Number of results to display per page
Search Results
19762. Relation of cholesterol metabolism and non-cholesterol sterols to insulin resistance
- Creator:
- Alena Šmahelová, Radomír Hyšpler, and Haas, T.
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, cholesterol, fytosteroly, physiology, phytosterols, non-cholesterol sterols, metabolic syndrom, cholesterol absorption, cholesterol synthesis, 14, and 612
- Language:
- English
- Description:
- Using non-cholesterol sterols investigation several authors postulated a hypothesis that in the metabolic syndrome cholesterol endogenous synthesis is increased and its absorption decreased. Our study is the first attempt to evaluate the direct relation of cholesterol metabolism to the principal pathogenetic phenomenon of the metabolic syndrome – namely to insulin resistance. We have measured insulin sensitivity by two methods – Quicki (Quantitative Sensitivity Check Index) and intravenous insulin tolerance test (Kitt) and 3 indirect markers - fasting insulin level, fasting C-peptide level and SHBG (sex hormone binding globulin). The investigation was performed in three groups of subjects with a different prevalence of insulin resistance: 72 non-diabetics with ischemic heart disease, 117 young blood donors and 63 type 2 diabetics on diet therapy only. Analyzing altogether 60 relationships – between four sterols (lathosterol, squalene, sitosterol and campesterol) and five markers of insulin resistance in three groups of subjects – we have found only six significant relations between cholesterol synthesis and absorption and insulin resistance in all groups of patients. Our results indicate that there exists a significant relationship between insulin sensitivity and indices of either increased cholesterol synthesis or decreased cholesterol absorption. Insulin resistance explains only a part of both abnormalities mentioned above., A. Šmahelová, R. Hypšler, T. Haas., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
19763. Relation of ventricular fibrillation threshold to heart rate during normal ventilation and hypoventilation in female Wistar rats: chronophysiological study
- Creator:
- Pavol Švorc, Imola Bračoková, and Igor Podlubný
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, srdeční rytmus, heart rate, rat, circadian, ventricular fibrillation threshold, hypoventilation, 14, and 612
- Language:
- English
- Description:
- The aim of our study was to verify the relationship between heart rate (HR) and ventricular fibrillation threshold (VFT) during different types of ventilation in female Wistar rats from the circadian point of view. The ex-periments were performed under pentobarbital anesthesia (40 mg/kg i.p., adaptation to a light-dark cycle 12:12 h, open chest experiments) and the obtained results were averaged independently of the seasons. The VFT measure-ments were performed during normal ventilation (17 animals) and hypoventilation (10 animals). The HR was re-corded immediately before the rise of ventricular arrhy-thmias. Results are expressed as arithmetic means ± S.D. and differences are considered significant when p<0.05. The basic pe-riodic characteristics were calculated using single and population mean cosinor tests. The results from our experiments have demonstrate that 1) the VFT and HR respond identically to hypoventilation by a decrease in the light and also in the dark phases, and 2) hypoventilation changes the 24-h course of the VFT without a change in the 24-h rhythm of the HR. It is concluded that the HR and VFT behave as two independent functional systems without apparent significant circadian dependence during both types of ventilation., P. Švorc, I. Bračoková, I. Podlubný., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
19764. Relationship between antioxidant potential and oxidative damage to lipids, proteins and DNA in aged rats
- Creator:
- Monika Sivoňová, Tatarková, Z., Zdeňka Ďuračková, Dušan Dobrota, Ján Lehotský, Matáková, T., and Peter Kaplán
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Biochemie. Molekulární biologie. Biofyzika, fyziologie živočichů, stárnutí, antioxidanty, peroxidázy, animal physiology, aging, antioxidants, peroxidases, comet assay, total sulfhydryl groups, 2, and 577
- Language:
- English
- Description:
- Oxidative stress has been implicated to play a major role in aging and age-related diseases. In the present study, we investigated the effects of aging on the total antioxidant capacity, uric acid, lipid peroxidation, total sulfhydryl group content and damage to DNA in adult (6 months), old (15 months) and senescent (26 months) male Wistar rats. The antioxidant capacity, determined by phycoerythrin-based TRAP method (total peroxyl radical-trapping potential) was significantly decreased in the plasma and myocardium of old and senescent rats, whereas plasma level of uric acid was elevated in 26-month-old rats. Age-related decline in plasma and heart antioxidant capacity was accompanied by a significant loss in total sulfhydryl group content, increased lipid peroxidation and higher DNA damage in lymphocytes. Correlations between TRAP and oxidative damage to lipids, proteins and DNA suggest that the decline in antioxidant status may play an important role in age-related accumulation of cell damage caused by reactive oxygen species., M. Sivoňová, Z. Tatarková, Z. Ďuračková, D. Dobrota, J. Lehotský, T. Matáková, P. Kaplán., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
