bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct magnetic resonance imaging of histological tissue samples at 3.0T
Authors: Meadowcroft Mark D. , Zhang Shutong , Liu Wanzhan , Park Bu Sik , Connor James R. , Collins Christopher M. , Smith Michael B. , Yang Qing X. 
Published: April 2007

AbstractDirect imaging of a histological slice is challenging. The vast difference in dimension between planar size and the thickness of histology slices would require an RF coil to produce a uniform RF magnetic (B1) field in a 2D plane with minimal thickness. In this work a novel RF coil designed specifically for imaging a histology slice was developed and tested. The experimental data demonstrate that the coil is highly sensitive and capable of producing a uniform B1 field distribution in a planar region of histological slides, allowing for the acquisition of high‐resolution T2 images and T2 maps from a 60‐μm‐thick histological sample. The image intensity and T2 distributions were directly compared with histological staining of the relative iron concentration of the same slice. This work demonstrates the feasibility of using a microimaging histological coil to image thin slices of pathologically diseased tissue to obtain a precise one‐to‐one comparison between stained tissue and MR images. Magn Reson Med 57:835–841, 2007. © 2007 Wiley‐Liss, Inc.
Reconstruction of undersampled dynamic images by modeling the motion of object elements
Authors: Prieto Claudia , Batchelor Philip G. , Hill D.L.G. , Hajnal Joseph V. , Guarini Marcelo , Irarrazaval Pablo 
Published: April 2007

AbstractDynamic MRI is restricted due to the time required to obtain enough data to reconstruct the image sequence. Several undersampled reconstruction techniques have been proposed to reduce the acquisition time. In most of these techniques the nonacquired data are recovered by modeling the temporal information as varying pixel intensities represented in time or in temporal frequencies. Here we propose a new approach that recovers the missing data through a motion estimation of the object elements (“obels,” or pieces of tissue) of the image. This method assumes that an obel displacement through the sequence has lower bandwidth than fluctuations in pixel intensities caused by the motion, and thus it can be modeled with fewer parameters. Preliminary results show that this technique can effectively reconstruct (with root mean square (RMS) errors below 4%) cardiac images and joints with undersampling factors of 8 and 4, respectively. Moreover, in the reconstruction process an approximation of the motion vectors is obtained for each obel, which can be used to quantify dynamic information. In this method the motion need not be confined to a part of the field of view (FOV) or to a portion of the temporal frequency. It is appropriate for dynamic studies in which the obels' motion model has fewer parameters than the number of acquired samples. Magn Reson Med 57:939–949, 2007. © 2007 Wiley‐Liss, Inc.
Probabilistic solution and bounds for serial inventory systems with discounted and average costs
Authors: Chao Xiuli , Zhou Sean X. 
Published: April 2007

AbstractWe consider the infinite horizon serial inventory system with both average cost and discounted cost criteria. The optimal echelon base‐stock levels are obtained in terms of only probability distributions of leadtime demands. This analysis yields a novel approach for developing bounds and heuristics for optimal inventory control polices. In addition to deriving the known bounds in literature, we develop several new upper bounds for both average cost and discounted cost models. Numerical studies show that the bounds and heuristic are very close to optimal.© 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007
Neurodevelopment of C57B/L6 mouse brain assessed by in vivo diffusion tensor imaging
Authors: Chahboune Halima , R. Ment Laura , B. Stewart William , Ma Xiaoxian , Rothman Douglas L. , Hyder Fahmeed 
Published: April 2007

