aPTT Tests Research Articles

Investigation of Hyaluronidase, Collagenase and Elastase Inhibitory Potentials and Comparative Evaluation of the Antimicrobial, Antioxidant and Homeostatic Activities of Two Natural Polysaccharides

The aim of this study was to investigate the hyaluronidase, collagenase and elastase inhibitory effects, which play important role for wound healing, together with the antibacterial, antioxidant and homeostatic activities of tragacanth gum (TG) and locust bean gum (LBG). The antimicrobial activities were tested against four bacteria and the antioxidant activities were estimated by the 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydrogen peroxide (H2O2) radical scavenging and β-carotene bleaching assays. Homeostatic effect was evaluated with the Prothrombin Time (PT) and Activated Partial Thromboplastin Time (aPTT) test parameters. The wound healing potentials were determined with the inhibition of hyaluronidase, collagenase and elastase enzymes. The TG showed antibacterial activity against Pseudomonas aeruginosa ATCC27853 and Escherichia coli ATCC25922. The results showed that TG and LBG possessed antioxidant properties including DPPH scavenging (21.0% and 17.6%, respectively) and H2O2 radical scavenging (59.4% and 79.0%, respectively) activities. The polysaccharides displayed significantly reducing PT and aPTT results. Between the two tested polysaccharides LBG showed significant hyaluronidase and collagenase inhibition activity at 10 mg/mL concentration. These findings show that these natural polysaccharides can be used to support of wound healing.

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.

Heparin-Induced Thrombocytopenia in Infants after Heart Surgery.

Heparin-induced thrombocytopenia (HIT) in infants is a rare disorder, and the diagnosis and management of HIT still remains challenging. Argatroban is a synthetic direct thrombin inhibitor (DTI) that is widely used for treating HIT. However, little is known about the efficacy of the activated clotting time (ACT) test in monitoring DTI treatment as an alternative to the routinely used activated partial thromboplastin time (aPTT). Between July 2013 and January 2015, four infants were diagnosed with HIT after surgical correction of congenital anomalies. In all cases, heparin was used during cardiopulmonary bypass (CPB). Diagnosis of HIT was based on the "4 Ts" pretest clinical scoring system, and platelet factor 4 (PF4) antibody was detected using enzyme-linked immunosorbent assay. Argatroban was used in treating HIT. When argatroban was infused, anticoagulation tests (aPTT, prothrombin time [PT], thrombin time [TT], and fibrinogen) were performed every 4 to 12 hours. ACT was used in addition to monitor the anticoagulation effect of argatroban. The target ACT was 1.5 to 3.0 times the baseline. ACT was measured every 2 to 4 hours and remeasured 1 hour after each dosage adjustment. Thrombocytopenia (defined as a 50% decrease in platelet count) occurred during the 3rd to 6th day postoperatively. After the diagnosis of HIT, argatroban was started immediately, and platelet counts stabilized and gradually increased. Anticoagulation effect of argatroban was successful monitored by ACT and aPTT. Poor correlation between the ACT test and aPTT test (R = 0.270, p = 0.092) was noted in one patient. ACT values increased rapidly after 3 to 7 days on argatroban treatment. In most cases, low dosage of argatroban was given ranging from 0.04 to 5.00 μg/kg/min. Argatroban may be an effective medicine in treating HIT in infants, in a reduced dosage. The great fluctuation in argatroban dosage during the course of HIT treatment necessitates close monitoring. ACT test may be reliable and convenient for monitoring HIT treatment and may contribute to positive clinical outcomes in infants. The efficacy of argatroban and the use of ACT monitoring in the management of HIT infants needs further study.

What should be the laboratory approach against isolated prolongation of a activated partial thromboplastin time?

