超声分子成像的机制及研究现状

随着分子生物学的迅速发展以及疾病分子机制的逐步阐明,医学影像学已深入到细胞及分子水平.超声分子成像技术是医学分子影像学领域中重要组成部分,在当今分子影像学中占据重要地位.本文对其成像机制及研究现状进行综述.     

移植细胞的影像学示踪

细胞治疗、基因治疗已逐渐成为现代医学治疗的一类重要方法。随着分子影像学的提出,能通过活体检测移植后的细胞,方法主要有磁共振成像、核医学成像、光学成像。     

光学分子影像学及其应用

光学分子影像学是一种快速发展的生物医学影像技术,它可以利用生物自发光或荧光蛋白或荧光染料,在分子和细胞层面上对在体的特定生物过程进行定性和定量研究。光学分子影像学同磁共振、核素成像等技术相比,具有无创性、高敏感性、成像价格低、近红外荧光穿透力强等优点。光学对比剂,特别纳米颗粒、纳米壳和量子点发展迅速。近红外(NIR)荧光染料标记的探针在转化到人类临床应用方面有着巨大的潜力。本文综述了当前光学分子影像学的发展现状及其在生物学、医学和药学中的应用。     

靶向超声分子成像技术在心血管疾病诊断中的研究进展

靶向超声分子成像技术是利用超声微泡表面的固有生物学特性构建成靶向超声微泡,或将靶向于病变组织特定分子的特异配体连接至超声微泡外壳,经静脉将靶向超声微泡注入体内,使其选择性地聚集于靶组织,通过对比超声检查产生靶组织细胞水平、分子水平显影1-2。该技术是目前分子影像学领域的研究热点,其具有高特异性、高敏感性、高空间时间分辨率、早期定量评价、分子显像、无创、无放射污染、相对安全性、仪器便携等优点3-7。近年来,其在涉及炎症、血栓、血管新生等心血管疾病的分子成像中得到广泛应用。本文就靶向超声分子成像技术在心血管疾病诊断中的研究进展予以综述。     

促进医工深度融合，打造品牌学术期刊

近年来,磁共振成像(MRI)技术发展迅速,新的快速成像的序列的出现,线圈技术的新进展,以及特定靶器官的MRI对比剂的研发与应用,使得MRI从单纯的形态学研究向形态与功能相结合的方向发展,并逐渐从宏观走向微观。分子影像学可用于基因治疗与表达的监测、肿瘤血管生成和受体成像等。     

靶向超声造影显像研究现状与进展

现代医学影像学已从传统的解剖结构成像,逐步发展进入了功能成像与分子显像时代,分子影像学的概念最早是由Weissleder等[1]提出,即应用影像学方法,对活体状态在细胞和分子水平的生物过程进行定性和定量研究。其目的是通过各种成像工具,对体内的重要分子,特别是对一些疾病的产生、发展有重要作用的分子及传导途径进行成像,以便对疾病进行早期诊断和治疗。     

超声分子影像学研究进展

随着超声分子探针技术的兴起,超声分子成像成为当前医学影像学研究的热点之一.分子探针的设计是超声分子成像研究的重点和先决条件.靶向超声微泡(球)造影剂在分子影像中的研究、应用,愈来愈受到关注,而多学科的融合使其具有更大的发展空间.     

靶向微泡造影剂超声分子成像的研究进展

分子影像学是指在传统的影像学方法中引入成像造影剂在分子或细胞水平观察、分析和测量生物体内某一生物学过程或疾病某一阶段特定分子标志物(如     

磁共振分子影像学研究进展

磁共振分子影像是分子影像学的重要分支,具有其他成像技术不可比拟的优越性和广阔的发展前景.近年来,新型磁共振靶向探针及成像序列的研发取得了一系列进展,包括可激活探针、19F成像、超极化成像以及化学交换饱和转移成像等方面,进一步拓展了磁共振分子影像的应用范围.此外,磁共振分子成像在多系统疾病的早期诊断、代谢成像、细胞示踪及基因分析等方面也发挥着巨大优势.尽管磁共振分子成像距离临床转化还存在着一定差距,随着成像技术的日新月异,其在临床疾病诊治中必将发挥重要价值.     

