bluuebunny/crossref_metadata_2025_split huggingface dataset:
Loss of Beta-Catenin Expression in Metastatic Gastric Cancer
Authors: Ebert Matthias P.A. , Yu Jun , Hoffmann Juliane , Rocco Alba , Röcken Christoph , Kahmann Sabine , Müller Oliver , Korc Murray , Sung Joseph J. , Malfertheiner Peter 
Published: April 2003

Purpose: Beta-catenin (β-catenin) participates in intercellular adhesion and is an integral part of the Wnt signaling pathway. The role of β-catenin in the pathogenesis of gastric cancer and its metastasis is largely unknown. Patients and Methods: Immunohistochemistry and Western blot analysis were used to analyze the expression of β-catenin in 87 human gastric cancers, in metastasis and cancer cell lines. The β-catenin and the adenomatous polyposis coli (APC) genes were analyzed for gene mutations. Furthermore, methylation of the β-catenin promoter in cell lines was assessed by treatment with 5′-azadeoxycytidine and sodium bisulfite genomic sequencing. Results: β-Catenin expression was present at either the cell membrane or the cytoplasm in 34 of 75 primary gastric cancers. Expression of β-catenin was significantly more frequent in intestinal-type (P = .0049) and well-differentiated gastric cancers (P < .001). There were no quantitative differences between gastric cancers and the nonmalignant gastric tissues, as determined by Western blot analysis. One of 18 metastatic cancer lesions and four of five gastric cancer cell lines expressed β-catenin protein. N87 cells, derived from the liver metastasis of a gastric cancer, did not express β-catenin. Treatment with 5′-azadeoxycytidine restored β-catenin protein levels in this cell line, which exhibited significantly more 5-methylcytosines in the β-catenin promoter compared with the other cell lines. Conclusion: β-Catenin expression is lost in a subgroup of primary gastric cancers, is frequently absent in metastases, and exhibits nuclear localization in cancers with either β-catenin or APC gene mutations. Interestingly, the loss of β-catenin expression in metastatic gastric cancers may result from hypermethylation of the β-catenin promoter.
Adaptive Randomized Study of Idarubicin and Cytarabine Versus Troxacitabine and Cytarabine Versus Troxacitabine and Idarubicin in Untreated Patients 50 Years or Older With Adverse Karyotype Acute Myeloid Leukemia
Authors: Giles Francis J. , Kantarjian Hagop M. , Cortes Jorge E. , Garcia-Manero Guillermo , Verstovsek Srdan , Faderl Stefan , Thomas Deborah A. , Ferrajoli Alessandra , O’Brien Susan , Wathen Jay K. , Xiao Lian-Chun , Berry Donald A. , Estey Elihu H. 
Published: April 2003

Purpose: Troxacitabine has activity in refractory myeloid leukemia, either as a single agent or when combined with cytarabine (ara-C) or with idarubicin. A prospective, randomized study was conducted in patients aged 50 years or older with untreated, adverse karyotype, acute myeloid leukemia (AML) to assess troxacitabine-based regimes as induction therapy. Patients and Methods: Patients were randomized to receive idarubicin and ara-C (IA) versus troxacitabine and ara-C (TA) versus troxacitabine and idarubicin (TI). A Bayesian design was used to adaptively randomly assign patients to treatment. Thus, although there was initially an equal chance for randomization to IA, TA, or TI, treatment arms with a higher success rate progressively received a greater proportion of patients. Results: Thirty-four patients were treated. Randomization to TI stopped after five patients and randomization to TA stopped after 11 patients. Defining success as complete remission (CR) that occurred within 49 days of starting treatment, success rates were 55% (10 of 18 patients) with IA, 27% (three of 11 patients) with TA, and 0% (zero of five patients) with TI. Because three CRs occurred after day 49, final CR rates were 55% (10 of 18 patients) with IA, 45% (five of 11 patients) with TA, and 20% (one of five patients) with TI. The probability that TA was inferior to IA was 70%, with a 5% probability that TA would have a 20% higher CR rate than IA. Survival was equivalent with all three regimens. Conclusion: Neither troxacitabine combination was superior to IA in elderly patients with previously untreated adverse karyotype AML.
Sex Differences in Estrogen-Dependent Transcription of Gonadotropin-Releasing Hormone (GnRH) Gene Revealed in GnRH Transgenic Mice
Authors: Thanky Niren R. , Slater Ruth , Herbison Allan E. 
Published: April 2003

