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排序方式: 共有751条查询结果,搜索用时 15 毫秒
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Johnson KS Chicken DW Pickard DC Lee AC Briggs G Falzon M Bigio IJ Keshtgar MR Bown SG 《Journal of biomedical optics》2004,9(6):1122-1128
The ability to provide the best treatment for breast cancer depends on establishing whether or not the cancer has spread to the lymph nodes under the arm. Conventional assessment requires tissue removal, preparation, and expert microscopic interpretation. In this study, elastic scattering spectroscopy (ESS) is used to interrogate excised nodes with pulsed broadband illumination and collection of the backscattered light. Multiple spectra are taken from 139 excised nodes (53 containing cancer) in 68 patients, and spectral analysis is performed using a combination of principal component analysis and linear discriminant analysis to correlate the spectra with conventional histology. The data are divided into training and test sets. In test sets containing spectra from only normal nodes and nodes with complete replacement by cancer, ESS detects the spectra from cancerous nodes with 84% sensitivity and 91% specificity (per-spectrum analysis). In test sets that included normal nodes and nodes with partial as well as complete replacement by cancer, ESS detects the nodes with cancer with an average sensitivity of 75% and specificity of 89% (per-node analysis). These results are comparable to those from conventional touch imprint cytology and frozen section histology, but do not require an expert pathologist for interpretation. With automation of the technique, results could be made available almost instantaneously. ESS is a promising technique for the rapid, accurate, and straightforward detection of metastases in excised sentinel lymph nodes. 相似文献
3.
Susan M. Orton Amy Peace-Brewer John L. Schmitz Kristie Freeman William C. Miller James D. Folds 《Clinical and Vaccine Immunology : CVI》2004,11(2):297-301
Detection and specificity of autoantibodies against extractable nuclear antigens (ENA) play a critical role in the diagnosis and management of autoimmune disease. Historically, the detection of these antibodies has employed double immunodiffusion (DID). Autoantibody specificity was correlated with diagnoses by this technique. Enzyme immunoassays have been developed by multiple manufacturers to detect and identify the specificity ENA autoantibodies. To address the relationship of ENA detection by DID and enzyme immunoassay, the performances of five immunoassays were compared. These included two DID and three enzyme-linked immunoassays (ELISA) (both screening and individual antigen profile kits). The sample set included 83 ENA-positive, antinuclear-antibody (ANA)-positive specimens, 77 ENA-negative, ANA-positive specimens, and 20 ENA- and ANA-negative specimens. Sensitivity and specificity were calculated by two methods: first, by using the in-house DID result as the reference standard, and second, by using latent class analysis, which evaluates each kit result independently. Overall, the results showed that the ELISA methods were more sensitive for detection of ENA autoantibodies than DID techniques, but presence and/or specific type of ENA autoantibody did not always correlate with the patient''s clinical presentation. Regardless of the testing strategy an individual laboratory uses, clear communication with the clinical staff regarding the significance of a positive result is imperative. The laboratory and the clinician must both be aware of the sensitivity and specificity of each testing method in use in the clinical laboratory.A diagnosis of autoimmune disease in patients is based upon clinical history, physical examination, and laboratory detection of antinuclear antibodies (ANAs). A particular class of ANAs specific for extractable nuclear antigens (ENA) was initially described in 1959 (3). Since that time, many different anti-ENA antibodies have been described. The detection of these autoantibodies and identification of their specificity have become well-established tools for the laboratory diagnosis of several autoimmune diseases. Studies of patients with ENA antibodies have shown that detection of these autoantibodies may have both diagnostic and prognostic significance, and the detection of anti-ENA antibodies has assumed an important role in the management of these patients (5, 16, 22). In most cases, ENA testing is ordered after an initial ANA screen. The indications for use are to establish a diagnosis in patients with suggestive clinical symptoms, to exclude a diagnosis of autoimmune disease in patients with few or uncertain clinical signs, to subclassify patients with a known diagnosis, and to monitor disease activity.Testing for anti-ENA antibodies has historically relied on gel-based immunoprecipitation techniques such as double immunodiffusion (DID) and counterimmunoelectrophoresis (2, 14). The associations of specific types of ENA autoantibodies with rheumatological diseases were established by using these gel-based immunoassay techniques (15). In the last decade, enzyme-linked immunoassay (ELISA) systems have been developed to detect and determine the specificity of anti-ENA antibodies. ELISA systems permit more rapid processing of more specimens with a faster turnaround time than gel-based assays. ELISA-based methods may also have increased sensitivity for detection of ENA antibodies. However, the increased sensitivity of these ELISAs may influence the clinical relevance of their detection because diagnostic specificity may be reduced (10, 12, 17, 24). As yet, a set of reference standards with known antibody specificities against defined antigen preparations is not available for evaluation of various methods or kits. Serum reference panels are available from the Association of Medical Laboratory Immunologists (4), but the specificities of these sera were determined by consensus results from multiple laboratories. The purpose of this study was to address the relationship between DID and ELISA methods for the detection and identification of anti-ENA antibodies by evaluating and comparing two DID kits and three ELISA kits. We evaluated both screening ELISAs and monospecific antigen ELISAs to determine anti-ENA specificity. 相似文献
4.
