Resistant mutations within the hepatitis B virus reverse transcriptase sequence in treatment failure patients with chronic HBV infection in Vietnam.

OBJECTIVES: We conducted this study to describe whether mutations in the gene coding for the enzyme reverse transcriptase (RT) were related to drugs used in the treatment of hepatitis B in Vietnam. METHODS: Patients receiving antiretroviral therapy with evidence of treatment failure were included in the study. The RT fragment was cloned using the polymerase chain reaction technique after being extracted from patients' blood samples. The nucleotide sequences were analysed using Sanger method. The HBV drug resistance database contains mutations associated to resistance to existing HBV therapies. Medical records were accessed to collect information on patient parameters, such as treatment, viral load, biochemistry, and blood count. RESULTS: Resistance mutations to lamivudine, telbivudine, and entecavir were found in the highest proportion (75-91.7%) of HBV samples from patients who had failed antiretroviral therapy. Only 20.8% of HBV strains had mutations exhibiting adefovir resistance, while none had mutations conferring tenofovir resistance. M204I/V, L180M, and L80I are frequent variants linked with resistance to lamivudine, telbivudine, and entecavir. In contrast, the A181L/T/V mutation was detected predominantly in tenofovir-resistant HBV strains. Following the drug resistance mutation test, patients achieved the greatest virological response after 24 weeks of therapy with tenofovir and entecavir at a daily dose of one tablet. CONCLUSION: Lamivudine, telbivudine, and entecavir were all highly resistant to the RT enzyme modifications in 24 treatment failure patients, with M204I/V, L180M, and L80I being the most prevalent mutations. Tenofovir resistance mutations have not been found in Vietnam.

Anti-neuroinflammatory effects of alkaloid-enriched extract from Huperzia serrata on lipopolysaccharide-stimulated BV-2 microglial cells.

CONTEXT: Alkaloid-enriched extract of Huperzia serrata (Thunb.) Trevis (Lycopodiaceae) (HsAE) can potentially be used to manage neuronal disorders. OBJECTIVE: This study determines the anti-neuroinflammatory effects of HsAE on lipopolysaccharide (LPS)-stimulated BV-2 microglial cells and the underlying mechanisms. MATERIALS AND METHODS: BV-2 cells were pre- or post-treated with different concentrations of HsAE (25-150 µg/mL) for 30 min before or after LPS induction. Cell viability was assessed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and no cytotoxicity was found. Nitric oxide (NO) concentration was determined using Griess reagent. The levels of prostaglandin E2 (PGE2), tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6 were determined using enzyme-linked immunosorbent assay. The levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 and the phosphorylation of mitogen-activated protein kinase (MAPK) were analyzed using western blotting. RESULTS: HsAE reduced LPS-induced NO production with half-maximal inhibitory concentration values of 99.79 and 92.40 µg/mL at pre- and post-treatment, respectively. Pre-treatment with HsAE at concentrations of 50, 100, and 150 µg/mL completely inhibited the secretion of PGE2, TNF-α, IL-6, and IL-1ß compared to post-treatment with HsAE. This suggests that prophylactic treatment is better than post-inflammation treatment. HsAE decreased the expression levels of iNOS and COX-2 and attenuated the secretion of pro-inflammatory factors by downregulating the phosphorylation of p38 and extracellular signal-regulated protein kinase in the MAPK signaling pathway. DISCUSSION AND CONCLUSIONS: HsAE exerts anti-neuroinflammatory effects on LPS-stimulated BV-2 cells, suggesting that it may be a potential candidate for the treatment of neuroinflammation in neurodegenerative diseases.

Neuroprotective effects of total alkaloids fraction of Huperzia serrata on scopolamine-induced neurodegenerative animals.

