bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and fragmentation of new 2‐phosphabicyclo[2.2.2]octene 2‐oxides
Authors: Keglevich György , Szelke Helga , Tamás Annamária , Harmat Veronika , Ludányi Krisztina , Vaskó Ágnes Gyöngyvér , Tőke László 
Published: November 2002

AbstractThe substitution pattern of the 2‐phosphabicyclo[2.2.2]octene framework and the skeleton itself were varied to obtain new cycloadducts usable in phosphorylations and to study their ability to undergo fragmentation. Thus, an N‐methyl and several P‐trialkylphenyl derivatives (7 and 9, respectively) were synthesized, together with two diaza species (8) whose stereostructure was evaluated by single crystal X‐ray analysis. Mechanistic studies on the UV light‐mediated photolysis of the P‐aryl phosphabicyclooctenes (9) in the presence of methanol supports the suggestion of a novel addition–elimination reaction path. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:626–632, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10052
Synthesis of 4‐phosphonyl‐1,3‐dithioles and 1,3‐dithiolanes via the Bu3P‐CS2 adduct
Authors: Xu Cheng‐Fu , Liu Yu‐Xiu , Wang Wen‐Hu , Cao Ru‐Zhen , Liu Lun‐Zu 
Published: November 2002

AbstractNew one‐pot syntheses of 2‐arylidene‐4‐phosphonyl‐1,3‐dithioles or 1,3‐dithiolanes were realized by reaction of the tributylphosphine‐carbon disulfide adduct with phosphonyl alkynes or phosphonyl alkenes and aldehydes in moderate yields. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:633–637, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10053
Synthesis, characterization, and biological studies of tri‐ and diorganotin(IV) complexes with 2′,4′‐difluoro‐4‐hydroxy‐[1,1′]‐biphenyle‐3‐carbolic acid: Crystal structure of [(CH3)3Sn(C13H7O3F2)]
Authors: Ahmad Fiaz , Ali Saqib , Parvez Masood , Munir Arshad , Mazhar M. , Khan Khalid M. , Shah Tasadaq Ali 
Published: November 2002

AbstractEight tri‐ and diorganotin(IV) carboxylates with general formulae R3SnL and R2SnL2 (where R = CH3, n‐C4H9, C6H5, C7H7, and L = 2′,4′‐difluoro‐4‐hydroxy‐[1,1′]‐biphenyl‐3‐carboxylic acid) were synthesized and characterized by UV–vis, IR, conductance, multinuclear (1H, 13C, and 119Sn) NMR spectroscopy, and mass spectrometry. The crystal structure of [(CH3)3Sn(C13H7O3F2)] indicates that the tin atom in the asymmetric unit exists in a trigonal bipyramidal geometry having a space group Pbca with an orthorhombic crystal system. These complexes were also screened for their antibacterial and antifungal activities. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:638–649, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10057
Synthesis of vinyl pyrophosphonate analogues of farnesyl pyrophosphate: New potential inhibitors of farnesyl protein transferase
Authors: Zgani Ibrahim , Menut Chantal , Montéro Jean Louis 
Published: November 2002

AbstractThe synthesis of new bioisosteric analogues of farnesyl pyrophosphate where a vinyl pyrophosphonate replaced the pyrophosphate moiety is described. These compounds have been prepared using a Horner–Wadsworth–Emmons procedure and a modified Michelson reaction. They have been evaluated for the inhibition of farnesyl protein transferase. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:654–661, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10081
1,3‐Dipolar cycloaddition of dipolar reagents to bis(styryl) sulfones
Authors: Padmavathi V. , Reddy K. Venugopal , Balaiah A. , Reddy T. V. Ramana , Reddy D. Bhaskar 
Published: November 2002

