检索结果-内蒙古大学图书馆

Effect of Contrast Agent Charge on Visualization of Articular Cartilage Using Computed Tomography: Exploiting Electrostatic Interactions for Improved Sensitivity

引用

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 2009年第37期131卷 13234-13235页

作者： Joshi, Neel S. Bansal, Prashant N. Stewart, Rachel C. Snyder, Brian D. Grinstaff, Mark W. Boston Univ Dept Chem Boston MA 02215 USA Boston Univ Dept Biomed Engn Boston MA 02215 USA Harvard Univ Dept Orthoped Surg Childrens Hosp Sch Med Boston MA 02215 USA

The synthesis and evaluation of a new class of cationic iodinated contrast agents for the imaging of cartilage using computed tomography (CT) are described. In direct comparisons with anionic contrast agents, the cationic contrast agents afforded higher equilibrium concentrations in the articular cartilage of ex vivo rabbit femurs and thus greater imaging sensitivity. Variations in CT intensity across the sample reflected the inhomogeneous distribution of glycosaminoglycans in the tissue as confirmed by histological analysis. We anticipate that this work represents the first step in the development of sensitive, nondestructive CT-based methods to characterize the biochemical properties of cartilage using cationic contrast agents.

关键词： Animals Cartilage, Articular/metabolism Cartilage, Articular/radiography Contrast Media/chemical synthesis Contrast Media/chemical synthesis Contrast Media/chemistry Contrast Media/chemistry Contrast Media/diagnostic use Contrast Media/diagnostic use Femur/metabolism Femur/radiography Glycosaminoglycans/metabolism Humans image processing, computer-assisted Iodine/chemistry Rabbits Static Electricity Static Electricity Tomography, X-Ray Computed

来源：评论

学校读者我要写书评

暂无评论

Computational strategies for metabolite identification in metabolomics

引用

BIOANALYSIS 2009年第9期1卷 1579-1596页

作者： Wishart, David S. Univ Alberta Dept Comp Sci Edmonton AB T6G 2E8 Canada Univ Alberta Dept Biol Sci Edmonton AB T6G 2E8 Canada Natl Inst Nanotechnol Edmonton AB T6G 2M9 Canada

Most metabolomic data are characterized by complex spectra or chromatograms containing hundreds of peaks or features. While there are many methods for aligning or comparing these spectral features, there are few approaches for actually identifying which peaks match to which compounds. Indeed, one of the biggest unmet needs in the field of metabolomics lies in the problem of compound identification. This review describes some of the newly emerging computational strategies in metabolomics that are being used to aid in the identification of metabolites from biofluid mixtures analyzed by NMR and MS. The most successful compound-identification strategies typically involve matching spectral features of the unknown compound(s) to curated spectral databases of reference compounds. This approach is known as the identification of 'known unknowns'. However, the identification of truly novel compounds (the 'unknown unknowns') is particularly challenging and requires the use of computer-aided structure elucidation methods being applied to the purified compound. The strengths and limitations of these approaches as applied to different analytical technologies (GC-MS, LC-MS and NMR) will be discussed, as will prospects for potential improvements to existing strategies.

关键词： Animals Chromatography, Liquid/methods Gas Chromatography-Mass Spectrometry/methods Humans image processing, computer-assisted Magnetic Resonance Spectroscopy/methods Metabolomics/methods

来源：评论

学校读者我要写书评

暂无评论

Neurodegenerative Diseases Target Large-Scale Human Brain Networks

引用

NEURON 2009年第1期62卷 42-52页

作者： Seeley, William W. Crawford, Richard K. Zhou, Juan Miller, Bruce L. Greicius, Michael D. Univ Calif San Francisco Dept Neurol Memory & Aging Ctr San Francisco CA 94143 USA Stanford Univ Sch Med Dept Neurol & Neurol Sci Stanford CA 94305 USA

During development, the healthy human brain constructs a host of large-scale, distributed, function-critical neural networks. Neurodegenerative diseases have been thought to target these systems, but this hypothesis has not been systematically tested in living humans. We used network-sensitive neuroimaging methods to show that five different neurodegenerative syndromes cause circumscribed atrophy within five distinct, healthy, human intrinsic functional connectivity networks. We further discovered a direct link between intrinsic connectivity and gray matter structure. Across healthy individuals, nodes within each functional network exhibited tightly correlated gray matter volumes. The findings suggest that human neural networks can be defined by synchronous baseline activity, a unified corticotrophic fate, and selective vulnerability to neurodegenerative illness. Future studies may clarify how these complex systems are assembled during development and undermined by disease.

