bluuebunny/crossref_metadata_2025 huggingface dataset:
Diphosphoinositol Polyphosphates: The Final Frontier for Inositide Research?
Authors: Safrany S. T. , Caffrey J. J. , Yang X. , Shears S. B.
Published: October 2004

The diphosphoinositol polyphosphates comprise a group of highly phosphorylated compounds which have a rapid rate of metabolic turnover through tightly-regulated kinase/phosphohydrolase substrate cycles. The phosphohydrolases occur as multiple isoforms, the expression of which is apparently carefully controlled. Cellular levels of the diphosphoinositol polyphosphates are regulated by cAMP and cGMP in a protein kinase-independent manner. These inositides can also sense a specific mode of intracellular Ca2+pool depletion. In this review, we will argue that these are characteristics of highly significant cellular molecules.
Differential Distribution of Four Hyperpolarization-Activated Cation Channels in Mouse Brain
Authors: Moosmang S. , Biel M. , Hofmann F. , Ludwig A.
Published: October 2004

Hyperpolarization-activated cation currents, termed Ih, are observed in a variety of neurons. Four members of a gene family encoding hyperpolarization-activated cyclic-nucleotide-gated cation channels (HCN1-4) have been cloned. The regional expression and cellular localization of the four HCN channel types in mouse brain was investigated using in situ hybridization. The expression of HCN1 was restricted to the olfactory bulb, cerebral cortex, hippocampus, superior colliculus and cerebellum. In contrast, HCN2 transcripts were found at high levels nearly ubiquitiously in the brain, and the strongest signals were seen in the olfactory bulb, hippocampus, thalamus and brain stem. HCN3 was uniformly expressed at very low levels throughout the brain. Finally, HCN4 transcripts were prominently expressed selectively in the thalamus and olfactory bulb. Some neurons expressed two or more HCN channel transcripts including hippocampal pyramidal neurons (HCN1, HCN2 and low levels of HCN 4) and thalamic relay neurons (HCN2 and HCN4). Our results demonstrate that each HCN channel transcript has a unique distribution in the brain. Furthermore, they suggest that the heterogeneity of neuronal Ih may be, at least in part, due to the differential expression of HCN channel genes.
Functional Characterisation of Dictyostelium Myosin II with Conserved Tryptophanyl Residue 501 Mutated to Tyrosine
Authors: Batra R. , Manstein D. J.
Published: October 2004

We created aDictyostelium discoideummyosin II mutant in which the highly conserved residue Trp-501 was replaced by a tyrosine residue. The mutant myosin alone, when expressed in aDictyosteliumstrain lacking the functional myosin II heavy chain gene, supported cytokinesis and multicellular development, processes which require a functional myosin inDictyostelium. Additionally, we expressed the W501Y mutant in the soluble myosin head fragment M761-2R (W501Y-2R) to characterise the kinetic properties of the mutant myosin motor domain. The affinity of the mutant myosin for actin was approximately 6-fold decreased, but other kinetic properties of the protein were changed less than 2-fold by the W501Y mutation. Based on spectroscopic studies and structural considerations, Trp-501, corresponding to Trp-510 in chicken fast skeletal muscle myosin, has been proposed to be the primary ATP-sensitive tryptophanyl residue. Our results confirm these conclusions. While the wild-type construct displayed a 10% fluorescence increase, addition of ATP to W501Y-2R was not followed by an increase in tryptophan fluorescence emission.
Rat Muscle Fructose-1,6-Bisphosphatase: Cloning of the cDNA, Expression of the Recombinant Enzyme, and Expression Analysis in Different Tissues
Authors: Al-Robaiy Samiya , Eschrich Klaus
Published: October 2004

The 1282 bp cDNA of an isoenzyme of fructose-1,6- bisphosphatase was cloned from rat muscle. It shows 70% positional identity to the cDNA of rat liver fructose- 1,6-bisphosphatase and is clearly the product of a gene different from that coding for the liver enzyme. After cloning of the coding region of the rat muscle fructose-1,6-bisphosphatase cDNA in an expression vector, the recombinant enzyme could be detected inE. colicell-free extracts by activity determination and Western blotting. Overexpressed fructose-1,6-bisphosphatase was found to be allosterically inhibited by AMP comparably to the enzyme isolated from rat muscle. Analysis of steady-state mRNA levels of various rat tissues with reverse-transcriptase polymerase chain reaction (RT-PCR) and Northern blotting revealed one or the two fructose-1,6-bisphosphatase isoenzyme mRNAs in most tissues tested with significant quantitative differences. Quantitative PCR using a homologous competitor showed that 1 μg of total RNA of rat muscle contains 1.7 × 106molecules of rat muscle fructose-1,6-bisphosphatase mRNA. 3 × 104copies of this message were found per μg total RNA of heart and kidney, respectively.
Fluorometric Microassays for the Determination of Cathepsin L and Cathepsin S Activities in Tissue Extracts
Authors: Werle Bernd , Staib Alexander , Jülke Britta , Ebert Werner , Zladoidsky Pavel , Sekirnik Andreja , Kos Janko , Spiess Eberhard
Published: October 2004

