Concentration Of Fibrin Degradation Products Research Articles

Optimizing DCD Liver Grafts With Prolonged Warm Ischemic Time Using Stabilized Plasmin in a Static Cold Storage Orthotopic Rat Liver Transplant Model.

The clinical success of liver transplantation has led to increased demand, requiring further expansion of the donor pool. Therapeutic interventions to optimize organs from donation after circulatory death (DCD) have significant potential to mitigate the organ shortage. Dysfunction in DCD liver grafts is mediated by microvascular thrombosis during the warm ischemic period, and strategies that reduce this thrombotic burden may improve graft function. We hypothesized that the administration of the fibrinolytic enzyme plasmin to the donor organ during the cold storage period would reduce the thrombotic burden and improve DCD liver graft function. In 2 separate cohorts, 32 syngeneic orthotopic rat liver transplants were performed in Lewis rats. Livers were procured from donors with 45 min of warm ischemic injury. Liver grafts were flushed with histidine-tryptophan-ketoglutarate preservation solution mixed with either plasmin (experimental group) or albumin (control group). All investigators were blinded to treatment group. After preparing the liver for implant using a modified cuff technique, the liver was stored for 1 h by static cold storage at 4 °C. Immediately before implantation, the liver graft was flushed, and this effluent was analyzed for fibrin degradation products to determine graft clot burden. Twenty-four hours following transplantation, animals were euthanized, and samples were collected. Recipient survival was significantly higher for DCD liver grafts treated with plasmin compared with control. Moreover, histology of liver graft tissue immediately before implant reflected significantly reduced congestion in plasmin-treated livers (score, mean ± SD: 0.73 ± 0.59 versus 1.12 ± 0.48; P = 0.0456). The concentration of fibrin degradation products in the final flush before implantation was significantly reduced in plasmin-treated livers (743 ± 136 versus 10 919 ± 4642 pg/mL; P = 0.0001), reflecting decreased clot burden in the graft. The present study demonstrates that plasmin improves survival and may reduce thrombotic burden in DCD liver grafts with prolonged warm ischemic injury, meriting further study.

Utility and safety of nafamostat mesilate for anticoagulation in dogs.

Surgical interventions are recommended for cases of advanced mitral regurgitation, however, limited facilities are available. The most prominent complication in such procedures is heparin-derived bleeding. An alternative anticoagulant to heparin, nafamostat mesilate (NM), can reduce the occurrence of complications associated with heparin such as bleeding or shock. This study aimed to evaluate the utility and safety of using NM during anaesthesia in canines. Six healthy adult Beagle dogs were anaesthetised, and NM was administered intravenously as a 10mg/kg bolus dose over 5min, followed by a continuous infusion of 10mg/kg/h over 20min. Blood tests and blood pressure measurements were performed at 0, 5, 25 and 55min after NM administration. Activated thromboplastin times at 0, 25 and 55min were 13.0 ± 0.7 s, 106.7 ± 13.3 s and 28.2 ± 2.9 s, respectively, with a significant difference between 0 and 25min (p < 0.01) only. No significant differences were observed in prothrombin time, antithrombin, fibrinogen and fibrin degradation product concentrations between timepoints. Activated clotting times (ACTs) at 0, 5, 25 and 55min were 119.5 ± 9.6 s, 826.7 ± 78.6 s, 924.8 ± 42.4 s and 165.2 ± 13.5 s, respectively. Significant differences were observed between 0 and 5min (p < 0.05) and between 0 and 25min (p < 0.05). Blood pressure changes occurred in four dogs (66.7%). No other serious adverse effects were observed. ACT results indicated that NM use in anaesthetised healthy dogs was sufficient to obtain procedural anticoagulation with minimal adverse effects. However, these preliminary data require validation in further studies on cardiopulmonary bypass surgery.

Programmable DARPin-based receptors for the detection of thrombotic markers

Cellular therapies remain constrained by the limited availability of sensors for disease markers. Here we present an integrated target-to-receptor pipeline for constructing a customizable advanced modular bispecific extracellular receptor (AMBER) that combines our generalized extracellular molecule sensor (GEMS) system with a high-throughput platform for generating designed ankyrin repeat proteins (DARPins). For proof of concept, we chose human fibrin degradation products (FDPs) as markers with high clinical relevance and screened a DARPin library for FDP binders. We built AMBERs equipped with 19 different DARPins selected from 160 hits, and found 4 of them to be functional as heterodimers with a known single-chain variable fragments binder. Tandem receptors consisting of combinations of the validated DARPins are also functional. We demonstrate applications of these AMBER receptors in vitro and in vivo by constructing designer cell lines that detect pathological concentrations of FDPs and respond with the production of a reporter and a therapeutic anti-thrombotic protein.

