Levels of Cell-Free DNA in Kidney Failure Patients before and after Renal Transplantation

Circulating cell-free DNA (cfDNA) has diverse applications in oncological, prenatal, toxicological, cardiovascular, and autoimmune diseases, diagnostics, and organ transplantation. In particular, mitochondrial cfDNA (mt-cfDNA) is associated with inflammation and linked to early vascular ageing (EVA) in end-stage kidney failure (ESKF), which could be a noninvasive marker for graft rejection and organ damage. Plasma samples from 44 ESKF patients, of whom half (n = 22) underwent either conservative therapy (non-HD) or hemodialysis (HD) before kidney transplantation (KT). These samples were analyzed at baseline and two years after KT. cfDNA was extracted from plasma and quantified using the fluorometric method. qPCR was used to quantify and differentiate the fractions of mt-cfDNA and nuclear cfDNA (nc-cfDNA). mt-cfDNA levels in KT patients decreased significantly from baseline to two years post-KT (p < 0.0268), while levels of total cfDNA and nc-cfDNA did not differ. Depending on therapy modality (HD vs. non-HD) before KT, total cfDNA levels were higher in HD patients at both baseline (p = 0.0133) and two years post-KT (p = 0.0421), while nc-cfDNA levels were higher in HD only at baseline (p = 0.0079). Males showed a nonsignificant trend of higher cfDNA levels. Patients with assessed vascular fibrosis (p = 0.0068), either alone or in combination with calcification plus fibrosis, showed reduced mt-cfDNA post-KT (p = 0.0195). Changes in mt-cfDNA levels suggests the impact of KT on the inflammatory state of ESKF, as evidenced via its correlation with high sensitivity C-reactive protein after KT. Further studies are warranted to assess if cfDNA could serve as a noninvasive method for monitoring the response to organ transplantation and even for amelioration of EVA status per se.

Alterations in Oxidative Stress Markers and Na,K-ATPase Enzyme Properties in Kidney after Fructose Intake and Quercetin Intervention in Rats

The study aimed to characterize the consequences of a 15-week intake of 10% fructose on the kidney, with the focus on oxidative stress markers and properties of the Na,K-ATPase enzyme. Various antioxidants naturally occurring in common food were demonstrated to be protective against fructose-induced deterioration of kidneys. Therefore, we also aimed to observe the effect of 6-week quercetin administration (20 mg/kg/day) that was initiated following the 9-week period of higher fructose intake, by determining the concentration of sodium, potassium, creatinine, urea, and glucose in blood plasma and oxidative status directly in the renal tissue. Kinetic studies of renal Na,K-ATPase were utilized for a deeper insight into the molecular principles of expected changes in this enzyme activity under conditions of presumed fructose-induced renal injury. Fructose intake led to increase in body weight gain, plasma glucose and sodium levels, and deterioration of kidney properties, although some compensatory mechanisms were observable. Quercetin administration improved glycemic control in rats exposed to fructose overload. However, an increase in plasma creatinine, a decrease in GSH/GSSG ratio in renal tissue homogenate, and a controversial effect on renal Na,K-ATPase enzyme suggest that quercetin treatment may not be beneficial in the condition of pre-existing renal pathology.

Plasmatic apelin shows a promising potential as a screening biomarker for atrial fibrillation

OBJECTIVES

Purpose of this study was to evaluate properties of apelin, a peptide detectable in peripheral blood, for atrial fibrillation (AF) detection in a diverse population of patients covering a broad spectrum from healthy to polymorbid patients.

BACKGROUND

AF is the most common cardiac arrhythmia with constantly increasing incidence and prevalence. Currently available diagnostic tools do not provide sufficient detection rate. Large proportion of patients with AF remains undiagnosed and the possibility of screening at-risk groups would be significantly beneficial.

METHODS

We designed this study as a multi-centre retrospective study. Study population included 183 patients. 64 in non-AF and 119 in AF group.

RESULTS

Apelin plasma concentration was significantly lower in AF group compared to non-AF group (p < 0.001). Receiver operating characteristic analysis of apelin as a predictor of AF scored area under the curve of 0.79, sensitivity = 0.941 and specificity = 0.578. Multivariate analysis using logistic regression adjusted for age, BMI, apelin, dilated LV, dilated LA, arterial hypertension, and gender showed only apelin and age to be statistically significant contributors for AF.

CONCLUSION

Apelin might be a promising biomarker for detecting AF in our study population. These results suggest promising potential of apelin as a screening biomarker for AF (Tab. 2, Fig. 1, Ref. 46). Text in PDF www.elis.sk Keywords: biomarker, apelin, arrhythmia, atrial fibrillation.

