bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of ribavirin, levovirin and viramidine on liver toxicological gene expression in rats
Authors: Fang Che , Srivastava Pramod , Lin Chin‐chung 
Published: November 2003

AbstractThe ribavirin/interferon‐α combination is currently the standard therapy for patients with chronic hepatitis C. However, ribavirin causes hemolytic anemia as a signiﬁcant side‐effect. Levovirin, an l‐enantiomer of ribavirin, possesses similar immunomodulatory activity to ribavirin but lacks direct antiviral activity or hemolytic anemia. Viramidine is a liver‐targeting prodrug of ribavirin with much less potential for hemolytic anemia. The aim of the present study is to proﬁle the hepatic toxicological gene response to ribavirin, levovirin and viramidine. Rats were dosed orally with 120 mg kg−1 day−1 of ribavirin and viramidine and 2000 mg kg−1 day−1 of levovirin for 8 days. Ribavirin did not cause any signiﬁcant change (> threefold) in gene expression as analyzed by the Affymetrix GeneChip technique. Levovirin decreased the mRNA level of CYP7A1 by fourfold but did not affect the expression of CYP27/CYP7B1 that functions as an alternative pathway for cholesterol metabolism. Viramidine down‐regulated both expressed sequence tag 233569 and heat shock protein 86 genes threefold. The changes at mRNA level of these genes were conﬁrmed by the reverse transcription competitive polymerase chain reaction technique. None of the compounds changed the liver/body weight ratio, the major cytochrome P‐450 protein levels or enzyme activities. The data indicated that a high dose of ribavirin, levovirin or viramidine did not cause signiﬁcant change at the transcription level of most of the liver toxicological genes. Copyright © 2003 John Wiley & Sons, Ltd.
Photocatalytic oxidation of cyclohexane over TiO2 nanoparticles by molecular oxygen under mild conditions
Authors: Li Xinyong , Chen Guohua , Po‐Lock Yue , Kutal Charles 
Published: November 2003

AbstractThe structure, physical characteristics and photocatalytic selective oxidation properties of nanometer‐size TiO2 particles produced by a sol–gel method were studied by X‐ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), X‐ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR) and photocatalytic selective oxidation measurements. Analysis of the XRD results shows that sol–gel‐produced TiO2 nanoparticles have the anatase structure at annealing temperatures ≤973 K, that the rutile structure begins to emerge at annealing temperatures ≥973 K and the particles have the pure rutile structure at 1023 K. DRS indicates that the obtained TiO2 nanoparticles exhibit a blue shift with decreasing crystallite size. Analysis of the XPS results shows that the TiO2 nanoparticles have a lot of oxygen vacancies. The EPR spectrum of TiO2 at 77 K is composed of a strong isotropic EPR Surface‐Ti3+ signal(I) at g = 1.926 and a weak broad Bulk‐Ti3+ signal (II) at g = 1.987. Quantitative EPR indicates that both signals show a size and temperature dependence. Photocatalytic oxidation of cyclohexane into cyclohexanol with high selectivity and activity has been obtained by activation of molecular oxygen over sol–gel‐produced TiO2 nanoparticles under mild conditions in dry solvent, which reveals that the quantum size effect and surface state effect of nanoparticles are key points for governing the selective photocatalytic reaction. The photocatalytic oxidation mechanism under dry solvent is different from that in aqueous solutions. Copyright © 2003 Society of Chemical Industry
Development of Fe‐, Sb‐, Bi‐ and Al‐impregnated silica catalysts using rice husk silica as a support for Friedel–Crafts benzylation of arenes
Authors: Shinde Ajit B , Shrigadi Nilesh B , Samant Shriniwas D 
Published: November 2003