Abstract
The mechanisms through which gonadal steroids exert feedback actions on the activity of the GnRH neurons are not understood. Using a series of GnRH-LacZ transgenic mice we have examined the manner in which gonadal steroids suppress GnRH mRNA expression in male and female mice. The long-term gonadectomy of 5.5-GNZ-3.5 transgenic mice resulted in significant increases in cellular GnRH mRNA expression (P &lt; 0.05) and plasma LH concentrations (P &lt; 0.01) in both sexes. However, cellular levels of LacZ mRNA and β-galactosidase, which provide an index of GnRH gene transcription, were only elevated in males after gonadectomy. This sexually differentiated response was also observed in mice gonadectomized for 2 wk. Estrogen replacement in gonadectomized males returned transgene expression to intact levels. Experiments in transgenic mice with 3′ and 5′ deleted GnRH-LacZ constructs revealed that the suppressive influence of estrogen on LacZ transcription in the male required a critical element located between −5.2 and −1.7 kb of the GnRH promoter. These studies show that the suppression of GnRH mRNA expression by estrogen in the male involves a decrease in GnRH gene transcription that is dependent on a distal GnRH promoter element. The same mechanism does not exist in females, indicating that gonadal steroids suppress GnRH mRNA levels in a sexually dimorphic manner.
Corticotropin-Releasing Hormone-Mediated Pathway of Leptin to Regulate Feeding, Adiposity, and Uncoupling Protein Expression in Mice
Authors: Masaki Takayuki , Yoshimichi Go , Chiba Seiichi , Yasuda Tohru , Noguchi Hitoshi , Kakuma Tetsuya , Sakata Toshiie , Yoshimatsu Hironobu 
Published: April 2003

Abstract
To examine the functional role of CRH in the regulation of energy homeostasis by leptin, we measured the effects of the CRH antagonist, α-helical CRH 8–41 (αCRH) on a number of factors affected by leptin activity. These included food intake, body weight, hypothalamic c-fos-like immunoreactivity (c-FLI), weight and histological characterization of white adipose tissue, and mRNA expressions of uncoupling protein (UCP) in brown adipose tissue (BAT) in C57Bl/6 mice. Central infusion of leptin into the lateral cerebroventricle (icv) caused significant induction of c-FLI in the paraventricular nucleus (PVN), ventromedial hypothalamic nucleus (VMH), dorsomedial hypothalamic nucleus, and arcuate nucleus. In all these nuclei, the effect of leptin on expression of cFLI in the PVN and VMH was decreased by treatment with αCRH. Administration of leptin markedly decreased cumulative food intake and body weight with this effect being attenuated by pretreatment with αCRH. In peripheral tissue, leptin up-regulated BAT UCP1 mRNA expression and reduced fat depositions in this tissue. Those changes in BAT were also decreased by treatment with αCRH. As a consequence of the effects on food intake or energy expenditure, treatment with αCRH attenuated the leptin-induced reduction of body adiposity, fat cell size, triglyceride contents, and ob mRNA expression in white adipose tissue. Taken together, these results indicate that CRH neurons in the PVN and VMH may be an important mediator for leptin that contribute to regulation of feeding, adiposity, and UCP expression.
A Middle East View of the Global Oil Situation
Authors: Bakhtiari A.M. Samsam 
Published: April 2003

Seen from a Middle Eastern perspective, the present global oil situation can be summarised within five major and inescapable trends: 1 The world's super giant and giant oil fields are dying off; 2 There are no more major frontier regions left to explore besides the earth's poles; 3 Production of non-conventional crude oil has been initiated at great costs – in Venezuela's Orinoco belt, Canada's Athabasca tar sands and ultra-deep waters; 4 Even OPEC's oil production has its limits; 5 No major primary energy rival can possibly take over from oil and gas in the medium term. Adding up these five trends, one can envision a global oil crunch at the horizon — – most probably within the present decade. Unfortunately, however, the general public will not heed such a rational vision. And, even if it did, it would be loath to respond to the implied threat. In its defence, it should be said that many actors are constantly and consistently reassuring it: the press (even parts of the specialised press), most politicians, some international institutions, a couple of major oil companies and naturally OPEC. But this can only last until petrol stations post ‘empty’, natural gas supplies are suddenly shunted and, eventually, the lights go off.
Anionic copolymerization of acrylonitrile and methylthiirane and some properties of their copolymers
Authors: Polotskaya G. A. , Kuznetsov Yu. P. , Belonovskaya G. P. , Fedorova G. N. 
Published: April 2003