Huperzia serrata contains Huperzine A (HupA)-an alkaloid used to treat cognitive dysfunction. In this study, we used the total alkaloids (HsAE) to investigate their potential in managing cognitive impairment in comparison with HupA. The antioxidant activity was measured by DPPH assay. In the cellular study, the cell viability and level of ACh of SH-SY5Y cells were evaluated after pretreated with HsAE and scopolamine. For in vivo assay, mice were pre-treated with HsAE, and HupA and undergone scopolamine injection for cognitive impairment. The behavioral tests including the Y-maze and Morris water maze test and the AChE activity, the SOD, CAT, MDA level in the hippocampus and cortex were evaluated. HsAE showed significant scavenging properties on DPPH radicals. HsAE was not toxic to SH-SY5Y cells, and can rescue these cells upon scopolamine treatment. Intriguingly, HsAE showed the neuroprotection against scopolamine-induced amnesia in mice. Moreover, HsAE decreased AChE activity, MDA level, increased antioxidative enzyme activity in the hippocampus as well as cortex of mice, which was relatively better than that of HupA. These findings suggested that HsAE may significantly protect the neurons of mice with scopolamine-induced memory impairment connected to AChE depletion and oxidative stress.

Mental Health Problems Among Front-Line Healthcare Workers Caring for COVID-19 Patients in Vietnam: A Mixed Methods Study.

Aim: Healthcare workers have directly provided care for COVID-19 patients, and have faced many additional sources leading to poor mental health. The study aimed to investigate the mental health problems and related factors among healthcare staff in Vietnam. Methods: A descriptive cross-sectional mixed methods study, combining quantitative and qualitative research methods, was performed among 400 healthcare workers working at the National Hospital for Tropical Diseases and Ninh Binh General Hospital from the first day of treatment for COVID-19 patients to May 01, 2020. Results: The results showed that 8.0% of participants had stress, 17.5% of participants had anxiety, and 14.8% of participants had depression. Approximately 50% of participants reported that they had at least one of these symptoms. The findings illustrated that stress, anxiety, and depression were associated with the position in a hospital, health status during the COVID-19 pandemic, family members/relatives infected with COVID-19, physical and mental support from friends, family, and community, department, years of working, and the average work hours per day of healthcare workers exposed to COVID-19. Conclusion: During the COVID-19 pandemic, healthcare workers who worked in the hospital providing treatment and care for COVID-19 patients dealt with mental health problems such as stress, anxiety, and depression. It is necessary to promote mental health among healthcare workers, to contribute to the fight against the COVID-19 outbreak in Vietnam.

Identification of NS5B Resistance-Associated Mutations in Hepatitis C Virus Circulating in Treatment Naïve Vietnamese Patients.

Introduction: Treatment of HCV infection with peginterferon and ribavirin results in a low sustained virologic response rate, but has a number of undesirable adverse effects. Direct-acting antivirals (DAAs) offer a high efficacy, low risk, and a short treatment time. However, the existence of resistance-associated mutations, particularly in the NS5B polymerase, can attenuate the efficacy of DAAs. The objective of this study was to identify amino acid changes in the NS5B gene linked to DAA resistance in treatment-naive Vietnamese chronic hepatitis C patients. Methods: Blood samples and treatment data were collected from 100 HCV-infected patients hospitalized at the National Hospital for Tropical Diseases between January and December 2020; the plasma was then isolated and stored at -80°C for molecular analysis. The NS5B gene fragments of 100 samples were amplified with specified primers and the nucleotide sequences were obtained using the Sanger sequencing system. The nucleotide sequences were then analyzed and compared to identify substitutions in the NS5B region. Results: A total of 100 HCV isolates from patients were classified into three genotypes, including genotypes 1, 3, and 6. The NS5B sequence analysis revealed many amino acid mutations in all genotypes, although these mutations were not strongly associated with resistance to DAAs like S282T. Analytical data on ribavirin-resistance mutations revealed that Q309R was predominantly found in genotype 1a, D310N was mostly found in genotype 1b, and N244I, T329I, A333E were not observed. The following mutations were shown to be related with DAAs resistance: E237G, S282R, L320F, V321A, and V321I. Furthermore, NS5B-resistance mutations were not associated with clinical characteristics, long-term virological response, or improvements in clinical parameters (liver enzymes or liver fibrosis index). Conclusion: Although NS5B mutations were found in treatment-naive Vietnamese patients, changes in the NS5B gene did not appear to be highly correlated with HCV ribavirin and DAA antiviral resistance.