AbstractSulfonyl bis pyrazolines and isoxazolines were prepared by 1,3‐dipolar cycloaddition of nitrile imines and nitrile oxides to E,E‐bis(styryl) sulfones. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:677–682, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10087
Protection against acetaminophen hepatotoxicity by clofibrate pretreatment: Role of catalase induction
Authors: Chen Chuan , Hennig Gayle E. , Whiteley Herbert E. , Manautou José E. 
Published: November 2002

AbstractMice pretreated with the peroxisome proliferator clofibrate (CFB) are highly resistant to acetaminophen (APAP)‐induced hepatotoxicity. The objective of the present study was to investigate whether the increase in hepatic catalase activity following CFB pretreatment plays a role in this hepatoprotection. An irreversible inhibitor, 3‐amino‐1,2,4‐triazole (3‐AT), was used to modulate catalase activity. Hepatic catalase activity in mice pretreated with CFB (500 mg/kg, i.p., for 10 days) was significantly inhibited by 3‐AT (100 or 500 mg/kg, i.p.). In addition, the lower dose of 3‐AT (100 mg/kg) had minimal effect on biliary and urinary excretion of APAP metabolites generated from a nontoxic dose, suggesting that APAP metabolism was not modulated by this dose of 3‐AT. The mortality rate of corn‐oil‐pretreated mice challenged with APAP (800 mg/kg, p.o.) was significantly increased by 3‐AT (100 mg/kg, i.p.) given 1 h before APAP. As expected, CFB pretreatment conferred full protection against APAP‐induced hepatotoxicity. The same 3‐AT treatment, however, did not abolish hepatoprotection in CFB‐pretreated mice, despite the marked inhibition of hepatic catalase activity. In conclusion, these results indicate that elevated catalase activity in mice exposed to CFB does not appear to mediate the hepatoprotection, suggesting that other cellular defense mechanisms are involved. © 2002 Wiley Periodicals, Inc. J Biochem Mol Toxicol 16:227–234, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.10043
Protective effect of arabic gum against cardiotoxicity induced by doxorubicin in mice: A possible mechanism of protection
Authors: Abd‐Allah Adel RA , Al‐Majed Abdulhakeem A. , Mostafa Adel M. , Al‐Shabanah Othman A. , Din Ayman Gamal El , Nagi Mahmoud N. 
Published: November 2002

AbstractArabic gum (AG) is a naturally occurring compound that has been proposed to posses potent antioxidant activity. In this study, the possible effects whereby AG could protect against cardiotoxicity induced by doxorubicin (DOX) in mice were carried out. Administration of single dose of DOX (15 mg/kg, i.p.) induced cardiotoxicity 72 h, manifested biochemically by a significant elevation of serum creatine kinase (CK) (EC 2.7.3.2). In addition, cardiotoxicity was further confirmed by the significant increase in lipid peroxides measured as malondialdehyde (MDA). Administration of AG (25 g/kg) orally for 5 days before and 72 h after DOX injection produced a significant protection against cardiotoxicity induced by DOX. This was evidenced by significant reductions in serum CK and cardiac lipid peroxides. The effect of AG was examined on the superoxide anion radical generated by enzymatic and nonenzymatic methods. The results indicate that AG is a potent superoxide scavenger. The superoxide scavenging effect of AG may explain, at least in part, the protective effect of AG against cardiotoxicity induced by DOX. © 2002 Wiley Periodicals, Inc. J Biochem Mol Toxicol 16:254–259, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.10046
Comparison of the characteristic of estrogenic action patterns of β‐HCH and heregulin β1 in MCF‐7 human breast cancer cells
Authors: Hatakeyama Mariko , Zou Enmin , Matsumura Fumio 
Published: November 2002

