bluuebunny/crossref_metadata_2025_split huggingface dataset:
Proteomic analysis of diet‐induced hypercholesterolemic mice
Authors: Park Ji Young , Seong Je Kyung , Paik Young‐Ki 
Published: January 2004

AbstractWe report here a proteomic analysis of differentially expressed liver proteins of both C57BL/6J (B6, atherosclerosis‐susceptible strain) and C3H/HeJ mice (C3H, atherosclerosis‐resistant strain), which were fed either control or a high‐fat enriched atherogenic diet for eight weeks. We observed differential patterns of plasma lipids between the two strains when both were fed atherogenic diets. That is, although low density lipoprotein cholesterol level was highly elevated in both, the levels of total cholesterol and triglyceride in B6 mice were much lower than those in C3H mice when they were fed atherogenic diets. However, the high density lipoprotein cholesterol level was increased in the latter but decreased in the former. Histopathological observation revealed that more prominent lipid droplets were present in B6 mice than in C3H mice, when they were maintained on the atherogenic diets. Proteomic analysis of liver tissues of these two strains showed that a total of 30 proteins were significantly changed in the livers obtained from both strains after being fed the atherogenic diet. Of these, 14 protein spots including carbonic anhydrase III, senescence marker protein 30 and selenium binding protein 2 were differentially changed only in B6 mice, which was also confirmed in part by Western blotting. An additional 16 protein spots including glutathione S‐transferase subclass, apolipoprotein E and chaperonin proteins were changed in both strains. We also identified 28 proteins that were differentially expressed in the livers of both B6 and C3H mice, regardless of diet feeding condition. Of these, 4 protein spots in B6 mice and 11 protein spots in C3H mice were up‐regulated. Thirteen strain specific protein spots including antioxidant protein 2, apolipoprotein E and apolipoprotein A‐I were also detected in different positions in two‐dimensional electrophoresis. These results suggest a clear distinction in differential expression of oxidative stress proteins and lipid metabolism related proteins between the two strains in response to atherogenic diet feeding, which might account for their difference in susceptibility to atherogenesis.
Snake venomics: Characterization of protein families in Sistrurus barbouri venom by cysteine mapping, N‐terminal sequencing, and tandem mass spectrometry analysis
Authors: Juárez Paula , Sanz Libia , Calvete Juan J. 
Published: January 2004

AbstractThe protein composition of the crude venom of Sistrurus barbouri was analyzed by two‐dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis. Proteins were separated by reversed phase high‐performance liquid chromatography and characterized by N‐terminal sequence analysis. The molecular mass and number of cysteine residues of the purified proteins were determined by matrix‐associated laser desorption/ionization‐time of flight mass spectrometry. Selected protein bands were subjected to in‐gel tryptic digestion and peptide mass fingerprinting. Analysis of the tandem mass spectrometry spectra of selected doubly‐charged peptide ions was done by collision‐induced dissociation in a quadrupole‐linear ion trap instrument. Our results show that the venom proteome of the pigmy rattlesnake S. barbouri is composed of proteins belonging to a few protein families, which can be structurally characterized by their disulfide bond contents.
Isolation of circulating human monocytes with high purity for proteomic analysis
Authors: Gonzalez‐Barderas Maria , Gallego‐Delgado Julio , Mas Sebastián , Duran Mari Carmen , Lázaro Alberto , Hernandez‐Merida Sergio , Egido Jesús , Vivanco Fernando 
Published: January 2004

