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I V Borisevich

Publications and source records attributed to I V Borisevich.

At least 19 recordsLinked to original sources
PubMed1996

DNA from Drosophila melanogaster beta-heterochromatin binds specifically to nuclear lamins in vitro and the nuclear envelope in situ.

A DNA fragment designated lambda 20p1.4 binds in vitro to polymerized Drosophila melanogaster lamin. In situ hybridization of lambda 20p1.4 to isolated polytene chromosomes revealed localization at the chromocenter and to the 49 CD region on the right arm of chromosome 2. About 120 copies of sequences homologous to lambda 20p1.4 were detected per haploid genome. Nucleotide (nt) sequence analysis demonstrates that lambda 20p1.4 is an A + T-rich, 1327-bp fragment containing four repeated units between nt 595 and 919. Results suggest that lamin interacts with a region of lambda 20p1.4 between nt 300 and 1000. Confocal immunofluorescence co-localization demonstrates that in situ, the major locus of lambda 20p1.4 hybridization, the chromocenter, is found juxtaposed to the nuclear envelope (lamina). This is the first demonstration that a DNA sequence that binds specifically to nuclear lamins in vitro, is located at or near the nuclear envelope in situ and, presumably, in vivo.

Animals↗
PubMed1996

[Beta-heterochromatin in Drosophila: molecular organization and function. Molecular biological analysis of a MAR/SAR DNA sequence in centromere heterochromatin of Drosophila melanogaster].

A molecular biological characteristic of a DNA fragment delta 20p1.4, which is a moderately repetitive sequence of the Drosophila melanogaster genome, is presented. The fragment is present in about 120 copies per haploid genome. The main pool of the delta 20p1.4 homologous DNA can be isolated, along with the nuclear matrix DNA, and consists of Hind III-EcoR I monomers 1.4-1.6 kb in length. The monomers may occur in the genome as both single copies and tandem clusters forming chromosomes fragments up to 6-10 kb in length. The region of the delta 20p1.4 fragment between nucleotides 350 and 905 polymerizes with purified lamin from D. melanogaster. The sites of the fragment that had physical contact with lamin in vitro were determined using an Exo III protection. It was demonstrated that ATATTT, A, and T boxes located in four nonperfect tandem repeats were involved in the contact, both DNA strains reacting with lamin.

Animals↗
PubMed1993

A molecular and cytogenetic analysis of lambda 20p7 fragment DNA from the proximal beta-heterochromatin of Drosophila melanogaster.

A DNA fragment from the Drosophila melanogaster genome, cloned in lambda 20p7, was derived independently from clones lambda 20 and lambda L [Baiborodin et al., Genetika 29 (1993) 403-416; Sharakhov et al., Genetika 29 (1993) 392-402]. In situ hybridization of lambda 20p7 DNA to the chromosomes of D. melanogaster demonstrated preferential hybridization of the fragment to the chromocenter of polytene chromosomes and to pericentric heterochromatin of chromosomes II, IV and X at the metaphase plate. Copy number per haploid genome for lambda 20p7 was estimated as approximately 200. Based on Southern blotting, the major portion of this moderate repeat was localized in the region of a 5.5-kb HindIII digest. In situ hybridization to polytene chromosomes from strain fs(2)B trophocytes revealed that repeats homologous to lambda 20p7 are located in the proximal heterochromatin which undergoes structural reorganization during tissue differentiation. The nucleotide sequence of two segments of the clone lambda 20p7, Dm0.9 and Dm270, was determined. Sequence analysis of the 300-bp Dm0.9 clone revealed that it contains 21-bp and 30-bp d(GT/CA) sequences, a 12-bp AT box, recognition sites for nuclear factors NFI and SpI, and a set of inverted repeats. Clone Dm270 contains an open reading frame (ORF). The deduced amino acid (aa) sequence shares homology with the gag-like gene from type-I (R1) ribosomal DNA insertion and may code for a polypeptide of 10 kDa. The Dm270 sequence was found to contain two direct repeats showing homology to the human CENP-B box.

