On the first day after foliar application, chitosan pentamer (CH5) and chitin pentamer (CHIT5) decreased net photosynthetic rate (PN) of soybean and maize, however, on subsequent days there was an increase in PN in some treatments. CH5 caused an increase in maize PN on day 3 at 10-5 and 10-7 M; the increases were 18 and 10 % over the control plants. This increase was correlated with increases in stomatal conductance (gs) and transpiration rate (E), while the intercellular CO2 concentration (Ci) was not different from the control plants. PN of soybean plants did not differ from the control plants except for treatment CH5 (10-7 M) which caused an 8 % increase on day 2, along with increased gs, E, and Ci. On days 5 and 6 the CHIT5 treatment caused a 6-8 % increase in PN of maize, which was accompanied by increases in gs, E, and Ci. However, there was no such increase for soybean plants treated with CHIT5. In general, foliar application of high molecular mass chitin (CHH) resulted in decreased PN, particularly for 0.010 % treated plants, both in maize and soybean. Foliar applications of chitosan and chitin oligomers did not affect (p > 0.05) maize or soybean height, root length, leaf area, shoot or root or total dry mass. and W. M. Khan, B. Prithiviraj, D. L. Smith.
The effect on traits of photosynthesis and water relations of assimilate demand was studied in olive tree that has strong alternate bearing. The diurnal and seasonal leaf gas exchanges, area dry mass, and saccharide and chlorophyll (Chl) contents were measured by comparing shoots with fruit of "on-trees" (heavy fruit load) with shoots without fruit on both "on-trees" and "off-trees" (light fruit load). In spite of large seasonal and diurnal differences, leaf net photosynthetic rate (PN), stomatal conductance (gs), sub-stomatal CO2 concentration (C1), transpiration rate (E), and respiration rate (RD) were not significantly influenced by fruit load or by the presence or absence of fruit on the shoot. An only exception was at the beginning of July when the one-year-old leaves on shoots with fruit had slightly higher PN and E than leaves on shoots without fruit. Water content, Chl and saccharide contents, and area dry mass of the leaf were not substantially influenced by the presence/absence of fruit on the shoot or fruit load. Hence the sink demand, associated with fruit growth, did not improve leaf photosynthetic efficiency in olive.
Activation of GABAB receptors leads to longer inhibitory postsynaptic potentials than activation of GABAA receptors. Therefore GABAB receptors may be a target for anticonvulsant therapy. The present study examined possible effects of GABAB receptor agonist SKF97541 on cortical and hippocampal epileptic afterdischarges (ADs). Epileptic ADs elicited by electrical stimulation of sensorimotor cortex or dorsal hippocampus were studied in adult male Wistar rats. Stimulation series were applied 6 times with 10- or 20-min interval. Either interval was efficient for reliable elicitation of cortical ADs but stimulation at 10-min intervals did not reliably elicit hippocampal ADs, many stimulations were without effect. SKF97541 in dose 1 mg/kg significantly prolonged cortical ADs. Duration of hippocampal ADs was not significantly changed by either dose of SKF97541 in spite of a marked myorelaxant effect of the higher dose. Our present data demonstrated that neither cortical nor hippocampal ADs in adult rats were suppressed by GABAB receptor agonist SKF97541. Proconvulsant effect on cortical ADs indicates a different role in these two brain structures. In addition, duration of refractory period for electrically-induced ADs in these two structures in adult rats is different., P. Fábera, P. Mares., and Obsahuje bibliografii
Agronomic traits, photosynthetic pigments, gas exchange, and chlorophyll (Chl) fluorescence parameters of red stem buckwheat (Fagopyrum dibotrys Hara) mutants induced by γ-radiation were compared with green control at seedling stage. Plant height, number of first-class branches, and rhizome biomass were inhibited significantly (p<0.01). Chl a, Chl b, and Chl a+b contents decreased with elevated dose of γ-rays, while increasing carotenoid content indicated that buckwheat was capable of adjusting to the radiation damage. Decrease in net photosynthetic rate was the result of both stomatal and non-stomatal limitations. Fluorescence parameters, such as F0, Fm, Fv/Fm, Fv/F0, ΦPS2, electron transport rate, and photochemical quenching declined significantly (p<0.01) as compared with control due to photoinhibition, while non-photochemical quenching increased to enhance thermal dissipation. Lower parameters implied that leaf tissue was damaged significantly by high dose of γ-radiation and therefore leaf senescence was accelerated. and C. F. Jia, A. L. Li.
