Thesis (doctoral)--Ludwig Maximilians-Universität zu München, 1979.

peripheral arterial disease (PAD), a limiting factor in the success of percutaneous transluminal angioplasty (PTA) is the development of restenosis secondary to vascular smooth muscle cell (SMC) proliferation. The aim of this study was to determine the effect of combination antiplatelet therapy on the ability of plasma, from patients undergoing PTA, to stimulate SMCs in vitro. We aimed to investigate the effect of combination treatment on levels of circulating adhesion molecules and factors which mediate SMC proliferation in experimental models. We also sought to demonstrate any association between changes in measured markers and the development of restenosis or vascular events. Methods Fifty patients were randomised to receive clopidogrel or placebo, for thirty days, in addition to their daily 75mg aspirin. To measure proliferative capacity, diluted plasma was incubated with 24h-growth-arrested rat vascular SMCs, and Extracellular-regulated-kinase (ERK)1/2 activation was analysed by Western blotting at baseline, 1-hour pre-PTA, and at 1-hour, 24-hours and 30-days post-PTA. Plasma platelet-derived growth factor (PDGF-BB), soluble (s)E-selectin, sICAM-1 (intracellular adhesion molecule-1) and von Willebrand factor (vWF) were measured by ELISA (Enzyme-linked immunosorbent assay), at the same time-points. Platelet activation was measured by flow cytometry of ADP-stimulated platelet fibrinogen binding at baseline and 1-hour post-PTA. Patients’ notes and all investigations were reviewed for 2 years post-PTA to record restenosis or vascular events. Results Samples were available for all 50 patients at baseline, 1-hour pre-PTA and 1-hour post-PTA timepoints. In this cohort ERK1/2 activation was significantly increased post-PTA in both the aspirin/clopidogrel and aspirin/placebo groups. Those who developed a symptomatic restenosis had a significantly higher level of SMC activation at the 1-hour post-PTA time-point. There was a statistically significant decrease in PDGF-BB, and increase in vWF, following loading with clopidogrel. sICAM-1 levels significantly decreased in the aspirin/placebo group following PTA. ADP-stimulated platelet fibrinogen binding was significantly inhibited by clopidogrel therapy post-PTA. Conclusions This is the first study to show in-vitro ERK1/2 activation (a marker of SMC proliferation) increases post-PTA. Patients developing a symptomatic restenosis had a significantly higher level of SMC activation at the 1-hour post-PTA time-point. Clopidogrel therapy had no significant effect on ERK1/2 activation, although it did reduce PDGF-BB in the larger cohort of patients. Further work is required to evaluate potential therapeutic treatments which may reduce peripheral PTA-induced smooth muscle cell activation.

by William, Wai-lun Lam. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves 85-95). / Chapter I. --- Introduction --- p.1 / Chapter II. --- Our Approach --- p.9 / Chapter III. --- Results and Discussion - Synthetic Strategy --- p.29 / Chapter IV. --- Results and Discussion - Pharmacological Activity --- p.44 / Chapter V. --- Conclusion --- p.49 / Chapter VI. --- Further Development --- p.53 / Chapter VII. --- Experimental Section --- p.55 / Chapter VIII. --- References --- p.85 / Chapter IX. --- Supplementary Materials --- p.96

