bluuebunny/crossref_metadata_2025 huggingface dataset:
Heligmosomoides polygyrus inhibits established colitis in IL‐10‐deficient mice
Authors: Elliott David E. , Setiawan Tommy , Metwali Ahmed , Blum Arthur , Urban Joseph F. , Weinstock Joel V.
Published: August 2004

Inflammatory bowel disease (IBD) is prevalent in industrialized countries, but rare in less‐developed countries. Helminths, common in less‐developed countries, may induce immunoregulatory circuits protective against IBD. IL‐10–/– mice given piroxicam develop severe and persistent colitis. Lamina propria mononuclear cells from colitic IL‐10–/– mice released IFN‐γ and IL‐12. The ongoing piroxicam‐induced colitis could be partially blocked with anti‐IL‐12 monoclonal antibody suggesting that the inflammation was at least partly IL‐12 dependent. Colonization of piroxicam‐treated colitic IL‐10–/– mice with Heligmosomoides polygyrus (an intestinal helminth) suppressed established inflammation and inhibited mucosal IL‐12 and IFN‐γ production. H. polygyrus augmented mucosal IL‐13, but not IL‐4 or IL‐5 production. Transfer of mesenteric lymph node (MLN) T cells from IL‐10–/– animals harboring H. polygyrus into colitic IL‐10–/– recipients inhibited colitis. MLN T cells from worm‐free mice did not. Foxp3 (scurfin) drives regulatory T cell function. H. polygyrus enhanced Foxp3 mRNA expression in MLN T cells that had regulatory activity. This suggests that H. polygyrus inhibits ongoing IL‐10–/– colitis in part through blocking mucosal Th1 cytokine production. Resolution of inflammation is associated with increased IL‐13 production and can be adoptively transferred by MLN T cells.
Oxidation of CH3NH2 and (CH3)2NH by NiIII(cyclam)(H2O)23+ in Aqueous Solutions
Authors: Shamir Dror , Zilbermann Israel , Maimon Eric , Meyerstein Dan
Published: August 2004

NiII(1,4,8,11‐tetraazacyclotetradecane)2+, NiIIL2+, is a good electrocatalyst for the oxidation of CH3NH2 and (CH3)2NH but not of (CH3)3N. The oxidation kinetics of the amines by NiIIIL(H2O)23+ indicate that the amines are good axial ligands to the tervalent nickel complex. The complexes NiIIIL[N(CH3)iH3−i](H2O)3+ are stronger oxidants than the complexes NiIIIL[N(CH3)iH3−i]23+. The oxidation is base‐catalyzed and obeys a second‐order rate law in NiIIILX2. It is proposed that the key step is NiIII−L(H2O)[N(CH3)iH2−i]2+ + NiIIILX2 → LNiII−N(=CH2)(CH3)i−1H2−i + NiIIL2+ + H3O+ + 2 X. Naturally, N(CH3)3 is not oxidized by this mechanism. Of special interest is the observation that the axial ligands CH3NH2 and (CH3)2NH are oxidized by the central cation, while the cyclam ligand, which has four secondary amine groups bound to the nickel(III) ion, and axially bound pendant primary amine groups, which are covalently linked to the macrocyclic ligand, are relatively stable. This difference in the behavior of axially bound amine groups is attributed to the free rotation of the axially bound N(CH3)iH3−i ligands that is required for the oxidation to proceed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
From Discrete to Extended Guests: A Novel Supramolecular [Hg6As4](AgCl3)2 Assembly Featuring One‐Dimensional (AgCl3)2− Anions
Authors: Oleneva Olga S. , Olenev Andrei V. , Dikarev Evgeny V. , Shevelkov Andrei V.
Published: August 2004

A novel supramolecular assembly [Hg6As4](AgCl3)2 has been prepared and its structure determined. It crystallizes in the monoclinic system, space group I2/a (no. 15), with the unit‐cell dimensions a = 14.690(1), b = 9.1851(7), c = 20.285(1) Å, β = 93.17(1)°, and Z = 4. The crystal structure comprises a three‐dimensional cationic host framework, [Hg6As4]4+, built of mercury and arsenic atoms and one‐dimensional ∞1(AgCl3)2− guest anions built of corner‐sharing [AgCl4] tetrahedra. The title compound is the first example of a perfectly ordered supramolecular architecture having an infinite chain anion as a guest moiety embedded into a mercury−pnicogen cationic framework. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis, X‐ray Structural Analysis and Spectroscopic Investigations (IR and 31P MAS NMR) of Mixed Barium/Strontium Fluoroapatites
Authors: Aissa Abdallah , Badraoui Béchir , Thouvenot René , Debbabi Mongi
Published: August 2004

Continuous solid solutions of barium/strontium fluoroapatites Ba(10−x)Srx(PO4)6F2 (Ba(10−x)SrxFAp; 0 ⩽ x ⩽ 10) were obtained in an aqueous medium. They were investigated by Rietveld structure‐refinement methods using powder X‐ray diffraction patterns and by chemical analysis, IR spectroscopy and 31P MAS NMR spectroscopy. Replacement of barium by strontium induces a regular decrease of the lattice constants a and c according to Vegard’s law. The results of the powder‐fitting structure refinements indicate a clear preference of strontium for the S(1) site of the apatitic structure. A high‐wavenumber shift of the IR absorption bands characteristic of PO4 internal modes is also observed, in agreement with the diminution of the ionic character of the M−O bonds. For increasing strontium content, a regular δiso increase is shown in the 31P MAS NMR spectra, from δ = 0.91 ppm for Ba10FAp to δ = 3.06 ppm for Sr10FAp. For all mixed Ba/Sr fluoroapatites, the low intensities of the spinning bands reflect the weak 31P chemical‐shift anisotropy, in agreement with the low distortion of the PO4 tetrahedron, as shown by Rietveld refinement. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Asymmetry in the link between the yield spread and industrial production: threshold effects and forecasting
Authors: Paya Ivan , Venetis Ioannis A. , Peel David A.
Published: August 2004

