bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distribution of 3-Hydroxy Fatty Acids in Tissues after Intraperitoneal Injection of Endotoxin
Authors: Szponar Bogumiła , Kraśnik Leonard , Hryniewiecki Tomasz , Gamian Andrzej , Larsson Lennart 
Published: February 2004

Abstract
Background: 3-Hydroxy fatty acids (3-OH FAs) with 10- to 18-carbon chain lengths are constituents of the endotoxin [lipopolysaccharide (LPS)] of gram-negative bacteria. We investigated whether these FAs may be used as chemical markers in measuring endotoxin concentrations in mammalian tissue samples.
Methods: We used gas-liquid chromatography–tandem mass spectrometry to measure 3-OH FAs in serum and tissues (heart, liver, and skeletal muscles) of rats after intraperitoneal injection of Escherichia coli LPS. One group of rats (group I) received a single LPS dose of 20 mg/kg of body weight; group II rats received the same total dose but over the course of 10 days (2 mg/kg each day). Rats receiving saline (group III) were used as controls.
Results: 3-OH FAs with chain lengths of 10, 12, 14, 16, and 18 carbons were detected in all studied types of samples. Group I rats had 50-fold and group II rats had 3-fold higher serum concentrations of 3-hydoxytetradecanoic acid (3-OH 14:0, the predominant 3-OH FA of E. coli LPS) than group III rats. Concentrations of 3-OH 14:0 in livers from group I and II rats were similar and fourfold higher than in group III rats, whereas concentrations of the same acid in skeletal and heart tissues did not differ among the three groups of rats. 3-OH 14:0 dominated in heart and liver of group III rats, whereas 3-OH 16:0 (followed by 3-OH 14:0) dominated in skeletal muscles and blood.
Conclusions: 3-OH FAs 10–18 carbons in length, probably originating from endotoxin and mitochondrial β-oxidation, are abundant in rat liver, skeletal muscles, and heart and can also be detected in blood. The widespread presence of these compounds in mammals limits their usefulness as LPS markers for endotoxin in clinical samples.
Detection of Cystic Fibrosis Mutations by Peptide Mass Signature Genotyping
Authors: Malehorn David E , Telmer Cheryl A , McEwen Sherri B , An Jiyan , Kinsey Ashley D , Retchless Adam C , Mason Christopher , Vieta William M , Jarvik Jonathan W 
Published: February 2004

Abstract
Background: The diversity of genetic mutations and polymorphisms calls for the development of practical detection methods capable of assessing more than one patient/one nucleotide position per analysis.
Methods: We developed a new method, based on peptide mass signature genotyping (PMSG), for the detection of DNA mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Exons of the gene were amplified, cloned, and expressed in Escherichia coli as peptide fusions, in natural as well as unnatural reading frames. Peptide analytes were purified by immobilized metal affinity chromatography and analyzed by matrix-assisted, laser desorption/ionization time-of-flight mass spectrometry. Synthetic and natural DNA samples with the 25 mutations recommended for CFTR carrier screening (Grody et al. Genet Med 2001;3:149–54) were assessed using the PMSG test for the CFTR gene.
Results: Peptide analytes ranged from 6278 to 17 454 Da and varied 30-fold in expression; highly expressing peptides were observed by electron microscopy to accumulate as inclusion bodies. Peptides were reliably recovered from whole-cell lysates by a simple purification method. CFTR mutations caused detectable changes in resulting mass spectrometric profiles, which were &gt;95% reliably detected in blinded testing of replicate synthetic heterozygous DNA samples. Mutation detection was possible with both sample pooling and multiplexing. The PMSG CFTR test was used to determine compound heterozygous mutations in DNA samples from cystic fibrosis patients, which were confirmed by direct DNA sequencing.
Conclusions: The PMSG test of the CFTR gene demonstrates unique capabilities for determining the sequence status of a DNA target by sensitively monitoring the mass of peptides, natural or unnatural, generated from that target.
Frequent Misdiagnosis and Mismanagement of Hyperprolactinemic Patients before the Introduction of Macroprolactin Screening: Application of a New Strict Laboratory Definition of Macroprolactinemia
Authors: Suliman Abdulwahab M , Smith Thomas P , Gibney James , McKenna T Joseph 
Published: February 2004

