Evaluation of hydrophobic properties of Yersinia enterocolitica strains isolated from humans and pigs]

The aim of the study was to evaluate the hydrophobic properties of Yersinia enterocolitica and to determine the influence of the culture conditions, such as: type of medium, temperature, and duration of the culture on the manifestation of these properties. The subject of the study were 117 of Y. enterocolitica strains isolated from humans and pigs. The ammonium sulphate salt aggregation test according to Lindahl modified method was used to evaluate the hydrophobic properties of Y. enterocolitica strains. Strains of Y. enterocolitica were cultured for 24 h at 25 degrees C on TSA (Difco) medium. During investigation of the influence of the culture conditions the chosen strains were incubated for 24 h and 48 h at 25 degrees C and 37 degrees C on TSA (Difco), LB (Difco), enrichment agar (Biomed), and enrichment agar with 5% sheep blood (Graso). A total of 44.5%, 17.9%, 9.4%, and 28.2% strains of Y. enterocolitica showed very strong hydrophobic properties, strong hydrophobic properties, some hydrophobic properties, and were non-hydrophobic, respectively when strains of Y. enterocolitica were cultured for 24 h at 25 degrees C on TSA medium. A total of 75.5% strains isolated from humans showed very strong hydrophobic properties and 13.5% strains were non-hydrophobic. Among strains isolated from pigs 30% showed very strong hydrophobic properties but 35% were non-hydrophobic. The hydrophobic properties of Y. enterocolitica depended on the temperature, duration of the culture and the type of media. The highest number of strains with very strong hydrophobic properties (89.6%) was obtained after 48 h of the incubation at 37 degrees C on the enrichment agar with 5% sheep blood. The highest number of non-hydrophobic strains of Y. enterocolitica (28.5%) was obtained after 24 h at 25 degrees C on TSA medium.     

Application of biochemical markers for identification of biological properties of animal semen

The use of biochemical markers for identification of biological properties of semen will help to develop new criteria that are accurate and objective in predicting and improving male fertility. Understanding and controlling the mechanisms involved in fertility is a key challenge, which is of fundamental importance in successful animal reproductive performance. Moreover, unraveling the unique molecular mechanism associated with sperm function might have considerable diagnostic value in the evaluation of male infertility. This review offered insights into some recent achievements and provided perspectives for possible applications of the biochemical markers of semen.     

Effect of chronic denervation on blood flow and ultrastructural and functional status of the tubule system of the solitary kidney

The sodium kidney treatment, local blood flow in the cortex and medulla as well as ultrametric parameters of mitochondria of different regions of the rat kidney duct system were studied under compensatory hypertrophy of kidneys (CHK) and against a background of aftereffects of single kidney decentralization (SKD). In all 120 experiments have been conducted. In the course of the first two weeks of the experiment the local blood flows in the cortex of SKD increased by 30% as compared to those under CHK and natriuresis+ was thrice as high (due to a decrease in proximal reabsorption). In this case coefficients of structural organization Km and of energy efficiency (Ke) of mitochondria lowered in cells of proximal ducts. Later on the intensity of local blood flows in the cortex of SKC was not only lower progressively than that under CHK but also of the control, simultaneously local blood flows in medulla being increased. The complete equalization of the sodium transport parameters of SKD up to their values under CHK did not occur. The rise of ultrametric parameters of the medullary ducts of SKD segments is associated with the intensification of their hemoperfusion.     

Modulation of protein tyrosine phosphorylation in gastric mucosa during re-epithelization processes

