bluuebunny/crossref_metadata_2025 huggingface dataset:
Polycyclic aromatic hydrocarbons in a highly industrialized urban estuary: Inventories and trends
Authors: Walker Shelby E. , Dickhut Rebecca M. , Chisholm-Brause Catherine
Published: November 2004

The abundance and composition of polycyclic aromatic hydrocarbons (PAHs) in sediments of the main stem and southern branch of the Elizabeth River (VA, USA), a highly industrialized urban estuary in the Chesapeake Bay (USA) watershed, were examined relative to historical and toxic effects levels. Total PAH concentrations in Elizabeth River sediments exceeded those observed in Baltimore Harbor and the Anacostia River, two other regions of concern in the Chesapeake Bay. The ΣPAH concentrations from samples collected in the vicinity of two former wood-treatment facilities in the Elizabeth River had the highest ΣPAH when compared to coastal and estuarine systems around the world. Using a linearized diffusion model equation, as much as 69% of the variability in channel sediment ΣPAH distribution could be ascribed to inputs associated with former wood-treatment facilities along the southern branch of the Elizabeth River. Comparison of PAH levels measured in channel samples to data collected during the early 1980s demonstrated a general trend toward reduction in contaminant concentrations for most regions of the Elizabeth River channel; however, steady-state and increased sediment PAH concentrations in the vicinity of the former wood-treatment facilities were observed. Based on examination of the contaminant levels in Elizabeth River sediments using established sediment-quality criteria, the southern branch of the river remains a clear hazard to benthic and pelagic organisms.
Feminization of female leukophore-free strain of Japanese medaka (Oryzias latipes) exposed to 17β-estradiol
Authors: Balch Gordon C. , Shami Karmi , Wilson Paul J. , Wakamatsu Yuko , Metcalfe Chris D.
Published: November 2004

The recently developed female leukophore-free (FLFII) strain of Japanese medaka (Oryzias latipes) carries DNA markers for the identification of genotypic sex. Information regarding genotypic sex is useful for tests in which endocrine-disrupting compounds may masculinize or feminize fish. In the present study, methods were developed to automate DNA extraction and profiling for rapid determination of genotypic sex. Adequate amounts of DNA were isolated by robotic extraction procedures from the caudal fin. New primers were developed to include an 18-base pair segment that is in the × chromosome of female medaka but is absent in the Y chromosome of male medaka. Automated profiling methods with 96-well plates permitted analysis of the genomic sex of medaka at rates of up to 500 fish/d. We investigated the sensitivity of the FLFII strain to the feminizing effects of the potent estrogen 17β-estradiol (E2), and we compared this sensitivity to that of a wild strain that has been used widely in the study of endocrine-disrupting compounds. All FLFII medaka exposed to 1 μg/L of E2 (n = 50) had the female gonadal phenotype (i.e., ovaries), and all but one wild-strain medaka exposed to 1 μg/L of E2 (i.e., 47 of 48 fish) had the female gonadal phenotype, indicating that the FLFII and wild strains have approximately equal sensitivities to the feminizing effects of E2. Analysis of the genotype of FLFII medaka confirmed that 100% of fish with the male genotype had been feminized to the female gonadal phenotype. The FLFII strain is an excellent teleost model for detecting feminization or masculinization of fish, and automated methods can be used for rapid analysis of the genotypic sex of FLFII medaka.
Highly persistent butyltins in northern marine sediments: A long-term threat for the Saguenay Fjord (Canada)
Authors: Viglino Liza , Pelletier Émilien , St.-Louis Richard
Published: November 2004

An exhaustive study of the distribution of butyltin species was conducted in the sediment of the Saguenay Fjord (Canada), a semi-enclosed marine system with sediment permanently submitted to sub-Arctic cold conditions. Concentrations of total butyltins (tributyltin [TBT], dibutyltin, and monobutyltin) ranged from 6 to 288 ng Sn/g dry weight and were typical of those reported for contaminated coastal areas despite limited seasonal traffic of commercial vessels in the fjord. The distribution profiles of butyltin species in four sediment cores clearly indicated the high persistence of TBT that was dominating other species. The particular oceanographic conditions of the Saguenay Fjord (low seawater temperature, anoxic sediments, and low exchange rate of deep waters) combined with a high sediment/pore-water partition coefficient (Kdobs = 1.0 × 104 to 1.2 × 104 L/kg) and a low sediment/water diffusive flux of TBT (J1 = 13 × 10−8 mol/m2/year) are responsible for the burial and preservation of TBT in this marine ecosystem. The half-life of TBT in deep sediment was estimated to be approximately 87 ± 17 years (± SEM), which implies a much slower degradation rate than any previously reported. Finally, a flood event that occurred five years before the sampling enabled us to calculate a very slow diffusive flux from the preflood to the postflood layer (J2 = 2 × 10−8 mol/m2/year), indicating an almost permanent sequestration of TBT in the buried layers.
Physicochemical and toxicological studies on 4-chloro-3,5-dinitrobenzoic acid in aqueous solutions
Authors: Lopez Jorge L. , Einschlag Fernando S. García , Rives Carina V. , Villata Laura S. , Capparelli Alberto L.
Published: November 2004

