The effects of training on hormonal concentrations in young soccer players

To test the hypothesis that football training would be accompanied by physiological adaptations and hormonal changes, we analyzed the effects of a whole football season on physical fitness and hormonal concentrations in youth football players. Male football players (n = 29, age 16.51 ± 0.7 years) in a regional professional league and male healthy control subjects (n = 30, age 17.1 ± 1 years) participated to the study. Blood cortisol, testosterone, and growth hormone (hGH) concentrations were assayed before the beginning of the training period (T0), just after the training period (T1), at the middle of the season (T2), and at the end of the season (T3). In each period physical tests and anthropometric measurements were also performed. Results showed significant differences in basal values of cortisol, testosterone, and growth hormone (hGH) in the four time points evaluated (P < 0.01). In addition, the concentrations of hGH were higher in the soccer players group than in control subjects (P < 0.001). Between the start of the training period and the end of the football season significant differences were observed in the anthropometric characteristics and in the physical form of the football players. Furthermore, the hormonal status was significantly correlated with the indicators of the lower limb power (squat-jump [SqJ], and counter-movement-jump [CMJ]) and those of aerobic performance (Yo–Yo intermittent recovery test level 1 (YYIRT1) and maximal oxygen consumption (VO_2max)).These data underscore the importance of establishing training protocols that present the potential to promote positive adaptations without, at the same time, provoking overtraining of young players.     

Novel complex hydrogels based on N-carboxyethyl chitosan and quaternized chitosan and their controlled in vitro protein release property

A novel pH-responsive hydrogel (CHC) composed of N-carboxyethyl chitosan (CEC) and N-[(2-hydroxy-3-trimethylammonium) propyl] chitosan chloride (HTCC) was synthesized by the redox polymerization technique. Turbidimetric titrations were used to determine the stoichiometric ratio of these two chitosan derivatives. The hydrogel was characterized by FT-IR, thermal gravimetric analysis (TGA), X-ray diffractometry (XRD), and scanning electron microscopy (SEM). The dynamic transport of water showed that the hydrogel reached equilibrium within 48 h. The swelling ratio of CHC hydrogel depended significantly on the pH of the buffer solution. The performance of the CHC as a matrix for the controlled release of BSA was investigated. It was found that the release behavior was determined by pH value of the medium as well as the intermolecular interaction between BSA and the hydrogels.     

RACK1 identified as the PCBP1‐interacting protein with a novel functional role on the regulation of human MOR gene expression

Poly C binding protein 1 (PCBP1) is an expressional regulator of the mu‐opioid receptor (MOR) gene. We hypothesized the existence of a PCBP1 co‐regulator modifying human MOR gene expression by protein–protein interaction with PCBP1. A human brain cDNA library was screened using the two‐hybrid system with PCBP1 as the bait. Receptor for activated protein kinase C (RACK1) protein, containing seven WD domains, was identified. PCBP1‐RACK1 interaction was confirmed via in vivo validation using the two‐hybrid system, and by co‐immunoprecipitation with anti‐PCBP1 antibody and human neuronal NMB cell lysate, endogenously expressing PCBP1 and RACK1. Further co‐immunoprecipitation suggested that RACK1‐PCBP1 interaction occurred in cytosol alone. Single and serial WD domain deletion analyses demonstrated that WD7 of RACK1 is the key domain interacting with PCBP1. RACK1 over‐expression resulted in a dose‐dependent decrease of MOR promoter activity using p357 plasmid containing human MOR promoter and luciferase reporter gene. Knock‐down analysis showed that RACK1 siRNA decreased the endogenous RACK1 mRNA level in NMB, and elevated MOR mRNA level as indicated by RT‐PCR. Likewise, a decrease of RACK1 resulted in an increase of MOR proteins, verified by ³H‐diprenorphine binding assay. Collectively, this study reports a novel role of RACK1, physically interacting with PCBP1 and participating in the regulation of human MOR gene expression in neuronal NMB cells.     

Theoretical studies on DNA-binding, DNA-photocleavage and spectral properties of Co(III) complexes [Co(phen)2(L)] (L = pip, hpip, hnaip)

Theoretical studies on the DNA-binding, DNA-photocleavage and spectral properties of Co(III) polypyridyl complexes [Co(phen)₂(L)]³⁺ (L = pip, hpip, hnaip) have been carried out, using the density functional theory (DFT), Hartree-Fock (HF) and configuration interaction singles (CIS) methods. The optimized geometric structures of these Co(III) complexes in aqueous solution are more close to experimental data than those in vacuo at the B3LYP/LanL2DZ level. Based on the optimized geometric structures in solution, the electronic structures of these Co(III) complexes were analyzed and the trend in the DNA-binding constants (K_b) was reasonably explained. In particular, via the analysis of natural charges of the complexes in ground state and excited state, it is very interesting to find the following: under UV or visible light irradiation, the Co(Ш) polypyridyl complexes undergo an intra-molecular electron transfer from S₀ state to T₁ state, and the positive charges on the main-ligand in the T₁ state are greatly increased, so as to form a radical cation with strong oxidation ability. Meanwhile, the change in geometry of the complexes under light irradiation also helps to the radical cation easily approaching and further oxidating DNA-base-pairs. These results offer the theoretical explanation for the photo-induced oxidation-reduction mechanism which was experimentally proposed on DNA-photocleavage by Co(Ш) polypyridyl complexes. In addition, the electronic absorption spectra of these complexes were calculated and simulated in aqueous solution using the time dependent DFT (TDDFT) method, in satisfying agreement with experimental results, and the properties of experimental absorption bands have been theoretically explained in detail.     

CHANGE IN BLOOD GELSOLIN CONCENTRATION IN RESPONSE TO PHYSICAL EXERCISE

Plasma gelsolin (pGSN) produced by muscle is an abundant protein of extracellular fluids capable of severing actin filaments and eliminating actin from the circulation. Additionally, pGSN modulates the cellular effects of some bioactive lipids. In this study we test the hypothesis that hormonal and metabolic adaptations to exercise are associated with changes in gelsolin concentration in blood. Plasma samples were collected from twenty healthy males recruited from untrained (UT, n=10) and endurance trained (ET, n=10) groups that performed 30-60 minutes of exercise on a cycloergometer at a workload corresponding to 70% of VO₂max. Gelsolin concentration was determined by quantitative Western blot analysis with an anti-human gelsolin antibody. The gelsolin concentration in UT and ET subjects before starting exercise ranged from 104 to 330 and 163 to 337 µg · ml^-1 respectively. After 30 minutes of exercise we observed a significant decrease of plasma gelsolin in the UT group (p<0.05) while the gelsolin concentration in the ET group rose on average from 244 to 271 µg · ml^-1. However, this increase did not reach statistical significance. Endurance training might increase the ability of muscle tissue to express plasma gelsolin as part of an adaptive mechanism.     

Non-destructive analysis of root growth in porous media

A technique is described for non-destructive observations and analysis of root growth in granular media, using time-lapse video in conjunction with a pressure cell. The pressure cell consists of one half of a traditional triaxial cell with a flat clear perspex front allowing growth of the root to be monitored using a video camera. The cell is connected to an external pressure supply, which is used to regulate precisely the confining pressure, and hence, the physical impedance to root growth. Preliminary results of the growth of root axes and the emergence of laterals of peas over a range of physical impedances are presented to illustrate the potential of this technique in studying root growth.