bluuebunny/crossref_metadata_2025 huggingface dataset:
Recent Results of ψ(2S) Decays from BES
Authors:   For the BES Collaboration., Wang Zheng
Published: March 2006

Results of many ψ(2S) hadronic decays and the results of ψ(2S) radiative/hadronic transitions from BES collaboration in the past year are presented. Measurement of [Formula: see text] and the preliminary result of searching for the decay ψ(3770) → ρπ are also reported.
MULTI-QUARK COMPONENTS IN BARYONS
Authors: Zou B. S.
Published: March 2006

A brief review on some recent progresses in our understanding of multi-quark components in baryons is presented. The multi-quark components in baryons seem to be mainly in colored quark cluster configurations rather than in "meson cloud" configurations or in the form of a sea of quark-antiquark pairs. The colored quark cluster multi-quark picture gives a natural explanation of empirical indications for a positive strangeness magnetic moment μs of the proton and the longstanding mass-reverse problem of S11(1535) and P11(1440) N* resonances. A model-prediction for the μs of the proton is given.
Recent Results on J/ψ Decays from BESII
Authors:   For the BES Collaboration., Fang Shuangshi
Published: March 2006

The new observation of X(1835) is reported using 58 million J/ψ events collected at BES II detector. We also present the measurements of J/ψ and ηc decays, of them some are the first measurements and some improve the precision in previous measurements.
TWO PARTICLE STATES IN A BOX AND THE S-MATRIX IN MULTI-CHANNEL SCATTERING
Authors: LIU CHUAN , FENG XU , HE SONG
Published: March 2006

Using a quantum mechanical model, the exact energy eigenstates for two-particle two-channel scattering are studied in a cubic box with periodic boundary conditions. A relation between the exact energy eigenvalue in the box and the two-channel S-matrix elements in the continuum is obtained. This result can be viewed as a generalization of the well-known Lüscher's formula which establishes a similar relation in elastic scattering.
CHIRAL SYMMETRY BREAKING AT NONZERO CHEMICAL POTENTIAL
Authors: Osborn J. C. , Splittorff K. , Verbaarschot J. J. M.
Published: March 2006

We consider chiral symmetry breaking at nonzero chemical potential and discuss the relation with the spectrum of the Dirac operator. We solve the so called Silver Blaze Problem that the chiral condensate at zero temperature does not depend on the chemical potential while this is not the case for the Dirac spectrum and the weight of the partition function.
The Kaon B-parameter in quenched QCD
Authors:   ALPHA-collaboration., SINT STEFAN
Published: March 2006

I report on a recent determination by the ALPHA collaboration of the kaon B-parameter using lattice QCD with Wilson type quarks. An effort is made to control all systematic errors except for the quenched approximation. The preliminary result for the renormalization group invariant parameter is [Formula: see text], which translates to [Formula: see text] in the [Formula: see text] scheme with anticommuting γ5.
LATTICE QCD AT NON-ZERO TEMPERATURE AND DENSITY WITH WILSON AND NEUBERGER QUARKS
Authors: LUO XIANG-QIAN , CHEN HE-SHENG , WU LIANG-KAI , YU XIAO-LU
Published: March 2006

We study lattice QCD at finite temperature and density with two flavors of Wilson quarks and overlap quarks. Transitions do appear at extreme conditions.
The 1/Nc Approach for Baryon Resonances
Authors: Lebed Richard F.
Published: March 2006

I give a brief overview of the model-independent analysis of unstable baryon resonances in the 1/Nc QCD expansion. This approach produces numerous surprising semi-quantitative phenomenological predictions that are supported by available observations.
BARYON CHIRAL PERTURBATION THEORY IN MANIFESTLY LORENTZ-INVARIANT FORM
Authors: SCHERER STEFAN
Published: March 2006

A successful effective field theory program requires besides the most general effective Lagrangian a perturbative expansion scheme for observables in terms of a consistent power counting method. We discuss a renormalization scheme for manifestly Lorentz-invariant baryon chiral perturbation theory generating a simple and consistent power counting for renormalized diagrams. The approach may be used in an iterative procedure to renormalize higher-order loop diagrams and also allows for implementing a consistent power counting when vector mesons are explicitly included.
Renormalization of the EWCL and its Application to LEP2
Authors: Yan Qi-Shu
Published: March 2006

We perform a systematic one-loop renormalization on the electroweak chiral Lagrangian (EWCL) up to O(p4) operators and construct the renormalization group equations (RGE) for the anomalous couplings. We examine the impact of the triple gauge coupling (TGC) measurement from LEP2 to the uncertainty of the S–T parameter at the Λ = 1TeV, and find that the uncertainty in the TGC measurements can shift S(Λ) at least 3.3σ.
Ds Asymmetry in Photoproduction
Authors: Hao Gang , Li Lin , Qiao Cong-Feng
Published: March 2006

By adopting two models of strange and antistrange quark distributions inside nucleon, the light-cone meson-baryon fluctuation model and the effective chiral quark model, we calculate the [Formula: see text] asymmetry in photoproduction in the framework of heavy-quark recombination mechanism. We find that the effect of asymmetry of strange sea to the Ds asymmetry is considerable and depending on the different models. Therefore, we expect that with the further study in electroproduction, e.g. at HERA and CEBAF, the experimental measurements on the [Formula: see text] asymmetry may impose a strong restriction on the strange-antistrange distribution asymmetry models.
T VIOLATION IN BARYONIC B DECAYS
Authors: GENG C. Q. , HSIAO Y. K.
Published: March 2006

