Publications by authors named "Samaan A"

Background: Instantaneous wave-free ratio (iwFR) is a well-validated method for functional evaluation of intermediate coronary lesions. A recently developed Murray law-based QFR (µQFR) allows wire-free FFR estimation using a high-quality single angiographic projection. We aim to determine the diagnostic accuracy of µQFR as compared to wire-based iwFR for physiological assessment of coronary lesions in a sample of Egyptian patients.

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Background: In heart failure with reduced ejection fraction (HFrEF), sodium-glucose co-transporter inhibitors (SGLT-2i) have persistently shown cardiovascular benefits through different trials. However, their impact on ventricular remodeling and cardiac hemodynamics has not been sufficiently studied. This study aimed to study how SGLT-2i initiation affects invasive hemodynamics and cardiac magnetic resonance imaging (CMR)-derived ventricular volumes, function, and fraction of the extracellular volume (ECV) in HFrEF patients with non-ischemic dilated cardiomyopathy (NIDCM).

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Multi-detector computed tomography (MDCT) is the gold standard non-invasive tool for evaluating aortic root dimensions. We assessed the agreement between 4D TEE and MDCT-derived aortic valve annular dimensions, coronary ostia height, and minor dimensions of sinuses of Valsalva (SoV) and sinotubular junction (STJ). In this prospective analytical study, we measured the annular area, annular perimeter, area-derived diameter, area-derived perimeter, left and right coronary ostial heights, and minor diameters of the SoV and the STJ using ECG-gated MDCT and 4D TEE.

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Background: Medical society recognition awards are important resources for physicians in advancing their careers. There is a need to better understand the representation of physician recipients by race and ethnicity, especially in women with intersectional identities.

Objective: To assess the proportions of American Academy of Physical Medicine and Rehabilitation (AAPM&R) award recipients by race and ethnicity and the intersection of gender.

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Shoulder Ablation Approaches.

Phys Med Rehabil Clin N Am

November 2021

The shoulder is structurally and functionally complex. Shoulder pain may be refractory to conventional treatments, such as physical therapy, pharmacotherapy, and corticosteroid injections. In such cases, radiofrequency ablation may serve as an alternative treatment plan.

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Postpolio syndrome (PPS) is a sequela with symptoms that often occur in patients who previously survived poliomyelitis. Pain is a characteristic feature of PPS. Although poliomyelitis is no longer commonly seen in the western world, there is a significant portion of patients living with PPS.

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Rheumatic heart disease affects primarily cardiac valves, it could involve the myocardium either primarily or secondary to heart valve affection. The influence of balloon mitral valvuloplasty (BMV) on left ventricular function has not been sufficiently studied. To determine the influence of balloon mitral valvuloplasty (BMV) on both global and regional left ventricular (LV) function.

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Mitral stenosis (MS) is associated with left atrial (LA) functional and morphological changes as a result of chronic increase in LA pressure. Relieving the mitral obstruction via balloon mitral valvuloplasty (BMV) might be associated with LA structural and functional remodeling. To study alterations of LA volume and functions 1 year following successful BMV in patients with isolated rheumatic severe mitral stenosis.

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Background: Floating right heart thrombi (RHT) represent an underdiagnosed, potentially hazardous, and to some extent rare phenomenon in patients presenting with acute pulmonary embolism (APE). Emergent treatment is usually required for such a condition.

Case Presentation: A 19-year-old young lady presented with progressive shortness of breath, marked renal impairment, thrombocytopenia, and a highly oscillating huge right atrial mass.

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In patients with rheumatic mitral stenosis (MS), some previous studies have investigated the influence of balloon mitral valvuloplasty (BMV) on left ventricular (LV) systolic function. However, the impact of BMV on LV twisting motion in this clinical setting has not been studied before yet. To describe changes in LV torsion in patients with rheumatic MS following BMV.

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Veno-arterial loop is a feasible and safe technique to facilitate mitral valve crossing for balloon mitral valvuloplasty in mitral stenosis patients.

