Environmental Factors Modulate Saxitoxins (STXs) Production in Toxic Dinoflagellate Alexandrium: An Updated Review of STXs and Synthesis Gene Aspects.

The marine dinoflagellate Alexandrium is known to form harmful algal blooms (HABs) and produces saxitoxin (STX) and its derivatives (STXs) that cause paralytic shellfish poisoning (PSP) in humans. Cell growth and cellular metabolism are affected by environmental conditions, including nutrients, temperature, light, and the salinity of aquatic systems. Abiotic factors not only engage in photosynthesis, but also modulate the production of toxic secondary metabolites, such as STXs, in dinoflagellates. STXs production is influenced by a variety of abiotic factors; however, the relationship between the regulation of these abiotic variables and STXs accumulation seems not to be consistent, and sometimes it is controversial. Few studies have suggested that abiotic factors may influence toxicity and STXs-biosynthesis gene (sxt) regulation in toxic Alexandrium, particularly in A. catenella, A. minutum, and A. pacificum. Hence, in this review, we focused on STXs production in toxic Alexandrium with respect to the major abiotic factors, such as temperature, salinity, nutrients, and light intensity. This review informs future research on more sxt genes involved in STXs production in relation to the abiotic factors in toxic dinoflagellates.

Polyphyletic origin of saxitoxin biosynthesis genes in the marine dinoflagellate Alexandrium revealed by comparative transcriptomics.

The marine dinoflagellate Alexandrium is known to form harmful algal blooms, and at least 14 species within the genus can produce saxitoxins (STXs). STX biosynthesis genes (sxt) are individually revealed in toxic dinoflagellates; however, the evolutionary history remains controversial. Herein, we determined the transcriptome sequences of toxic Alexandrium (A. catenella and A. pacificum) and non-toxic Alexandrium (A. fraterculus and A. fragae) and characterized their sxt by focusing on evolutionary events and STX production. Comparative transcriptome analysis revealed higher homology of the sxt in toxic Alexandrium than in non-toxic species. Notably, non-toxic Alexandrium spp. were found to have lost two sxt core genes, namely sxtA4 and sxtG. Expression levels of 28 transcripts related to eight sxt core genes showed that sxtA, sxtG, and sxtI were relatively high (>1.5) in the toxic group compared to the non-toxic group. In contrast, the non-toxic group showed high expression levels in sxtU (1.9) and sxtD (1.7). Phylogenetic tree comparisons revealed distinct evolutionary patterns between 28S rDNA and sxtA, sxtB, sxtI, sxtD, and sxtU. However, similar topology was observed between 28S rDNA, sxtS, and sxtH/T. In the sxtB and sxtI phylogeny trees, toxic Alexandrium and cyanobacteria were clustered together, separating from non-toxic species. These suggest that Alexandrium may acquire sxt genes independently via horizontal gene transfer from toxic cyanobacteria and other multiple sources, demonstrating monocistronic transcripts of sxt in dinoflagellates.

Two novel glutathione S-transferase (GST) genes in the toxic marine dinoflagellate Alexandrium pacificum and their transcriptional responses to environmental contaminants.

The present study identified two novel glutathione S-transferase (GST) genes from the toxic dinoflagellate Alexandrium pacificum and examined their molecular characteristics and transcriptional responses to algicides and environmental contaminants. Bioinformatic analysis revealed that both ApGSTs are cytosolic, belonging to the chi-like class (ApGST1) and an undefined class (ApGST2). The overall expression of ApGSTs showed similar patterns depending on the exposed contaminants, while they were differently regulated by polychlorinated biphenyl (PCB). Copper treatments (CuCl2 and CuSO4) did not significantly induce the expression of ApGSTs. The highest up-regulations of ApGST1 and ApGST2 were under 6-h treatments of 0.10 and 0.50 mg L-1 NaOCl. Interestingly, only ApGST1 increased significantly after 0.10, 0.50, and 1.00 mg L-1 of PCB exposure (6 h). Intracellular reactive oxygen species (ROS) increased considerably under NaOCl; however, it was not significantly higher in the PCB-treated cells. GST activity was increased by NaOCl and PCB treatments, but only PCB caused apoptosis. These results suggest that GSTs are involved in the first line of phase II detoxification, protecting dinoflagellate cells against oxidative damage.

Development of gelatin/agarose active coatings functionalized with Ocimum gratissimum L. essential oil for enhancing storability of 'Booth 7' avocado.