19765. Relationship between clinical, 24-hour, average day-time and night-time blood pressure and measures of arterial stiffness in essential hypertension
- Creator:
- Jan Rosa, Branislav Štrauch, Ondřej Petrák, Tomáš Pikus, Robert Holaj, Tomáš Zelinka, Dan Wichterle, and Jiří Widimský
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Patologie. Klinická medicína, patologická fyziologie, hypertenze, krevní tlak, pathological physiology, hypertension, blood pressure, arterial stiffness, 24 h blood pressure monitoring, 14, and 616
- Language:
- English
- Description:
- Arterial wall stiffness is considered an independent cardiovascular risk factor. Aim of this study was to evaluate relationship between clinical, 24-hour, average day-time and night-time blood pressure (BP) and measures of arterial stiffness assessed by pulse wave velocity (PWV) (using SphygmoCor applanation tonometer) in essential hypertension (severe-resistant (RH, n=29) and moderate hypertension (EH, n=35)) and in normotensive control subjects (n-29) (NCS) matched by age. After multiple regression analysis, PWV remains significantly correlated mainly with night-time pulse pressure and to a lesser extent with age. PWV was significantly higher in RH compared to moderate EH and NCS., J. Rosa, B. Štrauch, O. Petrák, T. Pikus, R. Holaj, T. Zelinka, D. Wichterle, J. Widimský Jr., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
19766. Relationship between flavonoids and photoprotection in shade-developed Erigeron breviscapus transferred to sunlight
- Creator:
- Zhou, R., Su, W. H., Zhang, G. F., Zhang, Y. N., and Guo, X. R.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, chlorophyll fluorescence, flavonoid, phenolics, protection, photodamage, 2, and 581
- Language:
- Multiple languages
- Description:
- Flavonoids are thought to participate in protection of the photosynthetic apparatus against photoinhibition under excessive light. Flavone glycoside, scutellarin, is a main active ingredient extracted from Erigeron breviscapus, the plant used in Chinese medicine. Shade-developed leaves of E. breviscapus were transferred from shade to full sunlight to quantify a relationship between the concentration of leaf scutellarin and tolerance to high radiation stress or the recovery from photoinhibition. The maximal quantum yield of PSII photochemistry showed a diurnal fluctuation in both shaded and sunlit leaves throughout the day. It indicated dynamic photoinhibition in the leaves of Erigeron, i.e., higher photoinhibition at solar noon and lower one in the morning and late afternoon. The sun-developed leaves reached the higher scutellarin content and values of nonphotochemical quenching coefficient with a lower degree of photoinhibition than the shade-developed leaves. When the shade-developed leaves were transferred to full sunlight, the content of scutellarin was declining continuously for 10 d and then was increasing for 15 d. After 50 d, all leaves became the sun-developed leaves with their scutellarin contents of about 138.5 ± 5.2 mg g-1(dry mass, DM) which was significantly higher than that of the shade-developed leaves [107.8 ± 9.8 mg g-1(DM)]. During acclimatization, the degree of photoinhibition was negatively correlated with the scutellarin content. Our results demonstrated a synchronous fluctuation between the flavonoid content and degree of protection against photoinhibition., R. Zhou, W. H. Su, G. F. Zhang, Y. N. Zhang, X. R. Guo., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
19767. Relationship between high aortic pulse pressure and extension of coronary atherosclerosis in males
- Creator:
- Jiří Pařenica, Petr Kala, Jarkovský, J., Martin Poloczek, Otakar Boček, Petr Jeřábek, Petr Neugebauer, Miroslav Vytiska, Ilona Pařenicová, Daniela Tomčíková, Monika Pávková Goldbergová, and Jindřich Špinar
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, věnčité tepny, ateroskleróza, coronary arteries, atherosclerosis, pulse pressure, coronary artery disease, 14, and 612
- Language:
- English
- Description:
- A high pulse pressure (PP) is a marker of increased artery stiffness and represents a well-e stablished independent predictor for cardiovascular morbidity and mortality. The objective of the research was to determine whether invasively measured central aortic PP was related to the presence and severity of coronary artery disease. In total 1075 consecutive stable male patients undergoing diagnostic coronary angiography with a preserved left ventricular function were included. Diseased coronary vessel (DCV) was defined by the presence of >50 % stenosis. Men were divided into 3 groups according to the increased value of PP. The average PP in the tertiles was 47.8±7.1 vs. 67.0±4.9 vs. 91.3±12.8 mm Hg (p<0,01). The si gnificant differences of DCV was found among tertiles (1.51±1.11 vs 1.80±1.04 vs. 1.99±0.98 DCV, p<0.01). Aortic PP together with age and hyperlipoproteinemia were found as factors with an independent relationship to DCV according to multivariate linear regression. In conclusions the increased value of aortic PP in the male population is independently connected with more severe atherosclerosis evaluated by the significant number of DCV., J. Pařenica ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
19768. Relationship between leaf soluble protein content and net photosynthetic rate in tropical deciduous tree species
- Creator:
- Naidu, C.V. and Swamy, P.M.