Abstract
Background: Macroprolactin (big big prolactin) has reduced bioactivity and is measured by immunoassays for prolactin when it accumulates in the plasma of some individuals. We applied normative data for serum prolactin after treatment of sera to remove macroprolactin to elucidate the contribution of macroprolactin to misleading diagnoses, inappropriate investigations, and unnecessary treatment.
Methods: We reviewed records of women attending a tertiary referral center who had prolactin &gt;1000 mIU/L. Application of a reference interval to polyethylene glycol (PEG)-treated hyperprolactinemic sera identified 21 patients in whom hyperprolactinemia was accounted for entirely by the presence of macroprolactin. Presenting clinical features, diagnoses, and treatment were compared in these patients and 42 age-matched true hyperprolactinemic patients.
Results: Prolactin concentrations in sera of 110 healthy individuals ranged from 78 to 564 mIU/L. The range of values for the sera after PEG treatment was 70–403 mIU/L. For macroprolactinemic samples, PEG treatment decreased mean (SD) prolactin from 1524 (202) mIU/L to 202 (27) mIU/L but decreased it only from 2096 (233) mIU/L to 1705 (190) mIU/L in true hyperprolactinemic patients (P &lt;0.01 between groups). Oligomenorrhea or amenorrhea and galactorrhea were the most common clinical features in both groups, although they occurred more frequently in true hyperprolactinemic patients (P &lt;0.05). Serum estradiol and luteinizing hormone concentrations were significantly higher in participants with macroprolactinemia than in those with true hyperprolactinemia (P &lt;0.05). Among participants with retrospectively identified macroprolactinemia, pituitary imaging was performed in 93% and treatment with dopamine agonist was prescribed in 87%.
Conclusions: Macroprolactin is a significant cause of misdiagnosis, unnecessary investigation, and inappropriate treatment. The use of an appropriate reference interval for the PEG immunoprecipitation procedure may be of particular importance in those patients who have an excess of both macroprolactin and monomeric prolactin.
Der Weg in die Brücke: ein neuer Bindungstyp für tertiäre Phosphane, Arsane und Stibane
Authors: Werner Helmut 
Published: February 2004

AbstractDie lange Zeit gehegte Annahme, dass tertiäre Phosphane, Arsane und Stibane nur als terminale Liganden an Übergangsmetalle koordinieren können, wurde erst in jüngster Zeit korrigiert. Bei Untersuchungen zur Reaktivität quadratisch‐planarer Carbenrhodium(I)‐Komplexe trans‐[RhCl(CRR′)(L)2] wurde gefunden, dass Verbindungen mit L=SbiPr3 thermisch in Zweikernkomplexe [Rh2Cl2(μ‐CRR′)2(μ‐SbiPr3)] überführt werden können, in denen sowohl die Carbeneinheiten als auch der Stibanligand verbrückende Positionen einnehmen. Während Versuche scheiterten, das Stiban in diesen Komplexen durch tertiäre Arsane oder Phosphane zu ersetzen, gelang die Synthese der Phosphan‐ bzw. Arsan‐verbrückten Verbindungen [Rh2(acac)2(μ‐CRR′)2(μ‐PR3)] und [Rh2(acac)2(μ‐CRR′)2(μ‐AsMe3)] durch Austausch der Brückenliganden nach Substitution der Chloroliganden durch Acetylacetonat. Die Acetylacetonatoliganden können durch anionische Lewis‐Basen ersetzt werden, was zu Monomeren [Rh2X2(μ‐CRR′)2(μ‐ER3)] oder kettenförmigen Dimeren [XRh(μ‐CRR′)2(μ‐ER3)Rh(μ‐X)2Rh(μ‐CRR′)2(μ‐ER3)RhX] führt.
Rationale Synthese kovalent gebundener organisch‐anorganischer Hybdridverbindungen
Authors: Peng Zhonghua 
Published: February 2004

AbstractKovalent über organische Einheiten mit delokalisiertem π‐Elektronensystem verbundene Polyoxometallat(POM)‐Hybridmaterialien haben zunehmendes Interesse geweckt. Diese Hybride wurden traditionell durch das nicht kontrollierbare Verknüpfen von Clustern synthetisiert, das Ergebnis war jedoch nicht vorhersagbar. Jetzt lassen sich solche Hybride durch etablierte organische Reaktionen herstellen, bei denen mit organischen Gruppen funktionalisierte POM‐Cluster als Bausteine eingesetzt werden. In diesem Kurzaufsatz werden einige aktuelle Fortschritte bei der Synthese von Hybriden vorgestellt, in denen organische und anorganische Einheiten über Imidobrücken verknüpft sind.
The Way into the Bridge: A New Bonding Mode of Tertiary Phosphanes, Arsanes, and Stibanes
Authors: Werner Helmut 
Published: February 2004