Novel active coating from gelatin/agarose (GA) functionalized with Ocimum gratissimum L. essential oil (OGO) had been developed as a medium to evaluate their properties before being applied for avocado preservation. The resultant coating films showed enhanced mechanical, water-barrier, bactericidal, antioxidant, and UV-shielding properties by adding OGO. The best tensile strength (2.91 MPa) and flexibility (45.82 %) was found in the GA film containing 5 % (w/w) of OGO (GA-OGO-5). Furthermore, this coating formulation presented moderate antibacterial activities against Listeria, Pseudomonas, Salmonella, and Escherichia. The GA-OGO-5 coating film also divulged the highest hydrophobicity and adequate antioxidant function (30.75 µg/mL) and thus, was chosen to coat on 'Booth 7' avocados by dipping method. The GA-OGO-5 coating layers were to be efficient to decline the respiration rate of avocado during 6-day storage at 25 °C and 64 %RH. Peel color, weight loss (5.22 %), total soluble solids (8.14 %), and solution pH (6.79) at the end of storage also indicated that the GA-OGO-5 coating presented the best effectiveness for enhancing the storability of avocado as compared to uncoated and GA-treated fruit. Therefore, the GA-OGO coating has been considered as an alternative post-harvest technique to enhance the avocado storability and could be further commercialized for industry application.

Effects of nitrate on the saxitoxins biosynthesis revealed by sxt genes in the toxic dinoflagellate Alexandrium pacificum (group IV).

The dinoflagellate Alexandrium pacificum (group IV) is of particular interest because of its involvement in harmful algal blooms and production of saxitoxin (STX), which causes paralytic shellfish poisoning. The toxicity from STX and its analogues (STXs) is suspected to be affected by nitrogen (N) availability. However, the toxicity-associated behavior and STX-biosynthesis gene responses of the toxic A. pacificum under N fluctuations have not been sufficiently investigated. In the present study, we identified the sxtI gene involved in sxt biosynthesis pathway and evaluated the effects of nitrate (NO3-) on STXs production and the expression of four sxt core genes (sxtA4, sxtG, sxtB, and sxtI). Quantification of total STXs levels in the cultures under different NO3- regimes showed that NO3- concentration influenced STXs production. In addition, the proportion and concentration of STXs varied depending on the NO3- concentration. Core sxt transcript abundance was also influenced by available NO3- in a time-dependent manner. Expressional levels and patterns of sxtI were correlated with those of sxtA and sxtB. The relationship between the toxins and sxt responses in A. pacificum under various NO3- regimes suggests the direct involvement of N in the STXs biosynthesis pathway. Understanding this link would provide a tool to understand the toxin dynamics of dinoflagellates following N shifts in marine environments.

Vitamin E intake and paraoxonase 1 (PON1) rs662 genetic polymorphism are associated with colorectal cancer risk in a Korean population.

Vitamin E and paraoxonase 1 (PON1) are associated with cancer development. However, their interactive effect on colorectal cancer (CRC) risk is inconclusive. We conducted a case-control study including 1,351 CRC patients and 2,670 controls at the Korean National Cancer Centre (KNCC). There was an inverse association between vitamin E intake and CRC risk (odds ratio (OR) = 0.31; 95% confidence interval (CI) = 0.22-0.42). We identified a reduced CRC risk among individuals with CC genotype of PON1 rs662 polymorphism compared with subjects carrying the T allele (OR = 0.74; 95% CI = 0.61-0.90). The highest interaction between vitamin E intake and PON1 rs662 variants was significant for the subjects carrying the CC genotype (p-interaction = 0.014). This study provided further supporting evidence that vitamin E intake is associated with lower odds of CRC. Furthermore, the activity of vitamin E is strengthened among individuals carrying C allele of the PON1 rs662 polymorphism.

Impact of clinical pharmacist-led interventions on switching from intravenous-to-oral antibiotics in patients with infectious diseases at a Vietnamese hospital.

