bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative data analysis methods for bead‐based DNA hybridization assays using generic flow cytometry platforms
Authors: Corrie S. R. , Lawrie G. A. , Battersby B. J. , Ford K. , Rühmann A. , Koehler K. , Sabath D. E. , Trau M. 
Published: March 2008

AbstractBead‐based assays are in demand for rapid genomic and proteomic assays for both research and clinical purposes. Standard quantitative procedures addressing raw data quality and analysis are required to ensure the data are consistent and reproducible across laboratories independent of flow platform. Quantitative procedures have been introduced spanning raw histogram analysis through to absolute target quantitation. These included models developed to estimate the absolute number of sample molecules bound per bead (Langmuir isotherm), relative quantitative comparisons (two‐sided t‐tests), and statistical analyses investigating the quality of raw fluorescence data. The absolute target quantitation method revealed a concentration range (below probe saturation) of Cy5‐labeled synthetic cytokeratin 19 (K19) RNA of c.a. 1 × 104 to 500 × 104 molecules/bead, with a binding constant of c.a. 1.6 nM. Raw hybridization frequency histograms were observed to be highly reproducible across 10 triplex assay replicates and only three assay replicates were required to distinguish overlapping peaks representing small sequence mismatches. This study provides a quantitative scheme for determining the absolute target concentration in nucleic acid hybridization reactions and the equilibrium binding constants for individual probe/target pairs. It is envisaged that such studies will form the basis of standard analytical procedures for bead‐based cytometry assays to ensure reproducibility in inter‐ and intra‐platform comparisons of data between laboratories. © 2008 International Society for Advancement of Cytometry
A framework to determine the optimal weight parameter of RED in next‐generation Internet routers
Authors: Zheng Bing , Atiquzzaman Mohammed 
Published: March 2008

AbstractActive buffer management can improve the performance of Transmission Control Protocol/Internet Protocol‐based networks. Random early detection (RED), an active queue management scheme, has been proposed by the Internet Engineering Task Force for next‐generation Internet routers. RED uses a number of parameters, such as buffer thresholds, a packet drop probability and a weight parameter. RED suffers from low throughput and large delay/jitter and induces instability in networks. Previous attempts to improve the performance of RED were based on modifying the thresholds and drop probabilities. In this paper, we show that an optimal value of the weight parameter can improve the performance of RED, and then develop a framework to determine the optimal value of the weight parameter. We show that the optimal weight parameter obtained from our framework improves the performance of RED. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis and Isomerisation Reactions of Tetranuclear and Octanuclear (Carbamato)zinc Complexes
Authors: Haywood Peter F. , Hill Matthew R. , Roberts Nicholas K. , Craig Donald C. , Russell Jennifer J. , Lamb Robert N. 
Published: March 2008

AbstractA new series of (diisopropylcarbamato)(oxido)zinc complexes were obtained by innovative synthetic approaches. The (carbamato)zinc clusters [Zn4(μ4‐O)(O2CNiPr2)6] (1) and [Zn8(μ4‐O)2(O2CNiPr2)12] (2) were synthesised by an identical reaction procedure involving protolysis of ZnEt2 with iPr2NH/CO2 and followed by stoichiometric hydrolysis. Recrystallisation of the reaction product from nitrile solvents yielded the tetrazinc complex 1. Conversely, recrystallisation from alkane solvents yielded crystals of the octazinc complex 2. The two structural isomers were readily interconverted simply by recrystallisation from the appropriate solvent. Both complexes were structurally characterised by X‐ray crystallography. The tetrazinc complex 1 has the quintessential basic zinc acetate type structure. Its dimer, the octazinc complex 2 is a new derivative of the [M8(μ4‐O)2(O2CNiPr2)12] class, examples of which are known for all other first‐row transition metals. The solution chemistry was investigated using variable‐temperature NMR spectroscopy and ESI‐MS. The new synthetic approach offers a route to other similar complexes. Thus, using Et2NH in place of iPr2NH yielded the known complex [Zn4(μ4‐O)(O2CNEt2)6] (3).(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Studies on Nickel(II) Complexes with Amide‐Based Ligands: Syntheses, Structures, Electrochemistry and Oxidation Chemistry
Authors: Singh Jyoti , Hundal Geeta , Gupta Rajeev 
Published: March 2008

