冠心病患者低密度脂蛋白与血小板GMP-140水平相关性研究

目的:探讨冠心病患者低密度脂蛋白与血小板功能活化产物GMP-140的关系。方法:应用酶联免疫分析法对120例研究对象进行了血浆LDL、GMP-140水平的测定,其中包括急性冠脉综合征组40例,稳定性心绞痛组40例,并与40例正常健康人作比较。结果:ACS患者血浆LDL和GMP-140水平均非常显著的高于正常人组(P<0.01),ACS组又高于SAP组(P<0.05),且血浆LDL与GMP-140水平呈正相关。结论:检测CHD患者血浆LDL和GMP-140水平的变化对CHD的发生和发展以及疗效和预后观察均具有重要的临床意义。     

冠心病患者低密度脂蛋白与血小板GMP-140水平相关性研究

目的：探讨冠心病患者低密度脂蛋白与血小板功能活化产物GMP-140的关系。方法：应用酶联免疫分析法对120例研究对象进行了血浆LDL、GMP-140水平的测定,其中包括急性冠脉综合征组40例,稳定性心绞痛组40例,并与40例正常健康人作比较。结果：ACS患者血浆LDL和GMP-140水平均非常显著的高于正常人组（P〈0.01）,ACS组又高于SAP组（P〈0.05）,且血浆LDL与GMP-140水平呈正相关。结论：检测CHD患者血浆LDL和GMP-140水平的变化对CHD的发生和发展以及疗效和预后观察均具有重要的临床意义。     

急性脑梗死患者介入治疗的疗效及对患者纤溶系统的影响

目的:研究急性脑梗死患者脑血管球囊成形支架置入术治疗的临床疗效及其对患者纤溶系统的影响。方法:选择我院收治的急性脑梗死患者68例,随机分为观察1组和观察2组,各34例,观察1组给予尿激酶100万U静脉溶栓治疗;观察2组给予脑血管球囊成形支架置入术治疗,术后口服氯吡格雷和阿司匹林。观察两组患者治疗前、治疗后1d、7d组织型纤溶酶原激活物(t PA)、血浆血管性假血友病因子(v WF)、纤溶酶原激活物特异性抑制物(PAI-1)水平,并选择同期体检健康者30例作为对照组。结果:治疗后观察2组血流再通明显高于观察1组(P0.05);治疗前所有患者v WF、PAI-1、t PA明显高于对照组,t PA/PAI-1明显低于对照组(P0.05),但观察1组和观察2组比较无统计学差异(P0.05);治疗后1d观察1组、观察2组t PA、t PA/PAI-1明显升高,PAI-1明显降低(P0.05),治疗后7d,观察1组t PA、t PA/PAI-1明显降低,观察2组v WF明显升高(P0.05)。结论:脑血管球囊成形支架置入术治疗急性脑梗死可使梗死的血管再次通畅,术后采用抗凝及抗血小板治疗,效果显著,且对体内纤溶系统无明显影响,相比静脉溶栓治疗临床效果更加显著。     

