共查询到20条相似文献,搜索用时 15 毫秒
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T Ohtsuki 《Canadian Metallurgical Quarterly》1993,42(2):73-81
Persisting postoperative pain of the thigh is a common problem of cementless hip endoprostheses occurring in about 15-20% of the patients. We performed a comparative study including patients with (n = 40) and without (n = 45) pain of the thigh. 85 cementless porous-coated anatomic (PCA) hip endoprostheses in 74 patients were examined. All patients underwent clinical examination including a standardized questionnaire, x-ray, and 3-phase bone scintigraphy. Slight or moderate 99mTc-MDP uptake in the area of the greater and lesser trochanter as well as at the tip was a common finding in PCA prostheses in patients without pain and was not a sign of loosening of the hip. Radiologically, there was no difference between patients with and without pain. However, persisting pain of the thigh in patients with PCA prosthesis corresponded with an increased uptake at the tip and the medial and lateral femur, not being a sign of loosening even in this group. The special biomechanical conditions of cementless prostheses causing inhomogeneous intraosseous stress distribution are supposed to be the reason for that. 相似文献
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Nebulisation is currently the most acceptable and practical delivery system for repeated applications of gene therapy to the lower airways of cystic fibrosis (CF) patients. We have assessed whether this route of administration offers other benefits with regard to respiratory gene transfer. A standard jet nebuliser (Acorn System 22, Medicaid) was used to transfer the reporter gene beta-galactosidase complexed with the cationic liposome DC-Chol/DOPE to three epithelial cell lines in vitro, two non-CF and one CF, using a novel collection system. In all three cell lines, nebulisation resulted in significantly (P < 0.05) improved transfection efficiency compared with instillation. At a constant DNA: liposome ratio of 1:5 (wt:wt), transfection efficiency was inversely related to increasing concentrations of DNA-liposomes before nebulisation. This effect was not related to the amount of DNA delivered and measurements of both zeta potential and mean aerodynamic particle size before and after nebulisation did not show concentration-related differences. The increased transfection efficiency did not relate either to the physical consequences of the nebulisation processes nor the effects of nebulisation on the complexes before instillation. Significantly increased transfection efficiency was seen following nebulisation with 95% O2/5% CO2 in comparison with 21% O2/78% N2 (air); this did not relate to changes in either the pH or temperature of the solution bathing the cells. The data confirm that nebulisation is appropriate for gene delivery to the lower airways in clinical practice and points to factors that may optimise gene transfer efficiency. 相似文献
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Questionnaire item responses were analyzed by testing the significance of the differences of percents in response categories, using a non-parametric test, and by testing the group differences in mean item scores, based on weights assigned the responses, using a critical ratio test. The two approaches gave equivalent results in almost all cases. Item mean scores correlated with percent-in-category generally .90 or higher. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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The odds ratio in a two-by-two table is widely used in case-control studies to measure association between disease and a binary risk factor. In this article we propose a more general measure of association, the comparative exposure ratio (CER), which is the ratio of the number of case-control pairs where the case has greater exposure divided by the number where the control has greater exposure. In simple cases, the CER is an odds ratio or a weighted combination of odds ratios. In more general cases, a CER continues to measure association even when an odds ratio computation is not feasible. Moreover, CERs improve on odds ratios in several ways: they do not require binary risk factors, or a choice of the scale of measurement of continuous risk factors; they make it possible to investigate multiple risk factors simultaneously, without multivariate parametric assumptions; they also can be used to detect patterns that might indicate possible causal pathways. We illustrate how various choices of the definition of 'greater exposure' make the CER a powerful and flexible tool. We give expressions for confidence intervals for CERs, and verify in a pilot simulation that they are valid. Finally, we illustrate with a case-control study of cervical dysplasia how exploratory inference using CERs can be carried out. 相似文献
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F Mu?oz-López 《Canadian Metallurgical Quarterly》1998,26(5):203-208