AbstractThe present work discusses the nickel chemistry in a set of amide‐based open‐chain ligands with subtle differences in the backbone or terminal amine substituents. The ligands coordinate to the Ni2+ ion through the Namide and Namine atoms maintaining a square‐planar geometry. Absorption spectra and NMR studies reveal that the solid‐state square‐planar geometry is retained in solution. The electrochemical results suggest that the NiIII/NiII redox couple primarily depends on the N4 donors, which is composed of two Namide and twoNamine atoms and not on the peripheral substituents. All four ligands with variable backbone and substituents are equally competent in stabilizing the NiIII state. On the basis of electrochemical findings, chemical oxidations were carried out, and they reveal generation of the NiIII state in two cases, whereas decomposition was observed in others. Preliminary alkene epoxidation reactions suggest that the present nickel complexes transiently stabilize the higher oxidation state of the nickel ion that possibly participates in the oxidation of the substrates.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Prion decontamination during the oleochemical process of fat hydrogenation
Authors: Müller Henrik , Stitz Lothar , Riesner Detlev 
Published: March 2008

AbstractThe human food and animal feed industry and even oleochemical manufacturing processes might be exposed to contamination from products of BSE‐infected cattle. Although the most important oleochemical raw material, i.e. tallow, is not considered to be a causal factor for BSE, the potential risk associated with tallow‐derived products has to be evaluated in the light of the specific production process. The main production process for oleochemicals, i.e. hydrolytic fat splitting of tallow yielding glycerol and a mixture of crude fatty acids, guarantees prion‐free products, safe for human consumption [1]. Fatty acids, however, are not necessarily produced by hydrolytic fat splitting. In order to evaluate these fatty acids with regard to prion safety, we analysed the industrial conditions of catalytic fat hydrogenation, which is widely applied to improve storage and flavour stability of fatty acids. Quantitative data for the degradation of the pathological prion protein and the inactivation of prion infectivity are presented. A risk assessment calculation demonstrates that the industrial conditions of fat hydrogenation are sufficiently effective to reduce the risk of BSE contamination to an acceptable minimum.
Retention behavior of trans isomers of eicosapentaenoic and docosahexaenoic acid methyl esters on a polyethylene glycol stationary phase
Authors: Mjøs Svein A. 
Published: March 2008

AbstractA polyethylene glycol (PEG) stationary phase was evaluated for the separation of mono‐trans isomers of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) methyl esters. The resolution patterns were compared to patterns achieved with previously applied conditions on a cyanopropyl phase. There were no overlaps between all‐cis EPA/DHA and their mono‐trans isomers on the PEG phase. Because of overlap between 22:0 and 22:1 isomers, the PEG column is not a good choice for analyses of EPA trans isomers in crude fish oils. However, if the saturated and monounsaturated fatty acids are not present in significant amounts, PEG can be a better choice than cyanopropyl columns.
Conjugated linoleic acid (CLA) production and lipase‐catalyzed interesterification of purified CLA with canola oil
Authors: Goli Sayyed Amir Hossein , Kadivar Mahdi , Keramat Javad , Fazilati Mohammad 
Published: March 2008

AbstractIn this study, two important isomers of CLA, i.e. c9,t11 and t10,c12, were produced up to ca. 73% of total fatty acids, employing alkali isomerization of safflower oil, followed by purification with only one‐step urea crystallization to 85.6%, while the recovery of the purification process was 35%. Interesterification (acidolysis) of purified CLA with canola oil was then conducted by Thermomyces lanuginosus lipase. The CLA content incorporated into the triacylglycerols (TG) was 26.6 mol‐% after 48 h of reaction time. Physical and chemical properties of the TG were then changed according to the degree of substitution of oleic acid in canola oil with CLA.
Virgin grape seed oil: Is it really a nutritional highlight?
Authors: Matthäus Bertrand 
Published: March 2008

