bluuebunny/crossref_metadata_2025 huggingface dataset:
Expression of allograft inflammatory factor 1 in tissues from patients with systemic sclerosis and in vitro differential expression of its isoforms in response to transforming growth factor β
Authors: Galdo Francesco Del , Maul Gerd G. , Jiménez Sergio A. , Artlett Carol M.
Published: July 2006

Objective

Allograft inflammatory factor 1 (AIF‐1), a protein initially identified in chronically rejected rat cardiac allografts, is involved in the immune response and proliferative vasculopathy that occurs during allograft rejection. Three well‐characterized isoforms of AIF‐1 result from alternative messenger RNA (mRNA) splicing. We previously identified a strong association of systemic sclerosis (SSc) with a polymorphism in AIF‐1 isoform 2. The purpose of this study was to investigate AIF‐1 expression in affected tissues from patients with SSc and to examine the regulation of its isoforms by transforming growth factor β (TGFβ).

Methods

AIF‐1 in the skin and lung tissues of patients with SSc was analyzed by immunochemistry. AIF‐1 isoform expression in response to TGFβ and interferon‐γ stimulation was examined by quantitative polymerase chain reaction (PCR).

Results

AIF‐1 protein was present in affected vessels of the lung and skin lesions of patients with SSc. Quantitative PCR showed an average of 14‐fold higher mRNA levels in affected SSc skin than in normal skin. Double‐label immunofluorescence staining demonstrated that T cells, macrophages, and endothelial cells in affected tissues expressed AIF‐1. Stimulation of peripheral blood mononuclear cells with TGFβ caused a specific and significant increase in the expression of AIF‐1 isoform 2 transcripts (P < 0.005), which was due to stabilization of AIF‐1 isoform 2 mRNA.

Conclusion

These data suggest that AIF‐1 plays an important role in the pathogenesis of SSc owing to its increased expression in affected tissues and to the specific stimulation of AIF‐1 isoform 2 by TGFβ.
Gout and the risk of acute myocardial infarction
Authors: Krishnan Eswar , Baker Joshua F. , Furst Daniel E. , Schumacher H. Ralph
Published: July 2006

Objective

To determine if hyperuricemia and gouty arthritis are independent risk factors for acute myocardial infarction (MI) and, if so, whether they are independent of renal function, diuretic use, metabolic syndrome, and other established risk factors.

Methods

We performed multivariable logistic and instrumental variable probit regressions on data from the Multiple Risk Factor Intervention Trial (MRFIT).

Results

Overall, there were 12,866 men in the MRFIT who were followed up for a mean of 6.5 years. There were 118 events of acute MI in the group with gout (10.5%) and 990 events in the group without gout (8.43%; P = 0.018). Hyperuricemia was an independent risk factor for acute MI in the multivariable regression models, with an odds ratio (OR) of 1.11 (95% confidence interval [95% CI] 1.08–1.15, P < 0.001). In multivariable regressions in which the above risk factors were used as covariates, gout was found to be associated with a higher risk of acute MI (OR 1.26 [95% CI 1.14–1.40], P < 0.001). Subgroup analyses showed that a relationship between gout and the risk of acute MI was present among nonusers of alcohol, diuretics, or aspirin and among those who did not have metabolic syndrome, diabetes mellitus, or obesity. In separate analyses, a relationship between gout and the risk of acute MI was evident among those with and without those hyperuricemia.

Conclusion

The independent risk relationship between hyperuricemia and acute MI is confirmed. Gouty arthritis is associated with an excess risk of acute MI, and this is not explained by its well‐known links with renal function, metabolic syndrome, diuretic use, and traditional cardiovascular risk factors.
Computer‐aided virtual reconstruction of Italian ancient clocks
Authors: Pennestrì E. , Pezzuti E. , Valentini P.P. , Vita L.
Published: July 2006

Italy has plenty of cultural heritages. The masterpieces are often placed in locations which are difficult to reach, moreover many artifacts, coming from man's creativity, have very complex functioning. The authors of this paper describe their experience in using the computer graphics capabilities in order to reproduce four ancient clocks functioning coming from different Italian regions. The study is based not only on the 3D‐shapes reconstruction but also on the simulation of their complex mechanisms in order to mimic their functioning. The realism of the reconstruction allows to use the graphical products in exhibits, museums and also for maintenance programs. The rendering techniques together with an accurate camera path, allow to get into the clock mechanisms and to appreciate all the features (and even secrets) that a simple glance cannot reveal. Copyright © 2006 John Wiley & Sons, Ltd.
Induction of Apoptosis in HeLa Cells by 3β‐Hydroxyurs‐12‐en‐27‐oic Acid
Authors: Zheng Quan‐Fang , Sun Hong‐Xiang , He Qiao‐Jun , Ye Yi‐Ping
Published: July 2006

