26 research outputs found
Disorder induced collapse of the electron phonon coupling in MgB observed by Raman Spectroscopy
The Raman spectrum of the superconductor MgB has been measured as a
function of the Tc of the film. A striking correlation is observed between the
onset and the frequency of the mode. Analysis of the data with
the McMillan formula provides clear experimental evidence for the collapse of
the electron phonon coupling at the temperature predicted for the convergence
of two superconducting gaps into one observable gap. This gives indirect
evidence of the convergence of the two gaps and direct evidence of a transition
to an isotropic state at 19 K. The value of the electron phonon coupling
constant is found to be 1.22 for films with T 39K and 0.80 for films with
T19K.Comment: 5 pages, 4 figure
Production of angiogenesis mediators and the structure of the vascular wall in the heart in ischemic cardiomyopathy
Background. In the pathogenesis of ischemic cardiomyopathy (ICMP), angiopoiesis remains unexplored.The aim. To describe the vasculature of the heart and the imbalance of angiogenesis mediators in the coronary circulation in association with the number of endothelial progenitor cells (EPC) and desquamated endothelial cells (DEC) in the blood of patients with coronary heart disease (CHD), suffering and not suffering from ICMP.Methods. Fifty-two patients with CHD (30 patients with ICMP, 22 patients without ICMP), 15 healthy donors were examined. The content of EPC (CD14+CD34+VEGFR2+) in the blood from the cubital vein and DEC (CD45–CD146+) in the blood from the coronary sinus and the cubital vein was determined by flow cytometry. The concentrations of VEGF-A (vascular endothelial growth factor A), PDGF (platelet-derived growth factor), and SDF-1 (stromal cell-derived factor 1) in blood plasma were recorded using immunofluorescence assay; the angiopoietin-2, MMP-9 (matrix metallopeptidase 9) were recorded using enzyme immunoassay. In myocardial biopsies the specific area of vessels and the expression of αSMA (smooth muscle alpha-actin) were determined by morphometric and immunohistochemical methods.Results. In the peripheral blood of patients with CHD, regardless of the presence of ICMP, the DEC content exceeded the physiological level, and the VEGF-A, PDGF, angiopoietin-2, and MMP-9 corresponded to the norm. In CHD patients without cardiomyopathy, there was an excess of SDF-1 and EPC in the blood from the cubital vein, and in ICMP, their physiological significance was noted. In the coronary blood flow in patients with CHD without cardiomyopathy, an increase in the concentration of PDGF was found, which was not determined in patients with ICMP, who had an increased content of DEC, angiopoietin-2 and MMP-9. The specific area of the vessels in the patients of the two groups was comparable; the expression of αSMA in ICMP was 6.2 times lower than in patients with CHD without cardiomyopathy.Conclusion. The development of ICMP is accompanied by impaired maturation of vessels in the myocardium, associated with the absence of a compensatory reaction of activation of cellular and humoral factors of angiogenesis
Role of Phagocytosis in the Pro-Inflammatory Response in LDL-Induced Foam Cell Formation; a Transcriptome Analysis
Excessive accumulation of lipid inclusions in the arterial wall cells (foam cell formation) caused by modified low-density lipoprotein (LDL) is the earliest and most noticeable manifestation of atherosclerosis. The mechanisms of foam cell formation are not fully understood and can involve altered lipid uptake, impaired lipid metabolism, or both. Recently, we have identified the top 10 master regulators that were involved in the accumulation of cholesterol in cultured macrophages induced by the incubation with modified LDL. It was found that most of the identified master regulators were related to the regulation of the inflammatory immune response, but not to lipid metabolism. A possible explanation for this unexpected result is a stimulation of the phagocytic activity of macrophages by modified LDL particle associates that have a relatively large size. In the current study, we investigated gene regulation in macrophages using transcriptome analysis to test the hypothesis that the primary event occurring upon the interaction of modified LDL and macrophages is the stimulation of phagocytosis, which subsequently triggers the pro-inflammatory immune response. We identified genes that were up- or downregulated following the exposure of cultured cells to modified LDL or