多层螺旋CT评价冠状动脉支架的体外实验

目的研究多层螺旋CT(MSCT)对冠状动脉支架的成像效果.方法将不同类型及内径的支架置入硅管内,制作成冠脉内支架模型.观察不同材料支架、灌注液、内径及MSCT重建层厚对支架成像效果的影响,并与冠脉内超声(ICUS)结果比较.结果钽制支架不能显示,而内径3 mm以上的不锈钢支架可以清晰的由MSCT显示;MSCT灌注对比剂时所测得的支架内径值明显低于灌注蒸馏水的结果(P＜0.05);3 mm和4 mm不同内径的支架相比,灌注对比剂时的剖面曲线最低CT值明显高于灌注蒸馏水的值(P＜0.05).且无论是灌注蒸馏水还是对比剂,内径4 mm的支架剖面曲线最低CT值都明显低于内径3 mm的支架(P＜0.05);与1.0 mm重建层厚相比,0.5 mm重建层厚可得到较清晰的图像;MSCT和ICUS对支架内径的测定结果有高度相关性(r=0.85,P＜0.05).结论MSCT可以对冠脉支架的形态进行评价,但其成像受支架材料、内径及重建条件的影响.     

Assessment of cellular proliferation of eccrine acrospiromas and eccrine sweat gland carcinomas by AgNOR counting and immunohistochemical demonstration of proliferating cell nuclear antigen (PCNA) and Ki-67

Argyrophil nucleolar organizer regions (AgNORs) were counted and immunostaining using antibodies raised against proliferating cell nuclear antigen (PCNA) and Ki-67 was carried out on eccrine acrospiroma and eccrine sweat gland carcinoma, to determine the malignant potential and prognosis of these tumours. Formalin-fixed and paraffin-embedded tissue specimens surgically excised from 25 patients with eccrine sweat gland carcinoma (20 cases of eccrine porocarcinoma, four cases of ductal sweat gland carcinoma and one case of malignant clear cell hidradenoma) and 25 patients with eccrine acrospiroma (16 cases of eccrine poroma, four cases of poroid hidradenoma and five cases of clear cell hidradenoma) were used. PCNA and Ki-67 labelling indices were categorized semiquantitatively into four grades. Significant differences were noted between eccrine sweat gland carcinoma and eccrine acrospiroma with these three methods (P < 0.01). When a cut-off of 5 was chosen, the AgNOR value distinguished eccrine sweat gland carcinoma from eccrine acrospiroma with high specificity and sensitivity. Moreover, we compared the results of these three methods between stages 1 or 2 (17 cases) and stage 3 (eight cases) eccrine sweat gland carcinomas, and no significant differences were observed. From these findings, these three methods are useful in discriminating malignant from benign lesions of eccrine tumours, but have no value in estimating the aggressiveness of eccrine sweat gland carcinomas.