No abstract available.
Animals* ; Viruses*

Genotypes of hepatitis C virus are clinically relevant to epidemiology, prognosis and therapeutical management of HCV infection. Our study aims to compare different methods for HCV genotyping. Hepatitis C genotypes and subtypes of infected patients in Ho Chi Minh city was determined by serological typing using HCV serotyping 1-6 (Murex company), by molecular typing using Innolipa HCV II assay (Innogenetics NY) and direct sequencing of core and NS5b region. Our results show that the hepatitis C virus by analysing the sequences of the core and NS5b regions gave concordant results. The NS5b region is reliable for the identification of HCV subtype 6 circulating in Viet Nam.
Hepacivirus ; Viruses

Haemagglutination Inhibition Technique was applied to study conversion anti-Japanese encephalitis (JE) virus antibodies in pigs in Hoai Duc, Ha Tay, in 2002. The results showed that antibody conversion in pigs occurs year-round. Vero and C6/36 cells were used to isolate JE virus. From 83 mosquito pools and 30 pig blood samples, 7 JE viruses strains were isolated from mosquito pools, and 4 JE viruses strains were isolated from pig blood samples. These JE viruses strains were isolated either in the epidemic or in the non epidemic season. Sequencing of E gene region of JE virus strains that were isolated from mosquitoes and pigs, circulating of genotype I of JE virus in North Vietnam in 2002
Encephalitis Virus, Japanese ; Encephalitis Viruses ; Encephalitis ; Viruses

No abstract available.
Bronchiolitis ; Respiratory Syncytial Viruses

The integrated cell culture-PCR (ICC-PCR) method has been suggested as an improved method for detection of viruses in water environments. We tested 57 source waters including finished water samples in Gyeonggi-do for enteric viral contamination using total culturable virus assay (TCVA) using BGMK cells and ICC-PCR. Nineteen of the 57 source water samples (33.3%) exhibited the cytopathic effect (CPE) on BGMK cells and no finished water did exhibited CPE. Nineteen samples (33.3%) of the 57 were positive for reoviruses. For the enteroviruses, only 3 samples (5.3%) of the 57 samples showed positive results. By using ICC-PCR method, 202 flasks from source water samples were positive for enteroviruses and reoviruses. Three samples from source water were positive for both viruses. However, any flasks tested was not co-infected with two types of viruses. While the enteric viral frequencies in TCVA and ICC-PCR were similar, the viral frequency for reoviruses at first passage in two type of method was higher in ICC-PCR (94.7%) than TCVA (56.9%).
Enterovirus ; Viruses ; Water

Natural killer (NK) cells play a pivotal role in early surveillance against virus infection and cellular transformation, and are also implicated in the control of inflammatory response through their effector functions of direct lysis of target cells and cytokine secretion. NK cell activation toward target cell is determined by the net balance of signals transmitted from diverse activating and inhibitory receptors. A distinct feature of NK cell activation is that stimulation of resting NK cells with single activating receptor on its own cannot mount natural cytotoxicity. Instead, specific pairs of co-activation receptors are required to unleash NK cell activation via synergy-dependent mechanism. Because each co-activation receptor uses distinct signaling modules, NK cell synergy relies on the integration of such disparate signals. This explains why the study of the mechanism underlying NK cell synergy is important and necessary. Recent studies revealed that NK cell synergy depends on the integration of complementary signals converged at a critical checkpoint element but not on simple amplification of the individual signaling to overcome intrinsic activation threshold. This review focuses on the signaling events during NK cells activation and recent advances in the study of NK cell synergy.
Killer Cells, Natural ; Viruses

No abstract available.
Hepatitis Viruses* ; Hepatitis*

In 2004, 10 poliovirus strains were isolated from 4 acute flaccid paralytic cases (AFP). All these poliovirus strains were confirmed as Sabin-like strains. 66 other non-polio enterovirus strains were also isolated including 29 echoviruses, coxsackie B viruses and 30 untyped enteroviruses. These virus strains were isolated from 489 stool specimens of 245 AFP cases. The results confirmed the free status of the stable sustaining poliomyelitis in Viet nam.
Viruses ; Enterovirus ; Poliomyelitis, Patients

17 wild-type measles strains were isolated from both sporadic cases and 4 outbreaks in the Northern, Centre, and Highland areas of Vietnam in 2000-2002. The sequence analysis of 450 nucleotides of the most variable COOH- terminus of N gene showed that established in the year 2000 with the representative of MVi/Beijing.CHI/9411, genotype H2 (Clade H) continued circulating in the North and Highland of Vietnam. This study also revealed that wild-type measles strains circulating in the Center fell into genotype HI (Clade H) with the representative of MVi/Hunan.CHI/93. It was the first time that genotype HI was discovered In Vietnam. The difference within each genotype is bigger, nevertheless, no more than 3.0% at nucleotide level. The wild-type strain isolated in Lai Chau belonging to genotype D5 (Clade D) has imported into Vietnam from Thailand was under consideration.
Measles ; Viruses ; Diagnosis

From 2000ml supernatant fluid of infected Aedes albopictus cells clone C6/36, Nam Dinh virus antigen was prepared by ultracentrifuge generating 5ml purified antigen. Protein content of the purified antigen is 4.4 mg/ml and antigen titer stabilizes for two years at - 80oC. The purified antigen was used for detecting IgM against Nam Dinh virus in cerebrospinal fluid from acute encephalitis syndrome patients by indirect IgM-ELISA. The examination of 814 cerebrospinal fluid samples of acute encephalitis syndrome, which were confirmed non-Japanese encephalitis during 1998 - 2004. The positive proportion with Nam Dinh virus antigen has been found to be 6.59 % - 20.06%. Most of positive cases in children were under 15 years old. Acute encephalitis syndrome cases due to Nam Dinh virus mainly occurred in May, June and July, in the same season of Japanese encephalitis in the Northern area of Vietnam.
Antigens ; Encephalitis ; Viruses ; Diagnosis