3β‐Hydroxyurs‐12‐en‐27‐oic acid (1), a pentacyclic triterpenoid isolated from the rhizomes of Astilbe chinensis, was structurally very similar to ursolic acid, with the only difference being the interchange of the COOH and Me group at C(14) and C(17). Ursane‐type triterpene with a COOH group at C(14) is present in a limited number of natural resources. Compound 1 was found to exhibit more distinctive cytotoxicity toward human cervical squamous carcinoma (HeLa) cells than ursolic acid, suggesting that the position of the COOH group significantly affects the cytotoxicity of ursane‐type pentacyclic triterpenes with a COOH group. To elucidate the underlying biological mechanism responsible for the cytotoxicity of 1, we investigated its growth‐inhibitory and apoptosis‐inducing effect on HeLa cells. Compound 1 induced a marked concentration‐ and time‐dependent inhibition of cell proliferation with an IC50 value of 6.80±0.88 μg/ml following 48 h incubation. The drug‐treated HeLa cells displayed typical morphological apoptotic characteristics and formation of DNA ladders in agarose‐gel electrophoresis. Flow cytometric analysis showed that the cell cycle was arrested in G0/G1 phase by 1, and the apoptotic rate of HeLa cells treated for 48 h with 20 μg/ml of 1 was 21.08±2.14%. Also, 1 increased and decreased the expression of Bax and Bcl‐2 proteins, respectively, and lowered the mitochondrial transmembrane potential (Δψm). The peptidic capase‐3 inhibitor DEVD‐CHO (NH2‐Asp‐Glu‐Val‐Asp‐CHO, at 2 μM) could increase the viability of HeLa cells previously treated with 1. These results indicate that 1 induces efficient cell apoptosis through down‐regulating Bcl‐2 expression, up‐regulating Bax expression, lowering Δψm, and by activating the caspase‐3 pathway.
Five New Iridoids from Patrinia rupestris
Authors: Yang Xiu‐Ping , Li Er‐Wei , Zhang Qi , Yuan Cheng‐Shan , Jia Zhong‐Jian
Published: July 2006

Five new iridoids, namely rupesin A–E (1–5, resp.), together with six known iridoids, 6–11, were isolated from the roots of Patrinia rupestris. Their structures were elucidated by spectroscopic methods including IR, UV, MS, and 1D‐ and 2D‐NMR experiments, and comparison with data of known analogues. Compounds 4 and 11, compounds 1, 2, 5, 6, 8, 9, and 10, and compounds 3, 4, and 8 showed significant antibacterial activities against Bacillus subtilis, Escherichia coli, and Staphylococcus aureus, respectively.
Four New Compounds from the Leaves of Acer truncatum
Authors: Dong Lang‐Ping , Liu Hai‐Yang , Ni Wei , Li Jun‐Zhu , Chen Chang‐Xiang
Published: July 2006

Four new compounds, 3‐(4‐hydroxy‐3,5‐dimethoxyphenyl)propyl formate (1), 2,6‐dimethoxy‐4‐[(1S)‐3‐methoxypropyl]phenol (2), (1R,2R)‐4‐[(3R)‐3‐hydroxybutyl]‐3,3,5‐trimethylcyclohex‐4‐ene‐1,2‐diol (3), and (1S,3R,3aR,6S,7S,9aR)‐decahydro‐1‐(hydroxymethyl)‐1,7‐dimethyl‐3a,7‐methano‐3aH‐cyclopentacyclooctene (4) were isolated from the leaves of Acer truncatum, together with twelve known compounds. Their structures were elucidated on the basis of extensive spectroscopic techniques. The absolute configuration of compound 3 was established by the modified Mosher's method. All compounds were evaluated for antibacterial activities.
Cytotoxic Sulfated Triterpene Glycosides from the Sea Cucumber Pseudocolochirus violaceus
Authors: Zhang Shu‐Yu , Yi Yang‐Hua , Tang Hai‐Feng
Published: July 2006

Bioassay‐guided fractionation of the active BuOH extract of the sea cucumber Pseudocolochirus violaceus resulted in the isolation of three new sulfated triterpene glycosides, i.e., violaceusides I, II, and III (1–3, resp.), as active compounds causing morphological abnormality of Pyricularia oryzae mycelia. Their structures were elucidated by spectroscopic methods including 2D‐NMR and MS experiments, as well as chemical evidence. Compounds 1–3 exhibit the same structural features, i.e., the presence of a 16‐oxo group in the holostane‐type triterpene aglycone with the C(7)C(8) bond, but differ in the side chains and the tetrasaccharide moieties. Compound 1 possesses one sulfate group, while 2 and 3 are disulfated glycosides. All the glycosides showed significant in vitro cytotoxicities against human gastric cancer MKN‐45 and human colon cancer HCT‐116 cells.
Synthesis, Structure and Magnetic properties of Chiral and Nonchiral Transition‐Metal Malates
Authors: Beghidja Adel , Rabu Pierre , Rogez Guillaume , Welter Richard
Published: July 2006

Carboxylate‐bridged complexes of transition metals, MII=MnII, FeII, CoII, NiII, ZnII, were synthesised by reaction of MII salts with dl‐malate and L‐malate under hydrothermal conditions. These complexes form four series of compounds, which have been fully characterised structurally, thermally and magnetically. The crystal structures of the new chiral compounds, [Mn(L‐mal)(H2O)] (1), [Fe(L‐mal)(H2O)] (2), [Co(L‐mal)(H2O)] (3) and [Zn(L‐mal)(H2O)] (4) as well as those of the bimetallic analogues [Mn0.63Co0.37(L‐mal)(H2O)] (5) and [Mn0.79Ni0.21(L‐mal)(H2O)] (6) have been solved by single‐crystal X‐ray diffraction. The six L‐malate monohydrates crystallise in the chiral space group P212121 and consist in a three‐dimensional network of metal(II) centres in octahedral sites formed by oxygen atoms. These structures were compared to those of the chiral trihydrate compounds [Co(L‐mal)(H2O)]⋅2 H2O (7), [Ni(L‐mal)(H2O)]⋅2 H2O (8) and [Co0.52Ni0.48(L‐mal)(H2O)]⋅2 H2O (9), which exhibit helical chains of MII centres, and those of dl‐malate dihydrates [Co(dl‐mal)(H2O)]⋅H2O (10) and [Ni(dl‐mal)(H2O)⋅H2O (11) and trihydrate [Mn(L‐mal)(H2O)]⋅2 H2O (12) highlighting the great flexibility of the coordination by the malate ligand. UV/Vis spectroscopic results are consistent with octahedral coordination geometry of high‐spin transition‐metal centres. Extensive magnetic characterisation of each homologous series indicates rather weak coupling interaction between paramagnetic centres linked through carboxylate bridges. Curie‐like paramagnetic, antiferromagnetic, ferromagnetic or weak ferromagnetic behaviour is observed and discussed on the basis of the structural features. The bimetallic compounds 5 and 6 represent new examples of chiral magnets.
Highly Selective Recognition of Adenine Nucleobases by Synthetic Hosts with a Linked Five‐Six‐Five‐Membered Triheteroaromatic Structure and the Application to Potentiometric Sensing of the Adenine Nucleotide
Authors: Hisamatsu Yosuke , Hasada Keiko , Amano Fumi , Tsubota Yasuhiro , Wasada‐Tsutsui Yuko , Shirai Naohiro , Ikeda Shin‐ichi , Odashima Kazunori
Published: July 2006

