Minimal Technical Requirements Research Articles

Standardized MRD quantification in European ALL trials: Proceedings of the Second International Symposium on MRD assessment in Kiel, Germany, 18–20 September 2008

Assessment of minimal residual disease (MRD) has acquired a prominent position in European treatment protocols for patients with acute lymphoblastic leukemia (ALL), on the basis of its high prognostic value for predicting outcome and the possibilities for implementation of MRD diagnostics in treatment stratification. Therefore, there is an increasing need for standardization of methodologies and harmonization of terminology. For this purpose, a panel of representatives of all major European study groups on childhood and adult ALL and of international experts on PCR- and flow cytometry-based MRD assessment was built in the context of the Second International Symposium on MRD assessment in Kiel, Germany, 18-20 September 2008. The panel summarized the current state of MRD diagnostics in ALL and developed recommendations on the minimal technical requirements that should be fulfilled before implementation of MRD diagnostics into clinical trials. Finally, a common terminology for a standard description of MRD response and monitoring was established defining the terms 'complete MRD response', 'MRD persistence' and 'MRD reappearance'. The proposed MRD terminology may allow a refined and standardized assessment of response to treatment in adult and childhood ALL, and provides a sound basis for the comparison of MRD results between different treatment protocols.

Quantitative hazard and risk analysis for fragments of high-explosive shells in air

A hazard and risk analysis is given for personnel from primary fragments of fast moving and variably oriented high-explosive sources with spatially distributed event probability of a single event, e.g. for conventional threat. The approach assumes scenarios with static person densities on earth's surface. The spatial initiation distribution is described with a probability density function along a curve. The density can be constructed using expert estimates, technical safety analysis of an existing fuzing system or minimal technical safety requirements for fuzing systems. Arena test data are used for dynamic point source launching conditions of representative fragments to compute the physical consequences. Hazard criteria visualize the fragment density. Vulnerability models determine the individual local risk. In addition using the person density collective risks are computed. The individual and collective risks can be compared with various risk criteria, in particular for F-N curves. In a case study the approach is applied to a fuzing system of an artillery shell. Thus the post launch safety and the overhead safety or post safe separation safety taking third party into account are assessed. In this case the hazards and risks of fragments dominate when compared to blast effects. Assessing multiple scenarios the initiation density can be assessed.

Optical Resonance-Enhanced Absorption-Based Near-Field Immunochip Biosensor for Allergen Detection

An optical immunochip biosensor has been developed as a rapid method for allergen detection in complex food matrixes, and its application evaluated for the detection of the egg white allergens, ovalbumin and ovomucoid. The optical near-field phenomenon underlying the basic principle of the sensor design is called resonance-enhanced absorption (REA), which utilizes gold nanoparticles (Au NPs) as signal transducers in a highly sensitive interferometric setup. Using this approach, a novel, simple, and rapid colorimetric solid-phase immunoassay on a planar chip substrate was realized in direct and sandwich assay formats, with a detection system that does not require any instrumentation for readout. Semiquantitative immunochemical responses are directly visible to the naked eye of the analyst. The biosensor shows concentration-dependent color development by capturing antibody-functionalized Au NPs on allergen-coated chips and has a detection limit of 1 ng/mL. To establish a rapid method, we took advantage of the physicochemical microenvironment of the Au NP-antibody bioconjugate to be bound directly over an interacting poly(styrene-methyl methacrylate) interlayer by an immobilized antigen. In the direct assay format, a coating time with allergen of only 5 min under "soft" nondenaturing conditions was sufficient for accurate reproducibility and sensitivity. In conclusion, the REA-based immunochip sensor is easy to fabricate, is reproducible and selective in its performance, has minimal technical requirements, and will enable high-throughput screening of affinity binding interactions in technological and medical applications.

Comparison of the maintenance of wakefulness test (MWT) to a modified behavioral test (OSLER) in the evaluation of daytime sleepiness

The objectives were to evaluate the correlation between sleep onset as defined by the Oxford sleep resistance (OSLER) test and by simultaneous electroencephalography (EEG) and to determine the correlation between sleep latencies measured by the OSLER test and maintenance of wakefulness test (MWT) performed on the same day. This was a prospective, cross-sectional study carried out in a tertiary-care university-based sleep laboratory. Participants were 11 consecutive subjects presenting to the sleep center with clinical indications for nocturnal polysomnography and MWT. The interventions included MWT and OSLER test. Mean sleep latencies for the OSLER and MWT in each subject were closely correlated (ICC = 0.94, [Intra-class correlation]P < 0.05). Sleep latency by OSLER and simultaneous measurement of EEG also had excellent agreement (ICC = 0.91) with a bias of -0.97 min. The OSLER test is a practical and reliable tool for evaluating daytime sleepiness when compared with the MWT. No obvious systematic adaptation was seen during sequential OSLER test performance. Given its portability and minimal technical requirements, the OSLER test may be useful for large-scale applications in the evaluation of daytime wakefulness and vigilance.

Assessment of bone healing during callus distraction by an automatic torsional stiffness metering system

The present article describes a newly developed device for the quantitative assessment of torsional in vivo stiffness of regenerating bone under callus distraction. Both the design and function of this device, and its use during bony consolidation are discussed. The device exhibited an accuracy of +/- 18% for stiffness under 0.1 Nm/degree, and +/- 5% stiffness above 0.1 Nm/degree. The average accuracy was +/- 14%. The data scatter for the stiffness measurement ranged between +/- 1.43% and +/- 7.68% (average: +/- 3.99%). The precision of a test machine was between +/- 0.01% and +/- 11.3% (average: +/- 3.65%). The method has the following advantages over existing methods for investigating healing: 1. no need to dismantle the external fixation for measurement; 2. preservation of the bone axis with minimal risk of misalignment during the bone healing process; 3. minimal technical requirements, with easy, noninvasive measurement; 4. no exposure to X-radiation.

A task for assessing vertigo elicited by repetitive head movements.

We developed a simple, inexpensive test for assessing vertigo in persons with peripheral vestibular disorders. The test was administered to 16 asymptomatic adults and 16 patients with chronic vertigo caused by peripheral vestibular disorders. Participants sat in a chair and as rapidly as possible transferred 25 beanbags one at a time from a basket placed on the floor to a basket held .91 m up in the air. The task was timed, and the participants rated the level of vertigo elicited on a 10-point scale. Patients took significantly more time to perform the task and reported significantly greater levels of vertigo than did the asymptomatic adults. Test scores did not differ significantly across test sessions or raters. Performance on this task reliably differentiated patients with vestibular disorders from asymptomatic adults. The test is inexpensive, takes less than 1 min to perform, and has minimal technical requirements, making it suitable for a variety of facilities and levels of staff expertise.

Cardiac Output Measurement in Critical Care Patients:

Thoracic Electrical Bioimpedance (TEB) is a method for measuring cardiac performance which is noninvasive, continuous, has minimal technical requirements, and no patient risk. We used a commercially available TEB device to measure cardiac output in patients with thermodilution catheters in place. We compared the cardiac output measurements for the two modalities. We also compared the average hospital cost for initial cardiac assessment using the two techniques. The mean difference between the two cardiac output measurements was small (0.23 +/- 0.56) and not affected by the magnitude of the cardiac output readings. There was a strong correlation between COTD and COTEB (r = 0.91) and the regression slope was 0.91 with a Y intercept of 0.76. Cost analysis demonstrated that the use of TEB was approximately $600 less than thermodilution. Thoracic electrical bioimpedance measurement of cardiac output may offer a valuable alternative to the invasive measurement of the thermodilution catheter.