Diagnostics of ataxia-telangiectasia by an express test based on the indirect immunofluorescence method

Ataxia-telangiectasia (AT) is a severe hereditary neurodegenerative disease developing in the presence of mutations in both alleles of the gene atm. This gene encodes the key protein of cell response to DNA damage—ATM protein kinase. During the appearance of double-strand DNA breaks, the ATM protein kinase is autophosphorylated and its active form appears in the cell—phospho-ATM (P-ATM)—revealed by a modified method of indirect immunofluorescence. In nuclei of cells containing the normal gene atm, after the effect of agents producing double-strand DNA breaks, P-ATM is detected, whereas in the cells carrying mutant variants of the gene atm P-ATM is not found. This peculiarity can be used in clinics for confirmation of diagnosis of AT in complicated cases.     

Cytogenetic Analysis of Hybrids Resistant to Yellow Rust and Powdery Mildew Obtained by Crossing Common Wheat (Triticum aestivum L., AABBDD) with Wheats of the Timopheevi Group (AtAtGG)

The karyotypes of 47 hybrid lines obtained from crosses of common wheat Triticum aestivum L. (cv. Rodina and line 353) with Triticum timopheevii(Zhuk.) Zhuk. (A ^t A ^t GG) and related species T. militinae Zhuk. et Migusch. (A ^t A ^t GG) and T. kiharae Dorof. et Migusch. (A ^t A ^t GGD ^sq D ^sq) were analyzed by C-banding. Most lines were resistant to yellow rust and powdery mildew. The introgression of alien genetic material to the common wheat genome was realized via substitutions of complete A ⁺-,G-, and D-genome chromosomes, chromosome arms, or their fragments. The pattern of chromosome substitutions in resistant lines differed from that in introgressive hybrids selected for other traits. Substitutions of chromosomes 6G, 2A^t, 2G, and 5G were revealed in 31, 23, 18, and 13 lines, respectively. Substitutions of chromosomes 4G, 4A^t, and 6A^t were not observed. In 15 lines, a 5BS.5BL-5GL translocation was identified. High frequency of substitutions of chromosomes 2A^t, 2G, 5G, and 6G indicate that they may carry the resistance genes and that they are closely related to the respective homoeologous chromosomes of common wheat that determines their high compensation ability.     

Comparative Contribution of СО2/Н2О Exchange Components to the Process of Adaptation to Drought in Xero-Halophytes from the Family Chenopodiaceae with Different Types of Photosynthesis

Russian Journal of Plant Physiology - Components of СО2/Н2О exchange (rates of apparent photosynthesis, transpiration, and dark respiration), as well as efficiency of...     

Serum albumin: Search for new sites of interaction with organophosphorus compounds by the example of soman

Albumin is known to be able to interact with organophosphorus compounds (OPCs), but neither amino acid residues of albumin that are responsible for this interaction nor the nature of the forming bonds have been finally established. Catalytic and pseudocatalytic functions of albumin are under consideration. Possible sites of interaction of albumin with soman have been elucidated by the methods of molecular modeling. Structures of the soman-albumin complexes have been determined by molecular docking. Stability of the obtained complexes has been evaluated by the method of molecular dynamics. The chemical bond between soman and the tyrosine-411 residue has been found to form only after deprotonation of the latter. The tyrosine-150 residue of albumin binds soman more effectively than tyrosine-411, and the tyrosine-150-deprotonation does not determine the efficacy of the binding (sorption) of soman, but affects the stability of the formed bound. It was proposed that the albumin residues of tyrosine-150 and serine-193 could serve as sites of the catalytic interaction with soman. We hypothesized that the deprotonation of an amino acid residue in one albumin site influenced initiation of the ligand binding in the other albumin site (allosteric albumin regulation).     

Microplate biochemical determination of Russian VX: influence of admixtures and avoidance of false negative results

Two microplate spectroscopic methods for determination of organophosphates, based on inhibition of acetylcholinesterase (AChE) activity, were further improved and evaluated for determination of the chemical weapon agent Russian VX (RVX) in aqueous solutions. The linear range of the Hestrin method (74.8-1120 pM) was 3.1-fold wider than that of the Ellman method (37.4-374 pM). Limits of detection and quantification of RVX for both methods were below the maximal allowable concentration of RVX in water-soluble washouts. One of the early products of RVX hydrolysis, N,N-diethylaminoethanethiol, like reduced glutathione, caused false negative results in the Ellman method at concentrations exceeding 10 μM; individual blanks were necessary to eliminate the effect. The Hestrin method showed greater specificity (~3 orders of magnitude) for analysis of samples containing mercaptans. A major product of RVX degradation, 2,2'-dithiobis(N,N-diethylethanamine), caused significant inhibition of AChE at concentrations of ≥0.1 mM (P<0.01) and had a false positive effect at higher concentrations (≥2 mM). For environmental monitoring of RVX, the method based on Hestrin is preferred over that based on Ellman, principally because the former method was less sensitive to interference from major admixtures and did not give rise to potentially dangerous false negative results.     

The effects of biogenic and abiogenic disulphides on endothelial cells in culture: Comparison of three methods of viability assessment

Effects of biogenic and abiogenic disulfides on viability of human umbilical vein endothelial cells in culture were studied using three methods: inclusion of neutral red (NR) into cells, quantification of intracellular ATP, and modifications of the Mosmann method (1983), the essence of which consists in reduction of tetrazolim salts—MTT and MTS—by cells (Mosmann, 1983). 2,2′-Dithio-bis(N,N-diethyl)dietanamine (DS) was used as an abiogenic sulfide. As for biogenic disulfides, we used oxydized glutathione (GSSG) and garlic oil (GO), the major component of which is diallyl disulfide (DADS). It has been established that DS and GO have a compatible cytotoxic effect (ES₅₀ amounts to ～0.6 mM), whereas GSSG at a concentration up to 1 mM had no effect on the viability of endothelial cells. It has been demonstrated for the first time that DS and GO can serve as mediators of plasma-membrane oxidoreductase activity, with tetrazolium salts being used as the substrate, which may cause a false-negative effect. In this connection, Mosmann’s method has serious limitations in evaluating the effect of disulfides on cell viability, although it can be used when studying the mechanism of their action.     

Possible Activation of С3 Photosynthesis in С4 Halophyte Kochia prostrata Exposed to an Elevated Concentration of СО2

Russian Journal of Plant Physiology - The effect of an elevated concentration of СО2 (800 ppm) on the growth rate, efficiency of photosystem I (PS I) and photosystem II (PS II), content...     

Hemodynamic indices of the cardiovascular system in children as related to their constitutional characteristics

In children five to seven years of age, the adaptation of their cardiovascular system to a high physical activity as related to their individual somatic characteristics was studied. The methods of rheography and bicycle ergometry were used under physical loads with the power increasing from 1 and 1.5 W/kg body weight. During exercises, load grading according to the body’s somatic characteristics led to a significant increase in the degree of the children’s functional training. In children of different somatotypes, the indices of absolute physical efficiency and of both cardiac output (Q) and stroke volume (SV) increased significantly. The increase in hemodynamic indices in girls was higher than in boys of the same age.