1.Circulation of Dengue viruses types in Ha Noi, 1998
Journal of Preventive Medicine 1998;8(3):50-52
A major epidemic of DF/DHF occurred at Ha Noi in 1998, and 3348 cases of have been reported. Serological surveillance confirmed that the epidemic of dengue fever was caused by dengue 3 and dengue 1 virus types 32/37 positive samples were dengue 3 (86.48%). Dengue virus type 3 was isolated in 6 districts of Ha Noi
Dengue Virus
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Dengue
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epidemiology
2.Procedure for rapid indentification of influenza A/H5N1 infection in NIHE, 2005
Journal of Preventive Medicine 2005;15(5):12-16
Rapid identification of influenza A virus (H5N1) is very important for endemic control and prevention. RT-PCR method proved good rapidity. The sensitivity and the specificity is needed to be improved with complete design of primer pairs.
Influenza A Virus, H5N1 Subtype
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Diagnosis
4.Oseltamivir resistance among influenza viruses: surveillance in northern Viet Nam, 2009–2012
Hoang Vu Mai-Phuong ; Nguyen Co Thach ; Nguyen Le Khanh Hang ; Nguyen Thi Kim Phuong ; Le Quynh Mai
Western Pacific Surveillance and Response 2013;4(2):26-33
Introduction: Antiviral resistance has been reported in seasonal influenza A viruses and avian influenza A(H5N1) viruses in Viet Nam, raising concerns about the efficacy of treatment.
Methods: We analysed specimens from two sources during the period 2009–2012: influenza-positive samples from influenza-like illness patients at sentinel clinics in northern Viet Nam and isolates from patients with confirmed A(H5N1) infections. Pyrosequencing was used to detect mutations: H275Y [for A(H1N1) and A(H5N1)], E119V [for A(H3N2)] and I117V [for A(H5N1)]. A neuraminidase inhibition assay was used to determine the Inhibitory Concentration 50 (IC50) values for all influenza A and B isolates.
Results: There were 341 influenza A positive samples identified; influenza A(H1N1)pdm09 was identified most frequently (n = 215). In 2009, oseltamivir resistance was observed in 100% (19 of 19) of seasonal A(H1N1) isolates and 1.4% (3/215) of A(H1N1)pdm09 isolates. This H275Y mutation was not found in influenza subtypes A(H5N1) or A(H3N2) isolates.
Discussion: In Viet Nam, seasonal and A(H5N1) influenza vaccines are not currently available; thus, effective treatment is required. The presence of oseltamivir-resistant viruses is therefore a concern. Active surveillance for oseltamivir resistance among influenza viruses circulating in Viet Nam should be continued.
5.Seroprevalence survey of avian influenza A(H5N1) among live poultry market workers in northern Viet Nam, 2011
Dung Tham Chi ; Dinh Pham Ngoc ; Nam Vu Sinh ; Tan Luong Minh ; Hang Nguyen Le Khanh ; Thanh Le Thi ; Mai Le Quynh
Western Pacific Surveillance and Response 2014;5(4):21-26
Objective:Highly pathogenic avian influenza A(H5N1) is endemic in poultry in Viet Nam. The country has experienced the third highest number of human infections with influenza A(H5N1) in the world. A study in Hanoi in 2001, before the epizootic that was identified in 2003, found influenza A(H5N1) specific antibodies in 4% of poultry market workers (PMWs). We conducted a seroprevalence survey to determine the seroprevalence of antibodies to influenza A(H5N1) among PMWs in Hanoi, Thaibinh and Thanhhoa provinces.Methods:We selected PMWs from five markets, interviewed them and collected blood samples. These were then tested using a horse haemagglutination inhibition assay and a microneutralization assay with all three clades of influenza A(H5N1) viruses that have circulated in Viet Nam since 2004.Results:The overall seroprevalence was 6.1% (95% confidence interval: 4.6–8.3). The highest proportion (7.2%) was found in PMWs in Hanoi, and the majority of seropositive subjects (70.3%) were slaughterers or sellers of poultry.Discussion:The continued circulation and evolution of influenza A(H5N1) requires comprehensive surveillance of both human and animal sites throughout the country with follow-up studies on PMWs to estimate the risk of avian–human transmission of influenza A(H5N1) in Viet Nam.