by Chu, Pui-ya. / Thesis (M.Phil.)--Chinese University of Hong Kong. / Bibliography: leaves 115-126. / ACKNOWLEDGEMENT / LIST OF ABBREVIATIONS / ABSTRACT --- p.1 / Chapter CHAPTER 1 --- INTRODUCTION / Chapter 1.1 --- PLATELET-ACTIVATING FACTOR (PAF) --- p.4 / Chapter 1.1.1 --- Metabolism of PAF --- p.4 / Chapter 1.1.1.1 --- Biosynthesis of PAF --- p.4 / Chapter 1.1.1.2 --- Degradation of PAF --- p.9 / Chapter 1.1.2 --- Systemic effects of PAF --- p.12 / Chapter 1.1.3 --- Structure - activity relationship of PAF --- p.16 / Chapter 1.2 --- PAF RECEPTORS --- p.19 / Chapter 1.2.1 --- PAF receptor on platelets --- p.19 / Chapter 1.2.2 --- PAF receptor on leukocytes --- p.20 / Chapter 1.2.3 --- PAF receptor on macrophages --- p.20 / Chapter 1.2.4 --- Antagonists of PAF --- p.20 / Chapter 1.2.4.1 --- Nonspecific inhibitors of PAF --- p.21 / Chapter 1.2.4.2 --- Specific antagonists of PAF --- p.21 / Chapter 1.3 --- SECOND MESSENGER SYSTEMS OF PAF --- p.22 / Chapter 1.3.1 --- Adenylate cyclase - cyclic adenosine mono- phosphate system --- p.26 / Chapter 1.3.2 --- Phospholipase C - phosphatidylinositol system --- p.28 / Chapter 1.3.3 --- Intracellular calcium --- p.29 / Chapter 1.3.4 --- The role of prostaglandins and leukotrienes --- p.30 / Chapter 1.3.5 --- Protein kinase C --- p.30 / Chapter 1.3.5.1 --- Dual action of PKC --- p.31 / Chapter 1.3.5.2 --- Down regulation of PKC --- p.33 / Chapter 1.4 --- THE FUNCTION OF MACROPHAGES --- p.33 / Chapter 1.4.1 --- Phagocytosis --- p.34 / Chapter 1.4.2 --- Antigen presentation --- p.34 / Chapter 1.4.3 --- Release of cytokines --- p.34 / Chapter 1.4.4 --- Respiratory burst --- p.35 / Chapter CHAPTER 2 --- METHODS / Chapter 2.1 --- PREPARATION OF PERITONEAL MACROPHAGES --- p.37 / Chapter 2.1.1 --- Preparation of reagents --- p.37 / Chapter 2.1.2 --- Preparation of peritoneal macrophages --- p.37 / Chapter 2.2 --- RADIOLIGAND BINDING ASSAY --- p.38 / Chapter 2.2.1 --- Reagents --- p.38 / Chapter 2.2.2 --- [3H]-PAF binding to TG-PEC --- p.39 / Chapter 2.2.2.1 --- Preparation of thioglycollate-elicited peritoneal macrophages --- p.39 / Chapter 2.2.2.2 --- Preparation of working solutions --- p.39 / Chapter 2.2.2.3 --- Assay of [3H]-PAF binding --- p.40 / Chapter 2.2.3 --- [3H]-PAF binding to resident PEC --- p.40 / Chapter 2.2.3.1 --- Preparation of resident peritoneal mcrophages --- p.41 / Chapter 2.2.3.2 --- Preparation of working solutions --- p.41 / Chapter 2.2.3.3 --- Assay of [3H]-PAF binding --- p.41 / Chapter 2.2.4 --- Preparation of drugs --- p.41 / Chapter 2.2.5 --- Data analysis --- p.42 / Chapter 2.3 --- MEASUREMENT OF INOSITOL PHOSPHATES --- p.42 / Chapter 2.3.1 --- Preparation of reagents --- p.42 / Chapter 2.3.2 --- Dowex column preparation --- p.43 / Chapter 2.3.3 --- Cell plating in 24 - well plastic trays --- p.44 / Chapter 2.3.4 --- Determination of total inositol phosphates --- p.44 / Chapter 2.3.5 --- Column separation --- p.45 / Chapter 2.3.6 --- Determination of inositol trisphosphate (IP3) --- p.46 / Chapter 2.4 --- MEASUREMENT OF INOSITOL PHOSPHATES ACCUMULATION AFTER PROLONGED PMA PRETREATMENT --- p.46 / Chapter 2.4.1 --- Preparation of phorbol-12-myristate-13-acetate (PMA) solutions --- p.47 / Chapter 2.4.2 --- Preparation of cells with PMA --- p.47 / Chapter 2.5 --- DETERMINATION OF