We study T violation in the three-body charmless baryonic decay of [Formula: see text] through the T-odd triple product correlation in the standard model. We find that the T violating asymmetry is 10%, which is accessible to the current B factories at KEK and SLAC, while the CP violating one 1.1%. We emphasize that this triple product correlation would be the first measurable direct T violating effect predicted in the standard model.
On the Chiral Quark Condensate at Finite Chemical Potential
Authors: Liu Yuxin , Chang Lei , Chen Huan , Wang Bin
Published: March 2006

We analyze the variation behavior of chiral quark condensates in vacuum and in strong interacting matter against the parameters in the effective gluon propagators in Dyson-Schwinger equation approach. The obtained results indicate that the quark confinement enhances the quark condensate, and the screening of the confinement suppresses the response of the condensate to the chemical potential.
QT RESUMMATION IN TRANSVERSELY POLARIZED DRELL-YAN PROCESS
Authors: KAWAMURA HIROYUKI , KODAIRA JIRO , SHIMIZU HIROTAKA , TANAKA KAZUHIRO
Published: March 2006

We calculate QCD corrections to transversely polarized Drell-Yan process at a measured QT of the produced lepton pair in the dimensional regularization scheme. The QT distribution is discussed resumming soft gluon effects relevant for small QT.
INCLUSIVE PRODUCTION OF FOUR CHARM HADRONS AT B-FACTORIES
Authors: Kang Daekyoung , Lee Jungil
Published: March 2006

Measurements by the Belle Collaboration of the exclusive J/ψ + ηc and inclusive [Formula: see text] productions in e+e- annihilation differ substantially from theoretical predictions based on the nonrelativistic QCD factorization approach. In order to test if such a discrepancy is originated from the large perturbative corrections to the hard-scattering amplitude, we study inclusive production of four charm hadrons in e+e- annihilation at B factories.
HADRON TOMOGRAPHY
Authors: BURKARDT MATTHIAS
Published: March 2006

Generalized parton distributions can be used to obtain information about the dependence of parton distributions on the impact parameter. Potential consequences for T -odd single-spin asymmetries are discussed.
NuTeV ANOMALY VERSUS STRANGE-ANTISTRANGE ASYMMETRY
Authors: MA BO-QIANG
Published: March 2006

We report the correction from the asymmetric strange-antistrange sea of the nucleon by using both the light-cone baryon-meson fluctuation model and the chiral quark model, and show that a significant part of the NuTeV anomaly can be explained by the strange-antistrange asymmetry. We also show that the calculated [Formula: see text] asymmetry are compatible with the NuTeV data by including some additional symmetric [Formula: see text] quark contribution.
A NEW SEARCH STRATEGY FOR THE HIGGS BOSON
Authors: SOFFER JACQUES
Published: March 2006

We propose a novel mechanism for exclusive diffractive Higgs production pp → Hpp, in which the Higgs carries a significant fraction of the projectile proton's momentum. This mechanism will then provide a clear experimental signal for Higgs production, due to the small background in this kinematic region. The key assumption underlying our analysis is the presence of intrinsic charm (IC) and intrinsic bottom (IB) fluctuations in the proton bound state, whose existence, at high light-cone momentum fraction x, has a substantial and growing experimental and theoretical support.
SHADOWING AND ANTISHADOWING IN NEUTRINO DEEP INELASTIC SCATTERING
Authors: SCHMIDT IVAN
Published: March 2006

The coherence of multiscattering quark nuclear processes leads to shadowing and antishadowing of the electromagnetic nuclear structure functions in agreement with measurements. This picture leads to substantially different antishadowing for charged and neutral current processes, particularly in anti-neutrino reactions, thus affecting the extraction of the weak-mixing angle sin 2 θW.
CURRENT ALGEBRA BASED EFFECTIVE CHIRAL THEORY OF MESONS AND A NEW EW THEORY
Authors: Li Bing An
Published: March 2006

A current algebra based effective chiral theory of pseudoscalar, vector, axial-vector mesons is reviewed. A new mechanism generating the masses and guage fixing terms of gauge boson is revealed from this effective theory. A EW theory without Higgs is proposed. The masses and gauge fixing terms of W and Z are dynamically generated. Three heavy scalar fields are dynamically generated too. They are ghosts.
THEORETICAL ASPECTS OF THE PION-PION INTERACTION
Authors: CAPRINI I. , COLANGELO G. , LEUTWYLER H.
Published: March 2006

We give a brief review of the theoretical description of low energy pion-pion scattering by the combined use of Chiral Perturbation Theory and Roy equations, an update of the Regge parametrization of ππ cross sections at high energies, and a short discussion of the scalar radius of the pion.
INVESTIGATION ON OXYGEN-EQUILIBRIUM EFFECTS OF LASER IGNITION OF ENERGETIC MATERIALS
Authors: XIANG SHI-BIAO , XIANG XU , HUA GUANG , CHEN LANG , FENG CHANG-GEN
Published: March 2006

An investigation on oxygen-equilibrium of laser ignition of energetic materials was carried out through experiments. The threshold energy of laser ignition of several systems such as Zr/KClO 4, Ti/KClO 4, and Mg/KClO 4 were measured with different system composition. The results show that the mass ratio of initial mixture powders has a significant effect on the threshold energy of ignition. The threshold energy presents a minimum with increasing mass ratio, which corresponds to an oxygen-rich system composition. That is, an oxygen-rich composition is favorable to laser ignition. The ignition requires lower threshold, or energetic materials have relatively higher laser sensitivity. Also the findings were theoretically analyzed.
FABRICATION OF BaFe12O19 NANOWIRES BY A HYDROTHERMAL PROCESS AND THEIR MAGNETIC PROPERTIES
Authors: WANG JUN , ZHU YUEJIN
Published: March 2006