AbstractWe describe a simple method for isolation of human blood monocytes with the high purity (95–98%) required for proteomic analysis, which avoids contamination by other blood cells (platelets and lymphocytes) and the most abundant plasma proteins (albumin and immunoglobulins). Blood monocytes were purified by gradient centrifugation followed by positive selection with specific monoclonal antibodies coupled to paramagnetic beads. The elution conditions of the positive selection step were modified to avoid contamination with albumin. This method is compatible with flow cytometry which was used to assess the purity of the cell population. From 28 mL of blood, 107 monocytes with > 96% purity are routinely obtained. From the isolated monocytes 200–250 μg of protein could be recovered. The whole method can be performed in three hours. Similar results were obtained using a negative selection step but with lower purity (92%), increased cost and longer time. After solubilization of monocytes, the proteins were analyzed by two‐dimensional gel electrophoresis (2‐DE) in the 3–10, 4–7, 6–9 and 6–11 pH range. DNA was the main contaminant that interfered with the 2‐DE and it was removed by treatment with DNAse. Image analysis of gels allowed the reproducible detection and quantification of 1500 spots in the 4–7 pH range and more than 2000 spots in total by combining (overlapping) 2‐D gels in the 4–7, 6–9 and 6–11 pH range. This method is useful for clinical studies of monocytes from a large number of patients due to its rapidity and reproducibility, which permits comparative analysis of normal versus pathological samples and which allows follow up of the expressed proteins of monocytes from each patient.
Proteomic analysis of lung biopsies: Differential protein expression profile between peritumoral and tumoral tissue
Authors: Alfonso Patricia , Catalá Myriam , Rico‐Morales María Luisa , Durante‐Rodríguez Gonzalo , Moro‐Rodríguez Ernesto , Fernández‐García Héctor , Escribano José M. , Álvarez‐Fernández Emilio , García‐Poblete Eduardo 
Published: January 2004

AbstractThe cellular proteome shows a dynamic profile and is subjected to changes in response to various stimuli and disease progression. Lung cancer remains the leading cause of cancer death in industrialized countries. In an attempt to find new disease markers, patients suffering from lung carcinoma have been selected to achieve differential protein expression patterns between normal and neoplasic tissue. After two‐dimensional electrophoresis, the spots of interest were digested and identified by matrix‐assisted laser desorption/ionization (MALDI) peptide mass fingerprinting. This information will provide a more comprehensive understanding of the disease progression and might constitute a method to complement histopathological diagnosis.
Proteomic analysis of the oxygen‐evolving complex of photosystem II under biotec stress: Studies on Nicotiana benthamiana infected with tobamoviruses
Authors: Pérez‐Bueno M. Luisa , Rahoutei Jaber , Sajnani Carlota , García‐Luque Isabel , Barón Matilde 
Published: January 2004

AbstractWe have previously shown that tobamovirus infection induces an inhibition of photosystem II electron transport, disturbing the oxygen‐evolving complex (OEC). In the infected plants, the OEC polypeptide pattern was modified when compared to healthy plants, the levels of the PsbP and PsbQ extrinsic proteins being lowered to different extents. In this work we have further investigated by two‐dimensional polyacrylamide gel electrophoresis (2‐DE) the changes on the OEC protein pattern of thylakoid membranes isolated from Nicotiana benthamiana Domin plants infected with the Spanish strain of pepper mild mottle virus. When the thylakoid membranes from healthy plants were analyzed for the presence of PsbO and PsbP proteins by 2‐DE (pI range 4–7) and further immunoassayed by using specific‐antisera against these two proteins, it was observed that four polypeptides cross‐reacted with each antiserum. These data, along with the N‐terminal amino acid sequence determined for the eight polypeptides, indicate that the N. benthamiana PsbO and PsbP proteins correspond to protein families. In the silver‐stained 2‐DE gels of thylakoid membranes isolated at different days postinoculation from virus‐infected plants, it was observed that the content of PsbP polypeptides decreased dramatically with respect to those of PsbO, during the progress of the infection. Interestingly, there was a differential decrease of the different PsbP proteins, indicative of a distinct regulation of their expression.
On optimal control of constrained linear systems with imperfect state information and stochastic disturbances
Authors: Perez Tristan , Haimovich Hernan , Goodwin Graham C. 
Published: January 2004

AbstractWe address the problem of finite horizon optimal control of discrete‐time linear systems with input constraints and uncertainty. The uncertainty for the problem analysed is related to incomplete state information (output feedback) and stochastic disturbances. We analyse the complexities associated with finding optimal solutions. We also consider two suboptimal strategies that could be employed for larger optimization horizons. Copyright © 2004 John Wiley & Sons, Ltd.
Feedback min‐max model predictive control using a single linear program: robust stability and the explicit solution
Authors: Kerrigan Eric C. , Maciejowski Jan M. 
Published: January 2004