AbstractThe milling by‐product of rice, rice husk, constitutes a major waste of the agricultural industry. It is mainly used as a fuel additive for various purposes, leaving behind residual ash which is rich in silica (Biogenic silica). In the present project, rice husk silica was impregnated with Fe3+, Sb3+, Bi3+ and Al3+ from both their aqueous and organic solutions. The resultant catalysts were activated at 120 °C and 550 °C and used for the Friedel–Crafts benzylation of benzene using benzyl chloride. Copyright © 2003 Society of Chemical Industry
Fixed bed modelling for acid dye adsorption onto activated carbon
Authors: Lee Vinci KC , Porter John F , McKay Gordon 
Published: November 2003

AbstractThe adsorption of three separate acid dyes onto activated carbon has been studied using fixed bed adsorption. A film‐pore diffusion model was developed and applied to the experimental breakthrough curve data. A sensitivity analysis showed that pore diffusion was the dominant mass transport mechanism. Pore diffusion coefficients were determined by an optimization routine with a minimization of the sum of errors squared. The external mass transfer coefficients were sensitive to the external fluid dynamic parameters, such as liquid flow rate and mean particle size. These fluid dynamic parameters did not affect the effective diffusion coefficient. The effective diffusion coefficient was not affected by changes in the fluid dynamic parameters but did change with differing initial dye concentrations. This may be due to a contribution from surface diffusion to the effective diffusion coefficient. Copyright © 2003 Society of Chemical Industry
Oxidative Degradation of trans‐1,4‐Polyisoprene Cast Films and Single Crystals by Enzyme‐Mediator Systems
Authors: Enoki Makiko , Doi Yoshiharu , Iwata Tadahisa 
Published: November 2003

AbstractDepolymerization and morphological changes of cast films and single crystals of trans‐1,4‐polyisoprene with three enzyme‐mediator systems, lipoxygenase/linoleic acid (LPO/LH), horseradish peroxidase/1‐hydroxybenzotriazole (HRP/1‐HBT) and laccase/1‐hydroxybenzotriazole/linoleic acid (laccase/1‐HBT/LH), were investigated by scanning electron microscopy and gel permeation chromatography. Treatment of cast film with a LPO/LH system involving radical generation via lipid peroxidation led to a marked decrease in the molecular weight of polymers. LPO/LH system resulted in the morphological damage of single crystals of trans‐1,4‐polyisoprene. Laccase/1‐HBT/LH also destroyed the single crystals and depolymerized emulsified trans‐1,4‐polyisoprene. On the contrary, spherulites appeared on the surface of cast films and the molecular weight slightly decreased after treatment with HRP/1‐HBT, indicating that the amorphous region was predominantly degraded and the crystal region remained unchanged. The morphology of single crystals remained unchanged during the treatment of HRP/1‐HBT system for 6 d. In addition, Fenton reagent/linoleic acid was used as a chemical initiator of lipid peroxidation for degradation of trans‐1,4‐polyisoprene cast films. This system reduced molecular weight of the cast films, as well as LPO/LH system.Scanning electron micrographs of trans‐1,4‐polyisoprene single crystals before (A) and after (B) treatment with the lipoxygenase/linoleic acid system.magnified imageScanning electron micrographs of trans‐1,4‐polyisoprene single crystals before (A) and after (B) treatment with the lipoxygenase/linoleic acid system.
Hydrogen‐Bonding Interaction and Crystalline Morphology in the Binary Blends of Poly(ε‐caprolactone) and Polyphenol Catechin
Authors: Zhu Bo , Li Jianchun , He Yong , Yoshie Naoko , Inoue Yoshio 
Published: November 2003

