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排序方式: 共有498条查询结果,搜索用时 16 毫秒
91.
Cancers of the oral cavity, pharynx, and esophagus are now suspected to have common etiologic factors and have been grouped together as “upper aerodigestive” cancers. Since this grouping is of relatively recent origin there have been no epidemiological studies on this group among Armed Forces personnel. 114 cases of upper aerodigestive cancers and an equal number of controls were studied. The largest number of cases were in the age group of 40–49 years with male preponderance. Lower level of education, smoking, quid chewing, and alcohol use were found to be the major risk factors for these cancers. A dose response relationship was observed for smoking, quid chewing and alcohol intake.KEY WORDS: Neoplasms, Smoking, Quid chewing, Alcohol 相似文献
92.
Femoral head avascular necrosis: correlation of MR imaging, radiographic staging, radionuclide imaging, and clinical findings 总被引:39,自引:0,他引:39
Mitchell DG; Rao VM; Dalinka MK; Spritzer CE; Alavi A; Steinberg ME; Fallon M; Kressel HY 《Radiology》1987,162(3):709-715
To better correlate the appearance of avascular necrosis (AVN) of the femoral head on magnetic resonance (MR) images with the stage of disease, MR images of 56 proved AVN lesions were compared with staging from corresponding radiographs (n = 56), Tc-99m scans (n = 41), and grade of symptoms (n = 28). Fractures complicating AVN were seen in 28 (50%) of 56 radiographs (radiographic stages III-V). With long repetition (TR) and echo delay (TE) times, a characteristic "double line sign" consisting of high signal intensity inside a low-intensity peripheral rim was seen in 45 lesions (80%). The central region within the rim was isointense with marrow fat on both short and long TR and TE images in 20 (71%) of 28 lesions uncomplicated by fracture (stages I-II) but in only four (14%) of 28 stage III-V lesions (P less than .001). Symptoms were least severe in lesions isointense with fat and most severe in lesions with low-signal central regions at short and long TRs and TEs. The peripheral double line sign on long TR/TE images may add specificity to the diagnosis of AVN by MR imaging. A chronologic pattern of central MR signal features is presented which may allow staging of AVN by MR imaging. 相似文献
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Drexler HG; Brenner MK; Coustan-Smith E; Wickremasinghe RG; Hoffbrand AV 《Blood》1987,70(5):1536-1542
The peripheral blood mononuclear cells from 16 patients with B-chronic lymphocytic leukemia (B-CLL, n = 13), B-prolymphocytic leukemia (B-PLL, n = 2) or hairy cell leukemia (n = 1) were incubated in the presence of the phorbol ester 12-0-tetradecanoylphorbol-13-acetate (TPA) and the calcium ionophore A23187. A synergy between these inducers was found with respect to morphological changes and B cell proliferation and differentiation. A23187 used alone did not activate the cells. B-CLL cells treated with the double stimulus acquired a plasmacytoid morphology, showed significantly higher incorporation of 3H-thymidine and 3H-uridine, and produced significantly higher amounts of monoclonal immunoglobulin compared with the same cells exposed to either of the inducers alone. These results indicate that phorbol ester and calcium ionophore act synergistically on B-CLL cells to induce proliferation and differentiation. B-PLL cells responded more vigorously to the signals provided by TPA and A23187. Previous studies showed that TPA and A23187 can mimic the two physiological second messengers diacylglycerol and inositol trisphosphate in the transduction of signals leading to cell activation, proliferation, and differentiation in normal B cells. The present findings suggest that the capacity of B- CLL and B-PLL cells to differentiate in response to signals of the second messenger pathway is intact. 相似文献