Activation of Coq6p, a FAD Monooxygenase Involved in Coenzyme Q Biosynthesis, by Adrenodoxin Reductase/Ferredoxin.

Adrenodoxin reductase (AdxR) plays a pivotal role in electron transfer, shuttling electrons between NADPH and iron/sulfur adrenodoxin proteins in mitochondria. This electron transport system is essential for P450 enzymes involved in various endogenous biomolecules biosynthesis. Here, we present an in-depth examination of the kinetics governing the reduction of human AdxR by NADH or NADPH. Our results highlight the efficiency of human AdxR when utilizing NADPH as a flavin reducing agent. Nevertheless, akin to related flavoenzymes such as cytochrome P450 reductase, we observe that low NADPH concentrations hinder flavin reduction due to intricate equilibrium reactions between the enzyme and its substrate/product. Remarkably, the presence of MgCl2 suppresses this complex kinetic behavior by decreasing NADPH binding to oxidized AdxR, effectively transforming AdxR into a classical Michaelis-Menten enzyme. We propose that the addition of MgCl2 may be adapted for studying the reductive half-reactions of other flavoenzymes with NADPH. Furthermore, in vitro experiments provide evidence that the reduction of the yeast flavin monooxygenase Coq6p relies on an electron transfer chain comprising NADPH-AdxR-Yah1p-Coq6p, where Yah1p shuttles electrons between AdxR and Coq6p. This discovery explains the previous in vivo observation that Yah1p and the AdxR homolog, Arh1p, are required for the biosynthesis of coenzyme Q in yeast.

Correction: Estimation of the cardiovascular risk using world health organization/international society of hypertension risk prediction charts in Central Vietnam.

[This corrects the article DOI: 10.1371/journal.pone.0242666.].

Estimation of the cardiovascular risk using world health organization/international society of hypertension risk prediction charts in Central Vietnam.

INTRODUCTION: Cardiovascular disease (CVD) being the leading cause of the morbidity and mortality in Vietnam, the objective of this study was to estimate the total 10-year CVD risk among adults aged 40-69 years by utilizing World Health Organization/International Society of Hypertension (WHO/ISH) risk prediction charts in Central Vietnam. MATERIALS AND METHODS: In this cross-sectional study, multi-staged sampling was used to select 938 participants from a general population aged from 40 to 69. The CVD risk factors were then collected throughout the interviews with a standardized questionnaire, anthropometric measurements and a blood test. The cardiovascular risk was calculated using the WHO/ISH risk prediction charts. RESULTS: According to the WHO/ISH charts, the proportion of moderate risk (10-20%) and high risk (>20%) among the surveyed participants were equal (5.1%). When "blood pressure of more than 160/100 mmHg" was applied, the proportion of moderate risk reduced to 2.3% while the high risk increased markedly to 12.8%. Those proportions were higher in men than in women (at 18.3% and 8.5% respectively, p-value <0.001, among the high-risk group), increasing with age. Male gender, smoking, ethnic minorities, hypertension and diabetes were associated with increased CVD risk. CONCLUSIONS: There was a high burden of CVD risk in Central Vietnam as assessed with the WHO/ISH risk prediction charts, especially in men and among the ethnic minorities. The use of WHO/ISH charts provided a feasible and affordable screening tool in estimating the cardiovascular risk in primary care settings.

HIV Prevalence and Factors Related to HIV Infection Among Transgender Women in Vietnam: A Respondent Driven Sampling Approach.

Transgender women are at higher risk of HIV infection, however, there is a lack of information about HIV infection and related factors among transgender women in Vietnam. From February 2018 to June 2018, 456 transgender women were recruited in the study using Respondent-Driven Sampling technique. Participants completed the computer-based questionnaire and were tested for HIV serostatus. Multivariable logistic regression was used to identify factors related to HIV infection. The prevalence of HIV infection was 77 (16.5%), of which 19 (24.7%) were not aware of their HIV-positive status prior to the study. Factors associated with HIV infection included popper use (aOR 2.01, p = 0.044) and having regular male partner(s) (aOR 0.42, p = 0.006). More efforts are needed to reduce the high prevalence of HIV infection, such as expanding the reach of HIV screening and prevention programs to the transgender women population, particularly for substance users.

Characterization of Entamoeba histolytica adenosine 5'-phosphosulfate (APS) kinase; validation as a target and provision of leads for the development of new drugs against amoebiasis.