AbstractHeterogeneous spatiotemporal patterns of C57B/L6 murine brain maturation during the first 7 weeks after birth (i.e. P15 to P45) were assessed in vivo by diffusion tensor imaging (DTI) at 9.4 T. Maps of apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were used to assess developmental changes. Because directionally encoded color (DEC) maps provide an efficient and straightforward way to visualize anisotropy direction, they were used to highlight the orientation‐dominant anisotropic tissues. In the corpus callosum, the increases in FA (∼0.4 to ∼0.6 from P15 to P45) were primarily dominant in the medial–lateral direction, whereas the ADC decreased slightly (∼0.8 × 10−3 to ∼0.5 × 10−3 mm2/s from P15 to P45). Similar increases in FA (∼0.3 to ∼0.4 from P15 to P45) and decreases in ADC (∼0.8 × 10−3 to ∼0.5 × 10−3 mm2/s from P15 to P45) were found in the cingulate, but these anisotropic changes were dominant in the anterior–posterior direction. In the caudate putamen, there were significant FA increases (∼0.1 to ∼0.2 from P15 to P45) dominant in the dorsal–ventral and anterior–posterior directions, whereas the ADC increased rapidly early in development (∼0.3 × 10−3 to ∼0.7 × 10−3 mm2/s from P15 to P17). There were no significant changes in tissue anisotropy in the somatosensory regions (whisker, forelimb), but the ADC decreased slightly (∼0.7 × 10−3 to ∼0.5 × 10−3 mm2/s from P15 to P45). Although the major differences in DEC values were mainly observed in white matter pathways, other cortical and subcortical regions showed some potential morphological changes that were consistent with classical histological findings. In summary, these results show that high‐resolution DTI at high magnetic fields allows detection and quantification of brain structures throughout normal development in C57B/L6 mice in vivo. Copyright © 2007 John Wiley & Sons, Ltd.
Developing MR reporter genes: promises and pitfalls
Authors: Gilad Assaf A. , Winnard Paul T. , van Zijl Peter C. M. , Bulte Jeff W. M. 
Published: April 2007

AbstractMR reporter genes have the potential to monitor transgene expression non‐invasively in real time at high resolution. These genes can be applied to interrogate the efficacy of gene therapy, to assess cellular differentiation, cell trafficking, and specific metabolic activity, and also assess changes in the microenvironment. Efforts toward the development of MR reporter genes have been made for at least a decade, but, despite these efforts, the field is still in its early developmental stage. This reflects the fact that there are potential pitfalls, caused by the low sensitivity of detection, the need for substrates with their associated undesirable pharmacokinetics, and/or the difficult and, in some cases, delayed interpretation of signal changes. Nevertheless, significant progress has been made during the last few years. Whereas enzyme‐based reporters were initially applied to NMR spectroscopic monitoring of changes in phosphor and fluorine metabolism, MRI‐based approaches are now emerging that rely on: (1) enzyme‐based cleavage of functional groups that block water (proton) exchange or protein binding of MR contrast agents; (2) expression of surface receptors that enable binding of specific MR contrast agents; (3) expression of para‐ and anti‐ferromagnetic (metallo)proteins involved with iron metabolism, such as tyrosinase, transferrin receptor, and ferritin. After an introduction to the basic principles of designing promoters, expression vectors, and cloning of transgenes, a fresh look is provided on the use of reporter genes for optical (including bioluminescent) and nuclear imaging, with which MR reporter genes compete. Although progress in the use of MR reporter genes has been slow, newer strategies that use metalloproteins or alternative contrast mechanisms, with no need for substrates, promise rapid growth potential for this field. Copyright © 2007 John Wiley & Sons, Ltd.
MR technology for biological studies in mice
Authors: Nieman Brian J. , Bishop Jonathan , Dazai Jun , Bock Nicholas A. , Lerch Jason P. , Feintuch Akiva , Chen X. Josette , Sled John G. , Henkelman R. Mark 
Published: April 2007

AbstractMouse models are crucial for the study of genetic factors and processes that influence human disease. In addition to tools for measuring genetic expression and establishing genotype, tools to accurately and comparatively assess mouse phenotype are essential in order to characterize pathology and make comparisons with human disease. MRI provides a powerful means of evaluating various anatomical and functional changes and hence is growing in popularity as a phenotypic readout for biomedical research studies. To accommodate the large numbers of mice needed in most biological studies, mouse MRI must offer high‐throughput image acquisition and efficient image analysis. This article reviews the technology of multiple‐mouse MRI, a method that images multiple mice or specimens simultaneously as a means of enabling high‐throughput studies. Aspects of image acquisition and computational analysis in multiple‐mouse studies are also described. Copyright © 2007 John Wiley & Sons, Ltd.
Non‐invasive MRI of mouse models of atherosclerosis
Authors: Weinreb David B. , Aguinaldo Juan Gilberto S. , Feig Jonathan E. , Fisher Edward A. , Fayad Zahi A. 
Published: April 2007

