Aims: The objective of the study was to isolate bacteriophages and conduct a comprehensive analysis of their potential against Xanthomonas oryzae pv. oryzae (Xoo) strains in the Mekong Delta, Vietnam. Methodology and results: Twelve Xoo strains were isolated from rice fields located in the Mekong Delta, Vietnam. Among these strains, three strains Xoo L019, L020 and L024, showed the highest disease index of bacterial blight. Four phages specific to Xoo were isolated from soil, water and leaf samples, and their morphologies were determined. In a test against 12 Xoo strains, phage L541, MLA23 or W41 could infect 10 of the 12 Xoo strains, while phage LBH01 could infect 8 of the 12 Xoo strains. The stability of the phages to pH, organic solvents, UV-A and UV-B was also evaluated. Conclusion, significance and impact of study The initial characterization of the phages indicates their potential as biocontrol agents against bacterial blight in rice. The study is one of the very first studies about Xoo phages in rice in Vietnam.

Background: Anaplastic lymphoma kinase (ALK) mutations have been identified as a prominent cause of some familial and sporadic neuroblastoma (NB). ALK expression in NB and its relationship with clinical and histopathological features remains controversial. This study investigated ALK expression and its potential relations with these features in NB. Methods: Ninety cases of NB at the Department of Pathology, University of Medicine and Pharmacy at Ho Chi Minh City, Viet Nam from 01/01/2018 to 12/31/2021, were immunohistochemically stained with ALK (D5F3) antibody. The ALK expression and its relations with some clinical and histopathological features were investigated. Results: The rate of ALK expression in NB was 91.1%. High ALK expression (over 50% of tumor cells were positive with moderate-strong intensity) accounted for 65.6%, and low ALK expression accounted for 34.4%. All the MYCN-amplified NB patients had ALK immunohistochemistry positivity, most cases had high ALK protein expression. The undifferentiated subtype of NB had a lower ALK-positive rate than the poorly differentiated and differentiated subtype. The percentages of ALK positivity were significantly higher in more differentiated histological types of NB (p = .024). There was no relation between ALK expression and: age group, sex, primary tumor location, tumor stage, MYCN status, clinical risk, Mitotic-Karyorrhectic Index, prognostic group, necrosis, and calcification. Conclusions ALK was highly expressed in NB. ALK expression was not related to several clinical and histopathological features. More studies are needed to elucidate the association between ALK expression and ALK gene status and to investigate disease progression, especially the oncogenesis of ALK-positive NB.

Background: The identification of idiopathic inflammatory myopathies (IIMs) requires a comprehensive analysis involving clinical manifestations and histological findings. This study aims to provide insights into the histopathological and immunohistochemical aspects of IIMs. Methods: This retrospective case series involved 56 patients diagnosed with IIMs at the Department of Pathology, University of Medicine and Pharmacy at Ho Chi Minh City, from 2019 to 2023. The histology and immunohistochemical expression of HLA-ABC, HLA-DR, C5b-9, Mx1/2/3, and p62 were detected. Results: We examined six categories of inflammatory myopathy, including immunemediated necrotizing myopathy (58.9%), dermatomyositis (DM; 23.2%), overlap myositis (8.9%), antisynthetase syndrome (5.4%), inclusion body myositis (IBM; 1.8%), and polymyositis (1.8%). The average age of the patients was 49.7 ± 16.1 years, with a female-to-male ratio of 3:1. Inflammatory cell infiltration in the endomysium was present in 62.5% of cases, perifascicular atrophy was found in 17.8%, and fiber necrosis was observed in 42 cases (75.0%). Rimmed vacuoles were present in 100% of cases in the IBM group. Immunohistochemistry showed the following positivity rates: HLA-ABC (89.2%), HLA-DR (19.6%), C5b-9 (57.1%), and Mx1/2/3 (10.7%). Mx1/2/3 expression was high in DM cases. p62 vacuole deposits were noted in the IBM case. The combination of membrane attack complex and major histocompatibility complex I helped detect IIMs in 96% of cases. Conclusions The diagnosis of IIMs and their subtypes should be based on clinical features and histopathological characteristics. Immunohistochemistry plays a crucial role in the diagnosis and differentiation of these subgroups.

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.

Purpose: Although some immune protection from close contact with individuals who have coronavirus disease 2019 (COVID-19) has been documented, there is limited data on the seroprevalence of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in individuals who were in lockdown with confirmed COVID-19 cases. This study investigated immunogenicity against SARS-CoV-2 in household members and people who lived near home-quarantined patients with COVID-19. Materials and Methods: This cross-sectional study was conducted during the community-based care that took place during lockdowns in District 10, Ho Chi Minh City, Vietnam from July to September 2021. SARS-CoV-2 antibody levels were determined in index cases of COVID-19, household contacts, and a no-contact group from the same area. Results: A total of 770 participants were included (355 index cases, 103 household contacts, and 312 no contacts). All index cases were unvaccinated, but >90% of individuals in the household and no-contact groups had received ≥1 vaccine dose. SARS-CoV-2 neutralizing antibodies (Nabs) were present in >77% of unvaccinated index cases versus 64%/65.4% in the householdo-contact groups (p=0.001). Antibody concentrations in unvaccinated index cases were significantly higher than those in household contacts and no contacts, with no difference between the latter groups. In all cases, antibody levels declined markedly ≥6 weeks after infection, and failed to persist beyond this time in the household and no-contact groups. Conclusion Community-based care may have helped to create community immunogenicity, but Nabs did not persist, highlighting a need for vaccination for all individuals before, or from 6 weeks after, infection with SARS-CoV-2.