We established a continuous semi-microassay, and for large-scale studies both a stopped and a continuous microtiter plate assay for the fluorometric determination of cathepsin L and cathepsin S activities in body fluids, tissues or cell extracts in the presence of cathepsin B. For the detection of enzymatic activities we used the synthetic substrate Z-Phe-Arg-AMC, and for discrimination between cathepsin L, S and cathepsin B the specific inhibitor CA-074 for blocking interfering cathepsin B activities was applied. Furthermore, we took advantage of the stability of cathepsin S at pH 7.5 for further differentiation between cathepsin L and cathepsin S activities. The kinetic assays were characterized in terms of imprecision, analytical sensitivity, accuracy and substrate concentration. The within-run coefficients of variation were found to be 4.9%–7.2% for the continuous semi-microassay, 10.3%–11.7% for the stopped, and 4.5%–11.8% for the continuous microtiter plate assay. The between-days coefficients of variation for the continuous semimicroassay were 8.1%–8.9%, while for the stopped and continuous microtiter plate assays the coefficients were 11.2%–13.5% and 5.8%–12.2%, respectively. Compared to the continuous semi-microassay, the stopped and the continuous microtiter plate assays showed 3-fold and 11-fold higher sensitivity, respectively. Comparison between the continuous enzyme activity assays at substrate concentrations of 40 μM and 200μM demonstrated a significant correlation of r = 0.97 and r = 0.99, respectively.

The newly developed microtiter plate assay will allow efficient, sensitive and high precision determination of cathepsin L and cathepsin S activities in large-scale studies of cysteine-cathepsin dependent diseases.
Molecular Characterization of a Novel Mammalian DnaJ-Like Sec63p Homolog
Authors: Skowronek Markus H. , Rotter Max , Haas Ingrid G.
Published: October 2004

We identified a human cDNA sequence encoding a polypeptide of 760 amino acids that shares 53% homology and 25.6% identity with the yeast DnaJ-like endoplasmic reticulum (ER) translocon component Sec63p. Three epitope-specific antisera revealed a protein of an apparent molecular mass of 83 kDa, both in human cell extracts and in dog pancreatic microsomes. Biochemical analyses show that it is an integral membrane protein of the rough ER, which has the DnaJ domain located in the ER lumen. The novel Sec63 protein could thus represent a key component of the mammalian ER protein translocation machinery.
Posttranslational Protein Translocation Across the Membrane of the Endoplasmic Reticulum
Authors: Rapoport Tom A. , Matlack Kent E.S. , Plath Kathrin , Misselwitz Benjamin , Staeck Oliver
Published: October 2004

Posttranslational protein translocation across the membrane of the endoplasmic reticulum is mediated by the Sec complex. This complex includes a transmembrane channel formed by multiple copies of the Sec61 protein. Translocation of a polypeptide begins when the signal sequence binds at a specific site within the channel. Binding results in the insertion of the substrate into the channel, possibly as a loop with a small segment exposed to the lumen. While bound, the signal sequence is in contact with both protein components of the channel and the lipid of the membrane. Subsequent movement of the polypeptide through the channel occurs when BiP molecules interact transiently with a luminal domain of the Sec complex, hydrolyze ATP, and bind to the substrate. Bound BiP promotes translocation by preventing the substrate from diffusing backwards through the channel, and thus acts as a molecular ratchet.
Import of Carrier Proteins into Mitochondria
Authors: Truscott Kaye N. , Pfanner Nikolaus
Published: October 2004

Carrier proteins located in the inner membrane of mitochondria are responsible for the exchange of metabolites between the intermembrane space and the matrix of this organelle. All members of this family are nuclear-encoded and depend on translocation machineries for their import into mitochondria. Recently many new translocation components responsible for the import of carrier proteins were identified. It is now possible to describe a detailed import pathway for this class of proteins. This review highlights the contribution made by translocation components to the process of carrier protein import into mitochondria.
The T-Knot Motif Revisited
Authors: Polticelli Fabio , Pascarella Stefano , Bordo Domenico , Bolognesi Martino , Ascenzi Paolo
Published: October 2004

The T-knot scaffold, a disulphide-reinforced structural motif shared by several proteins with very different biological functions, has been defined as ‘a stretch of the protein chain which comprises two strands of a β-sheet and three loops, knotted by two disulphides into the shape of the letter T’. In this communication we show that the presence of a central β-sheet is not a required structural feature for proteins sharing the T-knot topology. Moreover, superposition of the three-dimensional structures of representative members of the T-knot family highlights a common and structurally well-defined core, formed by the two knotted disulphides, substituting for a larger residue-based hydrophobic core. These results suggest that folding and stability of the T-knot scaffold mainly depend on the geometry of the two knotted disulphides and on the loop length, and that the secondary structure elements are not a prerequisite for motif formation. Accordingly, a redefinition of the T-knot motif is proposed.
Synthesis, Cytotoxicity and Antitumor Activity of Platinum(II) Complexes of Cyclopentanecarboxylic Acid Hydrazide
Authors: Kushev Daniel , Gorneva Galina , Taxirov Svetoslav , Spassovska Nadejda , Grancharov Konstantin
Published: October 2004

New platinum(II) complexes of cyclopentanecarboxylic
acid hydrazide (cpcah) were prepared, characterized
by elemental analysis, IR and 1H NMR spectra,
and evaluated for in vitro cytotoxicity in Friend
leukemia (FL) and A2780 ovarian tumor cells, induction
of apoptosis in FL cells, as well as for in vivo antitumor
activity toward murine L1210 leukemia and Lewis lung
carcinoma. The spectral analyses indicated a cissquare
planar structure of the complexes with hydrazide
ligand coordinated via the NH2 group. The
compounds exerted significantly lower in vitro and
in vivo toxicities as compared with those of cisplatin
(cis-diamminedichloroplatinum(II), DDP). On the other
hand, the complex [Pt(NH3)(cpcah)Cl2] exhibited antitumor
activity against L1210 leukemia in mice comparable
to that of cisplatin, resulting at a dose of
42 mg/kg (administered 3 times) in a T/C (mean survival
time) of 280%. This compound displayed an in
vitro macromolecular synthesis inhibition pattern
similar to that of DDP. At concentrations close to the
cytostatic ones (10–20 μM) this complex, as well as
DDP, was able to induce apoptosis in FL cells as shown
by neutral comet assay and morphological analysis.
We concluded that there is a correlation between the
ability of platinum complexes to induce apoptosis and
their antitumor activity.
Physical characterization of starch extrudates as a function of melting transitions and extrusion conditions
Authors: Blanche Stéphanie , Sun Xiuzhi
Published: October 2004

