bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multiple‐region gradient arrays for extended field of view, increased performance, and reduced nerve stimulation in magnetic resonance imaging
Authors: Parker Dennis L. , Hadley J. Rock 
Published: October 2006

AbstractThis article presents a novel design for magnetic resonance imaging (MRI) gradient systems. This design may allow the development of MRI scanners that are capable of imaging large regions with high performance while minimizing the potential for nerve stimulation. The general concept of the gradient system is that spatial oscillation is incorporated such that each gradient coil creates multiple, approximately linear gradient regions that oscillate in gradient polarity. Separate radiofrequency (RF) coil arrays are designed to be sensitive to the signals within each linear region and thus allow signal measurements to be obtained separately from each region. Enabling image acquisition in the transition region that separates each pair of adjacent linear regions requires a second gradient system with imaging regions that overlap and coincide with the transition regions of the first gradient system. Imaging the extended field of view (FOV) is accomplished by interleaved operation of the two gradient systems. Simulated annealing is used to create designs for both longitudinal and transverse gradient systems with two imaging regions. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Demographic correlates of body size changes in children undergoing treatment for acute lymphoblastic leukemia
Authors: Baillargeon Jacques , Langevin Anne‐Marie , Lewis Margaret , Estrada Jaime , Grady James J. , Mullins Judith , Pitney Aaron , Pollock Brad H. 
Published: October 2006

AbstractIntroductionWhile it is known that leukemia therapy is associated with obesity in survivorship, limited information is available on its time‐related pattern of development and its variation across patient subgroups. The goal of the present study was to examine demographic correlates of body mass index (BMI) changes over time from diagnosis through chemotherapy for children with B‐precursor acute lymphoblastic leukemia (ALL).MethodsThe study cohort consisted of 307 pediatric patients diagnosed with ALL who were treated at four South Texas pediatric oncology centers between 1990 and 2002. To minimize treatment‐related variability, we excluded patients who received cranial irradiation as part of their treatment. Variation in age‐ and gender‐standardized BMI z‐scores according to age at diagnosis, gender, and ethnicity were assessed.ResultsThe overall study cohort exhibited an increase in age‐ and gender‐adjusted BMI z‐scores for the first 24 months of chemotherapy followed by a slight decrease in BMI at 30 months (end of therapy). A repeated measures analysis indicated a statistically significant difference in the time‐related pattern of BMI changes for age at diagnosis (P = 0.001) but no significant effect for gender (P = 0.32) or Hispanic versus non‐Hispanic ethnicity (P = 0.89).DiscussionIn our cohort of ALL patients, BMI was elevated at diagnosis (mean standardized BMI z‐score = 0.22, standard deviation = 1.4) then increased and remained elevated for the entire duration of chemotherapy. Children who were 2–9 years of age at diagnosis began therapy with a substantially lower BMI and remained lower over the course of chemotherapy than patients aged 10–18 years at diagnosis. It will be important for future investigations to explore the biological and behavioral factors that may underlie such differential patterns of BMI change over time. Pediatr Blood Cancer 2007;49:793–796. © 2006 Wiley‐Liss, Inc.
A novel splice mutation in the TP53 gene associated with Leydig cell tumor and primitive neuroectodermal tumor
Authors: Stecher Chalotte W. , Grønbæk Kirsten , Hasle Henrik 
Published: October 2006

AbstractA 20‐month‐old boy presented with precocious puberty due to a Leydig cell tumor, and at the age of 6 years with a primitive neuroectodermal brain‐tumor (PNET). A novel splice site mutation of the TP53‐gene, likely to be associated with a nonfunctional protein, was found in the proband, his father and younger sister, but only the proband has so far developed malignancy. The clinical phenotype in the boy is suggestive of Li–Fraumeni syndrome, but the family does not strictly conform to the canonical definition. Pediatr Blood Cancer 2008;50:701–703. © 2006 Wiley‐Liss, Inc.
Myelodysplastic syndrome with trisomy 8 associated with Behçet syndrome: An immunologic link to a karyotypic abnormality
Authors: Thachil Jecko V. , Salim Rahuman , Field Anne , Moots Robert , Bolton‐Maggs Paula 
Published: October 2006