Effects of Taxifolin in Spontaneously Hypertensive Rats with a Focus on Erythrocyte Quality

Oxidative stress and multiple erythrocyte abnormalities have been observed in hypertension. We focused on the effects of angiotensin-converting enzyme 2 (ACE2) inhibition by MLN-4760 inhibitor on angiotensin peptides, oxidative stress parameters, and selected erythrocyte quality markers in spontaneously hypertensive rats (SHR). We also investigated the potential effects of polyphenolic antioxidant taxifolin when applied in vivo and in vitro following its incubation with erythrocytes. SHRs were divided into four groups: control, taxifolin-treated, MLN-4760-treated, and MLN-4760 with taxifolin. MLN-4760 administration increased the blood pressure rise independent of taxifolin treatment, whereas taxifolin decreased it in control SHRs. Body weight gain was also higher in ACE2-inhibited animals and normalized after taxifolin treatment. However, taxifolin did not induce any change in angiotensin peptide concentrations nor a clear antioxidant effect. We documented an increase in Na,K-ATPase enzyme activity in erythrocyte membranes of ACE2-inhibited SHRs after taxifolin treatment. In conclusion, ACE2 inhibition deteriorated some selected RBC properties in SHRs. Although taxifolin treatment did not improve oxidative stress markers, our data confirmed the blood pressure-lowering potential, anti-obesogenic effect, and some "erythroprotective" effects of this compound in both control and ACE2-inhibited SHRs. In vitro investigations documenting different effects of taxifolin on erythrocyte properties from control and ACE2-inhibited SHRs accentuated the irreplaceability of in vivo studies.

Na,K-ATPase Kinetics and Oxidative Stress in Kidneys of Zucker Diabetic Fatty (fa/fa) Rats Depending on the Diabetes Severity-Comparison with Lean (fa/+) and Wistar Rats

For a better insight into relations between type 2 diabetes mellitus (T2DM) and Na,K-ATPase properties in kidneys, we aimed to characterize two subgroups of ZDF obese (fa/fa) rats, with more and less developed T2DM, and compare them with two controls: lean (fa/+) and Wistar. Na,K-ATPase enzyme kinetics were estimated by measuring the ATP hydrolysis in the range of NaCl and ATP levels. As Na,K-ATPase is sensitive to oxidative stress, we evaluated selected oxidative stress parameters in kidney homogenates. Our results suggest that thiol-disulfide redox balance in the renal medulla and Na,K-ATPase properties in the renal cortex differ between both controls, while observed measurements in lean (fa/+) rats showed deviation towards the values observed in ZDF (fa/fa) rats. In comparison with both controls, Na,K-ATPase enzyme activity was higher in the renal cortex of ZDF rats independent of diabetes severity. This might be a consequence of increased glucose load in tubular fluid. The increase in lipid peroxidation observed in the renal cortex of ZDF rats was not associated with Na,K-ATPase activity impairment. Regarding the differences between subgroups of ZDF animals, well-developed T2DM (glycemia higher than 10 mmol/L) was associated with a higher ability of Na,K-ATPase to utilize the ATP energy substrate.

ZDF fa/fa rats show increasing heterogeneity in main parameters during ageing as confirmed by biometrics, oxidative stress markers and MMP activity

NEW FINDINGS

What is the central question of this study? To characterize ZDF fa/fa rats and two controls (Wistar and lean ZDF fa/+) during ageing. What is the main finding and its importance? ZDF fa/fa rats with lower glycaemia have a greater body and left ventricular weight, and lower plasma gelatinase activity compared with hyperglycaemic rats. As diabetes represents a heterogeneous metabolic disorder, the inhomogeneity of ZDF fa/fa rats may be beneficial in the study of its different aspects. Our experiments may promote a discussion regarding the suitable normoglycemic control for aged ZDF fa/fa rats, especially in experiments focused on myocardial tissue.

ABSTRACT

Zucker diabetic fatty rats (ZDF fa/fa) - an animal model for the study of type 2 diabetes (T2D), are considered as a uniform group in most experimental studies; however, there are indices regarding their growing inhomogeneity over time. The main objective of our study was to monitor particular biometric and biochemical parameters of ZDF fa/fa rats during development to T2D and compare them with two controls (Wistar and lean ZDF fa/+). According to fasting glycaemia, ZDF fa/fa were arbitrarily split into two phenotypes - obese ZDF (fa/fa)-FAT and diabetic ZDF (fa/fa)-DIA. Glycaemia was progressively rising only in ZDF (fa/fa)-DIA which also exhibited higher cholesterol levels compared with ZDF (fa/fa)-FAT. In addition, ZDF (fa/fa)-FAT revealed more pronounced left ventricular hypertrophy and greater body weight, differentiating them from ZDF (fa/fa)-DIA. Moreover, we investigated the activity of matrix metalloproteinases (MMPs), multifunctional enzymes involved in tissue remodelling. Rats in the ZDF (fa/fa)-FAT group revealed lower plasma MMP-2 and MMP-9 activity compared with ZDF (fa/fa)-DIA. However, increased myocardial MMP-2 activity indicated left ventricular remodelling in both ZDF phenotypes. As T2D in humans represents a heterogeneous metabolic disorder, the heterogeneity of ZDF fa/fa rats may be beneficial in the study of different aspects of this pathology. Moreover, Wistar rats could serve as a more appropriate control for aged ZDF fa/fa rats than commonly used fa/+ rats that showed an increase in left ventricular weight, carbonyl stress markers in the left myocardium and MMP-2 activity in both ventricles, indicating heart remodelling processes compared with the Wistar control group. This article is protected by copyright. All rights reserved.

