bluuebunny/crossref_metadata_2025_split huggingface dataset:
Case–control study of risk factors for breast cancer in Nigerian women
Authors: Okobia Michael , Bunker Clareann , Zmuda Joseph , Kammerer Candace , Vogel Victor , Uche Emmanuel , Anyanwu Stanley , Ezeome Emmanuel , Ferrell Robert , Kuller Lewis 
Published: July 2006

AbstractThis study evaluated the potential risk factors for breast cancer in Nigerian women using a case–control design of 250 women with breast cancer and their age‐matched female controls. Both cases and controls were recruited from 4 University Teaching Hospitals in Midwestern and Southeastern Nigeria. Data on the clinical and epidemiological characteristics were collected using interviewer‐administered structured questionnaires. The mean age of the cases and controls were 46.1 and 47.1 years, respectively. Fifty‐seven percent of the cases were premenopausal while 43% were postmenopausal. The association of risk factors with breast cancer was assessed using conditional logistic regression. Positive family history of breast cancer in first‐ and second‐degree relatives (Odds ratio [OR] = 8.07, 95% confidence interval [CI], 1.003, 64.95, p = 0.04), education of high school level and above (OR = 1.35, 95% CI 1.04, 1.74, p = 0.0205), age at first fullterm pregnancy (FFTP) greater than 20 years (OR = 1.32 95% CI 1.01, 1.71, p = 0.0413) and waist/hip ratio (WHR) (OR = 1.98, 95% CI 1.27, 3.10, p = 0.0026) were associated with increased risk of breast cancer in the final multiple conditional logistic regression model. The findings from this study have shown that sociodemographic characteristics, reproductive variables and anthropometric measures are significant predictors of breast cancer risk in Nigerian women. © 2006 Wiley‐Liss, Inc.
A minute lossy method for 2D‐gel images compression
Authors: Chan Yung‐Kuan , Liau Duan‐Li , Chen Yung‐Fu , Wu Hsien‐Chu , Chu Yen‐Ping 
Published: July 2006

AbstractThis article presents a compression method to encode a 2D‐gel image by using hybrid lossless and lossy techniques. In this method, areas containing protein spots are encoded using lossless method while the background is encoded using the lossy method. A 2D‐gel image usually covers a large portion of the background in which has colors that are close to white. The VQ codebook‐generating approach gives more codewords to describe the background; consequently, the proposed method can nearly precisely depict the background of the 2D‐gel image and exactly record protein spots without any losses. Therefore, it can provide a high compression ratio. Image compressed by this method can nearly be lossless reconstructed. The experimental results show that the compression ratio is significantly improved with acceptable image quality compared to the JPEG‐LS method. © 2006 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 16, 1–8, 2006
Antimicrobial effect of silver‐doped phosphate‐based glasses
Authors: Ahmed I. , Ready D. , Wilson M. , Knowles J.C. 
Published: July 2006

AbstractIn this study a range of phosphate‐based glasses (PBG) doped with silver have been investigated for their antimicrobial activities. In disk diffusion assays, these compositions demonstrated microbistatic effects against a range of organisms including Staphylococcus aureus, Escherichia coli, Bacillus cereus, Pseudomonas aeruginosa, methicillin‐resistant Staphylococcus aureus, and Candida albicans. The data obtained from the above studies allowed for an additional range of PBG containing lower amounts of silver to be studied for their effects on the growth and viability of S. aureus, E. coli, and C. albicans. PBG containing 3 and 5 mol % Ag were bactericidal for S. aureus and E. coli and significantly decreased the growth rate of C. albicans. A decrease in the dissolution rates of the glasses was seen with increasing Ag content over the range of concentrations investigated. Overall, 3 mol % Ag incorporated into the PBG investigated was sufficient to mount a potent antibacterial effect against the test organisms, and these compositions also gave excellent long‐term release of Ag ions into the medium. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Electrospinning biomedical nanocomposite fibers of hydroxyapatite/poly(lactic acid) for bone regeneration
Authors: Kim Hae‐Won , Lee Hae‐Hyoung , Knowles J. C. 
Published: July 2006

