bluuebunny/crossref_metadata_2025_split huggingface dataset:
μ‐Receptor agonism with alfentanil increases striatal dopamine D2 receptor binding in man
Authors: Hagelberg Nora , Kajander Jaana K. , Någren Kjell , Hinkka Susanna , Hietala Jarmo , Scheinin Harry 
Published: August 2002

AbstractAnimal studies indicate that μ‐opioids indirectly modulate neurotransmission in the nigrostriatal dopaminergic pathway. We used positron emission tomography (PET) to study the effects of alfentanil (a μ‐opioid receptor agonist) on striatal dopamine D2 receptor binding in eight healthy male volunteers. D2 receptor binding was determined by using [11C]raclopride as radioligand. Each subject underwent two PET sessions on the same day, the first without the drug (control) and the second during alfentanil infusion. Alfentanil was administered as target‐controlled infusion to maintain pseudo steady‐state plasma concentration of 80 ng/ml throughout the PET session. A freeze lesion model was used for pain testing at the end of both PET sessions. A mechanical pain stimulus of 5 N was rated by the subjects using a visual analog scale. Regions of interest for the putamen, caudate nucleus, and cerebellum were drawn on MRI images and transferred to PET images. Alfentanil increased the binding potential of [11C]raclopride in the putamen by 6.0% (P = 0.04) and in the caudate nucleus by 7.4% (P = 0.008). Alfentanil caused a small reduction in respiratory rate (P = 0.046) and oxygen saturation (P < 0.001), and a moderate consistent increase in end‐tidal CO2 (P < 0.001). Pain scores were significantly smaller after alfentanil PET scan (median VAS 9 (0–42) vs. 23.5 (15–52), P = 0.008). These results indicate that pharmacologically relevant concentrations of alfentanil increase D2 dopamine receptor binding in the striatum in man. This increase is assumed to reflect reduced dopamine release. Synapse 45:25–30, 2002. © 2002 Wiley‐Liss, Inc.
Age‐related changes in the striatal dopaminergic system in the living brain: A multiparametric PET study in conscious monkeys
Authors: Harada Norihiro , Nishiyama Shingo , Satoh Kengo , Fukumoto Dai , Kakiuchi Takeharu , Tsukada Hideo 
Published: August 2002

AbstractIn the present study, age‐related changes in the striatal dopaminergic system were examined in the living brains of conscious young (6.2 ± 1.5 years old) and aged (20.2 ± 2.6 years old) monkeys (Macaca mulatta) using positron emission tomography (PET). L‐[β‐11C]DOPA and [11C]β‐CFT were applied to determine dopamine presynaptic functions such as synthesis rate and transporter (DAT) availability, respectively. Striatal dopamine D1‐ (D1R) and D2‐like receptor (D2R) binding were measured with [11C]SCH23390 and [11C]raclopride, respectively. Although the markers of presynaptic terminals showed parallel age‐related declines, the reduction of dopamine synthesis rate measured with L‐[β‐11C]DOPA was slightly smaller than that of DAT determined with [11C]β‐CFT. The binding of [11C]raclopride to D2R in vivo was significantly reduced with aging, while that of [11C]SCH23390 to D1R showed no such marked age‐related reduction. When the DAT inhibitor GBR12909 (0.5 and 5 mg/kg) was administered, DAT availability, dopamine synthesis, and D2R binding were significantly decreased in a dose‐dependent manner in both age groups; however, the degrees of the decreases in these parameters were significantly higher in young rather than in aged animals. Dopamine concentration in the striatal extracellular fluid (ECF), as measured by microdialysis, was increased by administration of GBR12909 in a dose‐dependent manner and the degree of the increase in dopamine level decreased with age. These results demonstrate that age‐related changes of dopamine neuronal functions were not limited to the resting condition but were also seen in the functional responses to the neurotransmitter modulation. Synapse 45:38–45, 2002. © 2002 Wiley‐Liss, Inc.
Effects of lubeluzole on the methamphetamine‐induced increase in extracellular glutamate and the long‐term depletion of striatal dopamine
Authors: Wallace Tanya L. , Vorhees Charles V. , Gudelsky Gary A. 
Published: August 2002

