bluuebunny/crossref_metadata_2025_split huggingface dataset:
Uroplakin gene expression in normal human tissues and locally advanced bladder cancer
Authors: Olsburgh Jonathon , Harnden Patricia , Weeks Robert , Smith Barbara , Joyce Adrian , Hall Geoffrey , Poulsom Richard , Selby Peter , Southgate Jennifer 
Published: December 2002

AbstractThe uroplakins are widely regarded as urothelium‐specific markers of terminal urothelial cytodifferentiation. This study investigated the expression of the four uroplakin genes, UPIa, UPIb, UPII and UPIII, in a wide range of normal human tissues to determine tissue specificity and in advanced transitional cell carcinoma (TCC) to examine gene expression in primary and metastatic disease. In the urinary tract, all four uroplakins were expressed by urothelium and UPIII was also expressed by prostatic glandular epithelium. UPIa and UPII appeared to be urothelium‐specific, but UPIb was detected in several non‐urothelial tissues, including the respiratory tract, where it was associated with squamous metaplasia of tracheal and bronchial epithelia. The ten cases of primary TCC and corresponding lymph node metastases demonstrated that each uroplakin gene could be expressed at the mRNA level. No single uroplakin gene was expressed in all primary tumours or metastases, but 80% of the primary tumours and 70% of the lymph node metastases expressed at least one uroplakin gene. UPIII mRNA was often expressed in the absence of UPIII protein. These results confirm that in human tissues the expression of UPIa and UPII genes is highly specific to urothelium and suggest that the tight differentiation‐restricted expression of uroplakin genes in normal urothelium is lost following malignant transformation. Copyright © 2002 John Wiley & Sons, Ltd.
Expression of Mcl‐1 in mantle cell lymphoma is associated with high‐grade morphology, a high proliferative state, and p53 overexpression
Authors: Khoury Joseph D , Medeiros L Jeffrey , Rassidakis George Z , McDonnell Timothy J , Abruzzo Lynne V , Lai Raymond 
Published: December 2002

AbstractMantle cell lymphoma (MCL) is a distinct type of B‐cell non‐Hodgkin's lymphoma characterized by the t(11;14)(q13;q32) and cyclin D1 overexpression. Defects in apoptosis may contribute to pathogenesis. This study evaluated the expression of the anti‐apoptotic protein Mcl‐1 in two MCL cell lines and five frozen MCL tumours (four small‐cell, one blastoid/large‐cell) using western blot analysis. Mcl‐1 expression was also assessed in 36 formalin‐fixed, paraffin wax‐embedded MCL tumours (24 small‐cell, 12 blastoid/large‐cell) by immunohistochemistry. Western blot analysis revealed the expected 37 kD protein product in both MCL cell lines and in five frozen tumours, with the blastoid case having the highest expression level. Using a cut‐off of >10% immunolabelled cells for Mcl‐1, it was found that 12 of 36 MCL tumours were positive. Mcl‐1‐positive tumours had a higher frequency of blastoid/large‐cell morphology (8/12 versus 4/24, p = 0.009), p53 overexpression (3/10 versus 1/23, p = 0.04), and higher Ki67 immuno‐labelling (p = 0.002). It is concluded that expression of Mcl‐1 in MCL is heterogeneous. A relatively high level of Mcl‐1 expression correlates with high‐grade morphology, a high proliferative state, and p53 overexpression. Copyright © 2002 John Wiley & Sons, Ltd.
Type 2 nitric oxide synthase and protein nitration in chronic lung infection
Authors: Hopkins Natalie , Cadogan Elaine , Giles Shay , Bannigan John , McLoughlin Paul 
Published: December 2002

