Evaluation of the in Vitro Anti-Atherogenic Properties of Lipid Fractions of Olive Pomace,Olive Pomace Enriched Fish Feed and Gilthead Sea Bream (Sparus aurata) Fed with Olive Pomace Enriched Fish Feed

Given the pivotal role of Platelet-Activating-Factor (PAF) in atherosclerosis and the cardio-protective role of PAF-inhibitors derived from olive pomace, the inclusion of olive pomace in fish feed has been studied for gilthead sea bream (Sparus aurata). The aim of the current research was to elucidate the anti-atherogenic properties of specific HPLC lipid fractions obtained from olive pomace, olive pomace enriched fish feed and fish fed with the olive pomace enriched fish feed, by evaluating their in vitro biological activity against washed rabbit platelets. This in vitro study underlines that olive pomace inclusion in fish feed improves the nutritional value of both fish feed and fish possibly by enriching the marine lipid profile of gilthead sea bream (Sparus aurata) with specific bioactive lipid compounds of plant origin.     

Platelet transfusion in thrombocytopenic horses

Platelet transfusions might be indicated in horses with thrombocytopenia. The need for a transfusion cannot be determined by platelet numbers alone, as primary or co‐existing disease processes, platelet function and age of the recipient also need to be considered. In patients with no co‐morbidities, relevant bleeding is uncommonly observed with platelet counts >10 x 10⁹/l and a therapeutic approach with initiation of treatment when signs of bleeding are observed might be justified.     

Vortex mixing of feline blood to disaggregate platelet clumps

Abstract: Platelet clumping is a common cause of erroneous platelet counts in cats. Mixing of blood with a vortex mixer was evaluated as a method to disaggregate platelet clumps in feline blood and thus obtain accurate platelet counts. Whole blood samples from 42 cats with platelet clumping and 10 control cats without platelet clumping were mixed for 1 minute at the maximal setting using a standard vortex mixer. Blood smears (for subjective assessment of the type and amount of platelet clumping), platelet counts, and total leukocyte counts were evaluated before and after mixing. Vortex treatment of blood samples with platelet clumps caused an increased platelet count in all but 1 sample. Although most samples had strong increases in platelet counts after mixing, only a minority of samples (5 of 42) appeared to have all platelet clumps dispersed. Of 39 feline blood samples with platelet counts initially <200×10⁹ cells/L, 23 counts increased to >200×10⁹ cells/L and 34 counts increased to >100×10⁹ cells/L. Overall, mixing gave inconsistent and partial improvement in platelet counts. Total leukocyte counts were not significantly affected by vortex mixing. Vortex mixing of 10 feline blood samples without platelet clumping had no consistent effect on platelet or WBC counts. In conclusion, vortex mixing of feline blood does not appear to be a consistent means of correcting the problem of feline platelet clumping.     

Alterations in normal canine platelets during storage in EDTA anticoagulated blood

Abstract: Flow cytometric detection of platelet surface-associated IgG (PSAIgG) can be used to determine whether immunologic factors are contributing to thrombocytopenia in dogs. In vitro alterations in platelet activation and morphology, however, could impact the results of this test. The purpose of this study was to determine whether the PSAIgG test for immune-mediated thrombocytopenia was valid on whole blood in EDTA anticoagulant after 24–72 hours of storage, and to characterize other alterations in canine platelets that could impact immunologic testing. Platelets were harvested and analyzed immediately after blood collection and after 24, 48, and 72 hours of storage at 4°C. Spontaneous and thrombin-induced changes in the following platelet parameters were evaluated using flow cytometric techniques: PSAIgG, platelet microparticle formation, membrane expression of P-selectin and glycoprotein CD61, exogenous IgG binding, surface-exposed phosphatidylserine, and fibrinogen binding. The amount of PSAIgG increased 6-to 9-fold in stored samples compared with fresh samples. Platelet microparticle formation was spontaneous in stored samples and increased significantly over time. Membrane phosphatidylserine, P-selectin, and fibrinogen binding were not altered by storage, indicating that platelet activation was minimal in stored samples. Although storage decreased the percentage of platelets positive for CD61 by 8-to 10-fold compared with fresh samples, activation by high-dose thrombin partially restored the percentage of CD61-positive platelets in 24-hour-old samples. In conclusion, even though platelets stored in EDTA for up to 72 hours remain in a resting state, aged platelets have an increased tendency to form microparticles and have increased surface IgG and decreased surface CD61, which may contribute to false-positive results for tests of immune-mediated thrombocytopenia.     

