Publications by authors named "Petr Kacer"

67 Publications

Myocardial infarction caused by compression of the left coronary artery by an aortic pseudoaneurysm.

Anatol J Cardiol 2020 Dec;24(6):410-411

Department of Cardiac Surgery, University Hospital Královské Vinohrady; Prague-Czech Republic; 3rd Faculty of Medicine, Charles University; Prague-Czech Republic.

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http://dx.doi.org/10.14744/AnatolJCardiol.2020.01564DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7791293PMC
December 2020

A contemporary approach to a young female patient with Loeys-Dietz syndrome and an uncomplicated type B aortic dissection: a case report.

J Cardiothorac Surg 2020 Aug 31;15(1):231. Epub 2020 Aug 31.

Department of Cardiac surgery, Faculty Hospital Královské Vinohrady, Srobarova 50, 10034, Praha, Czech Republic.

Background: Aortic dissection is a relatively uncommon, but often catastrophic disease that requires early and accurate diagnosis. It often presents in patients with congenital connective tissue disorders. The current aortic surgical techniques are related with serious early and late complications. This case report emphasizes the importance of early diagnosis of aortic root dilatation and the risk of dissection, especially in patients with congenital connective tissue disorders. We present an alternative, contemporary and multidisciplinary approach based on the present state of knowledge.

Case Presentation: We present a rare case of a young female patient with Loeys-Dietz syndrome who was admitted with an uncomplicated aortic dissection (Stanford type B / DeBakey type III) and a dilated aortic root. After a period of close surveillance and extensive vascular imaging, thoracic endovascular aortic repair was deemed to be technically not possible. Medical treatment was optimized and our patient successfully underwent a personalised external aortic root support procedure (PEARS) as a contemporary alternative to existing aortic root surgical techniques.

Conclusions: This case highlights the importance of interdisciplinary approach, close follow-up and multimodality imaging. The decision to intervene in a chronic type B aortic dissection is still challenging and should be made in experienced centers by an interdisciplinary team. However, if an acute complication occurs, thoracic endovascular aortic repair TEVAR is the method of choice. In all cases optimal medical treatment is important. There is increasing evidence that personalized external aortic root support procedure PEARS is effective in stabilizing the aortic root and preventing its dilatation and dissection not only in patients with Marfan syndrome, but also in other cases of aortic root dilation of other etiologies. Moreover, many publications have reported the additional benefit of reduction or even eradication of aortic regurgitation by improving coaptation of the aortic valve leaflets in dilated aortas.
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http://dx.doi.org/10.1186/s13019-020-01274-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7457485PMC
August 2020

Post-infarction left ventricular free wall rupture: 12-years experience from the Cardiac Centre of the Institute of Clinical and Experimental Medicine in Prague, Czech Republic.

Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2020 Aug 18. Epub 2020 Aug 18.

Cardiac Centre, Institute of Clinical and Experimental Medicine, Prague, Czech Republic.

Background: Post-infarction left ventricular free wall rupture (LVFWR) is a feared and catastrophic complication of myocardial infarction that carries a high surgical and hospital mortality. Due to the rarity of this complication, little information exists on surgical treatment and outcomes.Goal and Methods: The goal of this study was to present our experience with LVFWR. We present a retrospective cohort of 19 consecutive patients who were surgically treated in the Cardiac Centre of the Institute of Clinical and Experimental Medicine in Prague between January 2006 and December 2017.

Results: Thirty-day mortality was 26%. Five patients died. Four patients died in the operating theatre and one patient on the ninth postoperative day following re-rupture. Seventy-four percent of the patient cohort survived and were discharged from hospital. The median length of follow-up was 45 months (range 0.75-150). No patient died during follow-up. Median postoperative ejection fraction was 45% (range 25-65%). Angina pectoris and dyspnea were investigated during follow-up and graded according to the Canadian cardiology society (CCS) and the New York Heart Association (NYHA) classifications. Fourteen patients had CCS class I, eight patients had NYHA class I dyspnea and six patients had NYHA class II. Re-rupture occurred after hospital discharge in one patient one month after the original surgery. The patient was treated successfully by urgent surgical intervention.

Conclusion: LVFWR is a catastrophic and challenging complication of myocardial infarction. Good outcomes can be achieved by rapid diagnosis and urgent surgical intervention as shown by our results.
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http://dx.doi.org/10.5507/bp.2020.022DOI Listing
August 2020

The Effect of Lipotoxicity on Renal Dysfunction in a Nonobese Rat Model of Metabolic Syndrome: A Urinary Proteomic Approach.

J Diabetes Res 2019 6;2019:8712979. Epub 2019 Dec 6.

Centre for Experimental Medicine, Institute for Clinical and Experimental Medicine, 14021 Prague, Czech Republic.

Introduction: The development of metabolic syndrome-associated renal dysfunction is exacerbated by a number of factors including dyslipidemia, ectopic deposition of lipids and their toxic metabolites, impairment of lipid metabolism, and insulin resistance. Renal dysfunction is also affected by the production of proinflammatory and profibrotic factors secreted from adipose tissue, which can in turn directly impair kidney cells and potentiate insulin resistance. In this study, we investigated the manifestation of renal lipid accumulation and its effect on renal dysfunction in a model of metabolic syndrome-the hereditary hypertriglyceridemic rat (HHTg)-by assessing microalbuminuria and targeted urinary proteomics. Male Wistar control rats and HHTg rats were fed a standard diet and observed over the course of ageing at 3, 12, and 20 months of age.

Results: Chronically elevated levels of triglycerides in HHTg rats were associated with increased levels of NEFA during OGTT and over a period of 24 hours (+80%, < 0.01). HHTg animals exhibited qualitative changes in NEFA fatty acid composition, represented by an increased proportion of saturated fatty acids ( < 0.05) and a decreased proportion of n-3 PUFA ( < 0.01). Ectopic lipid deposition in the kidneys of HHTg rats-triglycerides (+30%) and cholesterol (+10%)-was associated with markedly elevated microalbuminuria as ageing increased, despite the absence of microalbuminuria at the young age of 3 months in these animals. According to targeted proteomic analysis, 3-month-old HHTg rats (in comparison to age-matched controls) exhibited increased urinary secretion of proinflammatory parameters (MCP-1, IL-6, IL-8, < 0.01) and decreased urinary secretion of epidermal growth factor (EGF, < 0.01) before manifestation of microalbuminuria. Elevation in the urinary secretion of inflammatory cytokines can be affected by increased relative expression of MCP-1 in the renal cortex ( < 0.05).

Conclusions: Our results confirm dyslipidemia and ectopic lipid accumulation to be key contributors in the development of metabolic syndrome-associated renal dysfunction. Assessing urinary secretion of proinflammatory cytokines and epidermal growth factor can help in detecting early development of metabolic syndrome-associated renal dysfunction.
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http://dx.doi.org/10.1155/2019/8712979DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6925916PMC
June 2020

The effect of dicarbonyl stress on the development of kidney dysfunction in metabolic syndrome - a transcriptomic and proteomic approach.

Nutr Metab (Lond) 2019 1;16:51. Epub 2019 Aug 1.

1Centre for Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czech Republic.

Background And Aims: Dicarbonyl stress plays an important role in the pathogenesis of microvascular complications that precede the formation of advanced glycation end products, and contributes to the development of renal dysfunction. In renal cells, toxic metabolites like methylglyoxal lead to mitochondrial dysfunction and protein structure modifications.In our study, we investigated the effect of methylglyoxal on metabolic, transcriptomic, metabolomic and proteomic profiles in the context of the development of kidney impairment in the model of metabolic syndrome.

