10 research outputs found
Separation mechanisms of Co(III) complexes with EDTA-type ligands during salting-out TLC on impregnated and non-impregnated silica gel
No full textA separation mechanism of eight Co(III) complexes with ethylenediaminetetraacetate-type ligands belonging to two series during salting-out thin-layer chromatography on silica gel is investigated. The sorbent is impregnated with five poly(ethylene glycol)s with different molecular masses, and ammonium sulphate solutions are used as mobile phase. Additionally, on non-impregnated sorbent, mobile phases containing one of eight salts with ions of different lyotropic properties are used: kosmotropic Mg 2+ accompanied with SO 42- (kosmotrope), Cl - (border), NO 3- (chaotrope), ClO 4-(chaotrope), Cl - of Li + (kosmotrope), Na + (border), K + (chaotrope) and NH 4+ (chaotrope). Salting-out and salting-in effects were observed depending on salt nature. The combined retention mechanism of specific H-bonding and nonspecific hydrophobic interactions is proposed. © 2012 The Author. Published by Oxford University Press. All rights reserved
Oxidation of methionine residue in Gly-Met dipeptide induced by [Au(en)Cl<inf>2</inf>]<sup>+</sup> and influence of the chelated ligand on the rate of this redox process
No full textSpectroscopic (1H NMR and UV-vis) and electrochemical (CV) techniques have been applied to study the reaction of Gly-Met dipeptide with [Au(en)Cl2]+ complex having bidentate coordinated ethylenediamine (en) ligand. The final product in the investigated reaction was Gly-Met sulfoxide, formed by the oxidation of methionine residue with [Au(en)Cl2]+. The formation of Gly-Met sulfoxide proceeds through two steps including the monodentate coordination of thioether sulfur atom of methionine residue and release of en ligand from Au(III). In order to investigate the influence of the pH and Cl- concentration on this redox process, the reaction was performed in solution of KCl with the concentration varying from 0.01 to 0.50 M and in the pH range 2.00-5.00. The obtained kinetic data showed that oxidation of methionine residue in Gly-Met was 200 times slower in comparison to the same process with previously investigated [AuCl4]- complex. Difference in the oxidation rate of Gly-Met between these two complexes was attributed to the presence of chelated ethylenediamine ligand in [Au(en)Cl2]+. The finding that the oxidation of sulfur-containing peptides and proteins can be inhibited by structural modifications of gold(III) complexes introducing polydentate nitrogen-containing ligands can contribute in designing new gold(III) complexes with lower toxic side effects. © 2013 The Author(s)
A spectroscopic and electrochemical investigation of the oxidation pathway of glycyl-d,l-methionine and its N-acetyl derivative induced by gold(III)
No full textThe 1H nuclear magnetic resonance spectroscopy was applied to study the reaction of the dipeptide glycyl-D, L-methionine (H-Gly-D,L-Met-OH) and its N-acetylated derivative (Ac-Gly-D,L-Met-OH) with hydrogen tetrachloridoaurate(III) (H[AuCl 4]). The corresponding peptide and [AuCl 4] - were reacted in 1:1, 2:1, and 3:1 molar ratios, and all reactions were performed at pD 2.45 in 0.01 M DCl as solvent and at 25°C. It was found that the first step of these reactions is coordination of Au(III) to the thioether sulfur atom with formation of the gold(III)-peptide complex [AuCl 3(R-Gly-Met-OH-S)] (R=H or Ac). This intermediate gold(III) complex further reacts with an additional methionine residue to generate the R-Gly-Met-OH chlorosulfonium cation as the second intermediate product, which readily undergoes hydrolysis to give the corresponding sulfoxide. The oxidation of the methionine residue in the reaction between H-Gly-D,L-Met-OH and [AuCl 4]-was five times faster (k 2=0.363±0.074 M -1s -1) in comparison to the same process with N-acetylated derivative of this peptide (k 2=0.074±0.007 M -1s -1). The difference in the oxidation rates between these two peptides can be attributed to the free terminal amino group of H-Gly-D,L-Met-OH dipeptide. The mechanism of this redox process is discussed and, for its clarification, the reaction of the H-Gly-D,L-Met-OH dipeptide with [AuCl 4] - was additionally investigated by UV-Vis and cyclic voltammetry techniques. From these measurements, it was shown that the [AuCl 2] - complex under these experimental conditions has a strong tendency to disproportionate, forming [AuCl 4] - and metallic gold. This study contributes to a better understanding of the mechanism of the Au(III)-induced oxidation of methionine and methionine-containing peptides in relation to the severe toxicity of anti-arthritic and anticancer gold-based drugs. © The Author(s) 2011. This article is published with open access at Springerlink.com
Cardiac Magnetic Resonance in Hypertensive Heart Disease: Time for a New Chapter
