PT Tests Research Articles

Role of electrode configuration and morphology in printed prothrombin time sensors

Patients on long-term anticoagulation therapy require frequent testing of prothrombin time/international normalized ratio (PT/INR) to ensure therapeutic efficacy. Point-of-care (POC) PT tests for at-home monitoring eliminate the burden of visiting the clinic, but realizing a cost-effective and robust at-home POC test for PT has remained elusive. Recent demonstrations of printed PT sensors show promise for addressing the cost concerns; however, the printed sensors have lacked quality control to ensure reliability between tests. In this work, on-chip redundancy is introduced with fully printed impedimetric PT sensors by incorporating simultaneous testing with a single fingerstick volume of blood (8 µL). The influence of electrode dimensions and composition were studied, revealing an optimal electrode spacing of 200 µm and an unexpected dependence on the morphology of the electrodes. Three distinct silver morphologies were studied: aerosol jet printed silver nanoparticles (AgNPs), aerosol jet printed silver nanowires (AgNWs), and evaporated silver (Ag). In general, AgNPs exhibited the best PT sensor performance, due to relatively low conductance and high porosity. Overall, the printed impedimetric PT sensor functionalization was improved by incorporating simultaneous testing and, when combined with a handheld control device, shows promise for leading to a system that overcomes the challenges of commercial PT/INR coagulometers.

Dynamic association between phonemic awareness and disordered speech recognition moderated by transcription training.

Phonetic transcription of disordered speech samples is especially crucial for the assessment and treatment of functional or organic speech-sound disorders. Previous studies show that students who struggle with the identification and segmentation of speech sounds are more likely to encounter difficulties with clinical phonetic transcription. To clarify the connection between phonemic awareness and phonetic transcription in Mandarin-speaking undergraduate students, as well as the improvement of these skills after phonetic transcription training. A pretest-post-test design was adopted for this study. The experimental group (n = 38) consisted of students majoring in audiology and speech-language pathology who were given 12 weeks of transcription training. The control group (n = 33) consisted of audiology and speech-language pathology majors who completed the same module a year earlier without undergoing the transcription training. Two instruments were used to assess their skills: (1) the Phonemic Awareness Skill Test (PA test) and (2) the Phonetic Transcription Skill Test (PT test) designed for the purposes of the present study. Performance on most subtests of the PT and PA tests improved significantly at post-test for the experiment group, although only PT training was provided. After phonetic transcription training, the relationship between phonemic addition abilities and phonetic transcription strengthened. Phonemic identification was found to be a predictor of undergraduate students' PT skills of disordered speech samples. Results from this study provide insights into the role of phonetic transcription training in improving phonemic awareness and phonetic transcription skills. What is already known on the subject Phonetic transcription of disordered speech samples is especially crucial for the assessment and treatment of functional or organic speech-sound disorders. Phonemic awareness is not only an essential ability for reading alphabetic language but also associated with acquiring phonetic transcription skills. What this paper adds to existing knowledge A dynamically changing association between phonemic transcription and phonetic transcription during transcription training was reported. Phonetic transcription training of disordered speech samples acted as a driving force for deeper relationships between the two skills. What are the potential or actual clinical implications of this work? Training phonetic recognition and transcription equips future and practising speech-language pathologists with better skills in managing speech-sound disorders. Implications for phonemic awareness training also have the potential to extend to the literacy skills of alphabetic language speakers.

Fibrinogen level among children with liver cirrhosis

IntroductionThe liver has a major role in the production of coagulation factors, and cirrhotic patients have a series of coagulopathy disorders. The present study aimed to measure plasma fibrinogen levels in children with hepatic cirrhosis.MethodPatients younger than 18 years old after diagnosis of liver cirrhosis by biopsy were enrolled in the study. Laboratory data including hemoglobin, PT, PTT, INR, and liver function tests were recorded. Fibrinogen levels were measured using the Clauss method. PELD score for children less than 12 years and MELD Na for children over 12 years were used to measure the severity of the liver disease.ResultsFifty children with cirrhosis were studied. The mean fibrinogen level in the “PELD < 15” group was significantly higher than the other group (P < 0.001). There was no significant relationship between bleeding and fibrinogen levels. There was no significant relationship between PELD and bleeding in subjects (P = 0.87). The results of the study showed neither of these two factors (fibrinogen level and PELD) can play a predictive role in causing hemorrhage in patients.ConclusionOur study has shown that fibrinogen level is significantly associated with severity of liver cirrhosis and decreases with more severe disease (PELD levels), but platelet and fibrinogen cannot predict the severity of bleeding in these patients.