This study is a retrospective evaluation of patients who were subject to mixing study in our laboratory due to prolonged APTT. The preliminary diagnoses, clinical manifestations, and results of additional ordered tests were reviewed. The study aims to investigate whether repeating APTT test with a different assay prior to performing mixed study in patients with prolonged APTT would be a better alternative algorithmic approach in order to save both time and costs. We retrospectively evaluated 166 patients (65 females and 101 males) who were subject to mixing study due to isolated prolonged APTT. Additional ordered tests to identify the etiology and clinical findings were reviewed. All patients who had prolonged APTT as a result of testing with Hemosil Synthasil APTT reagent in ACL TOP analyzer were repeated with Stago Cephascreen APTT reagent in STA-R coagulation analyzer. APTT test was requested preoperatively in 72.2% of cases. Only 6.6% of the cases had history of bleeding. Correction with mixing study was achieved in 122 (73.5%) cases, among which 75 (45%) cases were found to have APTT test results within reference range when tested with Cephascreen reagent. In 44 (26.5%) cases, mixing study did not result in correction. Only 4 cases were confirmed to have lupus anticoagulants (LA), while 4 cases were diagnosed with hemophilia with inhibitors. Prolonged APTT results should always be retested using a different assay prior to mixing study. The clinician and the laboratory specialist should collaborate at the postanalytical phase.

High incidence of FXI deficiency in a Spanish town caused by 11 different mutations and the first duplication of F11: Results from the Yecla study.

Factor XI (FXI) deficiency is a rare disorder with molecular heterogeneity in Caucasians but relatively frequent and molecularly homogeneous in certain populations. To characterize FXI deficiency in a Spanish town of 60000 inhabitants. A total of 324764 APTT tests were screened during 20years. FXI was evaluated by FXI:C and by Western blot. Genetic analysis of F11 was performed by sequencing, multiplex ligation-dependent probe amplification and genotyping. Our study identified 46 unrelated cases and 170 relatives with FXI deficiency carrying 12 different genetic defects. p.Cys56Arg, described as founder mutation in the French-Basque population, was identified in 109 subjects from 24 unrelated families. This mutation was also identified in 2% of the general population. p.Cys416Tyr, c.1693G>A and p.Pro538Leu were identified in 7, 6 and 2 unrelated families, respectively. NGS analysis of the whole F11 gene revealed a common haplotype for each of the four recurrent mutations, suggesting a founder effect. The analysis of plasma FXI of four p.Pro538Leu homozygous carriers revealed that this variant was not activated by FXIIa. We identified four mutations previously described in other Caucasian subjects with FXI deficiency (p.Lys536Asn; p.Thr322Ile, p.Arg268Cys and c.325G>A) and four new gene defects: p.(Cys599Tyr) potentially causing a functional deficiency, p.(Ile426Thr), p.(Ile592Thr) and the first worldwide duplication of 1653bp involving exons 8 and 9. Bleeding was rare and mild. Our population-cohort study supplies new evidences that FXI deficiency in Caucasians is more common than previously thought and confirmed the wide underlying genetic heterogeneity, caused by both recurrent and sporadic mutations.

Comparison of different laboratory tests in the evaluation of hemorrhagic risk of patients using rivaroxaban in the critical care setting: diagnostic accuracy study

BackgroundRivaroxaban is a direct oral anticoagulant designed to dispense with the necessity of laboratory monitoring. However, monitoring rivaroxaban levels is necessary in certain clinical conditions, especially in the critical care setting.MethodsThis is a diagnostic accuracy study evaluating sensitivity and specificity of prothrombin time (PT), activated partial thromboplastin time (aPTT), and Dilute Russell viper venom time (dRVVT), to evaluate the hemorrhagic risk in patients taking rivaroxaban. The study used a convenience sample of 40 clinically stable patients using rivaroxaban to treat deep vein thrombosis or atrial fibrillation admitted in a private hospital in Brazil, compared to a group of 60 healthy controls. The samples from patients were collected two hours after the use of the medication (peak) and two hours before the next dose (trough).ResultsThe correlation with the plasmatic concentration measured by anti-FXa assay was higher for PT and dRVVTS. The PT and aPTT tests presented higher specificity, while dRVVT was 100% sensible.ConclusionsThere was a strong correlation between the tests and the plasma concentration of the drug. Additionally, our results demonstrated the potential use of dRVVT as a screening test in the emergency room and the need of a second test to improve specificity.