The objective of this study was to investigate the relationships between starch melt transition characteristics, extrusion conditions, and final product properties. Cornstarch was extruded using a corotating twin‐screw extruder at varying moisture content, medium/high screw configuration, and 300/400‐rpm screw speeds. Extrudates were evaluated for bulk density, expansion ratio, cell structure, bending strength, thermal and pasting properties. Temperature change (ΔT) was defined as the temperature difference between the native starch melting temperature and its melt temperature just behind the die during extrusion at a given moisture content. ΔT was significantly affected by starch moisture content and mechanical shearing, which controlled the melting behavior of the starch in the barrel. Amylose–lipid complex formation during extrusion increased as ΔT increased and leveled off at ΔT of about 20°C. Pasting peak viscosity of the starch extrudates decreased as ΔT increased and leveled off at ΔT of about 15°C. Within the same range of mechanical shearing intensity, extrudate bulk density and bending strength decreased linearly as ΔT increased. Extrudate expansion was negatively correlated to bulk density. © 2004 Wiley Periodicals, Inc. Adv Polym Techn 23: 277–290, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20017
Comparison of epoxy resins for applications in light‐emitting diodes
Authors: Huang Jan‐Chan , Chu Ying‐Po , Wei Ming , Deanin Rudolph D.
Published: October 2004

Epoxy resin is a material commonly used for the encapsulation of light‐emitting diodes (LED). Three epoxy resins were chosen in this study: D.E.R.‐331 was a bisphenol A type epoxy resin, Eporite‐5630 was a bisphenol A type epoxy resin modified with a UV stabilizer, and ERL‐4221 was a cyclo‐aliphatic epoxy resin. The curing agent was methyl hexahydrophthalic anhydride (MHHPA), and the catalyst was tetra‐butyl ammonium bromide (TBAB). Thermal, environmental, and optical properties of the cured epoxy resins were studied. It was found that cured ERL‐4221 had better UV resistance, but other properties of ERL‐4221 were lower because of the internal stress generated during the curing process. D.E.R.‐331 showed better thermal stability, but the aromatic groups in the main chains caused sensitivity to photodegradation. Eporite‐5630 had the advantages of D.E.R.‐331 and better UV resistance than D.E.R.‐331 because of the addition of UV stabilizer. Among the three materials, Eporite‐5630 was the best choice of the balance properties for LED applications. This finding may assist in the selection of epoxy resins used in LED technology. © 2004 Wiley Periodicals, Inc. Adv Polym Techn 23: 298–306, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20018
Information asymmetry and the role of traceability systems
Authors: Hobbs Jill E.
Published: October 2004

The role of food traceability systems in resolving information asymmetry is explored. Three functions of traceability systems are identified: ex post reactive systems that allow the traceback of affected products in the event of a contamination problem so as to minimize social costs, ex post systems that facilitate the allocation of liability, and information systems that provide ex ante quality verification. A taxonomy of traceability systems illustrates the multidimensional nature of the information problems related to food safety and food quality. A model of ex ante quality verification and ex post traceability systems is used to demonstrate the different functions and incentives of a traceability system. Finally, examples of private sector and regulatory traceability initiatives are discussed within the context of the ex post and ex ante models developed in the paper. [EconLit citations: Q130; Q180; L150.] © 2004 Wiley Periodicals, Inc. Agribusiness 20: 397–415, 2004.
Assessing the efficiency of exchange rate‐linked subsidies (ERLS) for non‐price export promotion: The case of cotton
Authors: Paudel Laxmi , Adhikari Murali , Houston Jack E. , Kinnucan Henry W.
Published: October 2004

Notwithstanding substantial federal financial support for the export promotion of agricultural products, ways to enhance the effectiveness of federal funding have not been discussed in empirical research. In this study, an equilibrium displacement framework was developed to evaluate whether the efficacy of export promotion expenditures could be increased by linking them with changes in the exchange rate. In our analysis, the gross gain to domestic cotton producers from the exchange rate linked subsidy scheme was positive. Findings support exchange rate linked subsidies for export promotion of agricultural products. [EconLit citations: Q110, Q130.] © 2004 Wiley Periodicals, Inc. Agribusiness 20: 481–493, 2004.
Logistics and supply chain strategies in grain exporting
Authors: Wilson William W. , Carlson Donald C.E. , Dahl Bruce L.
Published: October 2004

The grain shipping industry is highly competitive and has become technically advanced during the past decade. These changes, along with the introduction of innovative shipping mechanisms, have made logistics management an important source of opportunity and risk for grain shippers. A stochastic simulation model was developed to evaluate tradeoffs and effects of key variables on logistical costs in the grain supply chain for an individual firm. Average demurrage for the supply chain was $2.14 million ($0.70/mt or 1.8 cent/bu) with the highest demurrage costs for vessels and lowest for railcars. Of the random variables modeled, unexpected changes in export demand had the greatest impact on costs. [EconLit citation: Q130.] © 2004 Wiley Periodicals, Inc. Agribusiness 20: 449–464, 2004.
Calcium pump disorders of the skin
Authors: Foggia Lucie , Hovnanian Alain
Published: October 2004