We analyse the nonlinear behaviour of the information content in the spread for future real economic activity. The spread linearly predicts one‐year‐ahead real growth in nine industrial production sectors of the USA and four of the UK over the last 40 years. However, recent investigations on the spread–real activity relation have questioned both its linear nature and its time‐invariant framework. Our in‐sample empirical evidence suggests that the spread–real activity relationship exhibits asymmetries that allow for different predictive power of the spread when past spread values were above or below some threshold value. We then measure the out‐of‐sample forecast performance of the nonlinear model using predictive accuracy tests. The results show that significant improvement in forecasting accuracy, at least for one‐step‐ahead forecasts, can be obtained over the linear model. Copyright © 2004 John Wiley & Sons, Ltd.
Immunolocalization of extracellular matrix components and integrins during mouse liver development
Authors: Shiojiri Nobuyoshi , Sugiyama Yoshinori
Published: August 2004

Intrahepatic biliary cell differentiation takes place in periportal hepatoblasts under the influence of the subjacent connective tissue, the mechanism of which is still unclear. This study was undertaken to analyze the immunolocalization of extracellular matrix components and their cellular receptors during mouse liver development, with special attention given to biliary differentiation and vascular development. In young fetal mouse liver, primitive structures of sinusoids were developed between hepatic cords associated with hematopoietic cells demonstrated by immunohistochemistry of basal laminar components, the α6 integrin subunit, and PECAM-1. Portal veins and hepatic veins showed different staining intensities of α2, α3, and α6 integrin subunits from early stages of development. Anti-β4 integrin subunit antibodies reacted with portal veins, but not with hepatic veins after perinatal stages. Their different phenotypes may be related to the preferential differentiation of periportal bile ducts. In intrahepatic bile duct development, periportal hepatoblasts adjacent to the connective tissue were immunostained for each basal laminar component on the basal side at almost the same time; α3, α5, α6, and β4 integrin subunits were immunohistochemically detectable later than the basal laminar components. These staining patterns of intrahepatic bile duct cells clearly differed from those of extrahepatic bile duct cells from the beginning of their development, suggesting that these ducts are of different origins. In conclusion, the vascular structures, including sinusoids, portal veins, and hepatic veins, develop from early stages of liver development, and the extracellular matrix components may play important roles in biliary differentiation and vascular development. Supplementary material for this article can be found on the Hepatology website (http://interscience.wiley.com/jpages/0270-9139/suppmat/index.html). (Hepatology 2004;40:346-355.)
Direct enumeration and functional assessment of circulating dendritic cells in patients with liver disease†
Authors: Wertheimer Anne M. , Bakke Antony , Rosen Hugo R.
Published: August 2004

Chronic liver disease has been shown to be associated with diminished humoral and cellular immune function. Although antigen-presenting cells (APC) that initiate immune responses include various cells (B cells, endothelial cells, macrophages, etc.), the dendritic cell (DC) is a professional APC that activates naive T cells most efficiently. To examine the frequency and function of DCs in chronic liver disease, we studied circulating DCs from a cohort of 112 subjects (23 normal subjects, 29 subjects who had spontaneously recovered from hepatitis C virus [HCV] infection, 30 chronically infected HCV patients, and 30 patients with liver disease unrelated to HCV infection). Our analyses revealed significant reduction in both circulating myeloid (mDC) and plasmacytoid dendritic cells (pDC) in patients with liver disease. In contrast, examination of subjects with spontaneously resolved HCV infection revealed no significant difference in either circulating mDCs or pDCs. We found an inverse correlation with serum alanine aminotransferase (ALT) levels and both mDCs and pDCs frequency. In a subset of patients for whom intrahepatic cells were available, paired analysis revealed enrichment for DCs within the intrahepatic compartment. Interferon alfa (IFN-α) production in response to influenza A and poly (I:C) correlated with the frequency of circulating DCs, although IFN-α production was comparable on a per-DC basis in patients with liver disease. In conclusion, patients with liver disease exhibit a reduction in circulating DCs. Considering that DCs are essential for initiation and regulation of innate and adaptive immunity, these findings have implications for both viral persistence and liver disease. (Hepatology 2004;40:335-345.)
Role of TNF-α in ethanol-induced hyperhomocysteinemia and murine alcoholic liver injury
Authors: Ji Cheng , Deng Qinggao , Kaplowitz Neil
Published: August 2004

