Mapping of microvascular architecture in the brain of an Alzheimer's disease mouse model using MRI.

Increasing evidence suggests that alterations in cerebral microvasculature play a critical role in the pathogenesis of Alzheimer's disease (AD). The objective of this study was to characterize and evaluate the cerebral microvascular architecture of AD transgenic (Tg) mice and compare it with that of non-Tg mice using brain microvascular indices obtained by MRI. Seven non-Tg mice and 10 5xFAD Tg mice were scanned using a 7-T animal MRI system to measure the transverse relaxation rates of R2 and R2* before and after the injection of the monocrystalline iron oxide nanoparticle contrast agent. After calculating ΔR2* and ΔR2, the vessel size index (VSI), mean vessel diameter (mVD), mean vessel density, mean vessel-weighted image (MvWI) and blood volume fraction (BVf) were mapped. Voxel-based analyses and region of interest (ROI)-based analyses were performed to compare the indices of the non-Tg and Tg groups. Voxel comparisons showed that BVf, mVD, VSI and MvWI were greater in the Tg group than in the non-Tg group. Additionally, the ROI-based analysis showed that ΔR2*, BVf, mVD, MvWI and VSI increased in several brain regions of the Tg group compared with those in the non-Tg group. VSI and mVD increased in Tg mice; these findings indicated microvascular disruption in the brain that could be related to damage to the neurovascular unit in AD caused by cerebral amyloid angiopathy.

Difference in glenoid retroversion between two-dimensional axial computed tomography and three-dimensional reconstructed images.

BACKGROUND: The glenoid version of the shoulder joint correlates with the stability of the glenohumeral joint and the clinical results of total shoulder arthroplasty. We sought to analyze and compare the glenoid version measured by traditional axial two-dimensional (2D) computed tomography (CT) and three-dimensional (3D) reconstructed images at different levels. METHODS: A total of 30 cases, including 15 male and 15 female patients, who underwent 3D shoulder CT imaging was randomly selected and matched by sex consecutively at one hospital. The angular difference between the scapular body axis and 2D CT slice axis was measured. The glenoid version was assessed at three levels (midpoint, upper one-third, and center of the lower circle of the glenoid) using Friedman's method in the axial plane with 2D CT images and at the same level of three different transverse planes using a 3D reconstructed image. RESULTS: The mean difference between the scapular body axis on the 3D reconstructed image and the 2D CT slice axis was 38.4°. At the level of the midpoint of the glenoid, the measurements were 1.7°±4.9° on the 2D CT images and -1.8°±4.1° in the 3D reconstructed image. At the level of the center of the lower circle, the measurements were 2.7°±5.2° on the 2D CT images and -0.5°±4.8° in the 3D reconstructed image. A statistically significant difference was found between the 2D CT and 3D reconstructed images at all three levels. CONCLUSIONS: The glenoid version is measured differently between axial 2D CT and 3D reconstructed images at three levels. Use of 3D reconstructed imaging can provide a more accurate glenoid version profile relative to 2D CT. The glenoid version is measured differently at different levels.

Radiological and Clinical Effectiveness of a Novel Calcaneal Fracture Brace after Intra-articular Calcaneal Fracture Surgery.

BACKGROUND: After calcaneal fracture surgery, a short leg splint and cast are typically applied. However, these restrict joint exercises, which is inconvenient for patients. In addition, there is a risk of complications, such as pressure ulcers or nerve paralysis with a short leg cast. In this study, we evaluated clinical and radiological outcomes of the use of a specially designed calcaneal brace after calcaneal fracture surgery. METHODS: From among patients who underwent open reduction and internal fixation for calcaneal fracture between July 9, 2013 and May 31, 2017, 102 patients who wore a calcaneal fracture brace (group A) and 82 patients who wore a postoperative short leg cast (group B) were randomly chosen for this study. Radiological changes and clinical factors were compared between the two groups. After swelling at the surgical site decreased, a special calcaneal brace was applied to patients in group A. They were allowed to perform early weight bearing and joint motion. Patients in group B were immobilized in a short leg cast and were told to avoid weight bearing for 6 weeks. In each group, the Böhler's angle and Gissane's angle were measured and compared using postoperative and final follow-up radiographs. Pain (measured using a visual analogue scale [VAS]) and ankle joint range of motion (dorsiflexion, plantar flexion, eversion, and inversion) were measured serially until the final follow-up visit. RESULTS: There were no significant differences in the Böhler's angle or Gissane's angle between the two groups as measured postoperatively and at the final follow-up (paired t-test). Differences in the VAS pain score and eversion were also statistically nonsignificant between the two groups. However, group A had a significantly higher range of dorsiflexion (p = 0.021), plantar flexion (p = 0.012), and inversion (p = 0.045) of the ankle than group B (independent t-test). CONCLUSIONS: Application of the calcaneal fracture brace after open reduction and internal fixation of a calcaneal fracture not only maintained the fracture reduction but allowed for greater joint motion than the short leg cast. Thus, the calcaneal fracture brace can be considered an effective postoperative management option that enables early resumption of daily activities and facilitates postoperative joint motion.

On Postoperative Day Balloon Angioplasty for Salvage of Newly-Placed, Flow-Limiting Native Arteriovenous Fistula.

PURPOSE: To report result and usefulness of immediate postoperative balloon angioplasty of de novo arteriovenous fistula (AVF) with limited flow just after creation. MATERIALS AND METHODS: From January 1, 2012 to March 31, 2014, 1,270 patients received native AVF creations in a single vascular clinic. In twenty-four patients (1.9% of total AVF creation), immediate postoperative balloon angioplasty was performed because of limited flow on palpation (only pulsation or no thrill) just after AVF creation. Medical records were reviewed retrospectively; technical success (restoration of AVF flow)/clinical success (growing as functional AVF) rate, maturation time, primary patency rate and fistula survival outcome were analyzed during a mean 10.8 months of follow-up. RESULTS: Technical/clinical success rate was 95.8% (23/24 cases); AVF flow was restored after balloon angioplasty, and all the flow-restorated AVFs grew as functional AVFs with mean±standard deviation, 4.5±1.5 weeks of maturation time. In seven (30.4%) patients, a secondary balloon angioplasty was needed to enhance maturation. The overall primary patency after immediate postoperative balloon angioplasty was 69.6% at 1 and 6 months and 59.0% at 12 months. There was 1 complication (operation site hematoma). CONCLUSION: Immediate postoperative balloon angioplasty for salvage of newly-placed, flow-limiting native AVF is a useful, effective and safe procedure.

Gonadal tumors developed from consecutively transplanted spleens bearing gonad implants.

This study was conducted by consecutively transplanting spleens, which had gonads implanted previously. A total of 84 cases for infantile testicles and 106 cases for ovarian follicles were performed. In the case of ovarian implants, the results were determined by the total number of follicle implants. A modified spleen transplantation technique called double implantation of ovarian follicles was applied to increase the amount of the implants. In this technique, an extra spleen is implanted into the potential donor so that the ovarian follicles can be implanted to two different spleens, doubling the amount of implants. Through consecutive spleen transplantation, we observed the results beyond a typical rat's life span. In many of these cases, we found more aggressive forms of malignant tumor, seminoma and dysgerminoma. We present the results and discuss possible pathogenic mechanisms of tumor formation.