Blood Clotting Time Research Articles

Sulfonated polyphenylene oxide-based artificial lung membrane with prominent selectivity of CO2

The primary issues impeding oxygenation efficacy in extracorporeal membrane oxygenation (ECMO) are low CO2/O2 selectivity and insufficient permeability of CO2. Herein, sulfonated polyphenylene oxide (SPPO) was chosen as a candidate for the oxygenation membrane material. The CO2-affinitive sulfonic acid groups on the molecular chain of SPPO enhance the interaction between CO2 and the SPPO membrane; thereby, the CO2/O2 selectivity is effectively enhanced. When the solid content of the casting solution is 23%, the SPPO membrane achieves a CO2/O2 selectivity of 17.0, almost as selective as human alveoli. The blood clotting time, red blood cell adhesion, platelet adhesion, and hemolysis ratio were employed to evaluate the blood compatibility of SPPO materials. The results demonstrated that the manufactured SPPO membranes exhibited good hemocompatibility. This work offers novel thinking for researching and applying effective artificial lung membranes.

Epidemiological Aspects, Clinicopathology, Hemato-biochemistry and Therapeutic Management of Viperine Snake Envenomation in Buffaloes (Bubalus bubalis)

Background: Poisonous snakebite is a neglected tropical disease, frequently reported in animals including buffaloes. Snakebites are responsible for considerable morbidity and mortality in animals causing economic losses to dairy farmers. Methods: To establish the baseline data of epidemiology, clinical syndrome, hemato-biochemistry and diagnosis of viper snakebites and to standardize the treatment of viper snakebite in buffaloes. Result: The highest incidence of viper envenomation was observed during the monsoon and post-monsoon season in female buffaloes above 4 years of age. The clinical signs such as tachycardia, increased respiration rate, ascending swelling of affected limbs, asymmetrical swelling with dyspnea in case of bite over face and bleeding at the site of bite were observed in envenomed buffaloes. Hemato-biochemical analysis revealed neutrophilic leukocytosis, thrombocytopenia, prolonged capillary blood clotting time, elevated values of blood urea nitrogen (BUN) and creatinine. Post-mortem examination showed hemorrhages and blood-stained serous fluid in subcutaneous tissue and skeletal muscles of the affected limbs. The histopathological changes such as extensive myonecrosis and hemorrhages with marked edema in skeletal muscles, widespread interstitial and intra-alveolar hemorrhages and fibrinous microthrombi in pulmonary vasculature, multifocal to coalescing areas of massive hemorrhages and coagulative necrosis within hepatic parenchyma and marked degeneration of renal tubular epithelium were evident. Therapeutic regimen consisting of polyvalent anti-snake venom, with antibiotics, diuretics, vitamin B complex, styptics, fluids and corticosteroids in non-pregnant while non-steroidal anti-inflammatory drugs in pregnant buffaloes was used. The present treatment strategy showed subsidence of clinical signs, restoration of platelet count, blood clotting time, urea nitrogen and creatinine values depicting clinical recovery with 88.15% survival rate in treated buffaloes.

A Case of Snake Bite in a One-Year-Old Cross-Breed Cow – A Case Report

This clinical article reports a case of snake bite in a -year-old Friesian and white Fulani cross-breed cow at the Livestock Investigation Division of the National Veterinary Research Institute, Vom, Nigeria. The clinical signs observed during the physical examination are as follows: swollen brisket region and left forelimbs, anorexia, fever (39.2°C), and difficulty walking. The whole blood clotting time was positive (Absence of clotting for more than 2 h). The affected cow was treated using antibiotics, diuretics, and anti-inflammatory agents without the administration of anti-venom. The recovery was uneventful within 3 days following treatment.

