山莨菪碱对内毒素诱导山羊弥漫性血管内凝血(DIC)的影响

３０头杂交山羊随机分成３组，第Ⅰ组（ｎ＝６）作为对照组；第Ⅱ组（ｎ＝１２）静注大肠杆菌内毒素（１８００ＥＵ／ｋｇ）两次，间隔２４小时；第Ⅲ组（ｎ＝１２）在第Ⅱ组处理基础上提前１０分钟静注山莨菪碱（２．５ｍｇ／ｋｇ），于处理后第１、３、５、７、９、１２小时分别检测血小板数、血浆纤维蛋白原含量、血浆凝血酶原时间（ＰＴ）、血浆凝血酶时间（ＴＴ）、副凝试验３Ｐ和ＥＧＴ指标。结果表明：第Ⅱ组迅速发生ＤＩＣ，表现血小板减少、纤维蛋白原含量下降、ＰＴ和ＴＴ延长、３Ｐ和ＥＧＴ阳性（Ｐ＜０．０１）；而第Ⅲ组血小板数在１３小时明显高于第Ⅱ组，纤维蛋白原含量于第５小时后高于第Ⅱ组（Ｐ＜０．０１，Ｐ＜０．０５），ＰＴ和ＴＴ亦比第Ⅱ组显著缩短（Ｐ＜０．０１），３Ｐ和ＥＧＴ的阳性检出率低于第Ⅱ组，结果提示应用山莨菪碱能明显抑制血小板减少，阻止ＤＩＣ的发生     

Hemostatic abnormalities in equine colic

Hemostatic profiles were determined in 30 horses with clinical colic. Blood samples were obtained at the time of the animal's admission, and the following hemostatic tests were done: blood platelet count, plasma fibrinogen, plasma antithrombin, prothrombin time, partial thromboplastin time, thrombin time, protamine sulfate test for soluble fibrin monomer, and fibrin-fibrinogen degradation products. The patients were categorized in retrospect, according to the cause of the colic: group 1--colic associated with colitis and/or severe diarrhea, group 2--colic associated with torsion or obstruction of the intestine, and group 3--colic associated with impaction of the intestine or the presence of enteroliths. Of the 30 horses with colic, 28 had at least 1 abnormality in their coagulogram--the most frequent abnormalities being high plasma fibrinogen concentration, high circulating soluble fibrin monomer, or a long partial thromboplastin time or thrombin time. The horses in group 1 seemed to have the most severe coagulopathies, as indicated by the average number of demonstrable abnormalities. The horses in group 3 showed the fewest abnormalities--usually a high plasma concentrations of fibrinogen and/or soluble fibrin monomer. The results indicated that hemostatic abnormalities are not uncommon in horses with gastrointestinal disease and colic--the degree of severity depending to some extent on the cause of the colic.     

Disseminated intravascular coagulation in a horse with postpartum ulcerative colitis and laminitis

Hemostatic studies were conducted on a five year old Belgian mare presented two days postpartum with colic and laminitis that was unresponsive to treatment.

The mare was moderately thrombocytopenic with plasma fibrinogen levels more than twice that of a normal control horse. Platelet function as evaluated by aggregometry indicated that the circulating platelets were markedly hyporesponsive. Activated partial thromboplastin times and prothrombin times were prolonged. Para-coagulation tests (protamine sulfate and ethanol gelation) were strongly positive and fibrin degradation products were significantly elevated in the serum.

The laboratory data suggested that the clinical bleeding was the result of the development of disseminated intravascular coagulation. The data were compatible with intravascular activation of the clotting mechanism, consumption of hemostatic factors, inhibition of platelet function and enhanced stimulation of the fibrinolytic mechanism.

This report illustrates the complexity of the hemostatic abnormalities associated with pathological overactivation of the hemostatic mechanism. Factors such as tissue thromboplastins and/or endotoxins can stimulate disseminated intravascular coagulation, particularly during pregnancy or in the early postpartum period when a physiological “hypercoagulable” state already exists.