AbstractUntil recently, tertiary phosphanes, arsanes, and stibanes were considered to bind to transition‐metal centers only in a terminal coordination mode. Investigations on the reactivity of square‐planar trans‐[RhCl(CRR′)(L)2] compounds revealed that compounds in which L=SbiPr3 can be converted upon heating into dinuclear complexes [Rh2Cl2(μ‐CRR′)2(μ‐SbiPr3)] with the carbene and stibane ligands in bridging positions. Although attempts to replace the stibane in these complexes with a tertiary arsane or phosphane failed, substitution of the chloro ligands for acetylacetonates followed by bridge–ligand exchange allowed the preparation of the phosphane‐ and arsane‐bridged compounds [Rh2(acac)2(μ‐CRR′)2(μ‐PR3)] and [Rh2(acac)2(μ‐CRR′)2(μ‐AsMe3)]. The acac ligands can be replaced by anionic Lewis bases to give either monomeric [Rh2X2(μ‐CRR′)2(μ‐ER3)] or dimeric chain‐like [XRh(μ‐CRR′)2(μ‐ER3)Rh(μ‐X)2Rh(μ‐CRR′)2(μ‐ER3)RhX] molecules.
Rational Synthesis of Covalently Bonded Organic–Inorganic Hybrids
Authors: Peng Zhonghua 
Published: February 2004

AbstractHybrid materials based on covalently linked inorganic polyoxometalates (POMs) and organic species containing a delocalized π system have drawn increasing attention. These hybrids, traditionally prepared by cluster assembly approaches that lack predictability and controllability, can now be synthesized through common organic reactions by using organically functionalized POM clusters as building blocks. This minireview highlights some of the most recent advances on a particular type of hybrids where the organic and inorganic components are connected by an imido linkage.
Text mining: Generating hypotheses from MEDLINE
Authors: Srinivasan Padmini 
Published: February 2004

AbstractHypothesis generation, a crucial initial step for making scientific discoveries, relies on prior knowledge, experience, and intuition. Chance connections made between seemingly distinct subareas sometimes turn out to be fruitful. The goal in text mining is to assist in this process by automatically discovering a small set of interesting hypotheses from a suitable text collection. In this report, we present open and closed text mining algorithms that are built within the discovery framework established by Swanson and Smalheiser. Our algorithms represent topics using metadata profiles. When applied to MEDLINE, these are MeSH based profiles. We present experiments that demonstrate the effectiveness of our algorithms. Specifically, our algorithms successfully generate ranked term lists where the key terms representing novel relationships between topics are ranked high.
Making digital libraries effective: Automatic generation of links for similarity search across hyper‐textbooks
Authors: Melucci Massimo 
Published: February 2004

AbstractTextbooks are more available in electronic format now than in the past. Because textbooks are typically large, the end user needs effective tools to rapidly access information encapsulated in textbooks stored in digital libraries. Statistical similarity‐based links among hyper‐textbooks are a means to provide those tools. In this paper, the design and the implementation of a tool that generates networks of links within and across hyper‐textbooks through a completely automatic and unsupervised procedure is described. The design is based on statistical techniques. The overall methodology is presented together with the results of a case study reached through a working prototype that shows that connecting hyper‐textbooks is an efficient way to provide an effective retrieval capability.
Constructing an associative concept space for literature‐based discovery
Authors: van der Eijk C. Christiaan , van Mulligen Erik M. , Kors Jan A. , Mons Barend , van den Berg Jan 
Published: February 2004

AbstractScientific literature is often fragmented, which implies that certain scientific questions can only be answered by combining information from various articles. In this paper, a new algorithm is proposed for finding associations between related concepts present in literature. To this end, concepts are mapped to a multidimensional space by a Hebbian type of learning algorithm using co‐occurrence data as input. The resulting concept space allows exploration of the neighborhood of a concept and finding potentially novel relationships between concepts. The obtained information retrieval system is useful for finding literature supporting hypotheses and for discovering previously unknown relationships between concepts. Tests on artificial data show the potential of the proposed methodology. In addition, preliminary tests on a set of Medline abstracts yield promising results.
Unlocking the museum: A manifesto
Authors: Jörgensen Corinne 
Published: February 2004

AbstractAt the same time that the Internet is becoming more accessible to large numbers of people and information consumers are becoming information producers, traditional methods of organizing, describing, and providing access to “documents” are being overwhelmed by the ever‐increasing number of digitized materials. Another parallel occurrence is the disappearance of cultural and indigenous knowledge as environments and peoples cease to exist. Therefore, the knowledge and ability to build and describe collections needs to be spread among a larger distributed group of participants. Three mechanisms are needed to facilitate this “unlocking” of collections and their management: the distributed description and annotation of documents, distributed collection building, and distributed knowledge creation.
Time‐tracking of the research profile of a drug using bibliometric tools
Authors: Bordons María , Bravo Carmen , Barrigón Santos 
Published: February 2004

