槲皮素-7,4’-二硫酸酯对凝血酶诱导猪血小板聚集的抑制作用及其机制(英文)

目的:研究人工半合成槲皮素—槲皮素-7,4′-二硫酸酯二钠(disodium quercetin-7,4′-disulfate,DQD)对凝血酶(500 U·L~(-1))诱导猪血小板聚集的抑制作用及其机制。方法:用比浊法测定血小板聚集。Fura 2-AM荧光法检测胞浆游离钙浓度([Ca~(2 )]_i)。用组蛋白ⅢS,[γ-~(32)P]ATP与蛋白激酶C(PKC)酶液一起保温的方法测定Ca~(2 )/PL依赖的PKC活性。用SDS-PAGE分离骨架蛋白。结果:DQD对凝血酶诱导的血小板聚集有抑制作用,当DQD的浓度为100,200和400μmol/L时,抑制率分别为77％、86％和82％。DQD(10-80μmol/L)抑制凝血酶诱导的血小板胞外钙内流;DQD对凝血酶诱导的血小板胞内钙动员也有抑制作用。DQD(10-160μmol/L)抑制血小板胞浆Ca~(2 )/PL依赖的PKC,但DQD不影响胞膜PKC。DQD(20-200μmol/L)对凝血酶诱导的血小板肌动蛋白聚合有较强的抑制作用。结论:DQD对凝血酶诱导的猪血小板聚集有抑制作用,其分子作用机制是由于抑制血小板外钙内流、内钙动员、Ca~(2 )/PL依赖的PKC和肌动蛋白聚合。 血小板;;黄酮类;;槲皮素;;血小板聚集;;钙;;蛋白激酶C;;肌动蛋白类     

槲皮素对血小板聚集和胞浆游离钙的影响(英文)

目的:研究槲皮素对凝血酶诱导的血小板聚集和胞浆游离钙浓度的影响及钙对槲皮素的血小板聚集抑制效应的作用。方法:用荧光钙离子指示剂观察槲皮素对血小板胞浆游离钙的影响.结果:槲皮素明显抑制凝血酶诱导的血小板聚集和游离钙的升高.IC_(50)和95％可信区间分别为146.2(92.4～231.3)和78.5(49.5—124.4)μmol·L~(-1).槲皮素对血小板的抑制作用可被钙翻转.槲皮素对凝血酶诱导的钙释放无影响.结论:抑制钙内流是槲皮素抑制血小板聚集和[Ca~(2 )]_i升高的机制.     

MK-447对家兔凝血酶诱导的血小板聚集,ATP释放及细胞内游离钙动员的影响(英文)

目的:研究MK-447对家兔凝血酶诱导的血小板聚集释放反应及单细胞内钙水平的影响.方法:利用浊度法及测定PRP中ATP的含量评价聚集和释放反应,以荧光图像法分析细胞内钙浓度.结果:MK-447仅使兔多血小板血浆(PRP)透光度降低(DLT),即血小板变形,单血小板[Ca~(2 )]_i轻度增加(160 nmol·L~(-1)),并不被依他酸3 mmol·L~(-1)抑制.MK-447消除凝血酶诱导的DLT,聚集和ATP释放增强,呈剂量依赖性,且凝血酶介导的[Ca2 ]_i由369 ±45 nmol·L~(-1)增加到621±121 nmol·L~(-1).结论:MK-447的血小板变形与其[Ca~(2 )]_i释放有关.MK-447增强凝血酶的血小板聚集和ATP释放.MK-447的这一作用可能于[Ca2 ]_i的协同作用有关.     

凝血酶引起大鼠血小板神经肽Y释放的机制(英文)

目的:研究凝血酶引起血小板释放NPY的作用及其机制.方法:用血小板聚集仪记录凝血酶及ADP引起的血小板聚集;用放射免疫法测定血小板及血浆中的NPY;用Fura 2荧光测定法记录细胞内游离ca~(2 )([Ca~(2 )]_i). 结果:凝血酶在引起NPY释放的同时,细胞内游离钙([Ca~(2 )]_i)升高.依地酸基本消除凝血酶引起的[Ca~(2 )]_i增高,并显著减少凝血酶引起的NPY释放.维拉帕米对凝血酶的作用无显著影响.磷酸肌酸与磷酸肌酸激酶合用或消炎痛均可使凝血酶引起的NPY释放减少. 结论:凝血酶引起的血小板NPY释放与(1)细胞外ca~(2 )通过非电压依赖性钙通道进入及(2)花生四烯酸代谢物和ADP释放的正反馈机制有关.     