Physicochemical characterization of hazardous compounds often is required for the development of structure-reactivity correlations. Physical, chemical, and toxicological properties of target pollutants require determination for an efficient application of wastewater treatments. In the present work, we chose a chloro-nitro-aromatic derivative (4-chloro-3,5-dinitrobenzoic acid [CDNBA]), as a model compound on which to perform physicochemical and toxicological studies. Several properties of CDNBA are not available in the literature, although many aromatic nitro-compounds are considered hazardous materials. Measurements of solubility in water, acid dissociation constant, and kinetic parameters for the nucleophilic substitution of chlorine atom in alkaline media are reported. We also performed cytotoxicity studies of CDNBA and ultraviolet-irradiated CDNBA solutions. From the analysis of CDNBA solubility in water at different temperatures, an enthalpy of solution of 23.2 ± 2.5 kJ/mol was found. The study of the acid dissociation constant Kc by using conductivity measurements and the modified Gran's method yielded values for the equilibrium constant Ka of 2.36 × 10−3 and 2.26 × 10−3, respectively. The bimolecular rate constant for the reaction of CDNB− and hydroxyl ion (HO−) measured at room temperature and 0.1 M of ionic strength was 5.92/M·s, and the activation energy for this process was 70.7 ± 3.4 kJ/mol. Cytotoxicity assays with aqueous suspensions of Tetrahymenapyriformis showed lethal effects due to the pH change induced by CDNBA. On the other hand, in buffered solutions, a value of 104.47 μM was observed for the median effective concentration, that is, the concentration of CDNBA at which the proliferation was restricted to one half of the blank. Irradiation of CDNBA solutions increased the toxicity, suggesting the formation of intermediate products with higher cytotoxicity effects.
Aquatic risk assessment of a realistic exposure to pesticides used in bulb crops: A microcosm study
Authors: van Wijngaarden René P.A. , Cuppen Jan G.M. , Arts Gertie H.P. , Crum Steven J.H. , van den Hoorn Martin W. , van den Brink Paul J. , Brock Theo C.M.
Published: November 2004

The fungicide fluazinam, the insecticide lambda-cyhalothrin, and the herbicides asulam and metamitron were applied to indoor freshwater microcosms (water volume approximately 0.6 m3). The treatment regime was based on a realistic application scenario in tulip cultivation. Concentrations of each pesticide were equal to 0%, 0.2%, 0.5%, 2%, and 5% spray drift emission of label-recommended rates. Contribution of compounds to the toxicity of the pesticide package was established by expressing their concentrations as fractions of toxic units. The fate of the compounds in the water, and responses of phytoplankton, zooplankton, periphyton, macroinvertebrates, macrophytes, decomposition, and water quality were followed for 13 weeks. The half-lives of lambda-cyhalothrin, metamitron, and fluazinam were 1 to 2 d; that of asulam was >30d. No consistent effects could be demonstrated for the 0.2% treatment regime that was therefore considered the no-observed-effect concentrationcommunity (NOEC). The macroinvertebrate populations of Gammarus pulex, Asellus aquaticus, and Proasellus meridianus were the most sensitive end points, followed by species of copepods and cladocerans. Responses mainly were due to lambda-cyhalothrin. The 0.5% treatment regime resulted in short-term effects. Pronounced effects were observed at the 2% and 5% treatment levels. At the end of the experiment, the macrophyte biomass that consisted of Elodea nuttallii, showed a decline at the two highest treatment levels, asulam being the causal factor (NOEC: 0.5% treatment level). Primary production was reduced at the 5% treatment level only. In our experiment, the first-tier risk assessment procedure for individual compounds was adequate for protecting sensitive populations exposed to realistic combinations of pesticides. Spray drift reduction measures seem to be efficient in protecting aquatic ecosystems in agricultural areas.
Fitness cost of resistance to cadmium in the least killifish (Heterandria formosa)
Authors: Xie Lingtian , Klerks Paul L.
Published: November 2004

Fitness costs constrain the evolution of resistance to environmental stress in populations. We earlier reported on a rapid response to laboratory selection for cadmium resistance in the least killifish (Heterandria formosa). By the sixth generation, the three selection populations were threefold more resistant to cadmium than the control populations. Here, we report the fitness costs and trade-offs associated with this evolution of resistance. In the F3 and F4 generations, the selection populations produced smaller-sized offspring than the control populations. A comprehensive life-history traits study in the F7 generation showed that the selection populations had, on average, an 18% decrease in fecundity. The selection populations also had a smaller brood size, longer time to first reproduction, and shorter female life expectancy than the control populations. Our results strongly suggest that fitness costs and trade-offs were associated with the evolution of resistance to cadmium in the least killifish. The fitness costs and trade-offs may result from maintenance of the underlying resistance mechanisms, leading to changes in resource allocation in the cadmium-adapted fish.
High Mechanical Strength Double‐Network Hydrogel with Bacterial Cellulose
Authors: Nakayama A. , Kakugo A. , Gong J. P. , Osada Y. , Takai M. , Erata T. , Kawano S.
Published: November 2004

Double‐network (DN) hydrogels with high mechanical strength have been synthesized using the natural polymers bacterial cellulose (BC) and gelatin. As‐prepared BC contains 90 % water that can easily be squeezed out, with no more recovery in its swelling property. Gelatin gel is brittle and is easily broken into fragments under a modest compression. In contrast, the fracture strength and elastic modulus of a BC–gelatin DN gel under compressive stress are on the order of megapascals, which are several orders of magnitude higher than those of gelatin gel, and almost equivalent to those of articular cartilage. A similar enhancement in the mechanical strength was also observed for the combination of BC with polysaccharides, such as sodium alginate, gellan gum, and ι‐carrageenan.
The Synthesis of Novel Porous Functional Materials for use as Nitrosamine Traps
Authors: Xu Y. , Jiang Q. , Cao Y. , Wei Y. L. , Yun Z. Y. , Xu J. H. , Wang Y. , Zhou C. F. , Shi L. Y. , Zhu J. H.
Published: November 2004

