Anaerobic capacity of amateur mountain bikers during the first half of the competition season.

Sustained aerobic exercise not only affects the rate of force development but also decreases peak power development. The aim of this study was to investigate whether anaerobic power of amateur mountain bikers changes during the first half of the competition season. Eight trained cyclists (mean ± SE: age: 22.0 ±0.5 years; height: 174.6 ± 0.9 cm; weight: 70.7 ± 2.6 kg) were subjected to an ergocycle incremental exercise test and to the Wingate test on two occasions: before, and in the middle of the season. After the incremental exercise test the excess post-exercise oxygen consumption was measured during 5-min recovery. Blood lactate concentration was measured in the 4th min after the Wingate test. Maximum oxygen uptake increased from 60.0 ± 1.5 ml min(-1) kg(-1) at the beginning of the season to 65.2 ± 1.4 ml min(-1) kg(-1) (P < 0.05) in the season. Neither of the mechanical variables of the Wingate test nor excess post-exercise oxygen consumption values were significantly different in these two measurements. However, blood lactate concentration was significantly higher (P < 0.001) in season (11.0 ± 0.5 mM) than before the season (8.6 ± 0.4 mM). It is concluded that: 1) despite the increase of cyclists' maximum oxygen uptake during the competition season their anaerobic power did not change; 2) blood lactate concentration measured at the 4th min after the Wingate test does not properly reflect training-induced changes in energy metabolism.

The Plackett-Burman design in optimization of media components for biomass production of Lactobacillus rhamnosus OXY.

The central composite design was developed to search for an optimal medium for the growth of Lactobacillus rhamnosus OXY. The effect of various media components, such as carbon sources, simple and complex nitrogen sources, mineral agents, and growth factors (vitamins B, amino acids) was examined. The first-order model based on Plackett-Burman design showed that glucose, sodium pyruvate, meat extract and mineral salts significantly influenced the growth of the examined bacteria. The second-order polynomial regression confirmed that maximum biomass production could be achieved by the combination of glucose (12.38 g/l), sodium pyruvate (3.15 g/l), meat extract (4.08 g/l), potassium phosphate (1.46 g/l), sodium acetate (3.65 g/l) and ammonium citrate (1.46 g/l). The validation of the predicted model carried out in bioreactor conditions confirmed the usefulness of the new medium for the culture of L. rhamnosus OXY in large scale. The optimal medium makes the culture of the probiotic bacterium L. rhamnosus OXY more cost effective.

Differentiation of three Lactobacillus rhamnosus strains (E/N, Oxy and Pen) by SDS-PAGE and two-dimensional electrophoresis of surface-associated proteins.

SDS-PAGE of extracted surface-associated proteins of Lactobacillus rhamnosus strains E/N, Oxy, and Pen, was performed. The obtained protein patterns allowed differentiation of the examined strains, which was not accomplished by the commonly used RAPD genotypic method. The differentiation by the SDS-PAGE method proved to be a useful tool for strain-specific identification, which was further confirmed by 2DE analysis. Therefore, it can be used as an alternative or complementary method for both conventional and genotypic identification procedures, especially when closely related lactobacilli isolates are identified.

The effect of hormonal factors on the hearing organ in women, after surgical castration. Preliminary report.

BACKGROUND: Estrogens have not only direct and beneficial effect on relaxation of the arteries increasing the blood flow in the blood vessels, but also their level of secretion has considerable effect on synthesis of acetylcholine a neurotransmitter indispensable for appropriate functioning of the hearing organ. The aim of this study is analysis of the effect of hormones on the hearing organ in women who underwent surgical castration. MATERIAL: The study included 40 females, aged between 32 55 years who had undergone an operative treatment mainly because of uterine myoma. A group of 50 women aged between 32 50 years with appropriate hormone level comprised the control group. METHOD: Each woman investigated underwent the following examinations: gynaecological, otolaryngological and laboratory tests, such as: evaluation of levels of estradiol (E) and folliculin stimulating hormone (FSH). The assessment of hearing was carried out using tone and speech audiometry, tympanometry, test registration of auditory brain stem responses (ABR) and otoacoustic emissions (EOAE). The examinations mentioned above are performed in women as initial examinations before surgical treatment and as follow-up examinations 1, 3 and 12 months after the surgery. RESULTS: The results presented in this paper include initial examinations and follow-ups 3 months after the surgical treatment taking into consideration the correlation with the results of laboratory tests and the results obtained in the control group.