bluuebunny/crossref_metadata_2025_split huggingface dataset:
How is the molecular ion of α‐tocopherol formed under fast atom bombardment conditions?
Authors: Takayama Mitsuo 
Published: May 2005

AbstractThe mechanism for the formation of the M+· ion of α‐tocopherol, a viscous oily material, under fast atom bombardment (FAB) conditions without a liquid matrix was investigated by using positive‐ and/or negative‐ion electron impact, gas‐phase FAB, gas‐phase fast molecule bombardment and charge‐exchange reaction techniques. The results obtained could not be explained by the charge exchange alone, and they also suggested that M+· ion formation under FAB conditions is not due to direct collisions between analytes and fast atoms but to collision interactions between analyte molecules in a dense gas‐like phase formed immediately after the collision cascade caused by particle bombardment and/or in the collision cascade itself. It is argued that the formation of M+· ions under matrix FAB conditions is essentially due to collision interactions between analyte and matrix molecules. In order to understand the M+· ion fromation, the energetics are discussed from the standpoint of the chargeexchange ionization reaction.
Determination of the calcium antagonist SIM6080 in plasma by gas chromatography/chemical ionization mass spectrometry
Authors: Castelnovo Pierfrancesco 
Published: May 2005

AbstractA sensitive and selective gas chromatographic/mass spectrometric assay for the determination of the calcium antagonist SIM6080 in plasma was developed and validated. SIM6080 was extracted from plasma by a three‐step solvent extraction procedure and separated by capillary gas chromatography combined with mass spectrometric detection. Chemical ionization using ammonia as the reagent gas was used and the protonated molecular ion was monitored. The defluorinated analogue was used as an internal standard. The analysis of spiked plasma demonstrated good accuracy and precision of the assay with a quantitation limit of 0.5 ng ml−1 and a detection limit of 0.1 ng ml−1. The method was used for phase I pharmacokinetic studies.
Structural analysis of the CHO‐derived interleukin‐4 by liquid‐chromatography/electrospray ionization mass spectrometry
Authors: Tsarbopoulos Anthony , Pramanik Birendra N. , Nagabhushan Tattanahalli L. , Covey Thomas R. 
Published: May 2005

AbstractElectrospray (ES) ionization mass spectrometric analysis of CHO‐derived recombinant interleukin‐4 (IL‐4) before and after deglycosylation with peptide: N‐glycosidase F is described. That proved useful not only in deriving the size of the attached carbohydrate components but also in identifying the major glycoforms as the mono‐and disialylated complex‐type N‐linked oligosaccharides. Additional signals arising from glycoforms containing carbohydrate components with more extended or higher branching were also detected. Further mapping of CHO IL‐4 was carried out by combining proteolytic digestion and chromatographic separation of the resulting peptide mixture with on‐line ES mass spectrometric detection. Comparative analysis of the V8 protease digests of CHO IL‐4 and its deglycosylated product revealed the Asn38 N‐glycosylation site. Glycopeptide‐containing fractions were identified by searching the resulting raw ES data for signal pairs whose m/z values differ by the mass of various carbohydrate units adjusted for the signal's charge state (e.g. 97 u difference for a triply charged ES signal of a glycopeptide containing NeuAc units). Furthermore, ES mass spectrometric analysis at elevated orifice potentials allowed the rapid location of the glycopeptides in the total ion current chromatogram by monitoring several carbohydrate‐specific fragment ions. This high orifice‐induced fragmentation is a highly sensitive method for generating sugar diagnostic ions in chromatographically separated components, even when glycopeptide and peptide fragments are co‐eluting.
Poly(ADP‐ribose) polymerase‐1 activation in a primate model of multiple sclerosis
Authors: Kauppinen Tiina M. , Suh Sang Won , Genain Claude P. , Swanson Raymond A. 
Published: June 2005