AbstractIn comparison to refined grape seed oil which is neutral in taste and smell, the virgin oil is characterized by a pleasant vinous and fruity aroma, which also reminds of raisins if high‐quality raw material is used for the production. Difficulties arise from the susceptibility of the raw material to microbial and enzymatic deterioration as a result of the high moisture content after pressing the juices from the grapes. Grape seed oil has a high content (70%) of linoleic acid, whereas the total part of unsaturated fatty acids amounts to about 90%. In comparison to other edible oils, the oil contains, in addition to tocopherols, antioxidant‐effective tocotrienols. During the oil pressing process, only a small amount of phenolic compounds is transferred into the oil (0.01 mg/g), while most of these nutritionally interesting components remain in the press cake. Here, the content of phenolic compounds is about 2000 times higher. During storage of virgin grape seed oil, the pleasant sensory attributes change, and more and more degradation products like ethyl acetate, acetic acid or ethanol are detectable. Parts of the seed material, which come into the oil during pressing, result in a faster impairment of the oil.
All vertebrates started out with a glial blood‐brain barrier 4–500 million years ago
Authors: Bundgaard Magnus , Abbott N. Joan 
Published: March 2008

AbstractAll extant vertebrates have a blood‐brain barrier (BBB), a specialized layer of cells that controls molecular traffic between blood and brain, and contributes to the regulation (homeostasis) of the brain microenvironment. Such homeostasis is critical for the stable function of synapses and neural networks. The barrier is formed by vascular endothelial cells in most groups, but by perivascular glial cells (astrocytes) in elasmobranch fish (sharks, skates, and rays). It has been unclear which is the ancestral form, but this information is important, as it could offer insights into the roles of the endothelium and perivascular glia in the modern mammalian BBB. We have used electron microscopic techniques to examine three further ancient fish groups, with intravascular horseradish peroxidase as permeability tracer. We find that in bichir and lungfish the barrier is formed by brain endothelial cells, while in sturgeon it is formed by a complex perivascular glial sheath, but with no detectable tight junctions. From their BBB pattern, and position on the vertebrate family tree, we conclude that the ancestral vertebrate had a glial BBB. This means that an endothelial barrier would have arisen independently several times during evolution, and implies that an endothelial barrier gave strong selective advantage. The selective advantage may derive partly from greater separation of function between endothelium and astrocytic glia. There are important implications for the development, physiology, and pathology of the mammalian BBB, and for the roles of endothelium and glia in CNS barrier layers. © 2008 Wiley‐Liss, Inc.
IGF‐1 receptor‐mediated ERK/MAPK signaling couples status epilepticus to progenitor cell proliferation in the subgranular layer of the dentate gyrus
Authors: Choi Yun‐Sik , Cho Hee‐Yeon , Hoyt Kari R. , Naegele Janice R. , Obrietan Karl 
Published: March 2008

AbstractAdult progenitor cell proliferation in the subgranular zone (SGZ) of the dentate gyrus is a dynamic process that is modulated by an array of physiological process, including locomotor activity and novel environmental stimuli. In addition, pathophysiological events, such as ischemia and status epilepticus (SE), have been shown to stimulate neurogenesis. Currently, limited information is available regarding the extracellular stimuli, receptors, and downstream intracellular effectors that couple excitotoxic stimulation to progenitor cell proliferation. Here we show that pilocarpine‐induced SE triggers a set of signaling events that impinge upon the p42/44 mitogen‐activated protein kinase (MAPK) pathway to drive progenitor cell proliferation in the SGZ at 2‐days post‐SE. Increased proliferation was dependent on insulin‐like growth factor‐1 (IGF‐1), which was localized to activated microglia near the SGZ. Using a combination of techniques, we show that IGF‐1 is a CREB‐regulated gene and that SE triggered CRE‐dependent transcription in microglia at 2‐days post‐SE. Together, these data identify a potential signaling program that couples SE to progenitor cell proliferation. SE triggers CREB‐dependent transcription in reactive microglia. As a CREB‐target gene, IGF‐1 expression is upregulated, and by 2‐days post‐SE, IGF‐1 triggers MAPK pathway activation in progenitor cells and, in turn, an increase in progenitor cell proliferation. © 2008 Wiley‐Liss, Inc.
Hyperoxia promotes astrocyte cell death after oxygen and glucose deprivation
Authors: Danilov Camelia A. , Fiskum Gary 
Published: March 2008

