Understanding the Growth of Electrodeposited PtNi Nanoparticle Films Using Correlated In Situ Liquid Cell Transmission Electron Microscopy and Synchrotron Radiation.

Electrodeposition is a versatile method for synthesizing nanostructured films, but controlling the morphology of films containing two or more elements requires a detailed understanding of the deposition process. We used liquid cell transmission electron microscopy to follow the electrodeposition of PtNi nanoparticle films on a carbon electrode during cyclic voltammetry. These in situ observations show that the film thickness increases with each cycle, and by the fourth cycle, branched and porous structures could be deposited. Synchrotron studies using in situ transmission X-ray microscopy further revealed that Ni was deposited in the oxide phase. Ex situ studies of bulk electrodeposited PtNi nanoparticle films indicated the number of cycles and the scanning rate were the most influential parameters, resulting in a different thickness, a different homogeneity, a different nanoparticle size, and a different surface structure, while the precursor concentration did not have a significant influence. By varying the potential range, we were able to obtain films with different elemental compositions.

Infective endocarditis of the tricuspid valve. Surgical treatment with pericardial cylinder implantation.

Introduction: Infective endocarditis (IE) on the tricuspid valve usually requires the complete resection of the infected tissue and implantation of a valve prosthesis. Aim: We assumed that total elimination of artificial material and implantation of the entirely patient-derived biological material would reduce the recurrence of IE. Material and methods: The group consisted of 7 consecutive patients who underwent implantation of a cylindrical valve created from the patient's own pericardium in the tricuspid orifice. There were only men aged 43 to 73 years. Isolated tricuspid valve reimplantation with a pericardial cylinder was performed in 2 patients. Five (71%) patients needed additional procedures. The postoperative follow-up ranged from 2 to 32 months (median: 17 months). Results: In patients who underwent isolated tissue cylinder implantation, the average extracorporeal circulation (ECC) time was 77.5 minutes and aortic cross-clamp time was 58 minutes. In cases where additional procedures were performed the ECC and X-clamp times were 197.4 and 156.2 minutes, respectively. The function of the implanted valve was examined after weaning from the ECC by transesophageal echocardiogram, followed by transthoracic echocardiogram on day 5-7 after surgery revealed normal function of the prosthesis in all patients. There was no operative mortality. Two late deaths were observed. Conclusions: In the follow-up period none of the patients had a recurrence of IE within the pericardial cylinder. Degeneration with subsequent stenosis of the pericardial cylinder occurred in 3 patients. One patient was reoperated on; one had a transcatheter valve-in-valve cylinder implantation.

Myocardium of type 2 diabetic and obese patients is characterized by alterations in sphingolipid metabolic enzymes but not by accumulation of ceramide.

Data from animal experiments strongly suggest that ceramide is an important mediator of lipotoxicity in the heart and that accumulation of ceramide contributes to cardiomyocyte apoptosis associated with type 2 diabetes and obesity. However, it remains unknown whether a similar relationship is present also in the human heart. Therefore, we aimed to examine whether myocardial apoptosis in obese and type 2 diabetic patients is associated with elevated ceramide level. The study included 11 lean and 26 overweight or moderately obese subjects without (n = 11, OWT) or with (n = 15, T2D-OWT) a history of type 2 diabetes. Samples of the right atrial appendage were obtained from patients at the time of coronary bypass surgery. Compared with lean subjects, the extent of DNA fragmentation (a marker of apoptosis) was significantly higher in the myocardium of OWT patients and increased further in T2D-OWT subjects. However, the content of ceramide and sphingoid bases remained stable. Interestingly, the mRNA level of enzymes involved in synthesis and degradation of ceramide including serine palmitoyltransferase, sphingosine kinase 1, neutral sphingomyelinase, and ceramidases was markedly higher in the myocardium of OWT and T2D-OWT patients compared with lean subjects. Our results indicate that in the human heart, or at least in the atrium, ceramide is not a major factor in cardiomyocyte apoptosis associated with obesity and type 2 diabetes.

Circulating miR-30a-5p as a prognostic biomarker of left ventricular dysfunction after acute myocardial infarction.

Left ventricular (LV) dysfunction after acute myocardial infarction (AMI) is associated with an increased risk of heart failure (HF) development. Diverse microRNAs (miRNAs) have been shown to appear in the bloodstream following various cardiovascular events. The aim of this study was to identify prognostic miRNAs associated with LV dysfunction following AMI. Patients were divided into subgroups comprising patients who developed or not LV dysfunction within six months of the infarction. miRNA profiles were determined in plasma and serum samples of the patients on the first day of AMI. Levels of 14 plasma miRNAs and 16 serum miRNAs were significantly different in samples from AMI patients who later developed LV dysfunction compared to those who did not. Two miRNAs were up-regulated in both types of material. Validation in an independent group of patients, using droplet digital PCR (ddPCR) confirmed that miR-30a-5p was significantly elevated on admission in those patients who developed LV dysfunction and HF symptoms six months after AMI. A bioinformatics analysis indicated that miR-30a-5p may regulate genes involved in cardiovascular pathogenesis. This study demonstrates, for the first time, a prognostic value of circulating miR-30a-5p and its association with LV dysfunction and symptoms of HF after AMI.