Molecular Characterization and Biocompatibility of Exopolysaccharide Produced by Moderately Halophilic Bacterium Virgibacillus dokdonensis from the Saltern of Kumta Coast.

The use of natural polysaccharides as biomaterials is gaining importance in tissue engineering due to their inherent biocompatibility. In this direction, the present study aims to explore the structure and biocompatibility of the EPS produced by Virgibacillus dokdonensis VITP14. This marine bacterium produces 17.3 g/L of EPS at 96 h of fermentation. The EPS was purified using ion exchange and gel permeation chromatographic methods. The porous web-like structure and elemental composition (C, O, Na, Mg, P, S) of the EPS were inferred from SEM and EDX analysis. AFM analysis revealed spike-like lumps with a surface roughness of 84.85 nm. The zeta potential value of −10 mV indicates the anionic nature of the EPS. Initial molecular characterization showed that the EPS is a heteropolysaccharide composed of glucose (25.8%), ribose (18.6%), fructose (31.5%), and xylose (24%), which are the monosaccharide units in the HPLC analysis. The FTIR spectrum indicates the presence of functional groups/bonds typical of EPSs (O-H, C-H, C-O-H, C-O, S=O, and P=O). The polymer has an average molecular weight of 555 kDa. Further, NMR analysis revealed the monomer composition, the existence of two α- and six β-glycosidic linkages, and the branched repeating unit as → 1)[α-D-Xylp-(1 → 2)-α-D-Glcp-(1 → 6)-β-D-Glcp-(1 → 5)]-β-D-Frup-(2 → 2)[β-D-Xylp-(1 → 4)]-β-D-Xylp-(1 → 6)-β-D-Fruf-(2 → 4)-β-D-Ribp-(1 →. The EPS is thermally stable till 251.4 °C. X-ray diffraction analysis confirmed the semicrystalline (54.2%) nature of the EPS. Further, the EPS exhibits significant water solubility (76.5%), water-holding capacity (266.8%), emulsifying index (66.8%), hemocompatibility (erythrocyte protection > 87%), and cytocompatibility (cell viability > 80% on RAW264.7 and keratinocyte HaCaT cells) at higher concentrations and prolongs coagulation time in APTT and PT tests. Our research unveils the significant biocompatibility of VITP14 EPS for synthesizing a variety of biomaterials.

Phytochemical characterization and biological activities of butanolic extract of aerial parts of Tetraclinis articulata from Algeria

Tetraclinis articulata is a forest plant species that is widely used in North African folk medicine due to its immense bioactive potential. The objective of the present study was to characterize flavonoids present in butanolic extract of aerial part of T. articulata (TABE) and to test its antibacterial synergistic effect, anticoagulant and antioxidant properties. The analysis of the TABE by colorimetric tests and TLC revealed the presence of flavonoids. The dosage showed that the proportions of total flavonoids and flavonols were 19.25 ± 0.07 and 13.6 ± 1.6 mg QE/g DW, respectively. Besides, the greatest antibacterial activity of the extract was shown against S. aureus. In contrast no effect was observed against E. coli. Furthermore, the most synergistic potential inhibitory effect was noted in the case of E. coli, when the extract was combined with penicillin. In addition, the MICs was determined used microdilution method, the values obtained were ranged from 2.5 to 20 mg/ml. Moreover, the in vitro anticoagulant activity was assessed by PT and KCT tests. The results showed interesting anticoagulant activity, with KCT value of 55.4 s which is superior to that obtained by the anticoagulant drug –Lovenox- (39.37s). The antioxidant activity was evaluated in vitro using DPPH• method. The result expressed in terms of IC50 was found to be 0.04 mg/ml. To conclude, the TABE constitutes a valuable source of anticoagulant, antioxidant and antibacterial synergism metabolites, which makes it a potential candidate to isolate responsible flavonoids and to develop novel pharmaceutical formulations.