AbstractDevelopment of fibrous matrices of bioceramic–biopolymer nanocomposite offers great potential in the field of bone regeneration and tissue engineering. However, in order to produce electrospun fibers with homogeneous structure, it is essential for the ceramic powder to be fine and to remain stable in suspension. Herein, we developed a novel method whereby the bioceramic hydroxyapatite (HA) was kept in suspension in biopolymer poly(lactic acid) (PLA). The strategy was to introduce a surfactant hydroxysteric acid (HSA) between the hydrophilic HA powder and the hydrophobic chloroform‐dissolved PLA. The HA nanopowder was dispersed effectively in HSA and mixed homogeneously with PLA. Continuous and uniform fibers were generated successfully with diameters of ∼1–2 μm, and featured a well‐developed nanocomposite structure of HA nanopowder‐dispersed PLA. Initial cellular assays showed excellent cell attachment and proliferation and also enhanced expression of alkaline phosphatase at 7 days of culturing. The HA–PLA nanocomposite fibers may be potentially useful in tissue engineering applications, particularly as three‐dimensional substrates for bone growth. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Selective induction of mucin‐3 by hypoxia in intestinal epithelia
Authors: Louis Nancy A. , Hamilton Kathryn E. , Canny Geraldine , Shekels Laurie L. , Ho Samuel B. , Colgan Sean P. 
Published: July 2006

AbstractEpithelial cells line mucosal surfaces (e.g., lung, intestine) and critically function as a semipermeable barrier to the outside world. Mucosal organs are highly vascular with extensive metabolic demands, and for this reason, are particularly susceptible to diminished blood flow and resultant tissue hypoxia. Here, we pursue the hypothesis that intestinal barrier function is regulated in a protective manner by hypoxia responsive genes. We demonstrate by PCR confirmation of microarray data and by avidin blotting of immunoprecipitated human Mucin 3 (MUC3), that surface MUC3 expression is induced in T84 intestinal epithelial cells following exposure to hypoxia. MUC3 RNA is minimally detectable while surface protein expression is absent under baseline normoxic conditions. There is a robust induction in both the mRNA (first evident by 8 h) and protein expression, first observed and maximally expressed following 24 h hypoxia. This is followed by a subsequent decline in protein expression, which remains well above baseline at 48 h of hypoxia. Further, we demonstrate that this induction of MUC3 protein is associated with a transient increase in the barrier restorative peptide, intestinal trefoil factor (ITF). ITF not only colocalizes with MUC3, by confocal microscopy, to the apical surface of T84 cells following exposure to hypoxia, but is also found, by co‐immunoprecipitation, to be physically associated with MUC3, following 24 h of hypoxia. In exploration of the mechanism of hypoxic regulation of mucin 3 expression, we demonstrated by luciferase assay that the full‐length promoter for mouse Mucin 3 (Muc3) is hypoxia‐responsive with a 5.08 ± 1.76‐fold induction following 24 h of hypoxia. Furthermore, analysis of both the human (MUC3A) and mouse (Muc3) promoters revealed potential HIF‐1 binding sites which were shown by chromatin immunoprecipitation to bind the pivotal hypoxia‐regulating transcription factor HIF‐1α. Taken together, these studies implicate the HIF‐1α mediated hypoxic induced expression of mucin 3 and associated ITF in the maintenance of intestinal barrier function under hypoxic conditions. J. Cell. Biochem. 99: 1616–1627, 2006. © 2006 Wiley‐Liss, Inc.
Effect of EGF on [3H]‐thymidine incorporation and cell cycle regulatory proteins in primary cultured chicken hepatocytes: Involvement of Ca2+/PKC and MAPKs
Authors: Lee Min Young , Lee Sang Hun , Kim Yun Hee , Heo Jung Sun , Park Soo Hyun , Lee Jang Hern , Han Ho Jae 
Published: July 2006

AbstractThe reported studies on the metabolism in chicken hepatocytes in comparison with those of mammals are quite different. Therefore, this study examined the effect of EGF on DNA synthesis along with its related signal cascades in primary cultured chicken hepatocytes. EGF stimulated DNA synthesis in a dose (≥10 ng/ml)‐dependent manner, which correlated with the increase in CDK‐2 and CDK‐4 expression. The EGF‐induced increase in [3H]‐thymidine incorporation was blocked by AG 1478 (an EGF receptor tyrosine kinase antagonist), genistein, and herbimycin A (tyrosine kinase inhibitors), suggesting a role in the activation and tyrosine phosphorylation of the EGF receptor. In addition, the EGF‐induced stimulation of [3H]‐thymidine incorporation was prevented by staurosporine, H‐7, or bisindolylmaleimide I (protein kinase C inhibitors), suggesting a role of PKC. In addition, PD 98059 (a MEK inhibitor), SB 203580 (a p38 MAPK inhibitor), and SP 600125 (a JNK inhibitor) blocked the EGF‐induced stimulation of [3H]‐thymidine incorporation and CDK‐2/4 expression. Indeed, EGF increased the translocation of PKC from the cytosol to the membrane fraction, and increased the activation of p44/42 MAPK, p38 MAPK, and JNK. Moreover, EGF increased the CDK‐2, CDK‐4, cyclin D1, and cyclin E expression levels but decreased the p21 and p27 expression levels. These EGF‐induced increases were blocked by an EGF receptor antagonist, tyrosine kinase inhibitors, PKC inhibitors, and MAPKs inhibitors. In conclusion, EGF stimulates DNA synthesis of primary cultured chicken hepatocytes via Ca2+/PKC and the MAPKs signaling pathways. J. Cell. Biochem. 99: 1677–1687, 2006. © 2006 Wiley‐Liss, Inc.
Prevention of farnesylation of c‐Ha‐Ras protein enhances synergistically the cytotoxic action of doxorubicin in cycling but not in quiescent cells
Authors: Wȩsierska‐Ga̧dek Józefa , Kramer Matthias , Schmid Gerald 
Published: July 2006