AbstractEarly detection and characterization of atherosclerotic lesions susceptible to sudden rupture and thrombosis may decrease morbidity and mortality. Plaque development has been extensively studied using MRI in animal models of rapidly progressing atherosclerosis. These transgenic mice develop atherosclerotic plaques in the aortic root by 10 weeks of age and throughout the vasculature thereafter. Transplantation of lesion‐containing segments of the thoracic aorta into wild‐type mice results in nearly total reversal of atherosclerosis, making it possible to study both progression and regression of plaques in this model. MRI permits the non‐invasive accurate assessment of atherosclerotic plaque burden and the differentiation between the lipid and fibrous content of individual plaques, thus providing a non‐invasive approach to serially monitor the evolution of individual plaques in the mouse models. Emergence of novel contrast agents that target a diverse set of molecules within the plaque are now helping to elucidate the changes at the cellular and molecular levels during plaque progression and regression. Copyright © 2007 John Wiley & Sons, Ltd.
Radio frequency coil technology for small‐animal MRI
Authors: Doty F. David , Entzminger George , Kulkarni Jatin , Pamarthy Kranti , Staab John P. 
Published: April 2007

AbstractA review of the theory, technology, and use of radio frequency (RF) coils for small‐animal MRI is presented. It includes a brief overview of MR signal‐to‐noise (S/N) analysis and discussions of the various coils commonly used in small‐animal MR: surface coils, linear volume coils, birdcages, and their derivatives. The scope is limited to mid‐range coils, i.e. coils where the product (fd) of the frequency f and the coil diameter d is in the range 2–30 MHz‐m. Common applications include mouse brain and body coils from 125 to 750 MHz, rat body coils up to 500 MHz, and small surface coils at all fields. In this regime, all the sources of loss (coil, capacitor, sample, shield, and transmission lines) are important. All such losses may be accurately captured in some modern full‐wave 3D electromagnetics software, and new simulation results are presented for a selection of surface coils using Microwave Studio 2006 by Computer Simulation Technology, showing the dramatic importance of the ‘lift‐off effect’. Standard linear circuit simulators have been shown to be useful in optimization of complex coil tuning and matching circuits. There appears to be considerable potential for trading S/N for speed using phased arrays, especially for a larger field of view. Circuit simulators are shown to be useful for optimal mismatching of ultra‐low‐noise preamps based on the enhancement‐mode pseudomorphic high‐electron‐mobility transistor for optimal coil decoupling in phased arrays. Cryogenically cooled RF coils are shown to offer considerable opportunity for future gains in S/N in smaller samples. Copyright © 2007 John Wiley & Sons, Ltd.
MR in mouse models of cardiac disease
Authors: Epstein Frederick H. 
Published: April 2007

AbstractTransgenic and knockout mice can be used to study the genes and basic mechanisms involved in heart disease, and have therefore assumed a central role in modern cardiac research. MRI and MRS techniques have recently been developed for mice that enable the quantitative or semi‐quantitative in vivo assessment of cardiac anatomy, function, perfusion, infarction, Ca2+ influx, and metabolism. With these techniques, the normal mouse heart has been shown to be well suited as a model of human cardiac disease. The roles of individual genes in normal cardiac physiology have recently been studied by MR, including the role of neuronal nitric oxide synthase in β‐adrenergic stimulation, the roles of the inducible nitric oxide synthase and myoglobin in function, dilation, and energetics, and the role of cardiac troponin I in contractility. Furthermore, with a mouse model of myocardial infarction, the roles of the angiotensin II type 2 receptor, xanthine oxidase inhibitors, blood coagulation factor XIII, and inducible nitric oxide synthase in post‐infarct function and remodeling have been further elucidated. Non‐invasive in vivo MRI and MRS in mice provide a unique and powerful means for phenotyping genetically engineered mice and can improve our understanding of the roles of specific genes and proteins in cardiac physiology and pathophysiology. Copyright © 2007 John Wiley & Sons, Ltd.
MRI monitoring of focal cerebral ischemia in peroxisome proliferator‐activated receptor (PPAR)‐deficient mice
Authors: Pialat Jean‐Baptiste , Cho Tae‐Hee , Beuf Olivier , Joye Elisabeth , Moucharaffie Samir , Langlois Jean‐Baptiste , Nemoz Chantal , Janier Marc , Berthezene Yves , Nighoghossian Norbert , Desvergne Béatrice , Wiart Marlène 
Published: April 2007