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Left main coronary artery (LMCA) disease is associated with increased morbidity and mortality. Coronary artery bypass grafting surgery (CABG) has always been the standard revascularization strategy for this group of patients. However, with the recent developments in stents design and medical therapy over the past decade, several trials have been designed to evaluate the safety and efficacy of percutaneous coronary intervention (PCI) as an alternative to CABG surgery in patients with LMCA disease.

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Left atrial appendage aneurysm (LAAA) is a rare congenital structural heart disease. It is often diagnosed by echocardiography; however, other imaging modalities can add to its diagnosis and its potential effects on the surrounding structures. A 16-year-old boy presented with dyspnea and palpitation.

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Introduction And Hypothesis: The cardinal ligament (CL) still requires more precise anatomical mapping. We aim to elucidate the anatomy of the CL and the roles it plays in gynecological surgery.

Methods: Studies employed sharp dissection of 28 formalin-fixed cadaveric hemipelves and 10 unembalmed cadaveric hemipelves.

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We have shown that Vav and C-cbl are activated in the leukemogenic HTLV-I transformed rabbit T cell line RH/K34 but not in the asymptomatic one RH/K30. We extended these observations and investigated the activation of JAKs (Janus Kinase) and the STATs (signal transducers and activators of transcription) pathway in these cell lines. We found that Tyk2 and Stat3 are constitutively tyrosine phosphorylated in the leukemogenic cell line.

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B lymphocytes express the nonclassical class II molecule HLA-DO, which modulates the peptide loading activity of HLA-DM in the endocytic pathway. Binding to HLA-DM is required for HLA-DO to egress from the endoplasmic reticulum (ER). To gain insights into the mode of action of DO and on the role of DM in ER release, we sought to identify DM-binding residues on DO.

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In the endocytic pathway of antigen-presenting cells, HLA-DM catalyzes the exchange between class II-associated invariant chain peptide (CLIP) and antigenic peptides onto major histocompatibility complex class II molecules. At low pH of lysosomal compartments, both HLA-DM and HLA-DR undergo conformational changes, and it was recently postulated that two partially exposed tryptophans on HLA-DM might be involved in the interaction between the two molecules. To define contact regions on HLA-DM, we have conducted site-directed mutagenesis on those two hydrophobic residues.

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HLA-DO is an intracellular non-classical class II major histocompatibility complex molecule expressed in the endocytic pathway of B lymphocytes, which regulates the loading of antigenic peptides onto classical class II molecules such as HLA-DR. The activity of HLA-DO is mediated through its interaction with the peptide editor HLA-DM. Here, our results demonstrate that although HLA-DO is absolutely dependent on its association with DM to egress the endoplasmic reticulum, the cytoplasmic portion of its beta chain encodes a functional lysosomal sorting signal.

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Article Synopsis
  • HTLV-I infection was originally linked to T cell leukemia and neurologic diseases, but is now also associated with various autoimmune disorders like Sjogren's syndrome and uveitis.
  • A study on infected rabbits showed that all had antibodies against keratin and thyroglobulin, with some reacting to collagen, while other autoantibodies were rare.
  • The autoimmune responses were confirmed as being related to HTLV-I infection because uninfected controls did not show similar autoantibodies, and evidence suggested that the infection itself triggered these reactions.
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Human MHC class II antigens include HLA-DR, -DQ, and -DP molecules that present antigens to CD4+ T cells, as well as the non-classical molecules HLA-DM and -DO. HLA-DM promotes peptide binding to class II molecules in endocytic compartments and HLA-DO, which is physically associated with HLA-DM in B lymphocytes, regulates HLA-DM function. Antibodies specific for the DObeta chain were obtained by immunization of mice with a heterodimer consisting of a chimeric DObeta chain (DR/DObeta), containing 18 N-terminal residues of DRbeta, paired with the DRalpha chain and isolated from transfected murine fibroblasts.

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