OBJECTIVES: To evaluate the impact of clinical pharmacist-led interventions on the switch from intravenous (IV) to oral (PO) antibiotics among inpatients with infectious diseases. METHODS: A before-and-after study was conducted among inpatients aged 18 or older who were diagnosed with infectious diseases and received IV antibiotics for at least 24 h at the Thong Nhat Hospital during the pre-intervention (between January 2021 and June 2021) and intervention (between January 2022 and June 2022) periods. Information on patient characteristics, antibiotic usage, length of hospital stay and treatment outcomes was obtained from medical records. The interventions included introducing IV-to-PO switch guidelines to physicians and clinical pharmacists' feedback on eligible cases. The impact of the pharmacists' interventions was evaluated by comparing primary outcomes (switch rate and appropriateness of switching) and secondary outcomes (duration of IV therapy, length of hospital stay and treatment outcomes) between the two study periods. RESULTS: We included 99 patients in the pre-intervention and 80 patients in the intervention period. The proportion of patients who switched from IV-to-PO antibiotics increased from 44.4% in the pre-intervention period to 67.8% in the intervention period (p = 0.008). The overall rate of appropriate conversion increased significantly from 43.8% to 67.5% (p = 0.043). There were no statistically significant differences between the two periods with respect to the median duration of IV therapy (9 days vs. 8 days), length of hospital stay (10 days vs. 9 days) and treatment outcomes. Logistic regression analysis showed that the interventions resulted in a higher switch rate, whereas age was negatively associated with the switching rate. CONCLUSIONS: The implementation of clinical pharmacist-led interventions was effective in promoting IV-to-PO antibiotic conversion.

Survival Rates in Elderly Patients on Continuous Ambulatory Peritoneal Dialysis.

Purpose: The present study aimed at evaluating the survival rate, its associated factors, and the causes of death in elderly patients undergoing continuous ambulatory peritoneal dialysis (CAPD) in Vietnam. Patients and Methods: This is a retrospective, observational study conducted among patients aged ≥65 years who underwent CAPD at Thong Nhat Hospital, Ho Chi Minh City, Vietnam, from April 2012 to December 2020. The Kaplan-Meier method was used to calculate the cumulative survival rate, and the Log rank test was used to analyze the factors associated with the survival rate of patients. Results: This study enrolled a total of 68 patients with a mean age of 71.93 ± 7.44 years at the initiation of CAPD. The most common complication among kidney failure patients was diabetic nephropathy (39.71%). The rate of concomitant cardiovascular diseases was 58.82%. The average survival rate was 45.59 ± 4.01 months. Peritonitis was the most common factor causing death (31.25%), followed by cardiovascular diseases (28.12%) and malnutrition (25%). The factors that impacted the survival rate included concomitant cardiovascular diseases, low serum albumin (<35 g/dL), and an indication of CAPD due to exhausted vascular access for hemodialysis at baseline. The main factor associated with a shorter survival time was concomitant cardiovascular diseases. Conclusion: It is necessary to improve the survival time beyond 5 years for elderly patients undergoing CAPD, especially for those with concomitant cardiovascular diseases. Besides the prevention of peritonitis, adequate measures to protect from cardiovascular diseases and malnutrition will reduce the mortality rate in patients on CAPD.

Two novel superoxide dismutase genes (CuZnSOD and MnSOD) in the toxic marine dinoflagellate Alexandrium pacificum and their differential responses to metal stressors.

Superoxide dismutase (SOD) is an important antioxidant enzyme that is involved in the first line of defense against reactive oxygen species (ROS) within cells. Herein, we determined two novel CuZnSOD and MnSOD genes from the toxic marine dinoflagellate Alexandrium pacificum (designated as ApCuZnSOD and ApMnSOD) and characterized their structural features and phylogenetic affiliations. In addition, we examined the relative gene expression and ROS levels following exposure to heavy metals. ApCuZnSOD encoded 358 amino acids (aa) with two CuZnSOD-conserved domains. ApMnSOD encoded 203 aa that contained a mitochondrial-targeting signal and a MnSOD signature motif but missed an N-terminal domain. Phylogenetic trees showed that ApCuZnSOD clustered with other dinoflagellates, whereas ApMnSOD formed a clade with green algae and plants. Based on the 72-h median effective concentration (EC50), A. pacificum showed toxic responses in the order of Cu, Ni, Cr, Zn, Cd, and Pb. SOD expression levels dramatically increased after 6 h of Pb (≥6.5 times) and 48 h of Cu treatment (≥3.9 times). These results are consistent with the significant increase in ROS production in the A. pacificum exposed to Pb and Cu. These suggest that the two ApSODs are involved in the antioxidant defense system but respond differentially to individual metals.

Antibiotic use in gastrointestinal surgery patients at a Vietnamese national hospital.

