bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of taurine and Astragalus membranaceus on ion currents and their expression in cardiomyocytes after CVB3 infection
Authors: Su Yan‐Gang , Yang Ying‐Zhen , Bao Wei‐Sheng , Liu Gong‐Xin , Ge Jun Bo , Chen Haozhu 
Published: March 2003

AbstractTo investigate the effects of taurine and Astragalus membranaceus (AM) on ion currents and their expression in cardiomyocytes after Coxsackie virus B3 (CVB3) infection, hearts were removed from adult or newborn Sprague‐Dawley rats and digested by collagenase. CVB3 was inoculated to the medium and used for recording current of L‐type voltage‐dependent calcium channel (Ica), Na+ current (INa), outward potassium current (Iout), and inward rectifying potassium current (IKI). An in vivo model of viral myocarditis (VMC) was produced by intraperitoneal injection of CVB3 into BALB/c mice and the hearts were used for examining the expression of L‐type voltage‐dependent Ca2+ channel (LVDCC)α1 subunit and the voltage‐gated potassium channel (Kv). Ica and Iout were increased while IKI decreased after inoculation with CVB3 for 2 h. However, INa did not differ between normal and infected cells. The positive hybridization signals of the LVDCCα1 subunit (antigen) and Kv1.2, Kv2.1, and Kv4.2 were much reinforced after CVB3 infection. Taurine and AM could block the enhancement of Ica, Iout, and reduction of IKI after virus infection. Additionally, taurine and AM attenuated the increased expression level of LVDCCα1 subunit as well as Kv mRNA. Taurine and AM may exert their beneficial effect on VMC through modulating the changes in ion currents and expression. Drug Dev. Res. 58:57–60, 2003. © 2003 Wiley‐Liss, Inc.
Arterial baroreflex function and left ventricular hypertrophy
Authors: Miao Chao‐Yu , Su Ding‐Feng 
Published: March 2003

AbstractIt is well known that the arterial baroreflex (ABR) plays a key role in the regulation of heart rate and stabilization of blood pressure. Currently, it appears that ABR dysfunction is involved in the pathophysiology of cardiovascular disease states. Since the mid‐1990s, a number of studies have been carried out in our laboratory to explore the pathological significance of ABR function in cardiovascular damage. This minireview summarizes our research work on the topic of ABR function and left ventricular hypertrophy (LVH). On the basis of discussion concerning the importance of ABR dysfunction in hypertensive LVH and sinoaortic denervation‐induced LVH, we advance a new strategy for reversal of LVH, that is, restoration of impaired ABR function. We tested this hypothesis in animal models with ABR deficiency. It was found that improvement of impaired ABR function with long‐term treatment of ketanserin or candesartan was accompanied by reversal of LVH. The preliminary results indicate that it is feasible to target ABR for treatment of LVH. Drug Dev. Res. 58:61–64, 2003. © 2003 Wiley‐Liss, Inc.
Pharmacological characteristics of the novel antihypertensive drug, iptakalim hydrochloride, and its molecular mechanisms
Authors: Wang Hai 
Published: March 2003

AbstractThe purpose of the present study was to evaluate the pharmacological characteristics of the novel antihypertensive drug iptakalim hydrochloride and to investigate the molecular mechanisms underlying its antihypertensive action. In conscious hypertensive animals, oral administration of iptakalim hydrochloride at doses of 0.75, 1.5, 3.0, and 6.0 mg/kg in spontaneously hypertensive rats, or at doses of 0.125, 0.25, 0.5, and 1.0 mg/kg in renal hypertensive dogs (two‐kidney with one‐clip), decreased the blood pressure in a dose‐dependent manner. In conscious normotensive dogs blood pressure was not changed when iptakalim hydrochloride was given at doses of 0.8–3.2 mg/kg, but was decreased by 20 mmHg at the high dose of 12.8 mg/kg. Repeated administration of iptakalim hydrochloride decreased blood pressure in a dose‐dependent manner and also reversed the hypertensive cardiovascular remodeling. The molecular mechanisms underlying its antihypertensive action include ATP‐sensitive potassium channel activation and endothelin antagonism. Drug. Dev. Res. 58:65–68, 2003. © 2003 Wiley‐Liss, Inc.
Mechanism of the delayed onset of action after intravenous amiodarone for treatment of ventricular arrhythmias
Authors: Shi Guang‐fei , Xu Wei , Huang Shen‐shen , Cao Qiao‐lan 
Published: March 2003

