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1.
OBJECTIVE: To determine the effect of citrate concentration (3.2 vs 3.8%) on coagulation tests in dogs. DESIGN: Original study. ANIMALS: 30 clinically healthy dogs and 12 dogs with hereditary hemostatic disorders. PROCEDURE: Blood was collected from all dogs directly into collection tubes containing 3.2 or 3.8% buffered citrate. Prothrombin time (PT), activated partial thromboplastin time (aPTT), and fibrinogen concentration were measured by use of 3 clot-detection assay systems (2 mechanical and 1 photo-optic). Factor VIII and factor IX coagulant activities (FVIII:C and FIX:C, respectively) were determined by use of a manual tilt-tube method and a mechanical clot-detection device. RESULTS: Significant differences were not detected in median PT, fibrinogen concentration, FVIII:C, or FIX:C between 3.2 and 3.8% citrate for any assay system. A significant prolongation in aPTT for 3.2% citrate, compared with 3.8% citrate, was found in 1 mechanical system. CONCLUSIONS AND CLINICAL RELEVANCE: Citrate concentration does not significantly affect results of most coagulation assays, regardless of assay system. The aPTT was mildly influenced by the citrate concentration, although this was animal-, instrument-, and reagent-dependent. The choice of 3.2 or 3.8% citrate as an anticoagulant for coagulation tests has minimal influence on assay results in healthy dogs or dogs with hereditary hemostatic disorders.  相似文献   

2.
Veterinarians involved in Greyhound rescue have anecdotally observed that 10-15% of Greyhounds bleed profusely after simple surgical procedures. In most patients, platelet counts and hemostasis profiles are normal; therefore, it is possible that these dogs have platelet dysfunction. The PFA-100 is a novel point-of-care platelet function analyzer that has recently been evaluated as a rapid method to assess platelet function in dogs. The objectives of this study were to characterize platelet function in a group of healthy Greyhounds by means of the PFA-100. Blood samples were collected from the jugular vein from 30 healthy Greyhounds. CBC, biochemical profile, PFA-100 assay with collagen/epinephrine (COL-EPI) and collagen/ adenosindiphosphate (COL-ADP), plasma von Willebrand factor antigen concentration (vWF:Ag), and vWF collagen-binding assay (vWF:CBA) were performed. PFA-100 closure times (CTs) with COL/ADP ranged from 63 to 92 seconds (mean +/- SD, 74.7 +/- 7.9 seconds) and with COL/EPI from 87 to 238 seconds (138 +/- 41 seconds); vWF: Ag ranged from 22 to 120% (87.52 +/- 25.5%) and vWF: CBA ranged from 36 to 102% (77.4 +/- 17.3%); and platelet counts ranged from 147 to 265 x 10(9)/L (194.6 +/- 31.64 x 10(9)/L). Greyhound CTs were significantly shorter than CTs in a mixed population of 50 healthy non-Greyhound dogs, in which the COL/ADP CTs ranged from 61 to 172 seconds (mean +/- SD, 87 +/- 21.6 seconds), and the COL/ EPI CTs ranged from 81 to 300 seconds (mean +/- SD, 183 +/- 67.6 seconds; P = 0.005 for COL/ADP CT; P = 0.001 for COL/ EPI CT). Also, platelet counts were significantly lower (P = 0.001) and packed cell volume was significantly higher (P = 0.001) in the Greyhound than in the non-Greyhound group. The PFA-100 is a reproducible method that can be used in the clinical setting to assess platelet function in Greyhounds; however, normal CTs in healthy Greyhounds are shorter than in other breeds. The results obtained in this study will be used to screen for abnormal platelet function in Greyhounds with postoperative bleeding.  相似文献   

