Body mass and V'O2 at rest affect gross efficiency during moderate-intensity cycling in untrained young healthy men: correlations with V'O2MAX.

Seventeen young healthy physically active males (age 23 ±3 years; body mass (BM) 72.5 ±7.9 kg; height 178 ±4 cm, (mean ±SD)), not specifically trained in cycling, participated in this study. The subjects performed two cycling incremental tests at the pedalling rate of 60 rev x min-1. The first test, with the power output (PO) increases of 30 W every 3 min, was to determine the maximal oxygen uptake (V'O2max) and the power output (PO) at V'O2max, while the second test (series of 6 minutes bouts of increasing intensity) was to determine energy expenditure (EE (V'O2)), gross efficiency (GE (V'O2/PO)) and delta efficiency (DE(ΔV'O2/DPO)) during sub-lactate threshold (LT) PO. V'O2max was 3.79 ±0.40 L x min-1 and the PO at V'O2max was 288 ±27 W. In order to calculate GE and DE the V'O2 was expressed in W, by standard calculations. GE measured at 30 W, 60 W, 90 W and 120 W was 11.6 ±1.4%, 17.0 ±1.4%, 19.6 ±1.2% and 21.4 ±1.1%, respectively. DE was 29.8 ±1.9%. The subjects' BM (range 59-87 kg) was positively correlated with V'O2 at rest (p<0.01) and with the intercept of the linear V'O2 vs. PO relationship (p<0.01), whereas no correlation was found between BM and the slope of V'O2 vs. PO. No correlation was found between BM and DE, whereas GE was negatively correlated with BM (p<0.01). GE was also negatively correlated with V'O2max and the PO at V'O2max (p<0.01). We conclude that: V'O2 at rest affects GE during moderate-intensity cycling and GE negatively corelates with V'O2max and the PO at V'O2max in young healthy men.

Expression and secretion of albumin in male turkey (Meleagris gallopavo) reproductive tract in relation to yellow semen syndrome1.

Yellow semen syndrome (YSS) is the most widely recognized problem among male turkeys. Yellow semen is of low quality and, when used for insemination, results in reduction of fertility and hatchability. Elevated level of serum albumin-like protein accession no. XP_003205725 is a characteristic feature of yellow seminal plasma suggesting albumin role in YSS pathology. However, knowledge regarding the expression of albumin in the reproductive tract in relation to YSS is very limited. The aim of this study was to identify albumin secretion and localization sites in the turkey reproductive tract in relation to YSS. Reproductive tract tissues and liver originating from turkeys producing white semen (WS) and YSS were used for analysis of albumin mRNA expression and its localization using immunohistochemistry. Moreover, albumin abundance in tissues, blood and seminal plasma was analyzed using two dimensional electrophoresis and western blot analysis. Albumin mRNA expression was found in all parts of the reproductive tract. Apart from the liver, the highest expression of albumin was found in the ductus deferens in YSS turkeys. The testicular spermatids, Leydig, and myoid cells and the epithelium of the epididymis and ductus deferens were the main secretion sites of albumin in the reproductive tract in turkeys. Higher albumin abundance was found in the reproductive tract and seminal plasma of YSS toms compared to WS toms. Our results demonstrated that germ cells from spermatocytes to spermatids, Leydig cells, and myoid cells synthesized and secreted albumin in turkey testis, and epithelial cells are the main secretion sites in epididymis and ductus deferens. Ductus deferens secretion of albumin seems to be mostly responsible for YSS. Over-secretion by the ductus deferens may be the main origin of albumin abundance in YSS semen. Knowledge regarding disturbances of albumin secretion in relation to YSS may be useful for future work on studies related to better understanding the molecular basis of YSS.

Endurance training of moderate intensity increases testosterone concentration in young, healthy men.