P118: Effects of system design on laboratory utilization in the emergency department: the case for INR &amp; aPTT

Introduction: In the context of a shrinking healthcare budget, poor physician cost awareness, and continued over-utilization of low-value tests in the emergency department, we re-designed our computerized order entry system to reduce the use of coagulation testing. Methods: A hospital-based prospective pre-post analysis following de-bundling of INRPTT testing in two academic hospital emergency departments (annual visits 140,000). All participants aged 18 years or older undergoing evaluation and/or treatment at either of during the period of August 1, 2015 to July 24, 2016 were included. Primary outcome is coagulation testing utilization rates and associated costs. Results: Unbundling INR and aPTT testing resulted in significantly decreased bundled INRPTT testing relative to baseline (INRPTT tests per patient per day: 0.60 [95% CI: 0.57-0.62] vs. 0.98 [95% CI: 0.98-0.99], p=0.000), with significantly increased targeted testing (INR tests per patient per day: 0.39 [95% CI: 0.37-0.42] vs. 0.00 [95% CI: 0.00-0.01], p=0.000; PTT tests per patient per day: 0.33 [95% CI: 0.30-0.36] vs. 0.01 [95% CI: 0.00-0.01], p=0.000). As a result of unbundling, there was a significant decrease in costs associated with coagulation testing relative to baseline (Cost per day: $958.52 [INRPTT $592.78+INR $183.91+PTT $181.83] vs. $1,074.50 [INRPTT $1,069.76+INR $2.06+PTT $2.68], p=0.000), realizing estimated daily and yearly savings of $115.98 and $42,332.70, respectively. Conclusion: Compared to baseline practice patterns, unbundling coagulation testing resulted in the reduction of coagulation testing suggesting system design and user workflows to be an integral factor to provider practice patterns. Given the significant cost-savings, we recommend institutions carefully re-evaluate their system design and user workflows to optimize emergency department laboratory utilization.

Discovery of novel aminobenzisoxazole derivatives as orally available factor IXa inhibitors

Using structure based drug design, novel aminobenzisoxazoles as coagulation factor IXa inhibitors were designed and synthesized. Highly selective inhibition of FIXa over FXa was demonstrated. Anticoagulation profile of selected compounds was evaluated by aPTT and PT tests. In vitro ADMET and pharmacokinetic (PK) profiles were also evaluated.

A highly regular fucosylated chondroitin sulfate from the sea cucumber Massinium magnum: Structure and effects on coagulation

A fucosylated chondroitin sulfate MM was isolated from the sea cucumber Massinium magnum. Structure of this polysaccharide was determined using chemical and NMR spectroscopic methods. The backbone of MM was shown to consist mainly of chondroitin sulfate E units with a small portion (about 10%) of chondroitin sulfate A fragments. Practically one type of branches Fuc3S4S attached to O-3 of GlcA residues was found in the polysaccharide molecules. The main repeating units of MM are →4)-[α-l-Fuc3S4S-(1→3)]-β-d-GlcA-(1→3)-β-d-GalNAc4S6S-(1→, whereas the minor repeating units are →4)-[α-l-Fuc3S4S-(1→3)]-β-d-GlcA-(1→3)-β-d-GalNAc4S-(1→. Anticoagulant activity of MM determined in APTT and TT tests was shown to be lower than that of heparin, but higher than that of enoxaparin. In the experiments with purified proteins MM effectively potentiated inhibition of thrombin and factor Xa by ATIII. Besides, MM did not induce platelets aggregation in platelets rich plasma.

Haematology and coagulation profiles in cats with congenital portosystemic shunts.

