The impact of subthreshold levels of amyloid deposition on conversion to dementia in patients with amyloid-negative amnestic mild cognitive impairment.

Background: About 40-50% of patients with amnestic mild cognitive impairment (MCI) are found to have no significant Alzheimer's pathology based on amyloid PET positivity. Notably, conversion to dementia in this population is known to occur much less often than in amyloid-positive MCI. However, the relationship between MCI and brain amyloid deposition remains largely unknown.

Estimation of Stroke Volume Variance from Arterial Blood Pressure: Using a 1-D Convolutional Neural Network.

Background: We aimed to create a novel model using a deep learning method to estimate stroke volume variation (SVV), a widely used predictor of fluid responsiveness, from arterial blood pressure waveform (ABPW).

Methods: In total, 557 patients and 8,512,564 SVV datasets were collected and were divided into three groups: training, validation, and test. Data was composed of 10 s of ABPW and corresponding SVV data recorded every 2 s.

Early Impairment in the Ventral Visual Pathway Can Predict Conversion to Dementia in Patients With Amyloid-negative Amnestic Mild Cognitive Impairment.

Background: Around 15% to 20% of patients with clinically probable Alzheimer disease have been found to have no significant Alzheimer pathology on amyloid positron emission tomography. A previous study showed that conversion to dementia from amyloid-negative mild cognitive impairment (MCI) was observed in up to 11% of patients, drawing attention to this condition.

Object: We gathered the detailed neuropsychological and neuroimaging data of this population to elucidate factors for conversion to dementia from amyloid-negative amnestic MCI.

The cerebellum could serve as a potential imaging biomarker of dementia conversion in patients with amyloid-negative amnestic mild cognitive impairment.

Background And Purpose: As part of network-specific neurodegeneration, changes in cerebellar gray matter (GM) volume and impaired cerebello-cerebral functional networks have been reported in Alzheimer disease (AD). Compared with healthy controls, a volume loss in the cerebellum has been observed in patients with continuum of AD. However, little is known about the anatomical or functional changes in patients with clinical AD but no brain amyloidosis.

Elucidating the Risk Factors for Progression from Amyloid-Negative Amnestic Mild Cognitive Impairment to Dementia.

Background: Amyloid PET allows for the assessment of amyloid β status in the brain, distinguishing true Alzheimer's disease from Alzheimer's disease-mimicking conditions. Around 15-20% of patients with clinically probable Alzheimer's disease have been found to have no significant Alzheimer's pathology on amyloid PET. However, a limited number of studies had been conducted on this subpopulation in terms of clinical progression.

Delayed Functional Networks Development and Altered Fast Oscillation Dynamics in a Rat Model of Cortical Malformation.

Malformations of cortical development (MCD) is associated with a wide range of developmental delay and drug resistant epilepsy in children. By using resting-state functional magnetic resonance imaging (RS-fMRI) and event-related spectral perturbation (ERSP) of cortical electroencephalography (EEG) data, we tried to investigate the neural changes of spatiotemporal functional connectivity (FC) and fast oscillation (FO) dynamics in a rat model of methylazoxymethanol (MAM)-induced MCD. A total of 28 infant rats with prenatal exposure to MAM and those of age matched 28 controls with prenatal saline exposure were used.

MRI Successfully Reveals the Malformation of Cortical Development in Infant Rats.

Malformations of cortical development (MCDs) are major causes of intractable epilepsies. To characterize the early neuroimaging findings of MCDs, we tried to identify the MRI features consistent with pathological findings in an infant rat MCD model, prenatally exposed to methylazoxymethanol (MAM), by using newly developed MRI techniques. At gestational day 15, two doses of MAM (15 mg/kg intraperitoneally) or normal saline were injected into pregnant rats.

Who Should Pay for Interdependent Risk? Policy Implications for Security Interdependence Among Airports.

We study interdependent risks in security, and shed light on the economic and policy implications of increasing security interdependence in presence of reactive attackers. We investigate the impact of potential public policy arrangements on the security of a group of interdependent organizations, namely, airports. Focusing on security expenditures and costs to society, as assessed by a social planner, to individual airports and to attackers, we first develop a game-theoretic framework, and derive explicit Nash equilibrium and socially optimal solutions in the airports network.

Deep Learning-Based Stroke Volume Estimation Outperforms Conventional Arterial Contour Method in Patients with Hemodynamic Instability.

Although the stroke volume (SV) estimation by arterial blood pressure has been widely used in clinical practice, its accuracy is questionable, especially during periods of hemodynamic instability. We aimed to create novel SV estimating model based on deep-learning (DL) method. A convolutional neural network was applied to estimate SV from arterial blood pressure waveform data recorded from liver transplantation (LT) surgeries.

Effect of Prone Positional Apparatus on the Occurrence of Acute Kidney Injury After Spine Surgery.

Background And Objective: Increased intra-abdominal pressure with prone positioning for spinal surgery is associated with intraoperative hemodynamic alterations and the potential for postoperative complications. This study investigated the incidence of postoperative acute kidney injury (AKI) in patients undergoing spine surgery on a Jackson spinal table or a Wilson frame.