Magnetic BaFe 12 O 19 nanowires have been prepared by a hydrothermal process. The nanowires with diameters ~ 15 nm and lengths ~ 2 μ m are clearly visible in Transmission Electron Microscopy (TEM) image. The physical properties of the BaFe 12 O 19 nanowires were further characterized by X-ray diffraction (XRD) and magnetization measurement. The results of the magnetization measurement show that the sample displays ferromagnetic properties at room temperature and its saturation magnetization (Ms) reaches 13.36 emu/g. Annealing treatment of the sample in air at 800°C leads to the increasing of the saturation magnetization (Ms: 65.7 emu/g). It is suggested that the oxygen vacancies should be responsible for the low saturation magnetization, which is also supported by the magnetic property (Ms: 21.6 emu/g) of the sample annealed at 800°C in argon shield.
MÖSSBAUER STUDY OF Mg0.9Mn0.1CryFe2-yO4 SPINEL FERRITES
Authors: LAKSHMAN A. , SUBBA RAO P. S. V. , RAO K. H.
Published: March 2006

The effect of the substitution of paramagnetic trivalent chromium ions in stoichiometric magnesium–manganese ferrites has been studied with the composition Mg 0.9 Mn 0.1 Cr y Fe 2-y O 4 where y varies from 0.0, 0.1 to 0.9 in steps of 0.2. The single-phase cubic spinel structure of these samples has been confirmed from X-ray diffraction analyses. Mössbauer spectra of these samples studied at room temperature (300 K) showed two characteristic ferrimagnetic Zeeman sextets for lower concentration of Cr 3+ followed by relaxation phenomenon corresponding to y=0.9. The dependence of Mössbauer parameters, viz. isomer shift, quadrupole splitting, line width and hyperfine magnetic field on Cr 3+ concentration have been discussed. The variation of hyperfine magnetic field with increasing Cr 3+ content has been explained on the basis of Neel's molecular field model.
NONLINEAR NANO-OPTICS OF SURFACE PLASMONS AT THE "PLANCK SCALE"
Authors: SMOLYANINOV IGOR
Published: March 2006

Simple dimensional analysis of typical nonlinear optical phenomena in metal nanoparticles indicates that qualitatively new effects may be expected in nonlinear optics of surface plasmon polaritons. It appears that some of these effects are similar to well-known effects of quantum gravitational theory.
THIRTY-TWO GOLDBACH VARIATIONS
Authors: BORWEIN JONATHAN M. , BRADLEY DAVID M.
Published: March 2006

We give thirty-two diverse proofs of a small mathematical gem — the fundamental Euler sum identity [Formula: see text] We also discuss various generalizations for multiple harmonic (Euler) sums and some of their many connections, thereby illustrating both the wide variety of techniques fruitfully used to study such sums and the attraction of their study.
SUR LA CONJECTURE FAIBLE DE GREENBERG DANS LE CAS ABÉLIEN p-DÉCOMPOSÉ
Authors: THONG NGUYEN QUANG DO
Published: March 2006

Let p be an odd prime. For any CM number field K containing a primitive pth root of unity, class field theory and Kummer theory put together yield the well known reflection inequality λ+ ≤ λ- between the "plus" and "minus" parts of the λ-invariant of K. Greenberg's classical conjecture predicts the vanishing of λ+. We propose a weak form of this conjecture: λ+ = λ- if and only if λ+ = λ- = 0, and we prove it when K+ is abelian, p is totally split in K+, and certain conditions on the cohomology of circular units are satisfied (e.g. in the semi-simple case).
THE QUINTUPLE PRODUCT IDENTITY
Authors: COOPER SHAUN
Published: March 2006

The quintuple product identity was first discovered about 90 years ago. It has been published in many different forms, and at least 29 proofs have been given. We shall give a comprehensive survey of the work on the quintuple product identity, and a detailed analysis of the many proofs.
ON THE DISTRIBUTION OF NONLINEAR CONGRUENTIAL PSEUDORANDOM NUMBERS IN RESIDUE RINGS
Authors: EL-MAHASSNI EDWIN D. , WINTERHOF ARNE
Published: March 2006

The nonlinear congruential method is an attractive alternative to the classical linear congruential method for pseudorandom number generation. In this paper we present a new type of discrepancy bound for sequences of s-tuples of successive nonlinear congruential pseudorandom numbers over a ring of integers ℤM.
A NOTE ON PRIMES IN SHORT INTERVALS
Authors: CHAN TSZ HO
Published: March 2006

Montgomery and Soundararajan obtained evidence for the Gaussian distribution of primes in short intervals assuming a quantitative Hardy–Littlewood conjecture. In this article, we show that their methods may be modified and an average form of the Hardy–Littlewood conjecture suffices.
ON THE THETA SERIES ATTACHED TO $D_{m}^{+}$–LATTICES
Authors: KOHNEN WINFRIED , SALVATI MANNI RICCARDO
Published: March 2006

We show that the theta series attached to the [Formula: see text]-lattice for any positive integer divisible by 8 can be explicitly expressed as a finite rational linear combination of products of two Eisenstein series.
A REMARK ON A PAPER OF AHLGREN, BERNDT, YEE, AND ZAHARESCU
Authors: TAKLOO-BIGHASH RAMIN
Published: March 2006

A classical theorem of Ramanujan relates an integral of Dedekind eta-function to a special value of a Dirichlet L-function at s = 2. Ahlgren, Berndt, Yee and Zaharescu have generalized this result [1]. In this paper, we generalize this result to the context of holomorphic cusp forms on the upper half space.
DIOPHANTINE APPROXIMATION IN $\mathbf{Q}(\sqrt{-5})$ AND $\mathbf{Q}(\sqrt{-6})$
Authors: VULAKH L. YA.
Published: March 2006