关键词： Aged Brain/blood supply Brain/pathology Brain Mapping Brain Mapping Case-Control Studies Female Functional Laterality Humans image processing, computer-assisted Magnetic Resonance Imaging/methods Male Middle Aged Nerve Net/blood supply Nerve Net/pathology Neural Pathways/blood supply Neural Pathways/pathology Neurodegenerative Diseases/classification Neurodegenerative Diseases/pathology Oxygen/blood

来源：评论

学校读者我要写书评

暂无评论

When doing nothing is an option: The neural correlates of deciding whether to act or not

引用

NEUROimage 2009年第4期46卷 1187-1193页

作者： Kuehn, Simone Brass, Marcel Univ Ghent Fac Psychol & Educ Sci Dept Expt Psychol B-9000 Ghent Belgium Ghent Inst Funct & Metab Imaging B-9000 Ghent Belgium Max Planck Inst Human Cognit & Brain Sci Dept Psychol D-04103 Leipzig Germany

The neural basis of intentionally deciding between different response alternatives has been extensively investigated and associated with the rostral cingulate zone (RCZ), However, from daily experience we know that the decision whether to do something is often prior to the decision what to do. This raises the fundamental question whether the decision to act and the decision not to act can be considered as functionally equivalent. Interestingly, in the legal domain such an equivalence is implicitly assumed by punishing crimes of omission. The aim of the current study was to explicitly test this assumption by comparing the neural representation of intentional actions with intentional non-actions. Our results suggest, that weighing whether to act or not involves similar areas of the brain, namely RCZ and dorsolateral prefrontal cortex, independent of the outcome of this decision. This finding strongly supports the assumption that intentionally not acting can be considered as a mode of action. (C) 2009 Elsevier Inc. All rights reserved.

关键词： Adult Brain/physiology Brain Mapping Brain Mapping Decision Making/physiology Female Humans image processing, computer-assisted Magnetic Resonance Imaging Male Neural Pathways/physiology Photic Stimulation Reaction Time

来源：评论

学校读者我要写书评

暂无评论

Computed tomography of amyloid plaques in a mouse model of Alzheimer's disease using diffraction enhanced imaging

引用

NEUROimage 2009年第4期46卷 908-914页

作者： Connor, Dean M. Benveniste, Helene Dilmanian, F. Avraham Kritzer, Mary F. Miller, Lisa M. Zhong, Zhong Brookhaven Natl Lab Natl Synchrotron Light Source Upton NY 11973 USA Brookhaven Natl Lab Dept Med Upton NY 11973 USA SUNY Stony Brook Dept Anesthesiol Stony Brook NY 11794 USA SUNY Stony Brook Dept Radiat Oncol Stony Brook NY 11794 USA SUNY Stony Brook Dept Neurobiol & Behav Stony Brook NY 11794 USA

Our understanding of early development in Alzheimer's disease (AD) is clouded by the scale at which the disease progresses: amyloid beta (A beta) plaques, a hallmark feature of AD, are small (similar to 50 mu m) and low contrast in diagnostic clinical imaging techniques. Diffraction enhanced imaging (DEI), a phase contrast x-ray imaging technique, has greater soft tissue contrast than conventional radiography and generates higher resolution images than magnetic resonance microimaging. Thus, in this proof of principle study, DEI in micro-CT mode was performed on the brains of AD-model mice to determine if DEI can visualize A beta plaques. Results revealed small nodules in the cortex and hippocampus of the brain. Histology confirmed that the features seen in the DEI images of the brain were A beta plaques. Several anatomical structures, including hippocampal subregions and white matter tracks, were also observed. Thus, DEI has strong promise in early diagnosis of AD, as well as general studies of the mouse brain. (C) 2009 Elsevier Inc. All rights reserved.

