Unraveling the gut-brain connection: The association of microbiota-linked structural brain biomarkers with behavior and mental health.

Aim: The gut microbiota can influence human behavior. However, due to the massive multiple-testing problem, research into the relationship between microbiome ecosystems and the human brain faces drawbacks. This problem arises when attempting to correlate thousands of gut bacteria with thousands of brain voxels.

Increased brain fractional perfusion in obesity using intravoxel incoherent motion (IVIM) MRI metrics.

Objective: This research seeks to shed light on the associations between brain perfusion, cognitive function, and mental health in individuals with and without obesity.

Methods: In this study, we employed the noninvasive intravoxel incoherent motion (IVIM) magnetic resonance imaging (MRI) technique to examine brain fractional perfusion (FP) in two groups: individuals with obesity (N = 72) and healthy controls (N = 66). Additionally, we investigated potential associations between FP, cognitive function, and depressive symptoms in the participants with and without obesity.

The Longitudinal Changes in Subcutaneous Abdominal Tissue and Visceral Adipose Tissue Volumetries Are Associated with Iron Status.

Excess iron is known to trigger adipose tissue dysfunction and insulin resistance. Circulating markers of iron status have been associated with obesity and adipose tissue in cross-sectional studies. We aimed to evaluate whether iron status is linked to changes in abdominal adipose tissue longitudinally.

Microbiota alterations in proline metabolism impact depression.

The microbiota-gut-brain axis has emerged as a novel target in depression, a disorder with low treatment efficacy. However, the field is dominated by underpowered studies focusing on major depression not addressing microbiome functionality, compositional nature, or confounding factors. We applied a multi-omics approach combining pre-clinical models with three human cohorts including patients with mild depression.

Lower Locus Coeruleus MRI intensity in patients with late-life major depression.

Background: The locus coeruleus (LC) is the major noradrenergic source in the central nervous system. Structural alterations in the LC contribute to the pathophysiology of different neuropsychiatric disorders, which may increase to a variable extent the likelihood of developing neurodegenerative conditions. The characterization of such alterations may therefore help to predict progression to neurodegenerative disorders.

Obesity-associated deficits in inhibitory control are phenocopied to mice through gut microbiota changes in one-carbon and aromatic amino acids metabolic pathways.

Background: Inhibitory control (IC) is critical to keep long-term goals in everyday life. Bidirectional relationships between IC deficits and obesity are behind unhealthy eating and physical exercise habits.

Methods: We studied gut microbiome composition and functionality, and plasma and faecal metabolomics in association with cognitive tests evaluating inhibitory control (Stroop test) and brain structure in a discovery (n=156), both cross-sectionally and longitudinally, and in an independent replication cohort (n=970).

Obesity Impairs Short-Term and Working Memory through Gut Microbial Metabolism of Aromatic Amino Acids.

The gut microbiome has been linked to fear extinction learning in animal models. Here, we aimed to explore the gut microbiome and memory domains according to obesity status. A specific microbiome profile associated with short-term memory, working memory, and the volume of the hippocampus and frontal regions of the brain differentially in human subjects with and without obesity.

Serotonin Reuptake Inhibitor Drugs Are Associated with Contrast Extravasation and Clinical Outcome in Patients with Intracerebral Haemorrhage.

Background: Antidepressants that inhibit the reuptake of serotonin (SRIs) have been related to the appearance of intracerebral haemorrhage (ICH). Some studies have described bigger haematoma volumes in these patients. So far, no studies have demonstrated an association between SRIs and contrast extravasation (CE).

Glycated Hemoglobin, but not Insulin Sensitivity, is Associated with Memory in Subjects with Obesity.

Objective: Obesity has been related to later-life dementia. Serum glucose levels and insulin resistance are known to influence cognition in individuals with diabetes. This study aimed to evaluate memory function in middle-aged individuals with obesity in association with glucose metabolism and brain iron content.

Macrovascular Networks on Contrast-Enhanced Magnetic Resonance Imaging Improves Survival Prediction in Newly Diagnosed Glioblastoma.

