In silico evidence of Remdesivir action in blood coagulation cascade modulation in COVID-19 treatment

BACKGROUND Coronavirus disease 2019(COVID-19)has demonstrated several clinical manifestations which include not only respiratory system issues but also liver,kidney,and other organ injuries.One of these abnormalities is coagulopathies,including thrombosis and disseminated intravascular coagulation.Because of this,the administration of low molecular weight heparin is required for patients that need to be hospitalized.In addition,Remdesivir is an antiviral that was used against Middle East Acute Respiratory Syndrome,Ebola,Acute Respiratory Syndrome,and other diseases,showing satisfactory results on recovery.Besides,there is evidence suggesting that this medication can provide a better prognosis for patients with COVID-19.AIM To investigate in silico the interaction between Remdesivir and clotting factors,pursuing a possibility of using it as medicine.METHODS In this in silico study,the 3D structures of angiotensin-converting enzyme 2(ACE2),Factor I(fibrinogen),Factor II(prothrombin),Factor III(thromboplastin),Factor V(proaccelerin),Factor VII(proconvertin),Factor VIII(antihemophilic factor A),Factor IX(antihemophilic factor B),Factor X(Stuart-Prower factor),and Factor XI(precursor of thromboplastin(these structures are technically called receptors)were selected from the Protein Data Bank.The structures of the antivirals Remdesivir and Osetalmivir(these structures are called ligands)were selected from the PubChem database,while the structure of Atazanavir was selected from the ZINC database.The software AutoDock Tools(ADT)was used to prepare the receptors for molecular docking.Ions,peptides,water molecules,and other ones were removed from each ligand,and then,hydrogen atoms were added to the structures.The grid box was delimited and calculated using the same software ADT.A physiological environment with pH 7.4 is needed to make the ligands interact with the receptors,and still the software Marvin sketch®(ChemAxon®)was used to forecast the protonation state.To perform molecular docking,ADT and Vina software was connected.Using PyMol®software and Discovery studio®software from BIOVIA,it was possible to analyze the amino acid residues from receptors that were involved in the interactions with the ligands.Ligand tortions,atoms that participated in the interactions,and the type,strength,and duration of the interactions were also analyzed using those software.RESULTS Molecular docking analysis showed that Remdesivir and ACE2 had an affinity energy of-8.8 kcal/moL,forming a complex with eight hydrogen bonds involving seven atoms of Remdesivir and five amino acid residues of ACE2.Remdesivir and prothrombin had an interaction with six hydrogen bonds involving atoms of the drug and five amino acid residues of the clotting factor.Similar to that,Remdesivir and thromboplastin presented interactions via seven hydrogen bonds involving five atoms of the drug and four residues of the clotting factor.While Remdesivir and Factor V established a complex with seven hydrogen bonds between six antiviral atoms and six amino acid residues from the factor,and Factor VII connected with the drug by four hydrogen bonds,which involved three atoms of the drug and three residues of amino acids of the factor.The complex between Remdesivir and Factor IX formed an interaction via 11 hydrophilic bonds with seven atoms of the drug and seven residues of the clotting factor,plus one electrostatic bond and three hydrophobic interactions.Factor X and Remdesivir had an affinity energy of-9.6 kcal/moL,and the complex presented 10 hydrogen bonds and 14 different hydrophobic interactions which involved nine atoms of the drug and 16 amino acid residues of the clotting factor.The interaction between Remdesivir and Factor XI formed five hydrogen bonds involving five amino acid residues of the clotting factor and five of the antiviral atoms.CONCLUSION Because of the in silico significant affinity,Remdesivir possibly could act in the severe acute respiratory syndrome coronavirus 2 infection blockade by interacting with ACE2 and concomitantly act in the modulation of the coagulation cascade preventing the hypercoagulable state.

STRUCTURE-FUNCTION FEATURES AND EFFECTS ON BLOOD COAGULATION OF SNAKE VENOM SERINE PROTEASES*

Snake venoms,especially those from the two subfamilies,Crotalinae and Viperinae,contained a lot of serine proteases. They were responsible for the hemorrhage,shock,or disorder of blood coagulation after envenomation. They acted,by activating,inactivating,or other converting effects,on almost all the components of hemostatic and fibrinolytic systems. Their sequences were homologous to trypsin-kallikrein serine proteases. Variation of primary sequences out of active center results in the difference of substrate specificities and the further difference of biological and pharmacological activities. Because of their common and unique properties compared to their physiological corresponding factors,snake venom proteases are proved to be an excellent model for the study of protease substrate discriminating mechanism. Furthermore,they have found an important position both in basic research and application of hemostasis and thrombosis in clinic.

