Application Value of Plasma vWF and ADAMTS-13 in Evaluating Postoprative Vascular Endothelial Injury and Prognosis in Children with VSD / 中国实验血液学杂志

OBJECTIVE@#To dynamically observe the levels and activities of von Willebrand factor (vWF) and ADAMTS-13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) in plasma of children with congenital ventricular septal defect (VSD) during perioperative period, and explore the value of plasma vWF antigen (vWF:Ag) and ADAMTS-13 activity (ADAMTS-13: AC) in evaluating vascular endothelial injury and prognosis in children with VSD.@*METHODS@#In this cross-sectional study, a total of 74 children with VSD who underwent surgical treatment in TEDA International Cardiovascular Hospital from September 2018 to March 2019 were enrolled in the observation group. Among them, there were 28 cases of pure VSD, 32 cases of VSD combined with pulmonary hypertension, and 14 cases of VSD combined with valvular heart disease. 31 healthy children who underwent physical examination in Tianjin Children's Hospital during the same period were collected as the control group. The biochemical indexes of the children at admission were recorded. Peripheral plasma was collected at admission, postsurgery day 0 and day 1, respectively, and the levels of vWF activity (vWF:AC), vWF:Ag, ADAMTS-13 antigen (ADAMTS-13:Ag) and ADAMTS-13:AC were detected.@*RESULTS@#The level of plasma vWF:Ag and vWF:AC in the observation group before surgery were significantly lower than those in the control group (P<0.001), and increased continuously, on postsurgery day 0 and day 1 (P<0.001). The level of ADAMTS-13:Ag in the observation group before surgery was significantly higher than that in the control group (P<0.001), which decreased significantly on postsurgery day 0 (P<0.001), and increased significantly on postsurgery day 1 compared with postsurgery day 0 (P=0.033). The level of ADAMTS-13:AC in the observation group before surgery was significantly lower than that in the control group (P=0.015), which decreased significantly on postsurgery day 0 (P=0.037), and increased on postsurgery day 1, but the difference was not statistically significant (P=0.051). The changes of vWF and ADAMTS-13 in the three subgroups were basically similar to the observation group. vWF: Ag/ADAMTS-13: AC ratio on postsurgery day 0 and day 1 had high diagnostic value in vascular endothelial injury (AUC=0.80, P<0.001; AUC=0.93, P<0.001). Preoperative vWF and ADAMTS-13 levels, and related baseline indicators were not correlated with postoperative infection, bleeding, thrombosis,etc.@*CONCLUSION@#Preoperative vWF: Ag, vWF: AC and ADAMTS-13: AC levels in children with VSD are low, while the level of ADAMTS-13: Ag is high. After surgery, the levels of vWF: Ag and vWF: AC are increased and the level of ADAMTS-13: Ag is decreased. The postoperative vWF: Ag/ADAMTS-13: AC ratio shows high diagnostic value in evaluating vascular endothelial injury. There is no correlation between preoperative vWF and ADAMTS-13 levels with perioperative clinical events.

Molecular dynamics simulation of force-regulated interaction between glycoprotein Ib α and filamin / 生物医学工程学杂志

In resting platelets, the 17 th domain of filamin a (FLNa17) constitutively binds to the platelet membrane glycoprotein Ibα (GPIbα) at its cytoplasmic tail (GPIbα-CT) and inhibits the downstream signal activation, while the binding of ligand and blood shear force can activate platelets. To imitate the pull force transmitted from the extracellular ligand of GPIbα and the lateral tension from platelet cytoskeleton deformation, two pulling modes were applied on the GPIbα-CT/FLNa17 complex, and the molecular dynamics simulation method was used to explore the mechanical regulation on the affinity and mechanical stability of the complex. In this study, at first, nine pairs of key hydrogen bonds on the interface between GPIbα-CT and FLNa17 were identified, which was the basis for maintaining the complex structural stability. Secondly, it was found that these hydrogen bonding networks would be broken down and lead to the dissociation of FLNa17 from GPIbα-CT only under the axial pull force; but, under the lateral tension, the secondary structures at both terminals of FLNa17 would unfold to protect the interface of the GPIbα-CT/FLNa17 complex from mechanical damage. In the range of 0~40 pN, the increase of pull force promoted outward-rotation of the nitrogen atom of the 563 rd phenylalanine (PHE 563-N) at GPIbα-CT and the dissociation of the complex. This study for the first time revealed that the extracellular ligand-transmitted axial force could more effectively relieve the inhibition of FLNa17 on the downstream signal of GPIbα than pure mechanical tension at the atomic level, and would be useful for further understanding the platelet intracellular force-regulated signal pathway.