The influence of very small doses of alpha radiation on the stability of erythrocytes.

Our aim was to study the influence of low doses (0.2-4 µGy) of α radiation on the stability of human erythrocytes isolated from healthy and diabetic erythrocytes. Absorption spectroscopy was used to measure the level of red blood cell (RBC) hemolysis, along with Mössbauer spectroscopy, which is a highly specific method suited to monitoring various hemoglobin forms. States of hemoglobin are sensitive to a homeostatic imbalance in red blood cells. Changes in the membrane skeleton organization of irradiated erythrocytes isolated from healthy donors were studied using atomic force microscopy (AFM). Hemolysis, in healthy red blood cells, showed characteristic discontinuities, depending on the α particle flux and the exposure time to the low doses applied. This phenomenon was not observed in severe diabetic cases, which could be a result of modified protein-lipid-sugar complexes and the attenuation/absence of some antioxidative enzymatic processes in their RBC membranes. Similar effects were also observed for red blood cells treated with low doses of neutron and γ-radiation. AFM measurements demonstrated a reorganization of the RBC membrane skeleton network depending on the time of RBC exposure to α radiation. This suggests that the changes in the activity of the acute defense processes against free radicals which are activated within the erythrocyte membrane irradiated with α-particles could additionally be up- or down regulated by modifications to the membrane-skeleton network. However, even the highest dose of α radiation applied in these studies did not cause any significant changes in the ability of hemoglobin to transport oxygen. Microsc. Res. Tech. 80:131-143, 2017. © 2016 Wiley Periodicals, Inc.

miR-22-5p revealed as a potential biomarker involved in the acute phase of myocardial infarction via profiling of circulating microRNAs.

Acute myocardial infarction (AMI) is a life-threatening episode of coronary artery disease. Recently, circulating myocardial-derived microRNAs (miRNAs) have been reported as potential biomarkers of infarction. The present study aimed to identify differentially expressed miRNAs in patients with ST-segment elevation myocardial infarction that could be potentially dysregulated in response to early myocardial damage. miRNA expression profile analysis was performed using the Serum/Plasma Focus miRNA Polymerase Chain Reaction (PCR) panel of Exiqon A/S (Vedbaek, Denmark) on plasma samples of patients on the first day of AMI (admission) and on samples from the identical patients collected six months following AMI. Selected miRNAs were validated by reverse transcription­quantitative PCR (RT­qPCR) using independent patients with AMI and a control group of patients with a stable coronary artery disease. Thirty­two species of plasma miRNA were differentially expressed (P<0.05) on admission compared with six months following AMI. Subsequent validation in an independent patient group confirmed that miR­133b and miR­22­5p were significantly up­regulated in the serum of patients with AMI. The receiver operating characteristic (ROC) curve analysis demonstrated a diagnostic utility for miR-22-5p, which has not previously been reported to be associated with AMI. Among the selected miRNAs, miR­22­5p represents a novel promising biomarker for the diagnosis of AMI.

Single-centre experience in surgery of acute aortic type A dissection and true aortic arch aneurysm.

BACKGROUND: Surgery of the aortic arch is challenging. AIM: To assess the results of aortic arch surgery. METHODS: Analysis of 172 patients operated on arch dissection (emergency group: 97 patients) or aneurysm (elective group: 75 patients) between 2007 and 2014. Arch surgery was defined as a procedure requiring circumferential anastomosis at the level of the aortic arch or the descending aorta with the use of techniques of brain protection (deep hypothermic circulatory arrest [DHCA] or selective antegrade cerebral perfusion [SACP]) and/or debranching of at least one supra-aortic vessel. RESULTS: Men predominated in both groups (> 70%). Men were younger in the emergency group (55 vs. 66 years; p < 0.008). The operative risk was higher in the emergency group (19.2% vs. 12.5%; p < 0.001). Forty-nine per cent of the patients from the emergency group and 5% from the elective group were operated with antiplatelet therapy (p < 0.001). Extended hemiarch procedure was performed in 79% (n = 77) in the emergency and 76% (n = 57) in the elective group. Total arch replacement was performed in 19 (21%) patients from the emergency and 18 (24%) patients from the elective group. In these patients debranching was performed in 68% of the emergency patients group and in 67% of the elective group. Elephant trunk procedure (classic/frozen) was performed in 53% (n = 10) from the emergency and in 78% (n = 14) of patients from the elective group. Aortic valve sparing surgery was performed in 20% of patients from the emergency and 9% from the elective group (p = 0.063). DHCA was performed in 58% (n = 43) of patients from the elective group and 39% (n = 37) from the emergency group. SACP was performed in 61% (n = 58) of patients from the emergency and 42% (n = 31) from the elective group. Thirty-day mortality in the emergency group reached 33% (n = 32), and in the elective group 15% (n = 11; p = 0.007). In multivariate analysis, predictors of death in the emergency group were: Logistic EuroSCORE above 19.5%, extracorporeal circulation time above 228 min, and postoperative acute renal failure (ARF); and in the elective group: DHCA time above 26 min, rethoracotomy due to bleeding, and ARF. Follow-up was completed in 100% of patients in terms of vital status. The mean follow-up time of the patients from the emergency group was 24.3 ± 27.10 (min 0, max 92) months, and from the elective group 30.3 ± 24.5 (min 0, max 99) months. During the follow-up period all-cause mortality in the emergency group was 43% (n = 42/97), and in the elective group it was 36% (n = 27/75). CONCLUSIONS: Early mortality in the emergency group was higher, while long-term mortality did not differ among the groups. Postoperative ARF is a critical predictor of mortality in both groups.

