An increased risk of myocardial ischemic changes was demonstrated in patients suffering from panic disorder (PD). Using classical ECG methods, this risk cannot be evaluated in most patients. We measured the vectocardiogram (VCG) using Frank orthogonal leads and body surface maps (BSM) including 12-lead ECG. In our study of 11 PD patients (2 men, 9 women), without any seizures and pharmacological treatment and without cardiovascular symptoms, we found marked sinus tachycardia (heart rate 90.1±12.2 min-1) and a shorter R-R interval (678±93.6 ms) than in 27 controls (heart rate 73.6±7.7min-1, R-R 822.7±86.4 ms) (5 men, 22 women) (p<0.001). The VCG measured spatial QRS-STT angle was more opened (70.3±24.5°) than in the control group (49.5±19.5°) (p<0.05). The maximum (extremum) in depolarization (DIAM max 30, 40) and repolarization (RIAM max 35) of body surface isoarea and isointegral (RIIM max) maps was less positive (p<0.001) and the minimum (DIAM min 40) was less negative than in the controls (p<0.05) even in the period free of a panic attack. Our results showed the changes in the heart electric field parameters occurred in PD patients when compared to the control group., K. Pišvejcová, I. Paclt, J. Slavíček, O. Kittnar, A. Dohnalová, E. Kitzlerová., and Obsahuje bibliografii
We investigated how selected electromorphological parameters of myelinated axons influence the preservation of interspike intervals when the propagation of action potentials is corrupted by axonal intrinsic noise. Hereby we tried to determine how the intrinsic axonal noise influences the performance of axons serving as carriers for temporal coding. The strategy of this coding supposes that interspike intervals presented to higher order neurons would minimally be deprived of information included in interspike intervals at the axonal initial segment. Our experiments were conducted using a computer model of the myelinated axon constructed in a software environment GENESIS (GEneral NEural SImulation System). We varied the axonal diameter, myelin sheath thickness, axonal length, stimulation current and channel distribution to determine how these parameters influence the role of noise in spike propagation and hence in preserving the interspike intervals. Our results, expressed as the standard deviation of spike travel times, showed that by stimulating the axons with regular rectangular pulses the interspike intervals were preserved with a microsecond accuracy. Stimulating the axons with pulses imitating postsynaptic currents, greater changes of interspike intervals were found, but the influence of implemented noise on the jitter of interspike intervals was approximately the same., E. Kuriščák, S. Trojan, Z. Wünsch., and Obsahuje bibliografii
Escherichia coli (2x104 bacteria) of the non-pathogenic O86 strain or enteropathogenic O55 strain were administered into the pig amniotic cavity at 79 to 86 days of gestation for six or ten hours. Translocation of bacteria into fetal lungs was confirmed by cultivation as well as by light and electron microscopy. Infection caused an influx of macrophages that were immunostained in cryostat sections by monoclonal antibody recognizing calprotectin., I. Šplíchal, I. Trebichavský, A. Šplíchalová, L. Dítětová, M. Zahradníčková., and Obsahuje bibliografii
Aluminofluoride complexes (AlFx) form spontaneously in aqueous solutions containing fluoride and traces of aluminum ions and appear to act as phosphate analogs. These complexes have become widely utilized in laboratory investigations of various guanine nucleotide-binding proteins. Reflecting on many laboratory studies, a new mechanism of fluoride and aluminum action on the cellular level is being suggested. The long-term synergistic effects of these ions in living environment and their hidden danger for human health are not yet fully recognized., A. Strunecká, O. Strunecký, J. Patočka., and Obsahuje bibliografii
There are conflicting results concerning the receptor subtype(s) involved in calcium-mediated endothelin signaling in the glial cells. In order to elucidate the role of endothelin A and B receptors in these processes, we have studied the effect of a complex spectrum of endothelin receptor ligands on intracellular calcium concentration changes in proliferating and differentiated C6 rat glioma cells. Cell differentiation was induced by dibutyryl-cAMP and assessed by the glial fibrillar acidic protein content. Intracellular calcium changes were measured in cell suspensions using fluorescent probe Fura-2. The specific endothelin B receptor agonists sarafotoxin S6c and IRL-1620 did not influence the intracellular calcium concentration. However, calcium changes induced by endothelin-1 and especially by endothelin-3 after the pretreatment of cells with one of these endothelin B receptor specific agonists were significantly enhanced even above the values attained by the highest effective endothelin concentrations alone. Such endothelin B-receptor ligand-induced sensitization of calcium signaling was not observed in differentiated C6 cells. Moreover, endothelin-induced calcium oscillations in differentiated C6 cells were less inhibited by BQ-123 and BQ-788 than in their proliferating counterparts. In conclusion, the specific activation of endothelin B receptor in C6 rat glioma cells does not affect intracellular calcium per se, but probably does so through interaction with the endothelin A receptor. The pattern and/or functional parameters of endothelin receptors in C6 rat glioma cells are modified by cell differentiation., R. Malík, K. Vlašicová, A. Šedo., and Obsahuje bibliografii
