血小板数与巨核细胞、转化生长因子β1在川崎病动物模型中的动态变化

[目的]动态观察血小板数(PLT)、巨核细胞、转化生长因子β1(TGF-β1)在幼兔免疫性血管炎中的变化.[方法]用牛血清白蛋白复制幼兔免疫性血管炎的川崎病(KD)动物模型,每隔4 d分别检测血小板数、巨核细胞计数及分类、TGF-β1;并于d17、d28取冠状动脉、肝、脾、肾、脑等组织作病理学分析.[结果]PLT、巨核...     

Abnormal platelet function in C3-deficient mice

Summary.  Background and Objectives:  The complement system is a biochemical cascade composed of several plasma proteins that can interact with endothelial cells and blood cells, including platelets. In order to investigate the effect of the complement system on platelets, we studied platelet function in C3-deficient mice that lack complement activity. Method and Results:  Tail-cut bleeding time was prolonged and platelet aggregation in response to protease-activated receptor-4 (PAR4) peptide was decreased in C3-deficient mice as compared with wild-type littermates. Platelet aggregation in response to other agonists (ADP and collagen) was similar between C3-deficient mice and their normal littermates. Isolated platelets from wild-type mice aggregate less in C3-deficient plasma than in normal plasma, and, conversely, addition of plasma from wild-type mice or plasma-purified C3 improved aggregation of C3-deficient platelets. We also monitored the formation of murine arteriole or venule thrombi in an intravital microscopy thrombosis model. We found that C3-deficient mice had a significantly delayed thrombotic response in arterioles as compared with their wild-type littermates. Furthermore, thrombi in C3-deficient mice were less stable and embolized more frequently than those in wild-type mice. Conclusions:  Platelets of C3-deficient mice have subnormal function, resulting in a prolonged tail-cut bleeding time and delayed thrombosis after vessel wall injury.     

Pennogenin glycosides with a spirostanol structure are strong platelet agonists: structural requirement for activity and mode of platelet agonist synergism

Summary.  Background : Steroidal saponins have long attracted scientific attention, due to their structural diversity and significant biological activities. For example, total steroidal saponins extracted from the rhizome of Paris polyphylla Sm. var. yunnanensis (TSSPs) constitute an effective treatment for abnormal uterine bleeding. Objective : To determine the active constituents in TSSPs and elucidate the mechanisms that underlie their in vivo pharmacologic actions on hemostasis. Methods : Steroidal saponins were purified by chromatography, and their effects upon hemostasis and platelet function were evaluated by tail bleeding time in mice and rats, aggregometry, flow cytometry and Western blotting. Results : TSSPs promoted hemostasis in vivo and dose-dependently induced rat or human platelet aggregation in vitro . Using bioassay-guided separation, four known pennogenin glycosides with a spirostanol structure were identified as the active ingredients of TSSPs. A structure–activity assay showed that the aglycone and sugar moieties of pennogenin glycosides are both essential for their aggregatory activity. Their synergistic actions on platelet aggregation were observed with pennogenin glycosides and with other known platelet agonists, suggesting that these glycosides are platelet agonists. Aggregation in response to the pennogenin glycosides involved α_IIbβ₃ activation, was inhibited by cAMP, was dependent upon extracellular calcium, secreted ADP and thromboxane synthesis, and was mediated by phosphatidylinositol-3-kinase. Conclusion : We identified pennogenin glycosides with a spirostanol structure as the active ingredients of Paris polyphylla Sm. var. yunnanensis in promoting hemostasis in vivo . Their mode of their action on platelets suggests that they represent a new type of platelet agonist.     

Coronary heart disease is associated with mean platelet volume in type 2 diabetic patients

Background: Mean platelet volume (MPV) is an indicator of platelet activation which is a central process in the pathophysiology of coronary heart disease (CHD). The aim of the study was twofold; first to determine whether MPV values is increased in patients with DM, and secondly to evaluate the relation between diabetic complications and MPV. Methods: The study population included 258 patients divided into two groups. Group A composed of 158 type 2 diabetic patients with coexistent coronary artery disease (stenotic lesions of 50%) (78 women, 80 men; mean age 53.9_10.8; mean diabetes duration 13.1_6.0). One hundred subjects (48 women, 52 men; mean age 53.9_11) without type 2 diabetes with normal coronary angiographies were taken as the control group (group B). To evaluate the extension of CHD, Gensini scoring system was used. Results: The MPV was significantly different in the patient group compared to the controls (9.79 ± 1.5 fl vs 8.3 ± 0.9 fl, P<0.001). The existence of CHD was associated with MPV with odds ratio (95% CI) of 2.31 (1.55–4.42, p50.001). Conclusion: We have found that diabetic patients with coronary heart disease have significantly higher MPV values compared to control subjects without diabetes and with angiographically normal coronary arteries.     

Expression of platelet-derived endothelial cell growth factor and vascularity in the nasal mucosa from allergic rhinitis.

BACKGROUND: Angiogenesis plays critical roles in various pathological mechanisms. It has been hypothesized that the vascularity in allergic nasal mucosa is different from that in normal mucosa, and that changes in the vascular network contributes the pathogenesis of allergic rhinitis. OBJECTIVE: To determine whether hypervascularity and overexpression of the platelet-derived endothelial cell growth factor (PD-ECGF), an angiogenic factor, are found in allergic nasal mucosa and whether these two factors are associated with the allergic reaction. METHODS: We investigated the expression of PD-ECGF and counted microvessels in 51 nasal mucosae (30 samples from patients with allergic rhinitis and 21 samples as control from normal subjects) using an immunohistochemical technique. RESULTS: PD-ECGF expression in allergic nasal mucosae was significantly higher than that in control mucosae at the interstitium of the lamina propria (P = 0.0024) and nasal gland (P = 0.024). PD-ECGF positive areas were coincident with areas of high vascularity in the sections. The microvessel count in the lamina propria of allergic mucosae was higher than that of control mucosae (P = 0.050). Regarding the correlation with various clinical factors, the total nasal symptom score was significantly associated with both the PD-ECGF expression in the interstitium of the lamina propria (P < 0.05) and in the nasal gland (P < 0.005), as well as with the number of vessels (P < 0.05). CONCLUSION: PD-ECGF and hypervascularity in the nasal mucosa may be involved in the pathogenesis of allergic rhinitis.     