AbstractThe onset of action of intravenous amiodarone (AM) for treatment of ventricular arrhythmias often occurs after at least several hours' delay. To investigate the mechanism of this delayed action, we gave i.v. AM at an initial loading dose of 2.5 mg/kg or 5.0 mg/kg over 10 min, followed immediately by infusion of 7.5 μg/kg.min or 10 μg/kg.min for 20 h in eight dogs. The concentration of AM and its major metabolite, N‐desethylamiodarone (DA), in plasma and myocardial tissue were determined immediately after the loading dose and at 20 h after infusion, respectively, while electrophysiologic parameters were measured at the same times. The concentration of AM and DA in plasma were also determined serially. The results showed that the concentration of AM or DA in plasma or myocardial tissue rose to the peak level within 5–15 min after the loading dose, the sinus cycle length and AV conduction Wenckebach point measured at this time increased significantly relative to baseline (P<0.05), while the ventricular effective refractory period (VERP) and ventricular exciting time (VET) at this time did not increase significantly (P>0.05). The concentration of AM or DA in plasma declined rapidly during the continuous infusion period and remained at a stable low level until infusion stopped. The concentration of AM or DA in the myocardial tissue at 20 h after continuous infusion was lower than immediately after the loading dose. The sinus cycle length and AV conduction Wenckebach point were shortened close to the baseline level, while the VERP and VET were unchanged 20 h after infusion. The delayed onset of action for treatment of ventricular arrhythmias after i.v. administration of AM cannot be explained by higher concentration of AM or its metabolite in myocardial tissue. The specific mechanism(s) of action of i.v. AM in its control of arrhythmias remain to be determined. Drug Dev. Res. 58:145–148, 2003. © 2003 Wiley‐Liss, Inc.
Enduring maternal influences in a precocial rodent
Authors: Hennessy Michael B. 
Published: March 2003

AbstractThe guinea pig is highly developed at birth and requires little active maternal care. Yet the mother and other social figures markedly influence biobehavioral processes of the offspring. Here, responses of guinea pigs and nonhuman primates to maternal and other social separation procedures are compared, and influences of social partners on endocrine responses and behavior in periadolescent guinea pigs are described. © 2003 Wiley Periodicals, Inc. Dev Psychobiol 42: 225–236, 2003.
Does infant memory expression reflect age at encoding or age at retrieval?
Authors: Hartshorn Kristin , Rovee‐Collier Carolyn 
Published: March 2003

AbstractDo human infants express a memory acquired earlier in ontogeny in a manner appropriate to their age at encoding or their age at the time of retrieval? To answer this, we exploited the fact that retention is highly context dependent at 6 months but not at 8–9 months of age. Six‐month‐olds learned an operant response in one context, and their memory was maintained by monthly reinstatements in the original context. At 8 or 9 months of age, 1 month after the last (or only) reinstatement, infants were tested in either the same or a different context. During testing, infants' retention was no longer context dependent; rather, they responded robustly in both test contexts. These results revealed that infants expressed a memory acquired when they were younger in a manner appropriate to their test age. They were interpreted in terms of changes in the functional significance of context before and after infants self‐locomote. © 2003 Wiley Periodicals, Inc. Dev Psychobiol 42: 283–291, 2003.
Attention during looking and reaching as assessed by heart rate in 7½‐month‐old infants
Authors: O'Sullivan Laura P. , Berthier Neil E. 
Published: March 2003

AbstractAttention mediates the acquisition and encoding of information about the world and is central to motor action. Heart rate deceleration and behavioral inhibition are sensitive indices of the attentional process, but it is unknown whether these indices are valid in the context of overt action. The current study investigated the relationship between visual attention, action, and heart rate during reaching in 7½‐month‐old infants. We found that infants showed prolonged looking and large heart rate decelerations on reaching and looking trials. We conclude that overt action itself does not prevent the autonomic and behavioral changes that are also seen in attention to simple visual displays and that attention is maintained throughout the act of reaching. © 2003 Wiley Periodicals, Inc. Dev Psychobiol 42: 292–300, 2003.
MRF4 gene expression in Xenopus embryos and aneural myofibers
Authors: Ataian Yeganeh , Owens Jesse , Hinterberger Timothy 
Published: March 2003