No full textHypertension is one of the most important cardiovascular risk factors, associated with significant morbidity and mortality. Chronic high blood pressure leads to various structural and functional changes in the myocardium. Different sophisticated imaging methods are developed to properly estimate the severity of the disease and to prevent possible complications. Cardiac magnetic resonance can provide a comprehensive assessment of patients with hypertensive heart disease, including accurate and reproducible measurement of left and right ventricle volumes and function, tissue characterization, and scar quantification. It is important in the proper evaluation of different left ventricle hypertrophy patterns to estimate the presence and severity of myocardial fibrosis, as well as to give more information about the benefits of different therapeutic modalities. Hypertensive heart disease often manifests as a subclinical condition, giving exceptional value to cardiac magnetic resonance as an imaging modality capable to detect subtle changes. In this article, we are giving a comprehensive review of all the possibilities of cardiac magnetic resonance in patients with hypertensive heart disease
Relationship between QT dispersion and reperfusion in the acute myocardial infarction
No full textBackground. QT dispersion (QTd) represents the parameter of the expanded heterogeneity of myocard of ventricles. The aim of this study was to examine the dynamics of changes of QTd during the first 5 days of the acute myocardial infarction (AMI) in dependence to noninvasively estimated success of thrombolytic therapy. Methods. Thirty six patients with AMI were included in the study. All patients were treated with alteplaze according to rapid protocol. QTd (QTc max-QTc min) was measured immediately after the reception (0 min), after the thrombolytic therapy (90 min) and since the 2nd to the 5th day of the hospitalization. Reperfusion was estimated on the basis of electrocardiographic and biohumoral parameters. Results. In the group of 36 patients, 22 male and 11 female, both parameters of the reperfusion were not compatible in 3 patients. The other 23 patients had the reperfusion, while 10 patients did not have it. At the reception there was no significant difference of QTd between the group with reperfusion (79±34 ms) and the group without reperfusion (65±19 ms). After receiving alteplase, the average QTd in the group with reperfusion was 67±31 ms, which was not shorter in relation to the group without reperfusion (70±23 ms). Since the 2nd day of AMI, significantly smaller QTd in patients with reperfusion was not registered compared with the patients without the reperfusion (54±17 vs.73±20 ms), whereas since the 3rd day the difference became significant (46±16 vs. 87±24 ms). On the 4th day it was 43±12 vs. 78±21 ms, and on the 5th day it was 38±11 vs. 62±23 ms. On the 1st day significant difference of QTd between the groups with and without reperfusion was not registered in the group of patients with anterior AMI (0 min: 97±47 vs. 72±16; 90 min 68±47 vs. 72±20) whereas on the 2nd day it became statistically significant (51±15 vs. 74±20 on the 2nd day, 51±20 vs. 88±24 on the 3rd day, 46±10 vs. 81±19 on the 4th day and 40±8 vs. 69±22 ms on the 5th day. In the group of patients with inferolateral AMI, only on the 3rd day significant difference of QTd between the group with and the group without reperfusion was registered (43±14 vs. 69±29 ms), while in all other measuring it was not registered (0 min: 69±22 vs. 42±9; 90 min: 67±20 vs. 67±41; 55±19 vs. 60±25 on the 2nd day; 41±14 vs. 51±6 on the 4th day and 51±12 vs. 37±8 ms on the 5th day). Conclusion. Qt dispersion was of significantly shorter duration in patients with the successfully performed reperfusion in relation to the patients without the reperfusion. In patients with the anterior AMI, QTd was significantly different in patients with in relation to the patients without the reperfusion in distinction with the patients with inferolateral AMI
POST-PCI LAD ANEURYSM IN A SARS-COV2 IgG POSITIVE PATIENT
No full textABSTRACT
Since its outbreak in December 2019, COVID-19 infection became a pandemic disease, spreading in more than 200 countries within a short period of time. Despite the usual presentation as a respiratory infection, most commonly as bilateral pneumonia, the extra pulmonary manifestations are in greater focus for the last few months. Understanding the pathophysiological mechanisms of different clinical presentations and possible complications are of great importance for further treatment and prognosis. Cardiovascular complications are various including myocardial injury, arrhythmias, myocarditis, arterial, and venous thrombotic events, mainly presented as acute coronary syndrome and pulmonary embolism. Recently, specific hyperinflammatory syndrome within COVID-19 infection has been described in children and occasionally in adults, with features similar to those of Kawasaki disease, leading to multiorgan failure and shock. Although it’s presenting similarly to Kawasaki disease in terms of symptoms, the cases of Kawasaki like hyperinflammatory syndrome with the development of coronary artery aneurysms haven’t been described yet in adults. In this case report, we review a case of SARS-CoV-2 IgG positive 63-year old patient with a large aneurysm of the left anterior descending artery (LAD) after percutaneous coronary intervention and signs of possible viral myocardial involvement.