3.
OBJECTIVE: To investigate the effects of sodium citrate, low molecular weight heparin (LMWH), and prostaglandin E1 (PGE1) on aggregation, fibrinogen binding, and enumeration of equine platelets. SAMPLE POPULATION: Blood samples obtained from 4 Thoroughbreds. PROCEDURE: Blood was collected into syringes in the ratio of 9 parts blood:1 part anticoagulant. Anticoagulants used were sodium citrate, LMWH, sodium citrate and LMWH, or 300 nM PGE1/ml of anticoagulant. Platelet aggregation in response to ADP, collagen, and PGE1 was assessed, using optical aggregometry. Platelet activation was evaluated, using flow cytometry, to detect binding of fluorescein-conjugated anti-human fibrinogen antibody. Plasma concentration of ionized calcium was measured, using an ion-selective electrode. RESULTS: Number of platelets (mean +/- SEM) in samples containing LMWH (109.5+/-11.3 x 10(3) cells/microl) was significantly less than the number in samples containing sodium citrate (187.3+/-30.3 x 10(3) cells/microl). Increasing concentrations of sodium citrate resulted in reductions in platelet aggregation and plasma concentration of ionized calcium. Addition of PGE1 prior to addition of an agonist inhibited platelet aggregation in a concentration-dependent manner, whereas addition of PGE1 4 minutes after addition of ADP resulted in partial reversal of aggregation and fibrinogen binding. CONCLUSIONS AND CLINICAL RELEVANCE: A high concentration of sodium citrate in blood samples decreases plasma concentration of ionized calcium, resulting in reduced platelet aggregation and fibrinogen binding. Platelets tend to clump in samples collected into LMWH, precluding its use as an anticoagulant. Platelet aggregation and fibrinogen binding can be reversed by PGE1, which may result in underestimation of platelet activation.  相似文献   

4.
BACKGROUND: Some retired racing Greyhounds (RRG) that undergo surgery bleed excessively. Hypothesis: Greyhounds that bleed excessively will have one or more preoperative hemostatic abnormalities that can be used to predict the risk and severity of postoperative bleeding. ANIMALS: Eighty-eight RRG undergoing ovariohysterectomy or castration. METHODS: All dogs were evaluated preoperatively with a physical exam, CBC, platelet count, OSPT, APTT, platelet function with PFA-100(a); fibrinogen, d-dimer, plasminogen (Plmg), antiplasmin (AP), antithrombin (AT), and vWF concentration (vWF:Ag); vWF collagen binding assay (vWF:CBA), and Factor XIII assay. Assays were repeated in the dogs that bled, and in an age- and sex-matched control group of RRG. RESULTS: Twenty-six percent of the dogs had bleeding 36-48 hours after surgery. AP (P <.0001) and AT concentration (P= .007) were significantly lower, and vWF:CBA (P= .0284) was higher preoperatively in the dogs with excessive hemorrhage. A lower platelet count (P= .001) and hematocrit (P= .002), shorter OSPT (P= .0002) and higher plasma fibrinogen (P <.0001), and AP (P= .001) concentration were detected at the time of bleeding compared with preoperative values in the dogs that bleed excessively. The same findings were observed postoperatively for the control group, except for the decrease in hematocrit. CONCLUSIONS AND CLINICAL IMPORTANCE: The results indicate that this excessive postoperative bleeding is not attributable to a primary or secondary hemostatic defect, but could result from altered fibrinolysis.  相似文献   

5.
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.  相似文献   

6.
The objective of the study was to investigate the value of additional tests [platelet count, partial thromboplastin time (PTT), platelet function analysis using the PFA-100, Collagen binding assay (vWF:CBA), and Factor VIII activity], for use in conjunction with the von Willebrand factor antigen enzyme-linked immunosorbent assay (ELISA), as part of a newly developed diagnostic profile for improved characterization of patients with von Willebrand disease (vWD). The study population included 183 clinically healthy canines ranging in vWF:Ag concentration from 1% to 125%. The Asserachrom vWF:Ag ELISA assay was used as an external control for the determination of vWD status. Degree of association between the additional tests and vWF concentration was evaluated, and associations between the additional tests were also assessed, including their ability to distinguish dogs with vWD from those without vWD. In addition, a reference interval was determined for the PFA-100 platelet function analyzer. Strong associations were found between the PFA-100, vWF:CBA, and Asserachrom vWF:Ag assay, and a significant association was found between the PFA-100 and vWF:CBA. An association was detected between Factor VIII activity and the Asserachrom vWF:Ag assay, the vWF:CBA and the PFA-100; however, a corresponding pattern was not visually apparent in the raw data, making the association clinically irrelevant. The association between the platelet count and the PTT with the other additional tests was negligible. Based on our results, the vWF:CBA and PFA-100 would be valuable assets, in conjunction with a vWF:Ag assay, in a canine vWD diagnostic profile to further characterize patients with this disease.  相似文献   