关键词： Alzheimer Disease/pathology Alzheimer Disease/radiography Animals Brain/pathology Brain/radiography Disease Models, Animal image processing, computer-assisted Immunohistochemistry Immunohistochemistry Mice Mice, Transgenic Mice, Transgenic Senile Plaques/pathology Senile Plaques/radiography Tomography, X-Ray Computed/methods

来源：评论

学校读者我要写书评

暂无评论

Rates of Neuroretinal Rim and Peripapillary Atrophy Area Change A Comparative Study of Glaucoma Patients and Normal Controls

引用

OPHTHALMOLOGY 2009年第5期116卷 840-847页

作者： See, Jovina L. S. Nicolela, Marcelo T. Chauhan, Balwantray C. Dalhousie Univ Dept Ophthalmol & Visual Sci Halifax NS B3H 2Y9 Canada

Objective: To compare the rates of global and sectoral neuroretinal rim area (NRA) and peripapillary atrophy area (PPAA) change in open-angle glaucoma patients and normal control subjects and to determine the relationship between rates of NRA and PPAA change. Design: Prospective, longitudinal cohort study of cases and controls. Participants and Controls: Ninety-four patients with open-angle glaucoma and 54 control subjects. Methods: Patients and controls were imaged with confocal scanning laser tomography every 6 months. The NRA and PPAA in 1 eye were analyzed to determine the rate of change globally and in 12 30 sectors by regression analysis. Rates of global NRA and PPAA change were correlated. Sectors were ranked from 1 to 12 each according to the magnitude of NRA and PPAA change and were compared between patients and controls using rank-order correlation. Spatial concordance between rates of NRA and PPAA change was calculated as sector rank distance between correspondingly ranked sectors. Main Outcome Measures: Rates of global and sectoral NRA and PPAA change. Results: The mean (+/- standard deviation) follow-up was 8.6 +/- 2.9 years for patients and 7.1 +/- 3.6 years for controls. Globally, NRA declined more rapidly in patients compared with controls, expressed either in absolute units (medians, -5.33 x 10(-3) mm(2)/year and -1.25 x 10(-3) mm2/year, respectively;P = 0.006) or percentage of baseline NRA (medians, -0.42%/year and -0.07%/year, respectively;P = 0.001). The global rate of PPAA change was not significantly higher in patients compared with controls (12.66 x 10(-3) mm2/year and 9.43 x 10(-3) mm2/year, respectively;P = 0.173). Rates of global and sectoral NRA and PPAA change were correlated poorly in either group. There was a high correlation between ranked sectors of NRA change in patients and controls (P <= 0.001), indicating similar patterns of NRA decline in patients and controls;however, this was not the case for rates of PPAA change. Conclusions:

关键词： Case-Control Studies Disease Progression Glaucoma, Open-Angle/diagnosis Glaucoma, Open-Angle/physiopathology Gonioscopy Humans image processing, computer-assisted Intraocular Pressure/physiology Lasers/diagnostic use Longitudinal Studies Middle Aged Optic Atrophy/physiopathology Optic Disk/pathology Prospective Studies Retina/pathology Tomography Visual Acuity/physiology

来源：评论

学校读者我要写书评

暂无评论

Follicular lymphoma cells induce T-cell immunologic synapse dysfunction that can be repaired with lenalidomide: implications for the tumor microenvironment and immunotherapy

引用

BLOOD 2009年第21期114卷 4713-4720页

作者： Ramsay, Alan G. Clear, Andrew J. Kelly, Gavin Fatah, Rewas Matthews, Janet MacDougall, Finlay Lister, T. Andrew Lee, Abigail M. Calaminici, Maria Gribben, John G. Queen Mary Univ London Barts & London Sch Med Canc Res UK Clin Ctr Med Oncol Inst Canc London EC1M 6BQ England Canc Res UK Bioinformat & Biostat Serv London England Barts & London Natl Hlth Serv Trust London England

An important hallmark of cancer progression is the ability of tumor cells to evade immune recognition. Understanding the relationship between neoplastic cells and the immune microenvironment should facilitate the design of improved immunotherapies. Here we identify impaired T-cell immunologic synapse formation as an active immunosuppressive mechanism in follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL). We found a significant reduction in formation of the F-actin immune synapse in tumor-infiltrating T cells (P < .01) from lymphoma patients compared with age-matched healthy donor cells. Peripheral blood T cells exhibited this defect only in patients with leukemic-phase disease. Moreover, we demonstrate that this T-cell defect is induced after short-term tumor cell contact. After 24-hour coculture with FL cells, previously healthy T cells showed suppressed recruitment of critical signaling proteins to the synapse. We further demonstrate repair of this defect after treatment of both FL cells and T cells with the immunomodulatory drug lenalidomide. Tissue microarray analysis identified reduced expression of the T-cell synapse signature proteins, including the cytolytic effector molecule Rab27A associated with poor prognosis, in addition to reduced T-cell numbers and activity with disease transformation. Our results highlight the importance of identifying biomarkers and immunotherapeutic treatments for repairing T-cell responses in lymphoma. (Blood. 2009;114:4713-4720)

