bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling the information‐seeking behavior of social scientists: Ellis's study revisited
Authors: Meho Lokman I. , Tibbo Helen R. 
Published: March 2003

AbstractThis paper revises David Ellis's information‐seeking behavior model of social scientists, which includes six generic features: starting, chaining, browsing, differentiating, monitoring, and extracting. The paper uses social science faculty researching stateless nations as the study population. The description and analysis of the information‐seeking behavior of this group of scholars is based on data collected through structured and semi‐structured electronic mail interviews. Sixty faculty members from 14 different countries were interviewed by e‐mail. For reality check purposes, face‐to‐face interviews with five faculty members were also conducted. Although the study confirmed Ellis's model, it found that a fuller description of the information‐seeking process of social scientists studying stateless nations should include four additional features besides those identified by Ellis. These new features are: accessing, networking, verifying, and information managing. In view of that, the study develops a new model, which, unlike Ellis's, groups all the features into four interrelated stages: searching, accessing, processing, and ending. This new model is fully described and its implications on research and practice are discussed. How and why scholars studied here are different than other academic social scientists is also discussed.
Evaluation of infant methylenetetrahydrofolate reductase genotype, maternal vitamin use, and risk of high versus low level spina bifida defects
Authors: Volcik Kelly A. , Shaw Gary M. , Lammer Edward J. , Zhu Huiping , Finnell Richard H. 
Published: March 2003

AbstractBACKGROUNDSeveral studies have suggested that homozygosity for the C677T 5,10‐methylenetetrahydrofolate reductase (MTHFR) variant is a potential risk factor for neural tube defects (NTDs), as individuals homozygous for the C677T allele have slightly elevated homocysteine concentrations under conditions of low folic acid intake. It has been hypothesized that maternal folic acid supplementation prevents NTDs by partially correcting reduced MTHFR activity associated with the variant form of the enzyme.METHODSGenomic DNA was extracted from newborn screening blood spots obtained from 145 infants with spina bifida (SB) and 260 nonmalformed control infants. The MTHFR C677T genotype was determined by restriction enzyme digestion of PCR amplification products with Hinf1. We investigated whether infant MTHFR genotype influenced the risk for the anatomic level of the SB lesion (high vs. low); we also explored whether maternal vitamin use influenced this risk.RESULTSCompared to controls, the frequency of SB infants with the homozygous 677 TT genotype was greatest in those infants with high level SB defects (26%; odds ratio [OR] = 2.9; 95% confidence interval [CI] = 0.9–10.1) than for those with low level SB defects (22%; OR = 1.8; 95% CI = 0.9–3.2). Furthermore, homozygous 677TT infants whose mothers did not use vitamins containing folic acid had a modestly increased risk of SB (OR = 1.8; 95% CI = 0.8–3.9), with this risk increasing more than three‐fold (OR = 5.5; 95% CI = 0.8–28.1) for those infants with high level SB defects whose mothers did not use vitamins.CONCLUSIONSBased upon our observations, it is suggested that the association between the infant MTHFR homozygous variant genotype and spina bifida risk may be conditional upon both lesion level and maternal vitamin use. Birth Defects Research (Part A) 67:154–157, 2003. © 2003 Wiley‐Liss, Inc.
Combination therapy with folic acid and methionine in the prevention of retinoic acid‐induced cleft palate in mice
Authors: Reynolds Paul R. , Schaalje G. Bruce , Seegmiller Robert E. 
Published: March 2003

AbstractBACKGROUNDDuring formation of the secondary palate, clefting may result when critical developmental events are altered. The purpose of this study was to reduce the incidence of retinoic acid (RA)‐induced cleft palate (CP) in mice by the co‐administration of folic acid (FA), methionine (ME) or a combination of both.METHODSFour groups of time‐pregnant Swiss Webster mice were injected intraperitoneally with 50 mg/kg RA on gestational day (GD) 10. Likewise, 4.0 mg/kg FA and 187 mg/kg ME were administered on GD 8–11. The experiment included a control group (RA plus H2O) and three experimental groups, (RA plus therapeutic doses of FA, ME, or FA + ME). Necropsies were carried out on GD 18 and pups were analyzed for teratogenic effects.RESULTSLitters that received no therapy exhibited 100% CP with individual pups showing 76% susceptibility. Each therapy administered separately reduced the frequency of CP to approximately 6%, and the combination of FA and ME completely prevented the occurrence of RA‐induced cleft palate (0%). A second experiment was conducted in which therapy levels were decreased by 25%. Litters that did not receive therapy experienced 100% clefting and individual pups exhibited CP at 86%. These therapies administered separately did not alter significantly the frequency of cleft palate.The combined doses of FA and ME, however, lowered significantly the frequency of left palate to 46%. Decreases in limb and tail defects with FA + ME therapy were also observed in both experiments.CONCLUSIONSAlthough FA and ME, at appropriate levels, can reduce individually the frequency of RA‐induced cleft palate and other defects in mice, the results from the present study suggest that there is an additive interaction between the two therapeutic agents that can reduce further the teratogenic impact of RA. Further studies are needed to assess the mechanism of action of concomitant doses of FA and ME in the reduction of drug‐induced birth defects. Birth Defects Research (Part A) 67168–173, 2003. © 2003 Wiley‐Liss, Inc.
Embryonic and adult vasculogenesis
Authors: Drake Christopher J. 
Published: March 2003