7.
OBJECTIVE: To evaluate the effects of various storage conditions on one-stage prothrombin time (OSPT), activated partial thromboplastin time (APTT), and fibrinogen concentration of canine plasma collected for transfusion. SAMPLE POPULATION: Plasma from 9 dogs. PROCEDURE: Whole blood was collected from dogs by means of jugular venipuncture and centrifuged at 7,300 X g for 20 minutes at 0 C. A plasma extractor was then used to generate plasma. Aliquots of plasma were collected in segments of plastic tubing and in microcentrifuge tubes, and plasma collection bags, tubing segments, and microcentrifuge tubes were immediately frozen at -30 C. Additional tubing segments and microcentrifuge tubes were stored at 2 C. After 1 week of storage, all samples were thawed, and OSPT, APTT, and fibrinogen concentration were measured. Collection bags and microcentrifuge tubes were refrozen at -30 C, and values were measured again 30 days after blood collection. RESULTS: Values for OSPT, APTT, and fibrinogen concentration did not vary significantly with storage time, temperature, or container. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that storage for up to 30 days and at 2 C versus -30 C did not have any significant effect on hemostatic parameters of canine plasma obtained for transfusion.  相似文献   

8.
Albumin concentrations are routinely measured in dogs with bromcresol green (BCG)-binding assays on automated chemistry analyzers. Several variables affect this assay, including the length of reaction time, sample type, and lack of specificity of BCG for albumin. We observed that albumin concentrations measured with BCG appeared higher in heparinized plasma samples in sick dogs. The objective of this study was to determine the effect of anticoagulant and assay procedure on BCG albumin concentrations in clinically ill dogs. We hypothesized that albumin concentrations would be overestimated in heparinized plasma compared with serum because of the combination of heparin and fibrinogen. Furthermore, we hypothesized that the overestimation would be influenced by assay parameters. Blood was collected from 32 clinically ill dogs into tubes containing heparin, citrate, or no anticoagulant. Citrate was chosen to assess the effect of fibrinogen in the absence of heparin. Albumin concentration was measured in all 3 sample types from each dog using 2 different BCG procedures on an automated chemistry analyzer. The BCG procedures (standard and modified) differed in the wavelengths used for absorbance readings (standard, 600/700; modified, 570/505) and the time point at which absorbance was measured (standard, 100 seconds; modified, 40 seconds). In addition, the modified method incorporated a sample blank. Globulin fractions, fibrinogen concentration, and indices of lipemia, hemolysis, and icterus were evaluated for their contribution to the overestimation of albumin concentration in heparinized plasma compared with serum samples. Albumin concentrations were significantly higher (P 相似文献   

9.
OBJECTIVE: To evaluate the use of EDTA tubes for collection of blood samples for assays of secondary hemostasis in dogs. ANIMALS: 108 dogs of various ages, breeds, and sexes (19 healthy and 89 with abnormalities of secondary hemostasis). PROCEDURES: Blood samples were collected via cephalic venipuncture and transferred to sodium citrate tubes and EDTA tubes. Plasma was harvested from each type of tube for assays of concentrations of fibrinogen and D-dimer as well as prothrombin time, activated partial thromboplastin time, and antithrombin activity. Intra-assay and interassay precision and correlation coefficients for all hemostatic tests were calculated for each type of plasma sample. The effect of storage conditions on assay results for the 2 types of plasma samples was also evaluated. RESULTS: Results of hemostatic tests were highly correlated between citrated and EDTA-treated plasma samples. Intra-assay imprecision for all hemostatic tests with the exception of D-dimer concentration was < 10% for both citrated and EDTA-treated plasma samples; interassay imprecision was higher for EDTA-treated versus citrated plasma samples. Storage of plasma samples for 1 hour did not result in significantly different assay results for either type of plasma sample, but storage for 2 hours significantly affected values for EDTA-treated plasma samples. CONCLUSIONS AND CLINICAL RELEVANCE: Although evaluation of the sensitivity and specificity of hemostatic tests that use EDTA-treated plasma samples is required, EDTA may be a suitable alternative to sodium citrate as an anticoagulant for use in hemostatic testing in conditions in which tests could be performed within 1 hour after sample collection.  相似文献   