Materials And Methods: Dicarbonyl stress was induced by intragastric administration of methylglyoxal (0.5 mg/kg bw for 4 weeks) in a strain of hereditary hypertriglyceridaemic rats with insulin resistance and fatty liver.

Results: Methylglyoxal administration aggravated glucose intolerance (AUC < 0.05), and increased plasma glucose ( < 0.01) and insulin ( < 0.05). Compared to controls, methylglyoxal-treated rats exhibited microalbuminuria ( < 0.01). Targeted proteomic analysis revealed increases in urinary secretion of pro-inflammatory parameters (MCP-1, IL-6, IL-8), specific collagen IV fragments and extracellular matrix proteins. Urine metabolomic biomarkers in methylglyoxal-treated rats were mainly associated with impairment of membrane phospholipids (8-isoprostane, 4-hydroxynonenal).Decreased levels of glutathione ( < 0.01) together with diminished activity of glutathione-dependent antioxidant enzymes contributed to oxidative and dicarbonyl stress. Methylglyoxal administration elevated glyoxalase 1 expression ( < 0.05), involved in methylglyoxal degradation. Based on comparative transcriptomic analysis of the kidney cortex, 96 genes were identified as differentially expressed (FDR < 0.05). Network analysis revealed an over-representation of genes related to oxidative stress and pro-inflammatory signalling pathways as well as an inhibition of angiogenesis suggesting its contribution to renal fibrosis.

Conclusion: Our results support the hypothesis that dicarbonyl stress plays a key role in renal microvascular complications. At the transcriptome level, methylglyoxal activated oxidative and pro-inflammatory pathways and inhibited angiogenesis. These effects were further supported by the results of urinary proteomic and metabolomic analyses.
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http://dx.doi.org/10.1186/s12986-019-0376-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6670216PMC
August 2019

NanoTiO Sunscreen Does Not Prevent Systemic Oxidative Stress Caused by UV Radiation and a Minor Amount of NanoTiO is Absorbed in Humans.

Nanomaterials (Basel) 2019 Jun 17;9(6). Epub 2019 Jun 17.

Czech University of Life Sciences, Kamycka 129, 165 00 Prague 6, Czech Republic.

The present pilot study tested the efficiency of nanoTiO sunscreen to prevent the oxidative stress/inflammation caused by ultraviolet (UV) radiation using biomarkers in subjects' blood, urine, and exhaled breath condensate (EBC). In addition, the skin absorption of nanoTiO was studied. Six identical subjects participated in three tests: (A) nanoTiO sunscreen, (B) UV radiation, and (C) sunscreen + UV. The first samples were collected before the test and the second after sunscreen application and/or UV exposure. On day 4, the third samples were collected, and the sunscreen was washed off, and the fourth samples were collected on day 11. The following biomarkers were measured: malondialdehyde, 4-hydroxy--hexenal, 4-hydroxy--nonenal, aldehydes C6-C12, 8--Prostaglandin F2α, o-tyrosine, 3-chlorotyrosine, 3-nitrotyrosine, 8-hydroxy-2-deoxyguanosine, 8-hydroxyguanosine, 5-hydroxymethyl uracil, and leukotrienes, using liquid chromatography-electrospray ionisation-tandem mass spectrometry. Titania was measured using inductively coupled plasma mass spectrometry and TiO nanoparticles by transmission and scanning electron microscopy. Sunscreen alone did not elevate the markers, but UV increased the biomarkers in the plasma, urine, and EBC. The sunscreen prevented skin redness, however it did not inhibit the elevation of oxidative stress/inflammatory markers. Titania and nanoTiO particles were found in the plasma and urine (but not in the EBC) in all sunscreen users, suggesting their skin absorption.
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http://dx.doi.org/10.3390/nano9060888DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6631994PMC
June 2019

Improvement in the quality of life of patients with persistent or long-standing persistent atrial fibrillation after hybrid ablation.

J Interv Card Electrophysiol 2020 Apr 17;57(3):435-442. Epub 2019 Apr 17.

Cardiocenter, Department of Cardiac Surgery, Third Faculty of Medicine, Charles University and University Hospital Kralovske Vinohrady, Srobarova 50, 100 34, Prague, Czech Republic.

Background: Hybrid ablation (i.e., a combination of a thoracoscopic surgical ablation followed by a catheter ablation) is a treatment option for patients with non-paroxysmal atrial fibrillation (AF). Despite its promising efficacy, it is a surgical procedure with a relatively high risk of complications that could affect the quality of life (QoL) of patients, even when sinus rhythm is restored.

Objective: To describe changes in the QoL of patients with non-paroxysmal AF before and after a hybrid ablation.

Methods: Patients after hybrid ablation for persistent or long-standing persistent AF were prospectively studied. Follow-up visits were scheduled at 1, 3, 6, 9, and 12 months. The maintenance of SR was assessed using 1-week Holter recordings at 6 and 12 months and 24-h Holter recordings at 3 and 9 months, or via an implantable loop recorder. QoL was assessed using the Atrial Fibrillation Effect on Quality-of-life (AFEQT) and the EuroQoL-5Dimensions (EQ-5D) questionnaires before and 12 months after ablation.

Results: Seventy-five patients (49 men, age 62.9 ± 8.45 years, 48 (64%) with long-standing persistent AF) were enrolled. Fifty-two (69.3%, SR group) were AF-free during the 12-month follow-up, 16 (21.3%, PAROX group) had only paroxysms of AF after ablation, and 7 (9.3%, PERM group) were on rate control due to permanent AF reoccurrence. The AFEQT score increased significantly in the SR group from 59.9 ± 19.4 to 91.4 ± 10.8 (p < 0.001), and in the PAROX group from 58.8 ± 19.0 to 81.5 ± 14.1 (p = 0.002) but remained unchanged in the PERM group (44.6 ± 7.5 vs. 47.4 ± 5.5, p = 0.24). The EQ-5D score significantly decreased in the descriptive part (from 7.90 ± 2.61 to 6.64 ± 1.90, p = 0.0001) and increased on the visual analog scale (from 63.56 ± 19.11 to 79.30 ± 16.9, p < 0.0001) in the SR group. In the PAROX group, no significant change was present on either the descriptive part (p = 0.3) or in the visual analog scale (p = 0.48). Similarly, no significant changes were present on either the descriptive part (p = 0.93) or the visual analog scale (p = 0.4) in the PERM group.

Conclusion: The QoL of patients with non-paroxysmal AF and patients with AF paroxysms, after successful hybrid ablation, improved significantly in patients with SR. No significant improvement was present in patients on rate control after an unsuccessful ablation.
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http://dx.doi.org/10.1007/s10840-019-00546-7DOI Listing
April 2020

Deep Airway Inflammation and Respiratory Disorders in Nanocomposite Workers.

Nanomaterials (Basel) 2018 Sep 16;8(9). Epub 2018 Sep 16.

UMass, Lowell, Department of Biomedical and Nutritional Sciences, Zuckerberg College of Health Sciences, Lowell, MA 01854, USA.