The aim of this study was to investigate the effect of short-term, moderate intensity and low volume endurance training on gonadal hormone profile in untrained men. Fifteen young, healthy men performed an endurance training of 5-week duration on a cycle ergometer. Before and after the exercise program all participants completed a maximal incremental test. Concentration of testosterone (T), sex hormone-binding globulin (SHBG) and cortisol (C) as well as blood morphology were determined in venous blood samples at rest both before and after the training. The training program resulted in 3.7% improvement of maximal oxygen uptake (VO(2max)) and 8.2% improvement of power output reached at VO(2max) (PO (max)). This was accompanied by significant increase in T (from 18.84+/-5.73 nmol.l(-1) to 22.03+/-6.61 nmol.l(-1), p = 0.0004) and calculated fT concentration (from 374+/-116 pmol.l(-1) to 470+/-153 pmol.l(-1), p = 0.00005). Moreover, the training caused a significant decrease in SHBG concentration (from 34.45+/-11.26 nmol.l(-1) to 31.95+/-10.40 nmol.l(-1), p = 0.01), whereas no significant changes were found in the cortisol concentration (334+/-138 nmol.l(-1) vs. 367+/-135 nmol.l(-1) for pre- and post-training measures, respectively, p = 0.50) and T/C and fT/C ratios. We have concluded that short-term, moderate intensity and low volume endurance training can significantly increase testosterone concentration in previously untrained men.

The effect of endurance training on muscle strength in young, healthy men in relation to hormonal status.

The objective of this study was to establish the effect of moderate intensity endurance training on muscle strength in relation to hormonal changes in the body. Fifteen young, healthy men took part in 5 week endurance training performed on a cycloergometer. Before and after training program, exercise testing sessions were performed involving all participants. Training program significantly increased V(O2 max) (P<0.05) and time to fatigue at 50% of maximal voluntary isometric contraction (TTF 50% MVC), P<0.03, but it did not affect maximal voluntary isometric contraction (MVC). This was accompanied by an increase (P<0.001) in total plasma testosterone (T) and free testosterone (fT) concentrations, whereas a decrease in sex hormone-binding globulin (SHBG) (P<0.02), growth hormone (P<0.05), free triiodothyronine (P<0.001) and free thyroxine (P<0.02) concentrations was observed. No changes were found in plasma cortisol (C) and insulin-like growth factor-I (IGF-I) concentrations. Additionally, MVC was positively correlated to T/C, fT/C and IGF-I/C ratios after the training, whereas time to fatigue at 50% of MVC was closely positively correlated to the SHBG concentration, both before and after endurance training. We have concluded that moderate intensity endurance training resulting in a significant increase in V(O2 max), did not affect the MVC, but it significantly increased time to fatigue at 50% of MVC. This index of local muscular endurance was greater in subjects with higher concentration of SHBG, both before and after the training.

Endurance training increases plasma brain-derived neurotrophic factor concentration in young healthy men.

It is believed that brain derived neurotrophic factor (BDNF) plays an important role in neuronal growth, transmission, modulation and plasticity. Single bout of exercise can increase plasma BDNF concentration [BDNF](p) in humans. It was recently reported however, that elevated [BDNF](p) positively correlated with risk factors for metabolic syndrome and type 2 diabetes mellitus in middle age group of subjects. On the other hand it is well established that endurance training decreases the risk of diabetes and development of metabolic syndrome. In the present study we have examined the effect of 5 weeks of moderate intensity endurance training on the basal and the exercise induced changes in [BDNF](p) in humans. Thirteen young, healthy and physically active men (mean +/- S.E: age 22.7 +/- 0.5 yr, body height 180.2 +/- 1.7 cm, body weight 77.0 +/- 2.5 kg, V(O2max) 45.29 +/- 0.93 ml x kg-1 x min(-1)) performed a five week endurance cycling training program, composed mainly of moderate intensity bouts. Before training [BDNF]p at rest have amounted to 10.3 +/- 1.4 pg x ml(-1). No effect of a single maximal incremental cycling up to V(O2max) on its concentration was found (10.9 +/- 2.3 pg x ml(-1), P=0.74). The training resulted in a significant (P=0.01) increase in [BDNF]p at rest to 16.8 +/- 2.1 pg x ml(-1), as well as in significant (P=0.0002) exercise induced increase in the [BDNF](p) (10.9 +/- 2.3 pg x ml(-1) before training vs. 68.4 +/- 16.0 pg x ml(-1) after training). The training induced increase in resting [BDNF](p) was accompanied by a slight decrease in insulin resistance (P=0.25), calculated using the homeostatic model assessment version 2 (HOMA2-IR), amounting to 1.40 +/- 0.13 before and 1.15 +/- 0.13 after the training. Moreover, we have found that the basal [BDNF](p) in athletes (n=16) was significantly higher than in untrained subjects (n=13) (29.5 +/- 9.5 pg x ml(-1) vs. 10.3 +/- 1.4 pg x ml(-1), P=0.013). We have concluded that endurance training of moderate intensity increases both basal as well as the end-exercise [BDNF](p) in young healthy men. This adaptive response, contrariwise to the recent findings in patients with metabolic disorders, was accompanied by a slight decrease in insulin resistance.

