bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative analysis by flow cytometry of interstitial cells of Cajal, pacemakers, and mediators of neurotransmission in the gastrointestinal tract
Authors: Ördög Tamás , Redelman Doug , Horváth Viktor J. , Miller Lisa J. , Horowitz Burton , Sanders Kenton M.
Published: November 2004

Background

Interstitial cells of Cajal (ICCs) are mesenchymal cells that play critical roles in gastrointestinal motility as electrical pacemakers and mediators of neuromuscular neurotransmission. Although depletions of ICCs have been implicated in several gastrointestinal motor disorders, quantification of these cells has been difficult due to their varied morphology, regionally changing network density, and overall scarcity. Our goal was to evaluate flow cytometry (FCM) for the enumeration of ICCs.

Methods

We identified murine ICCs in live gastrointestinal muscles or primary cell cultures grown in the presence or absence of stem cell factor (SCF)–expressing STO fibroblasts with fluorescent Kit (CD117) antibodies. Because this technique also labels resident macrophages nonspecifically, we identified the latter with additional fluorescent antibodies. Dispersed cells were analyzed by FCM.

Results

ICCs represented 1.63 ± 0.17% of the total cell count in the distal stomach (n = 18 mice) and 5.85 ± 0.84% in the proximal colon and 6.28 ± 0.61% in the distal colon (n = 3 mice). In fundic muscles of W/WV mice (n = 5) that virtually lack ICCs, very few Kit+ cells were detected. FCM identified approximately 2.6‐ to 7.3‐fold more Kit+ ICCs in small intestinal cell cultures grown on STO fibroblasts expressing membrane‐bound SCF (n = 6) than in cultures stimulated with soluble SCF (n = 6).

Conclusions

FCM is a sensitive and specific method for the unbiased quantification of ICCs. © 2004 Wiley‐Liss, Inc.
Lectin‐based three‐color flow cytometric approach for studying cell surface glycosylation changes that occur during apoptosis
Authors: Batisse Chantal , Marquet Jeanine , Greffard Anne , Fleury‐Feith Jocelyne , Jaurand Marie‐Claude , Pilatte Yannick
Published: November 2004

Background

Changes in cell surface glycosylation that accompany apoptosis are thought to be involved in the recognition and removal of apoptotic cells by phagocytes, but in most instances these changes are ill defined. To improve our understanding of this phenomenon, we designed a trivariate flow cytometry procedure that allows direct comparison of cell surface glycosylation in apoptotic and viable cells

Methods

The annexin V/propidium iodide assay has been adapted for cell surface glycosylation analysis by combining the use of these two reagents with biotinylated lectins, and this has been used to investigate camptothecin‐induced apoptosis in U‐937 cells.

Results

Although numerous lectins are potent inducers of apoptosis, we found that it is possible to determine lectin concentrations that produce interpretable data without inducing significant cytotoxicity even when using apoptogenic lectins. That apoptosis is associated with a marked decrease in cell surface sialylation was confirmed by using the sialic acid–specific lectins Maackia amurensis agglutinin and Sambucus nigra agglutinin. These observations were corroborated by lectin blotting analysis with the same lectins.

Conclusions

Species‐ and cell‐dependent altered glycosylation patterns are likely to be associated with different modes of apoptosis. The easy and versatile method described in this report should be useful for exploring this field. © 2004 Wiley‐Liss, Inc.
Turbulence model and numerical scheme assessment for buffet computations
Authors: Goncalves Eric , Houdeville Robert
Published: November 2004

The prediction of shock‐induced oscillations over transonic rigid airfoils is important for a better understanding of the buffeting phenomenon. The unsteady resolution of the Navier–Stokes equations is performed with various transport‐equation turbulence models in which corrections are added for non‐equilibrium flows. The lack of numerical efficiency due to the CFL stability condition is circumvented by the use of a wall law approach and a dual time stepping method. Moreover, various numerical schemes are used to try and be independent of the numerical discretization.

Comparisons are made with the experimental results obtained for the supercritical RA16SC1 airfoil. They show the interest in using the SST correction or realizability conditions to get correct predictions of the frequency, amplitude and pressure fluctuations over the airfoil. Copyright © 2004 John Wiley & Sons, Ltd.
Föderalismus im Dienste der Wissenschaft
Authors: Hopt Klaus J.
Published: November 2004

Ein Pakt für Forschung kann Freiheit und Selbstverwaltung im internationalen Wettbewerb fördern
Reversed operation of glutamate transporter GLT‐1 is crucial to the development of preconditioning‐induced ischemic tolerance of neurons in neuron/astrocyte co‐cultures
Authors: Kawahara Koichi , Kosugi Tatsuro , Tanaka Motoki , Nakajima Takayuki , Yamada Takeshi
Published: November 2004