Two novel porous nitrosamine traps have been synthesized in order to eliminate carcinogens from the environment. A functional mesoporous material, CuO/SBA‐15, has been synthesized by using an in‐situ coating method, with the addition of a guest salt to the reaction system to modify the porous materials before the particles of SBA‐15 were incubated; the synthesis and modification processes were performed in a single step. The resulting mesoporous composites selectively adsorbN‐nitrosopyrrolidine (NPYR), a typical volatile nitrosamine, and are potential cigarette additives that can be used for the removal of nitrosamines from cigarette smoke, thereby protecting public health and the environment. In another reaction, silica gel is modified by being coated with magnesia and then corroded by NaOH solution.The magnesia is dispersed onto the silica by impregnating it with a magnesium acetate solution, followed by calcination. After corrosion of the calcined sample with caustic soda, only the silica particles that are completely covered by magnesia remain. This material exhibits a similar ability to SBA‐15 and zeolite NaY in its selective adsorption of NPYR.
Efficient Isolation and Solubilization of Pristine Single‐Walled Nanotubes in Bile Salt Micelles
Authors: Wenseleers W. , Vlasov I. I. , Goovaerts E. , Obraztsova E. D. , Lobach A. S. , Bouwen A.
Published: November 2004

We have investigated a wide variety of surfactants for their efficiency in dissolving isolated single‐walled carbon nanotubes (SWNTs) in water. In doing so, we have completely avoided the harsh chemical or mechanical conditions, such as acid or ultrasonic treatments, that are known to damage SWNTs. Bile salts in particular are found to be exceptionally effective in dissolving individual tubes, as evidenced by highly resolved optical absorption spectra, bright bandgap fluorescence, and the unprecedented resolution (∼ 2.5 cm–1) of the radial breathing modes in Raman spectra. This is attributed to the formation of very regular and stable micelles around the nanotubes providing an unusually homogeneous environment. Quantitative information concerning the degree of solubilization is obtained from absorption spectroscopy.
Blood and body fluid exposure risks among health care workers: Results from the Duke Health and Safety Surveillance System
Authors: Dement John M. , Epling Carol , Østbye Truls , Pompeii Lisa A. , Hunt Debra L.
Published: November 2004

Background

Health care workers (HCWs) are at risk of exposures to human blood and body fluids (BBF). Needlestick injuries and splashes place HCWs at risk for numerous blood‐borne infections including human immunodeficiency virus (HIV), hepatitis B (HBV), and hepatitis C (HCV). Utilizing a new comprehensive occupational health surveillance system, the objective of this research was to better define the BBF exposure risk and risk factors among employees of a large tertiary medical center.

Methods

A population of 24,425 HCWs employed in jobs with potential BBF exposures was followed for BBF exposure events from 1998 to 2002. BBF exposure rates were calculated for strata defined by age, race, gender, occupation, work location, and duration of employment. Poisson regression was used for detailed analyses of risk factors for BBF exposure.

Results

The study population reported 2,730 BBF exposures during the study period, resulting in an overall annual rate of 5.5 events/100 FTEs and a rate of 3.9 for percutaneous exposures. Higher rates were observed for males, persons employed less than 4 years, Hispanic employees, and persons less than 45 years of age. Much higher rates were observed for house staff, nurse anesthetists, inpatient nurses, phlebotomists, and surgical/operating room technicians. Poisson regression results strengthened and extended results from stratified analyses. Rates of percutaneous exposures from hollow needles were found to decrease over the study period; however, exposure rates from suture needles appear to be increasing.

Conclusion

While continued training efforts need to be directed toward new HCWs, our data also suggest that employees who have been in their job 1–4 years continue to be at higher risk of BBF exposures. This research also points to the need for better safety devices/products and work practices to reduce suture‐related injuries. Am. J. Ind. Med. 46:637–648, 2004. © 2004 Wiley‐Liss, Inc.
High Temperature X‐Ray Diffraction Studies on Sodium Yttrium Fluoride.
Authors: Mathews M. D. , Ambekar B. R. , Tyagi A. K. , Koehler J.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
One‐Pot Preparation of Dialkylcarbamoyl Azides from Tertiary Amines Using Triphosgene and Sodium Azide.
Authors: Gumaste V. K. , Deshmukh A. R. A. S.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Sonochemical Synthesis of Nanomaterials
Authors: Manoharan S. Sundar , Rao Manju Lata
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Ligand Reactivity: General Introduction
Authors: Pombeiro A. J. L. , Kukushkin V. Yu
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Higher Denticity Ligands
Authors: Pettinari C. , Marchetti F. , Drozdov A.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Thiophenols via the Newman—Kwart Rearrangement
Authors: Kusch Dirk
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Alkylation of Enolates
Authors: Hughes David L.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Using Single‐Molecule Fluorescence Spectroscopy to Study Electron Transfer
Authors: Holman Michael W. , Adams David M.
Published: November 2004

Techniques in single‐molecule fluorescence spectroscopy now allow sophisticated studies of photophysical processes in single molecules. As interest grows in the possibilities of molecular electronics, researchers have begun to turn these techniques to the study of electron transfer. Electron‐transfer reactions have now been detected and measured at the single‐molecule level in a variety of systems and on a variety of timescales by adapting techniques from previous single‐molecule fluorescence studies.
Bioorganometallic Chemistry: Reactions of Methyltitanocene Cation Complexes with a Singly Deprotected Methyl Glucopyranoside
Authors: Meyer zu Berstenhorst Birgit , Erker Gerhard , Kehr Gerald , Wasilke Julia‐Christina , Müller Jens , Redlich Hartmut , Pyplo‐Schnieders Jutta
Published: November 2004