Role and mechanisms of CHI3L1 in coronary artery lesions in a mouse model of Kawasaki disease-like vasculitis / 中国当代儿科杂志

OBJECTIVES@#To explore the role and potential mechanisms of chitinase-3-like protein 1 (CHI3L1) in coronary artery lesions in a mouse model of Kawasaki disease (KD)-like vasculitis.@*METHODS@#Four-week-old male SPF-grade C57BL/6 mice were randomly divided into a control group and a model group, with 10 mice in each group. The model group mice were intraperitoneally injected with 0.5 mL of lactobacillus casei cell wall extract (LCWE) to establish a mouse model of KD-like vasculitis, while the control group mice were injected with an equal volume of normal saline. The general conditions of the mice were observed on the 3rd, 7th, and 14th day after injection. Changes in coronary artery tissue pathology were observed using hematoxylin-eosin staining. The level of CHI3L1 in mouse serum was measured by enzyme-linked immunosorbent assay. Immunofluorescence staining was used to detect the expression and localization of CHI3L1, von Willebrand factor (vWF), and α-smooth muscle actin (α-SMA) in coronary artery tissue. Western blot analysis was used to detect the expression of CHI3L1, vWF, vascular endothelial cadherin (VE cadherin), Caspase-3, B cell lymphoma-2 (Bcl-2), Bcl-2 associated X protein (Bax), nuclear factor κB (NF-κB), and phosphorylated NF-κB (p-NF-κB) in coronary artery tissue.@*RESULTS@#The serum level of CHI3L1 in the model group was significantly higher than that in the control group (P<0.05). Compared to the control group, the expression of CHI3L1 in the coronary artery tissue was higher, while the expression of vWF was lower in the model group. The relative expression levels of CHI3L1, Bax, Caspase-3, NF-κB, and p-NF-κB were significantly higher in the model group than in the control group (P<0.05). The relative expression levels of vWF, VE cadherin, and Bcl-2 were lower in the model group than in the control group (P<0.05).@*CONCLUSIONS@#In the LCWE-induced mouse model of KD-like vasculitis, the expression levels of CHI3L1 in serum and coronary arteries increase, and it may play a role in coronary artery lesions through endothelial cell apoptosis mediated by inflammatory reactions.

Preparation and Application of Monoclonal Antibody Against Human von Willebrand Factor Propeptide / 中国实验血液学杂志

OBJECTIVE@#To develop monoclonal antibodies that can specifically recognize human von Willebrand factor (VWF) propeptide (VWFpp) in plasma, and establish a rapid and reliable method for the detection of VWFpp antigen in plasma by using the double-antibody sandwich ELISA with the obtained anti-VWFpp monoclonal antibody.@*METHODS@#The recombinant human VWFpp (D1 and D2 regions) protein expressed in eukaryotic cells was used as immunogen to immunize BALB/c mice with routine method, so as to obtain clones of fusion cells. After screening and identification, hybridoma cell lines secreting monoclonal antibodies against VWFpp were selected, and then double-antibody sandwich ELISA assay was used to construct VWFpp antigen detection kit for the determination of VWFpp in human plasma. The levels of VWFpp antigen in plasma of 12 leukemia patients who underwent bone marrow transplantation were dynamically detected.@*RESULTS@#Two hybridoma cell lines that can be subcultured continuously and secrete monoclonal antibodies against VWFpp were obtained and named SZ175 and SZ176 respectively. Identified by ELISA and Western blot, the antibodies could both specifically recognize VWFpp but couldn't recognize mature VWF (without propeptide). Based on the principle of double-antibody sandwich ELISA, monoclonal antibodies SZ175 and SZ176 were successfully made into a kit for detecting VWFpp antigen. The plasma VWFpp levels of leukemia patients before and after bone marrow transplantation were dynamically detected. The results showed that the plasma VWFpp levels of the patients after transplantation were significantly higher than those before transplantation.@*CONCLUSION@#Two monoclonal antibodies against VWFpp were successfully prepared, and a double-antibody sandwich ELISA detection kit for VWFpp antigen was constructed, which provides a powerful tool for further study on the biological function of VWFpp, the clinical diagnosis and classification of von Willebrand disease (VWD), and the prognostic monitoring of endothelial injury-related diseases.