AbstractThis study explores the usefulness of bibliometric analyses to detect trends in the research profile of a therapeutic drug, for which Aspirin was selected. A total of 22,144 documents dealing with Aspirin and published in journals covered by MEDLINE during the years 1965–2001 are studied. The research profile of Aspirin over the 37‐year period is analyzed through Aspirin subheadings and MeSH indexing terms. Half of the documents had Aspirin as a major indexing term, being the main aspects studied therapeutic uses (28% of the documents), pharmacodynamics (26%), adverse effects (18%), and administration and dosage (10%). A frequency data table crossing indexing terms × years is examined by correspondence analysis to obtain time trends, which are shown graphically in a map. Four time periods with a different distribution of indexing terms are identified through cluster analysis. The indexing term profile of every period is obtained by comparison of the distribution of indexing terms of each cluster with that of the whole period by means of the Chi‐2 test. The research profile of the drug tends to change faster with time. The most relevant finding is the expanding therapeutic profile of Aspirin over the period. The main advantages and limitations of the methodology are pointed out.
Process strategies to enhance pyruvate production with recombinant Escherichia coli: From repetitive fed‐batch to in situ product recovery with fully integrated electrodialysis
Authors: Zelić Bruno , Gostović Srđan , Vuorilehto K. , Vasić‐Rac̆ki Đurđa , Takors Ralf 
Published: February 2004

AbstractUsing the pyruvate production strain Escherichia coli YYC202 ldhA::Kan different process alternatives are studied with the aim of preventing potential product inhibition by appropriate product separation. This strain is completely blocked in its ability to convert pyruvate into acetyl‐CoA or acetate, resulting in acetate auxotrophy during growth in glucose minimal medium. Continuous experiments with cell retention, repetitive fed‐batch, and an in situ product recovery (ISPR) process with fully integrated electrodialysis were tested. Although the continuous approach achieved a high volumetric productivity (QP) of 110 g L−1 d−1, this approach was not pursued because of long‐term production strain instabilities. The highest pyruvate/glucose molar yield of up to 1.78 mol mol−1 together with high QP 145 g L−1 d−1 and high pyruvate titers was achieved by the repetitive fed‐batch approach. To separate pyruvate from fermentation broth a fully integrated continuous process was developed. In this process electrodialysis was used as a separation unit. Under optimum conditions a (calculated) final pyruvate titer of >900 mmol L−1 (79 g L−1) was achieved. © 2004 Wiley Periodicals, Inc.
Immobilization and biocatalytic activity of fungal protease on gold nanoparticle‐loaded zeolite microspheres
Authors: Phadtare Sumant , Vinod V.P. , Mukhopadhyay Kausik , Kumar Ashavani , Rao Mala , Chaudhari Raghunath V. , Sastry Murali 
Published: February 2004

AbstractGold nanoparticles are excellent biocompatible surfaces for the immobilization of enzymes. However, separation of the gold nanoparticle–enzyme bioconjugate material from the reaction medium is often difficult. In this study, we investigate the assembly of the gold nanoparticles on the surface of the amine‐functionalized zeolite microspheres in the formation of zeolite–gold nanoparticle “core‐shell” structures and, thereafter, the use of this structure in immobilization of fungal protease. The assembly of gold nanoparticles on the zeolite surface occurs through the amine groups present in 3‐aminopropyltrimethoxysilane (3‐APTS). The fungal proteases bound to the massive “core‐shell” structures were easily separated from the reaction medium by mild centrifugation and exhibited excellent reuse characteristics. The biocatalytic activity of fungal protease in the bioconjugate was marginally enhanced relative to the free enzyme in solution. The bioconjugate material also showed significantly enhanced pH and temperature stability and a shift in the optimum temperature of operation. © 2004 Wiley Periodicals, Inc.
Application of Plackett‐Burman design and response surface methodology to achieve exponential growth for aggregated shipworm bacterium
Authors: Ahuja S. K. , Ferreira G. M. , Moreira A. R. 
Published: February 2004