Amino Acid Sequence↗
PubMed1993

[Drosophila beta-heterochromatin: molecular organization and function. Characteristics of the DNA sequences from proximal beta-heterochromatin, associated with the nuclear envelope of Drosophila melanogaster].

To study the nucleotide sequence from the pericentric heterochromatin associated with the nuclear envelope, a residual DNA was extracted from the DNAse-treated nuclear lamins of Drosophila melanogaster tissue culture cell line Kc. The isolated DNA was cloned in lambda vector. The DNA library obtained was screened for the clones homologous to the pericentric heterochromatin. The experiments on in situ hybridization to the polytene chromosome of the nurse cell nuclei of the strain fs(2) B assigned the reiterated sequence, homologous to the lamin DNA clone, to the nuclear envelope associated regions of the proximal beta-heterochromatin which is known to undergo structural reorganization during cell differentiation. The nucleotide analysis of 300 bp from this sequence has established the presence of 21 bp and 300 bp d(GT/CA), 12 bp AT-box, the regions of recognition of the nuclear factor and the inverted repeats.

Animals↗
PubMed1993

[Drosophila beta-heterochromatin: molecular organization and function. Cloning and molecular biological analysis of the lambda 20 DNA fragment from Drosophila melanogaster beta-heterochromatin].

To isolate the DNA sequences specific for the pericentric heterochromatin of Drosophila we used two CREST-autoimmune sera which bind in the Western-blot analysis the nuclear antigens of 30 kDa, 43 kDa and 45 kDa molecular weight. Cloning of the DNA fragments associated with these CREST-specific proteins of Drosophila resulted in obtaining 8 clones. One of them, lambda 20, hybridized mainly to the chromomcenter of polytene chromosomes. The further analysis indicated that the lambda 20 DNA might belong to the proximal beta-heterochromatin of the polytene chromosomes of D. melanogaster.

Animals↗
PubMed1990

A new transposable element in Chironomus thummi.

A 1.7 kb long transposable element called TECth1 was found in the 3' flanking region of a Chironomus thummi Balbiani ring gene. As shown by sequence comparison with a second copy, TECth1 is characterized by a perfect terminal inverted repeat of 17 bp flanked by a duplicated target site of 8 bp, four internal imperfect inverted repeats of 17 to 26 bp and terminal regions of about 0.25 kb with a high number of short direct repeats of the consensus sequence ACTTT or permutated and mutated forms such as TTTAC or ACTAT. The terminal inverted repeats and the 8 bp target site duplication are reminiscent of Drosophila P and hobo elements but no long open reading frame starting with ATG is present, suggesting that the two TECth1 copies studied represent deletion derivatives of a longer element coding for its own transposase. In situ hybridization revealed about 75 labelled sites distributed over all chromosomes with the Balbiani ring locus most strongly labelled. Fifty percent of the sites are specific for a given individual, and these variable sites are often heterozygous for the element.

Animals↗
PubMedDate not supplied

[The laboratory diagnosis of an outbreak of hemorrhagic fever at Oblivskaya village, Rostov Province: proof of the etiological role of the Crimean-Congo hemorrhagic fever virus].

The results of the molecular biological detection of the etiologic agent of hemorrhagic fever in Rostov Province are presented. The role of the causative agents of Astrakhan rickettsial fever, hemorrhagic fever with the renal syndrome, Q fever, leptospirosis and listeriosis has been excluded by means of such immunochemical reactions as the direct and indirect immunofluorescent tests, the solid-phase immunoenzyme assay, the complement fixation test and the agglutination test. The relationship between the cases of hemorrhagic fever in the focus of the outbreak and Crimean-Congo hemorrhagic fever virus has been demonstrated due to the use of the polymerase chain reaction with preliminary reverse transcription.

