Strong Contrast Stagnation of Unilateral Vertebral Artery on Three-Dimensional Black Blood-Enhanced MRI Predicts Acute Medulla Infarction

Purpose This study aimed to evaluate angiographic and contrast enhancement (CE) patterns on three-dimensional (3D) black blood (BB) contrast-enhanced MRI in patients with acute medulla infarction. Materials and Methods From January 2020 to August 2021, we retrospectively analyzed stroke 3D BB contrast-enhanced magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) findings of patients visiting the emergency room for symptom evaluation of acute medulla infarction. In total, 28 patients with acute medulla infarction were enrolled in this study. Four types of 3D BB contrast-enhanced MRI and MRA were classified as follows: 1=unilateral contrast-enhanced vertebral artery (VA)+no visualization of VA on MRA; 2=unilateral enhanced VA+hypoplastic VA; 3=no enhanced VA+unilateral complete occlusion of VA; 4=no enhanced VA+normal VA (including hypoplasia) on MRA. Results Of the 28 patients with acute medulla infarction, 7 (25.0%) showed delayed positive findings after 24 hours on diffusion-weighted imaging (DWI). Of these patients, 19 (67.9%) showed CE of the unilateral VA on 3D BB contrast-enhanced MRI (type 1 and 2). Of the 19 patients with CE of VA on 3D BB contrast-enhanced MRI, 18 showed no visualization of enhanced VA on MRA (type 1), and 1 showed hypoplastic VA. Of the 7 patients with delayed positive findings on DWI, 5 showed CE of the unilateral VA and no visualization of the enhanced VA on MRA (type 1). Symptom onset to door time or initial MR check time was significantly shorter in the groups with delayed positive findings on DWI (P<0.05). Conclusion Unilateral CE on 3D BB contrast-enhanced MRI and no visualization of the VA on MRA are related to the recent occlusion of the distal VA. These findings suggest that the recent occlusion of the distal VA is related to acute medulla infarction, including delayed visualization on DWI

HEAT TRANSFER IN WAVY DUCT WITH DIFFERENT CORRUGATION ANGLE

ABSTRACT The present study investigates the effects of duct corrugation angle and flow velocity on the convective heat/mass transfer characteristics in wavy ducts applied in a primary surface heat exchanger. Local heat/mass transfer coefficients on the corrugated duct sidewall are determined using a naphthalene sublimation technique. The flow visualization technique is used to understand the overall flow structures inside the duct. The corrugation angles of the wavy ducts are 145º and 130º, and the duct aspect ratio is fixed at 7.3. The Reynolds numbers, based on the duct hydraulic diameter, vary from 1,000 to 5,000. The results show that secondary vortex flow cells, called TaylorGörtler vortices, exist periodically in the wavy duct. Therefore, non-uniform distributions of the heat/mass transfer coefficients are obtained on the duct walls. On the pressure-side wall, high heat/mass transfer cell-shaped regions appear due to the secondary vortex flows for both corrugation angles. On the suction-side wall, the heat transfer coefficients are lower than those on the pressure-side wall. The wavy duct with the corrugation angle of 130º has the stronger strength of the secondary vortex cells resulting in higher heat/mass transfer rates on the duct wall because the sharp turn enhances the development of the secondary flow cells

Fracture of a Polyethylene Tibial Post in a Scorpio Posterior-Stabilized Knee Prosthesis

We report the case of a polyethylene tibial post fracture in a 72-year-old woman 14 months after a Scorpio posterior-stabilized (PS) total knee arthroplasty. The polyethylene wear was found around the fracture site of the post, especially over the anterior aspect of the post base. The failure mechanism of the post fracture in the present case was anterior impingement with excessive wear over the base of the anterior aspect of the tibial post, which became a stress-riser of post and cam articulation. This is the first report of a polyethylene tibial post fracture of a Scorpio PS prosthesis

Dose-Dependent Neuroprotective Effect of Standardized Bee Venom Phospholipase A2 Against MPTP-Induced Parkinson’s Disease in Mice