     

Disseminated Intravascular Coagulation in Ponies with Surgically Induced Strangulation Obstruction of the Small Intestine

Total strangulation obstruction (S/O) of the jejuno-ileum was produced in a group of randomly selected ponies. Peripheral blood samples were collected prior to surgery and at 3-hour intervals following obstruction. A coagulation profile consisting of platelet count, fibrinogen titer (FT), prothrombin time (PT), activated partial thromboplastin time (APTT), and serial dilution protamine sulfate test (SDPS) for fibrin monomers (FM) and/or early fibrin degradation products (fdp) was evaluated. The packed cell volume (PCV) and total plasma protein (TPP) were also determined. Concurrent peritoneal fluid samples were assessed grossly. Sham-operated (sham) ponies were treated in a similar manner, excluding the production of a strangulation obstruction of the small intestine. Notable coagulopathies occurred in the S/O group. PT and APTT were increased significantly in samples collected within 6 hours of death. All S/O horses developed strongly positive SDPS reactions, while sham ponies, presurgical S/O ponies, and early S/O postsurgical samples were unremarkable. There were no significant shifts in the fibrinogen titer. Platelet counts were significantly decreased during the final 10% of sampling time in S/O horses. The coagulopathies observed in the S/O ponies appear to be secondary to the pathophysiologic changes produced by the S/O and not related to surgical trauma.     

骨折对大鼠凝血指标的影响

Wistar大鼠160只,随机分为8组,正常对照组、6h组、12h组、24 h组、3d组、5d组、7d组、14d组,每组各20只,除对照组外其他各组大鼠均手术使其一侧后肢股骨粉碎性骨折,各时段组大鼠采血测凝血指标:凝血酶原时间(PT)、凝血活酶时间(TT)、纤维蛋白原(FBG)后取患肢血管做病理学检查.两项检查结果表明,大鼠粉碎性骨折后,12 h至3d内的时间段是肢体深静脉血栓(DVT)形成的关键期,此后进入静脉血栓脱落导致肺栓塞的危险期,在骨折前或骨折后的前3d采取积极措施预防DVT可取得较理想的效果.动态监测创伤骨折大鼠凝血指标的变化,对早期预防创伤后深静脉血栓形成具有诊断价值.     

Evaluation of the effect of storage at -70 degrees C for six months on hemostatic function testing in dogs.

Freezing is a routine method of storage for plasma that is to be used in evaluating certain aspects of hemostatic function in many species. The purpose of this study was to evaluate the effect of storage at -70 degrees C for 6 mo on canine plasma samples. On fresh and frozen plasma from 12 clinically healthy dogs, prothrombin time, activated partial thromboplastin time, thrombin clotting time, fibrinogen determination, antithrombin III activity, fragment D and E assay, and protamine sulfate test were performed. Clinical agreement analysis was utilized to determine the effect of such storage on all assays. Individual differences detected between fresh and frozen samples were all within 2 standard deviations of the mean difference. With the exception of the activated partial thromboplastin time, storing canine plasma at -70 degrees C for 6 mo has no significant effect on hemostatic function, as assessed by these tests.     

Study of haemostatic disorders in experimentally induced leishmaniasis in Beagle dogs

Haemostatic alterations in dogs experimentally infected with Leishmania infantumwere studied before and after therapy with meglumine antimonate. Haemostatic function tests including platelet count, collagen-induced platelet aggregation, prothrombin time, activated partial thromboplastin time, thrombin time, plasma fibrinogen determination, and serum fibrinogen/fibrin degradation products concentration were performed. In the course of infection and before treatment, moderate thrombocytopenia (P<0·00001) decreased collagen induced platelet aggregation (P=0·0003), prolonged thrombin time (P=0·0117) and increased fibrinogen/fibrin degradation products were observed. Statistically significant differences of plasma fibrinogen concentration, prothrombin time, and activated partial thromboplastin time were not encountered. Haemostatic parameters returned to normal values after therapy. The results indicate that Leishmania infection may impair haemostasis suggesting induction of disseminated intravascular coagulation (DIC), and that treating dogs in an early stage of infection may potentially avoid the possibility of developing an uncompensated DIC.     

Afibrinogenemia and a circulating antibody against fibrinogen in a Bichon Frise dog

