bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetics and signaling requirements of CD40‐mediated protection from B cell receptor‐induced apoptosis
Authors: Eeva Jonna , Postila Ville , Mättö Mikko , Nuutinen Ulla , Ropponen Antti , Eray Mine , Pelkonen Jukka 
Published: September 2003

AbstractIn the present study we used a human follicular lymphoma cell line, HF1A3, as an in vitro model for the antigen‐driven selection process in germinal centers. Apoptosis can be induced in HF1A3 cells by B cell receptor (BCR) stimulation, but the molecular mechanisms and kinetics of this process are largely unknown. We demonstrate here that there is over 12 h delay between receptoractivation and the execution phase of apoptosis, i.e. disruption of mitochondrial membrane potential, release of cytochrome c from mitochondria, caspase‐3 activation and DNA fragmentation.New protein synthesis is required for mitochondrial alterations and subsequent apoptosis to occur, as these processes are completely blocked by the protein synthesis inhibitor cycloheximide. All the apoptotic events induced by BCR triggering are completely reversed by CD40 ligation with anti‐CD40 antibody. CD40 ligation can reverse the apoptotic process in HF1A3 cells almost until the first mitochondrial events take place demonstrating that CD40‐mediated protection operates very fast and at or before mitochondrial phase of apoptosis. Using specific inhibitors of cell signaling we coulddemonstrate that Raf‐extracellular signal‐regulated kinase, phosphatidylinositol 3‐kinase, p38 or protein kinase C activation pathways are not involved in CD40‐mediated protection from BCR‐induced apoptosis in HF1A3 cells.
Mini‐review: Regulation of cytotoxic T lymphocyte responses by dendritic cells: peaceful coexistence of cross‐priming and direct priming?
Authors: Melief Cornelis J. M. 
Published: September 2003

AbstractCross‐priming is the process whereby professional APC, mainly dendritic cells (DC), prime T cells by presenting antigens processed from proteins of other cells such as tumor cells or virus‐infected cells. It has been argued that the importance of cross‐priming of CD8+ CTL responses has been overemphasized, despite strong evidence that these mechanisms operate when infectious organisms, tumors or self antigens cannot efficiently access the biosynthetic MHC class I processing pathway of DC. Since DC are ideally equipped to capture exogenous antigen and also, particularly in the mature state, express costimulatory molecules, itis difficult to distinguish whether effects are due to cross‐presentation, costimulation, or both. Whether cross‐priming or cross‐tolerance occurs depends on the maturation state of the DC, as wellas the levels of MHC class I‐bound peptides they present. Cross‐presentation of tumor‐derived antigens has been demonstrated but, importantly, requires adequate APC activation to prime CTL responses. Similarly, cross‐presentation of antigens from infectious organisms appears to be common, and frequently leads to cross‐priming. Interactions between cross‐presenting DC, CD4+ cellsand CD8+ T cells in the establishment of immunological memory are still not well defined. Experiments utilizing DC depletion are needed to further examine the role of processes such as cross‐priming and costimulation in the immune response.
Enzyme activity of α‐chymotrypsin after derivatization with phenolic compounds
Authors: Rohn Sascha , Rawel Harshadrai M. , Wollenberger Ulla , Kroll Jürgen 
Published: September 2003

Abstractα‐Chymotrypsin was allowed to react with selected phenolic and related compounds (chlorogenic acid, m‐, o‐, p‐dihydroxybenzene, p‐benzoquinone). The derivatized enzymes obtained were characterized in terms of their activity. In vitro experiments illustrated that the enzymatic activity of the derivatives was adversely affected. The kinetics of the enzymatic reactions showed that the hydrolysis of selected food proteins becomes slower and the affinity of the enzyme to these substrates declined as measured by Michaelis‐Menten constant and maximum velocity of the enzymatic reaction. This enzyme inhibition depended on the reactivity of the phenolic and related substances tested as well as on the degree of the derivatization. Further, influence of the enzyme‐substrate ratio was also demonstrated. The effects of the derivatization are more pronounced with increasing concentration of the substrates.
Chemical and biochemical changes in prickly pears with different ripening behaviour
Authors: Silos‐Espino Héctor , Fabian‐Morales Lourdes , Osuna‐Castro Juan Alberto , Valverde María Elena , Guevara‐Lara Fidel , Paredes‐López Octavio 
Published: September 2003