We previously reported a link between ethanol-induced elevation of homocysteine, endoplasmic reticulum (ER) stress, and alcoholic liver injury in the murine model of intragastric ethanol feeding. We studied the role of TNFα in this setting by using TNFR1 knockout mice (C57 BL/6). There was a 7.4-fold increase of homocysteine in wild-type and a 6-fold increase in TNFR1 knockout mice with intragastric alcohol exposure for 4 weeks. Plasma TNFα increased in the wild-type (18.4 ± 3.3 pg/mL vs. 8.4 ± 1.3 pg/mL (control)) and in the knockouts (12.9 ± 1.4 pg/mL vs. 7.2 ± 1.6 pg/mL (control)). Similar extent of fatty liver was observed in both types. Increased ALT was observed in both groups. Necroinflammatory foci were increased significantly in ethanol-fed knockouts but not to the same extent as in the ethanol-fed wild type. Increase of hepatic apoptosis and reduction of S-adenosyl-L-methionine was detected in both types of animals fed ethanol. ER stress demonstrated by RT-PCR of mRNA of selective ER stress markers GRP78, CHOP, and SREBP1 was increased equivalently in both types of mice. Betaine administration decreased ER stress in conjunction with attenuation of the elevated plasma homocysteine in both types of animals. Betaine increased hepatic S-adenosyl-L-methionine by 28 fold in the knockouts and by 24-fold in wild type. In conclusion, TNFα makes a moderate contribution to the ALT elevation, necroinflammation, apoptosis, a small contribution to the fatty liver and no contribution to hyperhomocysteinemia and ER stress in intragastric alcohol fed mice. (Hepatology 2004;40:442-451.)
Long-term patency is expected with covered TIPS stents: This effect may not always be desirable!
Authors: Rössle Martin , Mullen Kevin D. , Jaeschke Hartmut , Mullen Kevin , Moradpour Darius
Published: August 2004

Background & Aims

A 50% dysfunction rate at 1 year is one of the main drawbacks of the transjugular intrahepatic portosystemic shunt procedure. Preliminary experimental and clinical studies suggest that the use of stents covered with polytetrafluorethylene could tremendously decrease this risk.

Methods

Eighty patients with cirrhosis and uncontrolled bleeding (n = 23), recurrent bleeding (n = 25), or refractory ascites (n = 32) were randomized to be treated by transjugular intrahepatic portosystemic shunts with either a polytetrafluorethylene-covered stent (group 1; 39 patients) or a usual uncovered prosthesis (group 2; 41 patients). Follow-up Doppler ultrasound was scheduled at day 7, at 1 month, and then every 3 months for 2 years. Angiography and portosystemic pressure gradient measurements were performed 6,12, and 24 months after the transjugular intrahepatic portosystemic shunt procedure and whenever dysfunction was suspected. Dysfunction was defined as a >50% reduction of the shunt at angiography or a portosystemic pressure gradient >12 mm Hg.

Results

After a median follow-up of 300 days, 5 patients (13%) in group 1 and 18 (44%) in group 2 experienced shunt dysfunction (P < 0.0001). Clinical relapse occurred in 3 patients (8%) in group 1 and 12 (29%) in group 2 (P < 0.05). Actuarial rates of encephalopathy were 21% in group 1 and 41% in group 2 at 1 year (not significant). Estimated probabilities of survival were 71% and 60% at year 1 and 65% and 41% at 2 years in groups 1 and 2, respectively.

Conclusions

The use of polytetrafluorethylene-covered prostheses improves transjugular intrahepatic portosystemic shunt patency and decreases the number of clinical relapses and reinterventions without increasing the risk of encephalopathy.
Haplotype-tagging RANTES gene variants influence response to antiviral therapy in chronic hepatitis C†
Authors: Wasmuth Hermann E. , Werth Alexa , Mueller Tobias , Berg Thomas , Dietrich Christoph G. , Geier Andreas , Gartung Carsten , Lorenzen Johann , Matern Siegfried , Lammert Frank
Published: August 2004

The response to antiviral therapy for chronic hepatitis C virus (HCV) is complex and is determined by both environmental and genetic factors. Recently, interacting gene polymorphisms of the chemokine RANTES have been shown to affect HIV disease progression. Our aim was to assess if these RANTES variants are associated with response to anti-HCV therapy. Three linked RANTES single nucleotide polymorphisms (403 G/A, Int1.1 T/C, and 3′ 222 T/C) were determined in 297 Caucasian patients who were treated for chronic HCV infection and 152 control subjects. Characteristic nucleotide combinations on single chromosomes (haplotypes) were reconstructed and tested for disease association. Four common RANTES haplotypes (prevalence 73%) were identified in patients and controls. There was a strong association of RANTES haplotype distribution with outcome of antiviral combination therapy (P = .007). Specifically, RANTES haplotypes carrying Int1.1 C and 3′ 222 C alleles were more frequent in nonresponders than in patients with a sustained response to antiviral therapy (odds ratio 1.9, P = .01). The influence of these RANTES haplotypes on the outcome of therapy was more pronounced in patients infected with HCV genotypes 1 and 4 (odds ratio 2.3, P = .02). Because RANTES haplotypes carrying Int1.1 C are known to down-regulate RANTES transcriptional activity in vitro, the haplotype analysis fits the hypothesis of a diminished T helper 1 lymphocyte response in patients with a negative response to antiviral therapy. In conclusion, RANTES haplotypes might contribute to the polygenic interaction between HCV and the host immune system and could help to risk stratify patients prior to antiviral therapy. (Hepatology 2004;40:327-334.)
Origin of serum hepatitis B virus in acute exacerbation: Comparison with HBV in the liver and from other exacerbation
Authors: Liu Chun-Jen , Kao Jia-Horng , Wang Hurng-Yi , Lai Ming-Yang , Chen Ting-Chih , Chen Pei-Jer , Chen Ding-Shinn
Published: August 2004