Objective: To explore the correlation of 24-hour ambulatory blood pressure (BP) monitoring (ABPM) parameters and cardiovascular risk factors in older adults with high-risk hypertension. Material and method: A cross-sectional study was conducted on 96 older adults (≥ 60 years old) with treated high-risk hypertension. Socio-demographic and cardiovascular risk information were gathered. The patients were performed 24-hour ABPM. Results: The mean age was 70.88 ± 7.86 years, and 64.6% were women. The prevalence of cardiovascular risk factors was as follows: dyslipidemia: 80.2%, family history of hypertension: 54.2%, diabetes mellitus: 51%, smoking: 24%, prior stroke: 11.5%. Significant differences in 24-hour, awake, and sleep systolic BP were observed between men and women. There were significant correlations between 24-hour mean systolic BP with age (r = 0.229, p = 0.025), dyslipidemia (r = 0.223, p = 0.029), family history of hypertension (r = 0.214, p = 0.036), BMI (r = 0.212, p = 0.039), waist circumference (r = 0.226, p = 0.027) and creatinine level (r = 0.207, p = 0.043). There were significant correlations between 24-hour mean diastolic BP with BMI (r = 0.289, p = 0.004) and prior stroke (r = -0.224, p = 0.029). There were significant correlations between 24-hour mean BP with BMI (r = 0.268, p = 0.009), waist circumference (r = 0.220, p = 0.032) and prior stroke (r = -0.215, p = 0.036). Conclusion: There were significant correlations between ABPM parameters and cardiovascular risk factors in older adults with high-risk hypertension.

Background: Little is known about the burden of hair loss following coronavirus disease 2019 (COVID-19) infection in older adults. This study investigated the prevalence and associated factors of hair loss in older outpatients in Vietnam. Materials and methods: Between March 2022 and July 2022, this multicenter cross-sectional study included 547 older patients (aged ≥ 60 years; mean age 68.5 ± 6.9 years; men 27.1%) from three post-COVID-19 clinics. Factors associated with hair loss were assessed using logistic regression. Results: In total, 63 patients (11.5%) experienced hair loss. All of the patients with hair loss exhibited diffuse type. In the adjusted model, factors associated with hair loss were women (odds ratio [OR], 3.36; 95% confidence interval [CI], 1.43 - 7.89; P = 0.005), single or divorced in marital status (OR, 3.27; 95% CI, 1.33 - 8.02; P = 0.01), and history of COVID-19 related hospitalization (OR, 5.17; 95% CI, 2.44 - 10.95; P < 0.001). Conclusion: Our study found a substantial prevalence of post-COVID-19 hair loss in older outpatients.

In this study, twenty-five yeast strains were isolated from soil samples collected in the gold mining ore in Gia Lai, Vietnam. Among them, one isolate named GL1 T could highly tolerate Cu 2+ up to 10 mM, and the isolates could also grow in a wide range of pH (3–7), and tem perature (10–40 ℃). Dried biomass of GL1 was able to remove Cu 2+ effectively up to 90.49% with a maximal biosorption capacity of 18.1 mg/g at pH 6, temperature 30 ℃, and incuba tion time 60 min. Sequence analysis of rDNA indicated this strain was closely related to Rhodotorula mucilaginosa but with 1.53 and 3.46% nucleotide differences in the D1/D2 domain of the 28S rRNA gene and the ITS1-5.8S rRNA gene-ITS2 region sequence, respect ively. Based on phylogenetic tree analysis and the biochemical characteristics, the strain appears to be a novel Rhodotorula species, and the name Rhodotorula aurum sp. nov. is pro posed. This study provides us with more information about heavy metal-tolerant yeasts and it may produce a new tool for environmental control and metal recovery operations.

COVID-19 ; Humans ; Kidney Transplantation ; Retrospective Studies ; SARS-CoV-2 ; Transplant Recipients

Objective: To assess the acceptance of coronavirus disease (COVID-19) vaccine among healthcare workers at two general hospitals in Vietnam when it is available. Methods: A cross-sectional study was conducted using a convenience sampling from January to February 2021 among 410 healthcare workers at two general hospitals in Vietnam via a self-administered questionnaire. A multivariable regression analysis was performed to determine predictors of vaccine acceptance including the demographic factors, COVID-19 knowledge, and vaccine beliefs based on the domains of Health Belief Model. Results: Among 410 healthcare workers, 76.10% showed vaccination willingness. Predictors of acceptance were determined that the group reporting as 'vaccine acceptance' was more likely to be positive towards the perceived susceptibility and severity of COVID-19 (OR 2.45; 95% CI 1.48-4.06, P<0.05), perceived benefits of vaccination, and cues to action (OR 4.36; 95% CI 2.35-8.09, and OR 5.49; 95% CI 2.84-10.61, respectively, all P<0.001), but less likely to have the perceived barriers to vaccination (OR 0.19; 95% CI 0.09-0.38; P<0.001) compared with the no acceptance group. Besides, people who had a good knowledge regarding the severity of illness were 3.37 times more likely to have identified as vaccine acceptance (OR 3.37; 95% CI 1.04-10.86, P<0.05). The demographic factors were also associated with willingness to receive the vaccine, with participants who were staff and received COVID-19 information from relatives were less likely to accept the vaccine over those who were doctors and not receiving information from relatives (OR 0.36; 95% CI 0.13-0.96, and OR 0.37; 95% CI 0.17-0.78, respectively, all P<0.05). Conclusions: A rate of willingness to get vaccinated against COVID-19 was relatively high with discrepancies between occupation, receiving information from relatives, knowledge toward the severity of illness, and the elements of Health Belief Model. The findings will provide information for the management authorities to develop relevant interventions to promote COVID-19 vaccination uptake.