Filgrastim, fibrinolysis, and neovascularization.

Segmental recanalization of chronically occluded arteries was observed in patients with chronic limb‐threatening ischemia (CLTI) treated with Filgrastim, a granulocyte colony stimulating factor, every 72 h for up to a month, and an infra‐geniculate programmed compression pump (PCP) for 3 h daily. Molecular evidence for fibrinolysis and neovascularization was sought. CLTI patients were treated with PCP alone (N = 19), or with Filgrastim and PCP (N = 8 and N = 6, at two institutions). Enzyme‐Linked Immunosorbent Assay was used to measure the plasma concentration of plasmin and of fibrin degradation products (FDP), and the serum concentration of proteins associated with neovascularization. In the PCP‐alone group, blood was sampled on Day 1 (baseline) and after 30 days of daily PCP. In the Filgrastim and PCP group, blood was drawn on Day 1, and 1 day after the 5th and the 10th Filgrastim doses. Each blood draw occurred before and after 2 h of supervised PCP. Significant (p < 0.01) PCP independent increases in the plasma concentration of plasmin (>10‐fold) and FDP (>5‐fold) were observed 1 day after both the 5th and the 10th Filgrastim doses, compared to Day 1. Significant (p < 0.05) increases in the concentration of pro‐angiogenic proteins (e.g., HGF, MMP‐9, VEGF A) were also observed. Filgrastim at this novel dosimetry induced fibrinolysis without causing acute hemorrhage, in addition to inducing a pro‐angiogenic milieu conducive to NV. Further clinical testing is warranted at this novel dosimetry in CLTI, as well as in other chronically ischemic tissue beds. Trial registration. https://clinicaltrials.gov/ct2/show/NCT02802852.

Pathogenesis and diagnosis of disseminated intravascular coagulation

Rytis Trojanas1 1Faculty of Medicine, Vilnius University, Vilnius, Lithuania Abstract Background. Disseminated intravascular coagulation is a condition in which systemic coagulation is activated, resulting in large amounts of fibrin in the lumen of small and midsize blood vessels. Thrombi made out of fibrin can disrupt blood flow to internal organs, causing multiple organ dysfunction syndrome. Gradual depletion of platelets and coagulation factors can result in bleeding and hemorrhagic necrosis, which can become the predominant sign of the disseminated intravascular coagulation. Aim: to review the newest literature and articles about disseminated intravascular coagulation, its pathophysiology, diagnostics and treatment options. Methods. The research of literature was conducted using PubMed, Wiley Online Library, Elsevier international databases. Keywords and their combinations were used during research: disseminated intravascular coagulation, coagulopathy, fibrinolysis, platelets, thrombocytopenia. 30 publications were analyzed and included. Conclusions. Disseminated intravascular coagulation is not a disease in itself, rather it occurs as a complication of systemic inflammation in sepsis, major trauma, malignant tumors or obstetric calamities. During systemic inflammation, large amount of tissue factor is exposed, consequently coagulation system is activated. Due to prolonged activation of coagulation, physiological anticoagulation and endogenous fibrinolysis are disturbed, also the activation of platelets is triggered. These processes result in generation of huge amounts of thrombin and fibrin. At the same time the risk of bleeding increase because of usage of platelets and coagulation factors. Disseminated intravascular coagulation diagnosis is based on international diagnostic criteria, which include platelet count, prothrombin time or international normalization ratio and the concentration of fibrin degradation products, like D-dimers. The keystone of treatment in disseminated intravascular coagulation is to treat the disease, which caused the syndrome at the first place. Keywords: disseminated intravascular coagulation, coagulopathy, fibrinolysis, platelets, thrombocytopenia.