AbstractAstrocyte dysfunction and death accompany cerebral ischemia/reperfusion and possibly compromise neuronal survival. Animal studies indicate that neuronal death, neurologic injury, and oxidative molecular modifications are worse in animals exposed to hyperoxic compared to normoxic ventilation during reperfusion after global cerebral ischemia. It is unknown, however, whether ambient O2 affects brain cell survival using in vitro ischemia paradigms where mechanisms of injury to specific cell types can be more thoroughly investigated. This study tested the hypothesis that compared with the supraphysiological level of 20% O2 normally used in cell culture, lower, more physiological O2 levels protect astrocytes from death following oxygen and glucose deprivation. Primary rat cortical astrocytes were cultured under either 7 or 20% O2, exposed to O2, and glucose deprivation for 4 h, and then exposed to normal medium under either 7 or 20% O2. Cell death and 3‐nitrotyrosine and 8‐hydroxy‐2‐deoxyguanosine immunoreactivities were assessed at different periods of reoxygenation. Astrocytes exposed to low levels of O2 during reoxygenation undergo less death and exhibit lower levels of protein nitration and nucleic acid oxidation when compared with those under high levels of O2 during reoxygenation. These results support the hypothesis that the 20% O2 normally used in cell culture exacerbates astrocyte death and oxidative stress in an in vitro ischemia/reperfusion model compared to levels that more closely approximate those that exist in vivo. © 2008 Wiley‐Liss, Inc.
Ca2+ entry through TRPC1 channels contributes to intracellular Ca2+ dynamics and consequent glutamate release from rat astrocytes
Authors: Malarkey Erik B. , Ni Yingchun , Parpura Vladimir 
Published: March 2008

AbstractAstrocytes can respond to a variety of stimuli by elevating their cytoplasmic Ca2+ concentration and can in turn release glutamate to signal adjacent neurons. The majority of this Ca2+ is derived from internal stores while a portion also comes from outside of the cell. Astrocytes use Ca2+ entry through store‐operated Ca2+ channels to refill their internal stores. Therefore, we investigated what role this store‐operated Ca2+ entry plays in astrocytic Ca2+ responses and subsequent glutamate release. Astrocytes express canonical transient receptor potential (TRPC) channels that have been implicated in mediating store‐operated Ca2+ entry. Here, we show that astrocytes in culture and freshly isolated astrocytes from visual cortex express TRPC1, TRPC4, and TRPC5. Indirect immunocytochemistry reveals that these proteins are present throughout the cell; the predominant expression of functionally tested TRPC1, however, is on the plasma membrane. Labeling in freshly isolated astrocytes reveals changes in TRPC expression throughout development. Using an antibody against TRPC1 we were able to block the function of TRPC1 channels and determine their involvement in mechanically and agonist‐evoked Ca2+ entry in cultured astrocytes. Blocking TRPC1 was also found to reduce mechanically induced Ca2+‐dependent glutamate release. These data indicate that Ca2+ entry through TRPC1 channels contributes to Ca2+ signaling in astrocytes and the consequent glutamate release from these cells. © 2008 Wiley‐Liss, Inc.
Hyperglycemia and downregulation of caveolin‐1 enhance neuregulin‐induced demyelination
Authors: Yu Cuijuan , Rouen Shefali , Dobrowsky Rick T. 
Published: March 2008

AbstractNeuregulins (NRGs) are growth factors which bind to Erb receptor tyrosine kinases that localize to Schwann cells (SCs). Although NRGs can promote cell survival, mitogenesis, and myelination in undifferentiated SCs, they also induce demyelination of myelinated co‐cultures of SCs and dorsal root ganglion (DRG) neurons. We have shown previously that Erb B2 activity increased in premyelinating SCs in response to hyperglycemia, and that this correlated with the downregulation of the protein caveolin‐1 (Cav‐1). As myelinated SCs undergo substantial degeneration in diabetic neuropathy, we used myelinated SC/DRG neuron co‐cultures to determine if hyperglycemia and changes in Cav‐1 expression could enhance NRG‐induced demyelination. In basal glucose, NRG1 caused a 2.4‐fold increase in the number of damaged myelin segments. This damage reached 3.8‐fold under hyperglycemic conditions, and was also associated with a robust decrease in the expression of Cav‐1 and compact myelin proteins. The loss of Cav‐1 and compact myelin proteins following hyperglycemia and NRG treatment was not due to neuronal loss, since the axons remained intact and there was no loss of PGP 9.5, an axonal marker protein. To examine if changes in Cav‐1 were sufficient to alter the extent of NRG‐induced demyelination, SC/DRG neurons co‐cultures were infected with antisense or dominant‐negative Cav‐1(P132L) adenoviruses. Either antisense‐mediated downregulation or mis‐localization of endogenous Cav‐1 by Cav‐1(P132L) resulted in a 1.5‐ to 2.4‐fold increase in NRG‐induced degeneration compared to that present in control cultures. These data support that hyperglycemia and changes in Cav‐1 are sufficient to sensitize myelinated SC/DRG co‐cultures to NRG‐induced demyelination. © 2008 Wiley‐Liss, Inc.
VEGF‐D promotes tumor growth and lymphatic spread in a mouse model of hepatocellular carcinoma
Authors: Thelen Armin , Scholz Arne , Benckert Christoph , von Marschall Zofia , Schröder Maik , Wiedenmann Bertram , Neuhaus Peter , Rosewicz Stefan , Jonas Sven 
Published: March 2008