AbstractIn this study, we compared the estrogenic action pattern of β‐HCH to another ErbB2 activating agent, heregulin β1 (HRG), along with 17β‐estradiol and epidermal growth factor, to understand the similarities and differences of their action mechanisms. Not surprisingly, most of the initial test results indicated that the two agents, β‐HCH and HRG, are remarkably similar in several estrogenicity tests. However, in‐depth biochemical studies revealed that there are some distinct differences between these two compounds in affecting ErbB2 and ErbB3 at early stages of their action. Immunocoprecipitation and Western blot studies indicated that β‐HCH mainly promotes dimerization of ErbB2 and ErbB3 at early time points, whereas HRG causes their dimerization with a rapid and significant rise in their tyrosine phosphorylation levels. These results indicate that, while both β‐HCH and HRG act through ErbB2, their initial actions differ. To understand the long‐term consequence of such differential actions of these two agents, we tested the effect of a number of standard pathway specific inhibitors on their actions to induce foci formation after 2 weeks of exposure. The most conspicuous difference between β‐HCH and HRG in MCF‐7 foci formation test was their response to 4‐hydroxytamoxifen and LY294002, a PI3K inhibitor, i.e., the action of β‐HCH was inhibited by 4‐hydroxytamoxifen but stimulated by LY294002, whereas that of heregulin was suppressed by LY294002 but stimulated by 4‐hydroxytamoxifen. It appears, therefore, that the action of the latter relies more heavily on the PI3K route as compared to that of the former which has been shown to mainly act through p42/44 MAPK. These differences may account for their differential sensitivities to 4‐hydroxytamoxifen. © 2002 Wiley Periodicals, Inc. J Biochem Mol Toxicol 16:209–219, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.10047
Phenotypic rescue after adeno‐associated virus‐mediated delivery of 4‐sulfatase to the retinal pigment epithelium of feline mucopolysaccharidosis VI
Authors: Ho Thucanh T. , Maguire Albert M. , Aguirre Gustavo D. , Surace Enrico M. , Anand Vibha , Zeng Yong , Salvetti Anna , Hopwood John J. , Haskins Mark E. , Bennett Jean 
Published: November 2002

AbstractBackgroundMucopolysaccharidosis VI (MPS VI), due to recessively inherited 4‐sulfatase (4S) deficiency, results in lysosomal storage of dermatan sulfate in numerous tissues. Retinal involvement is limited to the retinal pigment epithelium (RPE). This study aimed to determine whether recombinant adeno‐associated virus (AAV)‐mediated delivery of 4S would reverse the RPE pathology seen in MPS VI cats.MethodsAAV.f4S, containing the feline 4S cDNA, was delivered unilaterally to eyes of affected cats by subretinal or intravitreal injection. Contralateral eyes received AAV with the green fluorescent protein (GFP) reporter gene as control. At 2–11 months post‐injection, the cats were sacrificed and the treatment effects were evaluated histologically.ResultsBy ophthalmoscopy and histological analyses, GFP was evident as early as 4 weeks and persisted through the latest time point (11 months). Untreated and AAV.GFP‐treated diseased retinas contained massively hypertrophied RPE cells secondary to accumulation of dilated lysosomal inclusions containing dermatan sulfate. MPS VI eyes treated subretinally with AAV.f4S had minimal RPE cell inclusions and, consequently, were not hypertrophied.ConclusionsAAV‐mediated subretinal delivery of f4S provided correction of the disease phenotype in RPE cells of feline MPS VI, supporting the utility of AAV as a vector for the treatment of RPE‐specific as well as lysosomal storage diseases. Copyright © 2002 John Wiley & Sons, Ltd.
Polybrene and interleukin‐4: two opposing factors for retroviral transduction of bone‐marrow‐derived dendritic cells
Authors: Fresnay Stéphanie , Chalmers David E. , Ferrand Christophe , Colombain Christine , Newton Isobel , Yerly‐Motta Véronique , Lienard Agnès , Darodes de Tailly Patrick , Hervé Patrick , Tiberghien Pierre , Saas Philippe 
Published: November 2002