Prevention of peritoneal pelvic adhesion formation in women of reproductive age

The objective: a prevention of the peritoneal pelvic adhesions formation in women of reproductive age in the postoperative periodMaterials and methods. 132 women with tubal infertility were examined: І group – main one (n=68) and ІІ group – comparison group (n=64). In the postoperative period, the patients of the main group received treatment and prevention measures according to the developed approach (intraoperative administration of anti-adhesion gel 50 ml and 1 suppository of the tiotriazolin a day rectally from the 1st day after surgery for 14 days), and the comparison group – according to the traditional approach. 30 healthy women were examined as a control group.The level of fibrinogen, fibrinogen /fibrin degradation products (FDP), protein-bound hydroxyproline and free hydroxyproline were studied in blood. Pain syndrome was assessed on a 10-point scale.Results. An increase in fibrinogen and FDP levels in the plasma of all examined women were found. But in the main group the concentration of FDP from 4 hours after intervention was significantly higher (5.31±0.24 mg/l) compared to the comparison group (4.53±0.17 mg/l). The level of protein-bound hydroxyproline in the blood serum of the examined women demonstrated its significant increase in the comparison group 12 hours after surgery, with a maximum after 24 hours and maintaining the concentration in 1.9 times higher after 3 days (p&lt;0.05). The level of free hydroxyproline in the main group was significantly (in 1.4–1.6 times) higher than in the comparison group.The increase of the fibrinolytic capacity (p&lt;0.05) in the peritoneal fluid was found during postoperative period. The period of hyperemia in II group lasted 2 times longer than in I group. Also, II group predominates in the number of patients with hyperthermia for more than 3 days – 10 (15.6 %), compared with I group – 4 patients (5.8 %). The duration of stay in the hospital dominated in II group with a standard treatment regimen in the postoperative period – 3.1 %, compared with I group – 1.9 %.The patients after operation in I group evaluated postoperative pain on average by 1.8 points (p=0.00), in II group – at 3.6 points (p=0.06). Synthetic opioid analgesics and nonsteroidal anti-inflammatory drugs were administered intramuscularly for analgesia. The patients in II group required more injections per patient.Conclusions. The proposed approach is effective, pathogenetically reasonable and can be used as a pathogenetic prevention of adhesions formation in women of reproductive age.

THE INFLUENCE OF A POLYPEPTIDE PREPARATION ON A STRUCTURAL-FUNCTIONAL STATE PERIODONT IN ADJURANT PERIODONITIS (EXPERIMENTAL RESEARCH)

The aim of this article is to study the indices of cellular, humoral immunity and nonspecific resistance, indices of free radical lipid oxidation and thrombocytoactive properties of periodontal tissues in animals with adjuvant periodontitis.&#x0D; In our study, adjuvant periodontitis was reproduced by the method of A.M. Kaminsky, immunizing rats with a homologous periodontal tissue in admixture with a Freund's adjuvant in a 1: 1 ratio. The course consisted of four single injections of 0.2 ml per animal intramuscularly at weekly intervals. Immunization did not lead to changes in the development and behavior of rats. One month after immunization, experimental animals experienced symptoms characteristic of generalized periodontitis in humans. They were manifested in the form of gums, resorption of alveolar bone, mobility and tooth loss.&#x0D; The induction of adjuvant periodontitis in experimental animals led to a significant increase in lipid peroxidation processes in periodontal tissues and a decrease in SOD and catalase activity. In animals with adjuvant periodontitis, which have been injected with periodontal polypeptides, there is a decrease in the reactions of GF compared with patients. In particular, there was a 40.9% decrease in the level of TBK-active products, although the level of MDA accumulation in the incubation process had not decreased significantly. It is noteworthy that in this group of animals increased activity of AO enzymes, which in patients was sharply reduced.&#x0D; Significant changes in the BPO lipid state were also observed in the blood of animals. The peroxidation reactions were significantly reduced, but not as significantly as in periodontal tissues. In particular, spontaneous erythrocyte hemolysis was lower by 14.2%, the level of TBK-active products by 39.4%, and MDA by 34.9%. An increase in the activity of SOD and catalase was observed, as well as a 40.4% decrease in the concentration of ceruloplasmin, which testifies to the elimination of the inflammatory response upon introduction of polypeptides.&#x0D; The treatment of animals with periodontylline was accompanied by an increase in the anti-aggregation properties of periodontal tissues. This is confirmed by the following indicators of the aggregate: the angle of aggregation is reduced by 31.8%, the optical density by 29%, the aggregation time is increased by 42.9% compared with the group of animals with adjuvant periodontitis.&#x0D; The introduction of parodontilin had a pronounced effect on the condition of blood clotting and fibrinolysis. We observed a significant increase in recalcification time, thrombin, prothrombin time. If the disease has a significant increase in the time of euglobulin fibrinolysis, then in the treatment of this indicator becomes less by 69.4%, the products of para-coagulation disappear from the bloodstream and the concentration of fibrin degradation products decreases.&#x0D; The treatment of animals was accompanied by an increase in immunity, which was manifested by an increase in T and B lymphocytes and Ig G. titer.&#x0D; Studies have shown that the treatment of diseased animals with a polypeptide drug leads to an improvement in the cellular, humoral immunity and nonspecific resistance of the organism, as well as the presence of a pronounced immunomodulatory effect of periodontin. The previously established relationship between blood clotting systems, sex, immunity, nonspecific resistance of the organism is confirmed in these experimental studies. If the induction of periodontitis is primarily associated with autoimmune processes, leading to impaired homeostasis, then the introduction of periodontin has a modulating effect on both immunity and indicators of lipid peroxidation and microcirculatory and coagulative hemostasis . In animals, regression of dental symptoms was noted, signs of periodontal inflammation, bleeding, swelling disappeared, and tooth mobility decreased.&#x0D; These data indicate the high therapeutic efficacy of thymic drugs in the treatment of generalized periodontitis. Research in this area remains relevant.

