bluuebunny/crossref_metadata_2025_split huggingface dataset:
Magnetic resonance imaging and spectroscopy of transgenic models of cancer
Authors: Raman Venu , Pathak Arvind P. , Glunde Kristine , Artemov Dmitri , Bhujwalla Zaver M. 
Published: April 2007

AbstractThe complexity of cancer, where a single genetic alteration can have multiple functional effects, makes it a fascinating but humbling disease to study, and the necessity of investigating it in its entirety is more imperative than ever before. Advances in transgene technology have made it possible to create cancer cells, or mice with specific genetic alterations, and the application of an array of both functional and molecular non‐invasive MR methods to these transgenic cancer cells and mice to characterize their phenotypic traits is revolutionizing our understanding of cancer. With the establishment of multi‐modality molecular imaging centers within barrier or pathogen‐free facilities, multi‐parametric and multi‐modality imaging of transgenic mouse models of human cancer are becoming increasingly prevalent. In this review, we outline some of the methods currently available for generating transgenic mice and cancer cell lines. We also present examples of the application of MR methods to transgenic models that are providing novel insights into the molecular and functional characteristics of cancer and are leading to an era of ‘non‐invasive phenotyping’ of the effects of specific molecular alterations in cancer. Copyright © 2007 John Wiley & Sons, Ltd.
Postmortem delay does not change regional diffusion anisotropy characteristics in mouse spinal cord white matter
Authors: Kim Joong Hee , Trinkaus Kathryn , Ozcan Alpay , Budde Matthew D. , Song Sheng‐Kwei 
Published: April 2007

AbstractIt has been demonstrated previously that water diffusion anisotropy in vivo is equivalent to that observed ex vivo after perfusion fixation in the mouse brain. This finding supports the practice of ex vivo diffusion tensor imaging (DTI) measurement on perfusion‐fixed tissues. However, the validity of extrapolating ex vivo DTI measurements from immersion‐fixed autopsy specimens to the in vivo state is questionable because of variable postmortem delays often encountered before fixation. In this study, we investigated the effect of postmortem delay on the water diffusion anisotropy of ventrolateral spinal cord white matter from mice. Mouse spinal cords, each from the same animal, were examined using DTI in vivo, in situ after death before fixation, and ex vivo immersion fixed 10 h after death. Our results suggest that diffusion anisotropy in mouse spinal cord is preserved up to 10 h after death. Regional characteristics of diffusion anisotropy in mouse spinal cord white matter are equivalent in vivo, in situ after death (up to 10 h before fixation), and ex vivo 15 weeks after immersion fixation. Copyright © 2007 John Wiley & Sons, Ltd.
Application of MRS to mouse models of neurodegenerative illness
Authors: Choi Ji‐Kyung , Dedeoglu Alpaslan , Jenkins Bruce G. 
Published: April 2007

AbstractThe rapid development of transgenic mouse models of neurodegenerative diseases, in parallel with the rapidly expanding growth of MR techniques for assessing in vivo, non‐invasive, neurochemistry, offers the potential to develop novel markers of disease progression and therapy. In this review we discuss the interpretation and utility of MRS for the study of these transgenic mouse and rodent models of neurodegenerative diseases such as Alzheimer's (AD), Huntington's (HD) and Parkinson's disease (PD). MRS studies can provide a wealth of information on various facets of in vivo neurochemistry, including neuronal health, gliosis, osmoregulation, energy metabolism, neuronal–glial cycling, and molecular synthesis rates. These data provide information on the etiology, natural history and therapy of these diseases. Mouse models enable longitudinal studies with useful time frames for evaluation of neuroprotection and therapeutic interventions using many of the potential MRS markers. In addition, the ability to manipulate the genome in these models allows better mechanistic understanding of the roles of the observable neurochemicals, such as N‐acetylaspartate, in the brain. The argument is made that use of MRS, combined with correlative histology and other MRI techniques, will enable objective markers with which potential therapies can be followed in a quantitative fashion. Copyright © 2007 John Wiley & Sons, Ltd.
In Vivo mouse imaging and spectroscopy in drug discovery
Authors: Beckmann Nicolau , Kneuer Rainer , Gremlich Hans‐Ulrich , Karmouty‐Quintana Harry , Blé François‐Xavier , Müller Matthias 
Published: April 2007

