Lipids and DNA oxidation in Staphylococcus aureus as a consequence of oxidative stress generated by ciprofloxacin

Ciprofloxacin induced an increment of reactive oxygen species in sensitive strains of Staphylococcus aureus leading to oxidative stress detected by chemiluminescence while resistant strains did not suffer such stress. Oxidation of lipids was performed by employing thiobarbituric acid reaction to detect the formation of the amplified intermediate between reactive species oxygen and cytoplasmic macromolecules, namely malondialdehyde (MDA). The sensitive strain presented higher peroxidation of lipids than the resistant strain. The oxidative consequence for DNA was investigated by means of bacteria incubation with ciprofloxacin and posterior extraction of DNA, which was studied by high performance liquid chromatography (HPLC). Sensitive S. aureus ATCC 29213 showed an increase of 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG) respect controls without antibiotic; there was evident increase of the ratio between 8-oxodG and deoxyguanosine (dG) as a consequence of oxidation of dG to 8-oxodG considered the major DNA marker of oxidative stress. The resistant strain showed low oxidation of DNA and the analysis of 8-oxodG/dG ratio indicated lesser formation of 8-oxodG than S. aureus ATCC 29213.     

Systemic analysis: Individual typological characteristics of the human body

Statistical analysis of the distribution of the mean somatometric, functional, and psychophysiological parameters in the total sample of subjects with the use of the χ² and λ tests and low, medium, and high habitual physical activity (HPA) levels (LHPA, MHPA, and HHPA, respectively) at different ontogenetic stages (junior and senior school students and young adults of both sexes) showed wide quantitative and qualitative ranges of psychophysiological individuality in a healthy population and demonstrated that it is reasonable to distinguish three typological groups or functional constitutional types (FT-1 corresponding to LHPA; FT-2, to MHPA; and FT-3, to HHPA). Typical first- and second-order parameters, as well as the results of third-order tests characterizing the current state, were determined for each FT. In order to comprehensively assess the constitutional type (synthetic constitution) of the subjects with low, medium, and high HPAs, the integrated analysis of the set of their characteristics was performed using the principles of polythetic (multi-variate) classification. The results obtained using multivariate statistical methods confirmed the basic postulate of the concept of typological variability of physiological individuality that a healthy human population is qualitatively heterogeneous in morphological, functional, and psychophysiological traits. The integrated physiological and statistical analyses of the results provided a scientific basis for three functional constitutional types (FT-1, FT-2, and FT-3) corresponding to three synthetic constitutional types (C 0-1, C 00, and C 01). These data indicate that the systemic (constitutional) approach to the estimation of individual typological characteristics confirm a high informativeness of partial constitution (FT-1, FT-2, and FT-3) in the human biological organization, and the set of characters selected for analysis allows the synthetic constitutional types to be adequately differentiated on a formal basis.     

Correlation between pectate lyase activity and ability of diazotrophic Klebsiella oxytoca VN 13 to penetrate into plant tissues

Diazotrophic Klebsiella oxytoca VN 13 was able to lyse pectate, but the lytic activity of cultures grown on non-selective media was weak, and the enzyme was located mainly inside the cells. A small fraction of the population (10^-6 to 10^-5) was able to grow in a selective medium with sodium polygalacturonate as sole carbon source, and produced increased amounts of the pectinolytic enzyme pectate lyase. When wheat seeds were inoculated with these bacteria, increased levels of this enzyme correlated with a higher rate of internal colonization of wheat roots and with stimulation of wheat growth resulting in higher biomass. This suggests that colonization occurs via lyzed pectin layers. This revised version was published online in June 2006 with corrections to the Cover Date.     

The concept of typological variability of physiological individuality: III. Psychophysiological characteristics of functional types differing in habitual physical activity

Results of longitudinal studies were used to estimate the psychophysiological characteristics of preschool and young school children and young adults of both sexes belonging to functional types (FTs) with low, medium, and high habitual physical activity (HPA) levels (FT-1, LHPA; FT-2, MHPA, and FT-3, HHPA, respectively). Statistical analysis of the distributions of averaged psychophysiological parameters in the total sample with the use of the χ² and λ tests showed wide quantitative and qualitative ranges of psychophysiological individuality in a healthy population and demonstrated that it is reasonable to distinguish three typological groups (FT-1, FT-2, and FT-3). Typical first- and second-order parameters, as well as the results of third-order tests characterizing the current state, were determined for each FT. Determination of the psychophysiological characteristics of FT-1, FT-2, and FT-3 and their prevailing behavioral tendencies makes it possible to differentiate between strategies of organism-environment interaction and estimate their advantages and disadvantages.