Objectives The objectives of this study were, first, to report the haematological parameters and coagulation times for cats with a congenital portosystemic shunt (CPSS) and the influence of surgical shunt attenuation on these parameters; and, second, to identify any association between prolongation in coagulation profiles and incidence of perioperative haemorrhage. Methods This was a retrospective clinical study using client-owned cats with a CPSS. Signalment, shunt type (extra- or intrahepatic), degree of shunt attenuation (complete or partial), haematological parameters, prothrombin time (PT) and activated partial thromboplastin time (aPTT) test results, and occurrence of any perioperative clinical bleeding complications were recorded for cats undergoing surgical treatment of a CPSS at the Royal Veterinary College, UK, between 1994 and 2011. Results Forty-two cats were included. Thirty-six (85.7%) had an extrahepatic CPSS and six (14.3%) had an intrahepatic CPSS. Preoperatively, mean cell volume (MCV) and mean cell haemoglobin (MCH) were below the reference interval (RI) in 32 (76.2%) and 31 (73.8%) cats, respectively. Red blood cell count and mean cell haemoglobin concentration (MCHC) were above the RI in 10 (23.8%) and eight (19.1%) cats, respectively. Postoperatively, there were significant increases in haematocrit ( P = 0.044), MCV ( P = 0.008) and MCH ( P = 0.002). Despite the significant increase in MCV postoperatively, the median MCV postoperatively was below the RI, indicating persistence of microcytosis. Preoperatively, PT was above the upper RI in 14 cats (87.5%), and aPTT was above the upper RI in 11 cats (68.8%). No cat demonstrated a perioperative clinical bleeding complication. Conclusions and relevance Cats with a CPSS are likely to present with a microcytosis, but rarely present with anaemia, leukocytosis or thrombocytopenia. Surgical attenuation of the CPSS results in a significant increase in the HCT and MCV. Coagulation profiles in cats with a CPSS are likely to be prolonged, irrespective of shunt type, but do not appear to be associated with an increased risk of clinical bleeding.

REDucing Unnecessary Coagulation Testing in the Emergency Department (REDUCED)

The PT/INR (prothrombin time/international normalized ratio) and aPTT (activated partial thromboplastin time) were tests developed in the early 20th century for specific and unique indications. Despite this, they are often...

Clinical and Biological Determinants of Bleeding Manifestation in Congenital Factor XI Deficiency; A Systematic Review

Background: Congenital factor XI (FXI) deficiency is a rare inherited bleeding disorder caused by mutation of the FXI gene. Clinical manifestation and bleeding severity of FXI deficiency are varied. To our best knowledge, there are no studies investigating the predictors of bleeding in these patient population. Our study aims to investigate the clinical presentation of congenital FXI deficiency and to identify clinical, biological, and genetic determinants of bleeding.Methods: We conducted a systematic search in MEDLINE and EMBASE databases from inception to March 2016. We included the studies of congenital FXI deficiency. In terms of study design, we included prospective or retrospective studies as well as case series and case reports. We collected clinical characteristics of the patients including age, sex, family history of FXI deficiency, family history of bleeding, and site of bleeding. We also collected the laboratories including baseline aPTT, FXI level, and genetic test results.Results: There were 141 studies included in this review, involving 728 patients with reported congenital FXI deficiency. Forty-three percent of the patients were male. Clinical characteristics of the patients was demonstrated in Table 1. Of these, 421 (51.84%) patients had bleeding tendency. Surgical bleeding was the most common bleeding manifestation (31.88%), following bymucocutaneous bleeding (13.35%) and hypermenorrhea (9.11%). Factor XI gene mutation was found in 422 patients (57.97%). Type II mutation was the most common reported mutation (45.19%). With regards tozygosity of patients with gene mutation, 43.94% of patients had heterozygosity of factor XI gene mutation. Univariate analysis revealed that patients with baseline factor XI level less than 25% were associated with higher risk of bleeding (odd ratio 1.48 (95% confidence interval [CI]; 1.05 to 2.09). In addition, patients with combined mutation were at higher risk of bleeding when compared to patients with single mutation (odd ratio 2.83 (95% CI; 1.09-7.39).Conclusion: Our study found that patients with factor XI deficiency has mild bleeding manifestation. Half of the patients do not experience bleeding tendency. Surgical bleeding is the most common presentation in these patient population and likely to be the first bleeding symptom. Baseline factor XI level less than 25% is the predictor of bleeders as well as combined gene mutation. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

The Mayo Clinic Experience with Diagnosis and Treatment of Gardner-Diamond Syndrome

