scholarly journals Production and purification of constructed recombinant hirudin in BL21(DE3) strain

2017 ◽  
Vol 3 (1) ◽  
pp. 62 ◽  
Author(s):  
Adnan I. Al-Badran ◽  
Sabaa Ali Al-Fadal

Background/Objective: Hirudin, an extract from the leech, has powerful antithrombin activity affecting the blood coagulation pathway, it is the most potent natural inhibitor of thrombin, it binds thrombin with high affinity, so, the aim of this study was to build hirudin gene by overlapping extension PCR then cloning and expression in BL21(DE3) strain.Methods: Hirudin gene constructed with four modified primers then the final product amplified by two primers named as A, B by using overlapping extension PCR, for gene expression, BL21(DE3) strain was used under the control of T7 promoter in pET-16b vector and for hirudin production, LB broth medium was used as fermentation medium. Hirudin protein purified at first by (Immobilized metal affinity chromatography) IMAC, then this protein was dialysis and treated with factor Xa to eliminate His-tag. Then hirudin purified by DEAE sepharose and SP sepharose column, the concentration of protein determined by ELISA, furthermore the activity evaluated by thrombin titration and activated partial thromboplastin time (APPT) test.Results: Hirudin gene constructed in two round PCR first round produced two products (product1 117 bp while product 2,114 bp) the second-round PCR gave the final product 213 bp. The resulted band from gel electrophoresis for constructed vector pET-16b-HirudinS was (5,901 bp). The analysis on 15% SDS-PAGE for the SP sepharose column illustrated the hirudinS protein band with size about ~10.8. Concentration of produced hirudin within its solution reached to 1.75 ng, thrombin titration method showed that the hirudin protein required 300 µl from thrombin to clot, also, APPT test showed that hirudin elongated clotting time to 7min in comparison with 6min for aspirin and the statistical analysis results for APPT test illustrated that there was no significant difference between hirudin and aspirin.Conclusion: This study approved that overlapping extension PCR is a good strategy for building hirudin gene and it’s successfully expressed in BL21(DE3) strain.

1978 ◽  
Vol 40 (02) ◽  
pp. 397-406 ◽  
Author(s):  
Joyce Low ◽  
J C Biggs

SummaryComparative plasma heparin levels were measured in normal subjects injected subcutaneously with 5,000 units of the sodium and calcium salts of heparin. Plasma heparin levels were measured up to 7 hr post-injection by an anti-factor Xa assay (Denson and Bonnar 1973). Preliminary studies indicated that heparin levels were reproducible in subjects who received two injections of the same heparin. Peak plasma concentrations (Cmax) and the time at which peak concentration was reached (Tmax) varied greatly from subject to subject. In one group of subjects (15) two commonly used heparins, a sodium heparin (Evans) and a calcium heparin (Choay) were compared. Peak heparin concentrations were not significantly different. However the Tmax for the sodium heparin (1.5 hr) was significantly earlier than the Tmax for the calcium heparin (3 hr) and this was not due to a difference in the volume of the two heparin injections. No significant difference could be detected in the plasma clearance rate and the molecular weight distribution of the two heparins.In two other groups of subjects, sodium and calcium preparations from two manufacturers were compared. In general, the sodium salts gave rise to significantly higher plasma concentrations, which could be interpreted as a greater bioavailability of sodium salts. These results indicate that the salt of the heparin can influence the plasma concentration achieved after subcutaneous injection.


1998 ◽  
Vol 79 (02) ◽  
pp. 306-309 ◽  
Author(s):  
Dougald Monroe ◽  
Julie Oliver ◽  
Darla Liles ◽  
Harold Roberts ◽  
Jen-Yea Chang

SummaryTissue factor pathway inhibitor (TFPI) acts to regulate the initiation of coagulation by first inhibiting factor Xa. The complex of factor Xa/ TFPI then inhibits the factor VIIa/tissue factor complex. The cDNA sequences of TFPI from several different species have been previously reported. A high level of similarity is present among TFPIs at the molecular level (DNA and protein sequences) as well as in biochemical function (inhibition of factor Xa, VIIa/tissue factor). In this report, we used a PCR-based screening method to clone cDNA for full length TFPI from a mouse macrophage cDNA library. Both cDNA and predicted protein sequences show significant homology to the other reported TFPI sequences, especially to that of rat. Mouse TFPI has a signal peptide of 28 amino acid residues followed by the mature protein (in which the signal peptide is removed) which has 278 amino acid residues. Mouse TFPI, like that of other species, consists of three tandem Kunitz type domains. Recombinant mouse TFPI was expressed in the human kidney cell line 293 and purified for functional assays. When using human clotting factors to investigate the inhibition spectrum of mouse TFPI, it was shown that, in addition to human factor Xa, mouse TFPI inhibits human factors VIIa, IXa, as well as factor XIa. Cloning and expression of the mouse TFPI gene will offer useful information and material for coagulation studies performed in a mouse model system.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3672-3672 ◽  
Author(s):  
Yimin Pearl Wang ◽  
Rohan Kehar ◽  
Alla Iansavitchene ◽  
Alejandro Lazo-Langner