AbstractMultiple sclerosis (MS) is an immune‐mediated disabling neurological disorder involving inflammation, demyelination, axonal damage, and neurodegeneration. Poly(ADP‐ribose)polymerase‐1 (PARP‐1), a nuclear enzyme linked to DNA repair, has been shown to regulate the cellular inflammatory response through interactions with nuclear factor‐κB. Extensive PARP‐1 activation can, by separate mechanisms, also cause cell death. PARP‐1 activation in brain occurs in several settings associated with oxidative stress and DNA damage, and PARP‐1 inhibition has been shown to attenuate inflammation and improve neuronal survival in these settings. Here we studied the pattern of PARP‐1 activation in a nonhuman primate model of MS, marmoset (Callithrix jacchus) experimental allergic encephalomyelitis (EAE). Characteristic of this model is relapsing and remitting focal demyelination typical of human MS. Immunostaining for poly(ADP‐ribose), the enzymatic product of PARP‐1, showed PARP‐1 activation specifically in plaque areas of EAE brains. Robust immunostaining was found in astrocytes surrounding demyelinated EAE plaques and in scattered nearby microglia, oligodendrocytes, and neurons. The immunostaining also suggested PARP‐1 activation in occasional endothelial cells surrounded by microglia or infiltrating peripheral blood cells. Given the importance of PARP‐1 in both inflammation and cell death processes, these findings suggest that PARP‐1 activation may be a significant factor in the pathogenesis of MS. © 2005 Wiley‐Liss, Inc.
Biochemical and morphologic evidence of the interaction of oligodendrocyte membrane rafts with actin filaments
Authors: Taguchi Katsutoshi , Yoshinaka Koji , Yoshino Ken‐ichi , Yonezawa Kazuyoshi , Maekawa Shohei 
Published: June 2005

AbstractCytoskeletal structures under the cell membrane carry out pivotal roles in the maintenance and remodeling of the cell structures. Reforming of the cytoskeletal networks after partial extraction of membrane components could be a good clue to identify molecular components pertaining the interaction of cytoskeleton with membrane. A detergent extract from 3‐week‐old rat brain membrane fraction was found to make an actin‐based gel upon incubation at 25°C. Some protein components of the gelation products were recovered in a Triton‐insoluble low‐density microdomain fraction (raft) after depolymerization of actin filaments. Some of these proteins were identified as 2′,3′‐cyclic nucleotide‐3′‐phosphodiesterase (CNPase), proteolipid protein (PLP), and myelin oligodendrocyte glycoprotein (MOG) through electrospray time‐of‐flight (ESI‐TOF) analysis and Western blotting. Because these proteins are well‐known marker proteins of oligodendrocytes, localization of these proteins and cholesterol, a raft‐localized lipid, with actin filaments was studied using cultured oligodendrocytes. Clear colocalization of these proteins and cholesterol with actin filaments was observed after Triton treatment at 4°C before fixation. These results indicate that raft microdomains participate in the formation of cell shape through interaction with microfilaments in oligodendrocytes. © 2005 Wiley‐Liss, Inc.
PI3K/Akt‐dependent regulation of the transcription factor myocyte enhancer factor‐2 in insulin‐like growth factor‐1‐ and membrane depolarization‐mediated survival of cerebellar granule neurons
Authors: Wiedmann M. , Wang X. , Tang X. , Han M. , Li M. , Mao Z. 
Published: June 2005

AbstractSurvival signals such as insulin‐like growth factor‐1 (IGF‐1) or membrane depolarization convey their neuronal protective effects through the activation of signaling networks and nuclear factors. In cerebellar granule neurons, IGF‐1 mediates survival primarily through the PI3K/Akt pathway. The function of the transcription factor myocyte enhancer factor‐2 (MEF2) is required for mediating membrane depolarization‐dependent neuronal survival. However, whether PI3K/Akt regulates MEF2 and the role of MEF2 in IGF‐1‐mediated survival of neurons are unknown. In addition, the contribution of the PI3K/Akt pathway in membrane depolarization‐induced neuronal survival remains undefined. We show here that the PI3K/Akt pathway promotes the survival of cerebellar granule neurons derived from Long‐Evans rats following IGF‐1 stimulation or membrane depolarization through regulation of MEF2 activity. IGF‐1 stimulated the gene transactivation activity of MEF2 and its DNA binding potential. Moreover, regulation of MEF2 function by IGF‐1 was dependent on the activity of the PI3K/Akt signaling pathway. Blocking MEF2 function reduced IGF‐1‐induced survival of cerebellar granule neurons. Membrane depolarization stimulated phosphorylation of Akt in cerebellar granule neurons. Blocking of the PI3K/Akt pathway with either a pharmacological inhibitor of PI3K, LY294002, or dominant negative mutants of PI3K and Akt inhibited the membrane depolarization‐induced increase in MEF2 transactivation as well as its DNA binding activity and reduced neuronal survival. Together, these findings provide clear evidence to support an important role of the PI3K/Akt pathway in the regulation of nuclear survival factor MEF2 upon either IGF‐1 stimulation or membrane depolarization, thus placing MEF2 as a novel downstream effector of the PI3K/Akt pathway in neurons. © 2005 Wiley‐Liss, Inc.
Role of heat treatment in childhood cancers: Distinct resistance profiles of solid tumor cell lines towards combined thermochemotherapy
Authors: Debes Anette , Willers Reinhart , Göbel Ulrich , Wessalowski Rüdiger 
Published: June 2005