AbstractInflammation in the lung can lead to increased expression of inducible nitric oxide synthase (iNOS) and enhanced NO production. It has been postulated that the resultant highly reactive NO metabolites may have an important role in host defence, although they might also contribute to tissue damage. However, in a number of inflammatory lung diseases, including bronchiectasis, iNOS expression is increased but no elevation of airway NO can be detected. A potential explanation for this finding is that NO is rapidly scavenged by reaction with superoxide radicals, forming peroxynitrite, which is preferentially metabolized via nitration and nitrosation reactions. To test this hypothesis, anaesthetized, specific pathogen‐free rats were inoculated with Pseudomonas aeruginosa incorporated into agar beads (chronically infected group) or sterile agar beads (control group). Ten to 15 days later, the lungs were isolated and fixed. Pseudomonas organisms were isolated from the lungs of the chronically infected group. These lungs showed extensive inflammatory cell infiltration and tissue damage, which were not observed in control lungs. Expression of iNOS was increased in the chronically infected group when compared with the control group. However, the mean number of cells staining for nitrotyrosine in the chronically infected group was not significantly different from that in the controls, nor was there an excess of nitrotyrosine, nitrate, nitrite or nitrosothiol concentrations in the infected lungs. Thus, no evidence was found of increased NO metabolites in chronically infected lungs, including products of the peroxynitrite pathway. These findings suggest that chronic infection does not cause increased iNOS activity in the lung, despite increased expression of iNOS. Copyright © 2002 John Wiley & Sons, Ltd.
The yeast two‐hybrid system for identifying protein–protein interactions
Authors: Coates PJ , Hall PA 
Published: December 2002

AbstractThe yeast two‐hybrid assay is a system for identifying and analysing protein–protein interactions. Since the original description in 1989, the technique has provided insight into many biological pathways. A variety of adaptations to the technique have been developed that allow analysis of protein–DNA, protein–RNA, or small molecule–protein interactions. Recent developments now allow the use of these technologies to perform global analyses of all such interactions that occur in cells. The information gained from these approaches is uncovering many aspects of the complex networks that underlie normal cellular processes and how they are perturbed in disease states. Copyright © 2002 John Wiley & Sons, Ltd.
Kinetics of elimination of several heterocyclic carbamates in the gas phase
Authors: Brusco Yannely , Domínguez Rosa M. , Rotinov Alexandra , Herize Armando , Cordova Mary , Chuchani Gabriel 
Published: December 2002

AbstractThe kinetics of the gas‐phase elimination of several heterocyclic carbamates were determined in a static system over the temperature range 190.0–409.7 °C and the pressure range 26.5–125 Torr (1 Torr = 133.3 Pa). The reactions in seasoned vessels, with the free radical inhibitor cyclohexene and/or toluene always present, are homogeneous and unimolecular and obey a first‐order rate law. The observed rate coefficients are represented by the following Arrhenius equations: for tert‐butyl‐1‐pyrrolidine carboxylate, log k1 (s−1) = (11.36 ± 0.31) −(145.4 ± 3.1)­kJ mol−1 (2.303RT)−1; for 1‐(tert‐butoxycarbonyl)‐2‐pyrrolidinone, log k1 (s−1) = (11.54 ± 0.29) −(140.8 ± 2.8)­kJ mol−1 (2.303RT)−1; for tert‐butyl‐1‐pyrrole carboxylate, log k1 (s−1) = (12.12 ± 0.05) −(145.2 ± 1.0) kJ mol−1 (2.303RT)−1; and for 1‐ethylpiperazine carboxylate, log k1 (s−1) = (12.05 ± 0.19) −(188.2 ± 4.6) kJ mol−1 (2.303RT)−1. The saturated heterocyclic carbamates show a decrease in rates of elimination due to electronic factors. Heterocyclic carbamates with a nitrogen atom able to delocalize its electrons with π‐bonds present in the ring were found to enhance the rates due to resonance interactions. Copyright © 2002 John Wiley & Sons, Ltd.
Catalysis by organic phosphates of the glycation of human hemoglobin
Authors: Gil Herminia , Peña Mary , Vásquez Blanca , Uzcategui Jorge 
Published: December 2002