AbstractImaging modalities such as micro‐computed tomography (micro‐CT), micro‐positron emission tomography (micro‐PET), high‐resolution MRI, optical imaging, and high‐resolution ultrasound have become invaluable tools in preclinical pharmaceutical research. They can be used to non‐invasively investigate, in vivo, rodent biology and metabolism, disease models, and pharmacokinetics and pharmacodynamics of drugs. The advantages and limitations of each approach usually determine its application, and therefore a small‐rodent imaging laboratory in a pharmaceutical environment should ideally provide access to several techniques. In this paper we aim to illustrate how these techniques may be used to obtain meaningful information for the phenotyping of transgenic mice and for the analysis of compounds in murine models of disease. Copyright © 2007 John Wiley & Sons, Ltd.
Mouse MRI using phased‐array coils
Authors: Gareis Daniel , Wichmann Tobias , Lanz Titus , Melkus Gerd , Horn Michael , Jakob Peter M. 
Published: April 2007

AbstractThe advantages of array coil imaging in human whole‐body MR systems are well known and have gained relevance in many applications and MR techniques. In the field of small‐animal studies, this concept has become increasingly important. In this work, three different phased‐array coils for performing MRI on mice are presented. For imaging at 300 MHz, a four‐channel receive‐only phased‐array coil is introduced. One two‐channel and a four‐channel transmit/receive setup operating at 750 MHz show the feasibility of array coil imaging at 17.6 T. All of these coils show excellent performance and deliver high‐quality MR images of mice. Copyright © 2007 John Wiley & Sons, Ltd.
Quantitative MRI reveals aging‐associated T2 changes in mouse models of Alzheimer's disease
Authors: Falangola M. F. , Dyakin V. V. , Lee S. P. , Bogart A. , Babb J. S. , Duff K. , Nixon R. , Helpern J. A. 
Published: April 2007

AbstractIn this study, we used MRI to analyze quantitative parametric maps of transverse (T2) relaxation times in a longitudinal study of transgenic mice expressing mutant forms of amyloid precursor protein (APP), presenilin (PS1), or both (PS/APP), modeling aspects of Alzheimer's disease (AD). The main goal was to characterize the effects of progressive β‐amyloid accumulation and deposition on the biophysical environment of water and to investigate if these measurements would provide early indirect evidence of AD pathological changes in the brains of these mice. Our results demonstrate that at an early age before β‐amyloid deposition, only PS/APP mice show a reduced T2 in the hippocampus and cortex compared with wild‐type non‐transgenic (NTg) controls, whereas a statistically significant within‐group aging‐associated decrease in T2 values is seen in the cortex and hippocampus of all three transgenic genotypes (APP, PS/APP, and PS) but not in the NTg controls. In addition, for animals older than 12 months, we confirmed our previous report that only the two genotypes that form amyloid plaques (APP and PS/APP) have significantly reduced T2 values compared with NTg controls. Thus, T2 changes in these AD models can precede amyloid deposition or even occur in AD models that do not deposit β‐amyloid (PS mice), but are intensified in the presence of amyloid deposition. Copyright © 2007 John Wiley & Sons, Ltd.
4D cardiac MRI in the mouse
Authors: Feintuch Akiva , Zhu Yonghong , Bishop Jonathan , Davidson Lorinda , Dazai Jun , Bruneau Benoit G. , Henkelman R. Mark 
Published: April 2007

AbstractWith the introduction of mouse models for the study of cardiac morphogenesis, there arises a need for new imaging protocols that can capture both morphological and functional information. High‐resolution 2D cardiac cine MRI has often been used to quantify left and right ventricular function. In this study we propose a 3D isotropic cardiac cine MRI protocol with a voxel size of 200 µm3 as a means of studying cardiac multi‐chamber morphology and function. A black blood sequence was used to enhance blood myocardium contrast. Manual segmentation of the ventricles was used to measure ventricular volumes at end diastole and end systole. This method is demonstrated on an Irx4‐deficient mouse model. We have been able to identify the volumes of both ventricles dynamically and to show differences in ejection fraction in the mutant. We have also identified an abnormality of the papillary muscle in the mutant that had been missed in previous phenotyping with ultrasound and histology. Copyright © 2007 John Wiley & Sons, Ltd.
MRI of mouse models of neurological disorders
Authors: Anderson Stasia A. , Frank Joseph A. 
Published: April 2007