AbstractThe administration of a neurotoxic regimen of methamphetamine (MA) produces an acute elevation in the extracellular concentrations of dopamine and glutamate in the striatum and a long‐term depletion of striatal dopamine content in rats. The intent of the present study was to determine whether attenuation of the MA‐induced increase in extracellular glutamate would prevent the depletion of striatal dopamine. Male rats were treated with MA (10 mg/kg, i.p.) or vehicle every 2 h for four injections and concomitantly perfused intrastriatally with either artificial cerebrospinal fluid or lubeluzole (300 μM), a novel neuroprotectant that has been shown to prevent the increase in extracellular glutamate after the induction of neocortical infarct in rats. Lubeluzole significantly attenuated the MA‐induced increase in extracellular glutamate in the striatum without affecting the MA‐induced increase in extracellular dopamine or the MA‐induced hyperthermic response. Nevertheless, lubeluzole did not prevent the long‐term depletion of striatal dopamine produced by a neurotoxic regimen of MA. These results suggest that the MA‐induced depletion of striatal dopamine may not be dependent on the increased extracellular concentration of striatal glutamate. Synapse 40:95–101, 2001. © 2001 Wiley‐Liss, Inc.
Analyses of [18F]altanserin bolus injection PET data. II: Consideration of radiolabeled metabolites in humans
Authors: Price Julie C. , Lopresti Brian J. , Meltzer Carolyn C. , Smith Gwenn S. , Mason Neale S. , Huang Y. , Holt Daniel P. , Gunn Roger N. , Mathis Chester A. 
Published: August 2002

AbstractImaging serotonin‐2A (5‐HT2A) neuroreceptors with positron emission tomography (PET) and [18F]altanserin has been the focus of a series of PET studies, as [18F]altanserin is one of the most selective 5‐HT2A antagonist radiotracers. Previous animal studies showed that radiolabeled metabolites (radiometabolites) of [18F]altanserin crossed the blood–brain barrier (BBB) to localize nonspecifically in brain, consistent with a constant radioactivity “background.” In this work, we evaluated human bolus injection [18F]altanserin PET data with detailed consideration of the impact of BBB‐permeable metabolites on the specific binding parameters. Data were quantified using either single (parent radiotracer), dual (parent radiotracer and radiometabolites), or no arterial input function(s) (cerebellum as reference tissue input function). A step‐gradient high‐performance liquid chromatography (HPLC) analysis provided distinct separation of [18F]altanserin and four radiolabeled components in plasma. After [18F]altanserin injection, the step‐gradient data showed that the major BBB‐permeable radiometabolites approached constant levels in plasma (>50 min), consistent with a constant metabolite “background.” The single‐input Logan graphical results were highly correlated with the dual‐input results and its bias was fairly constant across regions and subjects, as similarly observed for a nongraphical reference tissue method. The most comprehensive and quantitatively valid analysis for bolus [18F]altanserin PET data was the dual‐input method that specifically accounted for BBB‐permeable metabolites, although the Logan analysis was preferred because it provided a good compromise between validity, sensitivity, and reliability of implementation. Further study is needed to better understand how the cerebellar kinetics of [18F]altanserin and its radiometabolites impact the reference tissue measures. Synapse 41:11–21, 2001. © 2001 Wiley‐Liss, Inc.
Viscous dampers at multiple levels for the historic preservation of Los Angeles City Hall
Authors: Youssef N. 
Published: August 2002

AbstractThis paper presents a case study of a seismic rehabilitation strategy, utilizing passive energy dissipation devices, for the preservation of a historic structure. The subject building is the Los Angeles City Hall, a 460 feet tall steel frame with unreinforced masonry infill. The rehabilitation consists of installing 416 high damping rubber bearings and 90 flat sliding bearings at its base in conjunction with 64 nonlinear viscous dampers. This paper presents the rationale for supplementing base isolation with viscous damping devices. The sensitivity of the global building response to the introduction of supplemental energy dissipation is also investigated. Copyright © 2001 John Wiley & Sons, Ltd.
“Maestro, what is ‘quality’?”: Language, literacy, and discourse in project‐based science
Authors: Moje Elizabeth B. , Collazo Tehani , Carrillo Rosario , Marx Ronald W. 
Published: August 2002

