The cold pressor test (CPT) triggers in healthy subjects a vascular sympathetic activation and an increase in blood pressure. The heart rate (HR) response to this test is less well defined, with a high inter-individual variability. We used traditional spectral analysis together with the non-linear detrended fluctuation analysis to study the autonomic control of HR during a 3-min CPT. 39 healthy young subjects (23.7 ± 3.2 years, height 180.4 ± 4.7 cm and weight 73.3 ± 6.4 kg) were divided into two groups according to their HR responses to CPT. Twenty subjects have a sustained increase in HR throughout the test with reciprocal autonomic interaction, i.e. increase in sympathetic activity and decrease vagal outflow. In the 19 remainders, HR decreased after an initial increase, with indication of involvement of both sympathetic and vagal outflow. Baseline evaluation of the subjects revealed no difference between the two groups. Nevertheless, a higher sympathetic activity at the skin level during CPT was present in the group with decreased HR. Further studies are needed to explain why healthy subjects react differently to the CPT and if this has potential clinical implications., L. Mourot, M. Bouhaddi, J. Regnard., and Obsahuje seznam literatury
We studied growth and photosynthesis of cucumber (Cucumis sativus) seedlings under two vapor-pressure deficit levels (VPD; 0.4 and 3.0 kPa), two salinity levels (0 mM and 34 mM NaCl), and two CO2 concentrations ([CO2]; 400 and 1,000 μmol mol-1). Relative growth rate (RGR) decreased with increasing VPD, but the causal factor differed between salinity levels and CO2 concentrations. Under ambient [CO2], RGR decreased with increasing VPD at low salinity mainly due to decreased leaf area ratio (LAR), and decreased net assimilation rate (NAR) at high salinity. The decrease in intercellular [CO2] (Ci) with decreasing stomatal conductance caused by high VPD did not significantly limit net photosynthetic rate (PN) at low salinity, but PN was potentially limited by Ci at high salinity. At high [CO2], high VPD reduced LAR, but did not affect NAR. This is because the decrease in Ci occurred where slope of PN-Ci curve was almost flat., T. Shibuya, K. Kano, R. Endo, Y. Kitaya., and Obsahuje bibliografii
The aim of this study was to investigate the effect of 7-oxo-DHEA (dehydroepiandrosterone) on the serum levels of steroid sexual hormones, gonadotropins, lipids and lipoproteins in men. 7-oxo-DHEA was applied onto the skin as a gel to 10 volunteers aged 27 to 72 years for 5 consecutive days. The single dose contained 25 mg 7-oxo-DHEA. Serum concentrations of testosterone, estradiol, cortisol, androstenedione, luteinizing hormone (LH), follicle-stimulating hormone (FSH), sex hormone binding globulin (SHBG), total cholesterol, HDL- and LDL-cholesterol, triglycerides, apolipoprotein A-I and B and lipoprotein(a) were measured before the beginning and shortly after the end of the steroid application. After the treatment, we noted the following significant changes: a decline of testosterone and estradiol levels, increase of LH, HDL-cholesterol and apolipoprotein A-I levels. The decrease of total cholesterol levels was of the borderline significance. A slight but significant increase was found in apolipoprotein B and lipoprotein(a). The most expressive was the fall of the atherogenic index. We suggest that the gel containing 7-oxo-DHEA might be a suitable drug for improving the composition of the steroid and lipid parameters in elderly men., J. Šulcová, M. Hill, Z. Mašek, R. Češka, A.Nováček, R. Hampl, L. Stárka., and Obsahuje bibliografii
In order to ascertain the kinetics of absorption and metabolism of transdermally administered dehydroepiandrosterone (DHEA), 10 men 29-72 years old (mean 52.4±14.5) received 50 mg DHEA/day in a gel applied onto the skin of the abdomen for 5 consecutive days. The objective was to establish the extent to which DHEA influences the levels of gonadotropins, sex hormone-binding globulin and lipids. It was found that DHEA is well absorbed and rapidly metabolized to its sulfate (DHEAS), androstenedione, and consequently to testosterone and estradiol. The DHEA levels that markedly increased after the first doses gradually declined already during the application, and this decline proceeded even after it was discontinued, reaching levels significantly lower than the original ones. On the other hand, the levels of DHEA metabolites (with the exception of DHEAS) rose during the application and reached values significantly higher than the basal ones within 5 weeks. This effect was accompanied by significantly decreased levels of LH. The