AbstractBackgroundSince information on the efficacy of hyperthermia in combination with chemotherapy on pediatric tumors is limited, we performed a systematic analysis on the synergistic effects of a combined application of heat and chemotherapy on 20 tumor cell lines derived from patients with neuroblastomas, Ewing tumors, germ cell tumors (GCT), and osteosarcomas.MethodsCisplatin (cDDP), a cross‐linking agent, and etoposide (VP‐16), a topoisomerase II inhibitor, were examined either alone or in combination with heat (42°C, 43°C) by using the XTT‐assay 1.ResultsOur data demonstrate that heat stress at 43°C for 1 hr, but not at 42°C, leads to a notable cytotoxic effect on the different tumor cells. The comparison of mean survival fractions reveals values between 62% for neuroblastoma cells and 76% for Ewing tumor cells. Analyzing the sensitivity to chemotherapy alone, our results show that cDDP (5 μg/ml) reduces cell growth to 47% in Ewing tumor cells, to 61% in neuroblastoma cells, to 75% in GCT cells, and to 76% in osteosarcoma cells. Treatment with VP‐16 (10 μg/ml) decreases cell survival to mean values between 58% (neuroblastomas) and 77% (osteosarcomas). Simultaneous application of heat and chemotherapy enhances synergistically cDDP cytotoxicity in all tumor types tested, whereas the efficacy of VP‐16 is only slightly influenced by additional application of hyperthermia. The cytotoxicity of cDDP (5 μg/ml) can be increased by a factor of between 1.5 and 2.5 at 42°C and from 2.6 to 14.0 at 43°C. Furthermore, the results show that the sensitivity to heat (43°C) as well as the sensitivity to chemotherapy and combined thermochemotherapy varies considerably between cell lines of the same tumor group.ConclusionsSimultaneous application of hyperthermia synergistically enhances the cytotoxicity of the alkylating agent cDDP, but not of the topoisomerase II inhibitor VP‐16, in a defined spectrum of cell lines from different pediatric tumor entities. © 2005 Wiley‐Liss, Inc.
Cord blood transplant in childhood ALL
Authors: Sawczyn Kelly K. , Quinones Ralph , Malcolm Janet , Foreman Nicholas , Garrington Tim , Gore Lia , Gao Dexiang , Giller Roger 
Published: June 2005

AbstractBackgroundOptimal therapy for high risk and relapsed acute lymphoblastic leukemia (ALL) remains uncertain. Wider availability of cord blood from related and unrelated donors has prompted studies of its use for hematopoeitic stem cell transplant (HSCT).ProcedureWe evaluated 26 consecutive cord blood transplants (CBT) for ALL performed at our center from 1996 to 2002 on studies using consistent conditioning therapy and graft‐versus‐host disease (GVHD) prophylaxis. Median patient age was 8.5 years (range, 0.5–24 year). Cord blood (CB) was from unrelated donors in 25/26 cases. Median CB nucleated cell dose was 3.26e7/kg (range, 0.8–12.9).ResultsWith median follow‐up of 548 days, 16/26 patients (62%) are event‐free survivors. Acute GVHD developed in 14/24 evaluable patients, reaching grade III–IV in 7 patients. Chronic GVHD occurred in 10/22 evaluable patients. Multivariate analysis showed higher total nucleated cell dose per kilogram to be the strongest predictor of event‐free survival.ConclusionsWe conclude that CBT can effectively treat ALL in children with high risk features and following relapse. © 2005 Wiley‐Liss, Inc.
Phase II study of gemcitabine in children with relapsed acute lymphoblastic leukemia or acute myelogenous leukemia (ADVL0022): A Children's Oncology Group Report
Authors: Angiolillo Anne L. , Whitlock J. , Chen Z. , Krailo M. , Reaman G. 
Published: June 2005

