Biomedical subjects

Andriy Ruryk

Publications and source records attributed to Andriy Ruryk.

3 recordsLinked to original sources

PubMed2005

Ability to differentiate between cp and ncp BVDV by microarrays: towards an application in clinical veterinary medicine?

Microarray expression profiling provides a comprehensive portrait of the transcriptional world enabling us to view the organism as a 'system' that is more than the sum of its parts. The vigilance of cells to environmental change, the alacrity of the transcriptional response, the short half-life of cellular mRNA and the genome-scale nature of the investigation collectively explain the power of this method. These same features pose the most significant experimental design and execution issues which, unless surmounted, predictably generate a distorted image of the transcriptome. Conversely, the expression profile of a properly conceived and conducted microarray experiment can be used for hypothesis testing: disclosure of the metabolic and biosynthetic pathways that underlie adaptation of the organism to infectious processes; the identification of co-ordinately regulated genes; the regulatory circuits and signal transduction systems that mediate the adaptive response; and temporal features of developmental programmes. The study of viral pathogenesis by microarray expression profiling poses special challenges and opportunities. Although the technical hurdles are many, obtaining expression profiles of an organism growing in tissue will probably reveal strategies for growth and survival of the virus in the host's cells. Here, we show data obtained using a tailored microarray system based on synthetic polynucleotides derived from human sequences (SIRS-Lab GmbH, Jena, Germany) to study the effect of cytopathogenic (cpe) and non-cytopathogenic (ncp) bovine viral diarrhoea virus (BVDV) infection of bovine macrophages, focusing on intracellular signalling molecules. Of the 575 genes present on the array, more than 70% showed a reaction with the oligonuleotides spotted on the array, and 26 genes were differentially expressed comparing cDNA derived from cpe and ncp infected cells. These data will help to further understand our knowledge regarding BVDV infection, and will especially help to understand differences in cellular responses to cpe and ncp biotypes.

Animals↗

PubMed2005

Transcription in response to physical stress--clues to the molecular mechanisms of exercise-induced asthma.

To clarify stress-induced immunological reactions and molecular events during exercise and the potential relevance to exercise-induced bronchoconstriction, transcriptional responses to standardized physical stress were determined. Six healthy, young volunteers underwent an endurance exercise of 90% of their individual anaerobic threshold for 90 min. Time-dependent alterations in the expression pattern of leukocytes from healthy, trained subjects were analyzed by DNA microarrays before and 2 h and 6 h after exercise. Starting out from a large collection of cDNA library clones comprising more than 70,000 human expressed sequence tags, we selected, designed, and immobilized oligonucleotide probes (60-70mers) for transcripts of 5000 stress- and inflammation-relevant genes. Exercise-induced stress provoked changes in the expression of 433 gene activities 2 h and/or 6 h after exercise, which could be grouped into six clusters. The most prominent feature was an enhanced transcription of two genes, coding for 5-lipoxygenase (ALOX5) and ALOX5-activating protein. Moreover, enhanced levels of leukotriene B4 (LTB4) and LTC4 (P<0.05) were detected in plasma after exercise. Our data demonstrate that exercise alters the activities of a distinct number of genes. In particular, they possibly provide novel insights into the molecular mechanisms of exercise-induced bronchoconstriction and suggest that enhanced transcription of ALOX5 and its activating protein together with a present predisposition of the subject critically contribute to exercise-induced asthma.

5-Lipoxygenase-Activating Proteins↗

PubMed2004

Expression profiling: toward an application in sepsis diagnostics.

Sepsis is a common and serious health problem whereby improvements in diagnosis are crucial in increasing survival rates. To test whether profiling transcription is applicable to sepsis diagnosis, we analyzed whole blood using a microarray containing probes for 340 genes relevant to inflammation. The patient's gene expression pattern was highly homogenous, resulting in 69% of differentially expressed genes. With a positive predictive value of 98%, a list of 50 differentially expressed genes was compiled, and randomly chosen transcripts were confirmed by PCR. Here, we present the first evidence that microarrays can identify typical gene expression profiles in the blood of patients with severe sepsis. Regardless of the heterogeneity of the patients, we observed a striking correlation between the conventional diagnostic classification and our approach. The unity of responses suggests that the principle of this multiparameter approach can be adapted to early stage sepsis diagnosis.

APACHE↗