Photosynthetic parameters including net photosynthetic rate (P N), transpiration rate (E), water-use efficiency (WUE), and stomatal conductance (g s) were studied in indoor C3 plants Philodendron domesticum (Pd), Dracaena fragans (Df), Peperomia obtussifolia (Po), Chlorophytum comosum (Cc), and in a CAM plant, Sansevieria trifasciata (St), exposed to various low temperatures (0, 5, 10, 15, 20, and 25°C). All studied plants survived up to 0°C, but only St and Cc endured, while other plants wilted, when the temperature increased back to room temperature (25°C). The P N declined rapidly with the decrease of temperature in all studied plants. St showed the maximum P N of 11.9 μmol m-2 s-1 at 25°C followed by Cc, Po, Pd, and Df. E also followed a trend almost similar to that of P N. St showed minimum E (0.1 mmol m-2 s-1) as compared to other studied C3 plants at 25°C. The E decreased up to ≈4-fold at 5 and 0°C. Furthermore, a considerable decline in WUE was observed under cold stress in all C3 plants, while St showed maximum WUE. Similarly, the g s also declined gradually with the decrease in the temperature in all plants. Among C3 plants, Pd and Po showed the maximum g s of 0.07 mol m-2 s-1 at 25°C followed by Df and Cc. However, St showed the minimum gs that further decreased up to -4-fold at 0°C. In addition, the content of photosynthetic pigments [chlorophyll a, b, (a+b), and carotenoids] was varying in all studied plants at 0°C. Our findings clearly indicated the best photosynthetic potential of St compared to other studied plants. This species might be recommended for improving air quality in high-altitude closed environments., S. M. Gupta, A. Agarwal, B. Dev, K. Kumar, O. Prakash, M. C. Arya, M. Nasim., and Obsahuje seznam literatury
The majority of the conservation strategies for threatened dragonflies are designed to protect only their aquatic habitats. Sympetrum depressiusculum is a species threatened not only by the destruction of its aquatic habitats but also by its association with a specific terrestrial environment. In this study, we aimed to identify the key elements of the terrestrial environment of adult S. depressiusculum. We used generalized linear mixed models to determine habitat preferences of adults and the particular features of habitat patches, such as vegetation cover, vegetation structure and the availability of potential prey. Our results indicate that S. depressiusculum adults preferred mainly riparian vegetation but beyond ponds they utilized only certain terrestrial habitats (abandoned fields, meadows, forest clearings). Adults responded positively to habitat patches with a high cover of vegetation and suitable vegetation structure. Adult abundance was affected also by the distance of patches from the natal site. In an agricultural landscape, the availability of such habitat patches may be limited and could influence the abundance and distribution of this species. We suggest that conservation efforts for this species should not only focus on the larval environment but also include suitable surrounding terrestrial habitats. Effective management around natal sites should concentrate on maintaining a heterogeneous landscape, which is extensively managed (e.g. leaving several fields fallow, maintaining managed hay meadows)., Michal Hykel, Filip Harabiš, Aleš Dolný., and Obsahuje bibliografii
Waterlogging is one of the critical factors controlling the distribution, regeneration, and survival of vegetation in wetlands. Here, we tested the hypothesis that Mitragyna parvifolia (Roxb.) Korth. and Syzygium cumini Keels, inhabiting the Keoladeo National Park, a Ramsar wetland (Bharatpur, India), are tolerant to waterlogging. The morphological and photosynthetic variables of four-month-old seedlings subjected to waterlogging, along with the concentrations of macroand micronutrients, were examined. After 35 days, treatment was halted due to high mortality of S. cumini seedlings in contrast to that of M. parvifolia seedlings. Significant declines in most of the studied variables were observed in both species when compared with their respective controls. In addition, M. parvifolia seedlings developed adventitious roots and lenticels and showed an increased root biomass. Based on the results, we concluded that adaptive traits displayed by M. parvifolia seedlings facilitate its tolerance to waterlogging in contrast to S. cumini seedlings., A. Bidalia, Z. Okram, M. Hanief, K. S. Rao., and Obsahuje bibliografii
The effect of water stress on the gas exchange (CO2, H2O), distribution, water potential (T*), membrane permeability and chlorophyll content was studied in two maize hybrids, of the high and low drought tolerance, in the vegetative phase of growth. Diťferences in the responses to drought between both hybrids were clearly marked. After 5 d of drought the decrease in the net photosynthetic rate uptake and losses, transpiration rate (E) and increase of stomata resistance (r^ were greater in the drought-resistant hybrid than in the drought-susceptible one. On the contrary, after 10 or 15 d of drought, the decrease of and 'P in whole seedlings was greater in the susceptible hybrid than in the resistant one. Significant differences between hybrids were also observed in the accumulation of *'^C, the membrane permeability and the chlorophyll content. For all treatments the amount of carbon accumulation in roots of the resistant hybrid increased, while that of the susceptible one decreased. In the drought-resistant hybrid we observed a greater chlorophyll stability and a smaller damage of cell membranes than in the sensitive one.