AbstractChemical and biochemical changes were studied in ripening prickly pears from three Opuntia morphospecies with different ripening behaviour: Naranjona (O. ficus‐indica( Blanca Cristalina (Opuntia sp.( and Charola (O. streptacantha( of early, intermediate, and late ripening, respectively. At fullyripe stage (commercial maturity( Blanca Cristalina showed the biggest fruits, the hardest texture, and its pulp had the highest protein content. There were no significant differences among morphospecies in pH or total soluble solids in fully ripe fruits. The three species exhibited considerable levels of vitamin C, dietary fibre, and minerals such as calcium, iron, and zinc. Protein expression was analysed in pulp and skin from every species at physiological and commercial maturity. Some proteins appeared at both stages, while many others expressed differentially. This study evaluated prickly pear components important for human nutrition and health, and provided basic information on pricky pear ripening, with a view to its control and to improving shelf life.
Assay of gliadin by real‐time immunopolymerase chain reaction
Authors: Henterich Nadine , Osman Awad A. , Méndez Enrique , Mothes Thomas 
Published: September 2003

AbstractPatients with coeliac disease (gluten‐sensitive enteropathy) are intolerant against gliadins from wheat and the respective proteins from related cereals and have to keep a lifelong gluten‐free diet. For control of gliadin in gluten‐free food sensitive assay techniques are necessary. We developed an immunopolymerase chain reaction (iPCR) assay for gliadin. In this technique immunological detection of gliadin by a monoclonal antibody R5 conjugated with an oligonucleotide is amplified by PCR. For quantification, iPCR was performed as real‐time PCR (real‐time iPCR) in one step. By means of real‐time iPCR, the sensitivity of gliadin analysis was increased more than 30‐fold above the level reached by enzyme immunoassay. Real time‐iPCR using R5 directly conjugated with oligonucleotide was clearly more sensitive than real time‐iPCR applying sequentially biotinylated R5, streptavidin, and biotinylated oligonucleotide. With directly conjugated R5 gliadin was detected at a concentration as low as 0.16 ng/mL corresponding to 16 μg gliadin/100 g food or 0.16 ppm (corresponding to 0.25 g of food extracted in 10 mL of solvent and 25‐fold dilution of the extract prior to analysis). This is the first report applying the highly sensitive technique of iPCR for gliadin analysis. Furthermore, this is the first approach to perform real‐time iPCR in one step without changing the reaction vessels after enzyme immunoassay for subsequent PCR analysis thus minimizing risks of contamination and loss of sensitivity.
Synthesis and Properties of Oligodeoxynucleotide Analogs with Bis(methylene) Sulfone Bridges
Authors: Eschgfäller Bernd , Schmidt Jürgen G. , König Marcel , Benner Steven A. 
Published: September 2003

AbstractA convergent, solution‐phase synthesis was developed for the bis(methylene) sulfone‐bridged oligodeoxynucleotide analogs (SNA) 5′‐d(HOCH2‐Tso2Tso2Tso2Cso2Tso2Tso2Tso2T‐CH2SO$\rm{_{3}^{-}}$)‐3′ (35b) and 5′‐d(HOCH2‐Tso2Tso2Tso2Tso2Tso2Tso2Tso2T‐CH2SO$\rm{_{3}^{-}}$)‐3′ (34c) (SO2 corresponds to CH2SO2CH2 instead of OP(O)(O−)(O). In these, the phosphodiester linkages are replaced by non‐ionic bis(methylene) sulfone linkers. The general strategy involved convergent coupling of 3′,5′‐bishomo‐β‐D‐deoxyribonucleotide analogs functionalized at the 6′‐end (CH2C(5′)) as bromides or mesylates and at the CH2C(3′) position as thiols, with the resulting thioether being oxidized to the corresponding sulfone. A single charge was introduced at the terminal CH2C(3′) position of the octamers to increase their solubility in water. During the synthesis, it became apparent that the key intermediates generated secondary structures through either folding or aggregation in a variety of solvents. This generated unusual reactivity and was unique for very similar structures. For example, although the dimeric thiol d(BzOCH2‐Tso2C‐CH2SH) (14b) was a well‐behaved synthetic intermediate, the tetrameric thiol d(TrOCH2‐Tso2Tso2Tso2toC‐CH2SH) derived from the corresponding thioacetate was rapidly converted to a disulfide by very small amounts of oxidant (28→29, Scheme 6), while the analogous tetrameric thiol d(BzOCH2‐Tso2TsTso2T‐CH2SH) (26), differing only by a single heterocycle, was oxidized much more slowly (Bz=PhCO, Tr=Ph3C, to=2‐MeC6H4CO (at N4 of dc)). The sequence‐dependent reactivity, well known in many classes of natural products (including polypeptides), is not prominent in natural oligonucleotides. These results are discussed in light of the proposal that the repeating negative charge in nucleic acids is key to their ability to serve as genetic molecules, in particular, their capability to support Darwinian evolution. The ability of 5′‐d(HOCH2‐Tso2Tso2Tso2Cso2Tso2Tso2Tso2T‐CH2SO$\rm{_{3}^{-}}$)‐3′ (35b) to bind as a third strand to duplex DNA was also examined. No triple‐helix‐forming propensity was detected in this molecule.
Application of a Potentiometric System with Data‐Analysis Computer Programs to the Quantification of Metal‐Chelating Activity of Two Natural Antioxidants: Caffeic Acid and Ferulic Acid
Authors: Borges Fernanda , Lima José L. F. C. , Pinto Isabel , Reis Salette , Siquet Christophe 
Published: September 2003