AbstractIn this paper we introduce a new stage cost and show that the use of this cost allows one to formulate a robustly stable feedback min–max model predictive control problem that can be solved using a single linear program. Furthermore, this is a multi‐parametric linear program, which implies that the optimal control law is piecewise affine and can be explicitly pre‐computed so that the linear program does not have to be solved on‐line. We assume that the plant model is known, is discrete‐time and linear time‐invariant, is subject to unknown but bounded state disturbances and that the states of the system are measured. Two numerical examples are presented; one of these is taken from the literature, so that a direct comparison of solutions and computational complexity with earlier proposals is possible. Copyright © 2004 John Wiley & Sons, Ltd.
Photoswitching of ferroelectric liquid crystals using chiral thioindigo dopants: The development of a photochemical switch hitter
Authors: Lemieux Robert P. 
Published: January 2004

AbstractBy virtue of its spontaneous polarization (PS), a ferroelectric SmC* liquid crystal can be switched between two states corresponding to opposite molecular tilt orientations using an electric field, thus producing an ON–OFF light shutter between crossed polarizers. Considerable efforts have been made over the past decade to develop photonic FLC light shutters because of their potential uses in dynamic holography and optical data storage. The ON–OFF switching of a FLC light shutter can be triggered by light via a photoinversion of PS using a photochromic dopant. The spontaneous polarization is a chiral bulk property that can be left‐handed (negative) or right‐handed (positive), depending on the absolute configuration of the chiral component of the SmC* phase. In the approach described herein, the magnitude of PS is modulated via the photoisomerization of a chiral thioindigo dopant that undergoes a large increase in transverse dipole moment upon trans–cis photoisomerization. The sign of PS is photoinverted using an “ambidextrous” thioindigo dopant containing a chiral 2‐octyloxy side chain that is coupled to the thioindigo core and induces a positive PS, and a chiral 2,3‐difluorooctyloxy side chain that is decoupled from the core and induces a negative PS. In the trans form, the 2,3‐difluorooctyloxy side chain predominates and the net PS induced by the dopant is negative. However, upon trans–cis‐photoisomerization, the increase in transverse dipole moment of the 2‐octyloxy/thioindigo unit raises its induced PS over that of the decoupled 2,3‐difluorooctyloxy side chain, and thus inverts the net sign of PS induced by the dopant from negative to positive. © 2004 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 3: 288–295; 2004: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.10067
Selective alkane CH‐bond functionalizations utilizing oxidative single‐electron transfer and organocatalysis
Authors: Schreiner Peter R. , Fokin Andrey A. 
Published: January 2004

AbstractAlkane CH‐bond functionalization methods not utilizing metal‐catalysis are discussed based on experimental and computational data, beginning with molecule‐induced homolysis (reactions of alkanes with dioxiranes). Electrophilic reactions are elaborated next with an emphasis on mechanistic details that reveal that many so‐called electrophilic CH or CC‐bond insertions can be rationalized by electron‐transfer reactions (inner sphere, H‐coupled, and outer sphere). Finally, radical functionalizations utilizing carbon‐centered (relatively stable) radicals generated under organocatalytic (phase‐transfer catalysis, PTC) conditions are presented as valuable alternatives to other radical‐chain alkane functionalizations. The remarkable chemo‐ and regioselectivities of these PTC radical reactions and the tolerance of high strain in certain aliphatic hydrocarbons make them particularly useful for laboratory‐scale halogenations, in particular, iodinations of unactivated alkane CH‐bonds. © 2004 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 3: 247–257; 2004: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.10070
Population growth impairment of aliphatic alcohols to Tetrahymena
Authors: Schultz T. Wayne , Seward‐Nagel Julie , Foster Karen A. , Tucker Vera A. 
Published: January 2004