AbstractThe non‐enzymic glycation of hemoglobin is catalyzed by 3‐phosphoglycerate, 2‐phosphoglycerate and 2‐glycerolphosphate, but not by sodium propionate. Solvent isotope effects were determined (k/k). Catalysis by 3‐phosphoglycerate, 2‐phosphoglycerate and 2‐glycerolphosphate, the observer solvent isotope effect of unity, and flat proton inventory tend to suggest that the proton abstraction step of the Amadori rearrangement by 3‐phosphoglycerate, 2‐phosphoglycerate and 2‐glycerolphosphate is the rate‐determining step in the non‐enzymatic glycation of hemoglobin. The solvent isotope effect of unity, and a flat proton inventory for sodium propionate are indicative that a functional group on the hemoglobin is the proton‐abstracting base in the Amadori rearrangement. Copyright © 2002 John Wiley & Sons, Ltd.
Dipole polarizability of the pyrazabole molecule in solution
Authors: Alvarado Ysaías J. , Soscún Humberto , Velazco Wendy , Labarca Paola H. , Cubillan Nestor , Hernández Javier 
Published: December 2002

AbstractThe dynamic and static dipole polarizabilities of pyrazabole (PYRZ) were investigated using a refractometric method and theoretical calculations. The experimental properties were studied within the Singer–Garito and Proutiere and co‐workers' approaches for dilute cyclohexane, THF and CH3CN solutions. These methodologies were appropriate to quantify the electronic polarizability and electric deformability of pyrazabole in the optical regime. The static dipole polarizabilities of pyrazabole were obtained from extrapolation to zero frequency of the corresponding dispersion Cauchy‐type curves, which gave a monotonic increasing in function of the squared frequency. The differences between these curves were analyzed as a function of the solvent effects. Additionally, a comparative study with pyrazole was carried out. The results indicated that both the static and dynamic electronic polarizability of pyrazabole are determinated from the linear optical response of the pyrazole ring. In fact, the polarizability of the two pyrazole rings is approximately 80% of the overall value for pyrazabole. The theoretical static properties were evaluated by using ab initio (Hartree–Fock) and DFT (B3LYP) methods with the 6–31+G(d,p) and 6–311++G(3d,3p) basis sets. The calculations were performed with fully optimized geometries. The B3LYP average static electronic polarizability value of pyrazabole is 1.877 × 10−23 esu, and the differences from the experimental static values are within −1.2 to 8.5%. These variations are mainly due to the solvent effects. Copyright © 2002 John Wiley & Sons, Ltd.
Synthesis and photophysical properties of Zn(II) porphyrin–C60 dyad with potential use in solar cells
Authors: Milanesio M. Elisa , Gervaldo Miguel , Otero Luis A. , Sereno Leonides , Silber Juana J. , Durantini Edgardo N. 
Published: December 2002

AbstractZn(II) porphyrin–C60 dyad (7) was synthesized by the coupling reaction between Zn(II) 5‐(4‐aminophenyl)‐10,15,20‐tris(4‐methoxylphenyl)porphyrin (4) and 1,2‐dihydro‐1,2‐methanofullerene[60]‐61‐carboxylic acid (6). The electron‐donor capacity of the porphyrin moiety in dyad 7 is enhanced by methoxy group substitution on the macrocycle peripheries and complexation with Zn(II). Spectroscopic studies showed only a very weak interaction between the chromophores in the grown state. The emission of the porphyrin moiety in dyad 7 is strongly quenched by the attached fullerene C60 moiety. Thermodynamically, dyad 7 shows a higher capacity to form a photoinduced charge‐separated state than the same dyad with free‐base porphyrin. This was confirmed by steady‐state photolysis in the presence of methylviologen as electron acceptor and N,N,N′,N′‐tetramethyl‐1,1′‐naphthidine as electron donor. Dyad 7 sensitizes a tin dioxide (SnO2) electrode and the generation of photoelectrical effect shows that a large photocurrent is generated for the dyad 7 in the region where C60 is mainly responsible for light absorption. Also, dyad 7 produces a higher photoelectric effect than the corresponding amidoporphyrin model. An alternative photoelectric mechanism, other than direct electron injection from the excited porphyrin to SnO2, could be occurring, probably involving a charge‐separated state of dyad 7. These results indicate that dyad 7 shows interesting properties for possible application in artificial solar energy conversion devices. Copyright © 2002 John Wiley & Sons, Ltd.
Thermodynamics of partitioning of some sulfonamides in 1‐octanol–buffer and liposome systems
Authors: Martínez Fleming , Gómez Alfredo 
Published: December 2002