The dimethyltitanocene/B(C6F5)3 system reacts with the 4‐unprotected methyl α‐D‐glucopyranoside derivative 5 (“HO‐carb.”) to yield the ionic complex [Cp2Ti(O‐carb.)]+[MeB(C6F5)3]− (10a). Spectroscopic studies have led us to believe that 10a is characterized by an internal ether‐chelate structure in solution that involves coordination of the 6‐OCH2Ph oxygen atom. Treatment of 10a with trimethylphosphane gives the open, non‐chelated complex 11a, in which the phosphane coordinates to the metal center. Reaction of the THF‐stabilized salt [Cp2TiCH3(THF)]+[BPh4]− (12a) with 5 gave complex 13a, with coordinated THF. Experiments with bis(methylcyclopentadienyl)titanium systems gave analogous results (complexes 10b, 11b and 13b). Zirconocenes react differently. Addition of dimethylzirconocene (14a) or dimethylbis(methylcyclopentadienyl)zirconium (14b) to 5 gave the neutral complexes 15a, 15b and methane. Treatment of 15a (15b) with B(C6F5)3 again resulted in the formation of an ionic chelate complex 16a (16b). A non‐chelated complex 18 was formed by treating the THF‐stabilized salt [Cp2ZrCH3(THF)]+[BPh4]− (17) with 5. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Inhibition of allogeneic T‐cell responses by dendritic cells expressing transduced indoleamine 2,3‐dioxygenase
Authors: Funeshima Naoko , Fujino Masayuki , Kitazawa Yusuke , Hara Yuko , Hara Yoshiaki , Hayakawa Kou , Okuyama Torayuki , Kimura Hiromitus , Li Xiao‐Kang
Published: November 2004

Background

Indoleamine 2,3‐dioxygenase (IDO) is an enzyme involved in the catabolism of tryptophan and has been shown to prevent rejection of the fetus during pregnancy by inhibiting alloreactive T cells.

Methods

In this study we investigated dendritic cells (DCs) that are transfected with IDO cDNA in the inhibition of T‐cell proliferation after antigen‐specific interaction. XS106 DCs, derived from A/J mice (H‐2k), were transduced with IDO with a gene‐delivery system using a recombinant adenoviral vector.

Results

Western blotting and immune staining revealed IDO expression in XS106 DCs transduced with IDO (XS106‐IDO DCs), and its catabolic effect was confirmed by an increase in kynurenine concentration. Fluorescence‐activated cell sorting revealed that XS106‐IDO DCs were not changeable for Ia, CD80, and CD86 expression. After XS106‐IDO DCs were co‐cultured with C57BL/6 allogeneic splenic T cells, the proliferation of the T cell was significantly inhibited. The co‐cultured T cells with XS106‐IDO DCs exhibited cell‐cycle arrest. Furthermore, injection of XS160‐IDO DCs into the footpads of C57BL/6 (H‐2b) mice demonstrated a reduced T‐cell response against allo‐antigen.

Conclusions

These results suggest that overexpression of IDO in the DCs effectively inhibited T‐cell proliferation, and may expand a new immunomodulatory strategy for the prevention of allo‐rejection of organ transplantation. Copyright © 2004 John Wiley & Sons, Ltd.
Tandem mass spectrometry of the B‐type procyanidins in wine and B‐type dehydrodicatechins in an autoxidation mixture of (+)‐catechin and (−)‐epicatechin
Authors: Sun Weixing , Miller Jack M.
Published: November 2004

We describe the characterization of the B‐type procyanidins in wine and the B‐type dehydrodicatechins (dimeric flavan‐3‐ols) obtained for the autoxidation of (+)‐catechin and (−)‐epicatechin by tandem mass spectrometry (MS/MS) coupled to reversed‐phase high‐performance liquid chromatography (HPLC). The MS/MS analysis demonstrates that the interesting major fragments derive from the dissociations of the C‐ring on the catechin or epicatechin unit, such as retro‐Diels–Alder reactions. The two kinds of dimers give completely different fragmentations because of the striking effect of the C—C interflavan linkage (IFL). For the natural dimers in wine, a catechin or epicatechin unit linking to the C‐4 position stabilizes the product ions by forming a large π–π hyperconjugated system, whereas a similar π–π system is formed within dehydrodicatechin B through the C—C IFL. Thus dissociation in MS/MS experiments was inhibited. Apparently, the fragmentations of the dimers differ from that of the monomer, which is very important in the study of the gas‐phase ion behaviour of the polymeric flavan‐3‐ols. In addition, two specific fragment ions at m/z 451 for native dimers and at m/z 393 for autoxidation species in HPLC/MS/MS were found to be very useful for analysing mixtures of B‐type procyanidins and B‐type dehydrodicatechins in food and beverages. Copyright © 2003 John Wiley & Sons, Ltd.
Classification and analysis of past climate information based on historical documentary sources for the Carpathian basin
Authors: Bartholy Judit , Pongrácz Rita , Molnár Zsófia
Published: November 2004