AbstractRecent curriculum design projects have attempted to engage students in authentic science learning experiences in which students engage in inquiry‐based research projects about questions of interest to them. Such a pedagogical and curricular approach seems an ideal space in which to construct what Lee and Fradd referred to as instructional congruence. It is, however, also a space in which the everyday language and literacy practices of young people intersect with the learning of scientific and classroom practices, thus suggesting that project‐based pedagogy has the potential for conflict or confusion. In this article, we explore the discursive demands of project‐based pedagogy for seventh‐grade students from non‐mainstream backgrounds as they enact established project curricula. We document competing Discourses in one project‐based classroom and illustrate how those Discourses conflict with one another through the various texts and forms of representation used in the classroom and curriculum. Possibilities are offered for reconstructing this classroom practice to build congruent third spaces in which the different Discourses and knowledges of the discipline, classroom, and students' lives are brought together to enhance science learning and scientific literacy. © 2001 John Wiley & Sons, Inc. J Res Sci Teach 38: 469–498, 2001
Science education as a civil right: Urban schools and opportunity‐to‐learn considerations
Authors: Tate William 
Published: August 2002

AbstractIn this article I make the case that urban science education is a civil rights issue and that to effectively address it as such we must shift from arguments for civil rights as shared physical space in schools to demands for high‐quality academic preparation that includes the opportunity to learn science. The argument is organized into two sections: first, a review of the school desegregation literature to make the case that urban science education for all is a civil rights issue; and second, an examination and critique of opportunity‐to‐learn literature, including an analysis of three opportunity‐to‐learn constructs to illustrate their potential as civil rights tools in science education. © 2001 John Wiley & Sons, Inc. J Res Sci Teach 38: 1015–1028, 2001
Human resources in Vietnam: The global challenge
Authors: Kamoche Ken 
Published: August 2002

AbstractThis article takes a critical look at the management of people in Vietnam. It examines the prevailing business
environment and the reform process and their implications for skill formation and the development of managerial
expertise. The analysis then proceeds to examine on a thematic basis some specific human resource practices in
four firms based in Hanoi—two state‐owned enterprises and two multinationals. The article analyzes
the traditional and emergent human resource practices showing how they reflect industrial and
historical‐cultural contextual factors. The discussion also considers the suitability and adequacy of these
practices while locating them within the international human resource management debate. This article thus
contributes to the critique of global human resource management by exploring the relevance of mainstream human
resource theory and practice to the Vietnamese case, especially given the increasing role of multinational firms
in the Vietnamese economy. © 2001 John Wiley & Sons, Inc.
Acute toxicity of sodium selenate to two daphnids and three amphipods
Authors: Brix Kevin V. , Henderson Douglas G. , Adams William J. , Reash Robin J. , Carlton Richard G. , Mcintyre Dennis O. 
Published: August 2002

AbstractThis study evaluated the acute toxicity of sodium selenate to two daphnid and three gammarid amphipod species. The daphnids,Ceriodaphnia dubiaandDaphnia pulex, were evaluated in 48‐hour static tests and the amphipods,Gammarus pseudolimnaeus,Gammarus lacustris, andHyalella azteca, were evaluated in 96‐hour static and flow‐through tests. Tests resulted in mean LC50's of 1.92, 9.12, 1.82, 3.05, and 1.95 mg/L selenium forC. dubia,D. pulex,G. pseudolimnaeus,G. lacustris, andH. azteca, respectively. The LC50's for theG. pseudolimnaeustests are more than 30‐fold higher than previously reported LC50's for the same or similar species. The explanation for these differing results appears to be partially, but not entirely, explained by differences in ambient pH between the new studies and previous ones. Depending on how the new data are included in U.S. EPA's selenium freshwater quality criterion data set, the selenate acute water quality criterion (i.e., Criterion Maximum Concentration) increases from 12.8 to as high as 583 μg/L selenium. © 2001 John Wiley & Sons, Inc. Environ Toxicol 16: 142–150, 2001
X‐ray absorption spectroscopic studies of Mn atoms in La1−xSrxMnO3+δ compounds
Authors: Mastelaro Valmor R. , de Souza Dulcina P. F. , Mesquita Rafael A. 
Published: August 2002

AbstractMn K‐edge x‐ray absorption spectroscopy was used to determine the local structure at the Mn site in LaMnO3, La0.7Sr0.3MnO3 and La0.5Sr0.5MnO3 samples. The x‐ray absorption near‐edge spectra (XANES) show an intermediate oxidation state of the Mn atoms, the edge position indicating an average valence of ∼3.4 for the LaMnO3 sample and an average valence of ∼3.7 for the La0.7Sr0.3MnO3 and La0.5Sr0.5MnO3 samples. Extended x‐ray absorption fine structure (EXAFS) analyses show that the local order around Mn atoms in the La0.7Sr0.3MnO3sample can be described as a regular MnO6 octahedron or as a distorted octahedron with two different Mn—O bond lengths. With regard to the La0.5Sr0.5MnO3 sample, the local structure around Mn atoms is appropriately described by a regular MnO6 octahedron. For this sample, the mean Mn—O bond length is shorter and is similar to that of Mn—O in the SrMnO3. Copyright © 2002 John Wiley & Sons, Ltd.
Glycogen—a covalently linked component of the cell wall in Saccharomyces cerevisiae
Authors: Arvindekar Akalpita U. , Patil Narayan B. 
Published: August 2002