Expression patterns and action analysis of genes associated with blood coagulation responses during rat liver regeneration

AIM: To study the blood coagulation response after partial hepatectomy (PH) at transcriptional level. METHODS: After PH of rats, the associated genes with blood coagulation were obtained through reference to the databases, and the gene expression changes in rat regenerating liver were analyzed by the Rat Genome 230 2.0 array. RESULTS: It was found that 107 genes were associated with liver regeneration. The initially and totally expressing gene numbers occurring in initiation phase of liver regeneration (0.5-4 h after PH), G0/G1 transition (4-6 h after PH), cell proliferation (6-66 h after PH), cell differentiation and structure-function reconstruction (66-168 h after PH) were 44, 11, 58, 7 and 44, 33, 100, 71 respectively, showing that the associated genes were mainly triggered in the forepart and prophase, and worked at different phases. According to their expression similarity, these genes were classified into 5 groups: only up-, predominantly up-, only down-, predominantly down-, up- and down-regulation, involving 44, 8, 36, 13 and 6 genes, respectively, and the total times of their up- and down-regulation expression were 342 and 253, respectively, demonstrating that the number of the up-regulated genes was more than that of the down- regulated genes. Their time relevance was classified into 15 groups, showing that the cellular physiological and biochemical activities were staggered during liver regeneration. According to gene expression patterns, they were classified into 29 types, suggesting that their protein activities were diverse and complex during liver regeneration.CONCLUSION: The blood coagulation response is enhanced mainly in the forepart, prophase and anaphase of liver regeneration, in which the response in the forepart, prophase of liver regeneration can prevent the bleeding caused by partial hepatectomy, whereas that in the anaphase contributes to the structure-function reorganization of regenerating liver. In the process, 107 genes associated with liver regeneration play an important role.

DYNAMIC MODEL AND SIMULATION OF THE PLATELETS'ROLE IN BLOOD COAGULATION

In order to confirm which process is the most important in the blood coagulation cascade,a dynamic model on the function of platelets in blood coagulation is presented based on biochemical experiments.Based on qualitative analysis and mathematical simulation,a series of conclusions about the influence of the activation rate of factor VIII and factor IX on the generation of thrombin(IIa)are drawn.It is evident that the pro-coagulation stimulus must exceed a threshold value to initiate the coagulation cascade.The value is related to the binding constant d_2 of the platelet. The stability of the equilibrium value is also related to the pro-coagulation stimulus. This article also evaluates the influence of the stimulus strength and the activated rate parameter of platelets on thrombin.The proportion of platelets activated at any given time is designated c.To each c,we obtain a maximum concentration of thrombin.It is evident that when the level of factor IX is below 1% of the normal level,the rate of thrombin generation reduces dramatically,resulting in severe bleeding tendency.

Pulsed cold plasma-induced blood coagulation and its pilot application in stanching bleeding during rat hepatectomy

This paper presents plasma-induced blood coagulation and its pilot application in rat hepatectomy by using a home-made pulsed cold plasma jet. Experiments were conducted on blood coagulation in vitro, the influence of plasma on tissue in vivo, and the pilot application of rat hepatectomy. Experimental results show that the cold plasma can lead to rapid blood coagulation. Compared with the control sample, the plasma-induced agglomerated layer of blood is thicker and denser, and is mostly composed of broken platelets. When the surface of the liver was treated by plasma, the influence of the plasma can penetrate into the liver to a depth of about 500 μm. During the rat hepatectomy, cold plasma was proved to be effective for stanching bleeding on incision. No obvious bleeding was found in the abdominal cavities of all six rats 48 h after the hepatectomy. This implies that cold plasma can be an effective modality to control bleeding during surgical operation.