前列地尔联合尼莫地平对动脉瘤性蛛网膜下腔出血后脑血管痉挛患者血管内皮功能及炎症因子水平的影响

目的:探讨前列地尔联合尼莫地平对动脉瘤性蛛网膜下腔出血(aSAH)后脑血管痉挛(CVS)患者血管内皮功能及炎症因子水平的影响。方法:选取76例于2015年3月～2017年8月间在中南大学湘雅医院住院治疗的aSAH后CVS患者为研究对象,按随机数字表法将患者分为对照组(n=38)及观察组(n=38)。对照组在常规治疗基础上采用尼莫地平治疗,观察组在对照组基础上加用前列地尔治疗。比较治疗前后两组患者的大脑前、后、中动脉平均血流速度,观察并比较两组患者血浆降钙素基因相关肽(CGRP)、内皮素-1(ET-1)水平以及血清血管内皮生长因子(VEGF)、白细胞介素-8(IL-8)、超敏C反应蛋白(hs-CRP)、肿瘤坏死因子-α(TNF-α)水平的变化情况,评价两组疗效并观察治疗过程中的不良反应发生情况。结果:与对照组比较,治疗后观察组大脑前、后、中动脉血流速度均明显降低(P0.05)。与治疗前比较,治疗后两组患者CGRP水平明显升高,与对照组比较,治疗后观察组CGRP水平明显升高(P0.05),而治疗后两组患者ET-1、VEGF水平明显下降,且观察组低于对照组(P0.05)。与治疗前比较,治疗后两组患者IL-8、hs-CRP、TNF-α水平均明显下降,且与对照组比较,观察组IL-8、hs-CRP、TNF-α水平均降低(P0.05)。观察组患者治疗的总有效率为92.11%,明显高于对照组的73.68%(P0.05)。观察组总不良反应发生率与对照组比较差异无统计学意义(P0.05)。结论:前列地尔与尼莫地平联合使用治疗aSAH后CVS能明显改善患者的血管内皮功能,降低炎症因子水平,且未增加用药的不良反应,治疗效果较好。     

烧伤患者血浆IGFBP-1水平的变化及临床意义

目的:探究烧伤患者血浆胰岛素样生长因子结合蛋白-1(IGFBP-1)水平的变化及其临床意义。方法:选择2013年1月-2015年1月我院收治的70例烧伤患者作为研究组,依据总体表烧伤面积(TBSA)将患者分为4个亚组:Ⅰ组(1%~15%)34例、Ⅱ组(16%~30%)9例、Ⅲ组(31%~50%)17例、Ⅳ组(51%~95%)10例;选取同期于我院体检健康者50例作为对照组。测定研究者IGFBP-1、胰岛素样生长因子(IGF-1)水平,分析其与TBSA的相关性。结果:在10d观察期内,Ⅲ组和Ⅳ组患者的IGF-1水平均显著低于对照组(P0.05),而Ⅱ组患者IGF-1水平仅在烧伤后1 d时与对照组存在差异(P0.05),且在烧伤后2 d,随着分级的增加,血浆IGF-1水平有下降的趋势,组间差异具有统计学意义(P0.05);研究组患者的IGFBP-1水平均显著高于对照组(P0.05);随着分级的增加,血浆IGFBP-1有上升的趋势,组间差异具有统计学意义(P0.05);线性相关性分析显示,烧伤患者血浆IGF-1水平与TBSA值呈负相关(r=-0.693,P0.05);血浆IGFBP-1水平与TBSA值呈正相关(r=0.377,P0.05)。结论:烧伤患者血浆IGF-1水平显著下降,而IGFBP-1水平则显著升高,与烧伤严重程度密切相关,二者可作为判断烧伤患者预后的重要预警指标。     

血清ANXA1、dickkopf-1与动脉瘤性蛛网膜下腔出血患者脑损伤程度和预后的关系

摘要 目的：探讨动脉瘤性蛛网膜下腔出血（aSAH）患者血清膜联蛋白AI（ANXA1）、dickkopf相关蛋白1（dickkopf-1）水平与脑损伤程度及与预后的关系。方法：选取中国人民解放军联勤保障部队第九〇一医院2018年11月-2021年5月收治的100例aSAH患者作为观察组,选取同期健康体检者101例作为对照组。检测两组血清ANXA1、dickkopf-1水平,比较两组血清ANXA1、dickkopf-1水平差异。分析血清ANXA1、dickkopf-1水平与aSAH患者脑损伤程度和手术治疗后预后的关系。结果：观察组血清ANXA1水平低于对照组（P<0.05）,dickkopf-1水平高于对照组（P<0.05）。Spearman相关性分析显示,血清ANXA1与Hunt-Hess评分、WFNS评分和改良Fisher评分呈负相关（P<0.05）;血清dickkopf-1与Hunt-Hess评分、WFNS评分和改良Fisher评分均呈正相关（P<0.05）。所有患者均随访半年,经统计术后预后不良患者有56例,预后不良发生率为56%。多因素Logistic回归分析显示,高ANXA1水平为aSAH患者预后不良的保护因素（P<0.05）;高dickkopf-1水平、高Hunt-Hess评分、高WFNS评分、高改良Fisher评分是aSAH患者预后不良的危险因素（P<0.05）。ROC曲线分析显示：联合血清ANXA1、dickkopf-1及Hunt-Hess评分、WFNS评分、改良Fisher评分对aSAH患者预后的评估价值最高,ROC-AUC（0.95CI）为0.843(0.748～0.942)。结论：aSAH患者血清ANXA1、dickkopf-1水平与脑损伤程度密切相关,是患者预后不良的影响因素。联合血清ANXA1、dickkopf-1与病情评分对aSAH患者预后具有较高的预测价值。     