Association Between Apelin and Atrial Fibrillation in Patients With High Risk of Ischemic Stroke

Background: Atrial fibrillation (AF) is associated with high risk of stroke preventable by timely initiation of anticoagulation. Currently available screening tools based on ECG are not optimal due to inconvenience and high costs. Aim of this study was to study the diagnostic value of apelin for AF in patients with high risk of stroke.

Methods: We designed a multicenter, matched-cohort study. The population consisted of three study groups: a healthy control group (34 patients) and two matched groups of 60 patients with high risk of stroke (AF and non-AF group). Apelin levels were examined from peripheral blood.

Results: Apelin was significantly lower in AF group compared to non-AF group (0.694 ± 0.148 vs. 0.975 ± 0.458 ng/ml, p = 0.001) and control group (0.982 ± 0.060 ng/ml, p < 0.001), respectively. Receiver operating characteristic (ROC) analysis of apelin as a predictor of AF scored area under the curve (AUC) of 0.658. Apelin's concentration of 0.969 [ng/ml] had sensitivity = 0.966 and specificity = 0.467. Logistic regression based on manual feature selection showed that only apelin and NT-proBNP were independent predictors of AF. Logistic regression based on selection from bivariate analysis showed that only apelin was an independent predictor of AF. A logistic regression model using repeated stratified K-Fold cross-validation strategy scored an AUC of 0.725 ± 0.131.

Conclusions: Our results suggest that apelin might be used to rule out AF in patients with high risk of stroke.

Testosterone, personality traits and aggressive driving among young male drivers

INTRODUCTION

Psychological testing to examine potentially aggressive behaviour is a gold standard, but it is not sufficient. Testosterone might increase an aggressive behaviour.

AIM

The aim of this study was to evaluate whether testosterone along with psychological assessment of fitness to drive could help to identify aggressive drivers.

METHODS

Male participants (n=150) aged from 20 to 25, who possessed a driving license and drive at least 100 km per week, were evaluated in this study using an Inventory of traffic-relevant personality characteristics, the Sensation Seeking Scale and the Buss-Durkee Aggression Inventory. Saliva was collected for testosterone and cortisol measurements. The five binomial logistic models with dependent variables Caused an accident, Driving license taken away, Court trial, Intoxicated driving and Sporty self-report were tested in this study.

RESULTS

The 'Intoxicated driving' model, was found to be statistically highly significant, explaining 48.8 % of the dependent variable's variance (χ2(16)=36.145, p<0.01). In this model with sensation seeking, actual testosterone and their interaction was highly significant and explained 20.4 % of intoxicated driving variability (χ2(3)=14.283, p<0.01). This was higher than sensation seeking scores only.

CONCLUSION

To conclude, salivary testosterone might prove a biological marker that improves the identification of those with a high probability of aggressive driving or its subtypes (Tab. 3, Ref. 53).

Beneficial Effect of Quercetin on Erythrocyte Properties in Type 2 Diabetic Rats

Diabetes mellitus is characterized by tissue oxidative damage and impaired microcirculation, as well as worsened erythrocyte properties. Measurements of erythrocyte deformability together with determination of nitric oxide (NO) production and osmotic resistance were used for the characterization of erythrocyte functionality in lean (control) and obese Zucker diabetic fatty (ZDF) rats of two age categories. Obese ZDF rats correspond to prediabetic (younger) and diabetic (older) animals. As antioxidants were suggested to protect erythrocytes, we also investigated the potential effect of quercetin (20 mg/kg/day for 6 weeks). Erythrocyte deformability was determined by the filtration method and NO production using DAF-2DA fluorescence. For erythrocyte osmotic resistance, we used hemolytic assay. Erythrocyte deformability and NO production deteriorated during aging-both were lower in older ZDF rats than in younger ones. Three-way ANOVA indicates improved erythrocyte deformability after quercetin treatment in older obese ZDF rats only, as it was not modified or deteriorated in both (lean and obese) younger and older lean animals. NO production by erythrocytes increased post treatment in all experimental groups. Our study indicates the potential benefit of quercetin treatment on erythrocyte properties in condition of diabetes mellitus. In addition, our results suggest potential age-dependency of quercetin effects in diabetes that deserve additional research.

Advanced glycation end products predict long-term outcome of catheter ablation in paroxysmal atrial fibrillation

PURPOSE

Oxidative stress is an important contributor to the etiology of atrial fibrillation (AF). Our aim was to study oxidative stress biomarkers in patients undergoing pulmonary vein isolation (PVI) for paroxysmal AF with radiofrequency catheter ablation and to assess its prognostic value in predicting long-term PVI outcome.

