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A P Anisimov

Publications and source records attributed to A P Anisimov.

At least 19 recordsLinked to original sources
PubMed2006

[Generation of vaccine strains of gram-negative bacteria with reduced adverse reactions].

The main shortcoming of the modem live and killed vaccines based on gram-negative bacterial strains is their ability to cause adverse reactions. The majority of the adverse reactions are associated with the effect of biological activity of lipopolysaccharide. The report covers the problems concerned with biogenesis of the lipid A, lipopolysaccharide structural component, responsible for its endotoxic activity, as well as with genes determining lipid A synthesis. The special attention is paid to gene-engineering technique for reduction of adverse reactions of vaccine strains that are based on the knock-out mutagenesis of genes waaM and/or waaN responsible for addition of lauroyl and myristoyl residues to the distal glucosamine unit lipid A, generating acyloxyacyl moieties.

Acyltransferases↗
PubMed2005

Effect of zosterin on protein-synthesizing activity of hepatocytes.

The effect of zosterin (pectin polysaccharide) on the protein-synthesizing function of mouse liver cells was studied after its intragastric administration of 1% gel zosterin. The drug modified the morphology and function of the nucleolar apparatus by changing the number and summary area of the nucleoli, content of Ag proteins, nucleolar/nuclear ratio, and increased protein content in hepatocyte cytoplasm.

Animals↗
PubMed2005

[Morpho-functional parameters of nucleoli in polyploid mucous and albumen cells of salivary gland in the snail Succinea lauta].

Variation of some characteristics of nucleoli of polyploid mucous and albumen cells was examined in salivary glands of the snail Succinea lauta. The number, total area and Ag-protein content of nucleoli, and DNA content in each nucleus were estimated on squashed preparations incubated with AgNO3, decolorized and then Feulgen stained. The ultrastructure of nucleoli was studied by electron microscopy. Differentiated mucous cells had 4c-8c-16c-32c nuclei; albumen cells had 8c-16c-32c-64c-128c nuclei. The ultrastructure of nucleoli of the two cell types was essentially the same. Normally, a large fibrous to granular zone was observed in the nucleoli, without a clear distinction between fibrous and granular components. At the same time, aggregations of granular matter could be discerned at the periphery of nucleoli. No fibrous centers were observed. Occassionally, nucleolonema-like structures occurred. Normally each nucleolus contacted several chromosomes. On squashed preparations, the least size of nucleoli was 2-3 microm, and the largest size amounted to 14 microm in mucous cells, and to 50-80 microm in albumen cells. The number of nucleoli rose from 1-2 in tetraploid nuclei to 2-3 in 32c-nuclei, and to 5-7 in 128c-nuclei. The disparity between the ploidy levels of nuclei and the numbers of nucleoli may be due, presumably, to aggregation of chromosome NORs. The Ag-protein content in the nucleoli, and the total nucleolar area displayed a strong mutual correlation. Both parameters differed significantly by 1.5-2.2 times in mucous and albumen cells of the same ploidy level. Thus, in albumen and mucous cells the total Ag-protein content in octaploid nuclei was 3.3 and 2.2 relative units (r. u.), respectively. In 16c- and 32c-nuclei of albumen cells, it was 7.6 and 15.1 r. u.; and in the same nuclei of mucous cells--3.8 and 6.8 r. u., respectively. On the whole, in albumen cells, in the course of 4 endocycles (4c-128c), the total Ag-protein content increased by 17 times. Therefore, the mean multiplication factor for this parameter was found to be 2.05 per endocycle. In mucous cells, in the course of 3 endocycles (4c-32c), the total Ag-protein content increased by 5.2 times against 8 times expected, with the mean multiplication factor equal to 1.75 per endocycle. Thus, in the course of polyploidization of albumen and mucous cell nuclei, the gene dosage effect was fully pronounced in the former, and only partly in the latter. This differtence is due obviously to peculiarities of differentiation of the two cell types, in particular, to differences in the number of activated ribosomal genes.

Animals↗
PubMed2002

[Yersinia pestis factors, assuring circulation and maintenance of the plague pathogen in natural foci ecosystems. Report 1].