Boosting with Omicron-matched or historical mRNA vaccines increases neutralizing antibody responses and protection against B.1.1.529 infection in mice

The B.1.1.529 Omicron variant jeopardizes vaccines designed with early pandemic spike antigens. Here, we evaluated in mice the protective activity of the Moderna mRNA-1273 vaccine against B.1.1.529 before or after boosting with preclinical mRNA-1273 or mRNA-1273.529, an Omicron-matched vaccine. Whereas two doses of mRNA-1273 vaccine induced high levels of serum neutralizing antibodies against historical WA1/2020 strains, levels were lower against B.1.1.529 and associated with infection and inflammation in the lung. A primary vaccination series with mRNA-1273.529 potently neutralized B.1.1.529 but showed limited inhibition of historical or other SARS-CoV-2 variants. However, boosting with mRNA-1273 or mRNA-1273.529 vaccines increased serum neutralizing titers and protection against B.1.1.529 infection. Nonetheless, the levels of inhibitory antibodies were higher, and viral burden and cytokines in the lung were slightly lower in mice given the Omicron-matched mRNA booster. Thus, in mice, boosting with mRNA-1273 or mRNA-1273.529 enhances protection against B.1.1.529 infection with limited differences in efficacy measured.

Etiologies of fever of unknown origin in HIV/AIDS patients, Hanoi, Vietnam.

BACKGROUND: Fever of unknown origin (FUO) is a challenge for clinicians treating patients with HIV/AIDS. CD4 counts can be helpful in the diagnosis and treatment. This study aimed to determine several common etiologies of FUO stratified by CD4 count levels in HIV/AIDS patients. METHODS: A cross-sectional retrospective and prospective study was conducted in 195 HIV/AIDS patients with FUO admitted to the National Hospital for Tropical Diseases from January 2016 to June 2019. Clinical parameters, immune status, and etiologies for each patient were recorded. Odds ratios were calculated to compare the distributions of common etiologies in groups with two different CD4 count levels: < 50 cells/mm3 and ≥ 50 cells/mm3. RESULTS: The proportions of opportunistic infections and noninfectious etiologies were 93.3% and 3.6%, respectively. Tuberculosis was the most common opportunistic infection (46.7%), followed by talaromycosis (29.2%) and Pneumocystis jiroveci (PCP) infection (20.5%). Tuberculosis was predominant in all CD4 level groups. Most patients with talaromycosis had CD4 counts below 50 cells/mm3. In total, 53.8% of the patients were infected by one pathogen. The risks of tuberculosis and talaromycosis in FUO-HIV patients were high when their CD4 counts were below 50 cells/mm3. CONCLUSIONS: Opportunistic infections, especially tuberculosis, are still the leading cause of FUO in HIV/AIDS patients. Tuberculosis and Talaromyces marneffei (TM) infection should be considered in patients with CD4 cell counts < 50 cells/mm3. This study implies that guidelines for appropriate testing to identify the etiology of FUO in HIV/AIDS patient based on the CD4 cell count should be developed, thereby reducing resource waste.

FLAVI: An Amino Acid Substitution Model for Flaviviruses.

Amino acid substitution models represent substitution rates among amino acids during the evolution. The models play an important role in analyzing protein sequences, especially inferring phylogenies. The rapid evolution of flaviviruses is expanding the threat in public health. A number of models have been estimated for some viruses, however, they are unable to properly represent amino acid substitution patterns of flaviviruses. In this study, we collected protein sequences from the flavivirus genus to specifically estimate an amino acid substitution model, called FLAVI, for flaviviruses. Experiments showed that the collected dataset was sufficient to estimate a stable model. More importantly, the FLAVI model was remarkably better than other existing models in analyzing flavivirus protein sequences. We recommend researchers to use the FLAVI model when studying protein sequences of flaviviruses or closely related viruses.