The complete description of the discrete part of the Lagrange and Markov spectra of the imaginary quadratic fields with discriminants -20 and -24 are given. Farey polygons associated with the extended Bianchi groups Bd, d = 5, 6, are used to reduce the problem of finding the discrete part of the Markov spectrum for the group Bd to the corresponding problem for one of its maximal Fuchsian subgroup. Hermitian points in the Markov spectrum of Bd are introduced for any d. Let H3 be the upper half-space model of the three-dimensional hyperbolic space. If ν is a hermitian point in the spectrum, then there is a set of extremal geodesics in H3 with diameter 1/ν, which depends on one continuous parameter. This phenomenon does not take place in the hyperbolic plane.
Transforming Growth Factor-β1 Induces Tissue Inhibitor of Metalloproteinase-1 Expression via Activation of Extracellular Signal-Regulated Kinase and Sp1 in Human Fibrosarcoma Cells
Authors: Kwak Hee-Jin , Park Myung-Jin , Cho Hyeyoung , Park Chang-Min , Moon Sang-Ik , Lee Hyung-Chan , Park In-Chul , Kim Mi-Suk , Rhee Chang Hun , Hong Seok-Il
Published: March 2006

The net balance of matrix metalloproteinases (MMP) and tissue inhibitor of metalloproteinases (TIMP) system has been known to be a key factor in tumor cell invasion. In the present study, we investigated the molecular mechanisms of anti-invasive and antimigrative activity of transforming growth factor (TGF)-β1 on HT1080 human fibrosarcoma cells. In in vitro Matrigel invasion and Transwell migration assays, TGF-β1 dose-dependently inhibited the invasion and migration of HT1080 cells, respectively. Gelatin zymography, Western blot, and real-time PCR analysis showed that TGF-β1 enhanced the expression and secretion of MMP-2, TIMP-1, and, to a lesser degree, MMP-9 but not membrane type 1-MMP and TIMP-2. The addition of recombinant TIMP-1 protein reduced the Matrigel invasion and Transwell migration of HT1080 cells, similar to TGF-β1. Because augmentation of TIMP-1 might be the major factor for the anti-invasive and antimigrative activity of TGF-β1, we investigated possible molecular mechanisms responsible for the expression of TIMP-1 induced by TGF-β1. Treatment of HT1080 cells with TGF-β1 rapidly phosphorylated three mitogen-activated protein kinases [MAPK; extracellular signal-regulated kinase 1/2 (ERK1/2), p38, and c-Jun NH2-terminal kinase] and Akt. Among these kinases, the inhibition of only ERK1/2 pathway by PD98059, a specific inhibitor of MAPK/ERK kinase(MEK)-1, and transfection of dominant-negative MEK 1 effectively blocked the TIMP-1 induction by TGF-β1. Mithramycin, a specific inhibitor of Sp1 transcription factor, but not curcumin, an inhibitor of activator protein-1, and transfection of Sp1 small interfering RNA significantly inhibited the TGF-β1-induced expression of TIMP-1. In addition, electrophoretic mobility shift assay showed that TGF-β1 up-regulated Sp1 DNA-binding activity, and PD98059 and mithramycin effectively inhibited these events. Finally, pretreatment of HT1080 cells with PD98059 and mithramycin, but not curcumin, restored the invasive activity of these cells. Taken together, these data suggest that TGF-β1 modulates the net balance of the MMPs/TIMPs the systems in HT1080 cells for anti-invasion and antimigration by augmenting TIMP-1 through ERK1/2 pathway and Sp1 transcription factor. (Mol Cancer Res 2006;4(3):209–20)
ATM Requirement in Gene Expression Responses to Ionizing Radiation in Human Lymphoblasts and Fibroblasts
Authors: Innes Cynthia L. , Heinloth Alexandra N. , Flores Kristina G. , Sieber Stella O. , Deming Paula B. , Bushel Pierre R. , Kaufmann William K. , Paules Richard S.
Published: March 2006

The heritable disorder ataxia telangiectasia (AT) is caused by mutations in the AT-mutated (ATM) gene with manifestations that include predisposition to lymphoproliferative cancers and hypersensitivity to ionizing radiation (IR). We investigated gene expression changes in response to IR in human lymphoblasts and fibroblasts from seven normal and seven AT-affected individuals. Both cell types displayed ATM-dependent gene expression changes after IR, with some responses shared and some responses varying with cell type and dose. Interestingly, after 5 Gy IR, lymphoblasts displayed ATM-independent responses not seen in the fibroblasts at this dose, which likely reflect signaling through ATM-related kinases, e.g., ATR, in the absence of ATM function. (Mol Cancer Res 2006;4(3):197–207)
SSeCKS/Gravin/AKAP12 Metastasis Suppressor Inhibits Podosome Formation via RhoA- and Cdc42-Dependent Pathways
Authors: Gelman Irwin H. , Gao Lingqiu
Published: March 2006

