Search results for "Virology"
showing 10 items of 2354 documents
Secondary impairment of pancreatic function as a cause of severe malabsorption in intestinal giardiasis: A case report
1997
We report the case of a 54-year-old male patient hospitalized for diarrhea and weight loss (8 kg over the previous three months). At admission, we observed pale oral and conjunctival mucosa and peripheral edema of the lower limbs. Stool frequency was 8-10 per day. Laboratory data were as follows: hemoglobin, 11 g/dL; total proteins, 4.3 g/dL; albumin, 2 g/dL; pseudocholinesterase, 1248 U/L; triglycerides, 54 mg/dL; serum cholesterol, 102 mg/dL; calcium, 7.9 mg/dL. Fecal fat was 8.2 g/24 hr. Fecal chymotrypsin (FCT) was 2.3 U/g. A duodenal probe was performed after administration of intravenous secretin and cerulein stimulation, and a contemporaneous mucosal biopsy was taken at the ligament …
No influence of oxygen levels on pathogenesis and virus shedding in Salmonid alphavirus (SAV)-challenged Atlantic salmon (Salmo salar L.)
2010
Abstract Background For more than three decades, diseases caused by salmonid alphaviruses (SAV) have become a major problem of increasing economic importance in the European fish-farming industry. However, experimental infection trials with SAV result in low or no mortality i.e very different from most field outbreaks of pancreas disease (PD). This probably reflects the difficulties in reproducing complex biotic and abiotic field conditions in the laboratory. In this study we looked at the relationship between SAV-infection in salmon and sub-lethal environmental hypoxia as a result of reduced flow-through in tank systems. Results The experiment demonstrated that constant reduced oxygen leve…
Transmission to Eels, Portals of Entry, and Putative Reservoirs of Vibrio vulnificus Serovar E (Biotype 2)
2001
ABSTRACT Vibrio vulnificus serovar E (formerly biotype 2) is the etiologic agent that is responsible for the main infectious disease affecting farmed eels. Although the pathogen can theoretically use water as a vehicle for disease transmission, it has not been isolated from tank water during epizootics to date. In this work, the mode of transmission of the disease to healthy eels, the portals of entry of the pathogen into fish, and their putative reservoirs have been investigated by means of laboratory and field experiments. Results of the experiments of direct and indirect host-to-host transmission, patch contact challenges, and oral-anal intubations suggest that water is the prime vehicle…
Phage-driven loss of virulence in a fish pathogenic bacterium
2012
Parasites provide a selective pressure during the evolution of their hosts, and mediate a range of effects on ecological communities. Due to their short generation time, host-parasite interactions may also drive the virulence of opportunistic bacteria. This is especially relevant in systems where high densities of hosts and parasites on different trophic levels (e.g. vertebrate hosts, their bacterial pathogens, and virus parasitizing bacteria) co-exist. In farmed salmonid fingerlings, Flavobacterium columnare is an emerging pathogen, and phage that infect F. columnare have been isolated. However, the impact of these phage on their host bacterium is not well understood. To study this, four s…
Role for calnexin and N-linked glycosylation in the assembly and secretion of hepatitis B virus middle envelope protein particles.
1998
ABSTRACT Unlike those of the S and the L envelope proteins, the functional role of the related M protein in the life cycle of the hepatitis B virus (HBV) is less understood. We now demonstrate that a single N glycan, specific for M, is required for efficient secretion of M empty envelope particles. Moreover, this glycan mediates specific association of M with the chaperone calnexin. Conversely, the N glycan, common to all three envelope proteins, is involved neither in calnexin binding nor in subviral particle release. As proper folding and trafficking of M need the assistance of the chaperone, the glycan-dependent association of M with calnexin may thus play a crucial role in the assembly …
Enhanced immunogenicity of multivalent MUC1 glycopeptide antitumour vaccines based on hyperbranched polymers.
2015
Enhancing the immunogenicity of an antitumour vaccine still poses a major challenge. It depends upon the selected antigen and the mode of its presentation. We here describe a fully synthetic antitumour vaccine, which addresses both aspects. For the antigen, a tumour-associated MUC1 glycopeptide as B-cell epitope was synthesised and linked to the immunostimulating T-cell epitope P2 derived from tetanus toxoid. The MUC1-P2 conjugate is presented multivalently on a hyperbranched polyglycerol to the immune system. In comparison to a related vaccine of lower multivalency, this vaccine exposing more antigen structures on the hyperbranched polymer induced significantly stronger immune responses in…
Involvement of actin-containing microfilaments in HSV-induced cytopathology and the influence of inhibitors of glycosylation.
1986
Two and a half hours after infection with a high dose of different strains of HSV-1 which induce rounding of cells, breakdown of actin containing microfilaments can be observed. At the periphery of the cell, actin containing knob-like protuberances were visible. Later on, actin seems to be located exclusively on the surface of cells. Observations were done by immunofluorescence microscopy, scanning electron-microscopy and immunoperoxidase staining of ultrathin sections. The envelope of HSV appears to be stained by anti-actin. Strain IES produces rounding of cells at a high dose of infection before fusion proceeds at 37 degrees C. Similar alterations were not observed with the fusing strains…
Synthetic MUC1 Antitumor Vaccine Candidates with Varied Glycosylation Pattern Bearing R/S-configured Pam3 CysSerLys4.
2016
The Toll-like receptor 2 ligand Pam3 CysSer is of particular interest for the construction synthetic vaccines because of its ability to stimulate of the innate immune system. Such vaccines usually comprise Pam3 CysSer with the natural R-configuration at the glycerol 2-position. Pam3 CysSer peptide vaccines with natural configuration have been shown to be more efficient than the corresponding R/S diastereomers. In order to clarify whether the effect of the configuration of Pam3 Cys on the immune response also applies to glycopeptide vaccines, MUC1 glycopeptide-lipopeptide vaccines bearing either R- or R/S-configured Pam3 CysSerLys4 were compared for their immunological effects. In order to f…
Cytomegalovirus inhibits the engraftment of donor bone marrow cells by downregulation of hemopoietin gene expression in recipient stroma
1998
ABSTRACT Cytomegalovirus (CMV) disease after bone marrow (BM) transplantation is often associated with BM graft failure. There are two possible reasons for such a correlation. First, a poor hematopoietic reconstitution of unrelated etiology could promote the progression of CMV infection by the lack of immune control. Alternatively, CMV infection could interfere with the engraftment of donor BM cells in recipient BM stroma. Evidence for a causative role of CMV in BM aplasia came from studies in long-term BM cultures and from the murine in vivo model of CMV-induced aplastic anemia. A deficiency in the expression of essential stromal hemopoietins, such as stem cell factor (SCF), has indicated …
Membrane insertion and topology of the p7B movement protein of Melon Necrotic Spot Virus (MNSV)
2007
AbstractCell-to-cell movement of the Melon Necrotic Spot Virus (MNSV) is controlled by two small proteins working in trans, an RNA-binding protein (p7A) and an integral membrane protein (p7B) separated by an amber stop codon. p7B contains a single hydrophobic region. Membrane integration of this region was observed when inserted into model proteins in the presence of microsomal membranes. Furthermore, we explored the topology and targeting mechanisms of full-length p7B. Here we present evidence that p7B integrates in vitro into the ER membrane cotranslationally and with an Nt-cytoplasmic/Ct-luminal orientation. The observed topology was monitored in vivo by fusing GFP to the Ct of p7B, enab…