AbstractThe specific intermolecular hydrogen‐bonding interaction between the ester carbonyl groups of poly(ε‐caprolactone) (PCL) and the phenolic hydroxyl groups of catechin has been studied by Fourier‐transform infrared spectroscopy (FT‐IR) and differential scanning calorimetry (DSC). According to quantitative curve‐fitting analysis of the FT‐IR spectra of PCL/catechin blends, it was found that the fraction of hydrogen‐bonded carbonyl groups of PCL increased with catechin content, while that of hydrogen‐bonded hydroxyl groups of catechin decreased. The calculated crystallinity of PCL in the binary blends, based on the curve‐fitting results, suggested that the crystallization of PCL was restrained in the blends with catechin. Only single glass transition temperature, Tg, was observed over the whole range of blend compositions, which was between those of the pure components. The melting point, Tm, depressed and Tg increased, indicating also the existence of strong intermolecular association. The blend composition dependence of Tg could be predicted very well by the Kwei equation with a positive ‘q’ value of 124. With the aid of small angle X‐ray scattering measurement, the segregation of catechin was investigated. It was found that the extent of extra‐lamellar segregation increased with catechin content. It was suggested that the crystal growth rate played the dominant role in the formation of morphology. With decreasing crystal growth rate of PCL component in the blends, enough time has been given to catechin molecules to diffuse into extra‐lamellar region.
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Synthesis and Characterization of Chitosan Grafted Oligo(L‐lactic acid)
Authors: Yao Fanglian , Liu Chang , Chen Wei , Bai Yun , Tang Zhiyuan , Yao Kangde 
Published: November 2003

AbstractChitosan grafted oligo(L‐lactic acid) copolymers with different length of side chain were prepared through the reaction of terminal aldehyde group of oligo(L‐lactic acid) (OLLA) and amino groups of chitosan. The mean molecular mass of the grafting OLLA chain was ca. 600 ∼ 5 000. The graft copolymers are soluble in DMSO, DMF and acetic acid. The synthesis method and structure described here provide chitosan‐g‐OLLA copolymers with broad applicability.Structure of chitosan‐g‐oligo(L‐lactic acid).magnified imageStructure of chitosan‐g‐oligo(L‐lactic acid).
Regularity of convolution type operators with PC symbols in Bessel potential spaces over two finite intervals
Authors: Castro L. P. 
Published: November 2003

AbstractConvolution type operators acting between Bessel potential spaces defined on a union of two finite intervals are studied from the point of view of their regularity properties. The operators are assumed to have kernels with Fourier transforms in the class of piecewise continuous matrix functions which is a frequent situation in several problems from mathematical physics. Various Wiener‐Hopf operators having the same regularity properties as the considered convolution type operators are presented. Moreover, besides a criterion for the Fredholm property, sufficient conditions for the invertibility of the operators in study are obtained. The approach is based on the consideration of relations between different kinds of operators. In this way, the transfer of regularity properties, between the related operators, appears as a natural consequence. An application to a wave diffraction problem with impedance conditions is illustrated. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Surfaces of Albanese general type and the Severi conjecture
Authors: Manetti Marco 
Published: November 2003

AbstractIn 1932, F. Severi claimed, with an incorrect proof, that every smooth minimal projective surface S of irregularity q = q(S) > 0 without irrational pencils of genus q satisfies the topological inequality 2c21 (S) ≥ c2(S).According to the Enriques‐Kodaira's classification, the above inequality is easily verified when the Kodaira dimension of the surface is ≤1, while for surfaces of general type it is still an open problem known as Severi's conjecture. In this paper we prove Severi's conjecture under the additional mild hypothesis that S has ample canonical bundle. Moreover, under the same assumption, we prove that 2c21 (S) = c2(S) if and only if S is a double cover of an abelian surface. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Epigenetic inactivation of TSLC1 gene in nasopharyngeal carcinoma
Authors: Hui Angela Bik‐Yu , Lo Kwok‐Wai , Kwong Joseph , Lam Eric Ching‐Wan , Chan Sylvia Yat‐Yee , Chow Lillian Shuk‐Nga , Chan Andrew Siu‐Chung , Teo Peter Man‐Lung , Huang Dolly P. 
Published: November 2003