AbstractMyelodysplastic syndrome (MDS) in children is often associated with chromosomal anomalies and trisomy 8 is a characteristic karyotypic feature in up to 20% of the cases. Behçet disease is a rare multisystem inflammatory disorder characterized by recurrent mouth and genital ulcers. MDS with trisomy 8 has been observed in adult patients with Behçet syndrome with some cases developing prior to the clinical manifestations of the latter. We present a female with a similar association and explain the importance of identifying the coexisting conditions. The immunological abnormalities, which may be observed in MDS and their possible mechanisms, are also discussed. Pediatr Blood Cancer 2008;50:649–651. © 2006 Wiley‐Liss, Inc.
Validation studies of the health improvement network (THIN) database for pharmacoepidemiology research
Authors: Lewis James D. , Schinnar Rita , Bilker Warren B. , Wang Xingmei , Strom Brian L. 
Published: October 2006

AbstractBackgroundThe Health Improvement Network (THIN) is a new medical records database that contains records from general practices some of which have or continue to participate in the General Practice Research Database (GPRD) and others that never participated in GPRD. We sought to replicate in THIN well‐established associations from the medical literature and to compare results from the GPRD practices to the non‐GPRD practices within THIN.MethodsUsing THIN data from 1986–2003, we conducted case‐control studies of associations between diseases (e.g., hypertension and stroke) and between diseases and drugs (e.g., aspirin and colon cancer). Conditional logistic regression was used to calculate odds ratios adjusted for potential confounders. Differences between GPRD and non‐GPRD practices were assessed by testing for a statistical interaction by practice type in each outcome‐exposure association.ResultsWe observed the expected positive associations (p < 0.05) of stroke with hypertension and diabetes mellitus; of myocardial infarction with hypertension, hypercholesterolemia, obesity, and smoking; and of peptic ulcer disease with aspirin, NSAIDs, and potassium. We observed the expected negative associations (p < 0.05) of colorectal cancer with aspirin, NSAIDs, and cox‐2 inhibitors. The expected protective effect of aspirin use for myocardial infarction was not observed. In all cases, the results obtained from the GPRD practices were similar to the results obtained from the non‐GPRD practices, only being statistically different for the associations of myocardial infarction with diabetes and aspirin use.ConclusionsTHIN data that are collected outside of the GPRD appear as valid as the data collected as part of the GPRD. Copyright © 2006 John Wiley & Sons, Ltd.
Cancer‐related mutations in BRCA1‐BRCT cause long‐range structural changes in protein–protein binding sites: A molecular dynamics study
Authors: Gough Craig A. , Gojobori Takashi , Imanishi Tadashi 
Published: October 2006

AbstractCancer‐associated mutations in the BRCT domain of BRCA1 (BRCA1‐BRCT) abolish its tumor suppressor function by disrupting interactions with other proteins such as BACH1. Many cancer‐related mutations do not cause sufficient destabilization to lead to global unfolding under physiological conditions, and thus abrogation of function probably is due to localized structural changes. To explore the reasons for mutation‐induced loss of function, the authors performed molecular dynamics simulations on three cancer‐associated mutants, A1708E, M1775R, and Y1853ter, and on the wild type and benign M1652I mutant, and compared the structures and fluctuations. Only the cancer‐associated mutants exhibited significant backbone structure differences from the wild‐type crystal structure in BACH1‐binding regions, some of which are far from the mutation sites. Backbone differences of the A1708E mutant from the liganded wild type structure in these regions are much larger than those of the unliganded wild type X‐ray or molecular dynamics structures. These BACH1‐binding regions of the cancer‐associated mutants also exhibited increases in their fluctuation magnitudes compared with the same regions in the wild type and M1562I mutant, as quantified by quasiharmonic analysis. Several of the regions of increased fluctuation magnitude correspond to correlated motions of residues in contact that provide a continuous path of fluctuating amino acids in contact from the A1708E and Y1853ter mutation sites to the BACH1‐binding sites with altered structure and dynamics. The increased fluctuations in the disease‐related mutants suggest an increase in vibrational entropy in the unliganded state that could result in a larger entropy loss in the disease‐related mutants upon binding BACH1 than in the wild type. To investigate this possibility, vibrational entropies of the A1708E and wild type in the free state and bound to a BACH1‐derived phosphopeptide were calculated using quasiharmonic analysis, to determine the binding entropy difference ΔΔS between the A1708E mutant and the wild type. ΔΔS was determined to be −4.0 cal mol−1 K−1, with an uncertainty of 2 cal mol−1 K−1; that is, the entropy loss upon binding the peptide is 4.0 cal mol−1 K−1 greater for the A1708E mutant, corresponding to an entropic contribution to the ΔΔG of binding (−TΔΔS) 1.1 kcal mol−1 more positive for the mutant. The observed differences in structure, flexibility, and entropy of binding likely are responsible for abolition of BACH1 binding, and illustrate that many disease‐ related mutations could have very long‐range effects. The methods described here have potential for identifying correlated motions responsible for other long‐range effects of deleterious mutations. Proteins 2007. © 2006 Wiley‐Liss, Inc.
A fast liquid chromatographic/mass spectrometric screening method for the simultaneous detection of synthetic glucocorticoids, some stimulants, anti‐oestrogen drugs and synthetic anabolic steroids
Authors: Mazzarino Monica , Botrè Francesco 
Published: October 2006