Thousands of researchers and workers worldwide are employed in nanocomposites manufacturing, yet little is known about their respiratory health. Aerosol exposures were characterized using real time and integrated instruments. Aerosol mass concentration ranged from 0.120 mg/m³ to 1.840 mg/m³ during nanocomposite machining processes; median particle number concentration ranged from 4.8 × 10⁴ to 5.4 × 10⁵ particles/cm³. The proportion of nanoparticles varied by process from 40 to 95%. Twenty employees, working in nanocomposite materials research were examined pre-shift and post-shift using spirometry and fractional exhaled nitric oxide (FeNO) in parallel with 21 controls. Pro-inflammatory leukotrienes (LT) type B4, C4, D4, and E4; tumor necrosis factor (TNF); interleukins; and anti-inflammatory lipoxins (LXA4 and LXB4) were analyzed in their exhaled breath condensate (EBC). Chronic bronchitis was present in 20% of researchers, but not in controls. A significant decrease in forced expiratory volume in 1 s (FEV1) and FEV1/forced vital capacity (FVC) was found in researchers post-shift ( ˂ 0.05). Post-shift EBC samples were higher for TNF ( ˂ 0.001), LTB4 ( ˂ 0.001), and LTE4 ( ˂ 0.01) compared with controls. Nanocomposites production was associated with LTB4 ( ˂ 0.001), LTE4 ( ˂ 0.05), and TNF ( ˂ 0.001), in addition to pre-shift LTD4 and LXB4 (both ˂ 0.05). Spirometry documented minor, but significant, post-shift lung impairment. TNF and LTB4 were the most robust markers of biological effects. Proper ventilation and respiratory protection are required during nanocomposites processing.
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http://dx.doi.org/10.3390/nano8090731DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6164906PMC
September 2018

Markers of Oxidative Stress in the Exhaled Breath Condensate of Workers Handling Nanocomposites.

Nanomaterials (Basel) 2018 Aug 10;8(8). Epub 2018 Aug 10.

Department of Biomedical and Nutritional Sciences, Zuckerberg College of Health Sciences, Lowell, MA 01854, USA.

Researchers in nanocomposite processing may inhale a variety of chemical agents, including nanoparticles. This study investigated airway oxidative stress status in the exhaled breath condensate (EBC). Nineteen employees (42.4 ± 11.4 y/o), working in nanocomposites research for 18.0 ± 10.3 years were examined pre-shift and post-shift on a random workday, together with nineteen controls (45.5 ± 11.7 y/o). Panels of oxidative stress biomarkers derived from lipids, nucleic acids, and proteins were analyzed in the EBC. Aerosol exposures were monitored during three major nanoparticle generation operations: smelting and welding (workshop 1) and nanocomposite machining (workshop 2) using a suite of real-time and integrated instruments. Mass concentrations during these operations were 0.120, 1.840, and 0.804 mg/m³, respectively. Median particle number concentrations were 4.8 × 10⁴, 1.3 × 10⁵, and 5.4 × 10⁵ particles/cm³, respectively. Nanoparticles accounted for 95, 40, and 61%, respectively, with prevailing Fe and Mn. All markers of nucleic acid and protein oxidation, malondialdehyde, and aldehydes C₆⁻C were elevated, already in the pre-shift samples relative to controls in both workshops. Significant post-shift elevations were documented in lipid oxidation markers. Significant associations were found between working in nanocomposite synthesis and EBC biomarkers. More research is needed to understand the contribution of nanoparticles from nanocomposite processing in inducing oxidative stress, relative to other co-exposures generated during welding, smelting, and secondary oxidation processes, in these workshops.
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http://dx.doi.org/10.3390/nano8080611DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6116291PMC
August 2018

Protein-losing enteropathy in an adult with non-ischaemic cardiomyopathy: complete reversal by heart transplantation.

ESC Heart Fail 2018 10 27;5(5):842-845. Epub 2018 Jul 27.

Department of Cardiac Surgery, Institute for Clinical and Experimental Medicine-IKEM, Vídeňská 1958/9, Prague, 140 21, Czech Republic.

Protein-losing enteropathy (PLE) due to leakage of lymph into the gut sometimes occurs in young patients after Fontan palliation but is very rarely reported with other aetiologies of chronic heart failure (HF). PLE leads to severe hypoalbuminemia and immunodeficiency and is associated with poor prognosis. The mechanisms and the predispositions to PLE are poorly understood. Here, we report an adult patient with advanced HF due to non-ischaemic non-dilated hypocontractile cardiomyopathy who developed severe PLE, probably owing to increased ventricular stiffness and constraint by atypically placed epicardial electrode encircling both ventricles. Importantly, both PLE and immunodeficiency completely resolved after heart transplantation.
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http://dx.doi.org/10.1002/ehf2.12342DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6165937PMC
October 2018

Neuroinflammation markers and methyl alcohol induced toxic brain damage.

Toxicol Lett 2018 Dec 4;298:60-69. Epub 2018 May 4.

Toxicological Information Centre, General University Hospital, Na Bojisti 1, 12000, Prague, Czech Republic; Department of Biomimetic Electrochemistry, J. Heyrovský Institute of Physical Chemistry of the AS CR, v.v.i, Dolejskova 2155/3, 18200, Prague, Czech Republic.

Methyl alcohol intoxication is a global problem with high mortality and long-term visual sequelae and severe brain damage in survivors. The role of neuroinflammation in the mechanisms of methyl alcohol-induced toxic brain damage has not been well studied. We measured the acute concentrations and dynamics of lipoxins LxA4 and LxB4 and the interleukins IL-4, IL-5, IL-9, IL-10, and IL-13 in the serum of patients treated with methyl alcohol poisoning and the follow-up concentrations in survivors two years after discharge from the hospital. A series of acute measurements was performed in 28 hospitalized patients (mean age 54.2 ± 5.2 years, mean observation time 88 ± 20 h) and the follow-up measurements were performed in 36 subjects who survived poisoning (including 12/28 survivors from the acute group). Visual evoked potentials (VEP) and magnetic resonance imaging of the brain (MRI) were performed to detect long-term visual and brain sequelae of intoxication. The acute concentrations of inflammatory mediators were higher than the follow-up concentrations: LxA4, 62.0 ± 6.0 vs. 30.0 ± 5.0 pg/mL; LxB4, 64.0 ± 7.0 vs. 34.0 ± 4.0 pg/mL; IL-4, 29.0 ± 4.0 vs. 15.0 ± 1.0 pg/mL; IL-5, 30.0 ± 4.0 vs. 13.0 ± 1.0 pg/mL; IL-9, 30.0 ± 4.0 vs. 13.0 ± 1.0 pg/mL; IL-10, 38.0 ± 5.0 vs. 16.0 ± 1.0 pg/mL; IL-13, 35.0 ± 4.0 vs. 14.0 ± 1.0 pg/mL (all p < 0.001). The patients with higher follow-up IL-5 concentration had prolonged latency P1 (r = 0.413; p = 0.033) and lower amplitude N1P1 (r = -0.498; p = 0.010) of VEP. The higher follow-up IL-10 concentration was associated with MRI signs of brain necrotic damage (r = 0.533; p = 0.001) and brain hemorrhage (r = 0.396; p = 0.020). Our findings suggest that neuroinflammation plays an important role in the mechanisms of toxic brain damage in acute methyl alcohol intoxication.
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http://dx.doi.org/10.1016/j.toxlet.2018.05.001DOI Listing
December 2018

Role of activation of lipid peroxidation in the mechanisms of acute methanol poisoning

Clin Toxicol (Phila) 2018 10 2;56(10):893-903. Epub 2018 Apr 2.

a Toxicological Information Centre , General University Hospital in Prague , Prague , Czech Republic.

