynivalenol (DON) on body weight and composition in the high‐fat (HF) diet‐induced obese mice, a model of human obesity.Methods and results: Female B6C3F1 mice were initially fed HF diets containing 45% kcal (HF45) or 60% kcal (HF60) as fat for 94 days to induce obesity. Half of each group was either continued on unamended HF diets or fed HF diets containing 10 mg/kg DON (DON‐HF45 or DON‐HF60) for another 54 days. Additional control mice were fed a low‐fat (LF) diet containing 10% kcal as fat for the entire 148‐day period. DON induced rapid decreases in body weights and fat mass, which stabilized to those of the LF control within 11 days. These effects corresponded closely to a robust transient decrease in food consumption. While lean body mass did not decline in DON‐fed groups, further increases were suppressed. DON exposure reduced plasma insulin, leptin, insulin‐like growth factor 1, and insulin‐like growth factor acid labile subunit as well as increased hypothalamic mRNA level of the orexigenic agouti‐related protein.Conclusion: DON‐mediated effects on body weight, fat mass, food intake, and hormonal levels in obese mice were consistent with a state of chronic energy restriction.
Chemopreventive effects of tea in prostate cancer: Green tea versus black tea
Authors: Henning Susanne M. , Wang Piwen , Heber David 
Published: May 2011

AbstractThe polyphenol compositions of green tea (GT) and black tea (BT) are very different due to post‐harvest processing. GT contains higher concentrations of monomeric polyphenols, which affect numerous intracellular signaling pathways involved in prostate cancer (CaP) development. BT polymers, on the other hand, are poorly absorbed and are converted to phenolic acids by the colonic microflora. Therefore, after consumption of GT, higher concentrations of polyphenols are found in the circulation, whereas after BT consumption the phenolic acid levels in the circulation are higher. The majority of in vitro cell culture, in vivo animal, and clinical intervention studies examine the effects of extracts of GT or purified (−)‐epigallocatechin‐3‐gallate (EGCG) on prostate carcinogenesis. These studies provide strong evidence supporting a chemopreventive effect of GT, but results from epidemiological studies of GT consumption are mixed. While the evidence for a chemopreventive effect of BT is much weaker than the body of evidence with regard to GT, there are several animal BT intervention studies demonstrating inhibition of CaP growth. This article will review in detail the available epidemiological and human clinical studies, as well as animal and basic mechanistic studies on GT and BT supporting a chemopreventive role in CaP.
The role of the concept of “history of safe use” in the safety assessment of novel foods and novel food ingredients. Opinion of the Senate Commission on Food Safety (SKLM) of the German Research Foundation (DFG)
Authors: Engel Karl‐Heinz , Vogel Rudi F. , Knorr Dietrich , Habermeyer Michael , Kochte‐Clemens Barbara , Eisenbrand Gerhard 
Published: May 2011

AbstractThe Council of the European Union has proposed a revision on the EU regulation on novel foods and novel food ingredients concerning safety assessment of traditional foods from non‐EU countries and their introduction onto the EU market. The proposal stipulates that such foods may be placed on the EU market if their history of safe use in the country of origin is appropriately documented. The present statement of the SKLM gives an overview on current discussions on practical implementation of the “history of safe use” concept as well as examples of its application. The SKLM, in principle, agrees with these concepts, underscores, however, in connection with convincing evidence for a “history of safe use” the need for a range of additional information to achieve a comprehensive risk assessment. In the opinion of the SKLM such information must comprise compositional data as well as experience on adverse effects. A list of questions considered essential is presented. The following opinion was adopted on December 23rd 2010.
Specific identification of iron oxide‐labeled stem cells using magnetic field hyperthermia and MR thermometry
Authors: Haddad Daniel , Hildenbrand Markus F. , Hiller Karl‐Heinz , Haddad‐Weber Meike , Jakob Peter M. 
Published: May 2011

SUMMARYCell‐based therapies represent important novel strategies for the improved treatment of various diseases. To monitor the progress of therapy and cell migration, noninvasive imaging methods are needed. MRI represents such a modality, allowing, for example, for the tracking of cells labeled with superparamagnetic iron oxide nanoparticles. Unfortunately, the labeled cells cannot always be identified nonambiguously in the MR images. In this article, we present the combination of two different types of MR experiment to identify iron oxide‐labeled cells nonambiguously. The labeled cells appear as hypointense spots on standard T2*‐weighted MR images. Furthermore, they can be heated magnetically and subsequently identified by MR thermometry as a result of their heat dissipation. Other hypointense regions in the MR images are not heated and do not show heat dissipation. A proof‐of‐principle study was successfully performed in vitro and in vivo. The positive identification of the iron oxide‐labeled cells was demonstrated in collagen type I hydrogel phantoms and in living mice with high spatial and temporal accuracy. The motion of the in vitro samples was corrected in order to improve the specificity of the identification of labeled cells. Therefore, this method possesses the potential for cell tracking without prior knowledge about the cells, and thus allows the noninvasive monitoring of cell‐based therapies, as long as the cells contain a sufficient amount of iron oxide for detection in MR thermometry and imaging. Copyright © 2011 John Wiley & Sons, Ltd.
A mass constraint formulation for structural topology optimization with multiphase materials
Authors: Gao Tong , Zhang Weihong 
Published: May 2011