磁共振波谱技术在肿瘤基因治疗效果评价中的应用价值

基因治疗作为一种新的肿瘤治疗手段,得到人们越来越多的重视。理想的基因治疗应能根据病变的性质和严重程度,调控治疗基因在肿瘤组织内以适当的水平或方式表达。如何无创性监控基因治疗的基因表达及疗效,成为目前肿瘤学和影像学研究的热点。磁共振波谱成像技术（magnetic resonance spectroscopy,MRS）作为一种无创性检查手段,可以检测细胞水平的代谢情况,     

应用超声造影剂介导体内基因治疗

超声结合微泡可以促进质粒向目标组织转移和释放,达到基因治疗的目的 .基因治疗可用于治疗多种疾病,如癌症、遗传性疾病、心血管疾病、中枢神经系统疾病等.本文就超声波结合微泡造影剂介导基因在心血管系统疾病及其他体内疾病中治疗进展及应用进行综述.     

Prospect and progress of gene therapy in treating atherosclerosis

Introduction: Despite considerable improvements in therapies, atherosclerotic cardiovascular diseases remain the leading cause of death worldwide. Therefore, in addition to current treatment options, new therapeutic approaches are still needed.

Areas covered: In this review, novel gene and RNA interference-based therapy approaches and promising target genes for treating atherosclerosis are addressed. In addition, relevant animal models for the demonstration of the efficacy of different gene therapy applications, and current progress toward more efficient, targeted and safer gene transfer vectors are reviewed.

Expert opinion: Atherosclerosis represents a complex multifactorial disease that is dependent on the interplay between lipoprotein metabolism, cellular reactions and inflammation. Recent advances and novel targets, especially in the field of RNA interference-based therapies, are very promising. However, it should be noted that the modulation of a particular gene is not as clearly associated with a complex polygenic disease as it is in the case of monogenic diseases. A deeper understanding of molecular mechanisms of atherosclerosis, further progress in vector development and the demonstration of treatment efficacy in relevant animal models will be required before gene therapy of atherosclerosis meets its clinical reality.     

Cardiac Metabolic Implications of Fat Depot Imaging

Purpose of Review

This article reviews recent developments in the application of positron emission tomography (PET) for personalized cardiac imaging.

Recent Findings

PET imaging has improved our understanding of various cardiovascular pathologies by probing the molecular pathways associated with specific cardiovascular diseases. The use of PET can improve disease detection and influence management strategies.

Summary

PET has improved our understanding of the pathophysiology of atherosclerosis by imaging several key features including calcification, inflammation, apoptosis, and hypoxia. Molecular imaging of myocardial inflammation and cardiac sympathetic innervation is well established and several new promising PET radiotracers have been developed. Roles for the molecular imaging of aortic valve disease and mitochondrial function are also emerging.

     

The use of molecular imaging of gene expression by radiotracers in gene therapy

Introduction: Progress with gene-based therapies has been hampered by difficulties in monitoring the biodistribution and kinetics of vector-mediated gene expression. Recent developments in non-invasive imaging have allowed researchers and clinicians to assess the location, magnitude and persistence of gene expression in animals and humans. Such advances should eventually lead to improvement in the efficacy and safety of current clinical protocols for future treatments.

Areas covered: The molecular imaging techniques for monitoring gene therapy in the living subject, with a specific highlight on the key reporter gene approaches that have been developed and validated in preclinical models using the latest imaging modalities. The applications of molecular imaging to biotherapy, with a particular emphasis on monitoring of gene and vector biodistribution and on image-guided radiotherapy.

Expert opinion: Among the reporter gene/probe combinations that have been described so far, one stands out, in our view, as the most versatile and easy to implement: the Na/I symporter. This strategy, exploiting more than 50 years of experience in the treatment of differentiated thyroid carcinomas, has been validated in different types of experimental cancers and with different types of oncolytic viruses and is likely to become a key tool in the implementation of human gene therapy.     

RNAi-mediated gene silencing in cancer therapy

Introduction: This review presents the intriguing success of RNA interference (RNAi)-mediated gene silencing and its advantages and obstacles in cancer therapy.

Areas covered: RNAi has implications in metabolic disease, viral hepatitis, cardiovascular and cerebrovascular diseases, HIV, neurodegenerative disorders and cancer. RNAi can enhance the specificity and efficacy of therapeutic intervention for human diseases while at the same time reducing toxicity. The existing research related to gene therapy suggests encouraging prospects of a new high-efficiency and low-toxicity anti-tumor therapy. Although gene therapy is still in the experimental research phase, in the near future, this method will become an important means for the treatment of cancer therapies and it will be widely used in clinical practice.