Sublethal ischemia leads to increased tolerance against subsequent prolonged cerebral ischemia in vivo. In the present study, we investigated the roles of the astrocytic glutamate (Glu) transporter GLT‐1 in preconditioning (PC)‐induced neuronal ischemic tolerance in cortical neuron/astrocyte co‐cultures. Ischemia in vitro was simulated by subjecting cultures to both oxygen and glucose deprivation (OGD). A sublethal OGD (PC) increased the survival rate of neurons significantly when cultures were exposed to a lethal OGD 24 h later. The extracellular concentration of Glu increased significantly during PC, and treatment with an inhibitor of N‐methyl‐D‐actetate (NMDA) receptors significantly reversed the PC‐induced ischemic tolerance of neurons, suggesting that the increase in extracellular concentration of Glu during PC was critical to the development of PC‐induced neuronal ischemic tolerance via the activation of NMDA receptors. Treatment with a GLT‐1 blocker during PC suppressed this increase in Glu significantly, and antagonized the PC‐induced neuronal ischemic tolerance. This study suggested that the reversed operation of GLT‐1 was crucial to the development of neuronal ischemic tolerance. © 2004 Wiley‐Liss, Inc.
Differential activation of astrocytes by innate and adaptive immune stimuli
Authors: Carpentier Pamela A. , Begolka Wendy Smith , Olson Julie K. , Elhofy Adam , Karpus William J. , Miller Stephen D.
Published: November 2004

The immunologic privilege of the central nervous system (CNS) makes it crucial that CNS resident cells be capable of responding rapidly to infection. Astrocytes have been reported to express Toll‐like receptors (TLRs), hallmark pattern recognition receptors of the innate immune system, and respond to their ligation with cytokine production. Astrocytes have also been reported to respond to cytokines of the adaptive immune system with the induction of antigen presentation functions. Here we have compared the ability of TLR stimuli and the adaptive immune cytokines interferon‐γ (IFN‐γ) and tumor necrosis factor‐α (TNF‐α) to induce a variety of immunologic functions of astrocytes. We show that innate signals LPS– and poly I:C lead to stronger upregulation of TLRs and production of the cytokines IL‐6 and TNF‐α as well as innate immune effector molecules IFN‐α4, IFN‐β, and iNOS compared with cytokine‐stimulated astrocytes. Both innate stimulation and adaptive stimulation induce similar expression of the chemokines CCL2, CCL3, and CCL5, as well as similar enhancement of adhesion molecule ICAM‐1 and VCAM‐1 expression by astrocytes. Stimulation with adaptive immune cytokines, however, was unique in its ability to induce upregulation of MHC II and the functional ability of astrocytes to activate CD4+ T cells. These results indicate potentially important and changing roles for astrocytes during the progression of CNS infection. © 2004 Wiley‐Liss, Inc.
Mannose receptor expression specifically reveals perivascular macrophages in normal, injured, and diseased mouse brain
Authors: Galea Ian , Palin Karine , Newman Tracey A. , Van Rooijen Nico , Perry V. Hugh , Boche Delphine
Published: November 2004

Perivascular macrophages are believed to have a significant role in inflammation in the central nervous system (CNS). They express a number of different receptors that point toward functions in both innate immunity, through pathogen‐associated molecular pattern recognition, phagocytosis, and cytokine responsiveness, and acquired immunity, through antigen presentation and co‐stimulation. We are interested in the receptors that are differentially expressed by perivascular macrophages and microglia in both the normal CNS as well as in neuroinflammation and neurodegeneration. In this article we report the use of a well‐characterized monoclonal antibody, 5D3, to localize the expression of the mannose receptor to perivascular macrophages in the normal CNS and in various models of brain pathology. Mannose receptor expression was limited to perivascular, meningeal, and choroid plexus macrophages in normal, inflamed, injured, and diseased CNS. In particular, activated microglia and invading hematogenous leukocytes were mannose receptor negative while expressing the F4/80 antigen, macrosialin (CD68), FcRII (CD32), scavenger receptor (CD204), and CR3 (CD11b/CD18). Since the perivascular macrophages expressing the mannose receptor are known to be the only constitutively phagocytic cells in the normal CNS, we injected clodronate‐loaded liposomes intracerebroventricularly in control mice to deplete these cells. In these mice, there was no detectable mannose receptor expression in perivascular spaces after immunocytochemistry with the 5D3 monoclonal antibody. This finding underlines the value of the monoclonal antibody 5D3 as a tool to study murine perivascular macrophages selectively. Mannose receptor expression by macrophages located at blood‐brain (perivascular), brain‐cerebrospinal fluid (CSF) (meningeal), and CSF‐blood (choroid plexus) interfaces supports a functional role of these cells in responding to external stimuli such as infection. © 2004 Wiley‐Liss, Inc.
Human embryonic stem cells differentiate into oligodendrocytes in high purity and myelinate after spinal cord transplantation
Authors: Nistor Gabriel I. , Totoiu Minodora O. , Haque Nadia , Carpenter Melissa K. , Keirstead Hans S.
Published: November 2004

Human embryonic stem cells (hESCs) demonstrate remarkable proliferative and developmental capacity. Clinical interest arises from their ability to provide an apparently unlimited cell supply for transplantation, and from the hope that they can be directed to desirable phenotypes in high purity. Here we present for the first time a method for obtaining oligodendrocytes and their progenitors in high yield from hESCs. We expanded hESCs, promoted their differentiation into oligodendroglial progenitors, amplified those progenitors, and then promoted oligodendroglial differentiation using positive selection and mechanical enrichment. Transplantation into the shiverer model of dysmyelination resulted in integration, differentiation into oligodendrocytes, and compact myelin formation, demonstrating that these cells display a functional phenotype. This differentiation protocol provides a means of generating human oligodendroglial lineage cells in high purity, for use in studies of lineage development, screening assays of oligodendroglial‐specific compounds, and treating neurodegenerative diseases and traumatic injuries to the adult CNS. © 2004 Wiley‐Liss, Inc.
Glial transcytosis of a photoreceptor‐secreted signaling protein, retinoschisin
Authors: Reid Silvia N.M. , Farber Debora B.
Published: November 2004

