Pyridoxal isonicotinoyl hydrazone (PIH) is a new tridentate Fe-chelating agent that should be very promising in many pathological states resulting from both an iron-overload and formation of free radicals. The aim of our study was to investigate the effect of PIH on the cardiovascular system focusing to the regulatory protein - cardiac troponin T (cTnT). The study was carried out in two groups of Chinchilla male rabbits: 1) PIH (50 mg/kg dissolved in 10 % Cremophor i.p., once a week, 10 administrations, n=8) and 2) Cremophor (2 ml/kg i.p. in the same schedule, n=7). Plasma concentrations of cTnT (as a marker of myocardial damage) were measured using a commercial kit (Roche). cTnT was within the physiological range (i.e. < 0.1 mg/l) during the whole experiment in the Cremophor group. In the PIH group, the cTnT levels were not significantly increased when compared with the control group or with the initial values (except with those before the 5th administration). Furthermore, we analyzed the cytosolic and myofibrillar fraction of cTnT in the left ventricular myocardium. Using SDS-PAGE and Western blot we resolved three isoforms. The profiling of TnT did not differ significantly between the PIH-treated group and the Cremophor-treated group. Our data concerning cTnT support the opinion that the possible cardiotoxicity of PIH is very low., M. Adamcová, J. Macháčková, V. Geršl, V. Pelouch, T. Šimůnek, I. Klimtová, R. Hrdina, P. Poňka., and Obsahuje bibliografii
Cardicola langeli n. sp. (Digenea: Aporocotylidae) infects the heart of sheepshead, Archosargus probatocephalus (Walbaum, 1792) (Perciformes: Sparidae) in the northern Gulf of Mexico off Horn Island (type locality), Mississippi, USA. The new species is described herein using light and scanning electron microscopy of adult specimens and can be most easily distinguished from the other 24 accepted species of Cardicola Short, 1953 by the combination of having (i) an ovovitelline duct that extends anteriad and that (ii) is posterior to the ootype, (iii) a male genital pore that is lateral to the oviducal seminal receptacle and (iv) a female genital pore lateral to the ootype. The new species is the only member of Cardicola so-far reported to have tegumental spines that are distally flattened and broad, rather than pointed. The new species generally resembles the two other species of Cardicola that infect sparids, i.e. Cardicola cardiocolum (Manter, 1947) (type species) from jolthead porgy, Calamus bajonado (Block et Schneider), in the Gulf of Mexico and Cardicola aurata Holzer, Montero, Repullés, Sitja-Bobadilla, Alvarez-Pellitero, Zarza et Raga, 2008, from gilthead seabream, Sparus aurata Linnaeus, in the Mediterranean Sea, by having a spheroid anterior sucker with concentric rows of minute spines anterior to the mouth and by having a similar general arrangement of the vitellarium, gonads and genitalia. However, it differs from them by having the combination of the aforementioned five features plus asymmetrical posterior caeca and a dextral posterior caecum that extends beyond the posterior margin of the ovary. Probable eggs of C. langeli n. sp. that contain a ciliated miracidium infect gill epithelium and are spheroid. An updated list of hosts, infection sites and geographic localities for the 25 accepted species of Cardicola is provided.
A topological space X has a rank 2-diagonal if there exists a diagonal sequence on X of rank 2, that is, there is a countable family {Un : n ∈ ω} of open covers of X such that for each x ∈ X, {x} = ∩ {St2 (x,Un): n ∈ ω}. We say that a space X satisfies the Discrete Countable Chain Condition (DCCC for short) if every discrete family of nonempty open subsets of X is countable. We mainly prove that if X is a DCCC normal space with a rank 2-diagonal, then the cardinality of X is at most c. Moreover, we prove that if X is a first countable DCCC normal space and has a Gδ-diagonal, then the cardinality of X is at most c.
For an uncountable monounary algebra $(A,f)$ with cardinality $\kappa $ it is proved that $(A,f)$ has exactly $2^{\kappa }$ retracts. The case when $(A,f)$ is countable is also dealt with.
