Allergen microarray: comparison of microarray using recombinant allergens with conventional diagnostic methods to detect allergen-specific serum immunoglobulin E

BACKGROUND: The availability of recombinant allergens and recent advances in biochip technology led to the development of a novel test system for the detection of allergen-specific IgE. OBJECTIVE: To test the performance of this allergen microarray in a serological analytical study. METHODS: Standard allergens contained in grass pollen (Phl p 1, Phl p 2, Phl p 5 and Phl p 6) and tree pollen (Bet v 1 and Bet v 2) were used as a model system. The detection of allergen-specific serum IgE using microarrays was compared with standard test systems: CAP/RAST and an in-house ELISA. In order to test the analytical sensitivity of the assays, geometric dilutions of a serum pool containing high levels of pollen-specific IgE from allergic individuals were tested in each system. To assess the analytical specificity, the sera of 51 patients with presumptive allergic symptoms were collected before diagnosis. Thereafter, the results for grass/tree-pollen-specific IgE were compared. RESULTS: The microarray has a good dynamic range similar to the CAP/RAST system. Microarray and ELISA showed comparable analytical sensitivity exceeding the CAP/RAST system. With respect to the analytical specificity, no significant cross-reactivity of the allergens was observed. For two of the allergens tested, weak positive signals were detected in the microarray test system, whereas they were not detectable by CAP/RAST. CONCLUSION: A good correlation of presently used methods to detect serum IgE and the novel microarray test system was observed. As a next step, a careful validation of this method for a multitude of allergens and a thorough clinical evaluation has to be provided. Microarray testing of allergen-specific IgE can be presumed to be the method of choice for a prospective component-resolved diagnosis of Type I allergy, and the basis for the design and monitoring of a patient-tailored specific immunotherapy in the future.     

可视化技术及其在抗击SARS中的应用

本文主要介绍了可视化技术,其中重点阐述了科学计算可视化、信息可视化和地学可视化,最后总结了可视化技术在这次抗击非典型肺炎中所起到的重要作用.     

Influence of stretch-shortening cycle on mechanical behaviour of triceps surae during hopping

Belli , A. & Bosco, A. 1992. Influence of stretch-shortening cycle on mechanical behaviour of triceps surae during hopping. Acta Physiol Scand 144 , 401408. Received 20 March 1 991 , accepted 3 December 1991. ISSN 0001–6772. Laboratories of Physiology, Universities of St Etienne and Lyon, France and Departments of Biology and Physical Activity, University of Jyväskylä, Finland. Six subjects performed a first series of vertical plantar flexions and a second series of vertical rebounds, both involving muscle triceps surae exclusively. Vertical displacements, vertical forces and ankle angles were recorded during the entire work period of 60 seconds per series. In addition, expired gases were collected during the test and recovery for determination of the energy expenditure. Triceps surae was mechanically modelled with a contractile component and with an elastic component. Mechanical behaviour and work of the different muscle components were determined in both series. The net muscular efficiency calculated from the work performed by the centre of gravity was 17.5±3.0% (mean ± SD) in plantar flexions and 29.9 ± 4.8% in vertical rebounds. The net muscle efficiency calculated from the work performed by the contractile component was 17.4 %% 2.9% in plantar flexions and 16.1 ± 1.47; in vertical rebounds. These results suggest that the muscular efficiency differences do not reflect muscle contractile component efficiency but essentially the storage and recoil of elastic energy. This is supported by the relationship (P < 0.01) found in vertical rebounds between the extra work and the elastic component work. A detailed observation of the mechanical behaviour of muscle mechanical components showed that the strategy to maximize the elastic work depends also on the force-velocity characteristics of the movement and that the eccentric-concentric work of the contractile component does not always correspond respectively to the ankle extension-flexion.     

Rectus “wrap around” flap for salvage of an infected ascending aortic graft

An application of the rectus abdominis muscle flap to salvage an infected prosthetic graft of the ascending thoracic aorta is presented. The length of this flap along with its width and thickness allows it to be wrapped around prosthetic grafts of the ascending aorta in a spiral fashion. This rectus muscle wrap around flap method is straightforward involving the use of one muscle rather than multiple muscles. The abdominal cavity is not opened as with the use of omentum. The procedure can be accomplished in a short time which is important in the critically ill patient.     

Prevention of ischemia-reperfusion injury by metabolic substrate—Mechanisms and surgical implications

Summary Background Despite new insights into mechanisms contributing to ischemia-reperfusion injury, new therapeutic interventions to reduce ischemia-reperfusion injury have thus far not been available for routine clinical use. In order to restore sufficient postischemic contractile function, such a therapy would be of great value in conjunction with reperfusion therapy for acute myocardial infarction and after cardiac surgery. This paper examines whether metabolic disturbances and energy depletion contribute to ischemia-reperfusion injury and whether metabolic interventions could alleviate ischemia-reperfusion injury. Methods Experimental and clinical studies are reviewed for evidence of a beneficial effect of metabolic interventions, in particular of increased glycolytic substrate, on ischemia-reperfusion injury. Results During ischemia, metabolism of the myocardium shifts to a preferential use of carbohydrates. Increased glycolytic substrate i.e. glucose-insulin-potassium infusion as metabolic support for ischemic myocardium is beneficial in reducing ischemia-reperfusion injury by increasing energy production via anaerobic glycolysis, decreasing circulating free fatty acids and intracellular free fatty acid accumulation, maintaining ion homeostasis, reducing cellular edema, and scavenging free radicals. During reperfusion, glucose-insulin-potassium, apart from increasing glycolysis and decreasing free fatty acid metabolism, provides substrate for replenishment of the citric acid cycle, which is important for optimal energy transfer. Conclusions During ischemia, glucose-insulin-potassium preserves energy reserves and maintains cell viability. During reperfusion, glucose-insulin-potassium improves energy transfer and increases contractile function. Experimental and clinical studies have proven glucose-insulin-potassium to be a safe and effective intervention to reduce ischemia-reperfusion injury.      