AbstractDeletion of 11q23 is a common genetic aberration in nasopharyngeal carcinoma (NPC). Multiple candidate tumor suppressor genes (TSG) were mapped to this region but few of them were investigated in NPC. TSLC1 (tumor suppressor in lung cancer) is recently reported to be a putative TSG on 11q23. This gene was found to be inactivated by promoter hypermethylation in non‐small cell lung carcinoma (NSCLC), liver cancer, and breast cancer. To study the role of TSLC1 gene in NPC tumorigenesis, we screened for mutations and aberrant methylation of TSLC1 gene in 5 NPC cell lines, 3 NPC xenografts, and 38 primary NPC cases. No somatic mutations of TSLC1 were detected in the NPC samples, but a 9‐bp (CCACCACCA) deletion in exon 8 was found in a primary NPC and its corresponding blood sample. Bisulfite sequencing revealed aberrant methylation of TSLC1 promoter in four NPC cell lines. Loss of TSLC1 gene expression was found in two cell lines (HK‐1 and CNE‐2) with dense methylation. Expression of this gene was restored in these cell lines after treatment with demethylating agent 5‐aza‐2′‐deoxycytidine. Our results showed that silencing of TSLC1 gene expression in NPC was associated with promoter hypermethylation. Promoter hypermethylation of TSLC1 gene was further illustrated in 34.2% (13/38) of primary NPCs. No aberrant promoter methylation was found in any of the four investigated normal nasopharyngeal epithelia. Frequent epigenetic inactivation of TSLC1 gene in NPC suggested that this gene is one of the target tumor suppressor genes of this endemic cancer. © 2003 Wiley‐Liss, Inc.
EGF‐ and cell‐cycle–regulated STAG1/PMEPA1/ERG1.2 belongs to a conserved gene family and is overexpressed and amplified in breast and ovarian cancer
Authors: Giannini Giuseppe , Ambrosini Maria Irene , Di Marcotullio Lucia , Cerignoli Fabio , Zani Massimo , MacKay Andrew Ray , Screpanti Isabella , Frati Luigi , Gulino Alberto 
Published: November 2003

AbstractThe abnormal activation of the epidermal growth factor (EGF) pathway is one of the most common findings in human cancer, and a number of molecular devices of laboratory and clinical relevance have been designed to block this transduction pathway. Because of the large number of cellular events that might be regulated through the activation of the four EGF receptor family members, it is possible that screening methodologies for the identification of new molecular targets working downstream of these pathways may provide new tools for cancer diagnosis and potentially prevention and therapy. In searching for EGF target genes, we have identified ERG1.2, the mouse homolog of the solid tumor‐associated gene STAG1. Both in humans and in mice, it belongs to a new gene family that can give origin to several protein isoforms through alternative splicing and/or multiple translation starts. Sequence analysis and experimental data suggest that ERG1.2 is likely to function as a membrane‐bound protein interacting with downstream signaling molecules through WW‐ and SH3‐binding domains. ERG1.2 is a cell‐cycle–regulated gene, and both ERG1.2 and STAG1 are induced by EGF and other growth factors at the transcript and protein levels. Finally, we have demonstrated that, besides prostate cancer and renal cell carcinoma, STAG1 was also overexpressed in breast and ovarian cancer cell lines and in breast primary tumors. Although in most cases STAG1 overexpression is probably due to the abnormal activation of the EGF pathway, we have also demonstrated genetic amplification and rearrangement of its locus in one breast cancer cell line and one primary ovarian cancer, suggesting that STAG1 might be a direct molecular target in the carcinogenetic process. Thus its overexpression might be regarded not only as a tumor marker but also as a potentially pathogenetic event. © 2003 Wiley‐Liss, Inc.
Two‐year follow‐up of subthalamic deep brain stimulation in Parkinson's disease
Authors: Herzog Jan , Volkmann Jens , Krack Paul , Kopper Florian , Pötter Monika , Lorenz Delia , Steinbach Meike , Klebe Stefan , Hamel Wolfgang , Schrader Bettina , Weinert Dieter , Müller Dieter , Mehdorn Hubertus M. , Deuschl Günther 
Published: November 2003