Gene expression profiling reveals potential prognostic biomarkers associated with the progression of heart failure.

BACKGROUND: Heart failure (HF) is the most common cause of morbidity and mortality in developed countries. Here, we identify biologically relevant transcripts that are significantly altered in the early phase of myocardial infarction and are associated with the development of post-myocardial infarction HF. METHODS: We collected peripheral blood samples from patients with ST-segment elevation myocardial infarction (STEMI): n = 111 and n = 41 patients from the study and validation groups, respectively. Control groups comprised patients with a stable coronary artery disease and without a history of myocardial infarction. Based on plasma NT-proBNP level and left ventricular ejection fraction parameters the STEMI patients were divided into HF and non-HF groups. Microarrays were used to analyze mRNA levels in peripheral blood mononuclear cells (PBMCs) isolated from the study group at four time points and control group. Microarray results were validated by RT-qPCR using whole blood RNA from the validation group. RESULTS: Samples from the first three time points (admission, discharge, and 1 month after AMI) were compared with the samples from the same patients collected 6 months after AMI (stable phase) and with the control group. The greatest differences in transcriptional profiles were observed on admission and they gradually stabilized during the follow-up. We have also identified a set of genes the expression of which on the first day of STEMI differed significantly between patients who developed HF after 6 months of observation and those who did not. RNASE1, FMN1, and JDP2 were selected for further analysis and their early up-regulation was confirmed in HF patients from both the study and validation groups. Significant correlations were found between expression levels of these biomarkers and clinical parameters. The receiver operating characteristic (ROC) curves indicated a good prognostic value of the genes chosen. CONCLUSIONS: This study demonstrates an altered gene expression profile in PBMCs during acute myocardial infarction and through the follow-up. The identified gene expression changes at the early phase of STEMI that differentiated the patients who developed HF from those who did not could serve as a convenient tool contributing to the prognosis of heart failure.

[Early and mid-term evaluation of the pulmonary autograft function in adolescents and adults]. / Ocena wczesna i srednioodlegla funkcji autograftu plucnego u mlodziezy i doroslych.

The aim of this study was to establish the indications to use of pulmonary autograft in the treatment of aortic valve disease in the adolescents and adults; early and mid-term an evaluation of autograft's function and function of left ventricle after Ross operation. In this procedure the patient's own pulmonary valve is removed together with the main trunk of the pulmonary artery and used to replace the aortic valve. Pulmonary homograft is used to reconstruction of right ventricular outflow tract. Between February 1994 and march 2001 in 1st Cardiac Surgery Department in 43 patients over 14 years of age Ross operation have performed. Mean age was 24.9 years. Indications for operation were predominant aortic stenosis in 29 patients, aortic incompetence in 7 patients, and complex aortic valve disease in 7 patients. Hospital mortality was 4.6%. In mid-term observation 41 patients left. All survivors remained in New York Heart Association functional class I and were free of complications and medications. In the all patients autograft's valve have functioned excellent (without or small regurgitation). Echocardiographic parameters of left ventricular function improved in the all patients. The indications to pulmonary autograft insertion in the adolescents and adults are small aortic ring, infective endocarditis and contraindications to anticoagulants using. The early and mid-term results confirm a high efficacy Ross operation in this age's group with low mortality. It completely relieves the abnormal loading conditions of the left ventricle, resulting in a complete recovery of left ventricular function.

Effects of low doses of gamma rays on the stability of normal and diabetic erythrocytes.

We studied the influence of low doses of γ radiation (from 0.04 to 1.8 mGy) on the stability of human red blood cells (RBC) from healthy donors and diabetic patients using absorption spectroscopy. Because of the alteration of many enzymatic pathways in diabetic RBCs resulting in strong modification of the lipid and protein membrane components one could expect that the ionizing γ-radiation should influence the stability of the healthy and diabetic cells in a different way. Indeed, distinct discontinuities and monotonic changes of hemolysis detected in the healthy and diabetic RBCs suggest that various enzymatic and chemical processes are activated in these membranes by γ radiation. Mössbauer measurements showed that only the highest applied dose of γ radiation caused modification of hemoglobin in both types of RBCs.