The effect of chronic hypercapnia on cardioprotection induced by chronic hypoxia was investigated in adult male Wistar rats exposed to isobaric hypoxia (10 % O2) for three weeks. In the first experimental group, CO2 in the chamber was fully absorbed; in the second group, its level was increased to 4.1 %. Normoxic controls were kept in atmospheric air. Anesthetized open-chest animals were subjected to 20-min LAD coronary artery occlusion and 3-h reperfusion for infarct size determination (TTC staining). Chronic hypoxia alone reduced body weight and increased hematocrit; these effects were significantly attenuated by hypercapnia. The infarct size was reduced from 61.9 ± 2.2 % of the area at risk in the normoxic controls to 44.5±3.3 % in the hypoxic group (P<0.05). Hypercapnia blunted the infarct size-limiting effect of hypoxia (54.8±2.4 %; P<0.05). It is concluded that increased CO2 levels in the inspired air suppress the development of the chronic hypoxia-induced cardioprotective mechanism, possibly by interacting with ROS signalling pathways., J. Neckář, O. Szárszoi, J. Herget, B. Ošťádal, F. Kolář., and Obsahuje bibliografii
Quercetin, a polyphenolic compound present in various types of food, has been shown to exert beneficial effects in different cardiac as well as non-cardiac ischemia/reperfusion (I/R) models in adult animals. However, there is no evidence about the effects of quercetin on I/R injury in non-mature animals, despite the fact that efficiency of some interventions against I/R is agedependent. This study was aimed to investigate the effects of chronic quercetin treatment on I/R injury in juvenile and adult rat hearts. Juvenile (4-week-old) as well as adult (12-week-old) rats were treated with quercetin (20 mg/kg/day) for 4 weeks, hearts were excised and exposed to 25-min global ischemia followed by 40-min reperfusion. Functional parameters of hearts and occurrence of reperfusion arrhythmias were registered to assess the cardiac function. Our results have shown that quercetin improved post-ischemic recovery of LVDP, as well as recovery of markers of contraction and relaxation, +(dP/dt)max and -(dP/dt)max, respectively, in juvenile hearts, but not in adult hearts. Quercetin had no impact on incidence as well as duration of reperfusion arrhythmias in animals of both ages. We conclude that the age of rats plays an important role in heart response to quercetin treatment in the particular dose and duration of the treatment. Therefore, the age of the treated subjects should be taken into consideration when choosing the dose of quercetin and duration of its application in prevention and/or treatment of cardiovascular diseases., M. Bartekova, J. Radosinska, D. Pancza, M. Barancik, T. Ravingerova., and Obsahuje bibliografii
The objectives of this study were to investigate the role of
endogenous opioids in the mediation of stress-induced
cardiomyopathy (SIC), and to evaluate which opioid receptors
regulate heart resistance to immobilization stress. Wistar rats
were subjected to 24 h immobilization stress. Stress-induced
heart injury was assessed by 99mTc-pyrophosphate accumulation
in the heart. The opioid receptor (OR) antagonists (naltrexone,
NxMB – naltrexone methyl bromide, MR 2266, ICI 174.864) and
agonists (DALDA, DAMGO, DSLET, U-50,488) were administered
intraperitoneally prior to immobilization and 12 h after the start
of stress. In addition, the selective µ OR agonists PL017 and
DAMGO were administered intracerebroventricularly prior to
stress. Finally pretreatment with guanethidine was used.