Antibodies, Viral↗
PubMedDate not supplied

[Crimean-Congo hemorrhagic fever in Rostov Province: the epidemiological characteristics of an outbreak].

The results of the epidemiological analysis of the outbreak of hemorrhagic fever which was caused by Crimean-Congo hemorrhagic fever virus and occurred during the period of July 3-19, 1999, in the Oblivskaya district of Rostov Province are presented. The specific epidemiological features of the outbreak have been determined. The possible versions of the appearance of the focus of infection and the role of Ixodes ticks in the circulation of the infective agent are discussed.

Adolescent↗
PubMedDate not supplied

[Dynamics of chromatin position within the interphase nucleus].

In this article we attempt to analyze the relationship between the processes, which occur in the nucleus, and the dynamics of chromatin, as well as to classify the changes in the position of chromatin in the cell nucleus during the lifetime of the cell. The proposed concept integrates possible types of chromatin movement within the nucleus.

Animals↗
PubMedDate not supplied

[Use of guinea pigs for assessing the efficacy of vaccines against Lassa fever].

The use of guinea pigs as a laboratory model was proven to be appropriate in investigating the vaccines developed against Lassa fever at the preclinical study stage. An adapted variant of Lassa virus was cultivated, which caused death of guinea pigs with respect for an agent's dose. Finally, it was shown to be possible to investigate the immunogenic and protective properties of the inactivated antigen of Lassa virus in experiments with guinea pigs.

Animals↗
PubMedDate not supplied

[Hemorrhagic (Marburg, Ebola, Lassa, and Bolivian) fevers: epidemiology, clinical pictures, and treatment].

The evaluation of the biological and epidemiological properties of Ebola, Marburg, Lassa, and Machupo viruses suggests that they are of social importance for health care authorities. The studies have created prerequisites to the development of reliable biosafety means against these pathogens. Particular emphasis is laid on the methods for infection diagnosis and on the studies to design specific protective agents--immunoglobulins and inactivated vaccines.

Animals↗
PubMedDate not supplied

[Preparation of hyperimmune horse serum against Ebola virus].

Immunization of horses with Ebola virus resulted in production of specific virus-neutralizing antibodies with their maximal level attained on days 28 to 42 postimmunization. Repeated cycles of immunization lead to increase of antibodies titer to 1:4096.

Animals↗
PubMedDate not supplied

[The evaluation in hamadryas baboons of the possibility for the specific prevention of Ebola fever].

The protective role of virus-neutralizing antibody was demonstrated in Ebola virus-infected animals (Papio hamadryas) used in experiments on the development of passive humoral immunity by using specific immunoglobulin. Two immunizations of the monkeys with purified concentrated Ebola virus antigen with complete Freund adjuvant was shown to confirm intensive immunity to subsequent challenge protecting 80% of the immunized animals. It is concluded that effective preparations may be developed for specific prophylaxis of Ebola fever.

Animals↗
PubMedDate not supplied

[A trial to produce an inactivated Lassa fever vaccine].

A single and double immunization of Papio hamadryas monkeys with an inactivated concentrated purified adsorbed preparation of Lassa virus in doses of 0.5-1.0 and 1.1-2.1 mg by protein, respectively, protected the animals against the development of the disease and occurrence of viremia after an intramuscular challenge with 0.4 PFU dose. Upon aerogenic infection of monkeys protection of 50% of the animals was achieved by a single immunization with the inactivated preparation in a dose 1.1 mg by protein.

Animals↗
PubMedDate not supplied

[Development and study of the properties of immunoglobulin against Ebola fever].

Immunoglobulin to Ebola fever has been for the first time prepared from hyperimmune equine blood sera by alcohol fractionation after Cohn. Preclinical study of the physicochemical and immunobiological properties of immunoglobulin showed that it protects up to 100% Papio hamadryas infected intramuscularly at doses of 110 to 29 LD50 Ebola virus. Scheme for the use of Ebola immunoglobulin has been experimentally validated.

Animals↗