Vimentin-positive epithelial cells in aggregated lymphoid nodules (Peyer's patches) in rabbits

Peculiarities of cytoskeleton in membranous cells and disposition of the latter in the cupola epithelium in aggregated lymphoid nodules++ (ALN) have been studied in the ileum of 5 rabbits. The material has been fixed in liquid nitrogen and in the mixture of paraformaldehyde and glutar aldehyde. Methods of immunomorphology, high resolving light and transmissive electron microscopy have been used. Monoclonal antibodies to vimentin are selectively bind with a specific population of the ALN cupola epithelial cells. These cells are regularly arranged in the epithelium of the cupola lateral part and they are absent in the epithelium of the intestinal crypts, villi and apex of the cupolas. In the lateral epithelium of the cupolas surface, nearer to their base vimentin-positive++ epitheliocytes make contacts with single interepitheliocytic lymphocytes, and nearer to the apex they surround compact groups of the interepitheliocytic lymphocytes. The vimentin-positive++ epitheliocytic cells are identified as M-cells.     

Genetico-demographic patterns of the prevalence of various forms of endogenous psychoses

Prevalence rates (PRs) for EFP (schizophrenic, schizoaffective and affective psychoses), with allowance for proband sex and age-of-onset data were studied in a subdivided population from the North-East of the European Region of the USSR. The population includes three subpopulations: a small old religious semi-isolate of Russians ("Rs"), aboriginal Komi people ("Ks")--an ethnic community of Ugro-Finnish lineage, and a mixed group of migrants ("Ms") from various regions of the USSR. The latter is mainly an urban population, while the "Rs" and "Ks" are, on the whole, rural populations. The total PR for EFP was found to be 0.97% for the "Rs", 0.63% for the "Ks" and 0.35% for the "Ms", whereas PRs-0.85-1.15% in other parts of the USSR, mainly for "panmixed" populations in large towns. The lower PRs for EFP in the "Ms" is caused by a backmigration flow involving certain groups of patients; consequently, the mean liability for "Ms" offsprings (as a whole) should also be lower. On the other hand, the lower PRs for EFP in the "Ks" is caused by underpresentation of clinically mild cases of the mental disease (mainly, pseudoneurotic schizophrenia), especially among female patients, probably due to that the so affected persons are sufficiently adapted to the cultural traditions of this rural population. It was shown that in the "Rs" the total PR for "nuclear" and paranoid schizophrenia is 0.68% versus 0.25% in a "panmixed" population. The increase is most likely caused by the high inbreeding level in the "Rs" semi-isolate, and if this is correct, we may suppose that at least one or two recessive genes are involved in the liability to the most heavy forms of schizophrenia. On the other hand, in the "Ms" (as in other "panmixed" populations) positive assortative mating among hereditary-predisposed persons is a more significant factor influencing family transmission of EFP, since the correlation between probands and their spouses is rpp = 0.31 (p less than 0.001) in the "Ms", as compared to rpp = 0.19 (p less than 0.1) in the "Rs". Thus, our general conclusion is that neither the place of inhabitance nor the life mode are the causal factors for EFP, but rather some genetic factors, more accurately, certain sets of specific genes.     

Localization of glycoconjugates in tissues of mammals revealed by means of labeled lectins

Histochemical peculiarities on binding of castor-oil plant, soybean and lentil lectins with tissues of the mucous membrane in the stomach, small and large intestine have been studied in the human being, rat, mouse, as well as the lectins mentioned and the maize agglutinin with the nervous tissue of the rat cerebral tissue. The reactions are carried out with nonfixed cryostat and deparaffinized histological slices. Lectins labelled with horseradish peroxidase are used. Certain specific peculiarities and differences concerning the lectin binding with tissues of the organs studied are determined. Predominant binding is noted of the soybean lectin with parietal and mucin-producing cells of the stomach, with epitheliocytes of the duodenal glands, with the brush border of the epithelial cells of the intestinal villi. The lentil and castor-oil plant lectins make contours of the basal membrane epithelium in the stomach and intestine. The lentil lectin also reacts with the germinative centers of the stomach lymphatic nodules and the castor-oil plant agglutinin--with the brush border of the small intestine epitheliocytes. The lectins used are predominantly bound with neurons of the subcortical formations of the rat brain and cerebral cortex. By means of labelled lectins of lentil, soybean, and castor-oil plant it is possible to reveal certain modifications of the rat small intestine glycoconjugates produced by means of the immortelle extract.     