In vitro studies have clearly shown that signaling/guidance proteins can diffuse to their targets. However, it is unclear whether they can travel by diffusion in vivo, or if they are distributed in the tissue by an active mechanism. Retinoschisin, a signaling molecule related to neuropilins, is synthesized and secreted by photoreceptor cells in the outer retina; then it interacts with inner retinal cells contributing to synaptic organization and optic nerve fiber integrity. We developed an assay to examine how retinoschisin, which is secreted a distance away, reaches its inner retinal targets. We found that retinoschisin is preferentially taken up and carried into the inner retina from the retinal outer border (the photoreceptor side) by Müller cells (the main glial cells of the vertebrate retina). This transcytosis is disrupted by DL‐α‐aminoadipic acid, a Müller cell/glia‐specific toxin. Our results suggest that glial uptake/transcytosis can provide an effective and precise alternative for distributing signaling molecules in the nervous system. © 2004 Wiley‐Liss, Inc.
Evaluation of cytocompatibility and bending modulus of nanoceramic/polymer composites
Authors: McManus Anastasia J. , Doremus Robert H. , Siegel Richard W. , Bizios Rena
Published: November 2004

In an attempt to simulate the microstructure and mechanical properties of natural bone, novel nanoceramic/polymer composite formulations were fabricated and characterized with respect to their cytocompatibility and mechanical properties. The bending moduli of nanocomposite samples of either poly(L‐lactic acid) (PLA) or poly(methyl methacrylate) (PMMA) with 30, 40, and 50 wt % of nanophase (<100 nm) alumina, hydroxyapatite, or titania loadings were significantly (p < 0.05) greater than those of pertinent composite formulations with conventional, coarser grained ceramics. The nanocomposite bending moduli were 1–2 orders of magnitude larger than those of the homogeneous, respective polymer. For example, compared with 0.06 GPa for the 100% PLA, the bending modulus of 50/50 nanophase alumina/PLA composites was 3.5 GPa. Osteoblast adhesion on the surfaces of the nanophase alumina/PLA composites increased as a function of the nanophase ceramic content. Most importantly, osteoblast adhesion on the 50/50 nanophase alumina/PLA substrates was similar to that observed on the 100% nanophase ceramic substrates. Similar trends of osteoblast adhesion were observed on the surfaces of the nanophase titania/polymer and nanophase hydroxyapaptite/polymer composites that were tested. In contrast, fibroblast adhesion on the nanophase composites was either similar or lower than that observed on the conventional composites with either PLA or PMMA and minimum on all tested neat nanophase substrates. The calcium content in the extracellular matrix of cultured osteoblasts was also enhanced on the nanoceramic/PLA composite substrates tested as a function of the nanophase ceramic loading and duration of cell culture. The results of the present in vitro study provide evidence that nanoceramic/polymer composite formulations are promising alternatives to conventional materials because they can potentially be designed to match the chemical, structural, and mechanical properties of bone tissue in order to overcome the limitations of the biomaterials currently used as bone prostheses. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 72A: 98–106, 2005
Metal‐polymer nanocomposites for integrated microfluidic separations and surface enhanced Raman spectroscopic detection
Authors: Connatser R. Maggie , Riddle Lance A. , Sepaniak Michael J.
Published: November 2004

The widespread development of microfluidics (μfluidics) has allowed the extension of efficient separations, fluid handling, and hyphenation with many detection modes to a small, portable, highly controllable physico‐chemical platform. Surface enhanced Raman spectroscopy (SERS) offers the powerful advantage of obtaining vibrational spectroscopic information about analytes in an aqueous matrix with negligible background. The mating of electrophoretic separations with vibrational spectroscopy on a μfluidic device will allow the chromatographic efficiency of capillary electrophoresis (CE) with the unequivocal analyte “fingerprinting” capability of detailed structural information. By utilizing SERS as a means of detection, this work promises to yield redress for the hindrances of electrophoretic separations, including uncertainty in analyte band identification due to changing migration times as well as compromised detection sensitivity for non‐fluorescent analytes. Our work represents the first steps toward developing CE‐SERS on a μfluidic platform with a region of novel metal‐pliable polymer nanocomposite SERS substrate fabricated directly into the device. The device fabrication material has been extensively employed by the μfluidics community for over five years. SERS detection can be achieved in real time or after the separations, with on‐column laser‐induced fluorescence employed as a secondary detection mode used for confirmation of efficiencies and band locations.
Regulation of lung cancer cell growth and invasiveness by β‐TRCP
Authors: He Nonggao , Li Chengxin , Zhang Xiaoli , Sheng Tao , Chi Sumin , Chen Kai , Wang Qian , Vertrees Roger , Logrono Roberto , Xie Jingwu
Published: November 2004