AbstractLymphatic spread is an important clinical determinant for the prognosis of hepatocellular carcinoma (HCC), but little is known about the control of lymphangiogenesis in HCC. We addressed expression and biological role of the pro‐(lymph), angiogenic protein VEGF‐D in this tumor entity. Using immunohistochemistry and in situ hybridization on specimens of HCC, cirrhotic and normal liver we found abundant expression of VEGF‐D exclusively in the tumor cells. The cognate receptor VEGFR‐3 was detected on blood and lymphatic vessels. By clinicopathological analysis VEGF‐D expression was correlated with pT‐stage of the primary, lymph node metastasis and lymphangiosis carcinomatosa. Three out of 4 human HCC cell lines expressed and secreted VEGF‐D. To approach its biological function, VEGF‐D deficient SKHep‐1 cells were stably transfected with VEGF‐D cDNA and effects on tumor progression were determined in vivo. Compared to mock‐transfected controls, subcutaneous tumors derived from VEGF‐D expressing cells were larger and more frequently metastasized to regional lymph nodes. VEGF‐D expressing tumors exhibited increased microvessel density and increased abundance of peri‐ and intratumoral lymphatics, as assessed by immunostaining for CD31 and for LYVE‐1 and/or podoplanin, respectively. Furthermore, coexpression of the soluble extracellular VEGFR‐3 domain blocked VEGF‐D‐induced tumor growth and lymphatic spread via reduction of angiogenesis and lymphangiogenesis. In the orthotopic approach, VEGF‐D expression resulted in an increased rate of intra‐ and extrahepatic as well as lymph node metastasis. In conclusion, our study suggests that expression of VEGF‐D is involved in growth and lymphatic spread of HCC. Therefore, VEGF‐D might represent a therapeutic target in HCC. © 2008 Wiley‐Liss, Inc.
Cervical cancer screening program integrating Pap smear and HPV DNA testing: A population‐based study
Authors: Chao Angel , Hsu Kuang‐Hung , Lai Chyong‐Huey , Huang Huei‐Jean , Hsueh Swei , Lin Sheue‐Rong , Jung Shih‐Ming , Chao Fang‐Yu , Huang Shang‐Lang , Huang Chu‐Chun , Yang Jung‐Erh , Chang Ting‐Chang 
Published: March 2008

AbstractWe conducted a population‐based cohort study to evaluate the complementary value of HPV testing to Papanicolaou (Pap) smear and the prevalence and genotype distribution of HPV in Taiwan. In this report, we described the design of the whole study and analyzed the cross‐sectional results. Female residents (age ≥ 30 years) of Taoyuan, Taiwan were invited. After signing informed consent, every participant had a Pap smear and a HPV testing. Patients with Pap ≥ atypical squamous cell of undetermined significance (Group I) or those with HPV‐positive but normal cytology (Group II) were referred for a colposcopic examination. A total of 10,014 women were eligible. The overall HPV prevalence was 10.8% (95% confidence interval 10.5%–11.4%) in the study population. A total of 37 types of HPV were identified and the leading three were HPV‐52, ‐18 and ‐58. There was a significant positive correlation of HPV prevalence with older age, postmenopausal status, current‐user of oral contraceptives and never‐user of hormone replacement therapy. Past users of oral contraceptives and never users of Pap were associated with higher risk of abnormal Pap, while age 40–49 strata had lower risk. Fifty‐nine cases of cervical intraepithelial neoplasia (CIN) 2 from Group I and additional 11 from Group II were identified. The improvement of sensitivity with additional HPV testing was 15.3%. Besides, no specific subgroup was found to most benefit from the combined strategy. The value of adding HPV test to conventional Pap smear has to be evaluated after longer‐term follow‐up of this population‐based cohort. © 2008 Wiley‐Liss, Inc.