Background: Salmonella typhi (S.typhi) is the major cause of human typhoid fever outbreaks. In fact, there were various typhoid fever outbreaks that occurred in China, and India that was caused by S.typhi strain without Vi antigen. Objective: To determine whether the S.typhi strains with mutation of gene encoding Vi antigen exists in Vietnam and the rate of mutation (if they exists). Subject and methods: 450 S.typhi isolates were collected in the Northern, Central and Southern Region of Vietnam during 1995 and 2005. The isolates were analyzed by the PCR method in order to detect mutants by using 2 primer pairs of tviB and DE. Results and Conclusion: There was no clear evidence on the relationship between the widely used Typhi Vi vaccine in Vietnam and the existence and spread of the mutation of gene encoding Vi antigen of S.typhi. 30 out of 450 isolates mutated losing the gene encoding of Vi antigen, making it 6.67%. These isolates were spread out between 1995 and 2005 throughout the Northern, Central and Southern Regions of Vietnam, with a peak in 1999. A noteworthy point was the rate of mutation of S.typhi losing the gene encoding of Vi antigen in Vietnam during the period of study. However, the mutation rate of S.typhi in Vietnam was still higher than the ratio of similar mutations being published in the other countries worldwide and higher than the recommended level of the World Health Organization.
gene mutation ; Salmonella typhi

Background: Investment to meet the man power requirements are recognized as urgent; especially to efficiently implement the National Strategy of Preventive Medicine. To strengthen the capability of provincial preventive medicine centers, the Ministry of Health has approved Decision No 05/2006QD-BYT for functions, tasks, authorization and organizational structure of Provincial Preventive Medicine Centers (PPMCs). Objectives: The study was conducted to evaluate the manpower and organization structure of northern PPMCs and provide recommendations for policy makers. Subjects and method: Using the cross-sectional descriptive method, the study covered the preventive medicine centers of 29 northern provinces between Jan to Jun 2007. The information was collected by interviews and self-reported questionnaires. Results:23/29 PPMCs have not met the criteria of man power stated in the Circular 08/2007/TTLB-BYT-BNV. Only 9/29 PPMCs were well organized in accordance with Decision 05/2006/QD-BYT of the Ministry of Health. The average number of staffs in PPMCs was 50+15. Medical staffs accounted for 53%, out of which 21.1% had postgraduate degrees; 32.2% had graduate degrees and 23.3% had been trained in preventive care. Conclusion: To meet the requirements provided by the Decision No05/2006QD-BYT, the man power and training for staffs in PPMCs should be improved and strengthened.
Man power ; Preventive medicine.

Background: DNA biosensor is based on micro-nano technologies aimed at developing a rapid diagnostic device of infectious diseases and diseases related to genetic change. Biosensors are compact size, high sensitivity and low cost\r\n', u'Objectives: To evaluate effect of biosensor in detecting specific gene fragments of Herpes Simplex virus type 1 and 2 (HSV)\r\n', u'Subjects and method: The electrical signals were recognized by means of transducer and from electrochemical detection of the hybridization between the probe 5\ufffd?AT CAC CGA CCC GGA GAG GGA C-3\ufffd?which were covalently immobilised onto the surface of micro electrodessensors in 3-aminopropyltri-ethoxysilance (APTS)-the conducting polymer matrix and the target (specific DNA sequences of HSV in the sample.\r\n', u'Results: The DNA sensor offers a very high sensitivity, a fast response time, less than 1 min with the DNA target concentration up to 1nM in aqueous media at room temperature.However, in order to detect target DNA in the real samples, samples must be extracted DNA, denatured DNA sequences from a double fiber to single fiber. The measurement should be done soon\r\n', u'Conclusion: The results show a large promise to develop quickly DNA sensors for widely application in bio-medical research \r\n', u'\r\n', u'
Biosensing Techniques ; CNBP protein ; human ;

