bluuebunny/crossref_metadata_2025_split huggingface dataset:
Persistence of nicotinic agonist RJR 2403‐induced working memory improvement in rats
Authors: Levin Edward D. , Christopher N. Channelle 
Published: August 2002

AbstractNicotinic systems are involved in the neural basis of memory function and nicotinic agonists have shown promise for the treatment of cognitive dysfunction. Both acute and chronic nicotinic treatment has been shown to improve memory performance. There is some evidence for the persistence of nicotine‐induced memory improvements lasting longer than the pharmacokinetic presence of nicotine. Novel nicotinic agonists may produce the beneficial effects of nicotine on cognitive function with fewer side effects. RJR 2403 (metanicotine or (E)‐N‐methyl‐4‐(3‐pyridinyl)‐3‐butene‐1‐amine) a preferential α4β2 nicotinic agonist has been shown in previous studies to improve memory function. The present study examined the persistence of oral RJR 2403 on memory performance in young adult Sprague‐Dawley rats (3–5 months old) 30 min, 1 h, and 6 h post‐administration (PO). In the first experiment, the typical inverted U‐shaped dose response curve for cognitive enhancing drugs was seen with RJR 2403 30 min after administration. The lower dose of 1 mg/kg (3.6 μmol/kg), but not higher doses of 3 or 10 mg/kg (10.8 or 36 μmol/kg), of RJR 2403 significantly (P < 0.05) improved working memory on the radial‐arm maze relative to placebo‐treated controls. In the second experiment, young adult rats were administered RJR 2403 (0, 0.3, or 1.0 mg/kg) and tested 1 h or 6 h following administration in separate treatment groups. The 0.3 mg/kg RJR 2403 dose (1.08 μmol/kg) caused a significant (P < 0.05) memory improvement 1 h after oral administration. Interestingly, both the 0.3 and 1.0 mg/kg RJR 2403 doses (1.08 and 3.6 μmol/kg) significantly (P < 0.05) improved memory six hours after administration. These data demonstrate the efficacy of oral RJR 2403 in improving cognitive performance and the long duration of action of RJR 2403 in young adult rats. In contrast, no significant memory improvement was seen in aged rats aged (24–26 months old) after RJR 2403 administration. The inability of RJR 2403 to enhanced cognitive functions in aged rats might be related to the decrease in the number of α4β2 nicotinic receptors, which occurs with age. A similar decreased responsiveness in aged rats has been seen with nicotine. The persistence of action of RJR 2403 provides additional promise for its potential as a treatment for cognitive dysfunction. However, the decreased responsiveness in subjects in populations with decreased nicotinic receptor number may limit the effectiveness of nicotinic therapies. Drug Dev. Res. 55:97–103, 2002. © 2002 Wiley‐Liss, Inc.
Stretch‐activated channels in the heart: Their role in arrhythmias and potential as antiarrhythmic drug targets
Authors: Saint David A. 
Published: August 2002

AbstractStretching the myocardium can have profound effects on its electrical activity, a process called mechanoelectric feedback. Mechanoelectric feedback can be powerful enough to trigger arrhythmias, and it is likely to be the underlying trigger for some clinically intractable arrhythmias. It seems likely that the response to stretch involves at least two types of mechanosensitive ion channels, a nonspecific cation channel, and a potassium channel (or channels). Currents carried by nonspecific cation channels have been well characterised in cardiac tissue, although the gene has not yet been identified. Very recently, a peptide toxin isolated from Grammastola spatulata has been shown to block this channel and to be an effective antiarrhythmic agent against stretch‐induced atrial arrhythmias. Stretch‐activated potassium currents and single channels have also been recorded in cardiac cells; in the case of these channels, the genes coding for them have recently been cloned and shown to be members of a new potassium channel gene family, the “tandem pore” channels. Although some nonspecific activators and blockers of these channels exist, there is at present no specific blocker, which limits investigation of the role of these channels in arrhythmogenesis. The potential for the development of blockers of both types of stretch‐activated channels as therapeutic agents is discussed. Drug Dev. Res. 55:53–58, 2002. © 2002 Wiley‐Liss, Inc.
Cardiovascular responses to pacifier experience and feeding in newborn infants
Authors: Cohen Morris , Brown David R. , Myers Michael M. 
Published: August 2002