AbstractVertebrate embryos express the transcription factor MRF4 during skeletal muscle differentiation. Previous studies of MRF4 expression in embryonic Xenopus laevis and its response to muscle denervation in adults have led to the suggestion that its transcription may be activated in myotomes and in multinucleate myofibers through an interaction with the motor nerves. We tested this hypothesis by assaying for MRF4 gene transcripts in early neurula stage embryos, beginning before the appearance of neurons. MRF4 transcripts were detectable by reverse transcriptase‐polymerase chain reaction (RT‐PCR) from at least stage 13–14, well before the differentiation of either nerves or myocytes. We also tested the nerve‐dependence of MRF4 gene expression in multinucleate myofibers by comparing transcript levels between interhyoideus muscles in normal larvae and muscles whose motor innervation had been prevented through surgical removal of the brain before cranial motor axon outgrowth. RT‐PCR demonstrated similar MRF4 transcript levels in the aneural muscles and controls. These results fail to support the hypothesis that MRF4 gene expression is triggered or is significantly up‐regulated in myogenic cells by signals from motor axons. © 2003 Wiley‐Liss, Inc.
Caenorhabditis elegans exoskeleton collagen COL‐19: An adult‐specific marker for collagen modification and assembly, and the analysis of organismal morphology
Authors: Thein Melanie C. , McCormack Gillian , Winter Alan D. , Johnstone Iain L. , Shoemaker Charles B. , Page Antony P. 
Published: March 2003

AbstractThe integral role that collagens play in the morphogenesis of the nematode exoskeleton or cuticle makes them a useful marker in the examination of the collagen synthesizing machinery. In this study, a green fluorescent protein–collagen fusion has been constructed by using the Caenorhabditis elegans adult‐specific, hypodermally synthesized collagen COL‐19. In wild‐type nematodes, this collagen marker localized to the circumferential annular rings and the lateral trilaminar alae of the cuticle. Crosses carried out between a COL‐19::GFP integrated strain and several morphologically mutant strains, including blister, dumpy, long, small, squat, and roller revealed significant COL‐19 disruption that was predominantly strain‐specific and provided a structural basis for the associated phenotypes. Disruption was most notable in the cuticle overlying the lateral seam cell syncytium, and confirmed the presence of two distinct forms of hypodermis, namely the circumferentially contracting lateral seam cells and the laterally contracting ventral–dorsal hypodermis. The effect of a single aberrant collagen being sufficient to mediate widespread collagen disruption was exemplified by the collagen mutant strain dpy‐5 and its disrupted COL‐19::GFP and DPY‐7 collagen expression patterns. Through the disrupted pattern of COL‐19 and DPY‐7 in a thioredoxin mutant, dpy‐11, and through RNA interference of a dual oxidase enzyme and a vesicular transport protein, we also show the efficacy of the COL‐19::GFP strain as a marker for aberrant cuticle collagen synthesis and, thus, for the identification of factors involved in the construction of collagenous extracellular matrices. Developmental Dynamics 226:000–000, 2003. © 2003 Wiley‐Liss, Inc.
Mouse Mix gene is activated early during differentiation of ES and F9 stem cells and induces endoderm in frog embryos
Authors: Mohn Deanna , Chen Siming W. , Dias Dora Campos , Weinstein Daniel C. , Dyer Michael A. , Sahr Kenneth , Ducker Charles E. , Zahradka Elizabeth , Keller Gordon , Zaret Kenneth S. , Gudas Lorraine J. , Baron Margaret H. 
Published: March 2003

AbstractIn frog and zebrafish, the Mix/Bix family of paired type homeodomain proteins play key roles in specification and differentiation of mesendoderm. However, in mouse, only a single Mix gene (mMix) has been identified to date and its function is unknown. We have analyzed the expression of mouse Mix RNA and protein in embryos, embryoid bodies formed from embryonic stem cells and F9 teratocarcinoma cells, as well as several differentiated cell types. Expression in embryoid bodies in culture mirrors that in embryos, where Mix is transcribed transiently in primitive (visceral) endoderm (VE) and in nascent mesoderm. In F9 cells induced by retinoic acid to differentiate to VE, mMix is coordinately expressed with three other endodermal transcription factors, well before AFP, and its protein product is localized to the nucleus. In a subpopulation of nascent mesodermal cells from embryonic stem cell embryoid bodies, mMix is coexpressed with Brachyury. Intriguingly, mMix mRNA is detected in a population (T+Flk1+) of cells which may contain hemangioblasts, before the onset of hematopoiesis and activation of hematopoietic markers. In vitro and in vivo, mMix expression in nascent mesoderm is rapidly down‐regulated and becomes undetectable in differentiated cell types. In the region of the developing gut, mMix expression is confined to the mesoderm of mid‐ and hindgut but is absent from definitive endoderm. Injection of mouse mMix RNA into early frog embryos results in axial truncation of developing tadpoles and, in animal cap assays, mMix alone is sufficient to activate expression of several endodermal (but not mesodermal) markers. Although these observations do not exclude a possible cell‐autonomous function for mMix in mesendodermal progenitor cells, they do suggest an additional, non–cell autonomous role in nascent mesoderm in the formation and/or patterning of adjacent definitive endoderm. Developmental Dynamics 226:000–000, 2003. © 2003 Wiley‐Liss, Inc.
Do eating disorders co‐occur with personality disorders? Comparison groups matter
Authors: Grilo Carlos M. , Sanislow Charles A. , Skodol Andrew E. , Gunderson John G. , Stout Robert L. , Shea M. Tracie , Zanarini Mary C. , Bender Donna S. , Morey Leslie C. , Dyck Ingrid R. , McGlashan Thomas H. 
Published: March 2003

