530 research outputs found
CoA_MRIData
No full textThis datasets contains cardiac MRI images for 20 patients post-coarctation repair. For each patient 2 images of cardiac geometry, and 2-3 phase-contrast flow images are available. This data is suitable for pulse wave velocity measurements.
All data is acquired under ethics 09-H0802-78 as approved by the London - Westminster research ethics committee, and has been fully anonymised.
Related publication - Van Engelen, Arna, Silva Vieira, Miguel, Rafiq, Isma, Cecelja, Marina, Schneider, Torben, de Bliek, Hubrecht, Figueroa, C. Alberto, Hussain, Tarique, Botnar, Rene M. Alastruey, Jordi, (2017), “Aortic length measurements for pulse wave velocity calculation: manual 2D vs automated 3D centreline extraction", Journal of Cardiovascular Magnetic Resonance, 2017, v 19, n 1, p32. http://dx.doi.org/10.1186/s12968-017-0341-
CoA_MRIData
No full textThis datasets contains cardiac MRI images for 20 patients post-coarctation repair. For each patient 2 images of cardiac geometry, and 2-3 phase-contrast flow images are available. This data is suitable for pulse wave velocity measurements. All data is acquired under ethics 09-H0802-78 as approved by the London - Westminster research ethics committee, and has been fully anonymised.Related publication - Van Engelen, Arna, Silva Vieira, Miguel, Rafiq, Isma, Cecelja, Marina, Schneider, Torben, de Bliek, Hubrecht, Figueroa, C. Alberto, Hussain, Tarique, Botnar, Rene M. Alastruey, Jordi, (2017), “Aortic length measurements for pulse wave velocity calculation: manual 2D vs automated 3D centreline extraction", Journal of Cardiovascular Magnetic Resonance, 2017, v 19, n 1, p32. http://dx.doi.org/10.1186/s12968-017-0341-
PET/CT and MR imaging biomarker of lipid-rich plaques using [(64)Cu]-labeled scavenger receptor (CD68-Fc)
No full textContinued uptake of modified low-density lipoproteins (LDL) by the scavenger receptor, CD68, of activated macrophages is a crucial process in the development of atherosclerotic plaques and leads to the formation of foam cells. Eight-weeks-old male Apolipoprotein E-deficient (ApoE(-/-)) mice (n=6) were fed a high-fat diet for 12 weeks. C57BL/6J wildtype (WT) mice served as controls (n=6). Positron emission tomography (PET) with an acquisition time of 1800s (NanoPET/CT scanner; Mediso, Hungary & Bioscan, USA) was carried out 24h after intravenous tail vein administration of 50µl (64)Cu-CD68-Fc (~20-30µg labeled protein/mouse containing approximately 10-12MBq (64)Cu-CD68-Fc per mouse). Three days after PET/CT, all mice received an intravenous administration of 0.2 mmol/kg body weight of a gadolinium-based elastin-binding contrast agent to assess plaque burden and vessel wall remodeling. Two hours after injection, mice were imaged in a 3T clinical MR scanner (Philips Healthcare, Best, NL) using a dedicated single loop surface coil (23mm). Enhanced (64)Cu-CD68-Fc uptake was found in the aortic arches of ApoE(-/-) compared to WT mice (ApoE(-/-) mice:10.5±1.5Bq/cm³ vs. WT mice: 2.1±0.3Bq/cm³; P=0.002). Higher gadolinium-based elastin-binding contrast agent uptake was also detected in the aortic arch of ApoE(-/-) compared to WT mice using R(1) maps (R(1)=1.47±0.06 s(-1) vs. 0.92±0.05 s(-1); P <0.001). Radiolabeled scavenger receptor ((64)Cu-CD68-Fc) may help to target foam cell rich plaques with high content of oxidized LDL. This novel imaging biomarker tool may have potential to identify unstable plaques and for risk stratification.</p
Noninvasive Imaging of Endothelial Damage in Patients with different HbA1c-levels, a Proof-of-Concept Study
Full text linkThe aim of this study was to compare endothelial permeability, which is considered a hallmark of CAD, between patients with different HbA1c-levels using an albumin-binding-MR-probe. This cross-sectional-study included 26 patients with clinical indication for x-ray-angiography, which were classified into 3 groups according to their HbA1c-levels (HbA1c<5.7%,<39mmol/mol; HbA1c=5.7-6.4%,39-47mmol/mol; HbA1c≥6.5%,48mmol/mol). Subjects underwent gadofosveset-enhanced-coronary-magnetic-resonance and x-ray-angiography including optical-coherence-tomography (OCT) within 24hours. Contrast-to-noise-ratios were assessed to measure the probe-uptake in the coronary-wall by coronary segment, excluding those with culprit lesions in x-ray-angiography. In the group of patients with HbA1c-levels between 5.7-6.4% 0.30 increased normalized CNR values were measured, compared to patients with HbA1c-levels <5.7% (0.30; 95% CI:[0.04, 0.57]). In patients with HbA1c levels ≥6.5%, we found 0.57 higher normalized CNR values as compared to patients with normal HbA1c-levels (0.57;95% CI:[0.28,0.85]) and 0.26 higher CNR values for patients with HbA1c-level≥6.5% as compared to patients with HbA1c-levels between 5.7-6.4% (0.26; 95% CI: [-0.04, 0.57]). Additionally late atherosclerotic lesions were more common in patients with high HbA1c-levels (HbA1c ≥6.5%:n=14 (74%); HbA1c 5.7-6.4%:n=6 (60%); HbA1c<5.7%:n=10 (53%)).In conclusion, coronary-magnetic-resonance imaging in combination with an albumin-binding probe suggests that both patients with intermediate and high HbA1c-levels are associated with a higher extent of endothelial damage of the coronary arteries as compared to patients with HbA1c-levels below 5.7.</p
A Polarographic Study of the Copper-formamidine Disulfide Dihydrochloride System in Aqueous Solution