The causes of Darier disease (DD) and Hailey–Hailey disease (HHD) have eluded clinicians and scientists for more than 60 years. DD is characterized by loss of adhesion between suprabasal epidermal cells associated with abnormal keratinization, while loss of epidermal cell‐to‐cell adhesion is predominant in HHD. The genes for both conditions have recently been identified using candidate positional cloning approaches. The gene for DD (ATP2A2) encodes a calcium transport ATPase of the sarco (endo)plasmic reticulum (SERCA2) Verboomen et al. [1992: Biochem J 286(Pt 2):591–595], while the gene for HHD (ATP2C1) codes for a secretory pathway for calcium and manganese transport ATPase of the Golgi apparatus (SPCA1) Hu et al. [2000: Nat Genet 24:61–65]. These results have provided completely new insights into the role of calcium and/or manganese in maintaining skin integrity. Although the precise disease mechanisms remain to be understood, these discoveries open a new field in research for the understanding and the treatment of these distressing disorders. © 2004 Wiley‐Liss, Inc.
Molecular genetics of hereditary hair and nail disease
Authors: van Steensel M.A.M. , van Geel M. , Steijlen P.M.
Published: October 2004

Hair and nail development have many similarities and are likely to share many developmental pathways. This is evident from the ectodermal dysplasias that affect both appendages. Of special interest are syndromic disorders as they show the effects of disturbances in molecular pathways that are essential for normal embryonic development. In this review, recent results from studies of syndrome affecting hair and nail development will be discussed. © 2004 Wiley‐Liss, Inc.
Progress in epidermolysis bullosa: Genetic classification and clinical implications
Authors: Uitto Jouni , Richard Gabriele
Published: October 2004

Epidermolysis bullosa (EB), a heterogenous group of genodermatoses, is characterized by fragility and blistering of the skin associated with extracutaneous manifestations. Based on clinical severity, constellation of the phenotypic manifestations, and the level of tissue separation within the cutaneous basement membrane zone (BMZ), EB has been divided into distinct subcategories. Traditionally, these include the simplex, junctional, and dystrophic forms of EB, and recently attention has been drawn to hemidesmosomal variants demonstrating tissue separation at the level of the hemidesmosomes. Specific mutations in ten distinct genes expressed within the cutaneous BMZ have been delineated in >500 families with different variants of EB. The types of mutations, their positions along the affected genes, and their consequences at the mRNA and protein levels provide explanation for the phenotypic variability and genetic heterogeneity of this group of genodermatoses. Elucidation of mutations in different forms of EB has direct translational applications for improved diagnosis and molecularly based classification with prognostic implications as well as for genetic counseling and DNA‐based prenatal testing in families with EB. © 2004 Wiley‐Liss, Inc.
Zwischenmolekulare Wechselwirkungen in Lösung: eine vereinfachende Quantifizierungsmethode
Authors: Hunter Christopher A.
Published: October 2004

Molekulare Erkennungsvorgänge in Lösung werden von vielen Faktoren beeinflusst. Dies hat bisher verhindert, dass die zwischenmolekularen Wechselwirkungen auf einer quantitativen Ebene verstanden werden. Unser gegenwärtiger Ansatz besteht darin, diese Effekte phänomenologisch in einzelne Wechselwirkungen aufzuteilen, sie zu klassifizieren, zu benennen und dann getrennt zu behandeln: aromatische Wechselwirkungen, Kation‐π‐Wechselwirkungen, CH‐O‐Wasserstoffbrücken und hydrophobe Wechselwirkungen sind einige Beispiele.1 Um hier Fortschritte zu erzielen, braucht es einen integrierten quantitativen Ansatz zur Bestimmung des relativen Ausmaßes der Wechselwirkungen, die das molekulare Erkennungsverhalten eines gegebenen Systems beeinflussen können. Hierzu wurde ein Modell entwickelt, das die theoretischen Ansätze und experimentellen Ergebnisse zu zwischenmolekularen Wechselwirkungen in der Gasphase, im festen Zustand und in Lösung stark vereinfacht beschreibt. Ziel ist es, eine halbquantitative thermodynamische Rangfolge dieser Effekte in Lösung bei Raumtemperatur zu erstellen.
Quantifying Intermolecular Interactions: Guidelines for the Molecular Recognition Toolbox
Authors: Hunter Christopher A.
Published: October 2004

Molecular recognition events in solution are affected by many different factors that have hampered the development of an understanding of intermolecular interactions at a quantitative level. Our tendency is to partition these effects into discrete phenomenological fields that are classified, named, and divorced: aromatic interactions, cation–π interactions, CHO hydrogen bonds, short strong hydrogen bonds, and hydrophobic interactions to name a few.1 To progress in the field, we need to develop an integrated quantitative appreciation of the relative magnitudes of all of the different effects that might influence the molecular recognition behavior of a given system. In an effort to navigate undergraduates through the vast and sometimes contradictory literature on the subject, I have developed an approach that treats theoretical ideas and experimental observations about intermolecular interactions in the gas phase, the solid state, and solution from a single simplistic viewpoint. The key features are outlined here, and although many of the ideas will be familiar, the aim is to provide a semiquantitative thermodynamic ranking of these effects in solution at room temperature.
Glucose oxidase electrodes of poly(o‐anisidine), poly(o‐toluidine), and their copolymer as biosensors: A comparative study
Authors: Borole D. D. , Kapadi U. R. , Mahulikar P. P. , Hundiwale D. G.
Published: October 2004