AbstractRas, the product of a proto‐oncogene, is a GTP‐hydrolyzing enzyme found mutated in approximately 50% of human cancers. “Gain of function” mutations of Ras lead to an escape of transformed cells from cell‐cycle control, rendering them independent to stimulation by growth factors, giving them almost unlimited proliferation capacity. The cytosolic precursor isoform of Ras is biologically inactive. After several post‐translational modifications, Ras is anchored to the plasma membrane and, thereby, the protein becomes activated. The finding that lipid modifications of Ras protein, particularly farnesylation, are essential for its signal transduction activity, gave rise to the concept that blocking farnesyl protein transferase (FPTase), the enzyme catalyzing the first step in the Ras modification cascade, would prevent proper membrane anchoring and provide an improved approach in the cure of tumors harboring Ras mutations. In the present study we used transformed rat cells overexpressing a temperature‐sensitive p53 protein, adopting wt conformation at 32°C and mutant conformation at 37°C. We treated the cells growing at 32 or 37°C with doxorubicin alone, or in combination with inhibitors of FPTase. Combined treatment was more efficient and the same inhibition of cell proliferation was reached at lower DOX concentrations. The treatment strongly affected the growth rate of tumor cells but only negligibly of normal cells. However, the inhibitors of FPTase prevented the membrane anchoring in both situations. These results show two striking advantages of the combined treatment: the desired cytostatic effect on tumor cells at lower drug concentrations and clearly reduced adverse effects on quiescent cells. J. Cell. Biochem. 99: 1664–1676, 2006. © 2006 Wiley‐Liss, Inc.
Heme oxygenase‐1 gene transfer inhibits angiotensin II‐mediated rat cardiac myocyte apoptosis but not hypertrophy
Authors: Foo Roger S.Y. , Siow Richard C.M. , Brown Morris J. , Bennett Martin R. 
Published: July 2006

AbstractCardiac myocyte apoptosis underlies the pathophysiology of cardiomyopathy, and plays a critical role in the transition from myocardial hypertrophy to heart failure. Angiotensin II (Ang II) induces cardiac myocyte apoptosis and hypertrophy which contribute to heart failure possibly through enhanced oxidative stress; however, the mechanisms underlying the activation of both pathways and their interactions remain unclear. In the present study, we have investigated whether overexpression of the antioxidant protein heme oxygenase‐1 (HO‐1) protects against apoptosis and hypertrophy in cultured rat cardiac myocytes treated with Ang II. Our findings demonstrate that Ang II (100 nM, 24 h) alone upregulates HO‐1 expression and induces both myocyte hypertrophy and apoptosis, assessed by measuring terminal deoxynucleotidyltransferase dUTP nick‐end labelling (TUNEL) staining, caspase‐3 activity and mitochondrial membrane potential. Ang II elicited apoptosis was augmented in the presence of tin protoporphyrin, an inhibitor of HO activity, while HO‐1 gene transfer to myocytes attenuated Ang II‐mediated apoptosis but not hypertrophy. Adenoviral overexpression of HO‐1 was accompanied by a significant increase in Ang II induced phosphorylation of Akt, however, Ang II‐mediated p38 mitogen activated protein kinase (MAPK) phosphorylation was attenuated. Inhibition of phosphotidylinositol‐3‐kinase enhanced myocyte apoptosis elicited by Ang II, however, p38MAPK inhibition had no effect, suggesting that overexpression of HO‐1 protects myocytes via augmented Akt activation and not through modulation of p38MAPK activation. Our findings identify the signalling pathways by which HO‐1 gene transfer protects against apoptosis and suggest that overexpression of HO‐1 in cardiomyopathies may delay the transition from myocyte hypertrophy to heart failure. J. Cell. Physiol. 209: 1–7, 2006. © 2006 Wiley‐Liss, Inc.
Regulation of protein phosphatase 1γ activity in hypoxia through increased interaction with NIPP1: Implications for cellular metabolism
Authors: Comerford Kathrina M. , Leonard Martin O. , Cummins Eoin P. , Fitzgerald Kathleen T. , Beullens Monique , Bollen Mathieu , Taylor Cormac T. 
Published: July 2006