Inorganic pyrophosphatase activity of the mouse spleen in the immune response and after treatment with bis-phosphonates

The inorganic pyrophosphatase activity was determined in different tissues of mice. The immunization of mice by sheep erythrocytes increased the inorganic pyrophosphatase activity of the spleen. The in vivo administration of bisphosphonates (40 mg per 1 g of mass), which are structural analogs of inorganic pyrophosphate (methylene bisphosphonic acid--MBPA, hydroxyethylidene bisphosphonic acid--HEBPA and aminomethylene bisphosphonic acid--AMBPA), inhibited the inorganic pyrophosphatase activity only by MBPA in the thymus and spleen but not in liver. The addition of MBPA, HEBPA as well as of phosphonoacetic acid, imidobisphosphate, bis(phosphonomethyl)-phosphonic acid, MBPA and phosphoric acid monoanhydride to cytosol from the mouse spleen led to the competitive (relative to the [Mg (PPi)2-] complex) inhibition of the inorganic pyrophosphatase activity. AMBPA didn't possess the analogous effect.     

Expression of ceruloplasmin gene in mammalian organs from the data of hybridization analysis with complementary DNA probes

Expression of ceruloplasmin (Cp)-coding gene in rat and human liver and brain tissues was studied by Northern blot hybridization and by in situ hybridization with cloned species-specific cDNA probes. In rat brain structures, different levels of Cp mRNA were detected, the maximal one was found in cerebellum. The steady-state level of Cp mRNA in rat and human brain was several times lower than in parenchymatous liver cells. The size heterogeneity of Cp mRNA was found. Polyadenylated RNA prepared from human liver contains two equally abundant Cp mRNAs differing in their chain length (3.6 and 4.5 kb) while brain polyadenylated RNA contains a single Cp mRNA (4.5 kb).     

Polymorphism of nucleotide sequences of human genomic DNA linked to a mucoviscidosis locus

Polymorphism in the restriction fragments length of human DNA sequences linked to mucoviscidosis locus was studied in the healthy control group and in the families affected by mucoviscidosis. The plasmid clones metH, pJ3.11,XV-2c and pKM.19 were used as hybridization probes. The allelic frequencies of the polymorphic loci were determined for total population and for affected families. The linkage disequilibrium between the disease locus and linked polymorphic loci detectable with XV-2c (TaqI endonuclease) and pKM.19 (PstI endonuclease) was demonstrated. The high informational value of DNA-diagnosis of mucoviscidosis in the family studies with the use of four DNA probes combination has been demonstrated.     

Glucoamylases encoded by variantSaccharomycopsis fibuligera genes: Structure and properties

The genes of two variant glucoamylases (GLA1 and GLU1) ofSaccharomycopsis fibuligera were expressed inSaccharomyces cerevisiae, and biochemical properties of the secreted enzymes were compared. It was found that three amino acid alterations in the signal peptide and N-terminal regions of the variants had no effect on the levels of the secreted enzymes. Amino acid alterations in the C-terminal region of the mature proteins influenced their specific activity, substrate specificity, as well as temperature and pH optima. Because of the glycosylation heterogeneity, the glucoamylases of each gene variant were isolated and purified in two forms (A and B), which were essentially similar in catalytic and physicochemical properties but differed in their thermal stability and ability to renaturate after thermal denaturation.     

Widespread formation of intracellular calcium carbonates by the bloom-forming cyanobacterium Microcystis

The formation of intracellular amorphous calcium carbonates (iACC) has been recently observed in a few cultured strains of Microcystis, a potentially toxic bloom-forming cyanobacterium found worldwide in freshwater ecosystems. If iACC-forming Microcystis are abundant within blooms, they may represent a significant amount of particulate Ca. Here, we investigate the significance of iACC biomineralization by Microcystis. First, the presence of iACC-forming Microcystis cells has been detected in several eutrophic lakes, indicating that this phenomenon occurs under environmental conditions. Second, some genotypic (presence/absence of ccyA, a marker gene of iACC biomineralization) and phenotypic (presence/absence of iACC) diversity have been detected within a collection of strains isolated from one single lake. This illustrates that this trait is frequent but also variable within Microcystis even at a single locality. Finally, one-third of publicly available genomes of Microcystis were shown to contain the ccyA gene, revealing a wide geographic and phylogenetic distribution within the genus. Overall, the present work shows that the formation of iACC by Microcystis is common under environmental conditions. While its biological function remains undetermined, this process should be further considered regarding the biology of Microcystis and implications on the Ca geochemical cycle in freshwater environments.