Protective effects of Dragon's Blood on blood coagulation and NO/iNOS level in myocardium and serum of rats in simulated microgravity

To investigate effects of Dragon＇s Blood（DB）,a traditional Chinese medicine,on blood coagulation and NO/iNOS level in myocardium and serum of rats in simulated microgravity for the first time,Sprague Dawley（SD）rats were randomly divided into six groups：（a）5-day control group,（b）5-day model group,（c）5-day drug group,（d）21-day control group,（e）21-day model group,and（f）21-day drug group.Blood coagulation and NO/iNOS level in myocardium and serum were examined after 5 and 21 days of simulated microgravity respectively.The results showed that blood of tail-suspended rats was in a hypercoagulable state that could not be converted with time extending.Conversely,DB changed these parameters towards normal level and the curative effects became better when tail-suspension lasted till the 21 st day.NO concentration of both myocardium and serum for two periods all increased markedly and DB could effectively reduce these increases except that of 21-day myocardium NO.Activity of iNOS increased markedly as early as 5 days and became more serious on the 21 st day,while DB showed preventive effect on the 21 st day.Western Blot analysis illustrated that the expression of iNOS in the 5-day model group increased significantly over the 5-day control group and the expression in the 5-day drug group dramatically returned to the normal level.The similar trend was observed on the 21-day groups without notable variances.The findings of this study can serve for the further use of Dragon＇s Blood in space diseases.

Perioperative coagulation activation after permanent pacemaker placement

BACKGROUND Bradyarrhythmias are typically treated with permanent pacemakers(PM). The elimination of bradyarrhythmia by PM implantation improves the patient’s quality of life and prognosis, but it can also result in a number of sequalae. It is still unclear how PM implantation affects the hemostasis system’s parameters and how such parameters relate to different consequences after PM placement.AIM To assess the blood coagulation factor activity in PM patients throughout the perioperative period.METHODS Patients treated in the Department of Surgical Therapy of Cardiac Arrhythmias and Pacing at the Ryazan State "Regional Clinical Cardiology Dispensary" from April 2020 to December 2021 were included in the study. Before surgery, 7 and 30 d after PM placement, peripheral venous blood samples were withdrawn to measure the level of blood coagulation factor Ⅰ(FⅠ) and the activity of blood coagulation factors Ⅱ(FⅡ), Ⅴ(FⅤ), Ⅶ(FⅦ), Ⅷ(FⅧ), ⅸ(Fⅸ), ⅹ(Fⅹ), Ⅺ(FⅪ), Ⅻ(FⅫ). We used an automatic coagulometer Sysmex CA 660(Sysmex Europe, Germany) and reagents from Siemens(Siemens Healthcare Diagnostics Products GmbH, Germany).RESULTS The study included 146 patients. The activity of factors FⅤ [147.7(102.1-247.55)% vs 103.85(60-161.6)% vs 81.8(67.15-130.65)%, P = 0.002], FⅧ [80.4(60.15-106.25)% vs 70.3(48.5-89.1)% vs 63.7(41.6-88.25)%, P = 0.039], Fⅸ [86.2(70.75-102.95)% vs 75.4(59.2-88.3)% vs 73.9(56.45-93.05)%, P = 0.014], Fⅹ [188.9(99.3-308.18)% vs 158.9(83.3-230)% vs 127.2(95.25-209.35)%, P = 0.022], FⅪ [82.6(63.9-103.6)% vs 69.75(53.8-97.6)% vs 67.3(54.25-98.05)%, P = 0.002], FⅫ [87.6(67.15-102.3)% vs 78.9(63.4-97.05)% vs 81.2(62.15-97.4)%, P < 0.001] decreased at 7 and 30 d after surgery;FⅡ activity [157.9(109.7-245.25)% vs 130(86.8-192.5)% vs 144.8(103.31-185.6)%, P = 0.021] decreased at 7 d and increased at 30 d postoperatively. There were no statistically significant changes in the FVII activity within 30 d after PM placement [182.2(85.1-344.8)% vs 157.2(99.1-259)% vs 108.9(74.9-219.8)%, P = 0.128]. Subgroup analysis revealed similar changes only in patients on anticoagulant therapy. FⅫ activity decreased in patients on antiplatelet therapy [82(65.8-101.9)% vs 79.9(63.3-97.1)% vs 89.7(75.7-102.5)%, P = 0.01] 7 d after surgery, returning to baseline values at 30 d postoperatively.CONCLUSION PM placement and anticoagulant therapy were associated with decreased activity of clotting factors FⅤ, FⅧ, Fⅸ, Fⅹ, FⅪ, FⅫ in the postoperative period. FⅧ activity did not decrease within 30 d after PM placement, which may indicate endothelial injury caused by lead placement.