AbstractEukaryotic cells sense decreased oxygen levels and respond by altering their metabolic strategy to sustain non‐respiratory ATP production through glycolysis, and thus promote cell survival in a hypoxic environment. Protein phosphatase 1 (PP1) has been recently implicated in the governance of the rational use of energy when metabolic substrates are abundant and contributes to cellular recovery following metabolic stress. Under conditions of hypoxia, the expression of the gamma isoform of PP1 (PP1γ), is diminished, an event we have hypothesized to be involved in the adaptive cellular response to hypoxia. Decreased PP1γ activity in hypoxia has a profound impact on the activity of the cAMP response element binding protein (CREB), a major transcriptional regulator of metabolic genes and processes. Here, we demonstrate a further mechanism leading to inhibition of PP1 activity in hypoxia which occurs at least in part through increased association with the nuclear inhibitor of PP1 (NIPP1), an event dependent upon decreased basal cAMP/PKA‐dependent signaling. Using a dominant negative NIPP1 construct, we provide evidence that NIPP1 plays a major role in the regulation of both CREB protein expression and CREB‐dependent transcription in hypoxia. Furthermore, we demonstrate functional sequellae of such events including altered gene expression and recovery of cellular ATP levels. In summary, we demonstrate that interaction with NIPP1 mediates decreased PP1γ activity in hypoxia, an event which may constitute an inherent part of the cellular oxygen‐sensing machinery and may play a role in physiologic adaptation to hypoxia. J. Cell. Physiol. 209: 211–218, 2006. © 2006 Wiley‐Liss, Inc.
Association between Australian rainfall and the Southern Annular Mode
Authors: Meneghini Belinda , Simmonds Ian , Smith Ian N. 
Published: July 2006

AbstractIn this study, we explore the relationships between seasonal Australian rainfall and the Southern Annular Mode (SAM). We produce two seasonal indices of the SAM: the Antarctic Oscillation Index (AOI), and an Australian regional version (AOIR) using ERA‐40 mean sea‐level pressure (MSLP) reanalysis data. The seasonal rainfall data are based on gridded monthly rainfall provided by the Australian Bureau of Meteorology.For the period 1958–2002 a significant inverse relationship is found between the SAM and rainfall in southern Australia, while a significant in‐phase relationship is found between the SAM and rainfall in northern Australia. Furthermore, widespread significant inverse relationships in southern Australia are only observed in winter, and only with the AOIR. The AOIR accounts for more of the winter rainfall variability in southwest Western Australia, southern South Australia, western and southern Victoria, and western Tasmania than the Southern Oscillation Index. Overall, our results suggest that changes in the SAM may be partly responsible for the current decline in winter rainfall in southern South Australia, Victoria, and Tasmania, but not the long‐term decline in southwest Western Australian winter rainfall. Copyright © 2006 Royal Meteorological Society.
Integrated catchment management in semiarid environments in the context of the European Water Framework Directive
Authors: Thornes J. B. , Rowntree K. M. 
Published: July 2006

AbstractTwo recent developments draw attention to the need for integrated catchment management. First is the European Union's (EU) Water Framework Directive (WFD), which insists on an integrated catchment management plan for each European river basin within the next 15 years. Second is the current trend for river restoration; practitioners have concluded that this can only be achieved through a thorough appreciation of the integrated character of catchments. This paper addresses the question as to whether it makes sense to apply the WFD methodology across the range of European catchments and, in particular, what special provisions need to be made for dry Mediterranean catchments. The Southern European rivers are episodic. They yield high and coarse sediment loads and some are still used as waste repositories. They interact intermittently with groundwater. Reference conditions, both geometrical and water quality, require different measures and observations from those of the temperate and Arctic régime rivers that dominate much of the rest of the EU. These properties are identified and discussed with reference to nested subcatchments of the River Segura in the Province of Murcia, Spain. New research in the Nogalte sub‐basin demonstrates a possible ‘reference site’ for this environment. Copyright © 2006 John Wiley & Sons, Ltd.
Hindcasting extreme events: the occurrence and expression of damaging floods and landslides in Southern Italy
Authors: Clarke M. L. , Rendell H. M. 
Published: July 2006