AbstractA fast liquid chromatographic/mass spectrometric (LC/MS/MS) screening method for the detection, in urine, of synthetic glucocorticoids, stimulants (formoterol, modafinil and mesocarb), anti‐oestrogens (finasteride, exemestane, anastrozole, letrozole and formestane) and synthetic anabolic steroids (stanozolol, gestrinone and tetrahydrogestrinone) is described. All these drugs (and/or their urinary metabolites) can be simultaneously extracted by a single liquid/liquid extraction step, at alkaline pH, after enzymatic hydrolysis with β‐glucuronidase, and assayed in 7 min by LC/MS/MS using electrospray ionization in positive ion mode and multiple reaction monitoring as the acquisition mode. All compounds show good reproducibility of both the retention times (CV% <2%) and the relative abundances (CV% <10%). The limits of detection for the anti‐oestrogens, glucocorticoids and steroids are in the range of 1–30 ng/mL, and for the stimulants are in the range of 100–200 ng/mL, thus satisfying the minimum required performance limits of the World Anti‐Doping Agency. Copyright © 2006 John Wiley & Sons, Ltd.
A high‐throughput liquid chromatography/tandem mass spectrometry method for simultaneous quantification of a hydrophobic drug candidate and its hydrophilic metabolite in human urine with a fully automated liquid/liquid extraction
Authors: Wang Perry G. , Zhang Jun , Gage Eric M. , Schmidt Jeffrey M. , Rodila Ramona C. , Ji Qin C. , El‐Shourbagy Tawakol A. 
Published: October 2006

AbstractABT‐869 (A‐741439) is an investigational new drug candidate under development by Abbott Laboratories. ABT‐869 is hydrophobic, but is oxidized in the body to A‐849529, a hydrophilic metabolite that includes both carboxyl and amino groups. Poor solubility of ABT‐869 in aqueous matrix causes simultaneous analysis of both ABT‐869 and its metabolite within the same extraction and injection to be extremely difficult in human urine. In this paper, a high‐performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS) method has been developed and validated for high‐speed simultaneous quantitation of the hydrophobic ABT‐869 and its hydrophilic metabolite, A‐849529, in human urine. The deuterated internal standards, A‐741439D4 and A‐849529D4, were used in this method. The disparate properties of the two analytes were mediated by treating samples with acetonitrile, adjusting pH with an extraction buffer, and optimizing the extraction solvent and mobile phase composition. For a 100 µL urine sample volume, the lower limit of quantitation was approximately 1 ng/mL for both ABT‐869 and A‐849529. The calibration curve was linear from 1.09 to 595.13 ng/mL for ABT‐869, and 1.10 to 600.48 ng/mL for A‐849529 (r2 > 0.9975 for both ABT‐869 and A‐849529). Because the method employs simultaneous quantification, high throughput is achieved despite the presence of both a hydrophobic analyte and its hydrophilic metabolite in human urine. Copyright © 2006 John Wiley & Sons, Ltd.
Determination of fourteen non‐steroidal anti‐inflammatory drugs in animal serum and plasma by liquid chromatography/mass spectrometry
Authors: Vinci Floriana , Fabbrocino Serena , Fiori Maurizio , Serpe Luigi , Gallo Pasquale 
Published: October 2006