AbstractWe studied 48 patients after bilateral subthalamic nucleus deep brain stimulation (STN‐DBS) who were evaluated 6 months after the surgical procedure using the Unified Parkinson's Disease Rating Scale (UPDRS) in a standardized levodopa test. Additional follow‐up was available in 32 patients after 12 months and in 20 patients after 24 months. At 6 months follow‐up, STN‐DBS reduced the UPDRS motor score by 50.9% compared to baseline. This improvement remained constant at 12 months with 57.5% and at 24 months with 57.3%. Relevant side effects after STN‐DBS included intraoperative subdural hematoma without neurological sequelae (n = 1), minor intracerebral bleeding with slight transient hemiparesis (n = 1), dislocation of impulse generator (n = 2), transient perioperative confusional symptoms (n = 7), psychotic symptoms (n = 2), depression (n = 5), hypomanic behaviour (n = 2), and transient manic psychosis (n = 1). One patient died because of heart failure during the first postoperative year. The current series demonstrates efficacy and safety of STN‐DBS beyond the first year after surgical procedure. Complications of STN‐DBS comprise a wide range of psychiatric adverse events which, however, were temporary. © 2003 Movement Disorder Society
Suggestive linkage to chromosome 19 in a large Cuban family with late‐onset Parkinson's disease
Authors: Bertoli‐Avella Aida M. , Giroud‐Benitez Jose L. , Bonifati Vincenzo , Alvarez‐Gonzalez Eduardo , Heredero‐Baute Luis , Van Duijn Cornelia M. , Heutink Peter 
Published: November 2003

AbstractThe identification of disease genes using family‐based approaches has provided important insights into the pathogenesis of Parkinson's disease (PD) demonstrating the importance of genetic studies on monogenic forms of the disease. We studied a large Cuban family with typical, late‐onset PD and probable autosomal dominant inheritance. Mean age at onset was 61.2 years (±12.53, 45–76). Other phenotypes such as essential tremor and atypical parkinsonism were observed in this family. We carried out a genome‐wide scan and linkage analyses. The genetic data were analyzed using a conservative model in which only patients with clinically definite or likely PD were considered affected, other phenotypes were regarded as “unknown.” Multipoint analyses yielded a maximum LOD of 2.26 between markers D19S221 and D19S840. Haplotype analysis showed a region on chromosome 19 shared by six of seven PD patients. The essential tremor phenotype and the atypical parkinsonism do not segregate with this haplotype, suggesting a different etiology. Our findings suggest the presence of a novel locus for PD on chromosome 19p13.3–q12. We propose that an oligogenic model with moderate contribution of two or three genes rather than a “pure” monogenic model might explain better the wide range in age at onset, the reduced penetrance and the phenotypical variability observed in PD families. © 2003 Movement Disorder Society
Randomized, double‐blind, 3‐month parallel study of the effects of pramipexole, pergolide, and placebo on parkinsonian tremor
Authors: Navan Prithiva , Findley Leslie J. , Jeffs Jim A.R. , Pearce Ronald K.B. , Bain Peter G. 
Published: November 2003

AbstractWe compared the antitremor effect of pramipexole, pergolide, or placebo in Parkinson's disease (PD). A double‐blind, randomly controlled, parallel protocol was deployed to examine the effects of placebo, pergolide, and pramipexole [doses escalated to 1.5 mg three times daily (t.i.d.) over 3 months] on a compound Tremor Index (TI) and Unified Parkinson's Disease Rating Scale (UPDRS) part III. Thirty PD patients (19 men, 11 women; mean age 69 years, range 54–80 years; mean disease duration 3.9 years, range, 0.5–10 years) participated in the study, with 10 patients in each arm. Six subjects failed to complete the study (4 on pergolide and 2 on placebo). Analysis of covariance demonstrated strong evidence for a treatment effect on both TI and UPDRS III. There was no significant difference between the active treatments on either TI or UPDRS III. Both pergolide and pramipexole were significantly better than placebo. The results indicate that pergolide and pramipexole (1.5 mg t.i.d.) have similar anti–PD tremor and UPDRS III actions that are significantly superior to placebo. Patients on pergolide were more likely to drop out because of adverse events than those on pramipexole. © 2003 Movement Disorder Society
Case‐control study of the α‐synuclein interacting protein gene and Parkinson's disease
Authors: Maraganore Demetrius M. , Farrer Matthew J. , Lesnick Timothy G. , De Andrade Mariza , Bower James H. , Hernandez Dena , Hardy John A. , Rocca Walter A. 
Published: November 2003