A 1.5-year-old female Bichon Frise dog was evaluated for a life-threatening hemorrhagic condition that occurred after ovariohysterectomy, requiring 4 whole-blood transfusions. A hemostatic profile, including activated clotting time (ACT), one-stage prothrombin time (OSPT), activated partial thromboplastin time (APTT), buccal mucosal bleeding time, and specific assays (heat-precipitation microhematocrit method and electroimmunoassay) for fibrinogen, were performed to investigate the coagulopathy. Clotting times for all tests having a fibrin clot endpoint (ACT, OSPT, APTT) and buccal mucosal bleeding time were prolonged. Plasma fibrinogen was not detected by heat-precipitation microhematocrit method or electroimmunoassay. Using the Ellis-Stransky method, a mixture of patient plasma and normal canine plasma with known fibrinogen content yielded substantially less than the calculated fibrinogen concentration, indicating the presence of an interfering substance. The interferent properties of the patient's plasma were retained following heat precipitation at 56 degrees C indicating the absence of a pyroglobulin or an abnormal fibrinogen molecule. Radial immunodiffusion assay using the patient's plasma and activated thrombin confirmed the existence of an inhibitor to the formation of fibrin. Western blot analysis using the patient's plasma identified an IgG antibody that reacted with the Beta- and gamma- but not the Alpha-subunits of canine fibrinogen. Antibody was detected in samples taken 8, 16, and 68 days after the surgery; peak titers were evident at day 16. These results supported a diagnosis of afibrinogenemia with a circulating antibody inhibitor to fibrin clot formation that developed secondary to blood transfusion.     

Study on biological variation of haemostatic parameters in clinically healthy dogs

Thromboelastography (TEG) may be a valuable supplement to the coagulation assays activated partial thromboplastin time (aPTT), prothrombin time (PT), thrombin time (TT), fibrinogen, antithrombin (AT) and D-Dimer currently used in most clinical pathology laboratories. Allowable imprecision and bias reference limits for analytical tests can be calculated based on measurements of biological variation. No studies to date have examined the effect of biological variation on these haemostasis parameters in the same group of dogs. Plasma samples were collected after a set protocol once weekly for five consecutive weeks from eight healthy dogs (four males and four females) and stored at -80 degrees C until analysis. Randomized duplicate coagulation tests and TEG analyses were performed on all plasma samples within one run. The data were analyzed for outliers and subsequently subjected to nested analysis of variance to obtain the coefficient of analytical, intra-individual and inter-individual variation. From these objective analytical performance standards for imprecision, critical difference, total error and the index of individuality were calculated to assess the utility of conventional population-based reference ranges. All the clotting times (aPTT, PT and TT), fibrinogen, AT and D-Dimer showed a degree of individuality, which may make the use of population-based reference ranges alone an insensitive interpretation criterion, whereas a population-based reference interval seems to be sensitive for interpreting all TEG parameters. Analytical performance standards for imprecision were only met for one of the coagulation assays, whereas all TEG parameters except the alpha angle, alpha achieved this analytical goal.     

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

Background: 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. Objective: 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. Methods: 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. Results: 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. Conclusion: These values for coagulation times, FDP concentration, and AT activity will provide a useful starting point in the diagnostic evaluation of ill adult alpacas.     

The Evaluation of Coagulation Profiles in Calves with Suspected Septic Shock

The purpose of the study reported here was to evaluate the haemostatic function in calves with suspected septic shock and to reflect the occurrence of disseminated intravascular coagulation (DIC). Twenty-six calves suspected of having septic shock (experimental group) and 10 clinically healthy calves (control group) were used. On admission, the experimental group of calves had been ill for an average of 2 days. Therapy was applied to the experimental group of calves. The packed cell volume (PCV), haemoglobin (Hb), white blood cell (WBC), red blood cell (RBC) and platelet (PLT) counts were determined. Blood smears for toxic neutrophil and schistocyte intensity were evaluated. For the coagulation profile, plasma activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), fibrinogen and fibrin/fibrinogen degradation products (FDPs) values were determined. Toxic neutrophils in blood smears were observed in 12 calves of the experimental group. APTT was prolonged in the experimental group compared with the control group (p < 0.05). Fibrinogen concentration was found to be higher in the experimental group than in the control group (p < 0.001). Total leukocyte counts were higher in the experimental group compared with the control group (p < 0.01). Platelet counts in the experimental group were lower than the control group (p < 0.001). However, when the individual values of coagulation profiles of each calf were evaluated, 8 calves had at least three abnormal coagulation profiles (APTT >72 s, PT >34.5 s, TT >33.7 s, FDPs >5 microg/ml, PLT < or = 150 x 10(3)/mm(3)) and abnormal erythrocyte morphology (schistocytes > or = 1). The most common abnormal tests in the coagulation profile were APTT and PT (7 cases), FDPs (6 cases), thrombocytopenia (4 cases), and schistocytes in blood smears (8 cases) in these 8 calves. The results of this study indicate that DIC might be a significant risk factor for mortality in calves with suspected septic shock.     