AbstractBackgroundGene transfer using retroviral transduction offers the advantage of long‐term transgene expression in developing strategies that use dendritic cells (DCs) for immunotherapy. The goal of this study was to infect DCs in an immature state in order to take advantage of their proliferating and tolerogenic potential.MethodsImmature DCs were generated from murine bone marrow (BM) using either GM‐CSF alone or GM‐CSF plus IL‐4. The cells were transduced directly with retroviral supernatants or by co‐culture with the GP + E‐86 retroviral packaging cell line in the presence of two different cationic polymers: polybrene and protamine sulfate. Phenotypic and functional characterization of the transduced cells were then performed.ResultsOur results show a low efficiency of retroviral infection of DCs in the presence of polybrene. This cationic polymer was found to be directly cytotoxic to murine DCs and thus favored the growth of contaminating macrophages. This effect was not observed using protamine sulfate. Furthermore, stimulation by IL‐4 early in the culture increased DC differentiation, proliferation and transduction. However, we found that DCs generated in GM‐CSF plus IL‐4 presented a more mature phenotype with an enhanced allogeneic stimulating activity. Finally, we showed that DCs themselves down‐regulated transgene expression in the co‐cultured packaging cell line in a promoter‐dependent manner.ConclusionsWe have defined optimal conditions to generate and transduce murine BM‐derived DCs. This included: the use of protamine sulfate during exposure to retroviral infectious supernatant and the addition of IL‐4 at an early stage of the culture. Nevertheless, this cytokine also induced DC maturation. These findings have potential implications in experimental gene therapy. Copyright © 2002 John Wiley & Sons, Ltd.
Visual framework for development and use of constitutive models
Authors: M. A. Hashash Youssef , C. Wotring Donald , I‐Chiang Yao John , Lee Jung‐Suk , Fu Qingwei 
Published: November 2002

AbstractAdvanced constitutive relations are used in geotechnical engineering to capture measured soil and rock behaviour in the laboratory, and in numerical models to represent the material response. These constitutive relations have traditionally been difficult to use, understand, and develop except by a limited number of specialists. This paper describes a framework for transforming the representation of constitutive relations, as well as stress and strain quantities from a series of mathematical equations and matrix quantities to multidimensional geometric/visual objects in a dynamic interactive colour‐rich display environment. The paper proposes a shift in current approaches to the development of constitutive equations and their use in numerical simulations by taking advantage of rapid advancements in information technology and computer graphics. A novel interactive visualization development and learning environment for material constitutive relations referred to as VizCoRe is presented. Visualization examples of two constitutive relations, the linear elastic with von Mises failure criteria and the Modified Cam Clay (MCC) are shown. These include two‐ and three‐dimensional renderings of stress states and paths and yield and failure surfaces. In addition, the environment allows for the visualization of the implicit integration algorithm used for the numerical integration of both constitutive models. Copyright © 2002 John Wiley & Sons, Ltd.
An algebraic preconditioning method for M‐matrices: linear versus non‐linear multilevel iteration
Authors: Kraus J. K. 
Published: November 2002

AbstractIn a recent work, the author introduced a robust multilevel incomplete factorization algorithm using spanning trees of matrix graphs (Proceedings of the 1999 International Conference on Preconditioning Techniques for Large Sparse Matrix Problems in Industrial Applications, Hubert H. Humphrey Center, University of Minnesota, 1999, 251–257). Based on this idea linear and non‐linear algebraic multilevel iteration (AMLI) methods are investigated in the present paper.In both cases, the preconditioner is constructed recursively from the coarsest to finer and finer levels. The considered W‐cycles only need diagonal solvers on all levels and additionally evaluate a second‐degree matrix polynomial (linear case), or, perform ν inner GCG‐type iterations (non‐linear case) on every other level. This involves the same type of preconditioner for the corresponding Schur complement. The non‐linear variant has the additional benefit of being free from any method parameters to be estimated. Based on the same type of approximation property similar convergence rates are obtained for linear and non‐linear AMLI, even for a very small number ν of inner iterations, e.g. ν =2,3. The presented methods are robust with respect to anisotropy and discontinuities in the coefficients of the PDEs and can also be applied to unstructured‐grid problems. Copyright © 2002 John Wiley & Sons, Ltd.
An HPLC method for the direct assay of the serotonin precursor, 5‐hydroxytrophan, in seeds of Griffonia simplicifolia
Authors: Lemaire Peter A. , Adosraku Reimmel K. 
Published: November 2002