Dyslipidemia in the metabolic syndrome (MS) is considered to be one of the most important risk factors for atherosclerosis. It is characterized by hypertriglyceridemia, low concentration of plasma HDL-cholesterol, predominance of small dense LDL particles and an increased concentration of plasma apolipoprotein B (apoB). The pathogenesis of this type of dyslipidemia is partially explained, but its genetic background is still unknown. To evaluate the influence of cholesterol ester transfer protein (CETP) TaqIB polymorphism, lipoprotein lipase (LPL) PvuII and HindIII polymorphisms, hepatic lipase (LIPC) G-250A polymorphism and apolipoprotein C-III (APOC3) SstI gene polymorphism on lipid levels in dyslipidemia of the metabolic syndrome, 150 patients with dyslipidemia of metabolic syndrome were included. 96 % of patients had type 2 diabetes. The patients did not take any lipid lowering treatment. The exclusion criterion was the presence of any disease that could affect lipid levels, such as thyroid disorder, liver disease, proteinuria or renal failure. Gene polymorphisms were determined using the polymerase chain reaction and restriction fragment length polymorphisms. The genotype subgroups of patients divided according to examined polymorphisms did not differ in plasma lipid levels with the exception of apoB. The apoB level was significantly higher in patients with S1S1 genotype of APOC3 SstI polymorphism when compared with S1S2 group (1.10±0.26 vs. 0.98±0.21 g/l, p=0.02). Similarly, patients with H-H- genotype of LPL HindIII polymorphism had significantly higher mean apoB, compared with H+H- and H+H+ group (1.35±0.30 vs. 1.10±0.26 g/l, p=0.02). In the multiple stepwise linear regression analysis, apoB level seemed to be influenced by APOC3 SstI genotype, which explained 6 % of its variance. The present study has shown that the S1 allele of APOC3 SstI polymorphism and the H- allele of LPL HindIII polymorphism might have a small effect on apoB levels in the Central European Caucasian population with dyslipidemia of metabolic syndrome.
Ginsenoside has been reported to have therapeutic effects for some types of cancer, but its effect on ovarian cancer cells has not been evaluated. In this study, we monitored the effects of ginsenoside-Rh2 (Rh2) on the inhibition of cell proliferation and the apoptotic process in the ovarian cancer cell line SKOV3 using an MTT assay and TUNEL assay. We found that Rh2 inhibited cell proliferation and significantly induced apoptosis. We confirmed the apoptotic effects of Rh2 using western blot analysis of apoptosis-related proteins. Specifically, the levels of cleaved poly ADP ribose polymerase (PARP) and cleaved caspase-3
significantly increased in SKOV cells treated with Rh2. Therefore, Rh2 clearly suppressed the growth of SKOV3 cells in vitro, which was associated with induction of the apoptosis pathway. Moreover, the migration assay showed that Rh2 inhibited the invasive ability of SKOV3 cells. Taken together, our results suggest that Rh2 has anticancer effects in SKOV3 cells through inhibition of cell proliferation and induction of apoptosis. Considering the therapeutic potential of Rh2, more studies should be carried out to facilitate the future application of this natural
product as a potential anti-cancer agent.
The present study was undertaken to investigate the effect of Glomus mosseae on chlorophyll (Chl) content, Chl fluorescence parameters and chloroplast ultrastructure of beach plum seedlings under 2% NaCl stress. The results showed that compared to control, both Chl a and Chl b contents of NaCl + G. mosseae treatment were significantly lower during the salt stress, while Chl a/b ratio increased significantly. The increase of minimal fluorescence of darkadapted state (F0), and the decrease of maximal fluorescence of dark-adapted state (Fm) and variable fluorescence (Fv) values were inhibited. The maximum quantum yield of PSII photochemistry (Fv/Fm), the maximum energy transformation potential of PSII photochemistry (Fv/F0) and the effective quantum yield of PSII photochemistry (ΦPSII) increased significantly, especially the latter two variables. The values of the photochemical quenching coefficient (qP) and the nonphotochemical quenching (NPQ) were similar between G. mosseae inoculation and noninoculation. It could be concluded that G. mosseae inoculation could protect the photosystem II (PSII) of beach plum, enhance the efficiency of primary light energy conversion and improve the primitive response of photosynthesis under salinity stress. Meanwhile, G. mosseae inoculation was beneficial to maintain the integrity of thylakoid membrane and to protect the structure and function of chloroplast, which suggested that G. mosseae can alleviate the damage of NaCl stress to chloroplast., X. M. Zai ... [et al.]., and Obsahuje bibliografii
We evaluated the effects of 2.5xlO-10 M or 5xlO-10 M concentrations of human pituitary prolactin (pPRL), human recombinant non-glycosylated (NG-PRL) and glycosylated (GL-PRL) prolactin on the proliferation of normal human lymphocytes with or without coactivation by interleukin-2 (IL-2). None of the PRL forms alone affected the lymphocyte proliferation in a serum-free medium, however, the stimulatory activity of IL-2 was significantly potentiated with all 3 PRL variants. Since the 5xlO~10 M concentrations of individual PRLs exerted the same effects, this result suggests that GL-PRL in primary lymphocyte culture is not a less mitogenic form, if sufficient amounts of IL-2 are available.
