bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phospholipase A2 activity of β‐bungarotoxin is essential for induction of cytotoxicity on cerebellar granule neurons
Authors: Chen Yu‐Jen 
Published: April 2005

AbstractThe aim of this study was to investigate the mechanism of the cytotoxic effect of β‐bungarotoxin (β‐BuTX), a presynaptic neurotoxin, on rat cerebellar granule neurons (CGNs). The maturation of CGNs is characterized by the prominent dense neurite networks that became fragmented after treatment with β‐BuTX, and this cytotoxic effect of β‐BuTX on CGNs was in a dose‐ and time‐dependant manner. The cytotoxic effect of β‐BuTX was found to be more potent than other toxins, such as α‐BuTX, cardiotoxin, melittin, and Naja naja atra venom phospholipase A2. Meanwhile, undifferentiated neuroblastoma neuronal cell lines, IMR‐32 and SK‐N‐MC, and astrocytes were found to be resistant to β‐BuTX. These results indicated that only the mature CGNs were sensitive to β‐BuTX insults. None of the following chemicals: antioxidants, K+‐channel activator, K+‐channel antagonists, intracellular Ca2+ chelator, Ca2+‐channel blockers, NMDA receptor antagonists, and nitric oxide synthase inhibitor tested, were able to reduce β‐BuTX‐induced cytotoxicity. However, secretory type phospholipase A2 inhibitors (glycyrrhizin and aristolochic acid) and a free radical scavenger (5,5‐dimethyl pyrroline N‐oxide, DMPO) could attenuate not only β‐BuTX‐induced cytotoxicity but also ROS production and caspase‐3 activation. These data suggest that phospholipase A2 activity of β‐BuTX may be responsible for free radical generation and caspase‐3 activation that accounts for the observed cytotoxic effect. It is proposed that the CGNs can be a useful tool for studying interactions of the molecules on neuronal plasma membrane with β‐BuTX that mediates the specific cytotoxicity. © 2005 Wiley Periodicals, Inc. J Neurobiol, 2005
Enhanced gene expression in the forebrain of hatchling and juvenile male zebra finches
Authors: Wade Juli , Tang Yu Ping , Peabody Camilla , Tempelman Robert J. 
Published: April 2005

AbstractThe molecular mechanisms regulating sexual differentiation of the brain are largely unknown, although progress is being made, particularly in some mammalian systems. To uncover more of the key factors, a screen was conducted for genes involved in sexually dimorphic development of the neural song system in zebra finches. cDNA microarrays were initially used to compare gene expression in the telencephalons of hatchling and juvenile males and females. Then, real‐time quantitative polymerase chain reaction (PCR) was employed to confirm sex differences, and the brain regions expressing the cDNAs of interest were localized using in situ hybridization. Several genes, including those likely to encode two ribosomal proteins (RPL17 and RPL37), SCAMP1, ZNF216, and a COBW‐domain containing protein, showed enhanced expression in the telencephalon of males compared to females. In several cases, expression in the song control nuclei specifically was detected only in males. Interestingly, the sequences of some of these cDNAs shared substantial homology with regions of the chicken Z chromosome (male birds are ZZ, females ZW). Thus, we have identified genes likely to be involved in masculinization of the structure and/or function of the song circuit, some of which could be initial triggers for the sexual differentiation process. © 2005 Wiley Periodicals, Inc. J Neurobiol, 2005
Synthesis of telechelic oligomers by atom transfer radical polymerization: A study of acrylate monomers
Authors: Otazaghine Belkacem , Boyer Cyrille , Robin Jean‐Jacques , Boutevin Bernard 
Published: April 2005

