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26772. The influence of angiotensin II on sex-dependent proliferation of aortic VSMC isolated from SHR
- Creator:
- Loukotová, J., Bačáková, L., Zicha, J., and Kuneš, J.
- Type:
- article, model:article, and TEXT
- Subject:
- spontaneously hypertensive rat, gender, tissue culture, aortic smooth muscle cells, and angiotensin II
- Language:
- English
- Description:
- The growth response to angiotensin II (Ang II) was studied using cultured vascular smooth muscle cells (VSMC) isolated from the aortae of male and female spontaneously hypertensive rats (SHR). Systolic and mean arterial blood pressure of 10-week-old males was significantly higher when compared to age-matched females. The specific growth rate of male VSMC was significantly higher on the third and sixth day after synchronisation. Angiotensin II in concentration 10~7 M stimulated the specific growth rate only in male VSMC during the exponential phase of growth. Moreover, doubling time was 3 hours shorter in male VSMC in comparison with the females. Our results suggest that both the increased specific growth rate and augmented growth-response of male VSMC to Ang II may explain the higher sensitivity of males to hypertensive stimuli.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
26773. The influence of ascorbic acid on the hepatic cytochrome P-450, and glutathione in guinea-pigs exposed to 2,4-dichlorophenol
- Creator:
- Nagyová, A. and Ginter, E.
- Type:
- article, model:article, and TEXT
- Subject:
- cytochrome P-450, ascorbic acid, glutathione, guinea-pig liver, and 2,4-dichlorophenol
- Language:
- English
- Description:
- Chlorophenols, mainly used as biocides, are compounds with a wide spectrum of toxic effects including teratogenic and carcinogenic actions. In this study, the effects of 2,4-dichlorophenol (2,4-DCP) on hepatic microsomal cytochrome P-450, NADPH-cytochrome c reductase activity, liver ascorbic acid (AA) and glutathione (GSH) content were studied in guinea-pigs with a low (2 mg/day/animal) or a high (50 mg/day/animal) ascorbic acid intake. The high AA intake significantly increased liver AA and GSH levels. There was a clear-cut correlation between liver AA and GSH levels. Administration of 2,4-DCP significantly decreased cytochrome P-450 and f iADPH-cytochrome c reductase activity in hepatic microsomes isolated from guinea-pigs with the low AA intake. Such a reduction was not observed in intoxicated guinea-pigs with the high AA intake. The results suggest that AA can play a protective role in 2,4-DCP toxicity.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
26774. The influence of changes in viticulture management on the butterfly (Lepidoptera) diversity in a wine growing region of southwestern Germany
- Creator:
- Schmitt, Thomas, Augenstein, Bettina, and Finger , Aline
- Type:
- article, model:article, and TEXT
- Subject:
- Conservation measures, dispersal ability, diversity indices, Lepidoptera, Rhineland-Palatinate, succession, transect counts, and vineyards
- Language:
- English
- Description:
- Viticulture is one of the most intensively managed agricultural ecosystems in Europe. Therefore, the conservation problems of vineyards and the ecological benefits of increasing the amount of fallow land are addressed using butterflies as a model group. We established 43 transects, each 100 m long, in a vineyard region in the vicinity of Trier (Rhineland-Palatinate, Germany) and recorded the butterflies observed along these transects on 20 occasions from late May to early August 2003. Transects crossed vineyards, fallow land and transitional areas of land. 4041 individuals of 34 species showed the typical pattern of relative abundance with few common and many relatively rare species. Fallow land had more individuals and species and a higher Shannon species diversity index than vineyards. Community evenness and average butterfly dispersal ability were highest in the vineyards. Principal Factor Analyses and UPGMA cluster analysis distinguished between fallow land and vineyards. The difference between early meadow and late forest fallow land areas was not strong, but the former tended to have a higher diversity than the latter. Vineyards thus might act as a sink for butterflies. Therefore, a clear separation between vineyards and fallow land is best for nature conservation. As young fallow land tends to have a higher diversity than older fallow land in this study, it is likely that the conservation value of vineyards for butterflies could be increased by active management of fallow land areas.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
26775. The influence of continental water storage on gravity rates estimates: case study using absolute gravity measurements from area of Lower Silesia, Poland
- Creator:
- Rajner, Marcin, Olszak, Tomasz, Rogowski, Jerzy, and Walo, Janusz