乳腺癌血行肺转移模型家兔血小板与凝血功能变化研究

目的 研究乳腺癌血行肺转移模型家兔血小板与凝血功能的变化规律。方法 取健康雌性新西兰白兔12只,随机分为2组：正常组和模型组,模型组家兔左侧第3乳房乳垫注射VX2组织悬液,再经耳缘静脉注射VX2细胞悬液,构建乳腺癌血行肺转移家兔模型。观察42 d内家兔精神状态、饮食情况,监测体重和肿瘤大小,检测血小板相关参数PLT、MPV、PDW、PCT和凝血相关指标PT、APTT、TT、FIB及D-二聚体;实验终点ELISA法检测血清CD63、CD62P、TXB₂及血浆GMP-140水平;取肿瘤组织和肺用10%甲醛固定、石蜡包埋、切片、HE染色,光学显微镜下观察肿瘤和肺组织形态变化。结果 家兔乳垫注射VX2组织悬液附加静脉注射VX2细胞悬液,能成功构建乳腺癌血行肺转移家兔模型,肺转移率100%,模型家兔血液处于高凝状态,14～42 d内,PLT、MPV、PCT均明显增加;10～30 d内,PT、APTT、TT均明显缩短,且FIB、D-二聚体含量均明显增加;血清CD63、CD62P、TXB₂及血浆GMP-140水平明显增高;模型家兔乳腺中肿瘤细胞增多、排列疏...     

血管性血友病因子裂解蛋白酶的稳定表达及其活性检测

本研究旨在得到重组的血管性血友病因子裂解蛋白酶(ADAMTS13),进一步研究其在血栓止血中的作用。利用脂质体将编码ADAMTS13全长序列的重组质粒pSecTag-ADAMTS13转染Hela细胞,用潮霉素(Hygromycin-B)筛选得到阳性克隆细胞株,并扩大培养,收集上清。利用Ni-NTA琼脂糖柱、梯度咪唑淋洗法纯化蛋白,SDS-PAGE和Westernblotting鉴定纯化产品纯度和免疫学活性,采用GST-His双抗夹心法测定蛋白剪切活性。结果显示,成功获得一株能恒定分泌重组ADAMTS13蛋白的细胞株ADAMTS2-4,每1L培养上清可纯化得到5.8mg重组蛋白。Western blotting结果显示,ADAMTS13多抗能与重组蛋白在190kDa处显单一条带,并且蛋白具有6.4U/mL的剪切活性(每毫升正常人混合血浆中ADAMTS13活性为1U)。重组蛋白具有较好的免疫原活性和酶活性,为进一步研究ADAMTS13作用机理和运用奠定了良好的基础。     