AbstractMRI has contributed to significant advances in the understanding of neurological diseases in humans. It has also been used to evaluate the spectrum of mouse models spanning from developmental abnormalities during embryogenesis, evaluation of transgenic and knockout models, through various neurological diseases such as stroke, tumors, degenerative and inflammatory diseases. The MRI techniques used clinically are technically more challenging in the mouse because of the size of the brain; however, mouse imaging provides researchers with the ability to explore cellular and molecular imaging that one day may translate into clinical practice. This article presents an overview of the use of MRI in mouse models of a variety of neurological disorders and a brief review of cellular imaging using magnetically tagged cells in the mouse central nervous system. Published in 2007 by John Wiley & Sons, Ltd.
Liver biopsy results in patients with sickle cell disease on chronic transfusions: Poor correlation with ferritin levels
Authors: Karam Lina B. , Disco Deborah , Jackson Sherron M. , Lewin David , Mckie Virgil , Baker Robert D. , Baker Susan S. , Laver Joseph H. , Nietert Paul J. , Abboud Miguel R. 
Published: April 2007

AbstractBackground:Chronic transfusions are effective in preventing stroke and other complications of sickle cell disease. The aim of this study was to determine whether serum ferritin levels correlated with liver iron content in sickle cell patients on chronic transfusion.Procedure:Forty‐four liver biopsy specimens from 38 patients with homozygous sickle cell anemia (HbSS) and one patient with sickle thalassemia receiving chronic transfusions were studied. Five patients underwent a second liver biopsy for follow up. Three ferritin measurements were used to calculate a mean for each patient. The association between serum ferritin levels and liver iron quantitation was measured using the Spearman rank correlation, and sensitivity and specificity were determined for selected threshold values of serum ferritin.Results:Serum ferritin levels ranged from 515 to 6076 ng/ml, liver iron concentration ranged from 1.8 to 67.97 mg/g dry weight. The amount of iron per gram liver dry weight was moderately correlated with serum ferritin values (r = 0.46). The correlation of duration of transfusion with serum ferritin (r = 0.40) and with liver iron content (r = 0.41) also indicated moderate correlation. Liver biopsy results led to changes in the management after 29/44 (66%) of the biopsies. Serum ferritin ≥2500 ng/ml predicted high liver iron content (≥7 mg/g), with a sensitivity of 62.5% and a specificity of 77.8%.Conclusion:We found a poor correlation between serum ferritin levels and liver iron content (LIC). Despite being on chelation therapy, many patients on chronic transfusion had high levels of liver iron. Measurement of LIC is highly recommended in these patients. Pediatr Blood Cancer 2008;50:62–65. © 2007 Wiley‐Liss, Inc.
The absence of donor‐derived IL‐13 exacerbates the severity of acute graft‐versus‐host disease following allogeneic bone marrow transplantation
Authors: Hildebrandt Gerhard C. , Choi Sung W. , Mueller Gunnar , Olkiewicz Krystyna M. , Moore Bethany B. , Cooke Kenneth R. 
Published: April 2007

AbstractAcute graft versus host disease (aGVHD) after allogeneic bone marrow transplantation (allo‐BMT) predominantly involves a Th1‐type cytokine response. Interestingly, the Th2‐cytokine, Interleukin‐13 (IL‐13), produced by alloreactive donor T cells in vitro was recently shown to correlate with clinical aGVHD severity. Using an established mouse model, we show that the systemic cytokine milieu following allo‐BMT with IL‐13−/− donors is characterized by decreases in serum Th2 cytokines and an increase in serum TNFα, and ultimately correlates with higher aGVHD mortality compared to allogeneic controls. In vitro studies further demonstrate that both exogenous and T cell‐derived IL‐13 can regulate TNFα production by macrophages following lipopolysaccharide stimulation. Thus, donor‐derived IL‐13 may have a role in modulating inflammatory cytokine release that is associated with aGVHD. Pediatr Blood Cancer 2008;50:911–914. © 2007 Wiley‐Liss, Inc.
Application of QF‐PCR for the prenatal assessment of discordant monozygotic twins for fetal sex
Authors: Fernández‐Martínez F. J. , Galindo A. , Moreno‐Izquierdo A. , Gómez‐Rodríguez M. J. , Moreno‐García M. , Grañeras A. , Barreiro E. 
Published: April 2007

