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PubMed1989

Hemostatic alterations in pigs fed sublethal doses of Sarcocystis miescheriana.

Effects of non-lethal Sarcocystis miescheriana infections on the blood coagulation system were investigated. Nine pigs were inoculated orally with 2 X 10(5) sporocysts (Group A) and nine pigs (Group B) served as non-infected controls. Blood samples were taken from the vena jugularis externa every 2 or 3 days until 19 days post-infection (dpi). The following parameters were investigated: partial thromboplastin time (PTT), prothrombin time (PT), thrombin time (TT), thrombin coagulase time (TCT), fibrinogen (FIB), factor (F) VIII, F XI, F XII, antithrombin III (AT III), alpha 2 macroglobulin (alpha 2 MG), alpha 2 antiplasmin (alpha 2 AP), pre-kallikrein (PK), and the number of circulating thrombocytes. All infected pigs suffered from acute sarcocystiosis between 12 and 19 dpi. Clinical illness was most severe from 14 to 17 dpi. At this time, PTT and FIB increased, and TT and TCT decreased slightly. The activities of the clotting factors increased at 17 and 19 dpi. However, only F VIII activity was significantly higher in the infected pigs than in the controls at 17 and 19 dpi. PK was significantly lower in the infected pigs at 12, 14, and 17 dpi. Thrombocyte counts were reduced with the onset of the acute phase of illness and some pigs had marked thrombocytopenia. These results indicate low-grade disseminated intravascular coagulation (DIC) in the course of mild S. miescheriana infections in pigs.

Animals↗
PubMedDate not supplied

Coagulation patterns in bovine left heart bypass with phospholipid versus heparin surface coating.

The current study was designed to evaluate tubing sets with either polymeric phospholipids or ionically bound heparin in six bovine experiments (body weight, 70 +/- 5 kg). No heparin was given systemically. Left heart bypass was started with 300 ml of clear priming solution and maintained over 6 hours (50 ml/kg/min). Coagulation studies included platelet counts, activated coagulation time (ACT), thrombin time (TT), fibrinogen (Factor I), antithrombin III (AT III), and fibrinopeptide A (FPA). Normalized platelet levels dropped from 100 +/- 12% before to 86 +/- 13% after 6 hours of left heart bypass for heparin, compared with 100 +/- 46% to 90 +/- 44% for phospholipid coating (NS). The ACT increased from 146 +/- 7 sec at 10 min to 159 +/- 16 sec after 6 hours for heparin, compared with 122 +/- 4 to 126 +/- 5 sec for phospholipid (p < 0.05). Thrombin time changed from 18 +/- 0 sec before to 19 +/- 1 sec after 6 hours for heparin, as compared with 16 +/- 1 sec to 18 +/- 1 sec for phospholipid (NS). Factor I levels decreased from 1.5 +/- 0.3 g/L to 1.3 +/- 0.1 g/L for heparin, compared with 1.5 +/- 0.2 g/L to 1.4 +/- 0.3 g/L for phospholipid. Antithrombin III levels changed from 102 +/- 26% to 91 +/- 7% for heparin, compared with 123 +/- 12% to 118 +/- 12% for phospholipid. Fibrinopeptide A levels changed from 100 +/- 60% to 130 +/- 13% for heparin, compared with 100 +/- 11% to 99 +/- 6% for phospholipid (P < 0.05). No macroscopic red clots were found in either group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Structural features of dermatan sulfates and their relationship to anticoagulant and antithrombotic activities.

Dermatan sulfate is a polydisperse, microheterogeneous sufated copolymer of N-acetyl-D-galactopyranose and idopyranosyluronic acid that is currently under clinical investigation as a new antithrombotic agent. The structure and activity of two pairs of dermatan sulfates, isolated from bovine and porcine mucosa, were studied. One dermatan sulfate from each species demonstrated high in vivo antithrombotic activity in the rat vena cava assay. The in vitro anticoagulant activity of each dermatan sulfate was determined using activated partial thromboplastin time (APTT), thrombin time (TT) (5 units), calcium thrombin time (CaTT) (5 units), Heptest, anti-factor Xa and anti-factor IIa antithrombin assays and heparin cofactor II amidolytic assays. The coagulation-based assays gave the best correlation to in vivo antithrombotic activity. The physical and chemical properties of each dermatan sulfate were determined using 1H-NMR and 13C-NMR spectroscopy, molecular weight determination, potentiometric titration, chemical degradative analysis, chondroitin lyase degradative analysis and oligosaccharide mapping. These analyses indicated that the major difference between dermatan sulfates from a particular species having high and low in vivo antithrombotic activity was their iduronic acid content. The relation between increased iduronic acid content and increased in vivo antithrombotic activity may be the result of the conformational flexibility of this residue.