Experimental research on TECA-I bioartificial liver support system to treat canines with acute liver failure

AIM: To evaluate the efficacy and safety of the TECA-I bioartificial liver support system (BALSS) in treating canines with acute liver failure (ALF). METHODS: Ten canines with ALF induced by 80% liver resection received BALSS treatment (BALSS group). Blood was perfused through a hollow fiber tube containing 1X10(10) porcine hepatocytes.Four canines with ALF were treated with BALSS without porcine hepatocytes (control group), and five canines with ALF received drug treatment (drug group). Each treatment lasted 6 hours. RESULTS: BALSS treatment yielded beneficial effects for partial liver resection induced ALF canines with survival and decreased plasma ammonia, ALT, AST and BIL. There was an obvious decrease in PT level and increase in PA level, and there were no changes in the count of lymphocytes, immunoglobulins (IgA, IgG and IgM) and complement (C3 and C4) levels after BALSS treatment. In contrast, for the canines with ALF in non-hepatocyte BALSS group (control group) and drug group, there were no significant changes in ammonia, ALT, AST, BIL, PT and PA levels. ALF canines in BALSS group, control group and drug group lived respectively an average time of 108.0h +/- 12.0h, 24.0h +/- 6.0h and 20.4h +/- 6.4h,and three canines with ALF survived in BALSS group. CONCLUSION: TECA-I BALSS is efficacious and safe for ALF canines induced by partial liver resection.

Preparation and Structure of a New Coagulation Factor XI Catalytic Domain for Drug Discovery

Human blood coagulation factor XI （FXI） is a key enzyme in the amplification phase of blood coagulation cascade, and is recognized as an important target for anti-coagulant development in recent years. We designed a new mutant form of FXIa catalytic domain rhFXI370-607 （N73Q-N113Q-C123S）, and report here the facile preparation, protein crystallization, and crystal structure of this protein. We highlight a few unique structural features of FXIa after comparison with the trypsin family serine proteases at sequence and structural levels. This work provides a foundation to develop new small molecular FXIa inhibitors with increased potency and specificity.

Effects of Taohong Siwu Decoction on coagulation function and PI3K/AKT/mTOR pathway after femoral artery anastomosis in rabbits

Objective:To observe the effect of Taohong Siyu Decoction on the coagulation function and the signaling pathway of PI3K(phosphatidylinositol 3-kinase)/AKT(protein kinase B)/mTOR(mammalian target of rapamycin)after femoral artery anastomosis in rabbits.Methods:30 New Zealand white rabbits were divided into blank control group,model control group,papavine hydrochloride injection group and low,medium and high dose groups of Taohong Siwu decoction by random number table method,with 5 rabbits in each group.The rabbits in the model control group,papavine hydrochloride injection group and low,medium and high dose groups of Taohong Siwu decoction were treated with the femoral artery simple intermittent end-to-end suture model.After the successful modeling,the low,medium and high dose groups of Taohong Siwu decoction were given the Taohong Siwu decoction,while the model control group,the blank control group and papavine hydrochloride injection group were given the same amount of normal saline.APTT(activated partial thromboplastin time),FIB(fibrinogen)and PI3K/AKT/mTOR concentrations were measured in aural venous blood samples from six groups of rabbits 30min before operation and 1d,2D,3D and 7d after operation,respectively.Statistical analysis was conducted on the data of the six groups.Results:Compared with blank control group,APTT of model control group was significantly shortened 1d to 7d after operation(P<0.05),FIB values were significantly increased from 1d to 7d after operation(P<0.05);Compared with model control group,APTT in Taohong Siwu decoction low-dose,medium-dose and high-dose groups were significantly prolonged 1d to 7d after operation(P<0.05),FIB value of Taohong Siwu decoction medium and high dose groups decreased significantly from 1d to 7d after operation(P<0.05),the FIB value of Taohong Siwu decoction low-dose group was significantly decreased from 2d to 7d after surgery(P<0.05);Compared with papaverine hydrochloride injection group,APTT in Taohong Siwu decoction medium dose group was significantly prolonged 2d to 7d after surgery(P<0.05),APTT of Taohong Siwu decoction high-dose group was significantly prolonged on 1d to 7d after operation(P<0.05).FIB in Taohong Siwu decoction medium and high dose groups decreased significantly 1d to 7d after operation(P<0.05);Compared with the blank control group,the expression concentrations of PI3K,Akt and mTOR in serum of the model control group were significantly increased from 1d to 7d after surgery(P<0.05);Compared with the model control group,the expression levels of PI3K,Akt and mTOR in serum were significantly increased in the low dose group of Taohong Siwu decoction and Papaverine Hydrochloride Injection group on postoperative 7 days(P<0.05),Taohong Siwu decoction high-dose group was significantly increased from 1d to 7d after surgery(P<0.05),the expression concentrations of PI3K and Akt in Taohong Siwu decoction medium dose group were significantly increased from 2d to 7d after operation(P<0.05),mTOR expression levels were significantly increased from 3d to 7d after operation(P<0.05);Compared with papaverine hydrochloride injection group,the expression concentrations of PI3K,Akt and mTOR in serum of Taohong Siwu decoction medium dose group were significantly increased from 3d to 7d after operation(P<0.05),the expression concentrations of PI3K and mTOR in Taohong Siwu decoction high-dose group were significantly increased from 1d to 7d after operation(P<0.05),and the expression concentration of Akt increased significantly from 3d to 7d after operation(P<0.05).Conclusion:The Taohong Siwu decoction can improve the coagulation function of rabbit femoral artery anastomosis,prevent thrombosis,activate PI3K/Akt/mTOR signaling pathway,promote angiogenesis,and improve tissue ischemia after artery anastomosis.