Methods: A total of 1374 patients who underwent spine surgery were divided into 2 groups: Jackson spinal table (n = 598) and Wilson frame group (n = 776).

Multimodal Magnetic Resonance Imaging Changes After -Methyl-d-Aspartate-Triggered Spasms in Infant Rats.

Objective: Despite the serious neurodevelopmental sequelae of epileptic encephalopathy during infancy, the pathomechanisms involved remain unclear. To find potential biomarkers that can reflect the pathogenesis of epileptic encephalopathy, we explored the neurometabolic and microstructural sequelae after infantile spasms using a rat model of infantile spasms and magnetic resonance imaging techniques.

Methods: Rats prenatally exposed to betamethasone were subjected to three rounds of intraperitoneal -methyl-d-aspartate (NMDA) triggering of spasms or received saline injections (controls) on postnatal days (P) 12, 13, and 15.

The administration of hydrogen sulphide prior to ischemic reperfusion has neuroprotective effects in an acute stroke model.

Emerging evidence has suggested that hydrogen sulfide (H2S) may alleviate the cellular damage associated with cerebral ischemia/reperfusion (I/R) injury. In this study, we assessed using 1H-magnetic resonance imaging/magnetic resonance spectroscopy (1H-MRI/MRS) and histologic analysis whether H2S administration prior to reperfusion has neuroprotective effects. We also evaluated for differences in the effects of H2S treatment at 2 time points.

Large-scale structural alteration of brain in epileptic children with mutation.

Objective: Mutations in gene encoding the alpha 1 subunit of the voltage gated sodium channel are associated with several epilepsy syndromes including genetic epilepsy with febrile seizures plus (GEFS +) and severe myoclonic epilepsy of infancy (SMEI). However, in most patients with mutation, brain imaging has reported normal or non-specific findings including cerebral or cerebellar atrophy. The aim of this study was to investigate differences in brain morphometry in epileptic children with mutation compared to healthy control subjects.

A New Rat Model of Epileptic Spasms Based on Methylazoxymethanol-Induced Malformations of Cortical Development.

Malformations of cortical development (MCDs) can cause medically intractable epilepsies and cognitive disabilities in children. We developed a new model of MCD-associated epileptic spasms by treating rats prenatally with methylazoxymethanol acetate (MAM) to induce cortical malformations and postnatally with -methyl-d-aspartate (NMDA) to induce spasms. To produce cortical malformations to infant rats, two dosages of MAM (15 mg/kg, intraperitoneally) were injected to pregnant rats at gestational day 15.

Agency Problems and Airport Security: Quantitative and Qualitative Evidence on the Impact of Security Training.

We analyze the issue of agency costs in aviation security by combining results from a quantitative economic model with a qualitative study based on semi-structured interviews. Our model extends previous principal-agent models by combining the traditional fixed and varying monetary responses to physical and cognitive effort with nonmonetary welfare and potentially transferable value of employees' own human capital. To provide empirical evidence for the tradeoffs identified in the quantitative model, we have undertaken an extensive interview process with regulators, airport managers, security personnel, and those tasked with training security personnel from an airport operating in a relatively high-risk state, Turkey.

Does Computer-Aided Diagnosis Permit Differentiation of Angiomyolipoma Without Visible Fat From Renal Cell Carcinoma on MDCT?

Objective: The purpose of this study was to evaluate the diagnostic value of computer-aided diagnosis (CADx) in differentiating angiomyolipoma without visible fat from renal cell carcinoma (RCC) on MDCT.

Materials And Methods: The study included 406 patients who had 47 angiomyolipomas without visible fat and 359 RCCs smaller than 4 cm, all of which were diagnosed on the basis of findings from nephrectomy or percutaneous biopsy performed at our institution between 2000 and 2011. MDCT (slice thickness, 2.

Structural abnormalities in benign childhood epilepsy with centrotemporal spikes (BCECTS).

Purpose: The aim of this study was to investigate cortical thickness and gray matter volume abnormalities in benign childhood epilepsy with centrotemporal spikes (BCECTS). We additionally assessed the effects of comorbid attention-deficit/hyperactivity (ADHD) on these abnormalities.

Methods: Surface and volumetric MR imaging data of children with newly diagnosed BCECTS (n = 20, 14 males) and age-matched healthy controls (n = 20) were analyzed using FreeSurfer (version 5.

Early infarct growth predicts long-term clinical outcome after thrombolysis.

Background: Ischemic lesion growth may be a surrogate marker of clinical outcome, but no such interrelationship after thrombolysis has yet been determined. We evaluated the association between early infarct growth on diffusion-weighted imaging (DWI) and long-term clinical outcome after thrombolysis.

Methods: We retrospectively reviewed outcomes in patients with acute middle cerebral artery territory stroke who had been treated with intravenous tissue plasminogen activator or intra-arterial urokinase.