AbstractTwo mechanisms account for the formation of blood vessels, vasculogenesis and angiogenesis. Unfortunately, the terms vasculogenesis and angiogenesis literally have the same meaning, i.e., the genesis of blood vessels, and thus do little to distinguish between the two processes. Despite the nomenclature, the two processes are clearly distinct. Vasculogenesis, the de novo formation of blood vessels from mesoderm, is driven by the recruitment of undifferentiated mesodermal cells to the endothelial lineage and the de novo assembly of such cells into blood vessels. Angiogenesis is the generation of new blood vessels from endothelial cells of existing blood vessels, a process driven by endothelial cell proliferation. Recent years have seen dramatic changes in our understanding of the process of vasculogenesis, expanding the scope of its occurrence beyond the earliest stages of development to include involvement in neovascular processes throughout development as well as in the adult. In this review, emphasis is placed on discussion of emerging perspectives on the process of vasculogenesis in both the embryo and the adult. Birth Defects Research (Part C) 69:73–82, 2003. © 2003 Wiley‐Liss, Inc.
X‐ray studies on ligands
Authors: Deschamps Jeffrey R. , Flippen‐Anderson Judith L. , George Clifford 
Published: March 2003

AbstractAdvances in x‐ray crystallographic data collection, structure solution, and refinement/validation have reduced the time required and expanded the range of samples amenable to x‐ray crystallographic studies. Consequently, we can now collect complete atomic resolution data sets on physically smaller crystals and solve larger problems by direct methods beyond what could have been accomplished even five years ago. Applying these improved methods to the study of opioid ligands has enhanced our knowledge of the opioid pharmacophore. Despite considerable progress, it is still difficult to define the pharmacophoric parameters required for highly selective and potent opioid peptides. In part this is due to the conformational flexibility remaining even in conformationally constrained peptides. © 2003 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 66:287–293, 2002.
Structural models for dimerization of G‐protein coupled receptors: The opioid receptor homodimers
Authors: Filizola Marta , Weinstein Harel 
Published: March 2003

AbstractAmong the most exciting functional features of G‐protein coupled receptors (GPCRs) that are coming into focus lately are those relating to the role and structural characteristics of their oligomerization (mostly homo‐ and heterodimers). The structural underpinnings of these novel functional insights are still not clear, as current experimental techniques have not yet succeeded in identifying the dimerization interfaces between GPCR monomers. Two computational approaches have recently been designed in our lab to provide reasonable three‐dimensional (3D) molecular models of the transmembrane (TM) regions of GPCR dimers based on a combination of the structural information of receptor monomers and analyses of correlated mutations in receptor families. The modeling of GPCR heterodimers has been described recently. We present here a related approach for modeling of GPCR homodimers that identifies the interfaces in the most likely configurations of the complexes. The approach is illustrated for the three cloned opioid receptor subtypes (OPRD, OPRM, and OPRK). © 2002 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 66:317–325, 2002
Chalcogenide‐Lewis Acid Mediated Reactions of Electron‐Deficient Alkynes with Aldehydes
Authors: Kinoshita Sayaka , Kinoshita Hironori , Iwamura Tatsunori , Watanabe Shin‐ichi , Kataoka Tadashi 
Published: March 2003