Hemostatic and Fibrinolytic Indices in Neonatal Foals with Presumed Septicemia

Thirteen coagulation tests evaluating hemostatic and fibrinolytic indices and serum cytokine and plasma endotoxin concentrations were obtained in 34 foals with a positive sepsis score (septic group) and 46 age-matched healthy foals. Compared to healthy foals, the prothrombin, activated partial thromboplastin, and whole blood recalcification times were significantly longer in septic foals. The fibrinogen and fibrin degradation products concentrations, percent plasminogen, alpha-2 antiplasmin, and plasminogen activator inhibitor activities, and tumor necrosis factor and interleukin-6 activities were greater in septic foals. Protein C antigen and antithrombin III activity were significantly lower in septic foals. Blood cultures were positive for growth and endotoxin was detected in 19 of 29 and 15 of 30 septic foals, respectively. In septicemic foals with detectable endotoxin in the plasma, the prothrombin and activated partial thromboplastin times were significantly longer and the plasminogen and antithrombin III activities were significantly less than in septic foals in which endotoxin was not detected. Twenty-three of the 34 septic foals did not survive. Septic foals that did not survive were most likely to have a positive blood culture in which a gram-negative organism was isolated. Histopathologic evidence of hemorrhage was evident in 11 foals at postmortem examination and thrombosis was identified in 2 foals. The prothrombin time was significantly longer in foals that had multisite hemorrhage at postmortem examination. The results of this study indicate that clinically relevant alternations in hemostatic and fibrinolytic indices occur in neonatal foals with septicemia and that derangements can be correlated with the presence of endotoxin in plasma. Derangements in hemostatic or fibrinolytic indices were helpful in identification of septic foals with increased risk of coagulopathy, but were not helpful in predicting hemorrhage as compared to thrombus formation. Survival of septicemic foals was correlated with gram-negative bacteremia, but not with the presence of endotoxin or coagulopathy.     

Development of a hamster model of Chlamydophila pneumoniae infection

The purpose of the study was to evaluate haemostatic function in cattle with abomasal displacement (AD) and to reflect the occurrence of disseminated intravascular coagulation (DIC). Ten adult cattle with left displacement of abomasum (LDA) (group I), 10 adult cattle with right displacement of abomasum with volvulus (RDA) (group II) and 10 clinically healthy adult cattle (control group) were used as material. Numbers of platelets (PLT) and coagulation tests (activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), serum fibrin/fibrinogen degradation products (FDPs), fibrinogen) were measured before the surgical treatment of cattle with LDA and RDA. APTT was prolonged only in group II compared with the control and group I (p<0.05). However, when the individual values of coagulation profiles of each cow were evaluated, two cattle in group I and three cattle in group II had at least three abnormal coagulation profiles, which reflect the occurrence of DIC. These cattle died after surgical treatment. The two cattle with LDA had abnormal APTT, FDPs and PLT values; three cattle with RDA had abnormal APTT, PT, TT, FDPs and PLT values. APTT (5 cases), FDPs (5 cases) and thrombocytopenia (5 cases) were the three most common abnormal tests on coagulation profile in the cattle with LDA and RDA. The results of the study indicate that cattle with AD had a spectrum of haemostatic dysfunction and that DIC was a significant risk factor for mortality.     

Influence of an omega-3 fatty acid-enriched ration on in vivo responses of horses to endotoxin.

Because certain inflammatory processes are dependent on the fatty acid composition of the cellular membrane, dietary manipulations that replace omega-6 fatty acids with omega-3 fatty acids may modify inflammatory responses. We investigated the effect of supplemental dietary linseed oil, containing the omega-3 fatty acid, alpha-linolenic acid, on in vivo responses of horses to endotoxin. One group of horses (n = 6) was fed a control pelleted ration (0% linseed oil), and another group of horses (n = 6) was fed an 8% linseed oil pelleted ration. After 8 weeks of consuming these rations, all horses were given 0.03 micrograms of Escherichia coli 055:B5 endotoxin/kg of body weight, infused over 30 minutes. Horses were monitored over 24 hours. Compared with baseline values within each ration group, endotoxin infusion caused significant (P less than 0.05) increase in rectal temperature, heart rate, and plasma concentration of thromboxane B2, 6-keto-prostaglandin F1 alpha, and fibrinogen and significant (P less than 0.05) decrease in total WBC count. Compared with baseline values within each ration group, endotoxin infusion failed to cause significant changes in prothrombin, activated partial thromboplastin, thrombin, or whole blood recalcification times, serum concentration of fibrin degradation products, PCV, or plasma total protein concentration. Before and after endotoxin infusion, horses given the linseed oil ration had longer mean whole blood recalcification time and activated partial thromboplastin time than did horses fed the control ration.     