Analytical Performance Evaluation of Siemens Sysmex CS-2500 and Sekisui CP-3000.

Automatic coagulation analyzers have been used in the last 50 years and have been developed considerably. Newly developed tests and methods cannot be conducted in routine laboratories without evaluating their performance. Therefore, their performance must be evaluated and approved before being used routinely. The aim of this study is to evaluate the analytical performance of Sysmex Coagulation System-2500 (CS-2500) and Sekisui CP-3000 automatic coagulation analyzer (CP-3000). For APTT, PT, and D-dimer tests, reference range verification study, a method comparison study was performed in both analyzers in accordance with CLSI protocols, and precision and accuracy were evaluated using internal and external quality control samples. In the evaluation of precision and accuracy, CV% and bias% values were calculated. Bland-Altman, Passing-Bablok regression analysis, and correlation coefficient were used in the comparison study. The CV% values calculated for APTT and PT in both analyzers were found to be below the CLSI recommendation of 5%. D-dimer test results meet the quality criteria recommended by CLSI. Accuracy for both analyzers was within the acceptable limits. The reference ranges recommended by the manufacturer have been veryfied. Regression equations for APTT, PT, and D-dimer are y = -3.313 + 1.188x, y = -0.0399 + 1.048x, and y = 0.155 + 0.655x, respectively, and r values were 0.904, 0.978, and 0.974, respectively. CS-2500 and CP-3000 analyzers are suitable for laboratory use for routine coagulation. Since the CP-3000 device is newly used in our country, it needs to be supported by more comparison studies.

Endothelial Activation Markers in Polytransfused Children with Beta Thalassemia: Study from a Tertiary Care Centre in India.

Beta thalassemia major is associated with a subclinical hypercoagulable state. Endothelial activation markers like soluble Intercellular adhesion molecule (sICAM-1) and E-selectin have been implicated in the pathogenesis of endothelial dysfunction and hemostatic alterations. In this study we aimed to study serum levels of sICAM-1 and E-selectin in polytransfused children with β thalassemia major and their association with serum ferritin and D-dimer levels. Sixty-two polytransfused β-thalassemia major children aged between 5 and 17years and 26 age and gender matched healthy controls were enrolled in the study. Complete blood count with peripheral smear, liver function tests, serum ferritin, coagulation tests [PT, APTT, D-dimer] and endothelial activation marker tests [ICAM-1 and E-selectin] were performed. PT, APTT and D-dimer levels were significantly higher in beta-thalassemia major patients than in control group (p = 0.003, p < 0.001, p < 0.001 respectively). Mean ICAM-1 and E-selectin levels were 731.34 ± 343.97ng/ml and 111.75 ± 40.13ng/ml respectively which were significantly higher than control group (p < 0.001, p < 0.001 respectively). No significant correlation of ICAM-1 and E-selectin was observed with serum ferritin, PT, APTT and D-dimer levels. The findings of the present study suggest that there is ongoing subclinical activation of coagulation cascade and fibrinolytic system in these patients. Endothelial activation markers may be used as early indicators of endothelial dysfunction to assess the thrombotic complications in beta thalassemia.

Investigation of chemical and biological properties of an acidic polysaccharide fraction from Pleurotus eous (Berk.) Sacc.

Pleurotus eous, pink oyster mushroom and functional food, is widely cultivated in Southern India. In this study, we successfully attempted, to isolate a new acidic polysaccharide fraction (PEPA-1a) possessing a molecular weight of 8.926 × 104 Da from the fruiting bodies of Pleurotus eous through ion-exchange and gel-filtration chromatographic techniques. Monosaccharide composition comprising glucose, galactose, rhamnose, mannose, and N-acetyl galactosamine were found to have the corresponding mole percentages of 20.25, 56.75, 3.06, 11.07, and 8.86, respectively. The antioxidant activity was assessed through seven in vitro tests, PEPA-1a showed significant antioxidant activity in a dose-dependent way, with EC50 values stretching from 1.08 to 4.91 mg/mL. Analyses of PEPA-1a towards in vitro anti-tumour showed high activity against HT29 (IC50 = 233.50 μg/mL) and PC3 cells (IC50 = 230.80 μg/mL). The anticoagulant activity estimated through APTT, PT and TT tests were found be effective. Also, the congo red analysis revealed the triple-helical structures of carbohydrates. The results indicate that consumption of P. eous polysaccharide may be beneficial for health and will serve as an exceptionally accessible natural source for food and pharmaceutical industries.