THE EFFECTS OF INJURIES IN THE EXTREMITIES ON HUMAN COAGULATION STATUS

Objective To investigate the changes of blood coagulation status and the safety of emergency microsurgery in patients with acute trauma to their extremities. Methods Forty seven patients with open injuries to the extremities were divided into 3 groups: in Group Ia (n=20), the patients presented with open injury to a single limb without traumatic shock and chest or head injuries, and they did not undergo microsurgery; while in Group Ib (n=13), an emergency microsurgery was done. In Group Ⅱ , the patients suffered from multiple compound fractures of the extremities with traumatic shock and chest or head injuries. The blood coagulation status of all the patients was evaluated by testing platelet count (PLC), platelet adhesiveness (PadT), serum antithrombin Ⅲ (AT- Ⅲ ), and D-dimer (D-Di) level. Results In Groups Ia and Ib, only PadT was increased and AT- Ⅲ declined preoperatively, then they returned to normal 24h postoperatively. In Group Ⅱ, at different periods after trauma, there was significant evidence of Pg and AT-Ⅲ decline accompanied by high increase of PadT and D-Di level; at 24h postoperatively, the mean values were 49.3% (PadT), 2.7mg/L (D-Di), 1..1g/L (Pg), and 69.1% (AT-Ⅲ), respectively. All these changes got significant difference (P<0.05) when compared with the normal value and those of Groups Ia and Ib, and did not completely return to normal even 72h after operation. Conclusion An emergency microsurgery could be safely performed in patients with ordinary open injuries to their limbs without traumatic shock, however it should be done with caution in cases of severe injuries with traumatic shock, because hypercoagulation status would follow in several hours after injuries. D-Di measurement may be used as a screening test to predict and assess hypercoagulation status more early after trauma.

Mathematical Model of Extrinsic Blood Coagulation Cascade Dynamic System

WTFZ] The blood coagulation system is very important to life. This paper presents a mathematical blood coagulation model for the extrinsic pathway. This model simulates clotting factor VIII , which plays an important role in the coagulation mechanism. The mathematical model is used to study the equilibrium stability, orbit structure, attractors and global stability behavior, with conclusions in accordance with the physiological phenomena. Moreover, the results provide information about blood related illnesses, which can be used for further study of the coagulation mechanism.

Prediction of return of spontaneous circulation in outof-hospital cardiac arrest with non-shockable initial rhythm using point-of-care testing: a retrospective observational study

BACKGROUND:Out-of-hospital cardiac arrest(OHCA) is a public health concern, and many studies have been conducted on return of spontaneous circulation(ROSC) and its prognostic factors.Rotational thromboelastometry(ROTEM?), a point-of-care testing(POCT) method, has been useful for predicting ROSC in patients with OHCA, but very few studies have focused on patients with non-shockable rhythm. We examined whether the parameters of POCT could predict ROSC in patients with OHCA and accompanying non-shockable rhythm.METHODS:This is a single-center, retrospective observational study. Complete blood count,blood gas, and ROTEM POCT measurements were used. This study included patients with nontraumatic OHCA aged 18 years or older who were transported to the emergency department and evaluated using POCT between January 2013 and December 2021. The patients were divided into the ROSC and non-ROSC groups. Prehospital information and POCT parameters were compared using receiver operating characteristic(ROC) curve analysis, and further logistic regression analysis was performed.RESULTS:Sixty-seven and 135 patients were in the ROSC and non-ROSC groups,respectively. The ROC curves showed a high area under the curve(AUC) for K^(+) of 0.77(95%confidence interval [CI]:0.71–0.83) and EXTEM amplitude 5 min after clotting time(A5) of 0.70(95%CI:0.62–0.77). The odds ratios for ROSC were as follows:female sex 3.67(95%CI:1.67–8.04);K^(+)0.64(95%CI:0.48–0.84);and EXTEM A5 1.03(95%CI:1.01–1.06).CONCLUSION:In OHCA patients with non-shockable rhythm, K^(+) level and the ROTEM parameter EXTEM A5 may be useful in predicting ROSC.