Structure and Function of Trypsin-Loaded Fibrinolytic Liposomes.

Protease encapsulation and its targeted release in thrombi may contribute to the reduction of haemorrhagic complications of thrombolysis. We aimed to prepare sterically stabilized trypsin-loaded liposomes (SSLT) and characterize their structure and fibrinolytic efficiency. Hydrogenated soybean phosphatidylcholine-based SSLT were prepared and their structure was studied by transmission electron microscopy combined with freeze fracture (FF-TEM), Fourier transform infrared spectroscopy (FT-IR), and small-angle X-ray scattering (SAXS). Fibrinolytic activity was examined at 45, 37, or 24°C on fibrin or plasma clots with turbidimetric and permeation-driven lysis assays. Trypsin was shown to be attached to the inner surface of vesicles (SAXS and FF-TEM) close to the lipid hydrophilic/hydrophobic interface (FT-IR). The thermosensitivity of SSLT was evidenced by enhanced fibrinolysis at 45°C: time to reduce the maximal turbidity to 20% decreased by 8.6% compared to 37°C and fibrin degradation product concentration in the permeation lysis assay was 2-fold to 5-fold higher than that at 24°C. SSLT exerted its fibrinolytic action on fibrin clots under both static and dynamic conditions, whereas plasma clot dissolution was observed only in the permeation-driven assay. The improved fibrinolytic efficiency of SSLT under dynamic conditions suggests that they may serve as a novel therapeutic candidate for dissolution of intravascular thrombi, which are typically exposed to permeation forces.

Haemostatic Changes during Pregnancy and Puerperium in Kano, North-Western Nigeria

Aim: Normal pregnancy is associated with haemostatic changes which have been linked to a complex physiological adaptation but these changes return to that of non-pregnant state at about 4 weeks of post-delivery. This study was undertaken to monitor the haemostatic changes during pregnancy and puerperium in North-Western Nigeria. Materials and methods: Ten pregnant women, aged 17-40 years were monitored for haemostatic changes from the first trimester to 6 weeks after delivery between August 2010 and October 2011 at Aminu Kano Teaching Hospital, Kano. Blood samples collected for platelet count, prothrombin time (PT), activated partial thromboplastin time (APTT), fibrin degradation products (FDP), fibrinogen level, d-dimer, protein C, factors VII and VIII activities were analysed using standard laboratory techniques. Results: There were significantly lower values of platelet count, factor VIII concentration and protein C activity of 275.5 ± 4.14 × 109/L, 93.2 ± 31.6% and 56.7 ± 13.4% during pregnancy compared to 378.5 ± 74.0 × 109/L, 122.5 ± 3.0% and 97.1 ± 14.6% respectively, during puerperium. The values of PT, factor VII concentration, fibrinogen level, FDP and D-dimer concentrations during pregnancy and puerperium showed no significant differences (P>0.05). Factors VII and VIII concentrations increased significantly as gestation advanced (P<0.05). Conclusion: The study concluded that changed values of platelet count, protein C and factor VIII concentrations during pregnancy, normalized at puerperal period while advanced gestation may pose a threat to pregnancy. It is recommended that

