Immunoelectron microscopy and ultrastructural studies of rotaviruses in Vero cell and primary monkey kidney cells

Background: The method of immunoelectron microscopy has been found more than 20 years. It is widely applied to detect and identify some types of virus in medical waste samples.\r\n', u'Objectives: To identify antigen location of Rota virus in organelle of the Vero cell and primary monkey kidney cells after infecting and to study the interaction between the virus and host cells.\r\n', u'Subjects and methods: The study was conducted on Rota virus G1P8 (KH0118) isolated from patients with symptoms of acute diarrhea, primary monkey kidney cells collected from Macaca mulatta monkey and the Vero cell of WHO. \r\n', u'Results: Gold particles (10nm) coated protein A and polyclonal antibodies were used to interact directly with Rotavirus proteins \r\n', u'These gold particles with high electron density revealed the antigen location of the Rota virus in the lysosome, pouch and other compartments of the cytoplasm.\r\n', u'Newly assembled viral particles could be identified only after 18-20hours post-infection. It is also noteworthy that viral particles and empty capsides (virus like particles) were comprised into cytoplasmic vesicles associated with the endoplasmic reticulum (ER)-Golgi system.\r\n', u'Conclusion: In order to better understand the interaction mechanism of virus and host cells, the use of this method together with specific monoclonal antibodies for each protein component of viruses and cells is essential.\r\n', u'\r\n', u'\r\n', u'

Study of the mutation of the CCR5 and SDF1 gene in the HIV-1 infected mothers and their children

Background: HIV (human immunodeficiency virus) is the virus that causes AIDS. This virus is passed from one person to another through blood-to-blood and sexual contact. In addition, infected pregnant women can pass HIV to their baby during pregnancy or delivery, as well as through breast-feeding. Objectives:To study the CCR5- 32 and SDF 1-3 A allelic frequence in the HIV -1 infected mothers and their children. Subjects and method: Amplificated on CCR5 and SDF1 gene by PCR and restriction of this fragment length polymorphisme (RLFP) assay for detection of the mutated gene by EcoR1 and Hpall. Results: No mutation of CCR5 was found but only mutation identified at the SDF1 gene. Mutation identified at the SDF1 gene of the mother was: homozygote 2.7% (accounted for 2/37 cases), heterozygote 40.54% (accounted for 15/37 cases) and at the children: homozygote 5.4% (accounted for 1/37 cases), heterozygote 45.95% (accounted for 17/37 cases). The CCR5 chemokin receptor is a co-receptor for M trofic HIV-1 strains, which predominate in the early stage of the HIV disease and SDF-1 natural ligand for the CXCR4 reception. The mutation of these genes protect from HIV-1 infection (slow progression).\r\n', u'Conclusion: It\u2019s necessary to find the mutation of CCR5 and CCR2b related the progression of HIV patients. \r\n', u'

Preliminary results of fetal DNA determination in maternal serum by nested PCR

Background: Prenatal diagnosis has become a standard part of obstetrics care. Genetic diagnoses are established prenatally through the sampling of fetal genetic material. So that the presence of fetal DNA in maternal plasma has led to exciting possibilities of non-invasive prenatal diagnosis. Objectives:In order to provide a reliable non-invasive method for diagnostic of the sex linked disorders. Subjects and method: Fetal gender was determined in 10 pregnant women in which 6 male fetus and 4 female fetus. They are between 34 and 36 weeks of gestation using DNA extracted from 1.6ml of each maternal serum. Maternal serum was put into vacutainer SST before delivery while two pregnant women were implemented by caesarean section at Hanoi Hospital for Obstetricts and Gynecology. Results:The 198bp SRY gene-specific sequence on Y chromosome, 261 bp ATL1 gene specific sequence on X chromosome were amplified in nested PCR. The results were confirmed by examination of newborn child after delivery.The mean level of using DNA extracted from maternal serum was 8.73 \xb1 2.36 ng/\xb5l. The mean level extracted fromperipheral blood was 66.2 \xb1 7.07 ng/\xb5l. Conclusion: The 198 bpSRY specific sequence we detected in 6 serum sample from pregnant women with male fetus. In the remaining cases bearing female foetuses only the 261 bp ATL1 gene sequence was detected. The result was completely concordant with the examination of the newborn child after delivery.

