Molecular nature of the Brucella polysaccharide antigen (poly-B)

Cyclic (1----2)-beta-D-glucan was isolated from killed cells of pathogenic Brucella melitensis 16M. Its structure was deduced mainly from the acid hydrolysis, methylation analysis and 13C-NMR spectroscopy data. The cycloglucan and demicellated lipopolysaccharide of B. melitensis 16M form a stable complex identical, by immunodiffusion test, to the earlier described polysaccharide B antigen.     

Effect of etimizol on behavioral responses, brain serotonin concentration and plasma corticosteroid levels

The influence of ethymisol on behavioural reactions was studied on 100 albino rats in the "open field" and "passive avoidance" tests. It was shown that a 5 mg/kg dose of this neurotropic drug with synaptic effect, changes behavioural reactions, lowers the general emotional stress and emotional memory of the electro-cutaneous stimulation. Simultaneously the level of corticosteroids in the blood plasma significantly rises, while the serotonin content in the hypothalamus decreases. A direct correlation between the changes in the emotional stress and the content of corticosteroids in blood plasma is noted. The effects of ethymisol partially persists after adrenalectomy. Ethymisol in optimal doses may be used for regulation and lowering of emotional stress.     

Study of the binding of iron ions by melanoprotein granules of the eye pigment epithelium using gamma-resonance spectroscopy

Interaction between Fe2+ ions and melanoproteid granules (MPG) of bovine eye pigment epithelium was studied by gammaresonance spectroscopy. MPG was found to form complexes with bi- and three-valent ferrum ions. MPG can both directly bind Fe2+ ions and oxidize them Fe3+ inactive in prooxidant state and bind the latter. The activity of ferrum ion binding increases when suspension is illuminated with visible light and pH of the incubation solution increases. The protein part of MPG does not participate in the complex formation with ferrum ions. The complex formation proceeds mainly by carboxyl, amino- and imino-groups of melanin polymer.     

Optimization of <Emphasis Type="Italic">Prochlorothrix hollandica</Emphasis> cyanobacteria culturing for obtaining myristoleic acid

Plankton filament cyanobacteria Prochlorothrix hollandica is characterized by a very high content of C₁₄ and C₁₆ fatty acids (FA) in the lipid membranes. Depending on culturing conditions of the cyanobacteria, total concentrations of myristic and myristoleic acids can reach 35% and those of palmitic and palmitoleic acids can reach 60% of all esterified FA cells. In P. hollandica, a variety of monounsaturated FA is represented by myristoleic and palmitic acids, and by hexadecenoic (C_16:1) acid with olefin bond of cis-configuration, located in the Δ4 position. The process of intensive culturing for P. hollandica cells to yield a maximal biomass in order to isolate the pure drug of myristoleic acid derivative has been optimized. The use of a threestage purification gives 30 mg of chromatographically pure myristoleic acid methyl ester from 17 g of P. hollandica raw biomass (dry mass is 3 g), which is 1% of dry cell mass.     

Location and identification of substituents with free amino group in lipopolysaccharides of gram-negative bacteria with the use of chromophore labelling

Interaction of ten different lipopolysaccharides (LPS) with 2,4-dinitrofluorobenzene yielded quantitatively yellow dinitrophenyl derivatives (DNP-LPS) to show the presence of substituents with free amino group. The DNP-LPS samples were degraded with 1% acetic acid, and after removal of lipid A precipitates the supernatants were separated on a Sephadex G-25 column to give coloured polysaccharide, oligosaccharide and monomeric fractions monitored at lambda DNP = 365 nm. The coloured materials, including DNP-derivative of lipid A, were dephosphorylated with hydrofluoric acid followed by identification of the released DNP-amines by thin layer chromatography (TLC) on silica gel. Subsequently, the dephosphorylated materials were hydrolysed with hydrochloric acid followed by TLC analysis. The approach allowed to detect, locate and identify the substituents with free amino group within the LPS molecules. Moreover, two types of core structures within LPS preparation from one strain were discovered for five microorganisms.     

Long non‐coding RNAs in melanoma

Melanoma is the most lethal cutaneous cancer with a highly aggressive and metastatic phenotype. While recent genetic and epigenetic studies have shed new insights into the mechanism of melanoma development, the involvement of regulatory non‐coding RNAs remain unclear. Long non‐coding RNAs (lncRNAs) are a group of endogenous non‐protein‐coding RNAs with the capacity to regulate gene expression at multiple levels. Recent evidences have shown that lncRNAs can regulate many cellular processes, such as cell proliferation, differentiation, migration and invasion. In the melanoma, deregulation of a number of lncRNAs, such as HOTAIR, MALAT1, BANCR, ANRIL, SPRY‐IT1 and SAMMSON, have been reported. Our review summarizes the functional role of lncRNAs in melanoma and their potential clinical application for diagnosis, prognostication and treatment.     

Protective effect of bixin on carbon tetrachloride-induced hepatotoxicity in rats

Background

The liver is an important organ for its ability to transform xenobiotics, making the liver tissue a prime target for toxic substances. The carotenoid bixin present in annatto is an antioxidant that can protect cells and tissues against the deleterious effects of free radicals. In this study, we evaluated the protective effect of bixin on liver damage induced by carbon tetrachloride (CCl₄) in rats.

Results

The animals were divided into four groups with six rats in each group. CCl₄ (0.125 mL kg^-1 body wt.) was injected intraperitoneally, and bixin (5.0 mg kg^-1 body wt.) was given by gavage 7 days before the CCl₄ injection. Bixin prevented the liver damage caused by CCl₄, as noted by the significant decrease in serum aminotransferases release. Bixin protected the liver against the oxidizing effects of CCl₄ by preventing a decrease in glutathione reductase activity and the levels of reduced glutathione and NADPH. The peroxidation of membrane lipids and histopathological damage of the liver was significantly prevented by bixin treatment.

Conclusion

Therefore, we can conclude that the protective effect of bixin against hepatotoxicity induced by CCl₄ is related to the antioxidant activity of the compound.