A Novel Three-dimensional Flow Chamber Device to Study Chemokine-directed Extravasation of Cells Circulating under Physiological Flow Conditions

Extravasation of circulating cells from the bloodstream plays a central role in many physiological and pathophysiological processes, including stem cell homing and tumor metastasis. The three-dimensional flow chamber device (hereafter the 3D device) is a novel in vitro technology that recreates physiological shear stress and allows each step of the cell extravasation cascade to be quantified. The 3D device consists of an upper compartment in which the cells of interest circulate under shear stress, and a lower compartment of static wells that contain the chemoattractants of interest. The two compartments are separated by porous inserts coated with a monolayer of endothelial cells (EC). An optional second insert with microenvironmental cells of interest can be placed immediately beneath the EC layer. A gas exchange unit allows the optimal CO₂ tension to be maintained and provides an access point to add or withdraw cells or compounds during the experiment. The test cells circulate in the upper compartment at the desired shear stress (flow rate) controlled by a peristaltic pump. At the end of the experiment, the circulating and migrated cells are collected for further analyses. The 3D device can be used to examine cell rolling on and adhesion to EC under shear stress, transmigration in response to chemokine gradients, resistance to shear stress, cluster formation, and cell survival. In addition, the optional second insert allows the effects of crosstalk between EC and microenvironmental cells to be examined. The translational applications of the 3D device include testing of drug candidates that target cell migration and predicting the in vivo behavior of cells after intravenous injection. Thus, the novel 3D device is a versatile and inexpensive tool to study the molecular mechanisms that mediate cellular extravasation.     

Effects of Rhizobium leguminosarum bv. viceae Strains Different in Their Symbiotic Effectiveness on Changes in cAMP and Hydrogen Peroxide Concentrations in Cells of Pea Seedlings

Russian Journal of Plant Physiology - Changes in hydrogen peroxide and cAMP concentrations in pea (Pisum sativum L.) seedlings inoculated with Rhizobium leguminosarum bv. viceae Frank (Rlv) were...     

Association of the Ile50Val Polymorphism of the Interleukin-4 Receptor Gene IL4RA with Chronic Viral Hepatitis

The Ile50Val polymorphism of the IL4RA gene was tested for association with chronic viral hepatitis and the character of its progression (the stage of hepatic fibrosis). In total, 61 patients were examined. The control group was a random sample of Tomsk residents (N = 128). Genotyping was based on RFLP analysis. The allele and genotype frequencies of the Ile50Val polymorphism did not significantly differ between the patients and the controls. However, a significant difference in genotype frequency distribution was observed for the patients with different stages of hepatic fibrosis. The frequency of heterozygotes Ile/Val in patients without signs of fibrosis was lower than in the control group (7.1% vs. 51.6%, P = 0.002), while the frequency of the homozygous genotypes was higher. In addition, this subgroup significantly differed in genotype frequency distribution from subgroups of patients with early or severe fibrosis (P = 0.035 and P = 0.004, respectively).__________Translated from Molekulyarnaya Biologiya, Vol. 39, No. 3, 2005, pp. 379–384.Original Russian Text Copyright © 2005 by Goncharova, Friedin, Dunaeva, E.V. Beloborodova, E.I. Beloborodova, Puzyrev.     

Permissible level of laser radiation of wavelength 10.6 microns

In a four-month experiment with 102 male rabbits and 42 HRS/U mice and 30 days after termination thereof, study was made of local and general response of an organism to the effect of laser radiation (10.6 microns wave length and energy exposition 1/7 of the threshold). The radiation tolerance level was estimated.     

Presenilin-1 Delta E9 Mutant Induces STIM1-Driven Store-Operated Calcium Channel Hyperactivation in Hippocampal Neurons

Presenilins regulate calcium homeostasis in the endoplasmic reticulum, and dysregulation of intracellular calcium has been implicated in the pathogenesis of Alzheimer disease. Elevated presenilin-1 (PS1) holoprotein levels have been detected in postmortem brains of patients carrying familial Alzheimer disease (FAD) PS1 mutations. This study examines the effect of the FAD presenilin mutant that lacks the ninth exon (PS1 ?E9) and does not undergo endoproteolysis on store-operated calcium (SOC) entry. Significant enhancement of SOC channel activation was detected by electrophysiological measurements in hippocampal neurons with PS1 ?E9 mutant expression. Here, we show that (i) the hyperactivation of SOC channels is mediated by the STIM1 sensor and can be attenuated by STIM1 knockdown or 2-aminoethoxydiphenyl borate application, (ii) the STIM2 is not involved in pathological changes of SOC entry, (iii) the pathological SOC entry demonstrates properties of both TRPC and Orai subunit composition, and (iiii) transgenic Drosophila flies with PS1 ?E9 expression in the cholinergic neuron system show short-term memory loss, which can be abolished by 2-aminoethoxydiphenyl borate feeding.     