Acute exacerbation (AE) of chronic hepatitis B is usually preceded by reemergence or increase of hepatitis B virus (HBV) in the serum. To investigate the origin of the reemergence or increase, we compared the identity of the serum viral genome to that in the liver and in previous AE by full-length sequencing. The full-length viral genome and extent of quasispecies were obtained from serum and liver biopsy specimens at the same time from 9 subjects with hepatitis B exacerbation (group I). Composition of viral quasispecies was compared by the genetic diversity and the average number of nucleotide substitutions within and between different viral sources. Another 2 patients with repeated AEs (group II) were also enrolled, and their serial serum alanine aminotransferase, HBV DNA levels and full-length sequences were determined. In all group I patients, serum viral genome was identical to that in the liver. The genetic diversity and the average number of nucleotide difference were also comparable between serum and liver tissue. In 2 group II patients, the viral variant that emerged after previous AE was not identical to that caused by the subsequent AE. Dominant viral strains for serial AEs in a single patient did not show a sequential evolution, but presented as a horizontal selection of a minor population from the original viral pool. In conclusion, the findings suggest that viral strain in serum reflects the intrahepatic strain of the AE. Random reactivation of the original HBV pool, rather than a sequential evolution of one strain, also contributes to the onset of repeated AE. Supplementary material for this article can be found on the Hepatology website (http://interscience.wiley.com/jpages/0270-9139/suppmat/index.html). (Hepatology 2004;40:310-317.)
Antiviral CD8-mediated responses in chronic HCV carriers with HBV superinfection
Authors: Boni Carolina , Amadei Barbara , Urbani Simona , Fisicaro Paola , Zerbini Alessandro , Mori Cristina , Missale Gabriele , Bertoni Roberto , Azzurri Annalisa , Del Prete Gianfranco , Ferrari Carlo
Published: August 2004

Hepatitis B virus (HBV) superinfection in chronic hepatitis C represents a natural model to investigate whether or not hepatitis C virus (HCV) can influence priming and maturation of antiviral T cells; whether or not HBV superinfection, which is known to determine control of HCV replication, can restore HCV-specific T cell responsiveness; and whether or not cytokines stimulated by HBV infection can contribute to HCV control. To address these issues, the function of CD8 cells specific for HBV and HCV was studied longitudinally in two chronic HCV patients superinfected with HBV. Patients with acute hepatitis B were also examined. Frequency and function of HBV tetramer+ CD8 cells were comparable in patients acutely infected with HBV with or without chronic HCV infection. HBV-specific CD8 cell function was efficiently expressed irrespective of serum HCV-RNA levels. Moreover, fluctuations of HCV viremia at the time of HBV superinfection were not associated with evident changes of CD8 responsiveness to HCV. Finally, no correlation was found between serum levels of interferon α, interleukin (IL)-12, IL-10, or IL-18 and control of HCV replication. In conclusion, HCV did not affect the induction of primary and memory HBV-specific CD8 responses. HCV-specific CD8 responses were undetectable when HCV-RNA was negative, showing that inhibition of HCV replication in the setting of a HBV superinfection was not sufficient to induce a restoration of CD8 reactivity against HCV. (H epatology 2004;40:289-299.)
C/EBP β isoforms LIP and LAP modulate progression of the cell cycle in the regenerating mouse liver
Authors: Luedde Tom , Duderstadt Moritz , Streetz Konrad L. , Tacke Frank , Kubicka Stefan , Manns Michael P. , Trautwein Christian
Published: August 2004

The CCAAT enhancer-binding protein (C/EBP) β gene can produce several N-terminally truncated isoforms. Liver-enriched activator protein (LAP) is a transcriptional activator in many systems, whereas liver-enriched inhibitory protein (LIP) is regarded as a functional LAP antagonist. In this study, we examined the impact of these two proteins on cell cycle progression in the regenerating liver. Adenoviral overexpression of LAP, in addition to its role as a transactivator of liver-specific genes, led to a delayed S-phase entry of hepatocytes after partial hepatectomy (PH) in vivo. This delay was accompanied by decreased expression of cyclin A and E as well as proliferating cell nuclear antigen and decreased cyclin-dependent kinase 2 activity at the G1/S boundary. This observation is not explained by increased p21CIP1/Waf1 expression or lack of phosphorylation of external LAP, but LAP overexpression triggered a decreased C/EBP-α/C/EBP-α-30 ratio and a reduced basal c-jun level in the liver. In contrast, adenoviral overexpression of LIP resulted in a stronger and earlier induction of cyclin A and E after PH, but did not change the timing and extent of cyclin-dependent kinase 2 activity or the amount of hepatocytes that entered S phase in this model. In the LIP expressing group, both C/EBP-α isoforms and c-jun were more strongly induced after PH. In conclusion, the LAP/LIP ratio is an important modulator of cell cycle progression during liver regeneration. In the context of previous studies, our results demonstrate that LAP, through a dose-dependent effect, withholds a dual activating and inhibiting role on hepatocyte proliferation in vivo. (Hepatology 2004;40:356-365.)
Intrahepatic cholestasis of pregnancy: Relationships between bile acid levels and fetal complication rates
Authors: Glantz Anna , Marschall Hanns-Ulrich , Mattsson Lars-Åke
Published: August 2004