Abstract5‐Hydroxytryptophan (1) is a naturally occurring amino acid found in significant levels in seeds of Griffonia simplicifolia and used in the treatment of the numerous effects of serotonin deficiency syndrome. An HPLC method has been developed for the direct assay of 1 in seeds of G. simplicifolia which overcomes the problems associated with previous techniques. By optimising the solvent extraction procedures and the HPLC conditions, levels of 1 could be estimated following a single‐step seed extraction. The chromatographic conditions, solvent system and the extraction technique developed make this method relatively simple, fast and efficient. Using the described methods, the highest ever levels of 1 (namely, 20.83% on a fresh weight basis) have been determined in seeds of G. simplicifolia obtained in Ghana. Copyright © 2002 John Wiley & Sons, Ltd.
Anthocyanin composition of the fruit of Coriaria myrtifolia L.
Authors: Escribano‐Bailón María Teresa , Santos‐Buelga Celestino , Alonso Gonzalo L. , Salinas María Rosario 
Published: November 2002

AbstractThe anthocyanin composition of the fruit of Coriaria myrtifolia L. and the changes which occur during ripening were studied using HPLC‐PAD and LC‐MS. Ten anthocyanins were detected and identified by their absorption and mass spectra as the 3‐glucoside and 3‐galactoside derivatives of delphinidin, cyanidin, petunidin, peonidin and malvidin. Fruit ripening was accompanied by substantial changes in the anthocyanin profile, with methoxylated anthocyanins, i.e. malvidin and peonidin, predominating in the final stages of ripening, and the trihydroxylated anthocyanin, delphinidin, during the earlier stages. Furthermore, galactoside derivatives were more abundant than glucosides in the ripe fruit. At full maturity, the fruits of C. myrtifolia were very rich in anthocyanins with a content of 10.7% (on a dry weight basis), a level which is higher than that found in most fruits usually considered to be anthocyanin‐rich. The ability to grow C. myrtifolia in damaged and nitrogen poor soils, together with the possibility of using this plant for the extraction of anthocyanin, makes it ideal for consolidating soils and repopulating semi‐desert or fire‐damaged areas. Copyright © 2002 John Wiley & Sons, Ltd.
Direct determination of alkaloid contents in Fumaria species by GC‐MS
Authors: Suau R. , Cabezudo B. , Rico R. , Nájera F. , López‐Romero J. M. 
Published: November 2002

AbstractThe isoquinoline alkaloids protopine, cryptopine, sinactine, stylopine, bicuculline, adlumine, parfumine, fumariline, fumarophycine, fumaritine, dihydrofumariline, parfumidine and dihydrosanguinarine have been determined and identified by gas chromatography–mass spectrometry in Fumaria agraria, F. bastardii, F. capreolata, F. sepium, F. densiflora, F. faurei, F. officinalis subsp. officinalis, F. parviflora, F. petteri subsp. calcarata and F. macrosepala. The chemotaxonomic significance of the results is discussed. Copyright © 2002 John Wiley & Sons, Ltd.
Determination of the diterpenoid, kaurenoic acid, in Annona glabra by HPLC
Authors: Oliveira Brás H. , Sant'Ana Antônio Euzébio G. , Bastos Denise Z. L. 
Published: November 2002