Higher prognostic value of soluble fibrin complexes than D-dimer and fibrin degradation product for disseminated intravascular coagulation in patients with liver cirrhosis

Fibrin-related markers may help differentiate disseminated intravascular coagulation (DIC) from liver cirrhosis-associated dysfunctional coagulation. We investigated the significance of three fibrin-related markers [D-dimer, fibrin degradation product (FDP), and soluble fibrin complexes (sFC)] for the assessment of DIC status and prognosis. We classified 235 patients with suspected DIC into two groups according to their condition: the liver cirrhosis group (n = 47) and the no liver cirrhosis group (n = 188). Prothrombin time (PT), and fibrinogen, sFC, D-dimer, antithrombin, and protein C concentrations were measured and DIC scores were calculated using four parameters: platelet count, D-dimer, fibrinogen, and PT. In the liver cirrhosis group, the sFC concentration increased significantly in accordance with DIC score compared with the no liver cirrhosis group, and this increase was more prominent than D-dimer and FDP concentration increases. For the diagnosis of overt DIC in patients with liver cirrhosis, the area under the concentration curve (AUC) was larger for sFC (0.746) than for D-dimer (0.733) and FDP (0.687). Cox analysis also indicated that an elevated sFC concentration is a more significant prognostic factor of DIC than D-dimer or FDP (hazard ratio: 10.78; P = 0.036) in liver cirrhosis group; however, it was not a prognostic factor in the no liver cirrhosis group. sFC is a powerful diagnostic and prognostic marker of DIC in patient with liver cirrhosis. The use of sFC is expected to enhance the diagnosis and prognosis of DIC, particularly in patients with liver cirrhosis.

Changing characteristic of blood coagulation factors and their correlation with blood coagulation status in different hepatic diseases

To investigate the correlation between pro coagulation factors and anti-coagulation factors synthesized by the liver, and the correlation between fibrin degradation products (FDP) and D-dimer (D-D) concentration and coagulation proteins synthesized by extra-hepatic tissues, in different liver diseases; to explore the relationship between coagulation and bleeding in hepatic diseases. Chronic hepatitis B (CHB) patients, CHB-related liver cirrhosis patients, CHB-related liver failure patients and healthy (normal) controls were selected for study and provided blood samples for analysis. The activity of coagulation factors (F) II, V, VII, VIII, IX, X, XI, and XII was detected using the one-stage clotting method. Coagulogram analysis, including activated partial thromboplastin time (APTT), thrombin time (TT), and prothrombin time (PT), was conducted by the solidification method. Antithrombin III (AT-III) and protein C (PC) activities were measured by chromogenic substrate assay. FDP concentration was detected using immunoturbidimetry. Tissue factor pathway inhibitor (TFPI), thrombomodulin (TM), von Willebrand factor (vWF), and tissue factor (TF) concentrations were measured by enzyme-linked immunosorbent assay (ELISA). With the exception of FVIII, coagulation factors and anticoagulant proteins synthesized by the liver were decreased and the coagulogram was extended for all patients. Likewise, the FDP and D-D concentrations were increased in blood. CHB patients, however, presented with increased levels of FVIII, TFPI, TM, vWF, and TF. Pairwise comparison indicated statistical differences existed among CHB, CHB-related liver cirrhosis, and liver failure patients: TFPI: 239.3+/-206.4, 315.0+/-258.6, and 319.5+/-298.1 -- higher than normal control: 104.0+/-87.1, F = 5.453, P less than 0.05; vWF: 70.3+/-29.5, 105.5+/-58.0, and 179.3+/-61.7 -- higher than normal control: 21.9+/-7.2, F = 20.104, P less than 0.05; TF: 85.9+/-85.7, 234.2+/-202.9, and 344.7+/-214.6 -- higher than normal control: 12.8+/-8.1, F = 8.619, P less than 0.05; FVIII: 157.2+/-53.4, 206.9+/-86.9, and 335.7+/-117.7 -- higher than normal control: 105.5+/-46.2, F = 13.418, P less than 0.05. In parallel to the progression of liver diseases, pro coagulation and anti-coagulation elements synthesized by the liver were reduced. In contrast, fibrinolysis activity was enhanced, which is expected to lead to an imbalance between blood clotting and anti-clotting factors. This may be an important cause for the bleeding that occurs in end-stage liver disease. Expressions of TFPI, TM, vWF, and TF significantly change in the early stage of liver diseases, as compared to normal (healthy) levels, and may represent a sensitive indicator of vascular injury.