In order to cover a millennium‐long period in climatological studies, several types of information must be taken into consideration. Beyond the regular meteorological observations, historical documentary data may serve as a basic source for the past centuries. For the Carpathian basin, Réthly collected historical documents containing meteorology‐related information. In order to facilitate the analysis of this documentary collection, a special code system using hierarchical subclasses has been defined and applied to approximately 15 000 collected climatological items. The spatial and temporal distributions of temperature‐ and precipitation‐related climate events and extremes have been evaluated using settlement and subregional scales. Also, the geographical distribution of extreme climatological events has been mapped. Annual and seasonal time series have been analysed for the Carpathian basin and compared with other reconstructed temperature and precipitation index time series from other geographical locations outside the Carpathian basin. Copyright © 2004 Royal Meteorological Society
Sunshine duration and daily courses of illuminance in Bratislava
Authors: Darula Stanislav , Kittler Richard
Published: November 2004

The occurrences of typical sky conditions during overcast days are close to the CIE Overcast Sky Standard in the Bratislava area; their variation is specified by the diffuse coefficient kdd = Dv/Ev where Dv is the horizontal diffuse illuminance and Ev is the extraterrestrial illuminance. Luminance distributions on cloudless days are close to the CIE Clear Sky Standard. Complex daylight conditions can be expected during cloudy days when moving clouds cause frequent sun disk shading with abrupt changes in illuminance levels. Since sunshine duration is one of the basic climatic parameters that describes sunny situations, the present study attempts to investigate its relation to daily illuminance levels. However, the average daily value of sunshine duration does not exactly correspond to the same illuminance course, as it depends on the temporal distribution of sunny periods within the day. Anyhow, the estimation of daytime illuminance levels is mainly influenced by the presence or absence of sunshine with frequent sky luminance patterns. Copyright © 2004 Royal Meteorological Society
Vibrational spectroscopic study of alkylenediammonium hexachlorostannate compounds, NH3(CH2)nNH3SnCl6 (n = 3 and 4)
Authors: Elyoubi M. , Ouasri A. , Jeghnou H. , Rhandour A. , Dhamelincourt M.‐C. , Dhamelincourt P. , Mazzah A.
Published: November 2004

The infrared and Raman spectra of propylenediammonium hexachlorostannate, NH3(CH2)3NH3SnCl6, and its butylenediammonium homologue, NH3(CH2)4NH3SnCl6, were recorded at ambient temperature and interpreted on the basis of literature data. All the characteristics of the IR and Raman bands of anions and cations in these compounds were identified. The combination bands observed in the 2300–1900 cm−1 infrared spectral region for both compounds indicate that they contain CNH3 groups. Evidence for the existence of weak hydrogen bonds was found on examining the 2400–3200 cm−1 infrared spectral region. Thus, anions and cations are weakly connected by hydrogen bonding inside the crystals. The anions were found, in these two compounds, to be slightly distorted from their free Oh octahedral symmetry. Copyright © 2004 John Wiley & Sons, Ltd.
Impact of regulatory labeling for troglitazone and rosiglitazone on hepatic enzyme monitoring compliance: findings from the state of Ohio medicaid program
Authors: Cluxton Robert J. , Li Zili , Heaton Pamela C. , Weiss Sheila R. , Zuckerman Ilene H. , Moomaw Charles J. , Hsu Van Doren , Rodriguez Evelyn M.
Published: November 2004

Purpose

Troglitazone, the first drug of the thiazolidinediones class for type II diabetes, was first marketed in March 1997 and was removed from the U.S. market 36 months later after 90 cases of liver failure were reported despite multiple warnings containing liver enzyme monitoring recommendations. Rosiglitazone has been available since June 1999 and is still on the market. The purpose of this study was to evaluate the impact of labeled hepatic
enzyme monitoring for troglitazone and rosiglitazone.

Methods

Drug cohorts were assembled, using population‐based fee‐for‐service Medicaid claims, for patients between 18 and 65 years of age who had received at least one troglitazone (n = 7226) or rosiglitazone (n = 1480) prescription between 1 April, 1997, and 21 March, 2000. The outcome of interest was the percentage of patients, based on their first treatment episode, who had baseline and post‐baseline liver enzyme testing.

Results

Overall baseline testing was under 9% before regulatory actions, increased to 14% after the first two ‘Dear Doctor’ letters issued by the FDA in October and December 1997, and peaked to about 26% afterwards. Coincident with the marketing of rosiglitazone and the fourth ‘Dear Doctor’ letter issued in June 1999, baseline testing dropped to 18%. Baseline testing increased 2.5‐fold (race‐sex‐age adjusted) after regulatory action. Achieving 50% post‐baseline testing took approximately 6 months for both drugs.

Conclusion

Regulatory actions had only modest effects on the incidence of liver monitoring. More effective and timely communication strategies, health provider prescribing interventions and modification of health provider behaviors to enhance compliance with recommended risk management measures need to be identified, evaluated and implemented. Copyright © 2004 John Wiley & Sons, Ltd.
Current two‐dimensional electrophoresis technology for proteomics
Authors: Görg Angelika , Weiss Walter , Dunn Michael J.
Published: November 2004