AbstractGlycogen in Saccharomyces cerevisiae is present in two pools, one soluble and intracellular, the other present in the cell wall and rendered water‐insoluble owing to its covalent linkage to cell wall β‐glucan. The insoluble glycogen fraction was solubilized using β‐1,3‐glucanase. The αβ‐glucan complex obtained showed intense red staining with iodine and was isolated from free β‐glucans by affinity chromatography using concanavalin A sepharose 4B. Further use of molecular sieving has confirmed that glycogen is linked to β‐glucan as the non‐retained fraction on Biogel P2 split into two peaks on treatment with amyloglucosidase. Partial acid hydrolysis and subsequent paper chromatography of the αβ‐glucan complex isolated revealed the presence of gentiobiose and other higher oligosaccharides, indicating that glycogen is linked to β‐1,3‐glucan through a β‐1,6 branch. The insoluble glycogen can be extracted in a soluble form by acetic acid treatment and is known as acid‐soluble glycogen. The presence of glycogen in the cell wall is confirmed by controlled enzymatic release of αβ‐glucan complex using lyticase from Arthobacter luteus without disruption of the plasma membrane, as can be visualized using electron microscopy. Copyright © 2002 John Wiley & Sons, Ltd.
A series of double disruptants for protein phosphatase genes in Saccharomyces cerevisiae and their phenotypic analysis
Authors: Sakumoto Naoko , Matsuoka Itsumi , Mukai Yukio , Ogawa Nobuo , Kaneko Yoshinobu , Harashima Satoshi 
Published: August 2002

AbstractThirty‐two protein phosphatase (PPase) genes were identified in Saccharomyces cerevisiae based on the nucleotide sequences of the entire genome. In an effort to understand the role of PPases and their functional redundancy in the cellular physiology of one of the reference eukaryotic organisms, a series of single and double PPase gene disruptants were constructed in the W303 strain background. Two single disruptants for the CDC14 and GLC7 genes were lethal. Double disruptants for 30 non‐essential PPase genes were constructed in all possible 435 combinations. No double disruptant showed synthetic lethality. Several phenotypes of the viable 30 single and 435 double disruptants were examined; temperature‐sensitive growth, utilization of carbon sources and sensitivity to cations and drugs. Four double disruptants exhibited synthetic phenotypes in addition to eight single ones: the pph21 pph22 double disruptant showed slow growth on complete medium, as did the sit4 and yvh1 single ones. In addition to the ptc1, ynr022c and ycr079w single disruptants, the ppz1 ppz2 double disruptant showed temperature‐sensitive slow growth. The msg5 ptp2 double disruptant, like the ynr022c single one, did not grow on complete medium containing 0.3 M CaCl2. The double msg5 ptc2 disruptant failed to grow on medium containing 1.0 M NaCl and, like the ynr022c single deletion, also could not grow on medium containing 0.3 M CaCl2. The synthetic phenotypes in the two latter cases where each of the PPases is categorized in a different phosphatase family led us to discuss the novel mechanism involved in the functional redundancy of the PPases. Copyright © 2002 John Wiley & Sons, Ltd.
Successful formation of a large chimpanzee group out of two preexisting subgroups
Authors: Seres Michael , Aureli Filippo , de Waal Frans B.M. 
Published: August 2002