10.
Background: Accurate determination of commonly measured coagulation values would be useful in the diagnosis and management of coagulopathies in domestic ferrets (Mustela putorius furo). We are unaware of reports of coagulation times in this species. Objectives: The purpose of this study was to determine reference values for prothrombin time (PT), activated partial thromboplastin time (PTT), fibrinogen concentration, and antithrombin (AT) activity in ferrets using selected methods and reagents. Methods: Blood samples obtained from 18 clinically healthy ferrets were anticoagulated with 0.129 M sodium citrate in a ratio of 9 parts blood to 1 part anticoagulant. Plasma was collected and stored at -70 degrees C until analysis. PT and PTT were measured with a fibrometer and with an ACL 3000 automated system. PTT was measured with and without the addition of ellagic acid. Fibrinogen was assayed by a turbidimetric method. AT activity was determined using a chromogenic assay and pooled ferret plasma (100% activity). Differences in methods and reagents were evaluated using paired t tests. Results: PT was significantly longer using the fibrometer (12.3+/-0.3, 11.6-12.7 seconds) compared with the ACL (10.9+/-0.3, 10.6-11.6 seconds) (P<.01). PTT was not significantly different with the fibrometer (18.7+/-0.9, 17.5-21.1 seconds) vs the ACL (18.1+/-1.1, 16.5-20.5 seconds), but was significantly longer on both analyzers when ellagic acid was added (fibrometer 20.4+/-0.8, 18.9-22.3 seconds; ACL 20.0+/-1.0, 18.6-22.1 seconds) (P<.01). Fibrinogen concentration was 107.4+/-19.8 mg/dL (90.0-163.5 mg/dL), and AT activity was 96%+/-12.7% (69.3-115.3%). Conclusion: These coagulation results for healthy ferrets will be useful in the evaluation of ferrets with coagulopathies, provided similar reagents and methods are used.  相似文献   

11.
Background:  Many causes of mortality in the European brown hare, such as bacterial and viral infections, anticoagulant poisoning, and trauma, may result in hemorrhage. There are, however, no reference values concerning blood clotting in this species.  Objectives:  The aim of this study was to determine reference values for blood coagulation times and related parameters in healthy European brown hares.  Methods:  Blood samples from 30 clinically healthy adult hares (15 males and 15 females) were obtained. Hares were physically restrained for blood collection from the cephalic vein into tubes containing citrate and EDTA.  Results:  Mean ± SD were obtained for thrombin time (TT) (13.97 ± 1.37 seconds), prothrombin time (PT) (13.32 ± 2.15 seconds), activated partial thromboplastin time (APTT) (16.73 ± 1.86 seconds), fibrinogen concentration (2.98 ± 1.06 g/L), and platelet count (355.28 ± 128.73 × 109/L). Conclusions: Reference values for blood coagulation times and other parameters associated with blood clotting will be useful in the laboratory evaluation of hemorrhage in the European brown hare.  相似文献   

12.
OBJECTIVE: To evaluate a point-of-care coagulation analyzer (PCCA) in dogs with coagulopathies and healthy dogs. ANIMALS: 27 healthy and 32 diseased dogs with and without evidence of bleeding. PROCEDURE: Prothrombin time (PT), activated partial thromboplastin time (aPTT), and activated clotting time (ACT) were determined, using a PCCA and standard methods. RESULTS: Using the PCCA, mean (+/- SD) PT of citrated whole blood (CWB) from healthy dogs was 14.5+/-1.2 seconds, whereas PT of nonanticoagulated whole blood (NAWB) was 10.4+/-0.5 seconds. Activated partial thromboplastin time using CWB was 86.4+/-6.9 seconds, whereas aPTT was 71.2+/-6.7 seconds using NAWB. Reference ranges for PT and aPTT using CWB were 12.2 to 16.8 seconds and 72.5 to 100.3 seconds, respectively. Activated clotting time in NAWB was 71+/-11.8 seconds. Agreement with standard PT and aPTT methods using citrated plasma was good (overall agreement was 93% for PT and 87.5% for aPTT in CWB). Comparing CWB by the PCCA and conventional coagulation methods using citrated plasma, sensitivity and specificity were 85.7 and 95.5% for PT and 100 and 82.9% for aPTT, respectively. Overall agreement between the PCCA using NAWB and the clinical laboratory was 73% for PT and 88% for aPTT. Using NAWB for the PCCA and citrated plasma for conventional methods, sensitivity and specificity was 85.7 and 68.4% for PT and 86.7 and 88.9% for aPTT, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: The PCCA detected intrinsic, extrinsic, and common pathway abnormalities in a similar fashion to clinical laboratory tests.  相似文献   

