To understand the potential causes of laboratory-acquired infections and to provide possible solutions that would protect laboratory personnel, samples from a viral laboratory were screened to determine the main sources of contamination with six subtypes of Rhinovirus. Rhinovirus contamination was found in the gloves, cuffs of protective wear, inner surface of biological safety cabinet (BSC) windows, and trash handles. Remarkably, high contamination was found on the inner walls of the centrifuge and the inner surface of centrifuge tube casing in the rotor. Spilling infectious medium on the surface of centrifuge tubes was found to contribute to contamination of centrifuge surfaces. Exposure to sodium hypochlorite containing no less than 0.2 g/L available chlorine decontaminated the surface of the centrifuge tubes from Rhinovirus after 2 min.
Equipment Contamination ; statistics & numerical data ; Humans ; Laboratories, Hospital ; manpower ; standards ; statistics & numerical data ; Occupational Exposure ; analysis ; statistics & numerical data ; Virus Diseases ; virology ; Viruses ; genetics ; growth & development ; isolation & purification

In eukaryotic cells, multivesicular bodies (MVBs) are required for trafficking of membrane proteins to lysosomes for selective destruction. The sorting of ubiquitylated membrane proteins into multivesicular bodies and the biogenesis of MVBs are mediated by the endosomal sorting complex required for transport (ESCRT). Topologically equivalent to the budding of intralumenal vesicles from the limiting membrane of the MVBs, the ESCRT complex is also involved in cytokinetic abscission, phagophore formation, and enveloped virus budding. Many retroviruses and RNA viruses encode "late-domain" motifs that are able to interact with the components of the ESCRT complex, and the interactions recruit ESCRT-III and VPS4 to the viral assembly and budding sites. Recently, few studies revealed that the ESCRT complex is also required for efficient egress of some DNA viruses, including Hepatitis B, Herpes simplex virus type-1, and Autographa californica multiple nucleopolyhedrovirus. Further examination of virus-ESCRT interactions should shed light on the detailed mechanism of virus assembly and budding.
Endosomal Sorting Complexes Required for Transport ; physiology ; Humans ; Viral Envelope Proteins ; metabolism ; Virus Assembly ; Virus Physiological Phenomena ; Virus Release ; Viruses ; growth & development

RNA silencing is a conserved eukaryotic pathway involved in the suppression of gene expression via sequence-specific interactions that are mediated by 21-23 nt RNA molecules. During infection, RNAi can act as an innate immune system to defend against viruses. As a counter-defensive strategy, silencing suppressors are encoded by viruses to inhibit various stages of the silencing process. These suppressors are diverse in sequence and structure and act via different mechanisms. In this review, we discuss whether RNAi is a defensive strategy in mammalian host cells and whether silencing suppressors can be encoded by mammalian viruses. We also review the modes of action proposed for some silencing suppressors.
Animals ; Gene Expression Regulation, Viral ; Gene Silencing ; Host-Pathogen Interactions ; Humans ; Mammals ; virology ; MicroRNAs ; genetics ; metabolism ; Plant Viruses ; physiology ; Plants ; virology ; RNA, Small Interfering ; genetics ; metabolism ; Repressor Proteins ; genetics ; metabolism ; Viral Proteins ; genetics ; metabolism ; Viruses ; growth & development

PURPOSE: Although progenitor cells may contribute to intimal hyperplasia (IH) after arterial injury, positive contribution of IH is variable with type of injury or cells. This study was designed to examine whether differentiated muscle derived stem cells (MDSC) attenuate IH in rat. METHODS: MDSCs were retrieved using preplate techniques from rat calf muscle and MDSCs (preplate 6th culture fraction, pp6) were exposed to VEGF (50 ng/ml) for endothelial differentiation prior to injection. Male rats were divided into two groups (cell treated vs. control) and underwent carotid balloon injury with 2-Fr catheter. The virus containing Green fluorescent protein (GFP) gene was transfected into cells for monitoring. Cells (5x10(6)) were indwelled into carotid artery for 30 minutes after injury and then blood flow was restored. Arteries were harvested at various intervals (1, 2 and 4 weeks) after injury. The intima to media thickness ratio (IMTR) was calculated with morphometric analysis. RESULTS: Endothelial surface markers such as VE-CADHERIN were strongly expressed on differentiated MDSCs. At 4 weeks after injury, IH was predominantly observed in control group compared to cell treated group. The intensity of GFP was strongly observed at 1 week and declined at 4 weeks in carotid artery wall at MDSC group. CD31(+) endothelial cells were observed at MDSC group compared to control. The mean IMTR in cell treated groups were significantly lower than control at 2 weeks (P=0.005) and 4 weeks (P< or =0.001). CONCLUSION: Our study demonstrates that MDSCs therapy promotes re-endothelialization and leads to attenuation of IH after balloon injury in rat.
Animals ; Antigens, CD ; Arteries ; Cadherins ; Carotid Arteries ; Catheters ; Endothelial Cells ; Humans ; Hyperplasia ; Male ; Muscles ; Rats ; Stem Cells ; Vascular Endothelial Growth Factor A ; Viruses