A new structure for an adenine‐selective host molecule, featuring the pertinent link of five‐six‐five‐membered heteroaromatic rings and two carbamoyl NH sites, was developed. This structure provides a correctly oriented array of complementary hydrogen bonding sites for the adenine nucleobase, which exploits both Watson–Crick and Hoogsteen‐type interactions. The complexation with adenine nucleobases by multiple hydrogen bonding was supported by 1H NMR spectroscopy. This type of host displayed high selectivity in complexation, with an accompanying fluorescent response to lipophilized adenosine in CHCl3. Furthermore, a remarkably selective potentiometric response was attained for adenosine 5′‐monophosphate over 5′‐GMP, 5′‐CMP, and 5′‐UMP by using an ion‐selective electrode with a PVC‐supported solvent polymeric membrane. This indicates recognition of water‐soluble nucleotide guests through the membrane–water interface. These findings are expected to form a reliable basis for the development of artificial sensing systems for mononucleotides in biological systems.
Electrochemically Degraded Dopamine Film for the Determination of Dopamine
Authors: Chang Hye‐Young , Kim Dong Il , Park Yu Chul
Published: July 2006

A dopamine (DA) polymer was deposited electrochemically on to a glassy carbon (GC) surface until the electrode surface was passivated. The DA film on the GC surface was re‐formed for high sensitivity and reproducibility by electrochemical degradation. The re‐formed electrode was sensitive and selective in the determination of DA in the presence of ascorbic acid. The linear range obtained by square‐wave voltammetry was between 0.1 and 2.1 μM (R=0.996, n=6) with a sensitivity of 1.2 μA μM−1 and a detection limit (S/N=3) of 0.04 μM. The electropolymerized DA film was stable and the re‐formed electrode was reproducible for DA determination.
A Novel Al(III)‐Selective Electrochemical Sensor Based on N,N′‐Bis(salicylidene)‐1,2‐phenylenediamine Complexes
Authors: Gholivand M. B. , Ahmadi F. , Rafiee E.
Published: July 2006

A polyvinylchloride membrane sensor based on N,N′‐bis(salecylidene)‐1,2‐phenylenediamine (salophen) as membrane carrier was prepared and investigated as a Al3+‐selective electrode. The sensor exhibits a Nernstian response toward Al(III) over a wide concentration range (8.0×10−7–3.0×10−2 M), with a detection limit of 6.0×10−7 M. The potentiometric response of the sensor is independent of the pH of the test solution in the pH range 3.2–4.5. The electrode possesses advantages of very fast response and high selectivity for Al3+ in comparison with alkali, alkaline earth and some heavy metal ions. The sensor was used as an indicator electrode, in the potentiometric titration of aluminum ion and in determination of Al3+ contents in drug, water and waste water samples.
Bioelectrochemical Magnetic Immunosensing of Trichloropyridinol: A Potential Insecticide Biomarker
Authors: Liu Guodong , Timchalk Charles , Lin Yuehe
Published: July 2006

A fast, simple and sensitive bioelectrochemical magnetic immunosensing method is developed to monitor a potential insecticide biomarker, trichloropyridinol (TCP), in environmental sample. A magnet/glassy carbon (MGC) working electrode was used to accumulate immunocomplex associated magnetic beads and separate free and unbound reagents after liquid phase competitive immunoreaction among TCP antibody coated magnetic beads, TCP analyte and horseradish peroxidase (HRP) labeled TCP. The activity of HRP tracers was monitored by square‐wave voltammetry (SWV) by scanning electrocactive enzymatic product in the presence of 3,3′,5,5′‐tetramethylbenzidine dihydrochloride and hydrogen peroxide (TMB‐H2O2) substrate solution. The electrochemical signal of enzymatic product was greatly enhanced by dual accumulation events: magnetic accumulation of enzyme tracers bound magnetic beads and constant potential accumulation of enzymatic product. The voltammetric characteristics of substrate and enzymatic product were investigated, and the parameters of SWV analysis and immunoassay were optimized. Under the optimal conditions the immunosensor was used to measure as low as 5 ng L−1 (ppt) TCP, which is 50‐fold lower than the value indicated by the manufacture of the TCP RaPID Assay kit (0.25 μg/L, colorimetric detection). The performance of the developed immunosensing system was successfully evaluated with river water samples spiked with TCP, indicating this convenient and sensitive technique offers great promise for decentralized environmental application. This technique could be readily used for detection of other environmental contaminants by developing specific antibodies against the contaminants and are expected to open new opportunities for environmental monitoring and public health.
Redox Properties of Ferricyanide Ion on Layer‐by‐Layer Thin Film‐Coated Gold Electrodes; Effects of Type of Polycationic Components in the Film
Authors: Takita Ryoichi , Okamura Yukiko , Endo Yoshihiro , Anzai Jun‐ichi
Published: July 2006