AbstractThis study examined the effects of sucking on a pacifier immediately before feeding on cardiovascular responses to feeding. Twenty‐eight bottle‐feeding infants were studied at 12 to 40 hr of age. Blood pressure and heart rate measurements were made during three periods: Period 1—while infants rested in their cribs before a regularly scheduled feeding, Period 2—while being held by the feeder immediately before feeding, and Period 3—during the first 3 to 5 min of feeding. Half of the infants were given a pacifier during Period 2. Blood pressures and heart rates increased across the periods; however, increases in systolic blood pressure during feeding were reduced for the group of infants given a pacifier prior to feeding. We suggest that cardiovascular responses to feeding in infants are comprised of multiple elements. Most of the systolic blood pressure responses to feeding are elicited by sucking whereas the heart rate response is dependent on both sucking and nutrient intake. © 2001 John Wiley & Sons, Inc. Dev Psychobiol 39: 34–39, 2001
Wherefore heart thou? Embryonic origins of cardiogenic mesoderm
Authors: Yutzey Katherine E. , Kirby Margaret L. 
Published: August 2002

AbstractThe developing heart in avian embryos has been examined extensively over the past several decades using classic embryologic and, more recently, molecular and genetic approaches. Still, conflicting reports arise as to the location and regulation of early heart progenitors in the embryo. In addition, a new source of cardiomyocytes has been identified recently that contributes to the outflow tract after the heart initially forms. The focus of this review is the examination of the tissue interactions, signaling molecules, and gene regulatory mechanisms that, together, control heart formation from primary and secondary heart forming fields of the embryo. Early studies of the induction and regulation of the secondary heart field indicate that at least some of the events of primary cardiomyogenesis are recapitulated when the conotruncal myocardium is recruited into the heart. The consideration of classic embryologic studies of the heart forming fields in terms of modern molecular and genetic tools provides reinforcing evidence for the location of cardiac progenitors in the embryo. The accurate definition of early cardiac regulatory events provides a necessary foundation for the generation of new therapeutic sources of cardiomyocytes. © 2002 Wiley‐Liss, Inc.
Taste bud development in the zebrafish, Danio rerio
Authors: Hansen Anne , Reutter Klaus , Zeiske Eckart 
Published: August 2002

AbstractTaste buds are chemosensory endorgans consisting of modified epithelial cells. Fish and other vertebrates use their taste bud cells to sample potential food, either selecting or rejecting substances according to their edibility. The adult gustatory system in fish has been studied thoroughly, including regeneration experiments. Taste buds occur in the epithelia of the lips, the mouth cavity, the oropharyngeal cavity, and also in the skin of the barbels, the head, and sometimes even all over the body surface. Despite its importance for feeding, little is known about the ontogeny of the fish taste system. We examined the development of taste buds in the zebrafish on the light microscopical and the scanning and transmission electron microscopical levels. Taste buds develop later than the olfactory organ and the solitary chemosensory cells, two other chemosensory systems in aquatic vertebrates. The first few taste bud primordia are visible within the epithelia of lips and gill arches 3 to 4 days after fertilization, and the first few taste buds with open receptor areas appear on the lips and simultaneously on the gill arches 4–5 days after fertilization, which coincides with the onset of feeding. Taste buds in the mouth cavity, on the head, and on the barbels are formed later in development. As seen in other fish, zebrafish taste buds contain elongate dark and light cells, termed according to their electron density. Dark cells with a cell apex of many short microvilli appear first, followed by the light cells with one large microvillus. In addition, the zebrafish has a third fusiform cell type, which appears last. This cell type is low in electron density and has a brush‐like apical ending with several small microvilli. This cell type has not been described previously. Furthermore, in zebrafish, the ontogenetic processes of taste bud formation differ from regenerative processes described in the literature. © 2002 Wiley‐Liss, Inc.
Postembryonic expression of Caenorhabditis elegans mab‐21 and its requirement in sensory ray differentiation
Authors: Ho Siu H. , So Gloria M.K. , Chow King L. 
Published: August 2002

