Pattern of growth and metabolism of thermotolerant microorganisms on media containing carbohydrates and hydrocarbons

Experiments were carried out to examine the growth and metabolism of thermotolerant yeast Candida tropicalis K-41 and bacteria Micrococcus freudenreichii that do not have a single temperature point but instead have an optimal temperature plateau at which the growth rate and biosynthetic activity remain unaltered or change insignificantly. Upon transition from the carbohydrate to the hydrocarbon pattern of nutrition these microorganisms show significant changes in metabolic processes: optimal concentration of biotin in the medium decreases significantly; the synthesis of riboflavin, nicotinic and pantothenic acids increases in yeast; the synthesis of nicotinic acid, biotin and vitamin B12 increases in bacteria. During microbial cultivation on hydrocarbons the content of cell lipids grows; yeast accumulate actively phospholipids and free fatty acids; bacteria build up intensively waxes and phospholipids. With the near-maximal growth rate the total synthesis of lipids decreases on carbohydrates and increases drastically on hydrocarbons, primarily at the expense of the above fractions.     

Monthly day/night changes and seasonal daily rhythms of sexual steroids in Senegal sole (Solea senegalensis) under natural fluctuating or controlled environmental conditions

In this paper we attempted to investigate the existence of daily fluctuations on plasma sexual steroids (17beta-estradiol, E(2) and testosterone, T) in Senegal sole (Solea senegalensis) females. We described the monthly day/night concentrations and seasonal daily rhythms in animals reared under natural photo- and thermo-period. In addition, the influence of the natural annual fluctuation of the water temperature on the plasma concentration of these steroids was investigated, using one group of Senegal sole under a natural photoperiod, but with an attenuated thermal cycle (around 17-20 degrees C) for one year. Although no significant day/night differences were detected in monthly samplings, the existence of an annual rhythm of E(2) and T (p<0.01) with an acrophase in February was revealed by COSINOR analysis. Maximum values were reached in March for both steroids (6.1+/-1.7 ng mL(-1) at mid-dark, MD and 4.0+/-0.6 ng mL(-1) at mid-light, ML for E2 and 1.4+/-0.4 ng mL(-1) at MD and 0.8+/-0.1 ng mL(-1) at ML for T) in anticipation of the spawning season (May-June). As regards seasonal daily rhythms, the presence of daily oscillations was revealed. At the spring solstice (21st March) a daily rhythm was observed for both steroids (COSINOR, p<0.01), with an acrophase at 20:00 h (E(2)) and at 21:08 h (T). In summer, autumn and winter no daily rhythms were observed due to the low steroid levels at those seasons. When Senegal sole females were submitted to an attenuated annual thermal cycle, the steroid rhythm disappeared (there was no surge in spring, as in the control group) and these fish did not spawn, despite being subjected to natural photoperiod conditions. This result underlined the importance of the natural annual fluctuation of water temperature and photoperiod on the synchronization of the spawning season and on the onset of steroidogenesis.     

Simultaneous determination of tricarboxylic acid cycle metabolites by high-performance liquid chromatography with ultraviolet detection

Here we describe a simple high-performance liquid chromatography (HPLC) procedure for the simultaneous detection and quantitation in standard solutions of 13 important metabolites of cellular energy metabolism, including 9 tricarboxylic acid (TCA) cycle components and 4 additional metabolites. The metabolites are detected by their absorbance at 210 nm. The procedure does not require prior derivatization, and an analysis can be carried out at ambient temperature within 15 min. The significance of the current work is that the current HPLC procedure should motivate the development of simplified TCA cycle enzyme assays, isotopomer analysis, and determination of selected TCA metabolite levels in plasma/tissues.     

A study of enzymatic hydrolysis of splenopentin and its analogs in human serum

Degradation of immunoactive peptide splenopentin and its analogue N-acetylsplenopentin in human serum has been investigated by 1H NMR spectroscopy. It is shown that degradation of splenopentin occurs due to hydrolysis of peptide bonds in its N-terminal part, whereas in N-acetylsplenopentin peptide bonds in C-terminal part of the molecule are cleaved. Degradation pathways and life times of these peptides in human serum are established.     

Investigation of mechanical properties,morphology, and biodegradability of compositions based on polylactide and polysaccharides

The blends of polylactide with ethyl cellulose and chitosan are obtained in a Brabender mixer under conditions of high temperature shear deformation at different initial ratios of the reagents. The investigation of physicomechanical properties of the compositions has shown that the systems have high rigidity. Polyethylene glycol (PEG) and high-molecular-weight polyolefin polydecene have been added to the compositions in order to improve their elasticity. It has turned out that polydecene scarcely affects the mechanical characteristics, while PEG leads to a noticeable increase in elongation at break. Biodegradability of the compositions is investigated by the mass loss of samples after holding in soil, fungus resistance tests, and the analysis of the film morphology by scanning electron microscopy after holding in soil. It is found that the introduction of the third component (PEG) leads to an increase in biodegradability of the compositions.     

Changes in collagen metabolism during the chronic electrical stimulation of the midbrain reticular formation

The content of 11-hydroxycorticosteroids, free and bound hydroxyproline in the peripheral blood, as well as the level of free and net hydroxyproline in the aortic wall and myocardium of rabbits were studied in chronic prolonged electrical stimulation of the mesencephalon reticular system. The experiments have shown that electrical stimulation leads to the activation of adrenal cortex function and is accompanied by alterations in collagen metabolism, accumulation of collagen in the aorta and decreased collagen level in the myocardium.     

Antitumor activity of some complex preparations in the culture of potato cells transformed by <Emphasis Type="Italic">Agrobacterium tumefaciens</Emphasis>

The complex preparations (CP) containing yeast mannan, diacetyl-2,4-dioxihexahydro-1,3,5-triasyne, cyanoguanidine, alcan-sulfo-acids, or secondary metabolites of Pseudomonas sp. manifest in the inhibitory activity against tumors induced by A. tumefaciens in the parenchymatous tissue of potato tubers. As a rule, antitumor activity of CP is higher in the prophylactic application compared to the therapeutic application of the preparations.     

Role of HLA DRB1*15 and HLA DRB1*16alleles in the genetic susceptibility to develop systemic lupus erythematosus (SLE) after Chikungunya and Zika viruses infection in México

Systemic lupus erythematosus (SLE) is a clinically and genetically heterogeneous disease particularly prevalent in Mexico. Althoughits etiology is unknown, genetic factors strongly influence its presenceas well as triggering factors, such as viral infections, including Cytomegalovirus and Epstein-Barr virus. Here,the study presents the appearance of de novoSLE (patients who did not present SLE before de virus infection, corroborated by serological analysis and negative for antinuclear antibodies) cases in Mexicans who live near the southern border of Mexico, who presented clinical symptoms of arthritic, hematological, mucocutaneous and renal SLE, after Zika and/ or Chikungunya virus infection. Low resolution class Ⅱ HLA typing was performed, which found a significantly increased frequency of HLA DRB1*02 (15 and 16)when compared to a group of 99 healthy individuals (P =0.001, OR=4.5, IC95% 1.8~11.0). All the patients were diagnosed with SLE 1 to 3 years after being confirmed with the Zika, and/or Chikungunya infection. At the point of acute viral infection, none of the patients presented clinical signs or symptoms of autoimmunity or were negative for antinuclear antibodies. In genetically susceptible individuals, Zika and Chikungunya viral infection can trigger SLE.