Everlasting reproduction of Yersinia pestis, plague bacillus in natural pestholes needs virulent causative agent to invade into the host entity, be potent to overcome protection powers of the rodent organism and to pullulate to entail bacteriemia for subsequent conveyance the plague bacillus to the new host by fleas. All of legs of life cyclic patterns of Yersinia pestis are maintained by a number of plague bacillus factors acting jointly or separately, participating at the different stages of infectious process or conveyance. However these factors provide the perpetuation of the plague bacillus in the ecosystems of natural pestholes only acting in conjunction independently on their distinct contributions. Not only biomolecules, organellas and bacteria systems ensured the pursuance of virulent properties, but other factors, essential for survival of Yersinia pestis and the relationship between separate virulence factors and expression of the different genes of housekeeping and virulence of plague bacillus are considered in this review. The report I covers the problems concerned with adaptational plasticity of Yersinia pestis, it represents the classification of plague causative factors, securing its perpetuation in the environmental space, and discussion the factors promoting plague bacillus survival in the host entity. Not only wellknown publications, but papers in out-of-the-way or hard-to-reach, especially for English-reading experts, editions, also were used to compile this communication. The English version of this review may be requested from Alerton Press.

Animals↗
PubMed2002

[Somatic polyploidy in neurons of the gastropod mollusca. III. Mitosis and endomitosis in the postnatal development of neurons in the Succinea snail central nervous system].

General morphology of chromatin, the number of chromosomes and chromocenters in normal condition and at the increase of bivalent cation (Ca2+, Mg2+) concentration were studied with the purpose to reveal mechanisms of polyploidization of neuron nuclei in the snail Succinea lauta (Gastropoda, Pulmonata). The morphology of nuclei was studied on squashed preparations. Normal diploid mitoses are described in the cerebral ganglia. A possibility is supposed that part of neurons or neuroblasts in the central nervous system (CNS) of succineid snail may divide mitotically. It has been shown that the basic mechanism of neuron postnatal growth is endomitotic polyploidization of nuclei. The transition from ordinary mitosis to polyploid cycles occurs via restitutional (polyploidizing) mitosis (4c2n-->4c4n). The next endocycles are carried out by means of classic endomitosis up to reaching the highest ploidy levels--4096n--16,384n. The study of general morphology of chromatin and chromocenters at normal condition and at artificial compactization enabled us to exclude any probability of polyteny in the CNS of lauta.

Animals↗
PubMed2002

[Morphofunctional parameters of nucleoli during development of the albumen gland polyploid cells in the snail Succinea lauta].

Ag-protein content, the total area and the number of nucleoli were estimated on AgNO3-methyl green stained squashed preparations of the albumen gland of Succinea lauta during polyploidization, differentiation and functioning of secretory cells. The investigation was made by means of morphometry and cytophotometry using the computer videoimage system. During the gland growth, the mean number of nucleoli increased from 1-2 in diploid (2c) nuclei to 3 in polyploid (16c-32c) nuclei, but commonly only one large nucleolus was formed in mature nuclei. As a whole, the area and Ag-protein content of nucleoli was changed proportionally to the gene dosage, but this dependence was not linear during several endocycles. Before 8c-level the coefficients of increase in each endocycle were more than 2 (2.7-4.0), and these decreased to 1.5-1.0 during the following endocycles (8c-16c-32c). The area of nucleoli increased more quickly than Ag-protein content in the course of endocycles of growing cells. On the contrary, a relative area of nucleoli decreased with the increase in ploidy levels in mature cells. This irregular dynamics reflects the influence of several factors of the nucleolar activity: endomitotic polyploidy (gene dosage effect), cell differentiation, inhibition of transcription, and its reactivation in mature cells. In addition, individual variations of nucleolar parameters in mature snails are associated with the rhythmical functioning of sexual system, and aging of animals.

Animals↗
PubMed2002

[Factors of Yersinia pestis providing circulation and persistence of plague pathogen in ecosystems of natural foci. Communication 2].