The surface of a gold (Au) electrode was coated with layer‐by‐layer (LbL) thin films composed of poly(vinyl sulfate) (PVS) and different type of poly(amine)s including poly(allylamine) (PAH), poly(ethyleneimine) (PEI) and poly(diallyldimethylammonium chloride) (PDDA) and redox properties of ferricyanide ion ([Fe(CN)6]3−) on the LbL film‐coated Au electrodes were studied. The LbL film‐coated electrodes exhibited redox response to [Fe(CN)6]3− ion when the outermost surface of the LbL film was covered with the cationic poly(amine)s while virtually no response was observed on the LbL film‐coated electrodes whose outermost surface was covered with PVS due to an electrostatic repulsion between [Fe(CN)6]3− ion and the negatively‐charged PVS layer. The redox properties of [Fe(CN)6]3− ion on the LbL film‐coated electrodes significantly depended on the type of polycationic materials in the LbL film. The LbL film‐coated electrodes which had been immersed in the [Fe(CN)6]3− solution for 15 min exhibited redox response even in a [Fe(CN)6]3− ion‐free buffer solution, suggesting that [Fe(CN)6]3− ion is confined in the films. In the buffer solution, redox peaks were observed between +0.1 and 0.4 V depending on the type of polycations in the film. Thus, [Fe(CN)6]3− ion can be confined in the film and the redox potential is polycation‐dependent.
Tape Casting of Graphite Material: A New Electrochemical Sensor
Authors: Chicharro M. , Bermejo E. , Moreno M. , Sánchez A. , Zapardiel A. , Rubio‐Marcos F. , Villegas M.
Published: July 2006

Tape casting is a feasible method for preparing ceramic tapes with different electrical and magnetic properties for multilayer ceramic devices. This paper describes the tape casting process for the preparation of a new kind of self‐standing carbon electrodes (SSCE) using different ratios of graphite and the organic additives generally used in the non‐aqueous tape casting process.
Lyotropic Liquid Crystal Templating of Groups 11 and 12 Metal Films
Authors: Bender Florian , Mankelow Rowena K. , Hibbert D. Brynn , Gooding J. Justin
Published: July 2006

Liquid crystal templating has been used to produce metal films with nanometer‐sized pores. While successful templating procedures have been reported for metals from some groups of elements (e.g., groups 9 and 10), no such reports are available for other groups. This work investigates liquid crystal templating procedures for metals from groups 11 and 12. TEM indicates that permanent mesoporous structures are obtained for templated cadmium while copper forms mesoporous structures only temporarily. Silver, gold and zinc could not be templated at all. Reasons for these observations are briefly discussed, underlining the importance of various factors influencing the templating process.
Dust deposition near an eroding source field
Authors: Hagen L. J. , Pelt S. Van , Zobeck T. M. , Retta A.
Published: July 2006

Deposition of suspended dust near eroding source fields can have detrimental effects on vegetation, as well as on soil and water quality. This study was undertaken to quantify dust deposition within 200 m of a source field during wind erosion events. Erosion was measured with BSNE samplers on a small field of Amarillo fine sandy loam at field at Big Spring, TX. Suspension‐sized dust discharge averaged 33 ± 5 per cent of the total sediment discharge and ranged from 18·0 to 147·4 kg m−1 during eight selected storm events. Within 200 m of the source field boundary, dust collected in deposition samplers placed above a vegetated surface averaged 34 per cent of initial dust discharge. Predicted deposition, according to a line source model, was 43 per cent. Actual deposition was likely near that predicted, because of lateral diffusion of the dust and some under‐sampling by the disk samplers. Thus, the line source model seems useful in estimating both the pattern and quantity of deposition. About 30 per cent of the suspended dust was deposited within the initial 50 m of vegetated surface, but only about 12–15 per cent was deposited in the initial 10 m. Published in 2006 by John Wiley & Sons, Ltd.
Statins and hepatic steatosis: Perspectives from the Dallas Heart Study
Authors: Browning Jeffrey D.
Published: July 2006

Non-alcoholic fatty liver disease (NAFLD) and cardiovascular disease are independently associated. Due to the efficacy of 3-hydroxy 3-methylglutaryl-coenzyme A reductase inhibitors (statins) in the prevention of cardiovascular disease, increasing interest has been shown in establishing the safety of these drugs in NAFLD. In this study, the relationship between statin use, hepatic triglyceride content (HTGC), and serum alanine aminotransferase (ALT) levels was examined in 2,264 Dallas Heart Study participants who were using no lipid-lowering agent (n = 2,124) or using only a statin for lipid management (n = 140). Statin use was not associated with a greater frequency of hepatic steatosis (38% vs. 34%) or elevated serum ALT (15% vs. 13%) by a pair-matched analysis. Statin use was also not associated with a greater prevalence of elevated serum ALT among subjects with hepatic steatosis (n = 638). This finding persisted when controlling for possible sample bias as a result of current prescribing practices for statins. Among subjects with serum lipid abnormalities who were not using a statin, hepatic steatosis was present in 60% of those with mixed hyperlipidemia and 83% of those with both mixed hyperlipidemia and an elevated serum ALT.

