Biomedical subjects

A Atanassova

Publications and source records attributed to A Atanassova.

4 recordsLinked to original sources

PubMed2000

Characterization of two distinct DP-related genes from Arabidopsis thaliana.

E2F/DP complexes play a pivotal role in the regulation of the G1/S transition in animals. Recently, plant E2F homologs have been cloned, but DP-related sequences have not been identified so far. Here we report that Arabidopsis thaliana contains at least two different DP-related genes, AtDPa and AtDPb. They exhibit an overall domain organization similar to that of their animal counterparts, although phylogenetic analysis demonstrated that they form a separate subgroup. AtDPs efficiently heterodimerize in vitro with the Arabidopsis E2F-related proteins, AtE2Fa and AtE2Fb through their dimerization domains. AtDPa and AtE2Fa are predominantly produced in actively dividing cells with highest transcript levels in early S phase cells.

Amino Acid Sequence↗

PubMed1997

Studies on the mouse rpL32 pseudogene family: features of a new member.

A new processed pseudogene (rpL32-5C) that belongs to the mouse rpL32 multigene family has been sequenced and compared to previously characterised mammalian rpL32 family members. rpL32-5C has intact direct terminal repeats of 13 nt, a poly A tail of 10 nt and it does not contain conserved promoter elements at its 5' end. The comparison with the L32 cDNA and 4A processed pseudogene shows a deletion of 25 nt in rpL32-5C as well as several nt substitutions that lead to frameshifts and interruption of the ORF. Most of the consistent substitutions occur in the third codon position lending support to the suggestion that all rpL32 processed pseudogenes have been derived from transcripts of the functional gene.

Animals↗

PubMed1995

Non-invasive electrogastrography. Part 1: Correlation between the gastric electrical activity in dogs with implanted and cutaneous electrodes.

Experiments were made on dogs with bipolar silver ball-shaped electrodes chronically implanted on the muscle wall of the stomach. The electrical activity of the gastric muscle wall (electrogastromyogram-EGMG) was characterized by slow potential changes during the quiescent period of the migrating myoelectric complex (MMC) and bursts of spike potentials during the activity period of MMC. Cutaneous (surface) electrodes were placed on the abdominal wall. Waves with a rhythm of 4.5-5 cpm were led off by the cutaneous electrodes (electrogastrogram-EGG), simultaneously with the EGMg. The bursts of spike potentials with the slow gastric potentials in the EGMG corresponded to an increase of the amplitude of the waves in the EGG. Good correlation was found between the number and frequency of spike potentials in a group and the wave amplitude in the EGG. EGG recorded on an electrogastrograph designed by us was characterized by low-amplitude waves corresponding to the slow waves during the period of quiescence of MMC and high-amplitude waves corresponding to the bursts of spike potentials during the activity period of MMC. Therefore it is possible to determine the MMC of the stomach by the changes in the amplitude of the waves in the EGG.

Action Potentials↗

PubMed1995

Non-invasive electrogastrography. Part 2. Human electrogastrogram.

The electrical activity of human stomach muscle wall-electrogastrogram (EGG), was led off by surface (cutaneous) electrodes placed on the abdominal wall and recorded on an electrogastrograph. A method for complete elimination of the cardiac artefact was elaborated and successfully implemented. It consists of a preliminary elimination of the QRS complex, based on its higher amplitude and slope. The eliminated intervals were replaced by linear segments. A subsequent low-pass filtering allowed to obtain a high quality EGG signal. The electrical activity of the stomach of healthy volunteers was characterized by waves with a frequency of 3.35 +/- 0.09 cpm during the quiescent periods and 2.99 +/- 0.14 cpm during the activity periods of the migrating myoelectrical complex (MMC). Bearing in mind the correlation between the bursts of spike potentials with the slow waves in the dog EGMG and the high-amplitude waves, characterizing the periods of activity in the dog EGG, we can better differentiate the periods of quiescence and activity by the amplitude of the waves. The wave amplitude during periods of quiescence was 81.13 +/- 20.61 microV, significantly different from the wave amplitude during periods of activity being 164.74 +/- 43.34 microV (n = 7). Thus with this method in visual inspection it is possible to identify MMC of the human stomach by the changes in the amplitude of the waves in the EGG.

Action Potentials↗