AbstractThe basic relationships of the anionic copolymerization of acrylonitrile and methylthiirane and some molecular weight, spectral and thermal characteristics of the copolymers have been investigated. Secondary reactions leading to structural transformations of polyacrylonitrile fragments in the copolymer are discussed.
Microscope investigations of morphological changes during the liquid‐induced crystallization of poly(2,6‐dimethyl‐1,4‐phenylene oxide)
Authors: Benecki W. , Pelzbauer Z. , Turska E. 
Published: April 2003

AbstractThe morphological changes caused in poly(2,6‐dimethyl‐1,4‐phenylene oxide) on swelling in selected liquids were studied. The rates of penetration of the swelling liquids into the samples and the rates of growth of the spherulites were investigated. A relationship was found to exist between the relative rates of the processes and the morphology of the surface of samples.
X‐ray studies of crystallization of poly(2,6‐dimethyl‐1,4‐phenylene oxide) on swelling in certain systems
Authors: Hurek J. , Turska E. 
Published: April 2003

AbstractThe processes of swelling and crystallization of poly(2,6‐dimethyl‐1,4‐phenylene oxide) (PPO) in polymer‐swelling agent systems as well as the structures obtained were investigated by means of wide‐angle x‐ray scattering. As the swelling agents we used mainly decalin and also α‐pinen and tetralin. The effect of the swelling parameters of PPO in decalin on the possibilities of obtaining various polymer structures was studied. The role played by a low‐molecular substance in the process of the formation of crystalline structure in PPO was examined. It was found that the crystallization mechanism depends mainly on the chemical properties of the polymer and the swelling agent.
Lichtinitiierte Polymer‐ und Polymerisationsreaktionen. Photoinitiierte radikalische Polymerisationen mit α‐substituierten Azoalkanen
Authors: Timpe H. J. , Schikowsky V. , Vergara R. 
Published: April 2003

AbstractAn Hand von vier Modellverbindungen wird geprüft, inwieweit α‐substituierte aliphatische Azoverbindungen als Photoinitiatoren für eine radikalische Polymerisation geeignet sind. α‐Hydroperoxy– und α‐Hydroxyazoalkane zerfallen nach Anregung ihres nπ*‐Übergangs mit Quantenausbeuten zwischen 0,40 und 1,0 in radikalische Produkte, die eine Polymerisation auslösen können. Das primäre Photoprodukt der α‐Hydroxyazoalkane ist offensichtlich ein Diazen, das anschließend fragmentiert. Bei der Photopolymerisation von Methylmethacrylat addieren sich die aus α‐Hydroperoxyazoalkanen entstehenden Radikale mit einer höheren Effizienz als die der Photolyse von α‐Hydroxyazoalkanen. Das führt auch zu einer höheren Quantenausbeute der durch α‐Hydroperoxyazoalkane initiierten Photopolymerisation. α‐Chlor‐ und α‐acetoxy‐substituierte Azoalkane sind nicht als Photoinitiatoren verwendbar, da deren Photoanregung zu keiner effektiven CN‐Bindungsspaltung führt.
Zur bestimmung von [η]‐M‐Beziehungen und mittleren moleküldimensionen für lineare polyphenylchinoxaline
Authors: Bauer J. , Bauer M. 
Published: April 2003

AbstractAus Messungen von Grenzviskositäten und Molmassenmittelwerten werden die Kuhn‐Mark‐Houwink‐Gleichungen sowie die n‐, w‐ und z‐ Mittel des quadratischen Endpunktabstands für lineare Polyphenylchinoxaline mit Schulz‐Flory‐Molmassenverteilungen berechnet.
Untersuchungen zur Copolymerisation von Ethylen mit But‐1‐en der Buten‐Fraktion
Authors: Kümpfel W. , Gorski U. , Heublein G. 
Published: April 2003