Introduction: The standard oral anticoagulant therapy administered to non-valvular AF patients has typically been Vitamin K Antagonists (VKA) particularly warfarin. In recent years, Direct Oral Anticoagulants (DOACs) including Direct Thrombin Inhibitors (DTI) and Direct Factor Xa inhibitors (FXa inhibitors) have become an alternative to warfarin. Randomized trials comparing warfarin and DOACs showed comparable effectiveness without significant additional major bleeding risk. However, bleeding events in RCTs may differ from those in daily use due to the routine exclusion of patients with a higher risk of bleeding from many studies. We aimed to assess bleeding risk between DOACs and warfarin in AF patients in observational studies and we also sought to determine differences between patients that were experienced or naïve to oral anticoagulants. Methods: A systematic literature search was conducted in the OVID MEDLINE® and EMBASE® electronic databases. Observational studies and randomized control trials (RCT) from 1990 to January 2019 were retrieved and examined by two independent reviewers. A pooled effect hazard ratio (HR) was calculated using a random effects model using the generic inverse variance method. Subgroup analyses according to previous exposure to anticoagulants, study type, funding type and DOAC type were conducted. The primary outcome was major bleeding risk. The secondary outcome was clinically relevant non-major bleeding. All studies must have used an established or validated definition of major bleeding. Results: The initial literature search identified 3359 potentially eligible citations. After primary screening, 150 articles were eligible for full text review and there were 35 studies including 2,356,201 patients that met the inclusion criteria. Overall, patients on DOACs were less likely to experience a bleeding event compared to warfarin (HR 0.78, 95%CI 0.71, 0.85, P<0.001). The results were consistent when analyzing patients receiving DTIs or FXa inhibitors (DTI: HR 0.76, 95% CI 0.67,0.87; FXa inhibitors: HR 0.79, 95% CI 0.69,0.89). However, among patients receiving factor Xa inhibitors, there was a significant difference in the risk of bleeding according to individual drug. Among patients receiving rivaroxaban the risk of bleeding was similar to warfarin (HR 0.98, 95%CI 0.91,1.06, p=0.60) whereas in those receiving apixaban there was a 40% reduction in the risk of bleeding compared to warfarin (HR 0.60, 95%CI 0.50,0.71, p<0.001) (Figure 1). Three studies reported information according to previous anticoagulant exposure. The overall pooled hazard ratio was 0.68 (95% CI 0.55, 0.82 p<0.001) in favor of patients on DOACs. In the subgroup analysis of previous anticoagulant use, the risk of bleeding was lower for DOACs compared to warfarin in both the experienced population (HR 0.70, 95%CI 0.51, 0.96) and the naïve population (HR 0.64, 95% CI 0.47,0.87). However, heterogeneity was moderate to high among both subgroups. Conclusion: This review and meta-analysis of observational studies including over 2.3 million patients showed that overall DOACs have a lower risk of major bleeding and clinically relevant non-major bleeding compared to warfarin. Most importantly, although the pooled effect estimate did not differ between DTIs and FXa inhibitors, among patients receiving FXa inhibitors there was a significant difference between individual agents. Patients on apixaban had a significantly lower risk of bleeding compared to warfarin in contrast to patients on rivaroxaban who had a similar risk. Disclosures No relevant conflicts of interest to declare.


