bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of resistance to vincristine and doxorubicin in neuroblastoma alters malignant properties and induces additional karyotype changes: A preclinical model
Authors: Kotchetkov Rouslan , Cinatl Jaroslav , Blaheta Roman , Vogel Jens‐Uwe , Karaskova Jana , Squire Jeremy , Hernáiz Driever Pablo , Klingebiel Thomas , Cinatl Jindrich 
Published: January 2003

AbstractCytotoxic drug treatment of neuroblastoma often leads to the development of drug resistance and may be associated with increased malignancy. To study the effects of long‐term cytotoxic treatment on malignant properties of tumor cells, we established 2 neuroblastoma cell sublines resistant to vincristine (VCR) and doxorubicin (DOX). Both established cell lines (UKF‐NB‐2rVCR20 and UKF‐NB‐2rDOX100) were highly resistant to VCR, DOX and vice‐versa but retained their sensitivity to cisplatin. UKF‐NB‐2rVCR20 and UKF‐NB‐2rDOX100 expressed significant amounts of P‐glycoprotein, while parental cells were P‐glycoprotein negative. GD2 expression was upregulated, whereas NCAM expression was decreased in both resistant cells. Spectral karyotype (SKY) analysis revealed complex aberrant karyotypes in all cell lines and additional acquired karyotype changes in both resistant cells. All cell lines harbored high levels of N‐myc amplification. Compared to parental cells, UKF‐NB‐2rVCR20 and UKF‐NB‐2rDOX100 exhibited more than 2‐fold increase in clonal growth in vitro, accelerated adhesion and transendothelial penetration and higher tumorigenicity in vivo. We conclude that development of drug resistance and acquisition of certain karyotypic alterations is associated with an increase of additional malignant properties that may contribute to the poor prognosis in advanced forms of NB. The 2 novel neuroblastoma cell sublines also provide useful models for the study of drug resistance in aggressive forms of neuroblastoma. © 2002 Wiley‐Liss, Inc.
Prospects for cannabinoids as anti‐inflammatory agents
Authors: Zurier Robert B. 
Published: January 2003

AbstractThe marijuana plant (Cannabis sativa) and preparations derived from it have been used for medicinal purposes for thousands of years. It is likely that the therapeutic benefits of smoked marijuana are due to some combination of its more than 60 cannabinoids and 200–250 non‐cannabinoid constituents. Several marijuana constituents, the carboxylic acid metabolites of tetrahydrocannabinol, and synthetic analogs are free of cannabimimetic central nervous system activity, do not produce behavioral changes in humans, and are effective antiinflammatory and analgesic agents. One cannabinoid acid in particular, ajulemic acid, has been studied extensively in in vitro systems and animal models of inflammation and immune responses. This commentary reviews a portion of the work done by investigators interested in separating the medicinal properties of marijuana from its psychoactive effects. Understanding the mechanisms of the therapeutic effects of nonpsychoactive cannabinoids should lead to development of safe effective treatment for several diseases, and may render moot the debate about “medical marijuana”. © 2002 Wiley‐Liss, Inc.
Effects of 1,25‐dihydroxyvitamin D3 on the distribution of androgen and vitamin D receptors in human prostate neonatal epithelial cells
Authors: Leman Eddy S. , Getzenberg Robert H. 
Published: January 2003

AbstractAlthough many studies have examined the mechanisms of 1,25‐dihydroxyvitamin D3 (calcitriol or 1,25 D) action in different prostate cancer cell lines, little is known regarding the influence of this steroid on the normal prostate. The presence of both VDR and AR in normal prostatic tissues raises the distinct possibility of an important role for this hormone in the normal gland. In order to ascertain the possible role of 1,25 D on both AR and VDR in the normal prostate, the effects of calcitriol and dihydrotestosterone (DHT) on the normal human neonatal prostatic epithelial cell line, 267B‐1, were examined. These studies were approached by focusing on how 1,25 D in the presence or absence of DHT affects the distribution of AR and VDR in the cytoplasmic and nuclear compartments of the cells in terms of their protein levels and DNA binding activities. Immunoblot analyses show that 1,25 D increases the AR protein level in both the cytoplasmic and nuclear fractions but not the VDR protein level. On the other hand, the gel shift assays demonstrate that 1,25 D increases both the AR– and VDR–DNA binding activities in the nuclear fraction, whereas there is no increase in DNA binding activities in the cytoplasmic fraction. Addition of DHT along with 1,25 D does not affect the DNA binding activities of both AR and VDR. Overall, these studies suggest that 1,25 D actions on the normal prostate cells may be mediated independently through AR and VDR, respectively. © 2002 Wiley‐Liss, Inc.
A comparative simulation analysis of propane dehydrogenation in composite and microporous membrane reactors
Authors: Hou Kaihu , Hughes Ronald 
Published: January 2003