Intrahepatic cholestasis of pregnancy (ICP), characterized by pruritus in the second half of pregnancy, entails an increased risk to the fetus. This study was designed to determine the incidence and fetal complication rates in ICP, and to define groups at increased risk. In an prospective cohort study conducted between February 1, 1999, and January 31, 2002, all 45,485 pregnancies in a defined region of Sweden (Västra Götaland) were screened for ICP, defined as otherwise unexplained pruritus of pregnancy in combination with fasting serum bile acid levels ≥10 μmol/L. Pruritus was reported by 937 (2.1%) women, and ICP was diagnosed in 693 (1.5%). Simple logistic regression analyses showed that the probability of fetal complications (spontaneous preterm deliveries, asphyxial events, and meconium staining of amniotic fluid, placenta, and membranes) increased by 1%-2% per additional μmol/L of serum bile acids. Complementary analyses showed that fetal complications did not arise until bile acid levels were ≥40 μmol/L. Gallstone disease and a family history of ICP were significantly (P < .001) more prevalent in the group of ICP patients with higher bile acid levels. In conclusion, we found an incidence of ICP in our population of 1.5%. From complication rates recorded prospectively, we could define a mild (81%) and a severe (19%) form of ICP, the latter with bile acid levels ≥40 μmol/L. No increase in fetal risk was detected in ICP patients with bile acid levels < 40 μmol/L, and we propose that these women be managed expectantly, which would significantly reduce the costs of medical care. (Hepatology 2004;40:467-474.)
HEK 293 cell suspension culture using fibronectin‐adsorbed polymer nanospheres in serum‐free medium
Authors: Ryu Ju Hee , Kim Sang‐Soo , Cho Seung‐Woo , Choi Cha Yong , Kim Byung‐Soo
Published: August 2004

Previously, we reported on suspension culture of anchorage‐dependent animal cells using plain polymer nanospheres in serum‐containing medium. For commercial cell culture, it is more advantageous to use serum‐free medium than serum‐containing medium. To culture anchorage‐dependent animal cells using polymer nanospheres in serum‐free medium, the nanospheres need to be coated with cell adhesion proteins. In this study, we utilized fibronectin‐adsorbed polymer nanospheres for suspension culture of anchorage‐dependent animal cells in serum‐free medium. Fibronectin was adsorbed onto poly(lactic‐co‐glycolic acid) nanospheres (433 nm in average diameter) by immersing the nanospheres in fetal bovine serum. The nanospheres were used to culture human embryonic kidney (HEK) 293 cells in serum‐free medium in stirred suspension bioreactors. Nanospheres attached between HEK 293 cells and promoted cell aggregate formation compared with culture without nanospheres. Most cells in the aggregates were viable over a 10‐day culture period. Importantly, the use of poly(lactic‐co‐glycolic acid) nanospheres promoted the cell growth significantly, compared with culture without nanospheres (3.8‐ vs 1.8‐fold growth). The nanosphere culture method developed in this study removes the time‐consuming and costly process of adaptation of anchorage‐dependent animal cells to suspension culture in serum‐free medium. This culture method may be useful for the large‐scale suspension culture of various types of anchorage‐dependent animal cells in serum‐free medium. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 71A: 128–133, 2004
In vitro study of cell‐promoting multiple‐armed peptides
Authors: Li Cheng , Zheng Yi , Imran Mir
Published: August 2004

The purpose of this study was to compare the effectiveness of several linear and branch cell‐binding peptides to promote cell growth in prosthetic vascular grafts. In this in vitro study, the peptides were covalently immobilized onto expanded polytetrafluoroethylene (ePTFE) vascular grafts. Cell‐growth properties were studied using primary human umbilical vein endothelial cells (HUVECs) and primary human umbilical artery smooth muscle cells (HUASMCs). Linear peptides (P15 and P15′) and multiple‐armed peptides (MAP4‐I and MAP4‐II) were covalently bonded onto ePTFE grafts by an atmospheric plasma coating method. X‐ray photoelectron spectroscopy and amino acid analysis were used to analyze the surface characteristics of the peptide‐coated samples. Cell adhesion, proliferation, and morphology were evaluated by culturing HUVECs and HUASMCs onto the surfaces of different samples: ePTFE control, chemically activated ePTFE, P15‐coated ePTFE, and MAP4‐coated ePTFE. The cell culture experiments were repeated several times to obtain statistically reliable cell‐growth data. Cell‐growth data were statistically analyzed by the two‐way statistical analysis of variance. The study showed that multiple‐armed MAP4 peptides were significantly more effective in promoting endothelial cells than the structurally similar linear P15 peptides. There were 800% more HUVECs proliferated on the MAP4‐coated ePTFE samples compared with the ePTFE control. MAP4 peptides were 80% more effective for promoting HUVECs than P15 peptides. In contrast, MAP4 peptides were significantly less effective for promoting HUASMCs than HUVECs. There were only about 100% more HUASMCs proliferated on the MAP4‐coated ePTFE samples compared with the ePTFE control. MAP4 and P15 peptides had similar cell‐promoting characteristics for SMCs. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 71A: 134–142, 2004
Three‐dimensional gait biomechanics in Parkinson's disease: Evidence for a centrally mediated amplitude regulation disorder
Authors: Morris Meg , Iansek Robert , McGinley Jennifer , Matyas Thomas , Huxham Frances
Published: August 2004

We examined whether people with Parkinson's disease (PD) have a central amplitude regulation disorder using three‐dimensional (3‐D) gait analyses to compare the effects of medication and attentional strategies on gait in 12 PD subjects and 12 matched comparison subjects. Subjects with PD first performed several 10‐m gait trials at preferred speed whileofflevodopa. They then walked at preferred speed on levodopa;offlevodopa with cues; andonlevodopa with cues. Control subjects walked at preferred speed and then with visual cues to match their stride length to PD values. As well as spatiotemporal footstep data, pelvic and lower limb kinematic profiles and angle–angle diagrams were produced for sagittal, coronal, and transverse plane movements using a 3‐D motion analysis system. In people with PD, decreased step length was accompanied by reduced movement amplitude across all lower limb joints, in all movement planes. When control subjects were required to walk with short steps matched to the size of PD comparisons, they displayed a similar multijoint reduction in amplitude. For PD subjects, both levodopa and visual cues increased movement amplitude across all lower limb joints. Amplitude increased further when levodopa and visual cues were combined, resulting in normalization of step length. This finding suggested that reduced step length is due to a mismatch between cortically selected movement amplitude and basal ganglia maintenance mechanisms. Levodopa and cues normalized amplitude across all joints by altering motor set and bypassing defective basal ganglia mechanisms. © 2004 Movement Disorder Society
Melting behavior of polyethylene/α‐olefin copolymers: Narrow composition distribution copolymers and fractions from Ziegler–Natta and single‐site catalyst products
Authors: Mirabella Francis M. , Crist Buckley
Published: August 2004