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Geologie. Meteorologie. Klimatologie, gravitace, hydrologie, gravity, hydrology, Dolní Slezsko, absolute gravity, FG5 instrument, hydrology loading, 7, and 551
- Language:
- English
- Description:
- In order to utilize the absolute gravity ( AG) measurements in terms of tectonic study it is necessary to reduce all disturbing environmental and instrumental effects. Many of those can be easily modelled and this step is done routinely during measurements (i.e. tide, polar motion, ocean tidal loading). Other remains in data and there is a lack of conventional models for them. Significant gravity variation is associated with changes of soil water at global scale. We study this effect for the Lower Silesia (South-western Poland) territory. Computed gravity changes can reach up to 2 μgal peak-to-peak amplitude with seasonal time scale. This effect is beyond of accuracy of modern ballistic gravimeter. Using real data collected with FG5 gravimeter we show here that neglecting of this phenomenon can lead to serious misinterpretation in term of secular gravity changes. This is emphasized especially when only sparse data of a few year time span is at our disposal. No attempt of modelling of local hydrology impact on effect was made, while in this study we concentrate on large scale water storage influence on measured gravity., Marcin Rajner, Tomasz Olszak, Jerzy Rogowski and Janusz Walo., and Obsahuje bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
26776. The influence of dietary lipid composition on skeletal muscle mitochondria from mice following eight months of calorie restriction
- Creator:
- Chen, Y., Hagopian, K., Bibus, D., Villalba, J. M., López, Lluch, G., Navas, P., Kim, K., and Ramsey, J. J.
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, mitochondrie, mitochondrias, dietary lipids, energy restriction, phospholipids, reactive oxygen species, 14, and 612
- Language:
- English
- Description:
- Calorie restriction (CR) has been shown to decrease reactive oxygen species (ROS) production an d retard aging in a variety of species. It has been proposed that alterations in membrane saturation are central to these ac tions of CR. As a step towards testing this theory, mice were assigned to 4 dietary groups (control and 3 CR groups) and fed AIN-93G diets at 95 % (control) or 60 % (CR) of ad libitum for 8 months. To manipulate membrane composition, the primary dietary fats for the CR groups were soybean oil (also used in the control diet), fish oil or lard. Skeletal muscle mitochondrial lipid composition, proton leak, and H 2 O 2 production were measured. Phospholipid fatty acid composition in CR mice was altered in a manner that reflected the n-3 and n-6 fatty acid profiles of their respective dietary lipid sources. Dietary lipid composition did not alter proton leak kinetics between the CR groups . However, the capacity of mitochondrial complex III to produce ROS was decreased in the CR lard compared to the other CR groups. The results of this study indicate that dietary lipid composition can influence ROS production in muscle mitochondria of CR mice. It remains to be determined if lard or other dietary oils can maximize the CR- induced decreases in ROS production., Y. Chen ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
26777. The influence of environmental factors on the supranivean activity of flies (Diptera) in Central Poland
- Creator:
- Soszyńska, Agnieszka
- Type:
- article, model:article, and TEXT
- Subject:
- Snow activity, atmospheric factors, phenology, Diptera, and Poland
- Language:
- English
- Description:
- More than half of the insects collected on snow in Central Poland were flies (Diptera). Altogether 83 species of Diptera from 27 families were identified, of which 9 families were recorded for the first time. Two thirds of the Diptera belonged to the Mycetophilidae and Trichoceridae, which were also very species-rich. Other families with many species were the Heleomyzidae, Sphaeroceridae and Phoridae. The peak activity was in the first part of December. Flies were most active on snow when the humidity ranged from 80 to 100%, temperatures between -1 to 5°C and the snow was from 20 to 40 cm deep. The occurrence of Trichoceridae was strictly associated with high humidities, in contrast to Drosophilidae and Heleomyzidae, which were most active at lower humidities. The activity of the flies of the most frequently recorded families was displaced towards either lower (Heleomyzidae and Limoniidae) or higher temperatures (Trichoceridae, Mycetophilidae). In contrast to other families, the supranivean activity of Phoridae was strictly associated with thin snow cover.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
26778. The influence of essential phospholipids (ESSENTIALE) on liver regeneration in gamma irradiated rats
- Creator:
- Kropáčová, K. and Mišúrová, E.