Introduction: Gardner-Diamond Syndrome (GDS), also known as psychogenic purpura, is a rare disorder characterized by unexplained recurrent painful bruising typically arising after physical and/or psycho-emotional stress. Classically ecchymoses (ecch) spontaneously appear and are associated with a prodrome of warmth and pain at the ecch sites. Prior GDS reports are limited to single cases or small series.Aims:To characterize presentation, natural history, management and long term outcomes (LTO) of GDS.Methods: In this retrospective study, after IRB approval, patients (pt) with GDS, encountered between 1976 and 2016, were identified from within Mayo Clinic Rochester clinical databases. Medical records of consenting pts were reviewed.Results: 75 females (ages 16-69 years (yr)) and 2 males (46-65 yr) met our study criteria. Pt presented 3.2 yrs (range 0-27) after onset of initial symptoms (sym). 52 pt (67.5%) had an antecedent history of physical abuse (n=2), trauma (n=12), an emotional event (n=13), surgery (n=11), or infection (n=3). Prodromal sensations prior to appearance of ecch in 55 pts (71.4%) were described as itching (n=15), burning (n=19), stinging (n=11), and/or pain (n=44). Other localized sym after appearance of ecch included swelling (n=46) and pain (n=67). Maximum size of ecch ranged from >0 and ≤5 cm (n=26), ≥6 and ≤ 10 cm (n=14), and >10 cm (n=13) and not described in 24 pts Systemic sym at time of ecch, reported in 49 pts, included malaise (n=26), myalgia (n=21), headaches (n=19), fevers (n=15), and abdominal pain (n=10). 50 (65%) of pts’ lesions were isolated to arms and legs, while 27 (35%) had trunk and head involvement in addition to extremity involvement. Ecch duration varied: 0-7 days (n=14), 1 week-1 month (n=31), or >1 month (n=5) and not described in 27 pts.Complete blood count was normal (nl) in 84% (64/76) of pts tested; anemia was the most common abnormality. PT, APTT, VWF, and Factor XIII screen were nl in 100% (67/67), 98.4% (63/64), 97.9% (46/47), and 100 % (30/30) of pts respectively. Platelet aggregation studies were nl in 83% (25/30) with abnormalities attributed to drug effect. Bleeding (bld) scores (ISTH BAT), calculated with exclusion of cutaneous (cut) manifestations in scoring, were: 0 (n=48), 1 (n=12), 2 (n=9), 4 (n=2), 5-6 (n=2), 7 (n=2), and 9 (n=2). 21 pts had testing with subcut injections of autologous red cells (SCIAR) with 9 positive and 2 equivocal. 28 pts had skin biopsies with the most common finding being subcut hemorrhages.45 pts (58.4%) underwent psychiatric (psych) evaluations and 7 (15%) pts were found not to have a psych dx. 42 pts had a psych dx including depression (n=23), hysterical personality (n=8), anxiety (n=2), personality disorder (n=2), psych other (n=7). Of these pts, 4 did not undergo further psych eval given prior dx. 42 pts had a history of a neurological dx including headaches (n=34), paresthesias (n=10), and seizures (n=7). Additional pharmacological treatments (pharmt) were recommended for 30 pts: antidepressants (n=4), antihistamines (n=13), anti-inflammatory/immunosuppressants (n=11), or hormonal (n=2) medications. 47 pts were treated with observation and/or counseling alone to address psychological stressors. 28 pts had follow-up (fu) at least 1 yr (1 to 34 yrs) after the initial visit. 13 of these pts had no mention of recurrence during fu while 15 pts had continued recurrence. Of those with recurrence, 7 pts continued to seek fu for GDS.Conclusion: In this large clinical cohort of GDS pts we confirm and expand on known clinical findings of GDS. Majority of pts had fairly benign disease (dz) manifestations; however, in a subset, a negative impact on pt quality of life was noted due mainly to persistent/recurrent pain. Refractory dz was mostly associated with ongoing/ recurrent stressors. The relatively low bld scores, together with laboratory assessments, support that GDS is primarily a dermal rather than a systemic bld diathesis. SCIAR did not provide additional value in dx. CBC, PT, APTT & VWF testing should be performed, and platelet testing considered, to rule out other hemostatic dz. Addressing stressors was the most effective treatment for pts, however pharmt was given for refractory dz. Though our study provides new insights regarding dx, therapy and LTO, future work investigating the pathophysiology leading to the hemostatic abnormalities in GDS would be valuable. DisclosuresNo relevant conflicts of interest to declare.