BACKGROUND: Invasive gastrointestinal surgery may be performed as an open or endoscopic procedure, such as laparoscopic semi-colon surgery, laparoscopic appendectomy, laparoscopic gastrectomy, and anal surgery, among other such operations. Regardless of the approach, the operative procedure interferes with the patient's gastrointestinal tract, necessitating the rational use of prophylactic antibiotics to improve treatment outcomes and minimize postoperative infections. OBJECTIVE: To investigate the prophylactic and postoperative antibiotic usage in patients who underwent invasive gastrointestinal surgery, and to identify factors associated with postoperative infection. DESIGN: This descriptive, cross-sectional study included 112 patients who underwent invasive gastrointestinal surgery at the Department of Gastroenterology, Thong Nhat Hospital. We conducted a cross-sectional study in all inpatients aged 18 years and older, who underwent invasive gastrointestinal surgery between January 2020 and December 2020. We recorded patient characteristics, the administration and appropriateness of antibiotics, as well as treatment outcomes. The appropriateness of prophylactic and postoperative antibiotic usage was assessed based on 2015 Vietnamese national guideline for antibiotic use. Multivariable logistic regression analysis was used to determine the factors associated with postoperative infection. RESULTS: Patients' mean age was 59.7 ± 17.2 years. Most surgeries (89.3%) were clean-contaminated procedures. The rates of appropriate types of antibiotics selected, doses, and overall rates of appropriateness of antibiotic prophylaxis were 68.0%, 76.4% and 54.7%, respectively. Of the patients investigated, 34.8% had at least one sign of postoperative infection; the overall appropriate rate of postoperative antibiotic was 38.5%. Old age was associated with postoperative infection and longer length of hospitalization. CONCLUSION: Implementation of the guidelines recommended for the prophylactic and therapeutic use of antibiotics is essential to improve treatment outcomes.

Flood risk mapping and analysis using an integrated framework of machine learning models and analytic hierarchy process.

In this study, a new approach of machine learning (ML) models integrated with the analytic hierarchy process (AHP) method was proposed to develop a holistic flood risk assessment map. Flood susceptibility maps were created using ML techniques. AHP was utilized to combine flood vulnerability and exposure criteria. We selected Quang Binh province of Vietnam as a case study and collected available data, including 696 flooding locations of historical flooding events in 2007, 2010, 2016, and 2020; and flood influencing factors of elevation, slope, curvature, flow direction, flow accumulation, distance from river, river density, land cover, geology, and rainfall. These data were used to construct training and testing datasets. The susceptibility models were validated and compared using statistical techniques. An integrated flood risk assessment framework was proposed to incorporate flood hazard (flood susceptibility), flood exposure (distance from river, land use, population density, and rainfall), and flood vulnerability (poverty rate, number of freshwater stations, road density, number of schools, and healthcare facilities). Model validation suggested that deep learning has the best performance of AUC = 0.984 compared with other ensemble models of MultiBoostAB Ensemble (0.958), Random SubSpace Ensemble (0.962), and credal decision tree (AUC = 0.918). The final flood risk map shows 5075 ha (0.63%) in extremely high risk, 47,955 ha (5.95%) in high-risk, 40,460 ha (5.02%) in medium risk, 431,908 ha (53.55%) in low risk areas, and 281,127 ha (34.86%) in very low risk. The present study highlights that the integration of ML models and AHP is a promising framework for mapping flood risks in flood-prone areas.

Curcumin and Paclitaxel Co-loaded Heparin and Poloxamer P403 Hybrid Nanocarrier for Improved Synergistic Efficacy in Breast Cancer.

INTRODUCTION: Multi-drug nanosystem has been employed in several therapeutic models due to the synergistic effect of the drugs and/or bioactive compounds, which help in tumor targeting and limit the usual side effects of chemotherapy. METHODS: In this research, we developed the amphiphilic Heparin-poloxamer P403 (HSP) nanogel that could load curcumin (CUR) and Paclitaxel (PTX) through the hydrophobic core of Poloxamer P403. The features of HSP nanogel were assessed through Fourier-transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), differential light scattering (DLS), and critical micelle concentration (CMC). Nanogel and its dual drug-loaded platform showed high stability and spherical morphology. RESULTS: The drug release profile indicated fast release at pH 5.5, suggesting effective drug distribution at the tumor site. In vitro research confirms lower cytotoxicity of HSP@CUR@PTX compared to free PTX and higher inhibition effect with MCF-7 than HSP@PTX. These results support the synergism between PTX and CUR. CONCLUSION: HSP@CUR@PTX suggests a prominent strategy for achieving the synergistic effect of PTX and CUR to circumvent undesirable effects in breast cancer treatment.