Thin films of poly(o‐anisidine) (POA), poly(o‐toluidine) (POT), and their copolymer poly(o‐anisidine‐co‐o‐toluidine) (POA‐co‐POT) were electropolymerized in solutions containing 0.1M monomer(s) and 1M H2SO4 as an electrolyte through the application of a sequential linear potential scanning rate of 50 mV/s between −0.2 and 1.0 V versus an Ag/AgCl electrode on a platinum electrode. A simple technique was used to construct glucose sensors through the entrapment of glucose oxidase (GOD) in thin films of POA, POT, and their copolymer POA‐co‐POT, which were electrochemically deposited on a platinum plate in phosphate and acetate buffers. The maximum current response was observed for POA, POT, and POA‐co‐POT GOD electrodes at pH 5.5 and at a potential of 0.60 V (vs Ag/AgCl). The phosphate buffer yielded a fast response in comparison with the acetate buffer in amperometric measurements. The POT GOD electrode showed a fast response and was followed by POA‐co‐POT and POA GOD electrodes. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1877–1884, 2004
Numerische Simulation der zeitlich variierenden Konzentration in statischen Mischern
Authors: Sulzer S. , Fleischli M.
Published: October 2004

No abstracts.
Einfache Vorhersagemethode zur Bestimmung der thermophysikalischen Eigenschaften von binären Kältemittelgemischen aus R125 + R143a
Authors: Fröba A. P. , Leipertz A. , Kremer H.
Published: October 2004

No abstracts.
Filmbildung bei der Entfeuchtung im Zentrifugalfeld
Authors: Stiborsky M. , Stahl W.
Published: October 2004

No abstracts.
Kinetik unerwünschter Agglomerationsprozesse bei der Lagerung und Verarbeitung amorpher Lebensmittelpulver
Authors: Palzer S. , Zürcher U.
Published: October 2004

No abstracts.
Fließeigenschaften feinstdisperser, gesättigter Haufwerke während ihrer Kompression im Zentrifugalfeld
Authors: Erk A. , Anlauf H. , Stahl W.
Published: October 2004

No abstracts.
Over‐expression of the p110β but not p110α isoform of PI 3‐kinase inhibits motility in breast cancer cells
Authors: Yip Shu‐Chin , El‐Sibai Mirvat , Hill Karen M. , Wu Haiyan , Fu Zheng , Condeelis John S. , Backer Jonathan M.
Published: October 2004

Phosphoinositide 3‐kinase (PI 3‐kinase) activity is required for growth factor‐induced cytoskeletal regulation and cell migration. We previously found that in MTLn3 rat adenocarcinoma cells, EGF‐stimulated induction of actin barbed ends and lamellipod extension specifically requires the p85/p110α isoform of PI 3‐kinase. To further characterize signaling by distinct PI 3‐kinase isoforms, we have developed MTLn3 cells that transiently or stably overexpress either p110α or p110β. Transient overexpression of p110β inhibited EGF‐stimulated lamellipod extension, whereas p110α‐transfected cells showed normal EGF‐stimulated lamellipod extension. Similar results were obtained by overexpression of kinase‐dead p110β, suggesting that effects on cytoskeletal signaling were due to competition with p85/p110α complexes. Stable overexpression of p110α appeared to be toxic, based on the difficulty in obtaining stable overexpressing clones. In contrast, cells expressing a 2‐fold increase in p110β were readily obtainable. Interestingly, cells stably expressing p110β showed a marked inhibition of EGF‐stimulated lamellipod extension. Using computer‐assisted analysis of time‐lapse images, we found that overexpression of p110β caused a nearly complete inhibition of motility. Cells overexpressing p110β showed normal activation of Akt and Erk, suggesting that overall PI 3‐kinase signaling was intact. A chimeric p110 molecule containing the p85‐binding and Ras‐binding domains of p110α and the C2, helical, and kinase domains of p110β, was catalytically active yet also inhibited EGF‐stimulated lamellipod extension. These data highlight the differential signaling by distinct p110 isoforms. Identification of effectors that are differently regulated by p110α versus p110β will be important for understanding cell migration and its role in metastasis. Cell Motil. Cytoskeleton 59:180–188, 2004. © 2004 Wiley‐Liss, Inc.
Rho expression and activation in vascular smooth muscle cells
Authors: Worth Nathalie F. , Campbell Gordon R. , Campbell Julie H. , Rolfe Barbara E.
Published: October 2004

Phenotypic modulation of smooth muscle cells (SMC) involves dramatic changes in expression and organization of contractile and cytoskeletal proteins, but little is known of how this process is regulated. The present study used a cell culture model to investigate the possible involvement of RhoA, a known regulator of the actin cytoskeleton. In rabbit aortic SMC seeded into primary culture at moderate density, Rho activation was high at two functionally distinct time‐points, first as cells modulated to the “synthetic” phenotype, and again upon confluence and return to the “contractile” phenotype. Rho expression increased with time, such that maximal expression occurred upon return to the contractile state. Transient transfection of synthetic state cells with constitutively active RhoA (Val14RhoA) caused a reduction in cell size and reorganization of cytoskeletal proteins to resemble that of the contractile phenotype. Actin and myosin filaments were tightly packed and highly organised while vimentin localised to the perinuclear region; focal adhesions were enlarged and concentrated at the cell periphery. Conversely, inhibition of endogenous Rho by C3 exoenzyme resulted in complete loss of contractile filaments without affecting vimentin distribution; focal adhesions were reduced in size and number. Treatment of synthetic state SMC with known regulators of SMC phenotype, heparin and thrombin, caused a modest increase in Rho activation. Long‐term confluence and serum deprivation induced cells to return to a more contractile phenotype and this was augmented by heparin and thrombin. The results implicate RhoA for a role in regulating SMC phenotype and further show that activation of Rho by heparin and thrombin correlates with the ability of these factors to promote the contractile phenotype. Cell Motil. Cytoskeleton 59:189–200, 2004. © 2004 Wiley‐Liss, Inc.
Rapid detection of phosphotyrosine proteins by flow cytometric analysis in Bcr‐Abl–positive cells
Authors: Desplat Vanessa , Lagarde Valérie , Belloc Francis , Chollet Claudine , Leguay Thibaut , Pasquet Jean‐Max , Praloran Vincent , Mahon François‐Xavier
Published: October 2004