Diagnóstico de la enfermedad de von Willebrand / Diagnosis of von Willebrand disease

La enfermedad de von Willebrand (EVW) es el trastorno hemorrágico hereditario más común, y se caracteriza por presentar disminución de la capacidad del factor von Willebrand (FVW) de unirse a las plaquetas y al colágeno de la matriz extracelular durante la hemostasia primaria, debido a defectos cuantitativos o cualitativos. La EVW se clasifica en tres fenotipos principales: el 1 y el 3 que son trastornos cuantitativos, y el 2 que se subclasifica en 2A, 2B, 2M y 2N, y refleja los trastornos cualitativos. Para su diagnóstico son necesarios varios pasos: 1) la evaluación del historial de sangrado personal y familiar del paciente, 2) detección inicial de trastornos hemorrágicos, 3) pruebas para la detección de la EVW, 4) pruebas para la tipificación de la EVW, y 5) el análisis molecular. Tanto la subclasificación de la EVW como su diagnóstico continúan planteando desafíos importantes, motivo por el cual se realiza esta revisión, de manera que los profesionales de la salud tengan una guía que los oriente al momento de tener pacientes con algún trastorno hemorrágico que amerite descartar una EVW e implementar un tratamiento adecuado

von Willebrand disease (VWD) is the most common hereditary bleeding disorder, and is characterized by a decreased ability of the von Willebrand factor (VWF) to bind to platelets and extracellular matrix collagen during primary hemostasis, due to quantitative or qualitative defects. VWD is classified into three main phenotypes: 1 and 3, which are quantitative disorders, and 2 (2A, 2B, 2M and 2N) that reflects qualitative disorders. Several steps are necessary for its diagnosis: 1) evaluation of the patient's personal and family bleeding history, 2) initial screening tests for bleeding disorders, 3) tests for the detection of VWD, 4) tests for the classification of VWD, and 5) molecular analysis. Both the subclassification of VWD and its diagnosis continue to represent important challenges, which we aimed to describe in this review, so that health professionals have a guide to assist them when they have patients with a bleeding disorder that requires exclusion of VWD, and implementation of an appropriate treatment.

Antígeno del factor von Willebrand (FVW: Ag) / von Willebrand factor antigen (VWF: Ag)

Utilidad clínica de la prueba El factor von Willebrand (FVW) es una glicoproteína compuesta por multímeros con pesos moleculares que pueden variar desde 500 KDa hasta 20.000 kDa, que se sintetiza en las células endoteliales y en los megacariocitos, y se almacena en los cuerpos de Weibel-Palade y en los gránulos alfa de las plaquetas [1]. El papel del FVW en la hemostasia primaria es mediar la adhesión de las plaquetas a los componentes de la matriz extracelular, a través de los complejos glucoproteicos plaquetarios GPIbα y αIIb3ß; en la hemostasia secundaria, se asocia con el factor VIII para prevenir su degradación y favorecer la generación de trombina para la formación del trombo final

Disseminated intravascular coagulation phenotype is regulated by the TRPM7 channel during sepsis