全蝎软膏对大鼠糖尿病皮肤溃疡创面愈合的效果评价

目的:探讨全蝎软膏治疗糖尿病皮肤创面愈合的作用及其机制。方法:采用SPF级SD大鼠构建糖尿病皮肤溃疡模型,将其随机平均分为对照组、模型组、全蝎软膏组和湿润烧伤膏组。造模后,分别在创面处涂抹全蝎软膏或湿润烧伤膏处理,空白组和模型组用PBS处理,观察和比较各组创面的愈合情况,并收集用药后3 d、7 d、10 d和14 d的创面肉芽组织进行HE染色,通过ELISA及荧光定量PCR检测肉芽组织内碱性成纤维细胞生长因子(bFGF)、血管性假血友病因子(v WF)、肿瘤坏死因子α(TNF-α)与Smad 4基因的表达。结果:成功构建大鼠糖尿病皮肤溃疡模型,成模率为96.15%。创伤后第3 d、7 d、10 d和14 d,各治疗组创面愈合率均显著高于模型组(P0.05),给药14 d时,全蝎软膏组创面愈合率已接近对照组水平。HE染色结果显示与模型组相比,全蝎软膏组中肉芽组织生长较快、毛细血管数量增多且组织纤维化程度较低。ELISA和荧光定量PCR检测结果显示与模型组和湿润烧伤膏组相比,全蝎软膏组肉芽组织内bFGF、v WF含量上调更显著(P0.05),而TNF-α含量与Smad 4 m RNA显著降低(P0.05)。结论:全蝎软膏可促进糖尿病皮肤溃疡创面肉芽组织的生长,可能与其抑制炎症反应并改善血管功能有关。     

顺铂化疗对下丘脑、血浆ghrelin和orexin 表达的影响

目的:观察顺铂化疗对下丘脑、血浆ghrelin、orexin表达和摄食量的影响。方法:Real-time PCR、ELISA法观察顺铂对大鼠下丘脑、血浆ghrelin、orexin表达及摄食量的影响;19名接受顺铂经导管动脉灌注化疗(TAI)的肝细胞患者(HCC),ELISA法检测化疗前和化疗后血浆ghrelin、orexin的变化,用直观类比标度(VAS)(0-10)评估食欲和摄食量。结果:每日腹腔注射顺铂6 mg/kg,1-5 d大鼠摄食量均显著减少(P0.05),且1-4 d血浆酰化ghrelin显著降低(P0.05),5d时浓度仍低于对照组,但无统计学意义。血浆非酰化ghrelin和总的血浆ghrelin没有明显变化(P0.05),而1-5天血浆orexin水平均明显降低(P0.05);顺铂注射1 d后,大鼠下丘脑ghreilin和orexin的mRNA表达量均显著减少(P0.05),ghrelin mRNA变化持续3 d,orexin mRNA在化疗后5 d仍低于对照组(P0.05);肝细胞癌患者化疗后1至8 d的摄食量明显降低,1 d和2 d时的血浆酰化ghrelin显著低于化疗前水平(P0.05)。3 d时逐渐恢复,化疗后3 d、4 d和7 d时血浆酰化ghrelin浓度与化疗前无统计学差异(P0.05)。血浆非酰化ghrelin和总的血浆ghrelin没有明显变化(P0.05);化疗后1~4 d时血浆orexin浓度均显著降低(P0.05),化疗后7 d时orexin基本恢复到化疗前水平(P0.05)。结论:顺铂可降低大鼠下丘脑和血浆ghrelin、orexin的mRNA表达,HCC的TAI会降低血浆酰化ghrelin、orexin、和摄食量。     

Stimulated secretion of endothelial von Willebrand factor is accompanied by rapid redistribution to the cell surface of the intracellular granule membrane protein GMP-140

We have examined the cell activation-dependent redistribution of the intracellular granule membrane protein GMP-140 of human endothelial cells. By dual-label immunofluorescence, the distribution of GMP-140 within cultured human umbilical vein endothelial cells was found to coincide with the distribution of von Willebrand factor (vWF), suggesting that GMP-140 is located in the membranes of vWF-containing storage granules. Stimulation of vWF secretion resulted in an increase in GMP-140 on the cell surface, as detected by increased binding of the monoclonal antibody S12 which recognizes the extracytoplasmic domain of GMP-140. For each agonist tested (histamine, thrombin, phorbol 12-myristate 13-acetate, and the calcium ionophore A23187) a dose-dependent redistribution of GMP-140 to the endothelial surface was observed which closely paralleled the dose-dependent secretion of vWF into the cell supernatant. When cells were maximally stimulated by histamine in the presence of antibody S12, a 4-fold increase in S12 uptake by the cells was observed. This increase occurred rapidly and reached a plateau by 10 min. In contrast, when histamine-stimulated cells were first fixed with paraformaldehyde or chilled to 4 degrees C before addition of antibody S12, only a transient increase in cell surface GMP-140 was detected. Under these conditions of arrested membrane turnover during antibody binding, cell surface GMP-140 was maximal 3 min after histamine stimulation and then declined to control levels by 20 min. These data suggest that stimulated secretion of vWF from endothelial cells entails fusion of vWF-containing storage granules with the plasma membrane. Once inserted into the plasma membrane, GMP-140 is subsequently removed from the endothelial surface, most likely by an endocytic mechanism.     

