BackgroundTo evaluate efficacy of post exercise tissue velocity imaging in diagnosing more than 70% coronary artery stenosis.MethodTwenty patients with angiographically proved significant coronary artery disease and 26 healthy controls were evaluated. Pulsed wave tissue velocity imaging was performed at rest and immediately after treadmill stress test. Medial and lateral part of mitral annulus and medial and lateral part of tricuspid annulus were evaluated.ResultNo change or reduction in systolic annular velocity after exercise at any of the four sites identified patients of significant coronary artery disease with 75% sensitivity and 73% specificity. Rise in the ratio of early diastolic inflow velocity to the corresponding early diastolic annular velocity above the identified site-specific cut-off value had sensitivity of 85% but specificity of 34.6%. A combination of no change or decrease in late diastolic annular velocity and no change or decrease in systolic annular velocity at any of the four sites had sensitivity of 75% and specificity of 88.46%.ConclusionPost exercise tissue velocity imaging can provide a useful, objective parameter for detection of ischemic heart disease on stress testing. 相似文献
Background: Using selected sample populations, we compared sensitivity and specificity of autoantibodies to guinea pig and human tissue transglutaminase to assess if the human antigen is superior for predicting coeliac disease. Methods: Four commercial enzyme-linked immunoassay kits using human tissue transglutaminase as antigen were used to measure autoantibody levels in serum samples from untreated adult coeliacs ( n = 32). They were from a series of 130 cases diagnosed between 1997 and 1999 and chosen to bias the group towards subjects with negative autoantibodies when measured with guinea pig tissue transglutaminase as antigen. Samples from 38 control subjects (biased towards false-positive levels with guinea pig antigen) were used to compare specificity. We also assessed if human antigen kits could differentiate between levels in normal subjects and in selective IgA deficiency. Results: Sensitivity for coeliac disease in this selected group using the human antigen kits ranged from 88% to 100%. Three kits showed significantly higher specificity (82%-97%, P < 0.05) than the guinea pig antigen kit (71%) for the samples studied. No kit achieved complete separation between normal autoantibody levels and lower levels in selective IgA deficiency. Conclusions: All human antigen kits showed significantly higher sensitivity for coeliac disease compared to guinea pig antigen ( P < 0.001). Receiver operating characteristic curves confirmed the superior diagnostic accuracy of the human antigen kits. 相似文献
Summary Human articular cartilage of different ages was cultured for 8 days and proteoglycan (PG) release into the medium was measured. Retinol and synovial co-culture increased the PG release of cartilage of all ages. The effect of retinol was dose-dependent. Synovium increased also the PG release of dead cartilage, whereas retinol did not. The increased PG release by synovial co-culture is therefore mainly the result of synovial enzymes acting directly on the matrix rather than of a factor inducing chondrocyte-mediated breakdown. 相似文献
Magnetic resonance (MR) studies were performed in 14 patients as early as possible (21–110 days) after bone marrow transplantation (BMT). MR characteristics of lumbar vertebral bone marrow were studied with T1-weighted spin-echo imaging, water- and fatselective imaging with a frequency-selective excitation technique, and point-resolved spatially localized proton spectroscopy. Signals from water and fat protons and their T1 and T2 values were analyzed. Water proton signal intensity correlated well with cellularity within bone marrow, as determined with parallel iliac crest biopsies. The fraction of signal from water in red bone marrow of patients with allogeneic transplants from siblings (four cases) was significantly higher than in four patients with autologous transplants. The latter showed very low cellularity in the period of about 4 weeks after BMT because of the cytotoxic pretreatment of the bone marrow. The MR results in six patients with allogeneic transplants from unrelated donors ranged widely, depending on the complications after BMT. Analysis of data obtained with the different techniques showed that water- and fat-selective MR imaging and spectroscopic methods are useful for noninvasive monitoring of hematopoietic reconstitution after BMT. 相似文献