METHODS

In this prospective cohort study, we included 62 patients (mean age 55±8 years, 12 females and 50 males) with paroxysmal AF and implanted ECG loop recorders who underwent PVI. Plasmatic concentrations of advanced glycation end-products (AGEs), fructosamine, advanced oxidation protein products, and thiobarbituric-acid reacting substances were measured before PVI. AF burden (percentage of time spent in AF) was continually assessed during the follow-up period (1063±271 days).

RESULTS

Nineteen patients (31%) were defined as optimal responders (oR) with AF burden < 0.5% after PVI. Remaining 43 patients (69%) were defined as sub-optimal responders. Concentration of AGEs was significantly lower in oR by 3.7 g/g (CI: -6.5 to -1.7; P=0.0003). After adjustment for age, sex, BMI, left atrial size, arterial hypertension, and AF burden before PVI, only low concentration of AGEs remained significantly associated with oR (odds ratio: 1.3; P=0.04). AGEs concentration achieved area under the curve of 0.78 for predicting optimal long-term PVI response.

CONCLUSIONS

AGEs concentration before PVI was associated with long-term PVI outcome in patients with paroxysmal AF. Further research will show if this biomarker could contribute to optimal patient selection for catheter ablation.

Concentration of apelin inversely correlates with atrial fibrillation burden

AIM

Asymptomatic atrial fibrillation (AF) detection and pulmonary veins isolation (PVI) outcome prediction remain challenging. Our aim was to study the association between apelin and paroxysmal AF in patients undergoing radiofrequency catheter PVI.

METHODS

Sixty-three consecutive patients (55 ± 8years, 12 females) with paroxysmal AF without a structural heart disease and implanted ECG loop recorders undergoing PVI and healthy control group of 34 persons (41 ± 9.5years, 21 females) were included. Apelin plasmatic concentrations were measured before and three months after PVI. AF burden was continually assessed for three years.

RESULTS

Apelin was significantly decreased in AF patients compared to the healthy controls (0.79 ± 0.09 vs 0.98 ± 0.06 ng/ml; p < 0.00001). Apelin plasmatic concentration of 0.89 ng/ml had 94 % specificity and 89 % sensitivity for AF prediction with the area under the curve (AUC) of 0.96. After propensity matching to sex, age and comorbidities, apelin concentration was significantly lower in AF group (0.78 ± 0.1 vs 0.99 ±0.06  ng/ml; p < 0.0001; AUC: 0.97). There was a significant inverse correlation between apelin concentration and AF burden both before and after PVI (Rho = ‒0.22; p = 0.05) and (Rho = ‒0.51; p = 0.006), respectively. There was no significant association between pre-PVI apelin and PVI long-term outcome.

CONCLUSION

In patients without a structural heart disease apelin showed a significant specificity and sensitivity for AF prediction and inversely correlated with AF burden (Tab. 3, Fig. 3, Ref. 34).

Nuclear and Mitochondrial Circulating Cell-Free DNA Is Increased in Patients With Inflammatory Bowel Disease in Clinical Remission

Background: The role of cell-free DNA (cfDNA) in the pathogenesis of inflammatory bowel disease (IBD) has been recently suggested. The aim of this study was to analyze circulating cfDNA and deoxyribonuclease (DNase) activity in IBD patients in clinical remission.

Materials and Methods: Plasma and serum were obtained from 72 patients with Crohn's disease and 28 patients with ulcerative colitis. Total cfDNA, nuclear DNA (ncDNA), mitochondrial DNA (mtDNA) and DNase activity were measured.

Results: IBD patients showed higher levels of both ncDNA and mtDNA compared to healthy controls. Concentration of ncDNA was higher in males compared to females, including patients and healthy controls. However, unlike males higher amount of ncDNA was found in female IBD patients compared to healthy controls. DNase activity was significantly lower in male IBD patients compared with healthy controls. In addition, there was a negative correlation between DNase activity and ncDNA levels in male IBD patients.

Conclusions: Herein we present increased amount of circulating ncDNA and mtDNA in IBD patients in clinical remission. Thus, unlike total cfDNA, circulating ncDNA and mtDNA might not represent the optimal biomarkers of disease activity. This is also the first report on sex difference in circulating ncDNA levels, possibly associated with lower DNase activity in males.

Age- and Phenotype-Dependent Changes in Circulating MMP-2 and MMP-9 Activities in Normotensive and Hypertensive Rats

Matrix metalloproteinases (MMPs) are important in the pathogenesis of numerous diseases. The present study aimed to monitor the activation of MMP-2 and MMP-9 in spontaneously hypertensive rats (SHR) and their normotensive counterparts-Wistar-Kyoto rats (WKY). The animals were divided according to age (7, 20, and 52 weeks) and phenotype into: WKY-7, WKY-20, WKY-52, SHR-7, SHR-20 and SHR-52 groups. MMP plasma activities were determined by gelatine zymography. We monitored selected parameters of oxidative stress and antioxidant status. N-terminal pro-brain natriuretic peptide (NT-proBNP) was determined as a marker of heart function and neurohumoral activation. SHR-7 showed higher MMP-2 activity compared with WKY-7, while SHR-52 showed lower MMP-2 and MMP-9 activities compared with WKY-52. Examining age-dependent changes in MMP activities, we found a decrease in MMP-2 activity and increase in MMP-9 activity with increasing age in both phenotypes. Parameters of oxidative stress and antioxidant status as well as NT-proBNP levels were not significantly worsened due to aging in SHR. Our results suggest that hypertension is accompanied by varying MMP activation during aging. The results of our study may indicate that MMP-2 inhibition is therapeutically applicable during the development of hypertension, while in developed, stabilized and uncomplicated hypertension, systemic MMP-2 and MMP-9 inhibition may not be desirable.