Biomimetic hydroxyapate/polydopamine composites with good biocompatibility and efficiency for uncontrolled bleeding.

Uncontrolled bleeding is thought to be the most deadly cause of pre-hospital, traffic, and military accidents death. However, the popular commercial hemostats can only realize the hemostasis of mild bleeding. Therefore, we developed polydopamine (PDA) composite materials (PMs), which applied hydroxyapatite as the parent body. The PMs were produced via lyophilization and functionalized with amino, phenol hydroxyls groups, which endowed hydrophobicity to materials. This ensured a high aggregation ability of blood cells to the PMs and they were tested to be as high as 300% compared with the negative control group. The clotting time was shortened to 79.7% compared with the usually used commercial hemostat (Celox) in the test of in vitro hemostasis. Through the results of PT and APTT tests, blood coagulation index test, and the analysis of intracellular Ca2+ activation, we further understood the mechanism of the hemostasis of the materials, which explained the low blood loss and quick coagulation time of the PM hemostats in detail. Besides, the low hemolysis and cytotoxicity of the PMs suggested the good biocompatibility of the hemostats, which was further proved by the regular morphology maintained by erythrocytes in the hemolysis tests. The study of nanoscale composites led the research for the methods of hemostasis.

Chitosan/alginate/hyaluronic acid polyelectrolyte composite sponges crosslinked with genipin for wound dressing application

Wound dressing composed of polyelectrolyte complexes (PECs), based on chitosan/alginate/hyaluronic acid (CS/ALG/HYA) crosslinked by genipin, was prepared by freeze-dried molding. Genipin as excellent natural biological crosslinker was chose for high biocompatibility and improving mechanical properties of materials. The CS/ALG/HYA sponges (CAHSs) were characterized by FTIR, XRD, DSC and SEM. Porosity, swelling behavior and mechanical properties and in vitro degradation of CAHSs were investigated. The cytotoxicity assay was carried out on HUVEC cells in vitro and the result proves the good biocompatibility of CAHSs. Hemolysis tests indicated that the prepared CAHSs were non-hemolytic material (hemolysis ratio < 5%, no cytotoxicity). PT and aPPT coagulation tests demonstrated that CAHS2 and CAHS3 could both activate the extrinsic and intrinsic coagulation pathway and thus accelerated blood coagulation. Further, in a rat full-thickness wounds model, the CAHS2 sponge significantly facilitates wound closure compared to other groups. CAHSs exhibited adjustable physical, mechanical and biological properties. Thus, the chitosan-based polyelectrolyte composite sponges exhibit great potential as promising wound dressings.

Prediction of Pile Capacity using Pile Loading Tests and C PT Tests

Prediction of Pile Capacity using Pile Loading Tests and C PT Tests

Bivalirudin and sirolimus co-eluting coronary stent: Potential strategy for the prevention of stent thrombosis and restenosis

Localized drug delivery with sustained elution characteristics from nanocarrier coated stents represents a viable therapeutic approach to circumvent concerns related to coronary stent therapy. We fabricated a Sirolimus (SRL) and Bivalirudin (BIV) releasing nanoparticles (NPs) coated stent for concurrent mitigation of vascular restenosis and acute stent thrombosis. SRL NPs were prepared by nanoprecipitation method whereas the BIV vesicles were generated using hydrophobic ion pair approach followed by micellization phenomenon. MTT assay and confocal microscopic analysis indicated superior anti-proliferative activity and higher cellular uptake of SRL NPs into human coronary artery smooth muscle cells, respectively. DSC and ATR-FTIR techniques confirmed the formation of complex between BIV and phosphatidylglycerol via some weak physical interactions. More than 2 fold rise in log P value was obtained for DSPG-BIV at 3:1 M ratio compared with native BIV solution. The SAXS analysis indicated formation of oligolamellar vesicles of DSPG-BIV complex which was preferentially entrapped into lipophilic lamellae of vesicles. APTT, PT, and TT tests revealed that the BIV vesicles caused significant prolongation of clotting time compared to native BIV solution. The SEM analysis showed uniform and defect free stent coating. In vitro release study demonstrated that SRL and BIV were eluted in a sustained manner from coated stents.