Modeling ADAMTS13-von Willebrand factor interaction: Implications for oxidative stress-related cardiovascular diseases and type 2A von Willebrand disease

The haemostatic potential of von Willebrand factor, a glycoprotein expressed by endothelial cells as ultra-large polymers (UL-vWF)¹, increases with its length, which in turn is regulated proteolytically by ADAMTS13, a zinc-metalloprotease selectively cleaving vWF at the Tyr1605-Met1606 bond. We have recently shown that in vitro oxidation of Met1606, under conditions mimicking those found in diseases characterized by high oxidative stress, severely impairs proteolysis by ADAMTS13, with a resulting pro-thrombotic effect caused by the accumulation of UL-vWF species. Conversely, Val1607Asp mutation, found in vWF from patients with type 2A von Willebrand disease, accelerates proteolysis of vWF, with a final hemorrhagic effect. Considering the physio-pathological importance of ADAMTS13-vWF interaction and the absence of experimental structural data, here we produced by homology modeling techniques a three-dimensional model of ADAMTS13 metalloprotease domain (M13). Thereafter, the vWF(1604-1607) peptide, containing the cleavable Tyr1605-Met1606 bond, was manually docked into the protease active site and the resulting model complex provided us key information for interpreting on structural grounds the variable effects that chemical modifications/mutations in vWF have on proteolysis by ADAMTS13.     

急性脑梗死患者相关生化指标检测的临床意义

目的：探讨急性脑梗死（ACI）患者治疗前后Hcy、ET-1、hs-CRP、TXA2水平和凝血纤溶指标的变化及临床意义。方法：分别采用ELISA法、发色底物法、凝血酶法、放射免疫法和免疫透射比浊法对68例ACI患者治疗前后Hcy、ET-1、hs-CRP、TXA2和各凝血纤溶指标水平进行检测,并以30例正常健康人作为对照组。结果：①ACI患者治疗前血浆Hcy、ET-1和血清hs-CRP、TXA2含量高于对照组（P〈0.01）,经过治疗,含量均明显下降,其中血浆Hcy、ET-1恢复至正常水平,与对照组间比较差异无统计学意义（P〉0.05）②轻、中、重型组间血浆ET-1和血清hs-CRP、TXA2含量逐渐增加,组间差异有显著性（P〈0.01或0.05）,而中重型患者血浆Hcy含量明显高于轻型患者（P〈0.01）。③经过治疗,ACI患者血浆vWF、GMP-140、Fg和F1＋2含量较治疗前显著下降,而血浆PS活性、PC活性与AT水平较治疗前明显上升（P〈0.01）,其中血浆PS和PC活性与对照组间比较差异无统计学意义（P〉0.05）。④ACI患者血浆中tPA水平低于对照组,血浆PAI-1含量高于对照组（P〈0.01）。治疗后血浆tPA增加,与对照组间差异无统计学意义（P〉0.05）,PAI-1减少,但仍显著高于对照组（P〈0.05）。结论：检测急性脑梗死（ACI）患者Hcy、ET-1、hs-CRP、TXA2和凝血纤溶指标水平的变化对于指导用药、病情观察和预后评估均有重要的临床意义。     