6.Sesquiterpenes from Curcuma zedoaria (Christm.) Rosc. Rhizomes and Their Alpha-Glucosidase Inhibitory Effects
Ngan Thi TRAN ; Phuong Nguyen Thi THU ; Mai-Ngan Thi LE ; Quynh-Mai Thi NGO
Natural Product Sciences 2024;30(4):300-303
Curcuma zedoaria (Christm.) Rosc. is a popular traditional herb to treat digestive disorders in Asian tropical countries. Previous studies indicated the presence of sesquiterpenoids, diterpenoids, and curcuminoids with various bioactivities. To enrich the phytocomposition data of this plant, this investigation was conducted.The dried rhizomes of C. zedoaria were collected in Hai Phong City (Vietnam), extracted with methanol and fractionated with n-hexane, CH2Cl2 , and EtOAc. Compounds were isolated from n-hexane soluble fraction by open column chromatography combined with thin layer chromatography from fraction n-hexane. Their chemical structures were elucidated by 1D, and 2D NMR spectra and comparison with reported data. As a result, a phytochemical investigation was conducted to isolate six sesquiterpenes from C. zedoaria. Their chemical structures were elucidated to be curcumenol (1), procurcumenol (2), neoprocurcumenol (3), 13-hydroxygermacrone (4), zederone (5), and curcumalactone (6). Among isolated compounds, compounds 1, 2, 4, and 5 were reported from C. zedoaria. Meanwhile, neoprocurcumenol (3) and curcumalactone (6) are isolated from this species for the first time. Compound 5 exhibited a mild inhibitory effect on α-glucosidase with an IC50 of 99.45 ± 0.50 μg/mL.
7.Sesquiterpenes from Curcuma zedoaria (Christm.) Rosc. Rhizomes and Their Alpha-Glucosidase Inhibitory Effects
Ngan Thi TRAN ; Phuong Nguyen Thi THU ; Mai-Ngan Thi LE ; Quynh-Mai Thi NGO
Natural Product Sciences 2024;30(4):300-303
Curcuma zedoaria (Christm.) Rosc. is a popular traditional herb to treat digestive disorders in Asian tropical countries. Previous studies indicated the presence of sesquiterpenoids, diterpenoids, and curcuminoids with various bioactivities. To enrich the phytocomposition data of this plant, this investigation was conducted.The dried rhizomes of C. zedoaria were collected in Hai Phong City (Vietnam), extracted with methanol and fractionated with n-hexane, CH2Cl2 , and EtOAc. Compounds were isolated from n-hexane soluble fraction by open column chromatography combined with thin layer chromatography from fraction n-hexane. Their chemical structures were elucidated by 1D, and 2D NMR spectra and comparison with reported data. As a result, a phytochemical investigation was conducted to isolate six sesquiterpenes from C. zedoaria. Their chemical structures were elucidated to be curcumenol (1), procurcumenol (2), neoprocurcumenol (3), 13-hydroxygermacrone (4), zederone (5), and curcumalactone (6). Among isolated compounds, compounds 1, 2, 4, and 5 were reported from C. zedoaria. Meanwhile, neoprocurcumenol (3) and curcumalactone (6) are isolated from this species for the first time. Compound 5 exhibited a mild inhibitory effect on α-glucosidase with an IC50 of 99.45 ± 0.50 μg/mL.