Prevalence of low automated platelet counts in cats: comparison with prevalence of thrombocytopenia based on blood smear estimation

Abstract: True thrombocytopenia is uncommon in cats; however, low platelet counts frequently are found using automated cell counters. Although this discrepancy is a well known problem, the prevalence of low automated platelet counts in feline blood samples has not been documented. We retrospectively compared the prevalence of low automated platelet counts with low blood smear-estimated platelet counts in feline blood samples. Results of blood sample analysis from 359 cats during a 1-year period at the University of Glasgow Veterinary Haematology Laboratory were examined. Smear estimates of platelet number were done in those cases in which records did not indicate adequate platelet numbers. Platelet counts obtained with an impedance counter (Minos Vet, Abx Hematologie) were <200×10⁹ cells/L in 256 samples (71%) and <50×10⁹ cells/L in 43 samples (12%). However, based on estimation of platelet numbers from blood smears, only 11 samples (3.1%) had platelet counts of <200×10⁹ cells/L and 9 samples (2.5%) had counts of <50×10⁹ cells/L. Four cats with thrombocytopenia estimated by blood smear evaluation had clinical signs of a bleeding disorder. Disorders associated with thrombocytopenia included neoplasia, cytotoxic chemotherapy, and infectious diseases. There was no evidence that delay due to mailing of samples was associated with lower automated platelet counts than would have been obtained on the day of sampling. The high prevalence of apparent thrombocytopenia in automated platelet counts was attributed to a combination of platelet aggregation and the impedance method of cell differentiation by size. Vigilance and careful examination of blood smears is required to identify the few cats with true thrombocytopenia.     

东北梅花鹿血液有形成分电子显微镜观察

东北梅花鹿血液有形成分的种类及基本结构与其他哺乳动物类似.其本身特点:红细胞形态除有圆饼状外,还含有一定数量的所谓“圆口状”细胞,红细胞无核,胞质均质,电子密度较高;中性粒细胞的嗜中性颗粒有椭圆形、圆形和杆状等多种形态,而且电子密度低;嗜酸粒细胞的嗜酸性颗粒只有一种,颗粒为圆球状,不含有蛋白结晶体;嗜碱粒细胞数量极少,其颗粒的数量亦较少,颗粒内含有更微细的小颗粒;血小板无核,内含有两种颗粒,即①特殊颗粒,数量较多,基质电子密度较高,②致密颗粒,数量较少,含有致密芯,呈牛眼状;此外胞质还有少量的线粒体和大量的核糖体等.     

Primary hemostasis

Objective: To review the current understanding of the mechanisms responsible for primary hemostasis and to give an overview of primary hemostatic syndromes in small animal patients. Current and future therapeutic options for dysfunction of primary hemostasis are discussed. Data sources: A thorough search of the human and veterinary literature using the keywords platelets, primary hemostasis, von Willebrand factor (vWF), von Willebrand disease, aspirin, thromboxane, and aggregation, were performed. Databases searched included OVID Medline, Pubmed, and CAB abstracts. Conclusions: Primary hemostasis occurs when platelets adhere to an injured or disrupted endothelial surface. Adherence is followed by activation, or the release of platelet granule contents. The agonists released from platelet granules recruit additional platelets and induce their activation and aggregation. Adhesion, activation, and aggregation are mediated by different receptors and ligands depending on the local blood flow conditions. vWF and adenosine diphosphate are the primary mediators of adhesion, activation, and aggregation under high shear conditions. During low shear conditions collagen, fibronectin, and laminin mediate adhesion, thromboxane A₂ promotes activation, while aggregation is mediated by glycoprotein Ib‐IX‐V (GP Ib–IX–V) and fibrinogen. Knowledge of the receptor interactions during different blood flow conditions is crucial to the understanding of the various inhibitors of primary hemostasis available to clinicians.     

Automated analysis of feline platelets in whole blood,including platelet count,mean platelet volume,and activation state

A new whole-blood flow cytometric method has been developed for counting and sizing platelets in samples from cats, a species in which platelet and red blood cell sizes overlap significantly. The method is a modified version of the two-angle laser light scattering technology used by Bayer H*System hematology analyzers. The new method provided accurate platelet counts and mean platelet volumes (MPV, fl) for cats. The method also measured mean platelet component concentration (MPC, g/dl), a parameter which was shown to be sensitive to platelet activation state, and which decreased in value as activation progressed.