牛病毒性腹泻—粘膜病病毒（BVDV）的分子生物学研究进展

牛病毒性腹泻—粘膜病病毒(Bovine viral diarrhea—mucosal disease virus,BVDV)是引起牛病毒性腹泻—粘膜病的病原，欧美牛体中普遍存在轻性或隐性感染，与猪瘟病毒(HCV)、羊边界病病毒(BDV)具有1种共同抗原，有交叉反应，牛体中的抗体检出率高。本文通过对BVDV的分子生物学的概述，总结BVDV最新的分子生物学研究进展，为进一步预防和控制BVDV提供理论依据。     

Platelet aggregation in dogs experimentally infected with Rickettsia rickettsii

Platelet aggregation studies were performed on nine Beagle dogs experimentally infected with Rickettsia rickettsia. Platelets from dogs with Rocky Mountain spotted fever tended to be more aggregable than controls.     

Glanzmann thrombasthenia in an Oldenbourg filly

An 18-month-old Oldenbourg filly was presented with a bleeding diathesis. Laboratory testing included platelet count, gingival bleeding time, prothrombin time (PT), activated partial thromboplastin time (aPTT), von Willebrand factor (vWf) antigen, clottable fibrinogen, clot retraction time, PFA-100 closure time, platelet aggregometry (on platelet-rich plasma), and thrombelastography (TEG). TEG was performed by using kaolin and tissue factor as coagulation activators. Expression of the platelet receptor for fibrinogen was assessed by flow cytometry by using anti CD41 (alpha(IIb) or glycoprotein IIb)/CD61 (beta(III) or glycoprotein IIIa) and anti-CD41 antibodies. Abnormal laboratory findings included prolonged oral mucosal bleeding time (>12 hours), prolonged closure time with collagen/ADP (>300 seconds), and absence of clot retraction after 60 minutes. TEG reaction times were similar with kaolin and tissue factor in the patient and a control horse. However, maximum amplitudes in the patient were decreased with both kaolin (43.7 mm; control, 63.9 mm) and tissue factor (37.7 mm; control, 57.8 mm). Platelet aggregation responses to ADP and collagen were profoundly reduced in the affected horse compared with a control. Flow cytometry showed an absence of CD41 and decreased expression of CD41/CD61-reacting antigen on the patient's platelets compared with those from a control horse. The laboratory findings supported a diagnosis of Glanzmann thrombasthenia, likely caused by a mutation in the gene encoding the GPIIb subunit.     

A comparison of platelet parameters in EDTA- and citrate-anticoagulated blood in dogs

BACKGROUND: Platelet aggregates are a common artifact in canine blood. Aggregates may affect the accuracy of platelet counts, with important consequences for patient care. OBJECTIVES: The purpose of this study was to determine if platelet counts in dogs were more accurate if blood was collected into citrate instead of EDTA as an anticoagulant. METHODS: Blood was collected from 50 dogs with neoplasia admitted to the oncology service at Cornell University. EDTA and citrate Vacutainer tubes were filled with blood in random order. Platelet counts and parameters (mean platelet volume [MPV], platelet distribution width [PDW], mean platelet component concentration [MPC], platelet component distribution width [PCDW], and automated platelet clump count [APCC]) were determined using an optical-based hematology analyzer (ADVIA 120). Blood smears from each anticoagulated sample were scored visually for platelet aggregates. RESULTS: The median platelet count was significantly lower (median decrease, 27 x 10(9)/L) in citrate-anticoagulated blood compared with EDTA-anticoagulated blood. This was attributed to platelet activation and aggregation: significantly more aggregates were seen in smears of citrate- than of EDTA-anticoagulated blood. Aggregates were typically small and not detected by the analyzer. Also, the MPV and MPC (or density) were significantly higher (median increase, 3 fL) and lower (median decrease, 33 g/L) in citrate-anticoagulated samples, respectively. CONCLUSIONS: Platelets aggregate, likely from activation, when blood from dogs with neoplasia is anticoagulated with citrate for hematology testing, resulting in lower platelet counts. Citrate also yields inaccurate results for MPV and MPC, likely because of inadequate sphering of platelets. Thus, we recommend that citrate not be used as an anticoagulant when accurate platelet counts are desired in dogs.     

Analysis of a commercial dimethyl‐sulfoxide‐stabilized frozen canine platelet concentrate by turbidimetric aggregometry

Objectives – To assess platelet function of a commercial dimethyl‐sulfoxide (DMSO)‐stabilized frozen platelet concentrate (PC) using turbidimetric aggregometry. Design – In vitro analysis. Setting – Research laboratory in a school of veterinary medicine. Animals – Five units of frozen PC in 6% DMSO were studied. Fresh platelet‐rich plasma (PRP), with and without 6% DMSO, from 6 healthy dogs were used as controls. Interventions – Turbidimetric platelet aggregation was measured after initiation of platelet aggregation by addition of adenosine diphosphate (ADP), collagen, or thrombin at concentrations of 30 μM, 20 μg/mL, and 0.5 U/mL, respectively. Measures were performed at thaw and repeated 2 hours after thaw for the frozen PC. Measurements and Main Results – Compared with PRP, the frozen PC showed decreased aggregation in response to thrombin (amplitude of 84% versus 25%, P=0.01), and collagen (amplitude of 13% versus 3%, P=0.05) but not ADP (6.5% versus 18%, P=0.2). Compared with frozen PC at thaw, the frozen PC at 2 hours after thaw showed decreased aggregation in response to thrombin, collagen, and ADP (P<0.05). There was no difference in aggregation between PRP in 6% DMSO and frozen PC. Conclusions – These in vitro data suggest there is a decrease in platelet response to agonists associated with the freeze‐thaw process in the commercially available 6% DMSO canine frozen PC.     