The melting temperature and heat of fusion were measured for an extensive series of compositionally uniform copolymers of ethylene with butene‐1, hexene‐1, and octene‐1. Fractions and whole polymers that exhibited minimal interchain compositional heterogeneity were from commercial copolymers made with either Ziegler–Natta (ZN) or single‐site metallocene catalysts. The present results do not support recent claims that ZN and corresponding metallocene catalyst copolymers melt at significantly different temperatures, nor the implication that comonomer incorporation is “blocky” in ZN copolymers. In five of the six comonomer/catalyst systems the dependencies of the melting temperature on comonomer type and amount were scarcely distinguishable. This common behavior is the same as that for a model random copolymer, so we conclude that most ethylene/α‐olefin copolymers have random distributions of ethylene sequences. The exception in the present study is a metallocene ethylene/butene‐1 copolymer that melts at lower temperatures and apparently has perceptibly alternating sequence distributions. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3416–3427, 2004
Children with smoking parents have a higher airway resistance measured by the interruption technique
Authors: Kooi Elisabeth M.W. , Vrijlandt Elianne J.L.E. , Boezen H. Marike , Duiverman Eric J.
Published: August 2004

Children exposed to environmental tobacco smoke, during or after pregnancy, are known to have decreased lung function. So far this has been measured using spirometry in schoolchildren and invasive techniques in newborns. The interruption technique (Rint) is a noninvasive technique to measure airway resistance in preschool children. Our aim in this study was to investigate the effect of passive smoke exposure on Rint values in preschool and school‐aged children. Rint values were obtained from 557 children in two nursery and two primary schools in the north of the Netherlands. Besides information on parental smoking habits, we collected data on characteristics that might affect airway resistance (respiratory symptoms, atopy, and family history for asthma), using a short questionnaire. Multiple linear regression was used to estimate the associations of these characteristics with Rint, for the whole group as well as for the preschool group separately. Atopy or a positive family history for asthma did not affect Rint values in the total group of 4–12‐year‐olds. However, as may be expected, height, age, weight, and having respiratory symptoms were associated with Rint. Moreover, Rint was significantly increased if parents smoked three or more cigarettes a day in the presence of their child. This result remained after subgroup analysis in the preschool children (4–6 years old). We conclude that passive smoke exposure is associated with a significantly higher airway resistance in preschool and school‐aged children measured by Rint. © 2004 Wiley‐Liss, Inc.
Estimates on the growth of meromorphic solutions of linear differential equations
Authors: Chiang Yik-Man , Hayman Walter K.
Published: August 2004

We give a pointwise estimate of meromorphic solutions of linear differential equations with coefficients meromorphic in a finite disk or in the open plane. Our results improve some earlier estimates of Bank and Laine. In particular we show that the growth of meromorphic solutions with ()>0 can be estimated in terms of initial conditions of the solution at or near the origin and the characteristic functions of the coefficients. Examples show that the estimates are sharp in a certain sense. Our results give an affirmative answer to a question of Milne Anderson.
Hyperelliptic components of the moduli spaces of quadratic differentials with prescribed singularities
Authors: Lanneau Erwan
Published: August 2004

Moduli spaces of quadratic differentials with prescribed singularities are not necessarily connected. We describe here all cases when they have a special hyperelliptic connected component. We announce the general classification theorem: up to the four exceptional cases in low dimensional stratum, any stratum of meromorphic quadratic differentials is either connected, or has exactly two connected components. In this last case, one component is hyperelliptic, the other not.
Symplectic homology and periodic orbits near symplectic submanifolds
Authors: Cieliebak Kai , Ginzburg Viktor L. , Kerman Ely
Published: August 2004

We show that a small neighborhood of a closed symplectic submanifold in a geometrically bounded aspherical symplectic manifold has non-vanishing symplectic homology. As a consequence, we establish the existence of contractible closed characteristics on any thickening of the boundary of the neighborhood. When applied to twisted geodesic flows on compact symplectically aspherical manifolds, this implies the existence of contractible periodic orbits for a dense set of low energy values.
Opioids in neuropathic pain: clues from animal studies
Authors: Dickenson Anthony H. , Suzuki Rie
Published: August 2004

For many years the clinical consensus was that opioids were ineffective in neuropathic pain. However this view is changing and here we discuss the mechanisms of opioid analgesia in terms of the changes that can occur in preclinical models of nerve injury. We argue that opioid mechanisms can be perturbed by neuropathy but in most cases these negative influences can be overcome by dose‐escalation.
The death domain protein p84N5, but not the short isoform p84N5s, is cell cycle‐regulated and shuttles between the nucleus and the cytoplasm
Authors: Gasparri Fabio , Sola Francesco , Locatelli Giuseppe , Muzio Marta
Published: August 2004