The aim of this study was to evaluate the association of A1166C polymorphism in angiotensin II type 1 receptor (AT1R) gene with baroreflex sensitivity (BRS in ms/mm Hg; BRSf in mHz/mm Hg) in man. BRS and BRSf were determined by a spectral method in 135 subjects (19-26 years) at a frequency of 0.1 Hz. Genotypes were detected by means of polymerase chain reaction and restriction analysis using enzyme DdeI. We compared BRS and BRSf among genotypes of this polymorphism. The frequency of genotypes of AT1R A1166C polymorphism was: 45.9 % (AA, n=62), 45.9 % (AC, n=62), 8.2 % (CC, n=11). Differences in BRS (p<0.05) and BRSf (p<0.01) among genotypes of this single nucleotide polymorphism were found (Kruskal-Wallis: BRS - AA: 7.9±3.3, AC: 8.6±3.6, CC: 5.9±2.3 ms/mm Hg; BRSf - AA: 12.0±4.0, AC: 12.0±5.0, CC: 8.0±3.0 mHz/mm Hg). Compared to carriers of other genotypes (AA+AC) the homozygotes with the less frequent allele (CC) showed significantly lower BRSf (Mann-Whitney: BRSf - AA+AC: 12.0±4.0, CC: 8.0±3.0 mHz/mm Hg; p<0.01) and borderline lower BRS (BRS - AA+AC: 8.2±3.5, CC: 5.9±2.5 ms/mm Hg; p=0.07). We found a significant association of A1166C polymorphism in AT1 receptor gene with baroreflex sensitivity. Homozygosity for the less frequent allele was associated with decreased baroreflex sensitivity., M. Jíra ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
The LRP5 gene is believed to be primarily associated with bone metabolism via Wnt signaling. The latter pathway, however, appears to control various other systems outside the skeleton. To find the relationships of the LRP5 gene to serum follicle stimulating hormone (FSH ) and luteinizing hormone (LH) in the cohort of normal postmenopausal women, we identified the C/T (c.4037:A1330V) polymorphism in the LRP5 gene using a restriction analysis of the PCR product in a cohort of 165 untreated pre- and post-menopausal women. In a subset of 111 post-menopausal women we analyzed the association between the LRP5 genotype and serum levels of sex-hormones including FSH and LH. The distribution of CC, TC and TT genotypes of the C/T polymorphism in the whole group was 73.9 %, 23.6 % and 2.4 %, respectively, which is comparable with other Caucasian populations. As no TT homozygote was found in the group of post-menopausal women, serum sex-hormones were compared between CC and TC genotypes. Women with the CT allele combination had markedly higher serum FSH levels as compared to carriers of the CC genotype (p<0.004). No differences between these genotypes were found in serum LH levels as well as the circulating sex-steroids such as estradiol, testosterone, dehydroepiandrosterone and/or its sulphate, androstenedione and SHBG. To conclude, the LRP5 gene is associated with circulating FSH in normal post-menopausal women in the present study. The mediating role of subtle undetectable variations in estrogen levels is discussed. We did not find any relationship between the LRP-5 genotype and serum LH levels., I. Žofková, M. Hill, K. Zajíčková., and Obsahuje bibliografii a bibliografické odkazy
The aim of this study was to evaluate the association of single nucleotide polymorphisms (SNPs) T-786C and G894T in the gene encoding eNOS with blood pressu re variability (BPV) in man. Blood pressure was recorded beat-t o-beat at rest three times in periods of one week (5 min, Finapres, breathing at 0.33 Hz) in 152 subjects (19-24 years). Systolic (SBPV0.1r/SBPV 0.1a) and diastolic (DBPV0.1r/DBPV 0.1a) blood pressure variabilities in relative (r.u.) and absolute (mmHg2/Hz) units were determined by the spectral method as spectral po wer at the frequency of 0.1 Hz. Genotypes of both polymorphisms were detected using polymerase chain reaction and re striction analysis using enzymes Msp I and Ban II. Significant diffe rences were observed in BPV among genotypes of T-786C SNP (p<0.05; Kruskal-Wallis), and among haplotypes of both SNPs (p<0.05; Kruskal-Wallis) as well. In T-786C SNP, carriers of less frequent allele (CC homozygotes and TC heterozygotes) showed significantly greater SBPV0.1r and SBPV0.1a compared to TT homozygote s (Mann-Whitney; p<0.05). The G894T variant showed no sign ificant differences, but, both SNPs were in linkage disequilib rium (D’=0.37; p<0.01). Carriers of haplotype CT/CT (CC homozygotes of -786C/T and TT homozygotes of G894T) displaye d significantly greater SBPV0.1r, SBPV0.1a and DBPV0.1a compared to carriers of other haplotype combinations (Kruskal-Wallis; p=0.015, p=0.048, and p=0.026, respectively). In conclusion, the haplotype formed by less frequent alleles of both eNOS variants was associated with increased systolic and diastolic BPV in this study., M. Jíra ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
