Ultra-high field cardiac MRI in large animals and humans for translational cardiovascular research.

A key step in translational cardiovascular research is the use of large animal models to better understand normal and abnormal physiology, to test drugs or interventions, or to perform studies which would be considered unethical in human subjects. Ultrahigh field magnetic resonance imaging (UHF-MRI) at 7 T field strength is becoming increasingly available for imaging of the heart and, when compared to clinically established field strengths, promises better image quality and image information content, more precise functional analysis, potentially new image contrasts, and as all imaging techniques, a reduction of the number of animals per study because of the possibility to scan every animal repeatedly. We present here a solution to the dual use problem of whole-body UHF-MRI systems, which are typically installed in clinical environments, to both UHF-MRI in large animals and humans.

Influence of using simulated or real patients on undergraduate medical students acquiring competencies in medical conversations in surgery: A prospective, controlled study.

Background: Communication with patients and their relatives as well as with colleagues and students is an essential part of every physician's daily work. An established method for teaching communication skills is using simulated patients (SPs). However, teaching with SPs is often subjectively perceived by medical students as less instructive than teaching with real patients (RPs).

Effects of image homogeneity on stenosis visualization at 7 T in a coronary artery phantom study: With and without B1-shimming and parallel transmission.

Background: To investigate the effects of B1-shimming and radiofrequency (RF) parallel transmission (pTX) on the visualization and quantification of the degree of stenosis in a coronary artery phantom using 7 Tesla (7 T) magnetic resonance imaging (MRI).

Methods: Stenosis phantoms with different grades of stenosis (0%, 20%, 40%, 60%, 80%, and 100%; 5 mm inner vessel diameter) were produced using 3D printing (clear resin). Phantoms were imaged with four different concentrations of diluted Gd-DOTA representing established arterial concentrations after intravenous injection in humans.

On the way to routine cardiac MRI at 7 Tesla - a pilot study on consecutive 84 examinations.

Introduction: Cardiac magnetic resonance (CMR) at ultrahigh field (UHF) offers the potential of high resolution and fast image acquisition. Both technical and physiological challenges associated with CMR at 7T require specific hardware and pulse sequences. This study aimed to assess the current status and existing, publicly available technology regarding the potential of a clinical application of 7T CMR.

The traveling heads 2.0: Multicenter reproducibility of quantitative imaging methods at 7 Tesla.

Object: This study evaluates inter-site and intra-site reproducibility at ten different 7 T sites for quantitative brain imaging.

Material And Methods: Two subjects - termed the "traveling heads" - were imaged at ten different 7 T sites with a harmonized quantitative brain MR imaging protocol. In conjunction with the system calibration, MP2RAGE, QSM, CEST and multi-parametric mapping/relaxometry were examined.

B shimming of the human heart at 7T.

Purpose: Inhomogeneities of the static magnetic B field are a major limiting factor in cardiac MRI at ultrahigh field (≥ 7T), as they result in signal loss and image distortions. Different magnetic susceptibilities of the myocardium and surrounding tissue in combination with cardiac motion lead to strong spatio-temporal B -field inhomogeneities, and their homogenization (B shimming) is a prerequisite. Limitations of state-of-the-art shimming are described, regional B variations are measured, and a methodology for spherical harmonics shimming of the B field within the human myocardium is proposed.

A Novel Mono-surface Antisymmetric 8Tx/16Rx Coil Array for Parallel Transmit Cardiac MRI in Pigs at 7T.

A novel mono-surface antisymmetric 16-element transmit/receive (Tx/Rx) coil array was designed, simulated, constructed, and tested for cardiac magnetic resonance imaging (cMRI) in pigs at 7 T. The cardiac array comprised of a mono-surface 16-loops with two central elements arranged anti-symmetrically and flanked by seven elements on either side. The array was configured for parallel transmit (pTx) mode to have an eight channel transmit and 16-channel receive (8Tx/16Rx) coil array.

Cerebellar transcranial direct current stimulation modulates the fMRI signal in the cerebellar nuclei in a simple motor task.

Background: In a seminal paper, Galea et al. (Modulation of cerebellar excitability by polarity-specific noninvasive direct current stimulation. 2009.

Networks of phobic fear: Functional connectivity shifts in two subtypes of specific phobia.

Anxiety disorders can be conceptualized by an abnormal interplay of emotion-processing brain circuits; however, knowledge of brain connectivity measures in specific phobia is still limited. To explore functional interactions within selected fear-circuitry structures (anterior cingulate cortex (ACC), amygdala, insula), we re-examined three task-based fMRI studies using a symptom provocation approach (n=94 subjects in total) on two different phobia subtypes (animal subtype as represented by snake phobia (SP) and blood-injection-injury subtype as represented by dental phobia (DP)), and a non-phobic healthy control group (HC). Functional connectivity (FC) analyses detected a negative coupling between the amygdala and the ACC in HC for both classes of phobic stimuli, while SP and DP lacked this inhibitory relationship during visual stimulus presentation.

Structural and Functional Magnetic Resonance Imaging of the Cerebellum: Considerations for Assessing Cerebellar Ataxias.

Magnetic resonance imaging (MRI) of the brain is of high interest for diagnosing and understanding degenerative ataxias. Here, we present state-of-the-art MRI methods to characterize structural alterations of the cerebellum and introduce initial experiments to show abnormalities in the cerebellar nuclei. Clinically, T1-weighted MR images are used to assess atrophy of the cerebellar cortex, the brainstem, and the spinal cord, whereas T2-weighted and PD-weighted images are typically employed to depict potential white matter lesions that may be associated with certain types of ataxias.

