Biological activity of a new recombinant human coagulation factor VIII and its efficacy in a small animal model.

Deficiency in human coagulation factor VIII (FVIII) causes hemophilia A (HA). Patients with HA may suffer from spontaneous bleeding, which can be life-threatening. Recombinant FVIII (rFVIII) is an established treatment and prevention agent for bleeding in patients with HA. Human plasma-derived FVIII (pdFVIII), commonly used in clinical practice, is relatively difficult to prepare. In this study, we developed a novel B-domain-deleted rFVIII, produced and formulated without the use of animal or human serum-derived components. rFVIII promoted the generation of activated factor X and downstream thrombin, and, similar to that of other available FVIII preparations, its activity was inhibited by FVIII inhibitors. In addition, rFVIII has ideal binding affinity to human von Willebrand factor. Activated FVIII (FVIIIa) could be degraded by activated protein C and lose its procoagulant activity. In vitro, commercially available recombinant FVIII (Xyntha) and pdFVIII were used as controls, and there were no statistical differences between rFVIII and commercial FVIII preparations, which demonstrates the satisfactory efficacy and potency of rFVIII. In vivo, HA mice showed that infusion of rFVIII rapidly corrected activated partial thromboplastin time, similar to Xyntha. Moreover, different batches of rFVIII were comparable. Overall, our results demonstrate the potential of rFVIII as an effective strategy for the treatment of FVIII deficiency.

Obesity predisposes to the risk of higher mortality in young COVID-19 patients.

Although emerging data demonstrated mortality of young COVID-19 patients, no data have reported the risk factors of mortality for these young patients, and whether obesity is a risk for young COVID-19 patients remains unknown. We conducted a retrospective study including 13 young patients who died of COVID-19 and 40 matched survivors. Logistic regression was employed to characterize the risk factors of mortality in young obese COVID-19 patients. Most of the young deceased COVID-19 patients were mild cases at the time of admission, but the disease progressed rapidly featured by a higher severity of patchy shadows (100.00% vs 48.70%; P = .006), pleural thickening (61.50% vs 12.80%; P = .012), and mild pericardial effusion (76.90% vs 0.00%; P < .001). Most importantly, the deceased patients manifested higher body mass index (odds ratio [OR] = 1.354; 95% confidence interval [CI] = 1.075-1.704; P = .010), inflammation-related index C-reactive protein (OR = 1.014; 95% CI = 1.003-1.025; P = .014), cardiac injury biomarker hs-cTnI (OR = 1.420; 95% CI = 1.112-1.814; P = .005), and increased coagulation activity biomarker D-dimer (OR = 418.7; P = .047), as compared with that of survivors. Our data support that obesity could be a risk factor associated with high mortality in young COVID-19 patients, whereas aggravated inflammatory response, enhanced cardiac injury, and increased coagulation activity are likely to be the mechanisms contributing to the high mortality.

[Optimization of extraction technology from compound Huanghuai based on coagulation activity and central composite design-response surface methodology].

To establish a method for the determination of coagulation activity in vitro by using fibrinogen plate method. The extraction route of compound Huanghuai was optimized by selecting thrombin as the reference substance. The comprehensive score of extract yield and the extraction transfer rate of baicalin and rutin was set as the dependent variable, with alcohol concentration, solvent volume and extraction time as the influence factors in central composite design for quadratic fitting, and the extraction process of compound Huanghuai was optimized by using response surface methodology. The results of thrombin concentration and precipitation zone area showed a good linear relationship in 0.4-16 U•mL⁻¹, r=0.997 5. The average recovery rate was 103.8% and the RSD was 4.7 %. The circle of precipitation area of compound Huanghuai combined extract was 38.81 mm², which was bigger than that of fractionated extract. The activity on the daily amount of compound Huanghuai extract was 84.28 U; and the optimum extraction technology was as follows: alcohol concentration 40%, extracted 3 times, the liquid-solid ratio 6∶1, and extraction time 2 h. The predicted value of comprehensive score was 94.26 and the measured value was 88.34, respectively, with a relative deviation of 6.28%. The coagulation activity of the intermediate obtained by optimal extraction process was better. So the method established in this paper was simple, fast and accurate for determination of coagulation activity of compound Huanhuai, which can be also used for the screening of follow-up process and quality control.

