Transducers,sensors, and instrumentation in clinical biomechanics

Successful measurements in any field are dependent on the availability of appropriate transducer materials and the associated instrumentation. In recent years there has been a most welcome advance in both these areas. If we consider first the transducer developments that have recently taken place, these have much to do with the discovery and application of new materials such as electroactive polymers, fibre optic devices and many others. Instrumentation has largely benefitted from the microelectronics revolution. Our ability to process and ultimately display data has improved to a remarkable extent. Indeed, the designer of instrumentation is under enormous pressure to convert the data into the digital domain as early as possible simply because the resulting instrument will usually be easier to design and construct, more accurate, more reliable, smaller and possibly more important still, cheaper. This paper reviews some of these developments, gives a number of examples of applications in the clinical biomechanics area and makes some predictions for future developments.     

Dosimetry in molecular nuclear therapy

Advanced personalized dosimetry for molecular nuclear therapy has been shown to be feasible in clinical practice. At the same time instrumentation and dosimetric software are still evolving at a high pace. Procedures developed so far differ in approach and sophistication, and standard operating procedures necessary for accurate patient specific dosimetry do not yet exist. For this reason we restricted ourselves to reviewing the literature and highlighting relevant developments.     

Cotrel-dubousset instrumentation for the correction of adolescent idiopathic scoliosis. Long-term results with an unexpected high revision rate

ABSTRACT: BACKGROUND: For many years, the CD instrumentation has been regarded as the standard device for the surgical correction of adolescent idiopathic scoliosis (AIS). Nevertheless, scientific long-term results on this procedure are rare. Therefore, we conducted a retrospective follow-up study of patients treated for AIS with CD instrumentation and spondylodesis. METHODS: A total of 40 patients with AIS underwent CD instrumentation in our department within 3 years and between 1990 and 1992. For the retrospective analysis, first all the patient documents were reviewed, and pre-/postoperative X-ray images as well as those at the latest follow-up were analysed. Furthermore, it was attempted to conduct a clinical survey using the SRS-24 questionnaire, which was sent to the patients after a preceding announcement on the phone. RESULTS: Radiologically, the frontal main curvature was improved from a preoperative angle of 69.2degrees to a postoperative angle of 35.4degrees, and the secondary curvature was improved from a preoperative angle of 42.6degrees to a postoperative angle of 20.5degrees. The latest radiological followup at average 57.4 months post surgery showed an average loss of correction of 9.6degrees (main curvature) and 4.6degrees (secondary curvature), respectively.Within the first 30 days post surgery, 3 out of 40 patients (7.5%) received early operative revision for the dislocation of hooks or rods.At an average of 45.7 months (range 11 to 142 months), 19 out of 40 patients (47.5%; including 2 patients with early revision) received late operative revisions: The reasons were late infection (10 out of 40 patients; 25%) with the development of fistulae (7 cases) or putrid secretion (3 cases), which was resolved with the complete removal of instrumentation after all. The average time until revision was 35.5 months (range 14 to 56 months) after CD instrumentation. Furthermore, complete implant removal was necessary in 8 out of 40 patients (20%) for late operate site pain (LOSP). The average time until removal of instrumentation was 62.7 months (range 18 to 146 months) post surgery; and one patient received partial device removal for prominent instrumentation 11 months post surgery. Altogether, only 22 out of 40 CD instrumentations (55%) were still in situ. After an average period of 14.3 years post surgery, it was possible to follow-up 14 out of 40 patients (35%) using the SRS-24 questionnaire. The average score was 93 points, without showing significant differences between patients with or without their instrumentation in situ. CONCLUSIONS: Retrospectively, we documented for the first time a very high revisions rate in patients with AIS and treated by CD instrumentation. Nearly half of the instrumentation had to be removed due to late infection and LOSP. The reasons for the high rate of late infections with or without fistulae and for LOSP were analysed and discussed in detail.     

Is abdominal implantation of devices a good alternative to external attachment? A comparative study in Adélie penguins

Bio-logging studies suffer from the lack of real controls. However, it is still possible to compare indirect parameters between control and equipped animals to assess the level of global disturbance due to instrumentation. In addition, it is also possible to compare the behaviour of free-ranging animals between individuals equipped with different techniques or instruments to determine the less deleterious approach. We instrumented Adélie Penguins (Pygoscelis adeliae) with internal or external time-depth recorders and monitored them in parallel with a control group during the first foraging trip following instrumentation. Foraging trip duration was significantly longer in the internally-equipped group. This difference was due to a larger number of dives, reflecting a lower foraging ability or a higher food demand, and longer periods of recovery at the surface. These longer recovery periods were likely to be due to a reduced efficiency to ventilate at the surface, probably because the implanted devices pressurised adjacent organs such as air sacs. Moreover, descent and ascent rates were slightly lower in externally-equipped penguins, presumably because external instrumentation increased the bird drag. Looking at our results, implantation appears more disadvantageous—at least for short-term deployment—than external equipment in Adélie Penguins, while this method has been described to induce no negative effects in long-term studies. This underlines the need to control for potential effects due to methodological aspects in any study using data loggers in free-ranging animals, to minimise disturbance and collect reliable data.     