Impact of antimicrobial stewardship intervention in clean and clean-contaminated surgical procedures at a Vietnamese national hospital.

OBJECTIVES: We investigated the characteristics of prophylactic antimicrobial use in clean and clean-contaminated surgical procedures and assessed the efficacy of a prophylactic antimicrobial stewardship intervention at Thong Nhat Hospital, Ho Chi Minh City, Vietnam. METHODS: A cross-sectional study was conducted on 354 patients who underwent either clean or clean-contaminated surgical procedures at Thong Nhat Hospital. Eligible patients were classified with respect to three periods of intervention from 2017 to 2020. Data collection included surgical procedures, patient characteristics, and prophylactic antimicrobial usage. We determined the efficacy of antimicrobial stewardship intervention based on comparisons among the primary outcome (the appropriateness of prophylactic antimicrobials) and secondary outcomes (postoperative antimicrobial prophylaxis (AP) prolongation, length of postoperative hospital stay, and cost of antimicrobials). RESULTS: The mean age of patients in periods 1, 2, and 3 was 54.5 ± 16.6, 50.2 ± 16.5, and 52.8 ± 17.3 years, respectively, with an overall male/female ratio of 1.1/1. No significant differences were detected in basic patient characteristics during the three periods. Majority of the surgical procedures were clean (56%-59%) and scheduled (85%-86%). Prophylactic antimicrobial stewardship intervention enhanced AP appropriateness (by 12.7%, 12.7%, and 39.0% in periods 1, 2, and 3, respectively, p < 0.001), decreased postoperative prophylactic antimicrobial duration [3.0 (0-6), 1.5 (0-5), and 0.0 (0-1) days, respectively, p < 0.001], and reduced average antimicrobial expenses (p < 0.001). CONCLUSIONS: The prophylactic antimicrobial stewardship interventions introduced at Thong Nhat Hospital had several positive impacts on the appropriateness of prophylactic antimicrobial use and treatment costs.

Curcuminoid Co-Loading Platinum Heparin-Poloxamer P403 Nanogel Increasing Effectiveness in Antitumor Activity.

Nanosized multi-drug delivery systems provide synergistic effects between drugs and bioactive compounds, resulting in increased overall efficiency and restricted side effects compared to conventional single-drug chemotherapy. In this study, we develop an amphiphilic heparin-poloxamer P403 (HP403) nanogel that could effectively co-load curcuminoid (Cur) and cisplatin hydrate (CisOH) (HP403@CisOH@Cur) via two loading mechanisms. The HP403 nanogels and HP403@CisOH@Cur nanogels were closely analyzed with 1H-NMR spectroscopy, FT-IR spectroscopy, TEM, and DLS, exhibiting high stability in spherical forms. In drug release profiles, accelerated behavior of Cur and CisOH at pH 5.5 compared with neutral pH was observed, suggesting effective delivery of the compounds in tumor sites. In vitro studies showed high antitumor activity of HP403@CisOH@Cur nanogels, while in vivo assays showed that the dual-drug platform prolonged the survival time of mice and prevented tail necrosis. In summary, HP403@CisOH@Cur offers an intriguing strategy to achieve the cisplatin and curcumin synergistic effect in a well-designed delivery platform that increases antitumor effectiveness and overcomes undesired consequences caused by cisplatin in breast cancer treatment.

Unveiling the genomic structures and evolutionary events of the saxitoxin biosynthetic gene sxtA in the marine toxic dinoflagellate Alexandrium.