缺血性中风与血小板颗粒膜蛋白关系的观察

目的：探讨血小板颗粒膜蛋白（ＧＭＰ１４０）在缺血性中风患者发病过程中的作用。方法：对３０例缺血性中风患者（观察组）和３０例健康体检者（健康对照组）采空腹静脉血３ｍｌ，用酶联免疫吸附双抗体夹心法测定血小板ＧＭＰ１４０含量。结果：缺血性中风患者的血小板ＧＭＰ１４０含量〔（６０．８５±６６．４２）μｇ／Ｌ〕明显高于健康对照组〔（１６．１８±１２．１３）μｇ／Ｌ〕，差异显著（Ｐ＜０．００１）。结论：缺血性中风患者血小板活化程度增高，在血栓形成过程中起重要作用；测定ＧＭＰ１４０含量可作为诊治缺血性中风的血液学指标之一。     

Mononuclear cell reactivity to food allergens in neonates, children and adults

A model of antigen‐specific T‐cell proliferative responses based on reciprocal patterns of responses to dietary and inhalant allergens has been suggested, the former being frequent in infancy but rare in adults, whereas the latter are preserved and expand between infancy and adulthood. We have evaluated the age‐related variations of mononuclear cell reactivity to food allergens. The cord blood mononuclear cells (CBMC) of 30 neonates without family history of atopy and the peripheral blood mononuclear cells (PBMC) of 20 healthy children and of 40 healthy adults were stimulated in vitro with β‐lactoglobulin (BLG) or ovalbumin (OVA) and the cultures were harvested after 7 days. Neonates, children and adults were compared for the percentages of positive responses and for the magnitude of response. Adult subjects showed significantly lower percentages of positive responses and reduced magnitude of response than those observed in neonates and children either in BLG or in OVA cultures. We have not observed a decrease of food allergen mononuclear cell reactivity between neonates and children for the frequency of positive responses. The magnitude of response of neonates was significantly lower than that of children in BLG cultures . Our results seem to confirm the loss of mononuclear cell reactivity to food allergens in adult age. However, other reports show conflicting data. We suggest that a rigorous standardization of the methodological steps of in vitro mononuclear cell stimulation with allergen is necessary.     

内毒素休克后家兔血管反应性的变化规律及器官差异

目的 了解内毒素休克后血管反应性的变化规律及器官差异.方法 家兔48只,随机分为6组,依次为正常对照组、给内毒素(LPS)后0.5、1、2、4、6小时组,分别测定各组肠系膜上动脉(SMA)、腹腔动脉(CA)和左肾动脉(LRA)离体血管环对去甲肾上腺素(NE)、乙酰胆碱(Ach)的收缩和舒张反应性.结果 内毒素休克后SMA对NE的收缩反应性早期轻度升高,晚期显著下降,对Ach的舒张反应性早期显著升高,晚期显著下降;CA对NE的收缩反应性早期显著升高,晚期显著下降,对Ach反应性呈持续高反应,峰值在早期;LRA认对NE的收缩反应性早期显著升高,晚期显著下降,对Ach的反应性早期显著升高,晚期无明显变化.结论 内毒素休克血管反应性呈现一定器官差异,这种差异可能与内毒素休克血流动力学改变及血液重分布有关.     

颅脑损伤急性期血小板参数的变化及其与继发性脑损害的关系

目的探讨颅脑损伤后患者血小板（PLT）参数的变化及其与继发性脑损害的关系。方法伤后24h内入院的非手术治疗的颅脑损伤患者163例，分别于伤后1d、3d及14d三个时间段采血测定外周血PLT数量、PLT平均体积（MPV）、PLT体积分布宽度（PDW）；于入院时、伤后1d、伤后7d进行GCS评分，并通过CT计算脑出血量及脑水肿体积；伤后6个月进行GOS预后评分。分析上述指标与PLT计数、MPV和PDW之间的关系。同时测定40例健康体检者外周血的PLT计数、MPV和PDW作为对照。结果伤后1d及3dPLT计数较对照组明显下降，MPV和PDW值明显增加（P〈0．05）；伤后14dPLT计数、MPV和PDW值均恢复正常；GCS〈8分者PLT计数明显低于GCS≥8分者，而MPV和PDW则明显高于GCS≥8分者（P〈0．05）；脑水肿体积伤后逐渐扩大，至伤后7d时水肿体积最大（P〈0．05）；脑水肿体积与PLT计数呈负相关关系（r＝-0．238，P〈0．05），与MPV和PDW的值呈正相关关系（r＝642、0．593，P〈0．05）；GOS评分与外周血PLIT计数呈正相关（r=0．883，P〈0．05），而与MPV和PDW值呈负相关（r=-0．235、－0．267，P〈0．05）。结论本结果提示，颅脑损伤后PLT参数的变化可能与伤后继发性脑损害有关；检测其变化有助于对颅脑损伤伤情、预后的判断，并为颅脑损伤治疗提供新思路。