AbstractReactions of but‐3‐yn‐2‐one (2) with aldehydes 1 in the presence of a Lewis acid and dimethyl sulfide (3 a) predominantly gave (E)‐α‐(halomethylene)aldols 4–5 in high yields, while reactions of methyl propiolate (6 a) mainly afforded (Z)‐3‐halogeno‐2‐(hydroxymethyl)acrylates 7–8 in low to moderate yields. A reaction of dimethyl acetylenedicarboxylate (10) with 1 a in the presence of TiCl4 and 1,1,3,3‐tetramethylthiourea (3 c) produced maleate (E)‐11 (40 %) and butenolide 12 (40 %). When a reaction of 6 a with 1 a was carried out in the presence of TiBr4 and 3 a (0.2 equiv) at −20 °C for 60 h, 3‐(methylthio)‐2‐(hydroxyalkyl)acrylate 9 a was obtained in an 8 % yield. Experiments were conducted in order to elucidate the formation mechanism of 9 a, and it was made clear that 9 a was formed via the processes of the Michael addition of sulfide 3 a to alkynoate 6 a and an aldol reaction with 1 a and demethylation.
Can patient selection for bladder preservation be based on response to chemotherapy?
Authors: Sternberg Cora N. , Pansadoro Vito , Calabrò Fabio , Schnetzer Sylvia , Giannarelli Diana , Emiliozzi Paolo , De Paula Francesco , Scarpone Paolo , De Carli Piero , Pizzo Maurizio , Platania Andrea , Amini Mostafà 
Published: March 2003

AbstractBACKGROUNDNeoadjuvant chemotherapy for patients with muscle‐invasive bladder carcinoma is given to treat micrometastases and to preserve the bladder. The objective of this study was to evaluate the possibility of bladder preservation in patients with muscle‐invasive bladder carcinoma who were treated with neoadjuvant methotrexate, vinblastine, doxorubicin, and cisplatin (M‐VAC) chemotherapy.METHODSOne hundred four consecutive patients with T2–T4,N0,M0 transitional cell carcinoma of the bladder were treated with 3 cycles of neoadjuvant M‐VAC chemotherapy. After clinical restaging, 52 patients underwent transurethral resection of the bladder (TURB) alone, 13 patients underwent partial cystectomy, and 39 patients underwent radical cystectomy.RESULTSThe median survival for the entire group was 7.49 years (95% confidence interval, 4.86–10.0 years). Forty‐nine patients (49%) were T0 at the time of TURB after receiving M‐VAC. Thirty‐one of 52 patients (60%) who received chemotherapy and underwent TURB alone were alive at a median follow‐up of 56 + months (range, 10–160 + months): Twenty‐three patients (44%) in that TURB group maintained an intact bladder. Of 13 responding patients with monofocal lesions who underwent partial cystectomy, only 1 patient required salvage cystectomy, and survival generally was good. The 5‐year survival rate for this group was 69%. With a long median follow‐up of 88 + months (range, 16–158 months), 4 patients (31%) were alive with a functioning bladder. In the radical cystectomy group, the median follow‐up was 45 months (range, 4–172 + months), and 15 of 39 patients (38%) patients remained alive. In 77 patients who had their tumors down‐staged to T0 or superficial disease, the median follow‐up was 63 months (range, 4–172 + months), and the 5‐year rate survival was 69%. This is in contrast to a 5‐year survival rate of only 26% in 27 patients who failed to respond and had a status ≥ T2 after receiving chemotherapy (median follow‐up, 31 months; range, 7–156 + months). The median survival for 27 elderly patients (age ≥ 70 years; median age, 73 years; range, 70–82 years) was 90 months (7.5 years). For elderly patients who underwent TURB and partial cystectomy, the 5‐year survival rate was 67% with a 109‐month (9‐year) median survival; 47% of patients preserved their bladders intact. The median follow‐up of the living elderly patients was 61 months (range, 20–120 + months).CONCLUSIONSBladder sparing in selected patients on the basis of response to neoadjuvant chemotherapy is a feasible approach that should be confirmed in prospective, randomized trials. Selected elderly patients are candidates for this approach. Cancer 2003;97:1644–52. © 2003 American Cancer Society.DOI 10.1002/cncr.11232
Stricture of the proximal esophagus in head and neck carcinoma patients after radiotherapy
Authors: Laurell Göran , Kraepelien Thomas , Mavroidis Panayiotis , Lind Bengt K. , Fernberg Jan‐Olof , Beckman Mats , Lind Magnus G. 
Published: March 2003