A chitosan macroporous hydrogel integrating enrichment, adsorption and delivery of blood clotting components for rapid hemostasis

Traditional hemostatic hydrogels face considerable limitations in achieving rapid control of severe bleedings, a crucial factor in reducing casualties in both military and civilian settings. This study presents a chitosan-based hemostatic hydrogel with interconnected secondary macropores designed to enhance interactions with blood clotting components by reducing diffusion resistance and increasing contact area. The macropores were created using a straightforward process involving NaOH-mediated SiO2 template dissolution and NH3 generation. The resulting macroporous structure increased the hydrogel's overall porosity without compromising its viscoelasticity. Functional studies demonstrated that the macroporous hydrogel effectively concentrated and adsorbed blood clotting components, while also facilitating the delivery of artificially embedded clotting factor to further expedite clot formation. These combined actions resulted in improve hemostatic efficacy, reducing whole blood clotting time by over 94 % in vitro. Furthermore, in vivo studies using rat tail amputation and liver injury models showed a reduction in blood loss by over 65 % and a decrease in bleeding time by over 70 %. Additionally, the porous chitosan hydrogel exhibited minimal biotoxicity and promoted biodegradability in vivo. In conclusion, this work introduces a macroporous chitosan-based hemostatic hydrogel with great potential for rapid hemorrhage control.

Ultralight 3D silk nanofiber scaffolds with enhanced hemostatic properties and biocompatibility for rapid hemostasis

Developing an effective hemostatic material that combines excellent biocompatibility with high blood absorption capacity remains a critical clinical challenge. In this study, ultralight three-dimensional (3D) silk fibroin (SF) scaffolds, composed of continuously interconnected nanofibers, are introduced as a novel hemostatic material. The distinctive fluffy nanofiber architecture endows the scaffolds with a remarkable porosity of 78.9 % and exceptional liquid absorption capacity. The integration of montmorillonite (MMT) further enhances the hemostatic properties of the scaffolds, while SF naturally promotes the intrinsic coagulation pathway. The scaffolds exhibit an impressive blood absorption capacity of 1687.7 %. In vitro evaluations indicate that the SF nanofiber scaffolds exhibit a blood clotting index rate of 24.6 %, a hemolysis ratio of less than 4 %, and outstanding biocompatibility. The blood coagulation time is significantly reduced from 449 s to 230 s. Additionally, the scaffolds show adhesion rates to erythrocytes and platelets of 52 % and 45.9 %, respectively. The nanofiber scaffolds aggregate and activate platelets extensively, accelerating the formation of platelet emboli, which collectively contribute to their superior hemostatic performance. Consequently, these nanofiber scaffolds hold substantial promise as absorbable hemostatic agents for achieving rapid hemostasis in clinical applications.

Relationships of 8 - Isoprostane and Vitamin K Levels With Blood Clotting Time In Last Stage of Hepatocellular Carcinoma Patients

Liver diseases are one of the most serious life-threatening diseases , and among the most important of these diseases is hepatocellular carcinoma, which poses a future challenge to public health. the goal of this work is to explore the existence association between the decrease level of vitamin K and an increase level of 8-isoprostane With a high rate of blood clotting time . The (PT ( in all patients it was high, and rate ranged from ( 21.00 -25.00), while in all the control group was normal . we also found that patients who suffer from HCC substantially reduced levels of VK2, The mean levels of Human VK2 were 135.78 ± 17.15 and 170.69 ± 18.15, in HCC patients / control respectively, However, Mean levels of Human 8-Isoprostane were 3436.44 ± 894.45 and 2389.13 ± 439.66, in HCC patients / control respectively; mean level turns out that it highly significant higher than in HCC patients compare to control . It is concluded that low levels of this vitamin in HCC patients may make liver cells less able to fend off the invasion and spread of cancer cells, while high levels of Human 8-Isoprostane raise the danger of HCC illness in ill individuals and, consequently, increase the risk of death.

Formulation and Evaluation of Haemocoagulase Gel for Dental Pulp- an In-vitro study.

