Importance of individual residues in hydrophobic patch PLVIVGL (1481-1487) in FV-Short for synergistic TFPIα cofactor activity with protein S, an alanine-scanning study: AlphaFold-mediated prediction of FV-Short/TFPIα/protein S trimolecular complex structure.

Background: In the splice variant factor (F)V-Short, 702 residues are deleted from the B domain, resulting in exposure of an acid region (AR2; 1493-1537) that binds TFPIα. FV-Short and protein S serve as synergistic TFPIα cofactors in inhibition of FXa. In the preAR2 region, a hydrophobic patch PLVIVGL (1481-1487) is crucial for synergistic TFPIα-cofactor activity and assembly of FV-Short, TFPIα, and protein S.

A hydrophobic patch (PLVIVG; 1481-1486) in the B-domain of factor V-short is crucial for its synergistic TFPIα-cofactor activity with protein S and for the formation of the FXa-inhibitory complex comprising FV-short, TFPIα, and protein S.

Background: Factor V-short (FV756-1458) is a natural splice variant functioning in synergy with protein S as tissue factor pathway inhibitor alpha (TFPIα)-cofactor in inhibition of factor Xa (FXa). An exposed acid region (AR2; 1493-1537) in the B domain binds TFPIα. The preAR2 (1458-1492) is crucial for the synergistic TFPIα-cofactor activity between FV-short and protein S and for assembly of a trimolecular FXa-inhibitory complex among FV-short, protein S, and TFPIα.

The preAR2 region (1458-1492) in factor V-Short is crucial for the synergistic TFPIα-cofactor activity with protein S and the assembly of a trimolecular factor Xa-inhibitory complex comprising FV-Short, protein S, and TFPIα.

Background: Factor V-Short (FV756-1458) is a natural splice variant in which 702 residues are deleted from the B domain. It exposes an acid region (AR2; 1493-1537) that binds tissue factor pathway inhibitor alpha (TFPIα). Protein S also interacts with TFPIα and serves as TFPIα-cofactor in factor Xa (FXa) inhibition.

Clinical and Pathogenic Characteristics of Lower Respiratory Tract Infection Treated at the Vietnam National Children's Hospital.

Lower respiratory tract infections are commonly caused by viruses and cause significant morbidity and mortality among children. Early identification of the pathological agent causing these infections is essential to avoid unnecessary antibiotic use and improve patient management. Multiplex PCR techniques were recently developed to detect multiple viral pathogens using a single PCR reaction.

Mycobacterial Blood Culture for Diagnosis of Tuberculosis in Vietnamese Children.

Diagnosis of pediatric tuberculosis is notoriously difficult. We investigated the additional yield of blood culture in hospitalized children in Vietnam. Among 554 enrolled clinically suspected patients, an additional 6 cases were diagnosed, while the incremental cost per case was USD500.

Attitude towards deceased donation in Ho Chi Minh City, Vietnam.

Describe the current state of deceased kidney donation in Southern Vietnam and to explore the knowledge, attitude and behaviour towards kidney donation after death. Factors associated with the decision to donate among selective populations in HoChi Minh city were explored. Self-administered questionnaire of 30 questions to people over 18 years in three different communities were studied, n = 1068; 77% and 63.

New functional test for the TFPIα cofactor activity of Protein S working in synergy with FV-Short.

Essentials Protein S and FV-Short are synergistic cofactors to Tissue Factor Pathway Inhibitor α (TFPIα). An assay for the TFPIα synergistic cofactor activity of protein S with FV-Short was developed. The assay was specific for the synergistic TFPIα-cofactor activity of free protein S.

Factor V-short and protein S as synergistic tissue factor pathway inhibitor (TFPIα) cofactors.

Background: FV-Short is a normal splice variant of Factor V (FV) having a short B domain, which exposes a high affinity-binding site for tissue factor pathway inhibitor α (TFPIα). FV-Short and TFPIα circulate in complex in plasma.

Objectives: The aim was to elucidate whether FV-Short affects TFPIα as inhibitor of coagulation FXa and to test whether the TFPIα-cofactor activity of protein S is influenced by FV-Short.

A simple questionnaire to detect chronic kidney disease patients from Long An province screening data in Vietnam.

Background: The prevalence of chronic kidney disease (CKD) in rural Vietnam is unknown. We wished to determine the prevalence of CKD and determine whether a simple questionnaire was able to detect individuals at high risk of CKD before expensive confirmatory laboratory testing.

Methods: A cross sectional study was performed.

High-Density Lipoprotein-Associated Apolipoprotein M Limits Endothelial Inflammation by Delivering Sphingosine-1-Phosphate to the Sphingosine-1-Phosphate Receptor 1.

Objective: Plasma high-density lipoproteins (HDL) are potent antiatherogenic and anti-inflammatory particles. However, HDL particles are highly heterogenic in composition, and different HDL-mediated functions can be ascribed to different subclasses of HDL. Only a small HDL population contains apolipoprotein M (ApoM), which is the main plasma carrier of the bioactive lipid mediator sphingosine-1-phosphate (S1P).

The Gas6-Axl Protein Interaction Mediates Endothelial Uptake of Platelet Microparticles.

Upon activation, platelets release plasma membrane-derived microparticles (PMPs) exposing phosphatidylserine on their surface. The functions and clearance mechanism of these microparticles are incompletely understood. As they are pro-coagulant and potentially pro-inflammatory, rapid clearance from the circulation is essential for prevention of thrombotic diseases.