Marine dinoflagellates Alexandriumare known to produce saxitoxin (STX) and cause paralytic shellfish poisoning (PSP) which can result in mortality in human. SxtA is considered a core gene for the biosynthesis of STX. However, its gene coding structure and evolutionary history have yet to be fully elucidated. Here, we determined the full-length sequences of sxtA cDNA and genomic coding regions from two toxic dinoflagellates, Alexandrium catenella (LIMS-PS-2645 and LIMS-PS-2647) andA. pacificum (LMBE-C4), characterised their domain structures, and resolved evolutionary events. The sxtA gene was encoded on the genome without introns, and was identical in length (4002 bp) between two A. catenella strains, but their sequences differed from A. pacificum (5031 bp). SxtA consists of four domains, sxtA1, sxtA2, sxtA3, and sxtA4; however, A. pacificum has an extra domain TauD near sxtA1. Each domain had >64.4% GC content, with the highest being 71.6% in sxtA3. Molecular divergence was found to be significantly higher in sxtA4 than in the other domains. Phylogenetic trees of sxtA and separate domains showed that bacteria diverged earliest, followed by non-toxic, toxic cyanobacteria, toxic dinoflagellates. While sxtA domains in Alexandrium were similar to the PKS-like structure with the conserved sxtA1, sxtA2, and sxtA3. PKS_KS may be replaced by sxtA4 in toxic Alexandrium. These suggest that sxtA in Alexandrium may have evolved by acquiring specific domains, whose modification and complexity markedly affect toxin biosynthesis.

Quality of life assessment in patients on chronic dialysis: Comparison between haemodialysis and peritoneal dialysis at a national hospital in Vietnam.

OBJECTIVES: End-stage renal disease (ESRD) is a chronic disease that can adversely affect the patient's quality of life (QoL) in terms of functional limitation and cognitive impairment. This study aimed to identify the factors associated with QoL in patients with ESRD undergoing dialysis at a national hospital in Vietnam. METHODS: A descriptive cross-sectional study was conducted among outpatients aged ≥18 years who underwent haemodialysis (HD) or peritoneal dialysis (PD) for at least 3 months at Thong Nhat Hospital, Ho Chi Minh City, Vietnam from May 2020 to July 2021. QoL was measured using the validated Vietnamese version of the EuroQol-5 Dimensional-5 Level (EQ-5D-5L). The factors associated with the QoL of patients with ESRD undergoing dialysis were identified using multiple linear regression analysis. RESULTS: In total, 131 (73.6%) and 47 (26.4%) patients underwent HD and PD, respectively. Overall, 178 (55.6%) patients were men (median age, 66 [56-79] years). The mean EQ-5D-5L score was significantly higher in patients undergoing PD than in those undergoing HD (0.848 ± 0.183 vs. 0.766 ± 0.231; p = 0.030). Older age (ß = -0.006; p < 0.001) and peptic ulcer disease (ß = -0.083; p = 0.029) were associated with lower QoL scores. PD treatment was associated with higher QoL scores (ß = 0.065; p = 0.046). CONCLUSIONS: It is necessary to improve the QoL of patients undergoing dialysis, especially of elderly patients and patients with peptic ulcer disease. PD may be a better method for maintenance dialysis, if applicable, in terms of QoL.

Validation of screening tools for common mental health disorders in the methadone maintenance population in Hanoi, Vietnam.

BACKGROUND: Common mental health disorders (CMDs), including depression, anxiety and post-traumatic stress disorder (PTSD) may worsen both HIV and drug use outcomes, yet feasible tools to accurately identify CMDs have received limited study in this population. We aimed to validate the Patient Health Questionnaire (PHQ-9), Generalized Anxiety Disorder screen (GAD-7) and Primary Care PTSD screen for DSM-5 (PC-PTSD-5) in a methadone maintenance therapy (MMT) patient population in Hanoi, Vietnam. METHODS: We conducted a cross-sectional survey. The PHQ-9, GAD-7, and PC-PTSD-5 were administered to MMT patients. A blinded interviewer administered the Mini-International Neuropsychiatric Interview (MINI) as the reference gold standard. Total scores of each tool were compared with the MINI diagnoses using a receiver operating characteristic curves, and we identified the optimal respective cut-off scores using the Youden's Index. RESULTS: We enrolled 400 MMT patients. Approximately 99.3% were male (n = 397) and 21.8% (n = 87) were HIV positive. The prevalence of major depressive disorder, generalized anxiety disorder and PTSD, respectively, was 10.5, 4 and 2%. Optimal cut-off scores for the PHQ-9, GAD-7 and PC-PTSD were ≥ 5, ≥3, and ≥ 4 with a sensitivity/specificity of 95.2%/91.9, 93.8%/87.5, and 62.5%/95.2%. CONCLUSIONS: The prevalence of CMDs in the MMT population was lower than expected. A lower cut-off score may be considered when screening for CMDs in this population. Further research should investigate the validity of somatic symptom-based screening tools among other drug-using or MMT populations.