In conclusion

, statin use was not associated with a higher frequency of hepatic steatosis or serum ALT abnormalities, even among those with hepatic steatosis. Individuals meeting criteria for statin therapy are likely to have coexistent hepatic steatosis.
The liver X-receptor alpha controls hepatic expression of the human bile acid–glucuronidating UGT1A3 enzyme in human cells and transgenic mice
Authors: Verreault Mélanie , Senekeo-Effenberger Kathy , Trottier Jocelyn , Bonzo Jessica A. , Bélanger Julie , Kaeding Jenny , Staels Bart , Caron Patrick , Tukey Robert H. , Barbier Olivier
Published: July 2006

Glucuronidation, an important bile acid detoxification pathway, is catalyzed by enzymes belonging to the UDP-glucuronosyltransferase (UGT) family. Among UGT enzymes, UGT1A3 is considered the major human enzyme for the hepatic C24-glucuronidation of the primary chenodeoxycholic (CDCA) and secondary lithocholic (LCA) bile acids. We identify UGT1A3 as a positively regulated target gene of the oxysterol-activated nuclear receptor liver X-receptor alpha (LXRα). In human hepatic cells and human UGT1A transgenic mice, LXRα activators induce UGT1A3 mRNA levels and the formation of CDCA-24glucuronide (24G) and LCA-24G. Furthermore, a functional LXR response element (LXRE) was identified in the UGT1A3 promoter by site-directed mutagenesis, electrophoretic mobility shift assays and chromatin immunoprecipitation experiment. In addition, LXRα is found to interact with the SRC-1α and NCoR cofactors to regulate the UGT1A3 gene, but not with PGC-1β.In conclusion,these observations establish LXRα as a crucial regulator of bile acid glucuronidation in humans and suggest that accumulation of oxysterols in hepatocytes during cholestasis favors bile acid detoxification as glucuronide conjugates. LXR agonists may be useful for stimulating both bile acid detoxification and cholesterol removal in cholestatic or hypercholesterolemic patients, respectively.Supplementary material for this article can be found on the HEPATOLOGY website(http://interscience.wiley.com/jpages/0270-9139/suppmat/index.html).
Induction of murine liver damage by overexpression of CD40 ligand provides an experimental model to study fulminant hepatic failure
Authors: Schmitz Volker , Dombrowski Frank , Prieto Jesús , Qian Cheng , Diehl Linda , Knolle Percy , Sauerbruch Tilman , Caselmann Wolfgang H. , Spengler Ulrich , Leifeld Ludger
Published: July 2006

Previously, we demonstrated that intrahepatic upregulation of the immunoactivating molecules CD40 and CD40 ligand (CD40L) are early mechanisms for liver cell damage in human and murine fulminant hepatic failure (FHF). In the present study, we investigated the functional effects of intrahepatic overexpression of CD40L by adenoviral-mediated gene transfer (AdCD40L) in mice. AdCD40L injection induced severe liver cell damage, which was associated with increased alanine aminotransferase (ALT) levels peaking at day 5 after vector administration (AdCD40L, 1,707 ± 279 U/L; Ad

LacZ

, 213 ± 25 U/L) and with lethality in half of the mice. Except for mild splenomegaly, no organs other than the liver were involved in inflammatory reactions. CD40–CD40L interaction was mandatory for liver damage, because CD40−/− mice were completely protected. Furthermore, CD40L-induced FHF depended on competent lymphocytes, because inflammatory reactions were strongly decreased in SCID and Rag1−/− mice. In contrast, neither natural killer T (NKT) cells nor Kupffer cells relevantly influenced histology as shown in NKT cell–deficient CD1d−/− mice and by gadolinium depletion of Kupffer cells. Furthermore, immunosuppression by dexamethasone and cyclosporin A was not sufficient to block CD40L damage.

In conclusion

, we present a model of FHF with strong similarities to human FHF with respect to time course and histological changes. This model suggests involvement of the CD40–CD40L system in FHF and might have important implications for future pathophysiological studies of this condition.
Carabid Beetles (Coleoptera, Carabidae) as Indicatorsof Hydrological Site Conditions in Floodplain Grasslands
Authors: Gerisch Michael , Schanowski Arno , Figura Wolfgang , Gerken Bernd , Dziock Frank , Henle Klaus
Published: July 2006

The relationship of carabid beetle species occurrence patterns and environmental variables characterising the hydrological regime has been studied at the River Elbe in Central Germany. Both flood duration and groundwater depth had major influence on species assemblages as the ordination of study plots mainly followed a gradient along these two variables. The simultaneous ordination of the plots according to species occurrence and environmental parameters showed a highly significant joint structure with the first two axes of a co‐inertia analysis, explaining >98% of the variance. A total of 27 species out of 129 caught fulfilled criteria of fidelity and specificity to the plots of the five clusters revealed by their abiotic conditions and were sufficiently abundant to be suitable indicators for one or a combination of clusters of plots. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Protective effects of isothiocyanates towards N‐nitrosamine‐induced DNA damage in the single‐cell gel electrophoresis (SCGE)/HepG2 assay
Authors: Arranz Nuria , Haza Ana I. , García Almudena , Möller Lennart , Rafter Joseph , Morales Paloma
Published: July 2006

The aim of this study was to investigate the protective effect of isothiocyanates towards N‐nitrosamine‐induced DNA damage in the single‐cell gel electrophoresis (SCGE)/HepG2 assay. None of the isothiocyanates (ITCs) concentrations tested in the presence or absence of formamidopyrimidine‐DNA glycosylase (Fpg) caused DNA damage per se. Combined treatments of HepG2 cells with phenethyl isothiocyanate (PEITC), allyl isothiocyanate (AITC) or indol‐3‐carbinol (I3C) and N‐nitrosopyrrolidine (NPYR) or N‐nitrosodimethylamine (NDMA) reduced the genotoxic effects of the N‐nitrosamines in a dose‐dependent manner. The protective effect of the three ITCs tested was higher towards NPYR‐induced oxidative DNA damage than against NDMA. The greatest protective effect towards NPYR‐induced oxidative DNA damage was shown by I3C (1 µM, 79%) and by PEITC (1 µM, 67%) and I3C (1 µM, 61%) towards NDMA (in presence of Fpg enzyme). However, in absence of Fpg enzyme, AITC (1 µM, 72%) exerted the most drastic reduction towards NPYR‐induced oxidative DNA damage, and PEITC (1 µM, 55%) towards NDMA. Our results indicate that ITCs protect human‐derived cells against the DNA damaging effect of NPYR and NDMA, two carcinogenic compounds that occur in the environment. Copyright © 2006 John Wiley & Sons, Ltd.
Human osteoblast response to silicon‐substituted hydroxyapatite
Authors: Botelho C.M. , Brooks R.A. , Best S.M. , Lopes M.A. , Santos J.D. , Rushton N. , Bonfield W.
Published: July 2006