13.
The objective of this study was to use a questionnaire 1) for characterization of hemorrhagic signs; 2) to assess its value as a predictor of von Willebrand Disease (vWD) status; and 3) for evaluation of the vWD diagnostic profile [platelet function analysis using the PFA-100, Collagen binding assay (vWF:CBA), and vWF antigen ELISA (vWF:Ag)], partial thromboplastin time (PTT) and Factor VIII activity (FVIII) as predictors of hemorrhagic risk. von Willebrand factor (vWF) concentration and function was assessed for each of the 165 canine participants using the vWD diagnostic profile. Hemorrhagic signs for each dog were obtained using a standardized questionnaire. Questionnaires were scored according to a previously prepared scoring key. Of the 165 dogs in the study, 43.6% had a low vWF concentration, with only 48.6% of dogs in this group having reports of hemorrhagic signs. Oral bleeding was the most commonly reported sign. The questionnaire had a sensitivity of 48.6% and a specificity of 78.5% for the prediction of vWD status. Using the Spearman correlation coefficient, a statistical association was found between the questionnaire and the vWD diagnostic profile components. However, this could not be translated into an ability to predict hemorrhage. The questionnaire allowed characterization of hemorrhagic signs in a large population of dogs over a range of vWF:Ag concentrations, and demonstrated that the vWD diagnostic profile was unsuccessful in the prediction of hemorrhagic risk. Although the sensitivity was insufficient for a screening tool, the questionnaire did have some discriminatory power in the prediction of vWD status.  相似文献   

14.
Background: Thrombelastography (TEG) and indicators of secondary and tertiary hemostasis might be altered in dogs with endotoxemia. Hypothesis: Endotoxemia influences measures of coagulation in dogs. Animals: Ten healthy cross‐bred dogs. Material and Methods: Prospective laboratory study between controls (n = 5) receiving 0.9% saline IV and the study group (n = 5) treated with low‐dose lipopolysaccharide (0.02 mg/kg IV). Physical examination and sampling for measurement of leukocytes, platelets, and coagulation variables were performed at time points 0, 1, 4, and 24 hours. Coagulation variables included kaolin‐activated TEG, 1‐stage prothrombin time (OSPT), activated partial thromboplastin time (aPTT), fibrinogen, factor VIII, antithrombin, protein C, protein S, activated protein C (APC)‐ratio calculated from aPTT with and without presence of APC), and D‐Dimers. Results: Endotoxemia‐induced clinical signs included lethargy (n = 5/5), diarrhea (n = 4/5), emesis (n = 4/5), and abdominal pain (2/5). After 1 hour there was severe leukopenia (2.5 ± 0.7 × 109/L; mean ± SD, P < .0001) and a 2.2‐fold increase in D‐Dimers (0.81 ± 0.64 mg/L, P < .0001). After 4 hours there was hyperthermia (40.3 ± 0.4°C, P < .0001) and increases in OSPT (10.5 ± 2.7 seconds, P < .0001), aPTT (16.7±5.2 seconds, P= 0.002). A significant decrease in fibrinogen (1.5±1.0 g/L, P= 0.001), protein C (31 ± 33%, P <.0001), protein S (63 ± 47%, P < .0001), TEG α (58 ± 19, P= .007), and TEG maximal amplitude (50 ± 19 mm, P= .003) was seen compared with the controls. APC‐ratio rose significantly (2.5 ± 0.2, P < .0001) without exceeding the reference interval (n = 4/5). Conclusion and Clinical Importance: D‐Dimers are the earliest indicator for endotoxemia‐associated coagulation abnormalities followed by decreased protein C concentration. APC‐ratio and TEG were not good screening variables.  相似文献   

15.
OBJECTIVE: To compare prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen concentration in canine blood samples collected via an indwelling IV catheter and direct venipuncture. ANIMALS: 35 dogs admitted to an intensive care unit that required placement of an IV catheter for treatment. PROCEDURES: Blood samples were collected via IV catheter and direct venipuncture at the time of catheter placement and 24 hours after catheter placement. Prothrombin time, APTT, and fibrinogen concentration were measured. RESULTS: 5 dogs were excluded from the study; results were obtained for the remaining 30 dogs. Agreement (bias) for PT was -0.327 seconds (limits of agreement, -1.350 to 0.696 seconds) and 0.003 seconds (limits of agreement, -1.120 to 1.127 seconds) for the 0- and 24-hour time points, respectively. Agreement for APTT was -0.423 seconds (limits of agreement, -3.123 to 2.276 seconds) and 0.677 seconds (limits of agreement, -3.854 to 5.207 seconds) for the 0- and 24-hour time points, respectively. Agreement for fibrinogen concentration was -2.333 mg/dL (limits of agreement, -80.639 to 75.973 mg/dL) and -1.767 mg/dL (limits of agreement, -50.056 to 46.523 mg/dL) for the 0- and 24-hour time points, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Agreement between the 2 techniques for sample collection was clinically acceptable for PT, APTT, and fibrinogen concentration at time 0 and 24 hours. It is often difficult or undesirable to perform multiple direct venipunctures in critically ill patients. Use of samples collected via an IV catheter to monitor PT and APTT can eliminate additional venous trauma and patient discomfort and reduce the volume of blood collected from these compromised patients.  相似文献   