Animals↗
PubMed1989

Comparative study on a new one-stage clotting assay for heparin and its low molecular weight derivatives.

The effects of a normal and a low molecular weight (LMW) heparin fraction were compared by four coagulation methods. Plasma samples of patients were investigated who were treated with normal heparin or with a LMW heparin. The study was undertaken to analyze the interrelationship between the coagulation methods: Heptest, activated partial thromboplastin time, thrombin clotting time, and S 2222 chromogenic anti-factor Xa test. The results showed a high correlation between Heptest and S 2222 anti-factor Xa method for unfractionated and LMW heparin (r = 0.91 and 0.90). Comparing the coagulation times in seconds of Heptest and aPTT, the correlations were r = 0.56 (normal heparin) and 0.15 (LMW heparin). The correlation between the coagulation times of Heptest and thrombin clotting time were r = 0.65 and 0.25, respectively. The correlations between the coagulation methods were higher, when coagulation times rather than transformed values to units per liter of the Heptest and of the S 2222 anti-factor Xa method were employed. Furthermore, the data demonstrate a high sensitivity of the Heptest to conventional and LMW heparin, whereas activated partial thromboplastin time and thrombin clotting time are less sensitive to either heparin. For laboratory control of LMW heparin, Heptest and S 2222 chromogenic method are reliable tests. Therapeutic ranges will have to be established.

Blood Coagulation Tests↗
PubMed2000

Platelet activation and its role in thrombin generation in platelet-induced thrombin generation time.

Platelet-induced thrombin generation time (PITT) is a newly developed global coagulation assay in which a small amount of partially anticoagulated platelet-rich plasma (PRP) is rotated in a disc-shaped cuvette within the light beam of a photometer. The time intervals from onset of rotation until aggregation and coagulation of the sample are registered. The aim of our study was to compare platelet activation with generation of thrombin during rotation of PRP in PITT system. Aliquots of PRP were taken before, 1, 3, and 8 min after the onset of rotation as well as at the beginning of aggregation and shortly before coagulation. Thrombin activity was measured with chromogenic substrate S-2238. We have also measured the level of generated prothrombin activation fragment 1+2 (F1+2), which reflects the concentration of liberated thrombin. Platelet activation was assayed by means of platelet factor 4 (PF4) and beta-thromboglobulin (beta-TG) concentration and registration of the aggregation. The concentrations of the F1+2, PF4, beta-TG increased very slowly from the beginning of the test until aggregation occurred. From the start of aggregation, the levels of F1+2 rose rapidly. In contrast to the F1+2 measurements, thrombin activity has not been detected from onset of rotation until the end of the test. Only trace thrombin activity was detectable just after the plasma sample had been clotted in the cuvette. Our results demonstrate that there exists a close relationship between platelet activation and thrombin generation. Viable platelets, which adhered to the cuvette walls, form an active template on which thrombin can be generated from prothrombin.

Adult↗
PubMed1982

Effects of dexamethasone on endotoxin shock in the anesthetized pony: hematologic, blood gas, and coagulation changes.