Human osteoblasts were cultured on hydroxyapatite (HA), 0.8 wt % silicon substituted hydroxyapatite (Si‐HA) and 1.5 wt % Si‐HA discs. The influence of these substrates on cell behaviour in vitro was assessed by measuring total protein in the cell lysate and the production of several phenotypic markers: collagen type I (COL I), alkaline phosphatase (ALP), osteocalcin (OC), and the formation of bone mineral. After 7 days, β‐glycerophosphate and physiological levels of hydrocortisone were added to the culture medium to stimulate cell differentiation and mineral production. There was a significantly higher production of ALP on 1.5 wt % Si‐HA at day 7 following which, the addition of hydrocortisone promoted the differentiation of cells on the other two substrates. Hydrocortisone addition also decreased the production of OC. During the period, when hydrocortisone was present, no significant difference in behavior was seen between cells on Si‐HA and HA; however, following removal of hydrocortisone, cells responded to 0.8 wt % Si‐HA with a significant increase in protein production. Using fluorescence microscopy, nodular structures labeled with tetracycline were observed on the surface of all substrates after 21 days. These structures were deposited on areas of high cell density but were not related to the presence or level of silicon in the substrate. These results indicate that human osteoblasts are affected by the presence of silicon in the HA substrate and that the timing of these effects may be dependent upon the level of silicon substitution. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Natural and chemically induced oligomeric ribonucleases: structural study by immobilized metal ion affinity electrophoresis and their functional relationship
Authors: Anissimova Maria V. , Baek Won‐Ok , Varlamov Valery P. , Mrabet Nadir T. , Vijayalakshmi Mookambeswaran A.
Published: July 2006

Oligomerization can endow proteins with novel structural and catalytic properties. The native dimer of bovine seminal ribonucleases (BS‐RNase) binds, melts and catalyses the hydrolysis of double‐stranded ribonucleic acids 30‐fold better than its pancreatic homologue, the monomeric RNase A. Chemically induced oligomers of pancreatic RNase A are also found to show an increase in enzyme activity on double‐stranded poly(A).poly(U) (Libonati, M. Bertoldi, M. and Sorrentino, S. (1996) Biochem. J. 318, 287‐290) and, therefore, can be considered as potential immunosuppressive and cytotoxic agents. We report here a study on the relationship between surface histidine topography in oligomeric forms of these ribonucleases and their catalytic properties. Subtle changes in structure conformation of both BS‐RNase and oligomeric RNase A are shown to result in a modification of the affinity of these proteins toward the immobilized transition‐metal chelate, IDA‐Cu(II). Because, such conformational change has been shown to correlate with an improvement of the newly acquired biological activities upon oligomerization, we can conclude that surface histidines topography constitutes an exquisite probe for the study of protein structure/function relationship. Copyright © 2006 John Wiley & Sons, Ltd.
Problems with identifying the ‘8200‐year cold event’ in terrestrial records of the Atlantic seaboard: a case study from Dooagh, Achill Island, Ireland
Authors: Head Katie , Turney Chris S. M. , Pilcher Jon R. , Palmer J. G. , Baillie M. G. L.
Published: July 2006

The Northern Hemisphere cooling event 8200 years ago is believed to represent the last known major freshwater pulse into the North Atlantic as a result of the final collapse of the North American Laurentide ice sheet. This pulse of water is generally believed to have occurred independently of orbital variations and provides an analogue for predicted increases in high‐latitude precipitation and ice melt as a result of anthropogenically driven future climate change. The precise timing, duration and magnitude of this event, however, are uncertain, with suggestions that the 100‐yr meltwater cooling formed part of a longer‐term cold period in the early Holocene. Here we undertook a multiproxy, high‐resolution investigation of a peat sequence at Dooagh, Achill Island, on the west coast of Ireland, to determine whether the 8200‐year cold event impacted upon the terrestrial vegetation immediately ‘downwind’ of the proposed changes in the North Atlantic. We find clear evidence for an oscillation in the early Holocene using various measures of pollen, indicating a disruption in the vegetation leading to a grassland‐dominated landscape, most probably driven by changes in precipitation rather than temperature. Radiocarbon dating was extremely problematic, however, with bulk peat samples systematically too young for the North Atlantic event, suggesting significant contamination from downward root penetration. The sustained disruption to vegetation over hundreds of years at Dooagh indicates the landscape was impacted by a long‐term cooling event in the early Holocene, and not the single century length 8200‐year meltwater event proposed in many other records in the North Atlantic region. Copyright © 2006 John Wiley & Sons, Ltd.
Reduction of catechin, rutin, and quercetin levels by interaction with food‐related microorganisms in a resting state
Authors: LoCascio Riccardo G , Mills David A , Waterhouse Andrew L
Published: July 2006

