肝内胆管细胞癌的CT诊断

目的:研究肝内胆管细胞癌的CT表现,提高对肝内胆管细胞癌的认识。方法:回顾性分析经手术及病理证实的26例肝内胆管细胞癌的CT表现,并与手术结果对比分析。结果:肝内胆管细胞癌的CT表现为低密度不规则肿块,边界欠清,增强扫描肿瘤边缘实质部分轻中度强化。增强扫描:动脉期无强化11例,轻度强化15例。延迟扫描26例均有不同程度延迟强化。结论:肝内胆管细胞癌的CT表现有一定的特征性,对于与肝内其他常见痛变的鉴别诊断有重要价值。     

多层螺旋CT在诊断小儿急性阑尾炎中的应用

目的:探讨多层螺旋CT对小儿急性阑尾炎的诊断价值。方法:回顾分析经临床手术病理证实的53例小儿急性阑尾炎的CT表现特点。所有患儿均行多排CT横断面扫描及MPVR重建。结果:53例中,单纯性阑尾炎2例;急性化脓性阑尾炎伴周围炎4例,其中1例合并紫癜;急性化脓性阑尾炎伴穿孔33例,其中1例合并回肠末端美克尔憩室;坏疽性阑尾炎伴穿孔6例;阑尾脓肿8例。CT平扫以及MPVR重建显示阑尾肿大、增粗(直径大于6mm)30例,阑尾内粪石27例,阑尾周围蜂窝织炎23例,阑尾周围脓肿8例,大量腹水6例。结论:多层螺旋CT扫描及重建技术能为小儿阑尾炎的诊断提供有力依据,提高临床术前诊断能力。     

牛磺酸对高糖培养下视网膜Mü ller细胞GFAP和TAUT表达的影响

目的：通过检测高糖培养条件下视网膜Mü ller细胞神经纤维酸性蛋白（glial fibrillary acid protein,GFAP）和牛磺酸转运蛋白（taurine transporter,TAUT）的表达变化,观察葡萄糖对Mü ller细胞牛磺酸（taurine）转运功能的影响,探讨牛磺酸对早期糖尿病视网膜病（DR）可能的保护作用.方法：高糖培养大鼠视网膜Mü ller细胞,用免疫细胞荧光化学双染色、Western blotting技术检测不同浓度牛磺酸干预下Mü ller细胞GFAP及TAUT的蛋白表达.结果：高糖可引起Mü ller细胞GFAP表达增强,TAUT表达减弱;牛磺酸可减弱高糖引起的Mü ller细胞GFAP表达增强,TAUT在0.1mmol/L～10 mmo1/L的牛磺酸干预后表达增强.结论：牛磺酸可以抑制高糖导致的Müller细胞功能改变.     

海金沙卵发生的组织化学研究

采用组织化学方法对海金沙（Lygodium japonicum （Thunb.） Sw.）卵发生进行了研究。高碘酸-锡夫反应（PAS反应）结果显示：颈沟和腹沟细胞外产生的黏性物质为多糖类物质;在卵细胞发生早期颈卵器细胞内均含有质体,且淀粉粒含量丰富,随着颈卵器的发育,卵细胞以及颈沟和腹沟细胞内淀粉粒数量和体积均逐渐减少,最后退化消失。苏丹黑B反应结果显示：海金沙颈沟和腹沟细胞外产生的黏性物质也含有脂类物质,而卵细胞内并未有明显脂类物质产生;卵细胞质膜处也并没有糖类或脂类物质的积累。本研究从组织化学角度佐证了海金沙的特殊性,即既有原始蕨类的特征,又有进化蕨类的特征。     

Probing intracellular vesicle trafficking and membrane remodelling by cryo-EM

Protein transport between the membranous compartments of the eukaryotic cells is mediated by the constant fission and fusion of the membrane-bounded vesicles from a donor to an acceptor membrane. While there are many membrane remodelling complexes in eukaryotes, COPII, COPI, and clathrin-coated vesicles are the three principal classes of coat protein complexes that participate in vesicle trafficking in the endocytic and secretory pathways. These vesicle-coat proteins perform two key functions: deforming lipid bilayers into vesicles and encasing selective cargoes. The three trafficking complexes share some commonalities in their structural features but differ in their coat structures, mechanisms of cargo sorting, vesicle formation, and scission. While the structures of many of the proteins involved in vesicle formation have been determined in isolation by X-ray crystallography, elucidating the proteins' structures together with the membrane is better suited for cryogenic electron microscopy (cryo-EM). In recent years, advances in cryo-EM have led to solving the structures and mechanisms of several vesicle trafficking complexes and associated proteins.     