Context: The role of activation of lipid peroxidation in the mechanisms of acute methanol poisoning has not been studied.

Objective: We measured the concentrations of lipid peroxidation markers in acutely intoxicated patients with known serum concentrations of methanol and leukotrienes.

Methods: Blood serum samples were collected from 28 patients hospitalized with acute intoxication and from 36 survivors 2 years after discharge. In these samples, concentrations of 4-hydroxy-trans-2-hexenal (HHE), 4-hydroxynonenal (HNE), and malondialdehyde (MDA) were measured using the method of liquid chromatography-electrospray ionization-tandem mass spectrometry.

Results: The maximum acute serum concentrations of all three lipid oxidative damage markers were higher than the follow-up serum concentrations: HNE 71.7 ± 8.0 ng/mL versus 35.4 ± 2.3 ng/mL; p < .001; HHE 40.1 ± 6.7 ng/mL versus 17.7 ± 4.1 ng/mL; p < .001; MDA 80.0 ± 7.2 ng/mL versus 40.9 ± 1.9 ng/mL; p < .001. The survivors without methanol poisoning sequelae demonstrated higher acute serum concentrations of the markers than the patients with sequelae. A correlation between measured markers and serum leukotrienes was present: HNE correlated with LTC4 (r = 0.663), LTD4 (r = 0.608), LTE4 (r = 0.771), LTB4 (r = 0.717), HHE correlated with LTC4 (r = 0.713), LTD4 (r = 0.676), LTE4 (r = 0.819), LTB4 (r = 0.746), MDA correlated with LTC4 (r = 0.785), LTD4 (r = 0.735), LTE4 (r = 0.814), LTB4 (r = 0.674); all p < .001. Lipid peroxidation markers correlated with anion gap (r= -0.428, -0.388, -0.334; p = .026, .045, .080 for HNE, HHE, MDA, respectively). The follow-up serum concentrations of lipid oxidation markers measured in survivors with and without visual/neurological sequelae 2 years after discharge did not differ.

Conclusion: Our results demonstrate that lipid peroxidation plays a significant role in the mechanisms of acute methanol poisoning. The acute concentrations of three measured biomarkers were elevated in comparison with the follow-up concentrations. Neuronal membrane lipid peroxidation seems to activate leukotriene-mediated inflammation as a part of the neuroprotective mechanisms. No cases of persistent elevation were registered among the survivors 2 years after discharge.
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http://dx.doi.org/10.1080/15563650.2018.1455980DOI Listing
October 2018

Ghrelin receptor antagonism of morphine-induced conditioned place preference and behavioral and accumbens dopaminergic sensitization in rats.

Neurochem Int 2017 Nov 27;110:101-113. Epub 2017 Sep 27.

Department of Pharmacology, Third Faculty of Medicine, Charles University, Ruska 87, Prague 10, 100 34, Czech Republic. Electronic address:

An increasing number of studies over the past few years have demonstrated ghrelin's role in alcohol, cocaine and nicotine abuse. However, the role of ghrelin in opioid effects has rarely been examined. Recently we substantiated in rats that ghrelin growth hormone secretagogue receptors (GHS-R1A) appear to be involved in acute opioid-induced changes in the mesolimbic dopaminergic system associated with the reward processing. The aim of the present study was to ascertain whether a ghrelin antagonist (JMV2959) was able to inhibit morphine-induced biased conditioned place preference and challenge-morphine-induced accumbens dopaminergic sensitization and behavioral sensitization in adult male rats. In the place preference model, the rats were conditioned for 8 days with morphine (10 mg/kg s.c.). On the experimental day, JMV2959 (3 and 6 mg/kg i.p.) or saline were administered before testing. We used in vivo microdialysis to determine changes of dopamine and its metabolites in the nucleus accumbens in rats following challenge-morphine dose (5 mg/kg s.c.) with or without JMV2959 (3 and 6 mg/kg i.p.) pretreatment, administered on the 12th day of spontaneous abstinence from morphine repeated treatment (5 days, 10-40 mg/kg). Induced behavioral changes were simultaneously monitored. Pretreatment with JMV2959 significantly and dose dependently reduced the morphine-induced conditioned place preference and significantly and dose dependently reduced the challenge-morphine-induced dopaminergic sensitization and affected concentration of by-products associated with dopamine metabolism in the nucleus accumbens. JMV2959 pretreatment also significantly reduced challenge-morphine-induced behavioral sensitization. Our present data suggest that GHS-R1A antagonists deserve to be further investigated as a novel treatment strategy for opioid addiction.
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http://dx.doi.org/10.1016/j.neuint.2017.09.013DOI Listing
November 2017

All muscarinic acetylcholine receptors (M-M) are expressed in murine brain microvascular endothelium.

Sci Rep 2017 07 11;7(1):5083. Epub 2017 Jul 11.

Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, 37134, Italy.

Clinical and experimental studies indicate that muscarinic acetylcholine receptors are potential pharmacological targets for the treatment of neurological diseases. Although these receptors have been described in human, bovine and rat cerebral microvascular tissue, a subtype functional characterization in mouse brain endothelium is lacking. Here, we show that all muscarinic acetylcholine receptors (M-M) are expressed in mouse brain microvascular endothelial cells. The mRNA expression of M, M, and M correlates with their respective protein abundance, but a mismatch exists for M and M mRNA versus protein levels. Acetylcholine activates calcium transients in brain endothelium via muscarinic, but not nicotinic, receptors. Moreover, although M and M are the most abundant receptors, only a small fraction of M is present in the plasma membrane and functions in ACh-induced Ca signaling. Bioinformatic analyses performed on eukaryotic muscarinic receptors demonstrate a high degree of conservation of the orthosteric binding site and a great variability of the allosteric site. In line with previous studies, this result indicates muscarinic acetylcholine receptors as potential pharmacological targets in future translational studies. We argue that research on drug development should especially focus on the allosteric binding sites of the M and M receptors.
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http://dx.doi.org/10.1038/s41598-017-05384-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5506046PMC
July 2017

Trans-generational neurochemical modulation of methamphetamine in the adult brain of the Wistar rat.

Arch Toxicol 2017 Oct 5;91(10):3373-3384. Epub 2017 May 5.

Department of Normal, Pathological and Clinical Physiology, Third Faculty of Medicine, Charles University, Prague, Czech Republic.

Chronic methamphetamine (METH) abuse has been shown to elicit strong neurotoxic effects. Yet, with an increasing number of children born to METH abusing mothers maturing into adulthood, one important question is how far do the neurotoxic effects of METH alter various neurotransmitter systems in the adult METH-exposed offspring. The purpose of this study was to investigate long-term trans-generational neurochemical changes, following prenatal METH exposure, in the adult Wistar rat brain. METH or saline (SAL-control animals) was administered to pregnant dams throughout the entire gestation period (G0-G22). At postnatal day 90, dopamine, serotonin, glutamate and GABA were measured in the adult brain before (baseline) and after a METH re-administration using in vivo microdialysis and liquid chromatography/mass spectrometry. The results show that METH-exposure increased basal levels of monoamines and glutamate, but decreased GABA levels in all measured brain regions. Acute challenge with METH injection in the METH-exposed group induced a lower increase in the monoamine system relative to the increase in the GABAergic and glutamatergic system. The data show that prenatal METH exposure has strong effects on the monoaminergic, GABAergic and glutamatergic system even when exposure to METH was limited to the prenatal phase. Toxicological effects of METH have therefore longer lasting effects as currently considered and seem to affect the excitatory-inhibitory balance in the brain having strong implications for cognitive and behavioral functioning.
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http://dx.doi.org/10.1007/s00204-017-1969-yDOI Listing
October 2017

Markers of nucleic acids and proteins oxidation among office workers exposed to air pollutants including (nano)TiO2 particles.

