Chronic smoking can cause imbalance in endocrine homeostasis and impairment of fertility in both sexes. The male reproductive system is more resilient, still the literature provides conflicting results about the influence of smoking on the steroid hormone levels. The data about smoking cessation are limited; there has not yet been a study primarily focused on changes in steroids levels. In our study, we analyzed levels of testosterone, dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulphate (DHEAS), cortisol and sex hormone-binding globulin (SHBG) in male smokers and during smoking cessation. Monitored analytes were determined by RIA. The free testosterone index was calculated. Basal samples of men successful and unsuccessful in smoking cessation did not differ and monitored hormones could hardly predict success of smoking cessation. After one year without smoking, a significant BMI increase and SHBG decrease in former smokers was observed. The decrease in total testosterone was non-significant. Changes in SHBG and testosterone did not correlate with BMI, presumably due to the direct effect of smoking cessation., H. Hruškovičová, ... [et al.]., and Obsahuje seznam literatury
A variety of plant protection products and other agrochemicals are used in agro-ecosystems. Products approved for integrated pest management (IPM) or organic farming should have minimal negative side effects on benefi cial insects. The Asian harlequin ladybird Harmonia axyridis (Pallas, 1773) (Coleoptera: Coccinellidae) has become a widespread and important generalist predator of certain agricultural pests, mainly aphids, throughout Europe. We studied the effects of two agrochemicals, Boundary SW® (auxiliary plant protection product) and Prev B2® (foliar boron fertilizer), usually regarded as “environmentally friendly” and known to have insecticidal side effects against some fruit and vegetable pests (e.g., aphids, spider mites, weevils), on the last larval instar and adults of Harmonia axyridis. The conventional organophosphate insecticide Reldan 22® was used as a chemical standard for evaluating the lethal effect, because this product is usually effective against a broad spectrum of insects, and indeed was immediately lethal for both the adults and larvae of this species. However, whereas Prev B2® had no effect, adult ladybirds sprayed with Boundary SW® survived only for up to 25 h and also none of the larvae completed their development. Thus, although our experiments were not made under natural conditions, the use of Boundary SW® cannot be recommended for IPM and organic farming in terms of safeguarding insect predators such as Harmonia axyridis until further more detailed testing.
To determine the relationship between hyperventilation and recovery of blood pH during recovery from a heavy exercise, short-term intense exercise (STIE) tests were performed after human subjects ingested 0.3 g · kg-1 body mass of either NaHCO3 (Alk) or CaCO3 (Pla). Ventilation (V.E) - CO2 output (V.co2) slopes during recovery following STIE were significantly lower in Alk than in Pla, indicating that hyperventilation is attenuated under the alkalotic condition. However, this reduction of the slope was the result of unchanged V.E and a small increase in V.co 2.A significant correlation between V.E and blood pH was found during recovery in both conditions. While there was no difference between the V.E - pH slopes in the two conditions, V.E at the same pH was higher in Alk than in Pla. Furthermore, the values of pH during recovery in both conditions increased toward the preexercise levels of each condition. Thus, although V.E - V.co 2 slope was decreased under the alkalotic condition, this could not be explained by the ventilatory depression attributed to increase in blood pH. We speculate that hy perventilation after the end of STIE is determined by the V.E - pH relationship that was set before STIE or the intensity of the exercise performed., T. Yunoki ... [et al.]., and Obsahuje seznam literatury
