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.

Aims: Microorganisms play a vital role in the breakdown of natural organic compounds and are valuable objects for worldwide enzyme production. The aim of this study was to identify favorable production conditions for Bacillus amyloliquefaciens D19 protease, followed by the purification and chemical characterization of this novel enzyme to assess its potential applications in various fields. Methodology and results: In this study, favorable conditions of protease production from B. amyloliquefaciens D19 were determined using a medium containing soluble starch (1.5%), earthworm extract (1.0%), yeast extract (0.5%), NaCl (1.0%), at pH 7.0-8.0, 37 °C for 36 h with 150 rpm shaking condition. The protease was purified and had a molecular weight of about 23 kDa. The optimum condition for casein hydrolysis was at 40 °C and pH 6.5-7.0 in the presence of 1.0 mM Na+ or 5.0 mM Zn2+. The enzymatic activity was maintained at 75-100% at 30-50 °C and in pH 6.0-10.0. The values of Vmax and KM were also determined as 1547 U/mg and 6.33 mg/mL, respectively. Conclusion, significance and impact of study The identified optimal conditions will serve as the foundation for the production of the 23 kDa B. amyloliquefaciens D19 protease, one of the smallest proteases within the Bacillus genus. Moreover, its notable heat resistance, broad pH tolerance, high substrate catalysis and moderate substrate binding affinity make this enzyme a promising candidate for various applications in the food-feed and brewing industries.

Objective: The purpose of this study was to identify factors associated with twin pregnancy following day 3 double embryo transfer (DET). Methods: This retrospective cohort study incorporated data from 16,972 day 3 DET cycles. The participants were women aged between 18 and 45 years who underwent in vitro fertilization with intracytoplasmic sperm injection (IVF/ICSI) at My Duc Assisted Reproduction Technique Unit (IVFMD), My Duc Hospital, located in Ho Chi Minh City, Vietnam. Results: Of the 16,972 day 3 DET cycles investigated, 8,812 (51.9%) resulted in pregnancy. Of these, 6,108 cycles led to clinical pregnancy, with 1,543 (25.3% of clinical pregnancies) being twin pregnancies. Factors associated with twin pregnancy included age under 35 years (odds ratio [OR], 1.5; 95% confidence interval [CI], 1.32 to 1.71; p<0.001) and cycles involving the transfer of at least one grade I embryo. Relative to the transfer of two grade III embryos, the risk of twin pregnancy was significantly elevated following the transfer of two grade I embryos (OR, 1.40; 95% CI, 1.16 to 1.69; p<0.001) or a combination of one grade I and one grade II embryo (OR, 1.27; 95% CI, 1.05 to 1.55; p=0.001). Conclusion By analyzing a large number of IVF/ICSI cycles, we identified several predictors of twin pregnancy. These findings can assist medical professionals in tailoring treatment strategies for couples with infertility.

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.

Objectives: Survey on erectile dysfunction in patients with lumbosacral disc herniation and evaluation of their clinical improvement after surgical treatment of spinal canal stenosis due to herniated disc. Materials and Methods: 35 patients with lumbosacral were treated with discectomy with posterior intervertebral fusion (PLIF) surgery from 10/2021 - 4/2022 at the Department of Neurology, Hue University of Medicine and Pharmacy Hospital. Patients were evaluated for erectile dysfunction and postoperative improvement using the IIEF-5, CSFQ-14, DASS-21, Oswestry scales. Results: The mean age was 48.49 ± 9.15 years old. 51.4% of patients had the most severe hernia at the L4-L5 disc, 28.6% L3-L4 and 20% L5-S1. 100% of patients with herniated disc have erectile dysfunction. Of which 40% had mild-moderate disorders, 34.3% had moderate disorders, 14.3% had severe disorders and 11.4% had mild disorders. The CSFQ-14 and DASS-21 scales were correlated with erectile dysfunction (p < 0.05). Surgery significantly improved pain (VAS score), activity limitation (ODI and JOA), degree of erectile dysfunction, changes in sexual function, depression and anxiety, stress of the patient 1 month after surgery (p < 0.05). Conclusions: Patients with lumbosacral disc herniation had a 100% erectile dysfunction rate with a mean IIEF-5 score of 11.69 ± 3.77. The CSFQ-14 and DASS-21 scores have a strong positive correlation with erectile dysfunction. Surgical treatment of spinal canal stenosis due to lumbosacral disc herniation improves the clinical status of herniated disc as well as improves erectile dysfunction in these patients.

