A patient with right and left atrial membranes: the role of transesophageal echocardiography and magnetic resonance imaging in diagnosis

A patient who had right and left atrial membranes was examined. The diagnosis and the hemodynamic significance of both membranes were detailed by transesophageal echocardiography and were confirmed by magnetic resonance imaging. Transesophageal imaging was found to be superior to routine echocardiography in visualization of these atrial structures.     

创伤后迟发性脑肿胀的临床特点与治疗

目的 探讨创伤后迟发性脑肿胀的临床特点、发病机制与治疗。方法 回顾性分析1998年1月～2005年6月年收治的17例迟发性脑肿胀患者的临床特点和救治情况。结果 所有颅脑损伤患者采用保守治疗后均有好转，但于伤后5-10d出现恶化，CT复查有脑肿胀，经加强综合脱水等治疗后16例治愈，1例死亡。结论 迟发性脑肿胀好发于对冲性额、颞叶挫裂伤伴明显蛛网膜下腔出血、硬膜下薄层血肿及早期CT有脑肿胀者。其发病机制可能与创伤后的迟发性脑血管痉挛、微循环障碍、静脉回流障碍及甘露醇作用下降等因素有关。此类患者病情隐蔽性强，应加强观察、积极行CT复查，如能早期明确诊断，保守治疗多数效果良好。     

Growth kinetics of microscopic hepatocellular neoplasms in carcinogen-resistant and carcinogen-responsive strains of mice.

The initiation and growth of microscopic hepatocellular neoplasms in C57BL/6 mice, considered relatively resistant to hepatocarcinogenesis, was compared with that of the more responsive C3H and B6C3F1 (C57BL/6 x C3H) strains. Tumors were induced by giving male mice injections of diethylnitrosamine when they were 15 days old. During the first 18 weeks postinjection, the growth rates of neoplasms in the three strains were almost identical (doubling time of 2.1 to 2.5 weeks). However, after that time, only the growth rates of the C57BL/6 neoplasms slowed; between 30 and 42 weeks the doubling time had increased to 13 weeks. In addition, at all sacrifice times the number of neoplasms in the C3H strain was at least 2.5 times higher than in the C57BL/6 and B6C3F1 strains. These results suggest that the genetic determinant(s) for inhibited tumor growth (expressed only in C57BL/6 mice) are recessive to those for unimpeded tumor growth (expressed in C3H and B6C3F1 mice), while the determinant(s) for large numbers of tumors (expressed only in C3H mice) are recessive to those for small numbers of tumors (expressed in C57BL/6 and B6C3F1 mice). In addition to the interstrain differences in tumor growth, two other types of tumor growth heterogeneity were identified. First, in each of the three strains, the largest tumors were found to grow faster than the smaller tumors. This suggests that the very broad range in tumor size that is seen in this model results from the long-term differences in the growth rates of individual neoplasms. Second, we found that in microscopic hepatic neoplasms in B6C3F1 mice, the thymidine labeling indices were 2.3 times greater in the outer 50-microns shell (2 cells thick) than in the next deeper 50-micron layer cells. This suggests that even in these minute neoplasms, gradients in blood-borne oxygen, nutrients, or growth factors are responsible for heterogeneous growth.     

Retrorenal colon: implications for percutaneous diskectomy

It has been recommended that computed tomography (CT) with the patient prone be performed in every patient undergoing percutaneous diskectomy; this would enable detection of a retrorenal location of the colon, which could interfere with the percutaneous procedure. In this evaluation of 346 prone CT studies, only one patient (0.29%) was found to have retrorenal or retropsoas bowel that would have been perforated at diskectomy. Because of this extremely low prevalence, the performance of prone CT in every patient undergoing percutaneous lumbar diskectomy is not believed to be necessary.