Number of results to display per page
Search Results
2742. Age structure of the population of Česká Kamenice in 1670 - 1750 /
- Creator:
- Dušek, Ladislav,
- Type:
- studie
- Subject:
- struktura obyvatelstva, seznamy poddaných, struktura věková, české země 1526-1792, historická demografie, společenská struktura, and města, obce
- Language:
- English
- Rights:
- unknown
2743. Age, genetic characteristics and number of cycles are critical factors to consider for successful protection of the murine heart with postconditioning
- Creator:
- Somers, S. J., Lacerda, L., Opie, L., and Lecour, S.
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, ischemie, ischemia, reperfusion, postconditioning, 14, and 612
- Language:
- English
- Description:
- Postconditioning (PostC) is a re cently discovered phenomenon whereby brief repetitive cycles of ischaemia with intermittent reperfusion following prolonged is chaemia elicit cardioprotection. This study investigated whether the age, genetic characteristics or number of repetitive cycles influenced the protective effect of PostC in mice. C57BL/6 floxed or non-floxed STAT-3 mice aged between 14-16 weeks (young) or 18-20 weeks (older) were perfused on a Langendorff apparatus and subjected to 35 min global ischaemia and 45 min reperfusion. PostC was elicited by either 3 (PostC-3) or 6 cycles (PostC-6) of 10s ischaemia and 10 s reperfusion. PostC-3 and PostC-6 in both young and older non-floxed mice reduced the myocar dial infarct size. In contrast, only PostC-3 reduced myocardial infarct size in young floxed mice. Neither PostC-3 nor PostC-6 reduced the in farct in older floxed mice. Our data reveal that genetic characteristics, a minute difference in age or the nu mber of postconditioning cycles are critical factors to be consid ered for the successful effect of ischaemic postconditioning in a murine model. Moreover, these factors should be taken into consideration for future experimental research or clinical applications of this protective phenomenon., S. J. Somers ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2744. Age, growth and diet of the Iberian loach, Cobitis paludica in two different environments
- Creator:
- Sánchez-Carmona, Ramona, Encina, Lourdes, Rodríguez-Ruíz, Amadora, and Rodriguez-Sánchez, Victoria
- Type:
- article and TEXT
- Subject:
- Cobitis paludica, lenitic hydrosystem, feeding strategies, and biological parameters
- Language:
- English
- Description:
- Several aspects of growth and feeding of C. paludica have been assessed in two different environments: a lenitic and a lotic hydrosystem, Portil lagoon and Rivera de Cala river respectively. Growth patterns showed some differences with Iberian loach growing slower in the lagoon than in the river. Because of this, although individuals of both populations reach sexual maturity in their second year (year-class 1+), specimens of lagoon population mature at smaller sizes. The C. paludica population in the river showed a better somatic condition than in the lagoon. In both hydrosystems, their diet was mainly chironomid larvae and ostracods, although the Portil lagoon Iberian loach population showed a clear trophic segregation between young of the year (year-class 0+) and sexually matures individuals (year-class ≥ 1+).
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/
2745. Age, growth and reproductive characteristics of the Turkmenian crested loach Metaschistura cristata (Nemacheilidae)
- Creator:
- Patimar, Rahman, Mortazaei Rishkhori, Khadijeh, and Sabiani, Alireza
- Type:
- article and TEXT
- Subject:
- age, growth, reproduction, Metaschistura cristata, and Iran
- Language:
- English
- Description:
- Metaschistura cristata is a small nemacheilid loach species found at a few localities only in Turkmenistan and Iran. The present study reports, for the first time, data on its biology, based on 747 specimens collected from the River Zanglanlou in north-eastern Iran. Specimens were collected at monthly intervals over two reproductive seasons from February to June 2007 and 2008. Maximum age, based on opercula readings, was 4+ years for both sexes. Specimens ranged in size from 25 to 87 mm total length and weighed from 0.09 to 4.91 g. Length-weight relationships implied positive allometric growth for both sexes and the sex ratio was 1 : 1.2 in favour of females. The Gonadosomatic indicated that peak reproduction occurred during April and May, with highest average values of 1.473 ± 0.99 for males and 12.9 ± 7.14 for females in April. Oocyte diameter ranged from 0.53 to 1.46 mm, with a mean value of 0.943 mm. Absolute and relative fecundity ranged between 114-1246 eggs and 79.47-1285.71 eggs/g, respectively. Absolute fecundity and oocyte diameter to fish size (length and weight) were directly correlated, while the relationship between relative fecundity and fish size (length and weight) showed an inverse power function.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/
2746. Age- and dose-specific anticonvulsant action of bumetanide in immature rats
- Creator:
- Pavel Mareš
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, ontogeneze, krysa obecná, amino, physiology, ontogeny, Rattus rattus, chloride transporter, GABA (gamma-aminobutyric acid), pentylenetetrazol, 14, and 612
- Language:
- English
- Description:
- GABA exhibits depolarizing action in the immature neurons due to high intracellular activity of chloride ions. It is maintained by cation-chloride cotransporter NKCC1 which is present in immature brain. Bumetanide is a specific inhibitor of this cotransporter. We studied possible anticonvulsant activity of bumetanide in pentyl enetetrazol-induced seizures in three age groups of rat pups (7, 12, and 18 days old). Pretreatment with bumetanide (0.2-1 mg/kg i.p.) resulted in dose-dependent decrease of incidence of the tonic phase of generalized tonic-clonic seizures in 12-day-old rats only. No effect was observed in younger and older animals. Higher dose of bumetanide (2.5 mg/kg) did not affect tonic convulsions but, on the contrary, decreased latencies of generalized seizures in 12-day-old animals. Lack of marked anticonvulsant effect is probably due to relative maturity of neurons in the brainstem where the generator of generalized seizures is localized. Age- and dose-specific suppression of the tonic phase needs further analysis. and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2747. Age-associated changes in Ca2+-ATPase and oxidative damage in sarcoplasmic reticulum of rat heart