AbstractThis work is focused on the topology optimization of lightweight structures consisting of multiphase materials. Instead of adopting the common idea of using volume constraint, a new problem formulation with mass constraint is proposed. Meanwhile, recursive multiphase materials interpolation (RMMI) and uniform multiphase materials interpolation (UMMI) schemes are discussed and compared based on numerical tests and theoretical analysis. It is indicated that the nonlinearity of the mass constraint introduced by RMMI brings numerical difficulties to attain the global optimum of the optimization problem. On the contrary, the UMMI‐2 scheme makes it possible to formulate the mass constraint in a linear form with separable design variables. One such formulation favors very much the problem resolution by means of mathematical programming approaches, especially the convex programming methods. Moreover, numerical analysis indicates that fully uniform initial weighting is beneficial to seek the global optimum when UMMI‐2 scheme is used. Besides, the relationship between the volume constraint and mass constraint is theoretically revealed. The filtering technique is adapted to avoid the checkerboard pattern related to the problem with multiphase materials. Numerical examples show that the UMMI‐2 scheme with fully uniform initial weighting is reliable and efficient to deal with the structural topology optimization with multiphase materials and mass constraint. Meanwhile, the mass constraint formulation is evidently more significant than the volume constraint formulation. Copyright © 2011 John Wiley & Sons, Ltd.
Worst‐case robust design optimization under distributional assumptions
Authors: Padulo Mattia , Guenov Marin D. 
Published: May 2011

AbstractPresented in this paper is a novel robust design optimization (RDO) methodology. The problem is reformulated in order to relax, when required, the assumption of normality of objectives and constraints, which often underlies RDO. In the second place, taking into account engineering considerations concerning the risk associated with constraint violation, suitable estimates of tail conditional expectations are introduced in the set of robustness metrics. A computationally affordable yet accurate implementation of the proposed formulation is guaranteed by the adoption of a reduced quadrature technique to perform the uncertainty propagation. The methodology is successfully demonstrated with the aid of an industrial test case performing the sizing of a mid‐range passenger aircraft. Copyright © 2011 John Wiley & Sons, Ltd.
Frequent promoter hypermethylation of BRCA2, CDH13, MSH6, PAX5, PAX6 and WT1 in ductal carcinoma in situ and invasive breast cancer
Authors: Moelans Cathy B , Verschuur‐Maes Anoek HJ , van Diest Paul J 
Published: May 2011

AbstractEpigenetic changes are considered to be a frequent event during tumour development. Hypermethylation of promoter CpG islands represents an alternative mechanism to inactivate tumour suppressor genes, DNA repair genes, cell cycle regulators and transcription factors. In search of epigenetic events related to progression, we used MS–MLPA (ME‐0002‐B1, MRC‐Holland, Amsterdam, The Netherlands) to compare the methylation status of 25 breast cancer‐related genes between laser‐microdissected ductal carcinoma in situ (DCIS) and adjacent invasive ductal cancer (IDC) lesions in 33 breast cancer patients. Using absolute methylation percentages or, alternatively, a 15% cut‐off for methylation, promoter methylation in DCIS and IDC was not significantly different for any of the genes studied. Aberrant methylation in at least 50% of both the DCIS and adjacent IDC lesions was observed for PAX6, BRCA2, PAX5, WT1, CDH13 and MSH6. Methylation of MSH6, however, was also frequent in normal breast tissue. In contrast, CDKN2A, CHFR, PYCARD and one of the two analysed RB1 CpG loci were rarely (<5%) methylated in both lesions. CDKN2A and GSTP1 showed significantly (p < 0.002) higher mean methylation levels in increasing grades (I, II, III) of DCIS (1% versus 4% versus 7% for CDKN2A and 6% versus 26% versus 28% for GSTP1). The mean number of methylated genes per sample increased with increasing grades of DCIS (p = 0.014) and IDC (p = 0.109). In contrast to the observations in DCIS, none of the analysed genes showed significantly higher methylation levels with increasing grades of IDC. In conclusion, there were no differences in promoter methylation between DCIS and IDC in the 25 analysed genes, suggesting that DCIS, at the epigenetic level, is as advanced as IDC. Promoter hypermethylation of PAX6, BRCA2, PAX5, WT1, CDH13 and MSH6 seems to be a frequent early event in breast cancer and methylation levels of GSTP1 (and CDKN2A, although still low) seem to increase with increasing DCIS grade. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Quantification of 5′‐Deoxy‐5′‐Methylthioadenosine in Heat‐treated Natural Rubber Latex Serum
Authors: Pitakpornpreecha Thanawat , Plubrukarn Anuchit , Wititsuwannakul Rapepun 
Published: May 2011