AbstractDescriptions of the formation of relatively large groups of unfamiliar chimpanzees (Pan troglodytes) in captivity are scarce in the literature. Nineteen chimpanzees from preexisting subgroups were introduced into a social group at the Yerkes Regional Primate Research Center. The group included two adult males, six adult females along with six dependent infants, and five unrelated juveniles, four of whom had been hand‐raised in a nursery unit. Here we provide details on dyadic and multiparty introductions as well as technical details on the indoor/outdoor compound. The introduction process itself took more than 3 weeks, and was completed without major injuries. The introductions combined with 4 years of follow‐up data on aggression, grooming, and affiliative behavior confirm that even chimpanzees from an environment that does not promote complex social skills can be formed into a large multimale–multifemale group. During the introductions, low rates of agonistic behavior among adult females were offset by high rates of affiliative behavior. The two adult males, however, showed contact aggression during the first 10 minutes, after which such behavior virtually disappeared, whereas affiliative behavior increased. Three months after their first introduction, the two males reversed dominance ranks within the group, and hierarchical stability has been maintained since. During the 4‐year postintroductory period, grooming rates slightly decreased, but group cohesion was maintained. The frequency of aggression among all adults, including the males, increased during the 4‐year period, but aggression was generally of low intensity after the first year. Zoo Biol 20:501–515, 2001. © 2002 Wiley‐Liss, Inc.
Effect of Ischemia/Reperfusion as a Systemic Phenomenon on Anastomotic Healing in the Left Colon
Authors: Kuzu Mehmet Ayhan , Tanık Adil , Kale İIlhami Taner , Aşlar Ahmet Keşşaf , Köksoy Cüneyt , Terzi Cem 
Published: August 2002

AbstractIntestinal ischemia/reperfusion provokes a local inflammatory response leading to a systemic inflammatory state. In this study we aimed to assess the effects of intestinal ischemia/reperfusion injury on anastomotic healing in the left colon with an intact vascular supply. A total of 94 Wistar albino rats were divided into three groups: sham‐operated control (group I, n= 25), 30 minutes of intestinal ischemia/reperfusion (group II, n= 40), and 7‐day allopurinol pretreatment and intestinal ischemia/reperfusion (group III, n= 29). After the reperfusion experiment, a segmental left colon resection and anastomosis were done. On postoperative days 3 and 7 anastomotic bursting pressure, anastomotic and operative complications, and intraabdominal adhesions were assessed. Mortality rates were 1/25, 16/40, and 4/29 for groups I, II, and III, respectively (p= 0.001). There was no difference among the groups for wound and anastomotic healing parameters evaluated by macroscopic criteria. On postoperative day 7 the mean bursting pressures were 220.3 ± 18.5, 162.0 ± 21.0, and 213.9 ± 24.7 for groups I, II, and II, respectively (p= 0.000). Significantly dense adhesions were found in group II (p= 0.000). Allopurinol pretreatment prevented the effects of ischemia/reperfusion on anastomotic healing of the left colon. Intestinal/ischemia reperfusion causes impairment of anastomotic healing of the left colon. In addition to remote organ effects, reperfusion injury may affect anastomotic healing in the viscera with an intact vascular supply.
Prevention of Renal Cell Carcinoma by Active Vitamin D3
Authors: Fujioka Tomoaki , Suzuki Yasushi , Okamoto Tomoshi , Mastushita Nozomi , Hasegawa Michihiko , Omori So 
Published: August 2002

AbstractWe studied the serum levels of 1,25‐dihydroxyvitamin D [1,25(OH)2D (Vit D)] in patients with renal cell carcinoma (RCC) and the influence of 1,25(OH)2D3 (Vit D3) on gap junctional intercellular communication (GJIC) during carcinogenesis. The serum Vit D levels were measured by a competitive protein‐binding assay using the chromatographic method. Using the [3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide] (MTT) assay, noncytotoxic concentrations of Vit D3 and the tumor promoters N‐nitrosodimethylamine (NDMA) and N‐ethyl‐N‐hydroxyethylnitrosamine (EHEN) were tested against cultured human renal proximal tubular cells (HRPTCs). GJIC function was assayed by the scrape‐loading dye transfer technique. Cx43 mRNA expression was also examined by the reverse transcriptase‐polymerase chain reaction (RT‐PCR). Serum Vit D levels in patients with RCC were lower than those in controls (p < 0.001). Patients with T3 to T4 (rapid‐growth) tumors had lower levels of Vit D than did patients with T1 to T2 (slow‐growth) tumors (p < 0.001). Vit D3 enhanced the GJIC function of HRPTCs (p < 0.05), whereas NDMA and EHEN suppressed it (p < 0.05). When the cells were treated with tumor promoters and Vit D3 simultaneously, the GJIC functions remained at pretreatment levels. We also demonstrated Cx43 mRNA expression in RPTECs treated with EHEN and VitD3 simultaneously. These data suggest that a decrease in the serum Vit D level is one of the risk factors for development and progression of RCC, and Vit D3 may prevent RCC by preserving GJIC during carcinogenesis.