Background

Constitutive tyrosine phosphorylation derived from Bcr‐Abl kinase activity is the major characteristic of Bcr‐Abl positive cells. In this study, we developed a method to detect the phosphotyrosine proteins by flow cytometry and we asked whether phosphorylation was affected by imatinib mesylate treatment.

Methods

Cells were treated or not with imatinib mesylate, fixed and permeabilized by PFA followed by saponin, then stained with anti‐phosphotyrosine (p‐tyr) monoclonal antibody and analyzed by flow cytometry.

Results

Optimal staining parameters were performed with p‐tyr antibody using K562 and LAMA84 lines that displayed high levels of tyrosine phosphorylation as compared to the control line, HL60. Tyrosine phosphorylation was inhibited by imatinib in a dose‐dependent manner, but not modified by other inhibitors demonstrating that the staining detected is specific to Bcr‐Abl phosphorylation. The staining of imatinib‐resistant cell lines such as the mutated BaF/Bcr‐AblT315I cell line or resistant CML patient cells, showed that hyperphosphorylation was not affected by imatinib treatment. In one CML patient, our technique permitted us to detect a small hyperphosphorylated population resistant to imatinib that appeared hyperphosphorylated and amplified at the time of relapse.

Conclusions

We have developed a flow cytometric technique presenting several advantages such as rapidity and sensitivity, which requires fewer cells than the Western blot. © 2004 Wiley‐Liss, Inc.
Calibration and validation of confocal spectral imaging systems
Authors: Lerner Jeremy M. , Zucker Robert M.
Published: October 2004

Background

Confocal spectral imaging (CSI) microscopic systems currently on the market delineate multiple fluorescent proteins, labels, or dyes within biological specimens by performing spectral characterizations. However, some CSI systems have been found to present inconsistent spectral profiles of reference spectra within a particular system and between related and unrelated instruments. This variability confirms that there is a need for a standardized, objective calibration and validation protocol.

Methods

Our protocol uses an inexpensive multi‐ion discharge lamp (MIDL) that contains Hg+, Ar+, and inorganic fluorophores that emit distinct, stable, spectral features in place of a sample. We derived reference spectra from the MIDL data to accurately predict the spectral resolution, ratio of wavelength to wavelength, contrast, and aliasing parameters of any CSI system. We were also able to predict and confirm the influence of pinhole diameter on spectral profiles.

Results

Using this simulation, we determined that there was good agreement between observed and theoretical expectations, thus enabling us to identify malfunctioning subsystems. We examined eight CSI systems and one nonconfocal spectral system, all of which displayed spectral inconsistencies. No instrument met its optimal performance expectations. In two systems, we established the need for factory realignment that had not been otherwise recognized.

Conclusions

We found that using a primary light source that emits an absolute standard “reference spectrum” enabled us to diagnose instrumental errors and measure accuracy and reproducibility under normalized conditions. With this information, a CSI operator can determine whether a CSI system is working optimally and make objective comparisons with the performance of other CSI systems. We determined that, if CSI systems were standardized to produce the same spectral profile of a MIDL lamp, researchers could be confident that the same experimental findings would be obtained on any CSI system. © 2004 Wiley‐Liss, Inc.
Human T‐lymphotropic virus type‐1 related adult T‐cell leukemia/lymphoma presenting as a parotid mass diagnosed by fine‐needle aspiration biopsy
Authors: Tong Guo‐Xia , Hernandez Osvaldo , Yee Herman T. , Zheng Shyun‐Hua , Yang Grace C.H.
Published: October 2004

A 48‐yr‐old black woman with a history of blood transfusions for menorrhagia secondary to uterine fibroids but no known Caribbean association presented with a 6‐wk history of a rapidly enlarging right parotid mass. At the time of presentation, she could not close her right eye. An aspiration biopsy showed small, medium, and large lymphoma cells with angulated nuclei, red macronucleoli, and basophilic cytoplasm with fine vacuoles. Flow cytometry indicated a (CD25+/CD7−) T‐cell lineage, suggesting an human T‐lymphotropic virus (HTLV) 1‐related T‐cell leukemia/lymphoma, which was confirmed by polymerase chain reaction (PCR)‐based amplification on DNA extracted from fresh tissue with specific oligonucleotide primers for HTLV‐1 DNA sequence. Histology showed interstitial infiltration and destruction of the parotid parenchyma by lymphoma cells without involvement of adjacent lymph nodes. Total body CT scan and magnetic resonance imaging (MRI) studies were negative for lymphadenopathy but showed liver metastasis. To our knowledge, this is the first reported case of HTLV‐1‐related primary parotid lymphoma as the initial presentation of adult T‐cell leukemia/lymphoma. Diagn. Cytopathol. 2004;31:333–337. © 2004 Wiley‐Liss, Inc.
Erratum: Synthesis of facial caricature using eigenspaces
Authors: Xu GuangZhe , Kaneko Masahide , Kurematsu Akira
Published: October 2004