BACKGROUND: Sepsis is an uncontrolled inflammatory response against a systemic infection that results in elevated mortality, mainly induced by bacterial products known as endotoxins, producing endotoxemia. Disseminated intravascular coagulation (DIC) is frequently observed in septic patients and is associated with organ failure and death. Sepsis activates endothelial cells (ECs), promoting a prothrombotic phenotype contributing to DIC. Ion channel mediated calcium permeability participates in coagulation. The transient reception potential melastatin 7 (TRPM7) non-selective divalent cation channel that also contains an α-kinase domain, which is permeable to divalent cations including Ca2+, regulates endotoxin-stimulated calcium permeability in ECs and is associated with increased mortality in septic patients. However, whether endothelial TRPM7 mediates endotoxemia-induced coagulation is not known. Therefore, our aim was to examine if TRPM7 mediates coagulation during endotoxemia. RESULTS: The results showed that TRPM7 regulated endotoxin-induced platelet and neutrophil adhesion to ECs, dependent on the TRPM7 ion channel activity and by the α-kinase function. Endotoxic animals showed that TRPM7 mediated neutrophil rolling on blood vessels and intravascular coagulation. TRPM7 mediated the increased expression of the adhesion proteins, von Willebrand factor (vWF), intercellular adhesion molecule 1 (ICAM-1), and P-selectin, which were also mediated by the TRPM7 α-kinase function. Notably, endotoxin-induced expression of vWF, ICAM-1 and P-selectin were required for endotoxin-induced platelet and neutrophil adhesion to ECs. Endotoxemic rats showed increased endothelial TRPM7 expression associated with a procoagulant phenotype, liver and kidney dysfunction, increased death events and an increased relative risk of death. Interestingly, circulating ECs (CECs) from septic shock patients (SSPs) showed increased TRPM7 expression associated with increased DIC scores and decreased survival times. Additionally, SSPs with a high expression of TRPM7 in CECs showed increased mortality and relative risk of death. Notably, CECs from SSPs showed significant results from the AUROC analyses for predicting mortality in SSPs that were better than the Acute Physiology and Chronic Health Evaluation II (APACHE II) and the Sequential Organ Failure Assessment (SOFA) scores. CONCLUSIONS: Our study demonstrates that sepsis-induced DIC is mediated by TRPM7 in ECs. TRPM7 ion channel activity and α-kinase function are required by DIC-mediated sepsis-induced organ dysfunction and its expression are associated with increased mortality during sepsis. TRPM7 appears as a new prognostic biomarker to predict mortality associated to DIC in SSPs, and as a novel target for drug development against DIC during infectious inflammatory diseases.

Proteomics of serum exosomes in children in the acute stage of Kawasaki disease: a prospective study / 中国当代儿科杂志

OBJECTIVES@#To study the biological processes and functions of serum exosomes in children in the acute stage of Kawasaki disease (KD), so as to provide new biomarkers for the early diagnosis of KD.@*METHODS@#In this prospective study, 13 children with KD who were treated in Children's Hospital of Soochow University from June 2019 to August 2020 were enrolled as the KD group, and 13 children who were hospitalized due to bacterial infection during the same period were enrolled as the control group. Whole blood was collected on the next morning after admission, serum samples were obtained by centrifugation, and exosomes were extracted through ultracentrifugation. Serum exosomes were analyzed by label-free quantitative proteomics, and differentially expressed proteins (DEPs) were screened out for functional enrichment analysis. A protein-protein interaction (PPI) network was plotted, and unique proteins were validated by targeted proteomics.@*RESULTS@#A total of 131 DEPs were screened out for the two groups, among which 27 proteins were detected in both groups. There were 48 unique DEPs in the KD group, among which 23 were upregulated and 25 were downregulated, and these proteins acted on "complement and coagulation cascades" and "the MAPK signaling pathway". Validation by targeted proteomics showed that FGG, SERPING1, C1R, C1QA, IGHG4, and C1QC proteins were quantifiable in the KD group. A total of 29 proteins were only expressed in the control group, among which 12 were upregulated and 17 were downregulated. Four proteins were quantifiable based on targeted proteomics, i.e., VWF, ECM1, F13A1, and TTR. A PPI network was plotted for each group. In the KD group, FGG and C1QC had close interaction with other proteins, while in the control group, VWF had close interaction with other proteins.@*CONCLUSIONS@#The serum exosomes FGG and C1QC in children in the acute stage of KD are expected to become the biomarkers for the early diagnosis of KD. For children with unexplained fever, detection of FGG, C1QC1, and VWF may help with etiological screening.

Research Advance in Treatment of Thrombotic Thrombocytopenic Purpura --Review / 中国实验血液学杂志

Thrombotic thrombocytopenic purpura (TTP) is a thrombotic microangiopathy, in which a severe deficiency of von Willebrand factor lyase results in thrombocytopenic clots that block blood vessels and eventually lead to terminal organ failure. Therapeutic plasma exchange is the cornerstone of TTP treatment which can greatly improves the survival rate of the patients. With the further exploration to the pathophysiological mechanism of TTP, other alternative therapies, new immunosuppressive agents, targeted antagonists, gene therapy and other emerging means gradually emerge, which are expected to further reduce the mortality and recurrence rate of the patients. In this review, the new developments in TTP treatment were summarized briefly.

