Search results for "VIROLOGY"

Mechanism of the Antiretroviral Effect of dsRNA

1994

The development of AIDS seems to be linked to an impairment of processes which are induced or activated by double-stranded RNA (dsRNA), such as the biosynthesis of interferon (IFN), production of 2′,5′-oligoadenylate (2-5A), ribonuclease L (RNase L) activity and different cell-mediated immune functions. A restriction of available bioactive dsRNA (or of dsRNA-dependent enzymes) may play an important role in the disease progression. The results summarized in this review show that defects in dsRNA-dependent pathways exhibited by AIDS patients can be reversed, at least in part, by exogenously supplied dsRNA.

Mapping antigenic epitopes of potato virus Y with antibodies affinity-purified by using overlapping synthetic peptides

1994

Synthetic, overlapping peptides representing the entire amino acid sequence of potato virus Y (PVY) coat protein were used to affinity-purify antibodies from polyclonal antisera to PVY. In testing the binding of the purified antibodies to PVY particles, antigenic epitopes were identified. The N-terminal and C-terminal regions of the PVY coat protein were found to contain most of the antigenic epitopes. The results will facilitate the development of detection methods for PVY based on synthetic peptides.

Riesenzellbildung und virusspezifische antigene bei herpesvirus hominis: Informationsflu� von der eltern-DNS

1969

Es wird uber den Einflus von Cytosin-Arabinosid, Hydroxy-Urea und von Mitomycin C auf die Entstehung membranstandiger oder extrahierbarer Antigene, auf die Riesenzellbildung sowie auf die Herpesvirus-bedingte Hemmung der Zell-RNS-Synthese berichtet. Durch die Verabreichung der drei Substanzen wird die Reduplikation der DNS des eingedrungenen Virus vollig blockiert. Trotzdem lassen sich die Phanomene der Riesenzellbildung, der Virus-Antigen-Synthese und der Synthesehemmung der Zell-RNS in vollem Umfange nachweisen.

Icosahedral dsDNA Bacterial Viruses with an Internal Membrane

2008

The icosahedral double-stranded DNA bacteriophages containing an internal membrane belong to two families, the Tectiviridae and the Corticoviridae. Members of the Tectiviridae have a linear dsDNA genome (e.g., PRD1) and those of the Corticoviridae have a circular genome (the only example being PM2). The DNA is covered by a membrane which is in turn covered by a protein capsid. The infection cycle begins when spikes on the capsid recognize the host cell receptor and the virus starts the delivery of the genome into the cell cytoplasm. The replication of the virus genome occurs in the cytoplasm. The members of the Tectiviridae may be virulent or temperate; PM2 is virulent. Virulent bacteriopha…

MRSA ST22-IVa (EMRSA-15 clone) in Palermo, Italy

2010

Summary: Epidemic spread of methicillin-resistant Staphylococcus aureus (MRSA) strains carrying the Staphylococcal Chromosomal Cassettes (SCC) mec type IV is being increasingly reported in many geographical areas. A survey to determine the prevalence and characteristics of MRSA SCCmec IV isolates identified in four general hospitals in Palermo, Italy, was carried out. During the period February–June 2009, SCCmec type IVa has been found in 12 out of 94 isolates. Nine isolates from all hospitals and all strains from a NICU outbreak occurring in the same period were attributed with the ST22-IVa (EMRSA-15) clone. In our setting, due to the changing MRSA epidemiology, detection of SCCmec IV coul…

Epidemic dissemination of Salmonella enterica spp. enterica serovar Bovismorbificans in southern Italy in the years 1989-1991.

1994

Epidemic strains of Salmonella enterica subsp. enterica serovar Bovismorbificans isolated in southern Italy during the years 1989-1991 were submitted to a molecular epidemiological study in comparison with isolates identified in the years 1980-1988 in the same geographic area. Genomic DNA fragments obtained by digestion with BglI or Eco RI hybridized with Escherichia coli rRNA to produce three distinct, but highly related patterns. Ribotype 1, which had never been identified before 1989, was found to characterize most of the strains identified between 1989 and 1991. Such a finding supports the hypothesis of emergence and spread of a new bacterial clone associated with the increased number o…

Coronavirus Disease (COVID-19) and Its Psychobehavioral Consequences

2021

Bleomycin: Action on growth of oncogenic RNA viruses and on cell transformation

1975

Bleomycin (BLM) inhibits cell proliferation of noninfected chick embryo fibroblasts by blocking their DNA synthesis selectively. Chick embryo fibroblasts have beentransformed by Schmidt-Ruppin D strain of Rous Sarcoma Virus. Transformation has been determined by a focus assay. Foci formation is strongly reduced by BLM. Virus replication is inhibited by BLM in growing and confluent monolayer cells. This result might be explained by the observation that this drug reduces proliferation of growing and of confluent monolayer cells very sensitively. During the first 24 hours after infection the BLM inhibitory effect is more pronounced than in the case of BLM-application during the period 24--48 h…

Infectious Entry Pathway of Enterovirus B Species

2015

Enterovirus B species (EV-B) are responsible for a vast number of mild and serious acute infections. They are also suspected of remaining in the body, where they cause persistent infections contributing to chronic diseases such as type I diabetes. Recent studies of the infectious entry pathway of these viruses revealed remarkable similarities, including non-clathrin entry of large endosomes originating from the plasma membrane invaginations. Many cellular factors regulating the efficient entry have recently been associated with macropinocytic uptake, such as Rac1, serine/threonine p21-activated kinase (Pak1), actin, Na/H exchanger, phospholipace C (PLC) and protein kinase Cα (PKCα). Another…

The case for simplifying and using absolute targets for viral hepatitis elimination goals

2021

The 69th World Health Assembly endorsed the Global Health Sector Strategy for Viral Hepatitis, embracing a goal to eliminate hepatitis infection as a public health threat by 2030. This was followed by the World Health Organization's (WHO) global targets for the care and management of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. These announcements and targets were important in raising awareness and calling for action; however, tracking countries’ progress towards these elimination goals has provided insights to the limitations of these targets. The existing targets compare a country's progress relative to its 2015 values, penalizing countries who started their programmes …