AbstractHere we report the successful implementation of the Plackett‐Burman multifactorial design to screen the limiting components for growth and subsequent use of the response surface methodology (RSM) to design a medium that supported exponential growth of the aggregated morphology of the shipworm bacterium,Teredinobacter turnirae. The results obtained with the help of Plackett‐Burman design indicated limitations of three components in the growth medium, MnCl2.4H2O, Na2CO3, and K2HPO4. The concentrations of these three components were further optimized using RSM. By increasing the concentrations of the above‐mentioned components by 4‐fold, 12‐fold, and 12‐fold, respectively, it became possible to achieve exponential growth of the culture. © 2004 Wiley Periodicals, Inc.
Optimized procedure for renaturation of recombinant human bone morphogenetic protein‐2 at high protein concentration
Authors: Vallejo Luis Felipe , Rinas Ursula 
Published: February 2004

AbstractThe human gene encoding the mature form of bone morphogenetic protein‐2 (hBMP‐2), a dimeric disulfide‐bonded protein of the cystine knot growth factor family, was expressed in recombinant Escherichia coli using a temperature‐inducible expression system. The recombinant protein was produced in the form of cytoplasmic inclusion bodies and the effect of different variables on the renaturation of rhBMP‐2 was investigated. In particular, variables such as pH, redox conditions, protein concentration, temperature, the presence of different types of aggregation suppressors, and host cell contaminants were studied with respect to their effect on aggregation during refolding and on the final renaturation yield of rhBMP‐2. It is shown that the renaturation yield is particularly sensitive to pH, temperature, protein concentration, and the presence of aggregation suppressors. In contrast, little effect of the redox conditions and the ionic strength on the renaturation yield was observed, as equal yields were obtained in a broad range of reduced to oxidized glutathione ratios and concentrations of NaCl, respectively. The aggregation suppressor 2‐(cyclohexylamino)ethanesulfonic acid (CHES) proved to be superior with respect to the final renaturation yield, although, in comparison to the more common arginine, it was less efficient in preventing aggregation of rhBMP‐2 during refolding. Detergent washing of inclusion bodies was sufficient, as further purification of rhBMP‐2 prior to refolding was without effect on the final renaturation yield. An increase in the concentration of renatured rhBMP‐2 was achieved by a pulsed refolding procedure by which up to a total amount of 2.1 mg mL−1 rhBMP‐2 could be transferred in seven pulses into the renaturation buffer with an overall refolding yield of 38%, corresponding to 0.8 mg mL−1 renatured dimeric rhBMP‐2. Furthermore, a simplified purification procedure is presented that also includes freeze‐drying for long‐term storage of biologically active rhBMP‐2. Finally, it is shown that the appearance of rhBMP‐2 variants could be avoided by using a host strain overexpressing rare codon tRNAs. © 2004 Wiley Periodicals, Inc.
MIRACLE: mass isotopomer ratio analysis of U‐13C‐labeled extracts. A new method for accurate quantification of changes in concentrations of intracellular metabolites
Authors: Mashego M. R. , Wu L. , Van Dam J. C. , Ras C. , Vinke J. L. , Van Winden W. A. , Van Gulik W. M. , Heijnen J. J. 
Published: February 2004

AbstractFirst, we report the application of stable isotope dilution theory in metabolome characterization of aerobic glucose limited chemostat culture of S. cerevisiae CEN.PK 113‐7D using liquid chromatography‐electrospray ionization MS/MS (LC‐ESI‐MS/MS). A glucose‐limited chemostat culture of S. cerevisiae was grown to steady state at a specific growth rate (μ) = 0.05 h−1 in a medium containing only naturally labeled (99% U‐12C, 1% U‐13C) carbon source. Upon reaching steady state, defined as 5 volume changes, the culture medium was switched to chemically identical medium except that the carbon source was replaced with 100% uniformly (U) 13C labeled stable carbon isotope, fed for 4 h, with sampling every hour. We observed that within a period of 1 h ∼80% of the measured glycolytic metabolites were U‐13C‐labeled. Surprisingly, during the next 3 h no significant increase of the U‐13C‐labeled metabolites occurred. Second, we demonstrate for the first time the LC‐ESI‐MS/MS‐based quantification of intracellular metabolite concentrations using U‐13C‐labeled metabolite extracts from chemostat cultivated S. cerevisiae cells, harvested after 4 h of feeding with 100% U‐13C‐labeled medium, as internal standard. This method is hereby termed “Mass Isotopomer Ratio Analysis of U‐13C Labeled Extracts” (MIRACLE). With this method each metabolite concentration is quantified relative to the concentration of its U‐13C‐labeled equivalent, thereby eliminating drawbacks of LC‐ESI‐MS/MS analysis such as nonlinear response and matrix effects and thus leads to a significant reduction of experimental error and work load (i.e., no spiking and standard additions). By coextracting a known amount of U‐13C labeled cells with the unlabeled samples, metabolite losses occurring during the sample extraction procedure are corrected for. © 2004 Wiley Periodicals, Inc.