Two‐dimensional gel electrophoresis (2‐DE) with immobilized pH gradients (IPGs) combined with protein identification by mass spectrometry (MS) is currently the workhorse for proteomics. In spite of promising alternative or complementary technologies (e.g.multidimensional protein identification technology, stable isotope labelling, protein or antibody arrays) that have emerged recently, 2‐DE is currently the only technique that can be routinely applied for parallel quantitative expression profiling of large sets of complex protein mixtures such as whole cell lysates. 2‐DE enables the separaration of complex mixtures of proteins according to isoelectric point (pI), molecular mass (Mr), solubility, and relative abundance. Furthermore, it delivers a map of intact proteins, which reflects changes in protein expression level, isoforms or post‐translational modifications. This is in contrast to liquid chromatography‐tandem mass spectrometry based methods, which perform analysis on peptides, whereMrand pIinformation is lost, and where stable isotope labelling is required for quantitative analysis. Today's 2‐DE technology with IPGs (Görget al.,Electrophoresis2000,21, 1037–1053), has overcome the former limitations of carrier ampholyte based 2‐DE (O'Farrell,J. Biol. Chem. 1975,250, 4007–4021) with respect to reproducibility, handling, resolution, and separation of very acidic and/or basic proteins. The development of IPGs between pH 2.5–12 has enabled the analysis of very alkaline proteins and the construction of the corresponding databases. Narrow‐overlapping IPGs provide increased resolution (δpI = 0.001) and, in combination with prefractionation methods, the detection of low abundance proteins. Depending on the gel size and pH gradient used, 2‐DE can resolve more than 5000 proteins simultaneously (˜2000 proteins routinely), and detect and quantify < 1 ng of proteinperspot. In this article we describe the current 2‐DE/MS workflow including the following topics: sample preparation, protein solubilization, and prefractionation; protein separation by 2‐DE with IPGs; protein detection and quantitation; computer assisted analysis of 2‐DE patterns; protein identification and characterization by MS; two‐dimensional protein databases.
Atom transfer radical polymerization of cyclohexyl methacrylate at a low temperature
Authors: Muñoz‐Bonilla Alexandra , López Madruga Enrique , Fernández‐García Marta
Published: November 2004

The atom transfer radical polymerization of cyclohexyl methacrylate (CHMA) is reported. Controlled polymerizations were performed with the CuBr/N,N,N′,N″,N″‐pentamethyldiethylenetriamine catalytic system with ethyl 2‐bromoisobutyrate as the initiator in bulk and different solvents (25 vol %) at 40 °C. The polymerization of CHMA in bulk resulted in a controlled polymerization, although the concentration of active species was relatively elevated. The addition of a solvent was necessary to reduce the polymerization rate, which was dependent on the dipole moment. Well‐controlled polymers were obtained in toluene, diphenyl ether, and benzonitrile solutions. Poly(cyclohexyl methacrylate) as a macroinitiator was used to synthesize the poly(cyclohexyl methacrylate)‐b‐poly(tert‐butyl methacrylate) block copolymer, which allowed a demonstration of its living character. In addition, two difunctional initiators, 1,4‐bis(bromoisobutyryloxy) benzene and 1,2‐bis(bromoisobutyryloxy) ethane, were used to initiate the atom transfer radical polymerization of CHMA. The experimental molecular weights of the obtained polymers were very close to the theoretical ones. These, along with the relative narrow molecular weight distributions, indicated that the polymerization was living and controlled. For confirmation, two different poly(tert‐butyl methacrylate)‐b‐poly(cyclohexyl methacrylate)‐b‐poly(tert‐butyl methacrylate) triblock copolymers were also synthesized. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 71–77, 2005
(Q)SARs for Predicting Skin Irritation and Corrosion: Mechanisms, Transparency and Applicability of Predictions
Authors: Walker John D. , Gerner Ingrid , Hulzebos Etje , Schlegel Kerstin
Published: November 2004

This paper describes previously‐developed (quantitative) structure‐activity relationships [(Q)SARs]for predicting skin irritation and corrosion, proposes mechanisms of skin irritation and corrosion, and discusses the transparency and applicability of predictions. This paper was written to set the tone for companion papers that describe three applications of skin irritation and corrosion (Q)SARs. The first companion paper describes physicochemical property limits that can be used to develop rules for identifying chemical substances with no skin irritation or corrosion potential. The second companion paper describes structural alerts that can be used to develop rules for identifying chemical substances with skin irritation or corrosion potential. The third companion paper describes the Skin Irritation Corrosion Rules Estimation Tool (SICRET), a user‐friendly tool that allows non‐(Q)SAR experts to identify chemical substances with skin irritation or corrosion potential based on physicochemical property limits and structural alerts.
Electrophysiological and pharmacological characterization of K+-currents in muscle fibres isolated from the ventral sucker ofFasciola hepatica
Authors: KUMAR D. , WHITE C. , FAIRWEATHER I. , McGEOWN J. G.
Published: November 2004

Fibres isolated from the ventral sucker ofFasciola hepaticawere identified as muscle on the basis of their contractility, and their actin and myosin staining. They were voltage-clamped at a holding potential of −40 mV and depolarization-activated outward currents were characterized both electrophysiologically and pharmacologically. Activation was well fitted by a Boltzmann equation with a half-maximal potential of +9 mV and a slope factor of −14·3 mV, and the kinetics of activation and deactivation were voltage-sensitive. Tail current analysis showed that the reversal potential was shifted by +46±3 mV when EKwas increased by 52 mV, confirming that this was a K+-current with electrophysiological characteristics similar to delayed rectifier and Ca2+-activated K+-currents in other tissues. The peak current at +60 mV was inhibited by 76±6% by tetrapentylammonium chloride (1 mM) and by 84±7% by Ba2+(3 mM), but was completely resistant to block by tetraethylammonium (30 mM), 3,4-diaminopyridine (100 μM) and 4-aminopyridine (10 mM). Penitrem A, a blocker of high-conductance Ca2+-activated K+-channels reduced the current at +60 mV by 23±5%. When the effects of Ca2+-channel blocking agents were tested, the peak outward current at +60 mV was reduced by 71±7% by verapamil (30 μM) and by 59±4% by nimodipine (30 μM). Superfusion with BAPTA-AM (50 μM), which is hydrolysed intracellularly to release the Ca2+-buffer BAPTA, also decreased the current by 44±16%. We conclude that voltage-and Ca2+-sensitive K+-channels are expressed in this tissue, but that their pharmacology differs considerably from equivalent channels in other phyla.
Convergence properties of gradient-based numerical motion-optimizations for manipulator arms amid static or moving obstacles
Authors: Park Jong-keun
Published: November 2004