Coagulation Profiles of Healthy Andalusian Donkeys are Different than Those of Healthy Horses

Coagulation disorders are frequently diagnosed, especially in hospitalized equidae, and result in increased morbidity and mortality. However, hemostatic reference intervals have not been established for donkeys yet. To determine whether the most common coagulation parameters used in equine practice are different between healthy donkeys and horses. Thirty-eight healthy donkeys and 29 healthy horses. Blood samples were collected to assess both coagulation and fibrinolytic systems by determination of platelet count, fibrinogen concentration, clotting times (prothrombin time [PT] and activated partial thromboplastin time [aPTT]), fibrin degradation products (FDP) and D-Dimer concentrations. PT and aPTT in donkeys were significantly (P < .05) shorter than those of horses. In contrast, FDP and D-Dimer concentrations were significantly (P < .05) higher in donkeys than in horses. The coagulation parameters most commonly determined in equine practice are different in donkeys compared with horses. Thus, the use of normal reference ranges reported previously for healthy horses in donkeys might lead to a misdiagnosis of coagulopathy in healthy donkeys, and unnecessary treatments in sick donkeys. This is the first report of normal coagulation profile results in donkeys, and further studies are warranted to elucidate the physiological mechanisms of the differences observed between donkeys and horses.

One‐stage prothrombin time, activated partial thromboplastin time, thrombin time, fibrin degradation product concentration, and antithrombin activity in healthy adult alpacas

Alpacas are increasingly presented to veterinarians for evaluation and care. Reports of alpaca reference intervals for one-stage prothrombin time (PT), activated partial thromboplastin time (aPTT), thrombin time (TT), concentration of fibrin degradation products (FDP), and antithrombin (AT) activities are scarce or nonexistent. The aim of this study was to determine values for blood coagulation times (PT, aPTT, and TT), FDP concentrations, and AT activities in healthy adult alpacas. Of blood samples collected from 35 clinically healthy adult alpacas via jugular venipuncture and placed into sodium citrate and FDP tubes, 29 samples were assayable for coagulation testing. PT, aPTT, and TT were determined by physical (mechanical) clot detection; AT activity was determined using a thrombin-specific chromogenic substrate end-point assay; and FDP concentrations were determined by the slide agglutination method. Median values and ranges (minimum-maximum) were determined for PT (8.7 seconds, 6.6-11.2 seconds), aPTT (17.3 seconds, 11.9-22.5 seconds), TT (10.2 seconds, 5.4-16.0 seconds), and AT activity (123.3%, 104.8-144.2%). The mean concentration of FDP was <8 μg/mL. These values for coagulation times, FDP concentration, and AT activity will provide a useful starting point in the diagnostic evaluation of ill adult alpacas.

Fibrin Degradation Enhances Vascular Smooth Muscle Cell Proliferation and Matrix Deposition in Fibrin-Based Tissue Constructs Fabricated In Vitro

Completely biological tissue replacements can be fabricated by entrapping cells in a molded fibrin gel. Over time, the fibrin is degraded and replaced with cell-produced extracellular matrix. However, the relationship between fibrin degradation and matrix deposition has not been elucidated. We developed techniques to quantify fibrin degradation products (FDP) and examine plasmin activity in the conditioned medium from fibrin-based constructs. Fibrin-based tissue constructs fabricated with vascular smooth muscle cells (vSMC) were cultured for 5 weeks in the presence of varied concentrations of the fibrinolysis inhibitor -aminocaproic acid and cellularity, and deposited collagen and elastin were measured weekly. These data revealed that increasing concentrations of -aminocaproic acid led to delayed and diminished FDP production, lower vSMC proliferation, and decreased collagen and elastin deposition. FDP were shown to have a direct biological effect on vSMC cultures and vSMC within the fibrin-based constructs. Supplementing construct cultures with 250 or 500μg/mL FDP led to 30% higher collagen deposition than the untreated controls. FDP concentrations as high as 250μg/mL were estimated to exist within the constructs, indicating that FDP generation during remodeling of the fibrin-based constructs exerted direct biological activity. These results help explain many of the positive outcomes reported with fibrin-based tissue constructs in the literature, as well as demonstrate the importance of regulating plasmin activity during their fabrication.

