A karyotype and chromatin study of the peripheral blood lymphocytes of patients with pigmented skin neoplasms

Rearrangements of genetic material in the peripheral blood lymphocyte nuclei have been found in patients with dysplastic pigmented nevi and malignant melanomas (15 cases), in contrast to the control (10 healthy persons). It is expressed as an increase in the number of chromosome aberrations in the karyotype and as a change of the Feulgen-positive substance correlation in the interphase nuclei of the given cells towards an increase in the active-functioning DNA structures.     

The results of and prospects for the study of the interphase nucleus of eukaryotes

Being devoted to studies in structural peculiarities of chromatin distribution of interphase nuclei from eucaryote cells, the paper embraces literature data and the authors' results in this field. Main tendencies in development of the method, based on the qualitative and quantitative estimation of hetero- and euchromatin nucleus substance are considered. Basic successes achieved while estimating experimental and clinical materials are indicated. It is determined as promising to put the method into practice.     

DNA Relatedness,Divergence, and Sibling Species of the Lactic Acid Bacterium Streptococcus thermophilus

Previously, five distinct groups with 80–90% intragroup DNA homology values were revealed among 19 lactic acid–producing bacterial strains. The study of 39 new strains of thermophilic streptococci in the present work allowed us to reveal the sixth DNA homology group. The nine strains of this group are close, at 55–70% DNA homology levels, to the type strain Streptococcus thermophilus ATCC 19258. Group VI showed a low level of DNA–DNA reassociation (20–30%) with the DNA homology groups I, II, III, and V. The intergroup DNA–DNA reassociation values determined from DNA renaturation rates varied from 20 to 50%. These data were interpreted as indicative of the existence of at least four sibling species among the thermophilic streptococci studied.     

Influence of tumor drug resistance phenotype on the dynamics of cisplatin-induced changes of rat peripheral lymphocyte chromatin structure in Guerin's carcinoma

The correlation between the tumor drug sensitivity and the degree of lymphocyte interphase nuclei chromatin damages induced by cisplatin in rats was found using sensitive and resistant to cisplatin variants of Guerin's carcinoma. Increased optical density of lymphocyte chromatin in first minutes after cisplatin injection both in rats without Guerin's carcinoma and with sensitive to cisplatin variants of this tumor was observed. Lymphocyte chromatin structure remains unchanged in rats with cisplatin resistant carcinoma. Normal blood cells are suppose to change their sensitiveness to cisplatin under the humoral influence of the growing tumor in according with its phenotype.     

Synthesis and biological evaluation of polymethoxylated 4-heteroarylcoumarins as tubulin assembly inhibitor

A series of syn-restricted polymethoxylated 4-heteroarylcoumarins--the isostuctural analogs of combretastatin A-4--was synthesized by Suzuki-Miyaura cross-coupling reaction and evaluated for antiproliferative activity. The 4-(1-methyl-1H-indol-5-yl)chromen-2-ones exhibit a potent cytotoxicity against HBL100 epithelial cell line with an IC(50) value amounting to 0.098 and 0.078 microM, respectively. The two compounds, having an indolyl moiety, potent inhibit in vitro microtubule assembly with a substoichiometric mode of action. A structure-activity relationship was discussed and the indolyl moiety was proved to be a good surrogate for the 3-hydroxy-4-methoxyphenyl ring of CA-4.     

Synthesis of Biogenic Amines by Lactic Acid Bacteria on Media of Plant and Animal Origin

Microbiology - The intestinal microbiota is known to perform an important role in terms of the host organism’s metabolism and life-sustaining activities. One of the main mechanisms of the...     

DNA content in nuclei of buccal epithelial cells in practically healthy people]

The results obtained have permitted establishing that changes of DNA content in epitheliocyte nuclei in practically healthy people can be induced by hormonal background in the organism, on the one hand, and by the level of cell differentiation in this globe of mucous membrane of the oral cavity, on the other hand.     

Changes in the phase variant spectra in the populations of lactic acid bacteria under antibiotic treatment

Effect of the antibiotics kanamycin and ampicillin on the growth and phase variation of the populations of four strains of lactic acid bacteria (Lactobacillus sp. M76AT, L. casei MB, Enterococcus faecium M, and E. faecium M3185) was studied. The presence of antibiotics in the medium resulted in a dose-dependent decrease in viable cell numbers and in partial or complete substitution of the dominant S variant with the minor Sm and Sb variants. The variants differed in colony morphology, as well as in some physiological, biochemical, biotechnological, and probiotic characteristics. The Sm type variants of all strains exhibited the highest resistance to antibiotics. High production of exopolysaccharides was found in Sb variants of lactobacilli and in S variants of enterococci. The highest antibacterial activity was found in Sm variants of lactobacilli, especially in Lactobacillus sp. M76AT. The latter is biotechnologically the most promising strain, since all variants fermented milk yielding the products with uniformly pronounced functional and organoleptic properties. These patterns are of importance for the understanding of the mechanisms of antibiotic resistance and for selection of the variants with desired properties, as well as for quality control of the lactic acid bacteria starter cultures.