AbstractDifferent acrylate oligomers were synthesized by atom transfer radical polymerization in the presence of a transfer agent and CuBr/1,1,4,7,10,10‐hexamethyltriethylenetetramine. The functionality in bromine was determined by 1H NMR. These oligomers were coupled in the presence of Cu(0) and the ligand 2,2′‐bipyridine. The coupling yield was determined by size exclusion chromatography and NMR analysis and depended on the nature of the monomer and not on the molecular weight. In other words, the preliminary functionalization of the brominated chain end with styrene increased the coupling yield. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2377‐2394, 2005
Association of polybutadiene living anions in cyclohexane
Authors: Matsuda Yasuhiro , Sato Takahiro , Oishi Yohei , Watanabe Hiroshi 
Published: April 2005

AbstractSimultaneous measurements of static and dynamic light scattering were made for cyclohexane solutions of living polybutadiene (PB) anion to characterize PB components existing in the solutions. There were two relaxation modes in the relaxation time spectra obtained by dynamic light scattering. The static structure factor and hydrodynamic radius of the major fast relaxation component obtained are explained by the unimer‐tetramer equilibrium model. The same model is also consistent with the data of the propagation reaction rate of the PB living anion in cyclohexane. The slow relaxation component is only minor (less than 1 wt %), but has a large radius of gyration of ca. 200 nm, and is assigned to aggregates consisting of a huge number of PB living anion chains. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1401–1407, 2005
Structure and properties of rubber/organic montmorillonite nanocomposites prepared by in situ anionic intercalation polymerization
Authors: Liao Mingyi , Shan Wei , Zhu Jiedong , Li Yang , Xu Hongde 
Published: April 2005

AbstractPolybutadiene (PB), polyisoprene (PI), and styrene–butadiene rubber/organic montmorillonite (OMMT) nanocomposites (NCs) were prepared by in situ anionic intercalation polymerization. The intercalation structure, chemical constitution, and morphology of the rubber/OMMT NCs were characterized with X‐ray diffraction, H NMR spectroscopy, and transmission electron microscopy; the thermal and dynamic mechanical properties of the rubber/OMMT NCs were characterized with differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis. The mechanical properties of PB/OMMT NC were also tested. The results showed that a certain extent of exfoliated rubber/OMMT could be prepared by anionic in situ intercalation polymerization. The incorporation of OMMT obviously changed the microstructure content of PB and PI: the concentrations of the 1,2‐unit, 3,4‐unit, and trans‐1,4‐unit increased dramatically with an increasing concentration of OMMT, and the concentration of the cis‐1,4 structure decreased. The addition of OMMT‐DK1B and OMMT‐DK4 had little effect on the molecular weight and molecular weight distribution, but the addition of OMMT‐DK1 reduced the molecular weight of rubber, and the molecular weight distribution became broad. The glass‐transition temperature, weight‐loss temperature, storage modulus, and loss modulus of the NCs evidently increased, but tan δ decreased. OMMT apparently enhanced the rubber matrix; for example, the breaking strength and hardness of PB/OMMT NC crosslinked rubber increased greatly, but the tear strength and permanent deformation did not change much. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1344–1353, 2005
2‐5A induces a conformational change in the ankyrin‐repeat domain of RNase L
Authors: Nakanishi Masayuki , Goto Yoshikuni , Kitade Yukio 
Published: April 2005

AbstractRNase L is responsible for the 2‐5A host defense system, an RNA degradation pathway present in cells of higher vertebrates that functions in both the antiviral and anticellular activities of interferon. The activity of RNase L is tightly regulated and is exerted only in the presence of 2‐5A. The postulated mechanism of its regulation is as follows: the N‐terminal half ankyrin‐repeat domain masks the C‐terminal half nuclease domain in the absence of 2‐5A. On binding 2‐5A at the ankyrin‐repeat domain, RNase L forms a homodimer and removes the ankyrin‐repeat domain from the nuclease domain to become the active form. A conformational change in the ankyrin‐repeat domain is a key step in this hypothetical mechanism, but there is as yet no evidence for such a change. To clarify the events induced by 2‐5A binding, we established procedures for expression and purification of the ankyrin‐repeat domain of human RNase L. Fluorescence spectra of the protein showed clear difference in the presence and absence of 2‐5A. The alterations in the spectra supported conformational changes of the protein. Time‐resolved anisotropy measurements indicated that 2‐5A binding led to a significant decrease in the rotational radius of the protein. In addition, 2‐5A provided the domain with resistance to protease digestion as a result of a conformational change. These results indicated that the ankyrin‐repeat domain of RNase L constricts its structure by binding of 2‐5A. This observation suggests a revised model of the 2‐5A‐induced activation of RNase L. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Universal biases in protein composition of model prokaryotes
Authors: Pascal Géraldine , Médigue Claudine , Danchin Antoine 
Published: April 2005