Beta‐transducin‐repeat‐containing protein (β‐TRCP) serves as a substrate‐recognition subunit of Skp1/Cullin/F‐box (SCF)β‐TRCPE3 ligases, involved in regulation of several important signaling molecules. SCFβ‐TRCPE3 ligases play a critical role in cell mitosis as well as in various signaling pathways. Here, we provide evidence to support that β‐TRCP negatively regulates cell growth and motility of lung cancer cells. With specific antibodies, we detect loss of β‐TRCP1 protein in several lung cancer cell lines. One cell line contains an inactivated mutation of theβ‐TRCP1gene. Loss of β‐TRCP1 protein is also found in subsets of lung cancer specimens. We observe that retrovirus‐mediated stable expression of β‐TRCP1 in β‐TRCP1 negative cells inhibits cell growth in soft‐agar and tumor formation in nude mice. Furthermore, expression of β‐TRCP1 alters cell motility, as indicated by morphological changes and a reduced level of active matrix metalloproteinase (MMP)11. Conversely, inactivation of β‐TRCP1 by specific siRNA accelerates cell invasion. Of the 10 known substrates of SCFβ‐TRCPE3 ligases, the protein level of cell division cycle 25 (CDC25)A is clearly affected in these lung cancer cells. Cells treated with CDC25A inhibitors become less invasive. Thus, loss of β‐TRCP1 may promote both growth and cell motility of lung cancer cells, possibly through regulation of CDC25A and the MMP11 level. © 2004 Wiley‐Liss, Inc.
Mutations and elevated transcriptional activity of conductin (AXIN2) in hepatoblastomas
Authors: Koch Arend , Weber Nina , Waha Andreas , Hartmann Wolfgang , Denkhaus Dorota , Behrens Jürgen , Birchmeier Walter , Schweinitz Dietrich von , Pietsch Torsten
Published: November 2004

Hepatoblastoma (HB) is the most frequent malignant liver tumour of childhood. Most HBs develop sporadically but their incidence is highly elevated in patients with familial adenomatous polyposis coli (FAP). These patients carry germline mutations in the adenomatous polyposis coli (APC) tumour suppressor gene. APC forms a multi‐protein complex involved in the WNT signalling pathway that controls the stability of β‐catenin, the central effector in this cascade. Whereas APC mutations are rare in sporadic HBs, a high frequency of β‐catenin mutations leading to overactivation of WNT signalling was previously found in these tumours. This pathway is negatively controlled by conductin (axin2), representing a further partner in this signalling complex. To investigate whether alterations in conductin may also be involved in the pathogenesis of sporadic HBs, 37 HBs and five HB cell lines were screened for mutations using single‐strand conformation polymorphism (SSCP) analysis, reverse transcription‐polymerase chain reaction (RT‐PCR), and direct sequencing. In two cases, larger deletions (52 and 1624 bp) leading to frameshifts were found. In addition, one HB carried a somatic point mutation. Expression analysis by competitive RT‐PCR in HBs revealed up‐regulation of conductin mRNA compared with adjacent liver samples. This mRNA overexpression resulted in increased conductin protein levels demonstrated by western blot analysis. Tumours with activating β‐catenin mutations revealed higher levels of conductin mRNA transcripts. This finding indicates that conductin is a direct target gene of WNT signalling in HBs, as has been demonstrated in other tissues. In summary, conductin mutations may represent an alternative mechanism leading to activation of WNT signalling in HBs. The overexpression of conductin mRNA in HBs reflects activation of the WNT pathway because conductin represents a target gene of WNT signalling in liver tissue. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Design of a polymer‐based phase modulator: validation of the various processes
Authors: Cornic Charles , Lucas Bruno , Moliton André
Published: November 2004

This work is devoted to the development of technology processes with the aim of realizing a phase modulator based on organic materials. At first, a semiconductor technology is adapted to polymers to elaborate waveguides, and to realize the stacking of layers of passive and active polymers compatible with processes on a silicon substrate. By using the reactive ion‐beam etching process, we obtained waveguides with good vertical walls and propagation losses of around 0.5 dB cm−1. For realization of the ‘whole‐polymer’ phase modulator, as a guiding layer we used the fluorinated polyimide, 6FDA/MPDA (Figure1), mixed with a colorant, Disperse Red One (DR1); this layer is sandwiched between two organic layers with lower indices. The lower cladding layer was realized with the 6FDA/MPDA polyimide, and the upper cladding layer with poly(methyl methacrylate) (PMMA) deposited on a thin anhydride‐(6 FDA) and diamine‐(ODA) based polyimide layer obtained by vapor deposition polymerization (VDP): this layer leads to a good adherence between the active layers, while the PMMA layer can also be covered with 6FDA/ODA which then acts as a protective layer. With an infrared camera, we have shown propagation of the guided wave in a configuration‐phase modulator, and thus validated a whole technological process. Copyright © 2004 Society of Chemical Industry

1. Molecular structure of the 6FDA/MPDA monomer.

magnified image

1. Molecular structure of the 6FDA/MPDA monomer.
Determining Contact Angles of Powders by Liquid Penetration
Authors: Teipel Ulrich , Mikonsaari Irma
Published: November 2004

The wettability of a powder is important, especially in chemical and pharmaceutical technologies when considering the manufacturing process and the properties of the final product. However, contact angle methods for powders are problematic. The common measurement techniques are the sessile drop method and the liquid penetration method. In this work the determination of contact angles of powders by liquid penetration is considered. In particular, we investigated the influence of the sample preparation and sampling device on the wetting process. A bulk with constant properties during the measurement must be guaranteed. We postulate a packing procedure to obtain reproducible measurements by ensuring constant powder properties.
Bulk Mechanical Behavior of Rootzone Sand Mixtures as Influenced by Particle Shape, Moisture and Peat
Authors: Mittal Bhavishya , Yi HoJae , Puri Virendra M. , McNitt Andrew S. , Mancino Charles F.
Published: November 2004