AbstractThe quantification of metal‐chelating activity of caffeic and ferulic acids (1 and 2, resp.) was successfully performed by using a potentiometric system with data‐analysis computer programs. The method was applied to two phenolic models, which have been systematically reported as antioxidants. Although a chain‐breaking mechanism was proposed, several studies pointed out the possibility of complexation of transition metals that can participate in single‐electron reactions and mediate the formation of oxygen‐derived free radicals. In this work, the complexation properties towards CuII were investigated by potentiometry with a glass electrode. Acidity constants of the ligands (phenolic acids) and the formation constants of the ligandmetal complexes were evaluated by potentiometry. The modeling of the titration curves and the data treatment were performed with the computer programs Superquad and Best. A detailed quantitative examination of the complexation species formed in the CuII/caffeic acid (1) and CuII/ferulic acid (2) systems is presented together with the formation constants (log β). Results have shown that the complexation properties of the two phenolic acids towards the transition metal are quite different: the activity of caffeic acid (1) was found higher than that of ferulic acid (2). The data are important to get insight into the mechanism of action of antioxidants, and, in this case, could partially explain the efficacy of caffeic acid in the protection of LDL oxidative damage. In addition, the analytical method developed could be applied to quantify the chelating activity of important biological compounds, such as allopurinol, uric acid, cinnamic acids, flavonoids, and anthocianins, and, in that way, could be a valuable tool to understand the mechanisms underlying their protective effects.
Novel Cytostatic Lanostanoid Triterpenes from Ganoderma australe
Authors: León Francisco , Valencia Meiser , Rivera Augusto , Nieto Ivonne , Quintana José , Estévez Francisco , Bermejo Jaime 
Published: September 2003

AbstractTwo new compounds 1 and 2, together with the known sterols ergosterol, 5,6‐dehydroergosterol, and ergosterol peroxide, and four polyoxygenated lanostanoid triterpenes named applanoxidic acid A (3), C (4), F (5), and G (6) were isolated from the fungus Ganoderma australe. The structures of the new compounds were elucidated by means of spectroscopic techniques, while the known triterpenoids 3–6 were identified by comparing their spectral data with those reported in the literature. Compounds 1–6 inhibited the viability and growth of the HL‐60 cell line.
Potentiometric, NMR, and Fluorescence‐Emission Studies on the Binding of Adenosine 5′‐Triphosphate (ATP) by Open‐Chain Polyamine Receptors Containing Naphthylmethyl and/or Anthrylmethyl Groups
Authors: Albelda M. Teresa , Aguilar Juan , Alves Sergio , Aucejo Ricardo , Díaz Pilar , Lodeiro Carlos , Lima Joao C. , García‐España Enrique , Pina Fernando , Soriano Conxa 
Published: September 2003

