Propofol anesthesia improves stroke outcomes over isoflurane anesthesia-a longitudinal multiparametric MRI study in a rodent model of transient middle cerebral artery occlusion.

General anesthesia is routinely used in endovascular thrombectomy procedures, for which volatile gas and/or intravenous propofol are recommended. Emerging evidence suggests propofol may have superior effects on disability and/or mortality rates, but a mode-of-action underlying these class-specific effects remains unknown. Here, a moderate isoflurane or propofol dosage on experimental stroke outcomes was retrospectively compared using serial multiparametric MRI and behavioral testing.

Distalization of perianal fistulas after loose silicone seton drainage is a myth.

Background: It is often stated that loose seton drainage results in distal migration of a fistula tract in perianal fistula. The aim of the present study was to assess this distalization of trans- and suprasphincteric perianal fistulas after a silicone seton has been inserted.

Methods: Consecutive patients who underwent loose seton placement for the management of a transsphincteric or suprasphincteric fistula between January 2016 and December 2021 with a pre- and postoperative magnetic resonance imaging (MRI) were included in the present retrospective study.

Hyperperfusion profiles after recanalization differentially associate with outcomes in a rat ischemic stroke model.

Futile recanalization hampers prognoses of ischemic stroke after successful mechanical thrombectomy, hypothetically through post-recanalization perfusion deficits, onset-to-groin delays and sex effects. Clinically, acute multiparametric imaging studies remain challenging. We assessed possible relationships between these factors and disease outcome after experimental cerebral ischemia-reperfusion, using translational MRI, behavioral testing and multi-model inference analyses.

Thermosensitive Biodegradable Hydrogels for Local and Controlled Cerebral Delivery of Proteins: MRI-Based Monitoring of and Protein Release.

Hydrogels have been suggested as novel drug delivery systems for sustained release of therapeutic proteins in various neurological disorders. The main advantage these systems offer is the controlled, prolonged exposure to a therapeutically effective dose of the released drug after a single intracerebral injection. Characterization of controlled release of therapeutics from a hydrogel is generally performed , as current methods do not allow for measurements of spatiotemporal distribution and release kinetics of a loaded protein.

imaging of cerebral glucose metabolism informs on subacute to chronic post-stroke tissue status - A pilot study combining PET and deuterium metabolic imaging.

Recanalization therapy after acute ischemic stroke enables restoration of cerebral perfusion. However, a significant subset of patients has poor outcome, which may be caused by disruption of cerebral energy metabolism. To assess changes in glucose metabolism subacutely and chronically after recanalization, we applied two complementary imaging techniques, fluorodeoxyglucose (FDG) positron emission tomography (PET) and deuterium (H) metabolic imaging (DMI), after 60-minute transient middle cerebral artery occlusion (tMCAO) in C57BL/6 mice.

Prolonged release of VEGF and Ang1 from intralesionally implanted hydrogel promotes perilesional vascularization and functional recovery after experimental ischemic stroke.

Injectable hydrogels can generate and support pro-repair environments in injured tissue. Here we used a slow-releasing drug carrying -forming hydrogel to promote post-stroke recovery in a rat model. Release kinetics were measured and with MRI, using gadolinium-labeled albumin (Galbumin), which demonstrated prolonged release over multiple weeks.

Remote Corticospinal Tract Degeneration After Cortical Stroke in Rats May Not Preclude Spontaneous Sensorimotor Recovery.

Recovery of motor function after stroke appears to be related to the integrity of axonal connections in the corticospinal tract (CST) and corpus callosum, which may both be affected after cortical stroke. In the present study, we aimed to elucidate the relationship of changes in measures of the CST and transcallosal tract integrity, with the interhemispheric functional connectivity and sensorimotor performance after experimental cortical stroke. We conducted in vivo diffusion magnetic resonance imaging (MRI), resting-state functional MRI, and behavior testing in twenty-five male Sprague Dawley rats recovering from unilateral photothrombotic stroke in the sensorimotor cortex.

Translational Value of Skilled Reaching Assessment in Clinical and Preclinical Studies on Motor Recovery After Stroke.

Background: Assessment of skilled reaching enables extensive analysis of upper limb function in clinical and preclinical studies on poststroke outcome. However, translational research if often limited by lack of correspondence between tests of human and rodent motor function.