AbstractMit klassischen ionisch‐koordinativen Katalysatoren auf Basis von Titanhalogeniden und aluminiumorganischen Verbindungen wird die Copolymerisation zwischen Ethylen und But‐1‐en aus einer technischen Buten‐Fraktion unter sucht. Die Selektivität des Einbaus von But‐1‐en in das Polymerisat steht in Beziehung zum Titanhalogenid, zur Art der aluminiumorganischen Verbindung, zur Temperatur und zur Katalysatormodifizierung mit Hex‐1‐en. Es wird gezeigt, daß die reaktive Trennung durch Selektivpolymerisation von Ethylen mit But‐1‐en direkt aus der Buten‐Fraktion möglich ist, wobei Produkte mit technisch üblichen Eigenschaftsparametern entstehen. Die Polymerisate werden charakterisiert durch GPC, Grenzviskositäten und Copolymerzusammensetzungen.
Zur Copolymerisation von α‐Methylstyren mit Diisobuten‐Isomeren
Authors: Heublein G. , Albrecht G. , Kümpfel W. 
Published: April 2003

AbstractMit Lewis‐Säuren und Protonensäuren wurden die kationisch initiierte Oligommerisierung von 2,4,4‐Trimethylpent‐1‐en und 2,4,4‐Trimethylpent‐2‐en, den Hauptbestandteilen des technischen Diisobutens, sowie die Copolymerisation dieses Isomergemisches mit α‐Methylstyren untersucht. Es traten Selektivitätsunterschiede zwischen den Isomeren bei der Oligomerisierung auf, wobei insbesondere dimere Produkte erhalten und Isomerisierungsreaktionen beobachtet wurden. Bei der Copolymerisation von α‐Methylstyren mit Diisobuten‐Gemischen unterschiedlicher Isomerzusammensetzung wurde festgestellt, daß in Abhängigkeit von den Reaktionsbedingungen maximal 25 Mol‐% Diisobuten in das Polymer eingebaut werden und ein hoher Anteil niedermolekularer Oligomerisate mit entsteht. Im Copolymerisat führt der Einbau von Diisobuten zur Erniedrigung der Molmassen und Erweichungsbereiche.
Modified acrylic polymers having high sorption capacity
Authors: Derbisher V. E. , Solomina T. I. , Protopopov P. A. , Khardin A. P. 
Published: April 2003

AbstractThe synthesis of ion exchanging polymers carrying carboxyl and hydrazide groups has been investigated. The ion exchangers were obtained by conversion of carboxylic acid polymers and copolymers to the corresponding acid fluorides and chlorides. The exchange capacity was found to be 3.9 to 14 mg‐equiv/g with polymeric hydrazines and 9 to 14 mg‐equiv/g with carboxyl‐containing polymers. The ion exchanging polymers obtained can be applied as sorbents of bivalent metals, in the textile industry etc.
Zur Charakterisierung der mechanischen Eigenschaften von Polymeren
Authors: Bauer A. , Schulze R.‐D. , Bodor G. 
Published: April 2003

AbstractAn Hand experimenteller Resultate wird der Nachweis erbracht, daß auch für Chemieseiden ein Dehnungsbereich existiert (ca. 0 bis 0,3%), für den genau wie bei kompakten Polymerfestkörpern die lineare Viskoelastizitätstheorie gilt. Bei diesem Material sind jedoch die auf Grund des polyfilen Charakters entstehenden Meßfehler zu berücksichtigen. Die mit unterschiedlichen mechanischen Untersuchungsmethoden ermittelten Moduli lassen sich unter Beachtung der Beanspruchungshöhe und ‐zeit in ein gemeinsames Bild einordnen. Das Maximum im Modulverlauf zeigt bei hochorientierten Proben den Beginn der irreversiblen Verformung an und ist abhängig von der Längenverteilung der Verbindungsmoleküle.
Morphologische Untersuchungen an Carboxymethylcellulosefilmen
Authors: Tiersch B. , Purz H. J. , Dautzenberg H. , Philipp B. 
Published: April 2003