Objective: Female sex workers (FSWs) are at high risk of human papillomavirus (HPV) infections and cervical cancer due to their high number of sexual partners. The objectives of this study were to determine the prevalence of HPV and identify risk factors for high-risk HPV infection among FSWs in Hanoi and Ho Chi Minh City (HCMC), Viet Nam. Methods: A cross-sectional study was conducted in Hanoi and HCMC between December 2017 and May 2018. We surveyed and screened 699 FSWs aged ≥18 years for HPV infection and abnormal cytology. A multivariable modified Cox regression model was used to determine risk factors for high-risk HPV infection. Results The overall prevalence of any HPV, high-risk HPV and HPV-16/18 infection in the 699 FSWs was 26.3%, 17.6% and 4.0%, respectively, and were similar in both cities. Multiple infections were identified in 127 participants (69.0%).HPV-52 was the most prevalent (7%), followed by HPV-58 (6%). Abnormal cytology was detected in 91 participants (13.0%). FSWs who are divorced (adjusted prevalence ratio [aPR]: 1.96, 95% confidence interval [CI]: 1.01–3.81), widowed (aPR: 3.26, 95% CI: 1.49–7.12) or living alone (aPR: 1.85, 95% CI: 1.01–3.39) were associated with a higher prevalence of high-risk HPV infection.

Objective: This study aimed to investigate the impact of hyperandrogenism (HA) on the outcomes of ovulation induction (OI) using gonadotropin and intrauterine insemination (IUI) in patients with polycystic ovary syndrome (PCOS). Methods: This was a retrospective cohort study including 415 patients undergoing OI using gonadotropin and IUI treatment between January 2018 and December 2020 at a single infertility center. Baseline characteristics, clinical and laboratory parameters, and pregnancy outcomes were investigated. Results: Among the study population, there were 105 hyperandrogenic (25.3%) and 310 non-hyperandrogenic patients (74.7%). The live birth rate was lower in the HA group than in the non-HA group, but this difference did not reach statistical significance due to the limited sample size (14.3% vs. 21.0%, relative risk=0.68; 95% CI, 0.41–1.14, p=0.153). No predictive factors for live birth were identified through logistic regression analysis. Conclusion HA did not negatively affect the outcomes of OI using gonadotropin and IUI cycles in Vietnamese women with PCOS. The result may not be applicable elsewhere due to the large variation in the characteristics of women with PCOS across races and populations.

Ischemic diseases are conditions associated with the restriction or blockage of blood supply to specific tissues. These conditions can cause moderate to severe complications in patients, and can lead to permanent disabilities. Since they are blood vessel-related diseases, ischemic diseases are usually treated with endothelial cells or endothelial progenitor cells that can regenerate new blood vessels. However, in recent years, mesenchymal stem cells (MSCs) have shown potent bioeffects on angiogenesis, thus playing a role in blood regeneration. Indeed, MSCs can trigger angiogenesis at ischemic sites by several mechanisms related to their trans-differentiation potential. These mechanisms include inhibition of apoptosis, stimulation of angiogenesis via angiogenic growth factors, and regulation of immune responses, as well as regulation of scarring to suppress blood vessel regeneration when needed. However, preclinical and clinical trials of MSC transplantation in ischemic diseases have shown some limitations in terms of treatment efficacy. Such studies have emphasized the current challenges of MSC-based therapies. Treatment efficacy could be enhanced if the limitations were better understood and potentially resolved. This review will summarize some of the strategies by which MSCs have been utilized for ischemic disease treatment, and will highlight some challenges of those applications as well as suggesting some strategies to improve treatment efficacy.