The clinical value of von Willebrand factor and VITRO score in evaluating disease progression in patients with HBV infection / 中华肝脏病杂志

Objective: To explore the clinical value of von Willebrand Factor (vWF) and VITRO score (vWF:Ag/platelet count) in assessing disease progression in patients with HBV infection. Methods: Randomly collect relevant clinical data of 308 patients with HBV infection (including 154 cases of chronic hepatitis B, 66 cases of hepatitis B cirrhosis in compensatory period, 88 cases of hepatitis B cirrhosis in decompensated period) from December 1, 2018 to January 5, 2021 in the Second Affiliated Hospital of Chongqing Medical University. The vWF values are measured by a uniform optical method, and all data are included using a uniform standard. Analyze the difference and significance of plasma vWF level and VITRO score in chronic hepatitis B, hepatitis B cirrhosis in the compensatory phase and decompensated phase. Results: The plasma vWF level and VITRO score of the chronic hepatitis B group were (139.47±76.44) and (0.86±0.8), respectively, and the hepatitis B cirrhosis compensated group was (164.95±67.12 and 1.44±1.14), respectively. Hepatitis cirrhosis decompensated group were (317.48±103.32 and 6.81±4.98), respectively; plasma vWF level and VITRO score increased with the progression of HBV infection, and the difference was statistically significant (F=133.669,P=0.000F=137.598,P=0.000).The plasma vWF level and VITRO score in patients with hepatitis B cirrhosis were (185.65±85.07 and 2.3±2.37) in the Child-Pugh A group, (304.74±105.81 and 6.37±5.19) in the B grade group, and (369.48±73.238.28±5.38) in the C grade group; plasma vWF level and VITRO score in patients with hepatitis B cirrhosis increased with the increase of Child-Pugh grade, and the difference was statistically significant (F=60.236, P=0.000F=32.854, P=0.000). The area under the curve (AUC) of plasma vWF level and VITRO score for diagnosing the decompensated stage of hepatitis B cirrhosis were 0.897 [95% confidence interval (CI): 0.855-0.940, P＜0.01], 0.949 [95% CI: 0.916-0.982, P＜0.01). When the vWF level and VITRO score were taken as cut-off values of 238.5% and 1.65, respectively, the sensitivity of diagnosing the decompensated stage of hepatitis B cirrhosis was 79.5% and 94.3%, the specificity was 92.3% and 87.7%, and the positive predictive value was 80.5% and 94.3%, the negative predictive value was 91.9% and 97.5%, and the diagnostic accuracy was 88.6% and 89.3%. Among the patients with decompensated hepatitis B cirrhosis, the level of vWF in the group with gastrointestinal bleeding (367.24±68.29)% was significantly higher than that in the group without gastrointestinal bleeding (286.15±109.69)%, and the difference was statistically significant (P＜0.001) The VITRO score of the group with gastrointestinal bleeding (9.12±5.4) was significantly higher than that of the group without gastrointestinal bleeding (5.36±4.13), and the difference was statistically significant (P＜0.01). The vWF level in the spontaneous peritonitis group was (341.73±87.92)% higher than that in the non-spontaneous peritonitis group (296.32±111.74)%, and the difference was statistically significant (P＜0.05). There was no statistical difference in VITRO score between the two groups. significance. Conclusion: Plasma vWF level and VITRO score can evaluate the progression of liver disease and the degree of decompensation of liver cirrhosis in patients with HBV infection, and have a predictive effect on various complications after decompensation of liver cirrhosis, and have certain guiding significance for early intervention measures.

Association between coagulation function and prognosis in patients with acute pancreatitis / 南方医科大学学报