Objectives: To determine (1) the translational value of skilled reaching performance for preclinical research by comparing the behavioral recovery profiles of skilled reaching characteristics between humans and rats recovering from stroke and (2) the relationship between skilled reaching performance and commonly used clinical outcome measures after stroke.

MRI response rate after short-course radiotherapy on rectal cancer in the elderly comorbid patient: results from a retrospective cohort study.

Background: The aim of the present study was to evaluate MRI response rate and clinical outcome of short-course radiotherapy (SCRT) on rectal cancer as an alternative to chemoradiotherapy in patients where downstaging is indicated.

Methods: A retrospective analysis was performed of a patient cohort with rectal carcinoma (cT1-4cN0-2 cM0-1) from a large teaching hospital receiving restaging MRI, deferred surgery or no surgery after SCRT between 2011 and 2017. Patients who received chemotherapy during the interval between SCRT and restaging MRI were excluded.

Animal Functional Magnetic Resonance Imaging: Trends and Path Toward Standardization.

Animal whole-brain functional magnetic resonance imaging (fMRI) provides a non-invasive window into brain activity. A collection of associated methods aims to replicate observations made in humans and to identify the mechanisms underlying the distributed neuronal activity in the healthy and disordered brain. Animal fMRI studies have developed rapidly over the past years, fueled by the development of resting-state fMRI connectivity and genetically encoded neuromodulatory tools.

Noninvasive Brain Stimulation to Enhance Functional Recovery After Stroke: Studies in Animal Models.

Background: Stroke is the leading cause of adult disability, but treatment options remain limited, leaving most patients with incomplete recovery. Patient and animal studies have shown potential of noninvasive brain stimulation (NIBS) strategies to improve function after stroke. However, mechanisms underlying therapeutic effects of NIBS are unclear and there is no consensus on which NIBS protocols are most effective.

The Use of Magnetic Resonance Imaging for Non-Invasive Assessment of Venofer® Biodistribution in Rats.

Purpose: The aim of this study was to determine the potential of magnetic resonance imaging to evaluate the biodistribution of exogenous iron within 24 h after one single injection of Venofer® (iron sucrose).

Methods: Venofer® was evaluated in vitro for its ability to generate contrast in MR images. Subsequently, iron disposition was assessed in rats with MRI, in vivo up to 3 h and post mortem at 24 h after injection of Venofer®, at doses of 10- and 40 mg/kg body weight (n = 2 × 4), or saline (n = 4).

Fourier Transform Infrared (FT-IR) and Laser Ablation Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) Imaging of Cerebral Ischemia: Combined Analysis of Rat Brain Thin Cuts Toward Improved Tissue Classification.

Microspectroscopic techniques are widely used to complement histological studies. Due to recent developments in the field of chemical imaging, combined chemical analysis has become attractive. This technique facilitates a deepened analysis compared to single techniques or side-by-side analysis.

In Vivo Molecular MRI of ICAM-1 Expression on Endothelium and Leukocytes from Subacute to Chronic Stages After Experimental Stroke.

Molecular MRI allows in vivo detection of vascular cell adhesion molecules expressed on inflamed endothelium, which enables detection of specific targets for anti-neuroinflammatory treatment. We explored to what extent MR contrast agent targeted to intercellular adhesion molecule-1 (ICAM-1) could detect endothelial- and leukocyte-associated ICAM-1 expression at different stages after experimental stroke. Furthermore, we assessed potential interfering effects of ICAM-1-targeted contrast agent on post-stroke lesion growth.

A novel approach to map induced activation of neuronal networks using chemogenetics and functional neuroimaging in rats: A proof-of-concept study on the mesocorticolimbic system.

Linking neural circuit activation at whole-brain level to neuronal activity at cellular level remains one of the major challenges in neuroscience research. We set up a novel functional neuroimaging approach to map global effects of locally induced activation of specific midbrain projection neurons using chemogenetics (Designer Receptors Exclusively Activated by Designer Drugs (DREADD)-technology) combined with pharmacological magnetic resonance imaging (phMRI) in the rat mesocorticolimbic system. Chemogenetic activation of DREADD-targeted mesolimbic or mesocortical pathways, i.