- Creator:
- Eva Babušíková, Ján Lehotský, Dušan Dobrota, Račay, P., and Peter Kaplán
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, aging, Ca2+-ATPase, protein damage, heart, oxidative stress, 14, and 612
- Language:
- English
- Description:
- Altered Ca2+ handling may be responsible for the development of cardiac contractile dysfunctions with advanced age. In the present study, we investigated the roles of oxidative damage to sarcoplasmic reticulum (SR) and expression of Ca2+-ATPase (SERCA 2a) and phospholamban in age-associated dysfunction of cardiac SR. SR vesicles were prepared from hearts of 2-, 6-, 15-, and 26-month-old Wistar rats. Although activity of Ca2+-ATPase decreased with advancing age, no differences in relative amounts of SERCA 2a and phospholamban protein were observed. On the other hand, significant accumulation of protein oxidative damage occurred with aging. The results of this study suggest that agerelated alteration in Ca2+-ATPase activity in the rat heart is not a consequence of decreased protein levels of SERCA 2a and phospholamban, but could arise from oxidative modifications of SR proteins. Cellular oxidative damage caused by reactive oxygen species could contribute to age-related alternations in myocardial relaxation., E. Babušíková ... [et al.]., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2748. Age-associated endothelial dysfunction in rat mesenteric arteries: roles of calcium-activated K+ channels (Kca)
- Creator:
- Zhou, E., Qing, D., and Li, J.
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, stárnutí, endoteliální dysfunkce, acetylcholin, aging, endothelial dysfunction, acetylcholine, potassium channels, mesenteric artery, 14, and 612
- Language:
- English
- Description:
- Age-associated changes in large blood vessels were characterized by increased arterial wall thickness, luminal dilation and impaired endothelial function. But little is known about the effect of age on structural and functional changes in small resistance arteries. The mechanisms underlying age-associated endothelial dysfunction in rat mesenteric resistance arteries were investigated in the present study. Small rat mesenteric arteries were excised and cannulated, and vascular endothelial functions were tested by acetylcholine (ACh). Our experiments showed (1) endotheliumdependent vasorelaxation induced by ACh was reduced in aged mesenteric arteries; (2) blockade of Kca channels markedly reduced the vasodilation in young and adult rats, the resultant reduction in aged rats was much smaller compared with young and adult rats; (3) inhibition of endothelial nitric oxide synthase (NOS) resulted in a significant reduction of vasodilation in young and adult, but there was a smaller reduction in aged rats. The results suggest that (1) endothelial function was impaired in mesenteric arteries of aged rats; (2) both Kca channels and nitric oxide (NO) contribute together to the ACh-induced vasorelaxation in small mesenteric arteries, and (3) both the impairment of Kca channel function and decreased NO account for the age-related endothelial dysfunction., E. Zhou, D. Qing, J. Li., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2749. Age-dependent changes in the function of mitochondrial membrane permeability transition pore in rat liver mitochondria
- Creator:
- Endlicher, René, Drahota, Zdeněk, Kučera, Otto, and Červinková, Zuzana
- Format:
- počítač and online zdroj
- Type:
- model:article and TEXT
- Subject:
- rat liver mitochondria, mitochondrial permeability transition pore, calcium retention capacity, and calcium-induced swelling
- Language:
- English
- Description:
- Mitochondria play an important role in the cell aging process. Changes in calcium homeostasis and/or increased reactive oxygen species (ROS) production lead to the opening of mitochondrial permeability transition pore (MPTP), depolarization of the inner mitochondrial membrane, and decrease of ATP production. Our work aimed to monitor age-related changes in the Ca2+ ion effect on MPTP and the ability of isolated rat liver mitochondria to accumulate calcium. The mitochondrial calcium retention capacity (CRC) was found to be significantly affected by the age of rats. Measurement of CRC values of the rat liver mitochondria showed two periods when 3 to 17-week old rats were tested. 3-week and 17-week old rats showed lower CRC values than 7-week old animals. Similar changes were observed while testing calcium-induced swelling of rat liver mitochondria. These findings indicate that the mitochondrial energy production system is more resistant to calcium-induced MPTP opening accompanied by the damaging effect of ROS in adult rats than in young and aged animals.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2750. Age-dependent changes of baroreflex efficiency in dahl rats: effects of high salt intake
- Creator:
- Nedvídek, J. and Zicha, J.
- Type:
- article, model:article, and TEXT
- Subject:
- baroreflex, heart rate, mean arterial pressure, age, salt intake, and phenylephrine
- Language:
- English
- Description:
- The age-dependent changes in baroreflex control of heart rate were studied in inbred Dahl rats. At the age of 8 weeks the baroreflex slope was significantly greater in salt-resistant (R/Jr) than in salt-sensitive (S/Jr) rats fed a low- salt diet. The reverse was true in 16-week-old animals. High salt intake (8 % NaCI diet for 4 weeks) suppressed baroreflex efficiency in both age groups of S/Jr animals whereas no effects occurred in R/Jr rats. Baroreflex slope was, however, significantly lower in young S/Jr rats with a severe form of salt hypertension than in adult salt-loaded S/Jr rats in which only a moderate blood pressure elevation was observed.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public