This study aims to develop a novel hemostatic gel of hemocoagulase, a snake venom-derived serine protease enzyme, by incorporating it into the matrix of bioadhesive polymers to prevent damage due to hemorrhage. Haemocoagulase was combined with polymers Carbopol 940 and HPMC K 100, and these formulations were evaluated for physical properties, efficacy, safety and stability. Batches F3 and F6 were selected for further studies on animal models, which were found to be safe without any skin irritation effect and effective as hemostats with blood clotting times of 1.24 ± 0.007 min and 1.36 ± 0.014 min, respectively, in a rat liver incision model. From this study, it can be suggested that the combination of hemocoagulase with bioadhesive polymer can provide a novel hemostatic tool for controlling bleeding.

Potential Bioactivities, Chemical Composition, and Conformation Studies of Exopolysaccharide-Derived Aspergillus sp. Strain GAD7.

This research identified a marine fungal isolate, Aspergillus sp. strain GAD7, which produces an acidic and sulfated extracellular polysaccharide (EPS) with notable anticoagulant and antioxidant properties. Six fungal strains from the Egyptian Mediterranean Sea were screened for EPS production, with Aspergillus sp. strain GAD7 (EPS-AG7) being the most potent, yielding ~5.19 ± 0.017 g/L. EPS-AG7 was characterized using UV-Vis and FTIR analyses, revealing high carbohydrate (87.5%) and sulfate (24%) contents. HPLC and GC-MS analyses determined that EPS-AG7 is a heterogeneous acidic polysaccharide with an average molecular weight (Mw¯) of ~7.34 × 103 Da, composed of mannose, glucose, arabinose, galacturonic acid, galactose, and lyxose in a molar ratio of 6.6:3.9:1.8:1.3:1.1:1.0, linked through α- and β-glycosidic linkages as confirmed by NMR analysis. EPS-AG7 adopted a triple helix-like conformation, as evidenced by UV-Vis (Congo Red experiment) and circular dichroism (CD) studies. This helical arrangement demonstrated stability under various experimental conditions, including concentration, ionic strength, temperature, and lipid interactions. EPS-AG7 exhibited significant anticoagulant activity, doubling blood coagulation time at a concentration of 3.0 mg/mL, and showed significant antioxidant activity, with scavenging activities reaching up to 85.90% and 58.64% in DPPH and ABTS+ assays at 5.0 mg/mL, and EC50 values of 1.40 mg/mL and 3.80 mg/mL, respectively. These findings highlight the potential of EPS-AG7 for therapeutic applications due to its potent biological activities.

Novel 3D Printed Biomaterials Based on Fish Scale Collagen and Plant Extracts and Its Hemostatic Efficacy

AbstractThis study focused on 3D printing‐preparation of novel biomaterials based on fish scale collagen and the following plant extracts: Eclipta alba L. Hassk leaf (EA), Piper betle L. leaf (PB), Perilla frutescens L. Britt leaf (PF), and Styphnolobium japonicum L. Schott flower bud (SJ). The characterizations of the obtained biomaterials were analyzed using infrared spectroscopy and stereo microscopy. Additionally, assessments of the biomaterials were conducted on the water contact angle, simulated body fluid contact angle, scratch resistance, color changes, and swelling degree in simulated body fluid. Furthermore, in‐vitro blood clotting time and the anti‐inflammatory ability of these biomaterials were also performed. The results indicated that the plant extracts contributed to modifying collagen, significantly improving the scratch resistance and water contact angle of the collagen/plant extract biomaterials. The plant extracts were dispersed consistently with the collagen matrix, impacting the vibrations of specific functional groups of collagen. Collagen/plant extract dressings exhibited great biocompatibility and anti‐inflammatory. The in‐vitro tests demonstrated that the ethanol EA extract notably enhanced the hemostatic effectiveness of collagen, suggesting the potential of collagen/plant extract biomaterials in hemostatic applications.