AbstractBackgroundTo determine the response rate and toxicity to gemcitabine administered as 10 mg/m2/min × 360 min weekly for 3 weeks in children with relapsed acute lymphoblastic leukemia (ALL) or acute myelogenous leukemia (AML). Gemcitabine is a deoxycytidine analog that inhibits DNA synthesis and repair and has a broad spectrum of antitumor activity.ProcedureFrom April 2001 to April 2003, 23 male and 9 female eligible patients were recruited for the Children's Oncology Group (COG) phase II study of Gemcitabine (ADVL0022).ResultsOne of 20 evaluable patients with ALL and none of 10 evaluable patients with AML had complete responses to gemcitabine; there were no partial responses. Grade 3 or 4 hematologic toxicity and liver toxicity were common during therapy. Only one patient was alive 1 year after entry. The estimated 1‐year overall survival probability for the 32 patients was 4% (SE = 3%).ConclusionsGemcitabine at the dose and schedule in this trial was not effective for children with relapsed AML or ALL. Pediatr Blood Cancer © 2005 Wiley‐Liss, Inc.
Conservative surgical approach for thyroid and lymph‐node involvement in papillary thyroid carcinoma of childhood and adolescence
Authors: Massimino Maura , Collini Paola , Leite Silvia Fagundes , Spreafico Filippo , Zucchini Nicola , Ferrari Andrea , Mattavelli Franco , Seregni Ettore , Castellani Maria Rita , Cantù Giulio , Fossati‐Bellani Franca , Rosai Juan 
Published: May 2005

AbstractBackgroundPrior to 1990s, papillary thyroid carcinomas (PTCs) in childhood/adolescence underwent a standard therapeutic approach (total thyroidectomy plus elective neck dissection, followed by radioactive iodine (RAI) ablation), with an overall survival of about 100%. The aim of this study is to outline the possibility of a conservative approach (hemithyroidectomy plus selective neck dissection of clinically involved nodes, followed by TSH‐suppressive therapy) in a selected group of patients.ProcedureFrom 1968 to 2001, 42 pediatric PTC patients were treated at our institution. Absence of distant metastases and a tumor clinically limited to one lobe were both present in 28 cases that underwent a radical (20 cases) or a conservative (8 cases) surgical approach at the thyroid level. At cervical node level, 10 patients underwent a radical and 32 a conservative surgical approach. Clinicopathologic features at onset, type of therapy (radical vs. conservative), post‐operative complications, and outcome till May 31, 2004 were recorded. The impact of the type of surgery on outcome was evaluated.ResultsOverall and progression‐free survival (PFS) curves were found to be independent of the type of therapy (radical vs. conservative) in subgroups of patients matched for extent of disease at onset. Post‐operative complications occurred only with radical surgical approaches.ConclusionsChildhood and adolescence PTCs show a high rate of spread but an excellent outcome independent of the type of therapy (radical vs. conservative). Taking into account the marked responsiveness to TSH‐suppression and the complications after radical therapy, in selected cases, a conservative approach should be considered, reserving more aggressive therapies in case of metastases or relapse. © 2005 Wiley‐Liss, Inc.
Relationship between mechanical properties and exfoliation degree of clay in polyurethane nanocomposites
Authors: Xia Hesheng , Shaw Stephen J , Song Mo 
Published: June 2005

AbstractExfoliated and intercalated polyurethane (PU) nanocomposites were prepared by in situ polymerization of polyol/organoclay mixture, chain extender and diisocyanate. Wide‐angle X‐ray diffraction and transmission electron microscopy confirmed an exfoliated structure for clay C30B and an intercalated structure for C20A in polyol and PU. The realization of exfoliated state for clay C30B in polyol during the mixing stage can provide an effective approach for controlling the exfoliation degrees by adjusting the content of intercalated and exfoliated organoclay C20A and C30B before polymerization. The effect of exfoliation degree on the mechanical and viscoelastic properties of PU was investigated. The addition of organoclay improved the tensile strength, modulus and elongation, but the hysteresis loss ratio and relaxation rate increased, and the relaxation time distribution became broad. The effect of organoclay on PU properties varied with the hard segment content. By increasing the exfoliation degree, the tensile strength and modulus increased, whereas the elongation decreased. The exfoliated PU nanocomposite had a lower relaxation rate and hysteresis loss ratio than the intercalated PU. Copyright © 2005 Society of Chemical Industry
Comparison of protein expression in human deltoideus and vastus lateralis muscles using two‐dimensional gel electrophoresis
Authors: Capitanio Daniele , Viganò Agnese , Ricci Enzo , Cerretelli Paolo , Wait Robin , Gelfi Cecilia 
Published: June 2005