Covalent Bonding of Heparin on the Crystallized Poly(lactic acid) (PLA) Membrane to Improve Hemocompability via Surface Cross-Linking and Glycidyl Ether Reaction.

The hemocompatibility of the dialysis membrane has been considered the key factor influencing the dialysis performance for curing the kidney malfunction. In this work, the commonly used anticoagulant heparin in the clinic was directly bonded to the poly(lactic acid) (PLA) membrane to improve the hemocompatibility via the glycidyl ether reaction. A novel precopolymer P(VP-VTES-GMA) was first prepared via free radical polymerization. The surface cross-linking of the precopolymer containing GMA segments enabled the membrane to anchor heparin through the glycidyl ether reaction. The chemical structure of the precopolymer was confirmed by 1H NMR. The surface chemistry was analyzed by XPS, toluidine blue staining, and solubility tests. The crystallization behavior, heat resistance, morphology, hydrophilicity, pore size, and pure water flux were investigated. The hemocompatibility was comprehensively investigated via APTT, PRT, PT, FIB, and platelet adhesion tests. The simulated dialysis performances relating to urea, creatinine, lysozyme, and BSA clearance were measured. All results demonstrated that the covalent bonding of heparin provided the PLA membrane with excellent hemcompatibility, hydrophilicity, heat resistance, and dialysis performance as well.

PEMERIKSAAN PROTHROMBIN TIME DAN ACTIVATED PARTIAL THROMBOPLASTIN TIME DENGAN HUMACLOT VA SERTA SYSMEX CA 500

Prothrombin Time (PT) and an activated Partial Thromboplastin Time (aPTT) are routine coagulation tests used for pre-operative screening. The analytical step as one of the laboratory test's stage that plays the role in the determination of the test is influenced by several factors, one of them is choosing its proper devices. The aim of this study was to know the correlation of the PT and aPTT test's result using Humaclot VA and Sysmex CA 500 devices. A cross sectional study has been done at the Clinical Pathology Laboratory of Wahidin Sudirohusodo Hospital Makassar started from May 2009 until June 2009. The data were analyzed with T and Pearson's Correlation test. From the 50 samples were obtained the percentage of the corresponding frequency of the PT results between Humaclot VA and Sysmex CA 500 about 84%, whereas the frequency of the corresponding results aPPT between Humaclot VA and Sysmex CA 500 is 76%, the Pearson correlation test for PT=0.58, and aPTT=0.38. There were found the suitability of PT, aPTT of Humaclot VA with CA 500 and both tools have a positive correlation.

Effect of Concomitant COPD on Blood Clotting in Patients with Stage II Hypertension

We know that comorbidity COPD and arterial hypertension has an adverse effect on the disease and the presence of complications in such patients. To determine the state of coagulation link of hemostasis, we have examined 150 people: 15 healthy (control), 36 patients with COPD II-III without GC (I group), 69 patients with essential hypertension with concomitant COPD (second group) and 30 patients GC II stage (third group). We found that comorbid course AH and COPD leads to imbalance in the blood coagulation system, which is manifested by slowing prothrombinase formation (coagulation I phase) evidenced prolongation of APTT and lebetoks test, combined with a strong activation of the final phase of clot formation, a reflection of what there is a significant increase in fibrinogen and RFMK and shortening ehitoks and antsystron tests.

Point-of-care PT and aPTT in patients with suspected deficiencies of coagulation factors.

There are several clinical settings and patient conditions especially in intensive care units, emergency departments, and operating theaters, where the coagulation status of a patient must be known immediately and point-of-care (POC) systems are beneficial due to low time to result. This noninterventional, single-blinded, multicenter study with prospectively collected whole blood samples was performed to evaluate the diagnostic accuracy of the CoaguChek PT Test (POC PT) and CoaguChek aPTT Test (POC aPTT) compared to standard laboratory testing in patients with suspected deficiencies of coagulation factors. In total, 390 subjects were included. Both POC PT and POC aPTT showed concordance with the laboratory PT and aPTT. Lot-to-lot variation was below 2% both for POC PT and for POC aPTT. The mean relative difference of capillary blood compared to venous blood was 0.2 % with POC PT and 8.4% with POC aPTT. The coefficients of variation for repeatability of POC PT using whole blood were found to be between 2% and 3.6%. Our findings suggest reliable quantitative results with this POC system to support on-site decision-making for patients with suspected deficiencies of coagulation factors in acute and intensive care.

