Laboratory strains of enteroviruses, as well as viruses isolated from raw wastewater, were found to exhibit enhanced infectivity in vitro when BGM cell monolayers were pretreated with the cationic polymer polyethyleneimine (PEI). Viruses were assayed by the cytopathic effect technique and as PFU under methylcellulose and agar overlays with monolayers treated with 0 to 5.0 x 10(-3)% (wt/vol) PEI...

Background: The ubiquitin-proteasome pathway plays an important role in selective protein degradation and regulates multiple cellular processes, including cell cycle progression, proliferation and apoptosis. Cancer cells are more sensitive to the pro-apoptotic effects of proteasome inhibition than normal cells, hence, proteasome inhibitors can be used as novel anticancer drugs. Further, influen...

Although hepatitis A virus (HAV) is typically transmitted by the fecal-oral route, little is known of its interactions with cells of the gastrointestinal tract. We studied the replication of HAV in polarized cultures of Caco-2 cells, a human cell line which retains many differentiated functions of small intestinal epithelial cells. Virus uptake was 30- to 40-fold more efficient when the inoculu...

We established a quantitative flow cytometric method for determination of herpes simplex virus type 1 (HSV-1) susceptibility to acyclovir (ACV), ganciclovir, and foscarnet in vitro. Susceptibility was defined in terms of the drug concentration which reduced the number of cells expressing HSV-1 glycoprotein C (gpC) with a fluorescence intensity of > or =10(2) by 50% (IC50). Flow cytometry allowe...

BACKGROUND Ticks have been long known as vectors of various pathogens, some of which can cause high fatality rates among infected individuals. Our enhanced tick surveillance around Nagasaki, Japan, led to the isolation and identification of a new strain of a recently identified Orbivirus, Muko virus (MUV). The orbiviruses have a wide host range, including humans, and is related to a spectrum of...

Cysteine proteinases are hypothesized to be important virulence factors of Entamoeba histolytica, the causative agent of amebic dysentery and liver abscesses. The release of a histolytic cysteine proteinase from E. histolytica correlates with the pathogenicity of both axenic strains and recent clinical isolates as determined by clinical history of invasive disease, zymodeme analysis, and cytopa...

Many viruses have been investigated for their oncolytic properties and potential use as therapeutic agents for cancer treatment. Most of these replication-competent viruses are human pathogens. We investigated the oncolytic properties of an animal virus which is non pathogenic for both its natural host and humans. Bovine enterovirus has previously been shown to exhibit a very wide tissue tropis...

A cytopathic agent was isolated in a baby hamster kidney (BHK)-21 cell-line from blood samples of cross-bred sheep showing typical bluetongue symptoms at Avikanagar in Rajasthan State, India. The cytopathic agent was identified as a bluetongue virus (BTV) by immunofluorescence, the immunoperoxidase test and electron microscopy of BHK-21 cells infected with the new isolate. The new isolate was t...

The effects of four ribonucleic acid virus inhibitors were evaluated in cell cultures and in mice to determine inhibitory effects against bluetongue virus and Colorado tick fever virus (CTFV). Test compounds included 1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxamide (ribavirin), 3-deazaguanine, 3-deazauridine, and 9-(S)-(2,3-dihydroxypropyl)adenine. Ribavirin-2',3',5'-triacetate (ribavirin tr...