Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 21

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  wirus choroby Mareka
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
The aim of the foregoing experiment was the determination and comparison of the nucleotide and amino acid sequences of the vIL-8 gene of Polish MDV strains. Twenty three samples isolated from field cases of Marek’s disease virus during the years 1976 2005 were used in the experiment. The presence of the gene was confirmed in all examined samples. No changes in the vIL8 sequence were stated, except of the three following strains, where singular nucleotide changes were observed: 16/05 (25 C→T; 243 C→T; 281 G→A), PZ /95 (25 C→T; 184 A→G; 243 C→T; 281G→A), 5/01 (168 C→T; 220 T→C), 11/02 (464 T→A), 23/99 (665 T→A), 14/05 (551 T→A, deletion of 680 base). These changes were reflected in amino acid sequences of the three isolates, as point and random changes: 16/05, PZ/95 (4 S→L, 31 G→D), and 14/05 (88 F→L). It appears that these changes did not show any pattern displaying association with the degree of the pathogenicity of the virus, and that the gene encoding vIL8 in most cases did not change within 30 years.
Medycyna Weterynaryjna
|
2010
|
tom 66
|
nr 12
s.810-817,rys.,tab.,bibliogr.
Tumors are one of the most important health problems for man and animals in the context of human health protection and food hygiene. It is well known that cancer diseases depend on genetic background and subtle molecular regulation of cell division and can be induced by three groups of carcinogens: biological (i.e. some viruses known as oncogenic viruses), physical and chemical. To date more than 50 various DNA (i.e. herpesviruses, adenoviruses, papillomaviriruses and polyomaviriruses) and RNA (retroviruses) viruses have been well documented as oncogenic viruses. Viruses (i.e. oncogenic herpesviruses and retroviruses) have evolved long-term survival strategies (latency) in the infected host. In the 1970s oncogen v-src of Rous sarcoma virus (RSV) were identified as a factor that can transform the cells of an infected host. At present we know more than 100 viral oncogens (v-jun) and antioncogens (tumor-supressor genes), that compete in cancer induction or supression, respectively. In contrast normal growth promoting genes (the host genes termed protooncogens, c-jun: i.e. growth factors, growth factor receptors and transcriptional factors) have been identified. Thus viral carcinogens can trigger oncogenesis by indirect (i.e. induction of immunosupression in the case of Kaposis’s sarcoma in HIV⁺/AIDS⁺ patients or by modification of host cell genome) or direct (i.e. altering the expression of host cell proteins at the point of viral DNA integration) mechanisms. Different molecular models of the replication of DNA and RNA viruses are essential for oncogenesis development in the infected cells and can influence the frequency of cancer induction. In contrast to RNA viral carcinogens DNA viruses are less efficient in tumor induction because the progeny of RNA viruses are continually being released from the virally transformed cells. In this paper the molecular mechanisms of viral oncogenesis in the context of human (EBV, HPV, HCV, HTLV-1) or animal (RSV, AMV, MDV) viruses is briefly described and discussed.
Marek’s disease is a viral disease, a type of poultry cancer. It is caused by MDV serotype 1 (Marek’s disease virus, MDV) viruses, also referred to as Gallid herpesvirus 2 belonging to the family Herpesviridae. The complete, fully infectious virus particles are present in the feathers and the nodules months can survive in the environment for many months. The use of isothermal amplification methods of genetic material (Loop-Mediated Isothermal Amplification, LAMP) virus MDV enables rapid and precise identification of the virus in difficult diagnostic material, including dust. By optimizing the reaction conditions and using at least two pairs of primers which bind to specific sites in the genome of the virus, this technique has high sensitivity and specificity. The technique makes it possible to detect of single copies of the meq oncogene – a unique region of DNA of the first type of virus MDV.
Marek’s disease (MD) is a lymphoproliferative disease of poultry caused by a cell-associated herpesvirus called Marek’s disease virus (MDV). The disease has a significant economic impact on the poultry industry. MD is the first oncogenic disease controlled by vaccination. Live vaccines are administered either to one-day old chicks or to 18-day old embryos. However, although MD vaccines target MDV replication in the cytolic phase and prevent lymphoma development, they do not prevent infection and replication of pathogenic strains of MDV. One of the important problems is an evolution toward greater virulence and the emergence of vvMDV and vv+MDV strains. The development of novel vaccines is necessary. DNA vaccines based on entire viral genomes cloned as bacterial artificial chromosomes (BAC) are considered. The genetic incorporation into recombinant vaccines of genes for immunomodulatory stimuli or vaccines from deletion mutants prepared from virulent MDV strains lacking vIL8 and gene meq are also under consideration.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.