AbstractThe European Union has regulated the use of non‐steroidal anti‐inflammatory drugs (NSAIDs) in animal production and requires its member states to detect their residues in different matrices. In this work, a detailed MS and MS/MS study by ion‐trap mass spectrometry of fourteen NSAIDs is described. Two multi‐residue reversed‐phase LC/ESI‐MS/MS methods were developed, one for the determination of salicylic acid, naproxen, carprofen, flurbiprofen, ibuprofen, niflumic acid and meclofenamic acid in the negative ion mode, and the other for the determination of ketoprofen, suxibutazone, diclofenac, mefenamic acid, tolfenamic acid, phenylbutazone and its metabolite oxyphenbutazone in the positive ion mode. It was thus possible to confirm up to 14 different NSAID residues in serum and plasma samples of farmed animals, after chromatographic separation by a linear gradient. These substances were chosen as representative of different chemical subclasses of NSAIDs. The two methods were also validated in‐house at three contamination levels, evaluating specificity and calculating mean recoveries, repeatability and within‐laboratory reproducibility. The MS/MS product ion spectra were successfully used for the qualitative identification of all the drugs tested. All the NSAIDs, apart from salicylic acid, were recovered in high amounts, ranging between 71.6% and 100.9%. Copyright © 2006 John Wiley & Sons, Ltd.
Collision‐induced dissociation of protonated tetrapeptides containing β‐alanine, γ‐aminobutyric acid, ϵ‐aminocaproic acid or 4‐aminomethylbenzoic acid residues
Authors: Talaty Erach R. , Cooper Travis J. , Osburn Sandra , Van Stipdonk Michael J. 
Published: October 2006

AbstractThe influence of the presence and position of a single β‐alanine, γ‐aminobutyric acid, ϵ‐aminocaproic acid or 4‐aminomethylbenzoic acid residue on the tendency to form b‐ and y‐type product ions was determined using a group of protonated tetrapeptides with general sequence XAAG, AXAG and AAXG (where X refers to the position of amino acid substitution). The hypothesis tested was that the ‘alternative’ amino acids would influence product ion signal intensities by inhibiting or suppressing either the nucleophilic attack or key proton transfer steps by forcing the adoption of large cyclic intermediates or blocking cyclization altogether. We found that specific b ions are diminished or eliminated completely when βA, γAbu, Cap or 4AMBz residues are positioned such that they should interfere with the intramolecular nucleophilic attack step. In addition, differences in the relative proton affinities of the alternative amino acids influence the competition between complementary bn and yn ions. For both the AXAG and the XAAG series of peptides, collision‐induced dissociation (CID) generated prominent b ions despite potential inhibition or suppression of intramolecular proton migration by the βA, γAbu, Cap or 4AMBz residues. The prominent appearance of b ions from the AXAG and XAAG peptide is noteworthy, and suggests either that proton migration occurs through larger, ‘whole’ peptide cyclic intermediates or that fragmentation proceeds through a population of [M+H]+ isomers that are initially protonated at amide O atoms. Copyright © 2006 John Wiley & Sons, Ltd.
Bayesian evaluation of group sequential clinical trial designs
Authors: Emerson Scott S. , Kittelson John M. , Gillen Daniel L. 
Published: October 2006

AbstractClinical trial designs often incorporate a sequential stopping rule to serve as a guide in the early termination of a study. When choosing a particular stopping rule, it is most common to examine frequentist operating characteristics such as type I error, statistical power, and precision of confidence intervals (Statist. Med. 2005, in revision). Increasingly, however, clinical trials are designed and analysed in the Bayesian paradigm. In this paper, we describe how the Bayesian operating characteristics of a particular stopping rule might be evaluated and communicated to the scientific community. In particular, we consider a choice of probability models and a family of prior distributions that allows concise presentation of Bayesian properties for a specified sampling plan. Copyright © 2006 John Wiley & Sons, Ltd.
Statistical methods for active extension trials
Authors: Hu Zonghui , Follmann Dean 
Published: October 2006

AbstractThis paper develops methods of analysis for active extension clinical trials. Under this design, patients are randomized to treatment or placebo for a period of time (period 1), and then all patients receive treatment for an additional period of time (period 2). We assume a continuous outcome is measured at baseline and at the end of the two consecutive periods. If only period 1 data is available, classic estimators of the treatment effect include the change score, analysis of covariance, and maximum likelihood (ML). We show how to extend these estimators by incorporating period 2 data which we refer to as the period 2 estimators. Under the assumption that the mean responses for treatment and placebo arms are the same at the end of period 2, the new estimators are unbiased and more efficient than estimators that ignore period 2 data. If this assumption is not met, the period 2 tests may be more powerful than period 1 tests, but the estimators are biased downward (upward) if the treatment effect during period 2 is larger (smaller) in treatment arm than the placebo arm. In general, the proposed period 2 procedure can provide an efficient way to supplement but not supplant the usual period 1 analysis. Copyright © 2006 John Wiley & Sons, Ltd.
The Oxidation of the Aldehyde Groups in Dialdehyde Starch
Authors: Haaksman Ingrid K. , Besemer Arie C. , Jetten Jan M. , Timmermans Johan W. , Slaghek Ted M. 
Published: October 2006