AbstractThe thermodynamics of partitioning of some structurally related sulfonamides have been determined in 1‐octanol–aqueous buffer and liposome systems. The partition coefficients were approximately tenfold higher in liposomes compared with 1‐octanol. The enthalpies of transfer from aqueous media to organic systems were positive in liposomes but negative or positive in 1‐octanol, whereas the entropies of transfer were positive in almost all cases. Copyright © 2002 John Wiley & Sons, Ltd.
Theoretical study of electron transfer to neopentyl chloride and phenyl‐substituted derivatives: existence of radical anions as intermediates
Authors: Mariano D. , Vera A. , Pierini Adriana B. 
Published: December 2002

AbstractAliphatic halides such as neopentyl, bicycloalkyl and polycycloalkyl halides can be substituted by mechanisms that involve electron transfer (ET) steps. The homogeneous or heterogeneous ET to these compounds follows a concerted dissociative pathway, that is, the C–halogen bond cleaves as the electron is being transferred. The ET to alkyl halides substituted by π‐electron acceptors, on the other hand, may follow a stepwise mechanism with radical anions as intermediates. Both mechanistic pathways are analyzed on the basis of AM1, B3LYP and MP2 calculations for neopentyl chloride (6) and its phenyl‐ and benzyl‐substituted derivatives 1‐chloro‐2‐methyl‐2‐phenylpropane (neophyl chloride, 7) and 1‐chloro‐2,2‐dimethyl‐3‐phenylpropane (8). The solvent effect was evaluated with Tomasi's continuum polarized model. While relatively stable π radical anions appear as intermediates on the AM1 potential surfaces of 7 and 8, B3LYP and MP2 favor a concerted dissociative pathway for these compounds. Based on the B3LYP and MP2 results, it can be concluded that the driving force for the dissociative ET to the three compounds depends mainly on their C—C1 bond dissociation. The strength of the C—C1 bond is similar for 6 and 8 and lower for 7. The difference in the C—C1 bond strength of 7 and 8 is ascribed to differences in the stabilizing effect of the phenyl substituent, through a bridge of variable length, and also to the stability of the radical formed in the cleavage. The theoretical results obtained are of help in the interpretation of the relative experimental reactivity previously obtained for the family. Copyright © 2002 John Wiley & Sons, Ltd.
Nickel‐ and palladium‐catalyzed olefin polymerization under high pressures
Authors: Suzuki Noriyuki , Yu Jian , Masubuchi Yuji , Horiuchi Akira , Wakatsuki Yasuo 
Published: December 2002

AbstractThe polymerization of 1‐hexene under high pressures (100–750 MPa) was investigated with nickel–α‐diimine complex/methylaluminoxane and palladium–α‐diimine complex/methylaluminoxane as catalyst systems. The catalytic activity of both the nickel and palladium complexes monotonously increased as pressure rose and became two to four times higher than that observed at atmospheric pressure. Palladium catalysts gave poly(1‐hexene)s with higher molecular weights under high pressure, whereas nickel‐catalyzed high‐pressure polymerizations gave polymers with higher molecular weights only at rather low monomer concentrations. The living‐like character in the palladium‐catalyzed polymerizations was somewhat enhanced under higher pressures, whereas the nickel‐catalyzed polymerizations under high pressures were not living. More branches were found in the polymers produced by nickel catalysts at higher pressures. The chain‐transfer reaction seemed to be accelerated by the high pressure in the nickel‐catalyzed reactions, although this was not apparent in the palladium‐catalyzed reactions. Dimers formed and were accompanied by high molecular weight polymers when nickel catalysts were used under high pressures and at high monomer concentrations. The possibility that very congested five‐coordinated species act as key intermediates for the dimerization is discussed. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 293–302, 2003
Determination of the cumulative degree of polymerization for the dead‐end polymerization of styrene
Authors: David G. , Boutevin B. , Robin J. J. 
Published: December 2002