latex beads (inert phagocytosis stimulators). Most of the identified master regulators were involved in the innate immune response, and some of them were encoding major pro-inflammatory proteins. The obtained results indicated that pro-inflammatory response to phagocytosis stimulation precedes the accumulation of intracellular lipids and possibly contributes to the formation of foam cells. In this way, the currently recognized hypothesis that the accumulation of lipids triggers the pro-inflammatory response was not confirmed. Comparative analysis of master regulators revealed similarities in the genetic regulation of the interaction of macrophages with naturally occurring LDL and desialylated LDL. Oxidized and desialylated LDL affected a different spectrum of genes than naturally occurring LDL. These observations suggest that desialylation is the most important modification of LDL occurring in vivo. Thus, modified LDL caused the gene regulation characteristic of the stimulation of phagocytosis. Additionally, the knock-down effect of five master regulators, such as IL15, EIF2AK3, F2RL1, TSPYL2, and ANXA1, on intracellular lipid accumulation was tested. We knocked down these genes in primary macrophages derived from human monocytes. The addition of atherogenic naturally occurring LDL caused a significant accumulation of cholesterol in the control cells. The knock-down of the EIF2AK3 and IL15 genes completely prevented cholesterol accumulation in cultured macrophages. The knock-down of the ANXA1 gene caused a further decrease in cholesterol content in cultured macrophages. At the same time, knock-down of F2RL1 and TSPYL2 did not cause an effect. The results obtained allowed us to explain in which way the inflammatory response and the accumulation of cholesterol are related confirming our hypothesis of atherogenesis development based on the following viewpoints: LDL particles undergo atherogenic modifications that, in turn, accompanied by the formation of self-associates; large LDL associates stimulate phagocytosis; as a result of phagocytosis stimulation, pro-inflammatory molecules are secreted; these molecules cause or at least contribute to the accumulation of intracellular cholesterol. Therefore, it became obvious that the primary event in this sequence is not the accumulation of cholesterol but an inflammatory response
Galectin 3 and non-classical monocytes of blood as myocardial remodeling factors at ischemic cardiomyopathy
Aims: To identify an imbalance of cardiac remodeling mediators and monocytes subpopulation in blood, distribution of myocardium macrophages in patients with ischemic cardiomyopathy (ICMP). Methods: The study engaged 30 patients with ICMP, 26 patients with coronary heart disease (CHD) without ICMP, 15 healthy donors. Concentrations of TGFb, MMP-9, MCP-1, galectin-3 were measured in plasma of blood from the coronary sinus and peripheral blood in CHD patients, as well as in peripheral blood in healthy donors, by enzyme immunoassay method. The ration of classical, intermediate, nonclassical, transitional monocytes in peripheral blood of patients and healthy donors was assessed by flow cytometry (expression CD14, CD16); the content of CD68+ macrophages in myocardium – by immunohistochemistry method. Results: In both samples of blood, the content of galectin-3 in patients with ICMP was higher than in CHD patients without ICMP and the level of TGFb was comparable between the groups. At ICMP, the concentration of MMP-9 in sinus blood was higher than that in CHD patients without ICMP in whom an excess of MCP-1 in the general blood flow was determined. The density of distribution of CD68+ cells in the myocardium in patients with ICMP was higher in the perianeurysmal zone than in the right atrium appendage. ICMP was characterized by a deficiency of non-classical monocytes, and CHD without ICMP – by an excess of intermediate cells in peripheral blood. Conclusion: Myocardium remodeling at ICMP is mediated by not so much TGFb but intracardiac galectin-3, which determines the subpopulation composition of blood monocytes
Lenalidomide for relapsed or refractory multiple myeloma