Association of apelin and AF in patients with implanted loop recorders undergoing catheter ablation

BACKGROUND

Previous studies showed an association between apelin and atrial fibrillation (AF). The aim of this study was to analyse the effect of pulmonary vein isolation (PVI) in patients with paroxysmal AF on plasmatic apelin concentrations.

METHODS

Nine consecutive patients (aged from 43 to 69 years, 3 females and 6 males) with documented paroxysmal atrial fibrillation and implanted loop recorders (ILR) for continuous ECG monitoring were included in this study. All the patients underwent a radiofrequency catheter ablation with PVI.

RESULTS

The plasmatic concentration of apelin increased after PVI. The average plasmatic concentration of apelin before PVI was 0.299 ng/ml (±0.16), 3 months after PVI 0.462 ng/ml (±0.10) and 9 months after PVI 0.565 ng/ml (±0.146). There was an increase in the concentration of apelin 3 months and 9 months after the PVI by 0.163 ng/ml (p=0.07) and by 0.266 ng/ml (p=0.01), respectively. The concentration of apelin inversely correlated with the AF burden (r=-0.44, p=0.03).

CONCLUSIONS

Our study showed a significant increase in apelin levels after the reduction of AF burden via PVI and an inverse correlation with AF burden. Apelin might be a promising marker of AF (Tab. 2, Fig. 2, Ref. 28).

Localization dependent sensitivity of cerebral Na,K-ATPase to irradiation induced oxidative imbalance in rats

Na,K-ATPase represents the key enzyme maintaining the ionic gradient across plasma membrane. It was documented that in directly irradiated organs the activity of this enzyme is decreased. The aim of present study was to clarify the remote effect of irradiation in mediastinal area on the activity of the Na,K-ATPase in selected brain regions in rats. Ionizing radiation in single dose 25 Gy induced alterations in oxidative status of blood plasma. Irradiation also decreased the activity of the Na,K-ATPase in cerebral cortex. Measurements of kinetic properties of the enzyme dependently on the concentration of energy substrate ATP or cofactor Na⁺ indicated that the lowered enzyme activity is probably a consequence of decreased number of active molecules of the enzyme, as suggested by lowered V_max values (by 13 - 14%). Immunoblot analysis revealed that this effect is connected namely to decreased presence of α2 and α3 subunits (by 25% and 30% respectively). Considering the current concepts about involvement of the malfunction of α2 α3 subunits in development of primary brain dysfunctions, it may be hypothesized that the lowered functionality of those subunits of Na,K-ATPase may represent a predisposition to neurodegenerative disorders after irradiation. The observed effect seems to be localization dependent as the enzyme in cerebellum resisted to irradiation.

Promotion of whole blood rheology after vitamin C supplementation: focus on red blood cells 1

Hemorheological properties represent significant contributors in the pathogenesis of cardiovascular diseases. As plasma vitamin C is inversely associated with blood viscosity in humans, we aimed to characterize the effect of vitamin C supplementation on hemorheology with an emphasis on erythrocyte functions. Twenty young healthy volunteers were asked to take vitamin C (1000 mg per day) for 3 weeks. We observed beneficial effect of intervention on multiple hemorheological parameters: whole blood viscosity in the range of medium to high shear rates, Casson yield stress, complex viscosity, and storage and loss moduli. As erythrocyte properties play a significant role in hemorheology, we characterized their deformability, nitric oxide production, and sodium pump activity in erythrocyte membranes. We can conclude that observed promotion in whole blood rheology may be consequence of improved erythrocyte functionality as concerns their ability to pass through narrow capillaries of the microcirculation, nitric oxide production, and sodium pump activity. Parameters reflecting oxidative stress and antioxidant status in plasma were not affected by our intervention. As improvement in hemorheology may play an important role in cardioprotection, it would be challenging to investigate the vitamin C supplementation to patients suffering from microcirculatory disturbances and worsened organ perfusion in the case of cardiovascular diseases.