AbstractBACKGROUNDIt is well recognized that many patients with head and neck carcinoma have problems with food intake and malnutrition. The objective of the current study was to determine the clinical pattern of patients with nonneoplastic stricture of the upper esophagus after radiotherapy for head and neck carcinoma.METHODSA retrospective chart study of 22 patients with stricture of the proximal esophagus diagnosed between 1993 and 1999 at Karolinska Hospital was performed. The dose volume histograms of the first 2 cm and 5 cm, respectively, of the proximal esophagus were calculated.RESULTSFive of the patients (23%) had total obliteration. The first 2 cm of the esophagus received at least 60 grays (Gy) in > 80% of the volume. Radiation injury was not reported to occur at doses < 60 Gy. There was a correlation found between dysphagia during radiotherapy and the development of proximal esophageal stricture. Stricture was diagnosed 1–60 months (median, 6 months) after radiotherapy. In 18 patients, the stricture was treated with single or repeated endoscopic dilation. These treatments allowed a nearly normal diet in 78% of the patients.CONCLUSIONSStricture of the upper esophagus is one deglutition disorder that is reported to occur after radiotherapy for head and neck carcinoma. In the current study, the authors emphasize the importance of knowing the tolerance of the normal esophagus to irradiation as well as early diagnosis of stricture of the proximal esophagus because this condition may lead to physical and emotional distress. Cancer 2003;97:1693–700. © 2003 American Cancer Society.DOI 10.1002/cncr.11236
Spatial test filters for dynamic model large‐eddy simulation with finite elements
Authors: Tejada‐Martínez A. E. , Jansen K. E. 
Published: March 2003

AbstractIn this article we will develop spatial filters required in the dynamic model of small‐scale turbulent fluid motions in large‐eddy simulation with finite elements. The characterization of these finite element filters is crucial because it is seen to have an impact on incompressible Navier–Stokes simulation results. Copyright © 2003 John Wiley & Sons, Ltd.
A preconditioner freeze strategy for numerical solution of compressible flows
Authors: Silva R. S. , Almeida R. C. , Galeão A. C. 
Published: March 2003

AbstractIt is well known that Krylov–Schwarz methods are well suited for solving linear systems of equations in high‐latency, distributed memory environments and constitute powerful tools when combined with Newton–Krylov methods to solve Computational Fluid Dynamics problems. Nevertheless, the computational costs related to the Jacobian and the preconditioner evaluation can sometimes be prohibitive. In this work a strategy to reduce these costs is presented, based on evaluating a new preconditioner only after it had been frozen for several time steps. Numerical experiments show the computational gain achieved with the proposed strategy. Copyright © 2003 John Wiley & Sons, Ltd.
A novel boundary element method to solve free torsion problems
Authors: Songying Chen , Leqin Wang , Guijun Li 
Published: March 2003

AbstractThe free torsion boundary integral equation is established using the Weighted Residual Method. The divergence free property of the boundary integrand is established. Evaluation of the warp function on the boundary is transformed into numerical evaluation of warp potential functions on the boundary of the free torsion pillar, with no singular numerical integrals. Copyright © 2003 John Wiley & Sons, Ltd.
Fluorescence lifetime‐resolved pH imaging of living cells
Authors: Lin Hai‐Jui , Herman Petr , Lakowicz Joseph R. 
Published: March 2003

AbstractBackgroundThe regulation and maintenance of intracellular pH are critical to diverse metabolic functions of the living cells. Fluorescence time‐resolved techniques and instrumentations have advanced rapidly and enabled the imaging of intracellular pH based on the fluorescence lifetimes.MethodsThe frequency‐domain fluorescence lifetime imaging microscopy (FLIM) and fluorophores displaying appropriate pH‐dependent lifetime sensitivities were used to determine the temporal and spatial pH distributions in the cytosol and vesicular compartment lysosomes.ResultsWe found that cytosolic pH levels are different in 3T3 fibroblasts, Chinese hamster ovary (CHO) cells, and MCF‐7 cells when using the pH probe carboxy‐SNAFL2. We also tracked the transient cytosolic pH changes in the living CHO cells after treatments with proton pump inhibitors, ion exchanger inhibitors, and weak base and acid. The intracellular lysosomal pH was determined with the acidic lifetime probes DM‐NERF dextrans, OG‐514 carboxylic acid dextrans, and LysoSensor DND‐160. Our results showed that the resting lysosomal pH value obtained from the 3T3 fibroblasts was between 4.5 and 4.9. The increase of lysosomal pH induced by the treatments with proton pump inhibitor and ionophores also were observed in our FLIM measurements.ConclusionsOur lifetime‐based pH imaging data suggested that FLIM can measure the intracellular pH of the resting cells and follow the pH fluctuations inside the cells after environmental perturbations. To improve the z‐axis resolution to the intracellular lifetime‐resolved images, we are investigating the implementation of the pseudo‐confocal capability to our current FLIM apparatus. Cytometry Part A 52A:77–89, 2003. © 2003 Wiley‐Liss, Inc.
Obsessions and compulsions in anorexia nervosa subtypes
Authors: Halmi Katherine A. , Sunday Suzanne R. , Klump Kelly L. , Strober Michael , Leckman James F. , Fichter Manfred , Kaplan Allan , Woodside Blake , Treasure Janet , Berrettini Wade H. , Al Shabboat Mayadah , Bulik Cynthia M. , Kaye Walter H. 
Published: March 2003