Podosomes are poorly understood actin-rich structures notably found in cancer cell lines or in v-Src-transformed cells that are thought to facilitate some of the invasive properties involved in tumor metastasis. The enrichment of the Tks5/Fish protein, a v-Src substrate, is required for formation of podosomes. We showed previously that the tetracycline-regulated reexpression of the Src-suppressed C kinase substrate (SSeCKS, also known as Gravin/AKAP12) inhibited variables of v-Src-induced oncogenic growth in NIH3T3, correlating with the induction of normal actin cytoskeletal structures and cell morphology but not with gross inhibition of Src phosphorylation activity in the cell. Here, we show that SSeCKS reexpression at physiologic levels suppresses podosome formation, correlating with decreases in Matrigel invasiveness, whereas there is no effect on total cellular tyrosine phosphorylation or on the phosphorylation of Tks5/Fish. Activated forms of RhoA and Cdc42 were capable of rescuing podosome formation in v-Src cells reexpressing SSeCKS, and this correlated with the ability of SSeCKS to inhibit RhoA and Cdc42 activity levels by >5-fold. Interestingly, although activated Rac I had little effect on podosome formation, it could partner with activated RhoA to reverse the cell flattening induced by SSeCKS. These data suggest that v-Src-induced Tks5 tyrosine phosphorylation is insufficient for podosome formation in the absence of RhoA- and/or Cdc42-mediated cytoskeletal remodeling. Additionally, they strengthen the notion that SSeCKS suppresses Src-induced oncogenesis by reestablishing actin-based cytoskeletal architecture. (Mol Cancer Res 2006;4(3):151–8)
Activation of Peroxisome Proliferator-Activated Receptor-γ Decreases Pancreatic Cancer Cell Invasion through Modulation of the Plasminogen Activator System
Authors: Sawai Hirozumi , Liu Joey , Reber Howard A. , Hines Oscar J. , Eibl Guido
Published: March 2006

Cancer cell invasion and metastasis require the concerted action of several proteases that degrade extracellular matrix proteins and basement membranes. Recent reports suggest the plasminogen activator system plays a critical role in pancreatic cancer biology. In the present study, we determined the contribution of the plasminogen activator system to pancreatic cancer cell invasion in vitro. Moreover, the effect of peroxisome proliferator-activated receptor (PPAR)-γ ligands, which are currently in clinical use as antidiabetic drugs and interestingly seem to display antitumor activities, on pancreatic cancer cell invasion and the plasminogen activator system was assessed. Expression of components of the plasminogen activator system [i.e., urokinase-type plasminogen activator (uPA), plasminogen activator inhibitor-1, and uPA receptor] was detected in six human pancreatic cancer cell lines. Inhibition of urokinase activity by specific synthetic compounds reduced baseline pancreatic cancer cell invasion. The PPAR-γ ligands 15-deoxy-Δ12,14-prostaglandin J2 and ciglitazone also attenuated pancreatic cancer cell invasion. This effect was abrogated by dominant-negative PPAR-γ receptors and pharmacologic PPAR-γ inhibitors. Moreover, activation of PPAR-γ by ligands increased plasminogen activator inhibitor-1 and decreased uPA levels in pancreatic cancer cells, and this was accompanied by a reduction in total urokinase activity. The present study shows that the plasminogen activator system plays an integral role in pancreatic cancer cell invasion in vitro. Activation of the nuclear receptor PPAR-γ by ligands reduced pancreatic cancer cell invasion, which was largely mediated by modulation of the plasminogen activator system. These findings further underscore the potential role of PPAR-γ ligands as therapeutic agents in pancreatic cancer. (Mol Cancer Res 2006;4(3):159–67)
The Influence of Age on in vitro Plasmin Generation in the Presence of Fibrin Monomer
Authors: Parmar Nagina , Mitchell Lesley G. , Berry Leslie R. , Andrew Maureen , Chan Anthony K.C.
Published: March 2006

Background and Objectives: The components of the fibrinolytic system interact to generate plasmin from its zymogen form, plasminogen. At birth, all the components of the fibrinolytic system are present but with differing plasma concentrations. The present study was undertaken to explore the effect of physiological, age-dependent factors of the fibrinolytic system during childhood on the capacity to generate plasmin. Design and Methods: Total plasmin generation was measured in venous plasma from umbilical cords and adults, on plastic and cell surfaces, in the presence of fibrin monomer, Desafib. Plasminogen, its inhibitors α2-antiplasmin and plasminogen activator inhibitor type 1, and plasmin-α2-antiplasmin complex in the time samples were assayed by enzyme-linked immunosorbent assay. The effect of addition of plasminogen on the plasmin generation in cord plasma and the effect of lipoprotein on adult and cord plasmin generation were measured. Results: On the surface of human umbilical vein endothelial cells, onset of plasmin generation was earlier (40 min) compared to plastic (60 min) but total plasmin generation was similar on both surfaces. The addition of plasminogen to cord plasma increased plasmin generation. Supplementation of lipoprotein in adult plasma had an inhibitory effect, but there was no significant effect in cord plasma. Interpretations and Conclusions: Plasmin generation is reduced in newborn compared to adult plasma. Decreased plasmin generation in cord plasma is likely due to decreased plasminogen concentration. The antifibrinolytic effect of lipoprotein is more pronounced in adults as compared to newborns due to the presence of higher plasminogen concentration.
Platelet Function of Newborns as Tested by Cone and Plate(let) Analyzer Correlates with Gestational Age
Authors: Levy-Shraga Y. , Maayan-Metzger A. , Lubetsky A. , Shenkman B. , Kuint J. , Martinowitz U. , Kenet G.
Published: March 2006