AbstractPeroxisome proliferator‐activated receptors (PPARs) are a potential target for neuroprotection in focal ischemic stroke. These nuclear receptors have major effects in lipid metabolism, but they are also involved in inflammatory processes. Three PPAR isotypes have been identified: α, β (or δ) and γ. The development of PPAR transgenic mice offers a promising tool for prospective therapeutic studies. This study used MRI to assess the role of PPARα and PPARβ in the development of stroke. Permanent middle cerebral artery occlusion induced focal ischemia in wild‐type, PPARα‐null mice and PPARβ‐null mice. T2‐weighted MRI was performed with a 7 T MRI scan on day 0, 1, 3, 7 and 14 to monitor lesion growth in the various genotypes. General Linear Model statistical analysis found a significant difference in lesion volume between wild‐type and PPAR‐null mice for both α and β isotypes. These data validate high‐resolution MRI for monitoring cerebral ischemic lesions, and confirm the neuroprotective role of PPARα and PPARβ in the brain. Copyright © 2007 John Wiley & Sons, Ltd.
Association of cell cycle‐related gene products and NF‐kappaB with clinical parameters in Langerhans cell histiocytosis
Authors: Amir Gail , Weintraub Michael 
Published: April 2007

AbstractBackgroundLangerhans cell histiocytosis (LCH) is a rare disorder characterized by the accumulation of abnormal Langerhans cells in one or several organs where they cause local tissue damage. The pathophysiology is not well understood. The aim of this study was to examine expression of various gene products that play a role in cell cycle and cell death and to look for an association with the extent of the disease at the time of diagnosis and with “risk bone” involvement.ProcedureHistologic slides from cases with biopsy proven disease were stained immunohistochemically for Bcl‐2, caspase‐3, Ki‐67, p53, and nuclear factor‐kappaB (NF‐κB) and the results were quantitated and compared with the clinical extent of the disease.ResultsIn patients with multisystem disease and “risk” bone involvement, a higher percentage of Langerhans cells stained with the anti‐apoptotic gene product Bcl‐2 (P = 0.0004; P = 0.001 respectively) and a lower percentage of these cells stained with the apoptosis marker caspase‐3 compared to patients with single system disease (P = 0.0001; P = 0.01 respectively). Proliferation marker Ki‐67 was expressed more frequently in multisystem disease compared to single system disease (P = 0.02) but an association with “risk” bone involvement was not found. Expression of p53 and NF‐κB did not discriminate between clinical subgroups.ConclusionsThe findings suggest that cell proliferation and suppression of apoptosis may be mechanisms of cell survival in the more aggressive forms of LCH (multisystem, risk bone involvement). Pediatr Blood Cancer 2008;50:304–307. © 2007 Wiley‐Liss, Inc.
Triple intrathecal therapy without cranial irradiation for central nervous system preventive therapy in childhood acute lymphoblastic leukemia
Authors: Lin Wei‐Ying , Liu Hsi‐Che , Yeh Ting‐Chi , Wang Lin‐Yen , Liang Der‐Cherng 
Published: April 2007

AbstractBackgroundTo evaluate the treatment results of central nervous system preventive therapy (CNSP) with triple intrathecal therapy (TIT) alone in children with acute lymphoblastic leukemia (ALL).MethodsWe retrospectively studied a cohort of 59 patients with median follow‐up time 50.6 months (range: 27–80 months) at a single institution in Taiwan. Patients with ALL were classified in risk groups at diagnosis. TPOG‐ALL‐93 protocols and TPOG‐ALL‐2002 protocols were used. Both protocols were for multicenter studies in Taiwan and contained protocols for standard‐risk (SR), high‐risk (HR), and very‐high‐risk (VHR) patients. In this study, we used TIT alone for CNSP. In all ALL patients, methotrexate, hydrocortisone, and cytarabine were given at age‐dependent doses.ResultsAs of October 2006, patients had a 3‐year event‐free survival and an overall survival 89.4 ± 4.1% (S.E.) and 93.1 ± 3.3%, respectively. Under TIT no patients had complications such as seizure, encephalitis, or infection, and no morbidities like those caused by cranial irradiation. In this study, we used TIT alone for CNSP and had no CNS relapse.ConclusionsIn the context of effective systemic therapy, TIT alone appears to be effective CNSP for most patients with ALL. Pediatr Blood Cancer 2008;50:523–527. © 2007 Wiley‐Liss, Inc.
Essential thrombocythemia in a child with elevated thrombopoietin concentrations and skeletal anomalies
Authors: Robins Edwin B. , Niazi Massoma 
Published: April 2007