AbstractObjectiveObsession and compulsions in anorexia nervosa (AN) patients are often confused with the preoccupations and rituals that are characteristic of obsessive‐compulsive disorder (OCD). We examined the type and frequency of characteristic OCD obsessions and compulsions in a large sample of AN patients.MethodIn personal interviews with 324 AN patients, we assessed lifetime histories of eating disorder symptomatology and obsessive‐compulsive behaviors with valid semistructured interviews. Checklist category sums on the Yale‐Brown Obsessive Compulsive Scale were compared between AN and OCD subjects using generalized estimating equations.ResultsLifetime obsessions and compulsions occurred in 68% of the AN restricting type and in 79.1% of the AN binge/purge type. The AN subgroups did not differ from OCD controls inr frequency of obsessions in the symmetry and somatic categories or in the compulsion categories of ordering and hoarding. In all other categories, the AN subgroups had a significantly lower frequency compared with the OCD controls.DiscussionSome common phenotype characteristics shared by most AN and OCD patients suggest these disorders may share common brain behavioral pathways. However, the lack of complete overlap indicates they most likely have different loci of pathology within those pathways. © 2003 by Wiley Periodicals, Inc. Int J Eat Disord 33: 308–319, 2003.
Early‐onset anorexia nervosa: Is there evidence of limbic system imbalance?
Authors: Chowdhury Uttom , Gordon Isky , Lask Bryan , Watkins Beth , Watt Hilary , Christie Deborah 
Published: March 2003

AbstractObjectiveThis study, part of a continuing effort to understand the pathophysiology of the brain in early‐onset anorexia nervosa, attempts to validate findings from an earlier study of regional cerebral blood flow and to correlate any abnormalities in blood flow with eating disorder psychopathology.MethodFifteen newly referred children and adolescents with a diagnosis of anorexia nervosa (AN) underwent regional cerebral blood flow (rCBF) examination using single‐photon computerized tomography (SPECT) and the Eating Disorders Examination (EDE) for children.ResultsMean age was 14 years 11 months (SD = 1.35). Mean weight for height ratio was 82.79 % (SD = 10.66). SPECT findings showed that 11 (73%) had asymmetry (hypoperfusion) of blood flow in at least one area. Regions of the brain showing hypoperfusion included the temporal lobe (n = 9), parietal lobe (n = 5), frontal lobe (n = 3), thalamus (n = 3), and the caudate nuclei (n = 1). The median EDE subscale scores were high for all four subscales. Those patients with hypoperfusion had higher median EDE subscale scores than those without hypoperfusion, although the differences were not statistically significant.ConclusionsMost patients in our study had abnormal rCBF, predominantly affecting the temporal lobe, confirming our previous findings. There was no association with the EDE scores. The findings support earlier suggestions of an imbalance in neural pathways or circuits, possibly within the limbic system. This hypothesis is considered within the context of current knowledge and suggestions made with regard to how it might be tested. © 2003 by Wiley Periodicals, Inc. Int J Eat Disord 33: 388–396, 2003.
The eating disorders medicine cabinet revisited: A clinician's guide to appetite suppressants and diuretics
Authors: Roerig James L. , Mitchell James E. , de Zwaan Martina , Wonderlich Stephen A. , Kamran Shehzad , Engbloom Sara , Burgard Melissa , Lancaster Kathryn 
Published: March 2003

AbstractObjectiveThis article explores the frequencies of use of alternative medications, available products, and their potential toxicities.MethodSurvey data were gathered from 39 consecutive patients diagnosed with bulimia nervosa who were seeking treatment. A survey of area outlets (health food stores, pharmacies, grocery stores) was conducted to establish a database of available agents. Putative active ingredients were identified. MEDLINE literature searches, as well as reviews of specialized texts, were performed to identify the potential toxicities of the ingredients.ResultsDiet pill use was found in 64% of patients; 18 % reported use in the past month. The survey identified 167 products. Diuretic use was found in 31% of patients; 21% reported use in the past month. Twenty‐five diuretic products were identified.DiscussionAlternative medicines are frequently used in the population of patients seeking treatment for bulimia nervosa. An abundance of products are available with potentially significant toxicities. © 2003 by Wiley Periodicals, Inc. Int J Eat Disord 33: 443–457, 2003.