16.
OBJECTIVE: To assess the effect of desmopressin (DDAVP) administration in Doberman Pinschers with type 1 von Willebrand disease (vWD) on plasma von Willebrand factor (vWF) multimers through determination of vWF collagen binding activity (vWF:CBA; a functional vWF assay dependent on the presence of high-molecular-weight [HMWI multimers), comparison of vWF antigen concentration (vWF:Ag) to vWF:CBA, and vWF multimer size distribution. ANIMALS: 16 Doberman Pinschers with type 1 vWD and 5 clinically normal control dogs. PROCEDURE: Plasma vWF:Ag and vWF:CBA assays and vWF multimer analysis were performed before and 1 hour after administration of DDAVP (1 microg/kg, SC). RESULTS: Following DDAVP administration, dogs with type 1 vWD had an increase in mean baseline values of plasma vWF:Ag and vWF:CBA from 10% to 17% for both variables. The mean vWF Ag:CBA ratio at baseline (0.95) was similar after DDAVP administration (0.97), indicating concordant increases in plasma vWF concentration and activity. In control dogs, mean plasma vWF:Ag and vWF:CBA increased from baseline values of 64% to 113% and 58% to 114%, respectively, and the vWF Ag:CBA ratios were unchanged (1.1 vs 1.0) after DDAVP administration. Plasma vWF multimer analysis revealed proportional increases in band intensity for all multimer sizes following DDAVP administration, in comparison to baseline for the control dogs and Doberman Pinschers with vWD, consistent with vWF Ag:CBA ratios of approximately 1. CONCLUSIONS AND CLINICAL RELEVANCE: Beneficial effects of DDAVP on primary hemostasis in Doberman Pinschers with type 1 vWD cannot be explained by preferential increases in HMW vWF multimers.  相似文献   

17.
The present study was to assess the effect of storage conditions on prothrombin time (PT), activated partial thromboplastin time (aPTT) and fibrinogen concentration in blood samples of healthy dogs. Thirty-five dogs of various breeds were included in the study. Citrated blood samples were obtained and plasma was divided into four aliquots to assess selected clotting parameters by means of a coagulometer. The first aliquot was analysed within 1 h after collection, while the remaining 3 were stored at 8℃ for 4, 8 and 24 h, respectively. One-way repeated measures analysis of variance documented a significant decreasing effect on PT at 24 h compared to 8 h and on fibrinogen concentration after 8 and 24 h compared to sampling time and at 4 and 24 h compared to 8 h post sampling. In conclusion, the results of this study indicate that only fibrinogen appears prone to significant decrease. In fact, aPTT is not substantially affected by refrigeration for at least 24 h post sampling and PT showed a statistical difference that does not necessary indicate biological significance as the results obtained were within reference intervals for the dog.  相似文献   

18.
During a study period from 1985 through 1988, plasma von Willebrand's factor antigen (vWF:Ag) concentration was measured as a marker for prevalence of the von Willebrand's disease (vWD) trait in Doberman Pinschers (doberman, n = 5,554), Scottish Terriers (scottie, n = 1,363), and Shetland Sheepdogs (sheltie, n = 4,279). Significant increase in prevalence of the trait was seen in scotties and shelties during this period. In 1988, 73% of dobermans, 30% of scotties, and 28% of shelties tested had abnormal vWF:Ag concentration (less than 50% vWF:Ag). We found significant differences between breeds with respect to age and vWF:Ag concentration of clinically affected dogs at time of diagnosis. The affected dobermans were older (doberman mean age, 4.6 years; scottie mean age, 1.7 years; sheltie mean age, 1.9 years) and had higher concentration of plasma vWF:Ag (doberman mean vWF:Ag, 15%; scottie mean vWF:Ag, 0%; sheltie mean vWF:Ag, 8%). Bleeding in affected dogs of all 3 breeds was observed predominantly from mucosal surfaces and from cutaneous sites of surgery or trauma. The most common site of mucosal bleeding in scotties and shelties was oral or nasal cavity, and in dobermans was the urogenital tract. Differences in clinical manifestations of vWD in purebred dogs may reflect heterogeneous defects within the vWF gene, causing a variety of abnormalities in production, structure, and function of vWF protein. Analogous to vWD in human beings, acquired deficiencies of vWF may also contribute to the clinical variability of vWD in dogs.  相似文献   