Undescribed compounds from Clinopodium chinense (Benth.) O. Kuntze and their coagulation activity studies.

Four rare compounds (1-4), including one 1,4-epoxy-benzoxepane derivative and one ringed prenylated naphthoquinoid skeleton, as well as one isopimarane-type diterpenoid and one megastigmane-type glycoside, along with three known megastigmane-type glycosides (5-7) were isolated from the ethanol extracts of C. chinense. Their structures were determined on the basis of 1D, 2D NMR, HR-ESI-MS and DP4+ analysis. Meanwhile, the in vitro evaluation indicated that compound 2 and 6 exhibited excellent procoagulant activities, which can significantly shorten prothrombin time (PT) and activated partial thromboplastin time (APTT), respectively.

Characterization of proteinous coagulant in Moringa tree seeds for water purification: Stepwise laboratory exercise for high-school students.

Coagulation is an important process in the context of water purification; and the seed protein of the moringa tree (Moringa oleifera) is a remarkably effective coagulant. The laboratory course described here is designed to provide high-school students with a stepwise, hands-on experience in investigating the protein-rich coagulant found in Moringa seeds. First, the seed powder was applied to model polluted water containing fine clay, food dyes, copper sulfate, and bacteria. This treatment changed the polluted water into clear water via coagulation; all students were convinced that the coagulation-inducing agent was a thermostable cationic protein. Finally, basic biochemical techniques (e.g., chromatographic separation and electrophoresis) were used to show that the target coagulant is a dimeric protein composed of 6.5 and 4.5 kDa subunits. Overall, this made it possible for the students to gain a deeper understanding (more comprehensive than the information taught in formal classes) of protein structure and its real-world implications. This stepwise exercise can be applied to research-based learning programs in high school, as it is an effective learning tool.

Production and characterization of a novel poly amino acid from a thermophilic bacterium, and preliminary testing of its coagulating potential for imminent wastewater treatment application.

The increasing demand for biopolymers across diverse fields, such as food, medicine, cosmetics, and environmental applications, has prompted researchers to explore novel molecules with enhanced functionalities that meet these demands. In this study, a thermophilic strain of Bacillus licheniformis was employed to produce a unique polyamino acid. This thermophilic isolate exhibited rapid growth at 50 °C in a sucrose mineral salts medium, resulting in a biopolymer concentration of 7.4 g/L. Interestingly, the biopolymer produced at different temperatures exhibited varying glass-transition temperatures (ranging from 87.86 °C to 104.11 °C) and viscosities (7.5 cP to 16.3 cP), suggesting that the fermentation temperature significantly influenced the degree of polymerization. Furthermore, the biopolymer was characterized using various techniques, including Thin Layer Chromatography (TLC), Fourier Transform Infrared (FTIR) spectroscopy, Liquid Chromatography-Electrospray Ionization-Mass Spectroscopy (LC-ESI MS), Nuclear Magnetic Resonance (NMR), and Differential Scanning Calorimetry-Thermogravimetric Analysis (DSC-TGA). The results revealed that the obtained biopolymer was a poly amino acid, with poly-γ-glutamic acid as the major monomeric component in the polymer backbone with a few appendages of aspartic acid residues in its side chain. Finally, the biopolymer demonstrated significant coagulation potential for water treatment applications, as evidenced by coagulation studies conducted under varying pH conditions using kaolin-clay as a model precipitant.

Prognostic Impact of Coagulation Activity in Patients Undergoing Curative Resection for Pancreatic Ductal Adenocarcinoma.

