Pseudo-aneurysms associated with intracranial surgery: case report

We describe a patient in whom two non-symptomatic internal carotid artery and middle cerebral artery pseudo-aneurysms were diagnosed 1 year following the surgical removal of a clinoidal meningioma. The unusual number, location, form and evolution (actual follow up of 6 years) of these pseudo-aneurysms differentiate them from other vascular lesions associated with surgery. It is important to understand the mechanism of vascular injury in order to understand imaging features and the possible methods of treatment.     

Unruptured large intracranial aneurysms in patients with transient cerebral ischemic episodes

This report analyzes the treatment of six patients with transient cerebral ischemic episodes in combination with large unruptured aneurysm. Priority treatment of the symptomatic lesions had to be delayed in five cases because the large aneurysms were ipsilateral to stenoses of the internal carotid artery. The hemodynamic effect of surgery on the compromised cerebral circulation was pre-examined with digital subtraction angiography and technetium-99m (^99mTc) single photon emission computed tomography. The data were correlated to aneurysm location and anatomical territory of the transient ischemic episodes. Only one patient showing a severe carotid stenosis contralateral to the large aneurysm, with decreased technetium uptake in the symptomatic hemisphere, required surgical correction of the stenosis first. In five patients, areas of reduced ^99mTc uptake were mostly found within vascular boundary zones with angiographically verified effective collateral circulation. Clipping of the large aneurysms in these patients ipsilaterally to the stenotic lesion or on the anterior communicating artery as first option did not substantially increase the risk of subsequent stroke.     

基因芯片技术在脑损伤研究中的应用

基因芯片技术是最近发展起来的新兴分子生物学技术,它的并行处理特点使大规模研究脑损伤后的基因改变成为切实可能。本文综述了新近用基因芯片技术在脑损伤后基因表达时序性改变及基因表达谱分析等研究中的应用。     

Results of randomized controlled trials of low-versus high-osmolality contrast media

The authors reviewed 100 randomized controlled trials (RCTs) conducted in humans to compare safety or efficacy of new low-osmolality contrast media (LOM) with that of high-osmolality contrast media (HOM). Findings of the 43 RCTs judged to be of the highest quality suggest that the efficacy of LOM in imaging is equal or superior to that of HOM for all routes of administration. Heat sensation occurred less often with LOM for all routes and pain occurred less often with LOM for intraarterial routes. No differences were seen in nephrotoxicity or in frequency of nausea, vomiting, urticaria, bronchospasm, laboratory test abnormalities, or neurologic events. Greater cardiovascular changes were seen with HOM, including increased or decreased heart rate, increased left ventricular end-diastolic pressure, decreased systolic pressure, and QT prolongation, depending on route of administration. To demonstrate whether a reduction in clinically significant adverse outcomes truly occurs with LOM, trials will need to enlist larger numbers of patients and employ appropriate outcome measures. Future trials should stratify patients according to their risk of adverse reactions to provide better information about benefits of LOM in low- versus high-risk patients.     

Isthmic spondylolysis of the lumbar spine: MR imaging at 1.5 T

The appearance on magnetic resonance (MR) images of the normal pars interarticularis in 13 patients was reviewed and contrasted with that of the pars in eight patients with spondylolysis. The pars defect usually had an intermediate signal intensity with all pulse sequences; however, this intensity was somewhat variable depending on the exact ratio of cartilage, fat, and fluid within each bone defect. The pars defect was best seen with spin-echo 600/20 (repetition time msec/echo time msec) images. In three cases, out-of-phase images showed the spondylolysis best, because of extension of fat to the borders of the defect. The sagittal view allowed one to separate spondylolysis from the joint space of posterior facets since the orientation of the defects is perpendicular to the facets; thus, a common pitfall encountered with cross-sectional axial imaging techniques is avoided. MR imaging poorly delineated bone fragments around the defect, which may produce nerve root impingement, but revealed other numerous complications that occur with spondylolysis, including spondylolisthesis and herniation of the disk above.     

Transabdominal versus endovaginal pelvic sonography: prospective study

Transabdominal and endovaginal pelvic sonograms were obtained in 108 nonpregnant patients referred for pelvic sonography. The studies were independently obtained by two radiologists and interpreted on the basis of identical clinical information. The sonograms were then compared for anatomic detail and abnormalities. A determination was made about which examination, if either, was superior. Follow-up was performed through a review of the medical records and follow-up studies. Overall, the endovaginal study was judged superior in 65 cases (60.2%), equal in 39 (36.1%), and inferior in four (3.7%). The authors conclude that the endovaginal examination can effectively replace the transabdominal examination as the initial approach for routine pelvic sonography.     

从平贝母茎叶中分离的平贝啶甙的结构

本文报道自平贝母(Fritillaria ussuriensis Maxim)的地上茎叶中分得一种新的甾体生物碱甙,定名为平贝啶甙(pingbeidinoside),mp 242～243.2℃[a]_D²⁵+6.9°(c 0.145,MeOH)。经IR,MS,¹HNMR和¹³CNMR谱解析,推定其结构为3β,16α,20-三羟基-Δ⁵-22,26-缩亚胺胆甾烷-25-O-α-D-葡萄糖甙。