AbstractThe levels of cellular organization in living organisms are the results of a variety of selection pressures. We have investigated here the final outcome of this integrated selective process in proteins of the best known microbial models Escherichia coli, Bacillus subtilis, and Methanococcus jannaschii, supposed to have undergone separate evolution for more than 1 billion years. Using multivariate analysis methods, including correspondence analysis, we studied the overall amino acid composition of all proteins making a proteome. Starting from and further developing previous results that had pointed out some general forces driving the amino acid composition of the proteomes of these model bacteria, we explored the correlations existing between the structure and functions of the proteins forming a proteome and their amino acid composition. The electric charge of amino acids measured against hydrophobicity creates a highly homogeneous cluster, made exclusively of proteins that are core components of the cytoplasmic membrane of the cell (integral inner membrane proteins). A second bias is imposed by the G+C content of the genome, indicating that protein functions are so robust with respect to amino acid changes that they can accommodate a large shift in the nucleotide content of the genome. A remarkable role of aromatic amino acids was uncovered. Expressed orphan proteins are enriched in these residues, suggesting that they might participate in a process of gain of function during evolution. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Risk assessment of dietary exposure to pesticides using a Bayesian method
Authors: Paulo M João , van der Voet Hilko , Jansen Michiel JW , ter Braak Cajo JF , van Klaveren Jacob D 
Published: April 2005

AbstractRisk assessment of pesticides can be a statistically difficult problem because pesticides occur only occasionally, but they may occur on multiple components in the diet. A Bayesian statistical model is presented which incorporates multivariate modelling of food consumption and modelling of pesticide measurements which are for a large part below a measurement threshold. It is shown that Bayesian modelling is feasible for a limited number of food components, and that in a data‐rich situation the model compares well with an empirical Monte Carlo modelling. Copyright © 2005 Society of Chemical Industry
Outcome of fetal renal pelvic dilatation diagnosed during the third trimester
Authors: Wollenberg A. , Neuhaus T. J. , Willi U. V. , Wisser J. 
Published: April 2005

AbstractObjectivesThe aim of this study was to evaluate renal function and the need for postnatal treatment—antibiotic therapy and/or surgery—in relation to the grade of fetal renal pelvic dilatation (RPD) found on third‐trimester ultrasound examination.MethodsThe retrospective study included 78 children, born between 1995 and 2000, with 115 dilated fetal renal pelvic units. The children were allocated to three groups based on pelvic anteroposterior diameter (APD) detected on third‐trimester ultrasound: APDs of 7–9.9 mm, 10–14.9 mm and ≥ 15 mm were classified as mild dilatation, moderate hydronephrosis and severe hydronephrosis, respectively. Renal function was assessed by scintigraphy.ResultsNone of the 20 children with mild dilatation experienced a urinary tract infection (UTI) or underwent surgery; two had associated renal or urinary tract abnormalities. In contrast, five out of 22 (23%) children with moderate hydronephrosis and 23 out of 36 (64%) with severe hydronephrosis had either a UTI or required surgery (P < 0.001); associated abnormalities were also more common (6 out of 22 and 15 out of 36, respectively). There was no significant correlation between the grade of antenatal RPD and postnatal ipsilateral renal function.ConclusionsThe need for postnatal treatment increased significantly with the grade of antenatal RPD. Children with antenatal mild dilatation were discharged early from follow‐up whereas those with moderate and severe fetal hydronephrosis needed close follow‐up by a multidisciplinary team. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
Two‐dimensional vs. two‐ plus four‐dimensional ultrasound in pregnancy and the effect on maternal emotional status: a randomized study
Authors: Rustico M. A. , Mastromatteo C. , Grigio M. , Maggioni C. , Gregori D. , Nicolini U. 
Published: April 2005

