bluuebunny/crossref_metadata_2025_split huggingface dataset:
The conserved histidine 166 residue of the human neonatal Fc receptor heavy chain is critical for the pH‐dependent binding to albumin
Authors: Andersen Jan Terje , Dee Qian Julie , Sandlie Inger 
Published: October 2006

AbstractThe MHC class I‐related neonatal Fc receptor (FcRn) serves in the homeostatic regulation of IgG and albumin by increasing their half‐lives. FcRn may bind IgG and albumin simultaneously, and in a pH‐dependent manner, with ligand binding at pH 6.0–6.5 and release at pH 7.0–7.4. The FcRn‐IgG interaction has been extensively characterized at the amino acid level and shown to depend on conserved histidine residues in the IgG‐Fc part that interact with negatively charged residues in the α‐2 domain of FcRn. The recently discovered FcRn‐albumin interaction remains to be elucidated. Guided by the pH dependence of the FcRn‐albumin interaction, we compared the sequence of the FcRn α‐2 domain from eleven different species, and identified histidine residues that were conserved in all (H166) or seven (H161) of these. Both residues are located directly opposite to the IgG interaction site in the folded molecule. We did in vitro mutagenesis (H161A or H166A) in combination with interaction studies (ELISA and surface plasmon resonance) with recombinant, soluble, purified receptors and IgG and albumin to investigate the role of the two histidine residues. Our results show clear evidence that the conserved H166 is a key player in the FcRn‐albumin interaction.
Simvastatin inhibits the MHC class II pathway of antigen presentation by impairing Ras superfamily GTPases
Authors: Ghittoni Raffaella , Napolitani Giorgio , Benati Daniela , Uliveri Cristina , Patrussi Laura , Laghi Pasini Franco , Lanzavecchia Antonio , Baldari Cosima T. 
Published: October 2006

AbstractStatins are widely used hypocholesterolemic drugs that inhibit 3‐hydroxy‐3‐methyl‐glutaryl‐coenzyme A reductase, a rate‐limiting enzyme of the mevalonate pathway whose biosynthetic endproduct is cholesterol. As a result of this activity, statins may perturb the composition of cell membranes, resulting in lipid raft disruption. Furthermore, by inhibiting protein prenylation, a process also dependent on mevalonate, statins block membrane targeting and activity of small GTPases. Antigen uptake, processing and presentation involve the interplay of Rab and Rho family GTPases. Furthermore, lipid rafts have been implicated both in antigen internalization by the BCR and in MHC class II clustering at the immunological synapse. Here we have addressed the effects of simvastatin on antigen processing and presentation by human B cells and dendritic cells. The results show that simvastatin potently suppresses tetanus toxoid processing and presentation to CD4+ T cells by HLA‐DR by inhibiting protein antigen uptake through both receptor‐mediated endocytosis and macropinocytosis. This effect can be largely accounted for by defective prenylation of Rho and Rab GTPases in the absence of any measurable perturbation of lipid rafts. In addition, simvastatin was found to preferentially affect the invariant chain‐dependent MHC class II pathway, thereby identifying this route of antigen processing and presentation as a selective target of statins.
Dimeric Complexes of Lanthanide(III) Hexafluoroacetylacetonates with4‐Cyanopyridine N‐Oxide: Synthesis, Crystal Structure, Magnetic and Photoluminescent Properties
Authors: Eliseeva Svetlana V. , Ryazanov Mikhail , Gumy Frédéric , Troyanov Sergey I. , Lepnev Leonid S. , Bünzli Jean‐Claude G. , Kuzmina Natalia P. 
Published: October 2006

