颈内动脉接近完全闭塞时的处理

目的由于卒中风险随着狭窄严重程度的增加而升高，因此认为颈内动脉（ICA）接近闭塞患者的卒中风险很高。在现有的随机试验中，还没有专门针对这种情况进行探讨，因此其处理尚存在争汶。方法：对相关文献进行系统评价。结果：对ICA接近闭塞患者的处理还存在争议：一些学者支持进行干预，而另一些学者则认为存在风险或没有益处而反对进行干预。在ICA接近闭塞的有症状患者中进行一项比较外科治疗与最佳内科治疗的多中心前瞻性随机试验似乎非常困难，因为这类研究需要大量的患者。尽管如此，基于目前的证据，似乎很难拒绝手术治疗。结论：由于目前对ICA接近闭塞患者的最佳处理方案仍存在着争议，因此需要前瞻性观察性研究以证实其在有症状和无症状人群中的患病率以及相关的卒中风险。基于目前的证据，大多数医疗中心选择手术治疗，但它相对干内科治疗的特粱尚右待证章．     

Intrapartum Care of a Woman With Aortic Aneurysms

Advances in technology and complex care have enabled women with various health problems to become and remain pregnant. Consequently, health-care practitioners are seeing an increasing number of pregnant women who have aortic aneurysms. This case study describes the culturally sensitive intrapartum care of a Middle Eastern woman with ascending and descending aortic aneurysms.     

Sucrase-isomaltase: a marker associated with the progression of adenomatous polyps to adenocarcinomas.

Adenocarcinomas of the colon arise from adenomatous polyps. We hypothesized that sucrase-isomaltase (SI), a glycoprotein hydrolase, found in normal small intestine, fetal colon, and colon carcinomas is a marker associated with progression of adenomatous polyps with dysplasia to adenocarcinomas. To examine this hypothesis, we performed immunostaining using a polyclonal antihuman SI antibody in 32 adenomatous polyps with varying degrees of dysplasia. In addition, sucrase enzyme activity was determined in three sets of simultaneously harvested polyps, cancer, and adjacent normal mucosa from the same patient. All severely dysplastic polyps (6/6) exhibited SI staining. Most polyps (85%) with 3+ staining (i.e., greater than 10% of polyp positive for SI) had severe dysplasia, whereas those with mild dysplasia had either 1% to 5% staining or no staining in 95% of the cases. These data indicate that the extent of SI immunostaining in polyps correlates with the degree of dysplasia (p = 0.0001). Sucrase-isomaltase activity in the polyps was 18.1 +/- 1.8 mU/mg (mean +/- SD); in adjacent carcinoma SI activity was 29.1 +/- 1.8 mU/mg. Adjacent mucosa showed no activity in all cases. In summary, our results suggest that SI expression correlates with the progression of dysplastic adenomatous polyps to carcinoma. Sucrase-isomaltase expression may be useful as a clinical marker to improve our prognostic capabilities in patients with dysplastic lesions of the colon, that is, inflammatory bowel disease.     

Laminin expression in colorectal carcinomas varying in degree of differentiation

We are studying the ability of colorectal carcinomas, which vary in degree of differentiation, to assemble a basement membrane and the relationship between differences in this ability and perturbations in laminin expression. For these studies, we are using human colorectal carcinoma cells grown both in vitro and in nude mice as well as tumors obtained at surgery. Immunoperoxidase staining of human tumors indicates that laminin is present in a defined basement membrane in moderately to well-differentiated tumors. This staining pattern is absent in poorly differentiated tumors. In these tumors, staining is discontinuous and sometimes observed intracellularly. The laminin synthesized by in vitro cells was immunoprecipitated and analyzed by acrylamide electrophoresis. Neither poorly nor well-differentiated carcinoma cells exhibit marked differences in the rate of synthesis of laminin. Differences are present in the rate at which newly synthesized laminin is secreted. These differences may result from alterations in posttranslational processing. Such alterations may contribute, along with other factors, to the inability of poorly differentiated tumors to make a basement membrane.     

X-radiation induces 8-hydroxy-2'-deoxyguanosine formation in vivo in rat mammary gland DNA

Ionizing radiation is a carcinogen that induces oxidative DNA damage. 8- Hydroxy-2'-deoxyguanosine (8-OHdG) is a relatively abundant, mutagenic lesion that is widely regarded as a reliable index of oxidative DNA damage. The purpose of this study was to examine the effects of X- radiation on levels of 8-OHdG in the context of an experimental model for breast cancer in which chronic radiation exposure has been shown to be carcinogenic in Sprague-Dawley rats. A secondary objective of this study was to determine if the use of phenol during DNA isolation affected the concentration of 8-OHdG subsequently measured. Our results indicate that a profoundly carcinogenic dose of radiation induced a small but significant increase in 8-OHdG concentration in mammary gland DNA, and that the use of a phenol-based versus a salt-based method of DNA isolation had no significant impact on the levels of 8-OHdG detected in either control or irradiated tissue.