AbstractWe have used two‐dimensional gel electrophoresis (2‐DE) and mass spectrometry (MS) to study the expression of contractile and regulatory proteins in human vastus lateralis and deltoideus muscles, in order to understand protein turnover and isoform switching in muscles with the same fiber‐type composition but different functional properties. We demonstrate a two‐ to six‐fold overexpression of enzymes associated with glycolysis, the tricarboxylic acid cycle, oxidative phosphorylation, and substrate transport in vastus lateralis compared to deltoideus. Expression levels of contractile protein isoforms correlated to the proportion of slow‐twitch fibers in deltoideus compared to vastus lateralis are consistent with the different contractile properties of the two muscles. Two proteins involved in free radical homeostasis were differentially expressed, suggesting a direct relationship between radical scavenging and the muscle function. The application of 2‐DE and MS to studies of muscle physiology thus offers a more comprehensive assessment of the molecular determinants of muscle function than traditional approaches.
Cancer‐related relationship communication in couples coping with early stage breast cancer
Authors: Manne Sharon L. , Ostroff Jamie S. , Norton Tina R. , Fox Kevin , Goldstein Lori , Grana Generosa 
Published: May 2005

AbstractThis longitudinal study examined the association between three types of communication strategies couples may use to handle stressors they experience during and after breast cancer treatment and psychological distress and relationship satisfaction of women with early stage breast cancer and their partners. Mutual constructive communication, mutual avoidance, and demand–withdraw communication strategies as well as psychological distress and marital satisfaction were rated by 147 patients and 127 partners during cancer treatment and 9 months later. Mutual constructive communication was associated with less distress and more relationship satisfaction for both patient and partner. Demand–withdraw communication was associated with higher distress and lower relationship satisfaction for both patient and partner. Mutual avoidance was associated with more distress for patient and partner but was not associated with relationship satisfaction. The negative association between mutual constructive communication and patient distress was stronger for patients with more physical impairment. Patients' perceptions of mutual constructive communication and mutual avoidance were associated with partners' distress, and patients' perceptions of mutual constructive and demand/withdraw communication were associated with partners' marital satisfaction. Clinical implications for couple‐focused communication skills training for cancer patients and their partners are discussed. Copyright © 2005 John Wiley & Sons, Ltd.
Water balance modelling of (Sub‐)Arctic rivers and freshwater supply to the Barents Sea Basin
Authors: Koster Eduard , Dankers Rutger , Linden Sandra van der 
Published: June 2005

AbstractRecently, changes in the freshwater supply by rivers to the Arctic Ocean have attracted a great deal of attention. However, quantitative assessments of changes in the annual and seasonal discharge regime of (Sub‐)Arctic rivers resulting from climate change are still far from accurate. The sensitivity of discharge to potential changes in climate in two river catchments of intermediate size (104–105 km2), the Tana River in northern Fennoscandia and the Usa River in northern Russia, both draining into the Barents Sea Basin, was evaluated using a spatially distributed water balance model. The tentative results show that discharge amounts during peak flow might remain more or less the same or show a slight increase. However, peakflow events are expected to occur about 20 days or more earlier in spring. Concerning annual discharge amounts a strong increase of 25% for the Usa River and even 39% for the Tana River is simulated in conformity with projected increases in precipitation. Obviously, the resulting increases of the annual freshwater influx from the Tana River (from 5.3 to 7.3 km3) and that of the Usa River (from 42 to 52 km3) into the Barents Sea are insignificant in absolute terms. But in relative terms they agree remarkably well with earlier estimates of changes in freshwater inflow by the very large (Sub‐)Arctic rivers. Copyright © 2005 John Wiley & Sons, Ltd.
Dielectric and pyroelectric properties of BaTiO3–PVC composites
Authors: Olszowy M. , Pawlaczyk Cz. , Markiewicz E. , Kułek J. 
Published: June 2005

AbstractDielectric relaxation and pyroelectric response of the barium titanate–poly (vinyl chloride) BaTiO3–PVC composites of 0–3 connectivity and volume fraction of ceramics ϕ from 0.0 to 0.4 were investigated. Dielectric properties of the composites were found to be a combination of those of pure PVC polymer and BaTiO3 ceramics: the value of dielectric permittivity increases with increasing volume fraction of the ceramics but the temperature dependence is determined by two relaxation processes in the polymer (at ∼270 K – the local motion of the small groups in the chain and at ∼350 K – the segmental molecular motion) and in the ceramics (dielectric anomaly at the phase transitions). The value of the pyroelectric coefficient p of poled composites increases with ϕ and depends on the light modulation frequency fm as p ∼ f–nm with n ≈ 0.9 to 1.1, dependently on ϕ. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)