SUPEROXIDE ANION PRODUCTION --- p.47 / Chapter 2.5.1 --- Preparation of drugs --- p.47 / Chapter 2.5.2 --- Assay of superoxide anion production --- p.48 / Chapter 2.5.3 --- Data analysis --- p.48 / Chapter 2.6 --- STATISTICAL METHOD --- p.48 / Chapter CHAPTER 3 --- RESULTS / Chapter 3.1 --- [3H]-PAF BINDING TO TG-PEC --- p.50 / Chapter 3.1.1 --- General properties --- p.50 / Chapter 3.1.2 --- Stereospecific of PAF receptor --- p.57 / Chapter 3.1.3 --- Comparison of [3H]-PAF binding to TG-PEC and TG-PMΦ from Balb/c mice --- p.57 / Chapter 3.1.4 --- Inhibition of specific binding of [3H]-PAF to murine and guinea pig TG-PEC by PAF --- p.57 / Chapter 3.1.5 --- Effects of PAF antagonists on the binding of [3H]- PAF to TG-PEC from Balb/c mice and guinea pigs --- p.60 / Chapter 3.1.6 --- Scatchard analysis of [3H]-PAF binding to murine and guinea pig TG-PMΦ --- p.65 / Chapter 3.2 --- SUPEROXIDE ANION PRODUCTION IN PERITONEAL MACROPHAGES --- p.69 / Chapter 3.2.1 --- Superoxide anion production induced by PAFin murine and guinea pig TG-PMΦ --- p.69 / Chapter 3.2.2 --- Effect of PMA on superoxide anion production in murine and guinea pig TG-PMΦ --- p.69 / Chapter 3.2.3 --- Effect of calcium ionophore on superoxide anion production in murine and guinea pig TG-PMΦ --- p.75 / Chapter 3.2.4 --- Effect of PAF antagonists on PAF - induced superoxide anion production in guinea pig TG-PMΦ --- p.75 / Chapter 3.3 --- PHOSPHOLIPASE C - PHOSPHATIDYLINOSITOL SYSTEM IN PERITONEAL MACROPHAGES --- p.79 / Chapter 3.3.1 --- Effect of PAF on the accumulation of inositol phosphates in the absence of LiCl --- p.79 / Chapter 3.3.2 --- Effect of PAF on the accumulation of inositol phosphates in the presence of LiCl --- p.79 / Chapter 3.3.2.1 --- Time course of [3H]-inositol phosphates accumulation induced by PAF in TG-PMΦ --- p.86 / Chapter 3.3.2.2 --- Effect of PAF on the accumulation of [3H]-IPs in TG- PMΦ from Balb/c mice and guinea pigs --- p.86 / Chapter 3.3.2.3 --- Effect of PAF antagonists on PAF-induced [3H]-IPs accumulation in TG-PMΦ from Balb/c mice and guinea pigs --- p.86 / Chapter 3.3.2.4 --- Effect of PMA on PAF-induced [3H]-IPs formation in TG-PMΦ from Balb/c mice and guinea pigs --- p.90 / Chapter 3.3.2.5 --- Effect of prolonged PMA pretreatment on PAF and PMA-induced [3H]-IPs accumulation in murine and guinea pig TG-PMΦ --- p.90 / Chapter 3.4 --- STUDIES OF RESIDENT PEC FROM Balb/c MICE --- p.96 / Chapter 3.4.1 --- Binding of 2nM [3H]-PAF to Balb/c mice resident PEC --- p.96 / Chapter 3.4.2 --- PAF-induced [3H]-IPs accumulation in murine resident PMΦ --- p.100 / Chapter 3.4.3 --- Binding of 0.2 nM [3H]-PAF to Balb/c mice resident PEC --- p.100 / Chapter 3.4.4 --- Superoxide anion production induced by PAF and PMA in murine resident PMΦ --- p.104 / Chapter CHAPTER 4 --- DISCUSSIONS / Chapter 4.1 --- PAF RECEPTOR ON PERITONEAL MACROPHAGES --- p.125 / Chapter 4.1.1 --- [3H]-PAF binding to peritoneal macrophages --- p.105 / Chapter 4.1.2 --- Expression of PAF receptor on Balb/c mice peritoneal macrophages --- p.107 / Chapter 4.2 --- SUPEROXIDE ANION PRODUCTION IN PERITONEAL MACROPHAGES --- p.108 / Chapter 4.3 --- PAF RECEPTOR AND POLYPHOSPHATIDYLINOSITOL SYSTEM IN PERITONEAL MACROPHAGES --- p.109 / Chapter CHAPTER 5 --- CONCLUSIONS --- p.112 / REFERENCES --- p.115

