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排序方式: 共有520条查询结果,搜索用时 15 毫秒
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493.
Coronary artery disease: prediction with in vitro electron beam CT 总被引:13,自引:0,他引:13
Mautner SL; Mautner GC; Froehlich J; Feuerstein IM; Proschan MA; Roberts WC; Doppman JL 《Radiology》1994,192(3):625
494.
Cholangiocarcinoma: imaging by MR 总被引:5,自引:0,他引:5
Magnetic resonance (MR) images and computed tomographic (CT) scans of nine patients with histologically proved cholangiocarcinoma were compared retrospectively to assess the potential of MR imaging in the detection and staging of the disease. Cholangiocarcinomas were demonstrated as soft-tissue masses by both techniques in seven of the nine patients. In three patients, the masses were more apparent with MR because of a greater degree of contrast between the tumor and the surrounding tissues. In all four patients with the scirrhous subtype of cholangiocarcinoma, the soft-tissue masses showed decreased signal intensity on the second spin-echo image (echo time = 56 msec). Displacement or encasement of the adjacent vessels was well demonstrated by MR. Distal extension of the tumor (hepatic metastases, regional lymphadenopathy) appeared on both MR images and CT scans but was more apparent with MR. Both MR and CT demonstrated intrahepatic bile duct dilatation, but CT demonstrated it more readily. MR appears to be an effective modality for the detection and staging of cholangiocarcinoma. 相似文献
495.
Twenty-four-hour urine chemistries and the risk of kidney stones among women and men 总被引:14,自引:0,他引:14
BACKGROUND: Results of a 24-hour urine collection are integral to the selection of the most appropriate intervention to prevent kidney stone recurrence. However, the currently accepted definitions of normal urine values are not firmly supported by the literature. In addition, little information is available about the relationship between risk of stone formation and the levels of urinary factors. Unfortunately, the majority of previous studies of 24-hour urine chemistries were limited by the inclusion of recurrent stone formers and poorly defined controls. METHODS: We obtained 24-hour urine collections from 807 men and women with a history of kidney stone disease and 239 without a history who were participants in three large ongoing cohort studies: the Nurses' Health Study I (NHS I; mean age of 61 years), the Nurses' Health Study II (NHS II; mean age of 42 years), and the Health Professionals Follow-up Study (HPFS; mean age of 59 years). RESULTS: Mean 24-hour urine calcium excretion was higher and urine volume was lower in cases than controls in NHS I (P < or = 0.01), NHS II (P < or = 0.13) and HPFS (P < or = 0.01), but urine oxalate and citrate did not differ. Among women, urine uric acid was similar in cases and controls but was lower in cases in men (P = 0.06). The frequency of hypercalciuria was higher among the cases in NHS I (P = 0.26), NHS II (P = 0.03), and HPFS (P = 0.02), but 27, 17, and 14% of the controls, respectively, also met the definition of hypercalciuria. The frequency of hyperoxaluria did not differ between cases and controls, but was three times more common among men compared with women. After adjusting for the other urinary factors, the relative risk of stone formation increased with increasing urine calcium levels and concentration in all three cohorts but not in a linear fashion. Compared with individuals with a urine calcium concentration of <75 mg/L, the relative risk of stone formation among those with a urine calcium concentration of > or =200 mg/L for NHS I was 4.34 (95% CI, 1.59 to 11.88), for NHS II was 51.09 (4.27 to 611.1), and for HPFS was 4.30 (1.71 to 10.84). There was substantial variation in the relative risks for stone formation for the concentration of other urine factors within the different cohorts. CONCLUSIONS: The traditional definitions of normal 24-hour urine values need to be reassessed, as a substantial proportion of controls would be defined as abnormal, and the association with risk of stone formation may be continuous rather than dichotomous. The 24-hour urine chemistries are important for predicting risk of stone formation, but the significance and the magnitudes of the associations appear to differ by age and gender. 相似文献
496.