Lactacystin-Induced Model of Hypertension in Rats: Effects of Melatonin and Captopril

Lactacystin is a proteasome inhibitor that interferes with several factors involved in heart remodelling. The aim of this study was to investigate whether the chronic administration of lactacystin induces hypertension and heart remodelling and whether these changes can be modified by captopril or melatonin. In addition, the lactacystin-model was compared with N^G-nitro-l-arginine-methyl ester (L-NAME)- and continuous light-induced hypertension. Six groups of three-month-old male Wistar rats (11 per group) were treated for six weeks as follows: control (vehicle), L-NAME (40 mg/kg/day), continuous light (24 h/day), lactacystin (5 mg/kg/day) alone, and lactacystin with captopril (100 mg/kg/day), or melatonin (10 mg/kg/day). Lactacystin treatment increased systolic blood pressure (SBP) and induced fibrosis of the left ventricle (LV), as observed in L-NAME-hypertension and continuous light-hypertension. LV weight and the cross-sectional area of the aorta were increased only in L-NAME-induced hypertension. The level of oxidative load was preserved or reduced in all three models of hypertension. Nitric oxide synthase (NOS) activity in the LV and kidney was unchanged in the lactacystin group. Nuclear factor-kappa B (NF-κB) protein expression in the LV was increased in all treated groups in the cytoplasm, however, in neither group in the nucleus. Although melatonin had no effect on SBP, only this indolamine (but not captopril) reduced the concentration of insoluble and total collagen in the LV and stimulated the NO-pathway in the lactacystin group. We conclude that chronic administration of lactacystin represents a novel model of hypertension with collagenous rebuilding of the LV, convenient for testing antihypertensive drugs or agents exerting a cardiovascular benefit beyond blood pressure reduction.

The relation between oxidative stress biomarkers and atrial fibrillation after pulmonary veins isolation

INTRODUCTION

The current paradigm claims a link between oxidative stress and atrial fibrillation. The aim of our research was to study a relation between the percentage of time spent in atrial fibrillation (AF burden) and concentrations of oxidative stress biomarkers, before and after pulmonary veins isolation (PVI).

METHODOLOGY

We included 19 patients (mean age 55±10years, 4 females and 15 males) with implanted loop recorders undergoing PVI. Plasmatic concentrations of advanced glycation end-products (AGEs), fructosamine, advanced oxidation protein products and thiobarbituric-acid reacting substances (TBARS) were measured and AF burden was recorded immediately before and 3months after the PVI. AF burden was also recorded 9months after the PVI.

RESULTS

Post procedural AGEs concentration significantly negatively correlated with AF burden after 3months (ρ=-0.63; p<0.01) and 9months (ρ=-0.5; p=0.04), respectively as well as TBARS concentration significantly negatively correlated with AF burden after 9months (ρ=-0.61; p=0.01).

CONCLUSION

Our study showed AGEs and TBARS to be potential predictors for AF burden after the PVI. We suppose that the more oxidative stress after the PVI is provoked, the more fibrotic tissue is produced. That means a better electrical isolation of pulmonary veins and consequently a lower AF burden.

Umbilical cord blood markers of oxidative stress in pregnancies complicated by preterm prelabor rupture of membranes

OBJECTIVE

To determine umbilical cord blood total antioxidant capacity (TAC), ferric reducing antioxidant power (FRAP), thiobarbituric acid-reacting substances (TBARS), advanced glycation end products (AGEs) and markers of oxidative stress in pregnancies complicated by preterm prelabor rupture of membranes (PPROM) and their associations with microbial invasion of the amniotic cavity (MIAC) and/or histological chorioamnionitis (HCA), funisitis and selected aspects of short-term neonatal morbidity.

MATERIALS AND METHODS

One hundred and sixty-five women with singleton pregnancies complicated by PPROM were included in this study. Blood samples were obtained by venipuncture from the umbilical cord vein after the delivery of the newborn. The umbilical cord blood concentrations of TAC, FRAP, TBARS and AGEs were measured.

RESULTS

The presence of MIAC, HCA and funisitis did not show differences in the umbilical cord blood TAC, FRAP, TBARS and AGEs concentrations. Positive correlations were found between the gestational age at sampling and umbilical cord blood TAC and AGEs concentrations (TAC: rho = 0.26; p = 0.001; AGEs: rho = 0.35; p < 0.0001). There was no association between umbilical cord blood TAC, FRAP, TBARS and AGEs concentrations and selected aspects of short-term neonatal morbidity.

CONCLUSIONS

Oxidative stress is associated with PPROM, as indicated by the presence of markers tested in the umbilical cord blood; however, the evaluated oxidative stress markers are not influenced by the presence of MIAC and/or HCA, and funisitis or subsequent development of selected aspects of short-term neonatal morbidity.

Effects of testosterone and estradiol on anxiety and depressive-like behavior via a non-genomic pathway

Besides their known slow genomic effects, testosterone and estradiol have rapid effects in the brain. However, their impact on mood-related behavior is not clear. The aim of this study was to investigate the non-genomic pathway of testosterone and estradiol in the amygdala in relation to anxiety and depressive-like behavior. Sham-operated and gonadectomized male rats (GDX) supplemented with testosterone propionate, estradiol, or olive oil were used. Five minutes after administration, anxiety and depression-like behavior were tested. Estradiol increased anxiolytic behavior in the open-field test compared to the GDX group, but administration of testosterone had no significant effect. Besides, c-Fos expression in the medial nucleus of the amygdala significantly increased after testosterone treatment compared to the GDX group, while no significant difference was observed in the central and the basolateral nuclei of the amygdala in the testosterone-treated group compared to the GDX group. In conclusion, estradiol had an anxiolytic effect via a rapid pathway, but no rapid effect of testosterone on anxiety was found. Further studies elucidating whether the rapid effect is mediated by a non-genomic pathway are needed.