2007 ◽  
Vol 64 (8) ◽  
pp. 538-542
Author(s):  
Svetlana Pavlovic ◽  
Sladjana Zivkovic ◽  
Goran Koracevic

Background/Aim. The inhibition of factor Xa (FX) by the use of low-molecular heparin (LMH) is important clinical procedure in patients with moderate and high risk for the developament of venous thromboembolism (VTE) and pulmonary embolism (PE). The aim of this study was to determine the level of inhibition of FXa by the use of prophylactic doses of LMH nadroparin-calcium and reviparine-sodium which were applied in urological patients with moderate risk for VTE and PE. Methods. The examination included 80 urological patients divided into 4 groups after urological, uroradiological and anesthesiological preoperative preparation and categorization of anesthesiological risk according to the ASA III classification. The first two groups, of 20 patients each, received the recommended doses of LMH in accordance with the preoperative risk, and an inhibition of FXa 48 hours after the surgical operation and four hours after the administration of LMH was determined. Heptest and homogenous anti-Xa test were used for monitoring of FXa inhibition. Since the obtained anti-Xa values were not satisfactory, two more groups were formed and given double the recommended doses. In these new groups, inhibition of FXa was in recommended range. Standard descriptive statistical parameters were used for describing the charateristics of the people from the formed groups. Results. All the patients examined were clinically estimated as patients of moderate risk, for VTE and PE. There were no statistically singificant difference in body weight of the patients who received nadroparin-calcium 0.3 ml and reviparine-sodium 0.25 ml and those who received their double doses, respectively. The level of FXa inhibition in the group in which the dose of nadroparin-calcium of 0.6 ml was applied was statistically significantly higher than in the group which received the dose of 0.3 ml (Mann-Whitney U test: Z = 5.416; p < 0.0001). The level of FXa in the group given reviparine-sodium 0.5 ml was significantly higher than in the group which received the half of this dose (Mann-Whitney U test: Z = 5.416; p < 0.0001). This research did not confirm a statistically significant difference in the levels of FXa inhibition in patients who received nadroparincalcium as VTE and PE prophilaxis in the dose of 0.6 ml and those who received reviparin-sodium 0.5 ml (in two doses of 0.25 ml) (Mann-Whitney U test: Z = 0.163; p > 0.05). Conclusion. According to biochemical monitoring, the recommended doses of LMH are insufficient for the prophylactic inhibition of FXa in urological pateints with moderate risk for VTE and PE, so the higher doses which inhibit FXa are recommended. .


Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Erin A Bohula ◽  
Robert P Giugliano ◽  
Christian T Ruff ◽  
Julia F Kuder ◽  
Sabina A Murphy ◽  
...  

Background: Edoxaban (edox), an oral factor Xa inhibitor with 50% renal clearance, was non-inferior to warfarin for prevention of thromboembolic events and significantly reduced bleeding in pts with AF. However, a detailed analysis of the impact of creatinine clearance (CrCl) on clinical outcomes with edox has not been described. Purpose: We evaluated the safety, efficacy and net clinical outcome of edox vs warfarin (warf) across the range of baseline CrCl in the ENGAGE AF-TIMI 48 trial. Methods: 14,071 AF pts at moderate-to-high risk of stroke were randomized to edox 60mg QD or warf. Severe renal dysfunction (CrCl<30ml/min) was exclusionary and a CrCl 30-50 resulted in a 50% dose reduction of edox (30mg QD). Endpoints of stroke or systemic embolism (SSE), ISTH major bleeding (MB) and the primary net clinical outcome of SSE/MB and all-cause mortality (ACM) were evaluated by intention-to-treat analysis by the pre-specified singular CrCl cutpoint of 50ml/min and additional exploratory cutpoints. Results: The relative risk of SSE with edox vs warf in the pre-specified analysis in those with CrCl≤50 (HR 0.87, 0.65-1.18) was similar to those with CrCl>50 (HR 0.87, 0.72-1.04; p-int=0.94). Evaluation by more granular, exploratory cutpoints demonstrated higher rates of SSE (Fig 1a; p-int<0.001) and ischemic stroke (p-int=0.05) with edox vs warf in the upper range of CrCl, but lower rates of bleeding were observed at all levels of CrCl with edox (Fig 1a; p-int=0.39). For the net clinical outcome (SSE/MB/ACM), there was no significant difference between edox and warf at higher levels of renal function due to the preserved effect on bleeding and mortality (Fig 1b; p-int 0.17). An on-treatment analysis with plasma drug levels will be shown. Conclusion: While there is a trend towards decreasing efficacy with increasing CrCl for edox compared to well-managed warfarin, the overall safety and net clinical benefit of edox compared to warfarin is consistent across renal function groups.


1992 ◽  
Vol 65 (2) ◽  
pp. 157-164 ◽  
Author(s):  
B. Kaiser ◽  
J. Fareed ◽  
D. Hoppensteadt ◽  
B. Birdsong ◽  
J.M. Walenga ◽  
...  