Effect of Subcutaneous Unfractionated Heparin Prophylaxis on Activated Partial Thromboplastin Time: A Retrospective Evaluation

Study ObjectiveCharacterize the incidence of elevated aPTT results in patients treated with prophylactic, subcutaneous unfractionated heparin (UFH). DesignRetrospective, cohort analysis. SettingSingle-center, university hospital. MeasurementsEvaluation of 257 patients with activated partial thromboplastin time (aPTT) testing both prior to and following subcutaneous (SC) unfractionated heparin (UFH) therapy. Main ResultsEvaluated patients received UFH 5000 units every 8 hours. Baseline aPTT values were within the normal range (mean±SD, 32.0±8.5 seconds). After initiation of UFH, aPTT values increased (mean±SD, 37.6±15.2 seconds). After 24 hours of SC UFH, mean aPTT values (mean±SD, 38.6±15.5) exceeded the normal laboratory range (23.3–35.7 seconds). An elevated aPTT result after UFH was associated with baseline aPTT, length of therapy, and weight-based UFH dose. A significant association was not identified between aPTT elevation and age, race, sex, history of liver disease, type of admission, or transfusion of blood products. ConclusionsTreatment with UFH resulted in a small, but significant, increase in aPTT.

Evaluating the anticoagulant effect of medicinal plants in vitro by cheminformatics methods

IntroductionThis study was designed to evaluate the anticoagulant effect of some medicinal plants using cheminformatics methods. Material and methodsDatabases such as PubMed and Google Scholar were searched to collect information regarding anticoagulant compounds and plants showing this bioactivity. According to the identified anticoagulant compounds, cheminformatics methods were set to find all similar compounds by using the PubChem Structure Search engine. Then, with the help of the identified similar compounds, 15 medicinal plants native to Iran containing at least one of the similar compounds were prepared and extracted in ethanol and the sample extracts were dissolved in DMSO. Three concentrations 1, 10 and 100μg/ml of extracts were prepared to investigate their anticoagulant effect. Finally, the anticoagulant effect of the selected medicinal plants was evaluated by in vitro PT and APTT assays. ResultsThe extracts of 5 plants, including Ocimum basilicum, Rosa persica, Trigonella foenum, Solanum nigrum and Cubeba officinalis at a concentration of 100μg/ml showed a significant anticoagulant effect on APTT test in comparison with the negative control. ConclusionIn this study, the anticoagulant effect was identified as a significant property of five medicinal plants. These plants can be regarded as likely candidates for prevention and treatment of complications in individuals with high risk of stroke or ischemia. Also, we suggest that these plants should be cautiously consumed with anticoagulant drugs (e.g. heparin) due to a risk of hemorrhage and increase in the effect of anticoagulant drugs.

Constructing bio-layer of heparin and type IV collagen on titanium surface for improving its endothelialization and blood compatibility.

The modification of cardiovascular stent surface for a better micro-environment has gradually changed to multi-molecule, multi-functional designation. In this study, heparin (Hep) and type IV collagen (IVCol) were used as the functional molecule to construct a bifunctional micro-environment of anticoagulation and promoting endothelialization on titanium (Ti). The surface characterization results (AFM, Alcian Blue 8GX Staining and fluorescence staining of IVCol) indicated that the bio-layer of Hep and IVCol were successfully fabricated on the Ti surface through electrostatic self-assembly. The APTT and platelet adhesion test demonstrated that the bionic layer possessed better blood compatibility compared with Ti surface. The adhesion, proliferation, migration and apoptosis tests of endothelial cells proved that the Hep/IVCol layer was able to enhance the endothelialization of the Ti surface. The in vivo animal implantation results manifested that the bionic surface could encourage new endothelialization. This work provides an important reference for the construction of multifunction micro-environment on the cardiovascular scaffold surface.