人血小板密度亚群在聚集反应,ATP释放及细胞内游离钙浓度的异质性(英文)

目的:研究人血小板密度亚群在聚集和释放反应及细胞内钙浓度的异质性。方法:Percoll间断梯度离心法。结果:正常人血小板分为高(HD),中(ID)和低(LD)密度三个亚群。血小板的大小随密度的降低而减小(r=0.978,P<0.01)。HD对凝血酶(Thr),ADP和血清素(5-HT)诱导的聚集反应明显强于LD(P<0.01),ATP释放反应,除5-HT无ATP释放外,与聚集反应的结果一致。尽管细胞内游离钙([Ca~(2 )]_i的静息水平各亚群相同,但Thr,ADP和5-HT的[Ca~(2 )]_i动员仍以HD最为明显。结论:人HD血小板的功能及活性均高于LD血小板。     

哒嗪酮类药J-894对血小板激活时钙流动的影响

目的：探讨J－894对血小板功能的影响是否与钙有关。方法：用荧光钙离子指法剂观察J－894对血小板胞浆游离钙的影响。结果：J－894通过减少钙内流和释放明显抑制比凝血酶引起的血小板[Ca2 ]的升高,剂量与效应相关,J－894对钙内流的抑制比对钙释放的抑制作用强。结论：J－894抗血小板聚集可能主要是抑制钙内流。     

MN-9202对兔血小板聚集、5-HT释放、TXB_2合成及Ca~(2 )转运的影响(英文)

目的:研究新二氢吡啶类钙拮抗剂MN-9202对兔血小板激活的影响,并探讨其作用机制。方法:以Fu-ra-2 AM为荧光探针,采用时间扫描方式记录血小板内Ca~(2 )的变化;分别用HPLC/ECD和放射免疫测定法检测5-HT及TXB_2。结果:MN-9202剂量依赖地抑制ADP或凝血酶诱导的血小板聚集,抑制TXA_2的释放并且能有效阻滞激活血小板胞内Ca~(2 )水平的增加。MN-9202 1μmol·L~(-1)能抑制胶原15mg·L~(-1)诱导的5-HT释放反应,但对胶原45mg·L~(-1)诱导的反应无抑制作用。结论:MN-9202阻滞血小板Ca~(2 )内流并抑制血小板花生四烯酸代谢及激活反应。     

钾通道开放剂降低血管平滑肌细胞内游离钙浓度(英文)

目的:研究PCO—Pin,Nic,Lem及RP对VMSC内[Ca~(2 )]_i的改变及其可能机制。方法:VSMC加入Fura-2 AM 2.5μmol·L~(-1)37℃下孵育50min,[Ca~(2 )]_i用荧光分光光度计检测。结果:4种PCO能较弱地抑制K~ 30 mmol·L~(-1)诱导的[Ca~(2 )]_i增加,但明显抑制ATP 0.1mmol·L~(-1)诱导的[Ca~(2 )]_i峰相及持续相增加,且呈剂量依赖性。格列苯脲完全阻断Pin,Lem及RP的作用,只部分抑制Nic的作用。无钙液中先给4种PCO,能显著抑制ATP诱导的[Ca~(2 )]_i峰相增加。结论:4种PCO均抑制ATP诱导的[Ca~(2 )]_i增加,此作用与减少细胞外钙内流及细胞内钙释放有关。     

异钩藤碱体外对家兔血小板聚集和胞浆游离钙离子浓度的影响

目的研究异钩藤碱对血小板内游离钙离子浓度([Ca2+]i)的影响,以探讨其抗血小板聚集作用的可能机制。方法比浊法测定家兔血小板聚集功能;双波长Fura-2荧光法测定血小板胞浆[Ca2+]i。结果异钩藤碱0.33~1.30mmol.L-1体外给药对ADP和凝血酶引起的血小板聚集有浓度依赖性的抑制作用。存在细胞外钙时,异钩藤碱对基础状态血小板的[Ca2+]i和ADP及凝血酶诱导的[Ca2+]i水平有浓度依赖性的降低作用,而无细胞外钙存在时,则均无明显影响,表明其可抑制血小板的外钙内流,对内钙释放无明显抑制作用。结论异钩藤碱可抑制血小板聚集,其作用机制可能与其抑制血小板胞浆[Ca2+]升高有关。     

卡托普利对高血压大鼠血小板内游离钙和血小板功能的影响

本文建立二肾一夹型肾血管性高血压大鼠(2KIC-RHR)动物模型,观察大鼠在高血压稳定期血小板胞浆内游离钙浓度([Ca~(2+)]_i)及血小板聚集率(PAg)的变化并研究了ACEI—卡托普利对高血压大鼠血小板内[Ca~（2+）]_i及血小板聚集功能的影响.结果发现:高血压大鼠血小板内[Ca~（2+）]_i及血小板聚集率均显著升高(P<0.01),卡托普利显著降低血压同时血小板内[Ca~（2+）]_i、血小板聚集率也明显减小(P<0.01).提示:2KIC—RHR在高血压稳定期存在血小板内钙代谢异常和血小板功能的改变,血小板活性的降低可能参与卡托普利的降压作用.     