AbstractObjectiveTo assess and compare lifetime rates of occurrence of eating disorders (ED) with four Axis II personality disorders (PD) and with major depressive disorder (MDD) without PD. The eating disorders met criteria outlined in the 4th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM‐IV).MethodSix hundred sixty‐eight patients recruited for the Collaborative Longitudinal Personality Disorders Study (CLPS) were reliably assessed with the Structured Clinical Interview for DSM‐IV Axis I Disorders and the Diagnostic Interview for DSM‐IV Personality Disorders. The distribution of ED diagnoses was compared among four PD study groups (schizotypal, borderline, avoidant, obsessive‐compulsive) and a fifth study group with MDD without any PD.ResultsThe distribution of lifetime diagnoses of anorexia nervosa (N = 40), bulimia nervosa (N = 56), and eating disorder not otherwise specified (N = 118) did not differ significantly across the five study groups, between the MDD group versus all PD groups, and among the four PD study groups.ConclusionsED diagnoses did not differentially co‐occur significantly across common Axis I and II disorders. The pattern of ED lifetime co‐occurrence rates demonstrates the powerful influence of base rates and highlights that declarations of comorbidity demand significant variations from base‐rate patterns. © 2003 by Wiley Periodicals, Inc. Int J Eat Disord 33: 155–164, 2003.
Vav1 transduces TCR signals required for LFA‐1 function and cell polarization at the immunological synapse
Authors: Ardouin Laurence , Bracke Madelon , Mathiot Anne , Pagakis Stamatis N. , Norton Trisha , Hogg Nancy , Tybulewicz Victor L. J. 
Published: March 2003

AbstractActivation of T lineage cells through the TCR by peptide–MHC complexes on APC is critically dependent on rearrangement of the actin cytoskeleton. Vav1 is a guanine nucleotide exchange factor for members of the Rho/Rac family of GTPases which is activated following TCR stimulation, suggesting that it may transduce TCR signals to the activation of some or all actin‐controlled processes. Weshow that Vav1‐deficient double‐positive thymocytes are less efficient at forming conjugates with APC presenting agonist peptide than wild‐type cells are. Furthermore we demonstrate that Vav1 is required for TCR‐induced activation of the integrin LFA‐1, which is likely to explain the defect in conjugate formation. However, once Vav1‐deficient cells form a conjugate, the assembly of proteins into an immunological synapse at the conjugate interface is normal. In contrast, thymocyte polarization is defective in the absence of Vav1, as judged by the relocalization of the microtubule‐organizing center. These data demonstrate that Vav1 transduces signals to only a subset of cytoskeleton‐dependent events at the immunological synapse.
Bis(sulfonyl)methyl Insertion into Alkenyl versus Phenyl Carbon−Hydrogen Bonds in the Reaction of Bis(sulfonyl)iodonium Ylides with Highly Phenylated Ethylenes
Authors: Adam Waldemar , Gogonas Efstathios P. , Hadjiarapoglou Lazaros P. 
Published: March 2003

AbstractThe reaction of bis(sulfonyl)iodonium ylides α−γ with triphenylethylene (2a) and tetraphenylethylene (2b) affords insertion products into the alkenyl and phenyl carbon−hydrogen bonds of the substrate. A mechanistically perplexing feature is the diversity displayed in the reactivity pattern of the bis(sulfonyl)iodonium ylides in their reaction with the phenylated alkenes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Snm as a Photolabile Protecting Group for the Cysteinyl Radical − Direct Evidence from Time‐Resolved IR and UV/Vis Spectroscopies
Authors: Kolano Christoph , Sander Wolfram 
Published: March 2003

