瘦素的表达与肿瘤的关系

瘦素（leptin）是由肥胖基因编码的一种蛋白质产物，与代谢调节密切相关，在人体能量平衡、脂肪代谢的调节以及在神经内分泌系统、生殖和造血系统的影响中起着重要的作用。瘦素与人类多种肿瘤相关，提示瘦素作为一种新的肿瘤标志物，在肿瘤的早期诊断中起重要作用。     

瘦素与运动的关系及其在运动训练监测中的应用

自1994年Zhang等[1]在小鼠中克隆出肥胖基因以来,有关其编码的表达产物———瘦素(Leptin)的生物学特性和生理学功能已有大量的研究。瘦素是一重要的内分泌调节因子,可以调节食欲、促进脂肪代谢和增加能量消耗等[2],在能量平衡和体重调节中发挥重要的作用。运动能影响机体的能量平衡,是能量消耗的一种重要形式。探讨运动与瘦素之间的关系已引起许多研究者的关注。本文主要对近几年的相关研究成果进行综述,重点论述一次运动和运动训练对瘦素的影响,并对瘦素作为运动训练监测指标的可能性进行了分析,最后指出了存在的问题及今后可能的研究发…     

胰岛素抵抗和瘦素与高血压

肥胖、高血压及糖尿病越来越成为重要的公共健康问题,胰岛素抵抗是其共同的发病基础。瘦素主要由皮下脂肪分泌,瘦素不仅与脂调节有关。而且与心血管调节有关,高血压患者可能存在瘦素抵抗,胰岛素抵抗和瘦素抵抗可能在高血压病发病过程具有具有一定作用,改善胰岛素抵抗和瘦素抵抗可能在高血压病治疗中具有重要意义。     

瘦素与创伤

瘦素是由肥胖基因编码合成的一种多肽类激素,存在于中枢及外周组织,与糖皮质激素、胰岛素及多种细胞因子存在广泛联系,受神经-内分泌系统和外周脂肪酸浓度调节.瘦素在能量代谢、神经内分泌、血管生成等方面发挥重要作用[1].近年来关于瘦素与创伤的关系研究报道较多.现综述如下. 1瘦素的生物学特征 1.1瘦素的结构 瘦素是肥胖基因的表达产物,由167个氨基酸组成.1994年Zhang等利用定位克隆技术首次成功克隆了小鼠的肥胖基因.     

瘦素对类风湿关节炎主要效应细胞的调控作用研究进展

瘦素是由脂肪组织合成的一种脂肪因子,最初研究显示其可作为调节体脂平衡的激素类物质发挥作用.深入研究后发现,瘦素具有与细胞因子白细胞介素-6(IL-6)类似的结构,其受体属于Ⅰ型细胞因子受体超家族成员.瘦素与其受体结合后,不仅可调节摄食及能量平衡,还兼具对免疫系统的调控作用.类风湿关节炎(RA)是由多种遗传和环境因素引起...     

瘦素应用于肥胖症研究

瘦素(leptin)是脂肪细胞合成和分泌的一种激素,是肥胖(ob)基因表达的产物,有抑制食欲、促进能量消耗的生理作用。多数研究表明,瘦素是脂肪分解和合成代谢的一个主要调节因子(负反馈),其水平的变化在临床上可作为早期高血脂症、脂肪肝等脂肪代谢率紊乱的灵敏指标。放射免疫分析(RIA)法对人血清(血浆)瘦素水平的精确测定和进一步研究表明,循环瘦素水平与体重指数(BMI)、年龄、性别、性激素及胰岛素内分泌等因素有关,特别是与BMI显著相关,提示多数肥胖个体存在瘦素抵抗。部分瘦素相对缺乏的肥胖者将有可能成为瘦素治疗的对象。瘦素的发现和应用使肥胖症及Ⅱ型糖尿病等相关疾病的研究进入了一个新阶段。     

瘦素和体重调节反馈模式的研究

瘦素(Leptin)被认为是一种外周组织反映脂肪量的信号,反馈作用于中枢神经系统。近年来,瘦素的负反馈系统已被部分揭示。下丘脑调节食欲和代谢的中枢受多种分子的协同作用,包括瘦素、神经肽Y(NPY),前阿片类黑色素原(POMC)等。根据已有的对瘦素的理解,建立一个关于瘦素负反馈的模型,可加深了解体内食欲和能量平衡调节机制。     