Development of small-diameter vascular grafts using PCL/PLA/gelatin/PVA/hyaluronic acid nanofibers containing VEGF/enoxaparin

The extending demands for narrow-diameter vascular grafts to restore damaged arteries have captivated researcher's attention. The absence of appropriate vascular substitutes is due to the poor patency rate of small-caliber synthetic grafts caused by thrombosis and vessel hemodynamic mismatch that induce intimal hyperplasia. We developed small-diameter vascular grafts in two layers through electrospinning. The inner layer was fabricated by gelatin/polyvinyl alcohol (PVA)/hyaluronic acid/enoxaparin and vascular endothelial growth factor (VEGFs) and the outer layer was manufactured via polycaprolactone (PCL)/polylactic acid (PLA)/hyaluronic acid. The products were characterized by atomic force microscope (AFM), scanning electron microscope (SEM), water contact angle (WCA), attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR), swelling test, mechanical test, and release rate. Blood compatibility tests including blood clotting time, hemolysis, and human platelet sedimentation were measured. The interactions of human umbilical vein endothelial cells (HUVECs) and human endometrial stem cells (hEnSCs) with nanofibrous vascular grafts were detected by SEM, viability assay, and DAPI staining. The results exhibited the produced small-diameter vascular grafts had proper antithrombotic properties due to two factors of VEGF and enoxaparin. After two months of the subcutaneous implantation of the scaffolds on the back of rats, the tubular vascular grafts lacked any macroscopic and histological signs of acute inflammation and had appropriate degradation rates. Furthermore, lumen patency was observed after 2 months. Consequently, VEGF and enoxaparin improves cell and blood compatibility in the small-diameter vascular grafts.

Hydrogel coating containing heparin and cyclodextrin/paclitaxel inclusion complex for retrievable vena cava filter towards high biocompatibility and easy removal

Aiming to improve the retrieval rate of retrievable vena cava filters (RVCF) and extend its dwelling time in vivo, a novel hydrogel coating loaded with 10 mg/mL heparin and 30 mg/mL cyclodextrin/paclitaxel (PTX) inclusion complex (IC) was prepared. The drug-release behavior in the phosphate buffer solution demonstrated both heparin and PTX could be sustainably released over approximately two weeks. Furthermore, it was shown that the hydrogel-coated RVCF (HRVCF) with 10 mg/mL heparin and 30 mg/mL PTX IC effectively extended the blood clotting time to above the detection limit and inhibited EA.hy926 and CCC-SMC-1 cells' proliferation in vitro compared to the commercially available bare RVCF. Both the HRVCF and the bare RVCF were implanted into the vena cava of sheep and retrieved at at 2nd and 4th week after implantation, revealing that the HRVCF had a significantly higher retrieval rate of 67 % than the bare RVCF (0 %) at 4th week. Comprehensive analyses, including histological, immunohistological, and immunofluorescent assessments of the explanted veins demonstrated the HRVCF exhibited anti-hyperplasia and anticoagulation properties in vivo, attributable to the hydrogel coating, thereby improving the retrieval rate in sheep. Consequently, the as-prepared HRVCF shows promising potential for clinical application to enhance the retrieval rates of RVCFs.

Structural, Biochemical Characterization and Molecular Mechanism of Cerastokunin: A New Kunitz-Type Peptide with Potential Inhibition of Thrombin, Factor Xa and Platelets.

The current investigation focused on separating Cerastes cerastes venom to produce the first Kunitz-type peptide. Based on its anti-trypsin effect, Cerastokunin, a 7.75kDa peptide, was purified until homogenity by three steps of chromatography. Cerastokunin was found to include 67 amino acid residues that were obtained by de novo sequencing using LC-MALDI-MSMS. Upon alignment with Kunitz-type peptides, there was a high degree of similarity. Cerastokunin's 3D structure had 12% α-helices and 21% β-strands with pI 8.48. Cerastokunin showed a potent anticoagulant effect by inhibiting the protease activity of thrombin and trypsin as well as blocking the intrinsic and extrinsic coagulation pathways. In both PT and aPPT, Cerastokunin increased the blood clotting time in a dose-dependent way. Using Lys48 and Gln192 for direct binding, Cerastokunin inhibited thrombin, Factor Xa and trypsin as shown by molecular docking. Cerastokunin exhibited a dose-response blockade of PARs-dependent pathway platelet once stimulated by thrombin. An increased concentration of Cerastokunin resulted in a larger decrease of tail thrombus in the mice-carrageenan model in an in vivo investigation when compared to the effects of antithrombotic medications. At all Cerastokunin doses up to 6mg/kg, no in vivo toxicity was seen in challenged mice over the trial's duration.