Neuro Endocrinol Lett 2016 Dec;37(Suppl1):13-16

Charles University and General University Hospital in Prague, 1st Faculty of Medicine, Department of Occupational Medicine, Prague, Czech Republic.

Objectives: Experimental studies using nanoscale TiO2 have documented lung injury, inflammation, oxidative stress, and genotoxicity. Human health data are extremely scarce.

Methods: In exhaled breath condensate (EBC) and urine of 22 office employees occupationally exposed to TiO2 during their visit in the production workshops for average 14±9 min/day a panel of biomarkers of nucleic acids and proteins oxidation was studied, specifically 8-hydroxy-2-deoxyguanosine (8-OHdG), 8-hydroxyguanosine (8-OHG), 5-hydroxymethyl uracil (5-OHMeU), o-tyrosine (o-Tyr), 3-chlorotyrosine (3-ClTyr), and 3-nitrotyrosine (3-NOTyr). Examination was performed also in 14 comparable controls.

Results: The median respirable TiO2 mass concentration in the workshops was 0.40 mg/m3, median number concentration was 2.32×104 particles/cm3 with 80% of the particles being <100 nm in diameter. All 6 markers of oxidation were elevated in EBC in factory office employees relative to controls (p<0.01). Significant association was found between their job in TiO2 production plant and 5 markers of oxidation (except 3-NOTyr) in the EBC in multivariate analysis. No elevation of markers was detected in the urine.

Conclusion: This pilot study suggests that even short nanoTiO2 exposure may lead to pulmonary oxidative stress; however this effect may be short-term and reversible. The clinical significance of these findings is unclear and more studies are needed.
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December 2016

Leukotriene-mediated neuroinflammation, toxic brain damage, and neurodegeneration in acute methanol poisoning.

Clin Toxicol (Phila) 2017 Apr 6;55(4):249-259. Epub 2017 Feb 6.

a Department of Occupational Medicine, First Faculty of Medicine , Charles University , Prague , Czech Republic.

Context: The role of neuroinflammation in methanol-induced toxic brain damage has not been studied.

Objective: We studied acute concentrations and the dynamics of leukotrienes (LT) in serum in hospitalized patients with acute methanol poisoning and in survivors.

Methods: Series of acute cysteinyl-LT and LTB4 concentration measurements were performed in 28/101 hospitalized patients (mean observation time: 88 ± 20 h). In 36 survivors, control LT measurements were performed 2 years after discharge.

Results: The acute maximum (C) LT concentrations were higher than concentrations in survivors: C for LTC4 was 80.7 ± 5.6 versus 47.9 ± 4.5 pg/mL; for LTD4, 51.0 ± 6.6 versus 23.1 ± 2.1 pg/mL; for LTE4, 64.2 ± 6.0 versus 26.2 ± 3.9 pg/mL; for LTB4, 59.8 ± 6.2 versus 27.2 ± 1.4 pg/mL (all p < 0.001). The patients who survived had higher LT concentrations than those who died (all p < 0.01). Among survivors, patients with CNS sequelae had lower LTE4 and LTB4 than did those without sequelae (both p < 0.05). The LT concentrations increased at a rate of 0.4-0.5 pg/mL/h and peaked 4-5 days after admission. The patients with better outcomes had higher cys-LTs (all p < 0.01) and LTB4 (p < 0.05). More severely poisoned patients had lower acute LT concentrations than those with minor acidemia. The follow-up LT concentrations in survivors with and without CNS sequelae did not differ (all p > 0.05). The mean decrease in LT concentration was 30.9 ± 9.0 pg/mL for LTC4, 26.3 ± 8.6 pg/mL for LTD4, 37.3 ± 6.4 pg/mL for LTE4, and 32.0 ± 8.8 pg/mL for LTB4.

Conclusions: Our findings suggest that leukotriene-mediated neuroinflammation may play an important role in the mechanisms of toxic brain damage in acute methanol poisoning in humans. Acute elevation of LT concentrations was moderate, transitory, and was not followed by chronic neuroinflammation in survivors.
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http://dx.doi.org/10.1080/15563650.2017.1284332DOI Listing
April 2017

The effects of liraglutide in mice with diet-induced obesity studied by metabolomics.

J Endocrinol 2017 04 30;233(1):93-104. Epub 2017 Jan 30.

Centre for Experimental Medicine and Diabetes CentreInstitute for Clinical and Experimental Medicine, Prague, Czech Republic

Liraglutide is the glucagon-like peptide-1 receptor agonist widely used for the treatment of type 2 diabetes mellitus. Recently, it has been demonstrated to decrease cardiovascular morbidity and mortality in patients with type 2 diabetes and high cardiovascular risk. Although the major modes of liraglutide action are well-known, its detailed action at the metabolic level has not been studied. To this end, we explored the effect of 2-week liraglutide treatment in C57BL/6 male mice with obesity and diabetes induced by 13 weeks of high-fat diet using NMR spectroscopy to capture the changes in urine metabolic profile induced by the therapy. The liraglutide treatment decreased body and fat pads weight along with blood glucose and triglyceride levels. NMR spectroscopy identified 11 metabolites significantly affected by liraglutide treatment as compared to high-fat diet-fed control group. These metabolites included ones involved in nicotinamide adenine dinucleotide metabolism, β-oxidation of fatty acids and microbiome changes. Although majority of the metabolites changed after liraglutide treatment were similar as the ones previously identified after vildagliptin administration in a similar mouse model, the changes in creatinine, taurine and trigonelline were specific for liraglutide administration. The significance of these changes and its possible use in the personalization of antidiabetic therapy in humans requires further research.
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http://dx.doi.org/10.1530/JOE-16-0478DOI Listing
April 2017

Distributions of therapeutically promising neurosteroids in cellular membranes.

Chem Phys Lipids 2017 03 30;203:78-86. Epub 2016 Dec 30.

J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 3, 182 23 Prague, Czech Republic. Electronic address:

Interactions of two neurosteroids, inhibiting membrane-bound N-Methyl-d-aspartate receptors, with phospholipid membranes are studied. Namely, endogenous pregnanolone sulfate is compared with pregnanolone glutamate, the latter being a novel synthetic steroidal inhibitor of these receptors with potential pharmaceutical use. Molecular-level details of steroid-phospholipid membranes interactions are scrutinized employing molecular dynamics simulations supported by quantum chemical calculations to assess steroid lipophilicity. Moreover, permeability of both species across membranes is experimentally evaluated by immobilized artificial membrane chromatography. We demonstrate that while there is no significant difference of lipophilicity and membrane permeability between the two steroids, they differ significantly regarding detailed localization in phospholipid membranes. The bulky glutamate moiety of pregnanolone glutamate is flexible and well exposed to the water phase while the sulfate group of pregnanolone sulfate is hidden in the membrane headgroup region. This dissimilarity of behavior in membranes can potentially account for the observed different activities of the two steroids toward membrane-bound N-Methyl-d-aspartate receptors.
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http://dx.doi.org/10.1016/j.chemphyslip.2016.12.004DOI Listing
March 2017

Repeated intraspecific divergence in life span and aging of African annual fishes along an aridity gradient.