Mechanical properties such as bulk modulus, shear modulus, and failure stress of rootzone sand mixtures are some of the key parameters in understanding the load‐response of sands used in professional golf courses. According to the United States Golf Association (USGA) specifications, appropriate particle size distributions and their shape are important for preparing putting greens and bunker sands. Despite being an important parameter, the influence of sand particle shape on the bulk mechanical properties of the rootzone mixtures has not been studied systematically using a fundamental tester. Toward this end, bulk mechanical properties were measured using a low‐pressure cubical (true) triaxial tester. In this study, four of the commonly used basic shapes, i.e., round, subround, subangular, and angular sand particles comprising rootzone mixtures with sphagnum peat (organics) were tested at two different moisture levels, air‐dried and 30 cm moisture tension conditions. For all rootzone sand mixtures, an increase in bulk modulus was observed with increasing isotropic pressure. The failure stress values increased with the increase in mean pressure for air dried samples. In general, moisture increased compressibility of sands and decreased failure strength and shear modulus values. Peat had a dominant influence on the mechanical response of all four sand shapes. When peat and moisture were added, the rootzone mixture became most compressible and easier to fail, with noticeable changes in bulk mechanical properties.
The Influence of Air Counter‐Flow Through Powder Materials as a Means of Reducing Cohesive Flow Problems
Authors: Johanson Kerry , Barletta Diego
Published: November 2004

The cohesive behavior of aerated solids controls fluidization behavior of bulk materials. Very cohesive materials cannot be easily fluidized. However, aeration is often used in contact bed situations to help maintain some cohesive materials in flowable conditions. The cohesive properties of aerated materials are not well understood. This paper presents a new test method to measure the effect of aeration on cohesive flow properties. These measurements could be used along with new design equations to predict arching and stable rathole formation of cohesive materials in aerated process equipment. Experimental results on fine silica powder and fluid catalytic cracking (FCC) catalyst show the evolution of the yield locus shape and the effective yield locus shape as a function of the degree of aeration. It was found that both the cohesion intercept and the yield locus slope are functions of the degree of aeration.
Stress Inhomogeneity in Powder Specimens Tested in the Jenike Shear Cell: Myth or Fact?
Authors: Bilgili Ecevit , Yepes Juan , Stephenson Luke , Johanson Kerry , Scarlett Brian
Published: November 2004

In the mechanical characterization of powders using the direct shear testers such as the Jenike shear cell, the existence of a uniform or well‐defined stress field in a powder specimen is assumed. This assumption has not been subjected to any serious scrutiny in the literature. In this study, the normal stress variation in a silica powder was locally determined by locating a pressure‐sensitive TekScan pad at the bottom section of a Jenike shear cell. A computer simulation of the consolidation and pre‐shearing stages of the Jenike test procedure was performed using the Discrete Element Method (DEM). The paper presents both experimental and computational evidence for the existence of a complex stress field in the powder specimen, thus clearly invalidating the long‐standing stress homogeneity assumption in the direct shear testing of powders. The implications of the stress inhomogeneity in terms of the accuracy of the material properties extracted from the Jenike test are also presented.
Identification of hypoxia‐inducible factor‐1α (HIF‐1α) polymorphism as a mutation in prostate cancer that prevents normoxia‐induced degradation
Authors: Fu Xinyu S. , Choi Eunis , Bubley Glenn J. , Balk Steven P.
Published: November 2004

BACKGROUND

Hypoxia‐inducible factor‐1α (HIF‐1α) regulates cellular responses to hypoxia and is rapidly degraded under normoxia through von Hippel‐Lindau (VHL) mediated ubiquitination. Although HIF‐1α stabilization appears to be the molecular basis for VHL‐associated cancers, stabilizing mutations in HIF‐1α have not been reported.

METHODS

A series of 15 metastatic androgen independent prostate cancers were examined for mutations in the oxygen‐dependent domain (ODD) of HIF‐1α by PCR amplification and DNA sequencing.

RESULTS

A somatic proline to serine mutation in codon 582 (P582S) was identified in one sample. Transfection studies with a HIF‐1α regulated reporter gene showed increased transcriptional activity that correlated with higher mutant HIF‐1α protein expression. Increased expression of the P582S mutant induced by iron chelation, which blocks proline hydroxylation of wild‐type HIF‐1α, was markedly attenuated. The mutant also showed increased stability under normoxic versus hypoxic conditions.

CONCLUSION

The P582S HIF‐1α is a stable variant and HIF‐1α mutation is a mechanism for enhancing HIF‐1α activity in human cancer. The recent identification of the identical P582S HIF‐1α as a polymorphism suggests that this variant may increase tumor susceptibility or cause more aggressive biological behavior. © 2004 Wiley‐Liss, Inc.
Characterization and PCR‐based detection of benzimidazole‐resistant isolates of Monilinia laxa in California
Authors: Ma Zhonghua , Yoshimura Michael A , Holtz Brent A , Michailides Themis J
Published: November 2004