The effects of dexamethasone (1 mg/kg of body weight) on hematologic, blood gas, and blood coagulation values in anesthetized ponies during endotoxin-induced shock were evaluated. Fifteen ponies were assigned to 3 groups of 5 ponies each: group 1, anesthetized nontreated and dexamethasone-treated controls; group 2, endotoxin, nontreated; group 3, endotoxin, dexamethasone treated. The hematologic changes in this endotoxin shock model included leukopenia and hemoconcentration. Significant hematologic effects were not seen in ponies after administration of dexamethasone. However, dexamethasone treatment resulted in an increased trend in total WBC counts and neutrophils. The blood gas changes reflected a respiratory component resulting from anesthesia and a greater metabolic component from the endotoxemia. The plasma lactate increase was significantly (P less than 0.05) less in ponies treated with dexamethasone, compared with plasma lactate in non-treated ponies. During endotoxin shock, the changes observed in the blood coagulation values included a significant (P less than 0.05) prolongation of the activated partial thromboplastin time and thrombin time and an insignificant prolongation of the prothrombin time. Dexamethasone treatment prevented prolongation of thrombin time and permitted only a mild prolongation of activated partial thromboplastin time. Seemingly, corticosteroids are useful in the treatment of clinical endotoxin shock in horses as indicated by their desirable effects on total WBC, neutrophils, cellular metabolism, and blood coagulation.

Acidosis↗
PubMed1984

The effect of platelet factor 4 (PF4) on assays of plasma heparin.

Platelet factor 4 (PF4) is a potent antiheparin in vitro. In view of the large amount of PF4 secreted from platelet alpha-granules during routine blood collection and processing techniques, the potential significance of this release was investigated using three measurements of heparin activity: the activated partial thromboplastin time (aPTT), the thrombin time, and factor Xa inactivation using the chromogenic substrate S2222 for assay of factor Xa. The results demonstrate that purified PF4 neutralizes heparin activity when added in increasing amounts to normal platelet-poor plasma containing a fixed concentration of commercial porcine gut mucosal heparin. This effect was seen when assaying heparin activity by all three methods. In addition, when heparin was added in increasing concentrations to pooled plasma samples that were collected from normal volunteers, there was neutralization of heparin activity in blood samples collected by routine citrate anticoagulation (CIT60) in comparison to blood samples collected simultaneously with platelet secretion inhibiting agents added to the anticoagulant (CIT+). This effect was seen when assaying heparin by the aPTT and thrombin time. These data confirm that both purified and secreted PF4 have significant antiheparin activity when heparin is added in vitro to normal plasma. Neutralization of circulating heparin by PF4 secreted during blood collection from anticoagulated patients could result in underestimation of the actual in vivo heparin concentration. In order to evaluate the significance of this effect, purified PF4 was added to plasma collected from heparinized patients and again PF4 neutralized heparin activity. This was seen, however, only when heparin activity was measured by the thrombin time or Xa inactivation assays. There was minimal shortening of the aPTT when PF4 was added in final concentrations up to 1000 ng/ml. When blood samples were simultaneously collected from anticoagulated patients by both routine and special collection methods, these results were confirmed. There was a significant difference between heparin activities measured in the CIT+ (secreted PF4 58 ng/ml) and CIT60 (secreted PF4 1074 ng/ml) plasma samples by both thrombin time and Xa inactivation. There was no difference, however, in the aPT when both types of plasma samples were simultaneously collected and assayed for each anticoagulated patient. This suggests that there may be circulating heparin fractions which can prolong the aPTT but which do not interact with PF4.(ABSTRACT TRUNCATED AT 400 WORDS)

Factor X↗
PubMed1993

A caesarean section model to characterize coagulation in the fetal and uterine circulation during late gestation in dairy cattle.

A study was conducted to measure a coagulation profile including prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), fibrinogen concentration (FIB), and plasminogen activity (PLA) in the jugular vein, umbilical vein and artery and uterine vein of 18 Holstein Friesian cows during late gestation. A caesarean section was performed on all cows before term in order to obtain blood samples from the different sources and to deliver the calves. Blood plasma obtained from the umbilical vein and artery had a longer prothrombin time but shorter activated partial thromboplastin time and lower concentrations of fibrinogen and plasminogen than peripheral blood plasma. Thrombin time was similar throughout all blood vessels. No significant differences existed between the two samples drawn from the jugular vein before and during surgery. Highest coefficients of correlation were found between blood samples drawn simultaneously from the jugular and uterine vein (R2 = 41 to 96%).

Animals↗
PubMed1985

Heparin-like anticoagulant associated with plasma cell myeloma.