Keywords: COVID-19, acute coronary syndrome, percutaneous coronary intervention, coronary aneurysm, Kawasaki disease, cardiac magnetic resonance
Obstructive Sleep Apnea and Cardiovascular Risk: The Role of Dyslipidemia, Inflammation, and Obesity
No full textIntroduction: The present study aimed to establish the role of lipid abnormalities and inflammatory markers for developing cardiovascular risk, as well as to address the importance of obesity as a common comorbidity in patients with obstructive sleep apnea (OSA). Methods: The study was conducted as a prospective cohort study including 120 patients with newly diagnosed OSA between 2019 and 2020, at University Clinical Hospital Center “Bezanijska kosa”, Belgrade, Serbia. The diagnosis was established by polysomnography. In all patients, sociodemographic data, respiratory, lipid, and inflammatory parameters were collected and complete echocardiographic study and 24-h blood pressure monitoring were performed. Results: The mean patient age was 55.7 ± 13.8 years. Study population was mostly male (70.0%) and obese (56.7%). At least 30 apneas or hypopneas per hour were present in 39.0% of patients. A strong positive correlation was found between OSA severity and BMI (r = 0.562, p < 0.001), both associated with lipid, inflammatory and respiratory parameters, and cardiovascular profile of patients with OSA (p < 0.05 for all). Echocardiographic study and 24-h blood pressure monitoring parameters were in turn correlated with lipid and inflammatory markers (p < 0.05 for all). Conclusion: The results of this study support the important role of dyslipidemia and inflammation, as well as coexistence of obesity in the pathogenesis of numerous conditions linked with an increased risk of cardiovascular morbidity and mortality in patients with OSA
Characteristics and Outcomes of Patients with Acute Coronary Syndrome and COVID-19
No full textAcute coronary syndrome (ACS) in patients with COVID-19 is triggered by various mechanisms and can significantly affect the patient’s further treatment and prognosis. The study aimed to investigate the characteristics, major complications, and predictors of mortality in COVID-19 patients with ACS. All consecutive patients hospitalized from 5 July 2020 to 5 May 2021 for ACS with confirmed SARS-Co-2 were prospectively enrolled and tracked for mortality until 5 June 2021. Data from the electronic records for age and diagnosis, matched non-COVID-19 and COVID-19 ACS group, were extracted and compared. Overall, 83 COVID-19 ACS patients, when compared to 166 non-COVID ACS patients, had significantly more prevalent comorbidities, unfavorable clinical characteristics on admission (acute heart failure 21.7% vs. 6.6%, p < 0.01) and higher rates of major complications, 33.7% vs. 16.8%, p < 0.01, and intrahospital 30-day mortality, 6.7% vs. 26.5%, p < 0.01. The strongest predictors of mortality were aortic regurgitation, HR 9.98, 95% CI 1.88; 52.98, p < 0.01, serum creatinine levels, HR 1.03, 95% CI 1.01; 1.04, p < 0.01, and respiratory failure therapy, HR 13.05, 95% CI 3.62; 47.01, p < 0.01. Concomitant ACS and COVID-19 is linked to underlying comorbidities, adverse presenting features, and poor outcomes. Urgent strategies are needed to improve the outcomes of these patients
Table1_Obstructive Sleep Apnea and Cardiovascular Risk: The Role of Dyslipidemia, Inflammation, and Obesity.DOCX
No full textIntroduction: The present study aimed to establish the role of lipid abnormalities and inflammatory markers for developing cardiovascular risk, as well as to address the importance of obesity as a common comorbidity in patients with obstructive sleep apnea (OSA).Methods: The study was conducted as a prospective cohort study including 120 patients with newly diagnosed OSA between 2019 and 2020, at University Clinical Hospital Center “Bezanijska kosa”, Belgrade, Serbia. The diagnosis was established by polysomnography. In all patients, sociodemographic data, respiratory, lipid, and inflammatory parameters were collected and complete echocardiographic study and 24-h blood pressure monitoring were performed.Results: The mean patient age was 55.7 ± 13.8 years. Study population was mostly male (70.0%) and obese (56.7%). At least 30 apneas or hypopneas per hour were present in 39.0% of patients. A strong positive correlation was found between OSA severity and BMI (r = 0.562, p Conclusion: The results of this study support the important role of dyslipidemia and inflammation, as well as coexistence of obesity in the pathogenesis of numerous conditions linked with an increased risk of cardiovascular morbidity and mortality in patients with OSA.</p