AbstractA series of new mixed‐ligand lanthanide complexes [Ln(hfa)3(4‐cpyNO)]2 (Ln = SmIII–HoIII and TmIII; hfa– = hexafluoroacetylacetonate; 4‐cpyNO = 4‐cyanopyridine N‐oxide) have been synthesised by treating the corresponding lanthanide hexafluoroacetylacetonates with 4‐cpyNO (molar ratio 1:1) in chloroform. Single‐crystal X‐ray analysis revealed that [Tb(hfa)3(4‐cpyNO)]2 and [Ho(hfa)3(4‐cpyNO)]2 are isostructural and are comprised of two types of symmetrically independent dimetallic molecules. Within a dimer, the eightfold‐coordinated metal atoms are bridged by two 4‐cpyNO ligands through the oxygen atoms of the N‐oxide groups. The magnetic susceptibility data for the GdIII and TbIII complexes indicate the presence of weak antiferromagnetic interactions within the dimetallic Ln2O2 units. The thermal stability of the [Ln(hfa)3(4‐cpyNO)]2 adducts was studied by thermogravimetric analysis and their volatility estimated from sublimation experiments under reduced pressure. The photoluminescent properties were measured for solid samples upon excitation at 330–360 nm. The mixed‐ligand complexes of SmIII, EuIII, TbIII, DyIII and TmIII exhibit metal‐centred luminescence in the entire visible spectral range with characteristic pink, red, green, yellow and blue emission, respectively. The introduction of ancillary 4‐cpyNO molecules into the coordination sphere of the lanthanide(III) ions was found to significantly affect their luminescence quantum yields. [Eu(hfa)3(4‐cpyNO)]2 thin films on quartz substrates were obtained by the vacuum evaporation technique and their photoluminescent properties were found to be enhanced when compared with those of the bulk samples. This suggests that these dimers could be good candidates for the fabrication of emitting layers for light‐emitting diodes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
4‐Substituted‐Phenyl(bisoxazoline)‐Rhodium Complexes: Efficiency in the Catalytic Asymmetric Reductive Aldol Reaction
Authors: Shiomi Takushi , Ito Jun‐ichi , Yamamoto Yoshihiko , Nishiyama Hisao 
Published: October 2006

AbstractElectronic effects of the substituents on the phenyl ring of the phenyl(bisoxazoline) ligand skeleton of rhodium catalysts was examined in the asymmetric reductive aldol reactions of acrylates and aldehydes. The electron‐withdrawing NO2 group of Rh(4‐NO2‐Phebox‐R)(OAc)2 showed an increase in the enantioselectivity of the products in the reductive reaction of methyl acrylate but not in the reactions of tert‐butyl‐ and trimethylsilyl acrylates. Theoretical calculations of the corresponding model rhodium‐Phebox complexes indicate that the remote electron‐withdrawing substituent slightly shortens the Rh–Cphebox bond. Also, the Rh–C bonds of Rh(4‐NO2‐Phebox‐iPr)(OAc)2 and the corresponding Rh(4‐H‐Phebox‐iPr)(OAc)2 were compared on the basis of X‐ray analysis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Transaction tax and market quality of the Taiwan stock index futures
Authors: Chou Robin K. , Wang George H. K. 
Published: October 2006

AbstractOn May 1, 2000, the Taiwan government reduced the tax levied on futures transactions on the Taiwan Futures Exchange from 5 to 2.5 basis points. This event provides a unique opportunity to test empirically the impact of a tax rate reduction on trading volume, bid‐ask spreads, and price volatility. Intraday and daily time series data from May 1, 1999, through April 30, 2001, are tested in a three‐equation structural model. Findings show that transaction taxes have a negative impact on trading volume and bid‐ask spreads, as trading volume increased and bid‐ask spreads decreased in the period following the reduction in the transaction tax. This study's analysis is not consistent with the argument that the imposition of a transaction tax may reduce price volatility because there are no significant changes in price volatility after the tax reduction. Further, it was found that although the reduction in the transaction tax did reduce tax revenues, the proportional decrease in tax revenues is less than the 50% reduction in the tax rate. Finally, tax revenues in the second and third year after the tax reduction increased, as compared to the year before the tax reduction. © 2006 Wiley Periodicals, Inc. Jrl Fut Mark 26:1195–1216, 2006
The attitudes to ageing questionnaire (AAQ): development and psychometric properties
Authors: Laidlaw K. , Power M. J. , Schmidt S. 
Published: October 2006

AbstractObjectiveThis paper describes the development of the Attitudes to Ageing Questionnaire (AAQ) which is a self‐report measure with which older people themselves can express their attitudes to the process of ageing.MethodThe development of the AAQ followed a coherent, logical and empirical process taking full account of relevant gerontological knowledge and modern and classical psychometric analytical methods. Pilot testing with 1,356 participants from 15 centres worldwide refined the scale and provided the basis for a field test. A total of 5,566 participants from 20 centres worldwide contributed to the further development of this new scale with the derivation involving both classical and modern psychometric methods.ResultsThe result is a 24‐item cross‐cultural attitudes to ageing questionnaire consisting of a three‐factor model encompassing psychological growth, psychosocial loss, and physical change. The three‐factor model suggests a way of conceptualizing and measuring successful ageing in individuals.ConclusionsThe AAQ provides researchers, clinicians and policy makers with a unique scale to measure the impact of successful ageing interventions. It also provides a vehicle for the measurement of how individuals age across cultures and under different economic, political and social circumstances. Copyright © 2006 John Wiley & Sons, Ltd.
Scaling model of a rainfall intensity‐duration‐frequency relationship
Authors: Bougadis John , Adamowski Kaz 
Published: October 2006