AbstractPropane dehydrogenation has been simulated for a composite membrane reactor and a microporous membrane reactor using plug‐flow reactor models, in which both were packed with Pt/Al2O3 catalyst in the tube‐side. The reaction kinetics employed in the analysis were obtained from experimental data produced in an integral fixed bed reactor with the same catalyst. Comparative studies were carried out to analyse the performances of reactors containing the different membranes in terms of contact time, flow pattern and flow rate of sweep gas, and pressure. In general, the composite membrane reactors gave the better performance for all cases investigated.© 2002 Society of Chemical Industry
Analysis of the elimination process of polymerisation inhibitors from styrene by means of adsorption
Authors: Rivero María J , Ibáñez Raquel , Ortiz M Inmaculada 
Published: January 2003

AbstractThis work is focused on the analysis, modelling and scale‐up of a process of styrene purification. The first step in synthetic rubber production is to eliminate 4‐tert‐butylcatechol (TBC) which is added to styrene to prevent homopolymerisation during transport and storage. This process is carried out on an industrial scale by means of adsorption onto activated alumina. Equilibrium experiments at 10 °C correlated to the Langmuir–Freundlich equation:

with a weighted standard deviation of 3.38%. Fixed bed column experiments were carried out on a laboratory scale to obtain breakthrough curves. A mathematical model that considers film and pore mass transfer resistances described satisfactorily the experimental results with a value of Dp = 3.96 × 10−9 m2 s−1 which was obtained from correlation of experimental data to simulated curves. Finally, a pilot plant was built and operated in order to verify the validity of the mathematical model and parameters obtained previously.© 2002 Society of Chemical Industry
Asynchroneity of maximum glacier advances in the central Spanish Pyrenees
Authors: García‐Ruiz José M. , Valero‐Garcés Blas L. , Martí‐Bono Carlos , González‐Sampériz Penélope 
Published: January 2003

AbstractThe deglaciation history of the Escarra and Lana Mayor glaciers (Upper Gállego valley, central Spanish Pyrenees) had been reconstructed on the basis of detailed geomorphological studies of glacier deposits, sedimentological and palynological analyses of glacial lake sediments and an accelerator mass spectrometry (AMS) 14C chronology based on minimum ages from glacial lake deposits. The maximum extent of the Pyrenean glaciers during the last glaciation was before 30 000 yr BP and pre‐dated the maximum advances of the Scandinavian Ice Sheet and some Alpine glaciers. A later advance occurred during the coldest period (around 20 000 yr BP), synchronous with the maximum global ice extent, but in the Pyrenees it was less extensive than the previous one. Later, there were minor advances followed by a stage of debris‐covered glaciers and a phase of moraine formation near cirque backwalls. The deglaciation chronology of the Upper Gállego valley provides more examples of the general asynchroneity between mountain and continental glaciers. The asynchroneity of maximum advances may be explained by different regional responses to climatic forcing and by the southern latitude of the Pyrenees. Copyright © 2002 John Wiley & Sons, Ltd.
Computational complexity on computable metric spaces
Authors: Weirauch Klaus 
Published: January 2003

AbstractWe introduce a new Turing machine based concept of time complexity for functions on computable metric spaces. It generalizes the ordinary complexity of word functions and the complexity of real functions studied by Ko [19] et al. Although this definition of TIME as the maximum of a generally infinite family of numbers looks straightforward, at first glance, examples for which this maximum exists seem to be very rare. It is the main purpose of this paper to prove that, nevertheless, the definition has a large number of important applications. Using the framework of TTE [40], we introduce computable metric spaces and computability on the compact subsets. We prove that every computable metric space has a c‐proper c‐admissible representation. We prove that Turing machine time complexity of a function computable relative to c‐admissible c‐proper representations has a computable bound on every computable compact subset. We prove that computably compact computable metric spaces haveconcisec‐proper c‐admissible representations and show by examples that many canonical representations are of this kind. Finally, we compare our definition with a similar one by Labhalla et al. [22]. Several examples illustrate the concepts. By these results natural and realistic definitions of computational complexity are now available for a variety of numerical problems such as image processing, integration, continuous Fourier transform or wave propagation.
Adaptation of the postpartum support questionnaire for mothers with multiple sclerosis
Authors: Gulick Elsie E. 
Published: January 2003