This paper demonstrates the convergence stability and the actual usefulness of the gradient-based motion optimizations for manipulator arms. An optimal motion-planning problem is converted into a finite-dimensional nonlinear programming problem that utilizes cubic or quintic B-splines as basis functions. This study shows that the numerically calculated gradient is a useful tool in finding minimum torque, minimum energy, minimum overload, and minimum time motions for manipulator arms in the presence of static or moving obstacles. A spatial 6-link manipulator is simulated without simplifying any of the kinematic, dynamic or geometric properties of the manipulator or obstacles.
Algorithms of trajectory planning with constrained deviation from a given end-effector path
Authors: Dulȩba Ignacy , Karcz–Dulȩba Iwona
Published: November 2004

In this paper two well known and two new methods, and corresponding algorithms, of trajectory planning with a constrained end-effector path tracking error are presented and compared. They are: an exact path following method, the Taylor's algorithm of following a straight line with prescribed accuracy, a local optimization method, and a method of local trajectory shortening. It appears that the last two methods provide path following with a prescribed accuracy while keeping a planned trajectory as short as possible. Presented algorithms can extend robot programming languages with a tool of trajectory planning.
Passive dynamic walking model with upper body
Authors: Wisse M. , Schwab A. L. , van der Helm F. C. T.
Published: November 2004

This paper presents the simplest walking model with an upper body. The model is a passive dynamic walker, i.e. it walks down a slope without motor input or control. The upper body is confined to the midway angle of the two legs. With this kinematic constraint, the model has only two degrees of freedom. The model achieves surprisingly successful walking results: it can handle disturbances of 8% of the initial conditions and it has a specific resistance of only 0.0725(−).
Symposium Report
Authors: Erbe Heinz-H. , Olling Gus
Published: November 2004

7TH IFAC SYMP. ON COST ORIENTED AUTOMATION (COA 2004), JUNE 7–9, 2004, OTTAWA/GATINEAU (CANADA)
Early and late Spanish–English bilinguals' acquisition of English word stress patterns
Authors: GUION SUSAN G. , HARADA TETSUO , CLARK J. J.
Published: November 2004

Guion, Clark, Harada and Wayland (2003) found that three factors affect English speakers' stress placement on bisyllabic non-words: syllabic structure, lexical class and stress patterns of phonologically similar real words. The current replication and extension included three groups (N = 30): native English speakers, early Spanish–English bilinguals, and late Spanish–English bilinguals. Participants produced and gave perceptual judgments on 40 non-words of varying syllabic structures in noun and verb sentence frames. A regression analysis used the three factors to predict stress placement in production and perception. All three groups showed significant effects from stress patterns of phonologically similar real words and lexical class. The effect of syllabic structure for early bilinguals was slightly different from that of native speakers and late bilinguals showed greatly reduced effects. Late bilinguals exhibited more initial stress overall, possibly due to L1 transfer. These results run counter to the prediction made by Long (1990) about age effects on phonological acquisition.
Crosslinguistic influence at the syntax–pragmatics interface: Subjects and objects in English–Italian bilingual and monolingual acquisition
Authors: SERRATRICE LUDOVICA , SORACE ANTONELLA , PAOLI SANDRA
Published: November 2004

The findings from a number of recent studies indicate that, even in cases of successful bilingual first language acquisition, the possibility remains of a certain degree of crosslinguistic influence when the choice between syntactic options is affected by discourse pragmatics. In this study we focussed on the use of referring expressions, prime candidates to test the interaction between syntax and pragmatics, and we compared the distribution of subjects and objects in the Italian and English of a bilingual child (1;10–4;6) with that of two groups of MLUw-matched monolinguals. All arguments were coded for syntactic function and for a number of discourse pragmatic features predicted to affect their realisation. Our main prediction was that unidirectional crosslinguistic influence might occur for the English–Italian bilingual child with respect to pronominal subject and object use after the instantiation of the C system. Specifically we predicted that in Italian the bilingual child might use overt pronominal subjects in contexts where monolinguals would use a null subject, and that he might use postverbal strong object pronouns in Italian instead of preverbal weak pronominal clitics. Conversely, we did not expect the overall proportion of overt objects, whether noun phrases or pronouns, to vary crosslinguistically as objects are always obligatorily overt in both languages regardless of discourse pragmatics. Our results confirmed these predictions, and corroborated the argument that crosslinguistic influence may occur in bilingual first language acquisition in specific contexts in which syntax and pragmatics interact.
Measuring the potential utility of seasonal climate predictions
Authors: Tippett Michael K. , Kleeman Richard , Tang Youmin
Published: November 2004

Variation of sea surface temperature (SST) on seasonal‐to‐interannual time‐scales leads to changes in seasonal weather statistics and seasonal climate anomalies. Relative entropy, an information theory measure of utility, is used to quantify the impact of SST variations on seasonal precipitation compared to natural variability. An ensemble of general circulation model (GCM) simulations is used to estimate this quantity in three regions where tropical SST has a large impact on precipitation: South Florida, the Nordeste of Brazil and Kenya. We find the yearly variation of relative entropy is strongly correlated with shifts in ensemble mean precipitation and weakly correlated with ensemble variance. Relative entropy is also found to be related to measures of the ability of the GCM to reproduce observations.
Influence of stochastic forcing on ENSO prediction
Authors: Zavala‐Garay J. , Moore A. M. , Kleeman R.
Published: November 2004

