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.     

Hemostatic agents: brain tissue reaction and effectiveness. A comparative animal study using collagen fleece and oxidized cellulose

In a series of 26 young rabbits, three cortical lesions were made in each hemisphere. Two of these holes were filled with collagen fleece (CF) and oxidized cellulose (OC), respectively, while the third was left empty as a control. The bleeding time was measured. Hemostasis with CF was statistically significantly faster than with OC, which in turn was statistically significantly faster than with no hemostatic agent. The animals were killed successively on Days 7, 14, 28, 42, and 241 after operation. Histopathological investigation showed that CF did not induce more tissue reaction that the control lesion and that CF was resorbed faster than OC. The removal of OC occurred from the borders of the material, moving gradually inward. With CF, there was an immediate ingrowth of reactive cells throughout the material. In contrast to OC, CF did not induce the formation of polynucleated giant cells. From these results, it can be concluded that CF is a fast, safe, and absorbable topical hemostatic agent suitable for use in neurosurgical procedures.     

Quantitative analysis of morphological features in Huntington''s disease

In an electron microscopic study neuronal nuclear membrane indentations and astrocyte/neuron ratios in the nucleus accumbens, caudate nucleus and frontal cortex were counted in 30 Huntington's disease patients and 23 controls. Discriminant analysis was performed and resulted in a discriminant equation, which was able to recognize all controls correctly. Three Huntington patients were not correctly recognized, although in only one patient the probability of being a control was higher than being a Huntington patient. This discriminant equation was used in four choreatic patients with a negative family history. Two patients were indicated as controls, one patient as being a Huntington patient, and one as dubious. The diagnostic yield of discriminant analysis is discussed.     

Partial meniscectomy via arthroscope in patients over 50 years old

Between July 1983 and July 1986 115 patients, aged 50 years and older, suffering from 122 meniscal tears, were treated by arthroscopic surgery. Of these, 109 patients with 116 meniscectomy could be seen for a follow-up examination 2 years postoperatively. Patients of 50 years and older are known to need a long hospitalisation and a long rehabilitation period after an open meniscectomy. A quarter of all patients had a knee accident in their past as the cause of their complaints. Their main complaints are pain and swelling. As could be expected we found degenerative changes in 78% of the knees. After arthroscopic surgery the hospital stay is short, 75% is back home within 2 days. Half of the patients needed physiotherapy afterwards, 80% of all arthroscopically treated patients were satisfied. The group of patients aged 70 years and older scored worse, 50% of this group was satisfied. Two patients with severe degenerative changes on the X-rays did well. There is a positive correlation between the changes found arthroscopically and the final result.