AbstractThe purposes of this study were to determine the dimensionality of the Postpartum Support Questionnaire adapted for mothers with multiple sclerosis through factor‐analytic techniques and to provide construct validity for the factored dimensions. One hundred and seventy‐four mothers with multiple sclerosis comprised the sample. Using a priori criteria, a three‐factor structure, resulting from principal components analysis with an orthogonal rotation consisting of 24 of the 28 items, was found to best represent the dimensionality of the instrument. The three support factors—emotional, instrumental, and informational—showed acceptable coefficient alpha reliabilities at the 1‐, 3‐, and 6‐month administrations. Evidence of construct validity was shown in that, as hypothesized, (a) mothers with comparatively lower emotional distress reported higher levels of emotional and instrumental support, and (b) mothers with one child reported receiving more informational support during the 6‐month postpartum period than did mothers with more than one child. The results support the use of the 24‐item Postpartum Support Questionnaire in assessing the adequacy of these specific dimensions of social support needed by mothers with multiple sclerosis during the postpartum period. © 2003 Wiley Periodicals, Inc. Res Nurs Health 26:30–39, 2003
Applications of inward matrix products and matrix wave functions to Hückel MO theory, Slater extended wave functions, spin extended functions, and Hartree method
Authors: Carbó‐Dorca Ramon 
Published: January 2003

AbstractThe operation of inward matrix product and the concept of extended wave functions are jointly invoked to set up a general theoretical framework to obtain a new look at old quantum chemical procedures like Hückel method, Hartree theory, and some related questions. Among the discussion of several problems, the spin orbitals are presented as a matrix signature option, associated with an extended wave function in matrix form, common to both Hückel and Hartree theories, as well as in the fundaments of Slater determinants construction. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
Allowed transitions in silicon isoelectronic ions
Authors: Saha B. , Mukherjee T. K. , Das A. K. , Mukherjee P. K. 
Published: January 2003

AbstractDipole‐allowed transitions have been studied for the first few members of the Si isoelectronic sequence. Transition energies, oscillator strengths, transition probabilities and quantum defect values have been estimated for the low‐ and high‐lying excited states of s and d symmetries up to the principal quantum number n=7 for these 3p open shell ions from P+ to Cr10+. Time‐dependent coupled Hartree–Fock (TDCHF) theory has been utilized to calculate such transition properties. Most of the results for transition energies, oscillator strengths, and transition probabilities for higher excited states are new. The transition energies for low‐lying excited states agree well with experimental data wherever available. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Comparison of the effect of video glasses and nitrous oxide analgesia on the perceived intensity of pain and unpleasantness evoked by dental scaling
Authors: Bentsen Bo , Wenzel Ann , Svensson Peter 
Published: January 2003

AbstractThe aim of this study was to evaluate whether distraction induced by video glasses had an effect on the perceived intensity of pain and unpleasantness during dental scaling compared with the effect of nitrous oxide (N2O) analgesia. The pain stimulus was dental scaling (removal of dental calculus) with an ultrasonic scaler. As a standardised, non‐dental painful stimulus, Von Frey filaments were used. A total of 26 patients with superficial chronic periodontitis were enrolled in this randomised, controlled clinical study. The effect of video glasses was compared with N2O in one session and the effect of video glasses versus a control situation in another. The patients rated the intensity of pain and unpleasantness evoked by dental scaling and Von Frey filament stimulation on 100‐mm visual analogue scales (VAS). For dental scaling, there was no effect of video glasses on the perceived pain (p=0.85) or unpleasantness (p=0.73) nor of N2O (p=0.69 and p=0.51, respectively) compared with the control situation. Similarly, no significant difference was found between VAS scores in the video glasses and N2O session (p=0.48, p=0.58). A significant effect of video glasses and was found on the perceived pain intensity produced by Von Frey filament stimulation compared with the control situation, but no significant difference was seen between these methods (p=0.07). Post‐treatment interviews of the patients revealed that 81% of the patients in the video and 65% in the N2O session stated that the method had some beneficial effect on their overall experience of the treatment situation. In conclusion, administration of video glasses or N2O did not affect the perceived intensity of pain and unpleasantness evoked by dental scaling.
Implicit attitude towards pictures of back‐stressing activities in pain‐free subjects and patients with low back pain: an affective priming study
Authors: Goubert Liesbet , Crombez Geert , Hermans Dirk , Vanderstraeten Guy 
Published: January 2003