植物生理生态学研究中的控制实验和测定仪器新进展

 现代植物生理生态学的发展是和测定仪器的进步同步进行的。小型轻便、智能、性能优良和高自动化程度是植物生理生态学仪器发展的必然趋势。该文以光合生理生态学的仪器为例,概述了该领域测定仪器的发展趋势及对学科发展的重要作用,并讨论了控制实验和实验设计中的假重复问题。     

超声波对感染根管消毒作用的实验研究

目的:通过与氢氧化钙药尖消毒作用的比较,验证超声波对感染根管的消毒作用并判断其消毒作用的临床应用价值。方法:10只3月龄的小型健康实验家兔随机分成二组后,制备成感染根管动物模型。对模型进行术前细菌培养后,分别做超声根管内消毒和氢氧化钙药尖消毒,术后细菌培养。结果:超声波和氢氧化钙对需氧菌和厌氧菌的杀灭作用无菌种之间的差别;但杀菌效果存在显著差异。实验发现超声波消毒的特点是:第一,无抗菌谱的差异。第二,无热效应,根管壁表面升温不明显。第三,作用无方向性,对任何角度方向上的有机物均能使其失活。第四,越是细小根管作用越强。这些正是根管消毒所要求的特殊条件。结论:1)超声波对感染根管的消毒作用明显优于氢氧化钙药尖。2)超声波对感染根管的消毒作用无抗菌谱的差异。3)超声波对感染根管具有较可靠的消毒作用,作为一种根管消毒手段值得进一步研究。     

医疗器械特色图书馆开展企业竞争情报服务初探

阐述医疗器械竞争情报的概念与类型;分析了我国医疗器械行业竞争情报工作的现状和医疗器械特色图书馆开展竞争情报服务的优势及存在问题;提出竞争情报服务的模式和内容。     

High-content proteomics: fluorescence multiplexing using an integrated,high-sensitivity,multiwavelength charge-coupled device imaging system

The detection of proteins in 2-D gels and their subsequent identification by MS is still the "gold standard" in proteomics. Fluorescent detection has increasingly replaced colorimetric and radiometric detection on gels and blots. The reasons for this are multiple and varied and include higher sensitivity, better quantitation, increased dynamic range, speed, safety and ease of use. Unlike other methods, fluorescent protein detection is also typically very consistent in response from protein to protein and in many cases is compatible with MS methods for protein identification. The superior sensitivity and benefits achieved by fluorescent techniques have spurred the development of instrumentation capable of delivering precise, sensitive, high-resolution image acquisition over a wide variety of excitation and emission wavelengths. This report focuses on applications using the highly sensitive, charge-coupled device based ProXPRESS multilabel imager, readily configurable for image acquisition over a wide variety of wavelengths (380-700 nm and ultraviolet (UV)) using xenon lamp or UV excitation. The ability to simultaneously detect enzyme activities or protein modifications with different color fluorescent probes in addition to total protein amounts (multiplexing) allows the further mining of proteomic data content from a single set of protein samples. To this end, the development of instrumentation that enables a multiplexing strategy will become central to in-depth proteomic studies. The ProXPRESS maximizes the efficiency of experimental strategies that require flexibility and multicolor fluorescence detection.     

Design of acridinium-9-carboxamides and anti-acridinium antibodies for chemiluminescent signal enhancement

A novel system of signal enhancement is presented in which every labeled antibody is capable of generating a signal. Three chemiluminescent acridinium-9-carboxamide haptens (1, 2, and 3) which incorporated differences in charge and location of the linker were designed and synthesized. Anti-acridinium polyclonal antibodies for each hapten were screened using surface plasmon resonance instrumentation to determine specificity for each hapten. Anti-acridinium 2 antibodies were found to be non-cross-reactive to acridinium 1. This property was exploited to design secondary antibody conjugates which would bind to primary antibodies labeled with 2 yet could still be labeled with the structurally similar acridinium 1. Consequently, both layers contributed to the overall chemiluminescent signal. This format is an advance over other signal amplification formats which employ non-signal-generating, labeled antibodies to construct multilayered systems.     