Radioactive sources in close contact offer an alternative to superficial radiation in the treatment of skin lesions. A flattening filter was designed for a lead surface applicator to improve the skin dose distribution of a high dose rate (HDR) brachytherapy unit (Nucletron). At three heights from the opening (10, 15 and 25 mm) of the cylindrical applicator, the 192Ir source can be driven into the centre of the applicator. Thin sheets of lead foil (0.2 mm) were cut into circular shapes and placed in the opening to build a cylindrical cone that acts as a flattening filter. The shape of the cone was optimized in an iterative process using a spreadsheet and the resulting dose distribution under the applicator was determined using radiosensitive film. The use of the filter improved the dose distribution in a plane perpendicular to the beam axis to be within +/- 5% of the central axis dose. The present applicator and flattening filter together with an HDR brachytherapy unit offer an alternative for skin irradiation where a superficial unit is not available or will be replaced with a more flexible device. As the depth dose characteristics can be modified using different source-to-surface distances, the dose throughout the patient's skin can be shaped as desired by the radiation oncologist using a compensator design type approach. 相似文献
5.
Proliferative and cytotoxic immune functions in ageing mice. I. Sequence of decline of reactivities measured under optimal and suboptimal sensitization conditions.
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Individual young adult, middle-aged, and old C57BL/6J male mice were tested for in vitro generated proliferative and cytotoxic responses to H-2 alloantigens under a variety of sensitization conditions. Proliferation in mixed lymphocyte culture (MLC) had decreased by 14 months of age (middle-aged), whether measured by directly assaying cultures in microtitre plates (micro MLC) or by labelling aliquots taken from large culture tubes (macro MLC). Cytotoxicity did not decline until a later age if sensitization was done in large tubes (macro cell-mediated lympholysis, CML). When cytotoxic activity was assayed by measuring lysis after addition of chromated cells to MLCs in microtitre plates (micro CML), differences were revealed between young and middle-aged animals. However, these conditions were suboptimal for generation of cytotoxicity even in young controls and showed even lower responses in the middle-aged group. It was concluded that proliferation showed an earlier, more severe decline than cytotoxicity with age as the proliferative response had declined by middle-age under all sensitization conditions used. With optimal sensitization conditions, senescent mice (26--30 months) showed a four- to ten-fold decrease in cytotoxicity compared with young adult mice. 相似文献
6.
Arngrímsson SA Petitt DS Borrani F Skinner KA Cureton KJ 《European journal of applied physiology》2004,92(4-5):524-532
To compare the effect of hyperthermia on maximal oxygen uptake (O2max) in men and women, O2max was measured in 11 male and 11 female runners under seven conditions involving various ambient temperatures (Ta at 50% RH) and preheating designed to manipulate the esophageal (Tes) and mean skin
temperatures at O2max. The conditions were: 25°C, no preheating (control); 25, 35, 40, and 45°C, with exercise-induced preheating by a 20-min walk at ~33% of control O2max; 45°C, no preheating; and 45°C, with passive preheating during which Tes and
were increased to the same degree as at the end of the 20-min walk at 45°C. Compared to O2max (l·min–1) in the control condition (4.52±0.46 in men, 3.01±0.45 in women), O2max in men and women was reduced with exercise-induced or passive preheating and increased Ta, ~4% at 35°C, ~9% at 40°C and ~18% at 45°C. Percentage reductions (7–36%) in physical performance (treadmill test time to exhaustion) were strongly related to reductions in O2max (r=0.82–0.84). The effects of hyperthermia on O2max and physical performance in men and women were almost identical. We conclude that men and women do not differ in their thermal responses to maximal exercise, or in the relationship of hyperthermia to reductions in O2max and physical performance at high temperature. Data are reported as mean (SD) unless otherwise stated. 相似文献
7.
Poly-guanosine motifs costimulate antigen-reactive CD8 T cells while bacterial CpG-DNA affect T-cell activation via antigen-presenting cell-derived cytokines 总被引:5,自引:0,他引:5
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Pathogen-derived pattern recognition ligands like lipopolysaccharide (LPS) and bacterial cytidine-guanosine (CpG)-DNA not only activate dendritic cells and macrophages but are also mitogenic for B cells. Less clear are the claimed effects of CpG-DNA on T cells, which range from direct activation, costimulation, or indirect transient activation via antigen-presenting cell (APC)-derived interferon type I (IFN type I). Here we demonstrate that CpG-DNA sequence specifically triggers macrophages to produce IFN type I, interleukin (IL)-12, IL-6 and tumour necrosis factor (TNF), but lacks the ability to directly costimulate T cells. Strikingly, poly-guanosine (poly-G) extensions to CpG-containing oligonucleotides (ODN) abolished the macrophage stimulatory potential yet generated T-cell costimulatory activities. In fact, independently of CpG-motifs, poly-G-ODN displayed the ability to costimulate T cells. Costimulation was operative on CD8 T cells but not CD4 T cells. Poly-G-mediated costimulation resulted in IL-2-driven T-cell proliferation and induced cytolytic T cells. Overall the data imply that poly-G motifs costimulate antigen reactive CD8 T cells, while CpG-DNA motifs fail to do so but may affect T-cell activation via APC derived cytokines such as IFN type I. 相似文献
8.
Inhibition of return (IOR) refers to slowed responses to targets presented at the same location as a preceding stimulus. We explored whether the IOR effect would increase with the number of cues preceding the target (a ‘cue’). Subjects performed a Posner cueing task with 1–5 cue presentations prior to the target, to which they made either a manual localization (Experiment 1) or target discrimination response (Experiment 2). The cues could be the same as (Experiment 1), or differ in shape from (Experiment 2), the target. The results showed that regardless of cue-target congruency the IOR effect increased dramatically with the number of preceding cues. This increase was driven mostly by a linear slowing of reaction times to targets presented on the same side as the cue(s), suggesting that a process such as sensory adaptation and/or habituation may be a contributing mechanism to the IOR effect. 相似文献
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