Effect of artificial colloids on blood coagulation during shock stage of severe burn injury

Background There are controversies about the use of artificial colloids. This research was aimed to determine the effect of various artificial colloids on blood coagulation in the shock stage of severe burn injury. Methods Totally, 18 female Ba-Ma mini-pigs were subjected to a 40% total body surface third-degree flame burn under anesthesia. Resuscitation therapy was applied 2 hours after the injury, using the burn shock fluid resuscitation formula commonly accepted in the surgical treatment of bums. The Ba-Ma mini-pigs were randomly assigned to three groups （six pigs in each group）： succinylated gelatin group （the artificial colloid used was succinylated gelatin Injection）, hydroxyethyl starch group （the artificial colloid used was hydroxyethyl starch （130/0.4））, and allogeneic plasma group （the colloid used was allogeneic plasma）. Blood samples were collected from the animals prior to the bum injury and again at intervals of 4, 8, 24 and 48 hours post-injury. The platelet count （PLT）, prothrombin time （PT）, international normalized ratio （INR）, activated partial thromboplastin time （APTT）, and fibrinogen （Fib） were measured, followed by a statistical analysis of all results. Results The PLT of succinylated gelatin group and hydroxyethyl starch group at intervals of 24 and 48 hours were （124.3±52.7）, （78.8±16.4）×10^9/L and （159.0±62.8）, （87.3±32.0）×10^9/L respectively. But in the allogeneic plasma group at intervals of 8, 24, and 48 hours were （234.3±52.6）, （136.0±47.4）, （75.8±31.0）×10^9/L. The decrease were all statistically significant （P 〈0.05, P 〈0.01） when compared to pre-burn （（383.3±77.9）, （382.7±65.7）, （381.0±49.4）×10^9/L）. The PLT among the three groups, at all the time points, had no statistical difference （P 〉0.05）. Compared to pre-burn （（10.8±0.9）, （11.4± 0.8）, （10.6±0.7） seconds）, the PT of succinylated gelatin group and hydroxyethyl starch group at 24 hours were （14.5±1.5） and （16.2±1.3） seconds, whereas in the allogeneic plasma group at 8 and 24 hours the PT were （13.0±0.9） and （14.5±1.5） seconds, i.e., an increase in the statistical significance （P 〉0.01）. Statistical significance was observed at 8 and 48 hours between the succinylated gelatin group and hydroxyethyl starch group, and at 48 hours between the hydroxyethyl starch and allogeneic plasma group （P 〈0.05）. The INR at 24 hours were （1.26±0.13） in the succinylated gelatin group, （1.40±0.11） in the hydroxyethyl starch group, and （1.13± 0.07） and （1.26±0.13） at 8 and 24 hours in the allogeneic plasma group. When compared with pre-bum （（0.94±0.08）, （0.99± 0.07）, and （0.92±0.06） seconds）, the other groups have increased significantly （P 〉0.01）. The comparison at 8 and 48 hours between the succinylated gelatin group and the hydroxyethyl starch group, at 48 hours between hydroxyethyl starch group and allogeneic plasma group showed statistical difference （P 〈0.01）. The APTT of succinylated gelatin group and hydroxyethyl starch group at 24 hours were （13.1±1.1） and （14.6±2.9） seconds. The APTT of the allogeneic plasma group at 4, 8 and 24 hours were （10.9±1.4）, （11.8±1.1）, and （13.7±1.5） seconds. Compared to pre-burn （（11.5±4.2）, （11.2±3.3）, （10.1±1.4） seconds）, they were statistically significant （P 〈0.05）. There was no statistical difference in the APTT between the three groups, at all the time points. The Fib of the succinylated gelatin group at 24 and 48 hours were （4.3±0.3） and （4.7±0.2） g/L, （4.1±0.3）, and （5.0±0.1） g/L in allogeneic plasma group, and at 8, 24, and 48 hours the Fib for the hydroxyethyl starch group was （2.9±0.4）, （4.0±0.5）, and （4.6±0.6） g/L. Compared to pre-burn （（2.4±0.2）, （2.5±0.3）, （2.6±0.5） g/L）, they were all statistically significant （P 〈0.01）. There was no statistical difference in APTT between the three groups, at all time points. Conclusion The changes of the indices in blood coagulation during the shock phase of a severe burn injury correlate with the stress response to the burn, rather than to the application of HES （130/0.4） and succinylated gelatin.