P84N5 is a death domain containing protein that interacts with the tumor suppressor retinoblastoma protein and induces apoptosis. We cloned and characterized two novel alternatively spliced versions of p84N5. The p84N5 short isoform (p84N5s) lacks the death domain and does not induce apoptosis. We showed that p84N5, but not p84N5s, is cell cycle regulated. We found that p84N5‐GFP chimera can rapidly shuttle between the nucleus and the cytoplasm. Taken together, these observations suggest that p84N5 may transmit signals from the nucleus to cytoplasmic effectors.
Involvement of MPK4 in osmotic stress response pathways in cell suspensions and plantlets of Arabidopsis thaliana: activation by hypoosmolarity and negative role in hyperosmolarity tolerance
Authors: Droillard Marie-Jo , Boudsocq Marie , Barbier-Brygoo Hélène , Laurière Christiane
Published: August 2004

Three of the protein kinases activated by hypoosmotic stress in Arabidopsis thaliana cell suspensions were previously characterized [FEBS, 2002, 527, 43–50] as mitogen‐activated protein (MAP) kinases and two of them corresponded to Arabidopsis mitogen‐activated protein kinase 6 (MPK6) (44 kDa) and MPK3 (39 kDa). The third MAP kinase was identified here to MPK4, using a corresponding specific antibody. Like MPK6 and MPK3, MPK4 activity is clearly inhibited by apigenin and MPK4 activation by hypoosmolarity needs upstream phosphorylation events. Activation of the 3 MAP kinases, MPK3, 4 and 6, was confirmed in plantlets submitted to hypoosmotic stress. The action of a biotic signal, flagellin, was also demonstrated to induce the activations of the 3 MAP kinases. Using the mutant displaying MPK4 gene inactivation, the independence of the MPK3 and MPK6 activations towards the presence of MPK4 was demonstrated, both in hypoosmotic and flagellin signalling pathways. Although MPK4 was not activated by hyperosmolarity in cell suspensions nor in seedlings, a possible negative regulation of hyperosmolarity resistance by MPK4 is suggested, based both on phenotype and downstream gene expression studies.
The role of AMPA and metabotropic glutamate receptors on morphine withdrawal in infant rats
Authors: Zhu Hongbo , Barr Gordon A.
Published: August 2004

Glutamate receptors, especially N‐methyl‐d‐aspartate (NMDA) receptors, are hypothesized to play key roles in opiate tolerance and withdrawal. There is also accumulating evidence that α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid (AMPA) receptor antagonists and group II metabotropic glutamate receptor (mGluR) agonists attenuate opiate withdrawal. However, most existing data are derived from adult animal models. Glutamate receptor types undergo dramatic developmental changes during early life. Thus, the pharmacological effects on opiate withdrawal of NMDA receptor, AMPA receptor, and mGluR antagonists in the developing organism may not be comparable to those in the adult. Indeed, NMDA receptor antagonists do not block morphine tolerance or withdrawal in the 7‐day‐old rat, but are partially effective in the 14‐day‐old, and fully effective in the 21‐day‐old. Thus, there is a transition period around the second post‐natal week for NMDA receptor antagonists to suppress opiate tolerance and withdrawal. A combination of in vivo and in vitro assays was used in the present studies to test the effect of drugs acting on AMPA and group II mGlu receptors on morphine withdrawal in rats at 7, 14, and 21 days of age. These ages represent the critical periods when various glutamate receptor subunits undergo differential change. In contrast to NMDA receptor antagonists’ early ineffectivness in suppressing morphine withdrawal, the AMPA receptor antagonist and the group II mGluR agonists were effective at all ages tested. Thus, for the human infant patient, pharmacotherapies to reduce opiate tolerance and withdrawal should focus on non‐NMDA ionotropic and metabotropic receptors.
Measuring Psychological “Knowledge” by Means of Instructors' Test Manuals
Authors: Furnham Adrian , Thompson Charlotte , Baluch Bahman
Published: August 2004

American social psychology textbooks often provide instructors' manuals that include Multiple Choice Quizzes (MCQ's) used by researchers examining the extent to which “lay people” could predict the outcomes of psychological research and theories. This study examined the extent to which students could choose a correct answer from social psychology instructors' manuals without having attended a related course. Three different manuals were used to look at tests of 57, 46, and 36 items, chosen to avoid technical jargon, real names, and experimental details, as well as to cover the broad range of social psychology. Subjects in Study 1 (n = 98 life sciences students) and Study 3 (n = 100 new students) got over 50% of the answers correct (53% and 52%, respectively), while in Study 2 (n = 139 student applicants) they got 48% correct. Scores were unrelated to gender and age, and there was no clear relationship between knowledge and particular areas of social psychology (i.e., social influone, prosocial behavior, attitude change). In the first study, prior knowledge of psychology did not relate to total score, while in the second sample, students who attended lectures did score higher than those who did not. In the third study, subjects who reported reading books, or who had how on social psychology courses, did score marginally higher. Implications of these findings are discussed.
Frequencies of standing Alfvén wave harmonics and their implication for plasma mass distribution along geomagnetic field lines: Statistical analysis of CRRES data
Authors: Takahashi Kazue , Denton Richard E. , Anderson Roger R. , Hughes W. Jeffrey
Published: August 2004

