Analysis of temporal requirements for myocardial tissue velocity imaging.

AIMS: Movements of myocardial walls include components of high velocity and short duration calling for a high sampling rate in the acquisition of tissue velocity imaging data. This study aims at establishing the optimal sampling requirements for tissue velocity imaging measurements. METHODS AND RESULTS: In 16 healthy individuals, tissue velocity imaging data were acquired at a frame rate of 141-203 frames/s for a subsequent off-line analysis using software enabling a reduction of the sampling rate to 50%, 25% and 12.5% of the initial frame rate. Different components of the myocardial velocity profile were measured at each of these frame rates. The deviation of the results from the initial values increased markedly at decreasing frame rates, producing an underestimation of peak systolic and diastolic velocities, most other measured parameters being overestimated. A cut-off point for an acceptable < or =10% deviation of the results corresponded to at least 70 frames/s for peak systolic and early diastolic velocity, and to at least 100 frames/s for other systolic and diastolic parameters. CONCLUSION: A high sampling rate is essential for a proper rendering of tissue velocity imaging signals, too low frame rates resulting in inferior accuracy of the results. This should be kept in mind while viewing reported tissue velocity imaging data.     

Time Course and Reversibility of Ethanol''s Suppressive Effects on Axon Sprouting in the Dentate Gyrus of the Adult Rat

Ethanol was administered chronically to adult rats in a liquid diet for 14 days preceding and for 5, 7, 8, 9, or 10 days following the unilateral destruction of the entorhinal cortex. Control groups received a diet of lab chow and water and were sacrificed at comparable survival times. An additional experimental group was given ethanol until 9 days after the lesion, then switched to lab chow and water and sacrificed 1 day later. Coronal sections through the dorsal hippocampal formation were stained and analyzed histochemically for the localization of acetylcholinesterase (AChE). Quantitative measurements of the histochemical patterns in the molecular layer of the dentate gyrus were obtained. Ethanol exposure inhibited the withdrawal of the acetylcholinesterase-stained septohippocampal fibers and limited the typical lesion-induced expansion of the pale-staining commissural/associational zone in the molecular layer of the denervated dentate gyrus. However, abstinence from ethanol for just 24 h released the inhibitory effect on the acetylcholinesterase-staining fibers, resulting in a significant expansion of the commissural/associational zone.     

Changes in serum 25-hydroxyvitamin D and cholecalciferol after one whole-body exposure in a commercial tanning bed: a randomized study

We wanted to evaluate the cutaneous synthesis of 25OHD and cholecalciferol after one whole-body exposure to ultraviolet radiation type B (UVB) in a randomized setup. Healthy volunteers were randomized to one whole-body exposure in a commercial tanning bed with UVB emission (UVB/UVA ratio 1.8-2.0%) or an identical placebo tanning bed without UVB. The output in the 280-320?nm range was 450?μW/cm(2). Blood samples were analyzed for 25OHD and cholecalciferol at baseline and during 7?days after treatment. We included 20 volunteers, 11 to UVB and 9 to placebo treatment. During the first 6?h, no significant differences in 25OHD between the groups were found. At the end of the study, we found a mean increase of 25OHD in the UVB group of 4.5?nmol/l (SD 7?nmol/l) compared to a decline of -1.2?nmol/l (SD 7?nmol/l) in the placebo group (p?=?0.1). A linear mixed model yielded an increase of 25OHD in the UVB group of 1.0?nmol/l per 24?h (p?相似文献   

Visualization of synthetic mesh utilizing optical coherence tomography

Introduction and hypothesis

Owing to the recent upsurge in adverse events reported after mesh-augmented pelvic organ prolapse (POP) repairs, our aim was to determine whether the location and depth of synthetic mesh can be measured postoperatively within the vaginal tissue microstructure using optical coherence tomography (OCT).

Methods

Seventeen patients with prior mesh-augmented repairs were recruited for participation. Patients were included if they had undergone an abdominal sacral colpopexy (ASC) or vaginal repair with mesh. Exclusion criteria were a postoperative period of <6 months, or the finding of mesh exposure on examination. OCT was used to image the vaginal wall at various POP-Q sites. If mesh was visualized, its location and depth was calculated and recorded.

Results

Ten patients underwent ASC and 7 patients had 8 transvaginal mesh repairs. Mesh was visualized in 16 of the 17 patients using OCT. In all ASC patients, mesh was imaged centrally at the posterior apex. In patients with transvaginal mesh in the anterior and/or posterior compartments, the mesh was visualized directly anterior and/or posterior to the apex respectively. Mean depth of the mesh in the ASC, anterior, and posterior groups was 60.9, 146.7, and 125.7 μm respectively. Mesh was visualized within the vaginal epithelial layer in all 16 patients despite the route of placement.

Conclusion

In this pilot study we found that OCT can be used to visualize polypropylene mesh within the vaginal wall following mesh-augmented prolapse repair. Regardless of abdominal versus vaginal placement, the mesh was identified within the vaginal epithelial layer.     

A 5-year retrospective study of survival of zirconia single crowns fitted in a private clinical setting

ObjectivesThe aim of this report was to evaluate the 5-year clinical performance and survival of zirconia (NobelProcera?) single crowns.MethodsAll patients treated with porcelain-veneered zirconia single crowns in a private practice during the period October 2004 to November 2005 were included. The records were scrutinized for clinical data. Information was available for 162 patients and 205 crowns.ResultsMost crowns (78%) were placed on premolars and molars. Out of the 143 crowns that were followed for 5 years, 126 (88%) did not have any complications. Of those with complications, the most common were: extraction of abutment tooth (7; 3%), loss of retention (15; 7%), need of endodontic treatment (9; 4%) and porcelain veneer fracture (6; 3%). No zirconia cores fractured. In total 19 restorations (9%) were recorded as failures: abutment tooth extraction (7), remake of crown due to lost retention (6), veneer fracture (4), persistent pain (1) and caries (1). The 5-year cumulative survival rate (CSR) was 88.8%.ConclusionsAccording to the present 5-year results zirconia crowns (NobelProcera?) are a promising prosthodontic alternative also in the premolar and molar regions. Out of the 143 crowns followed for 5 years, 126 (88%) did not have any complications. However, 9% of the restorations were judged as failures. Further studies are necessary to evaluate the long-term success.     

Ten years of enhancing neuro-imaging genetics through meta-analysis: An overview from the ENIGMA Genetics Working Group

Here we review the motivation for creating the enhancing neuroimaging genetics through meta-analysis (ENIGMA) Consortium and the genetic analyses undertaken by the consortium so far. We discuss the methodological challenges, findings, and future directions of the genetics working group. A major goal of the working group is tackling the reproducibility crisis affecting “candidate gene” and genome-wide association analyses in neuroimaging. To address this, we developed harmonized analytic methods, and support their use in coordinated analyses across sites worldwide, which also makes it possible to understand heterogeneity in results across sites. These efforts have resulted in the identification of hundreds of common genomic loci robustly associated with brain structure. We have found both pleiotropic and specific genetic effects associated with brain structures, as well as genetic correlations with psychiatric and neurological diseases.