AbstractObjectiveTo establish the utility of quantitative fluorescent polymerase chain reaction (QF‐PCR) in order to determine the zygosity of multiple pregnancies, as well as to define the origin of the most frequent aneuploidies in amniotic fluid samples.MethodsWe describe the case of a monochorionic (MC) diamniotic (DA) pregnancy with phenotypically discordant twins (nuchal cystic hygroma and non‐immune hydrops in twin A and no anomalies in twin B). QF‐PCR was performed for rapid prenatal diagnosis in uncultured amniocytes and subsequently in cultured cells. Polymorphic markers for chromosomes X, Y, 13, 18 and 21 were used for determination of zygosity as well as sex chromosome aneuploidy.ResultsTwin A showed a Turner Syndrome (TS) mosaicism pattern by QF‐PCR in uncultured amniocytes. The monozygotic origin of the pregnancy was determined. Interphase fluorescence in situ hybridization (I‐FISH) in this sample showed a mosaicism X0/XY (83/17%). Cytogenetic analysis revealed a 45,X0 karyotype in twin A and a 46,XY karyotype in twin B.ConclusionsQF‐PCR is a reliable tool for the determination of the zygosity independently of the chorionicity and the fetal sex in case of twin pregnancy. Testing both direct and cultured cells can provide useful results for genetic counselling in chromosomal mosaicisms. Copyright © 2007 John Wiley & Sons, Ltd.
The Influence of Pulse Frequency and Duty on the Deposition Rate in Pulsed Magnetron Sputtering
Authors: Kelly Peter J. , Onifade Ayokola A. , Zhou Yanwen , Clarke Gregory C. B. , Audronis Martynas , Bradley James W. 
Published: April 2007

AbstractThis paper investigates the influence of pulse frequency and duty on the deposition rate during the pulsed magnetron sputtering process. Whilst deposition rates increased with duty, they also showed a very marked decrease with pulse frequency. Detailed analysis of the data implies that there is a ‘dead time’ of the order of at least 500 ns at the beginning of each pulse‐on cycle, during which negligible sputtering takes place. As pulse frequency increases, the ‘dead time’ becomes a greater proportion of the total on‐time, thus leading to a fall in the deposition rate. Other factors also contributing to this effect include a reduction in the average power delivered to the target as pulse frequency is increased, and significant differences with frequency in the rate of change of target voltage at the beginning of each pulse on cycle.magnified image
Trends in Combining Techniques for the Deposition of New Application‐Tailored Thin Films
Authors: Dinescu Gheorghe , Ruset Cristian , Dinescu Maria 
Published: April 2007

AbstractA modern approach for the development of thin film deposition technology is to combine the classical principles of PVD and CVD techniques, and to assist them with the recent progress in plasma sources and reactors. The power of inter‐combining the deposition methods with new ideas and tools is discussed for a particular number of cases, such as the combination of magnetron sputtering with pulsed ion implantation, of pulsed laser deposition with low‐pressure radiofrequency directional plasma beams, and of magnetron sputtering with plasma‐beam‐enhanced chemical vapor deposition. The discussed cases are complemented with examples from literature, highlighting the recent trends in combining plasma based deposition techniques, and the need for an improvement in the terminology.magnified image
Helianthos: Roll‐to‐Roll Deposition of Flexible Solar Cell Modules
Authors: Hamers Edward A. G. , van den Donker Menno N. , Stannowski Bernd , Schlatmann Rutger , Jongerden Gert J. 
Published: April 2007

AbstractIn the development of the roll‐to‐roll deposition of amorphous silicon by means of plasma enhanced chemical vapor deposition, a number of different plasma aspects have been of importance. First, the understanding of process windows in terms of a dust free plasma has led to the formulation of an empirical scaling law for the dust free to dust forming transition in terms of the crucial process parameters such as, e.g., power and gas flows. Second, the homogeneity of deposition on an effective width of 30 cm has been demonstrated to be better than 5%. Increasing the deposition rate might be achieved by increasing the power density, but it scales only as (power density)0.77. A last important issue in roll‐to‐roll processing of long runs is process stability and on‐line quality control. The accurate measurement of self bias voltage and optical thickness of the deposited stacks have proven to be very useful in this context.magnified image
Immobilization of Tungsten Catalysts on Plasma Modified Membranes
Authors: Lopez Linda C. , Buonomenna Maria G. , Fontananova Enrica , Drioli Enrico , Favia Pietro , d'Agostino Riccardo 
Published: April 2007