Parkinson’s disease (PD) is a chronic progressive neurodegenerative movement disorder characterized by the selective loss of dopaminergic neurons within the substantia nigra (SN). While the precise etiology of dopaminergic neuronal demise is elusive, multiple lines of evidence indicate that neuroinflammation is involved in the pathogenesis of PD. We have previously demonstrated that subcutaneous administration of bee venom (BV) phospholipase A2 (bvPLA2) suppresses dopaminergic neuronal cell death in a PD mouse model. In the present study, we established standardized methods for producing bvPLA2 agent isolated from crude BV at good manufacturing practice (GMP) facility. The therapeutic efficacy of purified bvPLA2 agent was examined in MPTP-induced PD mice. Importantly, administration of purified bvPLA2 in a dose-dependent manner reversed motor deficits in PD mice as well as inhibited loss of dopaminergic neurons within the SN of PD mice. The concentration-dependent action of standardized bvPLA2 appeared to be related to the induction of CD4+CD25+Foxp3+ regulatory T cells (Tregs), which, in part, inhibits T helper 1 (Th1) and Th17 polarization and suppresses microglial activation in PD mice. Taken together, these results suggest that standardized bvPLA2 purified from BV shows a neuroprotective effect against PD and thus has a potential target for treatment of PD

Effect of moderate-intensity statin therapy on plaque inflammation in patients with acute coronary syndrome: A prospective interventional study evaluated by 18F-FDG PET/CT of the carotid artery

Background: Asian patients with acute coronary syndrome (ACS) are frequently prescribed moderate- -intensity statin in real practice, even during the early stage of ACS. Under assessment herein was the effect of moderate-intensity statin therapy on the resolution of plaque inflammation during the first month after ACS, a period with highest recurrent ischemic events, using dual time point 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT).Methods: This prospective study included statin-naïve patients with ACS and non-calcified carotid plaques (≥ 3 mm on ultrasound images). Baseline FDG PET/CT images of the carotid arteries of the patients were obtained. Then, all patients received atorvastatin (20 mg/day); follow-up FDG PET/CT images of the carotid arteries were then obtained after 1 month of therapy. The primary endpoint measurement was the change in the target-to-background ratio (TBR) of the carotid artery between the initial and follow-up FDG PET/CT scans.Results: Thirteen ACS patients completed the initial and follow-up FDG PET/CT scans. Moderate-intensity statin therapy failed to reduce plaque inflammation at 1 month after ACS (TBR 1.60 ± 0.20 at baseline vs. 1.50 ± 0.40 after therapy; p = 0.422) but significantly reduced serum low-density lipoprotein cholesterol (LDL-C) levels (mean LDL-C 101.2 ± 21.1 mg/dL at baseline vs. 70.7 ± 12.4 mg/dL after therapy; p &lt; 0.001). Changes in the TBR and serum LDL-C levels were not correlated (r = –0.27, p = 0.243).Conclusions: Dual time point FDG PET/CT imaging demonstrates that moderate-intensity statin therapy was insufficient in suppressed plaque inflammation within the first month after ACS in Asian patients, even though achieving target LDL levels

Pneumopericardium as a Complication of Pericardiocentesis

Pneumopericardium is a rare complication of pericardiocentesis, occurring either as a result of direct pleuro-pericardial communication or a leaky drainage system. Air-fluid level surrounding the heart shadow within the pericardium on a chest X-ray is an early observation at diagnosis. This clinical measurement and process is variable, depending on the hemodynamic status of the patient. The development of a cardiac tamponade is a serious complication, necessitating prompt recognition and treatment. We recently observed a case of pneumopericardium after a therapeutic pericardiocentesis in a 20-year-old man with tuberculous pericardial effusion

Biodegradable, flexible silicon nanomembrane-based NO x gas sensor system with record-high performance for transient environmental monitors and medical implants

Abstract: A novel transient electronics technology that is capable of completely dissolving or decomposing in certain conditions after a period of operation offers unprecedented opportunities for medical implants, environmental sensors, and other applications. Here, we describe a biodegradable, flexible silicon-based electronic system that detects NO species with a record-breaking sensitivity of 136 Rs (5 ppm, NO2) and 100-fold selectivity for NO species over other substances with a fast response (~30 s) and recovery (~60 s). The exceptional features primarily depend on not only materials, dimensions, and design layouts but also temperatures and electrical operations. Large-scale sensor arrays in a mechanically pliable configuration exhibit negligible deterioration in performance under various modes of applied loads, consistent with mechanics modeling. In vitro evaluations demonstrate the capability and stability of integrated NOx devices in severe wet environments for biomedical applications