- Type:
- article, model:article, and TEXT
- Subject:
- ESSENTIALE, essential phospholipids, irradiation, regenerating rat liver, cell proliferation, and chromosomal aberrations
- Language:
- English
- Description:
- Gamma irradiation with a dose of 5.7 Gy within 30 min before partial hepatectomy (PHE) caused latent damage in the intact rat liver. This was expressed in the course of proliferation induced in the liver remnant by inhibition of the regenerative process, which was indicated by a decreased mitotic index and cellularity, an increased ratio of metaphases/prophases and a high chromosomal aberration frequency. The preparation of essential phospholipids (ESSENTIALE) that was injected in a dose of 360 mg/kg (i.p.) either 24 h before irradiation or 30 min after irradiation or repeatedly before and after irradiation, markedly stimulated the process of liver regeneration after PHE in both nonirradiated and irradiated rats. It moderated all the alterations induced by irradiation, especially changes in cellularity. The most effective was the repeated administration of ESSENTIALE whereas its single administration before irradiation was more effective than that after irradiation. Our results suggest that ESSENTIALE has not only a stabilizing effect on cell membranes, but also mitigates damage of genetic material induced by irradiation.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
26779. The influence of female oviposition strategy on sibling cannibalism in the ladybird beetle Harmonia axyridis (Coleoptera: Coccinellidae)
- Creator:
- Osawa, Naoya
- Type:
- article, model:article, and TEXT
- Subject:
- Coccinellidae, egg fertility, Harmonia axyridis, oviposition strategy, and sibling cannibalism
- Language:
- English
- Description:
- I hypothesized that sibling cannibalism is one of maternal investment in that a female controls sibling cannibalism. To test the hypothesis, I conducted a laboratory experiment and field observations to investigate sibling cannibalism in relation to cluster size and cluster site in the ladybird beetle, Harmonia axyridis Pallas. In the laboratory experiment, cluster size significantly affected the number of cannibalized eggs per cluster (R2 = 0.516), while cluster size was significantly affected by the oviposition interval. Furthermore, there was a marginally significant positive relationship between cluster size and the percentage of sibling cannibalism per cluster. In the field, cluster size and the direct distance from a cluster site to an aphid colony (an indicator of intensity of non-sibling cannibalism) significantly affected the number of cannibalized eggs per cluster (R2 = 0.472). Furthermore, there was a significant positive relationship between the direct distance from a cluster to the nearest aphid colony and cluster size. However, there was not a significant relationship between the distance and the percentage of sibling cannibalism. These results may be caused by the weakness of the female's power to control sibling cannibalism. Thus, a female H. axyridis controls cluster size through the intensity of non-sibling cannibalism, which may be one of oviposition strategies in this species.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
26780. The influence of folate and antioxidants on homocysteine levels and oxidative stress in patients with hyperlipidemia and hyperhomocysteinemia
- Creator:
- Racek, J., Rusňáková, H., Trefil, L., and Siala, K.K.
- Type:
- article, model:article, and TEXT
- Subject:
- Homocysteine, Folate, Antioxidants, Oxidative stress, and Atherosclerosis
- Language:
- English
- Description:
- The aim of this study was to observe the effect of folate and antioxidants alone on homocysteine levels and oxidative stress markers, and to evaluate whether their co-administration promotes their effects. One hundred patients with hyperhomocysteinemia were randomized into four equal groups, which were then treated with folate, antioxidants or folate plus antioxidants for 2 months; group IV was a control group. Serum homocysteine, folate and oxidative stress markers were measured before the study, at the end of folate and/or antioxidants administration and 3 months later. Folate caused a significant decrease in homocysteine concentration. Antioxidants did not influence homocysteine concentration, but they improved the antioxidative defense (plasma antioxidant capacity and intraerythrocyte glutathione were increased) and partially prevented lipid peroxidation (malondialdehyde level was slightly decreased). Supplementation with folate had a similar effect on intracellular glutathione and plasma malondialdehyde. Simultaneous administration of folate and antioxidants did not show any additive effect with the exception of a slower decrease of folate concentration after its supplementation had been discontinued. Folate may be considered as an effective antioxidant in patients with hyperhomocysteinemia; this can be a result of decreased production of free radicals due to a reduced level of homocysteine. Its antioxidative effect cannot be promoted by co-administration of antioxidants.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public