Platelets play a pivotal role in hemostasis and thrombosis. It induces vascular retraction and clot formation through platelets activation and signal transmission, which promote ligands expressing on the surface of platelets, such as glycoproteins and P-selectin. Some surface glycoproteins gatherd to form complexes after activation. It bound to extracellular receptors such as collagen and thrombin to induce aggregation, which could also be induced by releasing agonists, such as arachidonic acid, adenosine diphosphate, epinephrine, serotonin and fibrinogen, to active the nearby platelets. The standard process of plateletapheresis in the Blood Center was to hold the platelets in still for one hour before stored on a vibrator. The process of holding platelets still for one hour before storage was omitted in some hospitals. It was not clear whether to omit the process has any effect on the quality of platelets. The expressions of P-selectin and vWF receptor, CD42b (Gp Ib£\) on platelets were analyzed by flow cytometry in this study. No significant differences (p= 0.77 and p= 0.62, respectively) were found. Similar results were obtained when functions of platelets were evaluated by agonists. It was concluded that leaving the platelets in room temperature for one hour to recover before keeping it on a vibrator would not enhance the functions of platelets aggregation significantly.

Class of 2009 Abstract / OBJECTIVES: An estimated 26.3 million Americans have Diabetes Mellitus (DM). Currently six classes of agents are approved for the treatments of Type 2 DM. Problems with current options have led to searches for new medications and adjunctive therapy. Prickly pear (Opuntia species) has been traditionally used by Mexicans and Pima Indians for the treatment of DM. This is a retrospective analysis of data obtained from a randomized placebo-controlled prospective experiment in 28 Type 2 DM rodents (ZDF). There were 2 negative control groups which consisted of non-DM rodents and ZDFs; each receiving water. The positive control group consisted of ZDFs who received rosiglitazone 4.75 mg/kg/day. The treatment group consisted of ZDFs who received 5-10 mL/kg/dose of Opuntia ficus indica (Jugo De Nopal) liquid, given twice daily. Weight, blood glucose and platelet aggregation were recorded and analyzed. At baseline, there were no significant differences in weight or blood glucose among ZDF groups. The lean control rodents had significantly lower blood glucose compared to the ZDF rodents (p<0.001). Treatment with Jugo de Nopal resulted in a statistically significant reduction in blood glucose (p<0.001), with a mean decrease in blood glucose of 7%. All treatment groups demonstrated a significant weight gain, however, the prickly pear group had significantly less weight gain than the rosiglitazone group (p=0.028). CONCLUSIONS: There was not a significant difference among the treatment groups with regard to platelet responsiveness. Further studies are necessary to determine the efficacy of prickly pear as a blood glucose lowering agent.

The incidence of stroke and re-infarction is noticeably high in the first few days following acute myocardial infarction. This finding has raised questions whether the systemic inflammatory reaction secondary to myocardial necrosis is involved. The inflammation might affect the activation of platelets leading to insufficient effect of the antiplatelet treatment given. Furthermore, the importance of platelet reactivity and inflammation in terms of long-term prognosis is not fully understood. The prognostic importance of C-reactive protein (CRP) in relation to clinical variables also needs to be clarified. The present studies are aimed at describing the dynamics of platelet function during the first days of an acute myocardial infarction, in relation to diabetes and inflammation. We also investigated whether increased platelet reactivity or the increased concentration of CRP in blood were related to a worse outcome. Finally, we examined if CRP levels contributed to a predictive model using clinical variables known to affect outcome in patients with AMI.  We used two novel platelet function tests to measure platelet reactivity; the PA-200 (a laser light aggregometer) and the PFA-100 (measures primary haemostasis in whole blood). Platelet aggregation increased during the initial course of an acute myocardial infarction. The increase in platelet aggregation was most pronounced in diabetics and in patients showing higher systemic inflammatory reaction, assessed by measuring the concentration of CRP in blood. The pronounced platelet aggregation occurred despite ongoing antiplatelet and antithrombotic treatment. There was a significant association between the levels of CRP and the degree of platelet reactivity. However, while the CRP levels were associated with a worse outcome (AMI, stroke and death), the results of the platelet function tests were not. The importance of CRP in predicting prognosis depended on which adjustments were made for confounding factors. CRP and prognostic variables in a statistical model predicting death, however, showed that CRP was excluded. Thus CRP did not predict outcome beyond clinical prognostic variables. The results of these studies reinforce the importance of clinical variables such as heart failure, age, atrial fibrillation, smoking status, diabetes and impaired kidney function - all of which were associated with worse prognosis in multivariable analysis.