Synthesis,Cytotoxicity and Antileishmanial Activity of Some N-(2-(indol-3-yl)ethyl)-7-chloroquinolin-4-amines

We report herein the condensation of 4,7-dichloroquinoline (1) with tryptamine (2) and D-tryptophan methyl ester (3) . Hydrolysis of the methyl ester adduct (5) yielded the free acid (6) . The compounds were evaluated in vitro for activity against four different species of Leishmania promastigote forms and for cytotoxic activity against Kb and Vero cells. Compound (5) showed good activity against the Leishmania species tested, while all three compounds displayed moderate activity in both Kb and Vero cells.     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

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Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

Lung disease and PKCs

The lung offers a rich opportunity for development of therapeutic strategies focused on isozymes of protein kinase C (PKCs). PKCs are important in many cellular responses in the lung, and existing therapies for pulmonary disorders are inadequate. The lung poses unique challenges as it interfaces with air and blood, contains a pulmonary and systemic circulation, and consists of many cell types. Key structures are bronchial and pulmonary vessels, branching airways, and distal air sacs defined by alveolar walls containing capillaries and interstitial space. The cellular composition of each vessel, airway, and alveolar wall is heterogeneous. Injurious environmental stimuli signal through PKCs and cause a variety of disorders. Edema formation and pulmonary hypertension (PHTN) result from derangements in endothelial, smooth muscle (SM), and/or adventitial fibroblast cell phenotype. Asthma, chronic obstructive pulmonary disease (COPD), and lung cancer are characterized by distinctive pathological changes in airway epithelial, SM, and mucous-generating cells. Acute and chronic pneumonitis and fibrosis occur in the alveolar space and interstitium with type 2 pneumocytes and interstitial fibroblasts/myofibroblasts playing a prominent role. At each site, inflammatory, immune, and vascular progenitor cells contribute to the injury and repair process. Many strategies have been used to investigate PKCs in lung injury. Isolated organ preparations and whole animal studies are powerful approaches especially when genetically engineered mice are used. More analysis of PKC isozymes in normal and diseased human lung tissue and cells is needed to complement this work. Since opposing or counter-regulatory effects of selected PKCs in the same cell or tissue have been found, it may be desirable to target more than one PKC isozyme and potentially in different directions. Because multiple signaling pathways contribute to the key cellular responses important in lung biology, therapeutic strategies targeting PKCs may be more effective if combined with inhibitors of other pathways for additive or synergistic effect. Mechanisms that regulate PKC activity, including phosphorylation and interaction with isozyme-specific binding proteins, are also potential therapeutic targets. Key isotypes of PKC involved in lung pathophysiology are summarized and current and evolving therapeutic approaches to target them are identified.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.     

Gender-related symptoms and correlates of alcohol dependence among men and women with a lifetime diagnosis of alcohol use disorders

This study explored gender-related symptoms and correlates of alcohol dependence in a crosssectional study of 150 men and 150 women with a lifetime diagnosis of alcohol use disorders (AUD). Participants were recruited in equal numbers from treatment settings, correctional centres and the general community. Standardized measures were used to determine participants' use of substances, history of psychiatric disorders and psychosocial stress, their sensation seeking and family history of substance use and mental health disorders. Multivariate analyses were used to detect patterns of variables associated with gender and the lifetime severity of AUD. Men had a longer history of severe AUD than women. Women had similar levels of alcohol dependence and medical and psychological sequelae as men, despite 6 fewer years of AUD. More women than men had a history of severe psychosocial stress, severe dependence on other substances and antecedent mental health problems, especially mood and anxiety disorders. There were differences in family history of alcohol-related problems approximating same-gender aggregation. The severity of a lifetime AUD was predicted by its earlier age at onset and the occurrence of other disorders, especially anxiety, among both men and women. The limitations in the generalizability of these findings due to sample idiosyncrasies are discussed.