AbstractThe toxicity of a series of 120 aliphatic alcohols was evaluated using the Tetrahymena pyriformis population growth impairment assay. For tertiary propargylic alcohols; primary, secondary, and tertiary homopropargylic alcohols; allylic alcohols; and saturated alcohols, a statistically robust structure‐activity model was developed for toxicity data [log (IGC50−1)] using the 1‐octanol/water partition coefficient (log Kow) as the lone descriptor [log (IGC50)−1 = 0.74 (log Kow) − 1.73; n = 97; r2 (adj.) = 0.933; r2 (pred.) = 0.932; s = 0.298; F = 1328; Pr > F = 0.0001]. Analysis of data for the primary propargylic alcohols yielded a separate, high‐quality log Kow‐dependent quantitative structure‐activity relationship (QSAR) [log (IGC50)−1 = 0.65 (log Kow) − 1.22; n = 10; r2 (adj.) = 0.969; r2 (pred.) = 0.964; s = 0.222; F = 254; Pr > F = 0.0001]. A comparison of the observed toxicity and that predicted by the first QSAR showed that the primary propargylic alcohols with log Kow values < 2.00 exhibited enhanced toxicity and that this increased toxicity was inversely related to hydrophobicity. In sharp contrast, analysis of the data for the secondary propargylic alcohols exhibited little relationship with log Kow (r2 = 0.339). Although the initial QSAR can be used to model the toxicity of any aliphatic alcohol for the T. pyriformis population growth impairment end point, the estimated potency would be underestimated for primary propargylic alcohols with log Kow values < 2.00. Moreover, estimates of toxic potency of secondary propargylic alcohols based on this QSAR should be viewed with limited confidence. The findings for β‐unsaturated alcohols in Tetrahymena were sharply different from that reported for fathead minnow acute mortality; this difference in toxicity is a result of a difference in the protocol used rather than in metabolism. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 1–10, 2004.
Toxicity of arsenic species to Lemna gibba L. and the influence of phosphate on arsenic bioavailability
Authors: Mkandawire Martin , Lyubun Yelena V. , Kosterin Paul V. , Dudel E. Gert 
Published: January 2004

AbstractThe toxicity of arsenic (As) species to Lemna gibba L. and the influence of PO on As bioavailability and uptake were tested in batch culture. L. gibba were exposed to six test concentrations of NaHAsO4 · 7H2O and NaAsO3, with 0, 0.0136, 13.6, and 40 mg L−1 KH2PO4. In batch culture As toxicity to L. gibba did not relate linearly to As concentration. The growth rate, related to frond number as recommended by OECD and ISO/DIN, was significantly inhibited in fronds exposed to 20–50 μg L−1 As(III) compared with fronds exposed to As(V). The growth rate was stimulated when plants were exposed to 50–250 μg L−1 of both As(III) and As(V). After exposure to 300–800 μg L−1 growth inhibition was significantly higher for As(III) than for As(V), whereas above 800 μg L−1 As(V) was inhibited the most. The bioaccumulation of As(III) and As(V) was significantly higher for P‐deficient cultures (0.98 ± 0.08 and 1.02 ± 0.19 g kg−1, respectively for 0.0136 mg L−1 PO) than for P‐sufficient cultures (243 and 343 mg kg−1 for 40 mg L−1, respectively). Plants exposed to As(V) had uptake and accumulation values slightly higher than did plants exposed to As(III). No significant differences in bioaccumulation were found between plants exposed to a concentration of As(III) >1 mg L−1 and those exposed to As(V) at the same concentration. This indicates a direct relationship to P content in the culture. Toxicity may result from the uptake of As(V) instead of PO as a result of ion competition during uptake because of close thermodynamic properties, which may change the interaction among components in the media. The toxicity pattern is interpreted as a manifestation of changing speciation in the batch culture and of the oxidation of As(III) to As(V) in an oxygen‐rich environment. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 26–34, 2004.
Mercury concentrations in migratory waterfowl harvested from Southern Nevada Wildlife Management Areas, USA
Authors: Gerstenberger Shawn L. 
Published: January 2004

AbstractMercury concentrations were determined in 14 species of migratory waterfowl harvested from Southern Nevada Wildlife Management areas during the 2001–2002 hunting season. Common mergansers (2.61 ± 0.87 ppm liver; 0.22 ± 0.04 ppm muscle), northern shovelers (3.51 ± 3.8 ppm liver; 0.16 ± 0.03 ppm muscle), and bufflehead (2.63 ± 0.24 ppm liver; 0.91 ppm muscle) had the highest concentrations of mercury in the liver and muscle of the species harvested. The relationships between muscle and liver concentrations were also examined. These data indicate that liver tissue can be used with reasonable confidence (r >.80 for most species) to predict mercury concentrations in muscle, the most commonly consumed portion of waterfowl. The mercury concentrations reported here are some of the highest reported in the scientific literature, and they identify certain species, such as the northern shoveler and common merganser, that have accumulated unusually high concentrations of mercury. Evidence for the use of these three species as possible bioindicators for mercury is also presented. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 35–44, 2004.
Evaluation of flushing of a high‐selenium backwater channel in the Colorado River
Authors: Hamilton Steven J. , Holley Kathy M. , Buhl Kevin J. , Bullard Fern A. , Weston L. Ken , McDonald Susan F. 
Published: January 2004

