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111.
Two cases are presented in which transverse esophageal folds were observed in children following ingestion of corrosive material. Strictures developed at the sites that initially manifested this serrated mucosal appearance. These findings lend additional credence to the concept that transverse folds, reflecting contractions of the muscularis mucosae, represent a pattern of pathologic motility rather than merely a variant of normal mucosal anatomy. 相似文献
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Miller DL; Simmons JT; Chang R; Ward BA; Shawker TH; Doppman JL; Chang AE 《Radiology》1987,165(3):785-790
A prospective, blinded comparison of three methods of hepatic contrast enhancement in computed tomography (CT) was conducted in 15 patients with colorectal carcinoma metastatic to the liver. Arterial portography (AP-CT) was performed with injection of contrast material into the superior mesenteric artery during CT. Delayed scanning (DS-CT) was performed 4 hours after intravascular administration of contrast material (mean dose, 280 mL). CT with an ethiodized oil emulsion (EOE-CT) was performed 1 hour after slow intravenous infusion of the emulsion. All patients underwent laparotomy following imaging studies. A lesion-by-lesion analysis of 56 metastases showed no significant differences in sensitivity (AP-CT, 77%; DS-CT, 83%; EOE-CT, 82%), but the false-positive rate for AP-CT was significantly higher than that for DS-CT (P less than .001) or EOE-CT (P less than .01). False-positive rates for EOE-CT and DS-CT were not significantly different. The predictive value of a positive test was 63% for AP-CT, 90% for DS-CT, and 81% for EOE-CT. AP-CT does not appear to be clinically useful for detection of hepatic metastases because of the high false-positive rate. No difference could be demonstrated between DS-CT and EOE-CT. DS-CT is a valuable method for hepatic contrast enhancement. 相似文献
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Lack of a co-promoting effect of a 60 Hz magnetic field on skin tumorigenesis in SENCAR mice 总被引:4,自引:3,他引:1
Sasser LB; Anderson LE; Morris JE; Miller DL; Walborg EF Jr; Kavet R; Johnston DA; DiGiovanni J 《Carcinogenesis》1998,19(9):1617-1621
It has been proposed that extremely low frequency (ELF) magnetic fields may
enhance tumorigenesis through a co-promotional mechanism. This hypothesis
has been further tested using the two-stage model of mouse skin
carcinogenesis, i.e. 12-O-tetradecanoylphorbol-13-acetate (TPA)- induced
promotion of skin tumors in mice initiated by a single subcarcinogenic dose
of 7,12-dimethylbenz[a]anthracene. Experimentation described herein
utilized the SENCAR mouse and examined the effect of a magnetic field on
skin tumor promotion induced by three different doses of TPA within its
dose-response range, i.e. 0.85, 1.70 or 3.40 nmol, administered twice per
week. SENCAR mice (56/treatment group) were exposed to a 60 Hz magnetic
field having a flux density of 2 mT for 6 h/day for 5 days/week and
compared with mice exposed to the ambient magnetic field. Tumor incidence
and multiplicity were monitored weekly for 23 weeks of TPA promotion.
Statistical evaluation of the effects of the magnetic field on tumor
incidence and multiplicity did not reveal any statistically significant
effects; thus, within the sensitivity limits imposed by the animal model
and the exposure parameters employed, no promotional or co-promotional
effect of a 2 mT magnetic field on skin tumor development in SENCAR mice
could be demonstrated.
相似文献