SARS病毒感染动物模型

SARS-CoV感染动物模型的建立可加深对SARS病原学的了解和发病机制的研究,加速实验室诊断技术的建立、抗病毒药物的筛选和疫苗的开发,同时也有助于给该病一个更精确的定义。可以说SARS动物模型的建立,不但是SARS研究的瓶颈问题,其应用更是贯穿SARS研究的整个过程。到目前为止,已经报道有4种非人灵长类动物(恒河猴、食蟹猴、绒猴、非洲绿猴)和6种啮齿类动物(大鼠、小鼠、豚鼠、田鼠、仓鼠、转基因鼠),以及雪貂、家猫等可以作为SARS动物模型用于实验研究,并已经开始利用动物模型进行疫苗和药物的安全性和有效性评价。本文就已报道的各类SARS动物模型进行综述,并根据动物模型和SARS患者的比对,提出动物模型建立的技术要点。     

Transgenic animal models of tauopathies

Tauopathies are a group of neurodegenerative disorders that include Alzheimer's disease, frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17) and other related diseases with prominent tau pathology. Research advances in the last several decades have characterized and defined tau neuropathologies of both neuron and glia in these diverse disorders and this has stimulated development of animal models of tauopathies. Indeed, animal models ranging from invertebrate species such as C. elegan to Drosophila melanogaster and mammalian transgenic mouse models of tauopathies have been generated and reported. This review summarizes the salient features of many of the known models of tauopathies.     

A systems approach to animal communication

Why animal communication displays are so complex and how they have evolved are active foci of research with a long and rich history. Progress towards an evolutionary analysis of signal complexity, however, has been constrained by a lack of hypotheses to explain similarities and/or differences in signalling systems across taxa. To address this, we advocate incorporating a systems approach into studies of animal communication—an approach that includes comprehensive experimental designs and data collection in combination with the implementation of systems concepts and tools. A systems approach evaluates overall display architecture, including how components interact to alter function, and how function varies in different states of the system. We provide a brief overview of the current state of the field, including a focus on select studies that highlight the dynamic nature of animal signalling. We then introduce core concepts from systems biology (redundancy, degeneracy, pluripotentiality, and modularity) and discuss their relationships with system properties (e.g. robustness, flexibility, evolvability). We translate systems concepts into an animal communication framework and accentuate their utility through a case study. Finally, we demonstrate how consideration of the system-level organization of animal communication poses new practical research questions that will aid our understanding of how and why animal displays are so complex.     

Cryoglobulinemic glomerulonephritis--lessons from animal models

In humans cryoglobulinemic glomerulonephritis (CGGN) may develop in the course of systemic cryoglobulinemia (CG) and is often associated with hepatitis C virus infection. It is believed that the glomerular injury in CG results from the deposition of immune complexes, but exact sequence of events in this process is unknown. Experimental models of CGGN provide an important tool to study pathogenesis of this type injury. This review describes two mouse models of CGGN and their use in understanding the role of various molecules involved in regulation of inflammatory and fibrosis pathways, such as complement components, Fc receptors, growth factors, and others; as well as illustrates their role in testing novel approaches of treatment in this type of renal injury.     

Dynamic models for animal orientation

The orientation of an animal moving in a plane towards a point-like mark is investigated. The control exerted by the optomotor (tracking) response on the motion of the animal is interpreted as an external force acting on the animal itself, which is modeled as a dipole or as a single point.The optomotor response is assumed as a rather general function of distance and angle. Differential equations governing the motion are derived and analyzed qualitatively and numerically. The role of distance-dependence and of the width of the visual field is investigated in detail and related to some typical kinds of paths in the plane, such as hitting the mark, coming close to the mark within a short distance, circular or undulating motion around the mark.A first version of this paper has been read at the Oberwolfach Conference on Mathematical Biology, June 1978     

Optogenetics in psychiatric animal models

Optogenetics is the optical control of neuronal excitability by genetically delivered light-activated channels and pumps and represents a promising tool to fuel the study of circuit function in psychiatric animal models. This review highlights three developments. First, we examine the application of optogenetics in one of the neuromodulators central to the pathophysiology of many psychiatric disorders, the dopaminergic system. We then discuss recent work in translating functional magnetic resonance imaging in small animals (in which optogenetics can be employed to reveal physiological mechanisms underlying disease-related alterations in brain circuits) to patients. Finally, we describe emerging technological developments for circuit manipulation in freely behaving animals.     