AbstractIn this paper, it is investigated whether an implicit evaluative‐negative attitude towards back‐stressing activities exists in pain‐free subjects and in chronic low back pain patients. Using an affective priming task, it was investigated whether pictures of threatening back‐stressing movements (primes) facilitate (respectively, slow down) the categorisation of subsequent evaluative‐negative (evaluative‐positive) words (targets). In study 1 using 20 pain‐free subjects, the affective priming effect indicated evidence for an implicit negative attitude towards pictures of back‐stressing activities. In study 2 using 30 low back pain patients, a reverse priming effect was found. In line with previous research, it is argued that this reverse priming effect is owing to the evaluative extremity of the primes: patients recognize the possibility that extreme primes will interfere with the categorisation of the targets and overcompensate for this possible effect. The implications for the prevention of negative attitudes towards back‐stressing activities in non‐clinical and clinical samples are discussed.
Methadone dose and post‐mortem blood concentration
Authors: CAPLEHORN JOHN R. M. , DRUMMER OLAF H. 
Published: January 2003

AbstractThe relationship of methadone dose with post‐mortem blood concentration was investigated using data collected from 1994 coronial cases in the Australian state of New South Wales. Data on 31 subjects were summarized using linear regression. The weight‐adjusted methadone dose, gender, methadone maintenance treatment status and its interaction with adjusted‐dose were all significant predictors of post‐mortem blood methadone concentration. Data on the death of a young man from the toxic effects of three daily doses of 30mg methadone are used to give an example of a pair of observed (0.74 mg/l) and predicted (0.48 mg/l) post‐mortem blood concentrations. The estimated post‐mortem blood concentration for male maintenance patients is at least twice the trough plasma levels estimated from previously published studies of living maintenance patients. The estimated post‐mortem blood concentration for female maintenance patients is at least three times the estimated trough level of living subjects. We conclude that post‐mortem methadone redistribution is probably the principal cause of the observed differences between males and females in post‐mortem blood concentrations and the differences between estimated concentrations for living and deceased subjects.
Involvement of a Protein Tyrosine Kinase in Production of the Polymeric Bioemulsifier Emulsan from the Oil-Degrading StrainAcinetobacter lwoffiiRAG-1
Authors: Nakar David , Gutnick David L. 
Published: January 2003

ABSTRACTThe genes associated with the biosynthesis of the polymeric bioemulsifier emulsan, produced by the oil-degradingAcinetobacter lwoffiiRAG-1 are clustered within a 27-kbp region termed theweecluster. This report demonstrates the involvement of two genes of theweecluster of RAG-1,wzbandwzc, in emulsan biosynthesis. The two gene products, Wzc and Wzb were overexpressed and purified. Wzc exhibited ATP-dependent autophosphorylating protein tyrosine kinase activity. Wzb was found to be a protein tyrosine phosphatase capable of dephosphorylating the phosphorylated Wzc. Using the synthetic substratep-nitrophenyl phosphate (PNPP) Wzb exhibited aVmaxof 12 μmol of PNPP min−1mg−1and aKmof 8 mM PNPP at 30°C. The emulsifying activity of mutants lacking eitherwzborwzcwas 16 and 15% of RAG-1 activity, respectively, suggesting a role for the two enzymes in emulsan production. Phosphorylation of Wzc was found to occur within a cluster of five tyrosine residues at the C terminus. Colonies from a mutant in which these five tyrosine residues were replaced by five phenylalanine residues along with those of a second mutant, which also lacked Wzb, exhibited a highly viscous colony consistency. Emulsan activity of these mutants was 25 and 24% of that of RAG-1, respectively. Neither of these mutants contained cell-associated emulsan. However, they did produce an extracellular high-molecular-mass galactosamine-containing polysaccharide. A model is proposed in which subunit polymerization, translocation and release of emulsan are all associated and coregulated by tyrosine phosphorylation.
The Iron-Binding Protein Dps Confers Hydrogen Peroxide Stress Resistance to
Campylobacter jejuni
Authors: Ishikawa Takahiko , Mizunoe Yoshimitsu , Kawabata Shun-ichiro , Takade Akemi , Harada Mine , Wai Sun Nyunt , Yoshida Shin-ichi 
Published: January 2003