Arthroscopy.

Arthroscopy has reduced the morbidity and period of hospitalisation associated with orthopaedic surgery and has increased the range of procedures that may be performed. From early operations on the knee it has expanded to include procedures for the shoulder, elbow, wrist, hip, ankle, and foot. For some joints the indications for surgery are clear, for others the clinical advantages are still being assessed. This expansion has also led to the recognition of complications, though the incidence is low. Specialist instrumentation has allowed a wide variety of operations previously needing open surgery to be carried out arthroscopically. The repertoire of arthroscopic procedures will undoubtedly continue to expand, and controlled studies are required to validate their efficacy, particularly in the management of degenerative joint diseases.     

Biolistic plant transformation

The biolistic process represents a completely new approach to the problem of how to deliver DNA into intact cells and tissues. High velocity microprojectiles are used to carry DNA or other substances past cell walls and membranes. Because DNA is being 'shot' into cells, it represents a type of biological ballistics, hence the term "biolistics".
There are several fundamental advantages to the biolistic process over other plant transformation techniques. The biolistic process appears to be effective regardless of species or tissue type, it is a rapid and very simple procedure, and it should facilitate the direct transformation of totipotent tissues such as pollen, embryos, meristems and morphogenic cell cultures. In addition, the biolistic process appears to be uniquely suitable for organelle transformation.
The disadvantages of the biolistic process are that it requires special instrumentation, and is still in the early stages of its development. Consequently, delivery efficiencies are still not as high as can be achieved in highly optimized transformation systems such as electroporation or agrobacterial-infection of tobacco. Furthermore, potential users should be prepared to spend some time adapting existing protocols to their specific species or tissue of interest.     

Label free biochemical 2D and 3D imaging using secondary ion mass spectrometry

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) provides a method for the detection of native and exogenous compounds in biological samples on a cellular scale. Through the development of novel ion beams the amount of molecular signal available from the sample surface has been increased. Through the introduction of polyatomic ion beams, particularly C(60), ToF-SIMS can now be used to monitor molecular signals as a function of depth as the sample is eroded thus proving the ability to generate 3D molecular images. Here we describe how this new capability has led to the development of novel instrumentation for 3D molecular imaging while also highlighting the importance of sample preparation and discuss the challenges that still need to be overcome to maximise the impact of the technique.     

Clinical proteomics: towards early detection of cancers

A key challenge in clinical proteomic of cancer is the identification of biomarkers that would allow early detection, diagnosis and monitor progression of the disease to improve long-term survival of patients. Recent advances in proteomic instrumentation and computational methodologies offer unique chance to rapidly identify these new candidate markers or pattern of markers. The combination of retentate affinity chromatography and surfaced-enhanced laser desorption/ionization time-of-flight (SELDI-TOF) mass spectrometry is one of the most interesting new approaches for cancer diagnostic using proteomic profiling. This review aims to summarize the results of studies that have used this new technology method for the early diagnosis of human cancer. Despite promising results, the use of the proteomic profiling as a diagnostic tool brought some controversies and technical problems and still requires some efforts to be standardised and validated.     

Instrumentation of off-the-shelf ultrasound system for measurement of probe forces during freehand imaging

Ultrasound is a popular and affordable imaging modality, but the nature of freehand ultrasound operation leads to unknown applied loads at non-quantifiable angles. The purpose of this paper was to demonstrate an instrumentation strategy for an ultrasound system to measure probe forces and orientation during freehand imaging to characterize the interaction between the probe and soft-tissue as well as enhance repeatability. The instrumentation included a 6-axis load cell, an inertial measurement unit, and an optional sensor for camera-based motion capture. A known method for compensation of the ultrasound probe weight was implemented, and a novel method for temporal synchronization was developed. While load and optical sensing was previously achieved, this paper presents a strategy for potential instrumentation on a variety of ultrasound machines. A key feature was the temporal synchronization, utilizing the electrocardiogram (EKG) feature built-in to the ultrasound. The system was used to perform anatomical imaging of tissue layers of musculoskeletal extremities and imaging during indentation on an in vivo subject and an in vitro specimen. The outcomes of the instrumentation strategy were demonstrated during minimal force and indentation imaging. In short, the system presented robust instrumentation of an existing ultrasound system to fully characterize the probe force, orientation, and optionally its movement during imaging while efficiently synchronizing all data. Researchers may use the instrumentation strategy on any EKG capable ultrasound systems if mechanical characterization of soft tissue or minimization of forces and deformations of tissue during anatomical imaging are desired.     