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2103-2103
Author(s):  
Omer Iqbal ◽  
Nasir Sadeghi ◽  
Fadi Bakhos ◽  
Debra Hoppensteadt ◽  
Jawed Fareed

Abstract Abstract 2103 Poster Board II-80 Abstract: Recent reports from the National Heart, Lung and Blood Institute indicate that as many as 3 million women (particularly young) in the United States suffer from a form of heart disease fundamentally different from that in men, characterized by more even plaque development inside major and smaller blood vessels, posing diagnostic and treatment challenges leading to increased morbidity and mortality. It is hypothesized that women have variable but attenuated hemostatic responses to anticoagulant drugs when compared to men. In order to validate this hypothesis the hemostatic responses in healthy males (n=10) and females (n=10) were evaluated by performing the global clotting assays, fibrinokinetic assays and thrombin generation assays in the presence of Rivaroxaban, an oral Factor Xa inhibitor likely to replace warfarin, Enoxaparin, a low molecular weight heparin and saline as a control. Blood (20 ml) was drawn from healthy volunteers, males (n=10) and females (n=10) and placed into citrated tubes with one part of 3.2% sodium citrate to 9 parts of blood. The citrated whole blood was supplemented with Rivaroxaban (FC=0.3mg/ml), Enoxaparin (FC=5mg/ml) and saline as a control. The samples were analyzed to determine the whole blood APTT and Heptest clotting assays. The remaining citrated blood was centrifuged at 3000 rpm to obtain platelet poor plasma that was aliquoted and kept frozen at -70°C until further analysis. The plasma was then thawed and supplemented with saline, rivaroxaban (FC=0.3mg/ml) and Enoxaparin (FC=5mg/ml). A statistically significant difference between males and females was noted in APTT (p=0.0442)) and Heptest (p=0.0345) assays in the saline control values. However, the anticoagulant response to supplementation of the plasma samples with rivaroxaban at a final concentration of 0.3ug/ml and Enoxaparin at 5 ug/ml showed a statistically significant difference between males and females in the Heptest (P=0.0423) while the APTT assay felt a little short of statistical significance (P=0.0511). Fibrinokinetics was performed and absorbance recorded (405 nm) at every minute for the next 30 minutes. There are gender-based differences in fibrinokinetic responses to anticoagulant drugs with females showing faster fibrin formation than males. The attenuated hemostatic responses observed in women compared to men may interfere in achieving adequate and effective anticoagulation leading to thrombotic complications. Time (min) 0 30 Gender Male ODs Female ODs Male - ODs Female - ODs Male - ODs Female - ODs Saline control 0.857±0.31 0.611±0.22 1.367±0.28 1.214±0.28 1.377±0.26 1.24±0.28 Rivaroxaban (0.3ug/ml) 0.853±0.32 0.602±0.21 1.353±0.27 1.221±0.18 1.363±0.27 1.23±0.18 Enoxaparin (5ug/ml) 0.713±0.35 0.507±0.24 0.794±0.33 0.621±0.23 0.802±0.33 0.629±0.23 Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 208-208 ◽  
Author(s):  
Takeshi Fuji ◽  
Satoru Fujita ◽  
Shintaro Tachibana ◽  
Yohko Kawai

