Cortical variability and asymmetry in normal aging and Alzheimer's disease

The onset of Alzheimer's disease (AD) is accompanied by a complex and distributed pattern of neuroanatomic change, difficult to distinguish clinically from dynamic alterations in normal aging. Extreme variations in the sulcal patterns of the human cortex have made it difficult to identify diffuse and focal variations in cortical structure in neurodegenerative disease. We report the first comprehensive 3D statistical analysis of deep sulcal structure in vivo, in both normal aging and dementia. High-resolution 3D T1-weighted fast SPGR (spoiled GRASS) MRI volumes were acquired from 10 patients diagnosed with AD (NINCDS-ARDRA criteria; age: 71.9 +/- 10.7 years) and 10 normal subjects matched for age (72.9 +/- 5.6 years), gender, educational level and handedness. Scans were digitally transformed into Talairach stereotaxic space. To determine specific patterns of cortical variation in dementia patients, 3D average and probabilistic maps of primary deep sulci were developed for both normal and AD groups. Major sulci (including supracallosal, cingulate, marginal, parieto-occipital, anterior and posterior calcarine sulci, and Sylvian fissures) were modeled as complex systems of 3D surfaces using a multi-resolution parametric mesh approach. Variations and asymmetries in their extents, curvature, area and surface complexity were evaluated. Three- dimensional maps of anatomic variability, structural asymmetry and local atrophy indicated severe regionally selective fiber loss in AD. A midsagittal area loss of 24.5% at the corpus callosum's posterior midbody (P < 0.025) matched increases in structural variability in corresponding temporo-parietal projection areas. Confidence limits on 3D cortical variation, visualized in 3D, exhibited severe increases in AD from 2 to 4 mm at the callosum to a peak SD of 19.6 mm at the posterior left Sylvian fissure. Normal Sylvian fissure asymmetries (right higher than left; P < 0.0005), mapped for the first time in three dimensions, were accentuated in AD (P < 0.0002), and were greater in AD than in controls (P < 0.05). Severe AD-related increases in 3D variability and asymmetry may reflect disease-related disruption of the commissural system connecting bilateral temporal and parietal cortical zones, regions known to be at risk of early metabolic dysfunction, perfusion deficits and selective neuronal loss in AD.      

Production of auto-anti-idiotypic antibody during the normal immune response to TNP-ficoll. I. Occurrence in AKR/J and BALB/c mice of hapten-augmentable, anti-TNP plaque-forming cells and their accelerated appearance in recipients of immune spleen cells

Attempts were made to elucidate the cause of the downward regulation of the splenic plaque-forming cell (PFC) response in AKR/J and BALB/c mice between days 4 and 7 after a single intravenous injection of 2,4,6,trinitrophenyl- lys-Ficoll(TNP-F). AKR/J spleen cells, taken 7 d after injection of TNP-F, were transferred, together with TNP-F, into normal AKR/J mice. The day-3 or – 4 PFC response of the recipients was much lower than that of recipients of normal cells. However, the suppression was only apparent because the presence of 10(-8)-10(-7) M 2,4,6-trinitrophenyl-ε-amino-n-caproic acid (TNP- EACA) (or 10(-7)-10(-6) M 2,4,-dinitrophenyl-ε-amino-n-caproic acid) in the PFC assay caused a dramatic increase in observed PFC, averaging 298 percent on day 3 and 122 percent on day 4. Recipients of normal cells showed no such hapten-augmentable PFC. T-depleted immune spleen cells did not cause any apparent suppression of the response to TNP-F, but hapten-augmentable PFC in recipient spleens were again prevalent. Suppression of the PFC response, as well as hapten-augmentable PFC, were seen after transfer of immune serum. It was postulated that hapten augmentation of PFC was caused by displacement of auto-anti-idiotypic antibody from the surface of blocked antibody- synthesizing cells. Further studies showed that such hapten-augmentable PFC occurred in the spleens of a large percentage of both AKR/J and BALB/c mice examined after day 4 of the primary response to TNP-F. Thus, it was hypothesized that the downward regulation of the magnitude and, possibly, also of the heterogeneity of the splenic-PFC response was due to an auto-antibody response to one or more major idiotypes of the anti-TNP response.     

牛心包衍生材料引导成骨效应的X射线和骨密度评估

目的:应用X射线和骨密度值评价碳化二亚胺交联处理的脱细胞牛心包的引导成骨作用。方法:实验于2004-09/2005-01在中南大学湘雅二医院中心实验室及湘雅二医院动物部完成。健康雄性成年新西兰白兔20只,在新西兰白兔双侧下颌体各制备7mm×7mm大小的骨缺损,一侧骨缺损上方紧贴骨面覆盖碳化二亚胺交联脱细胞牛心包,作为实验组;另一侧不作处理,作为对照组。每组又分4,8,12,16周4个时间点,每个时间点为5只。术后4,8,12,16周行X射线观察和双能X射线吸收仪测量骨密度,评价骨缺损修复情况。结果:纳入新西兰兔20只,均进入结果分析。①术后骨缺损区大体观察:术后12,16周时实验组骨缺损区创面平坦;对照组骨缺损区凸凹不平,中央有结缔组织长入,16周时仍有直径2mm以上的缺损,呈纤维性愈合。②两组兔术后骨缺损区X射线观察:自8周起,实验组骨缺损区密度均高于对照组。③兔骨密度变化:术后4,8,12,16周实验组骨密度均高于对照组,差异均有显著性意义[分别为(0.337±0.035),(0.304±0.027)g/cm2;(0.373±0.022),(0.354±0.025)g/cm2;(0.365±0.032),(0.341±0.031)g/cm2;(0.347±0.023),(0.311±0.028)g/cm2,P<0.05]。结论:X射线和骨密度评估结果均显示碳化二亚胺交联脱细胞牛心包有良好的引导骨组织再生作用。     

Glaucoma following congenital cataract surgery – the role of early surgery and posterior capsulotomy

Background  

To determine the rate of glaucoma following congenital cataract surgery at Moorfields Eye Hospital (MEH), and to investigate potential risk factors for glaucoma in our case series.     

