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Start Over Subject human physiology Date Unknown

273. Protective Effects of Topical Alpha-Tocopherol Acetate on UVB Irradiation in Guinea Pigs: Importance of Free Radicals

Creator:
Saral, Y., Uyar, B., Ahmet Ayar, Naziroglu, M., and Yilmaz, S.
Format:
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Type:
article, studie, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, Alpha-tocopherol, Antioxidants, Guinea pig, Lipid peroxide, Skin, Ultraviolet B, 14, and 612
Language:
English
Description:
Reactive oxygen species can be generated by daily exposure of the skin to ultraviolet light and may cause some subchronic and chronic skin disorders. The aim of this study was to investigate a possible preventive role of a-tocopherol acetate (ATA) on ultraviolet B (UVB) induced peroxidation by assessing lipid peroxide (LPO) levels and activity of reactive oxygen scavenging enzymes including glutathione peroxidase and superoxide dismutase (SOD) in guinea pigs. ATA was topically applied to the skin for three weeks before a single dose of 0.9 J/cm2 UVB irradiation on the skin and lipid peroxide levels and antioxidants in plasma, skin and liver and erythrocytes were determined after decapitation. Topical application of ATA prevented the UVB irradiation-induced reduction of scavenging enzyme activities in skin and erythrocytes. In conclusion, we suggest that topical applications of ATA before UVB irradiation is effective in protecting the skin from unwanted effects of UVB irradiation., Y. Saral, B. Uyar, A. Ayar, M. Naziroglu, S. Yilmaz., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

274. Proteomic analysis of peroxynitrite-induced protein nitration in isolated beef heart mitochondria

Creator:
Matej Kohutiar, Adam Eckhardt, Jiří Wilhelm, Šantorová, P, and Ivan Mikšík
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Type:
model:article and TEXT
Subject:
fyziologie člověka, human physiology, Mitochondrial proteome, Peroxynitrite, 3-nitrotyrosine, 2D electrophoresis, Mass spectrometry, 14, and 612
Language:
English
Description:
Summary Mitochondria are exposed to reactive nitrogen species under physiological conditions and even more under several pathologic states. In order to reveal the mechanism of these processes we studied the effects of peroxynitrite on isolated beef heart mitochondria in vitro. Peroxynitrite has the potential to nitrate protein tyrosine moieties, break the peptide bond, and eventually release the membrane proteins into the solution. All these effects were found in our experiments. Mitochondrial proteins were resolved by 2D electrophoresis and the protein nitration was detected by immunochemical methods and by nano LC-MS/MS. Mass spectrometry confirmed nitration of ATP synthase subunit beta, pyruvate dehydrogenase E1 component subunit beta, citrate synthase and acetyl-CoA acetyltransferase. Immunoblot detection using chemiluminiscence showed possible nitration of other proteins such as cytochrome b-c1 complex subunit 1, NADH dehydrogenase [ubiquinone] ironsulfur protein 2, elongation factor Tu, NADH dehydrogenase [ubiquinone] flavoprotein 2, heat shock protein beta-1 and NADH dehydrogenase [ubiquinone] iron-sulfur protein 8. ATP synthase beta subunit was nitrated both in membrane and in fraction prepared by osmotic lysis. The high sensitivity of proteins to nitration by peroxynitrite is of potential biological importance, as these enzymes are involved in various pathways associated with energy production in the heart., M. Kohutiar, A. Eckhardt, I. Mikšík, P. Šantorová, J. Wilhelm., and Seznam literatury
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

275. Purification and Properties of Ornithine Carbamoyltransferase from Loggerhead Turtle Liver

Creator:
Bellocco, E., Di Salvo, C., Lagan, G., Leuzzi, U., Tellone, E., Kotyk, A., and Galtieri, A.
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Type:
article, studie, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, Loggerhead turtle, Caretta caretta, Ornithine carbamoyltransferase, Enzyme kinetics, Enzyme thermostability, 14, and 612
Language:
English
Description:
Ornithine carbamoyltransferase has been purified from the liver of the loggerhead turtle Caretta caretta by a single-step procedure using chromatography on an affinity column to which the transition-state analogue, d-N-(phosphonoacetyl)- L-ornithine (d-PALO), was covalently bound. The procedure employed yielded an enzyme which was purified 373-fold and was judged to be homogeneous by nondenaturing and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme showed a specific activity of 224. The molar mass of the C. caretta enzyme was approximately 112 kDa, the single band obtained by SDS-PAGE indicated a subunit molar mass of 39.5 kDa; hence, the enzyme is a trimer of identical subunits. It catalyzes an ordered sequential mechanism in which carbamoyl phosphate binds first, followed by L-ornithine. The Michaelis constants were 0.858 mM for L-ornithine and 0.22 mM for carbamoyl phosphate, the dissociation constant of the enzyme-carbamoyl phosphate complex was 0.50 mM., E. Bellocco, C. Di Salvo, G. Lagan, U. Leuzzi, E. Tellone, A. Kotyk, A. Galtieri., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