Relationship between circulating tumor cells, blood coagulation, and urokinase-plasminogen-activator system in early breast cancer patients

Cancer is a risk factor for venous thromboembolism (VTE) and plasma d-dimer (DD) and tissue factor (TF) are established VTE associated markers. Circulating tumor cells (CTCs) are associated with the risk of VTE in metastatic breast cancer. This study aimed to correlate CTCs, blood coagulation and the urokinase plasminogen activator (uPA) system in primary breast cancer (PBC) patients. This prospective study included 116 PBC patients treated by primary surgery. CTCs were detected by quantitative RT-PCR assay for expression of epithelial (CK19) or epithelial-mesenchymal transition (EMT) genes (TWIST1, SNAIL1, SLUG, ZEB1, FOXC2). Plasma DD, TF, uPA system proteins were detected by enzyme-linked immunosorbent assays, while expressions of uPA system in surgical specimens were evaluated by immunohistochemistry. CTCs were detected in 27.6% patients. Patients with CTCs had a significantly higher mean plasma DD (ng/mL) than those of patients without CTCs (632.4 versus 365.4, p = 0.000004). There was no association between plasma TF and CTCs. Epithelial CTCs exhibit higher expression of uPA system genes compared to EMT_CTCs. Patients with CTCs had higher plasma uPA proteins than those of patients without CTCs; there was no correlation between tissue expression of uPA system, CTCs, DD or TF levels. In multivariate analysis CTCs and patients age were independent factors associated with plasma DD. We found association between plasma DD and CTCs indicating a potential role for activation of the coagulation cascade in the early metastatic process. CTCs could be directly involved in coagulation activation or increased CTCs could be marker of aggressive disease and increased VTE risk.

Abstract P1-04-02: Correlation between blood markers of hemostasis and circulating tumor cells (CTCs) in early breast cancer patients

Background: Cancer is a risk factor for venous thromboembolism (VTE) and plasma D-dimer (DD) and tissue factor (TF) are established blood markers associated with VTE. CTCs are an independent predictor of survival in early and metastatic breast cancer (BC) patients (pts) and CTCs are associated with the risk of VTE in metastatic BC pts. In this study, we hypothesized correlation between plasma DD and TF with presence of CTCs. Moreover, we hypothesized, that activation of urokinase plasminogen activator system (uPA) could be involved in CTCs released into peripheral blood (PB) as well as coagulation activation.

Methods: This prospective study included 119 early BC patients treated by primary surgery followed by systemic therapies when indicated, at the NCI in Slovakia from March to December 2012. Isolated peripheral blood mononuclear cells (PBMC) were depleted of hematopoietic cells (CD45+) using RossetteSepTM negative selection kit. RNA extracted from CD45-depleted PBMC was interrogated for expression of EMT-inducing transcription factors (TWIST1, SNAIL1, SLUG, ZEB1) and epithelial (CK19) gene transcripts by qRT-PCR. Expressions of gene transcripts in CD45- PBMC of pts and healthy donors (HD) were compared. Patient samples with higher epithelial and/or mesenchymal gene transcripts than those of HD (n = 60) were considered as CTC positive. Plasma DD, TF, uPA (urokinase-type plasminogen activator) and PAI-1 (plasminogen activator inhibitor) levels were detected by ELISA, while expressions of TF and uPA system in surgical specimens were evaluated by immunohistochemistry.

Results: CTCs were detected in 27.7% pts. The majority of CTCs exhibited either epithelial differentiation (13.5% pts) or mesenchymal phenotype (EMT markers in 15.1% of pts). A small fraction of CTCs showed co-expression of both markers (0.8%). Pts with any CTCs in PB had significantly higher mean ± SEM plasma DD levels (ng/mL) than those of pts without CTCs (632.4 ± 75.9 vs. 365.4 ± 47.0, p = 0.00002). This association was observed for both, epithelial CTCs (688.4 ± 110.4 vs. 400.7 ± 43.5 (p = 0.026) and mesenchymal CTCs (573.1 ± 105.8 vs. 415.6 ± 44.7, p = 0.0007). There was no association between plasma TF levels or breast tumor TF expression and CTCs. Patients with any CTCs had higher mean ± SEM plasma uPA (ng/mL) (374.6 ± 32.6 vs. 307.1 ± 20.3, p = 0.02) and PAI-1 (pg/mL) levels (5.3 ± 0.7 vs. 4.4 ± 0.4, p = 0.28), than those of patients without CTCs, however, there was no correlation between plasma uPA system activation and DD or TF levels. In multivariate analysis CTCs, patients age and tumor grade were independent factors associated with plasma DD levels.

