Dengue virus serotypes and related factors in children with dengue hemorrhagic fever in Southern Vietnam.

INTRODUCTION: After the Coronavirus Disease 2019 pandemic, a high number of cases and severe dengue in children were reported in some provinces in the south of Vietnam. This study aimed to determine the distribution of dengue virus serotypes and their correlation with demographic factors, disease severity, clinical manifestations, and laboratory findings. METHODOLOGY: This study employed a cross-sectional design. Ninety-six dengue-infected children admitted to Can Tho Children's Hospital between October 2022 and March 2023 were included. Confirmation of dengue infection was achieved through the real-time polymerase chain reaction (RT-PCR). RESULTS: Among the identified serotypes, DENV-2 accounted for the highest proportion (71.87%), followed by DENV-1 (23.96%), and DENV-4 (4.17%). DENV-3 was not detected. No significant demographic, disease severity, or laboratory differences were observed among the identified dengue serotypes. However, DENV-2 was associated with a higher occurrence of mucous membrane hemorrhages and gastrointestinal bleeding compared to other serotypes. CONCLUSIONS: Although DENV-2 was the most prevalent serotype responsible for dengue in children in southern Vietnam, it did not lead to more severe cases compared to other serotypes. This finding is crucial for evaluating the illness's prognosis.

Common Adverse Events from Mixing COVID-19 Vaccine Booster in Hanoi, Vietnam.

BACKGROUND: Mixing vaccines was proposed as a solution to tackle supply chain interruptions during the crisis of the COVID-19 pandemic. This study aimed to investigate the safety of mixing COVID-19 vaccines for a booster dose in Hanoi, Vietnam. METHOD: A cross-sectional study was conducted via a telephone-based interview to identify the adverse events following COVID-19 vaccination among 719 participants in Hanoi, Vietnam. RESULTS: In total, 45.76% of participants experienced at least one adverse event following two doses of the COVID-19 vaccine. Most of the adverse events were local effects with mild symptoms such as fever, headache, muscle pain, and/or pain at the site. In general, matching two doses in the same vaccines was not associated with the adverse events as compared to mixing vaccines (OR = 1.43, 96%CI: 0.93-2.2), except matching two doses of Pfizer (OR = 2.25, 95%CI: 1.33-3.82). CONCLUSION: The findings of this study suggest the overall safety of mixed vaccination. In light of the vaccine shortage, mixing vaccinations for COVID-19 prevention is a good solution. Further studies with larger cohorts and investigating immunity following mixing vaccines are needed to elucidate the mechanism.

Impact of heat-moisture and annealing treatments on physicochemical properties and digestibility of starches from different colored sweet potato varieties.

The objective of this study is to investigate the change in physicochemical properties and digestibility of starches isolated from colored sweet potato varieties under heat-moisture treatment (HMT) or annealing treatment (ANN). The results showed that morphology and X-ray diffraction patterns of the sweet potato starches remained unchanged after the HMT or ANN. The HMT significantly reduced peak viscosity, breakdown and setback and significantly increased pasting temperature, trough and final viscosities of the sweet potato starches. The swelling powers and solubility of the heat-moisture treated starches were significantly lower than those of the native or annealed starches. The decreased rapid digestible starch and the increased slowly digestible and resistant starch contents of the sweet potato starches after HMT or ANN as compared to those of the native starches were observed. The resistant starch (RS) contents of the heat-moisture treated sweet potato starches were in a range of 30.6-39.3%, significantly higher than those of the annealed starches (28.8-32.0%). The strong impact of the HMT on physicochemical properties and RS formation of the sweet potato starches compared to the ANN might be due to the high stability of the occurred interactions between starch molecules and amylopectin chains during treatment.

Resistant starch improvement of rice starches under a combination of acid and heat-moisture treatments.

The effects of a combination of acid and heat-moisture treatment on formation of resistant starch (RS) and characteristics of high-amylose, normal and waxy rice starches were investigated in this study. The degrees of polymerization of the rice starches treated with citric acid, lactic acid or acetic acid were significantly reduced as compared to the native starches. The RS contents of acid and heat-moisture treated rice starches were in a range of 30.1-39.0%, significantly higher than those of native rice starches (6.3-10.2%) and those of heat-moisture treated rice starches (18.5-23.9%). The acid and heat-moisture treatments reduced swelling power and viscosity, but increased solubility of the starches, while the crystalline structure did not change. Among the organic acids used, citric acid had the most impact on starch characteristics and RS formation, followed by lactic acid and acetic acid. The results are useful in production of RS for functional food application.

Effects of germination on nutritional composition of waxy wheat.

BACKGROUND: Germination is considered to improve the nutritive value, antioxidant capacity and functional properties of grains. In this study, changes in the chemical composition, nutritive value and antioxidant capacity of waxy wheat during germination were determined. RESULTS: Over a 48 h period of germination the protein and free lipid contents of germinated waxy wheat were not significantly different from those of the control, whereas the bound lipid content decreased significantly. An increase in levels of ash and dietary fibre was clearly observed for the 48 h-germinated wheat. The total free amino acid content of the 48 h-germinated wheat was 7881 mg kg⁻¹ flour (dry basis (d.b.)), significantly higher than that of the ungerminated wheat (2207 mg kg⁻¹ flour, d.b.). In particular, γ-aminobutyric acid increased from 84 mg kg⁻¹ flour (d.b.) in the control to 155 mg kg⁻¹ flour (d.b.) in the 48 h-germinated wheat. Germination did not significantly affect the fatty acid composition of both free and bound lipids of waxy wheat, whereas free phenolic compounds increased during germination, resulting in an increase in antioxidant capacity of germinated wheat. CONCLUSION: Germinated waxy wheat had a better nutritional composition, such as higher dietary fibre, free amino acid and total phenolic compound contents, than ungerminated waxy wheat. Therefore germinated waxy wheat should be used to improve the nutritional quality of cereal-based products.