AbstractThe male tail sensory rays in Caenorhabditis elegans are complex copulatory structures, the normal patterning of which requires a number of regulatory genes. Among them, mab‐21 specifies the identity of sensory ray 6. By using green fluorescent protein reporters, we identify multiple cis‐acting elements that control the developmental expression of mab‐21. Traced with a functional mab‐21:gfp gene driven by authentic regulatory sequences, mab‐21 expression could be detected in hypodermal, neuronal, muscle, and ray cells. We showed here that the expression of mab‐21 in the hypodermis and neuronal cells was dispensable for its function in ray 6. In contrast, its expression in the ray 6 structural cell and neurons as conferred by its 3′ enhancer was crucial for determining the correct ray 6 identity. © 2001 Wiley‐Liss, Inc.
Day hospitalization programs for eating disorders: A systematic review of the literature
Authors: Zipfel Stephan , Reas Deborah L. , Thornton Chris , Olmsted Marion P. , Williamson Donald A. , Gerlinghoff Monika , Herzog Wolfgang , Beumont Peter J. 
Published: August 2002

AbstractObjectivePartial day hospitalization programs for the treatment of eating disorders are increasingly being developed worldwide.MethodFirst, a systematic database search of day hospitalization programs for eating disorders, published in either English or German, was conducted. Programs that provided sufficient information on their program structure were summarized and compared across various dimensions. Second, the responsible program directors were contacted to provide additional information regarding outcome data, current trends, challenges, and future directions of their programs. Third, outcome data from day programs presented at international conferences were included to expand the base of the review.DiscussionAlthough the programs from different countries and health care environments varied in terms of their purpose and operated within very different health care systems, many similarities were found to exist, including the use of a multidisciplinary staff and reliance on group treatment as the primary means of therapy. Marked differences were noted in terms of inclusion criteria and intensity of care. © 2002 by Wiley Periodicals, Inc. Int J Eat Disord 31: 105–117, 2002; DOI. 10.1002/eat.10009
Development of body image, eating disturbance, and general psychological functioning in adolescent females: a replication using covariance structure modeling in an Australian sample
Authors: van den Berg Patricia , Wertheim Eleanor H. , Thompson J. Kevin , Paxton Susan J. 
Published: August 2002

AbstractObjectiveThe current study is a follow up to a covariance structure modeling (CSM) investigation of predictors of body image, eating dysfunction, and general psychological functioning in U.S. adolescent females.MethodFour hundred and seventy Australian girls (13–17 years old) completed measures of teasing history, body dissatisfaction, global psychological functioning, dietary restraint, and bulimic behaviors. They were also measured in order to compute body mass index (BMI).CSM techniques were used to analyze the relationships between these latent variables. Two a priori models were tested, one was selected, and post‐hoc model‐fitting was undertaken.ResultsThe final model indicated that BMI directly influenced teasing, which directly influenced body dissatisfaction. Body dissatisfaction influenced both global psychological functioning and restriction, whereas restriction had a direct influence on bulimia. Global psychological functioning also had a direct influence on bulimia.DiscussionThe results support previous research indicating that teasing and body dissatisfaction are risk factors for the development of eating disturbances. © 2002 by Wiley Periodicals, Inc. Int J Eat Disord 32: 46–51, 2002.
Pathways mediating sexual abuse and eating disturbance in children
Authors: Wonderlich Stephen , Crosby Ross , Mitchell James , Thompson Kevin , Redlin Jennifer , Demuth Gail , Smyth Joshua 
Published: August 2002