Homogeneity and Stability Evaluation of External Quality Assessment Control Materials for Four Coagulation Tests.

This study assessed the homogeneity and stability of control materials used in external quality assessment (EQA) of four coagulation tests, aiming to verify that these materials meet clinical testing requirements and to provide an evidence base for future improvement of laboratory coagulation test quality. The homogeneity and stability of control materials were assessed according to the relevant guidance. Homogeneity assessment involved 10 vials of samples obtained from 2 batches (each vial tested twice). The homogeneity of control materials in four coagulation tests was assessed using one-way analysis of variance, with standard deviation of uniformity (Ss) 0.3 σ as an assessment criterion. Stability assessment involved two vials of sam-ples obtained from two batches (each vial tested twice). The stability of control materials was assessed at cold storage, room temperature, temperature of 37°C. Reconstitution stability of control materials placed in cold storage and at room temperature, and long-term stability of reconstituted control materials stored frozen (-20°C and -80°C) were observed. Linear regression analysis was performed to assess long-term stability. The Ss values of EQA control materials for four coagulation tests were PT L1 Ss = 0.084, PT L2 Ss = 0.889, APTT L1 Ss = 0.164, APTT L2 Ss = 0.223, Fbg L1 Ss = 6.256, Fbg L2 Ss = 2.251, TT L1 Ss = 0.552, TT L2 Ss = 0.3111. PT, APTT, Fbg, and TT were associated with the standard deviation of uniformity values of 0.3 σ. Non-reconstituted samples were observed at 37°C for 2 hours and 4 hours, and at room temperature for 1 day. Reconstituted samples were observed when stored at 4°C for 4 hours and 8 hours, at room temperature for 4 hours, and at -20°C and -80°C for 6 months. Instability of reconstituted samples was observed in PT and APTT tests at 4°C for 8 hours and at -20°C for 5 months. EQA control materials presented with satisfactory homogeneity in four coagulation tests. Non-reconstituted samples presented with satisfactory stability at 37°C for 2 hours and 4 hours and at room temperature for 1 day, while reconstituted samples presented with satisfactory stability when refrigerated at 4°C for 4 hours, when kept at room temperature for 4 hours, and when frozen at -80°C for 6 months.

S2190 A Rare Presentation of Blue Rubber Bleb Nevus Syndrome in the Elderly

INTRODUCTION: Blue Rubber Bleb Nevus Syndrome (BRBNS) is a rare congenital condition consisting of venous malformations manifesting as blue blanchable rubbery blood filled sacks. BRBNS is often diagnosed in childhood to early adulthood, and can occasionally present with significant blood loss anemia requiring hospitalization and blood product transfusions. In the case below, we discuss a patient with no prior history of anemia who presented with suspected BRBNS associated GI bleeding manifesting in late adulthood. CASE DESCRIPTION/METHODS: 64 y/o female with hypertension and hypothyroidism, who presented to the ER with acute hematemesis, melena, and associated bilateral lower quadrant abdominal pain. The patient does not take any blood thinners nor NSAIDs. The physical exam was significant for epigastric tenderness and bilateral lower extremity pitting edema, but was otherwise largely unremarkable. The patient had no obvious rashes, hemangiomas, petechiae or skin lesions. Initial Hgb was 5.7 gm/dL with MCV 106 Femtoliters, PLTs 188,000 per mc/L. The PT, INR, renal function, and liver function tests were within normal limits. After 3 units of packed RBCs, her Hgb increased to 8.6 gm/dL. CT Abdomen/Pelvis w/ IV contrast: unremarkable. Upper endoscopy: A single vascular gastric abnormality consistent with arteriovascular malformation. Colonoscopy: Multiple venous malformations manifesting as blue blebs along the right-sided colon suggestive of BRBNS. No evidence of fresh or old blood. No biopsies were taken given concerns of possible profuse bleeding. Patient was discharged with outpatient follow up after hemoglobin stabilized. DISCUSSION: BRBNS is an autosomal dominant disease with venous malformations manifesting along the GI tract, skin, liver/spleen, kidneys, brain, retroperitoneum and other organs. The GI tract is the most common location, and often manifests as occult GI bleeding. BRBNS is often diagnosed during endoscopy with its characteristic blue blanching rubbery bleb appearance which distinguishes it from other vascular abnormalities. Biopsies of the blebs can aid in diagnosis. In the limited number of cases documented, the majority have been identified during childhood to early adulthood with rarely any cases presenting in late adulthood. Regardless of advanced age, BRBNS should remain in the differential for unexplained anemia or GI bleed when suspicious vascular lesions are encountered during endoscopy.