serum levels of lipids, namely of cholesterol (both HDL and LDL cholesterol), triglycerides, apolipoproteins A-I and B and lipoprotein(a) after DHEA application were not changed significantly, and the atherogenic index (AI) remained unaltered. However, some correlations between hormones and lipids were found. Negative correlations concerned the following indices: DHEA/Lp(a); DHEAS/cholesterol; DHEA, DHEAS, testosterone/TG; testosterone/AI. On the other hand, LH, FSH/cholesterol, FSH, SHBG/LDL cholesterol, FSH/Apo B, Lp(a) correlated positively. It can be concluded that transdermal short-time application of DHEA results in a decrease of endogenous DHEA after finishing the treatment, with a parallel marked increase in the levels of sex hormones. Using this application protocol, exogenous DHEA neither altered the lipid spectrum, nor did it influence the atherogenic index., J. Šulcová, M. Hill, R. Hampl, Z. Mašek, A. Nováček, R. Češka, L. Stárka., and Obsahuje bibliografii
The in vivo effects of recombinant human interleukin-1 receptor antagonist (rhIL-1Ra) administration on endogenous IL-1 levels in the circulation and conditioned media (CM) from different immunohematopoietic organ/tissues were studied in CBA mice under steady state and postirradiation conditions. In normal mice, constitutive IL-1 levels were demonstrated in the plasma, CM of peritoneal exudate cells and full-thickness skin explants with low or undetectable levels in CM of splenic and bone marrow cell suspensions. In irradiated mice (2 Gy, X rays) on day 3 post exposure a significant increase of IL-1 levels was seen in the circulation and CM of peritoneal exudate cells, with no significantly different levels in postirradiation bone marrow, spleen and skin. After rhIL-1Ra treatment of the animals (2 x 50 mg/mouse, i.p.), significantly elevated IL-1 levels were observed in the skin and CM of peritoneal exudate cells in normal mice, whereas slightly increased levels were detected in CM of splenic cells. The rhIL-1Ra administration in irradiated mice led to decreased IL-1 concentrations in the circulation, and CM of peritoneal exudate cells and skin. The results pointed out the importance of IL-1 secretion and receptor expression in the maintenance of homeostasis in steady state, as well as during recovery after irradiation. Modulatory effects of IL-1Ra on IL-1 production were dependent on basic endogenous IL-1 concentration., D. Bugarski, G. Jovčić, M. Kataranovski, Z. Ivanović, M. Petakov, N. Stojanović, P. Milenković., and Obsahuje bibliografii
The maize weevil, Sitophilus zeamais (Motschulsky), is a major pest of stored grain kernels. Irradiation is an established technique for controlling insects in stored grain and is a major stress factor affecting these insects. Since heat shock protein (hsp) genes respond to this stress, we proposed that hsps may be associated with irradiated stress tolerance in S. zeamais. The responses of the maize weevil to exposure to ultraviolet-C (UV-C) and microwave irradiation were assessed at four developmental stages: egg, larva, pupa and adult. The results revealed that exposure to UV-C (254 nm, < 8 h) did not affect the survival of the maize weevils; however, Szhsp70, Szhsc70 and Szhsp90 mRNA levels significantly increased during the first 1 h of UV-C exposure. The median lethal time (LT50) of exposure to microwave irradiation indicated that the adult stage was more tolerant of microwave irradiation than the other developmental stages. Microwave irradiation enhanced the expression of the three hsps, but the intensity of up-regulation differed among the three genes, with Szhsp70 the most highly up-regulated. Our experiments revealed that UV-C and microwave irradiation influenced the expression profile of hsp genes in S. zeamais. At the tissue level, the gene responses to UV-C and microwave irradiation varied greatly in different tissues., Jatuporn Tungjitwitayakul, Nujira Tatun, Boongeua Vajarasathira, Sho Sakurai., and Obsahuje bibliografii
Both prostaglandins (PGs) and vitamin E are known to deeply affect immune responses. It is shown here that they both influence T cell-mediated immunity through reciprocal interference on the expression of cyclic-AMP responsive element binding (CREB) family proteins. CREB1 protein of human T lymphocytes was significantly modulated by a brief treatment of 5 to 10 min with PGE2. On the contrary, vitamin E appeared to be ineffective on the CREB1 behavior, while it abolished the PGE2-induced modulation of this protein. The CREB2 protein expression was also affected by PGE2 treatment, but a longer period of incubation (>20 min) was needed to observe these changes. Vitamin E showed a strong enhancing effect on CREB2 that was partially reversed by the subsequent treatment with PGE2. Our results support the idea that there is reciprocal interference between PGE2 and vitamin E on PGE2-induced signals in T lymphocytes. These data are in agreement with the reports concerning different cell systems and experimental conditions., A. Valenti, I. Venza, M. Venza, V. Fimiani, D. Teti., and Obsahuje bibliografii