Evolution 2017 Feb 7;71(2):386-402. Epub 2016 Dec 7.

Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic, Květná 8, 603 65, Brno, Czech Republic.

Life span and aging are substantially modified by natural selection. Across species, higher extrinsic (environmentally related) mortality (and hence shorter life expectancy) selects for the evolution of more rapid aging. However, among populations within species, high extrinsic mortality can lead to extended life span and slower aging as a consequence of condition-dependent survival. Using within-species contrasts of eight natural populations of Nothobranchius fishes in common garden experiments, we demonstrate that populations originating from dry regions (with short life expectancy) had shorter intrinsic life spans and a greater increase in mortality with age, more pronounced cellular and physiological deterioration (oxidative damage, tumor load), and a faster decline in fertility than populations from wetter regions. This parallel intraspecific divergence in life span and aging was not associated with divergence in early life history (rapid growth, maturation) or pace-of-life syndrome (high metabolic rates, active behavior). Variability across four study species suggests that a combination of different aging and life-history traits conformed with or contradicted the predictions for each species. These findings demonstrate that variation in life span and functional decline among natural populations are linked, genetically underpinned, and can evolve relatively rapidly.
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http://dx.doi.org/10.1111/evo.13127DOI Listing
February 2017

Markers of lipid oxidative damage in the exhaled breath condensate of nano TiO production workers.

Nanotoxicology 2017 02 9;11(1):52-63. Epub 2016 Dec 9.

h UMass Lowell, Department of Public Health , College of Health Sciences , Lowell, MA , USA.

Nanoscale titanium dioxide (nanoTiO) is a commercially important nanomaterial. Animal studies have documented lung injury and inflammation, oxidative stress, cytotoxicity and genotoxicity. Yet, human health data are scarce and quantitative risk assessments and biomonitoring of exposure are lacking. NanoTiO is classified by IARC as a group 2B, possible human carcinogen. In our earlier studies we documented an increase in markers of inflammation, as well as DNA and protein oxidative damage, in exhaled breath condensate (EBC) of workers exposed nanoTiO. This study focuses on biomarkers of lipid oxidation. Several established lipid oxidative markers (malondialdehyde, 4-hydroxy-trans-hexenal, 4-hydroxy-trans-nonenal, 8-isoProstaglandin F2α and aldehydes C-C) were studied in EBC and urine of 34 workers and 45 comparable controls. The median particle number concentration in the production line ranged from 1.98 × 10 to 2.32 × 10 particles/cm with ∼80% of the particles <100 nm in diameter. Mass concentration varied between 0.40 and 0.65 mg/m. All 11 markers of lipid oxidation were elevated in production workers relative to the controls (p < 0.001). A significant dose-dependent association was found between exposure to TiO and markers of lipid oxidation in the EBC. These markers were not elevated in the urine samples. Lipid oxidation in the EBC of workers exposed to (nano)TiO complements our earlier findings on DNA and protein damage. These results are consistent with the oxidative stress hypothesis and suggest lung injury at the molecular level. Further studies should focus on clinical markers of potential disease progression. EBC has reemerged as a sensitive technique for noninvasive monitoring of workers exposed to engineered nanoparticles.
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http://dx.doi.org/10.1080/17435390.2016.1262921DOI Listing
February 2017

Toward Noninvasive Diagnosis of IgA Nephropathy: A Pilot Urinary Metabolomic and Proteomic Study.

Dis Markers 2016 9;2016:3650909. Epub 2016 Oct 9.

University of Chemistry and Technology, Technická 5, 166 28 Prague 6, Czech Republic.

IgA nephropathy is diagnosed by renal biopsy, an invasive procedure with a risk of significant complications. Noninvasive approaches are needed for possible diagnostic purposes and especially for monitoring disease activity or responses to treatment. In this pilot project, we assessed the utility of urine samples as source of biomarkers of IgA nephropathy. We used spot urine specimens from 19 healthy controls, 11 patients with IgA nephropathy, and 8 renal-disease controls collected on day of renal biopsy. Urine samples were analyzed using untargeted metabolomic and targeted proteomic analyses by several experimental techniques: liquid chromatography coupled with mass spectrometry, immunomagnetic isolation of target proteins coupled with quantitation by mass spectrometry, and protein arrays. No single individual biomarker completely differentiated the three groups. Therefore, we tested the utility of several markers combined in a panel. Discriminant analysis revealed that combination of seven markers, three metabolites (dodecanal, 8-hydroxyguanosine, and leukotriene C), three proteins (1-antitrypsin, IgA-uromodulin complex, and galactose-deficient IgA1), and heparan sulfate, differentiated patients with IgA nephropathy from patients with other renal diseases and healthy controls. Future studies are needed to validate these preliminary findings and to determine the power of these urinary markers for assessment of responses to therapy.
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http://dx.doi.org/10.1155/2016/3650909DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5075301PMC
February 2017

Markers of lipid oxidative damage among office workers exposed intermittently to air pollutants including nanoTiO2 particles.

Rev Environ Health 2017 Mar;32(1-2):193-200

Nanoscale titanium dioxide (nanoTiO2) is a commercially important nanomaterial used in numerous applications. Experimental studies with nanotitania have documented lung injury and inflammation, oxidative stress, and genotoxicity. Production workers in TiO2 manufacturing with a high proportion of nanoparticles and a mixture of other air pollutants, such as gases and organic aerosols, had increased markers of oxidative stress, including DNA and protein damage, as well as lipid peroxidation in their exhaled breath condensate (EBC) compared to unexposed controls. Office workers were observed to get intermittent exposures to nanoTiO2 during their process monitoring. The aim of this study was to investigate the impact of such short-term exposures on the markers of health effects in office workers relative to production workers from the same factory. Twenty-two office employees were examined. They were occupationally exposed to (nano)TiO2 aerosol during their daily visits of the production area for an average of 14±9 min/day. Median particle number concentration in office workers while in the production area was 2.32×104/cm3. About 80% of the particles were <100 nm in diameter. A panel of biomarkers of lipid oxidation, specifically malondialdehyde (MDA), 4-hydroxy-trans-hexenal (HHE), 4-hydroxy-trans-nonenal (HNE), 8-isoprostaglandin F2α (8-isoprostane), and aldehydes C6-C12, were studied in the EBC and urine of office workers and 14 unexposed controls. Nine markers of lipid oxidation were elevated in the EBC of office employees relative to controls (p<0.05); only 8-isoprostane and C11 were not increased. Significant association was found in the multivariate analysis between their employment in the TiO2 production plant and EBC markers of lipid oxidation. No association was seen with age, lifestyle factors, or environmental air contamination. The EBC markers in office employees reached about 50% of the levels measured in production workers, and the difference between production workers and office employees was highly significant (p<0.001). None of these biomarkers were elevated in urine. The approach presented here seems to be very sensitive and useful for non-invasive monitoring of employees exposed to air pollutants, including gases, organic aerosols, and nanoTiO2, and may prove useful for routine biomonitoring purposes. Among them, aldehydes C6, C8, C9, and C10 appear to be the most sensitive markers of lipid oxidation in similar occupational cohorts. One major challenge with sensitive biomonitoring techniques, however, is their non-specificity and difficulty in interpreting the meaning of their physiological values in the context of chronic disease development and damage-repair kinetics.
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http://dx.doi.org/10.1515/reveh-2016-0030DOI Listing
March 2017

Leukotrienes in exhaled breath condensate and fractional exhaled nitric oxide in workers exposed to TiO2 nanoparticles.