Obtaining and screening compound collections: a user's guide and a call to chemists

Advances in genetics, proteomics and cell biology over the past 20 years have unearthed a multitude of potential macromolecular targets for the selective treatment of disease. The challenge remains to find appropriate small molecule ligands for these proteins (or nucleic acids), and to use these ligands to validate novel disease targets. The advent of low-cost instrumentation has made industrial-style high-throughput screening possible in academic settings. Unfortunately for many, access to large collections of compounds is still limited and limiting. This article is aimed at the user who has an interest in compound screening but does not have ready access to large collections of small molecules. High-throughput screening need not be the exclusive domain of institutions and centers with vast resources and NIH Roadmap-funded compound repositories. As it turns out, many of the most interesting compounds are probably within arm's reach, in our laboratory freezers and in those of our colleagues.     

Clinical proteomics and mass spectrometry profiling for cancer detection

A key challenge in the clinical proteomics of cancer is the identification of biomarkers that would enable early detection, diagnosis and monitoring of disease progression to improve long-term survival of patients. Recent advances in proteomic instrumentation and computational methodologies offer a unique chance to rapidly identify these new candidate markers or pattern of markers. The combination of retentate affinity chromatography and mass spectrometry is one of the most interesting new approaches for cancer diagnostics using proteomic profiling. This review presents two technologies in this field, surface-enhanced laser desorption/ionization time-of-flight and Clinprot, and aims to summarize the results of studies obtained with the first of them for the early diagnosis of human cancer. Despite promising results, the use of the proteomic profiling as a diagnostic tool brought some controversies and technical problems, and still requires some efforts to be standardized and validated.     

Clinical proteomics and mass spectrometry profiling for cancer detection

A key challenge in the clinical proteomics of cancer is the identification of biomarkers that would enable early detection, diagnosis and monitoring of disease progression to improve long-term survival of patients. Recent advances in proteomic instrumentation and computational methodologies offer a unique chance to rapidly identify these new candidate markers or pattern of markers. The combination of retentate affinity chromatography and mass spectrometry is one of the most interesting new approaches for cancer diagnostics using proteomic profiling. This review presents two technologies in this field, surface-enhanced laser desorption/ionization time-of-flight and Clinprot?, and aims to summarize the results of studies obtained with the first of them for the early diagnosis of human cancer. Despite promising results, the use of the proteomic profiling as a diagnostic tool brought some controversies and technical problems, and still requires some efforts to be standardized and validated.     

A standard operating procedure for assessing liquid handler performance in high-throughput screening

The thrust of early drug discovery in recent years has been toward the configuration of homogeneous miniaturized assays. This has allowed organizations to contain costs in the face of exponential increases in the number of screening assays that need to be run to remain competitive. Miniaturization brings with it an increasing dependence on instrumentation, which over the past several years has seen the development of nanodispensing capability and sophisticated detection strategies. To maintain confidence in the data generated from miniaturized assays, it is critical to ensure that both compounds and reagents have been delivered as expected to the target wells. The authors have developed a standard operating procedure for liquid-handling quality control that has enabled them to evaluate performance on 2 levels. The first level provides for routine daily testing on existing instrumentation, and the second allows for more rigorous testing of new dispensing technologies. The procedure has shown itself to be useful in identifying both method programming and instrumentation performance shortcomings and has provided a means to harmonizing instrumentation usage by assay development and screening groups. The goal is that this type of procedure be used for facilitating the exchange of liquid handler performance data across the industry.     

The covalent attachment of multiple fluorophores to DNA containing phosphorothioate diesters results in highly sensitive detection of single-stranded DNA.

DNA fragments containing multiple internucleotidic phosphorothioate diesters, prepared by either chemical or enzymatic syntheses, are amenable to labeling with the fluorophore monobromobimane. With the incorporation of phosphorothioate diesters at each internucleotidic site, multiple fluorophores, ideally one for each nucleotide residue, can be covalently attached to the DNA fragment. The presence of multiple labels can be expected to interfere with analysis techniques, such as polyacrylamide gel electrophoresis. To avoid such problems, the fluorophores are introduced in a "postassay" fashion, that is, while the fragments are still embedded within the gel matrix. The detection limit (to the naked eye) for multiply labeled single-stranded DNA containing hundreds of base residues is in the low femtomole range. DNA containing greater than 1000 base residues can be visualized in some cases in the subfemtomole range without the use of sophisticated electronic instrumentation.