Sulfated polysaccharide from the red algae Gelidiella acerosa: Anticoagulant, antiplatelet and antithrombotic effects

A sulfated polysaccharide from the red algae Gelidiella acerosa (GaSP) was obtained through enzymatic extraction and subjected to chemical characterization by HPSEC, elemental microanalysis, FT-IR and NMR spectroscopies. The GaSP anticoagulant activity was investigated through APTT and PT tests and platelet aggregation assessed by turbidimetry. The antithrombotic and hemorrhagic activities were evaluated by venous thrombosis and hemorrhagic tendency models, respectively. FT-IR and NMR demonstrated that GaSP is a sulfated agaran. HPSEC and elemental microanalysis revealed a peak molar mass of 284.8 kDa and a degree of sulfation of 0.63, respectively. This molecule prolonged the coagulation time in 2.1 times and inhibited the platelet aggregation by 45%. Furthermore, it showed significant dose-dependent antithrombotic effect of 40%, 64% and 80% at 0.1, 0.5 and 1 mg/kg, respectively, without hemorrhage. These results suggest that GaSP has promising antithrombotic.

Blood acid-base, haematological and haemostatic effects of hydroxyethyl starch (130/0.4) compared to succinylated gelatin colloid infusions in normovolaemic dogs.

Synthetic colloids are commonly administered to dogs to treat absolute or relative hypovolaemia. Voluven® (tetrastarch 130/0.4) and Gelofusine® (succinylated gelatin) are available to veterinarians in South Africa. In humans, use of these products has caused acid–base derangements, changes in haematology and impaired haemostasis. We aimed to investigate these effects in healthy normovolaemic dogs. Eight healthy adult beagle dogs underwent a cross-over study, receiving Voluven® or Gelofusine® (10 mL/kg/h for 120 min) once each with a 14-day washout between treatments. Dogs were premedicated with dexmedetomidine (10 µg/kg intramuscularly). Anaesthesia was induced with propofol and the dogs were maintained with isoflurane-in-oxygen. The anaesthetised dogs were connected to a multi-parameter monitor to monitor physiological parameters throughout. Catheters placed in a jugular vein and dorsal metatarsal artery allowed sampling of venous and arterial blood. Blood was collected immediately prior to commencement of colloid infusion, after 60 min infusion and at the end of infusion (120 min) to allow for arterial blood gas analysis, haematology and coagulation testing (activated partial thromboplastin time [aPTT], prothrombin time [PT] and thromboelastography [TEG]). There was no effect, between treatments or over time, on blood pH. The haemoglobin concentration, erythrocyte count and haematocrit decreased significantly over time (all p < 0.01), with no differences between treatments, and remained within normal clinical ranges. There were no differences between treatments or over time for the TEG, aPTT and PT tests of haemostasis. At the dose studied, Voluven® and Gelofusine® had comparably negligible effects on blood acid–base balance and coagulation in normovolaemic dogs.

Oral tranexamic acid for bleeding during spinal surgery: A randomized double-blind placebo clinical trial