瘦素应用于肥胖症研究

瘦素（leptin)是脂肪细胞合成和分泌的一种激素,是肥胖（ob)基因表达的产物,有抑制食欲,促进能量消耗的生理作用。多数研究表明,瘦素是脂肪分解和合成代谢的一个主要调节因子（负反馈）,其水平的变化在临床上可作为早期高血脂症,脂肪肝等脂肪代谢率紊乱的灵敏指标。放射免疫分析（RIA）法对人血清（血浆）瘦素水平的精确测定和进一步研究表明,循环瘦素水平与体重指数（BMI）、年龄、性别,性激素及胰岛素内分泌等因素有关,特别是与BMI显著相关,提示多数肥胖个体存在瘦素抵抗,部分瘦素相对缺乏的肥胖者将有可能成为瘦素治疗的对象,瘦素的发现和应用使肥胖症及Ⅱ型糖尿病等相关疾病的研究进入了一个新阶段。     

瘦素和体重调节反馈模式的研究

瘦素（Leptin）被认为是一种外周组织反映脂肪量的信号，反馈作用于中枢神经系统。近年来，瘦素的负反馈系统已被部分揭示。下丘脑调节食欲和代谢的中枢受多种分子的协同作用，包括瘦素、神经肽Y（NPY），前阿片类黑色素原（POMC）等。根据已有的对瘦素的理解，建立一个关于瘦素负反馈的模型，可加深了解体内食欲和能量平衡调节机制。     

瘦素与高血压动脉粥样硬化关系的研究进展

瘦素是肥胖基因编码的一种具有内分泌功能的蛋白质产物,通过作用于瘦素受体而发挥一系列生物学效应。近年来大量研究显示瘦素与肥胖、高血压、糖尿病、动脉粥样硬化、脑卒中等疾病密切相关,其机制可能与加剧脂代谢紊乱、诱导氧化应激、增加交感神经活性、调节血管张力、促进内皮细胞炎性反应、诱导血管平滑肌细胞增殖迁移、增加泡沫细胞形成、促进血小板聚集及血栓形成等多种机制有关。本文对瘦素与高血压、动脉粥样硬化关系的研究进展进行了综述。     

非编码RNA的表观遗传学调控及在肿瘤中的异常表达

非编码RNAs（ncRNAs）在体内广泛存在,它通过表观遗传方式广泛参与多种重要的调控。对其表观遗传学调控机制还有不同观点,如通过采取RNA干扰的原理进行调控,或通过脱腺苷化作用、脱帽作用等导致靶mRNA的不稳定或抑制翻译等。这些作用使ncRNAs在肿瘤细胞中多表达异常并涉及其发生与发展的整个过程。本文综述了该领域的研究进展。     

多巴胺受体与肿瘤的关系研究进展

多巴胺是一种存在于哺乳动物中枢神经系统中的儿茶酚胺类神经递质,参与调节体内多种重要的生理活动,如情绪、内分泌等,主要通过与相应的多巴胺受体结合发挥其生理作用。多巴胺受体为G蛋白偶联受体,广泛分布于体内各种器官和组织细胞。目前研究显示,多巴胺受体广泛表达于多种肿瘤细胞,影响肿瘤细胞的发生、发展和转移等。针对这一特性,部分影响多巴胺受体表达的药物如甲硫哒嗪已被应用于肿瘤尤其是垂体瘤的基础研究和临床,现已成为泌乳素瘤的首选治疗方法。但是,多巴胺受体在恶性肿瘤中的作用到底是促癌,还是抑癌,仍然存在争论。作者综述了多巴胺受体与多种肿瘤的关系。     

Transarterial embolization of primary and secondary tumors of the skeletal system

Percutaneous transcatheteral embolizations of primary and secondary bone tumors are important minimal invasive angiographic interventions of the skeletal system. In most of the cases embolization is performed for preoperative devascularization or as a palliative measure to treat tumor-associated pain or other tumor bulk symptoms. The transarterial embolization of primary and secondary tumors of the skeletal system has been developed to a safe and very effective method. Indications, techniques, results and complications of this minimal invasive interventional therapy for treatment of primary and secondary bone tumors are described and discussed and compared with the newer literature and our own results.     

Radiologische Diagnostik maligner Tumoren des Muskuloskelettalsystems im Kindes- und Adoleszentenalter

Rhabdomyosarcoma, osteosarcoma and Ewing's sarcoma are the most common malignant tumors of the musculoskeletal system in childhood and adolescence representing about 10% of newly diagnosed cancers in children and adolescents.In the last two decades the prognosis of patients with such malignancies improved significantly. On the one hand because of the advances in chemotherapy and orthopedic surgery, on the other hand also because of the innovations in radiological diagnostics. The precise pre-therapeutical staging of tumors of the musculoskeletal system provides important prognostic information and has impact on the entire therapy management. During respectively after therapy, imaging is extremely important in the follow-up and in diagnosing a possible recurrent disease.Modern imaging diagnostics of musculoskeletal tumors basically consist of conventional X-ray, of computed tomography (CT) and magnetic resonance imaging (MRI), and of modalities of nuclear medicine such as szintigraphy, positron emission tomography (PET) and PET CT.     