19.
BACKGROUND: Few studies have been done to evaluate anticoagulants for use with blood samples from birds and reptiles. Heparin currently is the most commonly used anticoagulant in practice, but may adversely affect blood cell staining and quantitation. OBJECTIVE: The purpose of this study was to evaluate the effects of lithium heparin, K3-EDTA, and sodium citrate, with and without the addition of albumin, on hematologic variables in macaw (Ara sp) and python (Python molurus bivittatus) blood samples. METHODS: Blood samples from 10 macaws and 10 Burmese pythons were collected in heparin-coated syringes and placed into tubes containing either lithium heparin, K3-EDTA, or sodium citrate with and without the addition of 0.25 mL of a 22% bovine serum albumin solution. Cell lysis was determined by counting the number of lysed cells/200 WBCs in Wright's-Giemsa-stained blood smears and by qualitative evaluation of pink plasma in microhematocrit tubes. A CBC was done after 3, 12, and 24 hours of storage at 4 degrees C in anticoagulant-containing tubes and results were compared with those obtained at 0 hour for the heparin-coated syringe sample. A biochemical panel also was done at each time point in similarly stored lithium-heparin samples. RESULTS: Hemolysis was significantly increased in citrated samples from both macaws and pythons beginning at 12 hours. At 24 hours, 19 of 30 (63%) macaw samples in all anticoagulants had >100 lysed cells/200 WBCs. There were no significant differences in hematologic values in samples from pythons collected in heparin or EDTA at any time point. No significant differences were found in the number of lysed cells or in other hematologic data in samples with albumin. Glucose concentration decreased and potassium concentration increased significantly over time in heparinized blood samples. CONCLUSIONS: Based on the results of this study, whole blood samples anticoagulated with lithium heparin or EDTA should be evaluated within 12 hours (macaws) or 24 hours (pythons) of collection and stored at 4 degrees C for best results. Citrate should be avoided as it may result in increased cell lysis. The addition of albumin does not prevent cell lysis.  相似文献   

20.
OBJECTIVE: To develop an assay to measure canine von Willebrand factor (vWF):collagen-binding activity (CBA) to screen for type 2 von Willebrand disease (vWD) in dogs. SAMPLE POPULATION: 293 plasma samples submitted for analysis of canine vWF antigen (vWF:Ag) and 12 control plasma samples from dogs with inherited type 2 or 3 vWD. PROCEDURE: Bovine collagens were evaluated for suitability as binding substrate for vWF. Assay sensitivity to depletion, proteolytic degradation, or a genetic deficiency of high-molecular-weight vWF were determined. Amounts of vWF:Ag and vWF:CBA were measured. The ratio of vWF:Ag to vWF:CBA was used to discriminate between type 1 and type 2 vWD. RESULTS: An assay for canine vWF activity was developed by use of mixed collagen (types I and III). When vWF:Ag was used to subtype vWD, 48% of the dogs were classified as clinically normal, 9% as indeterminate, and 43% as type 1 vWD. Inclusion of vWF activity resulted in reclassification of 5% of those identified as type 1 to type 2 vWD. However, vWF:CBA of the reclassified dogs was not persistently abnormal, a finding compatible with acquired type 2 vWD. Some Doberman Pinschers had lower antigen-to-activity ratios than other breeds with type 1 vWD, suggesting that Doberman Pinschers have more functional circulating vWF. CONCLUSIONS AND CLINICAL RELEVANCE: Analysis of canine vWF activity should be included among the vWF-specific assays used to confirm type 2 vWD. The prevalence of inherited forms of type 2 vWD in screened dogs is lower than acquired forms that can result secondary to underlying disease.  相似文献   

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