AbstractThe interaction in aqueous solution of adenosine 5′‐triphosphate (ATP) with a series of open‐chain polyamines linked at one or both ends to anthrylmethyl or naphthylmethyl fragments was followed by potentiometric titration, 1H‐, 13C‐, and 31P‐NMR spectroscopy, and by steady‐state fluorescence measurements. The results revealed greater stabilities for the compounds containing one anthracene moiety than for those with one naphthalene moiety, the stabilities of the compounds with both ends N‐substituted with naphthylmethyl groups being close to those containing just one anthrylmethyl unit. The 1H‐NMR spectra showed that in all systems, there is involvement of π‐π stacking interactions in the stabilization of the adduct species. The competitive effect of the anions afforded by the supporting electrolyte was checked in some of the studied systems working at two different ionic strenghts (0.15M and 1.0M NaCl). The joint analysis of the spectrofluorimetric titrations and pH‐metric species‐distribution curves showed that for all the ATPreceptor systems, a quenching of the fluorescence occurred upon protonation of the adenine N(1)atom. Steady‐state fluorescence and time‐correlated single‐photon‐counting analysis of a system made up of ATP and a bis‐chromophoric polyamine receptor containing anthracene and naphthalene fluorophores established that the energy‐transfer process between the naphthalene and anthracene moieties is still operative despite the presence of ATP.
Malignant germ cell tumors in childhood: Results of the first Italian cooperative study “TCG 91”
Authors: Curto Margherita Lo , Lumia Francesca , Alaggio Rita , Cecchetto Giovanni , Almasio Piero , Indolfi Paolo , Siracusa Fortunato , Bagnulo Serenella , Bernardi Bruno De , Laurentis Tina De , Cataldo Andrea Di , Tamaro Paolo 
Published: September 2003

AbstractBackground and AimsAbout 20% of patients with germ cell tumor (GCT) are still resistant to therapy. To investigate which features are present in resistant patients, a multicenter study on GCT in children was undertaken to correlate clinical and laboratory parameters with the outcome.MethodsPatients aged less than 16 years, with histologically proven extracranial GCT were included.ResultsNinety‐five patients (median age 33 months, 45 males) were eligible. The site of the primary tumor was gonadal in 59, extragonadal in 36. The stage was I in 39; II in 5; IIIa (microscopic residue) in 7; IIIb (macroscopic residue) in 16; IIIc (unresectable) in 13; IV in 15. The treatment was surgery alone in 31; surgery plus radiotherapy in 1; chemotherapy ± surgery in 63. Post‐chemotherapy resection in 19 (10 complete, 9 partial). The chemotherapy regimen was carboplatin 400 mg/m2/day on days 1, 2; etoposide 150 mg/m2/day on days 1, 2; ifosfamide 1,500 mg/m2/day on days 21, 22; dactinomycin 1.5 mg/m2/day on day 21; vincristine 1.5 mg/m2/day on day 21. Three patients died because of toxicity and two non‐responders (to primary chemotherapy), died of progression; among the remaining 90 patients 20 relapsed, 9 are in second remission, 2 are alive with disease, and 9 died of disease progression (one from progression and intracranial hemorrhage). Overall survival was 82.7% and event‐free survival: 71.5%. Survival according to: (a) site: testis: 100%; ovary: 88%; sacrococcyx: 69.6%; other sites: 33.3% (P < 0.001); (b) stage: I and II: 100%; IIIa: 83.3%; IIIb: 84.6%; IIIc: 60.6%; IV: 53.2% (P < 0.001); (c) AFP levels: normal: 85.5%; 42–9,470 ng/ml: 84.6%; ≥10,000 ng/ml: 58.7% (P = 0.02). All the pts who had complete resection of the primary tumor at diagnosis or at delayed surgery, remained in remission.ConclusionsMultivariate analysis showed that the primary site of tumor was the only independent prognostic factor for survival and EFS. Med Pediatr Oncol 2003;41:417–425. © 2003 Wiley‐Liss, Inc.
Electrochemical behaviour of mixtures of phenazine with iodine in the solid state
Authors: Szadkowska Agnieszka , Wrona Piotr K. , Galus Zbigniew 
Published: September 2003