Abstract Abstract 208 Introduction: Edoxaban is an oral, direct factor Xa inhibitor in clinical development for the prevention and treatment of thromboembolic events. Two randomized, double-blind, double-dummy, phase 3 studies (STARS E-3 and STARS J-V) have been conducted to evaluate the efficacy and safety of edoxaban compared with enoxaparin for the prevention of venous thromboembolism (VTE) after total knee (TKA) or hip arthroplasty (THA). The objective of this pooled analysis was to investigate the effects of edoxaban on VTE and bleeding in key subgroups. Methods: Patients (N=1326) undergoing TKA or THA in Japan and Taiwan were randomized to receive oral edoxaban 30 mg once daily (qd) or subcutaneous enoxaparin 2000 IU twice daily (bid, equivalent to 20 mg bid) for 11–14 days. Edoxaban was initiated 6–24 hours after surgery and enoxaparin was initiated 24–36 hours after surgery, which is the standard of care in Japan. The primary efficacy outcome was the composite of symptomatic and asymptomatic deep vein thrombosis (DVT) and pulmonary embolism (PE). The principal safety outcome was the incidence of major and clinically relevant nonmajor (CRNM) bleeding. Results: A total of 1307 patients received at least 1 dose of edoxaban or enoxaparin. There were no clinically relevant differences in baseline characteristics between the treatment groups. The mean age was 68 years and mean body weight was 58.8 kg. Over 70% of patients received physiotherapy (intermittent pneumatic compression, elastic stocking). Overall, edoxaban significantly reduced the incidence of the composite of symptomatic and asymptomatic DVT and PE compared with enoxaparin (5.1% vs 10.7%, P<0.001). Subgroup analysis showed that edoxaban numerically reduced the incidence of the composite efficacy endpoint regardless of age or body weight. The effect was statistically significant in patients <75 years of age and in those <70 kg. Edoxaban was also significantly more effective than enoxaparin in the presence or absence of concomitant physiotherapy. The incidence of major and CRNM bleeding events was 4.6% vs 3.7% in the edoxaban and enoxaparin groups, respectively (P=0.427). Subgroup analysis of major and CRNM bleeding indicated no significant difference between edoxaban and enoxaparin in any of the patient subgroups evaluated, based on age, weight, or creatinine clearance. Conclusion: Edoxaban 30 mg qd is superior to enoxaparin 20 mg bid in the prevention of VTE events following TKA and THA without a statistically significant increase in bleeding in important patient subgroups likely to receive this treatment. Disclosures: Fuji: Daiichi Sankyo: Consultancy; Astellas: Consultancy; Showa Ikakogyo: Consultancy; Bayer: Consultancy. Fujita:Astellas: Consultancy; GlaxoSmithKline: Consultancy; Daiichi Sankyo: Consultancy; Bayer: Consultancy. Tachibana:Daiichi Sankyo: Consultancy. Kawai:Daiichi Sankyo: Consultancy; Toyama Chemical: Consultancy; Bayer: Consultancy.


2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Elodie Roels ◽  
Natali Bauer ◽  
Christelle Lecut ◽  
Andreas Moritz ◽  
André Gothot ◽  
...  

Abstract Background Canine idiopathic pulmonary fibrosis (CIPF) is a progressive interstitial lung disease mainly affecting old West Highland white terriers (WHWTs). The aetiology of CIPF is currently unknown and pathogenesis poorly understood. A genetic basis is strongly suspected based on the breed predisposition. CIPF shares clinical and pathological features with human IPF. In human IPF, coagulation disorders favouring a local and systemic pro-thrombotic state have been demonstrated in association with disease severity and outcome. The aim of this study was to compare the systemic haemostatic, fibrinolytic and inflammatory profiles of WHWTs affected with CIPF with breed-matched controls (CTRLs). Additionally, data collected in both groups were interpreted with regard to the reference intervals (when available) to assess possible pro-thrombotic features of the WHWT breed that may be related to CIPF predisposition. A total of 14 WHWTs affected with CIPF and 20 CTRLs were included. Results WHWTs affected with CIPF had prolonged activated partial thromboplastine time in comparison with CTRLs (12.2 ± 0.9 s vs. 11.5 ± 0.7 s, P = 0.028), whereas results obtained in both groups were all within reference ranges. There was no significant difference between groups for the other factors assessed including plasmatic concentrations of fibrinogen, D-dimers concentration, antithrombin III activity, protein S and protein C activities, anti-factor Xa activity, activated protein C ratio, serum C-reactive protein concentration, and rotational thromboelastometry indices. Platelet count and plasmatic fibrinogen concentration were found to be above the upper limit of the reference range in almost half of the WHWTs included, independently of the disease status. Conclusions Results of this study provide no clear evidence of an altered systemic haemostatic, fibrinolytic or inflammatory state in WHWTs affected with CIPF compared with CTRLs. The higher platelet counts and fibrinogen concentrations found in the WHWT breed may serve as predisposing factors for CIPF or simply reflect biological variation in this breed.


2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Cassiane S. O. Nunes ◽  
Marília L. C. da Silva ◽  
Geany P. Camilloto ◽  
Bruna A. S. Machado ◽  
Katharine V. S. Hodel ◽  
...  

The aim of this study was to evaluate the application of cocoa pulp as an adjunct for malt in beer production. The cocoa pulp was analyzed for humidity, proteins, lipids, sugars, total soluble solids, organic acids, and minerals. A study was carried out to reduce the cocoa pulp viscosity by enzymatic depectinization, making its use viable in beer production. The cocoa pulp showed relevant quantities of compounds important in fermentation, such as sugars, acids, and minerals. In fermentation using the adjunct, the proportions of pulp used were 10, 30, and 49%. A significant difference was found between the adjunct and all-malt worts. The 30% cocoa pulp concentration as an adjunct for malt in the fermentation medium contributed the most to the fermentative performance of the yeasts at both 15 and 22°C based on the consumption of apparent extract (°Plato), ethanol production, and cellular growth.


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