Previously unreported effects of tissue storage were recently observed in the authors' experimental magnetic resonance (MR) studies. To evaluate the effect of elapsed time after excision and storage temperature on tissue relaxation time measurements, tissue samples from the liver, pancreas, kidney, testis, spleen, and brain were obtained in rats. T1 and T2 were first measured within 5 minutes of excision, and between subsequent measurements, tubes were kept in a water bath at 40°C, at room temperature (28°C), or in an ice bath (4°C). Cellular and organellar integrity was assessed with electron microscopy and correlated with the MR findings. At 40°C (20-MHz spectrometer), the T1 of liver decreased from 280 msec ± 8 to 212 msec ± 10 during the first 60 minutes; the T1 of pancreas decreased from 276 msec ± 3 to 208 msec ± 2. Other tissues showed less than a 5% decrease in T1. T2 changes were smaller than T1 changes in all tissues. Electron microscopy of pancreatic acinar cells showed postmortem changes in mitochondria evolving over the first 60 minutes after death. Manganese loading experiments implicated mitochondrial manganese stores in the observed enhanced postmortem decrease in T1. This study calls into question reported relaxation time data for liver and pancreas. MR studies of excised tissues must account for time and temperature to prevent systematic experimental errors. 相似文献
Precise and accurate inversion-recovery (PAIR) magnetic resonance (MR) measurements of T1 were obtained in eight brain regions and cerebrospinal fluid of 26 healthy volunteers. Accuracy of the technique was assessed by measuring T1 in small fluid volumes with the PAIR technique and with two independent spectroscopic techniques. The mean difference between T1 measured with PAIR and with the two spectroscopic techniques was 3.1% ± 1.3. The precision (reproducibility) of measurements with the PAIR technique was excellent. The coefficient of variation (CV) across 16 measurements in a head phantom was 2.0%, compared with a CV of 2.7% across 45 separate measurements in a single subject. The within-subject CV was 1.8% ± 0.6 in white matter and 1.4% ± 1.0 in basal ganglia. The between-subject CV in 26 healthy volunteers was 3.6% ± 0.6 in white matter and 4.1% ± 1.9 in basal ganglia. Comparison between a patient with an active recurrent brain tumor and an agematched patient with an inactive brain tumor showed that T1 was significantly elevated throughout the brain of the active-tumor patient, especially in white matter tracts, even though no tumor or edema was detected in the white matter on standard MR images. Comparisons between five brain tumor patients and four healthy volunteers of similar age showed that T1 was significantly and substantially elevated throughout the white matter tracts and in the caudate nucleus, putamen, and thalamus. These results are consistent with the hypothesis that white matter tracts are selectively vulnerable to edema and that T1 increases in white matter are a sensitive indicator of patient status or tumor aggressiveness. 相似文献
Cultured epithelial autografts (CEA) have been used as an adjunct in the surgical management of extensive thermal burns. Unfortunately, the lack of a dermal matrix makes CEA susceptible to infection, shearing forces and limits their incorporation into the burn wound. A cultured composite autograft (CCA) has been developed in which autologous keratinocytes and fibroblasts are surgically harvested from the burn patient's normal skin. These components are proliferated and then combined to form an epidermal and dermal matrix, grown to confluence then applied.
Standard wound coverage techniques as well as CCA technology were utilized for successful wound closure in a 12 yr-old female with an 81% third degree burn. After fascial excision and allograft coverage, autografts were placed on her posterior burns and then 7500 cm2 of CCA was placed onto her anterior thorax, abdomen and lower extremities. Sixty percent of the burn was covered with CCA resulting in a success rate of 40%. No evidence of infection was noted, even in areas where CCA failed, although in those areas random epithelialization appeared to occur which then seemed to facilitate autograft placement. Early debridement and allografting followed by conventional autografts and CCA placement may provide an effective skin coverage strategy in patients with extensive deep burns. 相似文献