a1_We investigated the influence of salinity (0, 25, 50, or 75 mM NaCl) on gas exchange and physiological characteristics of nine citrus rootstocks (Cleopatra mandarin, Carrizo citrange, Macrophylla, Iranian mandarin Bakraii, Rangpur lime, Rough lemon, Sour orange, Swingle citrumelo, and Trifoliate orange) in a greenhouse experiment. Total plant dry mass, total chlorophyll (Chl) content, and gas-exchange variables, such as net photosynthetic rate (PN), stomatal conductance (g s), intercellular CO2 concentration, were negatively affected by salinity. In addition, ion concentrations of Cl- and Na+ increased by salinity treatments. Salinity also increased Mg2+ content in roots and reduced Ca2+ and Mg2+ concentrations in leaves. The K+ concentration in leaves was enhanced at low salinity (25 mM NaCl), whereas it decreased with increasing salinity stress. Salinity caused a decline in K+ contents in roots., a2_The rootstocks showed major differences in the extent of Cl- and Na+ accumulation in leaves and in their ability to maintain the internal concentrations of essential nutrients in response to different salinity. Therefore, in addition to inhibitory effects of high concentrations of Cl- and Na+, an imbalance of essential nutrients may also contribute to the reduction in gas exchange under saline conditions. Higher tolerance of rootstocks to salinity could be associated with the reduction of Cl- and Na+ uptake and transport to leaves, ability to keep higher Chl, gs, PN, and better maintenance of nutrient uptake even under high salinity. We found that Sour orange and Cleopatra mandarin were the rootstocks most tolerant to salinity of all nine studied. In addition, Trifoliate orange, Carrizo citrange, and Swingle citrumelo were the rootstocks most sensitive to salt stress followed by the Rough lemon and Macrophylla that showed a low-to-moderate tolerance, and Rangpur lime and Bakraii, with a moderate-to-high tolerance to high salinity., D. Khoshbakht, A.A. Ramin, B. Baninasab., and Obsahuje bibliografii
The present study was performed to evaluate the effects of sodium intake and of chronic cyclooxygenase-2 (COX-2) inhibition on systolic blood pressure (SBP) in heterozygous male transgenic rats harboring the mouse Ren-2 renin gene (TGR) and in transgene-negative normotensive Hannover Sprague-Dawley (HanSD). Twenty-eight days old TGR and
HanSD were randomly assigned to groups fed either normal salt (NS) or low sodium (LS) diets. COX-2 blockade was achieved with NS-398 (1 mg.kg
-1.day-1 in drinking water). During an experimental period of 26 days, SBP was repeatedly measured by tail plethysmography in conscious animals. We found that the LS diet prevented the development of hypertension in TGR and did not change SBP in HanSD. Low sodium intake also prevented proteinuria and cardiac hypertrophy in TGR. On the other hand, irrespective of sodium intake chronic COX-2 inhibition did not
alter the course of SBP in either TGR or HanSD. The present data indicate that TGR exhibit an important salt-sensitive component in the developmental phase of hypertension. They also suggest that systemic COX-2-derived prostaglandins do not act as vasodilatory counterregulatory agents in TGR in which an exaggerated vascular responsiveness to angiotensin II is assumed as the pathophysiological mechanism in the development of hypertension.
The combined effects of water status, vapour pressure deficit (VPD), and elevated temperature from heading to maturity were studied in barley. Plants growing at high VPD, either under well-watered or water deficit conditions, had higher grain yield and grain filling rate than plants growing at low VPD. By contrast, water stress decreased grain yield and individual grain dry matter at any VPD. Water regime and to a lesser extent VPD affected δ13C of plant parts sampled at mid-grain filling and maturity. The differences between treatments were maximal in mature grains, where high VPD increased δ13C for both water regimes. However, the total amount of water used by the plant during grain filling did not change as response to a higher VPD whereas transpiration efficiency (TE) decreased. The net photosynthetic rate (PN) of the flag leaves decreased significantly under water stress at both VPD regimes. However, PN of the ears was higher at high VPD than at low VPD, and did not decrease as response to water stress. The higher correlation of grain yield with PN of the ear compared with that of the flag leaf support the role of ear as the main photosynthetic organ during grain filling under water deficit and high VPD. The deleterious effects of combined moderately high temperature and drought on yield were attenuated at high VPD. and M. Sánchez-Díaz ... [et al.].