Active gastrointestinal bleeding:Use of hemostatic forceps beyond endoscopic submucosal dissection

To the best of our knowledge,this is the f irst report of the application of hemostatic forceps in active gastrointestinal(GI) bleeding that is not related to endoscopic submucosal dissection.An 86-year-old woman with chronic intake of low-dose aspirin had a Dieulafoy's lesion of the third duodenal portion.Bleeding control with epinephrine injection was unsuccessful.A 60-year-old man presented with a bleeding ulcer in the duodenal bulb.Ten days after combined endotherapy,he had recurrent bleeding from two minimal lesions in the same location.A 66-year-old woman under combined antithrombotic treatment was referred to us for chronic GI bleeding of unexplained origin.Endoscopy revealed active diverticular bleeding in the second duodenal portion.A 61-year-old woman underwent endoscopic mucosal resection of superficial gastric adenocarcinoma,which was complicated with immediate bleeding.In all cases,the blood was washed out using a water-jet-equipped,single-channel gastroscope with a large working channel.The bleeding points were pinched and retracted with hemostatic forceps.Monopolar electrocoagulation was performed using an electrosurgical current generator.Hemostasis was achieved.No complications occurred.In conclusion,hemostatic forceps may be an effective as well as safe alternative approach for active GI bleeding of various origins.

Clinical study on the related markers of blood coagulation in the patients with ANFH after SARS

The aim of this research was to investigate the blood coagulation function in the patients with avascular necrosis of the femoral head(ANFH)after severe acute respiratory syndrome(SARS).The expression of CD31,CD61,CD62p,CD63 and PAC-1 on platelet membrane was measured respectively by flowcytometry,and the plasma prothrombin time(PT),activated partial thromboplastin time(APTT),thrombin time(TT)and fibrinogen(Fbg)were mea-sured by blood clotting instrument in 26 patients with ANFH after SARS and in 17 healthy adults.The expression of CD31,CD61,CD 62p,CD63 and PAC-1 on platelet membrane in 26 patients was all lower than that in 17 healthy subjects(P<0.01).The levels of PT,APTT,TT and Fbg in 26 patients were all normal.There is no significant difference(P>0.05)in those markers between patients and 17 healthy adults.The blood may not be in hypercoagulable state in patients with ANFH after SARS.

Highly efficient artificial blood coagulation shortcut confined on Ca-zeolite surface

It is challenging to develop an in w'fro catalytic system to conduct natural surface-confined enzymatic reactions in a stable,efficient,and spatially defined manner.Here,we report that an artificial catalyst,which composes of trypsin and a calcium ion exchanged zeolite Y(trypsin/CaY),is capable of conducting surface-confined thrombin generation,and then constructs an artificial shortcut for classic,natural and complex blood coagulation cascade.The Ca2+within the microporous cages play a key role in trypsin/CaY hybrid through tuning the bio-inorganic interaction and spatial orientation of the protease,which allows trypsin/CaY to display greatly enhanced catalytic performance in coagulation process.The in vivo efficiency of the artificial coagulation shortcut is further confirmed in massive bleeding and hemophilia animal models.Rapid hemostasis is achieved by trypsin/CaY hybrid in a hemophilia A mice tail bleeding model,where natural clotting system fails in response to bleeding event due to factor VIII deficiency.In a rabbit lethal femoral artery injury model,the blood loss of the artificial catalyst is decreased by 4-7 fold when compared to state-of-art clay-or zeolite-based topical agents.

