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Visual agnosia is a neuropsychological syndrome characterized by a failure of object identification. Apperceptive agnosia, an object identification deficit caused by damage to early perceptual processes, has been explained by appealing to both damaged early sensory processes and to damaged preattentive grouping processes. Which of these two explanations best accounts for the behavior of these patients? We present results from two experiments designed to distinguish rival theoretical accounts of apperceptive agnosia. In our studies, we attempted to simulate apperceptive agnosia in neurologically intact subjects. Sensory-deficit accounts of the syndrome predict that degrading visual processing would make normal subjects perform like patients; grouping-deficit accounts predict that removing perceptual organization cues from visual displays would make normal subjects perform like patients. We were able to simulate the behavior of an apperceptive agnosic patient by removing perceptual organization cues, consistent with a grouping-deficit account of this syndrome. The implications for understanding both apperceptive agnosia and normal visual functioning are discussed. 相似文献
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PE Fields RJ Finch GS Gray R Zollner JL Thomas K Sturmhoefel K Lee S Wolf TF Gajewski FW Fitch 《Canadian Metallurgical Quarterly》1998,161(10):5268-5275
Using a TCR transgenic mouse bred onto a recombinase-activating gene-2-deficient background, we have examined the influence of B7.1 and B7.2 on activation of naive, CD8+ T cells in vitro. We found that B7.1 was a more potent costimulus than B7.2 for induction of proliferation and IL-2 production by naive CD8+ T cells. This difference appeared to be quantitative in nature, as determined using transfectants expressing various defined levels of B7.1 or B7.2, or using purified B7.1 or B7.2 fusion proteins. In contrast to the quantitative differences seen in stimulation of naive T cells, B7.1 and B7.2 were comparable in their ability to costimulate responses in T cells previously primed in vitro. In addition, primed, but not naive, T cells were capable of proliferating and producing IL-2 in response to a TCR stimulus alone, apparently in the absence of B7 costimulation. Lastly, we found that B7.1 and B7.2 were equivalently capable of driving differentiation of naive CD8+ T cells into an IL-4-producing phenotype when exogenous IL-4 was added to the primary culture or to an IFN-gamma-producing phenotype in the presence of IL-12. These results indicate that signals generated by B7.1 and B7.2 are qualitatively similar, but that B7.1 is quantitatively stronger than B7.2. Further, our results indicate that the activation state of the responding T cell may influence the efficiency with which the T cell can respond to a costimulatory signal provided by either B7.1 or B7.2. 相似文献
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RL Summitt TG Stovall GH Lipscomb SA Washburn FW Ling 《Canadian Metallurgical Quarterly》1994,171(6):1480-4; discussion 1484-7
OBJECTIVE: This study examines our continuing experience in performing vaginal hysterectomies and laparoscopy-assisted vaginal hysterectomies with an outpatient protocol. The purpose was to review factors associated with discharge and hospitalization. STUDY DESIGN: Surgical records from all women entering our previously reported outpatient hysterectomy protocol were reviewed. Demographics, surgical indications, intraoperative data, and postoperative data were studied, and their associations with patient discharge and hospitalization were determined. Specific attention was directed to complications. RESULTS: The study group consisted of 133 women. Twelve women (9.0%) were not discharged from the hospital and 5 (3.8%) required readmission. Surgical indications, the type of hysterectomy, and the requirement for pain medication revealed no association with hospitalization. The occurrence of an intraoperative complication (p < 0.000), the need for transfusion (p = 0.043), and postoperative antiemetics (p = 0.013) were statistically associated with hospitalization. In addition, low hematocrit values and elevated temperatures on the first and second postoperative days were associated with hospitalization. CONCLUSION: Long-term experience with outpatient hysterectomy reveals a hospitalization rate of 12.8%. Complications, blood loss, elevated temperatures, and postoperative nausea are the major determinants of patient discharge and hospitalization. Readmission rates continue to remain low. 相似文献
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FW Reckling 《Canadian Metallurgical Quarterly》1976,(115):169-171
Total joint replacement procedures should be restricted to older individuals or persons with limited physical activities or life expectancy. However, on occasion a total joint replacement may be the only means to avoid serious disability in a young, otherwise healthy individual. This report of a 19-year-old woman who underwent a total hip joint replacement following unsuccessful treatment of a severely comminuted intracapsular hip fracture. Subsequent to the total hip joint replacement the patient experienced a normal pregnancy and delivery. 相似文献
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F Beersiek H Schneiders A Mehdizadeh G Jacobs FW Eigler 《Canadian Metallurgical Quarterly》1976,101(47):1719-1723
During the last 4 years three so-called spontaneous perforations of the oesophagus were treated, twice by surgical intervention 12 anys after the rupture. Two patients survived. The classical history of retching or vomiting and retrosternal splitting pain is indicative, wht medium, amidotrizoate sodium (Gastrografin), from the oesophagus. Prognosis depends decisively on the time of operation after the rupture. Direct suture of the rupture with plastic coverage of the defect by sewing on of the gastric fundus or by plication of the fundus have proved valuable. 相似文献
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