To maintain continuous circulation of plague pathogen in natural foci, the pathogen should be capable of invading host organism, resisting the bactericide protective systems of rodent, and reproducing itself to maintain the content of bacteria at a level sufficient for further transmission by fleas to a new host. Each of these stages of the Yersinia pestis circulation is determined by a variety of factors of plague pathogen, which may act either individually or in combination. Each of the factors itself may be involved in the pathological process at different stages of its development or in pathogen transmission. However, it is only the aggregate of the factors (regardless of significant or insignificant individual contribution to the sum effect) that provides persistence of plague pathogen in natural foci. The plague pathogen factors providing its transmission from one host organism to the next as well as correlation of individual factors of pathogensis and expression of various household genes with plague pathogensis virulence are considered in the second communication. This review was compiled on the basis of not only well-known works but also some sources of limited availability, particularly, for English-speaking audience.

Animals↗
PubMed2002

[Evolutionary regularities of the somatic polyploidy manifestation in salivary glands of gastropod molluscs. IV. A subclass of Pectinibranchia: Orders Hamiglossa and Toxoglossa (Neogastropoda)].

Salivary glands of 12 species of carnivorous gastropod molluscs, making the Neogastropoda group have been investigated by histochemical methods and DNA cytophotometry. We studied the anatomical and histological structure of ordinary (acinous) and accessory (tubular) salivary glands, and of unpaired glands (Leiblen's, "framboisée", and poisonous). Cells of three types were distinguished: granular cells (with glycoproteid granular inclusions), mucocytes-I (with sulfatic acid mucopolysaccharides), and epithelial ciliated cells. In ordinary and accessory glands of the studied Neogastropods, polyploid cells with polyploidy levels from 4c to 16c were revealed together with diploid cells. The functional significance and phylogenetic tendencies of polyploidy manifestation in salivary glands of prosobranch gastropods are discussed.

Animals↗
PubMed2001

[Somatic polyploidy in neurons of the gastropod molluscs. II. Dynamics of DNA synthesis in the process of postnatal growth of CNS neurons in Succineid snail].

A study was made of the age dynamics of polyploidization and dynamics of DNA synthesis in neuron cell nuclei during the postnatal growth of the gastropod pulmonate snail Succinea lauta. According to cytophotometrical results, the degree of polyploidization in neuron nuclei increases from young to adult individuals, varying from 2c to 16,384c. In the visceral complex, the maximum and medium ploidy values of the neuron nuclei are higher by almost 4-8 times than those in cerebral and pedal ganglia. The medium level of ploidy in adult snails increases by 5.7 times in the visceral complex of ganglia and by 4.1-4.2 times in the pedal and cerebral ganglia. According to 3H-thymidine autoradiography, DNA synthesis in neuron nuclei occurs during the whole life of the snail. In young individuals the neurons have the highest activity of DNA synthesis--the index of labeled nuclei of neurons making in total 50.2%. In older age, a steady decrease in the index of labeled nuclei is observed--in total to 35.8% and 7.0% in small and large adult snails, respectively. The state of summer hibernation completely stops DNA syntheses in neurons, but emergency from hibernation is accompanied by restoration of DNA syntheses.

Animals↗
PubMed2001

[Evolutionary regularities of somatic polyploidy in salivary glands of the Gastropod molluscs. II. Subclass Pectinibranchia: order Anisorbranchia].

Salivary glands of 5 species of gastropod molluscs of the order Anisobranchia, the most ancient order within the subclass Pectinibranchia, have been investigated by histological and cytochemical methods, including DNA cytophotometry. Glandular cells of the following types were recognized: granular cells (with glycoproteid granular inclusions), mucocytes-I (including sulfatic acid mucopolysaccharides), mucocytes-II (including neutral and acid polysaccharides and proteins), and epithelial ciliated cells. All the described cell types are considered to be independent and their morphofunctional characteristics coincide with those of salivary gland cells of the gastropod molluscs of subclasses Cyclobranchia and Scutibranchia. It has been shown that somatic polyploidy in salivary glands in the Anisobranchia molluscs, likely as in those of other Archaeogastropoda (Cyclobranchia and Scutibranchia), is actually absent.

Animals↗
PubMed2001

[Morphofunctional parameters of the nucleoli during development of polyploid nutrient cells of gonads from the snail Succinea lauta].