Should sperm donors be paid? A survey of the attitudes of the general public

Gamete donation in assisted reproduction is an accepted treatment option for certain infertile couples. Traditionally, men donating spermatozoa have been paid a nominal fee, whilst women donating oocytes have not. The issue of payment for sperm donors has recently attracted attention following the Human Fertilisation and Embryology Authority's (HFEA) suggestion that such payment may be withdrawn. Prior to the final meeting of the HFEA working party which is examining this issue, here we report the results of a survey designed to solicit opinion on whether sperm donors should be paid, to identify social or other factors which influence this opinion, and to examine the influence of financial incentive on potential donors. We surveyed 717 individuals in three distinct groups: the general public, students (potential donors), and infertility patients (potential recipients). The majority of the potential donor group (students) was in favour of paying sperm donors, as were infertility patients. In contrast the general public was not. The opinion of the general public on this issue was influenced by their prior knowledge of whether donors were paid: those of the general public favouring the payment of sperm donors had a prior awareness that such payments were made. Although not in favour of paying sperm donors, the general public overwhelmingly approved of the use of donated spermatozoa for the treatment of infertile couples, and thought that ways should be sought to increase the availability of donor spermatozoa for the treatment of infertility and for research purposes. Within the potential donor group (students), the majority indicated that financial reward was an important factor which would influence their decision to donate spermatozoa. As the majority of both the potential recipients and potential donors feels that sperm donors should be paid, perhaps the views of these groups should carry significant weight when the decision whether or not to withdraw payment is taken. This is especially the case in view of the fact that the majority of the general public is in favour of the use of donated spermatozoa for the treatment of infertile couples.      

Academic uroradiology: the future

Radiologic education, research, and the practice of radiology will be of the highest quality in the future if academic departments stress organ-system subspecialization while continuing to integrate and interface with technique-based specialists. Planning should begin now to effect an orderly progression to an organ-system-based subspecialty structure for radiology training in general and for uroradiology specifically. Uroradiologists should remain as central consultants to their clinical counterparts, working collaboratively with urologists in clinical endeavors of mutual relevance. More fellowships in uroradiology should be offered that attempt to incorporate all imaging methods and procedures into the curriculum. These issues are addressed in the context of patient care, service, education, and cost containment.     

Intraoperative arteriography: comparison of conventional screen-film with photostimulable imaging plate radiographs

This prospective study compared images obtained with a photostimulable imaging plate with matched images obtained with a conventional screen-film combination in 26 patients undergoing intraoperative arteriography. Diagnostic accuracy of the two techniques was assessed objectively, and image quality was assessed subjectively. In 16 patients (62%), the radiation exposure was reduced by 50% for the imaging plate technique by decreasing the mAs level generally used for the screen-film combination. Because of the dynamic range of the imaging plate system, no repeat examinations were necessary, while 12% of the screen-film studies had to be repeated because of over- or under-penetration. Imaging plate studies required 6% more time for processing than screen-film studies. Receiver-operating-characteristic analysis indicated no difference in diagnostic accuracy between the two imaging techniques. Subjective evaluation also revealed no difference in observer preference for imaging plate or screen-film studies. The imaging plate technique is an excellent alternative to screen-film studies in the operating room.     

Intussusception following abdominal trauma

We reviewed the charts of 21 patients on the Trauma Service who were operated on for intestinal obstruction for the years 1983 through 1985. Six (28.6%) of the 21 patients had intussusception as the cause of their obstruction post-laparotomy for trauma. All were males ages 17 to 25 years. The mechanisms of injury were gunshot wounds in three, stab wounds in two, and blunt trauma in one. Five patients were hypotensive on admission with systolic BP less than 70, and two patients received uncrossmatched blood preoperatively. Injuries at exploration included liver laceration (six patients), gastric perforation (two patients), and diaphragmatic lacerations, splenic laceration, renal injury, and ventricular injury, one each. No patient suffered small intestinal injuries and we cannot explain the occurrence of intussusception. Intussusception occurred in the first 8 postoperative days in four patients and at 21 days, and 10 months, in the remaining two. The diagnosis was made twice by CT scan preoperatively. Jejunojejunal intussusception was common (five patients), jejunoileal in one and ileocolic in one (who also had a jejunojejunal intussusception). All patients were treated with manual reduction alone and none recurred. There were no postoperative complications and all patients were discharged by the eighth postoperative day. Our study suggests that early postoperative obstruction is caused by intussusception with unexpected frequency in trauma patients, and can be diagnosed by CT scan in some cases. Treatment with operative reduction has an excellent prognosis.