OBJECTIVE@#To explore the correlation of coagulation function with the severity and prognosis of acute pancreatitis (AP) and identify the laboratory markers for early prediction and dynamic monitoring of the prognosis of AP.@*METHODS@#We retrospectively analyzed the clinical data of patients with AP admitted less than 72 h after onset to our hospital from December 1, 2017 to November 30, 2018. The correlation of coagulation function-related markers at admission and their changes during hospitalization with the prognosis of the patients was analyzed.@*RESULTS@#We screened the data of a total of 1260 patients with AP against the inclusion and exclusion criteria, and eventually 175 patients were enrolled in this analysis, among whom 52 patients had severe AP (SAP) and 12 patients died. Logistic regression analysis identified vWF: Ag, PT, PC, AT Ⅲ and D-dimer markers at admission as independent risk factors for predicting SAP and death. Dynamic monitoring of the changes in coagulation function-related markers in the disease course had greater predictive value of the patients' prognosis, and the indicators including vWF: Agmax, PTmax, APTTmax, TTmax, FIBmin, D-dimermax, PLTmin, PCmin, PLGmin, AT Ⅲmin, and their variations were all independent risk factors for predicting SAP and death. ROC analysis suggested that dynamic monitoring of the changes in the indicators, especially those of △vWF: Ag, △PT, △APTT, △FIB, △TT, △D-dimer, △PLT, △PC, △AT Ⅲ, △PLG, could effectively predict SAP and death in these patients (with AUC range of 0.63-0.84).@*CONCLUSION@#Patients with AP have vascular endothelial injuries and coagulation disorders. The markers including vWF: Ag, PT, PC, AT Ⅲ and D-dimer at admission are independent risk factors for predicting SAP and death, and dynamic monitoring of the changes in vWF: Ag、PT、APTT、TT、FIB、D-dimer、PLT、PC、AT Ⅲ and PLG can further increase the predictive value.

Advance in the diagnosis and treatment of hereditary thrombotic thrombocytopenic purpura / 中华医学遗传学杂志

Congenital thrombotic thrombocytopenic purpura, also known as Upshaw-Schulman syndrome, is a rare autosomal recessive genetic disorder. The main pathogenesis is homozygous or compound heterozygous variants of von Willebrand factor lyase (ADAMTS13) gene mapped to chromosome 9q34, which may result in severe lack of ADAMTS13 which cleaves von Willebrand factor (vWF) multimers in the plasma and increase the risk of microvascular thrombosis, leading to various complications. The advance of research on the pathogenesis of cTTP, recombinant human ADAMTS13 and gene therapy have made breakthroughs which may lead to cure of cTTP. This article has provided a review for the latest progress made in the diagnosis and treatment of cTTP.

Effects of material interfaces on orientation and function of fibrinogen / 生物医学工程学杂志

Fibrinogen (Fg) in human plasma plays an important role in hemostasis, vascular repair and tissue integrity. The surface chemistry of extracellular matrix or biological materials affects the orientation and distribution of Fg, and changes the exposure of integrin binding sites, thereby affecting its adhesion function to platelets. Here, the quantity, morphology and side chain exposure of Fg adsorbed on hydrophilic, hydrophobic and avidin surfaces were measured by atomic force microscopy (AFM) and flow cytometry (FCM), then the rolling behavior of platelets on Fg was observed through a parallel plate flow chamber system. Our results show that the hydrophobic surface leads to a large amount of cross-linking and aggregation of Fg, while the hydrophilic surface reduces the adsorption and accumulation of Fg while causing the exposure and spreading of the α chain on Fg and further mediating the adhesion of platelets. Fg immobilized by avidin / biotin on hydrophilic surface can maintain the monomer state, avoid over exposure and stretching of α chain, and bind to the platelets activated by the A1 domain of von Willebrand factor instead of inactivated platelets. This study would be helpful for improving the blood compatibility of implant biomaterials and reasonable experimental design of coagulation

Biological Function of CysR Domain of ADAMTS13 / 中国实验血液学杂志

OBJECTIVE@#To investigate the biological function of Cysteine rich (CysR) domain of a disintegrin and metalloprotease with thrombospondin type 1 repeats-13 (ADAMTS13) on cleavage of von Willebrand factor (vWF) and provide experimental evidence for exploring the pathogenesis of thrombotic thrombocytopenic purpura (TTP).@*METHODS@#The six amino acids (EDGTLS) in ADAMTS13 CysR domain were point mutated one by one, and the mutant ADAMTS13 proteins were expressed and purified. The cleavage products of vWF polymer by wild-type or mutant ADAMTS13 under denaturing condition or shear stress were separated by 1% SeaKem HGT agarose gel and detected by Western blot.@*RESULTS@#The mutant ADAMTS13 plasmids (M1: Glu515Ala; M2: Asp516Ala; M3: Gly517Ala; M4: Thr518Ala; M5: Leu519Ala; M6: Ser520Ala) were successfully constructed and the proteins of wild-type and mutant ADAMTS13 were purified. Wild-type ADAMTS13 almost completely cleaved the vWF polymer under denaturing condition, while the cleavage activity of M1 mutant was significantly reduced in the same condition (P<0.01). The cleavage activity of M1 mutant of ADAMTS13 was also significantly reduced compared with that of the wild-type under shear stress (P<0.01). The activity of M1 mutant to cleave the FRETS-vWF73 was dramatically reduced compared with that of wild-type ADAMTS13. However, the binding ability of M1 mutant to vWF was similar with that of wild-type ADAMTS13.@*CONCLUSION@#The CysR domain of ADAMTS13 plays an important role in the digestion of vWF under denaturing condition and shear stress. The Glu515 amino acid residue might be an important site for substrate recognition.