No full textMany studies have been made on the solid complexes of thiourea with various metal ions. However, much less information is available on these systems in solutions. The copper(II)-thiourea system is especially intriguing. | Copper(II) complexes of thiourea (tu) are reported to be unstable (1) (2). Only one reference makes any attempt to describe the reaction products (3). They report that formamidine disulfide dihydrochloride (FDS*2HC1) and a copper(I) complex of thiourea result when cupric chloride is added to thiourea. However, it is felt by this author that inadequate proof is presented for the presence of FDS*2HC1 as a reaction product. In addition, if FDS*2HC1 is formed, it is surprising that complexation was not observed between the FDS*2HC1 and the copper present in the solution. If FDS*2HC1 can form complexes with copper, it would appear that cupric ions might be stabilized in the presence of thiourea.ProQuest Traditional Publishing Optio
Arterial spin labeling angiography using a triple inversion recovery prepulse
No full textArterial spin labeling is a well-known noninvasive angiography technique, which does not necessitate the use of a contrast agent. arterial spin labeling is still clinically underused because of several challenges: (1) long scan times because of the need for two acquisitions (labeled and nonlabeled datasets), (2) sensitivity to spatial misregistration because of the need for image subtraction, and (3) the need for precise planning and choice of an optimal inversion delay for best blood-to-background contrast. In this work, we propose a new arterial spin labeling method based on a triple-inversion-recovery sequence-arterial spin labeling. This approach exploits the ability of two nonselective inversion recovery prepulses to null the background signal over a wide range of T1 values, while maintaining the signal of labeled blood using a third slab selective inversion pulse. This technique therefore allows the acquisition of angiograms with a flexible inversion delay, easier planning procedure and no need for subtraction
Advanced Respiratory Motion Compensation for Coronary MR Angiography
No full textDespite technical advances, respiratory motion remains a major impediment in a substantial amount of patients undergoing coronary magnetic resonance angiography (CMRA). Traditionally, respiratory motion compensation has been performed with a one-dimensional respiratory navigator positioned on the right hemi-diaphragm, using a motion model to estimate and correct for the bulk respiratory motion of the heart. Recent technical advancements has allowed for direct respiratory motion estimation of the heart, with improved motion compensation performance. Some of these new methods, particularly using image-based navigators or respiratory binning, allow for more advanced motion correction which enables CMRA data acquisition throughout most or all of the respiratory cycle, thereby significantly reducing scan time. This review describes the three components typically involved in most motion compensation strategies for CMRA, including respiratory motion estimation, gating and correction, and how these processes can be utilized to perform advanced respiratory motion compensation
Optimized Methods for the Surface Immobilization of Collagens and Collagen Binding Assays
No full textFibrosis occurs in various tissues as a reparative response to injury or damage. If
excessive, however, fibrosis can lead to tissue scarring and organ failure, which is
associated with high morbidity and mortality. Collagen is a key driver of fibrosis, with
type I and type III collagen being the primary types involved in many fibrotic diseases.
Unlike conventional protocols used to immobilize other proteins (e.g., elastin, albumin,
fibronectin, etc.), comprehensive protocols to reproducibly immobilize different types
of collagens in order to produce stable coatings are not readily available. Immobilizing
collagen is surprisingly challenging because multiple experimental conditions may
affect the efficiency of immobilization, including the type of collagen, the pH, the
temperature, and the type of microplate used. Here, a detailed protocol to reproducibly
immobilize and quantify type I and III collagens resulting in stable and reproducible
gels/films is provided. Furthermore, this work demonstrates how to perform, analyze,
and interpret in vitro time-resolved fluorescence binding studies to investigate the
interactions between collagens and candidate collagen-binding compounds (e.g., a
peptide conjugated to a metal chelate carrying, for example, europium [Eu(III)]).
Such an approach can be universally applied to various biomedical applications,
including the field of molecular imaging to develop targeted imaging probes, drug
development, cell toxicity studies, cell proliferation studies, and immunoassays
René Géronimo Favaloro : pioneer of Cardiac Surgery
Full text linkDr. René G. Favaloro moved to the Cleveland Clinic in 1962 and proceeded to reshape the face of cardiac surgery as we knew it. Together with his colleagues at the Cleveland Clinic, Drs. Effler, Sones, Proudfit, Groves, Sheldon and countless others, he contributed to the double internal mammary arterymyocardial implantation by the Vineberg method, and by May 1967, he reconstructed the right coronary artery by the saphenous vein graft interposition. These landmark procedures paved the way for the aorto-coronary saphenous vein bypass graft in October 1967. Many similar breakthroughs ensued, with the application of the bypass technique to the left coronary artery, the combination of coronary artery bypass graft with left ventricular reconstruction and valve repair/replacement and finally, by December, a double bypass to the right coronary artery and anterior descending branch of the left coronary artery. In June, 1971, Dr. Favaloro decided to leave the Cleveland Clinic and return to Argentina where he created a medical centre, a teaching unit, a research department and finally an Institute of Cardiology and Cardiovascular Surgery. This was his greatest personal ambition. Over and above his brilliant mind and craft, Dr. Favaloro was a man of integrity, courage, honesty and humility, whose name will never cease to reverberate throughout the history of medicine.peer-reviewe
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