- Format:
- Type:
- model:internalpart and TEXT
- Language:
- Multiple languages
- Description:
- Leaf protein content and net photosynthetíc rate (P^) were estimated at monthly intervals in seven tropical deciduous tree species, námely Chukrasia tabularis, Dolichandrone atrovirens, Eugenia Jambolana, Gmelina arborea, Lannea coromandelica, Terminalia arjuna and Terminalia bellerica firom September 1990 to August 1991. Among the seven tree species examined, Terminalia arjuna exhibited a significant positive correlation (r = 0.81; p < 0.05) between leaf protein content and while in others it was found insignificant.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
19769. Relationship between net photosynthesis and tuber yield in potato grown under short days
- Creator:
- Singh, Lallan, Basu, P.S., and Sukumaran, N.P.
- Format:
- Type:
- model:internalpart and TEXT
- Language:
- Multiple languages
- Description:
- Field studies with segregating populations under short days showed a significant positive correlation between tuber yield and the light-saturated net photosynthetic rate (Fn) in the 4th leaf from the top, at the tuber formation stage, in two seasons. The leaf area per plant {A) at this stage and also at the tuber bulking stage had a significant positive correlation with tuber yield. The product of PN and A also showed a significant positive correlation with tuber yield at both of these stages, a stronger one than that between tuber yield and A at the tuber formation stage.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
19770. Relationship between oxygenation in inactive biceps brachii muscle and hyperventilation during leg cycling
- Creator:
- Ogata, Hisayoshi, Arimitsu, T., Matsuura, R., Yunoki, T., Horiuchi, M., and Yano, T.
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, svaly horních končetin, dýchání, human physiology, upper limb muscles, respiration, nadměrné dýchání, dodávka kyslíku, hyperventilation, oxygen supply, arterial carbon dioxide pressure, 14, and 612
- Language:
- English
- Description:
- Inactive forearm muscle oxygenation has been reported to begin decreasing from the respiratory compensation point (RCP) during ramp leg cycling. From the RCP, hyperventilation occurs with a decrease in arterial CO2 pressure (PaCO2). The aim of this study was to determine which of these two factors, hyperventilation or decrease in PaCO2, is related to a decrease in inactive biceps brachii muscle oxygenation during leg cycling. Each subject (n = 7) performed a 6-min two-step leg cycling. The exercise intensity in the first step (3 min) was halfway between the ventilatory threshold and RCP (170±21 watts), while that in the second step (3 min) was halfway between the RCP and peak oxygen uptake (240±28 watts). The amount of hyperventilation and PaCO2 were calculated from gas parameters. The average cross correlation function in seven subjects between inactive muscle oxygenation and amount of hyperventilation showed a negative peak at the time shift of zero (r = -0.72, p<0.001), while that between inactive muscle oxygenation and calculated PaCO2 showed no peak near the time shift of zero. Thus, we concluded that decrease in oxygenation in inactive arm muscle is closely coupled with increase in the amount of hyperventilation., H. Ogata, T. Arimitsu, R. Matsuura, T. Yunoki, M. Horiuchi, T. Yano., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public