Coagulation/fibrinolysis and inflammation markers are associated with disease activity in patients with chronic urticaria

The evaluation of disease severity and activity of chronic urticaria (CU) is essential for the adequate treatment of patients. However, there is no reliable biomarker for such evaluations. Recently, markers of blood coagulation and fibrinolysis have been revealed to be elevated in severe cases of CU. In this article, we studied the coagulation/fibrinolysis and inflammation markers and their relationship to disease activity in patients with CU. Plasma fibrin degradation products (FDP), d-dimer and serum C-reactive protein (CRP) were measured with the assessment of disease severity and skin reaction to autologous serum in 82 patients with CU and 37 patients with acute urticaria, idiopathic angioedema (AE) or inducible types of urticaria (IU). The levels of FDP in patients with CU were significantly higher than those in patients with IU, but no other differences in FDP, d-dimer and CRP were observed among patients with different types of urticaria. These markers of patients with CU were well correlated with each other and significantly associated with disease severity of CU, but not with skin reactions to autologous serum. In 37 patients with CU, levels of all these parameters reduced as their disease condition improved, while they increased when the disease became aggravated. Regarding FDP, this relationship was observed even if FDP concentrations were within normal range throughout the study. The measurement of plasma FDP, d-dimer and serum CRP may be useful for the assessment of disease activity of CU.

Fibrinolytic activity of the cerebrospinal fluid after subarachnoid haemorrhage.

The fibrinolytic activity of peripheral blood and cerebrospinal fluid was estimated by the fibrin plate method and by assays for fibrin degradation products in 11 patients with proven aneurysmal subarach-noid haemorrhage. Five of the patients were treated conservatively; the remaining 6, surgically. An increase in the fibrinolytic activity of the cerebrospinal fluid, as judged from the appearance of fibrin degradation products, occurred in all the patients on the third day after the initial haemorrhage. This fibrinolytic activity tended to decrease the first three weeks after the onset of the haemorrhage in 7 patients. In the remaining 4 it was still elevated at the end of the third week. In one of these patients haemorrhage recurred. Demonstration of high concentrations of fibrin degradation products in cerebrospinal fluid after surgery on the brain suggests the release of tissue activators from the damaged brain during the operation. Premature dissolution of the haemostatic plug at the site of the ruptured intra-cranial aneurysm might therefore be responsible for the rebleeding. Hence the use of anti-fibrinolytic drugs may be useful in the management of patients with subarachnoid haemorrhage.

Prospective Evaluation of Coagulation in Critically Ill Neonatal Foals

Coagulopathy is a potentially underrecognized complication of sepsis and septic shock in critically ill neonatal foals. Critically ill neonatal foals have abnormalities in coagulation that are associated with disease severity and outcome. Foals <72 hours old admitted to a neonatal intensive care unit. Prospective, observational study. Blood was collected at admission, 24, and 48 hours for platelet count, prothrombin time, activated partial thromboplastin time, antithrombin activity and concentrations of fibrin degradation products, and fibrinogen in plasma from all foals. Sixty-three foals were enrolled and classified as Septic Shock (12), Septic (28), and Other (23). At least 1 abnormal value was found in 18/28 (64%) samples from the Septic Shock group, 66/85 (78%) from the Septic group, and 30/59 (51%) from the Other group (P= .01). Coagulopathy (3 or more abnormal values) was present in 7/28 (25%) samples in the Septic Shock group, 14/85 (16%) samples in the Septic group, and 3/59 (5%) samples in the Other group (P= .0028). Clinically detectable bleeding occurred in 8/12 (67%) Septic Shock cases, 11/28 (39%) Septic cases, and 3/23 (13%) Other cases (P= .009). Foals in Septic Shock were 12.7 times more likely to have clinical evidence of bleeding than those in the Other group (95% CI 2.3-70, P= .004). Treatment with fluids or plasma did not have a detectable effect on coagulation values. Coagulopathy commonly occurs in critically ill neonatal foals, especially those with sepsis and septic shock.