Diagnostic accuracy of microscopic Observation Drug Susceptibility (MODS) assay for pediatric tuberculosis in Hanoi, Vietnam.

Introduction: Microscopic [corrected] Observation Drug Susceptibility (MODS) has been shown to be an effective and rapid technique for early diagnosis of tuberculosis (TB). Thus far only a limited number of studies evaluating MODS have been performed in children and in extra-pulmonary tuberculosis. This study aims to assess relative accuracy and time to positive culture of MODS for TB diagnosis in children admitted to a general pediatric hospital in Vietnam.

Coagulation factor V(A2440G) causes east Texas bleeding disorder via TFPIα.

The autosomal dominantly inherited east Texas bleeding disorder is linked to an A2440G variant in exon 13 of the F5 gene. Affected individuals have normal levels of coagulation factor V (FV) activity, but demonstrate inhibition of global coagulation tests. We demonstrated that the A2440G mutation causes upregulation of an alternatively spliced F5 transcript that results in an in-frame deletion of 702 amino acids of the large activation fragment, the B domain.

Activated protein C cofactor function of protein S: a critical role for Asp95 in the EGF1-like domain.

Protein S has an established role in the protein C anticoagulant pathway, where it enhances the factor Va (FVa) and factor VIIIa (FVIIIa) inactivating property of activated protein C (APC). Despite its physiological role and clinical importance, the molecular basis of its action is not fully understood. To clarify the mechanism of the protein S interaction with APC, we have constructed and expressed a library of composite or point variants of human protein S, with residue substitutions introduced into the Gla, thrombin-sensitive region (TSR), epidermal growth factor 1 (EGF1), and EGF2 domains.

Cloning and characterization of phosphomannose isomerase from Sphingomonas chungbukensis DJ77.

Phosphomannose isomerase (PMI) catalyzes the interconversion of fructose-6-phosphate and mannose-6-phosphate in the extracellular polysaccharide (EPS) synthesis pathway. The gene encoding PMI in Sphingomonas chungbukensis DJ77 was cloned and expressed in E. coli.

Cloning and characterization of phosphoglucose isomerase from Sphingomonas chungbukensis DJ77.

Phosphoglucose isomerase (PGI) is involved in synthesizing extracellular polysaccharide (EPS). The gene encoding PGI in Sphingomonas chungbukensis DJ77 was cloned and expressed in E. coli, and the protein was characterized.

Platelet factor 4 impairs the anticoagulant activity of activated protein C.

Platelet factor 4 (PF4) is an abundant platelet alpha-granule chemokine released following platelet activation. PF4 interacts with thrombomodulin and the gamma-carboxyglutamic acid (Gla) domain of protein C, thereby enhancing activated protein C (APC) generation by the thrombin-thrombomodulin complex. However, the protein C Gla domain not only mediates protein C activation in vivo, but also plays a critical role in modulating the diverse functional properties of APC once generated.

Mapping of the factor Xa binding site on factor Va by site-directed mutagenesis.

Activated coagulation factor V functions as a cofactor to factor Xa in the conversion of prothrombin to thrombin. Based on the introduction of extra carbohydrate side chains in recombinant factor V, we recently proposed several regions in factor Va to be important for factor Xa binding. To further define which residues are important for factor Xa binding, we prepared fifteen recombinant factor V variants in which clusters of charged amino acid residues were mutated, mainly to alanines.

Effects of prothrombin on the individual activated protein C-mediated cleavages of coagulation factor Va.

The factor Va (FVa) inactivation by activated protein C (APC), mediated by cleavages at Arg306 and Arg506 in FVa, is inhibited by both factor Xa (FXa) and prothrombin. Although FXa is known to specifically inhibit the Arg506 cleavage, the effect of prothrombin has not been confined to one cleavage site. We used recombinant FV variants, FV:R506Q/R679Q and FV:R306Q/R679Q, to investigate the effect of prothrombin on the individual cleavage sites.

Effects of factor Xa and protein S on the individual activated protein C-mediated cleavages of coagulation factor Va.

Activated protein C inhibits the procoagulant function of activated factor V (FVa) through proteolytic cleavages at Arg-306, Arg-506, and Arg-679. The cleavage at Arg-506 is kinetically favored but protected by factor Xa (FXa). Protein S has been suggested to annihilate the inhibitory effect of FXa, a proposal that has been challenged.

Enhanced rate of cleavage at Arg-306 and Arg-506 in coagulation factor Va by Gla domain-mutated human-activated protein C.

A Gla domain-mutated protein C variant, QGNSEDY, modified at positions 10-12, 23, 32-33, and 44, having enhanced affinity for negatively charged phospholipid and increased anticoagulant potential, was used to elucidate the importance of the interaction between the Gla domain and the phospholipid for the ability of activated protein C (APC) to inactivate factor Va (FVa). FVa degradation by wild type (WT)-APC and QGNSEDY-APC yielded similar fragments on Western blotting; QGNSEDY-APC was, however, considerably more efficient. The kinetic parameters for individual APC-mediated cleavages in FVa, i.

Importance of protein S and phospholipid for activated protein C-mediated cleavages in factor Va.

The procoagulant function of activated factor V (FVa) is inhibited by activated protein C (APC) through proteolytic cleavages at Arg306, Arg506, and Arg679. The effect of APC is potentiated by negatively charged phospholipid membranes and the APC cofactor protein S. Protein S has been reported to selectively stimulate cleavage at Arg306, an effect hypothesized to be related to reorientation of the active site of APC closer to the phospholipid membrane.