Long-term therapy of interferon-alpha induced pulmonary arterial hypertension with different PDE-5 inhibitors: a case report

BACKGROUND: Interferon alpha2 is widely used in hepatitis and high-risk melanoma. Interferon-induced pulmonary arterial hypertension as a side effect is rare. CASE PRESENTATION: We describe a melanoma patient who developed severe pulmonary arterial hypertension 30 months after initiation of adjuvant interferon alpha2b therapy. Discontinuation of interferon did not improve pulmonary arterial hypertension. This patient could be treated successfully with phosphodiesterase-5 inhibitor therapy. CONCLUSION: This is only the 5th case of interferon-induced pulmonary arterial hypertension and the first documented case where pulmonary arterial hypertension was not reversible after termination of interferon alpha2 therapy. If interferon alpha2 treated patients develop respiratory symptoms, pulmonary arterial hypertension should be considered in the differential diagnosis. For these patients phosphodiesterase-5 inhibitors, e.g. sildenafil or vardenafil, could be an effective therapeutic approach

Conditional Gene Knockout in Human Cells with Inducible CRISPR/Cas9.

The advent of the easily programmable and efficient CRISPR/Cas9 nuclease system has revolutionized genetic engineering. While conventional gene knockout experiments using CRISPR/Cas9 are very valuable, these are not well suited to study stage-specific gene function in dynamic situations such as development or disease. Here we describe a CRISPR/Cas9-based OPTimized inducible gene KnockOut method (OPTiKO) for conditional loss-of-function studies in human cells. This approach relies on an improved tetracycline-inducible system for conditional expression of single guide RNAs (sgRNAs) that drive Cas9 activity. In order to ensure homogeneous and stable expression, the necessary transgenes are expressed following rapid and efficient single-step genetic engineering of the AAVS1 genomic safe harbor. When implemented in human pluripotent stem cells (hPSCs), the approach can be then efficiently applied to virtually any hPSC-derived human cell type at various stages of development or disease

MEF2C-MYOCD and Leiomodin1 Suppression by miRNA-214 Promotes Smooth Muscle Cell Phenotype Switching in Pulmonary Arterial Hypertension.

BACKGROUND: Vascular hyperproliferative disorders are characterized by excessive smooth muscle cell (SMC) proliferation leading to vessel remodeling and occlusion. In pulmonary arterial hypertension (PAH), SMC phenotype switching from a terminally differentiated contractile to synthetic state is gaining traction as our understanding of the disease progression improves. While maintenance of SMC contractile phenotype is reportedly orchestrated by a MEF2C-myocardin (MYOCD) interplay, little is known regarding molecular control at this nexus. Moreover, the burgeoning interest in microRNAs (miRs) provides the basis for exploring their modulation of MEF2C-MYOCD signaling, and in turn, a pro-proliferative, synthetic SMC phenotype. We hypothesized that suppression of SMC contractile phenotype in pulmonary hypertension is mediated by miR-214 via repression of the MEF2C-MYOCD-leiomodin1 (LMOD1) signaling axis. METHODS AND RESULTS: In SMCs isolated from a PAH patient cohort and commercially obtained hPASMCs exposed to hypoxia, miR-214 expression was monitored by qRT-PCR. miR-214 was upregulated in PAH- vs. control subject hPASMCs as well as in commercially obtained hPASMCs exposed to hypoxia. These increases in miR-214 were paralleled by MEF2C, MYOCD and SMC contractile protein downregulation. Of these, LMOD1 and MEF2C were directly targeted by the miR. Mir-214 overexpression mimicked the PAH profile, downregulating MEF2C and LMOD1. AntagomiR-214 abrogated hypoxia-induced suppression of the contractile phenotype and its attendant proliferation. Anti-miR-214 also restored PAH-PASMCs to a contractile phenotype seen during vascular homeostasis. CONCLUSIONS: Our findings illustrate a key role for miR-214 in modulation of MEF2C-MYOCD-LMOD1 signaling and suggest that an antagonist of miR-214 could mitigate SMC phenotype changes and proliferation in vascular hyperproliferative disorders including PAH

Phosphodiesterase type 4 expression and anti-proliferative effects in human pulmonary artery smooth muscle cells

BACKGROUND: Pulmonary arterial hypertension is a proliferative vascular disease, characterized by aberrant regulation of smooth muscle cell proliferation and apoptosis in distal pulmonary arteries. Prostacyclin (PGI(2)) analogues have anti-proliferative effects on distal human pulmonary artery smooth muscle cells (PASMCs), which are dependent on intracellular cAMP stimulation. We therefore sought to investigate the involvement of the main cAMP-specific enzymes, phosphodiesterase type 4 (PDE4), responsible for cAMP hydrolysis. METHODS: Distal human PASMCs were derived from pulmonary arteries by explant culture (n = 14, passage 3–12). Responses to platelet-derived growth factor-BB (5–10 ng/ml), serum, PGI(2 )analogues (cicaprost, iloprost) and PDE4 inhibitors (roflumilast, rolipram, cilomilast) were determined by measuring cAMP phosphodiesterase activity, intracellular cAMP levels, DNA synthesis, apoptosis (as measured by DNA fragmentation and nuclear condensation) and matrix metalloproteinase-2 and -9 (MMP-2, MMP-9) production. RESULTS: Expression of all four PDE4A-D genes was detected in PASMC isolates. PDE4 contributed to the main proportion (35.9 ± 2.3%, n = 5) of cAMP-specific hydrolytic activity demonstrated in PASMCs, compared to PDE3 (21.5 ± 2.5%), PDE2 (15.8 ± 3.4%) or PDE1 activity (14.5 ± 4.2%). Intracellular cAMP levels were increased by PGI(2 )analogues and further elevated in cells co-treated with roflumilast, rolipram and cilomilast. DNA synthesis was attenuated by 1 μM roflumilast (49 ± 6% inhibition), rolipram (37 ± 6%) and cilomilast (30 ± 4%) and, in the presence of 5 nM cicaprost, these compounds exhibited EC(50 )values of 4.4 (2.6–6.1) nM (Mean and 95% confidence interval), 59 (36–83) nM and 97 (66–130) nM respectively. Roflumilast attenuated cell proliferation and gelatinase (MMP-2 and MMP-9) production and promoted the anti-proliferative effects of PGI(2 )analogues. The cAMP activators iloprost and forskolin also induced apoptosis, whereas roflumilast had no significant effect. CONCLUSION: PDE4 enzymes are expressed in distal human PASMCs and the effects of cAMP-stimulating agents on DNA synthesis, proliferation and MMP production is dependent, at least in part, on PDE4 activity. PDE4 inhibition may provide greater control of cAMP-mediated anti-proliferative effects in human PASMCs and therefore could prove useful as an additional therapy for pulmonary arterial hypertension