Asociación entre enfermedad de von Willebrand y angiodisplasia: ¿casualidad o causalidad? / Association between von Willebrand disease and angiodysplasia

Von Willebrand factor (vWf) is a fundamental multimeric plasma glycoprotein in the coagulation process. Its function is to mediate platelet adhesion and to stabilize circulating factor VIII. A functional or quantitative alteration of vWf gives rise to von Willebrand disease (vWD). The association between vWD and angiodysplasia was described in 1967, but it was only until 2011 that Starke et al demonstrated the in vitro and in vivo role of vWf in angiogenesis. Congenital or acquired vWf deficiency, especially of high molecular weight multimeters, not only favors bleeding, but also contributes to increased angiogenesis in these patients. The treatment should be focused both on the control of the acute episode of gastrointestinal bleeding, with vWf replacement therapy and local endoscopic treatment, as well as on the prevention of the progression of angiodysplasia and future bleeding. There are different published therapeutic approaches using vWf replacement that are not effective in all patients. Recently, angiogenesis inhibitor medications have been used.

Clinical analysis of 61 patients with thrombotic thrombocytopenic purpura / 北京大学学报(医学版)

OBJECTIVE@#To analyze and summarize the clinical features, diagnosis, treatment and prognosis of 61 patients with thrombotic thrombocytopenic purpura (TTP), so as to improve the ability of diagnosis and treatment.@*METHODS@#The clinical data of 61 TTP patients admitted to Peking University People's Hospital from January 2004 to March 2019 were retrospectively analyzed, and the clinical manifestations, blood routine, hemolysis indicators, and von Willebrand factor lyase (von Willebrand factor-cleaving protease, vWF-CP, also known as ADAMTS13) of these patients were observed. According to the outcome at the time of discharge, they were divided into survival group and death group, and the differences in clinical characteristics, neutrophil to lymphocyte ratio (NLR) and plasma exchange between the two groups were compared. The PLASMIC scores were calculated and compared with ADAMTS13 to determine the accuracy of the PLASMIC score in predicting ADAMTS13.@*RESULTS@#Among the 61 TTP patients, 22 were males and 39 were females, with an average age of (48±17) years. In the study, 48 cases had pentalogy, only 9 had triad, and the remaining 4 had no neuropsychiatric symptoms. Twenty-seven cases (44.3%) died and 34 cases (55.7%) survived. Among the 61 TTP patients, the platelet count was (12.9±9.5)×109/L, the hemoglobin (66.5±20.7) g/L, the percentage of erythrocyte fragments 3% (2%, 7%), and the plasma free hemoglobin increased to 360 (200, 457) mg /L, and the lactate dehydrogenase 1 508 (811, 2 133.8) U/L. The blood clotting was basically normal. The ADAMTS13 value of 30 patients was 49.0 (40.8, 61.3) μg/L, the ADAMTS activity of 10 patients was < 5%, and the remaining 21 patients were not checked. The PLASMIC score was 6-7 in 58 cases, 5 in 2 cases, and 4 in 1 case. The PLASMIC score predicted the decreased activity or the reduction of ADAMTS with a sensitivity as high as 97.5%. The NLR in the death group was higher than that in the survival group, but the difference was not statistically significant (P>0.05). The total amount and frequency of plasma exchange (PEX) in the death group were significantly less than those in the survival group, and the difference was statistically significant (P < 0.05). There was no significant difference in the treatment of glucocorticoids and human immunoglobulin between the two groups (P>0.05).@*CONCLUSION@#PEX can significantly improve the survival rate of TTP patients. PLASMIC score can easily and quickly predict the possibility of ADAMTS13 activity reduction, which is beneficial to the early diagnosis of TTP and PEX treatment. NLR can reflect the systemic inflammatory process, but its significance in TTP needs further study.