&lt;abstract&gt;&lt;sec&gt; &lt;title&gt;Objectives&lt;/title&gt; &lt;p&gt;This study aimed to evaluate the oral Tranexamic acid (TXA) effect on the bleeding during spine surgery amounts.&lt;/p&gt; &lt;/sec&gt;&lt;sec&gt; &lt;title&gt;Patients and Methods&lt;/title&gt; &lt;p&gt;In this randomized double-blind placebo clinical trial, patients with lumbar spinal cord and back pain disease, those who needed fusion or were candidates for bilateral or more or equal to two levels surgeries, and those who referred to the Neurosurgery Department, were included and randomly divided into two equal groups. TXA was orally administered at 25 mg/kg dosages four times a day before surgery and 500 mg in the morning of surgery. The bleeding amount during the operation was calculated based on the number of sterile pads used during the operation and the amount of bleeding collected in the suction device (suction) in milliliters. Each sterile pad soaked in blood is equal to 50 ml of bleeding. The suction blood content at the end of the operation (in milliliters), was also collected by bleeding in sterile pads and reported in milliliters. The difference in hemoglobin level 24 after surgery was compared to before surgery. The follow-up period was until discharge from the hospital.&lt;/p&gt; &lt;/sec&gt;&lt;sec&gt; &lt;title&gt;Results&lt;/title&gt; &lt;p&gt;No significant difference was seen in the demographic data between the two groups (&lt;italic&gt;p&lt;/italic&gt; &amp;lt; 0.05). Oral TXA had a positive effect on the intraoperative and postoperative bleeding amounts, and hospitalization duration, and it significantly reduced bleeding in the mentioned cases (&lt;italic&gt;p&lt;/italic&gt; &amp;lt; 0.05 in all cases). Moreover, no significant differences were observed in coagulation factors, including PT, INR, and coagulation tests between the two groups, even PTT was increased. Oral TXA increased nausea and vomiting experienced by patients in the intervention group (&lt;italic&gt;p&lt;/italic&gt; &amp;lt; 0.05).&lt;/p&gt; &lt;/sec&gt;&lt;sec&gt; &lt;title&gt;Conclusions&lt;/title&gt; &lt;p&gt;Overall, oral TXA significantly reduced the intraoperative and postoperative bleeding, as well as the hospitalization duration in patients undergoing spinal surgery in comparison with the placebo group. Because of its anti-fibrinolytic properties, TXA effectively controlled bleeding. Thus, the intraoperative bleeding amount was decreased with the TXA administration.&lt;/p&gt; &lt;/sec&gt;&lt;/abstract&gt;

Interference of lipemia in samples for routine coagulation testing using a Sysmex CS-5100 coagulometer.

Lipemia in samples can cause analytical errors in coagulation tests using photometric assays. To define the level of this interference, some studies assessed lipemic interferences by in vitro 'spiking' of different types of lipids obtaining interesting information, but spiked samples do not represent a real-world situation as natively lipemic samples do. A total of 101 samples flagged as 'lipemic' by a Sysmex CS-5100 coagulometer were analyzed for PT, aPTT, fibrinogen Clauss assay, antithrombin activity, D-dimer concentration, before and after a double high-speed centrifugation procedure to reduce lipemic interference. We evaluated using Bland-Altman test if high-speed centrifugation and retesting are justified, considering that's a resource-consuming procedure; when a statistically significant difference was found, quality specification for imprecision was considered and compared to the observed delta. Statistically significant differences were found for PT, antithrombin activity and fibrinogen. Considering the Bland-Altman plot, fibrinogen results were split into two groups, and statistically significant difference was confirmed only for samples >2g/L. For PT and antithrombin activity a mean percentual difference between the two determinations lower than within-subject biologic variation and one of the Fraser's quality specifications can be considered as a confounding 'noise' factor that is neither analytically nor clinically relevant. If the instrument determines a result on the first run, for PT, aPTT, D-dimer concentration and antithrombin activity tests, the double plasma high-speed centrifugation is unnecessary. It is instead necessary if fibrinogen >2g/L or if the instrument cannot determine a result on the first run.

Comparative Studies on the Oral Anticoagulant Activities of Orally Active Anti‐Xa and Anti‐IIa Agents in Whole Blood and Plasma and their Neutralization by FEIBA