Ag-protein contents, integral area and number of nucleoli in polyploidizing nuclei of gonadal nutrient cells of the snail Succinea lauta were estimated on the squashed preparations by means of morphometry and cytophotometry. 8 NORs of different size were found in haploid chromosome set of prophase spermatocytes (n = 22), but usually 1-2 nucleoli per 2c DNA are present in the nutrient cell nuclei. During genome multiplication from 2c to 32c-64c the Ag-proteins content of nucleoli increased proportionally to gene dosage, but irregularly: before 8c-level the coefficient of increasing in each endocycle was more than 2; from 8c to 16c it was 2; after 16c-level it usually decreased to 1.6-1.3. This dynamics reflects the effects of several factors on nucleolar activity: endomitotic polyploidy (gene dosage effect), differentiation and rhythmic functioning of tissue. Increasing indexes of integral area and the number of nucleoli during polyploidization were significantly less, than increasing index of Ag-proteins. The lag of nucleolar area for 4 cycles (2c-32c) was 32%, and number of nucleoli per diploid set decreased from 2 to 1. It may be due to NOR aggregation corresponding chromosomes. The photometric index of Ag-protein content more adequately reflects in the nucleolar activity during development and functioning of tissues.

Animals↗
PubMed2001

[Evolutionary regularities of the appearance of polyploidy in salivary glands of gastropod mollusks. III. A subclass of Pectinibranchia: Orders Discopoda, Echinospirida, Aspidophora and Entomostoma (Mesogastropoda)].

By means of histological methods and DNA cytophotometry, a study was made of the salivary glands of 16 species of gastropod molluscs belonging to the subclass Pectinibranchia and making a group of Mesogastropoda. Four cell types of salivary glands were distinguished: granular cells (with glycoproteid granular inclusions), mucocytes-I (with sulfatic acid mucopolysaccharides), mucocytes-II (with neutral and acid polysaccharides and proteins), and also the epithelial ciliated cells and mucous duct cells. Data of experiments on starvation and synchronous feeding of molluscs have testified that all described cell types are independent. In some species differentiation on protein and mucous departments within the glandular epithelium was shown. In some marine representatives of the orders Discopoda and Aspidophora polyploid cells with the ploidy levels from 8c to 32c were revealed along with diploid cells. The ecological and phylogenetic regularities of somatic polyploidy manifestation in Mesogastropoda are discussed.

Animals↗
PubMed2000

[Evolutionary regularities of somatic polyploidy manifestation in salivary glands of gastropod molluscs. I. Subclasses Cyclobranchia and Scutibranchia].

By means of histological and cytochemical methods, including DNA cytophotometry, the salivary glands of 11 species of molluscs of two old gastropod subclasses--Cyclobranchia and Scutibranchia (limpets)--have been investigated. In spite of some anatomical differences, the glandular epithelium of investigated molluscs includes functionally similar cell types: granular cells (with glycoproteid granular inclusions), mucocytes-I (that include sulfatic acid mucopolysaccharides), mucocytes-II (that include neutral and acid polysaccharides and proteins) and also the epithelial ciliated cells. Data of experiments on starvation and synchronous feeding of molluscs testify that all described cell types are independent. According to DNA cytophotometry data, the glandular cell nuclei are diploid in the main; only small part of the nuclei, varying in different species from 0.5 to 5.0%, displayed tetraploid DNA mass. A conclusion is made that in the oldest subclasses of gastropods (Cyclobranchia and Scutibranchia) somatic polyploidy, as a factor of tissue growth in salivary glands, is actually absent.

Animals↗
PubMed2000

[Somatic polyploidy in neurons from gastropod mollusks. I. Morphological characteristics of ganglia and neurons in the CNS of the snail Succinea lauta].

A study was made of general anatomy and histological organization of the central nervous system in Succinea lauta, a gastropod pulmonate snail. Neurons grow by means of polyploidy during the postnatal succineid ontogeny. In the adult individuals diameters of perikaria of large neurons increase 2.5 to 5 times, in comparison with young individuals. As a whole, in adult snails sizes of ganglian cells vary from 3 to 380 mkm. Most of giant neurons are in parietal, abdominal and pallial ganglia. The chromatin structure has been described in neurons of young and adult snails. The endomitotic mechanism of polyploidization in the succineid ganglioneurons is proposed.