A Simple and Nonenzymatic Method to Isolate Human Corpus Cavernosum Endothelial Cells and Pericytes for the Study of Erectile Dysfunction

Nesiritide protects endothelial function after balloon-induced trauma in the iliac artery in rabbits

To assess the effect of nesiritide on the endothelial function of iliac arteries following endothelia trauma. Right iliac artery trauma was created with a balloon catheter. Ten rabbits were treated with a 4-week subcutaneous injection of nesiritide at a fixed daily dose of 0.1mg/kg. Ten rabbits received daily normal saline injection. Plasma endothelin 1 (ET-1), nitric oxide (NO), and Von Willebrand Factor (vWF) were measured before and after the therapies. Tissue proliferating cell nuclear antigen (PCNA) was measured after the treatment. After the treatment, in the therapeutic group, the area under internal elastic membrane and the residual lumen area were higher than in the normal saline group (P <0.05). The plasma levels of ET-1 (91.6±6.8 vs 114.9±6.3 ng/L, P =0.001), vWF (134.6±10.8% vs 188.8±10.4%, P =0.001) and the ratio of PCNA positive expression (11.7±4.2% vs 36.2±11.4%, P =0.005) in the therapeutic group was lower than in the normal saline group, while the plasma levels of NO was higher (89.7±9.3 vs 43.5±5.3 µmol/L, P =0.001). Nesiritide inhibited remodeling of rabbit iliac artery following endothelial trauma. The inhibition of vascular remodeling may be related to the alleviated endothelial dysfunction and reduced expression of tissue proliferating cell nuclear antigen

El papel de la enfermedad de von Willebrand en la hemorragia uterina anormal / Von Willebrand Disease in Abnormal Uterine Bleeding

RESUMEN La hemorragia uterina anormal es un término empleado para las alteraciones en la regularidad, duración y/o volumen de sangrado menstrual y es considerada una causa común de consulta médica y en ocasiones supone un reto diagnóstico para el médico tratante. Dentro del abordaje de la etiología de dicha patología, las coagulopatías afectan alrededor del 13 por ciento de las mujeres, y la más común es la enfermedad de von Willebrand. El objetivo de este trabajo fue realizar una revisión de la literatura científica actual sobre el papel que cumple la enfermedad de von Willebrand en la hemorragia uterina anormal. Esta es una patología hereditaria derivada de una deficiencia del factor von Willebrand encargado de la adhesión plaquetaria. La prevalencia de esta enfermedad puede ser baja, sin embargo, cuando se estudia la población de mujeres con menorragia, la frecuencia puede ir de 5 a 20 por ciento. Se han descrito diferentes problemas ginecológicos asociados a la enfermedad de von Willebrand, tales como menorragia, dismenorrea y una importante deficiencia de hierro asociada a esta, además de una mayor incidencia de quistes ováricos, endometriosis, hiperplasia endometrial y pólipos endometriales. La literatura actual sugiere que se realice tamizaje a aquellas mujeres con cuadro clínico sugestivo. Con respecto al tratamiento la literatura reporta el uso de ácido tranexámico y anticonceptivos orales, pero el que mayor utilidad ha demostrado es la desmopresina(AU)

ABSTRACT Abnormal uterine bleeding is a term used for alterations in the regularity, duration and / or volume of menstrual bleeding and it is considered a common cause of medical consultation; sometimes it is a diagnostic challenge for the treating physician. Within the aetiology approach of said pathology, coagulopathies affect around 13 percent of women, and the most common is von Willebrand disease. The objective is to review the current scientific literature on the influence of von Willebrand disease in abnormal uterine bleeding. This is an inherited pathology derived from a deficiency of the von Willebrand factor responsible for platelet adhesion. The prevalence of this disease may be low, however, when studying the population of women with menorrhagia, the frequency can range from 5 to 20 percent. Different gynecological problems associated with von Willebrand disease have been described, such as menorrhagia, dysmenorrhea and a significant iron deficiency associated with it, in addition to a higher incidence of ovarian cysts, endometriosis, endometrial hyperplasia and endometrial polyps. The current literature suggests that those women with suggestive clinical symptoms should be screened. Regarding treatment, the literature reports the use of tranexamic acid and oral contraceptives, nonetheless desmopressin has proven to be most useful(AU)