The aim of this study was to investigate the effects of troglitazone (TRO) - a new insulin-sensitizing agent - on some metabolic parameters in an experimental model of hypertriglyceridemia and insulin resistance, hereditary hypertriglyceridemic rats, and to compare its effects with those of vitamin E, an antioxidant agent. Three groups of the above rats were fed diets with a high content of sucrose (70 % of energy as sucrose) for four weeks. The first group was supplemented with TRO (120 mg/kg diet), the second one with vitamin E (500 mg/kg diet), and the third group served as the control. Vitamin E supplementation did not lower serum triglycerides (2.42±0.41 vs. 3.39±0.37 mmol/l, N.S.) while TRO did (1.87±0.24 vs. 3.39±0.37 mmol/l, p<0.01). Neither TRO nor vitamin E influenced the serum levels of free fatty acids (FFA). Both drugs influenced the spectrum of fatty acids in serum phospholipids - TRO increased the levels of polyunsaturated fatty acids (PUFA) n-6 (36.04±1.61 vs. 19.65±1.56 mol %, p<0.001), vitamin E increased the levels of PUFA n-3 (13.30±0.87 vs. 6.79±0.87 mol %, p<0.001) and decreased the levels of saturated fatty acids (32.97±0.58 vs. 51.45±4.01 mol %, p<0.01). In conclusion, TRO lowered the level of serum triglycerides but vitamin E did not have this effect in hypertriglyceridemic rats. Compared with TRO, vitamin E had a different effect on the spectrum of fatty acids in serum phospholipids., Š. Chvojková, L. Kazdová, J. Divišová., and Obsahuje bibliografii
A cytoskeletal network contributes significantly to intracellular regulation of mechanical stresses, cell motility and cellular mechanics. Thus, it plays a vital role in defining the mechanical behaviour of the cell. Among the wide range of models proposed for dynamic behaviour of cytoskeleton, the soft glassy rheology model has gained special attention due to the resemblance of its predictions with the mechanical data measured from experiment. The soft glassy material, theory of soft glassy rheology and experiment on cytoskeleton has been discussed, which leads to a discussion of the unique features and flaws of the model. The soft glassy rheological model provides a unique explanation of the cytoskeleton ability to deform, flow and remodel. and Obsahuje seznam literatury
For lower-semicontinuous and convex stochastic processes Zn and nonnegative random variables ϵn we investigate the pertaining random sets A(Zn,ϵn) of all ϵn-approximating minimizers of Zn. It is shown that, if the finite dimensional distributions of the Zn converge to some Z and if the ϵn converge in probability to some constant c, then the A(Zn,ϵn) converge in distribution to A(Z,c) in the hyperspace of Vietoris. As a simple corollary we obtain an extension of several argmin-theorems in the literature. In particular, in contrast to these argmin-theorems we do not require that the limit process has a unique minimizing point. In the non-unique case the limit-distribution is replaced by a Choquet-capacity.
Cost-benefit analysis of foliar construction and maintenance costs and of carbon assimilation of leaves of differing life-span were conducted using two evergreen, three semi-deciduous, and three deciduous tree species of savannas of north Australia. Rates of radiant-energy-saturated CO2 assimilation (Pmax) and dark respiration were measured and leaves were analysed for total nitrogen, fat, and ash concentrations, and for heat of combustion. Specific leaf area, and leaf N and ash contents were significantly lower in longer-lived leaves (evergreen) than shorter-lived leaves (deciduous) species. Leaves of evergreen species also had significantly higher heat of combustion and lower crude fat content than leaves of deciduous species. On a leaf area basis, Pmax was highest in leaves of evergreen species, but on a leaf dry mass basis it was highest in leaves of deciduous species. Pmax and total Kieldahl N content were linearly correlated across all eight species, and foliar N content was higher in leaves of deciduous than evergreen species. Leaf construction cost was significantly higher and maintenance costs were lower for leaves of evergreen than deciduous species. Maintenance and construction costs were linearly related to each other across all species. Leaves of evergreen species had a higher cost-benefit ratio compared to leaves of deciduous species but with longer lived leaves, the payback interval was longer in evergreen than deciduous species. These results support the hypotheses that longer lived leaves are more expensive to construct than short-lived leaves, and that a higher investment of N into short-lived leaves occurs which supports a higher Pmax over a shorter payback interval. and D. Eamus ... [et al.].