Hemostatic nanofibers/chitosan composite aerogel for potential chemo-photothermal therapy

Incomplete resection of tumor tissue and bleeding during skin cancer surgery can easily lead to early tumor recurrence and metastasis. In this study, a three-dimensional doxorubicin (DOX) loaded poly (lactic-co-glycolic acid) (PLGA) nanofibers/chitosan (CS) aerogel composite with hemostasis and chemo-photothermal effect was successfully prepared by electrospinning and lyophilization. The highly porous PLGA/MXene/DOX nanofibers@CS aerogel (PMD@CS) demonstrated exceptional photothermal conversion and pH/temperature-responsive drug release properties, which inhibited the growth of tumor cells, showing a potential chemo-photothermal effect. Furthermore, the nanofibers/aerogel composite showed desired hemostatic efficacy and biocompatibility, with a blood coagulation index of 65.1 ± 1.9% and a blood coagulation time within 3 min, indicating its potential for rapid bleeding control. This nanofibers/aerogel composite with bifunction of chemo-photothermal synergetic therapy and hemostasis can be an antineoplastic biomedical material for the prevention of postoperative tumor recurrence and metastasis.

Preparation of an anticoagulant polyethersulfone membrane by immobilizing FXa inhibitors with a polydopamine coating

Anticoagulation treatment for patients with high bleeding risk during hemodialysis is challenging. Contact between the dialysis membrane and the blood leads to protein adsorption and activation of the coagulation cascade reaction. Activated coagulation Factor X (FXa) plays a central role in thrombogenesis, but anticoagulant modification of the dialysis membrane is rarely targeted at FXa. In this study, we constructed an anticoagulant membrane using the polydopamine coating method to graft FXa inhibitors (apixaban and rivaroxaban) on the membrane surface. Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and atomic force microscopy (AFM) were used to characterize the membranes. The apixaban- and rivaroxaban-modified membranes showed lower water contact angles, decreased albumin protein adsorption, and suppressed platelet adhesion and activation compared to the unmodified PES membranes. Moreover, the modified membranes prolonged the blood clotting times in both the intrinsic and extrinsic coagulation pathways and inhibited FXa generation and complement activation, which suggested that the modified membrane enhanced biocompatibility and antithrombotic properties through the inhibition of FXa. Targeting FXa to design antithrombotic HD membranes or other blood contact materials might have great application potential.

Spatiotemporally Controlled Release of Etamsylate from Bioinspired Peptide-Functionalized Nanoparticles Arrests Bleeding Rapidly and Improves Clot Stability in a Rabbit Internal Hemorrhage Model.

Achieving rapid clotting and clot stability are important unmet goals of clinical management of noncompressible hemorrhage. This study reports the development of a spatiotemporally controlled release system of an antihemorrhagic drug, etamsylate, in the management of internal hemorrhage. Gly-Arg-Gly-Asp-Ser (GRGDS) peptide-functionalized chitosan nanoparticles, with high affinity to bind with the GPIIa/IIIb receptor of activated platelets, were loaded with the drug etamsylate (etamsylate-loaded GRGDS peptide-functionalized chitosan nanoparticles; EGCSNP). Peptide conjugation was confirmed by LCMS, and the delivery system was characterized by DLS, SEM, XRD, and FTIR. In vitro study exhibited 90% drug release till 48 h fitting into the Weibull model. Plasma recalcification time and prothrombin time tests of GRGDS-functionalized nanoparticles proved that clot formation was 1.5 times faster than nonfunctionalized chitosan nanoparticles. The whole blood clotting time was increased by 2.5 times over clot formed under nonfunctionalized chitosan nanoparticles. Furthermore, the application of rheometric analysis revealed a 1.2 times stiffer clot over chitosan nanoparticles. In an in vivo liver laceration rabbit model, EGCSNP spatially localized at the internal injury site within 5 min of intravenous administration, and no rebleeding was recorded up to 3 h. The animals survived for 3 weeks after the injury, indicating the strong potential of the system for the management of noncompressible hemorrhage.