8.Sesquiterpenes from Curcuma zedoaria (Christm.) Rosc. Rhizomes and Their Alpha-Glucosidase Inhibitory Effects
Ngan Thi TRAN ; Phuong Nguyen Thi THU ; Mai-Ngan Thi LE ; Quynh-Mai Thi NGO
Natural Product Sciences 2024;30(4):300-303
Curcuma zedoaria (Christm.) Rosc. is a popular traditional herb to treat digestive disorders in Asian tropical countries. Previous studies indicated the presence of sesquiterpenoids, diterpenoids, and curcuminoids with various bioactivities. To enrich the phytocomposition data of this plant, this investigation was conducted.The dried rhizomes of C. zedoaria were collected in Hai Phong City (Vietnam), extracted with methanol and fractionated with n-hexane, CH2Cl2 , and EtOAc. Compounds were isolated from n-hexane soluble fraction by open column chromatography combined with thin layer chromatography from fraction n-hexane. Their chemical structures were elucidated by 1D, and 2D NMR spectra and comparison with reported data. As a result, a phytochemical investigation was conducted to isolate six sesquiterpenes from C. zedoaria. Their chemical structures were elucidated to be curcumenol (1), procurcumenol (2), neoprocurcumenol (3), 13-hydroxygermacrone (4), zederone (5), and curcumalactone (6). Among isolated compounds, compounds 1, 2, 4, and 5 were reported from C. zedoaria. Meanwhile, neoprocurcumenol (3) and curcumalactone (6) are isolated from this species for the first time. Compound 5 exhibited a mild inhibitory effect on α-glucosidase with an IC50 of 99.45 ± 0.50 μg/mL.
9.Sesquiterpenes from Curcuma zedoaria (Christm.) Rosc. Rhizomes and Their Alpha-Glucosidase Inhibitory Effects
Ngan Thi TRAN ; Phuong Nguyen Thi THU ; Mai-Ngan Thi LE ; Quynh-Mai Thi NGO
Natural Product Sciences 2024;30(4):300-303
Curcuma zedoaria (Christm.) Rosc. is a popular traditional herb to treat digestive disorders in Asian tropical countries. Previous studies indicated the presence of sesquiterpenoids, diterpenoids, and curcuminoids with various bioactivities. To enrich the phytocomposition data of this plant, this investigation was conducted.The dried rhizomes of C. zedoaria were collected in Hai Phong City (Vietnam), extracted with methanol and fractionated with n-hexane, CH2Cl2 , and EtOAc. Compounds were isolated from n-hexane soluble fraction by open column chromatography combined with thin layer chromatography from fraction n-hexane. Their chemical structures were elucidated by 1D, and 2D NMR spectra and comparison with reported data. As a result, a phytochemical investigation was conducted to isolate six sesquiterpenes from C. zedoaria. Their chemical structures were elucidated to be curcumenol (1), procurcumenol (2), neoprocurcumenol (3), 13-hydroxygermacrone (4), zederone (5), and curcumalactone (6). Among isolated compounds, compounds 1, 2, 4, and 5 were reported from C. zedoaria. Meanwhile, neoprocurcumenol (3) and curcumalactone (6) are isolated from this species for the first time. Compound 5 exhibited a mild inhibitory effect on α-glucosidase with an IC50 of 99.45 ± 0.50 μg/mL.
10.Sesquiterpenes from Curcuma zedoaria (Christm.) Rosc. Rhizomes and Their Alpha-Glucosidase Inhibitory Effects
Ngan Thi TRAN ; Phuong Nguyen Thi THU ; Mai-Ngan Thi LE ; Quynh-Mai Thi NGO
Natural Product Sciences 2024;30(4):300-303
Curcuma zedoaria (Christm.) Rosc. is a popular traditional herb to treat digestive disorders in Asian tropical countries. Previous studies indicated the presence of sesquiterpenoids, diterpenoids, and curcuminoids with various bioactivities. To enrich the phytocomposition data of this plant, this investigation was conducted.The dried rhizomes of C. zedoaria were collected in Hai Phong City (Vietnam), extracted with methanol and fractionated with n-hexane, CH2Cl2 , and EtOAc. Compounds were isolated from n-hexane soluble fraction by open column chromatography combined with thin layer chromatography from fraction n-hexane. Their chemical structures were elucidated by 1D, and 2D NMR spectra and comparison with reported data. As a result, a phytochemical investigation was conducted to isolate six sesquiterpenes from C. zedoaria. Their chemical structures were elucidated to be curcumenol (1), procurcumenol (2), neoprocurcumenol (3), 13-hydroxygermacrone (4), zederone (5), and curcumalactone (6). Among isolated compounds, compounds 1, 2, 4, and 5 were reported from C. zedoaria. Meanwhile, neoprocurcumenol (3) and curcumalactone (6) are isolated from this species for the first time. Compound 5 exhibited a mild inhibitory effect on α-glucosidase with an IC50 of 99.45 ± 0.50 μg/mL.