Agmatine attenuates the severity of immunometabolic disorders by suppressing macrophage polarization: an in vivo study using an ulcerative colitis mouse model.

Agmatine, an endogenous polyamine generated by the gut microbiota, positively affects host lifespan by regulating mononuclear cell or macrophage function. Although the regulatory pathways governing monocyte/macrophage differentiation have been well studied, the influence of the microbiome and its metabolites on monocyte/macrophage function have not been fully elucidated. To address this, we aimed to investigate the mechanisms whereby agmatine inhibits immunometabolic disorders using the colon of ulcerative colitis (UC) model mice.

A patient-specific circle of Willis blood flow model in predicting outcomes of balloon test occlusion.

Background And Purpose: Balloon test occlusion (BTO) evaluates cerebral ischemic tolerance before internal carotid artery (ICA) sacrifice but carries risks like dissection and thrombosis. This study introduces a new approach using a patient-specific circle of Willis (COW) blood flow model, based on non-invasive quantitative MR angiography (qMRA) measurements, to predict the outcomes of BTO.

Methods: We developed individualized COW blood flow models for 43 patients undergoing BTO.

Evaluating outcome associations with race after mechanical thrombectomy: an analysis of the NVQI-QOD acute ischemic stroke registry.

Background: Mechanical thrombectomy has become the standard of care for acute ischemic stroke due to large vessel occlusions. Racial differences in outcomes after mechanical thrombectomy for acute ischemic stroke have not been extensively studied. We evaluate the real-world evidence for differences between races in the outcomes of thrombectomy for large vessel occlusions using the NeuroVascular Quality Initiative-Quality Outcomes Database (NVQI-QOD).

Socioeconomic Inequities in the Surgical Management of Moyamoya Disease.

Background: Given the vasculopathic nature of moyamoya disease (MMD) and high susceptibility to ischemic events, patients with MMD often require surgical revascularization via an indirect or direct bypass, and analysis of disparities in receipt of appropriate management is critical.

Methods: The 2012-2016 Nationwide Inpatient Sample was queried for patients admitted with a diagnosis of MMD using International Classification of Diseases codes. Patient baseline demographics, hospital characteristics, and associated symptoms were collected.

Optimal timing and sequence of ventriculoperitoneal shunt and gastrostomy placement.

The optimal timing of ventriculoperitoneal shunt (VPS) and gastrostomy placement, relative to the safety of simultaneous versus staged surgery, has not been clearly delineated in the literature. To study the optimal inter-procedural timing relative to distal VPS infection and pertinent reoperation. A fifteen-year, retrospective, single-center study was conducted on adults undergoing VPS and gastrostomy within 30-days.

Perfusion-MRI is a Poor Indicator of Hemodynamic Compromise in Vertebrobasilar Disease in the VERiTAS Study.

Background And Purpose: Dynamic susceptibility perfusion MR imaging (DSC MRP) has been used to assess changes in cerebral perfusion attributable to vascular stenosis or occlusion that may predict stroke risk. However, DSC MRP is not validated for identifying hemodynamic compromise in the posterior circulation. We investigated the clinical utility of DSC MRP in vertebrobasilar (VB) atherosclerotic disease in the observational VERiTAS study.

Natural History of Hemodynamics in Vertebrobasilar Disease: Temporal Changes in the VERiTAS Study Cohort.

Background And Purpose: The role of regional hypoperfusion as a contributor to stroke risk in atherosclerotic vertebrobasilar disease has recently been confirmed by the observational VERiTAS (Vertebrobasilar Flow Evaluation and Risk of Transient Ischemic Attack and Stroke) Study. We examined the stability of hemodynamic status over time and its relationship to stroke risk in patients from this prospective cohort.

Methods: VERiTAS enrolled patients with recently symptomatic ≥50% atherosclerotic stenosis/occlusion of vertebral and/or basilar arteries.

A New Scoring System for Prediction of Underlying Vascular Pathology in Patients with Intracerebral Hemorrhage: The Modified Secondary Intracerebral Hemorrhage Score.

Background: Secondary intracerebral hemorrhage (SICH) score is used to predict risk of intracranial hemorrhage (ICH) associated vascular lesions. However, it has low clinical utility in identifying patients without need for neurovascular imaging. This study aims to develop a modified scoring system to capture patients with low risk of underlying vascular pathology, thereby decreasing need for vascular imaging and its associated morbidity.

Optimized Hemodynamic Assessment to Predict Stroke Risk in Vertebrobasilar Disease: Analysis From the VERiTAS Study.