Effects of Preoperative Aspirin Use on Mortality in Coronary Artery Bypass Grafting Patients

Background and Aim: Discontinuing aspirin use in patients before coronary artery bypass grafting (CABG) has focused on bleeding risks. The aim of this study was to determind the effect of aspirin use on overall mortality with this procedure.Materials and Methods: In a retrospective review was under taken of 2,252 consecutive isolated coronary artery bypass grafting (CABG) procedures performed between July 1995 and May 3003 in Tehran, Shriati hospital. Patients who had isolated CABG operations and received aspirin were analyzed and compared to nonusers undergoing similar bypass procedures during the same period. Aspirin use was defined by identification of ingestion within 7 days before the operation.Results: CABG patients using preoperative aspirin were less likely to experience in hospital hemorrhage compared to nonusers (P=0.0001). Significant difference was seen for transfusion of blood products, and need for reexploration for hemorrhage between patients who did and did not receive aspirin (P=0.0001).Mortality in multivariate (odds ratio [OR] =0.12, 95%confidence interval [0.05, 0.28] analysis was less to patients using aspirin compared to nonusers (p=0.0001).Conclusions : Preoperative aspirin use appears to be associated with a decreased risk of mortality in CABG patients with significant increase in hemorrhage, blood product requirements, or related morbidities

Experimental and numerical studies on microfluidic preparation and engineering of chitosan nanoparticles

Optimization of nanoparticle (NP) characteristics (e.g. size, shape, zeta potential, etc.) is essential to achieve desirable cell responses. In the current study, we intend to introduce an equation representing a prediction about hydrodynamic diameter of microfluidic (MF) preparation of chitosan-tripolyphosphate (CS-TPP) NPs as an influential factor on cell behavior. Both numerical simulation and experimental study have been employed for this study. TPP concentration, channel length and flow ratio (lateral flow to core flow) to find optimum mixing efficiency conditions using a computational fluid dynamics (CFD) in COMSOL 5.5 in a t-shaped MFD were evaluated numerically and consequently in experimental section, a cross-junction MFD was used for preparation of CS-TPP NPs based on optimum conditions obtained from numerical section to find a correlation between NPs hydrodynamic diameter, flow ratios and TPP concentrations. © 2020 Elsevier B.V

Mesenchymoma of the left atrium

Mr.M.H. 27 years old, is referred with symptoms and signs of inflow portion obstruction of the left heart. Laboratory test and echocardiography confirmed this diagnosis and revealed the presence of a tumor involving left atrium and mitral valve. The patients underwent operation and a tumor of left atrium with adhesion to the base of mitral valve posterior leaflet and another mass which existed on the mitral valve anterior leaflet were taken out. Histopathological examination of the tumor led to the diagnosis of mesenchymoma. Mesenchymoma is one of the rare connective tissue tumors and even more rarely is observed in the heart. Rare cases of cardiac mesenchymoma have been reported in literature since 1966 (A.D.) and this is the first case of mitral valve mesenchymoma to be introduced to literature

Low-dose dobutamine stress echocardiography cannot predict mitral regurgitation reversibility after coronary artery bypass grafting

Background: The ideal management of ischemic mitral regurgitation (MR) remains a clinical dilemma because of the suboptimal available therapeutic options. Recently, new concepts have emerged, pointing to the benefits of a patient selection approach when debating the management of moderate ischemic MR. We investigated the predictability of low-dose dobutamine stress echocardiography (DSE) in selecting candidates for CABG with moderate MR for valve repair. Methods: From November 2002 to May 2010, 110 candidates for first-time CABG, who were admitted to the cardiac surgery department in Day General Hospital (Tehran, Iran), were enrolled in the present cross-sectional study. DSE was performed for each case before CABG. Those with positive findings underwent CABG alone and those with negative results underwent concomitant CABG and mitral valve repair. The patients were followed up for a minimum of 60 months. Results: Of the 110 patients, 47 (42.72) had positive test results and underwent CABG alone and 63 (57.28) had negative DSE results and underwent concomitant CABG and mitral valve repair. The MR degree had decreased from 2.8 ± 0.3 preoperatively to 1.46 ± 0.6 early during the hospital stay and 1.9 ± 0.7 during late follow-up in the CABG group. It had decreased from 2.84 ± 0.4 preoperatively to 0.93 ± 0.65 postoperatively but then increased to 1.41 ± 0.9 during late follow-up, for a significant decrease in the combined group (P < .05). Conclusions: Despite its utility in selecting CABG patients with moderate ischemic MR for valve repair from a short-term perspective, the use of DSE cannot predict the long-term outcomes of these patients. © 2014 The American Association for Thoracic Surgery