Objective: To investigate antidiabetic and antioxidant activities of the extract and fractions from Vietnamese red seaweed Laurencia dendroidea. Methods: The seaweed Laurencia dendroidea was extracted by using microwave-assisted extraction method in 80％ methanol. The seaweed extract was then fractionated using different solvents (n-hexane, chloroform, ethyl acetate, butanol and water). These obtained fractions were evaluated for α-glucosidase inhibitory and antioxidant activities. Antioxidant activities were tested using DPPH, nitric oxide radical scavenging and metal chelating assays. The enzyme inhibition mode was determined using Lineweaver-Burk plot. For acidic and thermal stabilities, the ethyl acetate fraction was treated at pH 2.0 and 100 ℃, respectively. The residual inhibitory activity of the fraction was calculated based on the initial inhibitory activity. For in vivo antidiabetic activity, mice were divided into four groups, including normal control, diabetic control, diabetic mice treated with ethyl acetate fraction and diabetic mice treated with gliclazide. Blood glucose level of treated mice during acute and prolonged treatments was measured. To evaluate the toxicity of the ethyl acetate fraction, the body weight changes and activities of liver function enzymes (aspartate transaminase, alanine transaminase and gammaglutamyl transferase) were carried out. Results: The extract of Laurencia dendroidea showed strong α-glucosidase inhibitory and DPPH radical scavenging activities. Methanolic concentrations affected both α-glucosidase inhibitory and antioxidant activities. A 80％ aqueous methanol was the suitable solvent for extraction of enzyme inhibitors and antioxidants. Among solvent fractions, ethyl acetate fraction had the highest inhibitory activities against α-glucosidase with a mixed type of inhibition and the strongest antioxidant activities, and was stable under acidic and thermal conditions. The ethyl acetate fraction treated diabetic mice significantly reduced blood glucose level compared with the diabetic control group (13.16 mmol/L vs. 22.75 mmol/L after 3 hours of treatment). Oral administration of ethyl acetate fraction did not exhibit toxicity at a dose of 100 mg/kg body weight as determined by body weight changes and liver biochemical parameters. Conclusions: Laurencia dendroidea could be a potential source for production of antidiabetic and antioxidative agents.

Health financing has been considered as an important building block of a health system and has a key role in promoting universal health coverage in the Vietnam. This paper aims to describe the pattern of health expenditure, including total health expenditure and composition of health expenditure, over the last two decades in Vietnam. The paper mainly uses the data from Vietnam National Health Account and Vietnam Living Standards Survey. We also included data from other relevant published literature, reports and statistics about health care expenditure in Vietnam. The per capita health expenditure in Vietnam increased from US$ 14 in 1995 to US$ 86 in 2012. The total health expenditure as a share of GDP also rose from 5.2% in 1995 to 6.9% in 2012. Public health expenditure as percentage of government expenditure rose from 7.4% in 1995 to nearly 10% in 2012. The coverage of health insurance went up from 10% in 1995 to 68.5% in 2012. However, health financing in Vietnam was depending on private expenditures (57.4% in 2012). As a result, the proportion of households with catastrophic expenditure in 2012 was 4.2%. The rate of impoverishment in 2012 was 2.5%. To ensure equity and efficient goal of health system, policy actions for containing the health care out-of-pocket payments and their poverty impacts are urgently needed in Vietnam.
Developing Countries/*economics ; Financing, Government/economics/trends ; Health Expenditures/*statistics & numerical data/*trends ; *Healthcare Financing ; Insurance, Health/*economics/*trends ; Vietnam/epidemiology

Diphenyleneiodonium (DPI) has been widely used as an inhibitor of NADPH oxidase (Nox) to discover its function in cardiac myocytes under various stimuli. However, the effects of DPI itself on Ca2+ signaling and contraction in cardiac myocytes under control conditions have not been understood. We investigated the effects of DPI on contraction and Ca2+ signaling and their underlying mechanisms using video edge detection, confocal imaging, and whole-cell patch clamp technique in isolated rat cardiac myocytes. Application of DPI suppressed cell shortenings in a concentration-dependent manner (IC50 of ≅0.17 µM) with a maximal inhibition of ~70% at ~100 µM. DPI decreased the magnitude of Ca2+ transient and sarcoplasmic reticulum Ca2+ content by 20%–30% at 3 µM that is usually used to remove the Nox activity, with no effect on fractional release. There was no significant change in the half-decay time of Ca2+ transients by DPI. The L-type Ca2+ current (ICa) was decreased concentration-dependently by DPI (IC50 of ≅40.3 µM) with ≅13.1%-inhibition at 3 µM. The frequency of Ca2+ sparks was reduced by 3 µM DPI (by ~25%), which was resistant to a brief removal of external Ca2+ and Na+. Mitochondrial superoxide level was reduced by DPI at 3–100 µM. Our data suggest that DPI may suppress L-type Ca2+ channel and RyR, thereby attenuating Ca2+-induced Ca2+ release and contractility in cardiac myocytes, and that such DPI effects may be related to mitochondrial metabolic suppression.