Monilinia laxa is a pathogen of brown rot of stone fruit and almond in California, causing blossom blights and fruit rots. In this study, low‐level resistance to the benzimidazole fungicides benomyl and thiophanate‐methyl was detected in field isolates of M laxa collected from stone fruits and almonds in California. Low‐resistant (LR) isolates grew in potato dextrose agar (PDA) plates amended with benomyl and thiophanate‐methyl at 1 and 5 µg ml−1, respectively, but not in plates amended with benomyl at 5 µg ml−1 or thiophanate‐methyl at 50 µg ml−1. The benzimidazole LR isolates were characterized by temperature sensitivity and the DNA sequence of the β‐tubulin gene. The LR isolates showed high‐temperature sensitivity, being sensitive to 1 µg ml−1 of benomyl at 28 °C but resistant at 8–24 °C. Analysis of the DNA sequence of the β‐tubulin gene showed that the LR isolates had a point mutation at the amino‐acid position 240, causing substitution of leucine by phenylalanine. Based on the point mutation, a pair of allele‐specific PCR primers was developed for rapid detection of LR isolates of M laxa. In addition, a pair of PCR primers specific to M laxa was developed on the basis of the differences in the DNA sequence of the intron 6 of β‐tubulin gene from M laxa, M fructicola and other fungal species. The primer pair amplified the expected 376‐bp DNA fragment from all M laxa isolates tested, but not from 14 other fungal species isolated from stone fruit and almond crops. The restriction endonuclease BsmA I recognized the sequence GTCTCC in the PCR products from sensitive (S) isolates only, but not the GTTTCC sequence in the PCR products from LR isolates. The endonuclease digested the 376‐bp PCR products from S isolates to produce two bands (111 and 265 bp) on agarose gels. Thus, both allele‐specific PCR and the PCR‐restriction fragment length polymorphism (PCR‐RFLP) methods could be useful for rapidly detecting benzimidazole‐resistant isolates of M laxa from stone fruit and almond crops in California. Copyright © 2004 Society of Chemical Industry
Highly accurate relativistic universal Gaussian basis set for Dirac–Fock–Breit calculations
Authors: De Macedo L. G. M. , Barbosa R. C. , da Silva A. B. F.
Published: November 2004

A universal Gaussian basis set is presented to perform highly accurate Dirac–Fock–Breit calculations. The Gaussian‐type functions of our universal basis set satisfy the relativistic boundary conditions associated with the finite nucleus model, for a finite velocity of light, and conform to the so‐called kinetic balance at the nonrelativistic limit. The high accuracy obtained in our Dirac–Fock–Breit calculations is attributed to the fact that with our universal Gaussian basis set we are able to better represent the relativistic kinematics of an electron inside the nucleus. Results for the Dirac–Fock–Breit energies for a number of neutral atoms up to nobelium and some of their negative ions are presented and compared with the results of Parpia et al., obtained by employing a geometrical Gaussian basis set and a more accurate value for the velocity of light. The Dirac–Fock–Breit energy results presented in this work, using our universal Gaussian basis set, are among the best obtained with Gaussian‐type functions in the literature. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Maintaining the quality focus in the business‐to‐business auction model
Authors: Yasin Mahmoud M. , Czuchry Andrew J. , Bayes Paul E.
Published: November 2004

The growth of business‐to‐business auctions presents the quality‐focused business organization with many opportunities and some serious challenges. In this context, the absence of a well‐designed organizational e‐business auction‐based strategy has the potential to promote business practices which may erode organizational quality gains. This article presents a conceptual open system approach designed to improve the quality focus of business‐to‐business auctions practices. The open system approach advocated in this article is quality focused and supply‐chain sensitive. Copyright © 2004 John Wiley & Sons, Ltd.
The Three Gorges Dam Project from a systems viewpoint
Authors: Alberts Henry C. , Alberts Renée M. , Bloom Mitchel F. , LaFlamme A. Diane , Teerikangas Satu
Published: November 2004

The Three Gorges Dam on the Yangtze River is currently the largest construction project in the world. Because of its complexity, integration of social, environmental and technological systems, and tight coupling required by the schedule, the project should be managed using a systems approach. To find out if this was the case, the authors formed a research team, sponsored by the International Society of Systems Sciences, to tour the dam sight, interview managers and engineers, travel up the Yangtze to Chongqing, analyze problems posed by the critics of the dam and, finally, report back to the ISSS annual meeting in Shanghai following the trip. This paper reports on the team's observations, the results of the interviews and a systems model that analyzes the problems facing the dam builders. Finally, the paper concludes that the engineers and managers are aware of the interrelated problems and have planned for their solution. Copyright © 2004 John Wiley & Sons, Ltd.
Effects of in vitro exposure to low levels of organotin and carbamate pesticides on human natural killer cell cytotoxic function
Authors: Wilson Sharnise , Dzon Leticia , Reed Adrian , Pruitt Marilyn , Whalen Margaret M.
Published: November 2004