Immobilization of laccase on gold, silver and indium tin oxide by zirconium-phosphonate-carboxylate (ZPC) coordination chemistry.

In this paper we present a simple method allowing for stable laccase immobilization on various conducting surfaces that retains the activity of the enzyme. The strategy for laccase immobilization presented in this paper relies on Zr(4+) ion coordination chemistry that involves -COO- terminal groups present on the protein. Using a host of techniques, including surface plasmon resonance (SPR), quartz crystal microbalance (QCM) gravimetry, atomic force microscopy (AFM), surface enhanced Raman scattering (SERS), resonance Raman scattering (RR) and electrochemical techniques, we show that laccase bound to a surface coordinatively through zirconium phosphonate/carboxylate (ZPC) functionalities forms a stable enzymatic layer with the enzyme retaining its activity to a significant extent.

Phosphorylation potential in the dominant leg is lower, and [ADPfree] is higher in calf muscles at rest in endurance athletes than in sprinters and in untrained subjects.

It has been reported that various types of mammalian muscle fibers differ regarding the content of several metabolites at rest. However, to our knowledge no data have been reported in the literature, concerning the muscle energetic status at rest in high class athletes when considering the dominant and non-dominant leg separately. We have hypothesised that due to higher mechanical loads on the dominant leg in athletes, the metabolic profile in the dominant leg at rest in the calf muscles, characterized by [PCr], [ADP(free)], [AMP(free)] and DeltaG(ATP), will significantly differ among endurance athletes, sprinters and untrained individuals. In this study we determined the DeltaG(ATP) and adenine phosphates concentrations in the dominant and non-dominant legs in untrained subjects (n = 6), sprinters (n = 10) and endurance athletes (n = 7) at rest. The (mean +/- SD) age of the subjects was 23.4 +/- 4.3 years. Muscle metabolites were measured in the calf muscles at rest, by means of (31)P-MRS, using a 4.7 T superconducting magnet (Bruker). When taking into account mean values in the left and right leg, phosphocreatine concentration ([PCr]) and DeltaG(ATP) were significantly lower (p<0.05, Wilcoxon-Mann-Whitney test), and [ADP(free)] was significantly higher (p = 0.04) in endurance athletes than in untrained subjects. When considering the differences between the left and right leg, [PCr] in the dominant leg was significantly lower in endurance athletes than in sprinters (p = 0.01) and untrained subjects (p = 0.02) (25.91 +/- 2.87 mM; 30.02 +/- 3.12 mM and 30.71 +/- 2.88 mM, respectively). The [ADP(free)] was significantly higher (p = 0.02) in endurance athletes than in sprinters and untrained subjects (p = 0.02) (42.19 +/- 13.44 microM; 27.86 +/- 10.19 microM; 25.35 +/- 10.97 microM, respectively). The DeltaG(ATP) in the dominant leg was significantly lower (p = 0.02) in endurance athletes than in sprinters and untrained subjects (p = 0.01) (-60.53 +/- 2.03 kJ.M(-1); -61.82 +/- 1.05 kJ.M(-1), -62.29 +/- 0.73 kJ.M(-1), respectively). No significant differences were found when comparing [PCr], [ADP(free)], [AMP(free)], [Mg(2+)(free)], DeltaG(ATP) in the dominant leg and the mean values for both legs in sprinters and untrained subjects. Moreover, no significant differences were found when comparing the metabolites in non-dominant legs in all groups of subjects. We postulate that higher [ADP(free)] and lower DeltaG(ATP) at rest is a feature of endurance-trained muscle. Moreover,when studying the metabolic profile of the locomotor muscles in athletes one has to consider the metabolic differences between the dominant and non-dominant leg.

Resonance Raman evidence of immobilization of laccase on self-assembled monolayers of thiols on Ag and Au surfaces.