Ethnic and Geographical Aspects of the Prevalence of the Polymorphic Variants of Genes Associated with Tuberculosis

Specificity of the structure of gene pools of different ethno-territorial groups of the human population can underlie the epidemiological features of the spread of tuberculosis (TB) and the structure of the genetic component of the susceptibility to the disease. The variability of 62 genetic variants potentially associated with the risk of the development of TB in the Russian population of the city of Tomsk has been studied and the differentiation of various ethno-territorial groups of the world by these markers has been assessed. The studied sample comprised 445 Russian residents of the city of Tomsk without bronchopulmonary pathology. For comparison, the data on the variability of the genetic markers of interest in 26 populations from the 1000 Genomes Project was involved. In the Tomsk population, only the ancestral allele was found for seven of the 58 SNPs studied; the allele frequencies for 36 markers were within the limits of the values seen in other European populations; for 12 SNPs, the observed frequencies were closer to populations with a significant Mongoloid component. By the total of the SNPs, the Tomsk population, despite the geographical distance from the rest of the European populations, did not differ from them (in genetic distances and G_st statistics), although it had some features of the gene pool. Intergroup differentiation of the world populations by these SNPs reflects mainly interracial differences. The greatest differences in the genetic structure between the studied populations were seen for the markers localized in intergenic regions. Statistically significant differences were found when comparing the levels of the average expected heterozygosity between groups of “L4 carrier populations” of mycobacteria and “non-L4” populations, which indicates the impact of the prevalence of different pathogenic lineages of M. tuberculosis on the formation of population specificity of the allelic frequencies.     

Genes for fibrogenesis in the determination of susceptibility to myocardial infarction

A group of patients with ischemic heart disease and myocardial infarction (N = 156) and a reference population sample (N = 300) were genotyped for 58 single nucleotide polymorphisms (SNPs) in the genes involved in extracellular matrix function and collagen metabolism or associated with cardiovascular diseases and atherosclerotic plaque stability. Genotyping was performed by mass-spectrometry with two multiplex sets of 27 and 31 SNPs. The study revealed different genetic composition of predisposition to cardiovascular disease continuum (CVDC) syntropy (patients with concomitant conditions: hypercholesterolemia, hypertension, and type-II diabetes mellitus, N = 96) and to isolated myocardial infarction (without these conditions, N = 60). Only the KIAA1462 gene (rs3739998) showed associations with both CVDC syntropy (OR = 1.71; 95% CI 1.19–2.45; р = 0.003) and isolated infarction (OR = 1.58; 95% CI 1.05–2.40; р = 0.028). Isolated myocardial infarction was also associated with LIG1 (rs20579) (OR = 2.08; 95% CI 1.06–4.17; р = 0.028) and ADAMDEC1 (rs3765124) (OR = 1.63; 95% CI 1.07–2.50; р = 0.020). CVDC syntropy was associated with CDKN2BAS1 (rs1333049) (OR = 1.48; 95% CI 1.03–2.12; р = 0.029) and APOA2 (rs5082) (OR = 1.47; 95% CI 1.02–2.11; р = 0.035). So, genes involved in fibrogenesis contribute to predisposition to the myocardial infarction as well. Isolated myocardial infarction and CVDC syntropy can be considered as pathogenetically different cardiovascular conditions, with different genes that contribute to the susceptibility.     

Gene amplification in murine leukemia cells with multiple drug resistance acquired in vivo

The P388rm and P388rx cell lines resistant to antracycline antibiotics were obtained as a result of chemotherapy of mice bearing P388 leukemia, by means of increasing dosages of rubomycin and ruboxyl, respectively. These cell lines possessed cross-resistance to vinblastine, vincristine, colchicine, actinomycin D and some other drugs. Multidrug resistance (MDR) of P388rm and P388rx is due to decreased uptake of different cytotoxic compounds by the cells. Development of resistance to rubomycin and ruboxyl was accompanied by the appearance of additional chromosomal structures--long homogeneously staining regions (HSRs), double minute chromosomes and others usually containing amplified DNA sequences. Southern blot-hybridization with cloned DNA fragments amplified in Djungarian and Chinese hamster cell lines having MDR has revealed in P388rm and P388rx cells approximately 50-fold amplification of mdr and pC52 genes. Thus, in mouse leukemia cells which acquired MDR in vivo, as a result of chemotherapy, amplification is observed of the same genes that undergo amplification during selection of cell cultures for MDR in vitro.     

Role of lipids in molecular thermoadaptation mechanisms of seagrass Zostera marina

By using the combined approaches of microcalorimetric analysis and polarizing microscopy, the crystal-liquid crystal-isotropic melt phase transition of major phospholipids (phosphatidylcholine and phosphatidylethanolamine) and glycolipids (monogalactosyldiacylglycerol and digalactosyldiacylglycerol) isolated from marine seagrass Zostera marina were investigated. Here we discuss the results in view of the fatty acid structures of the lipids studied.