A higher degree of angiogenesis is associated with shortened survival in glioblastoma. Feasible morphometric parameters for analyzing vascular networks in brain tumors in clinical practice are lacking. We investigated whether the macrovascular network classified by the number of vessel-like structures (nVS) visible on three-dimensional T1-weighted contrast⁻enhanced (3D-T1CE) magnetic resonance imaging (MRI) could improve survival prediction models for newly diagnosed glioblastoma based on clinical and other imaging features.

Resting-State Functional Connectivity Magnetic Resonance Imaging and Outcome After Acute Stroke.

Background and Purpose- Physiological effects of stroke are best assessed over entire brain networks rather than just focally at the site of structural damage. Resting-state functional magnetic resonance imaging can map functional-anatomic networks by analyzing spontaneously correlated low-frequency activity fluctuations across the brain, but its potential usefulness in predicting functional outcome after acute stroke remains unknown. We assessed the ability of resting-state functional magnetic resonance imaging to predict functional outcome after acute stroke.

Low Levels of Caveolin-1 Predict Symptomatic Bleeding After Thrombolytic Therapy in Patients With Acute Ischemic Stroke.

Background And Purpose: Experimental models of cerebral ischemia demonstrate that the decrease in the caveolin-1 membrane protein results in an increase in endothelial permeability. Because this phenomenon is responsible for hemorrhagic transformation (HT) after cerebral ischemia, we aimed to determine whether caveolin-1 levels may predict bleeding after recombinant tissue-type plasminogen activator (r-tPA) administration in patients with acute stroke.

Methods: We studied 133 patients with a first hemispheric stroke treated with r-tPA within 4.

High-permeability region size on perfusion CT predicts hemorrhagic transformation after intravenous thrombolysis in stroke.

Objective: Blood-brain barrier (BBB) permeability has been proposed as a predictor of hemorrhagic transformation (HT) after tissue plasminogen activator (tPA) administration; however, the reliability of perfusion computed tomography (PCT) permeability imaging for predicting HT is uncertain. We aimed to determine the performance of high-permeability region size on PCT (HPrs-PCT) in predicting HT after intravenous tPA administration in patients with acute stroke.

Methods: We performed a multimodal CT protocol (non-contrast CT, PCT, CT angiography) to prospectively study patients with middle cerebral artery occlusion treated with tPA within 4.

The Gut Metagenome Changes in Parallel to Waist Circumference, Brain Iron Deposition, and Cognitive Function.

Context: Microbiota perturbations seem to exert modulatory effects on emotional behavior, stress-, and pain-modulation systems in adult animals; however, limited information is available in humans.

Objective: To study potential relationships among the gut metagenome, brain microstructure, and cognitive performance in middle-aged, apparently healthy, obese and nonobese subjects after weight changes.

Design: This is a longitudinal study over a 2-year period.

Diffusion tensor imaging as a prognostic biomarker for motor recovery and rehabilitation after stroke.

Purpose: Despite improved acute treatment and new tools to facilitate recovery, most patients have motor deficits after stroke, often causing disability. However, motor impairment varies considerably among patients, and recovery in the acute/subacute phase is difficult to predict using clinical measures alone, particularly in severely impaired patients. Accurate early prediction of recovery would help rationalize rehabilitation goals and improve the design of trials testing strategies to facilitate recovery.

Venous imaging-based biomarkers in acute ischaemic stroke.

Vascular neuroimaging plays a decisive role in selecting the best therapy in patients with acute ischaemic stroke. However, compared with the arterial system, the role of veins has not been thoroughly studied. In this review, we present the major venous imaging-based biomarkers in ischaemic stroke.

Hepatic iron content is independently associated with serum hepcidin levels in subjects with obesity.

Background & Aims: Serum hepcidin concentration is known to increase in parallel to circulating markers of iron stores. We aimed to investigate whether this is reflected at the tissue level in subjects with obesity.

Methods: Serum hepcidin and ferritin levels (ELISA) and hepatic iron content (using magnetic resonance imaging) were analyzed longitudinally in 44 participants (19 without obesity and 25 with obesity).

Intravoxel Incoherent Motion Metrics as Potential Biomarkers for Survival in Glioblastoma.

Objective: Intravoxel incoherent motion (IVIM) is an MRI technique with potential applications in measuring brain tumor perfusion, but its clinical impact remains to be determined. We assessed the usefulness of IVIM-metrics in predicting survival in newly diagnosed glioblastoma.