State-space models of individual animal movement

Detailed observation of the movement of individual animals offers the potential to understand spatial population processes as the ultimate consequence of individual behaviour, physiological constraints and fine-scale environmental influences. However, movement data from individuals are intrinsically stochastic and often subject to severe observation error. Linking such complex data to dynamical models of movement is a major challenge for animal ecology. Here, we review a statistical approach, state-space modelling, which involves changing how we analyse movement data and draw inferences about the behaviours that shape it. The statistical robustness and predictive ability of state-space models make them the most promising avenue towards a new type of movement ecology that fuses insights from the study of animal behaviour, biogeography and spatial population dynamics.     

Cytokines in animal models of cancer

Cytokines are a complex family of mediators that play a wide role in development, immunity, inflammation and tissue repair. Their use in therapy is still in its infancy and animal models have a key role to play in optimizing doses and schedules. Whilst xenogeneic and syngeneic transplantable systems have traditionally been used to look at the effects of cytokines in tumour models, oncogene transgenic mice prone to develop cancer, may now have a role to play. Moreover, gene therapy has allowed the investigation of ectopically expressed high and continous levels of cytokines. We will attempt to review the literature on the effect of cytokines and their combinations in these models of cancer.Abbreviations CML chronic myeloid leukemia - 5-FU 5-fluoruracil - FLC Friend leukemia cells - i.p. intraperitoneal - IFN interferon - IL interleukins - LAK lymphokine activated killer - s.c subcutaneous - SCCHN human squamous cell carcinoma of the head and neck - TNF tumour necrosis factor - PEG polyethylene-glycol     

Transgenic animal models of cardiovascular disease

Transgenic experimentation has become a crucial part of hypertension and atherosclerosis research, and is growing more important in several other areas of cardiovascular disease. It has recently made a particular contribution to understanding the role of the renin-angiotensin system in controlling hypertension. The study of blood pressure regulation, cardiac hypertrophy, atherogenesis and thrombosis are also benefiting from the transgenic approach.     

Neonatal animal models of opiate withdrawal

The symptoms of opiate withdrawal in infants are defined as neonatal abstinence syndrome (NAS). NAS is a significant cause of morbidity in term and preterm infants. Factors, such as polysubstance abuse, inadequate prenatal care, nutritional deprivation, and the biology of the developing central nervous system contribute to the challenge of evaluating and treating opiate-induced alterations in the newborn. Although research on the effects of opiates in neonatal animal models is limited, the data from adult animal models have greatly contributed to understanding and treating opiate tolerance, addiction, and withdrawal in adult humans. Yet the limited neonatal data that are available indicate that the mechanisms involved in these processes in the newborn differ from those in adult animals, and that neonatal models of opiate withdrawal are needed to understand and develop effective treatment regimens for NAS. In this review, the behavioral and neurochemical evidence from the literature is presented and suggests that mechanisms responsible for opiate tolerance, dependence, and withdrawal differ between adult and neonatal models. Also reviewed are studies that have used neonatal rodent models, the authors' preliminary data based on the use of neonatal rat and mouse models of opiate withdrawal, and other neonatal models that have been proposed for the study of neonatal opiate withdrawal.     

Tonic communication: continual effects of discrete signs in animal communication systems

Past investigations of communication among animals have neglected two aspects: (i) the role of time beyond the simple relation of “before” and “after” a sign has occurred, and (ii) the relative frequency of use of a sign within the total sign repertoire of a species. However, both aspects are potentially important. There is good evidence that a single, discrete sign can have an effect on the receiving animal which waxes and wanes as time progresses. If a sign is repeated, its effect may add to the residual effects of previously received signs and yield a cumulative, “tonic” effect in the receiving animal. Turning to the problem of relative frequency of use, we can expect that a sign which is repeated to achieve such a tonic effect will be performed more frequently than a sign with a “once-and-for-all” effect. The basic design feature of communication systems which utilize discrete signs yielding tonic effects are discussed, with emphasis on the similarities with the technical principle of pulse rate modulation; examples are given in which this kind of communication may play an important role.     

The role of junctional communication in animal tissues

Summary Permeable intercellular junctions are a common feature of most animal tissues. These junctions allow the free exchange of small ions and molecules between all the cells in coupled populations. Such limited syncytial interaction contributes to the integration of individual cells into organized tissues. Presented in the symposium on Molecular and Morphological Aspects of Cell-Cell Communication at the 31st Annual Meeting of the Tissue Culture Association, St. Louis, Missouri, June 1–5, 1980. This symposium was supported in part by Contract 263-MD-025754 from the National Cancer Institute and the Fogarty International Center.