276. Purified acetaminophen-glutathione conjugate is able to induce oxidative stress in rat liver mitochondria

Creator:
Tomáš Roušar, Nýdlová, E., Petr Česla, Pavla Křiváková, Otto Kučera, Patrik Pařík, and Zuzana Červinková
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, acetaminophen toxicity, glutathione, acetaminophenglutathione conjugate, 14, and 612
Language:
English
Description:
Acetaminophen overdose is the most often cause of acute liver injury. The toxic mechanism is linked to formation of an active metabolite that reacts with glutathione generating acetaminophen-glutathione conjugate (APAP-SG). This compound has been recognized to be non-toxic generally. Our preliminary results showed, however, that APAP-SG could possess a toxic effect too. Therefore, the aim of our study was to prepare, purify and to test possible toxicity of APAP-SG. We prepared APAP-SG using organic synthesis. The conjugate was purified by preparative HPLC and its structure was confirmed using mass spectrometry. Final purity of APAP-SG was >98 %. We estimated a toxic effect of APAP-SG in isolated rat liver mitochondria using a fluorescent ROS probe. We assessed ROS production in presence of complex I or complex II substrates. The increase of ROS-dependent fluorescence in presence of glutamate/malate was 104±13 % and 130±10 % in 1 mM and 5 mM APAP-SG, respectively, in comparison with controls. ROS production related to presence of complex II substrate was enhanced 4-times in APAP-SG (5 mM) treated mitochondria (compared to controls). We conclude, we proved our hypothesis that APAP-SG conjugate is able to induce a mitochondrial impairment leading to enhanced ROS production., T. Roušar, ... [et al.]., and Obsahuje seznam literatury
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

277. QT dispersion and electrocardiographic changes in women with gestational diabetes mellitus

Creator:
Eva Medová, Fialová, E., Mikuláš Mlček, Jaroslav Slavíček, Alena Dohnalová, Jiří Charvát, Eva Žákovičová, and Otomar Kittnar
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, QT dispersion, electrocardiography, gestational diabetes mellitus, 14, and 612
Language:
English
Description:
Gestational diabetes mellitus (GDM) represents additional risks to both mother and infant. Moreover it increases a woman's risk of cardiovascular disease in the postpartum. The aim of our study was therefore to detect changes of both the QT dispersion and the electrical heart field that could be typical for GDM. Body surface potential maps were obtained using the Cardiac 112.2 device from 26 young women with GDM and 54 young healthy pregnant women in the 36th week of pregnancy. The same recordings were obtained from 18 healthy women in the same age (19-36 years). The average QT dispersion (±SD) in women suffering from GDM was significantly higher (107±25 ms) both than in those with physiological pregnancy (73±18 ms) and than in the normal subjects (34±12 ms) (P<0.001). Moreover we have found in GDM patients shorter QRS complex 82.0±6.8 ms vs. 89.5±8.2 ms in healthy pregnant women and 90.8±7.9 ms in the control group (p=0.011), more horizontal electrical heart axis [16.4±20.1° vs. 42.4±28.7° and 74.6±39.2° respectively (P<0.05)] and lower some depolarization and repolarization amplitudes on isopotential and isointegral maps. According to these results we suppose that described electrocardiographic changes reflect a deterioration of the complete process of ventricular depolarization and repolarization in GDM., E. Medová, ... [et al.]., and Obsahuje seznam literatury
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