关键词： Actins/immunology Antineoplastic Agents/pharmacology Cell Communication/drug effects Cell Communication/immunology Coculture Techniques Coculture Techniques Fluorescent Antibody Technique Fluorescent Antibody Technique Humans image processing, computer-assisted Immune Tolerance/drug effects Immune Tolerance/immunology Immunological Synapses/drug effects Immunological Synapses/immunology Immunotherapy/methods Lymphoma, Follicular/immunology Microscopy, Confocal rab GTP-Binding Proteins/biosynthesis Thalidomide/analogs & derivatives Thalidomide/pharmacology Tissue Array Analysis T-Lymphocytes/drug effects T-Lymphocytes/immunology Tumor Escape/drug effects Tumor Escape/immunology

来源：评论

学校读者我要写书评

暂无评论

Brain encoding of acupuncture sensation - Coupling on-line rating with fMRI

引用

NEUROimage 2009年第3期47卷 1055-1065页

作者： Napadow, Vitaly Dhond, Rupali P. Kim, Jieun LaCount, Lauren Vangel, Mark Harris, Richard E. Kettner, Norman Park, Kyungmo Massachusetts Gen Hosp HMS MIT Martinos Ctr Biomed Imaging Boston MA 02114 USA Logan Coll Chiropract Dept Radiol Chesterfield MO USA Kyung Hee Univ Dept Biomed Engn Yongin South Korea MGH GCRC Biomed Imaging Core Charlestown MA USA Univ Michigan Dept Anesthesiol Chron Pain & Fatigue Res Ctr Ann Arbor MI 48109 USA

Acupuncture-induced sensations have historically been associated with clinical efficacy. These sensations are atypical, arising from sub-dermal receptors, and their neural encoding is not well known. In this fMRI study, subjects were stimulated at acupoint PC-6, while rating sensation with a custom-built, MR-compatible potentiometer. Separate runs included real (ACUP) and sham (SHAM) acupuncture, the latter characterized by non-insertive, Cutaneous stimulation. FMRI data analysis Was guided by the on-line rating timeseries, thereby localizing brain correlates of acupuncture sensation. Sensation ratings correlated with stimulation more (p<0.001) for SHAM (r=0.63) than for ACUP (r=0.32), ACUP induced stronger and more varied sensations with significant persistence into no-stimulation blocks, leading to more run-time spent rating low and moderate sensations compared to SHAM. ACUP sensation correlated with activation in regions associated with sensorimotor (SII, insula) and cognitive (dorsomedial prefrontal cortex (dmPFC)) processing, and deactivation in default-mode network (DMN) regions (posterior cingulate, precuneus). Compared to SHAM, ACUP yielded greater activity in both anterior and posterior dmPFC and dmPFC. fit contrast, SHAM produced greater activation in sensorimotor (SI, SII, insula) and greater deactivation in DMN regions. Thus, brain encoding of ACUP sensation (more persistent and varied, leading to increased cognitive load) demonstrated greater activity in both cognitive/evaluative (posterior dmPFC) and emotional/interoceptive (anterior dmPFC) cortical regions. Increased cognitive load and dmPFC activity may be a salient component of acupuncture analgesia - sensations focus attention and accentuate bodily awareness, contributing to enhanced top-down modulation of any nociceptive afference and central pain networks. Hence, acupuncture may function as a somatosensory-guided mind-body therapy. (C) 2009 Elsevier Inc. All rights reserved.

关键词： Acupuncture Therapy/psychology Adult Brain/physiology Brain Mapping Brain Mapping Female Humans image processing, computer-assisted Magnetic Resonance Imaging Male Pain/physiopathology Sensation/physiology Skin/innervation Young Adult

来源：评论

学校读者我要写书评

暂无评论

Correlation between Spectral Domain Optical Coherence Tomography Findings and Fluorescein Angiography Patterns in Diabetic Macular Edema

引用

OPHTHALMOLOGY 2009年第6期116卷 1158-1167页

作者： Yeung, Ling Lima, Veronica Castro Garcia, Patricia Landa, Gennady Rosen, Richard B. New York Eye & Ear Infirm Dept Ophthalmol Retina Serv New York NY 10003 USA Chang Gung Mem Hosp Dept Ophthalmol Chilung Taiwan New York Med Coll Valhalla NY 10595 USA