Observation of Nam Dinh virus multiplication on Aedes albopictus cell line clone C6/36 by electron microscopy

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.

Emerging a member of reoviridae family associated with acute encephalitis syndrome in Gia Lai province, 2005

Background: In recent years, some arbo viruses which causes acute encephalitis syndrome (AES) have been identified in serveral countries in the world such as Chandipura virus belonging to Rhabdoviridae family in India, Banna virus belonging to Reoviridae family in China. In Vietnam, apart from Japanese Encephalitis Virus which is considered as main cause of AES, there are a few intestinal viruses like Herpes symplex virus type 1 and 4 and Nam Dinh virus considering other causes of AES. Objective: To identify the hyppothesis that one virus strain parasitizing in mosquito in Gia Lai province causes AES in order to provide more information about virus strains which cause AES in Vietnam. Subjects and method: Aedes albopictus cell line clone C6/36 was used for the isolation of virus in 43 cerebrospinal fluid samples of patients who were treated in Gia Lai hospital, from January/2005 to July/2005. Result and Conclusion: One virus strain from a 3-year old girl in Gia Lai province was isolated in 2005. The virus coded 05VN225 has the morphology similar to other viruses belonging to Reoviridea family.The nucleic acid sequence of the virus was checked with specific primers of alphavirus and flavirus groups, Nam Dinh virus and Conti virus group B (reovirus) of the Reoviridae. The positive result was confirmed with reovirus primers. This member of the Reoviridae family was isolated from acute encephalitis syndrome in Vietnam in 2005. Further study on pathology of the virus is very necessary.

Assessment of knowledge and practices related to biosafety of researchers in microbiological laboratories of provincial centers for preventive medicine

Background: In recent years, due to the outbreak of new infectious diseases, re-emerging diseases and bio-terrorist threats, the biological safety for laboratories is essential\r\n', u'Objectives: to evaluate knowledge and practices related to biosafety of researchers in microbiological laboratories\r\n', u'Subjects and method: The study was carried out in the period 2006-2007. Questionnaires and checklists were used for the direct interview the knowledge and observe the practices related to biological safety of 97 laboratory technicians from microbiology laboratories of 22 provincial centers for preventive medicine, which represent for all areas in Vietnam.\r\n', u'Results: The percentage of technicians defines correctly the hazardous groups of some common pathogens are 8.2-33%. The percentage of technicians define correctly the transmission routes of Bacillus anthracis, Staphylococus, Streptococcus are 1%, 15% and 19.6%, respectively. The opinion that thay can wear the laboratory blouse out of laboratories, bring personal belongings into the laboratory and pipeting by mouth are 21.6%, 50.5% and 23.7%, respectively. Regarding laboratory practices: The percentage of technicians does not use gloves is 37.8%; pipeting by mouth: 22.6%. Over 40% technicians do not disinfect working area or washing hands with alcohol after experiments\r\n', u'Conclusion: The results of this study are a basis for planning programs to train, supervise and improve the operational quality of the microbiological laboratory of the provincial preventive health care centers.\r\n', u'\r\n', u'\r\n', u'

Application of the PCR technique in identification of fetal gender in amniotic liquid

Subjects: Amniotic liquids of 25-35 pregnant women in labor. Method: single blind DNA from 1.5 ml of amniotic liquid is reacted by PCR which show that the specific pair of AMELA and AMELB help for synthesis of gene TDF is decision factor for male gender belonging the short sequence of chromosome. The product of reaction will indicate the fetal gender. The correct of technique is 86.7%, and rest is false negative.