Anticoagulation activity of sulfated carboxymethyl cellulose/Azadirachta indica leaf powder-based bio-composite.

Polymeric bio-composites synthesized via a green approach using natural herbs have fascinating anticoagulant activity due to their eco-friendly and non-toxic behavior towards various physical and chemical actions. Herein, we introduce a simple and eco-friendly approach for the fabrication of a new hybrid type of bio-composite based on sulfated carboxymethyl cellulose (S-CMC) and Azadirachta indica leaf powder (S-CMC/NLP). First, a non-toxic sulfating agent called N(SO3Na)3 was used to modify carboxymethyl cellulose into S-CMC. With an ion exchange capacity of 0.25 meq. g-1, the level of sulfation (%) of S-CMC (modified polysaccharide) was measured to be 12.01%. Three types of S-CMC/NLP bio-composites were developed by varying the concentration of NLP. FE-SEM, EDX, and XRD were used to characterize the structural features of S-CMC/NLP bio-composites. FTIR spectroscopy indicated that the S-CMC/NLP bio-composite possesses COO-, -OH and SO3- groups, suggesting the structural similarity to heparin. In addition, the anticoagulant effect of the S-CMC/NLP bio-composite was investigated using PT and APTT assays. The APTT investigation confirmed that following the intrinsic pathway of the coagulation system, 2-NLP/S-CMC bio-composite dose-dependently (0.045-0.28 mg mL-1) prolonged the time of blood coagulation compared to control (pure plasma). The S-CMC/NLP bio-composite showed its potential as a new, safe, and effective candidate for anticoagulant activity.

Показники коагулограми у пацієнтів із постковідним синдромом

Coagulogram indicators were studied in patients with post-covid syndrome aged 24 to 80 years of both sexes, with different vaccination status against coronavirus infection. Determination of coagulogram parameters in patients with post-covid syndrome is an integral part of the examination of these patients. The coagulogram includes a number of indicators, such as blood clotting time, the level of fibrinogen, platelets and other factors that determine the blood coagulation system. It was determined that the indicators of the hemostasis system (APTT, PT, D-dimer, fibrinogen) exceed the permissible values, which indicates a significant impact of the post-covid syndrome on this system. An increase in these indicators may indicate the activation of the blood coagulation system, which may be associated with the risk of thrombosis or inflammatory processes. The levels of biological markers in vaccinated and unvaccinated patients vary in different ranges. However, D-dimer levels in vaccinated patients are slightly lower than in unvaccinated patients. This suggests that vaccination probably alleviates the course of the disease. The results of the study provide important information for diagnosing the state of hemostasis and determining the risk of thrombotic complications in patients with post-covid syndrome. Consideration of elevated levels of C-reactive protein and coagulogram indicators can serve as important markers for clinicians when making decisions about treatment and monitoring of patients.

