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1.
X-ray evaluation of rheumatoid joints is relatively inexpensive, is widely available and has standardised methods for interpretation. It also has limitations, including the inability to reliably determine structural change in less than 6-12 months, the need for experienced readers to interpret images and the limited acceptance of this technique in routine clinical practice. High-frequency ultrasound, with or without power Doppler, and magnetic resonance imaging of rheumatoid joints permit an increasingly refined analysis of anatomic detail. However, further research using these sensitive imaging technologies is required to delineate pathophysiological correlates of imaging abnormalities and to standardise methods for assessment.  相似文献   

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Left bundle branch block (LBBB) is related to abnormal cardiac conduction and mechanical asynchrony and is associated with hypertension and coronary artery disease. Improved evaluation of left ventricular (LV) mechanical asynchrony is needed, because of the increasing number of patients with LBBB and heart failure. In this paper, we describe tissue Doppler imaging (TDI), strain (rate) imaging and tissue tracking in LBBB patients. A variety of patterns of mechanical activation can be observed in LBBB patients. A recent development, referred to as tissue synchronisation imaging, colour codes TDI time-to-peak systolic velocities of segments and displays mechanical asynchrony. Furthermore, real-time 3D echocardiography provides new regional information about mechanical asynchrony. Contained in an LV model and projected on a bull''s eye plot, this modality helps to display the spatial distribution of mechanical asynchrony. Finally, segmental time-to-peak circumferential strain curves, produced by cardiac magnetic resonance imaging, provide additional quantification of LV mechanical asynchrony. Effects of LBBB on regional and global cardiac function are impressive, myocardial involvement seems to play a role and with the help of these novel imaging modalities, new insights continue to develop.  相似文献   

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A 35-year-old woman was referred for diagnostic evaluation of stitching pain under her left breast. The pain was not related to exercise. There were no cardiovascular risk factors. Physical examination, routine blood testing and chest X-ray were normal. Her ECG showed abnormal ST segments in III and aVF, and down-sloping ST segments with negative T waves in V3 to V4.  相似文献   

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Signals of different modalities are involved in the behaviour of the green stink bug, Nezara viridula (L.) (Pentatomidae, Heteroptera). Long range attraction is mediated by male pheromones, resulting in aggregation of bugs on the same plant where vibratory signals, vision and various chemical signals become important. Both males and females sing spontaneously. When both are on the plant, males start vibratory communication as often as females. Females induce the exchange of vibratory signals spontaneously or triggered by the male pheromone while males initiate the duet either spontaneously or after seeing the female. Males and females sing spontaneously and respond to signals of different modalities more often in the daylight than in the dark. Long lasting autonomous emission of the female calling song is present when triggered by the male pheromone and males respond to female calling predominantly by the emission of the courtship song.  相似文献   

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The role of heme oxygenase signaling in various disorders   总被引:3,自引:0,他引:3  
Modern methods of cell and molecular biology, augmented by molecular technology, have great potential for helping to unravel the complex mechanisms of various diseases. They also have the potential to help us try to dissect the events which follow the altered physiological conditions. Thus, there is every reason to believe that some of the potential mechanisms will be translated sooner or later into the clinic. Heme oxygenase (HO)-related mechanisms play an important role in several aspects of different diseases. In the past several years, significant progress has been made in our understanding of the function and regulation of HO. The objective of this article is to review current knowledge relating to the importance of HO mechanism in various diseases including myocardial ischemia/reperfusion, hypertension, cardiomyopathy, organ transplantation, endotoxemia, lung diseases, and immunosuppression. The morbidity and mortality of these diseases remain high even with optimal medical management. Furthermore, in this review, we consider various factors influencing the HO system and finally assess current pharmacological approaches to their control.  相似文献   