Understanding the morphology of teeth is crucial in restorative dentistry in terms of restoring teeth’ anatomy, aesthetics, and function. Objectives: (1) this study describes an innovative method of teaching and learning tooth anatomy that applied shading techniques to 3D drawing the molar occlusal surfaces; (2) the study aims to survey learners’ opinions about the method’s effectiveness. Materials and methods: This study was conducted on 118 third-year dental students at the University of Medicine and Pharmacy, Hue University, from March to May 2022. The 3D occlusal surface drawing was developed and applied in teaching, and feedback was received from students. All statistical analysis was analyzed using SPSS version 26.0. Results: Instructions for 3D drawing were detailed and explained step-by-step, from forming to shading the occlusal surfaces. Subsequently, 57.3% - 90.9% of students self-assessed their proficiency in comprehending the characteristics of the occlusal anatomy. 73.3% - 95.8% of students agreed on the utility. 73.1% of students agreed to be willing to apply the 3D drawing method in learning other subjects. Conclusion: Instructions for 3D drawing were built step-by-step, from forming to shading the occlusal surfaces. After completing the course, a high percentage of students agreed on the advantages of this method. Further studies are needed to evaluate the effectiveness of the 3D drawing method in clinical practice

Artichoke (Cynara scolymus L.) is a perennial plant belonging to the Asteraceae family originating from the Mediterranean region. In Vietnam, there are some varieties of artichoke which are extensively cultivated and propagated in highland areas, however, there have been limited detailed scientific publications on the chemical composition and biological activity of artichoke grown in Vietnam. Therefore, this study provides a detailed description of the extraction, isolation, and structural determination of 20 natural secondary metabolites present in harvested artichoke. The antioxidant activity of the extract and the 9 isolated compounds are tested in 1,1-diphenyl-2-picrylhydrazyl radical scavenging and ex vivo malondialdehyde model. Among the selected compounds, 1-caffeoylquinic acid, 3-caffeoylquinic acid, chlorogenic acid, 4-caffeoylquinic acid, cynarin, 1,5-dicaffeoylquinic acid, 4,5-di-caffeoylquinic acid, cynaroside, and scolymoside exhibited strong radical scavenging activity with IC50 values ranging from 5.7 to 61.6 µM. In the malondialdehyde assay, 1,3-dicaffeoylquinic acid (or cynarin) showed the strongest activity with an IC50 value of 24.7 µM, followed by 1,5-di-caffeoylquinic acid (66.8 µM), and 4,5-di-caffeoylquinic acid (127.3 µM). This outcome contributes to establishing a database on the phytochemical and antioxidant activity of the Vietnamese artichoke.

Background: Viet Nam confirmed its first case of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on 23 January 2020 among travellers from Wuhan, China, and experienced several clusters of community transmission until September. Viet Nam implemented an aggressive testing, isolation, contact tracing and quarantine strategy in response to all laboratory-confirmed cases. We report the results of SARS-CoV-2 testing during the first half of 2020 in northern Viet Nam. Methods: Between January and May 2020, 15 650 upper respiratory tract specimens were collected from 14 470 suspected cases and contacts in northern Viet Nam. All were tested for SARS-CoV-2 by real-time RT-PCR. Individuals with positive specimens were tested every three days until two tests were negative. Positive specimens from 81 individuals were cultured. Results: Among 14 470 tested individuals, 158 (1.1%) cases of SARS-CoV-2 infection were confirmed; 89 were imported and 69 were associated with community transmission. Most patients (122, 77%) had negative results after two tests, while 11 and 4 still tested positive when sampled a third and fourth time, respectively. SARS-CoV-2 was isolated from 29 of 81 specimens (36%) with a cycle threshold (Ct) value <30. Seven patients who tested positive again after testing negative had Ct values >30 and negative cultures. Conclusion Early, widespread testing for SARS-CoV-2 in northern Viet Nam identified very few cases, which, when combined with other aggressive strategies, may have dramatically contained the epidemic. We observed rapid viral clearance and very few positive results after clearance. Large-scale molecular diagnostic testing is a critical part of early detection and containment of COVID-19 in Viet Nam and will remain necessary until vaccination is widely implemented.