AbstractThe electrochemical behaviour of mixtures of phenazine (P) with iodine (I2) in the solid state was investigated. Three types of electrochemical experiments were conducted: (i) EMF measurements of the Ag/AgI/I2:P system for various I2 : P ratios, (ii) cyclic voltammetric (CV) experiments and (iii) potentiometric measurements of the open cell potentials after different cathodic charges were injected into the I2 : P pellets. In the first case, a detailed analysis of the observed electromotive force was presented. The Gibbs free energy of the I2 : P complex determined was in good agreement with earlier results. In the second case, the CV curves corresponding to the electrode processes of phenazine mixed with graphite in the solid state indicate that the mass and charge transfer, which occur in the pellets, are faster than expected. The potentiometric experiments confirm this conclusion. Additional experiments, conducted with pellets of different thickness, indicate that although, in comparison with an equilibrated pellet, the concentration profiles are modified in small layers (diffusion layers) neighbouring the electrodes, the electrode reaction probably occurs in the whole pellet. A tentative mechanism of these processes is discussed. Copyright © 2003 John Wiley & Sons, Ltd.
Career Centered High School Education and Post–High School Career Adaptation
Authors: Gore Susan , Kadish Stacey , Aseltine Robert H. 
Published: September 2003

AbstractThis study examines the quality of the transition into employment roles among a socioeconomically diverse cohort of 1,143 high school seniors who were interviewed as seniors in 1998 and 2 years later. Focusing on both subjective and objective dimensions of work adaptation, analyses examine differences in these outcomes associated with taking a high school career‐major versus a more traditional academic program. This type of major is intended to assist in the career development and economic adaptation of more disadvantaged young adults and follows from an ecological model emphasizing the importance of connections between educational and employment institutions in the socialization of young people. Results indicate small but significant effects of having the career‐major for the perceptual variables. Group differences were not found for the variables assessing more objective qualities of their jobs. The discrepancy between subjective and objective outcomes may suggest a short‐term psychological optimism in the absence of an objective situation that would justify this view. Discussion centers on the need for stronger institutional support for school‐work connections.
Nuance, Complexity, and Context: Qualitative Methods in Genetic Counseling Research
Authors: Beeson Diane 
Published: September 2003

AbstractBecause of its potential for capturing complexity and process and its focus on communicating the meaning in human action, qualitative research is rapidly gaining acceptance in a wide variety of disciplines. Various qualitative approaches to research support its potential usefulness in genetic counseling research. Formulation of research questions and selection of appropriate qualitative methods are the first step. Interviewing, narrative analysis, focus groups, ethnography/participant observation, and participatory action research are only some of the most popular techniques that may be suitable in various situations. Processes of evaluation, analysis, and even ethical issues often differ somewhat from quantitative research. This article discusses these issues and the potential value of qualitative methods for research related to genetic counseling.
An Oral History of the National Society of Genetic Counselors
Authors: Heimler Audrey 
Published: September 2003

AbstractMaster's level genetic counselors formed a professional society in 1979, 8 years after the first master's degree training program graduation. This paper presents an oral history of the early years of the National Society of Genetic Counselors (NSGC), reviews the symbiotic development and definition of a profession and a professional society, and discusses events and achievements attributed to the NSGC since its incorporation. This retrospective historical account is based on personal and collective oral history, NSGC archival material and other sources.
Ultrasonic scaler tip performance under various load conditions
Authors: Lea S. C. , Landini G. , Walmsley A. D. 
Published: September 2003

AbstractObjectives: The aim of this investigation was to assess the effect of loading on ultrasonic scaler tip displacement amplitude, using a scanning laser vibrometer.Material and Methods: Four generators were selected for this investigation including: Cavitron Select (Dentsply), Cavitron SPS (Dentsply), Piezon Master 400 (EMS) and Mini Piezon (EMS). The insert designs used with these generators included the TFI‐10 and TFI‐3 (with the Dentsply generators) and P‐tip (with the EMS generators). The insert tips were contacted against tooth surfaces with loads of 0.25, 0.5 and 1.0 N. The scanning laser vibrometer was then used to scan the vibrating scalers at various generator power settings.Results: The tips generally showed an increase in displacement amplitude with increasing power setting, although this increase was often nonlinear. Displacement amplitudes of like tips were generally found to be significantly different from each other at all loads. For individual inserts, loading caused a significant difference in tip response from the unloaded situation and also between loads.Conclusions: This investigation has demonstrated that there is a high variability associated with dental ultrasonic scaler inserts. Clinicians and researchers should be aware of this variability as it may affect both clinical procedures and future research.