IntroductionOrally bioavailable anticoagulants include, Apixaban, Betrixaban, Edoxaban, and Rivaroxaban which are anti Xa drugs approved for various indications. Dabigatran is an anti‐IIa drug which is primarily approved for atrial fibrillation. While these drugs are claimed to have targeted actions toward Factor Xa or IIa, current data suggests that their actions may involve other target sites. This study was designed to compare the relative anticoagulant effects of each of these drugs in whole blood and retrieved plasma, using PT, aPTT and TT tests. Additionally the neutralization of these drugs by an activated prothrombin complex concentrate FEIBA was also investigated.MaterialsPowdered forms of Apixaban, Betrixaban, Edoxaban, Rivaroxaban and Dabigatran were obtained from commercial sources. All drugs were dissolved at a stock concentration of 1 mg/mL in saline. Working concentrations were prepared at 100 ug/mL and 10 ug/mL. Freshly drawn citrated whole blood from healthy volunteers (n=10) was supplemented with each of these agents at a graded concentration of 0 to 1 ug/mL. Whole Blood, PT and aPTT were measured using the ST4 (Diagnostica Stago) instrument. Whole blood supplemented with each of these drugs was centrifuged to obtain retrieved plasma from each of these agents. The retrieved plasma was also analyzed for PT and aPTT. All results were compiled in terms of mean and standard deviation. These studies were repeated in the presence of 0.1 U/mL of FEIBA to determine the relative neutralization of their anticoagulant effects.ResultsAll of the five drugs produced concentration dependent anticoagulant effects in both the PT and aPTT tests. In the whole blood, the PT prolongation was different for each agent, with the rank order Dabigatran &gt; Edoxaban &gt; Betrixaban &gt; Rivaroxaban &gt; Apixaban &gt; Saline. The prolongation of the aPTT in the whole blood followed the rank order Betrixaban &gt; Dabigatran &gt; Rivaroxaban &gt; Edoxaban = Apixaban &gt; Saline. All five drugs produced an increase in the PT in the retreat plasma with rank order Dabigatran &gt; Edoxaban &gt; Apixaban &gt; Rivaroxaban &gt; Betrixaban &gt; Saline. In the aPTT assay the increase in clotting times followed the rank order Dabigatran &gt; Betrixaban &gt; Rivaroxaban &gt; Edoxaban &gt; Apixaban. FEIBA supplementation at a 0.1 U/ml to each of the drugs supplemented at 1 ug/ml markedly neutralized their anticoagulant effects in the PT and aPTT assay systems. At this concentration FEIBA did not have any significant effects on the PT and aPTT assays.ConclusionsThese studies suggest that in comparison to the anti‐Xa agents, Dabigatran produces relatively stronger anticoagulant effects in the PT and aPTT assays in both whole blood and retrieved plasma. FEIBA at a relatively low level of 0.1 U/ml was capable of neutralizing the anticoagulant effects of the newer oral anticoagulant drugs and may be helpful in the control of potential bleeding complications with these drugs.Support or Funding InformationNone.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Measurement of rivaroxaban concentrations demonstrates lack of clinical utility of a PT, dPT and APTT test in estimating levels.

Rivaroxaban concentrations were measured in 127 inpatient samples using an HPLC-MS/MS assay. We compared this measurement with a calibrated anti-Xa assay and performed PT, aPTT and dilute PT tests to assess the value of clot-based assays in clinical decision-making. The correlation between the anti-Xa assay and the HPLC-MS/MS at therapeutic concentrations was strong (R2 =0.98). The PT, RecombiPlasTin 2G, and aPTT, Actin FS, showed a linear dose-response but poor correlation (R2 =0.32 and 0.44, respectively) and at dilutions of 1 in 150 to 1 in 750 the dilute PT assay also showed poor correlation with rivaroxaban concentrations measured by specific assays. A normal PT or aPTT alone did not identify a likely safe rivaroxaban concentration to allow surgery or invasive procedures, but the combination of normal PT and aPTT identified a group of patients with rivaroxaban levels less than 90ng/mL. Combined normal PT and aPTT had specificity and sensitivity of 0.97 (95% CI 0.92-0.99) and 0.37 (95% CI 0.1-0.74) for a rivaroxaban concentration < 32ng/mL. The PT and aPTT show poor correlation with rivaroxaban levels measured by calibrated anti-Xa and HPLC-MS/MS assays. A normal combined PT and APTT identified low rivaroxaban levels with high specificity but lacked sensitivity. The dPT assay at several dilutions could not be used to quantify rivaroxaban in clinical samples. The utility of these PT, aPTT and dilute PT assays in a clinical setting is very limited, and results generated must be interpreted with caution.