AbstractIntensity‐duration‐frequency (IDF) relationships are currently constructed based on an at‐site frequency analysis of rainfall data separately for different durations. These relationships are not accurate and reliable since they depend on many assumptions such as distribution selection for each duration; they require a large number of parameters, and are not time‐independent.In this study, scaling properties of extreme rainfall are examined to establish scaling behaviour of statistical non‐central moments over different durations. A scale invariance concept is explored for disaggregation (or downscaling) of rainfall intensity from low to high resolution and is applied to the derivation of scaling IDF curves. These curves are developed for gauged sites based on scaling of the generalized extreme value (GEV) and Gumbel probability distributions.Numerical analysis was performed on annual maximum rainfall series for the province of Ontario, for storm durations of 5, 10, 15, and 30 min (the typical time of concentration for small urban catchments) and 1, 2, 6, 12, and 24 h (the typical time of concentration for larger rural watersheds).Results show that rainfall does follow a simple scaling process. Estimates found from the scaling procedure are comparable to estimates obtained from traditional techniques; however, the scaled approach was more efficient and gives more accurate estimates compared with the observed rainfall total at all stations. Copyright © 2006 John Wiley & Sons, Ltd.
Male characteristics on female mud snails caused by antifouling bottom paints
Authors: Smith Blakeman S. 
Published: October 2006

AbstractThis study continues an investigation of ananatomical abnormality, named ‘imposex’, which consists of a superimposition of male characteristics on to a functionally normal female reproductive anatomy of the dioecious snail Nassarius obsoletus Say. Imposex is prevalent in natural populations living near yacht basins and rarely found distant from them. In the current study caged snails were transferred between a yacht basin and a distant ‘clean’ locality where the natural population of snails was normal. Imposex was induced in some normal snails kept at the marina and suppressed, but not lost in abnormal snails kept at the clean locality. A similar positive result was obtained in the laboratory by exposing normal snails to organotincontaining antifouling paints and abnormal snails to clean sea water. Results were negative in parallel tests of various marina‐associated materials which did not contain organotin. The laboratory studies have thus identified a causative factor of the anatomical abnormalities common near yacht basins in the natural environment. They also provide a rare, if not unique, example of a chemical agent which causes the appearance of superfluous anatomical features in an animal.
The inhibitory effect of serum from diethyldithiocarbamate treated rats on bovine adrenal dopamine‐β‐hydroxylase activity
Authors: Jarvis J. A. E. , Magos L. , Jacobs R. 
Published: October 2006

AbstractThe activity of serum dopamine‐β‐hydroxylase does not depend solely on the presence of exogenous inhibitors: its activity also depends on the rate of release into plasma and is influenced by sympathetic activity or pathological conditions. This fluctuation may disguise the effect of an exogenous inhibitor on the enzyme. It has been shown in the present work that boiling of serum obtained from sodium diethyldithiocarbamate treated rats did not eliminate the dopamine‐β‐hydroxylase inhibitory effect on a bovine adrenal dopamine‐β‐hydroxylase preparation. Thus it is possible to measure the dopamine‐β‐hydroxylase inhibitory effect of an exogenous inhibitor of this type without interference from the enzyme present in serum. Serum taken from rats treated with sodium diethyldithiocarbamate depressed in a time and dose dependent way the activity of bovine adrenal dopamine‐β‐hydroxylase preparation.
Absorption of the toxins of lantana camara L. from the digestive system of sheep
Authors: Pass Michael A. , McSweeney Christopher S. , Reynoldson James A. 
Published: October 2006

AbstractWhen lantana was given into different regions of the alimentary tract, absorption sufficient to cause intoxication occurred from the stomachs, small intestine and large intestine, but absorption from the small intestine was quantitatively the most important. However, it was shown that the passage of ingesta into the small intestine decreased markedly a few hours after the toxin was given and it is suggested that absorption from all areas of the gastrointestinal tract is important for the progression of the disease. When bile was diverted away from the small intestine, animals were still intoxicated by lantana. This indicates that bile is not important for absorption of lantana toxins. Other experiments indicated that the lantana toxins are transported to the liver mainly in the portal blood.
The role of nitroaromatic compounds in the direct‐acting mutagenicity of diesel particle extracts
Authors: Pederson T. C. , Siak J‐S. 
Published: October 2006