Resonance Raman (RR) and surface-enhanced Raman scattering (SERS) spectroscopy have been used to study immobilization of laccase on self-assembled monolayers (SAMs) of thiols containing carboxylic and amino groups, deposited on silver and gold electrodes. A new, indirect way of monitoring laccase bound to the thiol-coated Ag and Au surfaces is presented. It was demonstrated that by recording the resonance Raman spectra of the colored product of the oxidation of syringaldazine (4-hydroxy-3,5-dimethoxybenzaldehydeazine) by laccase in the presence of molecular oxygen, one may easily confirm binding as well as enzymatic activity of laccase immobilized on the SAMs modified silver and gold surfaces.

Immobilization of tyrosinase on poly(indole-5-carboxylic acid) evidenced by electrochemical and spectroscopic methods.

A conducting, polymeric film of poly(indole-5 carboxylic acid) has been prepared by electrochemical polymerization for covalent immobilization of an enzyme belonging to the family of phenoloxidases-tyrosinase. The polymer was characterized by cyclic voltammetry, UV-VIS and Raman spectroscopy in a buffer solution. As the polymer contains pendant carboxylic groups one-step carbodiimide method was used to immobilize tyrosinase on the polymer matrix. Immobilization of tyrosinase was confirmed by surface enhanced resonance Raman scattering spectra (SERRS) and by cyclic voltammetry as well. Tyrosinase was shown to retain its biological activity when being immobilized on the polymer surface. As proved by the electrochemical and spectroelectrochemical (UV-VIS) experiments, tyrosinase covalently bonded to the polymer matrix effectively catalyzes oxidation of catechol. The reduction current of o-quinones was measured as a function of catechol concentration. The linear dependence was found to be 15 microM of catechol with sensitivity of 250 mA/M cm2.

Interleukin 2 receptor positive T lymphocytes in renal allograft recipients: association with CMV infection.

The number of interleukin 2 receptor positive T cells freshly isolated from peripheral blood as well as stimulated in culture with PHA was determined in renal allograft recipients with stable graft function, rejection and CMV infection. The most typical phenotype was observed during CMV infection. Patients with CMV had very low levels of circulating positive cells which responded normally to mitogen stimulation in vitro.

Immune monitoring after renal transplantation. I. HLA-D expression on T cells from renal allograft recipients.

The expression of class II antigens (HLA-DR, DP and DQ) on resting and PHA-activated T cells from renal allograft recipients was studied. A tendency for increase in DR+/DQ+ T cells was noted in azathioprine and cyclosporine-treated recipients undergoing rejection. Low inducible HLA-D expression (especially DP) was associated with CMV infection. Cyclosporine (but not azathioprine) lowered the rate of synthesis of HLA-D by T cells activated in vitro.

Immune monitoring after renal transplantation. II. Post-transplant disturbances in the CD3 complex expression may be caused by immunosuppression.

The in vitro effect of major immunosuppressive agents on the CD3-TCR complex expression on T cells was studied. Cyclosporine and azathioprine caused a marked diminution of alpha/beta, but not gamma/delta and CD3 chains detectability. Prednisolone effect was less manifested. Our data suggest that the reported decrease in alpha/beta chains expression on T cells from renal allograft recipients may be caused by post-transplant immunosuppression.

Rejection-associated upregulation of the alpha/beta-T cell receptor expression on T cells of renal allograft recipients.

Peripheral T lymphocytes of renal allograft recipients were phenotyped for their expression of the CD3-T cell receptor (TCR) complex. The majority of T cells from patients with stable graft function had normal CD3 but diminished TCR alpha/beta heterodimer expression, while TCR gamma/delta + T cells were increased in some cases. Acute rejection was associated with an increase in TCR alpha/beta + T cells to normal levels.

Immunosuppressive drugs inhibit class II antigen (HLA-D) synthesis by B and T lymphocytes.

The influence of immunosuppressive drugs on class II (HLA-D) antigen synthesis and expression by monocytes and B and T cells was studied. The constitutive HLA-D expression on monocytes and malignant B cells was resistant, while the acquisition of those markers by stimulated T cells very sensitive to immunosuppression. Active derivative of cyclophosphamide (4HCy) and cyclosporine proved to be most efficacious inhibitors of class II antigens.