278. QT Dispersion and T-Loop Morphology in Late Pregnancy and After Delivery

Creator:
Lechmanová, M., O. Kittnar, M. Mlček, J. Slavíček, A. Dohnalová, Š. Havránek, J. Kolařík, A. Pařízek, Mikuláš Mlček, Jaroslav Slavíček, Alena Dohnalová, Štěpán Havránek, Kolařík, J., and Pařízek, A.
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Type:
article, studie, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, QT dispersion, Electrocardigraphy, Vectorcardiography, T-loop morphology, Pregnancy, 14, and 612
Language:
English
Description:
The aim of the study was to detect changes of both the QT dispersion and T-loop morphology resulting from the changed spatial position of the heart during pregnancy. Electrocardiographic and vectorcardiographic recordings were obtained from 37 healthy women 19-36 years old in the 36th to 40th week of physiological pregnancy and 2 to 6 days after delivery. The same recordings were obtained from 18 healthy women of the same age. The average QT dispersion (±S.D.) in normal subjects was significantly lower (34±12 ms) than in those in late pregnancy (73±18 ms) (P<0.001). The average amplitude of T-loop (Ta) in women in late pregnancy was significantly (P<0.001) smaller (532±98 mV) and the width of T-loop (Tw) was wider (21.24±11.48 deg) than in the control group (793±114 mV and 7.17±3.02 deg, respectively). The partial post-partum restoration of all parameters was not significant. In all groups, the QT dispersion was significantly correlated with Tw but not with Ta. According to these results we can conclude that the QT dispersion is an indirect reflection of the complete process of ventricular repolarization, reflected in the morphology of the T-loop., M. Lechmanová, O. Kittnar, M. Mlček, J. Slavíček, A. Dohnalová, Š. Havránek, J. Kolařík, A. Pařízek., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

279. Rare Variant of Apolipoprotein E (Arg136->Cys) in a Subject with Normal Lipid Values

Creator:
Hubáček, J. A., Jan Piťha, Zdenka Škodová, and Rudolf Poledne
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Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, Apolipoprotein E, Rare mutation, Lipid metabolism, 14, and 612
Language:
English
Description:
During the screening of apolipoprotein (apo) E gene polymorphism with PCR and subsequent restriction analysis, we have identified a female carrier with a mutant allele Arg136 ® Cys. This proband had normal lipid parameters and no history of coronary artery disease (CAD). We did not confirm the previously described connection between apo E Arg136 ® Cys mutation and elevated lipid levels. In the case of this mutation, other factors (environmental and/or genetic) are important for the development of lipid metabolism disorders., J. A. Hubáček, J. Piťha, Z. Škodová, R. Poledne., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

280. Rat Spatial Memory Tasks Adapted for Humans: Characterization in Subjects with Intact Brain and Subjects with Medial Temporal Lobe Lesions

Creator:
Bohbot, V.D., Robert Jech, Evžen Růžička, Lynn Nadel, Kalina, M., Kateřina Seltenreichová, and Bureš, J.
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Type:
article, studie, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, 14, and 612
Language:
English
Description:
a1_In the present paper we describe five tests, 3 of which were designed to be similar to tasks used with rodents. Results obtained from control subjects, patients with selective thermo-coagulation lesions to the medial temporal lobe and results from non-human primates and rodents are discussed. The tests involve memory for spatial locations acquired by moving around in a room, memory for objects subjects interacted with, or memory for objects and their locations. Two of the spatial memory tasks were designed specifically as analogs of the Morris water task and the 8-arm radial-maze tasks used with rats. The Morris water task was modeled by hiding a sensor under the carpet of a room (Invisible Sensor Task). Subjects had to learn its location by using an array of visual cues available in the room. A path integration task was developed in order to study the non-visual acquisition of a cognitive representation of the spatial location of objects. In the non-visual spatial memory task, we blindfolded subjects and led them to a room where they had to find 3 objects and remember their locations. We designed an object location task by placing 4 objects in a room that subjects observed for later recall of their locations. A recognition task, and a novelty detection task were given subsequent to the recall task. An 8-arm radial-maze was recreated by placing stands at equal distance from each other around the room, and asking subjects to visit each stand once, from a central point. A non-spatial working memory task was designed to be the non-spatial equivalent of the radial maze. Search paths recorded on the first trial of the Invisible Sensor Task, when subjects search for the target by trial and error are reported., a2_An analysis of the search paths revealed that patients with lesions to the right or left hippocampus or parahippocampal cortex employed the same type of search strategies as normal controls did, showing similarities and differences to the search behavior recorded in rats. Interestingly, patients with lesions that included the right parahippocampal cortex were impaired relative to patients with lesions to the right hippocampus that spared the parahippocampal cortex, when recall of the sensor was tested after a 30 min delay (Bohbot et al. 1998). No differences were obtained between control subjects and patients with selective thermal lesions to the medial temporal lobe, when tested on the radial-maze, the non-spatial analogue to the radial-maze and the path integration tasks. Differences in methodological procedures, learning strategies and lesion location could account for some of the discrepant results between humans and non-human species. Patients with lesions to the right hippocampus, irrespective of whether the right parahippocampal cortex was spared or damaged, had difficulties remembering the particular configuration and identity of objects in the novelty detection of the object location task. This supports the role of the human right hippocampus for spatial memory, in this case, involving memory for the location of elements in the room; learning known to require the hippocampus in the rat., V.D. Bohbot, R. Jech, E. Růžička, L. Nadel, M. Kalina, K. Štěpánková , J. Bureš., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public