a1_Soil water deficit is a major limitation to agricultural productivity in arid regions. Leaf photosynthesis can quickly recover after rewatering and remains at a higher level for a longer period, thus increasing crop yield and water-use efficiency (WUE). We tested our hypothesis that leaf photosynthesis and root activity of water-stressed cotton (Gossypium hirsutum L.) plants could quickly recover after rewatering at a certain growth stage and it should not influence a cotton yield but increase WUE. Treatments in this study included two degrees of water stress: mild water stress (V1) and moderate water stress (V2) imposed at one of four cotton growth stages [i.e., S1 (from the full budding to early flowering stage), S2 (from early flowering to full flowering), S3 (from full flowering to full bolling), and S4 (from full bolling to boll-opening)]. The soil water content before and after the water stress was the same as that in the control treatment (CK, 70-75% of field capacity). Water deficit significantly reduced the leaf water potential, net photosynthetic rate, and stomatal conductance in cotton. The extent of the decline was greater in S2V2 treatment compared to others. Water deficit also reduced root activity, but the extent of inhibition varied in dependence on soil depth and duration. When plants were subjected to S1V1, the root activity in the 20-100 cm depth recovered rapidly and even exceeded CK one day after rewatering. An overcompensation response was observed for both photosynthesis and aboveground dry mass within one to three days after rewatering. Compared with the CK, S1V1 showed no significant effect on the yield but it increased total WUE and irrigation WUE., a2_These results suggest that even a short-term water stress during the S1, S2 and S4 stages mitigated, with respect to the root activity, the negative effect of drought and enhanced leaf photosynthesis compensatory effects of rewatering in order to increase cotton WUE with drip irrigation under mulch in arid areas., H. H. Luo, Y. L. Zhang, W. F. Zhang., and Obsahuje seznam literatury
To evaluate the preclinical efficacy and safety of human mesenchymal stem cells (hMSC) rapidly expanded in growth medium for clinical use with human se rum and recombinant growth factors, we conducted a controlled, randomized trial of plasma clots with hMSC vs. plasma clots only in critical segmental femoral defects in rnu/rnu immunodeficient rats. X-ray, microCT and histomorphometrical evaluation were pe rformed at 8 and 16 weeks. MSC were obtained from healthy volunteers and patients with lymphoid malignancy. Human MSC survived in the defect for the entire duration of the trial. MSC from healthy volunteers, in contrast to hMSC from cancer patients, significantly improved bone healing at 8, but not 16 weeks. However, at 16 weeks, hMSC significantly improved vasculogenesis in residual defect. We conclude that hMSC from healthy donors significantly contributed to the healing of bone defects at 8 weeks and to the vascularisation of residual connective tissue for up to 16 weeks. We found the administration of hMSC to be safe, as no adverse reaction to human cells at the site of implantation and no evidence of migration of hMSC to distant organs was detected., R. Pytlík, C. Rentsch, T. Soukup, L. Novotný, B. Rentsch, V. Kanderová, H. Rychtrmocová, M. Kalmárová, D. Stehlík, M. Trněný, O. Slanař., and Obsahuje bibliografii
Anticoccidial efficacy of a drug combination containing monensin at 8 p.p.m. plus the new antioxidant duokvin at 120 p.p.m. in the feed was compared with that of monensin alone at the recommended level of 100 p.p.m. against a field isolate of the coccidium Eimeria acervulina Tyzzer, 1929 in a battery study. Both monensin and monensin duokvin combination were effective against E. acervulina when judged by weight gain, feed conversion and faecal scores. There was no significant difference in the chemoprophylactic activity of either treatments. Neither monensin at 100 p.p.m. nor the combination proved effective in terms of oocyst production. In accordance with the earlier findings with E. lenella, the combination seems appropriate for field trials.