AbstractAn Carboxymethylcellulosefilmen, bei deren Herstellung sowohl die Zusammensetzung der wäßrigen Gießlösung hinsichtlich Polymerkonzentration, Alkalität, sowie durch Zusätze niedermolekularer Salze variiert wurde, als auch Konzentration und Konzentrationsverhältnis der Fällbadkomponenten H2SO4 und Na2SO4 verändert wurden, erfolgten elektronenmikroskopische Untersuchungen mit dem Ziel, zur weiteren Klärung des Koagulationsprozesses bei hydrophilen Polymeren beizutragen. Aus den durch Umsetzung der alkalischen Na‐CMC‐Lösung mit CS2 und anschließende Koagulation im sauren Bad in Anwesenheit, sowie auch nach Entfernung der sulfidischen Nebenprodukte (Na2S, Na2CS3) erhaltenen Fällungsstrukturen wurden weiterführende Aussagen zur Bildung größerer Hohlräume in solchen Fällungsstrukturen erhalten.
Ethylen‐Polymerisation mit trägerfixierten Organometallverbindungen. I. Herstellung der katalysatoren
Authors: Sommer H. , Giesemann J. , Ulbricht J. 
Published: April 2003

AbstractTetrabenzylzirkonium wird auf Aluminiumoxid mit unterschiedlichem Gehalt von Hydroxylgruppen an der Oberfläche, erzeugt durch Erhitzen zwischen 200 und 800°C, fixiert. In Abhängigkeit von der Hydroxylgruppenkonzentration tragen die gebildeten Zirkoniumverbindungen zwei oder drei solvolytisch abspaltbare Benzylgruppen, falls bei der Umsetzung die Konzentration des Zirkoniumorganyls kleiner als die der Hydroxylgruppen ist. Wird dagegen ein Überschuß des Organyls eingesetzt, so läßt sich danach nur noch eine Benzylgruppe abspalten.
Studien zur Verzweigung von Kettenmolekülen. XXIV. Über die Lösungsmittelabhängigkeit der Kontraktionsfaktoren g und g′ des Polyethylens niederer Dichte
Authors: Arndt K. F. , Schröder E. , Wulfert Ch. 
Published: April 2003

AbstractZur Bestimmung der Zahl von Langkettenverzweigungen müssen Voraussetzungen über den Zusammenhang zwischen den Meßgrößen g und g′ mit dem Kontraktionsfaktor im ungestörten Zustand g0 getroffen werden. Die Zwei‐Parameter‐Theorie läßt Schlußfolgerungen über die Beziehungen zwischen g′—g0′, g—g0 sowie g′—g und g0′—g0 zu, die durch Experimente überprüft werden.
Investigation of the synthesis and of some properties of polyketones from diphenyl oxide and iso‐ and terephthaloyl chloride
Authors: Gileva N. G. , Zolotuchin M. G. , Salazkin S. N. , Rafikov S. R. , Hörhold H.‐H. , Raabe D. 
Published: April 2003

AbstractThe polycondensation of diphenyl oxide with isophthaloyl chloride in methylene chloride and nitrobenzene has been studied and optimum conditions of the polyketone synthesis were established. The effect of the chemical structure of homo‐ and copolymers of diphenyl oxide and iso‐ and terephthaloyl chloride on their properties is investigated.
Synthesis and thermal properties of poly(arylene metalsulfides)
Authors: Sergeev V. A. , Nedel'Kin V. I. , Pavlova S. A. , Žuravleva I. V. , Ševljakova N. P. 
Published: April 2003

AbstractNew thermostable polymers of the general formula [ArXArSMeS], where X is O, S or CC bond, and Me is Pb or Cd, were prepared. Properties and thermal degradation of these polymers in an inert medium and in air have been investigated. Main products of degradation were determined and the activation energy of the reaction leading to gaseous products were determined.
Isomerism of modell amino acids and complex formation of model amino acids and polyamidoacids with aprotic polar solvents
Authors: Šibaev L. A. , Dauengauer S. A. , Denisov V. M. , Kol'Cov A. I. , Sazanov Ju. N. , Žukova T. I. 
Published: April 2003