Conclusion: This prospective study showed for the first time a positive association between plasma D-dimer levels and CTCs indicating a potential role for activation of the coagulation cascade in the early metastatic process. We hypothesize that CTCs could be directly involved in coagulation activation in breast cancer patients, or alternatively an increased CTCs count could be a marker of more aggressive disease and increased risk of VTE. Future studies will need to address the prognostic implications of these observations with the potential for therapeutic interventions for the metastatic process.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-04-02.

The role of dynamic contrast-enhanced MRI in differentiation of local recurrence and residual soft-tissue tumor versus post-treatment changes

OBJECTIVES

To evaluate the reliability of dynamic contrast-enhanced MRI in the diagnosis of local recurrence of malignant soft-tissue tumors after receiving treatment.

METHODS

From March 2002 till December 2009 we performed dynamic contrast enhanced MRI in 95 patients with soft-tissue tumor after receiving treatment (surgery, radiotherapy, chemotherapy). Patients were classified according to five types of TIC.

RESULTS

The recurrent disease was suspected in 47 patients and the biopsy was recommended. In 8 cases (TIC II), the biopsy was performed due to long-term post-treatment changes. Histological results proved STT recurrence in 45 patients; in 10 patients (8 with TIC II), biopsy revealed hypervascular granulation tissue, florid inflammation and reactive changes. The sensitivity for dynamic contrast-enhanced MR examination was 100 %, specificity 80 %, positive predictive value (PPV) 95.7 % and negative predictive value (NPV) 100 %.

CONCLUSION

Our results indicate that TICs III, IV and V raise high suspicion of local tumor recurrence and require percutaneous imaging-guided biopsy. TIC of type II usually represents a pseudomass and the biopsy should be performed only in selected cases with increased risk of recurrent disease based on multidisciplinary approach. On the basis of literature review as well as our experiences we created a reliable algorithm proposed for diagnosing the residual or recurrent soft-tissue tumors (Tab. 2, Fig. 6, Ref. 20).

Stereotactic vacuum-assisted breast biopsy: our experience and comparison with stereotactic automated needle biopsy

OBJECTIVES

To evaluate and compare the outcome of stereotactically guided percutaneous, directional, vacuum-assisted breast biopsy (VAB) with the outcome of those performed with 14-gauge automated gun.

METHODS

Between January 2008 and January 2011, altogether 257 stereotactic biopsies were performed in our institute; 193 with the 14-gauge automated needle and 64 with a directional, vacuum-assisted instrument. Patients with malignant or high risk lesions were encouraged to undergo an excisional biopsy. We evaluated and compared concordance between the biopsy results and subsequent examinations (surgical excision or follow up) for both methods.

RESULTS

VAB demonstrated 57 (89 %) benign lesions, 2 (3 %) high risk and 5 (8 %) malignant lesions. We obtained post-bioptic mammographic or histological evaluation for altogether 51 lesions, with one (12.5 %) false negative case, one case of underestimation of borderline lesion, and no false positive cases. Clusters of microcalcifiation were completely removed in 18 lesions (28 %).

CONCLUSION

Vacuum-assisted biopsy outperformed the 14-gauge automated needle biopsy with a lower disease underestimation, sensitivity and false-negative rates; however these differences were not statistically significant due to small data files and relatively small number of identified malignant lesions in the vacuum-assisted biopsy group.VAB completely removed significantly more clusters of microcalcifications in comparison to the automated needle biopsy, which significantly reduced the need for surgery in benign lesions (Tab. 7, Fig. 3, Ref. 32).

On the origin of reactive oxygen species and antioxidative mechanisms in Enterococcus faecalis

Enterococci cause serious infections due to a number of virulence factors and wide-spread antibiotic resistance. A molecular mechanism involved in the pathogenesis of enterococcal infections is oxidative stress. Enterococcus faecalis produces a variety of antioxidative enzymes involved in the oxidative stress response, a process that is regulated by several transcriptional regulators. In addition, direct production of free radicals derived from oxygen has been proved and hypothesized, respectively, to contribute to the pathogenesis of colorectal cancer and periodontitis. The understanding of molecular mechanisms behind the production of free radicals and the antioxidative status in E. faecalis might suggest new alternatives for the treatment of enterococcal infections and related diseases.

Digitalization in radiology--6 years in the St. Elisabeth Oncology Institute

OBJECTIVES

To determine advantages and specific problems of film-free digital hospital focused on radiology department.

BACKGROUND

In the St. Elisabeth Oncology Institute in Bratislava we have more than 6-year experience with digital modalities and the PACS system. During this period many difficulties occurred and are expected to rise with an increasing number of digital modalities.

METHODS

Statistical evaluation of a 6-year period in numerous graphs and schemes.

RESULTS

The amount of data can be seen in graphs, which show the amount of examinations and data volume from different modalities for specific time period to October 2007 and present volumes and increase of data amount in megabytes (MB) in the last 6 years.

CONCLUSION

Despite of systematic capacity increase it is a long-term archiving and economical problem. It is crucial to solve the daily amount of data, backup copies, type of archiving media, and priority of data accessibility (Tab. 1, Fig. 5, Ref. 9). Full Text (Free, PDF) www.bmj.sk.