The basic philosophy behind data assimilation forecasting is that accurate knowledge of the initial conditions at the beginning of the forecast will produce reliable predictions. In this work we explore this idea under the assumption that El Niño–Southern Oscillation (ENSO) behaves as a stochastically forced phenomenon using the Kleeman intermediate model. This work provides a quantification of how the stochastic forcing (SF) is a limiting factor in increasing the predictability of ENSO via data assimilation in this intermediate model. Different cases are considered corresponding to the presence or absence of SF during different stages of the forecast process (i.e., assimilation and prediction or validation). Within each case, different strong‐constraint assimilation methodologies are used. These methodologies show that better results can be obtained when information about the thermal structure of the upper ocean is considered and when interaction between the atmosphere and ocean is allowed in the assimilation process. Considering the best possible scenario, where observations of heat content are available at every grid point and time step, the presence of SF decreases the skill of the forecasts to about 12 months. This is similar to the skill reported by many operational and experimental seasonal prediction systems that use strong‐constraint data assimilation. Therefore our results suggest that there is little room for improvement in forecast skill as a result of strong‐constraint data assimilation.
Identification of a novel allele HLA‐B*5610 in a Chinese potential bone marrow donor
Authors: Wu G.‐G. , Cheng L.‐H. , Zhou D. , Deng Z.‐H. , Zou H.‐Y. , Wei T.‐L. , Li Z. , Li D.‐C. , Gao S.‐Q. , Zhao T.‐M.
Published: November 2004

Abstract:  A novel HLA‐B allele, B*5610, has been identified in a potential bone marrow donor, his mother and brother using DNA‐based typing and molecular cloning methods. The B*5610 allele differs from the closest matching HLA sequence of B*5602 by two nucleotide substitutions in exon 3, 559 C→A and 560 T→C, resulting in an amino acid change from Leu (CTG) to Thr (ACG) at codon 187. This new allele was segregated together with A*24020101 and DRB1*140101 in the proband's family. Serology study revealed that B*5610 is associated with B22 specificity. A PCR‐SSP method was developed to distinguish B*5610 from other B*56 alleles. No further individuals with B*5610 were detected in 5000 Chinese bone marrow blood donors.
Pediatric renal transplantation: A single Belgian center experience over 20 years
Authors: Van Damme‐Lombaerts R. , Herman J. , Coosemans W. , Pirenne J.
Published: November 2004

Abstract: Between 1980 and 2000, 100 renal transplantations were performed in 91 children at the pediatric unit of the University Hospital Leuven. The proportion of living‐related donors (LRD) was 20%. Patient survival rates were 94% at 3 yr, 91% at 5 yr, and 87% at 10 yr. The commonest causes of death were bacterial infections and cardiovascular complications, which underscores the need for aggressive preventative procedures in this area after transplantation. The overall actuarial graft survival was 82% at 3 yr (n = 73), 74% at 5 yr (n = 53), and 56% at 10 yr (n = 29). In the LRD group, the graft survival was 10% better than the overall actuarial graft survival rate. The overall incidence of acute rejection was 55% but has shown a decrease to 34% in more recent years (1993–99). The major causes of graft failure were chronic rejection and recurrence of the initial disease, and these remain a major concern. Improvement of these results could be achieved by tight immunosuppression management, early aggressive treatment of infection and rejection, and careful educational and psychological support.
Construction of ectopic xenogeneic bone marrow structure associated with persistent multi‐lineage mixed chimerism by engraftment of rat bone marrow plugs into mouse kidney capsules
Authors: Hara Hidetaka , Ohdan Hideki , Tokita Daisuke , Onoe Takashi , Zhou Wendy , Asahara Toshimasa
Published: November 2004

Abstract: Poor bone marrow (BM) engraftment in a xenogeneic combination results at least in part from the limited engraftment capacity of BM‐derived stromal cells, which support hematopoietic repopulation in a species‐specific fashion. We attempted to construct a BM stromal microenvironment by engraftment of BM plug fragments into kidney capsules in a rat‐to‐mouse combination. BM plugs from F344/N Jcl‐rnu/rnu (F344 nu) rats were transplanted into the kidney capsules of C.B‐17 scid/scid (C.B‐17 scid) mice treated with rabbit anti‐asialo‐GM1 serum to deplete natural killer (NK) cells and then with 3 Gy of whole body irradiation. As a conventional control, an equivalent amount of F344 nu bone marrow cells (BMCs) was intravenously injected into C.B‐17 scid mice treated with a similar conditioning regimen. In both mouse recipients of rat BM plug engraftment in the kidney capsules and recipients of intravenous injection of rat BMC suspension, comparable extents of donor rat class I+ cells were persistently detected in the peripheral blood. However, the differentiation of rat‐derived B cells in the mouse recipients of rat BM plugs was more rapid than that in the recipients of rat BMC suspension. In the late phase (10 weeks after BM transplantation), the percentage of rat‐derived T cells (CD4+ cells) in the mouse recipients of rat BM plugs was significantly higher than that in the recipients of rat BMC suspension. At this time point, ectopic BM structure consisting of bone, mesenchymal cells, and hematopoietic progenitors was constructed in the kidney capsules of mice that received rat BM plugs. Most of the cells in the ectopic BM were derived from the donor rat. Thus, engraftment of BM plugs into the kidney capsules results in the construction of a donor‐derived BM microenvironment, facilitating multilineage mixed xenogeneic chimerism.