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1392. Ultrastructural characteristics of aortic endothelial cells in borderline hypertensive rats exposed to chronic social stress
- Creator:
- Ľudmila Okruhlicová, Katarína Dlugošová, Mitašíková, M., and Iveta Bernátová
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- article, články, model:article, and TEXT
- Subject:
- Experimentální medicína, kardiovaskulární fyziologie, stres (psychologie), hypertenze, endotel, potkan, cardiovascular physiology, stress (psychology), hypertension, endothelium, Rattus norvegicus, social stress, ultrastructure, 14, and 616-092
- Language:
- English
- Description:
- Genetic predisposition and social stress may represent important risk factors in etiology of hypertension associated with endothelial dysfunction. Perturbations of endothelial structural integrity are also critical for the pathogenesis of vascular diseases. We examined effect of chronic social stress on structure of aortic endothelium in bord erline hypertensive (BHR) and normotensive Wistar rats. Male BHR – offspring of Wistar mothers and SHR fathers and age-matched W were exposed to 6-week crowding stress (5 rats/cage, 200 cm2/rat). Aortic tissue was processed for electron microscopy and NO synthase activity measurement. Crowding stress significantly increased blood pressure in BHR compared to basal values (140±3 mm Hg vs. 130±3 mm Hg, p<0.05) and reduced enzyme activity by 37 % (p<0.01) in the aorta of BHR. Local slight structural alterations of endothelium were found in non-stressed BHR (p<0.001) when compared with Wistar rats. Chronic stress caused marked (p<0.005) subcellular injury of endothelial cells in aorta of BHR characterized by mitochondrial damage, presence of vacuoles, increased number of lysosomes, Weibel-Palade bodies, changes of intercellular connections and local disruption of endothelium, while only slight changes were seen in Wistar rats. Results suggest increased sensitivity of aortic endothelium of BHR to chronic crowding that may contribute to acceleration of arterial dysfunction., Ľ. Okruhlicová, K. Dlugošová, M. Mitašíková, I. Bernátová., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1393. Ultrastructural distribution of the S100A1 Ca2+-binding protein in the human heart
- Creator:
- Bohumil Maco, Mandinova, A., Dürrenberger, M. B., Schäfer, B. W., Uhrík, B., and Heizmann, C. W.
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- Subject:
- Fyziologie člověka a srovnávací fyziologie, imunocytochemie, immunocytochemistry, human heart muscle, Ca2+-binding proteins, S100A1, 14, and 612
- Language:
- English
- Description:
- Impaired calcium homeostasis and altered expression of Ca2+-binding proteins are associated with cardiomyopathies, myocardial hypertrophy, infarction or ischemia. S100A1 protein with its modulatory effect on different target proteins has been proposed as one of potential candidates which could participate in these pathological processes. The exact localization of S100A1 in human heart cells on the ultrastructural level accompanied with biochemical determination of its target proteins may help clarify the role of S100A1 in heart muscle. In the present study the distribution of the S100A1 protein using postembedding (Lowicryl K4M) immunocytochemical method in human heart muscle has been determined quantitatively, relating number of antigen sites to the unit area of a respective structural component. S100A1 antigen sites have been detected in elements of sarcoplasmic reticulum (SR), in myofibrils at all levels of sarcomere and in mitochondria, the density of immunolabeling at Z-lines being about 3 times and at SR more than 5 times higher than immunolabeling of remaining structural components. The presence of the S100A1 in SR and myofibrils may be related to the known target proteins for S100A1 at these sites., B. Maco, A. Mandinová, M.B. Dürrenberger, B.W. Schäfer, B. Uhrík, C.W. Heizmann., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1394. Unrecognized origin signals disturbing water-tubes tiltmeters measurements in geodynamic laboratory of SRC in Ksiaz
- Creator:
- Kaczorowski, Marek
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- Type:
- article, články, model:article, and TEXT
- Subject:
- Geologie. Meteorologie. Klimatologie, geodynamika, geodynamics, Earth tides, water-tube tiltmeters, disturbances of plumb line variations, infrasound measurements, natural sources of micro-vibrations, atmospheric resonance, interaction between ocean-atmosphere and ionosphereatmosphere, 7, and 551
- Language:
- English
- Description:
- The harmonic oscillations of water level changes with several hundred nanometers amplitudes and 10-3 [Hz] frequencies are irregularly observed with the water-tube tiltmeter. The effects are observed only by one of four gauges - the one closest to the entrance to underground. The other three gauges of water-tube tiltmeters are situated at the ends of the corridors and are significantly more distant from the entrance to the underground. The atmospheric pressure signals affect level of water in the instrument by inverse barometric effect. The water-tube tiltmeters can register water level variations associated with inverse barometric effects, which were produced by air pressure signals until 10-5 [Pa] magnitude. The amplitude of harmonic oscillations of water level is significantly large and amounts to 1/10 of tidal amplitude, that is 300 to 500 nanometers, which corresponds to 5 x 10-3 [Pa] of air pressure variations. Harmonic oscillations appear irregularly and their time of duration changes from few days until several weeks. The length of atmospheric wave of 10-3 [Hz] frequencies is of 1000 [km] and cannot be explained by any phenomenon from the outside surroundings or the inside of the underground. Resonance frequencies of air column in the hundred meters long underground corridors are of the order of single Hz. Absence of similar signals in measurements from the other three gauges suggests that the harmonic signals are not propagated through the Earth’s solid body but through the atmospheric medium. The observed micro-vibrations of air pressure are very low infrasounds which can be produced in large dimension space of thousand kilometers size. The open question is what is the origin of micro-vibrations registered by the water-tube tiltmeter., Marek Kaczorowski., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1395. Uridine - an indicator of post-exercise uric acid concentration and blood pressure
- Creator:
- Dudzinska, W., Lubkowska, A., Dolegowska, B., Suska, M., and Janiak, M.
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- Subject:
- Fyziologie člověka a srovnávací fyziologie, kyselina močová, krevní tlak, tělesná cvičení, uric acid, blood pressure, exercises, uridine, 14, and 612
- Language:
- English
- Description:
- Studies have shown that uridine concentration in plasma may be an indicator of uric acid production in patients with gout. It has been also postulated that uridine takes part in blood pressure regulation. Since physical exercise is an effective tool in treatment and prevention of cardio-vascular diseases that are often accompanied by hyperuricemia and hypertension, it seemed advisable to attempt to evaluate the relationship between oxypurine concentrations (Hyp, Xan and UA) and that of Urd and BP after physical exercise in healthy subjects. Sixty healthy men (17.2±1.71 years, BMI 23.2±2.31 kg m-2, VO2max 54.7±6.48 ml kg-1 min-1) took part in the study. The subjects performed a single maximal physical exercise on a bicycle ergometer. Blood for analyses was sampled three times: immediately before exercise, immediately after exercise, and in the 30th min of rest. Concentrations of uridine and hypoxanthine, xanthine and uric acid were determined in whole blood using high-performance liquid chromatography. We have shown in this study that the maximal exercise-induced increase of uridine concentration correlates with the post-exercise increase of uric acid concentration and systolic blood pressure. The results of our study show a relationship between uridine concentration in blood and uric acid concentration and blood pressure. We have been the first to demonstrate that a maximal exercise-induced increase in uridine concentration is correlated with the post-exercise and recovery-continued increase of uric acid concentration in healthy subjects. Thus, it appears that uridine may be an indicator of post-exercise hyperuricemia and blood pressure., W. Dudzinska, A. Lubkowska, B. Dolegowska, M. Suska, M. Janiak., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1396. Urinary urea nitrogen excretion during the hyperinsulinemic euglycemic clamp in type 1 diabetic patients and healthy subjects
- Creator:
- Pavel Wohl, Eva Krušinová, Marta Klementová, Petr Wohl, Simona Kratochvílová, and Terezie Pelikánová
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- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, diabetologie, inzulín, kalorimetrie, diabetology, insulin, calorimetry, substrate utilization, urinary urea nitrogen excretion, glycemic clamp, indirect calorimetry, 14, and 612
- Language:
- English
- Description:
- The hyperinsulinemic euglycemic clamp (HEC) combined with indirect calorimetry (IC) is used for estimation of insulin-stimulated substrate utilization. Calculations are based on urinary urea nitrogen excretion (UE), which is influenced by correct urine collection. The aims of our study were to improve the timing of urine collection during the clamp and to test the effect of insulin on UE in patients with type 1 diabetes (DM1; n=11) and healthy subjects (C; n=11). Urine samples were collected (a) over 24 h divided into 3-h periods and (b) before and during two-step clamp (1 and 10 mIU.kg-1.min-1; period 1 and period 2) combined with IC. The UE during the clamp was corrected for changes in urea pool size (UEc). There were no significant differences in 24-h UE between C and DM1 and no circadian variation in UE in either group. During the clamp, serum urea decreased significantly in both groups (p<0.01). Therefore, UEc was significantly lower as compared to UE not adjusted for changes in urea pool size both in C (p<0.001) and DM1 (p<0.001). While UE did not change during the clamp, UEc decreased significantly in both groups (p<0.01). UEc during the clamp was significantly higher in DM1 compared to C both in period 1 (p<0.05) and period 2 (p<0.01). The UE over 24 h and UEc during the clamp were statistically different in both C and DM1. We conclude that urine collection performed during the clamp with UE adjusted for changes in urea pool size is the most suitable technique for measuring substrate utilization during the clamp both in DM1 and C. Urine collections during the clamp cannot be replaced either by 24-h sampling (periods I-VII) or by a single 24-h urine collection. Attenuated insulin-induced decrease in UEc in DM1 implicates the impaired insulin effect on proteolysis. and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1397. Use of 3D geometry modeling of osteochondrosis-like iatrogenic lesions as a template for press-and-fit scaffold seeded with mesenchymal stem cells
- Creator:
- Petr Krupa, Pavel Kršek, Javorník, M., Otto Dostál, Robert Srnec, Dušan Usvald, Pavel Proks, Helga Kecová, Evžen Amler, Josef Jančář, Peter Gál, Ladislav Plánka, and Alois Nečas
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- Subject:
- Fyziologie člověka a srovnávací fyziologie, chrupavka, mezenchymální kmenové buňky, cartilage, mesenchymal stem cells, CT imaging, tissue segmentation, joint resurfacing, miniature pig, 14, and 612
- Language:
- English
- Description:
- Computed tomography (CT) is an effective diagnostic modality for three-dimensional imaging of bone structures, including the geometry of their defects. The aim of the study was to create and optimize 3D geometrical and real plastic models of the distal femoral component of the knee with joint surface defects. Input data included CT images of stifle joints in twenty miniature pigs with iatrogenic osteochondrosis-like lesions in medial femoral condyle of the left knee. The animals were examined eight and sixteen weeks after surgery. Philips MX 8000 MX and View workstation were used for scanning parallel plane cross section slices and Cartesian discrete volume creation. On the average, 100 slices were performed in each stifle joint. Slice matrices size was 512 x 512 with slice thickness of 1 mm. Pixel (voxel) size in the slice plane was 0.5 mm (with average accuracy of ± 0.5 mm and typical volume size 512 × 512 × 100 voxels). Three-dimensional processing of CT data and 3D geometrical modelling, using interactive computer graphic system MediTools formerly developed here, consisted of tissue segmentation (raster based method combination and 5 % of manual correction), vectorization by the marching-cubes method, smoothing and decimation. Stifle- joint CT images of three individuals of different body size (small, medium and large) were selected to make the real plastic models of their distal femurs from plaster composite using rapid prototyping technology of Zcorporation. Accuracy of the modeling was ± 0.5 mm. The real plastic models of distal femurs can be used as a template for developing custom made press and fit scaffold implants seeded with mesenchymal stem cells that might be subsequently implanted into iatrogenic joint surface defects for articular cartilage-repair enhancement., P. Krupa, P. Kršek, M. Javorník, O. Dostál, R. Srnec, D. Usvald, P. Proks, H. Kecová, E. Amler, J. Jančář, P. Gál, L. Plánka, A. Nečas., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1398. Use of chemical dosimetry for comparison of ultrasound and ionizing radiation effects on cavitation
- Creator:
- Bohumil Kratochvíl and Vojtěch Mornstein
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- Subject:
- Fyziologie člověka a srovnávací fyziologie, ultrazvuk, ionizující záření, ultrasound, ionizing radiation, cavitation effects, gray equivalent dose, dosimetry, 14, and 612
- Language:
- English
- Description:
- A comparison of the effects of ultrasound produced by low- and high-frequency ultrasonic apparatuses upon biological systems is one of the basic problems when studying ultrasound cavitation effects. One possibility for how to compare these effects is the indirect method which uses well-known physical quantities characterizing the interaction of ionizing radiation with matter and which also converts these quantities to one common physical quantity. The comparison was performed with two methods applied to the chemical dosimetry of ionizing radiation. The first method employed a twocomponent dosimeter which is composed of 50 % chloroform and 50 % re-distilled water (i.e. Taplin dosimeter). The other method used a modified iodide dosimeter prepared from a 0.5 M potassium iodide solution. After irradiation or ultrasound exposure, measurable chemical changes occurred in both dosimeters. The longer the exposure, the greater the chemical changes. These effects are described by the relationship of these changes versus the exposure times in both dosimeters. The UZD 21 ultrasonic disintegrator (with a frequency of 20 kHz, 50 % power output) was used as a lowfrequency ultrasound source, and the BTL-07 therapeutic instrument (with a frequency of 1 MHz and intensity of 2 W/cm2) was used as a high-frequency cavitation ultrasound source. For comparison, a 60Co gamma source was applied (60Co, gamma energies of 1.17 and 1.33 MeV, activity of 14 PBq). Results of this study have demonstrated that the sonochemical products are generated during exposure in the exposed samples of both dosimeters for all apparatuses used. The amount of these products depends linearly upon the exposure time. The resulting cavitation effects were recalculated to a gray-equivalent dose (the proposed unit is cavitation gray [cavitGy]) based on the sonochemical effects compared to the effects of ionizing radiation from the 60Co source., B. Kratochvíl, V. Mornstein., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1399. Use of electrogastrography in preclinical studies of cholinergic and anticholinergic agents in experimental pigs
- Creator:
- Jaroslav Květina, Ilja Tachecí, Pavlík, M., Marcela Kopáčová, Stanislav Rejchrt, Tomáš Douda, Martin Kuneš, and Jan Bureš
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- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, electrogastrography, experimental pigs, atropine, neostigmine, 14, and 612
- Language:
- English
- Description:
- Electrogastrography (EGG) is a non-invasive method for the assessment of gastric myoelectrical activity. Porcine EGG is comparable with human one. The purpose of this study was to evaluate the effect of atropine and neostigmine on the EGG in experimental pigs. Adult female pigs were administrated atropine (1.5 mg i.m., n=6) and neostigmine (0.5 mg i.m., n=6) after the baseline EGG, followed by a 90-min trial recording (MMS, Enschede, the Netherlands). Running spectral analysis was used for the evaluation. The results were expressed as dominant frequency of slow waves and EGG power (areas of amplitudes). Neostigmine increased continuously the dominant frequency and decreased significantly the EGG power. Atropine did not change the dominant frequency significantly. However, atropine increased significantly the EGG power (areas of amplitudes) from basal values to the maximum at the 10-20-min interval. After that period, the areas of amplitudes decreased significantly to the lowest values at the 60-90-min interval. In conclusion, cholinergic and anticholinergic agents affect differently EGG in experimental pigs., J. Květina, I. Tachecí, M. Pavlík, M. Kopáčová, S. Rejchrt, T. Douda, M. Kuneš, J. Bureš., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1400. Use of low-cost mems technology in early warning system against landslide threats
- Creator:
- Ćmielewski, Bartłomiej, Kontny, Bernard, and Ćmielewski, Kazimierz
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- article, články, model:article, and TEXT
- Subject:
- Geologie. Meteorologie. Klimatologie, sesuvy půdy, landslides, monitoring, accelerometer, early warning system, MEMS, 7, and 551
- Language:
- English
- Description:
- Modern methods of monitoring landslides are based on observations of both: direct surveying (GNSS, electronic tachymetry, geometric levelling) and remote sensing (terrestrial and aerial photogrammetry, laser scanning, interferometry), as well as surface and subsurface geotechnical observations (e.g. inclinometers, extensometers, piezometers, etc.). Due to the high cost of installation of these devices and its measurement, the implementations of these methods are usually used on well-define d objects, with established landslide activity and high risk to people’s lives. The main objective of the project was to design, create and do practical tests of simple and inexpensive measurement devices, which detect first symptoms of a potential landslide movements and alert of an existing threat. These devices would be some kind of an early warning system that would register the occurrence of the first movements of the surface layers of soil, which would be a signal to start of geodetic and geotechnical monitoring of potential landslides., Bartłomiej Ćmielewski, Bernard Kontny and Kazimierz Ćmielewski., and Obsahuje bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public