AbstractCrystalline complexes of pyromellitdianilic acid (PMA) with dimethylformamide, dimethylacetamide, N‐methyl‐2‐pyrrolidone and dimethylsulphoxide have been synthesized and investigated for the first time. Their composition was determined. It was shown that polyamic acids form similar complexes with aprotic solvents. The isomeric composition of PMA complexes was investigated and isomerization of PMA in solution under mild conditions was observed.
Texturuntersuchungen an Polyvinylidenfluorid (PVDF). Teil I. Untersuchungen zum Orientierungszustand einachsig gereckter PVDF‐Folien der Modifikation I in Abhängigkeit von der Einwirkung eines elektrischen Feldes
Authors: Geiss D. , Ruscher Ch. 
Published: April 2003

AbstractDer Orientierungszustand in einachsig gereckten PVDF‐Folien, deren geordnete Bereiche aus der orthorhombischen Modifikation I bestehen, läßt sich als uniaxial planarer Texturtyp beschreiben. Die Änderung des Orientierungszustandes als Folge der Einwirkung eines elektrischen Feldes ≦ 2 MV · cm−1 wird als Änderung der bevorzugten Ausrichtung der Netzebene (200) in eine bevorzugte Ausrichtung der Netzebene (020) parallel zur Folienoberfläche interpretiert. Diese Änderung entspricht einer teilweisen Ausrichtung der molekularen Dipole der TT‐Konformation in den geordneten Bereichen in Richtung des einwirkenden elektrischen Feldes.
Permanent‐antielektrostatische Modifizierung von Polyacrylnitril‐Faserstoffen mit Blockcopolyetherester. 1. Mitt.: Löseverhalten und antielektrostatische Wirksamkeit der Modifikatoren
Authors: Albrecht W. , Becker M. , Gröbe V. , Makschin W. , Dietrich K. , Mann G. 
Published: April 2003

AbstractBlockcopolyetherester werden hinsichtlich antielektrostatischer Wirksamkeit und Löseverhalten in Dimethylformamid und dessen Gemischen mit Wasser charakterisiert. Das gegenüber nicht derivatisiertem Polyethylenglykol günstigere Leitfähigkeitsverhalten dieser Substanzklasse ist durch Besonderheiten in der Struktur begründet. Es wird eine Vorauswahl für den Einsatz als Antistatikum für PAN vorgenommen. Danach stellen Blockcopolyetherester mit 80 bis 85 Masse‐% Polyethylenglykol 4000 günstige Modifikatorkomponenten dar.
Chemical factors affecting soiling and soil release from cotton‐containing durable press fabrics. Part XII: Inclusion of different additive compounds in crosslinked cotton
Authors: Hebeish A. , Ibrahim N. A. , Amin S. A. , Hana H. L. 
Published: April 2003

AbstractThe effect of inclusion of carboxymethyl cellulose, hydroxyethyl cellulose, methylhydroxyethyl cellulose, polyvinylalcohol or tetraoxalyl urea in crosslinked cotton on the behaviour of the latter to aqueous and nonaqueous oily soiling was investigated. Inclusion of these additives in cotton crosslinked in absence of softener enhanced aqueous and oily soil resistance, provided that the additive was applied after the finishing pad. Incorporation of softener in the finishing bath turned the effect of the additive to the opposite. The effect of the additives in the crosslinked cotton on hydrophilicity and other properties of the finished product was also studied.
Potassium persulphate‐cupric ion induced grafting of acrylonitrile to nylon 6 fibres
Authors: Shalaby S. E. , El‐Shahed M. F. , Heibeish A. 
Published: April 2003

AbstractPolyamide 6‐acrylonitrile graft copolymers were prepared without formation of homopolymer by using an initiation system consisting of potassium persulphate, cupric ion and a surface active substance. The graft yield was determined in dependence on the concentration of cupric ion, persulphate and acrylonitrile as well as time and temperature of polymerization. A mechanism of the grafting reaction is suggested.
The dielectric properties of grafted cotton
Authors: Hanna A. A. 
Published: April 2003

AbstractThe dielectric constant and the dielectric loss of native cotton and cotton grafted with methyl methacrylate, styrene and vinyl acetate were measured at different temperatures and frequencies. The results indicate that grafting results in a decrease of the dielectric constant and the dielectric loss, which may be due to a decrease in the number of the polar groups. The apparent activation energy of relaxation is calculated.