AbstractThe cysteinyl radical and the methyl(phenyl)thiocarbamic acid radical have been generated by laser flash photolysis (266 nm) of BOC−Cys(Snm)−OH in acetonitrile and characterized both by time‐resolved (IR and UV/Vis) and standard spectroscopic methods (UV, IR, and NMR). The mode of action of the Snm unit [methyl(phenyl)thiocarbamic acid] is similar to the so‐called “caging” technique. Cleavage of the disulfide bridge by irradiation is possible in acceptable quantum yields. Time‐resolved IR (TR‐IR) spectroscopic experiments using the step‐scan FTIR technique allowed the detection of the methyl(phenyl)thiocarbamic acid radical (νC=O = 1607.7 and 1579.3 cm−1), which has a lifetime of about 3 µs. Because of the weak absorptions in the IR spectrum and the tendency for fast recombination to BOC‐protected cystine, the cysteinyl radical cannot be monitored by TR‐IR spectroscopy. Time‐resolved UV/Vis spectroscopy revealed the formation of both of these radicals and permitted the determination of the decay rates of the methyl(phenyl)thiocarbamic acid radical in the presence of several quenchers. NMR spectroscopic studies of the photolysis of BOC−Cys(Snm)−OH allowed us to identify N‐methylaniline, carbonyl sulfide, and BOC‐protected cystine as the major products. This study clearly demonstrates that the thiol protection group Snm is a suitable photolabile protecting group. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Generalization of positive attitude as a function of subgroup and superordinate group identifications in intergroup contact
Authors: González Roberto , Brown Rupert 
Published: March 2003

AbstractThe role of category salience in mediating the effects of intergroup contact was examined. One theoretical model proposes that some psychological salience of subgroup categories is necessary to facilitate the generalization of attitude change beyond the immediate contact situation. Another argues that a re‐categorization of the subgroups into a new superordinate category is more beneficial, whilst a third suggests that de‐categorizing the situation entirely is optimal. An alternative view, which combines the first two models, proposes a Dual Identity strategy (simultaneous high superordinate and high subgroup categorization) as an important mediator of the relationship between contact variables and intergroup attitudes. In the study, participants (N = 114) undertook a cooperative intergroup task under four conditions of category salience: ‘subgroup’, ‘superordinate’, ‘superordinate and subgroup’, and ‘no group salience’. Evaluative ratings and symbolic reward allocations both for the groups encountered (contact) and those outside the situation (generalization) provided measures of intergroup bias. Bias within the contact situation was mainly eliminated in all conditions. However, on the more generalized bias measures, only the ‘superordinate’ and ‘superordinate and subgroup’ (Dual Identity strategy) conditions maintained this low level; in the other two conditions intergroup bias resurfaced. A combination of the first two models is proposed. Copyright © 2002 John Wiley & Sons, Ltd.
Mechanism of action of quaternary diamino quenchers in capillary zone electrophoresis
Authors: Verzola Barbara , Sebastiano Roberto , Righetti Pier Giorgio , Gelfi Cecilia , Lapadula Marta , Citterio Attilio 
Published: March 2003

AbstractThe synthesis of two novel amino compounds, able to quench and reverse the electroosmotic low (EOF) in capillary electrophoresis is here reported. These chemicals are derivatives of two previously described quaternarized piperazines, 1‐(4‐iodobutyl)‐1,4‐dimethylpiperazin‐1‐ium iodide (M1C4I) and 1‐(4‐iodobutyl)4‐aza‐1‐azoniabicyclo[2.2.2] octane iodide (M7C4I), believed to bind covalently to the silica surface via alkylation of ionized silanols through their terminal, reactive iodine. The novel compounds, although unable to form a covalent bond, due to lack of the o‐butyl iodine, are found to be very efficient in suppressing protein interaction with the wall and reversing the EOF. On the basis of their behavior in solution, the minimal structural motifs for strong binding of amino compounds to the silica wall have been derived and are thought to be: (i) the presence of two quaternary nitrogens in the molecule; (ii) a correct distance between said charged nitrogens, represented by a butyl chain (C4); (iii) an hydrophobic “decoration” of the molecules, consisting on a high CH2/N ratio (in the present case 8:1).