AbstractThis article explores the use of a new relation correcting theoretical (DPn) with experimental values obtained in the dead‐end polymerization of styrene with azocompound. The syntheses were realized for several starting initiator‐to‐monomer ratios (C0's); values comprised between 10 and 0.1%, and the experimental (DPn) were obtained by size exclusion chromatography. Concerning the theoretical (DPn), a new relation is proposed considering the loss of initiating radicals [I · ] used in primary termination and both stationary states of I · and M · (macromolecular radicals) introduced as Bamford. Finally, (DPn)cum, previously defined by us, is introduced to consider the monomer conversion during oligomerization. Our relation fit very well in a large range of C0's, contrary to the application of the usual Mayo rule, and a discussion of validity is proposed. Our model also allows the prediction of (DPn)cum in a large range of telechelic oligomers from 10 to 150. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 236–247, 2003
Cationic cyclopolymerization of new divinyl ethers: The effect of ether and ester neighboring functional groups on their cyclopolymerization tendency
Authors: Rahman Md. Saifur , Hashimoto Tamotsu , Kodaira Toshiyuki 
Published: December 2002

AbstractThe cationic polymerization of two new divinyl ethers, 1‐(2‐vinyloxyethoxy)‐2‐[(2‐vinyloxyethoxy)carbonyl]benzene (2) and 1,2‐bis[(2‐vinyloxyethoxy)carbonyl]benzene (3), as well as 1,2‐bis(2‐vinyloxyethoxy)benzene (1), with BF3OEt2 in CH2Cl2 at 0 °C at low initial monomer concentrations ([M]0 = 0.15 and 0.075 M) gave soluble polymers with relatively high molecular weights and broad molecular weight distributions (MWDs), whereas reactions with the HCl/ZnCl2 initiating system yielded soluble polymers with relatively narrow MWDs (weight‐average molecular weight/number‐average molecular weight ≲ 1.6) under similar reaction conditions. An NMR structural analysis of the HCl/ZnCl2‐mediated polymers from the divinyl ethers showed that poly(1) had virtually no unreacted vinyl ether groups throughout the polymerization (monomer conversion = 28–98%), whereas poly(2) and poly(3) possessed some amount of unreacted vinyl ether groups in the initial stage of the polymerization; the content of the vinyl groups of poly(2) was 18 mol % at a 15% monomer conversion, and the content of the vinyl groups of poly(3) was 31 mol % at an 18% monomer conversion. Therefore, divinyl ether 1 underwent cyclopolymerization exclusively to give almost completely cyclized polymers [degree of cyclization (DC) ∼ 100%], whereas divinyl ethers 2 and 3 exhibited a lower cyclopolymerization tendency [DC for poly(2) = 82%; DC for poly(3) = 69%]. The differences in the cyclopolymerization tendencies among the divinyl ethers can be explained by the differences in the solvation powers of the neighboring functional groups adjacent to the vinyl ether moiety with the active center: the ether oxygen of the ether neighboring group solvates intramolecularly with the active center to accelerate the intramolecular propagation, but such an interaction is less effective with the more electron‐deficient oxygen attached to the carbonyl group of the ester neighboring group. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 281–292, 2003
Polymerization of vinyl chloride with half‐titanocene/methylaluminoxane catalysts
Authors: Endo Kiyoshi , Saitoh Makoto 
Published: December 2002