Spinal tumors

Spinal tumors are uncommon lesions but may cause significant morbidity in terms of limb dysfunction. In establishing the differential diagnosis for a spinal lesion, location is the most important feature, but the clinical presentation and the patient's age and gender are also important. Magnetic resonance (MR) imaging plays a central role in the imaging of spinal tumors, easily allowing tumors to be classified as extradural, intradural-extramedullary or intramedullary, which is very useful in tumor characterization. In the evaluation of lesions of the osseous spine both computed tomography (CT) and MR are important. We describe the most common spinal tumors in detail. In general, extradural lesions are the most common with metastasis being the most frequent. Intradural tumors are rare, and the majority is extramedullary, with meningiomas and nerve sheath tumors being the most frequent. Intramedullary tumors are uncommon spinal tumors. Astrocytomas and ependymomas comprise the majority of the intramedullary tumors. The most important tumors are documented with appropriate high quality CT or MR images and the characteristics of these tumors are also summarized in a comprehensive table. Finally we illustrate the use of the new World Health Organization (WHO) classification of neoplasms affecting the central nervous system.     

CT与MRI时代X线平片在骨肿瘤诊断中的作用

在科技快速发展的今天，CT和MRI等成像技术发展很快，在影像诊断中起到重要作用，而忽略了常规X光平片的作用。由于骨关节结构和X光平片的特点，X光平片在骨肿瘤的诊断中有非常重要的作用。根据我们大量的临床经验，下面就X光平片、CT和MRI检查方法各自的优势和缺点及在骨肿瘤诊断中的作用作一介绍。     

Imaging of extranodal lymphoma with PET/CT

Hodgkin disease (HD) and non-Hodgkin lymphoma (NHL) represent a spectrum of malignant neoplasms arising from the lymphoid system with an incidence of around 8% of all malignancies. Although they are generally known as tumors of lymph nodes, 25% to 40% of HD/NHL tumors, especially NHL, arise at extranodal sites along the gastrointestinal tract, head and neck, orbit, central and peripheral nervous system, thorax, bone, skin, breast, testis, thyroid, and genitourinary tract. Extranodal involvement is an important pretreatment prognostic factor for patients with lymphoma and its incidence has increased in the past 2 decades. Imaging plays an important role in the noninvasive pretreatment assessment of patients with extranodal lymphoma. This involvement can be subtle and may be overlooked during computed tomography (CT). Positron emission tomography/CT (PET/CT) has evolved into an important imaging tool for evaluation of lymphomas, facilitating the detection of affected extranodal sites even when CT shows subtle or no obvious lesions. Familiarity with extranodal manifestations and suggestive PET/CT features in different sites is important for accurate evaluation of lymphoma. This article reviews the extranodal PET/CT imaging findings regarding HD and NHL.     

PET imaging in oncology

The role of positron emission tomography (PET) during the past decade has evolved rapidly from a pure research tool to a methodology of enormous clinical potential. Perhaps the most striking development is the use of PET in oncology. PET imaging is approved in the United States for lung, lymphoma, colon, and melanoma cancer imaging. Data are accumulating rapidly to attest the efficacy of Fluorine-18 fluorodeoxyglucose (FDG) imaging in a wide variety of malignant tumors with sensitivities and specificities often in the high 90s. FDG uptake has been shown in tumors of the head and neck, ovary, breast, musculoskeletal system, and neuroendocrine system as well. The major role of PET has emerged as a reliable method for evaluating and staging recurrent disease. But it also has an important role in differentiating benign and malignant primary tumors. This has been shown particularly well in the differential diagnosis of solitary lung nodules. Although FDG has emerged as the dominant radiopharmaceutical for PET imaging in oncology, numerous other compounds are being evaluated. It is likely that more specific and efficacious compounds will be introduced during the next decade. F-18, because of its highly favorable physical characteristics, is likely to become the technetium of PET imaging. The next decade will witness an explosive growth of PET technology in oncologic imaging.     

Imaging of vascular tumors with an emphasis on ISSVA classification

The International Society for the Study of Vascular Anomalies (ISSVA) classification is becoming the international standard classification system for vascular tumors and vascular malformations. The ISSVA classification strictly distinguishes vascular tumors (neoplastic lesions) from vascular malformations (non-neoplastic lesions) based on whether there is a proliferation of vascular endothelial cells present, and it is an extremely useful classification system for determining therapeutic measures. For vascular tumors, it is clinically significant in terms of discriminating infantile hemangioma and rapidly involuting congenital hemangioma, which are expected to spontaneously regress, from other vascular tumors requiring treatment. Needless to say, clinical courses are important for diagnosis, and it is also important for radiologists to understand imaging findings on vascular tumors because such tumors have unique findings on diagnostic images. In this paper, vascular tumors are classified based on the ISSVA classification, and clinical and imaging findings are reviewed.