This study investigated the effect of solar ultraviolet radiation (UVR) and temperature on a chain length and photosynthetic performance of diatom Chaetorceros curvisetus. The cells were cultured in large quartz tubes and exposed to PAR, PAR + UV-A (PA), or PAR + UV-A + UV-B (PAB) radiation at 20°C and 28°C for six days, respectively. After recovery for 1 h, the cells were exposed again to three different radiations for 1 h. Then, a change in the photochemical efficiency (FPSII) was examined and UVR-induced photoinhibition was calculated. The percentage of long chains (more than five single cells per chain) in C. curvisetus significantly increased from 8.2% (PAR) to 38.9% (PAB) at 20°C; while it was not notably affected at 28°C. Mycosporine-like amino acids (MAAs) concentration obviously increased by irradiance increment from PAR to PAB at 20°C. Chlorophyll (Chl) a concentration significantly declined with increasing irradiance at 20°C. Both MAAs and Chl a concentrations were not obviously changed by irradiance at 28°C. Before and after reexposure, FPSII was significantly reduced both at 20°C and 28°C. UVR-induced photoinhibition at 20°C (39%) was higher than that at 28°C (30.9%). Solar UV radiation, especially UV-B, could significantly influence the percentage of long chains of C. curvisetus, especially at low temperature. UVR-induced photoinhibition can be alleviated by higher temperatures., W. Guan, X. Peng, S. Lu., and Obsahuje seznam literatury
The formation of economic yield and fruit quality of Roxburgh rose (Rosa roxburghii Tratt.) depends essentially on its source-sink interaction. Thus, a pruning experiment was conducted to assess the effects of source-sink regulation on photosynthetic physiology and fruit yield of Roxburgh rose, which was of great significance to production. Cutting off vegetative branches reduced physiological fruit loss and malformed fruits but increased single fruit quality and yield. Results revealed that the stomatal characteristics, the composition of mesophyll tissue, and photosynthesis of leaves on reproductive branches were significantly affected by the ratio of the vegetative and reproductive shoots. Our data indicated that the source-sink ratio could reflect the balance between vegetative growth and reproductive growth of the tree during the whole fruit period. Fruit tree pruning had guiding significance for improving the fruit yield of Roxburgh rose.
The chlorophyll (Chl) and protein degradation during dark incubation of leaf discs was reduced by Sr2+, Ca^^, and spermine (Spm) treatments. Sr2+ inhibited most effectively the Chl degradation, which was remarkable 48 h after the treatment. The Chl degradation appeared in control discs within 24 h in the dark and Chl content decreased by about 50 % during 96 h. The proteins retained at least during 48 h of dark treatment in the presence of Sr2+, Ca2+, or Spm. The retardation effect of Sr2+, Ca2+ and Spm on the Chl loss and the disintegration of thylakoid membrane proteins may be due to a cationic protection of thylakoid membranes.
The aim of the study was to investigate the effects of stable adenosine receptor agonists on bone marrow hematopoiesis by utilizing the model of hematopoietic damage induced by 5-fluorouracil (5-FU), a cycle-specific cytotoxic agent. Effects of a non-selective agonist NECA activating all the known adenosine receptors (A1, A2A, A2B, A3) and of the selective agonists for A1 (CPA), A2A (CGS 21680), and A3 (IB-MECA) adenosine receptors were investigated. Experiments were performed with B10CBAF1 mice under in vivo conditions. Adenosine receptor agonists were given in single injections before 5-FU administration and the effects were determined 4 days later. The numbers of femoral marrow nucleated cells and hematopoietic progenitor cells (CFC-GM and BFU-E) were taken as indices of the effects. The non-selective agonist NECA given at a dose of 200 nmol/kg induced biphasic time-dependent effects, i.e. protection and sensitization, when given 10 h and 22 h before 5-FU administration, respectively. The use of isomolar doses of selective receptor agonists indicated that the protective effects of NECA were induced by activation of A2A and A2B receptors, while the sensitizing action of NECA was mediated via A3 receptors. In addition, it was observed that A1 receptors induced protection when activated by administration of CPA 22 h before 5-FU. These findings are discussed with respect to the action of adenosine receptor agonists on the cell cycle state and on the cell cycle-independent cellular protective mechanisms.