BACKGROUND: Amoebiasis, caused by Entamoeba histolytica infection, is a global public health problem. However, available drugs to treat amoebiasis are currently limited, and no effective vaccine exists. Therefore, development of new preventive measures against amoebiasis is urgently needed. METHODOLOGY/PRINCIPAL FINDINGS: Here, to develop new drugs against amoebiasis, we focused on E. histolytica adenosine 5'-phosphosulfate kinase (EhAPSK), an essential enzyme in Entamoeba sulfolipid metabolism. Fatty alcohol disulfates and cholesteryl sulfate, sulfolipids synthesized in Entamoeba, play important roles in trophozoite proliferation and cyst formation. These processes are closely associated with clinical manifestation and severe pathogenesis of amoebiasis and with disease transmission, respectively. We validated a combination approach of in silico molecular docking analysis and an in vitro enzyme activity assay for large scale screening. Docking simulation ranked the binding free energy between a homology modeling structure of EhAPSK and 400 compounds. The 400 compounds were also screened by a 96-well plate-based in vitro APSK activity assay. Among fifteen compounds identified as EhAPSK inhibitors by the in vitro system, six were ranked by the in silico analysis as having high affinity toward EhAPSK. Furthermore, 2-(3-fluorophenoxy)-N-[4-(2-pyridyl)thiazol-2-yl]-acetamide, 3-phenyl-N-[4-(2-pyridyl)thiazol-2-yl]-imidazole-4-carboxamide, and auranofin, which were identified as EhAPSK inhibitors by both in silico and in vitro analyses, halted not only Entamoeba trophozoite proliferation but also cyst formation. These three compounds also dose-dependently impaired the synthesis of sulfolipids in E. histolytica. CONCLUSIONS/SIGNIFICANCE: Hence, the combined approach of in silico and in vitro-based EhAPSK analyses identified compounds that can be evaluated for their effects on Entamoeba. This can provide leads for the development of new anti-amoebic and amoebiasis transmission-blocking drugs. This strategy can also be applied to identify specific APSK inhibitors, which will benefit research into sulfur metabolism and the ubiquitous pathway terminally synthesizing essential sulfur-containing biomolecules.

Plasma asymmetric dimethylarginine and its association with some of cardiovascular disease risk factors in chronic kidney disease

@#Introduction: Chronic kidney disease (CKD) usually has increase of asymmetric dimethylarginine (ADMA) levels. ADMA is a cardiovascular disease (CVD) risk factor and its elevation associated with other CVD risk factors at CKD leads to increasing risk of death. In this article, we aimed to identify levels and elevation proportion of plasma ADMA in CKD as well as association between ADMA with CVD risk factors. Methods: This cross-sectional study was performed at Hue Central Hospital from 2012-2016 on 176 CKD and 64 control subjects. ADMA levels were measured by using the enzyme linked immunosorbent assay (ELISA) method. Results: Mean ADMA level was markedly higher (p<0.001) in all patients combined (0.73±0.24µmol/L) than in control subjects (0.47±0.13µmol/L). Mean ADMA levels in advanced kidney disease were higher than control subjects. ADMA levels correlated inversely and relatively strictly to estimated glomerular filtration rate (eGFR) (r = -0.689; p<0.001), haemoglobin (r = -0.525; p<0.001) and haematocrit (r = - 0.491; p<0.001); correlated favourably and relatively strictly to serum creatinine (r = 0.569; p<0.001) and serum urea (r = 0.642; p<0.001). ADMA elevation was predicted simultaneously by eGFR<60 mL/min/1.73m2 (p<0.001), anaemia (p=0.002), body mass index (BMI) (p=0.011) and high sensitivity C-reactive protein (hs-CRP) (p=0.041). Cutoff of ≥0.68µmol/L, ADMA levels predict reduction of eGFR<60 mL/min/1.73m2 , sensitivity of 86.9 %, specificity of 82.6%, area under ROC 92.4% (95%CI: 88.6-96.1%).

A Flow Cytometry Method for Dissecting the Cell Differentiation Process of Entamoeba Encystation.