J Breath Res 2016 06 30;10(3):036004. Epub 2016 Jun 30.

Department of Occupational Medicine, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Na Bojišti 1, 128 00 Prague 2, Czech Republic.

Human health data regarding exposure to nanoparticles are extremely scarce and biomonitoring of exposure is lacking in spite of rodent pathological experimental data. Potential markers of the health-effects of engineered nanoparticles were examined in 30 workers exposed to TiO2 aerosol, 22 office employees of the same plant, and 45 unexposed controls. Leukotrienes (LT) B4, C4, E4, and D4 were analysed in the exhaled breath condensate (EBC) and urine via liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). Fractional exhaled nitric oxide (FeNO) and spirometry was also measured. The median particle number concentration of the aerosol in the production ranged from 1.98  ×  10(4) to 2.32  ×  10(4) particles cm(-3); about 80% of the particles were  <100 nm in diameter. Median total mass concentration varied between 0.4 and 0.65 mg m(-3). All LT levels in workers' EBC were elevated relative to the controls (p  <  0.01). LTs in the EBC sample were correlated with titanium levels. Urinary LTs were not elevated in the workers and office employees. Office workers had higher LTB4 in EBC (p  <  0.05), and higher levels of FeNO (p  <  0.01). FeNO was higher in office employees with allergic diseases and was negatively correlated with smoking (p  <  0.01). In spirometry significant impairment in the workers was seen only for %VCIN and %PEF (both p  <  0.01). Multiple regression analysis confirmed a significant association between production of TiO2 and all cysteinyl LTs in EBC (p  <  0.01) and impaired %VCIN and %PEF (both p  <  0.01). LTB4 was also associated with smoking (p  <  0.01). LT levels complemented our earlier findings of DNA, protein, and lipid damage in the EBC of workers with nanoTiO2 exposures. Cysteinyl LTs in EBC analysis suggest inflammation and potential fibrotic changes in the lungs; they may be helpful for monitoring the biological effect of (nano)TiO2 on workers. Spirometry was not sensitive enough.
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http://dx.doi.org/10.1088/1752-7155/10/3/036004DOI Listing
June 2016

Opposing effects of oxidative challenge and carotenoids on antioxidant status and condition-dependent sexual signalling.

Sci Rep 2016 Mar 22;6:23546. Epub 2016 Mar 22.

Institute of Vertebrate Biology, v.v.i., The Czech Academy of Sciences, Květná 8, Brno 603 65, Czech Republic.

Several recent hypotheses consider oxidative stress to be a primary constraint ensuring honesty of condition-dependent carotenoid-based signalling. The key testable difference between these hypotheses is the assumed importance of carotenoids for redox homeostasis, with carotenoids being either antioxidant, pro-oxidant or unimportant. We tested the role of carotenoids in redox balance and sexual signalling by exposing adult male zebra finches (Taeniopygia guttata) to oxidative challenge (diquat dibromide) and manipulating carotenoid intake. As the current controversy over the importance of carotenoids as antioxidants could stem from the hydrophilic basis of commonly-used antioxidant assays, we used the novel measure of in vivo lipophilic antioxidant capacity. Oxidative challenge reduced beak pigmentation but elicited an increase in antioxidant capacity suggesting resource reallocation from signalling to redox homeostasis. Carotenoids counteracted the effect of oxidative challenge on lipophilic (but not hydrophilic) antioxidant capacity, thereby supporting carotenoid antioxidant function in vivo. This is inconsistent with hypotheses proposing that signalling honesty is maintained through either ROS-induced carotenoid degradation or the pro-oxidant effect of high levels of carotenoid-cleavage products acting as a physiological handicap. Our data further suggest that assessment of lipophilic antioxidant capacity is necessary to fully understand the role of redox processes in ecology and evolution.
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http://dx.doi.org/10.1038/srep23546DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4802301PMC
March 2016

Native T1 Relaxation Time and Extracellular Volume Fraction as Accurate Markers of Diffuse Myocardial Fibrosis in Heart Valve Disease - Comparison With Targeted Left Ventricular Myocardial Biopsy.

Circ J 2016 Apr 17;80(5):1202-9. Epub 2016 Mar 17.

Department of Cardiology, Institute for Clinical and Experimental Medicine.

Background: The aim of our study was to investigate the relationship between the cardiac magnetic resonance (CMR)-derived native T1 relaxation time and myocardial extracellular volume (ECV) fraction and the extent of diffuse myocardial fibrosis (DMF) on targeted myocardial left ventricular (LV) biopsy.

Methods and results: The study population consisted of 40 patients (age 63±8 years, 65% male) undergoing valve and/or ascending aorta surgery for severe aortic stenosis (77.5%), root dilatation (7.5%) or valve regurgitation (15%). The T1 relaxation time was assessed in the basal interventricular septum pre- and 10-min post-contrast administration using the modified Look-Locker Inversion recovery sequence prior to surgery. LV myocardial biopsy specimen was obtained during surgery from the basal interventricular septal segment matched with the T1 mapping assessment. The percentage of myocardial collagen was quantified using picrosirius red staining. The average percentage of myocardial collagen was 22.0±14.8%. Both native T1 relaxation time with cutoff value ≥1,010 ms (sensitivity=90%, specificity=73%, area under the curve=0.82) and ECV with cutoff value ≥0.32 (sensitivity=80%, specificity=90%, area under the curve=0.85) showed high accuracy to identify severe (>30%) DMF. The native T1 relaxation time showed significant correlation with LV mass (P<0.01).

Conclusions: Native T1 relaxation time and ECV at 10 min after contrast administration are accurate markers of DMF. (Circ J 2016; 80: 1202-1209).
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http://dx.doi.org/10.1253/circj.CJ-15-1309DOI Listing
April 2016

The effect of prolonged simvastatin application on serotonin uptake, membrane microviscosity and behavioral changes in the animal model.

Physiol Behav 2016 May 23;158:112-20. Epub 2016 Feb 23.

Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220 Prague, Czech Republic; National institute of Mental Health, Topolova 748, Klecany 250 67, Czech Republic; Department of Zoology, Ecology and Ethology Research Group, Faculty of Science, Charles University in Prague, Prague, Czech Republic. Electronic address:

Simvastatin and other statins (HMG-CoA (3-hydroxy-3-methylglutaryl coenzyme A) reductase inhibitors) are extensively used in clinical practices and are very effective in decreasing serum low-density lipoprotein cholesterol. However, their effect on cholesterol synthesis in central nervous system and its behavioral consequences have not been fully understood yet. We have studied selected biologic traits potentially affected by statin treatment - serotonin (5-HT) uptake in platelets, membrane microviscosity in erythrocytes, cholesterol level in the brain (amygdala; hippocampus and prefrontal cortex), as well as behavioral changes in an elevated plus maze and open field test in male Long-Evans rats, which were treated by simvastatin (30mg/kg per day) for 2 or 4weeks. We demonstrated: 1) a decrease in both serotonin transporter (SERT) activity and membrane microviscosity after treatment with simvastatin, 2) lower cholesterol content in all tested brain regions in animals from the simvastatin treated group, and 3) longer time spent in the open arms and a higher number of entrances to the closed arms in the elevated plus maze by animals from the simvastatin group compared to animals from the control group, but no differences in behavior in the open field test. Taken together, our results confirmed complex alterations, including behavioral changes, after the cholesterol lowering treatment. Furthermore, we discuss the possibility that the behavioral changes, traditionally interpreted as an anxiolytic effect, may be interpreted as increased impulsivity. We also confirmed that such behavioral changes may be attributed to changes in serotonergic neurotransmission.
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http://dx.doi.org/10.1016/j.physbeh.2016.02.029DOI Listing
May 2016

Oxidative stress markers are elevated in exhaled breath condensate of workers exposed to nanoparticles during iron oxide pigment production.