AIM: To investigate the role of protein tyrosine phosphorylation in gastric wound formation and repair following ulceration.METHODS: Gastric lesions were induced in rats using restraint cold stress. To investigate the effect of oxidative and nitrosative cell stress on tyrosine phosphorylation during wound repair, total activity of protein tyrosine kinase (PTK), protein tyrosine phosphatase (PTP), antioxidant enzymes, nitric oxide synthase (NOS), 2’,5’-oligoadenylate synthetase, hydroxyl radical and zinc levels were assayed in parallel.RESULTS: Ulcer provocation induced an immediate decrease in tyrosine kinase (40% in plasma membranes and 56% in cytosol, P < 0.05) and phosphatase activity (threefold in plasma membranes and 3.3-fold in cytosol), followed by 2.3-2.4-fold decrease (P < 0.05) in protein phosphotyrosine content in the gastric mucosa. Ulceration induced no immediate change in superoxide dismutase (SOD) activity, 30% increase (P < 0.05) in catalase activity, 2.3-fold inhibition (P < 0.05) of glutathione peroxidase, 3.3-fold increase (P < 0.05) in hydroxyl radical content, and 2.3-fold decrease (P < 0.05) in zinc level in gastric mucosa. NOS activity was three times higher in gastric mucosa cells after cold stress. Following ulceration, PTK activity increased in plasma membranes and reached a maximum on day 4 after stress (twofold increase, P < 0.05), but remained inhibited (1.6-3-fold decrease on days 3, 4 and 5, P < 0.05) in the cytosol. Tyrosine phosphatases remained inhibited both in membranes and cytosol (1.5-2.4-fold, P < 0.05). NOS activity remained increased on days 1, 2 and 3 (3.8-, 2.6-, 2.2-fold, respectively, P < 0.05). Activity of SOD increased 1.6 times (P < 0.05) days 4 and 5 after stress. Catalase activity normalized after day 2. Glutathione peroxidase activity and zinc level decreased (3.3- and 2-fold, respectively, P < 0.05) on the last day. Activity of 2’,5’-oligoadenylate synthethase increased 2.8-fold (P < 0.05) at the beginning, and 1.6-2.3-fold (P < 0.05) during ulcer recuperation, and normalized on day 5, consistent with slowing of inflammation processes.CONCLUSION: These studies show diverse changes in total tyrosine kinase activity in gastric mucosa during the recovery process. Oxidative and nitrosative stress during lesion formation might lead to the observed reduction in tyrosine phosphorylation during ulceration.     

Cytogenetic analysis of peripheral blood lymphocytes in glass workers occupationally exposed to mineral oils

Chromosome aberration tests were carried out in a group of 31 pressed glass makers operating an automatic line of press-and-blow machines known to release mineral oil mists containing relatively high concentrations of the mutagenic chemicals belonging to a class of polycyclic aromatic hydrocarbons (PAH). The workers were exposed to the mineral oil aerosol levels that did not exceed the Czechoslovak maximum allowable concentration limit of 5 mg . m-1 of air. The tests revealed that the frequency of aberrant cells (% AB.C.) and the value of breaks per cell (B/C) ratio found in mineral oil-exposed workers were increased significantly, accounting for 4.65 +/- 0.29% AB.C. (0.0532 B/C) vs. 1.13 +/- 0.19% AB.C. (0.0113 B/C) seen in matching controls. Also, a higher rate of dicentrics, reciprocal translocations and cells with pulverization was observed in this group of glass workers. These finding are considered as evidence suggesting that these workers might experience an increased risk of genetic injury due to exposure to mineral oil mists.     

Presence of allotypic determinants on polypeptide subunits of rabbit gamma globulin

Inhibition of passive haemagglutination showed the presence of the allotypic specificities Aa1 Aa2, Aa3, Ab4, Ab5 and Ab6 on polypeptide subunits of rabbit IgG belonging to the phenotypes Aa1-3/Ab4-4 Aa2-2/Ab4-4, Aa3-3/Ab4-4, Aa3-3/Ab4-5 and Aa3-3/Ab4-6, prepared by oxidative sulphitolysis followed by isolation on Sephadex G-100 in 6m urea and 0.05m formic acid. The determinants Aa1, Aa2 and Aa3 were found only on H chains and Ab4, Ab5 and Ab6 only on L chains. Of the latter, Ab4 and Ab5 were found in both fractions, i.e. L₁ and L₂, of the light chains, while Ab6 was found only in fraction L₁.     

Accumulation of amino acids and phenolic compounds in biochemical plant responses to feeding of two different herbivorous arthropod pests

The study aimed at comparing the changes in the content of free amino acids, phenolic compounds and the activity of PAL and TAL caused by two piercing-sucking arthropods: the grape mealybug (Pseudococcus maritimus Ehrh.) and the two-spotted spider mite (Tetranychus urticae Koch) in the leaves of orchid and strawberry, respectively. The obtained results show that the amino acid content and the ratio of amino acids to phenolic compounds increased in both plant species infested by the mealybug and the mite. However, such response was weakly dependent on changes in activity of the analysed enzymes. The pest feeding affected accumulation of the phenolic compounds, since the induction of the PAL activity in mealybug-infested orchid leaves during the first 5 h of the experiment preceded the increase in phenolic compounds during the first week of insect feeding. Instead, the increased activity of TAL was accompanied by elevated levels of phenolic compounds in the leaves of strawberry infested by mites. Mechanisms of biochemical plant responses induced by infestation of the studied herbivorous arthropods are discussed.