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41.
T cell responsiveness to an epitope is affected both by its affinity for the presenting MHC molecule and the affinity of the MHC-peptide complex for TCR. One limitation of cancer immunotherapy is that natural tumor antigens elicit relatively weak T cell responses, in part because high-affinity T cells are rendered tolerant to these antigens. We report here that amino acid substitutions in a natural MHC class I-restricted tumor antigen that increase the stability of the MHC-peptide-TCR complex are significantly more potent as tumor vaccines. The improved immunity results from enhanced in vivo expansion of T cells specific for the natural tumor epitope. These results indicate peptides that stabilize the MHC-peptide-TCR complex may provide superior antitumor immunity through enhanced stimulation of specific T cells.  相似文献   
42.
The aims of this work were to measure the accuracy of one continuous speech recognition product and dependence on the speaker's gender and status as a native or nonnative English speaker, and evaluate the product's potential for routine use in transcribing radiology reports. IBM MedSpeak/Radiology software, version 1.1 was evaluated by 6 speakers. Two were nonnative English speakers, and 3 were men. Each speaker dictated a set of 12 reports. The reports included neurologic and body imaging examinations performed with 6 different modalities. The dictated and original report texts were compared, and error rates for overall, significant, and subtle significant errors were computed. Error rate dependence on modality, native English speaker status, and gender were evaluated by performing ttests. The overall error rate was 10.3 +/- 3.3%. No difference in accuracy between men and women was found; however, significant differences were seen for overall and significant errors when comparing native and nonnative English speakers (P = .009 and P = .008, respectively). The speech recognition software is approximately 90% accurate, and while practical implementation issues (rather than accuracy) currently limit routine use of this product throughout a radiology practice, application in niche areas such as the emergency room currently is being pursued. This methodology provides a convenient way to compare the initial accuracy of different speech recognition products, and changes in accuracy over time, in a detailed and sensitive manner.  相似文献   
43.
Numerous mitochondria ranging from slightly larger than normal to several micrometers in diameter (giant) were found in about one-half the serous secretory cells in the surface epithelium of the normal gerbil trachea and proximal bronchi. Tracheal serous cells of mice also were found to contain numerous giant mitochondria. Clara cells of gerbil bronchioles contained abundant giant mitochondria in addition to normal tubular mitochondria and the second population of enlarged spherical mitochondria that have been described in Clara cells of several genera. In contrast, mouse Clara cells revealed the normal tubular and the enlarged spherical mitochondria but no giant mitochondria. A survey of a number of cell types in gerbils failed to disclose hypertrophied mitochondria outside tracheobronchial surface epithelium and bronchioles. The mitochondrial enlargement resulted from an increase of matrix but not cristae. The expansion of matrix displaced the relatively sparse cristae into small collections compressed against the outer membrane. The prevalence of giant mitochondria and of granular endoplasmic reticulum is similar among cells, and these two organelles are codistributed within cells. The megamitochondria and granular reticulum occupy a central stratum, whereas normal mitochondria occur in the apical and basal regions. The giant mitochondria are considered related to a normal biologic activity that is characteristic of respiratory tract epithelium of mice and gerbils selectively and is more prominent in secretory cells than in ciliated cells.  相似文献   
44.
The validity of the biochemical identification of bacteria presumes that the inoculum consists of a pure growth of bacteria. The detection of mixtures of bacteria with the Analytab Enteric (API 20E) system was tested. Using a computer to predict the response of the API 20E system to mixed cultures, the presence of a mixture was not detected in 15% of all pairwise combinations of 324 common organisms of the Enterobacteriaceae family and in 19% of all pairwise combinations of Enterobacteriaceae with four gram-positive cocci. These theoretic predictions were confirmed experimentally for selected mixtures in which the bacteria were combined in equal concentrations. These results indicate that a purity subculture plate must be used to insure the detection of mixtures of bacteria, because the API 20E system fails to detect a large number of mixtures and may erroneously identify the organisms in such mixtures.  相似文献   
45.
Summary The repair of all hypospadias in one stage represents state of the art in virtually all instances. Implicit in the repair of hypospadias is the correction of chordee, the construction of the neourethra such that the meatus is located on the tip of the glans, and the creation of a penis which is cosmetically appropriate. Described in this paper are most of the currently employed methods utilized for the repair of hypospadias in a single stage. The techniques described herein, in skilled hands, yield good results in 85–90% of cases. Repairs of hypospadias which have been designed and which are recommended for the occasional operator have no place in today's surgical therapy.  相似文献   
46.
Analysis of X-ray crystallographic data for cephalosporins and 1- oxacephalosporins shows that, although the 1-methyl-1H- tetrazol -5- ylthiomethyl side chain at position 3 of a bicyclic beta-lactam nucleus has certain conformational preferences, it also has considerable flexibility. Both the C4 = C3-C3'-S and C3-C3'-S-C5" torsional angles are frequently observed in the vicinity of +/- 90 degrees. The distance between the tetrazole ring carbon C5" and the 4-carboxyl carbon ranges from 4.07 to 5.65 A. Mean bond lengths and bond angles for the 3 and 4 side chains are tabulated.  相似文献   
47.
The diagnostic criteria of the third edition of the DSM-III often state that one diagnosis cannot be made if it is "due to" another disorder. Using data from the National Institute of Mental Health Diagnostic Interview Schedule, with a sample of 11,519 subjects from a community population, we found that if two disorders were related to each other according to the DSM-III exclusion criteria, then the presence of a dominant disorder greatly increased the odds of having the excluded disorder. We also found that disorders, which DSM-III says are related to each other, were more strongly associated than disorders, which DSM-III says are unrelated. However, we also found there was a general tendency toward co-occurrence, so that the presence of any disorder increased the odds of having almost any other disorder, even if DSM-III does not list it as a related disorder. We concluded that empirical studies are needed to study the assumptions underlying the use of a diagnostic hierarchy.  相似文献   
48.
49.
Maternal and Child Health Journal - Low birthweight (LBW) is a significant public health problem in sub-Saharan Africa and LBW in rural Zambia is high. Our study explored the prevalence of LBW for...  相似文献   
50.
Lipomas are common benign tumours that can occur in most parts of the body. Lipomas arising from the deep temporal fat pad, found between the two layers of the deep temporal fascia, are rare, however; there has been only one documented case report to our knowledge. We describe a second case arising from the temporal fat pad in a patient treated at our unit, having previously reported the first one, and discuss the relevant anatomy and management.  相似文献   
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