Salinity Affects Saxitoxins (STXs) Toxicity in the Dinoflagellate Alexandrium pacificum, with Low Transcription of SXT-Biosynthesis Genes sxtA4 and sxtG.

Salinity is an important factor for regulating metabolic processes in aquatic organisms; however, its effects on toxicity and STX biosynthesis gene responses in dinoflagellates require further elucidation. Herein, we evaluated the physiological responses, toxin production, and expression levels of two STX synthesis core genes, sxtA4 and sxtG, in the dinoflagellate Alexandrium pacificum Alex05 under different salinities (20, 25, 30, 35, and 40 psu). Optimal growth was observed at 30 psu (0.12 cell division/d), but cell growth significantly decreased at 20 psu and was irregular at 25 and 40 psu. The cell size increased at lower salinities, with the highest size of 31.5 µm at 20 psu. STXs eq was highest (35.8 fmol/cell) in the exponential phase at 30 psu. GTX4 and C2 were predominant at that time but were replaced by GTX1 and NeoSTX in the stationary phase. However, sxtA4 and sxtG mRNAs were induced, and their patterns were similar in all tested conditions. PCA showed that gene transcriptional levels were not correlated with toxin contents and salinity. These results suggest that A. pacificum may produce the highest amount of toxins at optimal salinity, but sxtA4 and sxtG may be only minimally affected by salinity, even under high salinity stress.

Assessing the appropriateness of antimicrobial therapy in patients with sepsis at a Vietnamese national hospital.

OBJECTIVES: To assess the appropriateness of empirical antimicrobial therapy for sepsis and septic shock and determine factors associated with patient treatment outcomes at a Vietnamese national hospital. METHODS: A cross-sectional study was conducted on 134 patients diagnosed with sepsis and/or septic shock at Thong-Nhat Hospital, Ho Chi Minh City, Vietnam, from January 2018 to June 2018. Appropriateness of antimicrobial therapy was defined as physician adherence to antimicrobial guidelines using the Sanford Guide to Antimicrobial Therapy and the Vietnam national guidelines. Bayesian model averaging technique was used to identify the related factors associated with patient treatment outcomes. RESULTS: The median age of patients was 70 years. Organisms were identified in 54.5% of cases and predominated by Escherichia coli and staphylococci. Appropriate empirical antimicrobial agents were initiated in 56.6% (n = 73) of all cases. Of these patients, 31 cases (42.5%) and 61 cases (83.6%) received the antimicrobials in accordance with recommendations related to dosage and route of administration, respectively, bringing the overall rate of appropriate empirical antimicrobial therapy down to 23.3%. Patients who progressed to septic shock, received inappropriate antimicrobial therapy and required ICU admission were more likely to suffer treatment failure. CONCLUSIONS: The study findings suggest that clinicians should appropriately adhere to antimicrobial guidelines, especially in patients with septic shock and those who require ICU care, to improve treatment outcomes.

Psychometric performance of the perceived stigma of substance abuse scale (PSAS) among patients on methadone maintenance therapy in Vietnam.

BACKGROUND: People who inject drugs (PWID) and patients on methadone maintenance therapy (MMT) face severe stigma and discrimination. However, there are limited measures assessing stigma towards individuals with substance use disorders or MMT patients, particularly in Vietnam, and few studies have examined the psychometric properties of existing measures. This study aims to examine the performance of the eight-item Perceived Stigma of Substance Abuse Scale (PSAS), created in the United States, among a population of MMT patients in Vietnam. METHODS: A cross-sectional survey was conducted among 400 adult patients enrolled in an urban MMT clinic. Substance use stigma was measured using the PSAS. We conducted confirmatory factor analysis (CFA) and assessed construct validity, reliability and known-group validity. RESULTS: The original eight-item scale was unidimensional, but yielded mixed goodness-of-fit indicators. Ultimately, dropping two items and allowing the errors of the items related to childcare to correlate improved the goodness-of-fit indicators. (RMSEA = 0.025; CFI = 0.999; and SRMR = 0.018). The shortened scale demonstrated acceptable reliability (Cronbach's α = 0.766). The mean stigma scores were significantly higher among individuals not working, but did not significantly vary by length of time in MMT, marital status, education attainment, HIV status, depression, concurrent injection drug use or missed methadone dose. CONCLUSIONS: The shortened six-item scale demonstrated good construct validity and acceptability reliability, but it did not demonstrate many a priori hypothesized known-group validity associations. Further research should consider a mixed-methods validation approach.