AbstractThe polymerization of vinyl chloride (VC) with half‐titanocene /methylaluminoxane (MAO) catalysts is investigated. The polymerization of VC with the Cp*Ti(OCH3)3/MAO catalyst (Cp* = η5‐pentamethylcyclopentadienyl) afforded high‐molecular‐weight poly(vinyl chloride) (PVC) in good yields, although the polymerization proceeded at a slow rate. With the Cp*TiCl3/MAO catalyst, the polymer was also obtained, but the polymer yield was lower than that with the Cp*Ti(OCH3)3/MAO catalyst. The polymerization of VC with the Cp*Ti(OCH3)3/MAO catalyst was influenced by the MAO/Ti mole ratio and reaction temperature, and the optimum was observed at the MAO/Ti mole ratio of about 10. The optimum reaction temperature of VC with the Cp*Ti(OCH3)3/MAO catalyst was around 20 °C. The stereoregularity of PVC obtained with the Cp*Ti(OCH3)3/MAO catalyst was different from that obtained with azobisisobutyronitrile, but highly stereoregular PVC could not be synthesized. From the elemental analyses, the 1H and 13C NMR spectra of the polymers, and the analysis of the reduction product from PVC to polyethylene, the polymer obtained with Cp*Ti(OCH3)3/MAO catalyst consisted of only regular head‐to‐tail units without any anomalous structure, whereas the Cp*TiCl3/MAO catalyst gave the PVC‐bearing anomalous units. The polymerization of VC with the Cp*Ti(OCH3)3/MAO catalyst did not inhibit even in the presence of radical inhibitors such as 2,2,6,6,‐tetrametylpiperidine‐1‐oxyl, indicating that the polymerization of VC did not proceed via a radical mechanism. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 248–256, 2003
Polyelectrolyte complexes. V. Solid‐state properties of some polycation/azo dye complexes controlled by the dye structure
Authors: Dragan Stela , Timpu Daniel 
Published: December 2002

AbstractThe solid‐state properties of some polycation/azo dye complexes according to the dye structure were studied in this work. One polycation contained about 95 mol % N,N‐dimethyl‐2‐hydroxypropyleneammonium chloride units in the backbone (PCA5), and eight azo dyes, different in either the number of sulfonic groups or their distribution, were used as opposite components. The selected azo dyes were as Crystal Scarlet, Congo Red, Crocein Scarlet MOO, Ponceau SS, Amaranth, Ponceau S, Direct Blue 1, and Direct Red 80. Information on the compensation degree of the oppositely charges was obtained by the elemental analysis of the solid‐state polycation/dye complexes (the experimental contents of chlorine, nitrogen, and sulfur were compared with the calculated values). Differential scanning calorimetry was employed to probe the strength of the intermolecular interactions in the PCA5/dye complexes. Wide‐angle X‐ray diffraction was used to assess the supramolecular order of the solid‐state complexes. The physical properties of the PCA5/azo dye complexes (the complex stoichiometry, glass‐transition temperature, decomposition temperature, and degree of supramolecular order) were influenced mainly by the dye structure but also by the polycation concentration and the presence of NaCl. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 264–272, 2003
Compositional and configurational sequence determination of methyl methacrylate/ethyl acrylate copolymers by one‐ and two‐dimensional nuclear magnetic resonance spectroscopy
Authors: Brar A. S. , Hooda Sunita , Kumar Rajeev 
Published: December 2002

AbstractEthyl acrylate (E)/methyl methacrylate (M) copolymers of different compositions were prepared, and their compositions were determined with 1H NMR spectra. The complete spectral assignments, in terms of the compositional and configurational sequences of these copolymers, were made with the help of distortionless enhancement by polarization transfer and two‐dimensional heteronuclear single quantum coherence spectroscopy. The α‐(CH3)M, CH (E), CH2, and 〉CO carbons of both M and E units were found to be sensitive to various compositional and configurational sequences. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 313–326, 2003