AbstractThe isolation of ent‐kaur‐16‐en‐19‐oic acid (1) from the leaves and bark of Annona glabra and its determination by reversed‐phase HPLC with a photodiode array detector is described. The results indicate that 1 accumulates in the bark of the plant with only very low concentrations in the leaves. Levels of 1 varied throughout the year being highest for bark and leaves in the autumn (5.29 ± 0.23 and 0.27 ± 0.01 mg/g dry weight, respectively) and lowest in the spring for bark and in the winter for leaves (4.00 ± 0.25 and 0.11 ± 0.01 mg/g dry weight, respectively). Copyright © 2002 John Wiley & Sons, Ltd.
Investigation of Bradykinin metabolism in human and rat plasma in the presence of the dual ace/NEP inhibitors GW660511X and omapatrilat
Authors: Heudi Olivier , Ramirez‐Molina Cesar , Marshall Peter , Amour Augustin , Peace Simon , McKeown Stephen , Abou‐Shakra Fadi 
Published: November 2002

AbstractSeveral studies have suggested that the accumulation of bradykinin, or that of one its metabolites BK1–8, is involved in the occurrence of side effects such as AE associated with the use of various ACEi. In this work a novel approach combining HPLC‐UV on‐line with oaTOF‐MS and ICPMS was applied to investigate in human and rat plasma the metabolism of labelled BK (79/81Br‐Phe5) BrBK in the presence of two new dual ACE/NEP inhibitors (GW660511X and omapatrilat) currently under clinical trial.In human plasma the BrBK half‐life values in the absence or in the presence of GW660511X (3.8 µM) or omapatrilat (32 nM) were 38.7 ± 2.4, 51.2 ± 4.7 and 114.7 ± 9.3 min, respectively and BrBK was degraded into BrBK1–8, BrBK1–7, BrBK1–5 and Br‐Phe5. In the presence of inhibitors, however, the levels of these resultant metabolites were different. Unlike GW660511X, omapatrilat abolished the production of BrBK1–5 and BrBK1–7, suggesting a better ACE inhibition effect over GW660511X as no NEP activity was found. In addition the production of BrBK1–8 was enhanced in the presence of these inhibitors with a greater accumulation being observed with omapatrilat. The production of Br‐Phe5 was reduced with GW660511X while no significant change was observed with omapatrilat after 4 h of incubation. In rat plasma the BrBK half‐life values in the absence or in the presence of GW660511X (530 nM) or omapatrilat (50 nM) were 9.31 ± 1.7, 22.06 ± 3.1 and 25.3 ± 1.7 min, respectively and BrBK was degraded into BrBK1–8, BrBK1–7, BrBK1–5 and Br‐Phe5 plus BrBK2–9, BrBK4–8 and BrBK2–8 metabolites not found in human plasma. GW660511X and omapatrilat reduced the production of BrBK1–5 and BrBK1–7 with more effect being observed with omapatrilat. GW660511X and omapatrilat increased the production of both BrBK1–8 and Br‐Phe5 but not that of BrBK4–8 and BrBK2–8.This study shows that the potency of GW660511X in comparison with omapatrilat is more than 100‐fold lower in human, but less than 10‐fold lower in rat plasma, suggesting that rat may not be a suitable in vivo model for the evaluation of ACE/NEP inhibition in relation to effects in humans. Copyright © 2002 European Peptide Society and John Wiley & Sons, Ltd.
Post‐synthesis incorporation of a lipidic side chain into a peptide on solid support
Authors: Douat Céline , Heitz Annie , Paris Marielle , Martinez Jean , Fehrentz Jean‐Alain 
Published: November 2002

AbstractA new strategy for the synthesis of lipopeptides has been developed. Using Weinreb (N‐methoxy, N‐methyl) amide as an aldehyde function precursor on the side chains of Asp or Glu residues, this new strategy avoids the synthesis of a lipidic amino acid residue before its incorporation in the peptide sequence. The aldehyde generated on the solid support can react with ylides leading to unsaturated or saturated side chains or with various nucleophiles to yield non‐coded amino acid residues incorporated into the sequence. Copyright © 2002 European Peptide Society and John Wiley & Sons, Ltd.