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Herceptin is widely regarded as the most important development in the treatment of breast cancer since Tamoxifen and the development of the multidisciplinary team (MDT). It is particularly exciting from an oncological polint of view as it represents success in the emerging field of specific targeted therapies to specific molecular abnormalities in tumour cells. This review will focus on the nature of the Her2 overexpression and the role of herceptin in the treatment of early breast cancer.  相似文献   

8.
The role of backscattering in SHG tissue imaging   总被引:1,自引:0,他引:1       下载免费PDF全文
We investigate the properties of second-harmonic generation (SHG) tissue imaging for the functional biological unit fascia, skeletal muscle, and tendon. Fascia and Achilles tendon primarily consist of similar collagen type I arrays that can be imaged using SHG microscopy. For muscle, it is the myosin molecules represented within the A bands. For fascia and tendon tissue samples, we observe, in addition to a stronger signal in forward images, vastly different features for the backward versus the forward images. In vivo as well as intact ex vivo thick tissue imaging requires backward detection. The obtained image is a result of the direct backward components plus a certain fraction of the forward components that are redirected (backscattered) toward the objective as they propagate within the tissue block. As the forward and the backward images are significantly different from each other for the imaged collagen type I tissue, it is crucial to determine the fraction of the forward signal that contributes to the overall backward signal. For intact ex vivo SHG imaging of Achilles tendon, we observe a significant contribution of forward features in the resulting image. For fascia, the connective tissue immediately surrounding muscle, we only observe backward features, due to low backscattering in muscle.  相似文献   

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生物膜是将细胞与环境分开的第一道屏障,是环境胁迫造成损伤的主要位点.脂肪酸是生物膜的主要组成成分,不饱和脂肪酸在决定生物膜的生理特性中具有重要作用,增加脂肪酸的不饱和程度能增加膜脂的流动性.近年来,很多研究发现,生物通过脂肪酸脱饱和维持膜的流动性来适应外界环境变化.本文主要从不饱和脂肪酸在环境温度胁迫、盐胁迫、氧化胁迫、酸碱胁迫、干旱胁迫、乙醇胁迫及铝胁迫中的作用研究进展进行了综述.  相似文献   

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A recent overview of the results of all trials of adjuvant chemotherapy suggests a clinically and statistically significant advantage for premenopausal women with positive axillary nodes. The results of the same approach for all other women with early breast cancer are very disappointing. These data suggest that contrary to the original hypothetical model, adjuvant chemotherapy is exerting its effect indirectly via chemical castration. In contrast, the results of trials of adjuvant tamoxifen have been more promising and, again, in contrast to the original premises, it would appear that a modest improvement in survival and delay in recurrence can be achieved amongst all groups of women independent of age, nodal status and oestrogen receptor content of the primary tumour. In order to explain these counter-intuitive observations, it is necessary to elaborate an alternative biological model. This paper describes the current thinking on the mode of action of the "anti-oestrogens" and the possible role of inhibitory growth factors activated indirectly by anti-oestrogens. Future trials of adjuvant systemic therapy for early breast cancer should include studies on the duration of tamoxifen, comparing 2 yr with longer, and a comparison of tamoxifen alone with polychemotherapy for premenopausal node positive patients.  相似文献   

15.
Intracoronary brachytherapy has recently emerged as a new therapy to prevent restenosis. Initial experimental work was achieved in animal models and the results were assessed by histomorphometry. Initial clinical trials used angiography to guide dosimetry and to assess efficacy. Intravascular ultrasound (IVUS) permits tomographic examination of the vessel wall, elucidating the true morphology of the lumen and transmural components, which cannot be investigated on the lumenogram obtained by angiography. This paper reviews the use of IVUS in the clinical studies of brachytherapy conducted to date. IVUS allows clinicians to make a thorough assessment of the remodeling of the vessel and appears to have a major role to play in facilitating understanding of the underlying mechanisms of action in this emerging field. The authors propose that state-of-the-art IVUS techniques should be employed to further knowledge of the mechanisms of action of brachytherapy in atherosclerotic human coronary arteries.  相似文献   