Coagulation and fibrinolysis in the dog.

A range of tests of coagulation and fibrinolysis was measured in "normal" dogs and compared with values obtained in "normal" humans by the same methods. The hematocrit platelet count, fibrinogen and plasminogen were similar in dogs and in humans. The prothrombin and partial thromboplastin times were considerably shorter in the dog than in man but the thrombin clotting time was comparable. Fibrinolysis was more active in dogs but the levels of fibrin degradation products were low, suggesting that there was no significant fibrin deposition and lysis occurring in vivo.     

Endotoxin-induced changes in the hemostatic system in neonatal calves: the effect of antiserum to a mutant Escherichia coli (J-5)

Changes in the hemostatic system were studied in 22 neonatal calves given a small dosage of Escherichia coli endotoxin (0.5 microgram/kg) by slow (5-hour) IV infusion. The effect of pretreatment with an antiserum to mutant of E coli O111:B4 (J-5) was evaluated. The platelet count, plasma fibrinogen concentration, prothrombin time, and activated partial thromboplastin time changed significantly from base line during and after endotoxin infusions in all calves. The mean platelet count was significantly decreased from 1 through 24 hours after endotoxin infusion was started. Mean plasma fibrinogen was decreased 2 through 12 hours after endotoxin infusion was started. The mean prothrombin time and activated partial thromboplastin time were significantly greater than base line at 3 to 6 hours and 3 to 12 hours, respectively, after endotoxin infusion was started. Serum concentration of fibrinolytic degradation products remained less than 10 micrograms/ml. Bovine J-5 antiserum did not prevent the endotoxin-induced changes in the hemostatic system of these neonatal calves.     

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.     

Changes in the blood coagulation profile after ovariohysterectomy in female dogs

This study investigated changes in the coagulation profile of 10 healthy female dogs subjected to ovariohysterectomy. Blood samples were collected three times--before, directly after and 24 h after surgery. Plasma samples were analyzed to determine thrombin time (TT), prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen content, D-dimer content and antithrombin (AT) III activity. The results revealed post-operative haemostatic system disorders related to prolonged APTT, higher fibrinogen and D-dimer concentrations and lower levels of AT III activity.     

Clinical relevance of monocyte procoagulant activity in horses with colic

Endotoxin-activated monocytes express a thromboplastin-like procoagulant activity on the cell surface that may serve as a focal point for formation of microvascular thrombi. Because coagulopathy is a common sequela to endotoxemia in the equine species, we investigated the ability of monocytes, isolated from horses with colic, to express procoagulant activity. On the day of admission, and on the third and fifth day of hospitalization, monocytes were isolated from 30 adult horses with colic. A coagulation profile, including prothrombin time, activated partial thromboplastin time, thrombin time, and plasma fibrinogen and serum fibrin degradation products concentrations, was determined at each sample collection. The concentration of endotoxin in the plasma was quantitated at the time of admission. Ten clinically normal adult horses served as controls. The procoagulant activity of monocytes isolated from horses with colic was significantly (P less than 0.05) greater than that of the monocytes isolated from clinically normal horses. On the first and third day of hospitalization, the mean prothrombin time was significantly (P less than 0.05) longer in horses with colic, compared with clinically normal horses, and was the most common abnormality in the coagulation profile on the day of admission (25/30; 83%). Mean fibrin degradation products concentration was significantly (P less than 0.05) greater in horses with colic on the day of admission and was the second most common abnormality in the coagulation profile on day 1 (23/30; 77%). In horses with colic, the mean prothrombin and activated partial thromboplastin times were significantly (P less than 0.05) longer in horses that did not survive, compared with horses that survived.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of haemolysis, lipaemia and bilirubinaemia on prothrombin time, activated partial thromboplastin time and thrombin time in plasma samples from healthy dogs

Interferences caused by haemolysis, lipaemia and bilirubinaemia on prothrombin time (PT), activated partial thromboplastin time (APTT) and thrombin time (TT in normal canine plasma samples were studied using commercially available reagents and a steel ball coagulometer. Haemolysis significantly interfered with APTT (P = 0.0076) and TT (P = 0.0292). Regression analysis showed that TT was significantly shortened as haemoglobin concentrations increased. Lipaemia increased as demonstrated by regression analysis. Bilirubin significantly interfered with PT (P=0.0003) and APTT (P=0.002). Although statistically significant, none of the differences found were of clinical relevance.