The issue of platelet function in infants and neonates is of interest, and current data are debatable. A new method for assessing platelet function involves using the cone and plate(let) analyzer (CPA), applicable for small (0.2 ml) whole blood volumes. We used polystyrene surface-coated plates to evaluate cord blood neonatal platelet function under flow. One hundred and sixty full-term and 29 preterm infants born at the Sheba Medical Center between March 2003 and January 2004 were evaluated for platelet adhesion measured as surface coverage (SC; the percentage of total area covered by platelets) and platelet aggregation, defined as the average size (AS) of the aggregates. Platelets from preterm infants displayed less platelet adhesion than did those from full-term infants. Platelet SC correlated with gestational age in all infants (p < 0.05), and both groups exhibited similar aggregation (AS). AS values, however, were significantly lower than the normal adult range in our laboratory. Infants born to mothers with pregnancy-induced hypertension displayed significantly lower SC. No association was found between CPA and postnatal complications. Conclusion: CPA provides a rapid, feasible option for testing platelet function in neonates. Its potential predictive value deserves further attention, and more extensive studies are warranted.
Maternal Selective Serotonin Reuptake Inhibitor Intake Does Not Seem to Affect Neonatal Platelet Function Tests
Authors: Maayan-Metzger A. , Kuint J. , Lubetsky A. , Shenkman Boris , Mazkereth R. , Kenet G.
Published: March 2006

Recently, concerns have been raised regarding the potential impairment of neonatal platelet function and the potential risk of bleeding in neonates born to mothers treated with selective serotonin reuptake inhibitors (SSRI). Our aim was to test whether the platelet function of neonates born to SSRI-treated mothers was impaired when compared to non-SSRI-exposed neonates. In a single-center prospective study, platelet function was evaluated using a cone and platelet analyzer (CPA) device and compared between mother-infant pairs as well as normal non-SSRI-exposed infants. Twenty-seven SSRI-exposed and 27 non-SSRI-exposed full-term neonates and their 23 mothers were tested. No correlation was found between SSRI exposure among either neonates or mothers and parameters of surface coverage (SC) and average size (AS), manifesting platelet function as tested by CPA. SC was similar among SSRI-exposed babies as compared to those in the control group, whereas the size of platelet aggregates (AS) was higher among controls. Neither maternal diseases nor SSRI intake were associated with impaired platelet function and lower SC values, nor were any perinatal conditions. None of the babies suffered from bleeding. We conclude that maternal SSRI therapy does not impair whole-blood CPA-tested platelet function of healthy full-term neonates.
Current Issues in Prophylactic Therapy for Persons with Hemophilia
Authors: Dunn Amy L. , Abshire Thomas C.
Published: March 2006

Factor VIII or IX replacement in a prophylactic manner is utilized for many patients with moderate to severe hemophilia A or B. Studies have shown it to be effective in reducing or preventing degenerative joint disease in many but not all patients. However, many unanswered questions still exist and optimization of this expensive treatment regimen is needed. This paper recounts the current products that are available for use and explores the literature regarding different treatment regimens. It explores age at initiation, dose, interval between infusions, joint health outcomes, barriers to compliance and age at discontinuation of prophylaxis. Individualized treatment is recommended. Collaborative efforts are needed to improve outcomes for all persons with hemophilia.
New Approaches in the Management of Inhibitor Patients
Authors: Young Guy
Published: March 2006

The most serious current complication of factor replacement therapy for hemophilia patients is the development of neutralizing antibodies to the factor termed inhibitors. Patients with high-titer inhibitors frequently develop serious bleeding complications which do not respond to standard factor replacement therapy. Therefore, they must be treated with the so-called bypassing agents, recombinant factor VIIa and activated prothrombin complex concentrates, neither of which is as effective as standard factor replacement in patients without inhibitors. Immune tolerance therapy aimed at eradicating inhibitors is successful in a majority of patients; however, a sizable minority will have life-long inhibitors and often develop debilitating joint disease. The ultimate goal is to develop strategies aimed at preventing inhibitor development though these have not been realized yet. Until this is achieved, additional novel approaches are needed to improve the treatment of bleeding episodes and to better treat arthropathy once it develops. Finally, there is no laboratory monitoring device which can predict the clinical response of patients to bypassing agents. Thus another goal of current research is to develop such a tool which will enable the individualization of bypassing agent.
Elevated α1-Antitrypsin Is a Risk Factor for Arterial Ischemic Stroke in Childhood
Authors: Burghaus Beate , Langer Claus , Thedieck Sabine , Nowak-Göttl Ulrike
Published: March 2006

α1-antitrypsin (α1-AT) is a physiological inhibitor of activated protein C (APC) and therefore decreased APC activity. APC itself causes an anticoagulant effect by inactivating factors Va and VIIIa. The present case-control study was performed to evaluate the role of the elevated α1-AT concentration in pediatric patients with ischemic stroke (IS). α1-AT concentrations were measured along with established prothrombotic risk factors 6–12 months after the acute thrombotic onset in 81 Caucasian children with IS aged 1 month to 18 years. The cutoff values defined as age-dependent 90th percentiles were obtained from 229 healthy controls. Median (range) values of α1-AT were significantly higher in patients compared with control subjects [122.0 mg/dl (61.4–224.0) vs. 114.0 mg/dl (66.8–156.0); p = 0.016]. In addition, 14 of the 81 patients (17.3%) compared with 10 of the 162 controls (6.2%) had α1-AT concentrations above the 90th age-dependent percentiles (p = 0.012). Multivariate analysis performed in a 1:2 matched case-control setting adjusted for the presence of established prothrombotic risk factors showed a significantly increased odds ratio (OR) and 95% confidence interval (CI) for patients with elevated α1-AT >90th percentiles and IS (OR/CI: 4.0/1.64–9.92; p = 0.0024). Data shown here give evidence that total α1-AT concentrations above the 90th age-dependent percentiles independently increase the risk of IS 4.0-fold in Caucasian children.
3′ End Processing of the Prothrombin mRNA in Thrombophilia
Authors: Danckwardt Sven , Hartmann Kathrin , Gehring Niels H. , Hentze Matthias W. , Kulozik Andreas E.
Published: March 2006