Naltrexone did not alter the cardiac 99mTc-PP accumulation in
stressed rats. NxMB aggravated stress-induced cardiomyopathy
(P=0.005) (SIC). The selective µ OR agonist DALDA, which does
not cross the blood-brain barrier, completely prevented
(P=0.006) SIC. The µ OR agonist DAMGO exhibited weaker effect
than DALDA. The selective δ ligand (DSLET) and κ OR ligand
(U-50,488) did not alter stress-induced 99mTc-pyrophosphate
accumulation in the heart. Intracerebroventricular administration
of the µ OR agonists aggravated SIC. Pretreatment with
guanethidine abolished this effect (P=0.01). Guanethidine alone
exhibited cardioprotective properties. A stimulation of central
µ OR promotes an appearance of SIC. In contrast, stimulation of peripheral µ OR contributes to an increase in cardiac tolerance to
stress
The purpose of this study was to assess the endocrine status, thoracic impedance, blood concentration, and hemodynamic dose-responses using different angles of passive head-up tilt (HUT) ranging from 12° to 70° in the same subjects. Measurements were performed during 20 min supine position (pre-HUT), 30 min upright (HUT12, HUT30, HUT53, or HUT70), and 20 min supine (post-HUT); subjects 70 min in the supine position only (HUT0) served as resting controls. Norepinephrine increased above resting control values by 19, 44, 80, and 102 %; epinephrine by 30, 41, 64, and 68 %; aldosterone by 29, 62, 139, and 165 %; plasma renin activity n. s., 41, 91, and 89 %; vasopressin n.s., 27, 47, and 59 %; thoracic bioimpedance n. s., 8, 13, and 16 %; heart rate n. s., 5, 26, and 45 %, and mean arterial pressure n. s., 5, 7, and 10 %; at min 27 of HUT12, HUT30, HUT53, and HUT70, respectively. Pulse pressure decreased with HUT53 and HUT70 by 4 and 10 %. Hematocrit increased by 0.2, 1.7, 6.3, and 7.2 %, respectively. Blood density increased by 2.3 and 3.0 g/l, plasma density by 1.7 and 1.8 g/l with HUT53 and HUT70. After finishing HUT, heart rate fell to values which stayed below pre-HUT, and also below resting control levels for ł 5 min ("post-orthostatic bradycardia") even after the lowest orthostatic load (HUT12). Thoracic impedance and arterial pressure remained increased after terminating HUT30, HUT53, and HUT70. In conclusion, passive orthostatic loading of different extent produces specific dose-responses of different magnitude in the endocrine system, blood composition, thoracic impedance, and hemodynamic variables. The heart rate is depressed even after HUT12, while arterial blood pressure and thoracic impedance exceed pre-stimulus levels after greater head-up tilt, indicating altered cardiovascular response after passive orthostasis., Z. László, A. Rössler, H. G. Hinghofer-Szalkay., and Obsahuje bibliografii
Present study was aimed to investigate sympathetic responses to mental stress with hypothesis that the presence of obesity in patients with hypertension has a modifying effect. Young male subjects, 8 with hypertension grade I, with BMI<25 kg/m2 (HT), 10 with hypertension grade I, and BMI>30 kg/m2 (HT OB), 14 healthy controls with BMI<30 kg/m2 (OB), and 13 healthy controls with BMI<25 kg/m2 (C) underwent the Stroop test. ECG was recorded continuously to evaluate heart rate variability (HRV). Blood pressure (BP) and catecholamine concentrations were measured at baseline, at the end of mental stress test and 15 min thereafter. Patients with HT demonstrated increased adrenaline concentrations and enhanced stress-induced noradrenaline release compared to that in healthy controls. In obese subjects, stress-induced increase of systolicBP was lower compared to lean individuals. Stress exposure induced a significant rise in the low frequency power component of HRV, however the increase was lower in the HT OB group compared to C. Obesity in patients with hypertension did not lead to a different reaction in comparison with lean hypertensive subjects. The present data demonstrate higher sympathoadrenal activity in early-stage of hypertension. Obesity is connected with higher resting systolicBP and modifies the HRV response to mental stress., A. Garafova, A. Penesova, E. Cizmarova, A. Marko, M. Vlcek, D. Jezova., and Obsahuje bibliografii
Our aim was to test the hypothesis that the occurrence of extrasystoles in higher decennia is proportional to the altitude. The occurrence of supraventricular (SVPB) and ventricular (VEB) extrasystoles, values of systolic and diastolic blood pressure and the heart rate were studied in 20 healthy elderly men (50-64 years) during cable cabin transportation to a moderate altitude. These values were measured in stations located at 898 m, 1764 m, and 2632 m above sea level during the transportation in both directions. Our records show that the values of blood pressure and heart rate were within normal limits during the whole period of transportation. Both SVPB and VEB were increasing during the ascent and decreasing to the initial values during the descent compared to the values at altitude of 898 m. The highest values (6 to 7-times exceeding the initial ones) were measured at the summit. The results have demonstrated that the occurrence of SVPB and VEB is proportional to the altitude. The increased incidence in the number of extrasystoles is suggested to be mediated by beta-adrenoceptors., Š. Kujaník, M. Sninčák, K. Galajdová, K. Racková., and Obsahuje bibliografii