AbstractThe Salmonella mutation assay has been adapted to a number of experimental procedures used to characterize the chemical components and molecular mechanisms involved in the direct‐acting mutagenicity of diesel particle extracts. The mutagens were found to be unreactive towards purified DNA. Mutagenic activity was decreased in nitroreductase‐deficient bacteria and increased in the absence of oxygen, suggesting that bacterial enzymes activate the mutagens. The extract was fractionated by thin layer chromatography using both normal and reverse phase silica gel plates. On normal silica plates, a separation was made between unsubstituted PAH, nitro‐PAH and the more polar aromatic compounds. About a third of the mutagenic activity in the particle extract was recovered in fractions containing monosubstituted nitro‐PAH compounds. The absorption spectra and reverse phase chromatographic properties indicate 1‐nitropyrene is a predominant component but not the only mutagen in these fractions. The remaining activity was in the more polar fractions, and mutagenicity assays using anaerobic conditions and nitroreductase‐deficient bacteria suggest they contain other nitro‐substituted compounds.
Pulmonary function testing of animals chronically exposed to diluted diesel exhaust
Authors: Gross Kenneth B. 
Published: October 2006

AbstractThe purpose of this work was to assess the potential effect that chronic inhalation of diesel exhaust may have on lung mechanics and lung volume. Noninvasive pulmonary function tests that produced data on lung air flows and volumes have been conducted repeatedly on 25 male Fischer‐344 rats exposed to diesel exhaust at a particulate concentration of 1500 μg m−3, 20 h per day, 51/2 days per week, for 612 days. The same tests were conducted on 25 clean air control animals. When the data were normalized, the majority of tests did not reveal any significant deviation from the norm for the first year of exposure. In the second year, the functional residual capacity and its component volumes – expiratory reserve and residual volume, maximum expiratory flow at 40% of vital capacity, maximum expiratory flow at 20% of vital capacity and the forced expiratory volume in 0.1 s – were significantly greater in the diesel exposed animals. The data are inconsistent with known clinically significant adverse health effects. Although the lung volume changes in the diesel exposed animals could be indicative of emphysema or other forms of chronic obstructive lung disease, this interpretation is contradicted by the air flow data which suggest simultaneous lowering of the resistance of the smaller airways. The observations are not consistent with documented clinical lung disease in man.
Changes in thyroid hormones following liver intoxication with carbon tetrachloride
Authors: Mourelle Marisabel , Rubalcava Boanerges 
Published: October 2006

AbstractThe metabolism of thyroid hormones was studied after carbon tetrachloride (CCl4) liver damage. Thyroxine (T4) and triiodothyronine (T3) levels fell and reached a nadir in the first 24 hours after CCl4 administration. Thyroxine binding globulins (TBG) and thyroid stimulating hormone (TSH) also decreased, reaching their lower values in the same period. Blood and liver T4 turnover measured in CCl4 treated rats were faster than in control animals. Therefore, at least three phenomena appear to be involved after CCI4 intoxication in rats: (1) increased utilization and turnover of thyroxine by the regenerating liver; (2) diminished thyroid hormone secretion by the thyroid gland, and (3) reduced concentration of serum iodothyronine carrier proteins. The results support the concept that the liver participates in the metabolic regulation of T3 and T4 which, in turn, control hepatocellular growth.
Combined hemoperfusion‐hemodialysis in organophosphate poisoning
Authors: Nagler J. , Braeckman R. A. , Willems J. L. , Verpooten G. A. , de Broe M. E. 
Published: October 2006