Amoebiasis is caused by Entamoeba histolytica infection, a protozoan parasite belonging to the phylum Amoebozoa. This parasite undergoes a fundamental cell differentiation process from proliferative trophozoite to dormant cyst, termed "encystation." The cysts formed by encystation are solely responsible for the transmission of amoebiasis; therefore, Entamoeba encystation is an important subject from both biological and medical perspectives. Here, we have established a flow cytometry strategy for not only determining the percentage of formed cysts but also for monitoring changes in cell populations during encystation. This strategy together with fluorescence microscopy enables visualization of the cell differentiation process of Entamoeba encystation. We also standardized another flow cytometry protocol for counting live trophozoites. These two different flow cytometry techniques could be integrated into 96-well plate-based bioassays for monitoring the processes of cyst formation and trophozoite proliferation, which are crucial to maintain the Entamoeba life cycle. The combined two systems enabled us to screen a chemical library, the Pathogen Box of the Medicine for Malaria Venture, to obtain compounds that inhibit either the formation of cysts or the proliferation of trophozoites, or both. This is a prerequisite for the development of new drugs against amoebiasis, a global public health problem. Collectively, the two different 96-well plate-based Entamoeba bioassay and flow cytometry analysis systems (cyst formation and trophozoite proliferation) provide a methodology that can not only overcome the limitations of standard microscopic counting but also is effective in applied as well as basic Entamoeba biology.

Prevalence, Awareness, Treatment, and Control of Hypertension and Its Risk Factors in (Central) Vietnam.

INTRODUCTION: The objective of this study is to describe the prevalence, awareness, treatment, and control of hypertension and its associated risk factors in (Central) Vietnam. METHODS: In this cross-sectional study, a multistage sampling was used to select 969 participants from the general population aged from 40 to 69 years. The cardiovascular risk factors were collected throughout the interviews with a standardized questionnaire. Multivariate logistic regression analysis was conducted to test the relationship between the prevalence, awareness, treatment, and control of hypertension and the prevalence of risk factors. RESULTS: The prevalence of hypertension was 44.8%. It was higher in men than in women (51.3% versus 39.7%, p < 0.001). In total 67.3% (74.5% in women, 60.1% in men; p = 0.001) of the participants were aware of their hypertension, 33.2% (37.5% in women, 28.9% in men; p = 0.01) of the participants were treated, and 12.2% (16.7% in women, 7.8% in men; p < 0.001) of the hypertensive participants' hypertension was controlled. Age, gender, place of residence, body mass index, and diabetes were found to be independent risk factors for hypertension. CONCLUSION: The prevalence of hypertension in Vietnam is high, and the proportion of treated and controlled patients is rather low.

Immunological responses induced by asd and wzy/asd mutant strains of Salmonella enterica serovar Typhimurium in BALB/c mice.

Attenuated bacteria have long been developed as vaccine candidates but can have some disadvantages, such as the potential for damage to immune organs due to insufficient clearance. To minimize these disadvantages, we generated Salmonella enterica serovar Typhimurium mutants SHJ2104 (asd::cm) and HTSaYA (wzy::km, asd::cm). The wzy gene codes for the O-antigen polymerase, which is involved in lipopolysaccharide (LPS) biosynthesis, and asd codes for aspartate beta-semialdehyde dehydrogenase, which participates in cell wall formation. The strains synthesized LPS with a short-chain length, and showed lower cytotoxicity and reduced intracellular proliferation in animal cells compared to wild-type bacteria. After oral infection, the mutants were cleared in immune tissues, including the Peyer's patch, mesenteric lymph node, and spleen, within 5 days. The LD50 of the mutants in Balb/c mice was estimated to be 10(6) higher than wild-type bacteria when administered either via an oral or i.p. route, indicating that the two strains are highly attenuated. To compare the immune response to and protective effects of the mutants against wild-type bacterial infection, we inoculated the mutants into mice via an oral (1x10(10)CFU) or i.p. (1x10(7) CFU) route once or twice at a two week interval. All immune responses, such as serum IgG and secretory IgA levels, cytokine production, and delayed hypersensitivity, were highly induced by two rounds of immunization. HTSaYA and SHJ2104 induced similar immune responses, and mice immunized with HTSaYA or SHJ2104 via an i.p. route were protected against wild-type Salmonella infection even at 100-fold of the LD(50) (5x10(6) CFU). Taken together, these data indicate that HTSaYA and SHJ2104 could be developed as live attenuated Salmonella vaccine candidates.

The situation and features of chronic renal failure in a delta commune of Thua Thien Hue province

Objectives: determination of morbidity rate of chronic renal failure and causes of disease. Subjective: People with ages of 15 and above. Results: The morbidity rate of the chronic renal failure was 1% (female more frequent than male) in which phase I : 0,27%, phase II: 0,55%; phase III : 0.09%. The chronic pyelitis was the leading cause of the chronic renal failure (63,4%) in which 36, 3% of these accompanied with urinary stone.