BACKGROUND/AIM: The aim of this study was to elucidate the clinical impact of coagulation disorders on outcomes after curative resection of pancreatic ductal adenocarcinoma. PATIENTS AND METHODS: Preoperative coagulation activity in 135 patients, who had undergone curative resections for pancreatic ductal adenocarcinoma was retrospectively evaluated and the impact on survival outcomes analyzed. RESULTS: A prolonged prothrombin time-international normalized ratio (PT-INR) (≥1.1) was detected in 23/135 patients (17%). Univariate analysis that showed prolonged PT-INR was associated with worse relapse-free (hazard ratio=1.79, p=0.044) and overall (hazard ratio=2.18, p=0.004) survival. Multivariate analyses showed prolonged PT-INR, large tumor (>30 mm), and lymph node metastasis were independent predictors of poor overall survival. CONCLUSION: Prolonged PT-INR may be a predictor of poor prognosis in patients with pancreatic ductal adenocarcinoma who have undergone curative resection. Coagulation disorders may be a therapeutic target for improving outcomes of pancreatic ductal adenocarcinoma.

Chemical constituents and coagulation activity of Syringa oblata Lindl flowers.

The leaves and bark of Syringa oblata Lindl are used as folk medicine which has heat-clearing, detoxifying, dampness-removing and jaundice-relieving effects. There are many studies about leaves of S. oblata because of its abundant resource, however, less reports about the components of S. oblata flowers. The previous studies on S. oblate flowers were mainly focused on the volatile components and its traditional pharmacological activity. Thus, this study aimed to investigate the nonvolatile chemical constituents and the coagulation activity of S. oblate flowers. The chemical constituents of S. oblate flowers were isolated with various column chromatographies and coagulation activity of the major constituents was investigated by assaying the activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT) and fibrinogen (FIB) on plasma of rabbit in vitro. Fifteen known compounds (namely compound 1-15) were isolated from S. oblata flowers. Compound 6, 10, 11 and 14 were isolated from Syringa genus for the first time. Compound 1, 2, 4, 5, 8 and 9 were isolated from the plant for the first time. The results of coagulation activity showed that water part of S. oblate flowers, lauric acid and kaempferol-rutinose significantly shorten PT (P < 0.001), TT (P < 0.001) and APTT (P < 0.001) compared with blank group, thus revealed that water extract of S. oblate flowers, lauric acid and kaempferol-rutinose possessed the procoagulant activity, but the effects were not better than that of Yunnan Baiyao as positive control.

Sulfur-Containing Monoterpenoids as Potential Antithrombotic Drugs: Research in the Molecular Mechanism of Coagulation Activity Using Pinanyl Sulfoxide as an Example.

In this article we present the synthesis of enantiomerically pure sulfoxide and study the influence of this compound on hemostasis. Detailed NMR studies and molecular dynamics simulations using sodium dodecyl sulfate (SDS) membrane models indicated that the bicyclic fragment of sulfoxide was embedded into the SDS micelle whereas the -SO(CH2)2OH fragment remained on the surface of the micelle and was in contact with the solvent. We also found that the pro-coagulative activity of sulfoxide was due to its ability to inhibit platelet activation and inhibited the catalytic activity of phospholipid surface which was involved in formation of coagulation clotting factor complexes.

Preparation of Astragalus membranaceus lectin and evaluation of its biological function.

Astragalus membranaceus lectin (AML) was abstracted as a supposedly novel agglutinin of 67 kDa from the seeds of Astragalus membranaceus. The seeds of Astragalus membranaceus were treated with acetate, ammonium sulfate precipitation, and purified by HiTrap SP XL ion column and Superdex G25 gel filtration chromatography to obtain the AML. AML contained 16.4% sugar, ~70% polar amino acids and ~30% hydrophobic amino acids. The AML exhibited agglutination activity toward human and animal erythrocytes, particularly human blood type O and rabbit erythrocytes. It also exhibited acid/alkali resistance and thermal denaturation above 64°C. Compared with human normal liver HL-7702 cells, different concentrations of AML (6.25, 12.50, 25.00 and 50.00 µg/ml) exhibited superior inhibitory effects on the growth of SGC-7901, HepG2 and H22 carcinoma cell lines, and displayed marked antibacterial effects on bacteria; the half maximal inhibitory concentration for B. dysenteriae, S. aureus and E. coli were 85.4, 80.2 and 65.3 µg/ml, respectively.