C 反应蛋白、白细胞计数与脑梗死体积及近期预后的关系

目的:研究血清C反应蛋白水平、白细胞计数与急性脑梗死患者的梗死灶体积大小以及预后的关系。方法:检测70例急性脑梗死患者(CI组)、64例腔隙性脑梗死患者(LCI组)和80例健康人(对照组)的血浆CRP水平,并进行白细胞计数。在CI及LCI组人院当天和4周时进行临床神经功能缺损程度评分(NDS)评定以判断预后。结果:CI组血浆CRP水平高于LCI组及对照组(P<0.01),LCI组高于对照组(P<0.01);CI组白细胞计数高于LCI组及对照组(P<0.01),LCI组高于对照组(P<0.05);血浆CRP水平及白细胞计数正常组患者住院4周时显著进步和进步的比率明显高于血浆CRP水平及白细胞计数异常组(均P<0.01),而无变化和死亡的比率明显低于异常组(均P<0.01)。结论:ACI患者血浆CRP水平和白细胞计数均明显升高;脑梗死急性期血清CRP水平、白细胞计数可能与脑梗死患者梗死体积大小以及近期预后有密切的关系。     

Predicting pathological von Willebrand factor unraveling in elongational flow

The globular-to-unraveled conformation transition of von Willebrand factor (vWF), a large polymeric glycoprotein in human blood plasma, is a crucial step in the process of clotting at sites of vascular injury. However, unraveling of vWF multimers in uninjured vasculature can lead to pathology (i.e., thrombus formation or degradation of vWF proteins by enzyme ADAMTS13, making them nonfunctional). To identify blood flow conditions that might induce pathological unraveling of vWF multimers, here we have computed the globular-to-unraveled transition rate of vWF multimers subjected to varying strain rate elongational flow by employing an enhanced sampling technique, the weighted ensemble method. Weighted ensemble sampling was employed instead of standard brute-force simulations because pathological blood flow conditions can induce undesired vWF unraveling on timescales potentially inaccessible to standard simulation methods. Results here indicate that brief but periodic exposure of vWF to the elongational flow of strain rate greater than or equal to 2500 s⁻¹ represents a source of possible pathology caused by the undesired unraveling of vWF multimers.     

Topographic distribution of a granule membrane protein (GMP-140) that is expressed on the platelet surface after activation: an immunogold-surface replica study

Monoclonal and polyclonal antibodies have been developed that recognize a 140 kD glycoprotein on the plasma membrane of activated, but not unstimulated, platelets. This glycoprotein is found in resting platelets as an alpha-granule membrane protein and has therefore been named GMP-140. After thrombin stimulation, alpha-granules fuse with the surface-connected canalicular system and GMP-140 is redistributed to the plasma membrane. In the present study, we immunolabeled unstimulated and activated human platelets and analyzed the distribution of GMP-140 over broad expanses of the plasma membrane using surface replication techniques. Fixed platelets were allowed to settle onto poly-L-lysine-coated coverslips and immunolabeled with polyclonal anti-GMP-140, followed by protein A gold. After critical-point drying, rotary-shadowed surface replicas were made. GMP-140 was not present on the surfaces of unstimulated platelets, but thrombin stimulation resulted in the massive expression of GMP-140 on the cell surface, with the immunogold label monodispersed. In contrast, we recently found that GPIIb-IIIa, the fibrinogen receptor, is monodispersed on unstimulated platelets and clustered on activated platelets. Although GMP-140's hemostatic function is unknown, its monodispersed surface pattern implies significant differences form GPIIb-IIIa with respect to ligand binding and/or cytoskeletal interaction.     

Copeptin as a Marker for Severity and Prognosis of Aneurysmal Subarachnoid Hemorrhage

Background

Grading of patients with aneurysmal subarachnoid hemorrhage (aSAH) is often confounded by seizure, hydrocephalus or sedation and the prediction of prognosis remains difficult. Recently, copeptin has been identified as a serum marker for outcomes in acute ischemic stroke and intracerebral hemorrhage (ICH). We investigated whether copeptin might serve as a marker for severity and prognosis in aSAH.

Methods

Eighteen consecutive patients with aSAH had plasma copeptin levels measured with a validated chemiluminescence sandwich immunoassay. The primary endpoint was the association of copeptin levels at admission with the World Federation of Neurological Surgeons (WFNS) grade score after resuscitation. Levels of copeptin were compared across clinical and radiological scores as well as between patients with ICH, intraventricular hemorrhage, hydrocephalus, vasospasm and ischemia.