A facial caricature expresses features of an individual face compactly and effectively. It is used in newspapers, magazines, home pages, and also used to represent an anthropomorphic agent and so on. This paper presents a method of synthesizing a caricature having higher flexibility in controlling individual shape features of various parts of a face, as well as features of arrangements and inclines of these parts. Firstly, an eigenspace is calculated for contour shape of each facial part such as the eyebrows, eyes, and mouth. In addition, an eigenspace for arrangements of various facial parts is obtained. Next, differences of the shapes and arrangements of the facial parts with the average face are calculated and then the orthogonal expansion to the basis vectors (eigenvectors) is carried out on these differences. Magnifying powers are determined according to the coefficients obtained by the orthogonal expansion and an emphasizing procedure is performed on eigenvectors. The difference between the slope of each facial part of the average face and that of an input face is emphasized using a quadratic function. A final caricature can be obtained by adding the average shape, average arrangement and average slope to these results. The effectiveness of the proposed caricature synthesis method is verified by subjective evaluation tests on synthesized facial caricatures. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 88(2): 65–76, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20088
Improvement of levitation characteristics in a magnetic bearing system using HTSC‐permanent magnet hybrid structure
Authors: Ohashi Shunsuke
Published: October 2004

Magnetic bearing using pinning force of a permanent magnet and a high‐temperature superconductor has been developed. Additional permanent magnet is introduced to increase the levitation force of the magnetic bearing. In this hybrid magnetic bearing system, levitation force is mainly given by the repulsive force of the permanent magnets, and stability for the lateral direction is given by pinning force of the superconductor.

The experimental device is developed. A ring‐type superconductor and a bulk one are examined. Levitation characteristics of the hybrid magnetic bearing are measured. The bulk superconductor shows better characteristics of both levitation and lateral stability than the ring one. Levitation force of the hybrid system becomes about twice as large as that of the nonhybrid one. Although, the repulsive force of the permanent magnet decreases the lateral stability of the system, its influence becomes small by choosing an adequate position of the permanent magnets and the superconductor. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 150(1): 71–77, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10350
A vision of an electric power architecture for the next generation
Authors: Matsumoto Yoshihiko , Yanabu Satoru
Published: October 2004

Since the present hierarchical power grid structure and AC interface are mature and rigid, a new electric power system architecture is proposed here to save the earth by making use of renewable energy sources. The architecture consists of a new concept and a historical technology, that is, a network of many “electric clusters” with a DC interface. The cluster includes dispersed electric power generators, electric appliances, electric storage, and “electric power routers.” The router is equipment to resourcefully route electrical energy between neighboring clusters and to manage electrical energy in the cluster. The transfers of electrical energy (between clusters and within clusters) and the generation of electricity from renewal energy sources (such as sunlight, wind, tides, and biogas) are intermittent and have very wide dynamic ranges, so that the interface must make use of DC. When we achieve an energy society with this architecture, we will be able to reduce energy consumption, greenhouse gas emissions, and materials use. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 150(1): 18–25, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20039
PTEN permits acute increases in D3‐phosphoinositide levels following TCR stimulation but inhibits distal signaling events by reducing the basal activity of Akt
Authors: Seminario Maria‐Cristina , Precht Patricia , Bunnell Stephen C. , Warren Sarah E. , Morris Christa M. , Taub Dennis , Wange Ronald L.
Published: October 2004

Phosphoinositide 3‐kinase (PI3K) is important in TCR signaling. PI3K generates phosphatidylinositol 3, 4, 5‐trisphosphate (PI‐3,4,5‐P3), which regulates membrane localization and/or activity of multiple signaling proteins. PTEN (phosphatase and tensin homologue deleted on chromosome 10) opposes PI3K, reversing this reaction. Maintaining the balance between these two enzymes is important for normal T cell function. Here we use the PTEN‐null Jurkat T cell line to address the role of PTEN in modulating proximal and distal TCR‐signaling events. PTEN expression at levels that restored low basal Akt phosphorylation (an indicator of PI‐3,4,5‐P3 levels), but which were not themselves cytotoxic, had minimal effect on TCR‐stimulated activation of phospholipase Cγ1 and Ca2+ flux, but reduced the duration of extracellular signal‐regulated kinase (Erk) activation. Distal signaling events, including nuclear factor of activated T cells (NFAT) activation, CD69 expression and IL‐2 production, were all inhibited by PTEN expression. Notably, PTEN did not block TCR‐stimulated PI‐3,4,5‐P3 accumulation. The effect of PTEN on distal TCR signaling events was strongly correlated with the loss of the constitutive Akt activation and glycogen synthase kinase‐3 (GSK3) inhibition that is typical of Jurkat cells, and could be reversed by expression of activated Akt or pharmacologic inhibition of GSK3. These results suggest that PTEN acts in T cells primarily to control basal PI‐3,4,5‐P3 levels, rather than opposing PI3K acutely during TCR stimulation.
A new species of BomareaMirbel, subgenus Wichuraea (M.Roem.) Baker (Alstroemeriaceae)
Authors: Hofreiter A.
Published: October 2004