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Meta-analysis methodology is developed for combining sibpair linkage results across multiple studies employing different study designs, some employing quantitative traits (e.g., blood pressure) and some employing qualitative traits (e.g., clinical hypertension), under the assumption that the underlying (disease) trait loci are the same. Pooling results based on three commonly used sibpair methods is considered: the affected sibpair method for dichotomous traits and, for quantitative traits, the Haseman-Elston regression method and the Risch-Zhang extremely discordant sibpair method. The proportion of genes shared identical by descent (IBD) by a sibpair of certain trait outcomes is chosen as a common effect to be pooled across studies. Variation in the observed IBD proportions among individual studies is modeled using a random effects model. A heterogeneity test is provided to assess the variability among individual studies. When results from all three types of studies are available, we derive pooled estimates of IBD proportions both for sibpairs with extremely concordant trait values and for sibpairs with extremely discordant trait values, and construct a combined test of linkage based on the difference of the two estimates. Simulation studies demonstrate the need for and the advantage of meta-analysis of linkage results. We also present some guidelines for reporting linkage studies bearing potential future meta-analysis in mind. 相似文献
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Data from a simple paired comparison design illustrated that "robustness" arguments and nonparametric procedures do not contradict the need to know what form the distribution of the observations really has. (11 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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P Dittrich 《Canadian Metallurgical Quarterly》1996,135(20):647-652
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H Funahashi 《Canadian Metallurgical Quarterly》1998,87(6):1047-1052
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KG Moder 《Canadian Metallurgical Quarterly》1998,81(6):539-44, 547; quiz 547-8
LEARNING OBJECTIVES: Reading this article will familiarize the reader with the application and interpretation of different autoantibody tests used in rheumatology. DATA SOURCES: Recent rheumatologic textbooks, relevant review articles, and seminal articles in English regarding specific tests. RESULTS: An understanding of this review should enable the reader to approach diagnostic testing systematically in a patient with a suspected connective tissue disease. CONCLUSIONS: The proper use and interpretation of appropriate immunologic tests are important in the diagnosis and treatment of patients with connective tissue diseases. 相似文献
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LT Weaver 《Canadian Metallurgical Quarterly》1998,14(10):826-829
To assess the association of polymorphisms at the sulphonylurea receptor (SUR1) gene with the development of Type 2 diabetes mellitus, 456 subjects, 236 with Type 2 diabetes and 220 non-diabetic controls, were analysed for variants at exon 7, exon 22 and intron 24 of the SUR1 gene by the polymerase chain reaction and restriction fragment length polymorphism. The T761T substitution in exon 22 of the SUR1 gene was not found in either diabetic patients or non-diabetic controls. Both the exon 7 variant and the intron 24 variant were present in both groups at similar frequencies. No significant association was seen between either variant and obesity. Diabetic patients homozygous for the -3C allele of intron 24 had a higher ratio of positive family history than patients homozygous for the -3T allele (p = 0.03). We conclude that these polymorphisms are not major determinants of diabetes and obesity in the Japanese population. 相似文献
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Two dichotomous screening tests are often compared by performing both tests in a sampled population, and submitting positive results on either test to verification by the reference standard. Unbiased estimates of the true positive and false positive rates of each test cannot be estimated directly. However, unbiased estimates of the relative true positive and relative false positive rates may be obtained. When one test has a higher true positive rate at the expense of a higher false positive rate, the trade-off is represented by the ratio of extra false positives detected to extra true positives detected. A 95% confidence interval for this ratio is derived. This ratio is prevalence dependent and only applies to the sampled population. For target populations of different prevalence, estimates of the ratio may be obtained if one of the following applies: (i) the test characteristics of one test are known; (ii) the relative prevalence is known; and (iii) certain assumptions are made. 相似文献
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Comments on M. B. Jones's (see record 1971-07242-001) article advocating the use of heritability (HER) as a criterion in psychological test construction, pointing out a disadvantage of using HER as a criterion. One cannot maximize the HER of an intelligence test and then use that test to demonstrate that intelligence is inherited. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献