Functional and Molecular Characterization of C91S Mutation in the Second Epidermal Growth Factor-Like Domain of Factor VII.

BACKGROUND: Coagulation Factor VII is a vitamin K-dependent serine protease which has a pivotal role in the initiation of the coagulation cascade. The congenital Factor VII deficiency is a recessive hemorrhagic disorder that occurs due to mutations of F7 gene. In the present study C91S (p.C91S) substitution was detected in a patient with FVII deficiency. This mutation has not been characterized by a functional study. OBJECTIVES: In this study, we aimed to evaluate the impact of C91S substitution on factor VII expression and function. MATERIALS AND METHODS: The F7 complete cDNA was isolated from HepG2 cell line and inserted into the pcDNA3.1 mammalian expression vector. The desired mutation was generated by the site-directed mutagenesis and the wild-type and mutated constructs were transfected into CHO-K1 cells. The protein activity and antigen level (antigen concentration) were validated in the culture medium and cell lysate of the transiently transformed cells. An immunocytochemistry procedure was also performed to evaluate the intracellular localization of the mutated and the wild-type FVII, as well. RESULTS: The present in vitro study has demonstrated that C91S antigen expression was increased in the transfected CHO-K1 cells compared to the wild-type (WT) protein. Despite an increased protein secretion, the factor VII coagulant activity was diminished following C91S substitution when it was assessed by a standard one-stage analysis. In addition, the immunocytochemistry procedure revealed that there was no difference in the intracellular localization of the C91S mutated FVII compared to the WT protein. CONCLUSIONS: Our results present that C91S mutation has an effect on the coagulation activity, secretion, biosynthesis, and probably folding of the FVII leading to the FVII deficiency.

Procoagulant Substance and Mechanism of Myristica fragrans.

The effect and mechanisms of Myristica fragrans on blood clotting were evaluated by evaluating blood coagulation time and the fibrinolytic system. The compounds 2 and 5 were isolated from the herbal extract and their activities were assessed for the first time. None of the tested compounds had fibrinolytic activity, but could inhibit the fibrinolytic activity of urokinase. Compound 2 showed the highest inhibitory activity (IC50 = 1.747 mg·mL-1) followed by compounds 4 (IC50 = 1.818 mg·mL-1) and 1 (IC50 = 2.407 mg·mL-1), which were higher than that of the compound in Danshen drug tablets (IC50 = 6.577 mg·mL-1) used in China. Moreover, compounds 1 and 2 showed strong α-glucosidase inhibitory activity in a dose-dependent manner with IC50 values 21.76 ± 0.59 and 21.31 ± 0.00 µg·mL-1, respectively. These results demonstrated that the compounds are promising candidates as procoagulant and antidiabetic agents.

Novel HIT antibody detection method using Sonoclot® coagulation analyzer.

INTRODUCTION: Since heparin-induced thrombocytopenia (HIT), caused by the generation of antibodies against platelet factor 4 (PF4)/heparin complexes (HIT antibodies), may induce serious complications due to thrombosis, a prompt diagnosis is desirable. Functional tests with platelet activation to detect HIT antibodies are useful for diagnosis of HIT, in particular (14)C-selotonin release assay (SRA). However, they are complicated and so can be performed only in limited laboratories. We tested if a blood coagulation test using Sonoclot® analyzer can serve for the detection of HIT antibodies. MATERIALS AND METHODS: A murine monoclonal antibody (HIT-MoAb) against PF4/heparin complexes was used as an alternative to human HIT antibodies. To the mixture of HIT-MoAb and heparin (0.5 U/mL, final), whole blood obtained from a healthy volunteer was added, and then the activated clotting time (ACT), clot rate (CR), and area under the curve (AUC) were measured with Sonoclot® analyzer for 30minutes. RESULTS: The HIT-MoAb (30 to 100µg/mL, final) concentration dependently suppressed the anticoagulation activity (prolongation of ACT and decrease of CR and AUC) of heparin. CONCLUSIONS: The suppression of anticoagulation effect of heparin by HIT-MoAb was demonstrated by measurements using Sonoclot® analyzer. This method may provide a new tool for screening of HIT antibodies.