Background Atherosclerotic vertebrobasilar disease is a significant etiology of posterior circulation stroke. The prospective observational VERiTAS (Vertebrobasilar Flow Evaluation and Risk of Transient Ischemic Attack and Stroke) study demonstrated that distal hemodynamic status is a robust predictor of subsequent vertebrobasilar stroke risk. We sought to compare predictive models using thresholds for posterior circulation vessel flows standardized to age and vascular anatomy to optimize risk prediction.

Quantification of blood flow patterns in the cerebral arterial circulation of individual (human) subjects.

There is a growing research interest in quantifying blood flow distribution for the entire cerebral circulation to sharpen diagnosis and improve treatment options for cerebrovascular disease of individual patients. We present a methodology to reconstruct subject-specific cerebral blood flow patterns in accordance with physiological and fluid mechanical principles and optimally informed by in vivo neuroimage data of cerebrovascular anatomy and arterial blood flow rates. We propose an inverse problem to infer blood flow distribution across the visible portion of the arterial network that best matches subject-specific anatomy and a given set of volumetric flow measurements.

A patient-specific cerebral blood flow model.

In clinical practice, many complex choices in treatment of complex cerebrovascular diseases have to be made. A patient-specific mathematical blood flow could aid these decisions. For certain cases, less accuracy is required and more simplistic models might be feasible.

Primary hepatic mucosa-associated lymphoid tissue lymphoma: A case report and literature review.

Rationale: Primary hepatic mucosa-associated lymphoid tissue (MALT) lymphoma is a rare disease, and there is no consensus yet on the treatment modalities. Here, we report a new case of MALT lymphoma and review the current literature on this disease.

Patient Concerns: A 73-year-old man was admitted to our department following the incidental finding of a solitary 1.

An efficient full space-time discretization method for subject-specific hemodynamic simulations of cerebral arterial blood flow with distensible wall mechanics.

A computationally inexpensive mathematical solution approach using orthogonal collocations for space discretization with temporal Fourier series is proposed to compute subject-specific blood flow in distensible vessels of large cerebral arterial networks. Several models of wall biomechanics were considered to assess their impact on hemodynamic predictions. Simulations were validated against in vivo blood flow measurements in six human subjects.

Hypoperfusion Symptoms Poorly Predict Hemodynamic Compromise and Stroke Risk in Vertebrobasilar Disease.

Background and Purpose- Cerebral hypoperfusion symptoms (defined as symptoms related to change in position, effort or exertion, or recent change in antihypertensive medication) have been used in stroke studies as a surrogate for detecting hemodynamic compromise. However, the validity of these symptoms in identifying flow compromise in patients has not been well established. We examined whether hypoperfusion symptoms correlated with quantitative measurements of flow compromise in the prospective, observational VERiTAS study (Vertebrobasilar Flow Evaluation and Risk of Transient Ischemic Attack and Stroke).

Cost-Effectiveness of Quantitative Magnetic Resonance Angiography Screening and Submaximal Angioplasty for Symptomatic Vertebrobasilar Disease.

Background and Purpose- The VERiTAS (Vertebrobasilar Flow Evaluation and Risk of Transient Ischemic Attack and Stroke) study demonstrated posterior circulation distal flow status, determined by quantitative magnetic resonance angiography, is a robust predictor of vertebrobasilar stroke risk in patients with symptomatic atherosclerotic vertebrobasilar disease. Flow-compromised high-risk patients may benefit from flow-restoring endovascular procedures, such as submaximal angioplasty. In this study, we examine the cost-effectiveness of quantitative magnetic resonance angiography screening to identify patients who may benefit from submaximal angioplasty to restore vertebrobasilar flow.

Quantification of near-wall hemodynamic risk factors in large-scale cerebral arterial trees.

Detailed hemodynamic analysis of blood flow in pathological segments close to aneurysm and stenosis has provided physicians with invaluable information about the local flow patterns leading to vascular disease. However, these diseases have both local and global effects on the circulation of the blood within the cerebral tree. The aim of this paper is to demonstrate the importance of extending subject-specific hemodynamic simulations to the entire cerebral arterial tree with hundreds of bifurcations and vessels, as well as evaluate hemodynamic risk factors and waveform shape characteristics throughout the cerebral arterial trees.

Large-scale subject-specific cerebral arterial tree modeling using automated parametric mesh generation for blood flow simulation.