J Breath Res 2016 Feb 1;10(1):016004. Epub 2016 Feb 1.

Charles University in Prague and General University Hospital in Prague, First Faculty of Medicine, Department of Occupational Medicine, Na Bojišti 1, 128 00 Prague 2, Czech Republic.

Markers of oxidative stress and inflammation were analysed in the exhaled breath condensate (EBC) and urine samples of 14 workers (mean age 43  ±  7 years) exposed to iron oxide aerosol for an average of 10  ±  4 years and 14 controls (mean age 39  ±  4 years) by liquid chromatography-electrospray ionization-mass spectrometry/mass spectrometry (LC-ESI-MS/MS) after solid-phase extraction. Aerosol exposure in the workplace was measured by particle size spectrometers, a scanning mobility particle sizer (SMPS) and an aerodynamic particle sizer (APS), and by aerosol concentration monitors, P-TRAK and DustTRAK DRX. Total aerosol concentrations in workplace locations varied greatly in both time and space. The median mass concentration was 0.083 mg m(-3) (IQR 0.063-0.133 mg m(-3)) and the median particle concentration was 66 800 particles cm(-3) (IQR 16,900-86,900 particles cm(-3)). In addition, more than 80% of particles were smaller than 100 nm in diameter. Markers of oxidative stress, malondialdehyde (MDA), 4-hydroxy-trans-hexenale (HHE), 4-hydroxy-trans-nonenale (HNE), 8-isoProstaglandin F2α (8-isoprostane) and aldehydes C6-C12, in addition to markers of nucleic acid oxidation, including 8-hydroxy-2-deoxyguanosine (8-OHdG), 8-hydroxyguanosine (8-OHG), 5-hydroxymethyl uracil (5-OHMeU), and of proteins, such as o-tyrosine (o-Tyr), 3-chlorotyrosine (3-ClTyr), and 3-nitrotyrosine (3-NOTyr) were analysed in EBC and urine by LC-ESI-MS/MS. Almost all markers of lipid, nucleic acid and protein oxidation were elevated in the EBC of workers comparing with control subjects. Elevated markers were MDA, HNE, HHE, C6-C10, 8-isoprostane, 8-OHdG, 8-OHG, 5-OHMeU, 3-ClTyr, 3-NOTyr, o-Tyr (all p  <  0.001), and C11 (p  <  0.05). Only aldehyde C12 and the pH of samples did not differ between groups. Markers in urine were not elevated. These findings suggest the adverse effects of nano iron oxide aerosol exposure and support the utility of oxidative stress biomarkers in EBC. The analysis of urine oxidative stress biomarkers does not support the presence of systemic oxidative stress in iron oxide pigment production workers.
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http://dx.doi.org/10.1088/1752-7155/10/1/016004DOI Listing
February 2016

Ghrelin and endocannabinoids participation in morphine-induced effects in the rat nucleus accumbens.

Psychopharmacology (Berl) 2016 Feb 28;233(3):469-84. Epub 2015 Oct 28.

Department of Organic Technology ICT, Laboratory of Medicinal Diagnostics, Technicka 5, Prague 6, 166 28, Czech Republic.

Rationale And Objectives: In addition to dopamine, endocannabinoids are thought to participate in neural reward mechanisms of opioids. Number of recent studies suggests crucial involvement of ghrelin in some addictive drugs effects. Our previous results showed that ghrelin participates in morphine-induced changes in the mesolimbic dopaminergic system associated with reward processing. The goal of the present study was to test whether the growth hormone secretagogue receptor (GHS-R1A) antagonist JMV2959 was able to influence morphine-induced effects on anandamide (N-arachidonoylethanolamine, AEA) and 2-arachidonoylglycerol (2-AG) in the nucleus accumbens shell (NACSh).

Methods: We used in vivo microdialysis to determine changes in levels of AEA and 2-AG in the NACSh in rats following (i) an acute morphine dose (5, 10 mg/kg s.c.) with and without JMV2959 pretreatment (3, 6 mg/kg i.p.) or (ii) a morphine challenge dose (5 mg/kg s.c.) with and without JMV2959 (3, 6 mg/kg i.p.) pretreatment, administered during abstinence following repeated doses of morphine (5 days, 10-40 mg/kg). Co-administration of ghrelin (40 ug/kg i.p.) was used to verify the ghrelin mechanisms involvement.

Results: Pretreatment with JMV2959 significantly and dose-dependently reversed morphine-induced anandamide increases in the NACSh in both the acute and longer-term models, resulting in a significant AEA decrease. JMV2959 significantly intensified acute morphine-induced decreases in accumbens 2-AG levels and attenuated morphine challenge-induced 2-AG decreases. JMV2959 pretreatment significantly reduced concurrent morphine challenge-induced behavioral sensitization. JMV2959 pretreatment effects were abolished by co-administration of ghrelin.

Conclusions: Our results indicate significant involvement of ghrelin signaling in morphine-induced endocannabinoid changes in the NACSh.
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http://dx.doi.org/10.1007/s00213-015-4119-3DOI Listing
February 2016

Reward related neurotransmitter changes in a model of depression: An in vivo microdialysis study.

World J Biol Psychiatry 2015 Oct 7;16(7):521-35. Epub 2015 Oct 7.

c Department of Pharmacology , Third Faculty of Medicine, Charles University , Prague , Czech Republic , and.

Objectives: The self-medication hypothesis assumes that symptoms related to potential monoaminergic deficits in depression may be relieved by drug abuse. The aim of this study was to elucidate the neurotransmitter changes in a rat model of depression by measuring their levels in the nucleus accumbens shell, which is typically involved in the drug of abuse acquisition mechanism.

Methods: Depression was modelled by the olfactory bulbectomy (OBX) in Wistar male rats. In vivo microdialysis was performed, starting from the baseline and following after a single methamphetamine injection and behaviour was monitored. The determination of neurotransmitters and their metabolites was performed by high-performance liquid chromatography combined with mass spectrometry.

Results: OBX animals had lower basal levels of dopamine and serotonin and their metabolites. However, γ-aminobutyric acid (GABA) and glutamate levels were increased. The methamphetamine injection induced stronger dopamine and serotonin release in the OBX rats and lower release of glutamate in comparison with sham-operated rats; GABA levels did not differ significantly.

Conclusions: This study provides an evidence of mesolimbic neurotransmitter changes in the rat model of depression which may elucidate mechanisms underlying intravenous self-administration studies in which OBX rats were demonstrated to have higher drug intake in comparison to intact controls.
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http://dx.doi.org/10.3109/15622975.2015.1077991DOI Listing
October 2015