AbstractWe report on a patient treated with combined prolonged hemoperfusion (HP, Adsorba 300 C, Gambro, Sweden) and hemodialysis (HD, C‐DAK 1.2, Cordis Dow, USA) for severe dimethoate poisoning. This procedure was adopted since the combination of dialysis and adsorption may improve overall drug removal. Combined HP–HD was performed during 24 h using the same charcoal column and dialyser. Adequate heparinization was obtained by monitoring the whole blood activated partial thromboplastin time. The patient (a 34‐year‐old female) ingested approximately 10 g of dimethoate (Teletox 10) in a suicide attempt, 30 min before admission to the hospital. On admission, serum level of dimethoate (analysed by gas chromatography) was 2340 ng ml−1. She received conventional treatment and combined HP–HD was started within 2 h after admission. At this time serum levels had risen to 3110 ng ml−1. However, they declined constantly during the epuration and after 18 h no more dimethoate could be detected in the serum. She was discharged 3 days after treatment. During the 24 h of HP–HD treatment, 110.8 mg dimethoate entered the epuration system via the plasma. 55.3 mg were extracted by the charcoal column and 25.3 mg by hemodialysis.
Acrylamide neurotoxicity in the mouse: A behavioral, electrophysiological and morphological study
Authors: von Burg R. , Penney D. P. , Conroy P. J. 
Published: October 2006

AbstractThe development of acrylamide induced neutrotoxicity was followed for 3 weeks in the mouse by behavioral testing, determination of conduction velocities and electron microscopic examination of peripheral nerves. Neurotoxic signs began to appear during the second week of treatment. A condition of severe intoxication developed within 21 days. Behavioral assessment for neurological deficits proved to be more sensitive than sensory or motor conduction velocity determinations either in isolated preparations or in situ. In general, such electrophysiological determinations did not result in reproducible, statistically significant, differences from control animals until the third week of acrylamide administration. However, there was a suggestion that temperature reduction may provide a provocative change to increase the sensitivity of such electrophysiological measurements. Electron microscopic examination of the nerves of severely poisoned animals revealed myelin corrugation and delamination to be the most consistent damage. Acrylamide appeared to produce a nonselective attack since degenerating fibers were found intermingled with almost normal fibers of approximately the same diameter. In general, the production of neutrotoxicity in the mouse closely resembled that seen in the rat but some differences were noted.
Placental transport and embryonic utilization of essential metabolites in the rat at the teratogenic dose of cadmium
Authors: Webb M. , Samarawickrama G. P. 
Published: October 2006

AbstractAdministration of Cd2+ to the 12–day pregnant rat caused a dose‐dependent inhibition of placental 65Zn2+ transport. At 4 h after the injection of the teratogenic dose (1.25 mg Cd2+ per kg body weight), transport of 65Zn2+ to the embryo was inhibited by 75%. This inhibition decreased with time and at 48 h was no longer statistically significant. In contrast with Zn2+, the administration of Cd2+ did not affect the transport of sugar, amino acids and nucleic acid precursors from the maternal circulation to the embryo at any time. The incorporation of [14C]thymidine into embryonic DNA, however, was inhibited by about 50% at 4 h and by 75% at 20 h. By 48 h it returned to control levels. Incorporation of [14C]formate into DNA also was reduced. Inhibition of the incorporation of L‐[14C]leucine into protein was apparent at 20 h, but not at 4 h, after the administration of Cd2+. Inhibition of DNA synthesis, which led to a significant reduction in embryonic DNA concentration at 20 h, was associated with a marked decrease in the activity in embryonic thymidine kinase. In extracts of embryos from Cd2+‐treated dams, the activity of this enzyme was restored to the control level by the addition of 7.7 μM zinc acetate to the assay system. In vivo, the simultaneous injection of Zn2+ at a 2:1 atomic ratio with Cd2+ prevented the inhibition of thymidine incorporation into DNA. At the teratogenic dose, only about 16 ng Cd2+ per g wet weight is incorporated into the embryo. The inhibition of placental transport, particularly of Zn2+, therefore, may be of prime importance in the teratogenic response.
Comparative studies on the distribution of gold, copper and zinc in the livers and kidneys of rats and hamsters after treatment with sodium [195/Au]‐aurothiomalate
Authors: Mogihricka Ewa M. , Webb M. 
Published: October 2006

AbstractThe distribution of gold, copper and zinc in the livers and kidneys of female rats and hamsters was determined after intraperitoneal injection of sodium [195Au]‐aurothiomalate. After five doses of sodium [195Au]‐aurothiomalate (1 mg Au(I) per kg body weight), the hepatic and renal concentrations of Au were greater in rats than in hamsters. In the former species, treatment with the Au(I)‐compound led to an increase in the Cu‐concentration of the kidney and to the synthesis of a (Cu, Au)‐metallothionein. In either species binding of Au to the hepatic metallothionein was insignificant. The renal (Cu, Au)‐metallothionein from the sodium [195Au]‐aurothiomalate‐treated rat appeared to be extremely heterogeneous and was resolved into at least four components on ion exchange chromatography.