Phenolic acid composition of sprouted wheats by ultra-performance liquid chromatography (UPLC) and their antioxidant activities.

The phenolic acid profiles of flours from two Canadian wheat classes, Canadian Western Red Spring (CWRS) and Canadian Western Amber Durum (CWAD), were investigated using two different extraction mediums and analysed on an ultra-performance liquid chromatography (UPLC) system at different degrees of sprout damage. A sound (non-sprouted) control sample as well as two different sprouted sub-samples, derived from different germination protocols of the control, were prepared for both the CWAD and CWRS. Free phenolic acids were extracted from the ground whole wheat meal using three repetitive 80% ethanol extractions. Bound phenolic compounds were subsequently released from the residue by alkaline hydrolysis followed by triplicate extraction with diethyl ether:ethyl acetate (1:1, v/v). Twelve phenolic acid standards were clearly resolved and quantified using a short 5min elution gradient. Seven phenolic acids (4-hydroxybenzoic, vanillic, caffeic, syringic, p-coumaric, ferulic and sinapic) were detected in the CWRS and CWAD alcoholic and alkaline extracts. Syringic acid was the main compound in the free phenolic alcoholic extracts of the wheat meal representing 77.0% and 75.3% of the total amount of detected free phenolic compounds for CWRS and CWAD, respectively. However, the major released phenolic compound detected in the alkaline hydrolysed extracts was ferulic acid accounting for 72.3% and 71.0% for CWRS and CWAD respectively total bound phenolics. During germination, syringic acid levels rose as the length of germination time increased, resulting in the increase in total phenolic compound and antioxidant activity of the sprouted wheat flours. There was an increase in total phenolic compounds and the antioxidant activity of the alcoholic extracts from the CWRS and CWAD wheat flours as the germination time was extended. As a result, the sprouted wheats exhibits better nutritional properties than un-germinated wheat and could be used to improve the nutrition value in food products.

Distribution of phenolic compounds in the graded flours milled from whole buckwheat grains and their antioxidant capacities.

Whole buckwheat grains were milled into 16 flour fractions using the gradual milling system and the phenolic compounds and the antioxidant capacity of each flour fraction were investigated. The phenolic and flavonoid contents of both free and bound phenolic extracts of buckwheat flour fractions significantly increased in the order from the fraction number 1 (phenolics less rich fraction) to the fraction number 16 (phenolics rich fraction). The phenolic compounds in buckwheat existed primarily in free form, whereas the flavonoids existed in grain in insoluble bound forms, bound to cell wall materials. The amounts of ferulic acid and rutin increased from 2.5 and 2.5µg/g flour of the phenolics less rich fraction to 609.5 and 389.9µg/g flour of the phenolics rich fraction of grain, respectively. The higher phenolic contents in the phenolics rich fractions exhibited the stronger antioxidant capacity than the phenolics less rich fractions. As a result, the flour milled from the outer layers of buckwheat grains with large amount of phenolic compounds and antioxidant capacity are considered to have significant health benefits.

Sequences of clustered epitopes in Gag and Nef potentially presented by predominant class I human leukocyte antigen (HLA) alleles A and B expressed by human immunodeficiency virus type 1 (HIV-1)-infected patients in Vietnam.

The aim of this study was to define pluriepitopic regions in Gag and Nef possibly relevant in the perspective of a vaccine design in a vietnamese population. The protein sequences derived from gag and nef genes and phenotyping of the class I human leukocyte antigens (HLA) A and B alleles were established for 28 human immunodeficiency virus type 1 (HIV-1)-infected patients from Ho Chi Minh City, Vietnam. The protein sequences display polymorphism mutations as compared with a B reference strain (HXB2). The most frequently represented HLA-A and -B alleles were HLA-A11, A02, and A33 expressed by 35.7, 23.2, and 21.4% of the patients, respectively, and HLA-B75, B46, and B62 expressed by 35.7, 25, and 17.9% of the patients, respectively. This study allows us to determine four pluriepitopic regions in Gag and Nef that should be chosen for a vaccine design in a Vietnamese population.

HIV type 1 isolates from 200 untreated individuals in Ho Chi Minh City (Vietnam): ANRS 1257 Study. Large predominance of CRF01_AE and presence of major resistance mutations to antiretroviral drugs.

HIV-1 isolates from 200 untreated patients recruited in 2001 and 2002 in the south part of Vietnam and particularly in Ho Chi Minh City were sequenced in the RT, protease, and env genes. Out of 200 isolates 198 belonged to CRF01_AE while only one subtype B and one intersubtype (B-CRF01_AE) recombinant could be observed. Of the isolates 6.5% had major resistance mutations to antiretroviral drugs.