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Biomedical subjects

Iu A Berlin

Publications and source records attributed to Iu A Berlin.

At least 19 recordsLinked to original sources
PubMed2000

[Synthesis and fluorescent properties of 5-(1-pyrenylethynyl)-2'- deoxyuridine-containing oligodeoxynucleotides].

Novel reagents for the fluorescent labeling of oligo- and polynucleotides have been prepared: 5-(1-pyrenylethynyl)-2'-deoxyuridine 3'-phosphoramidite and a solid support carrying this nucleoside. Oligonucleotides containing one or several modified units have been synthesized, and the fluorescence of these probes has been shown to change upon hybridization with the complementary sequence.

Fluorescent Dyes↗
PubMed1997

[Novel reagent for labeling of biomolecules--activated derivative of pyrene dichromophore with excimeric fluorescence].

N-[2-(1-pyrenyl)ethyl]-1-pyrenylacetamide, bis[2-(1-pyrenyl)ethyl]amine, and N,N-bis[2-(1-pyrenyl)ethyl]succinamide were synthesized from 1-pyrenylacetic acid. These compounds contain adjacent pyrene residues and display excimer fluorescence. The latter compound, as a pentafluorophenyl ester, was used to prepare fluorescently labeled oligodeoxyribonucleotide (5)CAGGAAACAGCTATGAC. For N,N-bis[2-(1-pyrenyl)ethyl]succinamide, the excimer-to-monomer fluorescence ratio and intensity of fluorescence in water-methanol solutions changed in the presence of single-stranded and double-stranded oligonucleotides, upon attachment to an oligonucleotide, and upon hybridization of the resulting conjugate with the complementary nucleotide sequence.

Chromatography, High Pressure Liquid↗
PubMed1995

[New polymorphic variants of the gene for human blood coagulation factor IX].

The polymorphism of Alu-repeats, which are located in the introns of the human factor IX gene (copies 1-3), was studied. To identify polymorphic variants, direct sequencing of PCR products that contained appropriate repeats was used. In each case, 20 unrelated X chromosomes were studied. A polymorphic Dra I site was found near the 3'-end of Alu copy 3 within the region of the polyA tract. A PCR-based testing system with internal control of restriction hydrolysis was suggested. Testing 81 unrelated X chromosomes revealed that the frequency of the polymorphic Dra I site is 0.23. Taq I polymorphism, which was revealed in Alu copy 4 of factor IX gene in our previous work, was found to be closely linked to Dra I polymorphism. Studies in linkage between different types of polymorphisms of the factor IX gene revealed the presence of a rare polymorphism in intron A that was located within the same minisatellite region as the known polymorphic insertion 50bp/Dde I. However, the size of the insertion in our case was 26 bp. Only one polymorphic variant was found among over 150 unrelated X chromosomes derived from humans from Moscow and its vicinity.

Base Sequence↗
PubMed1994

[New site-specific endonucleases from strains of Bacillus].

In a search for new restriction endonucleases type II, among forty bacterial strains of the Bacillus genus two strains producing site-specific endonucleases have been found. Endonucleases BbvAIII and BspFI, isolated from B. brevis BLM B-677 and B. species F, are shown to be true isoschisomers of BspMII (Kpn2I) and Sau3AI, respectively.

Bacillus↗
PubMed1993

[Use of the polymerase chain reaction to detect beta-thalassemia mutations in heterozygous carriers from Azerbaijan while performing prenatal DNA-diagnosis].

Prenatal DNA-diagnosis of beta-thalassemia in a family from Azerbaijan revealed two mutations new for this region--G-A transition at codon 15 and G-C transversion at position 5 of the intron 1. Prenatal diagnosis was carried out by direct sequencing of in vitro amplified (PCR) beta-globin gene fragments with a modified Sanger technique using thermostable DNA polymerase. The absence of parents mutations in the fetal DNA allowed us to conclude that the fetus is normal. The diagnosis was proved at hematological testing of the baby borne.