PURPOSE: Viral infection is known as one of the dominant risk factors for wheezing in children hospitalized before 2 years of age. Although the major viral pathogen associated with wheezing is respiratory syncytial virus (RSV), the mechanisms of wheezing remain unclear. Vascular endothelial growth factor (VEGF) is a major mediator of angiogenesis and vascular permeability. The aim of this study was to evaluate the relationship between VEGF concentration and wheezing in children with acute RSV bronchiolitis. METHODS: Ninety-four children with acute bronchiolitis who were admitted to Korea University Anam Hospital were enrolled in this study. Based on the proven viral agents, children with bronchiolitis were divided into 2 groups: those who were infected with RSV (RSV (+) group, n=51) and those who were not (RSV (-) group, n=43). A complete history taking, physical examination and routine laboratory tests were performed on all children. VEGF levels in serum and nasopharyngeal aspirates (NPA) were determined by ELISA. RESULTS: NPA VEGF levels were significantly higher in the RSV (+) group than in the RSV (-) group (331.8+/-197.8 vs. 204.5+/-97.0 pg/mL, P=0.002). The duration of wheezing is significantly longer in the RSV (+) group than in the RSV (-) group (3.8+/-2.7 days vs. 2.4+/-1.8 days, P=0.037). CONCLUSION: The results of this study suggest that children with RSV bronchiolitis may have significantly higher NPA VEGF levels than those without, which may be associated with a longer duration of wheezing in those with RSV bronchiolitis.
Bronchiolitis ; Capillary Permeability ; Child ; Enzyme-Linked Immunosorbent Assay ; Humans ; Korea ; Physical Examination ; Respiratory Sounds ; Respiratory Syncytial Viruses ; Risk Factors ; Vascular Endothelial Growth Factor A ; Vascular Endothelial Growth Factors

PURPOSE: Of various effects of relaxin, we assumed that anti-fibrotic effects, neovascularization effects and vasodilatation effects of relaxin might enhance the survival rate of skin flap. In the current study, we used adenovirus expressing relaxin genes to examine whether these genes could enhance the survival rate of a skin flap. METHODS: A total of 30 Sprangue-Dawley rats were divided into three groups: RLX group (10; relaxin virus injected group), CTR group (10; no gene coded virus injection group), and PBS group (10; PBS injected group). Each group was intradermally injected with the virus (107 PFU) and PBS 48 hours before and immediately before the flap elevation. A distally based flap 3 x 9 cm in size was elevated on the dorsal aspect of each rat. Following this, a flap was placed in the original location and then sutured using a #4-0 Nylon. A surviving area of the flap was measured and then compared on postoperative days 3, 7 and 10. Using a laser Doppler, the amount of blood flow was measured. On postoperative day 10, tissues were harvested for histologic examination and the number of blood vessels was counted. RESULTS: There was a significant increase in the area of the flap survival in the RLX group on postoperative days 3 and 7. The Doppler measurement also showed significantly increased blood flow immediately after the operation and on postoperative days 7 and 10. The number of blood vessels was significantly greater in the RLX group in the tissue harvested on postoperative day 10. The VEGF concentration was significantly higher in the RLX group than others in the tissues harvested on postoperative day 10. CONCLUSION: Following an analysis of the effects of relaxin-secreting adenovirus on the survival of a flap, the surviving area of the flap and the blood flow also increased. A histopathology also showed an increase in the number of blood vessels and the concentration of VEGF.
Adenoviridae ; Animals ; Blood Vessels ; Genetic Therapy ; Nylons ; Rats ; Relaxin ; Skin ; Survival Rate ; Vascular Endothelial Growth Factor A ; Vasodilation ; Viruses