Neuroprotective effect of Cerebralcare Granule after cerebral ischemia/reperfusion injury

Cerebralcare Granule（CG） improves cerebral microcirculation and relieves vasospasm,but studies investigating its therapeutic effect on cerebral ischemia/reperfusion injury are lacking.In the present study,we administered CG（0.3,0.1 and 0.03 g/m L intragastrically） to rats for 7 consecutive days.We then performed transient occlusion of the middle cerebral artery,followed by reperfusion,and administered CG daily for a further 3 or 7 days.Compared with no treatment,high-dose CG markedly improved neurological function assessed using the Bederson and Garcia scales.At 3 days,animals in the high-dose CG group had smaller infarct volumes,greater interleukin-10 expression,and fewer interleukin-1β-immunoreactive cells than those in the untreated model group.Furthermore,at 7 days,high-dose CG-treated rats had more vascular endothelial growth factor-immunoreactive cells,elevated angiopoietin-1 and vascular endothelial growth factor expression,and improved blood coagulation and flow indices compared with untreated model animals.These results suggest that CG exerts specific neuroprotective effects against cerebral ischemia/reperfusion injury.

Combination of Shuxuetong and aspirin protects against cerebral ischemia/reperfusion injury through ameliorating coagulation and fibrinolysis system

Objective：To explore the influence of the combination of Shuxuetong（SXT）and aspirin on coagulation and fibrinolytic system of rats.Methods：Suture method was applied to establish focal cerebral ischemia-reperfusion injury models in rats.SD rats were randomly divided into sham group,middle cerebral artery occlusion/reperfusion（MCAO/R）group,aspirin group,SXT group,and SXT＋aspirin group（S＆A）.The neurological deficits were assessed according to Longa’s grade 5 scoring method.The cerebral edema was detected by measuring the content of water in brain tissue.The volume of cerebral infarction was observed by 2,3,5-Triphenyltetrazolium chloride（TTC）staining.Blood plasma was collected by abdominal aortic method to test maximum platelet aggregation rate and four blood coagulation.CD61,CD62p,6-keto prostaglandin F1αantithrombinⅢ（AT-Ⅲ）,D-dimer,plasminogen activator inhibitor-1（PAI-1）,tissue factor（TF）,tissue plasminogen activator（t-PA）,platelet thromboxaneand von Willebrand factor（v WF）content in rat plasma were detected by ELISA.Results：SXT combined with aspirin could improve the neurological deficits,alleviate cerebral edema,and decrease the cerebral infarct value.Compared with the sham operation group,fibrinogen（FIB）,6-AT-III,and t-PA in model group were significantly decreased;Compared with the model group,the above-mentioned indexes in SXT and aspirin treatment group were significantly increased.The prothrombin time（PT）,activated partial thromboplastin time（APTT）,thrombin time（TT）,D-dimer,PAI-1,TF,TXB2,and v WF of the model group were significantly increased;The above-mentioned indexes in blood SXT＋aspirin treated group were significantly decreased.There was a significant difference between the combined group and SXT group.The maximum concentration of plateletsin aspirin treated rats was significantly decreased,however,MPAR was reversed in SXT＋aspirin treated group.Conclusion：SXT combined with aspirin can effectively inhibit platelet activation,regulate the maximum concentration of platelets,and improve coagulation function and fibrinolysis system.

Hemostasis Efficacy and Mechanism of Cold Atmospheric Air Plasma

The capacity of a cold atmospheric-pressure air plasma (CAAP) device for advanced first aid is presented. Using swine as an animal model, two trials: 1) a large, curved cut in hindquarters area and 2) amputation of a front leg, were performed. Cold atmospheric-pressure air plasma effluent, which carries reactive oxygen species (ROS) atomic oxygen (OI), is applied for wound treatments. Swift hemostasis of the wounds by the CAAP treatment was demonstrated. The pressure applied by a finger on the cut arteries in trial 1 and the tourniquet applied in trial 2 could be removed immediately after the treatment and there was no re-bleed in both cases. CAAP hemostasis mechanism was explored via in-vitro tests. The tests on sodium citrate mixed blood-droplet samples show that 1) the heat delivered by the CAAP has no impact on the observed clot formation, 2) plasma effluent activates platelets to promote coagulation state and cascade, and 3) the degree of clotting increases with the total amount of applied OI by means of the CAAP effluent. It took only 16 s of the CAAP treatment to reach full clotting, which was considerably shortened from the natural clotting time of about 25 minutes. The tests on smeared blood samples show that the reduction of the platelet count and the increase of RBC count are proportional to the amount of applied OI. A plausible CAAP hemostasis mechanism is concluded from the in vitro test results and the animal model trials.