AbstractObjectiveTo assess whether the addition of four‐dimensional (4D) ultrasound to a conventional two‐dimensional (2D) scan in the second/third trimester of pregnancy facilitates maternal recognition of specific fetal structures and movements and causes an emotional impact, as subjectively perceived by the woman.MethodsFifty‐two women were randomly assigned to 2D ultrasound only (Group 1), while 48 women underwent 2D plus 4D ultrasound (Group 2). All the women completed two questionnaires. One questionnaire listed the fetal structures and movements that the women had recognized during the 2D scan or, for those women who also underwent a 4D scan, during the combination of the two; the other questionnaire required the women to score on an analog scale whether they had seen all the fetal parts and movements that they wished to see, whether they were satisfied with the scan, and if the scan had changed for the better their perception of the fetus. A subgroup of 46 women completed the Maternal Antenatal Attachment Scale (MAAS) designed to measure antenatal emotional attachment.ResultsSimilar percentages of women in the two groups visualized fetal structures and movements, but facial expressions and hand‐to‐mouth movements were twice as likely to be seen with 4D ultrasound, although this difference did not reach statistical significance. The percentage of women who reported that they had seen all the fetal parts and movements that they wished to see, and of those who were satisfied overall with the scan, were similar in the two groups. There was no difference in the percentage of women who felt that the scan had changed for the better their perception of the fetus. Although the MAAS scores were similar in the two groups, there were more women with positive quality, intensity and global attachment among those who had undergone a 4D scan. Women who had seen all the fetal parts and movements they wished to see (whether with 2D or 2D plus 4D) answered more frequently that the scan had changed for the better their perception of the fetus.ConclusionThis randomized study indicates that the addition of 4D ultrasound does not change significantly the perception that women have of their baby nor their antenatal emotional attachment compared with conventional 2D ultrasound. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
Differential MMP‐2 activity of ligament cells under mechanical stretch injury: An in vitro study on human ACL and MCL fibroblasts
Authors: Zhou David , Lee Hwa Sung , Villarreal Francisco , Teng Annabelle , Lu Erick , Reynolds Shirley , Qin Chuan , Smith Joel , Sung K. L. Paul 
Published: April 2005

AbstractRecent studies have revealed that following injuries, ligament tissues such as anterior cruciate ligaments (ACL), release large amounts of matrix metalloproteinases (MMPs). These enzymes have a devastating effect on the healing process of the injured ligaments. Although these enzymes are produced following ligament injuries, because of different healing capacities seen between the medial collateral ligament (MCL) and ACL, we were curious to find if the MMP activity was expressed and modulated differently in these tissues. For this purpose ACL and MCL fibroblasts were seeded on equi‐biaxial stretch chambers and were stretched in different levels. The stretched cells were assayed using Zymography, Western Blot and global MMP activity assays. The results showed that within 72 h after injurious stretch, production of 72 kD pro‐MMP‐2 increased in both ACL and MCL. However, the ACL fibroblasts generated significantly more pro‐MMP‐2 than the MCL fibroblasts. Furthermore we found in ACL pro‐MMP‐2 was converted more into active form. With 4‐aminophenyl mercuric acetate (APMA) treatment, large amounts of pro‐MMP‐2 were converted into active form in both. This indicates that there is no significant difference between ACL and MCL fibroblasts in post‐translational modification of MMP‐2. The fluorescent MMP activity assays revealed that the MMP family activities were higher in the injured ACL fibroblasts than the MCL. Since the MMPs are critically involved in extracellular matrix (ECM) turnover, these findings may explain one of the reasons why the injured ACL hardly repairs. The higher levels of active MMP‐2 seen in the ACL injuries may disrupt the delicate balance of ECM remodeling process. These results suggest that the generation and modulation of MMP‐2 may be directly involved in the different responses seen in ACL and MCL injuries. © 2005 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Receptor mechanisms of antipsychotic drug atypicality
Authors: Reynolds GP 
Published: April 2005