AbstractExtreme rainstorm events across the Mediterranean have caused significant loss of life and damage to property and livelihoods. Italy is particularly vulnerable to natural hazards with recent events such as the 1996 floods in Versilia and the 1998 mass‐movement failures at Sarno causing the deaths of 174 people. We have analysed 50 years of rainfall records to hindcast extreme rainstorms that have affected the eastern Basilicata region of southern Italy. Historical and archive data of individual floods and landslides have been compared with their antecedent rainfall conditions in order to characterize the nature of events that cause damage to society and infrastructure. Analysis of extreme‐event frequency shows a decreasing annual trend related to changes in regional climate conditions in the western and central Mediterranean driven by changes in the strength of the North Atlantic Oscillation. Land‐degradation problems associated with floods and landslides are decreasing due to a drier winter climate coupled with improved hazard mitigation. Copyright © 2006 John Wiley & Sons, Ltd.
The corrosion resistance of a Fe/Cu composite
Authors: Molera P. , Sanz‐Soro F. , Suñol J. J. 
Published: July 2006

AbstractA composite made from a mixture of iron and copper powders was produced and characterised. The Cu addition favours the production of sintered Fe in the powder metallurgy industry processes. The corrosion behaviour in different electrolytic solution (sodium chloride or hydrochloric, acetic or sulphuric acids) and the corrosion rates were obtained from the weight loss and potentiodynamic methods – intersection and linear polarisation resistance. The values in hydrochloric and sulphuric acid vary slightly with respect to the average value of 78 mV/decade. The values obtained in acetic acid and sodium chloride are higher probably due to the formation of a thin film layer over the metallic surface. The morphology was analyzed through the observation by optical and scanning electron microscopy. It has been determined the nature of the oxide layer, Fe3O4, by X‐ray photoelectron spectroscopy (XPS), isolating the composite from the atmosphere. Thus, this oxide layer acts as a corrosion protective surface.
The Influence of Solvent Properties and Functionality on the Electrospinnability of Polystyrene Nanofibers
Authors: Pattamaprom Cattaleeya , Hongrojjanawiwat Walaiporn , Koombhongse Piyawit , Supaphol Pitt , Jarusuwannapoo Teeradech , Rangkupan Ratthapol 
Published: July 2006

AbstractSummary: In order to produce nanometer‐sized fibers at an industrial scale, not only the morphology but also the production rate of fibers is important. The effect of solvent properties and functionality on the production rate of electrospun PS nanofibers was investigated using eighteen different solvents. The solution concentration was varied between 10 and 30% w/v. Electrospinning of PS solutions was carried out at various applied voltages and tip‐to‐collector distances The production rate of the obtained PS nanofibers was quantified in terms of electrospinnability. We found that the chance for the resulting PS solution to be spinnable is greater for solvents with high dipole moment and low viscosity. The solvent that provided the highest electrospinnability for polystyrene was DMF and the functionalities that promoted high dipole moment and thus high spinnability were the carbonyl group and the nitrogen group with free electrons. General guidelines for choosing suitable solvents for successful production of electrospun nanofibers have also been proposed.SEM image of PS 685D at 200× magnification and the %‐coverage of the fibers obtained by using DMF, chloroform, and 1,4‐dioxane.magnified imageSEM image of PS 685D at 200× magnification and the %‐coverage of the fibers obtained by using DMF, chloroform, and 1,4‐dioxane.
Preparation and Characterization of Polyurethane Hybrids from Reactive Polyhedral Oligomeric Silsesquioxanes
Authors: Zhang Shiling , Zou Qichao , Wu Limin 
Published: July 2006

AbstractSummary: Hybrid polyester resins containing polyhedral oligomeric silsesquioxanes (POSS), and their polyurethanes were prepared using reactive POSS as a substitution for partial diol monomer. They were investigated by FT‐IR, rheometry, dynamic mechanical analysis, wide‐angle X‐ray diffraction, contact‐angle measurement, atomic force microscopy, and thermogravimetric analysis, respectively. The results showed that the hybrid polyester‐POSS resins had a shear thinning behavior, and the more the POSS was embedded, the stronger the shear thinning behavior, and the higher the viscosity. Incorporation of POSS could increase the glass transition temperature and thermal stability and decrease the surface free energy of the polyurethanes. When the POSS content was relatively high, the POSS molecules in hybrid polyurethane‐POSS had a strong self‐assembling ability to form nanocrystalline domains.Loss tangent curves of polyurethanes.magnified imageLoss tangent curves of polyurethanes.