Objective: To study the relationship between spectral domain optical coherence tomography (SD-OCT) findings and fluorescein angiography (FA) patterns in patients with diabetic macular edema (DME). Design: Retrospective, observational, cross-sectional study. Participants: We included 59 eyes from 59 patients with DME that had SD-OCT/scanning laser ophthalmoscope (SLO) and FA performed on the same day. Eyes with macular edema owing to other ocular diseases were excluded. Methods: The relationship between SD-OCT and FA findings was evaluated by superimposing and aligning the SLO images onto the FA photos. The SLO image of the OPKO/OTI Spectral OCT/SLO (OPKO-OTI, Miami, FL) corresponds with the exact origin and orientation of the SD-OCT scan, which was then correlated with the FA image. Foveal and extrafoveal regions were studied separately. Leakage on FA and pathologic changes on OCT were graded by using standard photographs. Pathologic changes studied in the OCT images included edema and cystic spaces in the inner and outer retina, loss of retinal layers, and foveal cysts. Main Outcome Measures: Correlation between SD-OCT changes and corresponding FA patterns. Results. The outer retina was the predominant location of fluid in DME. The severity of the outer retinal edema on OCT was positively correlated with the severity of leakage on FA (r = 0.735;P<0.001). Cystic changes in the inner and outer retina were also correlated with the severity of fluorescein leakage (r = 0.507 and P<0.001;r = 0.561 and P<0.001, respectively). Loss of inner retinal layers on OCT was highly correlated with capillary nonperfusion on FA (r = 0.953;P<0.001). Large foveal cysts on SD-OCT corresponded to cystoid leakage patterns on FA. Conclusions: Pathologic changes on SD-OCT correlated well with FA findings. Loss of inner retinal layers was specifically correlated with capillary nonperfusion and severe ischemia. Judgment of whether management of DME based on fine retinal structural changes inf

关键词： Capillary Permeability Cross-Sectional Studies Diabetic Retinopathy/diagnosis Diabetic Retinopathy/physiopathology Female Fluorescein Angiography/methods Humans image processing, computer-assisted Macular Edema/diagnosis Macular Edema/physiopathology Male Middle Aged Ophthalmoscopy Retrospective Studies Retrospective Studies Tomography, Optical Coherence/methods Tomography, Optical Coherence/methods

来源：评论

学校读者我要写书评

暂无评论

An fMRI study of cytokine-induced depressed mood and social pain: The role of sex differences

引用

NEUROimage 2009年第3期47卷 881-890页

作者： Eisenberger, Naomi I. Inagaki, Tristen K. Rameson, Lian T. Mashal, Nehjla M. Irwin, Michael R. Univ Calif Los Angeles Dept Psychol Los Angeles CA 90095 USA Northwestern Univ Dept Psychol Evanston IL 60208 USA Univ Calif Los Angeles Cousins Ctr Psychoneuroimmunol Semel Inst Neurosci & Human Behavior Los Angeles CA 90095 USA

Although research has demonstrated a relationship between proinflammatory cytokine activity and depressive symptoms, the neurocognitive processes underlying this relationship have remained largely unexplored. Here, we examined the effect of proinflammatory cytokine activation on the neural correlates of socially painful experience and associated depressed mood. Participants received either low-dose endotoxin or placebo through intravenous injection. Levels of the proinflammatory cytokine, IL-6. were repeatedly assessed through hourly blood draws: self-reported depressed mood was assessed hourly as well, Two hours post-injection, participants completed a neuroimaging session in which they were socially excluded during an online ball-tossing game. Replicating previous research, individuals exposed to endotoxin, compared to placebo, showed increases in IL-6 levels and depressed mood. Although there were no meaningful differences between the endotoxin and control groups in neural responses to social exclusion, there were sex differences in the relationships between IL-6 increases and neural responses to exclusion among subjects exposed to endotoxin. Among females, but not males, exposed to endotoxin, increases in IL-6 were associated with increases in social pain-related neural activity (dorsal anterior cingulate cortex, anterior insula) that mediated the relationship between IL-6 increases and depressed mood increases. Implications of these sex differences in the neural correlates of cytokine-associated depressed mood and social pain are discussed. (C) 2009 Elsevier Inc. All rights reserved.

关键词： Adolescent Adult Brain Mapping Brain Mapping Cytokines/blood Depression/blood Depression/immunology Depression/physiopathology Endotoxins/immunology Estradiol/blood Female Humans Hydrocortisone/blood image processing, computer-assisted Interleukin-6/blood Magnetic Resonance Imaging Male Progesterone/blood Sex Characteristics Social Isolation Young Adult

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：