Clinical and genetic studies have led to the discovery of specific genotypes that predispose to thromboembolism in adults and children. The exploration of the underlying pathologies has revealed a broad variety of affected molecular mechanisms. Most recently, the functional analysis of the prothrombin (F2) 20210*A variant revealed increased efficiency of 3′ end processing as a novel genetic mechanism predisposing to human disease. Here, we review the 3′ end processing of the human F2 mRNA and demonstrate how clinically relevant mutations in the F2 gene contribute to thrombophilia by interfering with a tightly balanced architecture of noncanonical 3′ end formation signals.
Postthrombotic Syndrome in Children
Authors: Manco-Johnson Marilyn J.
Published: March 2006

The postthrombotic syndrome (PTS) is a clinical condition of limb pain along with physical findings that range from swelling to stasis ulcers following one or more episodes of deep vein thrombosis (DVT). While venous thromboembolism has recently gained increased recognition in children, the sequelae of limb thrombi are being recognized in a substantial proportion of affected children, and with varying degrees of severity. PTS is caused by both obstructed as well as refluxed venous blood flow, with combined effects of obstruction and reflux resulting in earlier, and more extensive symptoms. PTS can be diagnosed using an evaluation tool adapted from an international adult scale. Certain risk factors predispose children to PTS including elevations in factor VIII activity and D-dimer, clot occlusiveness, clot persistence, number of venous segments involved and duration of observation following DVT. Optimal prevention and treatment have not yet been determined, although antithrombotic therapy to facilitate rapid clot resolution, elevation, compression, moderate exercise and achievement of optimal body weight are likely to improve outcome.
Exercise-Induced Deep Vein Thrombosis of the Upper Extremity
Authors: Brandão Leonardo R. , Williams Suzan , Kahr Walter H.A. , Ryan Clodagh , Temple Michael , Chan Anthony K.C.
Published: March 2006

Paget-Schroetter syndrome or effort-related upper extremity deep vein thrombosis is a rare condition that usually afflicts young healthy individuals, most commonly males. The cause is multifactorial but almost always involves extrinsic compression of the subclavian vein at the thoracic inlet, causing venous stenosis from repetitive trauma. The diagnosis of this condition may be difficult, and its delay may contribute to potential complications including thrombosis progression, pulmonary embolism, thrombosis recurrence, and post-thrombotic syndrome. Similarly, the best therapeutic option has not been established and in the lack of evidence-based guidelines, treatment may be extremely challenging especially in children, in whom long-term complications can be particularly disabling.
Exercise-Induced Deep Vein Thrombosis of the Upper Extremity
Authors: Brandão Leonardo R. , Williams Suzan , Kahr Walter H.A. , Ryan Clodagh , Temple Michael , Chan Anthony K.C.
Published: March 2006

Upper-extremity deep venous thrombosis (UEDVT) is an increasingly important clinical problem in children. These events are classified as primary or secondary, with the latter being the most common and usually associated with the presence of a central venous line. Among primary UEDVT, the so-called Paget-Schroetter syndrome, effort-related or exercise-induced upper-extremity thrombotic event represents an extremely rare finding that has never been described in a pediatric series. The objective of the second part of this two-part article is to report the first pediatric series in a group of adolescents with this condition from a single center, describing their clinical features, management, and outcome. A retrospective chart review of 6 patients seen between December 2003 and April 2005 was conducted, with a median follow-up of 9 months (range 2–17). Four females and two males, all Caucasian, were enrolled with a median age of 16 years (range 14–17). In all cases, strenuous exercise was present in the month preceding diagnosis and mild trauma was present in only one case (weight lifting). At presentation, all patients had objective swelling of the affected limb for a median of 4 days (range 2–14), and 4 patients had UEDVT of the dominant arm. Thrombophilia investigation revealed that 50% had a combined prothrombotic state at presentation, and all patients were/are being treated with anticoagulation for 6 months (low-molecular-weight heparin followed by warfarin). Continuation of the initial symptoms was present in all cases but one at the 3-month clinic follow-up (last case has yet to reach 3 months of follow-up), and residual moderate to severe postthrombotic syndrome was present in all 3 cases followed for more than 12 months. Of those 3 patients followed for more than 1 year, 2 patients recurred despite having complete resolution of the thrombus after 6 months of anticoagulation, and the third patient underwent surgery with clinical improvement. Adolescents with UEDVT treated only with anticoagulation seem to have a poor outcome.
Long-Term Treatment of Thrombosis with Enoxaparin in Pediatric and Adolescent Patients
Authors: Merkel Nick , Günther Gudrun , Schobess Rosemarie
Published: March 2006

Thrombosis is a rare event in childhood and adolescence. Nevertheless, increasing numbers of invasive diagnostic and therapeutic procedures also result in increasing numbers of thromboses in pediatric cases, necessitating effective antithrombotic treatment regimens. In recent years, low-molecular-weight heparins (LMWH) in particular have been proved to be a safe and effective alternative to unfractioned heparins. However, the application of LMWH in pediatric patients has not been supported by a single controlled study so far. Furthermore, there is no official approval of these drugs for children. In this pilot study 27 children with deep venous thromboses (DVT) were treated with the LMWH enoxaparin at a dosage of 1.5 mg/kg body weight b.i.d. in neonates and infants and 1 mg/kg body weight b.i.d. in children. This dosage was lowered for prophylaxis if therapeutic success was achieved. The aim of the study was to investigate both, efficacy with respect to patency rates and safety during acute and long-term follow-up. Sufficient therapeutic success required a rapid production of anti-Xa target activity and was reached in 85% of the treated patients, who showed patency of the affected vessel at last follow-up. The mean duration of treatment with full dosage was 16.5 days, followed by prophylaxis over a mean duration of 9.8 months. Rethrombosis or adverse events including heparin-induced thrombocytopenia were not observed in any patient. In conclusion, enoxaparin provides an effective and safe alternative to unfractioned heparins in the treatment of thrombosis in infancy, childhood and adolescence.
Safety and Efficacy of Danaparoid (Orgaran®) Use in Children
Authors: Bidlingmaier Christoph , Magnani Harry N. , Girisch Monika , Kurnik Karin
Published: March 2006