Uric Acid Is Protective After Cerebral Ischemia/Reperfusion in Hyperglycemic Mice.

Hyperglycemia at stroke onset is associated with poor long-term clinical outcome in numerous studies. Hyperglycemia induces intracellular acidosis, lipid peroxidation, and peroxynitrite production resulting in the generation of oxidative and nitrosative stress in the ischemic tissue. Here, we studied the effects of acute hyperglycemia on in vivo intercellular adhesion molecule-1 (ICAM-1) expression, neutrophil recruitment, and brain damage after ischemia/reperfusion in mice and tested whether the natural antioxidant uric acid was protective.

Magnetic resonance imaging of local and remote vascular remodelling after experimental stroke.

The pattern of vascular remodelling in relation to recovery after stroke remains largely unclear. We used steady-state contrast-enhanced magnetic resonance imaging to assess the development of cerebral blood volume and microvascular density in perilesional and exofocal areas from (sub)acutely to chronically after transient stroke in rats. Microvascular density was verified histologically after infusion with Evans Blue dye.

Intranasally administered mesenchymal stem cells promote a regenerative niche for repair of neonatal ischemic brain injury.

Previous work from our group has shown that intranasal MSC-treatment decreases lesion volume and improves motor and cognitive behavior after hypoxic-ischemic (HI) brain damage in neonatal mice. Our aim was to determine the kinetics of MSC migration after intranasal administration, and the early effects of MSCs on neurogenic processes and gliosis at the lesion site. HI brain injury was induced in 9-day-old mice and MSCs were administered intranasally at 10days post-HI.

PECAM-1-targeted micron-sized particles of iron oxide as MRI contrast agent for detection of vascular remodeling after cerebral ischemia.

An increasing amount of studies have provided evidence for vascular remodeling, for example, angiogenesis, after cerebral ischemia, which may play a significant role in post-stroke brain plasticity and recovery. Molecular imaging can provide unique in vivo whole-brain information on alterations in the expression of specific endothelial markers. A possible target for molecular magnetic resonance imaging (MRI) of post-stroke (neo)vascularization is platelet endothelial cell adhesion molecule-1 (PECAM-1).

MRI of ICAM-1 upregulation after stroke: the importance of choosing the appropriate target-specific particulate contrast agent.

Purpose: Magnetic resonance imaging (MRI) with targeted contrast agents provides a promising means for diagnosis and treatment monitoring after cerebrovascular injury. Our goal was to demonstrate the feasibility of this approach to detect the neuroinflammatory biomarker intercellular adhesion molecule-1 (ICAM-1) after stroke and to establish a most efficient imaging procedure.

Procedures: We compared two types of ICAM-1-functionalized contrast agent: T 1-shortening gadolinium chelate-containing liposomes and T2(*)-shortening micron-sized iron oxide particles (MPIO).

Nanoclusters of iron oxide: effect of core composition on structure, biocompatibility, and cell labeling efficacy.

Inorganic nanocrystals have a variety of applications in medicine. They may serve as contrast agents, therapeutics, and for in vitro diagnostics. Frequently, the synthesis route yields hydrophobically capped nanocrystals, which necessitates their subsequent coating to render a water-soluble and biocompatible probe.

Imaging neuroinflammation after stroke: current status of cellular and molecular MRI strategies.

Cellular and molecular magnetic resonance imaging (MRI) strategies for studying the spatiotemporal profile of neuroinflammatory processes after stroke are increasingly being explored since the first reports appeared about a decade ago. These strategies most often employ (super)paramagnetic contrast agents, such as (ultra)small particles of iron oxide and gadolinium chelates, for MRI-based detection of specific leukocyte populations or molecular inflammatory markers that are involved in the pathophysiology of stroke or plasticity. In this review we describe achievements, limitations and prospects in the field of cellular and molecular MRI of neuroinflammation in preclinical and clinical stroke.

Molecular MRI of Inflammation in Atherosclerosis.

Inflammatory activity in atherosclerotic plaque is a risk factor for plaque rupture and atherothrombosis and may direct interventional therapy. Inflammatory activity can be evaluated at the (sub)cellular level using in vivo molecular MRI. This paper reviews recent progress in contrast-enhanced molecular MRI to visualize atherosclerotic plaque inflammation.