甘草酸抑制肝星状细胞增殖的分子机制初步研究

目的探讨甘草酸(glycyrrhizin,GL)抑制肝星状细胞(hepatic stellate cell,HSC)增殖的分子机制。方法采用血小板源生长因子-BB(platelet derived growth factor-BB,PDGF-BB)与GL共同处理肝星状细胞系,MTT与流式细胞术检测细胞周期,定量RT-PCR检测PDGF受体β(PDGFreceptorβ,PDGFRβ)的表达情况;用CCl4处理大鼠,制备肝损伤后肝纤维化模型,分离肝组织进行原代培养,定量RT-PCR检测PDGFRβ的表达情况。结果体外研究表明GL抑制PDGF-BB介导的促HSC增殖作用,同时GL还能够抑制HSC中PDGFRβ的表达;体内研究表明CCl4处理可以上调PDGFRβ的转录水平,而GL可以有效抑制此过程。结论PDGFRβ是GL治疗肝纤维化的作用靶点。     

Effects of pentoxifylline, platelet activating factor and prostaglandin F 2-alpha on Giant Panda (Ailuropoda melanoleuca) post-thawed sperm in vitro fertilizing capability

Is it possible that Giant Panda (Ailuropoda melanoleuca) post-thawed sperm fertilization is improved with pentoxifylline (PF), platelet activated factor (PAF) and prostaglandin F 2-alpha (PGF_2α)? In our study Giant Panda post-thawed sperm was incubated in Ham’s F-10 medium with different concentration of PF, PAF and PGF_2α under 37°C. The effects of PF, PAF and PGF_2α on Giant Panda post-thawed sperm fertility were evaluated through sperm motility, survival time, sperm membrane integrity, acrosome state and heterospecific egg penetration. The results were that PF, PAF and PGF_2α all can affect Giant Panda post-thawed sperm in vitro fertilizing capability. In the experiment: 1 mg·mL^?1 PF was most suitable for improving Giant Panda post-thawed sperm in vitro fertilizing capability. In the 1 mg·mL^?1 PF group, sperm survival time was (15.33±4.73) h, the heterospecific egg penetration was 51.44% after incubating for 4 hours, the heterospecific egg penetration was 7.49% after incubating for 6 hours. The results of the 1 mg·mL^?1 PF group were significantly higher than those of the control group (P<0.01). The results were also higher than those of the other treatment groups; Treated Giant Panda post-thawed sperm with 50 ng·mL^?1 PAF had a better effect than 100 ng·mL^?1 PAF, but the sperm fertilizing capability was damaged when incubation time exceeded 2 hours; 50 ng·mL^?1 PGF_2α had no significant effect on Giant Panda postthawed sperm, but when the PGF_2α treated concentration was increased, sperm in vitro fertilizing capability decreased because of the damaged motility and declined acrosomal reaction rate. The conclusions suggest that it is possible to improve post-thawed Giant Panda sperm fertility with 1 mg·mL^?1 PF.     

妊娠三江白猪相关性血小板早孕预测模型与分析

在对４５头配种后的三江白猪的外周血小板数值进行统计分析的基础上,应用聚类分析和非线性回归方法建立了三江白猪相关性血小板早孕预测模型。根据这些模型所确立的方法对１１２头具有正常繁殖机能的配种后的三江白猪进行超早期妊娠诊断的试验,其结果与实际分娩产仔的符合率分别为：模型１：７９．３８％,模型２：８４．５％;模型３：８９．５３％。因此,这些模型所确立的方法,能够准确地预测三江白猪的超早期妊娠情况。     

四种槲皮素水溶性衍生物对凝血酶诱导兔血小板聚集的影响

目的 :研究四种人工半合成槲皮素水溶性衍生物 ,即乙氧基槲皮素、槲皮素磷酸酯 (B)、槲皮素单硫酸酯和槲皮素二硫酸酯对凝血酶诱导兔血小板聚集的影响。方法 :用比浊法检测血小板聚集。结果 :乙氧基槲皮素对血小板聚集无影响 ;槲皮素磷酸酯 (B)、槲皮素单硫酸酯和槲皮素二硫酸酯对血小板聚集有抑制作用 ,IC5 0 分别为 80μ mol/ L、95μ mol/ L和 1 85μ mol/ L。结论 :槲皮素磷酸酯 (B)、槲皮素单硫酸酯和槲皮素二硫酸酯具有抗血小板活性