Human natural killer (NK) lymphocytes play a central role in immune system defense against viral infection and against the formation of primary tumors. Organotin (OT) pesticides have been used in industrial and agricultural applications, and OT contamination has been reported in water, sediment, and fish. Carbamate pesticides are currently used in agricultural chemicals. Two specific carbamates used in agriculture are ziram and maneb; ziram also is used as an additive in rubber products including latex gloves. In previous studies we demonstrated that at concentrations in the 150–200 nM range, the OTs tributyltin (TBT) and triphenyltin (TPT) were capable of disrupting the function of human NK cells after incubations to as short as 24 h. Previously, we also examined the effects of ziram and maneb at higher concentrations on the cytotoxic function of human NK cells. The current study examined the effects of exposure of up to 6 days to lower concentrations of each of these compounds on the cytotoxic function of NK cells. The OTs were studied at concentrations ranging from 200 to 10 nM; ziram was studied at concentrations of 2.5 μM–125 nM and maneb at concentrations of 10–1 μM. These conditions were studied both in highly purified NK cells and in a mixture of lymphocytes containing both T and NK cells. As little as 25 nM TBT decreased the function of purified NK cells after 24 and 48 h, whereas 10 nM TBT was effective after 6 days. The lowest level of TPT that was effective at 24 h was 50 nM whereas the results after 48 h and 6 days were similar to those seen with TBT. The presence of T lymphocytes diminished the effects of both TBT and TPT on NK cytotoxic function. A concentration of ziram as low as 125 nM produced significant loss of cytotoxic function in highly purified NK cells (65% decrease in function after 6 days). The toxicity of each of the compounds studied increased very significantly with length of exposure. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 554–563, 2004
Inflammatory activity in river‐water samples
Authors: Wichmann G. , Daegelmann C. , Herbarth O. , Strauch G. , Schirmer K. , Wöstemeyer J. , Lehmann I.
Published: November 2004

Contamination of the urban aquatic environment with chemical and biological substances could have a long‐term impact on human health because these substances threaten the integrity of the urban ecosystem and the availability of high‐quality water for recreation and consumption. In light of this, the aim of the present study was to assess the potential immunological effects of water sampled at various sites along the River Saale near the city of Halle (in the state of Sachsen‐Anhalt, Germany). For the control, Ficoll‐separated peripheral blood mononuclear cells (PBMC) of healthy donors were cultured for 24 h in either filter‐sterilized river water or drinking‐water samples. Cell vitality was assessed using the MTT bioassay. Cytokines in culture supernatants were measured by ELISA. Endotoxin concentrations in the water samples were assessed by the limulus amoebocyte lysate (LAL) test. River water and drinking water showed comparably weak cytotoxic effects on PBMC. Drinking water did not exert any effect on cytokine secretion. In contrast, all river‐water samples triggered secretion of proinflammatory cytokines, as shown for TNF‐α, IL‐1β, and IL‐6. Free endotoxin was detected in all river‐water samples. However, the highest inflammatory activity regarding induction of all three cytokines, as well as the highest endotoxin content as determined by LAL, was found in a water sample taken immediately downstream of a wastewater treatment plant. Inhibition studies using the monoclonal anti‐CD14 antibody biG14, which is known to suppress binding of lipopolysaccharide (LPS) to CD14 via binding CD14 itself, revealed that free endotoxin was indeed the major inducer of proinflammatory cytokines in the river‐water samples. Taken together, the results suggest that the microorganism‐derived endotoxin is a widely distributed contaminant in the urban aquatic environment that should be considered in routine monitoring and in assessing ecosystem and human health. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 594–602, 2004.
Histological evidence of intersex in feral sharptooth catfish (Clarias gariepinus) from an estrogen‐polluted water source in Gauteng, South Africa
Authors: Barnhoorn I. E. J. , Bornman M. S. , Pieterse G. M. , van Vuren J. H. J.
Published: November 2004

This is the first histological evidence of intersex in a fish species inhabiting a South African water source. One hundred catfish (Clarias gariepinus) were collected randomly from the Marais Dam (MD) and the Rietvlei Dam (RVD) in the Rietvlei Nature Reserve (RNR), South Africa. These dams drain water from a stream that receives effluent from industrial sites, agricultural activities, informal settlements, and municipal treatment plants. Each fish was evaluated macroscopically and had blood drawn, and its gonads were macroscopically and histologically examined to verify intersex potentially related to endocrine disruption. Gonadal histology of several fish showed primary oocytes scattered in testicular tissue, indicative of intersex. The results showed intersexuality in 20% of fish from both the dams. The GSI value for intersex fish was closer to male GSI values, suggesting that the sampled intersex fish were more likely to have occurred from the feminization of male catfish. Target chemical analyses showed that the water, sediment, and serum samples tested positive for p‐nonylphenol (p‐NP). The p‐NP level in water and sediment at MD was 6360 and 4.0 μg/kg, respectively, whereas in sediment at RVD it was 113 μg/kg. Commonly found in the effluent from sewage treatment plants, p‐NP in water and sediment indicates estrogenic water pollution, which might affect wildlife and humans dependent on these sources. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 603–608, 2004.
Impact of aminopolycarboxylates on aquatic organisms and eutrophication: Overview of available data
Authors: Schmidt Carsten K. , Brauch Heinz‐Jürgen
Published: November 2004

Aminopolycarboxylic acids, which include ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), diethylenetriaminepentaacetic acid (DTPA), 1,3‐propylenediaminetetraacetic acid (1,3‐PDTA), β‐alaninediacetic acid (β‐ADA), and methylglycinediacetic acid (MGDA), constitute a class of complexing agents that occur in a wide range of domestic products and that are used intensively as metal sequestrants in several industrial applications. Because they are highly polar and partially nondegradable, aminopolycarboxylates are released into the aquatic environment in significant quantities, mainly via wastewater. The historical and current use of aminopolycarboxylates and their ubiquitous presence in surface waters prompted many studies about their possibly detrimental impact on aquatic organisms. This review summarizes the available data and information on the eutrophication potential and toxicity of aminopolycarboxylates to a multitude of aquatic organisms including vertebrates, invertebrates, algae, bacteria, and protozoa. This article also addresses how the ecotoxic effects of aminopolycarboxylates are dependent on their speciation, that is, on their presence in a free or a metal‐complexed form. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 620–637, 2004.
On Quantum-Like Probabilistic Structure of Mental Information
Authors: Khrennikov Andrei
Published: November 2004