Animals↗
PubMed1999

[Factors providing the blocking activity of Yersinia pestis].

Discusses published data on the specific mechanism of Y. pestis transfer by "blocked" fleas. Special attention is paid to individual phenotypical signs and genetic determinants of Y. pestis whose expression correlates with the blocking activity of bacteria. Prospects for further research are outlined.

Phenotype↗
PubMed1997

[Genome multiplication mechanisms in the development of albumen gland polyploid cells of Succinea lauta (Gastropoda:Pulmonata). V. Polyploidizing mitosis and endomitosis].

Mechanisms of polyploidization of albumen gland cells of S. lauta have been studied using squash preparations in combination with autoradiography of DNA synthesis. During the growth period of the gland normal and abnormal (polyploidizing) mitoses were noticed in addition to endomitoses. Diploid foot cells and poorly differentiated secretory cells are reproduced by the normal mitosis (2c : 2c). These poorly differentiated secretory cells go then through polyploidization by different means. Tetraploid nuclei are substantially formed by abnormal mitoses (4c), which take 40-60% of all mitoses. Metaphase blocks (C-mitosis type) dominate among them; anaphase blocks and their sequences (bladed nuclei) occur rarely. The abnormal polyploid series 3c-6c ... and hypoploid (2c, 3c) mitoses originate from asymmetric mitoses (1c : 3c). Singular nuclei are defined as endomitotic even in the first cycles (4c, 6c). The second and following cycles of the main polyploid nuclei series ... 8c-16c-32c and of alternative series ... 12c-24c pass through endomitosis of classical (insect) type (Geitler, 1939). Unlabelled endomitoses were observed in an hour, while labeled ones were seen in 8-24 hours after 3H-thymidine injection. So, endomitosis can be defined as a real phase of the cell cycle. Integrity of the nuclear envelope as the formal feature of endomitosis was proven at the ultrastructural level (Anisimov, 199). It is emphasized that the normal mitosis is followed by an abnormal polyploidizing mitosis and then by endomitosis. These processes could be considered as compatible and successive polyploidization mechanisms. This conclusion is in agreement with dynamics and speed of DNA and RNA synthesis during cell polyploidization and differentiation (Anisimov, 1988, 1994b, 1995b).

Animals↗
PubMed1997

[Genome multiplication mechanisms in the development of albumen gland polyploid cells of Succinea lauta (Gastropoda:Pulmonata). VI. Ultrastructural research of endomitotic structure].

This ultrastructural study of endomitosis in polyploid albumen gland cells of succineid snail. S. lauta was made to extend the previous research (Anisimov, 1997). The investigation was prosecuted on ultrathin sections by means of transmission electron microscopy. The insertion of 3H-thymidine and 3H-uridine into the nuclei and the light microscopy control of nuclear ploidy allowed to identify glands on early and intensive polyploidization stages and to ignore pseudoendomitotic terminally differentiated cells. Considering ultrastructural qualities and information about the cell population kinetics enabled us to discriminate between predifferentiation (2-4c), protodifferentiation (4-8c) and promoted differentiation (8-16c) cell stages. The endomitotic cycle was observed synchronously with the development of cytoplasmatic structures and secretion production in differentiating cells of ploidy levels 4-8-16c. According to morphological condition of the chromatin and chromosomes, G1-, S- and G2-interphase periods can be determined, such as successive stages of endomitosis (endopro-, meta-, ana-, and telophase). The following main features of endomitosis are accentuated: the normal (mitotic) chromosome cycle with total compaction in endometaphase and differential decompaction in interphase; the absence of the mitotic spindle; integrity of the nuclear envelope, nucleolus and contacts between them and chromosomes; part of chromosomes split nonsimultaneously and incompletely in the endoanaphase, or endomitosis with diplochromosomes rarely occurs. Chromosome nondisjunction is a temporary process that does not lead to a permanent chromosome endoreduplication (polyteny). It is emphasized that the normal chromosome cycle is combined with a complete block of cytoplasmic structures. Possible reasons of mitotic cycle reduction during the transition of differentiating cells to endomitotic polyploidy are discussed.

Animals↗