Comparative genomic hybridization as a new method for detection of genomic imbalance

Comparative Genomic Hybridization (CGH) is a molecular cytogenetic analysis that allows identification of genomic changes by comparing the copy number of DNA sequences in cells of tested tissue and the reference specimen. CGH is based on competitive suppressive in situ hybridization of two differently labeled DNA probes (tested and reference, karyotypically normal, fluorochrome-labeled DNAs) with metaphase chromosomes of a healthy subject. First described by Kallioniemi et al. in 1992, the CGH assay has been widely used for identification and characterization of both numerical and structural chromosome abnormalities in cells of different tissues at various pathological conditions in humans, especially in tumor diseases. We discuss the specific features and quality control of comparative genomic hybridization, its advantages and limitations in detection of genomic imbalance and the prospects for development of this technology.     

Mosquitoes (Diptera: Culicidae) of anthropogenic territories in the North of Tomsk Region (by an example of the Strezhevoy town)

An ecological-faunistic analysis of mosquitoes has been carried out in the Strezhevoy town (Tomsk Region). Thirty-one species of mosquitoes have been recorded in the territory examined. The population peak of mosquitoes is recorded in the 1-2 ten-days of July. Characteristics of the biotopic distribution and daily activity of the dominant mosquito species are revealed. Limiting factors of daily activity of mosquitoes in the investigated territory are characterized.     

The cyclooxygenases

Cyclooxygenases (COXs) catalyze the rate-limiting step in the production of prostaglandins, bioactive compounds involved in processes such as fever and sensitivity to pain, and are the target of aspirin-like drugs. COX genes have been cloned from coral, tunicates and vertebrates, and in all the phyla where they are found, there are two genes encoding two COX isoenzymes; it is unclear whether these genes arose from an early single duplication event or from multiple independent duplications in evolution. The intron-exon arrangement of COX genes is completely conserved in vertebrates and mostly conserved in all species. Exon boundaries largely define the four functional domains of the encoded protein: the amino-terminal hydrophobic signal peptide, the dimerization domain, the membrane-binding domain, and the catalytic domain. The catalytic domain of each enzyme contains distinct peroxidase and cyclooxygenase active sites; COXs are classified as members of the myeloperoxidase family. All COXs are homodimers and monotopic membrane proteins (inserted into only one leaflet of the membrane), and they appear to be targeted to the lumenal membrane of the endoplasmic reticulum, where they are N-glycosylated. In mammals, the two COX genes encode a constitutive isoenzyme (COX-1) and an inducible isoenzyme (COX-2); both are of significant pharmacological importance.     

Detection of aneuploidy in spontaneous abortions using the comparative hybridization method

Comparative genomic hybridization (CGH) technique was used to examine a set of ten spontaneous abortions whose cell cultures were characterized by the lack of proliferation in vitro, and thereby, were not available for the analysis by means of routine cytogenetic methods. Five abortions (50%) had aneuploidy of autosomes, including trisomy 10, 14, 18, and 21, and monosomy 22. The latter variant of unbalanced chromosomal abnormalities is rarely detected in spontaneous abortions by use of conventional cytogenetic methods. The results were validated by using fluorescent in situ hybridization (FISH) analysis with centromere-specific DNA probes. Embryos with trisomy 10 and monosomy 22 displayed mosaicism with the frequencies of abnormal cell clones constituting 68 and 33% respectively. The advantages and limitations of the applying of CGH technique for detection of genomic abnormalities in both nonmosaic and mosaic forms are discussed.     

'Navius' kissing stents for coronary bifurcation stenosis,recreating a new metallic carina: an IVUS-assessed case report

We report a case of implantation of a new design of stent which allows creation of a double-hemispheric lumen for the treatment of a bifurcational stenosis. The unfavourable outcome following the implantation of this stent is described.     

Comparative Genomic Hybridization As a New Method for Detection of Genomic Imbalance

Comparative Genomic Hybridization (CGH) is a molecular cytogenetic method for detecting chromosomal imbalances by comparing the copy number of DNA sequences in cells of tested tissue and the reference specimen. CGH is based on two-color fluorescence suppressive in situ hybridization of genomic test and reference DNAs, each labeled with a different fluorochrome, to metaphase chromosomes of a healthy individual. First described by Kallioniemi et al. in 1992, the CGH assay has been widely used for identification and characterization of both numerical and unbalanced structural chromosome abnormalities in cells of different tissues at various pathological conditions in humans, especially in tumor diseases. We discuss the specific features and quality control of comparative genomic hybridization, its advantages and limitations in detection of genomic imbalance and the prospects for development of this technology.     

Investigation of polyandry in honey bees (<Emphasis Type="Italic">Apis mellifera</Emphasis>) using microsatellites

Polyandry is a specific phenomenon increasing genetic diversity. To analyze the level of polyandry and to assess the contribution of drones to the genetic diversity of honey bee colonies, three microsatellite loci (A008, Ap049, and AC117) were studied in honey bees from colonies of different origin (Middle Russian race, Carpathian race, and hybrids) in Tomsk Province. The share of the introduced paternal alleles varied between colonies from 6.67 to 28.00%. The highest genetic diversity was observed in hybrid colonies (25–28% of introduced paternal alleles).     

Biosynthesis of chlorophyll P-680 of photosystem II in greening leaves of plants adapted to heat shock

In etiolated pea and maize leaves illuminated after incubation at 38 degreesC, a new dark reaction was shown manifested in the bathochromic shift of spectral bands and accompanied by esterification of the product of protochlorophyllide photochemical reduction--Chld 684/676: Chld 684/676 --> Chl 688/680. After completion of the reaction a rapid (20-30 sec) quenching of the fluorescence of the reaction product (Chl 688/680) was observed. The reaction Chld 684/676 --> Chl 688/680 is inhibited under anaerobic conditions and in the presence of cyanide; the reaction accompanied by Chl 688/680 fluorescence quenching is not observed in pea mutants with impaired function of photosystem II reaction centers. The spectral properties of the formed Chl form with the absorption maximum at 680 nm, fluorescence quenching, and simultaneous synthesis of pheophytin suggest that the reaction is connected with the chlorophyll of photosystem II reaction center--P-680.     

Late thrombotic occlusion of a malapposed stent 10 months after intracoronary brachytherapy

We report a patient who received a stent following intracoronary 3-irradiation. Despite a good initial angiographic result, the stent appeared to be not fully expanded on intravascular ultrasound imaging at 6-month follow-up. Four months later, sudden thrombotic occlusion occurred shortly after aspirin cessation.