AbstractObjectiveTo examine the relationship between childhood maltreatment and eating disorders in a sample of children.MethodTwenty 10–15‐year‐old female children who were receiving treatment following reported childhood sexual abuse and 20 age‐matched controls were compared on a series of measures assessing eating disorder behaviors, body image concerns, substance use, mood, impulsive behavior, and self‐concept.ResultsSexually abused children reported higher levels of eating disorder behaviors, impulsive behaviors, and drug abuse than controls. Furthermore, behavioral impulsivity provided the strongest mediational effect between a history of childhood sexual abuse and purging and restrictive dieting behavior. Drug use proved to be a significant secondary mediator of the childhood sexual abuse eating disorder behavior association.DiscussionThese data support the hypothesis that childhood sexual abuse is related to disordered eating in children, and extend similar findings that have been previously reported with adults. Behavioral impulsivity and drug use appear to be significant mechanisms that influence eating disorder behavior following childhood sexual abuse. © 2001 by John Wiley & Sons, Inc. Int J Eat Disord 29: 270–279, 2001.
The role of perfectionism and excessive commitment to exercise in explaining dietary restraint: Replication and extension
Authors: McLaren Lindsay , Gauvin Lise , White Donna 
Published: August 2002

AbstractThe etiological complexity of the eating disorders has incited researchers to examine how personality characteristics and other variables operate jointly in the development of deviant eating patterns.ObjectiveThis study investigated the independent, interactive, and indirect prediction of dietary restraint by perfectionism and excessive commitment to exercise.MethodMultiple regression analyses designed to test moderating and mediating models were conducted on a sample of female university students (n = 269).ResultsSeveral dimensions of perfectionism, as well as excessive commitment to exercise, significantly and independently predicted dietary restraint in these women. There was no evidence for an interaction effect. Mediation analyses suggested that for selected dimensions of perfectionism, the direct relationship between perfectionism and dietary restraint is partially explained by excessive commitment to exercise.DiscussionInterventions aimed at challenging perfectionistic standards in the context of dieting need to address not only one's self‐standards, but one's perceptions of standards held by others. The mediating role of excessive exercise commitment pinpoints this variable as an alternative intervention target in the prevention of excessive dieting. © 2001 by John Wiley & Sons, Inc. Int J Eat Disord 29: 307–313, 2001.
Neutron production rate and plasma characteristics of spherically convergent beam fusion
Authors: Yamauchi Kunihito , Takeuchi Yasushi , Ogino Yutaka , Watanabe Masato , Okino Akitoshi , Sunaga Yoshitaka , Hotta Eiki 
Published: August 2002

AbstractExperimental and simulation results of a spherical glow discharge for a portable neutron source are presented. The experimental device is a 45‐cm‐diameter, 31‐cm‐high stainless‐steel cylindrical chamber, in which a spherical mesh‐type anode 30 cm in diameter is installed. The spherical grid cathode consists of 2.0‐mm‐diameter stainless‐steel wire, which is made into an open spherical grid of 5‐cm diameter. The system is maintained at a constant pressure of 1 to 15 mTorr by feeding hydrogen or deuterium gas. The basic characteristics of breakdown voltages versus pressure and electrostatic potential profiles were measured for hydrogen discharge. Using deuterium, a steady‐state neutron production of 104 s–1 was observed at a discharge of 40 kV, 2 mA. Motions of ions and electrons in the device were simulated by using a particle code, which is one‐dimensional in coordinate system and two‐dimensional in velocity space. It was confirmed by both the measurement and simulation that a virtual anode is formed in the central part inside the grid cathode. © 2001 Scripta Technica, Electr Eng Jpn, 135(2): 1–8, 2001
Settlement type and local government environmental policy in Hungary: the role of local economic structure and local government resources
Authors: Pickvance Chris 
Published: August 2002