Immune-mediated heparin-induced thrombocytopenia (HIT) is an uncommon but serious complication of therapy with heparins. It affects all ages and requires replacement of the causative anticoagulant. However, information on alternative antithrombotic use in children with HIT is limited. This paper reviews 27 published and 7 unpublished case reports of children aged 2 weeks to 17 years treated with danaparoid. Thirty-three suffered from HIT or suspected HIT, and 1 child without HIT had a high bleeding risk. All children had severe underlying problems increasing their thrombotic and/or bleeding risk. HIT diagnosis was confirmed serologically or clinically in 26 cases (78.8%). Danaparoid regimens were similar to those used in adults, but in general, younger children needed higher daily doses of danaparoid to achieve the same target plasma anti-Xa levels than teenagers or adults. Of those with a known outcome 28/33 children (84.8%) survived, 7 having suffered from a serious adverse event. Five deaths occurred including 1 thrombotic and 2 major bleeds. Three of the in total 4 major bleeding events occurred in children undergoing surgery with cardiopulmonary bypass. We conclude that despite the reported adverse events danaparoid can be used as an alternative antithrombotic for children who are intolerant of the heparins, except in cases requiring cardiopulmonary bypass surgery.
A Novel AAAS Gene Mutation (p.R194X) in a Patient with Triple A Syndrome
Authors: Dusek Tina , Korsic Marta , Koehler Katrin , Perkovic Zdravko , Huebner Angela , Korsic Mirko
Published: March 2006

Objective: The clinical and molecular data of a patient with triple A syndrome are reported. Patient: A 21-year-old male who was diagnosed for adrenal insufficiency at the age of 2 years after a severe attack of adrenal crisis. At the age of 4 years, achalasia and alacrima were diagnosed. Puberty started at the age of 17 years. At the same time, symptoms of central, peripheral, and autonomic nervous system dysfunction were noted. Later on, at the age of 20 years, a bone age delay of 6 years and severe osteoporosis was diagnosed. Results: A compound heterozygous AAAS mutation consisting of two mutations was found: a C > T transition in exon 7 resulting in a change of arginine at amino acid position 194 into a stop codon (Arg194X) at one allele, and a C > T transition in exon 12 resulting in a change of glutamine at amino acid position 387 into a stop codon (Gln387X) on the other allele. Conclusion: The mutation in exon 7 (p.R194X) of the AAAS gene is a novel mutation which has not been found in any other family so far, whereas the second was already found in some other families. This case adds to the clinical and molecular spectrum of triple A syndrome and may provide a new insight into the functions of AAAS gene.
Quantitative Follow-Up of the Cutaneous Barrier Function in Wound Healing
Authors: Rodrigues Luís M. , Pinto Pedro C. , Magro José M. , Furtado Nuno , Roberto Maria Angélica
Published: March 2006

Background: Cutaneous ‘barrier’ recovery is a main objective in wound healing. Despite its potential interest, transepidermal water loss (TEWL) measurement has not yet entered the healing follow-up routine, in part due to instrumental limitations. Objective: To develop an experimental model using TEWL data, to quantify the in vivo ‘barrier’ function. Methods: Thermal burn trauma patients referred for autografting surgery, were submitted to a 24-hour ‘plastic occlusion stress test’ (POST) in the grafted and donor areas during the healing process, and TEWL data were parameterised as the evaporation half-life and the dynamic water mass. Results: Chosen parameters clearly differentiate the 2 processes at the grafted and donor sites, with the latter involving a slower recovery. Conclusion: The interest of TEWL as an indicator of the ‘barrier’ recovery in such a complex condition is well demonstrated, especially if rigorously obtained allowing a quantitative follow-up and results comparison.
Experiences with Nonfunctioning Neuroendocrine Neoplasms of the Pancreas
Authors: Kang Chang Moo , Kim Kyung Sik , Choi Jin Sub , Lee Woo Jung , Kim Byong Ro
Published: March 2006

Aim: We present our experiences in the treatment of nonfunctioning neuroendocrine neoplasms of the pancreas to define the natural history and to suggest proper management. Method: From August 1993 to June 2005, the medical records of 19 patients with the diagnosis of nonfunctioning neuroendocrine (islet cell) neoplasms of the pancreas were retrospectively reviewed with respect to patient characteristics, characteristics of neoplasms, surgical procedures, and long-term outcomes in the Yonsei University Medical Center, Seoul, Korea. Results: The median age of the patients (10 males and 9 females) was 51 years. Abdominal pain and discomfort (58%) were the most frequent symptoms. Tumors with a median size of 3.5 cm were noted in the head of the pancreas in 9 patients and in the body or in the tail of the pancreas in 10 patients. Thirteen patients (68%) had neoplasms with malignant features. Twelve patients (63%) underwent surgical resection, and curative resection was performed in 10 patients (53%). Unresectable neoplasms (p = 0.0055), distant metastases (p = 0.0124), and macroinvasion to adjacent organs (p = 0.024) had significantly adverse effects on the mean survival. Neither palliative surgery nor adjuvant chemoradiation therapy seemed to be effective. Conclusions: Early detection of nonfunctioning neuroendocrine neoplasms of the pancreas is important, and curative resection should be attempted for a good prognosis.