Results

Copeptin levels were significantly associated with the severity of aSAH measured by WFNS grade (P = 0.006), the amount of subarachnoid blood (P = 0.03) and the occurrence of ICH (P = 0.02). There was also a trend between copeptin levels and functional clinical outcome at 6-months (P = 0.054). No other clinical outcomes showed any statistically significant association.

Conclusions

Copeptin may indicate clinical severity of the initial bleeding and may therefore help in guiding treatment decisions in the setting of aSAH. These initial results show that copeptin might also have prognostic value for clinical outcome in aSAH.     

Levels of Selected Trace Elements, Phytohormones, and Sugars in Pseudomonas-Infected Lycopersicum esculantum Mill Plants

The present study investigated the levels of trace elements (Zn, Cu, Fe, Pb, and Cd), major elements (Ca and K), phytohormones (trans-Zeatin [t-Z] and gibberellic acid [GA]), and sugars (sucrose and glucose) following inoculation with Pseudomonas syringae pv. tomato strain. The results of the trace elements analysis showed that Fe (in the first, fourth, eighth, and tenth study days), Cd (in the fourth, eighth, and tenth study days), Cu (in the fourth and eighth study days), and Zn (in the eighth and tenth study days) increased in bacterium-infected tomato plants, compared to healthy plants. The levels of Pb, Ca, and K did not meaningfully determine a change after inoculation with pathogen. In this vein, the increase accumulation rates of Cu, Zn, and Fe in the injured plants can be an important indicator for the plant defense processes towards pathogen attack. Furthermore, in the first, fourth, eighth, and tenth study days, the glucose and sucrose contents crucially decreased in bacterium-infected plants compared to the control groups. The lowest level of sucrose in bacterium-infected plants was observed on the first day. The findings displayed that, when endogenous t-Z levels did not change after inoculation with virulent bacterium strain, there was a reduction in the first, fourth, eighth, and tenth days in the level of GA when compared with the control group levels. Therefore, there may be a link between lower GA level and enhancement in the expression of defense-related genes. The results of this study showed that there are complex relationships among levels of sugar, trace element, and endogenous phytohormone in the regulation of defense mechanisms against bacterial pathogen attacks.     

Structural and biosynthetic studies of the granule membrane protein, GMP-140, from human platelets and endothelial cells

GMP-140 is an integral membrane glycoprotein of apparent Mr = 140,000 located in secretory storage granules of platelets and vascular endothelial cells. When these cells are activated, GMP-140 redistributes from the membrane of the granules to the plasma membrane. To gain insight into the potential function of GMP-140, we examined aspects of its structure and biosynthesis. The amino acid composition of platelet GMP-140 revealed elevated numbers of cystinyl (6.1%), prolinyl (7.2%), and tryptophanyl (2.1%) residues. GMP-140 contained 28.8% carbohydrate by weight, distributed among N-acetylneuraminic acid, neutral sugar, and N-acetylglucosamine residues. Enzymatic removal of N-linked oligosaccarides reduced the protein's apparent Mr by more than 50,000. The biosynthesis of GMP-140 in HEL cells, which share biochemical features with megakaryocytes, was studied by pulse-chase labeling with [35S]cysteine followed by immunoprecipitation. HEL cells synthesized a heterogeneous GMP-140 precursor of 98-125 kDa which converted to a mature 140-kDa form within 40-60 min. Removal of high mannose oligosaccarides by endo-beta-N-acetylglucosaminidase H treatment reduced the apparent Mr of the precursor but not the mature protein. Tunicamycin-treated HEL cells synthesized three to four precursors of 80-92 kDa, suggesting the possibility of heterogeneity of GMP-140 at the protein level. Exposure of activated platelets to proteases followed by Western blotting indicated that most of the mass of GMP-140 was located on the extracytoplasmic side of the membrane. Our studies indicate that GMP-140 is a cysteine-rich, heavily glycosylated protein with a large extracytoplasmic domain. These features are compatible with a receptor function for the molecule when it is exposed on the surface of activated platelets and endothelial cells.