Expert opinion: RNAi-based drug development is still in preclinical trial and several challenges limit the use of RNAi in the clinic. It is believed that further investigation of the mechanisms of RNAi-based therapies will help overcome these limitations and provide powerful weapons in the oncology clinic.     

Multimodality imaging for the diagnosis and treatment of constrictive pericarditis

ABSTRACT

Introduction: Constrictive pericarditis can result in debilitating congestive right heart failure and has been considered an important cause of morbidity and mortality in patients with cardiovascular disease. Multimodality imaging continues to play a fundamental role in the individual approach to diagnosis, management, and prognosis of patients with this clinical syndrome.

Areas covered: This article gives an overview of the clinical spectrum of constrictive pericardial diseases and the role of multimodality imaging in the diagnosis of constrictive pericarditis. There is a focus on the emerging role of cardiac magnetic resonance (CMR) for the diagnosis, management, and prognostication of patients with constrictive pericarditis based on more recent case series, retrospective and prospective studies, which have helped to define the role of CMR.

Expert opinion: Advanced multimodality imaging assists with identification of both overt and subclinical pericardial inflammation. This allows the pericardiologist to recognize patients with potentially reversible disease, trial medical therapy, and thereby avoid mechanical removal of the pericardium. Further, pericardial characterization by CMR has provided novel information about the natural history of these pericardial conditions, which can help tailor therapy and improve prognosis.     

相位对比磁共振血流测量原理、影响因素及在心血管疾病中的应用

相位对比磁共振成像是一种无创评价血流动力学的有价值的方法 ,能够用于评估心血管系统疾病的严重程度.本文综述相位对比磁共振血流测量的原理、影响因素及在心血管系统疾病中的应用.     

Imaging of vascular biology in the heart

The potential of molecular imaging in visualizing pathophysiologic processes underlying the development, progression, and regression of disease makes it a powerful tool for early detection, risk stratification, and tracking response to therapy. We have seen remarkable advances in molecular imaging of vascular diseases in recent years. To date, most studies have addressed the feasibility of molecular imaging in animal models of human disease, and translation into clinical practice is expected in the near future. Although there is a large body of literature, some groundbreaking, on cardiovascular molecular imaging going back to a decade ago, this review mainly focuses on recent advances in molecular imaging of vascular diseases of the heart.     

Effect of the interleukin-1B gene on serum oxidized low-density lipoprotein levels

ObjectivesTo investigate the association of the + 3953 IL-1B gene polymorphism in healthy subjects with serum oxidized LDL (oxLDL) levels.Design and methodsWe selected 255 subjects who were non-smokers and who had no cardiovascular or other chronic degenerative diseases, and we measured the oxLDL and other glucose levels, lipid biomarkers and biological variables that are related to cardiovascular metabolism. The + 3953 IL-1B gene polymorphism was determined using molecular genetics techniques (PCR-RFLP).ResultsA significant association among the + 3953 IL-1B genotypes and the oxLDL level was observed. The TT genotype presented lower oxLDL levels than the other genotypes. A multivariate analysis showed that this result was independent of the sex, age, obesity and hypertension status of the subjects.ConclusionsOur results suggest that the IL-1B gene polymorphism affects the modulation of serum oxLDL levels.     

Mesenchymal stem cells at the intersection of cell and gene therapy

Importance of the field : Mesenchymal stem cells have the ability to differentiate into osteoblasts, chondrocytes and adipocytes. Along with differentiation, MSCs can modulate inflammation, home to damaged tissues and secrete bioactive molecules. These properties can be enhanced through genetic-modification that would combine the best of both cell and gene therapy fields to treat monogenic and multigenic diseases.

Areas covered in this review: Findings demonstrating the immunomodulation, homing and paracrine activities of MSCs followed by a summary of the current research utilizing MSCs as a vector for gene therapy, focusing on skeletal disorders, but also cardiovascular disease, ischemic damage and cancer.

What the reader will gain: MSCs are a possible therapy for many diseases, especially those related to the musculoskeletal system, as a standalone treatment, or in combination with factors that enhance the abilities of these cells to migrate, survive or promote healing through anti-inflammatory and immunomodulatory effects, differentiation, angiogenesis or delivery of cytolytic or anabolic agents.

Take home message: Genetically-modified MSCs are a promising area of research that would be improved by focusing on the biology of MSCs that could lead to identification of the natural and engrafting MSC-niche and a consensus on how to isolate and expand MSCs for therapeutic purposes.