The subgenus Wichuraea of Bomarea (Alstroemeriaceae) was recently revised by Hofreiter & Tillich (2003). A new species, Bomarea peruviana Hofreiter, sp. nova, was col‐lected by Weigend et al. in Peru in the Departments Ancash and Cajamarca. The new species belongs to the Glaucescens (Northern) group within Wichuraea. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Functional principal component analysis of fMRI data
Authors: Viviani Roberto , Grön Georg , Spitzer Manfred
Published: October 2004

We describe a principal component analysis (PCA) method for functional magnetic resonance imaging (fMRI) data based on functional data analysis, an advanced nonparametric approach. The data delivered by the fMRI scans are viewed as continuous functions of time sampled at the interscan interval and subject to observational noise, and are used accordingly to estimate an image in which smooth functions replace the voxels. The techniques of functional data analysis are used to carry out PCA directly on these functions. We show that functional PCA is more effective than is its ordinary counterpart in recovering the signal of interest, even if limited or no prior knowledge of the form of hemodynamic function or the structure of the experimental design is specified. We discuss the rationale and advantages of the proposed approach relative to other exploratory methods, such as clustering or independent component analysis, as well as the differences from methods based on expanded design matrices. Hum Brain Mapp 24:109–129, 2005. © 2004 Wiley‐Liss, Inc.
Role of PRIP‐1, a novel Ins(1,4,5)P3 binding protein, in Ins(1,4,5)P3‐mediated Ca2+ signaling
Authors: Harada Kae , Takeuchi Hiroshi , Oike Masahiro , Matsuda Miho , Kanematsu Takashi , Yagisawa Hitoshi , Nakayama Kei‐ichi I. , Maeda Katsumasa , Erneux Christophe , Hirata Masato
Published: October 2004

PRIP‐1 was isolated as a novel inositol 1,4,5‐trisphosphate [Ins(1,4,5)P3] binding protein with a domain organization similar to phospholipase C‐δ1 (PLC‐δ1) but lacking the enzymatic activity. Further studies revealed that the pleckstrin homology (PH) domain of PRIP‐1 is the region responsible for binding Ins(1,4,5)P3. In this study we aimed to clarify the role of PRIP‐1 at the physiological concentration in Ins(1,4,5)P3‐mediated Ca2+ signaling, as we had previously used COS‐1 cells overexpressing PRIP‐1 (Takeuchi et al., 2000, Biochem J 349:357–368). For this purpose we employed PRIP‐1 knock out (PRIP‐1−/−) mice generated previously (Kanematsu et al., 2002, EMBO J 21:1004–1011). The increase in free Ca2+ concentration in response to purinergic receptor stimulation was lower in primary cultured cortical neurons prepared from PRIP‐1−/− mice than in those from wild type mice. The relative amounts of [3H]Ins(1,4,5)P3 measured in neurons labeled with [3H]inositol was also lower in cells from PRIP‐1−/− mice. In contrast, PLC activities in brain cortex samples from PRIP‐1−/− mice were not different from those in the wild type mice, indicating that the hydrolysis of Ins(1,4,5)P3 is enhanced in cells from PRIP‐1−/− mice. In vitro analyses revealed that type1 inositol polyphosphate 5‐phosphatase physically interacted with a PH domain of PRIP‐1 (PRIP‐1PH) and its enzyme activity was inhibited by PRIP‐1PH. However, physical interaction with these two proteins did not appear to be the reason for the inhibition of enzyme activity, indicating that binding of Ins(1,4,5)P3 to the PH domain prevented its hydrolyzation. Together, these results indicate that PRIP‐1 plays an important role in regulating the Ins(1,4,5)P3‐mediated Ca2+ signaling by modulating type1 inositol polyphosphate 5‐phosphatase activity through binding to Ins(1,4,5)P3. © 2004 Wiley‐Liss, Inc.
Corticotropin‐releasing hormone induces keratinocyte differentiation in the adult human epidermis
Authors: Zbytek Blazej , Slominski Andrzej T.
Published: October 2004

Previously we documented that human epidermis exclusively expresses corticotropin releasing hormone receptor 1 (CRH‐R1). To define the role of CRH in the epidermis, we investigated its effects on differentiation of normal human adult epidermal keratinocytes. Thus, CRH inhibited proliferation in a dose dependent fashion and significantly decreased Ki‐67 antigen expression. This effect was independent of either the presence or the absence of growth factors in the medium. Flow cytometry analysis demonstrated that CRH inhibited the transition from G0/1 to S phase of the cell cycle, which was accompanied by an increased expression of cdk inhibitor p16 (Ink4a) protein. The antiproliferative effect was attenuated by protein kinase C inhibitor (GF109203X) but not by H89 (protein kinase A inhibitor), PD98059, or SB203580 (MAP kinase inhibitors). The cell cycle withdrawal was associated with the induction of keratinocyte differentiation. Thus, CRH stimulated the expression of cytokeratin 1 and involucrin, and inhibited cytokeratin 14 on both mRNA and protein levels. It also increased cell granularity and cell size. Furthermore, CRH induced signal transduction cascade that included stimulation of inositol 1,4,5‐triphosphate, which was time and dose dependent. CRH also increased activator protein‐1 DNA binding activity with JunD identified as the most important element. Thus, activation of CRH‐R1 induces a non‐random and sequential signal transduction cascade governing both keratinocyte differentiation and the inhibition of cell proliferation through G0/1 arrest. We propose that this program, triggered by CRH interaction with CRH‐R1, includes induction of a transduction pathway involving the sequential activation of phospholipase C, protein kinase C, activator protein‐1 (including Jun D), and p16. © 2004 Wiley‐Liss, Inc.