Ghrelin is a new endogenous peptide, discovered in 1999 by Kojima et al., as the result of a search for an endogenous ligand for an orphan receptor of known structure and function. Ghrelin is composed of 28 amino acids and is produced mostly by cells of the stomach, hypothalamus, and hypophysis, but it has also been detected in other tissues. Its discovery is related to the development of a new hypothesis regarding the regulation of growth hormone secretion. It is an antagonist of somatostatin. Ghrelin activates the release of growth hormone from the somatotrophic cells of the hypophysis. It participates in the regulation of energy homeostasis, increases food intake, decreases energy output and exerts a lipogenetic effect. Its metabolic effects do not depend on the GH/IGF-I system, but are mediated by the NPY/Y1 and AGRP receptor system. Ghrelin influences the secretion and motility of the gastrointestinal tract, especially the stomach. The presence of ghrelin and its receptors has also been demonstrated in many other tissues. Its function in these tissues has not yet been studied, thus providing many possibilities for further research., M. Rosická, M. Kršek, Z. Jarkovská, J. Marek, V. Schreiber., and Obsahuje bibliografii
Single unit recordings were made from the motor cortex of conscious cats with glass micropipettes that allowed ionophoretic application of 0.5 M glutamate in 2 M NaCl or 0.5 M ACPD (1S,3R-1-amino-cyclopentane-1,3-dicarboxylic acid, a mGluR agonist) in 2 M NaCl. Activity in response to a 70 dB click (1 ms rectangular pulse to loudspeaker) was studied before, during, and immediately after applying each agent locally as a paired US (90 nA current 570 ms after click for 300 ms in combination with glabella tap). A 70 dB hiss sound was presented 4.4 sec after the click as a discriminative stimulus (DS). CS and DS were presented 10 times initially (adaptation); then CS, US plus tap, and DS (approximately 10 times as conditioning); and then CS and DS (2-10 times to test post-conditioning). Glutamate potentiated the mean, early, 8-16 ms response to the click after conditioning (t=18.2, p<0.0001), but not the baseline activity which decreased from a mean of 17 spk/sec to 7 spk/sec (t=3.71, p<0.001). Baseline activity increased to 31 spk/sec when glutamate was applied during conditioning (t=3.30, p<0.005). ACPD reduced the intermediate, 64-72 ms response to the click after conditioning (t=8.18, p<0.0001), and potentiated the late 104-112 ms response (t=15.4, p<0.0001). Baseline activity was slightly increased after conditioning with ACPD. Saline did not potentiate the response to click. The results indicate that glutamate agonists that differ in their receptor affinities can induce different CRs when used as locally applied USs to condition neuronal responses to a click CS in the motor cortex of cats., Ch. D. Woody., and Obsahuje bibliografii
Positive effects of repeated administration of diclofenac, an inhibitor of prostaglandin synthesis, in terms of prevention of tumor development and stimulation of hematopoiesis have been observed in C3H mice transplanted subcutaneously with G:5:113 fibrosarcoma cells. Fourteen-day treatment with diclofenac (3.75 mg/kg/day) started from day 5 after tumor cell transplantation. Measurements of tumors and hematological examinations were performed on day 30. The results strongly suggest the possibility that inhibitors of prostaglandin synthesis (non-steroidal anti-inflammatory drugs) may be used in oncological practice where the observed effects are highly desirable., M. Hofer, Z. Hoferová, P. Fedoročko, N. O. Macková., and Obsahuje bibliografii
The use of reversible lesion techniques in memory research was pioneered in the laboratory of Jan Bureš and Olga Burešova. We use the occasion of Jan’s 75th birthday to briefly review the experimental utility of this approach. Two experiments from our current research are reported in which reversible lesioning methods are used to ask otherwise experimentally untenable questions about memory retrieval. The first experiment used intra-hippocampal injections of tetrodotoxin to temporarily inactivate the hippocampus during retrieval of a well-learned place avoidance navigation memory. This revealed that the hippocampus is necessary for place avoidance retrieval but that the extinction of place avoidance can occur independently of retrieving the memory and intact hippocampal function. The second experiment used KCl-induced cortical spreading depression in an interhippocampal transfer paradigm to demonstrate that a Y-maze memory that is learned by only one cortical hemisphere can be made to transfer to the other hemisphere by forcing the rat to swim, a unique stressful experience that occurred in a different apparatus, different behavioral context, and involved different behaviors than the Y-maze training. This demonstrates, we believe for the first time behaviorally, that memories can be activated outside of the behavioral context of their acquisition and expression in rats., K. Ježek, M. Wesierska, A. A. Fenton., and Obsahuje bibliografii
To determine whether changes in partial pressure of CO2 participate in mechanism enlarging the lung functional residual capacity (FRC) during chronic hypoxia, we measured FRC and ventilation in rats exposed either to poikilocapnic (group H, FIO2 0.1, FICO2 <0.01) or hypercapnic (group H+CO2, FIO2 0.1, FICO2 0.04-0.05) hypoxia for the three weeks and in the controls (group C) breathing air. At the end of exposure a body plethysmograph was used to measure ventilatory parameters (V´E, fR, VT) and FRC during air breathing and acute hypoxia (10 % O2 in N2). The exposure to hypoxia for three weeks increased FRC measured during air breathing in both experimental groups (H: 3.0±0.1 ml, H+CO2: 3.1±0.2 ml, C: 1.8±0.2 ml). During the following acute hypoxia, we observed a significant increase of FRC in the controls (3.2±0.2 ml) and in both experimental groups (H: 3.5±0.2 ml, H+CO2: 3.6±0.2 ml). Because chronic hypoxia combined with chronic hypercapnia and chronic poikilocapnic hypoxia induced the same increase of FRC, we conclude that hypercapnia did not participate in the FRC enlargement during chronic hypoxia., H. Maxová, M. Vízek., and Obsahuje bibliografii