AbstractEssential thrombocythemia is a rare myleoproliferative disorder in pediatrics. This myleoproliferative disorder is characterized by excessive proliferation of megakaryocytes and sustained elevation of platelet count. Reactive thrombocytosis is a more common cause of elevated platelet counts among children. We describe a 2‐year‐old child with essential thrombocythemia, skeletal anomalies, and elevated thrombopoietin concentrations. The child's mother was also subsequently diagnosed with essential thrombocythemia and had elevated thrombopoietin concentrations. Chromosomal studies on the mother, child and other family members were normal. Pediatr Blood Cancer 2008;50:859–861. © 2007 Wiley‐Liss, Inc.
Analysis of outcome for patients with mass lesions of the central nervous system due to Langerhans cell histiocytosis treated with 2‐chlorodeoxyadenosine
Authors: Dhall Girish , Finlay Jonathan L. , Dunkel Ira J. , Ettinger Lawrence J. , Kellie Stewart J. , Allen Jeffrey C. , Egeler R. Maarten , Arceci Robert J. 
Published: April 2007

AbstractPurposeTo assess the activity and tolerability of 2‐chlorodeoxyadenosine (2‐CDA) in treating mass lesions of the central nervous system (CNS) due to Langerhans cell histiocytosis (LCH).Patients and MethodsThe records of eight children and four adults with CNS LCH who were treated with 2‐CDA were reviewed. The pattern of CNS disease included involvement of the hypothalamic‐pituitary axis, gadolinium enhancing parenchymal as well as dural and choroid plexus based mass lesions, and atrophy. 2‐CDA (5–13 mg/m2/day) was given on 3–5 consecutive days and repeated every 2–8 weeks for a period ranging from 3 to 12 months.ResultsEight patients demonstrated a complete radiographic response to 2‐CDA with resolution of all enhancing mass lesions and four patients showed a sustained, partial radiographic response. One patient died from a non‐treatment related cause without evidence of LCH on autopsy. With a follow‐up ranging from 2 to 10 years after completion of therapy, the 11 surviving patients remain in continuous remission or are progression free. Prolonged bone marrow suppression was the most common toxicity (four patients). Permanent sequelae of CNS LCH, such as panhypopituitarism, diabetes insipidus (DI) and neurocognitive dysfunction, were not found to be reversible with 2‐CDA therapy.Conclusions2‐CDA is an active agent in patients with CNS LCH, with the possible exception of neurodegenerative disease, and should be further evaluated in a prospective multi‐center clinical trial for LCH patients with enhancing mass lesions of the CNS. Pediatr Blood Cancer 2008;50:72–79. © 2007 Wiley‐Liss, Inc.
Bone marrow assessment in Langerhans cell histiocytosis
Authors: Minkov Milen , Pötschger Ulrike , Grois Nicole , Gadner Helmut , Dworzak Michael N. 
Published: April 2007

AbstractBackgroundBone marrow changes and their relation to blood cytopenia in patients with Langerhans cell histiocytosis (LCH) have not been extensively studied to date. The aim of the present study was to characterize the bone marrow changes in LCH patients and to ascertain their relation to disease severity.MethodsFifty‐seven marrow samples of LCH patients were studied by conventional cytology, immunocytochemistry (ICC) and flow cytometry (FCM).ResultsOn conventional cytology there was no significant difference between LCH cases and controls with respect to cellularity, number of monocytes and progenitor cells, and presence of histiocytes and hemophagocytosis. The numbers of nucleated cells, CD34pos cells, and CD14pos cells on FCM did not differ, either. The CD1a staining by ICC was positive in 14/41 LCH samples, and was consistently negative in controls. FCM staining for CD1a was positive in 12/54 samples, but also in 5/35 controls. The number of the CD1apos cells in LCH marrows was usually very low (<10–20 cells/slide by ICC, or <0.5% of the leukocytes by FCM). The CD1a staining was more frequently positive and more pronounced in patients with severe disease.ConclusionsThe combination of conventional aspirate cytology with ICC (CD1a staining) appears to be the most reliable tool for bone marrow assessment in LCH. Pediatr Blood Cancer 2007;49:694–698. © 2007 Wiley‐Liss, Inc.