AbstractNovel catalytic membranes were developed by coupling low‐temperature plasma treatments with the chemical immobilization of W‐based catalysts. Poly(vinylidene fluoride) membranes were pre‐treated with Ar, and then treated with NH3 radiofrequency glow discharges in order to obtain a surface rich in amino groups, which are suitable anchor sites for the immobilization of tungsten‐based heterogeneous catalysts. In particular, we have focused our interest on tungstate ions (WO), which catalyze the oxidation of secondary amines to nitrones, and on decatungstate (W10O) and phosphotungstate (W12PO) ions, which can both be used as catalysts for the degradation of organic pollutants such as phenol.magnified image
A new model for ordinal pain data from a pharmaceutical study
Authors: Chuang Christy , Agresti Alan 
Published: April 2007

AbstractFor the pain data analysed previously by Cox and Chuang. This paper proposes a new model that assumes monotone scores for ordered response categories. This proposed model possesses several attractive features and allows a stochastic ordering of the drugs under comparison. Such a model also provides insight regarding the ordinal scale used to classify response. Estimation of the parameters in the model is obtained by use of BMDP3R.
Choosing the number of controls in a matched case‐control study, some sample size, power and efficiency considerations
Authors: Taylor Jeremy M. G. 
Published: April 2007

AbstractThis paper investigates the efficiency of using multiple controls in a case‐control study, when there is a single binary exposure variable. Specifically, we consider the asymptotic power of the Cochran1 test statistic against non‐local alternatives of interest. When it is desirable to take multiple controls per case, we show that the marginal return rapidly diminishes as the number of controls per case increases. The effect is as strong, if not stronger, for non‐local alternatives as it is for local alternatives. Hence, it is rarely worth choosing more than three controls per case. We also provide a table of sample sizes necessary to achieve 80 per cent power for some odds ratios not equal to one. We extend the results to a special case when there are two binary exposure variables.
Box‐jenkins modelling of some viral infectious diseases
Authors: Helfenstein Ulrich 
Published: April 2007

AbstractDuring the last few years Box‐Jenkins models have become of increasing importance in such fields as economics and industry. They have been used for forecasting and for detecting relations between different time series. Similar applications are also relevant in epidemiology.Since many people who are concerned with the analysis of medical data are not familiar with this subject, a short non‐technical introduction to Box‐Jenkins models is given. The model‐building process is demonstrated in some detail using monthly case reports of the two seasonal endemic diseases chicken‐pox and mumps, and the relation between these two time series is investigated. It is found that both diseases may be represented by simple models which have basically the same statistical structure and that they are related at time‐lag O but not at other time‐lags.
Statistical methods for relating several exposure factors to several diseases in case‐heterogeneity studies
Authors: Thomas D. C. , Goldberg M. , Dewar R. , Siemiatycki J. 
Published: April 2007

AbstractStatistical methods for characterizing risks are now well‐developed, although little attention has focussed on the problem of risk identification, as in the surveillance of adverse drug reactions or occupational cancers. In this paper we consider the analysis of studies in which one ascertains and compares cases of several disease groups in terms of exposure histories. We address the problem of adjusting each risk for the confounding effects of all the other risks in the data. Data analysis consists of multidimensional contingency tables or polychotomous logistic regression. The latter approach focuses attention on the exposure‐disease relations of primary interest rather than on those among the exposure factors and higher‐order interactions, and applies easily to many exposure variables and to continuous exposure variables. We describe a stepwise approach to selecting effects for inclusion in the model. Application to preliminary data from a study aimed at identification of hitherto unsuspected occupational carcinogens illustrates the general approach.
Prediction of sudden infant death syndrome: An independent evaluation of four scoring methods
Authors: Peters Tim J. , Golding Jean 
Published: April 2007

AbstractThe performances of four published risk prediction systems for sudden infant death syndrome (SIDS) were compared for the 34 cases of SIDS and 48 explained deaths among a cohort of all births in the U.K. during one week in April 1970.With cut‐points for the scores which would include about 20 per cent of the population, the sensitivities of the scoring methods ranged from identifying 40 per cent of the explained deaths to 70 per cent of SIDS. The highest sensitivities were achieved with the Sheffield ‘at birth’ system and a system based on both data from Oxford and general observations from the literature, with the latter system providing the most powerful predictor of SIDS for the study sample.