AbstractThe paper contributes to our understanding of local environmental policy and democratization in post‐socialist societies by providing a picture of the realities of local government environmental policy in Hungary. After outlining the economic, political and organizational context of environmental policy in Hungary, the paper presents the results of a national interview survey of 600 local governments. It is suggested that settlement type (ranging from capital city to small village) is a key influence for two reasons: their characteristic local economic structure and the resources available to their local governments.Local governments in larger settlements are more likely to be committed to local environmental policy due to their greater resources, and perceived environmental problems and preferred environmental policies vary between localities with different economic structures and sizes. There is a moderate degree of confidence in the effectiveness of local government environmental policy. The survey shows a near‐universal concern for changing the local economic structure, which has significant environmental implications (especially clear in the popularity of hi‐tech industry and tourism), but there is a polarization between localities regarding the expected speed of economic change. Care is taken to distinguish local environmental policy from the local effects of supra‐local policies. Copyright © 2002 John Wiley & Sons, Ltd and ERP Environment.
Structure–activity analysis of the potentiation by aminothiols of the chromosome‐damaging effect of bleomycin in G0 human lymphocytes
Authors: Hoffmann George R. , Buccola Janet , Merz Miriam S. , Littlefield L. Gayle 
Published: August 2002

AbstractThe radioprotective aminothiols 2‐[(aminopropyl)amino] ethanethiol (WR‐1065) and cysteamine (CSM) potentiate the induction of chromosomal damage by the radiomimetic compound bleomycin (BLM) in G0 human lymphocytes. To investigate the mechanism of potentiation, we measured the clastogenic activity of BLM in the cytokinesis‐block micronucleus assay in the presence and absence of amines, thiols, and aminothiols. The hydroxy analog of WR‐1065, 2‐(3‐aminopropylamino) ethanol (WR‐OH), potentiates BLM only slightly, indicating the critical nature of the thiol group. As thiols, WR‐1065 and CSM may donate electrons for the activation of Fe+2‐BLM or for the regeneration of Fe+2‐BLM from inactive Fe+3‐BLM. The amines putrescine, spermidine, and spermine all potentiate BLM, but they are weaker potentiators than the aminothiols, and they are effective only at high concentrations. Their activity, like that of WR‐OH, is probably a consequence of conformational alteration of DNA. Dithioerythritol (DTE) and 2‐mercaptoethanol (2‐ME), thiols lacking an amino group, are less effective potentiators of BLM than are the aminothiols. The thiol group of WR‐1065 and CSM is therefore essential, but insufficient, for explaining the strong enhancement of BLM activity. The cationic nature of CSM and WR‐1065, conferred by the amino groups, evidently concentrates the active thiol function at the site of BLM action on DNA. As expected on this basis, the diamine WR‐1065 is a more effective potentiator of BLM than is the monoamine CSM, whereas cysteine and N‐acetylcysteine (NAC), which lack a net positive charge, potentiate BLM only weakly. These studies suggest that potentiation of the clastogenic action of BLM by aminothiols can be explained by the combination of a thiol‐mediated redox mechanism and an amine‐mediated targeting of the thiol function to DNA. Environ. Mol. Mutagen. 37:117–127, 2001 © 2001 Wiley‐Liss, Inc.
Improved method for measuring the ensemble average of strand breaks in genomic DNA
Authors: Bespalov Vyacheslav A. , Conconi Antonio , Zhang Xiaoyi , Fahy Deirdre , Smerdon Michael J. 
Published: August 2002

AbstractThe cis‐syn cyclobutane pyrimidine dimer (CPD) is the major photoproduct induced in DNA by low wavelength ultraviolet radiation. An improved method was developed to detect CPD formation and removal in genomic DNA that avoids the problems encountered with the standard method of endonuclease detection of these photoproducts. Since CPD‐specific endonucleases make single‐strand cuts at CPD sites, quantification of the frequency of CPDs in DNA is usually done by denaturing gel electrophoresis. The standard method of ethidium bromide staining and gel photography requires more than 10 μg of DNA per gel lane, and correction of the photographic signal for the nonlinear film response. To simplify this procedure, a standard Southern blot protocol, coupled with phosphorimage analysis, was developed. This method uses random hybridization probes to detect genomic sequences with minimal sequence bias. Because of the vast linearity range of phosphorimage detection, scans of the signal profiles for the heterogeneous population of DNA fragments can be integrated directly to determine the number‐average size of the population. Environ. Mol. Mutagen. 38:166–174, 2001 © 2001 Wiley‐Liss, Inc.