Structural and functional MRI abnormalities of cerebellar cortex and nuclei in SCA3, SCA6 and Friedreich's ataxia.

Spinocerebellar ataxia type 3, spinocerebellar ataxia type 6 and Friedreich's ataxia are common hereditary ataxias. Different patterns of atrophy of the cerebellar cortex are well known. Data on cerebellar nuclei are sparse.

Dysregulation of anergy-related factors involved in regulatory T cells defects in Systemic Lupus Erythematosus patients: Rapamycin and Vitamin D efficacy in restoring regulatory T cells.

Aim: Systemic Lupus Erythematosus (SLE) patients display dysfunctions in T cell activation and anergy. Therefore the aims of our study were to explore the expression of anergy-related factors in CD4 T cells in relationship with regulatory T cells (Tregs) frequency in SLE patients and to identify strategies to redress these defects.

Method: Casitas B-cell lymphoma b (Cbl-b) and 'gene related to anergy in lymphocytes' (GRAIL) proteins were analyzed in peripheral blood mononuclear cells (PBMCs) from SLE patients and healthy donors (HD) by immunoblotting.

Peripheral blood lymphocytes analysis detects CD100/SEMA4D alteration in systemic sclerosis patients.

It was suggested that the immune system plays an important role at least in the amplification of the main elements in systemic sclerosis (SSc), an autoimmune disease with an incompletely elucidated pathogenesis. Elucidation of the mechanisms involved in the interaction between T and B cells, major players of the immune system, could contribute to a better understanding of some of clinical and pathological manifestations of SSc. Recently, abnormalities in Semaphorin 4D (Sema4D/CD100) or CD72, two contrareceptors involved in T and B cells cooperation, were associated with autoimmunity.

PI3K/Akt signaling in peripheral T lymphocytes from systemic lupus erythematosus patients.

PI3K/Akt/mTOR signaling pathway plays an important role in cellular proliferation and growth signaling. It was demonstrated that murine models presenting activated PI3K/Akt/mTOR signaling pathway in lymphocytes develop features of systemic autoimmunity, linking this pathway to autoimmune diseases. Therefore, the goal of our study was to analyze this signaling axis in Systemic Lupus Erythematosus (SLE), the prototype of systemic autoimmune diseases, focusing on Akt and p70S6k, two components of this pathway.

Role of cellular immunity in systemic sclerosis pathogenesis: update on CD4+T cells population studies.

Immunologic abnormalities observed in Systemic Sclerosis (SSc) patients consist of chronic mononuclear cell infiltration of affected tissues, dysregulation of lymphokine and growth factor production, and autoantibodies production. Expansion of CD4+T cells within the tissue seems to involve their activation that precedes this process. Therefore, CD4+T cells activation, as an early immune event, appears to be an important process in the development and maintaining of SSc.

Quantification and molecular characterization of regulatory T cells in connective tissue diseases.

The aim of our study was to investigate and characterize regulatory T cells (Treg) in peripheral blood of patients with connective tissue diseases (Systemic lupus erythematosus, systemic sclerosis, Sjögren's syndrome, poly- and dermatomyositis) as compared with blood from healthy controls. Treg cells were quantified and phenotypically characterized by flow cytometry while the expression level of Foxp3 mRNA was evaluated by real time PCR. A reduced percentage of peripheral blood Treg cells was found in patients than in controls, irrespective of the type of connective tissue disease.

Roles of CD147 on T lymphocytes activation and MMP-9 secretion in systemic lupus erythematosus.

The cellular and molecular mechanisms involved in many abnormalities described in Systemic Lupus Erythematosus (SLE) are still unclear. Some of these abnormalities referred to the hyperactivation of T lymphocytes and the enhanced secretion of MMP-9 by peripheral blood mononuclear cells (PBMCs). Therefore, in this paper we investigated the potential role of CD147 molecule in these abnormalities.

Serum levels of matrix metalloproteinases MMP-2 and MMP-9 and their tissue natural inhibitors in breast tumors.

In this study, the levels of matrix metalloproteinases MMP-2 and MMP-9 were simultaneously analyzed with the levels of their tissue natural inhibitors TIMP-1 and TIMP-2 in sera of patients with breast tumors. At the same time, the activity of these two matrix metalloproteinases was evaluated. The decrease of TIMP-2 level in sera from patients with breast cancer as well as an imbalance between MMP-2 and TIMP-2 in neoplasic processes were found.

MMP-9 and MMP-2 gelatinases and TIMP-1 and TIMP-2 inhibitors in breast cancer: correlations with prognostic factors.

The goal of our study was to analyse the prognostic values for some matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) in breast cancer. We evaluated the activity and the expression levels of MMP-9, MMP-2, TIMP-1 and TIMP-2 in malignant versus benign fresh breast tumor extracts. For this purpose, gelatinzymography, immunoblotting and ELISA were used to analyse the activity and expression of MMPs and TIMPs.

Matrix metalloproteinase-9 and its natural inhibitor TIMP-1 expressed or secreted by peripheral blood mononuclear cells from patients with systemic lupus erythematosus.

Matrix metalloproteinase-9 (MMP-9) was involved in inflammation and immune system dysfunctions. Besides immunologic abnormalities, systemic lupus erythematosus (SLE) also presents chronic inflammatory components. Therefore, a role of MMP-9 in SLE pathology might be supposed.