A 54-year-old man with plasma cell myeloma had sustained bleeding develop after prophylactic hip hemiarthroplasty. Routine coagulation studies revealed significant prolongation of the prothrombin time, activated partial thromboplastin time, and thrombin time. Further evaluation showed failure of the activated partial thromboplastin time to correct in a 1:1 mixture with pooled normal plasma, correction of the prolonged thrombin time by addition of protamine, and a normal reptilase time. A purified preparation of the immunoglobulin component of patient plasma produced the same pattern of coagulation abnormalities, suggesting the paraprotein possessed heparin-like anticoagulant activity. This appears to be a rare mechanism of bleeding diathesis in plasma cell myeloma.

Blood Coagulation↗
PubMed2005

Anticoagulant 1,2,3,4,6-pentagalloyl-beta-D-glucopyranose isolated from geranium (Pelargonium inquinans Ait).

Geranium (Pelargonium inquinans Ait) leaves were extracted with 80% MeOH, and partitioned into n-hexane, ethyl acetate, BuOH and H2O to isolate the anticoagulant principles. The EtOAc fraction was found to be the most active, and was further purified using silica and octadecylsilane column chromatography employing a bioassay-guided fractionation method. The active compound was isolated and identified as 1,2,3,4,6-pentagalloyl-beta-D-glucopyranose (PGG) (compound I). The isolated anticoagulant significantly prolonged the activated partial thrombin time (APTT) and thrombin time (TT) using normal human plasma. One microgram of 1,2,3,4,6-pentagalloyl-beta-D-glucopyranose showed 0.063 heparin units in the APTT and 2.73 heparin units in the TT for anti-thrombosis. This is the first report of the isolation of PGG from geranium plants.

Anticoagulants↗
PubMed1987

Use of clinical pathology in evaluation of horses with colic.

Clinical pathology is a valuable adjunct to physical examination of cases of colic. The present review considers evaluation of cases of colic for three main purposes: (1) making a prognosis, (2) deciding whether to operate, and (3) making a diagnosis. Blood tests noted to be useful for prognostication were hematocrit, lactate and urea nitrogen concentrations, pH, anion gap, fibrin/fibrinogen degradation products, antithrombin III activity, prothrombin time, and thrombin time. Horses with a poor prognosis often have relative polycythemia, marked lactic acidosis, high anion gap, azotemia, and coagulation abnormalities evidenced by increased fibrin/fibrinogen degradation products, decreased antithrombin III activity, and prolonged prothrombin and thrombin times. The decision to operate is usually a clinical one, supported by relative polycythemia, hyperglycemia, and, possibly, abnormal peritoneal fluid analysis. Diagnosis of the primary problem (causing the colicky signs) is also often based largely on physical examination. However, peritoneal fluid analysis provides worthwhile data, especially in cases of peritonitis or intestinal ischemia and infarction.

Animals↗
PubMed2002

Plasma markers of hypercoagulability in patients with serious infections and risk of septic shock.

Hyperthrombinogenesis due to bacterial septicemia may aggravate the risk of irreversible septic shock. In 22 patients with septicemia complicating urinary or alimentary infections, daily assessment of hemostasis was performed throughout 1 week. Standard screening of hemostasis revealed significantly increased mean values of prothrombin time, fibrinogen, and fibrinogen degradation product (FDP) concentration. However, platelet counts, activated partial thromboplastin times (APTT), thrombin times, ethanol gelation tests, and antithrombin activity remained within the normal range. By contrast, except for insignificant changes in protein C activity and activated factor VII content, specific markers of plasma hypercoagulability, that is, thrombin-antithrombin (TAT) complexes, prothrombin activating factor F 1+2, activated factor XII (XIIa), and dimer D were all markedly increased. Pathologic levels of TAT and Xlla were found in 82% and 73% of all plasma samples, respectively. The augmentation of TAT correlated with prolongation of thrombin time and increases in F 1+2 levels. The increase in XIIa correlated with thrombocytopenia, prolongation of APTT, exhaustion of antithrombin, and accumulation of F 1+2 and FDP in the plasma. Moreover, a significant increase in XIIa, stronger positivity of the ethanol gelation test, a greater increase in FDP, and a more pronounced decrease in protein C activity were observed in 8 patients with fatal septic shock. This study suggests the usefulness of TAT and XIIa measurements in the early recognition of plasma hypercoagulation in serious infections.