Evaluation of coagulation markers in the plasma of healthy cats and cats with asymptomatic hypertrophic cardiomyopathy

Thrombosis and arterial thromboembolism are frequent complications of feline cardiomyopathy, especially when associated with left atrial enlargement. Markers of activated coagulation may be used to evaluate the coagulation status of cats with hypertrophic cardiomyopathy (HCM) in relation to left atrial size. The objective of this study was to compare plasma concentrations of thrombin-antithrombin complex (TAT), D-dimer, and fibrin degradation products (FDP) between clinically healthy cats and cats with HCM. Prothrombin time (PT), activated partial thromboplastin time (aPTT), and antithrombin activity were also compared and the association between left atrial (LA) size and coagulation results in cats with HCM was evaluated. Blood samples from 19 clinically healthy cats and 20 cats with HCM were obtained. All cats with HCM were asymptomatic and had no signs of heart failure. LA diameter and LA to proximal aortic (Ao) diameter ratio (LA:Ao) were determined by echocardiography. Reference intervals for D-dimer and TAT concentrations in plasma of healthy cats were established as 0.09-0.32 microg/mL and 2.0-20.0 microg/L, respectively. TAT, D-dimer, and FDP concentrations were increased in 5, 3, and 2 cats with HCM, respectively. TAT and D-dimer concentrations, and PT and aPTT were not significantly different between groups. Antithrombin activity was significantly decreased in cats with HCM (P=.03) despite marked range overlap. LA and LA:Ao were not correlated with coagulation results. Laboratory evidence of hypercoagulability was found in 45% of cats with HCM. Left atrial size was not associated with laboratory evidence of hypercoagulability. Association between coagulation markers and risk of thrombosis has yet to be evaluated in cats with HCM.

Relationships among tumor burden, tumor size, and the changing concentrations of fibrin degradation products and fibrinolytic factors in the pleural effusions of rabbits with VX2 lung tumors

The VX2 tumor is derived from a papilloma virus-induced rabbit epithelial cell line. If VX2 tumor cells (trapped in a plasma clot) are introduced intravenously into NZW rabbits, the cells lodge in the lung capillary bed and produce tumors. Independently of the tumor burden (ie, the total tumor weight per rabbit), approximately 15% of rabbits with VX2 lung tumors accumulate an effusion in the interpleural space and this pleural effusion contains products of hemostasis. We hypothesized that these products were of intra-tumoral origin and that they changed in concentration as tumor burden increased. Interrelationships among lung-, tumor-weights, and pleural effusion volumes, and the concentrations of fibrinolytic factors, their catabolic products, and other proteins of pleural effusions were measured in rabbits with a wide range of tumor burdens. Positive correlations between tumor burden and total lung weight and between pleural effusion volume and net lung weight suggested that interstitial fluid from the stroma of tumors passed directly into the extravascular space of the lung(s) and into the interpleural space(s). Analyses of pleural effusions indicated that plasminogen-, alpha(2)-antiplasmin-, and plasminogen activator inhibitor-1-related proteins, urokinase-like- and tissue-plasminogen activator activities, and vascular endothelial growth factor increased in concentration up to a tumor burden of approximately 20-25 g. Plasmin activity and intact fibrinogen were absent. The concentration of fibrin(ogen) degradation products did not change significantly up to a tumor burden of approximately 25 g but increased substantially as tumor burdens exceeded 25 g. In conclusion, interstitial fluid from tumors enters the extravascular space of the host and may accumulate with fluid from non-tumor sources as a pleural effusion. The concentrations of fibrinolytic factors and their products in pleural effusions reflect the tumor burden of the rabbit. Conceivably, the components of a malignant effusion contain much information about the extent of tumor growth.

Rapid detection of fibrinogen and fibrin degradation products using a smart QCM-sensor

We have developed a rapid immunosensor for fibrinogen and fibrin degradation products (FDP) that combines a quartz crystal microbalance (QCM) with the agglutination reaction of anti-FDP antibody immunized latex beads. We measured FDP concentration successfully in human serum within 10 min with a smart QCM-sensor. The detection range of the smart QCM-sensor is covered with screening concentration of FDP in serum (less than 10 μg ml −1 of FDP).