Jung Eun Lee Edward Giovannucci Stephanie A Smith-Warner Donna Spiegelman Walter C Willett Gary C Curhan 《Cancer epidemiology, biomarkers & prevention》2006,15(12):2445-2452
BACKGROUND: Fruits and vegetables rich in antioxidants have been proposed to reduce the risk of renal cell cancer. However, few prospective studies have examined the intakes of fruits, vegetables, and antioxidant vitamins in relation to the risk of renal cell cancer. METHODS: We prospectively examined the associations between the intakes of fruits, vegetables, vitamins A, C, and E, and carotenoids and risk of renal cell cancer in women and men. We followed 88,759 women in the Nurses' Health Study from 1980 to 2000, and 47,828 men in the Health Professionals Follow-up Study from 1986 to 2000. We assessed dietary intake every 2 to 4 years using a validated semiquantitative food frequency questionnaire. The Cox proportional hazards model was used to estimate study-specific multivariate relative risks (RR), which were pooled using a random effects model. RESULTS: A total of 248 (132 women and 116 men) incident renal cell cancer cases were ascertained during 2,316,525 person-years of follow-up. The consumption of fruits and vegetables was associated with a decreased risk of renal cell cancer in men (multivariate RR, 0.45; 95% CI, 0.25-0.81, for >or=6 servings of fruit and vegetable intake/d versus <3 servings/d; P test for trend = 0.02), but not in women (multivariate RR, 1.17; 95% CI, 0.66-2.07, for the same contrast; P test for trend = 0.25; P test for between-studies heterogeneity = 0.02). Intakes of vitamins A and C from food and carotenoids were inversely associated with the risk of renal cell cancer in men only, but we cannot exclude the possibility that this was due to other factors in fruit and vegetables. No clear association was observed for vitamin E in women or men. CONCLUSIONS: Fruit and vegetable consumption may reduce the risk of renal cell cancer in men. 相似文献
497.
498.
Fluid intake and the risk of bladder cancer in men 总被引:9,自引:0,他引:9
Michaud DS Spiegelman D Clinton SK Rimm EB Curhan GC Willett WC Giovannucci EL 《The New England journal of medicine》1999,340(18):1390-1397
BACKGROUND: Studies in animals have shown that the frequency of urination is inversely associated with the level of potential carcinogens in the urothelium. In humans, an increase in total fluid intake may reduce contact time between carcinogens and urothelium by diluting urinary metabolites and increasing the frequency of voiding. The data on fluid intake in relation to the risk of bladder cancer are inconclusive. METHODS: We examined the relation between total fluid intake and the risk of bladder cancer over a period of 10 years among 47,909 participants in the prospective Health Professionals Follow-up Study. There were 252 newly diagnosed cases of bladder cancer during the follow-up period. Information on total fluid intake was derived from the reported frequency of consumption of the 22 types of beverages on the food-frequency questionnaire, which was completed by each of the 47,909 participants who were free of cancer in 1986. Logistic-regression analyses were performed to adjust for known and suspected risk factors for bladder cancer. RESULTS: Total daily fluid intake was inversely associated with the risk of bladder cancer; the multivariate relative risk was 0.51 (95 percent confidence interval, 0.32 to 0.80) for the highest quintile of total daily fluid intake (>2531 ml per day) as compared with the lowest quintile (<1290 ml per day). The consumption of water contributed to a lower risk (relative risk, 0.49 [95 percent confidence interval, 0.28 to 0.86] for > or =1440 ml [6 cups] per day vs. <240 ml [1 cup] per day), as did the consumption of other fluids (relative risk, 0.63 [95 percent confidence interval, 0.39 to 0.99] for >1831 ml per day vs. <735 ml per day). CONCLUSIONS: A high fluid intake is associated with a decreased risk of bladder cancer in men. 相似文献
499.
500.
Curhan GC Knight EL Rosner B Hankinson SE Stampfer MJ 《Archives of internal medicine》2004,164(14):1519-1524
BACKGROUND: Analgesics are commonly used and may impair kidney function. However, limited prospective information is available on the long-term effects of aspirin, other nonsteroidal anti-inflammatory drugs (NSAIDs), and acetaminophen on renal function. METHODS: A total of 1697 women participating in the Nurses' Health Study provided information on a mailed questionnaire in 1999 about lifetime use of acetaminophen, aspirin, and NSAIDs and provided blood samples in 1989 and 2000. The main outcome was change in estimated glomerular filtration rate (GFR) in 11 years. Multivariate logistic regression was used to determine the odds of developing the outcome according to lifetime analgesic intake. RESULTS: The mean +/- SD estimated GFR decreased from 88 +/- 17 to 79 +/- 17 mL/min per 1.73 m(2). There were no substantial differences in the unadjusted or estimated GFR levels among the categories of lifetime intake for the 3 analgesic groups at baseline or after 11 years. Acetaminophen use was associated with an increased risk of a GFR decline of at least 30 mL/min per 1.73 m(2) (P trend =.01) and a GFR decline of 30% or greater (P trend<.001), but aspirin and NSAID use were not. Compared with women consuming less than 100 g of acetaminophen, multivariate-adjusted odds ratio (95% confidence intervals) for a decline in GFR of at least 30 mL/min per 1.73 m(2) for women consuming more than 3000 g was 2.04 (1.28-3.24). CONCLUSIONS: Higher lifetime use of aspirin and NSAIDs is not associated with renal function decline, but high acetaminophen use may increase the risk of loss of renal function. The absolute risk of renal function decline due to even high lifetime analgesic intake seems to be modest. 相似文献