AbstractThis paper describes the difference in relative reactivity of the aldehyde groups present in dialdehyde starch towards different oxidising agents. The oxidation of dialdehyde starch with peracetic acid and sodium bromide leads to only partial oxidation to give mono‐aldehyde‐carboxy starch, while oxidation with sodium chlorite results in dicarboxy derivatives. In order to obtain a more in depth insight into this phenomenon, the products obtained after partial oxidation via both routes were isolated and characterised. The results showed a pronounced difference in preferences between the two carbonyl groups towards the different oxidising agents.
Detecting spurious timeouts in wireless cellular networks using DS‐Agent
Authors: Xin Fei , Jamalipour Abbas 
Published: October 2006

AbstractLarge and sudden variations in packet transmission delays are often unavoidable in wireless networks. Such large delays, refer to as delay spikes (DSs), are likely to exceed several times the typical network round‐trip‐time figures, which can cause TCP spurious timeouts. The spurious timeouts lead to unnecessary retransmissions and reduction of the TCP sender's transmission rate, and degradation of TCP throughput. In this paper we propose a new scheme called DS‐Agent. The spurious timeout is detected by a DS‐Agent and thus TCP sender can response to this spurious timeout accordingly. The simulation results show the better performance of DS‐Agent scheme compared with F‐RTO and TCP Reno in the presence of DSs which is caused by mobility. Copyright © 2006 John Wiley & Sons, Ltd.
Monitoring left ventricular function in adults receiving anthracycline‐containing chemotherapy
Authors: Belham Mark , Kruger Anton , Mepham Sophie , Faganello Giorgio , Pritchard Colin 
Published: October 2006

AbstractAims:To assess prospectively (1) the incidence of early anthracycline‐induced cardiotoxicity; (2) the best predictor for identifying individuals at risk of developing functional cardiotoxicity; and (3) the most sensitive standard echocardiographic measure for the detection of anthracycline‐induced changes in left ventricular (LV) function.Methods:Sixty‐seven consecutive patients (45 male, mean age 50±18 years) requiring doxorubicin‐containing chemotherapy were enrolled. Clinical and echocardiographic assessments occurred before they received any anthracycline, after low‐dose anthracyclines and 1–3 months after completion of their chemotherapy.Results:Twenty six percent of patients without significant pre‐existing cardiac disease developed cardiotoxicity. The parameter that best predicted the development of functional cardiotoxicity was the change in EF between baseline and low dose with an area under the curve of 0.92. The Tei index detected declines in LV function earlier in the course of treatment with anthracyclines and to a greater significance than any other standard echocardiographic measurement but did not predict functional cardiotoxicity.Conclusions:All patients receiving potential cardiotoxic chemotherapy should be under the care of a cardiologist and have their EF monitored closely.
Barré–Lieou syndrome and the problem of the obsolete eponym
Authors: Foster C A , Jabbour P 
Published: October 2006

Background: Eponym lists in major sources can give an aura of legitimacy to discredited diagnoses, as exemplified by the case of Barré–Lieou syndrome, a ‘rare’ vestibular disorder.Methods: A literature review for information on the posterior cervical syndrome of Barré–Lieou.Results: Barré–Lieou syndrome includes very common symptoms – tinnitus, dizziness, and head or neck pain – attributed to ischaemia caused by cervical sympathetic nerve compression. Its original description brings together many unrelated disorders, and its causative mechanism has been discredited. However, it appears credulously in a number of eponym lists, and references to the syndrome are steadily increasing on the internet in general and on alternative medicine and legal profession websites in particular.Conclusion: By inclusion in eponym lists, without a disclaimer, a syndrome can be given legitimacy before the general public. A syndrome, such as Barré–Lieou syndrome, that is useless to the medical profession can unfortunately prove to be very useful for litigants and disability claimants.