Plausible biochemical mechanisms of chemotherapy-induced cognitive impairment (“chemobrain”), a condition that significantly impairs the quality of life of many cancer survivors

Increasing numbers of cancer patients survive and live longer than five years after therapy, but very often side effects of cancer treatment arise at same time. One of the side effects, chemotherapy-induced cognitive impairment (CICI), also called “chemobrain” or “chemofog” by patients, brings enormous challenges to cancer survivors following successful chemotherapeutic treatment. Decreased abilities of learning, memory, attention, executive function and processing speed in cancer survivors with CICI, are some of the challenges that greatly impair survivors' quality of life. The molecular mechanisms of CICI involve very complicated processes, which have been the subject of investigation over the past decades. Many mechanistic candidates have been studied including disruption of the blood-brain barrier (BBB), DNA damage, telomere shortening, oxidative stress and associated inflammatory response, gene polymorphism of neural repair, altered neurotransmission, and hormone changes. Oxidative stress is considered as a vital mechanism, since over 50% of FDA-approved anti-cancer drugs can generate reactive oxygen species (ROS) or reactive nitrogen species (RNS), which lead to neuronal death. In this review paper, we discuss these important candidate mechanisms, in particular oxidative stress and the cytokine, TNF-alpha and their potential roles in CICI.     

Bilan initial d’imagerie de l’adénocarcinome pancréatique : données de la littérature sur la place actuelle de la tomographie par émission de positons au 18F-fluorodéoxyglucose (TEP FDG)

In pancreatic adenocarcinoma, initial imaging is essential to better select patients for surgery. Recent literature analysis of F18-Fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET) in pancreatic adenocarcinoma is summarized in the present article. Performances of FDG PET in the fields of lymph node involvement, metastatic involvement and therapeutic efficacy assessment are described for its correct use in pancreatic adenocarcinoma.     

Lateralization of olfactory processes

Over the last ten years, methods of cerebral imaging have revolutionized our knowledge of cognitive processes in humans. An impressive number of papers dealing with cerebral imaging for olfaction have been published to date. Whereas the early works revealed those structures participating in the processing of odours presented passively to subjects, researchers later recorded brain activity when subjects performed specific olfactory tasks based on memory, emotion and identification. From these results, we suggest that there is a dissociation of olfactory processes, with involvement of the right hemisphere in memory processes and the left hemisphere in emotional processes. The review concludes with a summary of how these lateralized processes are consistent with the gestalt-nature of our olfactory perception.     

Capillaries within compartments: microvascular interpretation of dynamic positron emission tomography data

Measurement of exchange of substances between blood and tissue has been a long-lasting challenge to physiologists, and considerable theoretical and experimental accomplishments were achieved before the development of the positron emission tomography (PET). Today, when modeling data from modern PET scanners, little use is made of earlier microvascular research in the compartmental models, which have become the standard model by which the vast majority of dynamic PET data are analysed. However, modern PET scanners provide data with a sufficient temporal resolution and good counting statistics to allow estimation of parameters in models with more physiological realism. We explore the standard compartmental model and find that incorporation of blood flow leads to paradoxes, such as kinetic rate constants being time-dependent, and tracers being cleared from a capillary faster than they can be supplied by blood flow. The inability of the standard model to incorporate blood flow consequently raises a need for models that include more physiology, and we develop microvascular models which remove the inconsistencies. The microvascular models can be regarded as a revision of the input function. Whereas the standard model uses the organ inlet concentration as the concentration throughout the vascular compartment, we consider models that make use of spatial averaging of the concentrations in the capillary volume, which is what the PET scanner actually registers. The microvascular models are developed for both single- and multi-capillary systems and include effects of non-exchanging vessels. They are suitable for analysing dynamic PET data from any capillary bed using either intravascular or diffusible tracers, in terms of physiological parameters which include regional blood flow.     

痛觉的脑功能成像研究进展

本文综述了近年来关于痛觉功能性脑成像的研究进展,痛觉的感觉辨别成分似与外侧丘脑、初级和次级躯体感觉区及岛叶皮层有关,而伤害性信息的认知－注意过程则与顶叶后部和前额中皮层有关。扣带回的不同部分调节着痛觉认知和情感的不同方面。文章最后对临床各种疼痛特别是神经源性痛病人的成像研究进行了分析。