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The relative importance of the sarcoplasmic reticulum (SR) as a source of Ca2+ in the excitation-contraction coupling of mammalian myocytes was tested. Shortening and intracellular Ca2+ transients of electrically paced, isolated,adult rat myocytes were found to be absolutely dependent on the presence of a functional SR and were completely abolished by the SR Ca2+-ATPase inhibitors cyclopiazonic acid and thapsigargin or by the Ca2+-release channel opener ryanodine.Neonatal rat cardiomyocytes, on the other hand, elicited consistent intracellular Ca2+-transients even after complete functional inhibition of the SR. The transients, however, were markedly prolonged. Also isolatedadult guinea pig myocytes maintained the ability to shorten after a complete inhibition of the SR Ca2+-ATPase by either thapsigargin or cyclopiazonic acid. The twitches and the intracellular Ca2+-transients, however, were considerably longer after inhibition of the SR Ca2+-ATPase. Different results were obtained after preincubation of the cells with 10 M ryanodine to induce emptying of the SR Ca2+ pool. In this case, Ca2+ spikes and twitches were also markedly reduced in size, in addition to being prolonged. When a SR Ca2+-pump inhibitor was added to ryanodine-treated cells, the size of the Ca2+-transients and the capacity of the cells to shorten increased. Ryanodine leaves the activity of the Ca2+-pump of the SR intact and thus leads to an underestimation of the amount of excitatory Ca2+-flowing into the cell.The results show that, while the significance of the SR in regulating the Ca2+-transients and shortening of cardiomyocytes varies depending on the species and the stage of development, SR function is of paramount importance for the occurrence of rapid twitches.Abbreviations EGTA ethylene glycol-bis-(beta amino ethyl ether)N,N,N,N tetraacetic acid - MOPS morpholinopropane sulfonic acid - SR sarcoplasmic reticulum - BSA bovine serum albumin - HEPES N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid  相似文献   

18.
Functional magnetic resonance imaging (fMRI) and positron emission tomography measure local changes in brain hemodynamics induced by cognitive or perceptual tasks. These measures have a uniformly high spatial resolution of millimeters or less, but poor temporal resolution (about 1s). Conversely, electroencephalography (EEG) and magnetoencephalography (MEG) measure instantaneously the current flows induced by synaptic activity, but the accurate localization of these current flows based on EEG and MEG data alone remains an unsolved problem. Recently, techniques have been developed that, in the context of brain anatomy visualized with structural MRI, use both hemodynamic and electromagnetic measures to arrive at estimates of brain activation with high spatial and temporal resolution. These methods range from simple juxtaposition to simultaneous integrated techniques. Their application has already led to advances in our understanding of the neural bases of perception, attention, memory and language. Further advances in multi-modality integration will require an improved understanding of the coupling between the physiological phenomena underlying the different signal modalities.  相似文献   

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Unlike other types of breast cancers (BCs), no specific therapeutic targets have been established for triple negative breast cancer (TNBC). Therefore, chemotherapy and radiotherapy are the only available adjuvant therapeutic choices for TNBC. New emerging reports show that TNBC is associated with higher numbers of intratumoral tumor infiltrating lymphocytes. This is indicative of host anti-TNBC immune surveillance and suggesting that immunotherapy can be considered as a therapeutic approach for TNBC management. Recent progress in molecular mechanisms of tumor-immune system interaction and cancer vaccine development studies, fast discoveries and FDA approvals of immune checkpoint inhibitors, chimeric antigen receptor T-cells, and oncolytic virotherapy have significantly attracted attention and research directions toward the immunotherapeutic approach to TNBC. Here in this review different aspects of TNBC immunotherapies including the host immune system-tumor interactions, the tumor microenvironment, the relevant molecular targets for immunotherapy, and clinical trials in the field are discussed.  相似文献   

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