Orientador: Luís Carlos Spolidorio / Banca: Joni Augusto Cirelli / Banca: Raquel Fernanda Gerlach / Resumo: O objetivo deste trabalho foi avaliar o efeito da administracao da aspirina (Asp), do clopidogrel (Clo) e da ticlopidina (Tic) sobre o processo de reparacao dos tecidos periodontais apos inducao experimental de periodontite em ratos. Primeiramente avaliou-se a acao destas drogas sobre a expressao das citocinas pro-inflamatorias: TNF-α, IL-6 e TXA2 no tecido gengival de 25 ratos subdivididos em 5 grupos (n=5), 15 dias apos a instalacao da ligadura ao redor do primeiro molar inferior. Para avaliacao do reparo dos tecidos periodontais, setenta e dois ratos (Rattus norvegicus albinus, Holtzman) foram distribuídos aleatoriamente em 6 grupos (n=12), sendo 1 controle e 5 submetidos a periodontite atraves da instalacao de ligadura bilateral na regiao de primeiro molar inferior. Apos 15 dias, o grupo controle e um grupo com periodontite foram sacrificados. Para a inducao do reparo dos tecidos periodontais, as ligaduras dos animais dos outros 4 grupos foram removidas e os ratos foram tratados com solucao de NaCl 0.9%, Asp (30mg/kg), Clo (75 mg/kg) e Tic (300 mg/kg), diariamente, via gavagem. Apos 15 dias de tratamento, os animais foram sacrificados, as hemi- mandibulas do lado direito removidas para analise histologica e as do lado esquerdo para avaliacao macroscopica, microtomografia computadorizada e analise da expressao, atividade especifica e co-localizacao das metaloproteinases de matriz (MMPs) -2 e -9 atraves de zimograma e zimografia in situ. Apos a retirada da ligadura, houve reparacao do osso alveolar e reparacao do tecido gengival representado pela recomposicao da arquitetura tecidual do epitélio e do tecido conjuntivo. O tratamento com Asp comprometeu a reparacao óssea alveolar na face mesial e acelerou na area de furca, ao passo que nao influenciou na recomposicao da arquitetura do tecido epitelial e... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this study was to evaluate the effect of administration of aspirin (Asp), clopidogrel (Clo) and ticlopidine (Tic) in the process of periodontal tissue repair after induction of experimental periodontitis in rats. First, we evaluated the action of these drugs on the expression of pro-inflammatory cytokines: TNF-α, IL-6 and TXA2 in the gingival tissue of 25 rats randomly distributed in five equal groups (n=5), 15 days after ligature placement around lower first molars. For periodontal tissue evaluation, seventy-two rats (Rattus norvegicus albinus, Holtzman) were randomly distributed in 6 equal groups (n=12). One control and 5 submitted to a ligature-induced periodontitis model in the region of lower first molar bilaterally. After 15 days, the control group and a group with periodontitis were sacrificed. To induce periodontal tissue repair, ligatures from the other 4 groups were removed and the rats treated with NaCl 0.9%, Asp (30 mg/kg), Clo (75 mg/kg) and Tic (300 mg/kg) daily by gavage. After 15 days of treatment, animals were killed, the right mandibles were removed for histological analysis and the left side to macroscopic, microtomography evaluation and expression, activity and colocalization of matrix metalloproteinases (MMPs) -2 and -9 by zymogram and in situ zymography. After removal of the ligature, there was repair of the alveolar bone and gingival tissue represented by the restoration of tissue architecture of the epithelium and connective tissue. Treatment with Asp undertook the repair of the mesial alveolar bone and accelerated the repair of furcation area, while not influenced the restoration of tissue architecture and epithelial tissue. Treatment with Tic undertook the repair of mesial alveolar bone and furcation the area, as well as the repair of gingival epithelial... (Complete abstract, click electronic access below) / Mestre

α,α′-Bis[3-(N,N-diethylcarbamoyl)piperidino]-p-xylene enhances human blood platelet membrane integrity by exerting a stabilizing action at the level of the dense tubular system in surface membrane complexes known to sequester platelet calcium.

Diss. (sammanfattning) Umeå : Umeå universitet, 2010.