ABSTRACTIntroduction5′‐Deoxy‐5′‐methylthioadenosine (MTA) is one of the biologically active components found in natural rubber latex (NRL) serum, a common waste product from rubber plantations. In this study the contents of MTA in heat‐treated NRL serum were measured in order to assess the potential of the serum as an alternative source of MTA.ObjectiveTo devise an HPLC/UV‐based quantitative analytical protocol for the determination of MTA, and to determine the effect of heat treatment on the content of MTA in NRL serum from various sources.MethodologyAn HPLC/UV‐based determination of MTA using an acidic eluant was devised and validated. In the heat treatment, the effect of refluxing times on MTA liberation was evaluated.ResultsThe quantification protocol was validated with satisfying linearity, limits of detection and quantitation, precisions for peak areas and recovery percentages from intra‐ and inter‐day operations. The amounts of MTA in the NRL sera from various sources increased with heat treatment to yield 5–12 μg MTA/mL of serum.ConclusionThe devised protocol was found to be satisfyingly applicable to the routine determination of MTA in NRL serum. The effect of heat treatment on the content of MTA also indicated another possible use for NRL serum, normally discarded in vast amounts by the rubber industry, as an alternative source of MTA. Copyright © 2011 John Wiley & Sons, Ltd.
Viscoelasticity and thermal stability of poly(arylene ether nitrile) nanocomposites with various functionalized carbon nanotubes
Authors: Zhan Yingqing , Yang Xulin , Meng Fanbin , Lei Yajie , Zhong Jiachun , Zhao Rui , Liu Xiaobo 
Published: May 2011

AbstractPoly(arylene ether nitrile) (PEN) nanocomposites containing various functionalized multi‐walled carbon nanotubes (MWCNTs) were prepared through a solution‐casting method. The as‐prepared PEN nanocomposites were investigated using parallel‐plate rheometry and thermogravimetric analysis, aimed at examining the effect of surface functionalization on the dispersion of MWCNTs from the viscoelastic and thermal properties. The linear viscoelasticy results indicated that 4‐aminophenoxyphthalonitrile‐grafted MWCNTs presented better dispersion in the PEN matrix than purified and carboxylic MWCNTs because the corresponding composite showed the lowest rheological percolation threshold, which was further confirmed from scanning electron microscopy, dissolution experiments and solution rheological experiments. The thermogravimetric analysis results revealed that the presence of 4‐aminophenoxyphthalonitrile‐grafted and carboxylic MWCNTs retarded the depolymerization compared with purified MWCNTs, showing a marked increase in the temperature corresponding to a loss of 5 wt% (increased by 14–22 °C) and maximum rate of decomposition (increased by 4–8 °C). Both the state of dispersion and the surface functionalization of MWCNTs are very important to the thermal stability of the PEN matrix. Copyright © 2011 Society of Chemical Industry
Thermal properties and non‐isothermal crystallization behavior of poly(trimethylene terephthalate)/poly(lactic acid) blends
Authors: Zou Hantao , Wang Luoxin , Yi Changhai , Gan Houlei 
Published: May 2011

AbstractThermal properties and non‐isothermal melt‐crystallization behavior of poly(trimethylene terephthalate) (PTT)/poly(lactic acid) (PLA) blends were investigated using differential scanning calorimetry and thermogravimetric analysis. The blends exhibit single and composition‐dependent glass transition temperature, cold crystallization temperature (Tcc) and melt crystallization peak temperature (Tmc) over the entire composition range, implying miscibility between the PLA and PTT components. The Tcc values of PTT/PLA blends increase, while the Tmc values decrease with increasing PLA content, suggesting that the cold crystallization and melt crystallization of PTT are retarded by the addition of PLA. The modified Avrami model is satisfactory in describing the non‐isothermal melt crystallization of the blends, whereas the Ozawa method is not applicable to the blends. The estimated Avrami exponent of the PTT/PLA blends ranges from 3.25 to 4.11, implying that the non‐isothermal crystallization follows a spherulitic‐like crystal growth combined with a complicated growth form. The PTT/PLA blends generally exhibit inferior crystallization rate and superior activation energy compared to pure PTT at the same cooling rate. The greater the PLA content in the PTT/PLA blends, the lower the crystallization rate and the higher the activation energy. Moreover, the introduction of PTT into PLA leads to an increase in the thermal stability behavior of the resulting PTT/PLA blends. Copyright © 2011 Society of Chemical Industry