AbstractWe conducted a case‐control study of the α‐synuclein–interacting protein gene (SNCAIP, also known as synphilin‐1) and Parkinson's disease (PD). A total of 319 PD cases and 195 controls were genotyped for four SNCAIP variants, including a microsatellite repeat in intron 4 and three restriction fragment length polymorphisms (RFLP) proximal to the 5′ terminal of exons 1, 4, and 6. None of the variants were found associated with PD overall. Global score statistics were not significant for four, three, and two loci haplotypes. All four loci were in linkage disequilibrium for cases, controls, or both groups combined (P < 0.0001). Recursive partitioning showed no interactions between variants of the SNCAIP gene and variants of the α‐synuclein gene (SNCA) or the parkin (PARK2) gene. © 2003 Movement Disorder Society
Arm chorea secondary to an unruptured giant aneurysm
Authors: De Madariaga Luis M. Barreiro , Sian José E. , Parera Ignacio Casas , Micheli Federico 
Published: November 2003

AbstractWe describe the case of a 20‐year‐old male who developed right‐arm choreic movements secondary to a giant unruptured aneurysm impinging upon the left thalamus, putamen, globus pallidus, cerebral peduncle, midbrain, and subthalamic nucleus. The aneurysm was treated successfully with coils and a supraclinoid balloon. Abnormal movements initially failed to ameliorate, but within a few months, it was possible to discontinue symptomatic haloperidol therapy, with only mild residual abnormal movements. © 2003 Movement Disorder Society
Solution 1H and 13C NMR of new chiral 1,4‐oxazepinium heterocycles and their intermediates from the reaction of 2,4‐pentanedione with α‐L‐amino acids and (R)‐(—)‐2‐phenylglycinol
Authors: Concepción Lozada M. , Lobato Carlos E. , Enríquez Raúl G. , Ortíz Benjamín , Toscano Rubén A. , Gnecco Dino , Galindo Alberto , Reynolds William F. 
Published: November 2003

AbstractThe reaction of 2,4‐pentanedione (1) with (R)‐(—)‐2‐phenylglycine methyl ester (2), (R)‐(—)‐2‐phenylglycinol (3) and the proteinogenic amino acids (2S,3R)‐(—)‐2‐amino‐3‐hydroxybutyric acid (L‐threonine) (4) and (R)‐(—)‐2‐amino‐3‐mercaptopropionic acid (L‐cysteine) (5) methyl esters was investigated. The corresponding enamines 6, 7 and 8 were isolated and characterized spectroscopically whereas 9, which is unstable, was transformed in situ into 13. Treatment of 7, 8 and 9 with boron trifluoride etherate afforded the new [1,4]oxazepines 10, 11 and [1,4]thiazepine (12) as their BF3O− salts. The structures of the enamines and their corresponding seven‐membered heterocycles were assessed by 1D and 2D NMR spectroscopy. Variable‐temperature experiments revealed different molecular mobility behavior among these heterocycles. Copyright © 2003 John Wiley & Sons, Ltd.
An alternative spin‐state‐selective pulse sequence element
Authors: Bouguet‐Bonnet S. , Mutzenhardt P. , Canet D. 
Published: November 2003

AbstractA simple modification of the spin‐state‐selective excitation (S3E) pulse sequence element is proposed. The new sub‐sequence, dubbed S2ED for spin‐state echo differentiation, can be used in a very versatile way, in addition to the standard features of S3E. Experimental verifications were performed by editing α/β–HSQC–α/β spectra of nitrogen‐15‐labelled ubiquitin. Copyright © 2003 John Wiley & Sons, Ltd.