We report the activity of lenalidomide (revlimide – R), lenalidomide plus dexamethasone (Rd), lenalidomide plus bortezomib plus dexamethasone (RVd) in 34 patients with relapsed and refractory myeloma. For patients who received lenalidomide the overall response rate was 70.5 %. 38 % patients achieved very good partial response (VGPR) + complete response (CR). Median overall survival (OS) was 48 months. Lenalidomide may overcome the poor prognostic impact of various factors, particularly elevated beta (2)-microglobulin. Lenalidomide is highly active in elderly patients (> 65 years). Significantly increased OS with a lenalidomide-based induction and lenalidomide maintenance therapy was revealed. The median duration of the overall response without lenalidomide maintenance therapy was 10 months. The median duration of the overall response with lenalidomide maintenance therapy was 20 months (р < 0,05). Median OS with lenalidomide maintenance therapy was not reached. Median OS without lenalidomide maintenance therapy was 36 months (р < 0.05). Side effects were predictable and manageable. The most common adverse events reported were neutropenia (38.3 %) and thrombocytopenia (23.7 %). Serious adverse events were rare.</p
Role of Phagocytosis in the Pro-Inflammatory Response in LDL-Induced Foam Cell Formation; a Transcriptome Analysis
Excessive accumulation of lipid inclusions in the arterial wall cells (foam cell formation) caused by modified low-density lipoprotein (LDL) is the earliest and most noticeable manifestation of atherosclerosis. The mechanisms of foam cell formation are not fully understood and can involve altered lipid uptake, impaired lipid metabolism, or both. Recently, we have identified the top 10 master regulators that were involved in the accumulation of cholesterol in cultured macrophages induced by the incubation with modified LDL. It was found that most of the identified master regulators were related to the regulation of the inflammatory immune response, but not to lipid metabolism. A possible explanation for this unexpected result is a stimulation of the phagocytic activity of macrophages by modified LDL particle associates that have a relatively large size. In the current study, we investigated gene regulation in macrophages using transcriptome analysis to test the hypothesis that the primary event occurring upon the interaction of modified LDL and macrophages is the stimulation of phagocytosis, which subsequently triggers the pro-inflammatory immune response. We identified genes that were up- or downregulated following the exposure of cultured cells to modified LDL or latex beads (inert phagocytosis stimulators). Most of the identified master regulators were involved in the innate immune response, and some of them were encoding major pro-inflammatory proteins. The obtained results indicated that pro-inflammatory response to phagocytosis stimulation precedes the accumulation of intracellular lipids and possibly contributes to the formation of foam cells. In this way, the currently recognized hypothesis that the accumulation of lipids triggers the pro-inflammatory response was not confirmed. Comparative analysis of master regulators revealed similarities in the genetic regulation of the interaction of macrophages with naturally occurring LDL and desialylated LDL. Oxidized and desialylated LDL affected a different spectrum of genes than naturally occurring LDL. These observations suggest that desialylation is the most important modification of LDL occurring in vivo. Thus, modified LDL caused the gene regulation characteristic of the stimulation of phagocytosis. Additionally, the knock-down effect of five master regulators, such as IL15, EIF2AK3, F2RL1, TSPYL2, and ANXA1, on intracellular lipid accumulation was tested. We knocked down these genes in primary macrophages derived from human monocytes. The addition of atherogenic naturally occurring LDL caused a significant accumulation of cholesterol in the control cells. The knock-down of the EIF2AK3 and IL15 genes completely prevented cholesterol accumulation in cultured macrophages. The knock-down of the ANXA1 gene caused a further decrease in cholesterol content in cultured macrophages. At the same time, knock-down of F2RL1 and TSPYL2 did not cause an effect. The results obtained allowed us to explain in which way the inflammatory response and the accumulation of cholesterol are related confirming our hypothesis of atherogenesis development based on the following viewpoints: LDL particles undergo atherogenic modifications that, in turn, accompanied by the formation of self-associates; large LDL associates stimulate phagocytosis; as a result of phagocytosis stimulation, pro-inflammatory molecules are secreted; these molecules cause or at least contribute to the accumulation of intracellular cholesterol. Therefore, it became obvious that the primary event in this sequence is not the accumulation of cholesterol but an inflammatory response