#2781 Renal cortical necrosis—a rare cause of acute kidney injury

Abstract Background and Aims Renal cortical necrosis (RCN) is a rare and catastrophic cause of acute kidney injury (AKI). It is characterized by ischemic destruction of all the elements of renal cortex due to marked reduction in renal arterial perfusion of renal cortex due to vascular spasm and microvascular injury. It can be patchy or diffuse depending upon the cause and extent of hypoperfusion. Snake bite is rare cause of RCN. Incidence of RCN following snake bite has been reported to be as high as in 25% of the bitten patients to <1%. Lack or delay in receiving anti snake venom (ASV) has been observed to be a contributing factor in development of RCN following snake bite. Method A 45-year-old female had an unknown bite on foot while returning to home at twilight. She had intense pain at site of bite with slight ooze of blood. Overnight she had vomiting and pain abdomen. Subsequently she developed progressive fall in urine output and dyspnoea. After about 36 hours of bite at the time of admission in hospital she had anuria, prolonged whole blood clotting time, tachypnoea, hypoxemia and required oxygen (O2) to maintain normal O2 saturation. She was given two doses of polyvalent ASV 6 hours apart which corrected her coagulation defect. Investigations showed: haemoglobin—9 gm/dl, total leucocyte count—18700/mcl, platelet—1.15 lakh/mcl, blood urea—88 mg/dl and serum creatinine—10.5 mg/dl. She was managed with haemodialysis and supportive care. Even after 3 weeks of onset of AKI, she had anuria so a kidney biopsy was done. Results kidney biopsy on light microscopy examination showed 9 glomeruli; 8 revealing global tuft necrosis along with necrosis of adjacent tubules and vasculature and necrotic process affected around 60% of sampled cortical area consistent with cortical necrosis (Fig. 1). She was continued with haemodialysis support and urine output and pre-dialysis serum creatinine were monitored. Her urine output after 3 months of onset of AKI is around one litre per day but her pre-dialysis serum creatinine stays in the range of 9-10 mg/dl and so she continues to receive biweekly haemodialysis. Conclusion In our index case, there was delay in getting ASV which may have contributed to development of RCN. So, early treatment of snake bite is important to prevent this catastrophic complication.

Glass bead-activated clotting time (gb-ACT) for monitoring the anticoagulation effects in elderly patients with high risk of venous thromboembolism (VTE)

ABSTRACT Background To find a new bedside method to monitor the anticoagulation effects of low-molecular-weight heparins (LMWHs) in patients with a high risk of venous thromboembolism (VTE). Research design and methods A total of 32 hospitalized patients (aged ≥60 years) who were at high risk of VTE were assigned to receive subcutaneous LMWH for 5 to 14 days. Plasma anti-factor Xa (anti-Xa) activity was conducted by a chromogenic method, and the glass bead-activated whole blood clotting time (gb-ACT) value was obtained by a Sonoclot Analyzer. Results A correlation between the gb-ACT values and the anti-Xa levels was suggested (R = 0.447, p = 0.002), and it was stronger in the older group aged 80 years above (R = 0.467, p = 0.008) and in the group of patients with an eGFR of 30 ~ 60 mL/min (R = 0.565, p = 0.005). The area under the curve (AUC) for gb-ACT by receiver operating characteristic (ROC) curve evaluation was 0.725 (p = 0.011), and the gb-ACT >282.5s provided a sensitivity of 60% and specificity of 74% for anti-Xa >0.800 IU/ml. Conclusions The gb-ACT values detected by a Sonoclot Analyzer could act as a novel bedside method in the monitoring of LMWH anticoagulation.

Protein disulfide isomerase uses thrombin-antithrombin complex as a template to bind its target protein and alter the blood coagulation rates.

During inflammation and situations of cellular stress protein disulfide isomerase (PDI) is released in the blood plasma from the platelet and endothelial cells to influence thrombosis. The addition of exogenous PDI makes the environment pro-thrombotic by inducing disulfide bond formation in specific plasma protein targets like vitronectin, factor V, and factor XI. However, the mechanistic details of PDI interaction with its target remain largely unknown. A decrease in the coagulation time was detected in activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT) on addition of the purified recombinant PDI (175 nM). The coagulation time can be controlled using an activator (quercetin penta sulfate, QPS) or an inhibitor (quercetin 3-rutinoside, Q3R) of PDI activity. Likewise, the PDI variants that increase the PDI activity (H399R) decrease, and the variant with low activity (C53A) increases the blood coagulation time. An SDS-PAGE and Western blot analysis showed that the PDI does not form a stable complex with either thrombin or antithrombin (ATIII) but it uses the ATIII-thrombin complex as a template to bind and maintain its activity. A complete inhibition of thrombin activity on the formation of ATIII-thrombin-PDI complex, and the complex-bound PDI-catalyzed disulfide bond formation of the target proteins may control the pro- and anti-thrombotic role of PDI.