Four dsRNA bands were extracted from Pleurotus ostreatus TD300 by the dsRNA isolation technique with sizes of 8.2 kb, 2.5 kb, 2.1 kb, and 1.1 kb, respectively. Four virus-eliminated methods, i. e. hyphal tips cut (HTC), protoplast regeneration (PR), single spore hybridization (SSH), and frozen and lyophilized (FL), were applied to prepare virus-eliminated strains, and one virus-eliminated strain was selected for each virus-elimination method. The virus-eliminated strains were named as HTC8, PR15, FL01, and SSH11, respectively. There were low concentration of 8.2 kb dsRNA remained in HTC8, as well as low concentration of 8.2 kb and 2.5 kb dsRNA remained in FL01. However, no dsRNA remained in PR15 and SSH11. The hyphal growth rate and laccase activity of the virus-eliminated strains increased, especially HTC8 and PR15, whose hyphal growth rate was higher by 22.73% and 18.18%, and laccase activities higher by 145.83% and 134.38% than that of the original strain, respectively. The conclusion is that hyphal tips cut and protoplast regeneration are suitable to prepare virus-eliminated strains of edible fungi.
Food Microbiology ; Freeze Drying ; Hybridization, Genetic ; Hyphae ; virology ; Pleurotus ; cytology ; genetics ; growth & development ; virology ; Protoplasts ; virology ; RNA, Double-Stranded ; analysis ; isolation & purification ; RNA, Fungal ; analysis ; isolation & purification ; Spores, Fungal ; genetics ; virology ; Viruses ; isolation & purification

Gene Expression Regulation, Viral ; Proteomics ; methods ; trends ; Viral Proteins ; analysis ; genetics ; Viruses ; genetics ; growth & development ; metabolism

Background: Virus is one of main causes of children acute encephalitis syndrome in countries of Asia south-east. In Vietnam, apart from Japanese Encephalitis Virus which is considered as main cause of children acute encephalitis syndrome, there are other viral pathologies, of which is Nam Dinh virus. Nam Dinh virus \ufffd?a novel Arbovirus was isolated from acute encephalitis syndrome patient in northern Vietnam, 2002. The circulation of this virus has been recognized in the north, central, and highland regions. Objective: To observe the multiplication of Nam Dinh virus on the Aedes albopictus cell line clone C6/36. Materials and method: In this study the ultra-thin section method was used to observe the multiplication of the Nam Dinh virus on the Aedes albopictus cell line clone C6/36, 48 hours post-infection. Results and Conclusion: Nam Dinh encephalitis virus got used to Aedes albopictus cell line clone C6/36 and damaged cells, 24-48 hours post-infection. Its multiplication is taking place in the cytoplasm, a typical characteristic of RNA virus. Nucleocapsids of the virus were found in vacuoles of the cell. Proteincapsid of the virus was synthesized in a rough endoplasmic reticulum (rER). After assembling in the cytoplasm, the virus is released from the cell by budding and used the cell membrane as its envelope.
Viruses/growth & ; development ; Encephalitis ;

The aim was to develop a cell culture system capable of producing high titer lentiviral vector stocks with recombinant vaccinia viruses as helpers. BHK21 was co-transfected by three main plasmids containing the transducing plasmid pVECRNA, the packaging plasmid pGAGPOL and the envelop plasmid pVSVG, and thereafter infected with the vaccinia vTF-3 containing bacteriophage T7 RNA polymerase gene using Lipofectamine2000. After 4 days incubation, the culture supernatant of lentiviral vectors was collected and judged by RT-PCR and the Western blot, the results showed that lentiviral vectors were found in the culture supernatant; approximately (11.71 +/- 0.80) x 10(11) copies of lentiviral vector RNA were present per mL of cell culture supernatant, as detected by Real-time PCR; the vector stocks with titers was up to (1.3 +/- 0.18) x 10(8) tu/mL, as detected by flow cytometry , which is one order of magnitude higher than the output of classical manufacture system. These results suggest that the new poxviral/lentiviral hybrid system for efficient lentiviral vector production was initially established. It provides the basis for the future development of industrial application.
Cell Culture Techniques ; methods ; DNA-Directed RNA Polymerases ; genetics ; Genetic Vectors ; Helper Viruses ; Lentivirus ; genetics ; growth & development ; Plasmids ; genetics ; Recombination, Genetic ; Reverse Transcriptase Polymerase Chain Reaction ; methods ; Transfection ; Vaccinia virus ; genetics ; Viral Proteins ; genetics