A reconstructed computerized tomographic comparison of Ni-Ti rotary GT files versus traditional instruments in canals shaped by novice operators

AIM: The aim of this study was to compare the effects of preparation with conventional stainless steel Flexofiles and Gates Glidden burs versus nickel-titanium GT rotary files in the shaping of mesial root canals of extracted mandibular molars. METHODOLOGY: A total of 54 canals from 27 mesial roots of mandibular molar teeth were prepared using one of two methods by novice dental students. One canal in each root was prepared by a crown-down approach. utilizing stainless steel Flexofiles and Gates Glidden burs. The other canal was prepared using nickel-titanium GT rotary files in a crown-down fashion as recommended by the manufacturer. Preoperative CT scans of each root were recorded and 50 canal specimens were available for postoperative comparisons. Following canal shaping, postoperative scans were superimposed on the original images. Changes in canal area, canal transportation and thickness of remaining root structure at strategic levels of the root were analyzed. The time taken for each method was also noted. RESULTS: At the coronal and mid-root coronal one-third sections, the rotary GT files produced a significantly smaller postoperative canal area (P < 0.05). In the mid-root sections there was significantly less transportation of the root canal toward the furcation, and less thinning of the root structure with GT files compared to the stainless steel files (P < 0.05). Overall, there was greater conservation of structure coronally and more adequate shape in the mid-root level. The GT rotary technique was significantly faster than the stainless steel hand-held file technique (P < 0.0001). Two GT instruments fractured during the study. CONCLUSIONS: Under the conditions of this study, novice dental students were able to prepare curved root canals with Ni-Ti GT rotary files with less transportation and greater conservation of tooth structure, compared to canals prepared with hand instruments. The rotary technique was significantly faster.     

Conflict control processing in adults with developmental dyslexia: An event related potentials study

ObjectiveThe present study investigated the time course for processing conflict in dyslexic adults using a flanker task.MethodsSixteen dyslexic and 15 control adults performed a flanker task comprising congruent and incongruent trials in which participants had to indicate the direction of targets surrounded by flankers. Early negative potentials associated with orienting of attention (i.e., N1) and conflict monitoring (i.e., N2) and two positive potentials associated with conflict resolution (i.e., P3b and Nogo P3) were recorded.ResultsThe behavioral data showed differences between incongruent and congruent trials for reaction times in both groups but for error rate only in dyslexics. As in previous studies, controls displayed greater N1, N2 and NoGo P3 as well as a smaller P3b in incongruent trials. Dyslexics lacked N1, N2 and P3b modulation whereas NoGo P3 effect was preserved.ConclusionDyslexics showed impairments in conflict monitoring and in some aspects of conflict resolution (i.e., the allocation of attentional resources) whereas other aspects of conflict resolution (i.e., the inhibition) were preserved.SignificanceThis is the first study to investigate conflict control processing in dyslexic adults using ERPs. Results provide evidence for deficits in orienting of attention, conflict monitoring and allocation of attentional resources in dyslexics.     

Three-dimensional computed tomography is not indicated for the classification and characterization of calcaneal fractures

This study determined inter- and intra-observer reliability for measurement of the angles of Böhler and Gissane, for the decision between surgical or conservative management and for the three mostly used classification systems for calcaneal fractures with the use of 2D-CT imaging versus 2D- and 3D-CT imaging.     

Contributions of human hippocampal subfields to spatial and temporal pattern separation

We sought to explore the roles of the hippocampal subregions and adjacent medial temporal lobe regions in pattern separation and any differential contributions based on sequential or spatial information. Young adults performed an incidental‐encoding task on a sequence of four objects presented on the screen in one of eight locations while we collected high‐resolution functional MRI brain scans. We employed five trials of interest: first presentations, exact repetitions, lures in which the same objects were repeated in different locations (spatial lures), lures in which the same objects were presented in a different sequential order (sequential lures), and lures in which both the spatial location and sequence were changed (both lures). We found no evidence for spatial or sequential specialization in the hippocampal subfields, consistent with the hypothesis that the dentate gyrus acts as a universal pattern separator. Likewise, we did not observe specialization for the perirhinal or parahippocampal cortices for spatial or sequential information, though both regions show evidence for associative processing in this task. © 2013 Wiley Periodicals, Inc.     

A congenital complex including muscular interventricular septal aneurysm in an adult: case report and review of literature

Muscular interventricular septum is an extremely rare location for congenital aneurysm. A 48-year-old patient with a muscular interventricular septum aneurysm coexisting with atrial septal defect, pulmonary stenosis and ventricular preexcitation is presented. Three-dimensional echocardiographic reconstruction of the lesion aided in a precise morphologic and quantitative assessment of the condition. The review of 10 previously reported patients with the entity is presented.     

联合信号转导和转录激活因子3与热休克蛋白90鉴别良恶性嗜铬细胞瘤的探讨

目的:通过检测热休克蛋白90(HSP90)与信号转导和转录激活因子3(STAT3)在良恶性肾上腺嗜铬细胞瘤中的表达情况,探讨HSP90和STAT3在早期诊断恶性嗜铬细胞瘤中的价值。方法:采用免疫组织化学技术检测94例良恶性肾上腺嗜铬细胞瘤组织标本中HSP90和STAT3的表达差异,同时用蛋白免疫印迹法检测24例手术标本中HSP90和STAT3的表达差异,并分析两者联合诊断恶性嗜铬细胞瘤的效用。结果:HSP90和STAT3在恶性嗜铬细胞瘤中阳性表达率分别为66.67%和83.33%,在良性嗜铬细胞瘤中的阳性表达率分别为22.37%和26.32%,在正常肾上腺髓质组织中无表达,恶性嗜铬细胞瘤组与良性嗜铬细胞瘤组之间HSP90和STAT3的表达均存在显著性差异(P=0.001,P0.001);Western Blot分析结果显示HSP90和STAT3在恶性嗜铬细胞瘤中的蛋白表达水平远高于良性嗜铬细胞瘤。联合HSP90和STAT3诊断恶性嗜铬细胞瘤时阳性预测值为0.70。结论:HSP90和STAT3在恶性嗜铬细胞瘤中的表达高于良性嗜铬细胞瘤组织,且联合HSP90和STAT3可有效诊断恶性嗜铬细胞瘤。