Methods: Fifteen patients with glioblastoma underwent MRI including spin-echo echo-planar DWI using 13 b-values ranging from 0 to 1000 s/mm2.

Adipose tissue R2* signal is increased in subjects with obesity: A preliminary MRI study.

Objective: Circulating and adipose tissue markers of iron overload are increased in subjects with obesity. The aim is to study iron signals in adipose tissue.

Methods: Adipose tissue R2* values and hepatic iron concentration (HIC) were evaluated using magnetic resonance imaging (MRI) in 23 middle-aged subjects with obesity and 20 subjects without obesity.

Obesity Is Associated With Gene Expression and Imaging Markers of Iron Accumulation in Skeletal Muscle.

Context: Different genetic and imaging iron markers are known to be increased in the liver, adipose tissue, and brain of obese subjects.

Objective: We aimed to investigate these markers in human skeletal muscle. DESIGN, SETTING, PATIENTS, AND OUTCOME MEASURES: Markers of iron accumulation were measured in three different territories: Iron gene markers (TFRC1, TF, SLC11A2, FTL, FTH1, and SLC40A1) were studied in abdominal rectus abdominis (Cohort 1, n = 26) and quadriceps (Cohort 2, n = 13) muscle using real-time PCR, whereas paravertebral muscle R2* signal (as surrogate of iron content) (Cohort 3, n = 43) was evaluated by means of magnetic resonance imaging.

Dynamic Magnetic Resonance Angiography Provides Collateral Circulation and Hemodynamic Information in Acute Ischemic Stroke.

Background And Purpose: Contrary to usual static vascular imaging techniques, contrast-enhanced dynamic magnetic resonance angiography (dMRA) enables dynamic study of cerebral vessels. We evaluated dMRA ability to assess arterial occlusion, cerebral hemodynamics, and collateral circulation in acute ischemic stroke.

Methods: Twenty-five acute ischemic stroke patients with proximal anterior circulation occlusion underwent dMRA on a 3T scanner within 12 hours of symptoms onset.

Gut Microbiota Interacts With Brain Microstructure and Function.

Context: Evidence from animals suggests that gut microbiota affects brain structure and function but evidence in humans is scarce.

Objective: This study sought to evaluate potential interactions among gut microbiota composition, brain microstructure, and cognitive tests in obese and nonobese subjects.

Design, Setting, And Participants: This was a cross-sectional study at a tertiary hospital including 20 consecutive obese and 19 nonobese subjects similar in age and sex.

High-resolution blood-pool-contrast-enhanced MR angiography in glioblastoma: tumor-associated neovascularization as a biomarker for patient survival. A preliminary study.

Introduction: The objective of the study was to determine whether tumor-associated neovascularization on high-resolution gadofosveset-enhanced magnetic resonance angiography (MRA) is a useful biomarker for predicting survival in patients with newly diagnosed glioblastomas.

Methods: Before treatment, 35 patients (25 men; mean age, 64 ± 14 years) with glioblastoma underwent MRI including first-pass dynamic susceptibility contrast (DSC) perfusion and post-contrast T1WI sequences with gadobutrol (0.1 mmol/kg) and, 48 h later, high-resolution MRA with gadofosveset (0.

Lower serum osteocalcin concentrations are associated with brain microstructural changes and worse cognitive performance.

Objective: Rodent models have found that osteocalcin crosses the blood-brain barrier and regulates behaviour. No data are available on osteocalcin's effects on brain microstructure and cognitive performance in humans. We evaluated the association between serum osteocalcin concentrations and (i) brain microstructural changes on magnetic resonance imaging (MRI) and (ii) neuropsychological performance.

Nonalcoholic fatty liver disease and age are strong indicators for atherosclerosis in morbid obesity.

Objective: Whether nonalcoholic fatty liver disease (NAFLD) can predict atherosclerosis in obese patients remains unclear. The aim of our study was to investigate the usefulness of NAFLD and other cardiometabolic parameters in predicting subclinical atherosclerosis in obese patients.

Design, Patients And Measurements: We studied 314 consecutive obese subjects (223 women; mean age, 45·04 ± 9·34 years; body mass index 44·3 ± 5 kg/m(2) ) and 47 healthy lean individuals.