Flavonoids are plant secondary metabolites abundant in foods and beverages of plant origin. These compounds are free radical scavengers and their consumption is linked to reduced incidence of coronary heart disease. In this study, two wine‐related microorganisms and one probiotic bifidobacteria strain were examined for their ability to absorb and/or transform the common flavonoids: quercetin, rutin, and catechin. Flavonoid absorption and/or transformation was determined using a resting cell assay (RCA) combined with high‐performance liquid chromatographic detection of the flavonoid losses. RCAs with Pediococcus pentosaceus ATCC 25745, Saccharomyces cerevisiae ATCC 36026, and Bifidobacterium longum DJO10A resulted in losses of rutin and quercetin. Further analysis of cell pellets indicated that, unlike rutin and catechin, most of the quercetin present in the assay was transported/adsorbed only into metabolically active cells. In 24 h the net quercetin loss from the resting cells of P. pentosaceus, S. cerevisiae, and B. longum was 21.3%, 27.1%, and 63.4%, respectively. These results suggest that these microorganisms, which are frequently present or added to food products, can decrease the overall concentration of quercetin, either through absorption or transport into the cell. The implications for the overall bioavailability of quercetin in humans remain to be determined. Copyright © 2006 Society of Chemical Industry
Frictional behaviour of experimental synthetic and semi‐synthetic gear oils
Authors: Godet A. , Roussel G. , Thebault M.
Published: July 2006

The use of synthetic and semisynthetic lubricants combined with a proper selection of additives, can help reduce friction between gear teeth, as shown on a tribometer simulating gear tooth contact. Accurate efficiency measurements on a loaded industrial power divider show good agreement with friction measurements on the tribometer, except for the viscosity effects that appear not to be significant in the simulated gear tooth contact and are an influencing parameter in the gear box. Changing the viscosity grade from 320 to 100 can reduce the friction losses by about 20%, but such an improvement has been found with a fully synthetic lubricant with a very high performance additive treatment, without any risk since the viscosity grade was 220. The effect of the additive was assumed to be about 5%; the overall friction reduction was about 20%. In worm gears, significant improvements are also achieved with the synthetic oil (about 8% efficiency increase), but the best energy saving fluids appear to be polyglycol base lubricants (with a measured efficiency improvement of about 17%).
Physical properties and testing of organosilicon esters for their applicability as synthetic lubricants
Authors: Čermák J. , Sasíh M. , Kolář D. , Dobeš P.
Published: July 2006

The constantly growing needs of the operational parameters of machines and engines, especially for aeronautical use, have brought about greater demands on lubricating oils. Various synthetic materials have been used since the Second World War,1 in increasing quantity, as substitutes for mineral based oil: esters from organic alcohols and mono‐ or dicarboxyl acids are among the most widespread. Quite a different type of synthetic oil is organosilicon compounds, known as ‘silicones’.

This paper reports experimental data for a group of silicon compounds examined in comparison with other materials normally used as bases for synthetic lubricants.
The relationship between the chemical structure of ester base fluids and their influence on elastomer seals, and wear characteristics
Authors: van der Waal G.
Published: July 2006

The intention of this paper is to examine the relationship between the chemical structure of ester base fluids and their influence on elastomer seals and wear characteristics. It presents background information about esters, some of which can be considered as blending components for mineral oil and/or polyalphaolefins, while others have properties so similar to mineral oil that in principle substitution is possible. It examines the effects of ester base fluids on a number of properties of elastomers, including modulus, tensile strength, elongation at break, hardness, and volume changes. It also explains a method of selecting synthetic base fluids for performance upgrading or viscosity purposes, using a ‘non‐polarity index’ which allows more speedy comparison and selection of ester base fluids.
The influence of molecular structure on the frictional behaviour of lubricating fluids
Authors: Hentschel K.‐H.
Published: July 2006

In order to establish correlations between the chemical structure or constitution of fluid lubricants and their friction characteristics under elastohydro dynamic conditions, a number of model test fluids were tested in a twin‐disk machine. As test fluids, special saturated mono‐, bi‐, and tricyclic compounds, alkanes and polyethers were selected. The traction coefficients were shown to be strongly dependent on the chemical structure of the lubricants and on operational parameters. High coefficient values mostly arise from lubricant molecules that are shaped unregularly, with indentations and teeth as seen with Stuart‐Briegleb models, and allowing only heavily hampered rotational intramolecular motions along single bond axes. Low traction coefficients derive from lubricant molecules with a thread‐like shape and a minimum of structural subunits or functional groups involved in significant intermolecular interactions. In order to account for the results obtained, several paradigms and hypotheses are established and discussed in detail.
Commercial developments in synthetic lubricants — a European overview
Authors: Williamson E. I.
Published: July 2006

Many useful papers are published about the technical development and testing of synthetic lubricants and functional fluids, yet it is also important to appreciate the market environment in which these products are used. However, hard data on market shares and producers' intentions are difficult to obtain, because of the obvious demands of commercial secrecy. This paper represents the author's assessment of the European commercial context, examines recent demand for different classes of synthetic lubricant and functional fluid, and their applications, and offers a considered assessment of the situation in the 1990s.
The characteristics and applications of synthetic lubricating greases
Authors: Schateva M. , Ficko M. , Kostić S.
Published: July 2006

Based on the need to develop indigenous synthetic base greases, the authors' organisation produced candidate greases based on polyesters of adipic acid, thickened with modified bentonites. The formulation and performance of these greases are presented, demonstrating their lubricity and stability characteristics, and conclusions are drawn as to their suitability, according to these characteristics, for various applications, including those in a petroleum‐origin fuel environment.
Silicone fluids: Synthesis, properties and applications
Authors: Huber P. , Kaiser W.
Published: July 2006

This paper describes the structure and derivation of ‘classical’ silicone fluids, giving the reactions for the production of dimethyl fluids by Miiller‐Rochow synthesis, polymerisation, direct synthesis, hydrosilylation, and transesterification. The properties of siloxanes are described, and the applications of silicone fluids and compounds are discussed in relation to their properties, particularly insolubility in water, viscosity‐temperature characteristics, and dielectric properties.
Antioxidant kinetics in synthetic lubricants field testing
Authors: Bigarre I. , Légeron J.‐P.
Published: July 2006

With the increases in engine performance, lubricants technology has quickly made great strides. The selection of mineral base oils has become more stringent, and the use of synthetic lubricants has been an important feature, allowing better perfonnance characteristics, among which is longer drain periods.1,2.