Adult↗
PubMed1999

Assessing heparin neutralization following cardiac surgery: sensitivity of thrombin time-based assays versus protamine titration methods.

Adequate assessment of heparin neutralization following cardiac surgery is critical in reducing the patient's exposure to protamine. Both excessive protamine and residual heparin have been associated with postoperative bleeding and poor patient recovery. The activated clotting time (ACT) is the preferred intraoperative heparin monitor, while both protamine titration (i.e. a protamine-containing ACT) and thrombin time methods have been used to detect circulating residual heparin after protamine administration. Following initial protamine dosing using the protamine response test (PRT), postoperative monitoring was employed in the operating room prior to transport of the patient to intensive care. Two point-of-care assays, the thrombin time (TT) and the protamine dose assay (PDA), were evaluated to determine their relative heparin sensitivity and their usefulness to quantitate protamine dose. The PDA, which is based on the ACT, was shown in laboratory and clinical studies to detect residual heparin above 0.25 units/ml and to quantify additional minidoses of protamine (as low as 25 mg) required to obtain complete heparin neutralization. Differential evaluation of the TT and heparin neutralized thrombin time (HNTT) was shown in laboratory studies to be more sensitive to small amounts of residual heparin than the ACT. Clinical evaluations confirmed that additional protamine is required in approximately 12% of cardiac surgical cases managed using the PRT system. Both the PDA and TT/HNTT provided useful postoperative assessment of the adequacy of heparin neutralization. The TT/HNTT had slightly improved heparin sensitivity even in the presence of significant fibrinogen loss. These point-of-care assays provide the opportunity to optimize heparin and protamine management in the cardiac surgery patient.

Anticoagulants↗
PubMed1999

Comparative blood coagulation studies in the ostrich.

Blood coagulation of the ostrich was compared to that of mammalian (man and sheep), avian (chicken) and reptilian (puff adder) systems. The international normalised ratio (INR), partial thromboplastin time (PTT), thrombin time and fibrin degradation were determined, as well as the various coagulation factors in venous ostrich plasma, using human physiological substrates. Thromboplastin was isolated from fresh brain tissue with the exception of the reptile for which lung tissue was used. The levels of markers of the coagulation [antithrombin III (AT), factor X (FX) and prothrombin], the fibrinolytic (alpha2-antiplasmin) and the kallikrein system were determined using chromogenic substrates. Elevated values for INR, PTT and thrombin time were obtained as compared to known human standards. It was found that factors VII, IX, X, XI and XII were absent from ostrich plasma. A study of the homologous and heterologous thromboplastin activities indicated that ostrich plasma exhibited a lower thromboplastic activity when compared to human standards, but was comparable to avian and reptilian values. Ostrich plasma revealed 42.2% FX, 72.9% AT, 35.3% prothrombin, 115.6% alpha2-antiplasmin and 19.8% plasma kallikrein, relative to human plasma. All the results suggest that the ostrich coagulatory system has not evolved to include all the complex myriad of reactions found in the human system.

Animals↗
PubMed1976

Bleeding in uremic patients after carbenicillin.

Hemorrhagic diathesis was observed in patients with renal insufficiency after carbenicillin at serum levels greater than 300 mug/ml. Normal coagulation factors (F. I, II, V, VII, VIII, X), normal PTT, normal platelet counts, negative ethanol gelation test (fibrin monomers) were found as well as a prolongation of thromboplastin time (Quick), thrombin time, reptilase time and thrombin coagulase time. Platelet function was disturbed. In addition, the plasmatic system was involved: inhibition of fibrinogen-fibrin conversion (Belitser assay) and enhanced antithrombin III activity; in vivo the latter was ascribed to a heparin-like activity. In vitro, abnormal III was seen: however an enhanced antithrombin III activity in vitro was not found with carbenicillin and various penicillin derivatives. This study demonstrates that carbenicillin, in addition to its known effect on platelet function, also disturbs the plasmatic coagulation system. This additional effect of carbenicillin is clinically important since protamin chloride effectively blocks bleeding without interfering with antibacterial activity. Both penicillin and penicillin derivatives have been shown to interfere with hemostasis and to cause clinically manifest hemorrhagic diathesis (Fleming and Fish 1947, Lurie et al. 1970a, b, McClure et al. 1970, Yudis et al. 1972, Demos 1971, Waisbren et al. 1971). Carbenicillin interferes with ADP-, collagen- or thrombin-induced platelet aggregation and with the release reaction both in vivo (McClure et al. 1970, Cazenae et al. 1973) and in vitro (McClure et al. 1970, Cazenave et al. 1973). In addition Lurie and colleagues (1970b) concluded that an inhibition of the conversion of fibrinogen to fibrin is involved although no experimental details were given. Later Brown and colleagues (1974) concluded that carbenicillin at usual dose levels "only affects the platelet component of hemostasis and has little effect on fibrin formation or other phases of coagulation in patients with normal renal function".