SummaryRecent advances in antipsychotic treatment of schizophrenia have offered several new compounds which avoid many of the limitations of the classical antipsychotics. These so-called ‘atypical’ antipsychotics have fewer extrapyramidal side effects, greater efficacy against negative symptoms and greater efficacy in otherwise treatment-resistant patients. However, the mechanism of action of these atypical antipsychotics is still unclear. The several receptors currently implicated in the pharmacological profile of these atypical antipsychotics include subtypes of those for dopamine, serotonin, noradrenaline, and acetylcholine among others. The current hypotheses for possible mechanisms of action of atypical antipsychotics are discussed along with the experimental correlates of antipsychotic efficacy in animal models.
Sexual dysfunction: The unspoken side effect of antipsychotics
Authors: Peuskens J , Sienaert P , De Hert M 
Published: April 2005

SummaryAlthough only a few studies have been performed and published data are scarce, it seems clear that sexual dysfunctions frequently occur during treatment with antipsychotics in 30–60% of patients with schizophrenia. It is important to evaluate the occurrence of sexual dysfunction and its relation to antipsychotic treatment.
Risk factors for augmentation of the flow of blood to the lungs in pulmonary atresia with intact ventricular septum after radiofrequency valvotomy
Authors: Alwi Mazeni , Kandavello Geetha , Choo Kok-Kuan , Aziz Bilkis A. , Samion Hasri , Latiff Haifa A. 
Published: April 2005

Some patients with pulmonary atresia with an intact ventricular septum, mild to moderate right ventricular hypoplasia, and a patent infundibulum remain duct dependent on the flow of blood through the arterial duct despite adequate relief of the obstruction within the right ventricular outflow tract.The objective of our study was to review the risk factors for stenting of the patent arterial duct, or construction of a Blalock-Taussig shunt, in the patients with pulmonary atresia and an intact ventricular septum who remain duct-dependent following radiofrequency valvotomy and dilation of the imperforate pulmonary valve.We reviewed the data from 53 patients seen between November 1995 and December 2001. Of the 47 patients who survived, 6 required stenting of the patent arterial duct, while 4 needed construction of a modified Blalock-Taussig shunt to augment the flow of blood to the lungs at a mean of 7 plus or minus 5.7 days following the initial intervention. The remaining 37 patients required no additional procedures. We compared the findings in these two groups.The mean diameter of the tricuspid valve in the patients requiring early reintervention was 8.5 plus or minus 3.7 millimetres, giving a Z-score of −1.1 plus or minus 1.47, whilst those in the group without early reintervention had values of 10.7 plus or minus 2.2 millimetres, giving a Z-score of −0.58 plus or minus 1.18 (p equal to 0.003). No statistically significant differences were found in right ventricular morphology, McGoon ratio, or residual obstruction across the right ventricular outflow tract after decompression of the right ventricle.The diameter of the tricuspid valve, therefore, appears to be the only factor predicting the need for augmentation of flow of blood to the lungs. As just over one-fifth of our survivors required such augmentation, we hypothesize that stenting of the patent arterial duct may be performed as an integral part of primary transcatheter therapy in patients with pulmonary atresia and intact ventricular septum who have moderate right ventricular hypoplasia and a small tricuspid valve.