The relationship among the frequencies of the harmonics of standing Alfvén waves depends on the variation of plasma mass density along the geomagnetic field line. This in turn means that observed standing wave frequencies may be used to infer the mass density variation, which is difficult to measure with particle instruments on spacecraft. Determination of the density variation is important in understanding mass transport processes in the ionosphere‐magnetosphere system and also in improving magnetospheric diagnostic techniques using ULF waves. We investigate the frequencies of multiharmonic toroidal standing Alfvén waves detected in the electric and magnetic fields measured by the Combined Release and Radiation Effects Satellite (CRRES). The data cover the entire CRRES mission period from July 1990 to October 1991. Using a semi‐automated procedure, we identify over 4000 samples of the fundamental toroidal frequency (f1), which are often accompanied by the second (f2) and third (f3) harmonics. Most (∼3000) fundamental frequency samples are taken at dipole L shells from 4 to 8 and at magnetic local time (MLT) from 1200 to 1800, and we perform statistical analyses of the frequencies in this L‐MLT domain. The most frequently observed ratios are f2/f1 ∼ 2.5 and f3/f1 ∼ 4.0 for 4 ≤ L < 6 and f2/f1 ∼ 2.8 and f3/f1 ∼ 4.3 for 6 ≤ L < 7. These observations are compared with the theoretical ratios obtained for the density variation of the form ρ = ρeq(LRE/R)α, where ρeq is the equatorial mass density, L is the magnetic shell parameter, R is geocentric distance to the field line, and the power law density index α is a free parameter. We find that α ∼ 0.5 fits the average observed frequency ratios at 4 ≤ L < 6, consistent with a diffusive equilibrium solution. No single value of α fits the average observed frequency ratios at 6 ≤ L < 7. In that case, theoretical solutions indicate that the mass density is locally peaked at the equator; that is, the mass density decreases as one moves off‐equator, then increases again toward the ionosphere. Combined with the results of recent studies of electron density (which have not found such a peak in density at the magnetic equator), this indicates that heavy ions are preferentially concentrated at the magnetic equator.
Water exchange and tidal currents through the Bussol' Strait revealed by direct current measurements
Authors: Katsumata Katsurou , Ohshima Kay I. , Kono Tokihiro , Itoh Motoyo , Yasuda Ichiro , Volkov Yury N. , Wakatsuchi Masaaki
Published: August 2004

An outflow from the Sea of Okhotsk to the North Pacific was measured at the Bussol' Strait, the largest strait connecting these basins, from 31 August to 11 September 2001. Yo‐yo casts of a lowered acoustic Doppler current profiler were performed at 13 stations across the narrowest part of the strait. Time series covering more than approximately 24 hours were obtained for each station, and the semidiurnal and diurnal tides were separated. The diurnal tide at the spring tide shows a remarkable peak of the amplitude of 1.1 m s−1 at the depth below 1000 m in the western channel of the strait. The upper part of the mean component flows toward the Pacific, and the lower part flows in the opposite direction. The outflow is in excess of the inflow, and net transport through the strait is 8.2 to 8.8 Sv (1 Sv = 106 m3 s−1). The outflow is strong in two density ranges. The upper layer peak around 26.8 σθ corresponds to the density of North Pacific Intermediate Water and the temperature‐salinity characteristics of this outflow were actually observed in this density range across downstream the Oyashio off the southeastern coast of Hokkaido. Net heat and salt exchanges between the Sea of Okhotsk and the North Pacific are estimated; net heat flux of −34 TW and net salt flux of −1.9 × 106 kg s−1 are exchanged from the Sea of Okhotsk to the North Pacific.
Drifter measurements in a laboratory rip current
Authors: Kennedy Andrew B. , Thomas David
Published: August 2004

This paper investigates circulation in a laboratory rip current system using large numbers of Lagrangian drifters, with supplementary current meter and water level measurements. These represent the most dense measurements to date of laboratory rip circulation over a large spatial area. Overall, circulation is found to be very unsteady, with strong changes in circulation apparent at many length and time scales. Drifter and current meter measurements are compared in the rip channel, and Stokes drift is found to be a significant component of drifter velocities in this region. Estimated generation of circulation is compared with computed bottom friction dissipation, with good agreement. The mean cellular circulation about a dividing streamline is found to be surprisingly small when compared with computed rates of generation of circulation. Finally, the divergence of volume flux computed using drifters is found to be significant, with depth‐varying wave‐induced mass transport, depth‐varying Eulerian velocities, and velocity/drifter concentration effects the likely sources of error.
Observations of banding in first‐year Arctic sea ice
Authors: Cole David M. , Eicken Hajo , Frey Karoline , Shapiro Lewis H.
Published: August 2004

Horizontal banding features, alternating dark and bright horizontal bands apparent in ice cores and stratigraphic cross sections have long been observed in first‐year sea ice and are frequently associated with bands of high and low brine or gas porosity. Observations on the land‐fast ice near Barrow, Alaska, in recent years have revealed particularly striking banding patterns and prompted a study of their macroscopic and microscopic characteristics. The banding patterns are quantified from photographs of full‐depth sections of the ice, and examples are presented from the Chukchi Sea and Elson Lagoon. Statistics on band spacing are presented, and the growth records for three seasons are employed to estimate their time of formation. These data provide insight into the periodicity of the underlying phenomena. Micrographs are used to examine the microstructural variations associated with various banding features and to quantify the geometry of the constituent brine inclusions associated with high‐ and low‐porosity bands. The micrography revealed that the area fraction of brine inclusions varied by a factor of nearly 3 through the more pronounced high‐ and low‐porosity bands. Vertical micrographs obtained shortly after the materials' removal from the ice sheet showed that significantly larger inclusions form abruptly at the start of the high‐porosity bands and frequently terminate abruptly at the end of the band. Crystallographic observations indicated that the high‐porosity bands supported the nucleation and growth of crystals having substantially different orientations from the very well aligned columnar structure that characterized the bulk of the sheet.