We describe methodology of cognitive experiments (based on interference of probabilities for mental observables) which could verify quantum-like structure of mental information, namely, interference of probabilities for incompatible observables. In principle, such experiments can be performed in psychology, cognitive, and social sciences. In fact, the general contextual probability theory predicts not only quantum-like trigonometric (cos θ) interference of probabilities, but also hyperbolic (cosh θ) interference of probabilities (as well as hyper-trigonometric). In principle, statistical data obtained in experiments with cognitive systems can produce hyperbolic (cosh θ) interference of probabilities. We introduce a wave function of (e.g., human) population. In general, we should not reject the possibility that cognitive functioning is neither quantum nor classical. We discuss the structure of state spaces for cognitive systems.
Probability distribution of low‐altitude propagation loss from radar sea clutter data
Authors: Gerstoft Peter , Hodgkiss William S. , Rogers L. Ted , Jablecki Michael
Published: November 2004

This paper describes the estimation of propagation loss and its statistical properties on the basis of observations of radar sea clutter data. This problem is solved by first finding an ensemble of relevant refractivity model parameters, and each refractivity model is weighted according to its data likelihood function. A parabolic equation propagation model is used both in mapping from environmental model to radar clutter data and also when mapping to propagation loss. Two different methods are then used for mapping from a statistical description of refractivity parameters to a statistical description of propagation loss. In the first approach, all of the sampled models explored in the inversion are used to give a statistical description of propagation loss. Alternatively, the environmental model is sampled from the probability for the refractivity model parameters and then mapped into propagation loss. This can be done efficiently if we are using the one‐dimensional marginal distributions instead of the full distribution for the environmental parameters.
Gender, Body, and Feminine Performance: Edna St. Vincent Millay's Impact on Anne Sexton
Authors: Michailidou Artemis
Published: November 2004

This paper will discuss Edna Millay's influence on Anne Sexton, with particular reference to issues such as gender politics, femininity, performativity, and the female body. Through close comparative readings of some of the two women's most representative poems, I analyze, firstly, how Millay's outspokenness and daring self-presentation as a woman writer facilitated Sexton's handling of material that was previously considered unacceptable for poetry and, secondly, how Sexton expanded the scope of women's writing in a manner that paid tribute to the earlier poet's innovation. My paper maintains that Millay's repeated attempts to explore gender and interrogate the concept of ‘authentic’ femininity anticipated Sexton's overtly feminist works. Ultimately, I am arguing that, despite the literary climate of the 1960s (which urged the rejection of poets like Mi May) and despite her own ambiguous feelings for the earlier poet, Sexton eventually recovered Mil lay as an important literary predecessor for her generation, consistently imitated her artistic posturing, performance strategies, and self-presentation, and finally acknowledged her unique contribution to women's writing.
Nancy Cunard's English Journey
Authors: Joannou Maroula
Published: November 2004

This essay analyses Nancy Cunard's contribution to the struggle for racial justice in England and her work with the black communities in Liverpool and London (whose histories and experiences differ radically from their counterparts in the United States) in the 1940s. It chronicles for the first time her campaign to safeguard the African collections in the Liverpool Museum and her specific contribution to the archive of black British history. This includes not only the monumental the Negro Anthology (1934) but also the tract, The White Man's Duty (1943) arguing for an end to British imperialism and for race relations legislation. Cunard is situated within a history of the Communist left in Britain and the United States. Her insistence on the primacy of race differentiates her from other white left activists in her day for whom issues of gender and race were or secondary importance compared to those of class (Cunard, 1944). Using unpublished archive material from the Harry Ransom Center in Austin, Texas I show that Cunard's work constitutes one segment in the rich and varied mosaic of black cultural activity in the 1930s and 1940s and discuss how Cunard knew and worked alongside some of the key figures in the black British politics of her day including Una Marson, Learie Constantine, John Carter, Harold Moody, Rudolph Dunbar and Paul Robeson. A prolific writer, publisher and political activist, Cunard presented a white readership with documentation which prompted them to question their own prejudice and rendered problematic the imaging of black people as fixed embodiments of a Eurocentric sense of reality. Cunard's work in the 1930s and 1940s predates the sailing of the Empire Windrush and the accelerated immigration to Britain from the Commonwealth after the Nationality Act of 1948. It adds to our knowledge of earlier black history, narratives, settlements, and anti-racist struggles.
Quantification of reactive mixing in laminar microflows
Authors: Vikhansky A.
Published: November 2004

We propose numerical methods for the estimation of the yield of reaction in laminar flows. The methods are based on backward tracking of tracer particles. In the case of fast reaction (high Damköhler number) the degree of mixing at a particular point can be calculated by a backward random-walk Monte Carlo simulation. This procedure is applicable for both chaotic and nonchaotic regions. In a chaotic flow the reaction-diffusion equation can be approximated by a one-dimensional equation in Lagrangian coordinates along the stable manifold of a fluid element. An adaptive tracking technique of the stable manifold allows the numerical quantification of the effect of the flow on a finite rate chemistry.