ABSTRACT

We identified and characterized the iron-binding protein Dps from
Campylobacter jejuni
. Electron microscopic analysis of this protein revealed a spherical structure of 8.5 nm in diameter, with an electron-dense core similar to those of other proteins of the Dps (DNA-binding protein from starved cells) family. Cloning and sequencing of the Dps-encoding gene (
dps
) revealed that a 450-bp open reading frame (ORF) encoded a protein of 150 amino acids with a calculated molecular mass of 17,332 Da. Amino acid sequence comparison indicated a high similarity between
C. jejuni
Dps and other Dps family proteins. In
C. jejuni
Dps, there are iron-binding motifs, as reported in other Dps family proteins.
C. jejuni
Dps bound up to 40 atoms of iron per monomer, whereas it did not appear to bind DNA. An isogenic
dps
-deficient mutant was more vulnerable to hydrogen peroxide than its parental strain, as judged by growth inhibition tests. The iron chelator Desferal restored the resistance of the Dps-deficient mutant to hydrogen peroxide, suggesting that this iron-binding protein prevented generation of hydroxyl radicals via the Fenton reaction. Dps was constitutively expressed during both exponential and stationary phase, and no induction was observed when the cells were exposed to H
2
O
2
or grown under iron-supplemented or iron-restricted conditions. On the basis of these data, we propose that this iron-binding protein in
C. jejuni
plays an important role in protection against hydrogen peroxide stress by sequestering intracellular free iron and is expressed constitutively to cope with the harmful effect of hydrogen peroxide stress on this microaerophilic organism without delay.
Comparative Analyses of the Complete Genome Sequences of Pierce's Disease and Citrus Variegated Chlorosis Strains of
Xylella fastidiosa
Authors: Van Sluys M. A. , de Oliveira M. C. , Monteiro-Vitorello C. B. , Miyaki C. Y. , Furlan L. R. , Camargo L. E. A. , da Silva A. C. R. , Moon D. H. , Takita M. A. , Lemos E. G. M. , Machado M. A. , Ferro M. I. T. , da Silva F. R. , Goldman M. H. S. , Goldman G. H. , Lemos M. V. F. , El-Dorry H. , Tsai S. M. , Carrer H. , Carraro D. M. , de Oliveira R. C. , Nunes L. R. , Siqueira W. J. , Coutinho L. L. , Kimura E. T. , Ferro E. S. , Harakava R. , Kuramae E. E. , Marino C. L. , Giglioti E. , Abreu I. L. , Alves L. M. C. , do Amaral A. M. , Baia G. S. , Blanco S. R. , Brito M. S. , Cannavan F. S. , Celestino A. V. , da Cunha A. F. , Fenille R. C. , Ferro J. A. , Formighieri E. F. , Kishi L. T. , Leoni S. G. , Oliveira A. R. , Rosa V. E. , Sassaki F. T. , Sena J. A. D. , de Souza A. A. , Truffi D. , Tsukumo F. , Yanai G. M. , Zaros L. G. , Civerolo E. L. , Simpson A. J. G. , Almeida N. F. , Setubal J. C. , Kitajima J. P. 
Published: January 2003

ABSTRACT

Xylella fastidiosa
is a xylem-dwelling, insect-transmitted, gamma-proteobacterium that causes diseases in many plants, including grapevine, citrus, periwinkle, almond, oleander, and coffee.
X. fastidiosa
has an unusually broad host range, has an extensive geographical distribution throughout the American continent, and induces diverse disease phenotypes. Previous molecular analyses indicated three distinct groups of
X. fastidiosa
isolates that were expected to be genetically divergent. Here we report the genome sequence of
X. fastidiosa
(Temecula strain), isolated from a naturally infected grapevine with Pierce's disease (PD) in a wine-grape-growing region of California. Comparative analyses with a previously sequenced
X. fastidiosa
strain responsible for citrus variegated chlorosis (CVC) revealed that 98% of the PD
X. fastidiosa
Temecula genes are shared with the CVC
X. fastidiosa
strain 9a5c genes. Furthermore, the average amino acid identity of the open reading frames in the strains is 95.7%. Genomic differences are limited to phage-associated chromosomal rearrangements and deletions that also account for the strain-specific genes present in each genome. Genomic islands, one in each genome, were identified, and their presence in other
X. fastidiosa
strains was analyzed. We conclude that these two organisms have identical metabolic functions and are likely to use a common set of genes in plant colonization and pathogenesis, permitting convergence of functional genomic strategies.