A predominance of small, dense low-density lipoproteins (LDL) is characteristic of the dyslipidemic state seen in type 2 diabetes. However, no study has investigated the association in gestational diabetes mellitus (GDM), which is pathophysiologically similar to type 2 diabetes. We hypothesized that LDL particle size is reduced in GDM cases compared with controls. Gradient gel electrophoresis was used to characterize LDL subclass phenotypes in non-fasting intrapartum plasma from 105 GDM cases and 96 controls. All participants were free of pre-existing diabetes or hypertension. The authors used logistic regression to estimate odds ratios (OR) and 95 % confidence intervals (CI) adjusted for confounders. Women with this phenotype had a significant 4.9-fold (95 % CI: 1.1-23.2) increased risk of GDM compared with those with the large, buoyant phenotype. The magnitude of this association was attenuated when plasma triglyceride and other confounders were included in the model (OR=4.2, 95 % CI: 0.5-39.5). Mean LDL particle size in GDM cases was smaller compared with controls (270.1 vs. 272.7Å, p=0.003). The OR of GDM risk was 1.8 (95 % CI: 0.9-3.3) for every 10-Å reduction in LDL particle size. Large prospective studies are needed to evaluate the association between smaller LDL particle size in early pregnancy with subsequent GDM risk., C. Qiu, C. Rudra, M. A. Austin, M. A. Williams., and Obsahuje bibliografii a bibliografické odkazy
We assessed association between novel biomarkers of cardiovascular disease and conven tional factors in 40 years old subjects (208 men and 266 women) from the general population of Slovakia. FER HDL (cholesterol esterifi cation rate in HDL plasma), AIP - Atherogenic Index of Plasma [Log(TG/HDL-C)] as markers of lipoprotein particle size, and CILP2, FTO and MLXIPL polymorphisms, were examined in relation to biomarkers and conventional risk factors. Un ivariate analyses confirmed correlation between AIP, FERHDL and the most of measured parameters. Relations between AIP and CILP2, FTO and MLXIPL were not significant. However, CILP2 was significantly related to FERHDL in both genders. In multivariate analysis BMI was the strongest correlate of AIP levels. In multivariate model variability of FER HDL was best explained by AIP (R2 =0.55) in both genders with still significant effect of CILP2 SNP in men. In a model where AIP was omitted, TG leve ls explained 43 % of the FER HDL variability in men, while in women HDL-C was the major determinant (42 %). In conclusions, FERHDL and AIP related to the known markers of cardiovascular risk provide means to express their subtle interactions by one number. Our novel finding of association between CILP2 polymorphism and FERHDL supports its role in lipid metabolism., K. Rašlová ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Insulin resistance is present in patients with Type 2 diabetes mellitus as well as in obese patients without diabetes. The aim of our study was to compare insulin action in diabetic and control persons with or without obesity and to evaluate the influence of serum cholesterol, serum triglyceride and blood pressure on metabolic variables of insulin action. We examined 42 Type 2 diabetic patients and 41 control persons with body mass index (BMI) from 21.1 to 64.5 kg.m-2, and 33 to 71 years old. The isoglycemic hyperinsulinemic clamp technique was performed at an insulin infusion rate of 1 mU.kg-1.min-1 during 120 min. We evaluated the metabolic clearance rate of glucose (MCRG, ml.kg-1.min-1) as the most important indicator of insulin action by isoglycemic clamp. The Pearson's correlation and multiple regression models were used to compare studied factors with the insulin action. We found following predictors of insulin resistance expressed in the relationship with MCRG: BMI (r = -0.68, p<0.001), plasma glucose concentration (r = -0.66, p<0.001), cholesterol (r=-0.55, p<0.001), triglycerides (r = -0.54, p<0.001) and mean blood pressure (r = -0.38, p<0.01). From the multiple regression analysis we conclude that obesity may have even greater influence on the insulin action than diabetes mellitus itself., G. Šindelka, J. Škrha, M. Prázný, T. Haas., and Obsahuje bibliografii