Advances in processing of surface myoelectric signals: Part 1

During sustained voluntary or electrically elicted muscle contractions the surface myoelectric signal is nonstationary and it undergoes progressive changes reflecting the modifications of the motor unit action potentials and their propagation velocity. In particular, during sustained electrical stimulation, the evoked signals show progressive amplitude, time scaling and shape modification. The quantitative evaluation of these changes is important for non-invasive muscle characterisation and may be performed in either the time or frequency domain using parametric and nonparametric spectral analysis as well as alternative methodologies. The paper introduces the detection techniques, reviews and compares the methods of spectral estimation based on FFT and autoregressive models, and discusses their applications and limitations in extracting information from the surface myoelectric signal with particular regard to myoelectric manifestations of localised muscle fatigue during sustained contractions.     

断腕再植术后手内在肌挛缩

探讨断腕再植术后手内在肌挛缩的发生率、治疗方法及预防。方法:作者总结了近24年内进行断腕再植并得到随访的63例资料,对其中发生手内在肌挛缩41例的发病机理、治疗结果及预防进行了分析和讨论。结果:63例断腕再植术后有41例发生手内在肌挛缩,发生率为65％。缺血时间超过16小时与16小时内的断腕再植术后手内在肌挛缩的发生率,两者差异有显著性意义(t=3.81,p<0.05)。二期行手内在肌手术矫正者效果不理想。结论:断腕再植术后手内在肌挛缩的处理关键在于预防。清创后用肝素化全血对离断手进行灌注,早期行手内在肌筋膜间区减压,将会取得较好的效果。     

Effects of Ethanol on the Contractile Function of the Heart: A Review

Chronic ethanol consumption leads to a number of alterations in the contractile function of the heart and is a leading cause of cardiomyopathy. Ethanol also has an acute negative inotropic effect mediated by direct interaction with cardiac muscle cells, although this action is often masked by indirect actions resulting from enhanced release of catecholamines in vivo. This article reviews the effects of ethanol on the contractile function of the heart. The specific targets affected by ethanol in cardiac muscle cells are discussed in terms of potential mechanisms underlying the depressions of contractility resulting from both acute and chronic actions of ethanol.     

生物代谢过程的热力学研究——乙醇生成的理论转化率及代谢能级特征

根据生物代谢状态方程和代谢反应一般表达式,解析由葡萄糖生成乙醇的生物代谢过程。结果表明,该过程是一个可达到热力学最大可能性的过程,该代谢过程的热力学最大可能性转化率为51.1%,方程的解与依据代谢途径直接核算的结果一致,说明这些代谢途径已实现了热力学上的最大可能性。研究表明由葡萄糖生成乙醇的代谢过程具有非连续的能级特征。研究结果为深入解析代谢过程的物理意义奠定了基础。     

Effect of prior exercise in Pi/PC ratio and intracellular pH during a standardized exercise. A study on human muscle using [31P]NMR

Seven subjects underwent a standard localized exercise of calf muscles in order to investigate whether the metabolic exercise-induced steady-state, as revealed by the evaluation of inorganic phosphate/phosphocreatine ratio, depends on the conditioning of the muscle just prior to the exercise. The experimental protocols consisted of two separate experiments using first [³¹P]nuclear magnetic resonance spectroscopy and second (on 3 subjects) infrared oxyphotometry to respectively follow variation of energy metabolism and tissular deoxygenation. The exercise consisted of 240 successive plantar flexions (0.5 Hz frequency) against a high load equivalent to SO% of the maximal voluntary contraction. This exercise was accomplished before cold exercise and after warm exercise, a warming-up period bringing to approximately 50% of Vo_2max. The results showed that: (1) steady-state level of phosphate/phosphocreatine and intracellular acidosis was significantly lowered by warming-up; (2) cold and warm exercise steady-state of calculated adenosine diphosphate values were not significantly different; (3) cold exercise rapidly induced a high tissular deoxygenation that is not observed during warm exercise; and (4) time-constant of phosphocreatine resynthesis is lowered after warm exercise but the initial slope of time-evolution is not modified. Parallel experiments also showed that phosphate/phosphocreatine steady-state was not modified in comparison with warm exercise when the same power of exercise was reached by stepwise incrementation of the charge. From these results we postulate that a better tissue oxygenation due to a global or localized warming-up allows to reach the same mechanical performance with a lower decrease of PCr content, owing to a faster adjustment of oxidative metabolism during the transitional period. However the aerobic pathway flux during the steady-state is probably the same before and after the warming-up despite different values of phosphate/phosphocreatine. As a consequence it can be assumed that this ratio is not a good indicator of the rate of muscle oxidative metabolism during the steady-state phase of the exercise.