Adult↗
PubMed1985

Abnormal coagulation results in patients with Hodgkin's disease.

Case records of 177 patients admitted with Hodgkin's disease were reviewed to assess the frequency and significance of coagulation abnormalities. Prolongation of the prothrombin time, activated partial thromboplastin time, or thrombin time occurred in 56 patients, 32 percent of all evaluable cases. The most frequent clotting abnormalities involved the prothrombin time, which was increased in 43 patients (24 percent). Prothrombin time prolongation correlated with bulky or advanced disease as defined by stage (p = 0.001), constitutional symptoms (p less than 0.0001), massive mediastinal involvement (p = 0.02), and elevated alkaline phosphatase levels (p less than 0.0001). Abnormal coagulation test results followed the course of disease, normalizing with tumor regression and reappearing during relapse. Despite the surprising incidence of abnormal coagulation results, bleeding complications were reported in only two cases. Patients undergoing invasive procedures in the presence of clotting abnormalities fared no worse than those in whom procedures were cancelled. There is no evidence that complete staging evaluation should be comprised because of these abnormal test values. Extensive hematologic testing revealed no single mechanism to explain the coagulation factor disorders found in Hodgkin's disease.

Adult↗
PubMed1994

Artificial ultraviolet whole-body radiation does not modify serum lipoprotein, plasma fibrinogen, plasminogen or antithrombin III concentrations in post-myocardial infarction patients.

The relationship of ischaemic heart disease (IHD) to seasonal and latitude variation has prompted speculation that exposure to the ultraviolet component of solar radiation may reduce IHD risk. This hypothesis was partially tested by exposing 14 post-myocardial infarction patients to a 6 week course of artificial whole-body ultraviolet radiation (UVR). Serum lipoprotein and plasma coagulation factor concentrations were measured before and after the course of UVR. Results were compared with similar measurements from a placebo-controlled group of 13 post-myocardial patients. Despite a more than two-fold rise in mean serum 25-OHD, serum lipoprotein and plasma fibrinogen, antithrombin III and plasminogen concentrations did not change significantly in the UVR group. Significant but minor change in prothrombin time and thrombin time in the placebo group appear unlikely to be of biological significance. Seasonal and latitude variation in these IHD risk factors appear unrelated to corresponding variation in solar UVR exposure.

Antithrombin III↗
PubMed1988

Effect of venom sac extract of the Oriental hornet (Vespa orientalis) on coagulation factors.

Venom sac extract of the Oriental hornet significantly prolongs the prothrombin time and the activated partial thromboplastin time both in vitro in human plasma and in vivo in cats. Activity of factors VIII and IX in plasma is reduced to less than 1% within 5 min even with 1 microgram of venom sac extract per ml. The activity of purified factor VIII, as well as semipurified factors IX and X, in factor IX complex was also significantly reduced after incubation with the venom. The decrease of factors II, V, VII, X, XI and XII activity to 9%, 11%, 11%, 29%, 1.7% and 0.7% of normal, respectively, is dose- and time-dependent. Thrombin time, plasma fibrinogen and fibrin degradation products are not affected. The anticoagulant activity is not reversed by dialysis and is abolished completely by heating; it resides mainly in fractions with mol.wts above 5000. The venom has a proteolytic activity on 14C-globin which is partially inhibited by trasylol and ethylenediaminetetraacetic acid. Thus, the venom sac extract exhibits both serine and metaloprotease activities which may affect the activity of the plasma coagulation factors.

Bee Venoms↗