Azerbaijan↗
PubMed1992

[Artificial DNA splicing using directed ligation].

An approach to the directed genetic recombination in vitro has been devised, which allows for joining, in a predetermined chemical-enzymatic way, a series of DNA segments to give a precisely spliced polynucleotide sequence (DNA Splicing by Directed Ligation, SDL). The approach makes use of amplification, by several polymerase chain reactions (PCR), of the chosen DNA segments. The corresponding primers contain recognition sites of the class IIS restriction endonucleases, yielding protruding ends of unique primary structures. The protruding ends of the segments to be joined together are structurally predetermined to make them mutually complementary. Ligation of the mixture of the segments so synthesized gives the desired sequence in an unambiguous way. The suggested approach has been exemplified by the synthesis of a totally processed (intronless) gene encoding human mature interleukin-1 alpha.

Base Sequence↗
PubMed1991

[Allele polymorphism of the DNA loci MET, D7S8, D7S23, linked to the cystic fibrosis gene in some populations of the USSR, in high risk families and in cystic fibrosis patients].

RELP analysis of DNA loci MET, D7S8 and D7S23 was carried out in Leningrad population and partially in populations of Moscow, Azerbaijan, Ukraine, Buryatia as well as in individuals from high risk families and in cystic fibrosis (CF) patients by means of blot hybridization and polymerase chain reaction. Allelic polymorphism of all loci studied in these three groups was found to be quite similar to that in the North-Western Europe and in whites of the North America. Linkage disequilibrium of the alleles studied with the CF gene was especially pronounced for alleles of the D7S23 locus and gradually decreases from KM-19 through CS-7 to XV-2c DNA probes. The data witness genetic homogeneity of the CF mutation in European populations of the USSR and its similarity to this mutation in Western Europe. The significance of these data for potential diagnosis of CF and for heterozygous carrier detection is discussed.

Alleles↗
PubMed1990

[Synthesis of the mature human interleukin-1(alpha) gene by amplification of an mRNA-cDNA duplex in vitro].

Mixture of polyadenylated mRNAs from human monocytes has been subjected to the reverse transcription specifically initiated from the mRNA encoding interleukin 1 alpha by a synthetic polynucleotide complementary to the mRNA's coding 3'-end to yield the corresponding mRNA-cDNA duplex. Under conditions of the polymerase chain reaction, with the above polynucleotide as a downstream primer and an upstream primer corresponding to the beginning of the mature interleukin 1 alpha (AA 113-271) gene, the mRNA-cDNA duplex yielded the desired gene, whose structure was proved by the restriction and sequence analyses. The gene, containing translation initiation and termination triplets, can be used for producing interleukin 1 alpha in various expression systems and as a probe in studies of the lymphokine's biosynthesis. This method of the gene synthesis does not need construction and analysis of cDNA libraries nor synthesis of double-stranded DNA, and can, in principle, make use of the total (non-fractionated) cellular RNA.

Base Sequence↗
PubMed1989

[Structure of the recombination zone during abnormal excision of the transducing bacteriophage lambda plac9].

Investigating molecular mechanism of illegitimate recombinations in prokaryote we study transducing bacteriophages of the lambda lac series. We have carried out physical mapping of bacteriophage lambda plac9 DNA and, by comparing the obtained results with the data on the structure of lambda DNA and lac operon of E. coli, located the phage-bacterial junction corresponding to the lambda-lac9 abnormal excision and elucidated the nucleotide sequence around the junction. It led to the primary structure of phage and bacterial segments in the lysogenic bacterium which took part in the recombinational act leading to the abnormal excision and lambda lac9 formation. Structural homology of the partners in the lambda plac9 excision proved to be lower than in case of the earlier studied lambda plac5 and lambda plac10 whose excision proceeded regioselectively. Various aspects of the crossover area, including the crossover point's probable position and enzymic systems participating in the abnormal excision, are discussed.

Bacteriophage lambda↗