Adrenergic Signaling Strengthens Cardiac Myocyte Cohesion.

RATIONALE: The sympathetic nervous system is a major mediator of heart function. Intercalated discs composed of desmosomes, adherens junctions, and gap junctions provide the structural backbone for coordinated contraction of cardiac myocytes. OBJECTIVE: Gap junctions dynamically remodel to adapt to sympathetic signaling. However, it is unknown whether such rapid adaption also occurs for the adhesive function provided by desmosomes and adherens junctions. METHODS AND RESULTS: Atomic force microscopy revealed that ß-adrenergic signaling enhances both the number of desmoglein 2-specific interactions along cell junctions and the mean desmoglein 2-mediated binding forces, whereas N-cadherin-mediated interactions were not affected. This was accompanied by increased cell cohesion in cardiac myocyte cultures and murine heart slices. Enhanced desmoglein 2-positive contacts and increased junction length as revealed by immunofluorescence and electron microscopy reflected cAMP-induced reorganization of intercellular contacts. The mechanism underlying cAMP-mediated strengthening of desmoglein 2 binding was dependent on expression of the intercalated disc plaque protein plakoglobin (Pg) and direct phosphorylation at S665 by protein kinase A: Pg deficiency as well as overexpression of the phospho-deficient Pg-mutant S665A abrogated both cAMP-mediated junctional remodeling and increase of cohesion. Moreover, Pg knockout hearts failed to functionally adapt to adrenergic stimulation. CONCLUSIONS: Taken together, we provide first evidence for positive adhesiotropy as a new cardiac function of sympathetic signaling. Positive adhesiotropy is dependent on Pg phosphorylation at S665 by protein kinase A. This mechanism may be of high medical relevance because loss of junctional Pg is a hallmark of arrhythmogenic cardiomyopathy.

Contribution to a study on the iodine deficiency among Thai minority at Chieng Sinh commune, Son La province

An clinical examination and quantification of urinary iodine were performed in 1,513 Th¸i people with ages of 6-70 at Chieng Sinh commune Son La province. Results showed that the rate of goiter was 11.76% and at mild level of local goiter and the urinary iodine was at adequate level (more than microgram/dl). However, it should monitor continuously to evaluate timely the iodine deficiency

Study on synthesis of b-aminocetone derivatives of vanilline and preliminary investigation of their biological effects

By condensing azometines of vanilline and aromatic amines with acetophenon, synthesized 7 b-Aminocetones. The structure of obtained products have been characterized by elemental analyses and IR, UV spectroscopy. The compounds have been tested for antibacterial and antifungal activities. Result b-Aminocetone of vanilline have great effect in antibacterial and antifungal activities.

Study on the synthesis and bioactivities of beta-aminoceton derivatives of 5 bromo-vanilin

By the condensation of azometines, 5-bromovalline with azomatic ketones, six beta-aminoketones was formed. All compounds was tested on 10 strains of bacteria and candida albicans in vitro. The results showed that synthesized compounds had strong antibacterial and antifungal activities.

Study on synthesis of some compounds of azometine base, derivatives of vanilline and exploration of its biological effects

Synthesis research and test on biological activities of some azomethines from vanilline and 5-Nitro vanilline. 10 azomethines can be obtained by condensing vanilline and 5-Nitro Vanilline with aromatic amines such as aniline, pAB, p.Bromoe aniline, or.Toluidin, anthraniclic acid. The structures of obtained products have been characterized by element analyses and IR, UV spectroscopy. The compounds have been tested for antibacterial activities on positive gram bacteria rather than on negative ones. Azomethines of 5-Nitro vanillin have great effect in antibacterial and antifungal activities.