In this paper, we present a novel technique for automatic parametric mesh generation of subject-specific cerebral arterial trees. This technique generates high-quality and anatomically accurate computational meshes for fast blood flow simulations extending the scope of 3D vascular modeling to a large portion of cerebral arterial trees. For this purpose, a parametric meshing procedure was developed to automatically decompose the vascular skeleton, extract geometric features and generate hexahedral meshes using a body-fitted coordinate system that optimally follows the vascular network topology.

Neurosurgical Emergency Transfers: An Analysis of Deterioration and Mortality.

Background: Neurological deterioration and mortality are frequent in neurosurgical patients transferred to tertiary centers, but the precise predictors leading to them are unclear.

Objective: To analyze and quantify risk factors predicting deterioration and death in neurosurgery transfers.

Methods: A consecutive review of all transfers with cranial pathology to a tertiary academic neurosurgery service was performed over a 2-year period.

Higher Stroke Risk with Lower Blood Pressure in Hemodynamic Vertebrobasilar Disease: Analysis from the VERiTAS Study.

Background: Despite concerns regarding hypoperfusion in patients with large-artery occlusive disease, strict blood pressure (BP) control has become adopted as a safe strategy for risk reduction of stroke. We examined the relationship between BP control, blood flow, and risk of subsequent stroke in the prospective Vertebrobasilar Flow Evaluation and Risk of Transient Ischemic Attack and Stroke (VERiTAS) study.

Methods: The VERiTAS study enrolled patients with recent vertebrobasilar (VB) transient ischemic attack or stroke and ≥50% atherosclerotic stenosis or occlusion of vertebral or basilar arteries.

Effect of Hemodynamics on Stroke Risk in Symptomatic Atherosclerotic Vertebrobasilar Occlusive Disease.

Importance: Atherosclerotic vertebrobasilar (VB) occlusive disease is a significant etiology of posterior circulation stroke, with regional hypoperfusion as an important potential contributor to stroke risk.

Objective: To test the hypothesis that, among patients with symptomatic VB stenosis or occlusion, those with distal blood flow compromise as measured by large-vessel quantitative magnetic resonance angiography (QMRA) are at higher risk of subsequent posterior circulation stroke.

Design, Setting, And Participants: A prospective, blinded, longitudinal cohort study was conducted at 5 academic hospital-based centers in the United States and Canada; 82 patients from inpatient and outpatient settings were enrolled.

Detection of unruptured intracranial aneurysms on noninvasive imaging. Is there still a role for digital subtraction angiography?

Background: To determine the utility of digital subtraction angiography (DSA) in patients with unruptured intracranial aneurysms (UIA) detected on noninvasive imaging, such as magnetic resonance angiography (MRA) and computed tomography angiography (CTA). The follow-up of patients with untreated UIAs involves serial imaging; however, this diagnosis may be based on false positive (FP) results. We examined the incidence of FPs in our institutional series.

Donor Selection in Flow Replacement Bypass Surgery for Cerebral Aneurysms: Quantitative Analysis of Long-term Native Donor Flow Sufficiency.

Background: Graft selection in extracranial-intracranial bypass surgery for cerebral aneurysms has traditionally been based on clinical impression and operator preference. However, decision making can be optimized with a donor selection algorithm based on intraoperative flow data.

Objective: To present long-term follow-up and quantitative assessment of flow sufficiency for native donors selected in this manner.

Increased prevalence and rupture status of feeder vessel aneurysms in posterior fossa arteriovenous malformations.

Background: Posterior fossa arteriovenous malformations (AVMs) are considered to have a higher risk of poor outcome, as are AVMs with associated aneurysms. We postulated that posterior fossa malformations may be more prone to associated feeder vessel aneurysms, and to aneurysmal source of hemorrhage.

Objective: To examine the prevalence and hemorrhagic risk of posterior fossa AVM-associated feeder vessel aneurysms.

Hemodynamic Features of Symptomatic Vertebrobasilar Disease.

Background And Purpose: Atherosclerotic vertebrobasilar disease is an important cause of posterior circulation stroke. To examine the role of hemodynamic compromise, a prospective multicenter study, Vertebrobasilar Flow Evaluation and Risk of Transient Ischemic Attack and Stroke (VERiTAS), was conducted. Here, we report clinical features and vessel flow measurements from the study cohort.

Intracranial blood flow changes after extracranial carotid artery stenting.

Background: Carotid artery stenting is an endovascular treatment option for patients with extracranial carotid stenosis. However, intracranial blood flow changes following stenting have not been established.

Objective: To determine the effects of stenting on intracranial blood flow.