AbstractConcern has been raised that selenium contamination may be adversely affecting endangered fish in the upper Colorado River basin. The objective of the study was to determine if operation of a water control structure (opened in December 1996) that allowed the Colorado River to flow through a channel area at Walter Walker State Wildlife Area (WWSWA) would reduce selenium and other inorganic elements in water, sediment, aquatic invertebrates, and forage fish. Endangered Colorado pikeminnow were collected and muscle plug samples taken for selenium analysis. Selenium concentrations in filtered water were 21.0 μg/L in 1995, 23.5 μg/L in 1996, 2.1 μg/L in 1997, and 2.1 μg/L in 1998. Selenium concentrations in sediment cores and sediment traps were 8.5 μg/g in 1995, 8.2 μg/g in 1996, 4.8 μg/g in 1997, and 1.1 μg/g in 1998. Selenium concentrations in aquatic invertebrates were 27.4 μg/g in 1996, 15.5 μg/g in 1997, and 4.9 μg/g in 1998. Selenium concentrations in forage fish were 27.2 μg/g in 1996, 20.2 μg/g in 1997, and 8.6 μg/g in 1998. Selenium concentrations in muscle plugs of Colorado pikeminnow were 9.8 μg/g in 1995, 9.5 μg/g in 1996, 9.0 μg/g in 1997, and 10.3 μg/g in 1998. Although selenium concentrations in water, sediment, aquatic invertebrates, and forage fish decreased substantially after operation of the water control structure, a corresponding change in Colorado pikeminnow did not seem to occur. Selenium concentrations in muscle plugs decreased with increasing fish total length and weight, did not change between repeat sampling in the same year or recapture in subsequent years, and seemed to be most closely associated with the mean monthly river flow for the March–July period. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 51–81, 2004.
Extraction of cyanobacterial endotoxin
Authors: Papageorgiou John , Linke Thomas A. , Kapralos Con , Nicholson Brenton C. , Steffensen Dennis A. 
Published: January 2004

AbstractTo simplify our efforts in acquiring toxicological information on endotoxins produced by cyanobacteria, a method development study was undertaken to identify relatively hazard‐free and efficient procedures for their extraction. One article sourced and two novel methods were evaluated for their ability to extract lipopolysaccharides (LPSs) or endotoxins from cyanobacteria. The Limulus polyphemus amoebocyte lysate (LAL) assay was employed to compare the performance of a novel method utilizing a 1‐butanol–water (HBW) solvent system to that of Westphal's (1965) phenol–water system (HPW) for the extraction of endotoxin from various cyanobacteria. The traditional HPW method extracted from 3‐ to 12‐fold more endotoxin from six different cyanobacterial blooms and culture materials than did the novel HBW method. In direct contrast, the novel HBW method extracted ninefold more endotoxin from a non–microcystin producing Microcystis aeruginosa culture as compared to the HPW method. A solvent system utilizing N,N′‐dimethylformamide–water (HDW) was compared to both the HPW and HBW methods for the extraction of endotoxin from natural samples of Anabaena circinalis, Microcystis flos‐aquae, and a 1:1 mixture of Microcystis aeruginosa/Microcystisflos‐aquae. The LAL activities of these extracts showed that the novel HDW method extracted two‐ and threefold more endotoxin from the Anabaena sample that did the HBW and HPW methods, respectively. The HDW method also extracted approximately 1.5‐fold more endotoxin from the Microcystis flos‐aquae sample as compared to both the HBW and HPW methods. On the other hand, the HBW method extracted 2‐ and 14‐fold more endotoxin from the Microcystis flos‐aquae/Microcystis aeruginosa mixture than did the HPW and HDW methods, respectively. Results of this study demonstrate that significant disparities exist between the physicochemical properties of the cell wall constituents not only of different cyanobacterial species but also of different strains of the same cyanobacterial species, as showing by the varying effectiveness of the solvent systems investigated. Therefore, a sole method cannot be regarded as universal and superior for the extraction of endotoxins from cyanobacteria. Nevertheless, the ability of the novel HBW and HDW methods to utilize easily handled organic solvents that are less hazardous than phenol render them attractive alternatives to the standard HPW method. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 82–87, 2004.