Dry calcareous grasslands are among the most species-rich and endangered ecosystems in the Central- European landscape. They are of anthropogenic origin and mainly a result of grazing by domestic animals. Due to land-use changes in the last century, particularly in the 1960s, they were often abandoned or afforested. Therefore, in 1975 long-term experiments were started in the southwestern Germany (Baden-Württemberg) to determine the effectiveness of alternative management treatments in maintaining grasslands and their species composition. The aim of this study was to assess the effect of grazing (reference management treatment), mowing once a year, mulching twice a year, mulching every second year, burning once a year and succession (abandonment) on the population structure (in terms of density, age structure, reproduction mode) and seasonal germination niche of a dwarf shrub, Helianthemum nummularium, and a herbaceous plant, Lotus corniculatus. To study the age structure, annual ring analyses were applied. The classification of the reproduction mode, either by seed or vegetatively, was carried out by differentiating the central under-ground organ either as a root (in this case the individual has established from seed) or rhizome (the individual has developed from clonal multiplication). The seasonal germination niche was derived from the age structure. Management clearly affected population density and age structure. Highest density of individuals was found in the grazing and the lowest in the succession treatment. In the mulching every second year and succession treatments populations were senescent. Management also affected reproduction mode in H. nummularium. Regeneration by seed was especially enhanced by mowing and burning but was inhibited by mulching twice and succession. In the latter treatments H. nummularium reproduced only clonally. Helianthemum nummularium germinated mainly in autumn but burning by breaking the dormancy of seeds initiated germination in spring. A similar pattern was detected in L. corniculatus: burning increased germination rate in spring. Comparing population characters (density, age, reproduction mode) to the traditionally used grazing treatment, mowing was most similar and for L. corniculatus additionally burning. This is in contrast to the assessment of the vegetation of the management treatments where mowing and mulching twice per year maintain a similar floristic composition. Finally, the analysis of the population structure revealed important mechanisms behind population and vegetation dynamics.
The presence of gravel in soils modifies the porosity, pore connectivity and pore size distribution in the soil matrix as well as the soil matrix-gravel interfaces. The aim of the present study is to investigate the effect of relative volume of gravel in samples with gravel mass fractions of 5,10, 20 wt% and varying bulk densities (1.3, 1.45, 1.55, 1.60, 1.65 g cm–3) on (i) total porosity, field capacity, plant available water holding capacity, (ii) pore size distribution and (iii) thermal capacity of repacked sandy and silty soils. The focus of the study was to determine if laboratory measured soil water retention curves considering (i), (ii), and (iii) can be predicted by a gravel-based weighting factor, Rv, considering comprehensive significance tests. The sand-gravel mixtures show a decrease in the volume fractions of macropores and wide cores pores with an increase in the gravel contents, while the silt-gravel mixtures show an opposite trend. The root mean square errors (RMSE) between measured and fitted volumetric water contents, θ, between 0.006 and 0.0352 and between 0.002 and 0.004 for Rv-weighted volumetric water contents indicate that the van Genuchten-based Peters-Durner- Iden (PDI) model is appropriate for fitting. The soil water retention curves with mass gravel contents of up to 10 wt% for silt and 20 wt% for sand can be well predicted by weighting factors (relative volume of rock fragments) in the range between 0.045 and 0.058 for silt, and between 0.112 and 0.119 for sand. The results also indicate a decrease in the Rv-weighted saturated, cvsat, and dry, cvdry, thermal capacity with an increase in the gravel contents for both soils. Further investigations are needed to examine if and whether measured sand- and silt-gravel mixtures with mass gravel contents below 10 % or rather 20 % can be predicted with a weighting factor.