The model couples stomatal conductance (gs) and net photosynthetic rate (PN) describing not only part of the curve up to and including saturation irradiance (Imax), but also the range above the saturation irradiance. Maximum stomatal conductance (gsmax) and Imax can be calculated by the coupled model. For winter wheat (Triticum aestivum) the fitted results showed that maximum PN
(Pmax) at 600 µmol mol-1 was more than at 350 µmol mol-1 under the same leaf temperature, which can not be explained by the stomatal closure at high CO2 concentration because gsmax at 600 µmol mol-1 was less than at 350 µmol mol-1. The irradiance-response curves for winter wheat had similar tendency, e.g. at 25 °C and 350 µmol mol-1 both PN and gs almost synchronously reached the maximum values at about 1 600 µmol m-2 s-1. At 25 °C and 600 µmol mol-1 the Imax corresponding to Pmax and
gsmax was 2 080 and 1 575 µmol m-2 s-1, respectively. and Z.-P. Ye, Q. Yu.
The correlation between baroreflex sensitivity (BRS) and the spectrum component at a frequency of 0.1 Hz of pulse intervals (PI) and systolic blood pressure (SBP) was studied. SBP and PI of 51 subjects were recorded beat-to-beat at rest (3 min), during exercise (0.5 W/kg of body weight, 9 min), and at rest (6 min) after exercise. BRS was determined by a spectral method (a modified alpha index technique). The subjects were divided into groups according to the spectral amplitude of SBP at a frequency of 0.1 Hz. The following limits of amplitude (in mm Hg) were used: very high ≥ 5.4 (VH); high 5.4 > H ≥ 3 (H); medium 3 > M ≥ 2 (M), low < 2 (L). We analyzed the relationships between 0.1 Hz variability in PI and BRS at rest, during the exercise and during recovery in subgroups VH, H, M, L. The 0.1 Hz variability of PI increased significantly with increasing BRS in each of the groups with identical 0.1 Hz variability in SBP. This relationship was shifted to the lower values of PI variability at the same BRS with a decrease in SBP variability. The primary SBP variability increased during exercise. The interrelationship between the variability of SBP, PI and BRS was identical at rest and during exercise. A causal interrelationship between the 0.1 Hz variability of SBP and PI, and BRS was shown. During exercise, the increasing primary variability in SBP due to sympathetic activation was present, but it did not change the relationship between variability in pulse intervals and BRS., N. Honzíková, A. Krtička, Z. Nováková, E. Závodná., and Obsahuje bibliografii
A data base was generated for quantifying effects of thermal time (degree-days) on the appearance of new leaves, the expansion of such leaves to maximum area, their death, the appearance of new internodes below the node associated with such leaves, and the extension of these internodes to maximum length. The data base for a list of crop (agronomic and horticultural), weed, and native Tallgrass Prairie plants has been summarized, with equations for the above events as a function of degree days, with appropriate base temperatures and maximum cut-off temperatures, in a Java applet which is available at a website with the URL <http://th190-50.agn.uiuc.edu>. Associated graphical plots such as shown in this paper are also given. Branching behavior was accounted for. These events predict the effect of thermal time on leaf age and its height in the plant canopy, both important factors needed for upscaling functions for leaf behavior to those for behavior of the plant canopy. The data base is evolving to include coefficients for other species. Coefficients are used to predict the leaf area index of the canopy, which is important for predicting evapotranspiration from the crop and the protection of the soil from erosion. and X. Pan ... [et al,].
Two new species of coccidian parasites are described from African reptiles. Oocysts of Eimeria foulshami sp. n. from the plated lizard Gerrhosaurus major bottegoi Del Prato of Sudan are ellipsoidal, 24.1 × 14.9 (23-26.5 × 14-17.8) µm with a bilayered, colourless oocyst wall and lack polar granules. The ellipsoidal sporocysts average 8.6 × 4.6 (7-10.6 × 4.4-7) µm and possess a prominent, globular, sporocyst residuum. Oocysts of Caryospora regentensis sp. n. from the green mamba Dendroaspis viridis Hallowell of Kenya are spherical to subspherical, 16.8 × 16.4 (16-17.6 × 15-17.2) µm with a bilayered oocyst wall and a single polar granule. The ellipsoidal sporocysts average 13.0 × 10.3 (10.2-14 × 9.2-11) µm and possess a Stieda and substieda body and a prominent globular sporocyst residuum. Oocysts of Caryospora legeri Hoare, 1933 are reported from a hissing sand snake, Psammophis sibilans sibilans L. from Nigeria, representing a new geographical record. The oocysts are slightly larger than the type, but otherwise identical. Caryospora psammophi Bray, 1960 and C. hermae Bray, 1960 from Psammophis sibilans phillipsi, oocysts of which are morphologically similar to and overlap in dimensions with C. legeri Hoare, 1933, are synonymised with the latter species. Eimeria samiae Iskander et Tadros, 1979 is emended to E. samyadeli to reflect the gender of the person the species was named after and because E. sami is preoccupied. In addition to these findings, Eimeria bohemi Modrý, Šlapeta et Koudela, 2000 and oocysts of an unidentified spherical Eimeria sp. are reported from Chamaeleo dilepis dilepis Leach from Cameroon.