These evolutions have not led to the elimination of performance additives, which must be included in the composition of every engine lubricant. Among these, antioxidants play a prominent part: they participate in the protection of the lubricant against degradation b y oxidative agents. The ways in which they act are complicated and not entirely understood even today: essentially the initiator, ie oxygen from air, reacts with the lubricant to form peroxides, and then radicals which are themselves secondary oxidative agents.

According to the chemical structure of the antioxidant additives, a break in these chain reactions can occur. Thus it is important to select the best compounds for each lubricant: this can be achieved by experimentation and by specific identification of the antioxidant agents which are used.
DSC‐cell ‐ A versatile tool to study thermo‐oxidation of aviation lubricants
Authors: Zeman Alfred
Published: July 2006

The versatility of a differential scanning calorimetry (DSC) cell in studying thermal and/or thermal‐oxidative degradation of lubricants is shown using ester‐based aviation turbine oils as an example.

The following applications are discussed: 1. quality control of fresh and used oils by pressure differential scanning calorimetry; 2. influence of metal catalysis on oil degradation; 3. identification of volatile degradation products by PDSC gas chromatography‐mass spectrometry via a TENAX trap; 4. determination of spontaneous ignition temperatures; 5. influence of metall metal oxides, wear debris and oil degradation products on ignition behaviour; 6. inhibition of spontaneous ignition by antioxidants.
Process variables in the manufacture of polyalphaolefins
Authors: James B. D. , Dain C. J.
Published: July 2006

The production of polyalphaolefins is described, including three catalyst systems — free radical, Ziegler‐type, and cationic polymerization. The mechanism of oligomerization is given, and the distribution of products according to temperature, time and promoter type. As this reaction is incomplete, and monomer remains, product distillation is necessary to remove this.
Diester compressor lubricants in petroleum and chemical plant service
Authors: Wits J. J.
Published: July 2006

Diesters are the largest volume of esters manufactured, and are derived from adipic, azelaic or sebacic acids. Their various advantages over petroleum‐based compressor oils are discussed, and the development of an extended‐life diester lubricant is described.
Correlations among the structure and flow characteristics of polyolefin compositions
Authors: Bartha L. , Deák G. , Bobest É.
Published: July 2006

Hydrocarbon mixtures containing olefins were produced from waste polyethylene, and oils were synthesized from various fractions of these. Various properties of these products are presented including viscosity and pour point.
Lubrication of hydroelectric turbine thrust bearings with a diester‐based synthetic lubricant
Authors: Boehringer R. H. , Neff F.
Published: July 2006

A diester‐based lubricant was found to reduce friction substantially in the thrust bearings of a hydroelectric turbine, compared with a conventional petroleum oil. Bearing temperatures were immediately reduced by 10–11 °C and bearing failures were eliminated. Revenue savings estimated at $10,000,000 per year have been made due to an increase in power production, and the elimination of repair work and downtime costs.1
Current and future polyalphaolefins
Authors: Blackwell J. W. , Bullen J. V. , Shubkin R. L.
Published: July 2006

Polyalphaolefins currently have a market share of less than 1 per cent in Europe, but this is expected to double in the next 5 years. This paper looks at additive response, rheology, volatility, and oxidation resistance of PAOs; of particular importance are their low temperature capabilities. The results of various tests are given, in comparison with mineral‐based oils. In conclusion, research is under way to investigate the possibilities of ‘tailor‐making’ PAOs by varying production process variables and using a variety of starting olefin streams.
Viscosity properties of base lubricating oils containing mineral oil, synthetic ester oil and polymeric additives
Authors: Luksa Adam
Published: July 2006

This paper presents the results of investigations into the physical properties, in terms of volatility, pour point and viscosity, of a composition base oil, whose components included mineral‐and ester‐based oils, and a polymeric thickener. The presence of the ester had limited effect, and this was improved by addition of the thickener.
Development and testing of a screw compressor fluid based on two‐stage hydrotreated base oils, and comparison with a synthetic fluid
Authors: Cohen Stephen C.
Published: July 2006

This paper reports the development and testing of a rotary screw compressor lubricant based on two‐stage severely hydrotreated petroleum base oil, and compares the fluid's performance with that of a synthetic polyalphaolefinbased compressor fluid. It was found that performance was in most respects the same for both fluids. Laboratory and performance testing also shows equivalent extended service life greater than one year, with reduced maintenance and energy savings.
Influence of reinforcement and lubrication on abrasive wear performance of polyamide
Authors: Bijwe J. , Mathur J. N. , Tewari U. S.
Published: July 2006

This paper presents the results of studies on the wear performance of various composites of polyamide (nylon 6,6) reinforced with short carbon fibres and lubricated with a solid lubricant, PTFE, under adverse sliding conditions (abrasive wear). The effects of increasing amounts of fillers, fibre orientation, and experimental parameters such as load, and abrading particle size were investigated. The studies revealed that fillers that are very much suitable for adhesive wear applications are detrimental for the abrasive wear mode. Moreover, wear performance showed deterioration with increasing amount of filler concentration. The combination of heterogeneous fillers proved to be detrimental for wear performance. Efforts were made to correlate these investigations with appropriate mechanical properties. It was found that wear performance was greatly influenced by selected experimental parameters. Worn surfaces were examined with SEM to have better insight of the wear mechanism.